/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
 * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
 * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * a) Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * b) Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the distribution.
 *
 * c) Neither the name of Cisco Systems, Inc. nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <netinet/sctp_os.h>
#include <sys/proc.h>
#include <netinet/sctp_var.h>
#include <netinet/sctp_sysctl.h>
#include <netinet/sctp_header.h>
#include <netinet/sctp_pcb.h>
#include <netinet/sctputil.h>
#include <netinet/sctp_output.h>
#include <netinet/sctp_uio.h>
#include <netinet/sctp_auth.h>
#include <netinet/sctp_timer.h>
#include <netinet/sctp_asconf.h>
#include <netinet/sctp_indata.h>
#include <netinet/sctp_bsd_addr.h>
#include <netinet/sctp_input.h>
#include <netinet/sctp_crc32.h>
#include <netinet/sctp_lock_bsd.h>
/*
 * NOTES: On the outbound side of things I need to check the sack timer to
 * see if I should generate a sack into the chunk queue (if I have data to
 * send that is and will be sending it .. for bundling.
 *
 * The callback in sctp_usrreq.c will get called when the socket is read from.
 * This will cause sctp_service_queues() to get called on the top entry in
 * the list.
 */
static uint32_t
sctp_add_chk_to_control(struct sctp_queued_to_read *control,
    struct sctp_stream_in *strm,
    struct sctp_tcb *stcb,
    struct sctp_association *asoc,
    struct sctp_tmit_chunk *chk, int hold_rlock);

void
sctp_set_rwnd(struct sctp_tcb *stcb, struct sctp_association *asoc)
{
        asoc->my_rwnd = sctp_calc_rwnd(stcb, asoc);
}

/* Calculate what the rwnd would be */
uint32_t
sctp_calc_rwnd(struct sctp_tcb *stcb, struct sctp_association *asoc)
{
        uint32_t calc = 0;

        /*
         * This is really set wrong with respect to a 1-2-m socket. Since
         * the sb_cc is the count that everyone as put up. When we re-write
         * sctp_soreceive then we will fix this so that ONLY this
         * associations data is taken into account.
         */
        if (stcb->sctp_socket == NULL) {
                return (calc);
        }

        KASSERT(asoc->cnt_on_reasm_queue > 0 || asoc->size_on_reasm_queue == 0,
            ("size_on_reasm_queue is %u", asoc->size_on_reasm_queue));
        KASSERT(asoc->cnt_on_all_streams > 0 || asoc->size_on_all_streams == 0,
            ("size_on_all_streams is %u", asoc->size_on_all_streams));
        if (stcb->asoc.sb_cc == 0 &&
            asoc->cnt_on_reasm_queue == 0 &&
            asoc->cnt_on_all_streams == 0) {
                /* Full rwnd granted */
                calc = max(SCTP_SB_LIMIT_RCV(stcb->sctp_socket), SCTP_MINIMAL_RWND);
                return (calc);
        }
        /* get actual space */
        calc = (uint32_t)sctp_sbspace(&stcb->asoc, &stcb->sctp_socket->so_rcv);
        /*
         * take out what has NOT been put on socket queue and we yet hold
         * for putting up.
         */
        calc = sctp_sbspace_sub(calc, (uint32_t)(asoc->size_on_reasm_queue +
            asoc->cnt_on_reasm_queue * MSIZE));
        calc = sctp_sbspace_sub(calc, (uint32_t)(asoc->size_on_all_streams +
            asoc->cnt_on_all_streams * MSIZE));
        if (calc == 0) {
                /* out of space */
                return (calc);
        }

        /* what is the overhead of all these rwnd's */
        calc = sctp_sbspace_sub(calc, stcb->asoc.my_rwnd_control_len);
        /*
         * If the window gets too small due to ctrl-stuff, reduce it to 1,
         * even it is 0. SWS engaged
         */
        if (calc < stcb->asoc.my_rwnd_control_len) {
                calc = 1;
        }
        return (calc);
}

/*
 * Build out our readq entry based on the incoming packet.
 */
struct sctp_queued_to_read *
sctp_build_readq_entry(struct sctp_tcb *stcb,
    struct sctp_nets *net,
    uint32_t tsn, uint32_t ppid,
    uint32_t context, uint16_t sid,
    uint32_t mid, uint8_t flags,
    struct mbuf *dm)
{
        struct sctp_queued_to_read *read_queue_e = NULL;

        sctp_alloc_a_readq(stcb, read_queue_e);
        if (read_queue_e == NULL) {
                goto failed_build;
        }
        memset(read_queue_e, 0, sizeof(struct sctp_queued_to_read));
        read_queue_e->sinfo_stream = sid;
        read_queue_e->sinfo_flags = (flags << 8);
        read_queue_e->sinfo_ppid = ppid;
        read_queue_e->sinfo_context = context;
        read_queue_e->sinfo_tsn = tsn;
        read_queue_e->sinfo_cumtsn = tsn;
        read_queue_e->sinfo_assoc_id = sctp_get_associd(stcb);
        read_queue_e->mid = mid;
        read_queue_e->top_fsn = read_queue_e->fsn_included = 0xffffffff;
        TAILQ_INIT(&read_queue_e->reasm);
        read_queue_e->whoFrom = net;
        atomic_add_int(&net->ref_count, 1);
        read_queue_e->data = dm;
        read_queue_e->stcb = stcb;
        read_queue_e->port_from = stcb->rport;
        if (stcb->asoc.state & SCTP_STATE_ABOUT_TO_BE_FREED) {
                read_queue_e->do_not_ref_stcb = 1;
        }
failed_build:
        return (read_queue_e);
}

struct mbuf *
sctp_build_ctl_nchunk(struct sctp_inpcb *inp, struct sctp_sndrcvinfo *sinfo)
{
        struct sctp_extrcvinfo *seinfo;
        struct sctp_sndrcvinfo *outinfo;
        struct sctp_rcvinfo *rcvinfo;
        struct sctp_nxtinfo *nxtinfo;
        struct cmsghdr *cmh;
        struct mbuf *ret;
        int len;
        int use_extended;
        int provide_nxt;

        if (sctp_is_feature_off(inp, SCTP_PCB_FLAGS_RECVDATAIOEVNT) &&
            sctp_is_feature_off(inp, SCTP_PCB_FLAGS_RECVRCVINFO) &&
            sctp_is_feature_off(inp, SCTP_PCB_FLAGS_RECVNXTINFO)) {
                /* user does not want any ancillary data */
                return (NULL);
        }

        len = 0;
        if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_RECVRCVINFO)) {
                len += CMSG_SPACE(sizeof(struct sctp_rcvinfo));
        }
        seinfo = (struct sctp_extrcvinfo *)sinfo;
        if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_RECVNXTINFO) &&
            (seinfo->serinfo_next_flags & SCTP_NEXT_MSG_AVAIL)) {
                provide_nxt = 1;
                len += CMSG_SPACE(sizeof(struct sctp_nxtinfo));
        } else {
                provide_nxt = 0;
        }
        if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_RECVDATAIOEVNT)) {
                if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_EXT_RCVINFO)) {
                        use_extended = 1;
                        len += CMSG_SPACE(sizeof(struct sctp_extrcvinfo));
                } else {
                        use_extended = 0;
                        len += CMSG_SPACE(sizeof(struct sctp_sndrcvinfo));
                }
        } else {
                use_extended = 0;
        }

        ret = sctp_get_mbuf_for_msg(len, 0, M_NOWAIT, 1, MT_DATA);
        if (ret == NULL) {
                /* No space */
                return (ret);
        }
        SCTP_BUF_LEN(ret) = 0;

        /* We need a CMSG header followed by the struct */
        cmh = mtod(ret, struct cmsghdr *);
        /*
         * Make sure that there is no un-initialized padding between the
         * cmsg header and cmsg data and after the cmsg data.
         */
        memset(cmh, 0, len);
        if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_RECVRCVINFO)) {
                cmh->cmsg_level = IPPROTO_SCTP;
                cmh->cmsg_len = CMSG_LEN(sizeof(struct sctp_rcvinfo));
                cmh->cmsg_type = SCTP_RCVINFO;
                rcvinfo = (struct sctp_rcvinfo *)CMSG_DATA(cmh);
                rcvinfo->rcv_sid = sinfo->sinfo_stream;
                rcvinfo->rcv_ssn = sinfo->sinfo_ssn;
                rcvinfo->rcv_flags = sinfo->sinfo_flags;
                rcvinfo->rcv_ppid = sinfo->sinfo_ppid;
                rcvinfo->rcv_tsn = sinfo->sinfo_tsn;
                rcvinfo->rcv_cumtsn = sinfo->sinfo_cumtsn;
                rcvinfo->rcv_context = sinfo->sinfo_context;
                rcvinfo->rcv_assoc_id = sinfo->sinfo_assoc_id;
                cmh = (struct cmsghdr *)((caddr_t)cmh + CMSG_SPACE(sizeof(struct sctp_rcvinfo)));
                SCTP_BUF_LEN(ret) += CMSG_SPACE(sizeof(struct sctp_rcvinfo));
        }
        if (provide_nxt) {
                cmh->cmsg_level = IPPROTO_SCTP;
                cmh->cmsg_len = CMSG_LEN(sizeof(struct sctp_nxtinfo));
                cmh->cmsg_type = SCTP_NXTINFO;
                nxtinfo = (struct sctp_nxtinfo *)CMSG_DATA(cmh);
                nxtinfo->nxt_sid = seinfo->serinfo_next_stream;
                nxtinfo->nxt_flags = 0;
                if (seinfo->serinfo_next_flags & SCTP_NEXT_MSG_IS_UNORDERED) {
                        nxtinfo->nxt_flags |= SCTP_UNORDERED;
                }
                if (seinfo->serinfo_next_flags & SCTP_NEXT_MSG_IS_NOTIFICATION) {
                        nxtinfo->nxt_flags |= SCTP_NOTIFICATION;
                }
                if (seinfo->serinfo_next_flags & SCTP_NEXT_MSG_ISCOMPLETE) {
                        nxtinfo->nxt_flags |= SCTP_COMPLETE;
                }
                nxtinfo->nxt_ppid = seinfo->serinfo_next_ppid;
                nxtinfo->nxt_length = seinfo->serinfo_next_length;
                nxtinfo->nxt_assoc_id = seinfo->serinfo_next_aid;
                cmh = (struct cmsghdr *)((caddr_t)cmh + CMSG_SPACE(sizeof(struct sctp_nxtinfo)));
                SCTP_BUF_LEN(ret) += CMSG_SPACE(sizeof(struct sctp_nxtinfo));
        }
        if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_RECVDATAIOEVNT)) {
                cmh->cmsg_level = IPPROTO_SCTP;
                outinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmh);
                if (use_extended) {
                        cmh->cmsg_len = CMSG_LEN(sizeof(struct sctp_extrcvinfo));
                        cmh->cmsg_type = SCTP_EXTRCV;
                        memcpy(outinfo, sinfo, sizeof(struct sctp_extrcvinfo));
                        SCTP_BUF_LEN(ret) += CMSG_SPACE(sizeof(struct sctp_extrcvinfo));
                } else {
                        cmh->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
                        cmh->cmsg_type = SCTP_SNDRCV;
                        *outinfo = *sinfo;
                        SCTP_BUF_LEN(ret) += CMSG_SPACE(sizeof(struct sctp_sndrcvinfo));
                }
        }
        return (ret);
}

static void
sctp_mark_non_revokable(struct sctp_association *asoc, uint32_t tsn)
{
        uint32_t gap, i;
        int in_r, in_nr;

        if (SCTP_BASE_SYSCTL(sctp_do_drain) == 0) {
                return;
        }
        if (SCTP_TSN_GE(asoc->cumulative_tsn, tsn)) {
                /*
                 * This tsn is behind the cum ack and thus we don't need to
                 * worry about it being moved from one to the other.
                 */
                return;
        }
        SCTP_CALC_TSN_TO_GAP(gap, tsn, asoc->mapping_array_base_tsn);
        in_r = SCTP_IS_TSN_PRESENT(asoc->mapping_array, gap);
        in_nr = SCTP_IS_TSN_PRESENT(asoc->nr_mapping_array, gap);
        KASSERT(in_r || in_nr, ("%s: Things are really messed up now", __func__));
        if (!in_nr) {
                SCTP_SET_TSN_PRESENT(asoc->nr_mapping_array, gap);
                if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_nr_map)) {
                        asoc->highest_tsn_inside_nr_map = tsn;
                }
        }
        if (in_r) {
                SCTP_UNSET_TSN_PRESENT(asoc->mapping_array, gap);
                if (tsn == asoc->highest_tsn_inside_map) {
                        /* We must back down to see what the new highest is. */
                        for (i = tsn - 1; SCTP_TSN_GE(i, asoc->mapping_array_base_tsn); i--) {
                                SCTP_CALC_TSN_TO_GAP(gap, i, asoc->mapping_array_base_tsn);
                                if (SCTP_IS_TSN_PRESENT(asoc->mapping_array, gap)) {
                                        asoc->highest_tsn_inside_map = i;
                                        break;
                                }
                        }
                        if (!SCTP_TSN_GE(i, asoc->mapping_array_base_tsn)) {
                                asoc->highest_tsn_inside_map = asoc->mapping_array_base_tsn - 1;
                        }
                }
        }
}

static int
sctp_place_control_in_stream(struct sctp_stream_in *strm,
    struct sctp_association *asoc,
    struct sctp_queued_to_read *control)
{
        struct sctp_queued_to_read *at;
        struct sctp_readhead *q;
        uint8_t flags, unordered;

        flags = (control->sinfo_flags >> 8);
        unordered = flags & SCTP_DATA_UNORDERED;
        if (unordered) {
                q = &strm->uno_inqueue;
                if (asoc->idata_supported == 0) {
                        if (!TAILQ_EMPTY(q)) {
                                /*
                                 * Only one stream can be here in old style
                                 * -- abort
                                 */
                                return (-1);
                        }
                        TAILQ_INSERT_TAIL(q, control, next_instrm);
                        control->on_strm_q = SCTP_ON_UNORDERED;
                        return (0);
                }
        } else {
                q = &strm->inqueue;
        }
        if ((flags & SCTP_DATA_NOT_FRAG) == SCTP_DATA_NOT_FRAG) {
                control->end_added = 1;
                control->first_frag_seen = 1;
                control->last_frag_seen = 1;
        }
        if (TAILQ_EMPTY(q)) {
                /* Empty queue */
                TAILQ_INSERT_HEAD(q, control, next_instrm);
                if (unordered) {
                        control->on_strm_q = SCTP_ON_UNORDERED;
                } else {
                        control->on_strm_q = SCTP_ON_ORDERED;
                }
                return (0);
        } else {
                TAILQ_FOREACH(at, q, next_instrm) {
                        if (SCTP_MID_GT(asoc->idata_supported, at->mid, control->mid)) {
                                /*
                                 * one in queue is bigger than the new one,
                                 * insert before this one
                                 */
                                TAILQ_INSERT_BEFORE(at, control, next_instrm);
                                if (unordered) {
                                        control->on_strm_q = SCTP_ON_UNORDERED;
                                } else {
                                        control->on_strm_q = SCTP_ON_ORDERED;
                                }
                                break;
                        } else if (SCTP_MID_EQ(asoc->idata_supported, at->mid, control->mid)) {
                                /*
                                 * Gak, He sent me a duplicate msg id
                                 * number?? return -1 to abort.
                                 */
                                return (-1);
                        } else {
                                if (TAILQ_NEXT(at, next_instrm) == NULL) {
                                        /*
                                         * We are at the end, insert it
                                         * after this one
                                         */
                                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                                                sctp_log_strm_del(control, at,
                                                    SCTP_STR_LOG_FROM_INSERT_TL);
                                        }
                                        TAILQ_INSERT_AFTER(q, at, control, next_instrm);
                                        if (unordered) {
                                                control->on_strm_q = SCTP_ON_UNORDERED;
                                        } else {
                                                control->on_strm_q = SCTP_ON_ORDERED;
                                        }
                                        break;
                                }
                        }
                }
        }
        return (0);
}

static void
sctp_abort_in_reasm(struct sctp_tcb *stcb,
    struct sctp_queued_to_read *control,
    struct sctp_tmit_chunk *chk,
    int *abort_flag, int opspot)
{
        char msg[SCTP_DIAG_INFO_LEN];
        struct mbuf *oper;

        if (stcb->asoc.idata_supported) {
                SCTP_SNPRINTF(msg, sizeof(msg),
                    "Reass %x,CF:%x,TSN=%8.8x,SID=%4.4x,FSN=%8.8x,MID:%8.8x",
                    opspot,
                    control->fsn_included,
                    chk->rec.data.tsn,
                    chk->rec.data.sid,
                    chk->rec.data.fsn, chk->rec.data.mid);
        } else {
                SCTP_SNPRINTF(msg, sizeof(msg),
                    "Reass %x,CI:%x,TSN=%8.8x,SID=%4.4x,FSN=%4.4x,SSN:%4.4x",
                    opspot,
                    control->fsn_included,
                    chk->rec.data.tsn,
                    chk->rec.data.sid,
                    chk->rec.data.fsn,
                    (uint16_t)chk->rec.data.mid);
        }
        oper = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
        sctp_m_freem(chk->data);
        chk->data = NULL;
        sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_1;
        sctp_abort_an_association(stcb->sctp_ep, stcb, oper, false, SCTP_SO_NOT_LOCKED);
        *abort_flag = 1;
}

static void
sctp_clean_up_control(struct sctp_tcb *stcb, struct sctp_queued_to_read *control)
{
        /*
         * The control could not be placed and must be cleaned.
         */
        struct sctp_tmit_chunk *chk, *nchk;

        TAILQ_FOREACH_SAFE(chk, &control->reasm, sctp_next, nchk) {
                TAILQ_REMOVE(&control->reasm, chk, sctp_next);
                if (chk->data)
                        sctp_m_freem(chk->data);
                chk->data = NULL;
                sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
        }
        sctp_free_remote_addr(control->whoFrom);
        if (control->data) {
                sctp_m_freem(control->data);
                control->data = NULL;
        }
        sctp_free_a_readq(stcb, control);
}

/*
 * Queue the chunk either right into the socket buffer if it is the next one
 * to go OR put it in the correct place in the delivery queue.  If we do
 * append to the so_buf, keep doing so until we are out of order as
 * long as the control's entered are non-fragmented.
 */
static void
sctp_queue_data_to_stream(struct sctp_tcb *stcb,
    struct sctp_association *asoc,
    struct sctp_queued_to_read *control, int *abort_flag, int *need_reasm)
{
        /*
         * FIX-ME maybe? What happens when the ssn wraps? If we are getting
         * all the data in one stream this could happen quite rapidly. One
         * could use the TSN to keep track of things, but this scheme breaks
         * down in the other type of stream usage that could occur. Send a
         * single msg to stream 0, send 4Billion messages to stream 1, now
         * send a message to stream 0. You have a situation where the TSN
         * has wrapped but not in the stream. Is this worth worrying about
         * or should we just change our queue sort at the bottom to be by
         * TSN.
         *
         * Could it also be legal for a peer to send ssn 1 with TSN 2 and
         * ssn 2 with TSN 1? If the peer is doing some sort of funky TSN/SSN
         * assignment this could happen... and I don't see how this would be
         * a violation. So for now I am undecided an will leave the sort by
         * SSN alone. Maybe a hybrid approach is the answer
         *
         */
        struct sctp_queued_to_read *at;
        int queue_needed;
        uint32_t nxt_todel;
        struct mbuf *op_err;
        struct sctp_stream_in *strm;
        char msg[SCTP_DIAG_INFO_LEN];

        strm = &asoc->strmin[control->sinfo_stream];
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                sctp_log_strm_del(control, NULL, SCTP_STR_LOG_FROM_INTO_STRD);
        }
        if (SCTP_MID_GT((asoc->idata_supported), strm->last_mid_delivered, control->mid)) {
                /* The incoming sseq is behind where we last delivered? */
                SCTPDBG(SCTP_DEBUG_INDATA1, "Duplicate S-SEQ: %u delivered: %u from peer, Abort association\n",
                    strm->last_mid_delivered, control->mid);
                /*
                 * throw it in the stream so it gets cleaned up in
                 * association destruction
                 */
                TAILQ_INSERT_HEAD(&strm->inqueue, control, next_instrm);
                if (asoc->idata_supported) {
                        SCTP_SNPRINTF(msg, sizeof(msg), "Delivered MID=%8.8x, got TSN=%8.8x, SID=%4.4x, MID=%8.8x",
                            strm->last_mid_delivered, control->sinfo_tsn,
                            control->sinfo_stream, control->mid);
                } else {
                        SCTP_SNPRINTF(msg, sizeof(msg), "Delivered SSN=%4.4x, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                            (uint16_t)strm->last_mid_delivered,
                            control->sinfo_tsn,
                            control->sinfo_stream,
                            (uint16_t)control->mid);
                }
                op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_2;
                sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                *abort_flag = 1;
                return;
        }
        queue_needed = 1;
        asoc->size_on_all_streams += control->length;
        sctp_ucount_incr(asoc->cnt_on_all_streams);
        nxt_todel = strm->last_mid_delivered + 1;
        if (SCTP_MID_EQ(asoc->idata_supported, nxt_todel, control->mid)) {
                /* can be delivered right away? */
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                        sctp_log_strm_del(control, NULL, SCTP_STR_LOG_FROM_IMMED_DEL);
                }
                /* EY it wont be queued if it could be delivered directly */
                queue_needed = 0;
                if (asoc->size_on_all_streams >= control->length) {
                        asoc->size_on_all_streams -= control->length;
                } else {
#ifdef INVARIANTS
                        panic("size_on_all_streams = %u smaller than control length %u", asoc->size_on_all_streams, control->length);
#else
                        asoc->size_on_all_streams = 0;
#endif
                }
                sctp_ucount_decr(asoc->cnt_on_all_streams);
                strm->last_mid_delivered++;
                sctp_mark_non_revokable(asoc, control->sinfo_tsn);
                sctp_add_to_readq(stcb->sctp_ep, stcb,
                    control,
                    &stcb->sctp_socket->so_rcv, 1,
                    SCTP_READ_LOCK_NOT_HELD, SCTP_SO_LOCKED);
                TAILQ_FOREACH_SAFE(control, &strm->inqueue, next_instrm, at) {
                        /* all delivered */
                        nxt_todel = strm->last_mid_delivered + 1;
                        if (SCTP_MID_EQ(asoc->idata_supported, nxt_todel, control->mid) &&
                            (((control->sinfo_flags >> 8) & SCTP_DATA_NOT_FRAG) == SCTP_DATA_NOT_FRAG)) {
                                if (control->on_strm_q == SCTP_ON_ORDERED) {
                                        TAILQ_REMOVE(&strm->inqueue, control, next_instrm);
                                        if (asoc->size_on_all_streams >= control->length) {
                                                asoc->size_on_all_streams -= control->length;
                                        } else {
#ifdef INVARIANTS
                                                panic("size_on_all_streams = %u smaller than control length %u", asoc->size_on_all_streams, control->length);
#else
                                                asoc->size_on_all_streams = 0;
#endif
                                        }
                                        sctp_ucount_decr(asoc->cnt_on_all_streams);
#ifdef INVARIANTS
                                } else {
                                        panic("Huh control: %p is on_strm_q: %d",
                                            control, control->on_strm_q);
#endif
                                }
                                control->on_strm_q = 0;
                                strm->last_mid_delivered++;
                                /*
                                 * We ignore the return of deliver_data here
                                 * since we always can hold the chunk on the
                                 * d-queue. And we have a finite number that
                                 * can be delivered from the strq.
                                 */
                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                                        sctp_log_strm_del(control, NULL,
                                            SCTP_STR_LOG_FROM_IMMED_DEL);
                                }
                                sctp_mark_non_revokable(asoc, control->sinfo_tsn);
                                sctp_add_to_readq(stcb->sctp_ep, stcb,
                                    control,
                                    &stcb->sctp_socket->so_rcv, 1,
                                    SCTP_READ_LOCK_NOT_HELD,
                                    SCTP_SO_LOCKED);
                                continue;
                        } else if (SCTP_MID_EQ(asoc->idata_supported, nxt_todel, control->mid)) {
                                *need_reasm = 1;
                        }
                        break;
                }
        }
        if (queue_needed) {
                /*
                 * Ok, we did not deliver this guy, find the correct place
                 * to put it on the queue.
                 */
                if (sctp_place_control_in_stream(strm, asoc, control)) {
                        SCTP_SNPRINTF(msg, sizeof(msg),
                            "Queue to str MID: %u duplicate", control->mid);
                        sctp_clean_up_control(stcb, control);
                        op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_3;
                        sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                        *abort_flag = 1;
                }
        }
}

static void
sctp_setup_tail_pointer(struct sctp_queued_to_read *control)
{
        struct mbuf *m, *prev = NULL;
        struct sctp_tcb *stcb;

        stcb = control->stcb;
        control->held_length = 0;
        control->length = 0;
        m = control->data;
        while (m) {
                if (SCTP_BUF_LEN(m) == 0) {
                        /* Skip mbufs with NO length */
                        if (prev == NULL) {
                                /* First one */
                                control->data = sctp_m_free(m);
                                m = control->data;
                        } else {
                                SCTP_BUF_NEXT(prev) = sctp_m_free(m);
                                m = SCTP_BUF_NEXT(prev);
                        }
                        if (m == NULL) {
                                control->tail_mbuf = prev;
                        }
                        continue;
                }
                prev = m;
                atomic_add_int(&control->length, SCTP_BUF_LEN(m));
                if (control->on_read_q) {
                        /*
                         * On read queue so we must increment the SB stuff,
                         * we assume caller has done any locks of SB.
                         */
                        sctp_sballoc(stcb, &stcb->sctp_socket->so_rcv, m);
                }
                m = SCTP_BUF_NEXT(m);
        }
        if (prev) {
                control->tail_mbuf = prev;
        }
}

static void
sctp_add_to_tail_pointer(struct sctp_queued_to_read *control, struct mbuf *m, uint32_t *added)
{
        struct mbuf *prev = NULL;
        struct sctp_tcb *stcb;

        stcb = control->stcb;
        if (stcb == NULL) {
#ifdef INVARIANTS
                panic("Control broken");
#else
                return;
#endif
        }
        if (control->tail_mbuf == NULL) {
                /* TSNH */
                sctp_m_freem(control->data);
                control->data = m;
                sctp_setup_tail_pointer(control);
                return;
        }
        control->tail_mbuf->m_next = m;
        while (m) {
                if (SCTP_BUF_LEN(m) == 0) {
                        /* Skip mbufs with NO length */
                        if (prev == NULL) {
                                /* First one */
                                control->tail_mbuf->m_next = sctp_m_free(m);
                                m = control->tail_mbuf->m_next;
                        } else {
                                SCTP_BUF_NEXT(prev) = sctp_m_free(m);
                                m = SCTP_BUF_NEXT(prev);
                        }
                        if (m == NULL) {
                                control->tail_mbuf = prev;
                        }
                        continue;
                }
                prev = m;
                if (control->on_read_q) {
                        /*
                         * On read queue so we must increment the SB stuff,
                         * we assume caller has done any locks of SB.
                         */
                        sctp_sballoc(stcb, &stcb->sctp_socket->so_rcv, m);
                }
                *added += SCTP_BUF_LEN(m);
                atomic_add_int(&control->length, SCTP_BUF_LEN(m));
                m = SCTP_BUF_NEXT(m);
        }
        if (prev) {
                control->tail_mbuf = prev;
        }
}

static void
sctp_build_readq_entry_from_ctl(struct sctp_queued_to_read *nc, struct sctp_queued_to_read *control)
{
        memset(nc, 0, sizeof(struct sctp_queued_to_read));
        nc->sinfo_stream = control->sinfo_stream;
        nc->mid = control->mid;
        TAILQ_INIT(&nc->reasm);
        nc->top_fsn = control->top_fsn;
        nc->mid = control->mid;
        nc->sinfo_flags = control->sinfo_flags;
        nc->sinfo_ppid = control->sinfo_ppid;
        nc->sinfo_context = control->sinfo_context;
        nc->fsn_included = 0xffffffff;
        nc->sinfo_tsn = control->sinfo_tsn;
        nc->sinfo_cumtsn = control->sinfo_cumtsn;
        nc->sinfo_assoc_id = control->sinfo_assoc_id;
        nc->whoFrom = control->whoFrom;
        atomic_add_int(&nc->whoFrom->ref_count, 1);
        nc->stcb = control->stcb;
        nc->port_from = control->port_from;
        nc->do_not_ref_stcb = control->do_not_ref_stcb;
}

static int
sctp_handle_old_unordered_data(struct sctp_tcb *stcb,
    struct sctp_association *asoc,
    struct sctp_stream_in *strm,
    struct sctp_queued_to_read *control,
    uint32_t pd_point,
    int inp_read_lock_held)
{
        /*
         * Special handling for the old un-ordered data chunk. All the
         * chunks/TSN's go to mid 0. So we have to do the old style watching
         * to see if we have it all. If you return one, no other control
         * entries on the un-ordered queue will be looked at. In theory
         * there should be no others entries in reality, unless the guy is
         * sending both unordered NDATA and unordered DATA...
         */
        struct sctp_tmit_chunk *chk, *lchk, *tchk;
        uint32_t fsn;
        struct sctp_queued_to_read *nc;
        int cnt_added;

        if (control->first_frag_seen == 0) {
                /* Nothing we can do, we have not seen the first piece yet */
                return (1);
        }
        /* Collapse any we can */
        cnt_added = 0;
restart:
        fsn = control->fsn_included + 1;
        /* Now what can we add? */
        TAILQ_FOREACH_SAFE(chk, &control->reasm, sctp_next, lchk) {
                if (chk->rec.data.fsn == fsn) {
                        /* Ok lets add it */
                        sctp_alloc_a_readq(stcb, nc);
                        if (nc == NULL) {
                                break;
                        }
                        memset(nc, 0, sizeof(struct sctp_queued_to_read));
                        TAILQ_REMOVE(&control->reasm, chk, sctp_next);
                        sctp_add_chk_to_control(control, strm, stcb, asoc, chk, inp_read_lock_held);
                        fsn++;
                        cnt_added++;
                        chk = NULL;
                        if (control->end_added) {
                                /* We are done */
                                if (!TAILQ_EMPTY(&control->reasm)) {
                                        /*
                                         * Ok we have to move anything left
                                         * on the control queue to a new
                                         * control.
                                         */
                                        sctp_build_readq_entry_from_ctl(nc, control);
                                        tchk = TAILQ_FIRST(&control->reasm);
                                        if (tchk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                                                TAILQ_REMOVE(&control->reasm, tchk, sctp_next);
                                                if (asoc->size_on_reasm_queue >= tchk->send_size) {
                                                        asoc->size_on_reasm_queue -= tchk->send_size;
                                                } else {
#ifdef INVARIANTS
                                                        panic("size_on_reasm_queue = %u smaller than chunk length %u", asoc->size_on_reasm_queue, tchk->send_size);
#else
                                                        asoc->size_on_reasm_queue = 0;
#endif
                                                }
                                                sctp_ucount_decr(asoc->cnt_on_reasm_queue);
                                                nc->first_frag_seen = 1;
                                                nc->fsn_included = tchk->rec.data.fsn;
                                                nc->data = tchk->data;
                                                nc->sinfo_ppid = tchk->rec.data.ppid;
                                                nc->sinfo_tsn = tchk->rec.data.tsn;
                                                sctp_mark_non_revokable(asoc, tchk->rec.data.tsn);
                                                tchk->data = NULL;
                                                sctp_free_a_chunk(stcb, tchk, SCTP_SO_NOT_LOCKED);
                                                sctp_setup_tail_pointer(nc);
                                                tchk = TAILQ_FIRST(&control->reasm);
                                        }
                                        /* Spin the rest onto the queue */
                                        while (tchk) {
                                                TAILQ_REMOVE(&control->reasm, tchk, sctp_next);
                                                TAILQ_INSERT_TAIL(&nc->reasm, tchk, sctp_next);
                                                tchk = TAILQ_FIRST(&control->reasm);
                                        }
                                        /*
                                         * Now lets add it to the queue
                                         * after removing control
                                         */
                                        TAILQ_INSERT_TAIL(&strm->uno_inqueue, nc, next_instrm);
                                        nc->on_strm_q = SCTP_ON_UNORDERED;
                                        if (control->on_strm_q) {
                                                TAILQ_REMOVE(&strm->uno_inqueue, control, next_instrm);
                                                control->on_strm_q = 0;
                                        }
                                }
                                if (control->pdapi_started) {
                                        strm->pd_api_started = 0;
                                        control->pdapi_started = 0;
                                }
                                if (control->on_strm_q) {
                                        TAILQ_REMOVE(&strm->uno_inqueue, control, next_instrm);
                                        control->on_strm_q = 0;
                                        SCTP_STAT_INCR_COUNTER64(sctps_reasmusrmsgs);
                                }
                                if (control->on_read_q == 0) {
                                        sctp_add_to_readq(stcb->sctp_ep, stcb, control,
                                            &stcb->sctp_socket->so_rcv, control->end_added,
                                            inp_read_lock_held, SCTP_SO_NOT_LOCKED);
                                }
                                sctp_wakeup_the_read_socket(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED);
                                if ((nc->first_frag_seen) && !TAILQ_EMPTY(&nc->reasm)) {
                                        /*
                                         * Switch to the new guy and
                                         * continue
                                         */
                                        control = nc;
                                        goto restart;
                                } else {
                                        if (nc->on_strm_q == 0) {
                                                sctp_free_a_readq(stcb, nc);
                                        }
                                }
                                return (1);
                        } else {
                                sctp_free_a_readq(stcb, nc);
                        }
                } else {
                        /* Can't add more */
                        break;
                }
        }
        if (cnt_added && strm->pd_api_started) {
                sctp_wakeup_the_read_socket(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED);
        }
        if ((control->length > pd_point) && (strm->pd_api_started == 0)) {
                strm->pd_api_started = 1;
                control->pdapi_started = 1;
                sctp_add_to_readq(stcb->sctp_ep, stcb, control,
                    &stcb->sctp_socket->so_rcv, control->end_added,
                    inp_read_lock_held, SCTP_SO_NOT_LOCKED);
                sctp_wakeup_the_read_socket(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED);
                return (0);
        } else {
                return (1);
        }
}

static void
sctp_inject_old_unordered_data(struct sctp_tcb *stcb,
    struct sctp_association *asoc,
    struct sctp_queued_to_read *control,
    struct sctp_tmit_chunk *chk,
    int *abort_flag)
{
        struct sctp_tmit_chunk *at;
        int inserted;

        /*
         * Here we need to place the chunk into the control structure sorted
         * in the correct order.
         */
        if (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                /* Its the very first one. */
                SCTPDBG(SCTP_DEBUG_XXX,
                    "chunk is a first fsn: %u becomes fsn_included\n",
                    chk->rec.data.fsn);
                at = TAILQ_FIRST(&control->reasm);
                if (at && SCTP_TSN_GT(chk->rec.data.fsn, at->rec.data.fsn)) {
                        /*
                         * The first chunk in the reassembly is a smaller
                         * TSN than this one, even though this has a first,
                         * it must be from a subsequent msg.
                         */
                        goto place_chunk;
                }
                if (control->first_frag_seen) {
                        /*
                         * In old un-ordered we can reassembly on one
                         * control multiple messages. As long as the next
                         * FIRST is greater then the old first (TSN i.e. FSN
                         * wise)
                         */
                        struct mbuf *tdata;
                        uint32_t tmp;

                        if (SCTP_TSN_GT(chk->rec.data.fsn, control->fsn_included)) {
                                /*
                                 * Easy way the start of a new guy beyond
                                 * the lowest
                                 */
                                goto place_chunk;
                        }
                        if ((chk->rec.data.fsn == control->fsn_included) ||
                            (control->pdapi_started)) {
                                /*
                                 * Ok this should not happen, if it does we
                                 * started the pd-api on the higher TSN
                                 * (since the equals part is a TSN failure
                                 * it must be that).
                                 *
                                 * We are completely hosed in that case
                                 * since I have no way to recover. This
                                 * really will only happen if we can get
                                 * more TSN's higher before the
                                 * pd-api-point.
                                 */
                                sctp_abort_in_reasm(stcb, control, chk,
                                    abort_flag,
                                    SCTP_FROM_SCTP_INDATA + SCTP_LOC_4);

                                return;
                        }
                        /*
                         * Ok we have two firsts and the one we just got is
                         * smaller than the one we previously placed.. yuck!
                         * We must swap them out.
                         */
                        /* swap the mbufs */
                        tdata = control->data;
                        control->data = chk->data;
                        chk->data = tdata;
                        /* Save the lengths */
                        chk->send_size = control->length;
                        /* Recompute length of control and tail pointer */
                        sctp_setup_tail_pointer(control);
                        /* Fix the FSN included */
                        tmp = control->fsn_included;
                        control->fsn_included = chk->rec.data.fsn;
                        chk->rec.data.fsn = tmp;
                        /* Fix the TSN included */
                        tmp = control->sinfo_tsn;
                        control->sinfo_tsn = chk->rec.data.tsn;
                        chk->rec.data.tsn = tmp;
                        /* Fix the PPID included */
                        tmp = control->sinfo_ppid;
                        control->sinfo_ppid = chk->rec.data.ppid;
                        chk->rec.data.ppid = tmp;
                        /* Fix tail pointer */
                        goto place_chunk;
                }
                control->first_frag_seen = 1;
                control->fsn_included = chk->rec.data.fsn;
                control->top_fsn = chk->rec.data.fsn;
                control->sinfo_tsn = chk->rec.data.tsn;
                control->sinfo_ppid = chk->rec.data.ppid;
                control->data = chk->data;
                sctp_mark_non_revokable(asoc, chk->rec.data.tsn);
                chk->data = NULL;
                sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
                sctp_setup_tail_pointer(control);
                return;
        }
place_chunk:
        inserted = 0;
        TAILQ_FOREACH(at, &control->reasm, sctp_next) {
                if (SCTP_TSN_GT(at->rec.data.fsn, chk->rec.data.fsn)) {
                        /*
                         * This one in queue is bigger than the new one,
                         * insert the new one before at.
                         */
                        asoc->size_on_reasm_queue += chk->send_size;
                        sctp_ucount_incr(asoc->cnt_on_reasm_queue);
                        inserted = 1;
                        TAILQ_INSERT_BEFORE(at, chk, sctp_next);
                        break;
                } else if (at->rec.data.fsn == chk->rec.data.fsn) {
                        /*
                         * They sent a duplicate fsn number. This really
                         * should not happen since the FSN is a TSN and it
                         * should have been dropped earlier.
                         */
                        sctp_abort_in_reasm(stcb, control, chk,
                            abort_flag,
                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_5);
                        return;
                }
        }
        if (inserted == 0) {
                /* Its at the end */
                asoc->size_on_reasm_queue += chk->send_size;
                sctp_ucount_incr(asoc->cnt_on_reasm_queue);
                control->top_fsn = chk->rec.data.fsn;
                TAILQ_INSERT_TAIL(&control->reasm, chk, sctp_next);
        }
}

static int
sctp_deliver_reasm_check(struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct sctp_stream_in *strm, int inp_read_lock_held)
{
        /*
         * Given a stream, strm, see if any of the SSN's on it that are
         * fragmented are ready to deliver. If so go ahead and place them on
         * the read queue. In so placing if we have hit the end, then we
         * need to remove them from the stream's queue.
         */
        struct sctp_queued_to_read *control, *nctl = NULL;
        uint32_t next_to_del;
        uint32_t pd_point;
        int ret = 0;

        if (stcb->sctp_socket) {
                pd_point = min(SCTP_SB_LIMIT_RCV(stcb->sctp_socket) >> SCTP_PARTIAL_DELIVERY_SHIFT,
                    stcb->sctp_ep->partial_delivery_point);
        } else {
                pd_point = stcb->sctp_ep->partial_delivery_point;
        }
        control = TAILQ_FIRST(&strm->uno_inqueue);

        if ((control != NULL) &&
            (asoc->idata_supported == 0)) {
                /* Special handling needed for "old" data format */
                if (sctp_handle_old_unordered_data(stcb, asoc, strm, control, pd_point, inp_read_lock_held)) {
                        goto done_un;
                }
        }
        if (strm->pd_api_started) {
                /* Can't add more */
                return (0);
        }
        while (control) {
                SCTPDBG(SCTP_DEBUG_XXX, "Looking at control: %p e(%d) ssn: %u top_fsn: %u inc_fsn: %u -uo\n",
                    control, control->end_added, control->mid, control->top_fsn, control->fsn_included);
                nctl = TAILQ_NEXT(control, next_instrm);
                if (control->end_added) {
                        /* We just put the last bit on */
                        if (control->on_strm_q) {
#ifdef INVARIANTS
                                if (control->on_strm_q != SCTP_ON_UNORDERED) {
                                        panic("Huh control: %p on_q: %d -- not unordered?",
                                            control, control->on_strm_q);
                                }
#endif
                                SCTP_STAT_INCR_COUNTER64(sctps_reasmusrmsgs);
                                TAILQ_REMOVE(&strm->uno_inqueue, control, next_instrm);
                                if (asoc->size_on_all_streams >= control->length) {
                                        asoc->size_on_all_streams -= control->length;
                                } else {
#ifdef INVARIANTS
                                        panic("size_on_all_streams = %u smaller than control length %u", asoc->size_on_all_streams, control->length);
#else
                                        asoc->size_on_all_streams = 0;
#endif
                                }
                                sctp_ucount_decr(asoc->cnt_on_all_streams);
                                control->on_strm_q = 0;
                        }
                        if (control->on_read_q == 0) {
                                sctp_add_to_readq(stcb->sctp_ep, stcb,
                                    control,
                                    &stcb->sctp_socket->so_rcv, control->end_added,
                                    inp_read_lock_held, SCTP_SO_NOT_LOCKED);
                        }
                } else {
                        /* Can we do a PD-API for this un-ordered guy? */
                        if ((control->length >= pd_point) && (strm->pd_api_started == 0)) {
                                strm->pd_api_started = 1;
                                control->pdapi_started = 1;
                                sctp_add_to_readq(stcb->sctp_ep, stcb,
                                    control,
                                    &stcb->sctp_socket->so_rcv, control->end_added,
                                    inp_read_lock_held, SCTP_SO_NOT_LOCKED);

                                break;
                        }
                }
                control = nctl;
        }
done_un:
        control = TAILQ_FIRST(&strm->inqueue);
        if (strm->pd_api_started) {
                /* Can't add more */
                return (0);
        }
        if (control == NULL) {
                return (ret);
        }
        if (SCTP_MID_EQ(asoc->idata_supported, strm->last_mid_delivered, control->mid)) {
                /*
                 * Ok the guy at the top was being partially delivered
                 * completed, so we remove it. Note the pd_api flag was
                 * taken off when the chunk was merged on in
                 * sctp_queue_data_for_reasm below.
                 */
                nctl = TAILQ_NEXT(control, next_instrm);
                SCTPDBG(SCTP_DEBUG_XXX,
                    "Looking at control: %p e(%d) ssn: %u top_fsn: %u inc_fsn: %u (lastdel: %u)- o\n",
                    control, control->end_added, control->mid,
                    control->top_fsn, control->fsn_included,
                    strm->last_mid_delivered);
                if (control->end_added) {
                        if (control->on_strm_q) {
#ifdef INVARIANTS
                                if (control->on_strm_q != SCTP_ON_ORDERED) {
                                        panic("Huh control: %p on_q: %d -- not ordered?",
                                            control, control->on_strm_q);
                                }
#endif
                                SCTP_STAT_INCR_COUNTER64(sctps_reasmusrmsgs);
                                TAILQ_REMOVE(&strm->inqueue, control, next_instrm);
                                if (asoc->size_on_all_streams >= control->length) {
                                        asoc->size_on_all_streams -= control->length;
                                } else {
#ifdef INVARIANTS
                                        panic("size_on_all_streams = %u smaller than control length %u", asoc->size_on_all_streams, control->length);
#else
                                        asoc->size_on_all_streams = 0;
#endif
                                }
                                sctp_ucount_decr(asoc->cnt_on_all_streams);
                                control->on_strm_q = 0;
                        }
                        if (strm->pd_api_started && control->pdapi_started) {
                                control->pdapi_started = 0;
                                strm->pd_api_started = 0;
                        }
                        if (control->on_read_q == 0) {
                                sctp_add_to_readq(stcb->sctp_ep, stcb,
                                    control,
                                    &stcb->sctp_socket->so_rcv, control->end_added,
                                    inp_read_lock_held, SCTP_SO_NOT_LOCKED);
                        }
                        control = nctl;
                }
        }
        if (strm->pd_api_started) {
                /*
                 * Can't add more must have gotten an un-ordered above being
                 * partially delivered.
                 */
                return (0);
        }
deliver_more:
        next_to_del = strm->last_mid_delivered + 1;
        if (control) {
                SCTPDBG(SCTP_DEBUG_XXX,
                    "Looking at control: %p e(%d) ssn: %u top_fsn: %u inc_fsn: %u (nxtdel: %u)- o\n",
                    control, control->end_added, control->mid, control->top_fsn, control->fsn_included,
                    next_to_del);
                nctl = TAILQ_NEXT(control, next_instrm);
                if (SCTP_MID_EQ(asoc->idata_supported, control->mid, next_to_del) &&
                    (control->first_frag_seen)) {
                        int done;

                        /* Ok we can deliver it onto the stream. */
                        if (control->end_added) {
                                /* We are done with it afterwards */
                                if (control->on_strm_q) {
#ifdef INVARIANTS
                                        if (control->on_strm_q != SCTP_ON_ORDERED) {
                                                panic("Huh control: %p on_q: %d -- not ordered?",
                                                    control, control->on_strm_q);
                                        }
#endif
                                        SCTP_STAT_INCR_COUNTER64(sctps_reasmusrmsgs);
                                        TAILQ_REMOVE(&strm->inqueue, control, next_instrm);
                                        if (asoc->size_on_all_streams >= control->length) {
                                                asoc->size_on_all_streams -= control->length;
                                        } else {
#ifdef INVARIANTS
                                                panic("size_on_all_streams = %u smaller than control length %u", asoc->size_on_all_streams, control->length);
#else
                                                asoc->size_on_all_streams = 0;
#endif
                                        }
                                        sctp_ucount_decr(asoc->cnt_on_all_streams);
                                        control->on_strm_q = 0;
                                }
                                ret++;
                        }
                        if (((control->sinfo_flags >> 8) & SCTP_DATA_NOT_FRAG) == SCTP_DATA_NOT_FRAG) {
                                /*
                                 * A singleton now slipping through - mark
                                 * it non-revokable too
                                 */
                                sctp_mark_non_revokable(asoc, control->sinfo_tsn);
                        } else if (control->end_added == 0) {
                                /*
                                 * Check if we can defer adding until its
                                 * all there
                                 */
                                if ((control->length < pd_point) || (strm->pd_api_started)) {
                                        /*
                                         * Don't need it or cannot add more
                                         * (one being delivered that way)
                                         */
                                        goto out;
                                }
                        }
                        done = (control->end_added) && (control->last_frag_seen);
                        if (control->on_read_q == 0) {
                                if (!done) {
                                        if (asoc->size_on_all_streams >= control->length) {
                                                asoc->size_on_all_streams -= control->length;
                                        } else {
#ifdef INVARIANTS
                                                panic("size_on_all_streams = %u smaller than control length %u", asoc->size_on_all_streams, control->length);
#else
                                                asoc->size_on_all_streams = 0;
#endif
                                        }
                                        strm->pd_api_started = 1;
                                        control->pdapi_started = 1;
                                }
                                sctp_add_to_readq(stcb->sctp_ep, stcb,
                                    control,
                                    &stcb->sctp_socket->so_rcv, control->end_added,
                                    inp_read_lock_held, SCTP_SO_NOT_LOCKED);
                        }
                        strm->last_mid_delivered = next_to_del;
                        if (done) {
                                control = nctl;
                                goto deliver_more;
                        }
                }
        }
out:
        return (ret);
}

uint32_t
sctp_add_chk_to_control(struct sctp_queued_to_read *control,
    struct sctp_stream_in *strm,
    struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct sctp_tmit_chunk *chk, int hold_rlock)
{
        /*
         * Given a control and a chunk, merge the data from the chk onto the
         * control and free up the chunk resources.
         */
        uint32_t added = 0;
        bool i_locked = false;

        if (control->on_read_q) {
                if (hold_rlock == 0) {
                        /* Its being pd-api'd so we must do some locks. */
                        SCTP_INP_READ_LOCK(stcb->sctp_ep);
                        i_locked = true;
                }
                if (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_CANT_READ) {
                        goto out;
                }
        }
        if (control->data == NULL) {
                control->data = chk->data;
                sctp_setup_tail_pointer(control);
        } else {
                sctp_add_to_tail_pointer(control, chk->data, &added);
        }
        control->fsn_included = chk->rec.data.fsn;
        asoc->size_on_reasm_queue -= chk->send_size;
        sctp_ucount_decr(asoc->cnt_on_reasm_queue);
        sctp_mark_non_revokable(asoc, chk->rec.data.tsn);
        chk->data = NULL;
        if (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                control->first_frag_seen = 1;
                control->sinfo_tsn = chk->rec.data.tsn;
                control->sinfo_ppid = chk->rec.data.ppid;
        }
        if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                /* Its complete */
                if ((control->on_strm_q) && (control->on_read_q)) {
                        if (control->pdapi_started) {
                                control->pdapi_started = 0;
                                strm->pd_api_started = 0;
                        }
                        if (control->on_strm_q == SCTP_ON_UNORDERED) {
                                /* Unordered */
                                TAILQ_REMOVE(&strm->uno_inqueue, control, next_instrm);
                                control->on_strm_q = 0;
                        } else if (control->on_strm_q == SCTP_ON_ORDERED) {
                                /* Ordered */
                                TAILQ_REMOVE(&strm->inqueue, control, next_instrm);
                                /*
                                 * Don't need to decrement
                                 * size_on_all_streams, since control is on
                                 * the read queue.
                                 */
                                sctp_ucount_decr(asoc->cnt_on_all_streams);
                                control->on_strm_q = 0;
#ifdef INVARIANTS
                        } else if (control->on_strm_q) {
                                panic("Unknown state on ctrl: %p on_strm_q: %d", control,
                                    control->on_strm_q);
#endif
                        }
                }
                control->end_added = 1;
                control->last_frag_seen = 1;
        }
out:
        if (i_locked) {
                SCTP_INP_READ_UNLOCK(stcb->sctp_ep);
        }
        sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
        return (added);
}

/*
 * Dump onto the re-assembly queue, in its proper place. After dumping on the
 * queue, see if anything can be delivered. If so pull it off (or as much as
 * we can. If we run out of space then we must dump what we can and set the
 * appropriate flag to say we queued what we could.
 */
static void
sctp_queue_data_for_reasm(struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct sctp_queued_to_read *control,
    struct sctp_tmit_chunk *chk,
    int created_control,
    int *abort_flag, uint32_t tsn)
{
        uint32_t next_fsn;
        struct sctp_tmit_chunk *at, *nat;
        struct sctp_stream_in *strm;
        int do_wakeup, unordered;
        uint32_t lenadded;

        strm = &asoc->strmin[control->sinfo_stream];
        /*
         * For old un-ordered data chunks.
         */
        if ((control->sinfo_flags >> 8) & SCTP_DATA_UNORDERED) {
                unordered = 1;
        } else {
                unordered = 0;
        }
        /* Must be added to the stream-in queue */
        if (created_control) {
                if ((unordered == 0) || (asoc->idata_supported)) {
                        sctp_ucount_incr(asoc->cnt_on_all_streams);
                }
                if (sctp_place_control_in_stream(strm, asoc, control)) {
                        /* Duplicate SSN? */
                        sctp_abort_in_reasm(stcb, control, chk,
                            abort_flag,
                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_6);
                        sctp_clean_up_control(stcb, control);
                        return;
                }
                if ((tsn == (asoc->cumulative_tsn + 1) && (asoc->idata_supported == 0))) {
                        /*
                         * Ok we created this control and now lets validate
                         * that its legal i.e. there is a B bit set, if not
                         * and we have up to the cum-ack then its invalid.
                         */
                        if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) == 0) {
                                sctp_abort_in_reasm(stcb, control, chk,
                                    abort_flag,
                                    SCTP_FROM_SCTP_INDATA + SCTP_LOC_7);
                                return;
                        }
                }
        }
        if ((asoc->idata_supported == 0) && (unordered == 1)) {
                sctp_inject_old_unordered_data(stcb, asoc, control, chk, abort_flag);
                return;
        }
        /*
         * Ok we must queue the chunk into the reasembly portion: o if its
         * the first it goes to the control mbuf. o if its not first but the
         * next in sequence it goes to the control, and each succeeding one
         * in order also goes. o if its not in order we place it on the list
         * in its place.
         */
        if (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                /* Its the very first one. */
                SCTPDBG(SCTP_DEBUG_XXX,
                    "chunk is a first fsn: %u becomes fsn_included\n",
                    chk->rec.data.fsn);
                if (control->first_frag_seen) {
                        /*
                         * Error on senders part, they either sent us two
                         * data chunks with FIRST, or they sent two
                         * un-ordered chunks that were fragmented at the
                         * same time in the same stream.
                         */
                        sctp_abort_in_reasm(stcb, control, chk,
                            abort_flag,
                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_8);
                        return;
                }
                control->first_frag_seen = 1;
                control->sinfo_ppid = chk->rec.data.ppid;
                control->sinfo_tsn = chk->rec.data.tsn;
                control->fsn_included = chk->rec.data.fsn;
                control->data = chk->data;
                sctp_mark_non_revokable(asoc, chk->rec.data.tsn);
                chk->data = NULL;
                sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
                sctp_setup_tail_pointer(control);
                asoc->size_on_all_streams += control->length;
        } else {
                /* Place the chunk in our list */
                int inserted = 0;

                if (control->last_frag_seen == 0) {
                        /* Still willing to raise highest FSN seen */
                        if (SCTP_TSN_GT(chk->rec.data.fsn, control->top_fsn)) {
                                SCTPDBG(SCTP_DEBUG_XXX,
                                    "We have a new top_fsn: %u\n",
                                    chk->rec.data.fsn);
                                control->top_fsn = chk->rec.data.fsn;
                        }
                        if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                                SCTPDBG(SCTP_DEBUG_XXX,
                                    "The last fsn is now in place fsn: %u\n",
                                    chk->rec.data.fsn);
                                control->last_frag_seen = 1;
                                if (SCTP_TSN_GT(control->top_fsn, chk->rec.data.fsn)) {
                                        SCTPDBG(SCTP_DEBUG_XXX,
                                            "New fsn: %u is not at top_fsn: %u -- abort\n",
                                            chk->rec.data.fsn,
                                            control->top_fsn);
                                        sctp_abort_in_reasm(stcb, control, chk,
                                            abort_flag,
                                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_9);
                                        return;
                                }
                        }
                        if (asoc->idata_supported || control->first_frag_seen) {
                                /*
                                 * For IDATA we always check since we know
                                 * that the first fragment is 0. For old
                                 * DATA we have to receive the first before
                                 * we know the first FSN (which is the TSN).
                                 */
                                if (SCTP_TSN_GE(control->fsn_included, chk->rec.data.fsn)) {
                                        /*
                                         * We have already delivered up to
                                         * this so its a dup
                                         */
                                        sctp_abort_in_reasm(stcb, control, chk,
                                            abort_flag,
                                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_10);
                                        return;
                                }
                        }
                } else {
                        if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                                /* Second last? huh? */
                                SCTPDBG(SCTP_DEBUG_XXX,
                                    "Duplicate last fsn: %u (top: %u) -- abort\n",
                                    chk->rec.data.fsn, control->top_fsn);
                                sctp_abort_in_reasm(stcb, control,
                                    chk, abort_flag,
                                    SCTP_FROM_SCTP_INDATA + SCTP_LOC_11);
                                return;
                        }
                        if (asoc->idata_supported || control->first_frag_seen) {
                                /*
                                 * For IDATA we always check since we know
                                 * that the first fragment is 0. For old
                                 * DATA we have to receive the first before
                                 * we know the first FSN (which is the TSN).
                                 */

                                if (SCTP_TSN_GE(control->fsn_included, chk->rec.data.fsn)) {
                                        /*
                                         * We have already delivered up to
                                         * this so its a dup
                                         */
                                        SCTPDBG(SCTP_DEBUG_XXX,
                                            "New fsn: %u is already seen in included_fsn: %u -- abort\n",
                                            chk->rec.data.fsn, control->fsn_included);
                                        sctp_abort_in_reasm(stcb, control, chk,
                                            abort_flag,
                                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_12);
                                        return;
                                }
                        }
                        /*
                         * validate not beyond top FSN if we have seen last
                         * one
                         */
                        if (SCTP_TSN_GT(chk->rec.data.fsn, control->top_fsn)) {
                                SCTPDBG(SCTP_DEBUG_XXX,
                                    "New fsn: %u is beyond or at top_fsn: %u -- abort\n",
                                    chk->rec.data.fsn,
                                    control->top_fsn);
                                sctp_abort_in_reasm(stcb, control, chk,
                                    abort_flag,
                                    SCTP_FROM_SCTP_INDATA + SCTP_LOC_13);
                                return;
                        }
                }
                /*
                 * If we reach here, we need to place the new chunk in the
                 * reassembly for this control.
                 */
                SCTPDBG(SCTP_DEBUG_XXX,
                    "chunk is a not first fsn: %u needs to be inserted\n",
                    chk->rec.data.fsn);
                TAILQ_FOREACH(at, &control->reasm, sctp_next) {
                        if (SCTP_TSN_GT(at->rec.data.fsn, chk->rec.data.fsn)) {
                                if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                                        /* Last not at the end? huh? */
                                        SCTPDBG(SCTP_DEBUG_XXX,
                                            "Last fragment not last in list: -- abort\n");
                                        sctp_abort_in_reasm(stcb, control,
                                            chk, abort_flag,
                                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_14);
                                        return;
                                }
                                /*
                                 * This one in queue is bigger than the new
                                 * one, insert the new one before at.
                                 */
                                SCTPDBG(SCTP_DEBUG_XXX,
                                    "Insert it before fsn: %u\n",
                                    at->rec.data.fsn);
                                asoc->size_on_reasm_queue += chk->send_size;
                                sctp_ucount_incr(asoc->cnt_on_reasm_queue);
                                TAILQ_INSERT_BEFORE(at, chk, sctp_next);
                                inserted = 1;
                                break;
                        } else if (at->rec.data.fsn == chk->rec.data.fsn) {
                                /*
                                 * Gak, He sent me a duplicate str seq
                                 * number
                                 */
                                /*
                                 * foo bar, I guess I will just free this
                                 * new guy, should we abort too? FIX ME
                                 * MAYBE? Or it COULD be that the SSN's have
                                 * wrapped. Maybe I should compare to TSN
                                 * somehow... sigh for now just blow away
                                 * the chunk!
                                 */
                                SCTPDBG(SCTP_DEBUG_XXX,
                                    "Duplicate to fsn: %u -- abort\n",
                                    at->rec.data.fsn);
                                sctp_abort_in_reasm(stcb, control,
                                    chk, abort_flag,
                                    SCTP_FROM_SCTP_INDATA + SCTP_LOC_15);
                                return;
                        }
                }
                if (inserted == 0) {
                        /* Goes on the end */
                        SCTPDBG(SCTP_DEBUG_XXX, "Inserting at tail of list fsn: %u\n",
                            chk->rec.data.fsn);
                        asoc->size_on_reasm_queue += chk->send_size;
                        sctp_ucount_incr(asoc->cnt_on_reasm_queue);
                        TAILQ_INSERT_TAIL(&control->reasm, chk, sctp_next);
                }
        }
        /*
         * Ok lets see if we can suck any up into the control structure that
         * are in seq if it makes sense.
         */
        do_wakeup = 0;
        /*
         * If the first fragment has not been seen there is no sense in
         * looking.
         */
        if (control->first_frag_seen) {
                next_fsn = control->fsn_included + 1;
                TAILQ_FOREACH_SAFE(at, &control->reasm, sctp_next, nat) {
                        if (at->rec.data.fsn == next_fsn) {
                                /* We can add this one now to the control */
                                SCTPDBG(SCTP_DEBUG_XXX,
                                    "Adding more to control: %p at: %p fsn: %u next_fsn: %u included: %u\n",
                                    control, at,
                                    at->rec.data.fsn,
                                    next_fsn, control->fsn_included);
                                TAILQ_REMOVE(&control->reasm, at, sctp_next);
                                lenadded = sctp_add_chk_to_control(control, strm, stcb, asoc, at, SCTP_READ_LOCK_NOT_HELD);
                                if (control->on_read_q) {
                                        do_wakeup = 1;
                                } else {
                                        /*
                                         * We only add to the
                                         * size-on-all-streams if its not on
                                         * the read q. The read q flag will
                                         * cause a sballoc so its accounted
                                         * for there.
                                         */
                                        asoc->size_on_all_streams += lenadded;
                                }
                                next_fsn++;
                                if (control->end_added && control->pdapi_started) {
                                        if (strm->pd_api_started) {
                                                strm->pd_api_started = 0;
                                                control->pdapi_started = 0;
                                        }
                                        if (control->on_read_q == 0) {
                                                sctp_add_to_readq(stcb->sctp_ep, stcb,
                                                    control,
                                                    &stcb->sctp_socket->so_rcv, control->end_added,
                                                    SCTP_READ_LOCK_NOT_HELD, SCTP_SO_NOT_LOCKED);
                                        }
                                        break;
                                }
                        } else {
                                break;
                        }
                }
        }
        if (do_wakeup) {
                /* Need to wakeup the reader */
                sctp_wakeup_the_read_socket(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED);
        }
}

static struct sctp_queued_to_read *
sctp_find_reasm_entry(struct sctp_stream_in *strm, uint32_t mid, int ordered, int idata_supported)
{
        struct sctp_queued_to_read *control;

        if (ordered) {
                TAILQ_FOREACH(control, &strm->inqueue, next_instrm) {
                        if (SCTP_MID_EQ(idata_supported, control->mid, mid)) {
                                break;
                        }
                }
        } else {
                if (idata_supported) {
                        TAILQ_FOREACH(control, &strm->uno_inqueue, next_instrm) {
                                if (SCTP_MID_EQ(idata_supported, control->mid, mid)) {
                                        break;
                                }
                        }
                } else {
                        control = TAILQ_FIRST(&strm->uno_inqueue);
                }
        }
        return (control);
}

static int
sctp_process_a_data_chunk(struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct mbuf **m, int offset, int chk_length,
    struct sctp_nets *net, uint32_t *high_tsn, int *abort_flag,
    int *break_flag, int last_chunk, uint8_t chk_type)
{
        struct sctp_tmit_chunk *chk = NULL;     /* make gcc happy */
        struct sctp_stream_in *strm;
        uint32_t tsn, fsn, gap, mid;
        struct mbuf *dmbuf;
        int the_len;
        int need_reasm_check = 0;
        uint16_t sid;
        struct mbuf *op_err;
        char msg[SCTP_DIAG_INFO_LEN];
        struct sctp_queued_to_read *control, *ncontrol;
        uint32_t ppid;
        uint8_t chk_flags;
        struct sctp_stream_reset_list *liste;
        int ordered;
        size_t clen;
        int created_control = 0;

        if (chk_type == SCTP_IDATA) {
                struct sctp_idata_chunk *chunk, chunk_buf;

                chunk = (struct sctp_idata_chunk *)sctp_m_getptr(*m, offset,
                    sizeof(struct sctp_idata_chunk), (uint8_t *)&chunk_buf);
                chk_flags = chunk->ch.chunk_flags;
                clen = sizeof(struct sctp_idata_chunk);
                tsn = ntohl(chunk->dp.tsn);
                sid = ntohs(chunk->dp.sid);
                mid = ntohl(chunk->dp.mid);
                if (chk_flags & SCTP_DATA_FIRST_FRAG) {
                        fsn = 0;
                        ppid = chunk->dp.ppid_fsn.ppid;
                } else {
                        fsn = ntohl(chunk->dp.ppid_fsn.fsn);
                        ppid = 0xffffffff;      /* Use as an invalid value. */
                }
        } else {
                struct sctp_data_chunk *chunk, chunk_buf;

                chunk = (struct sctp_data_chunk *)sctp_m_getptr(*m, offset,
                    sizeof(struct sctp_data_chunk), (uint8_t *)&chunk_buf);
                chk_flags = chunk->ch.chunk_flags;
                clen = sizeof(struct sctp_data_chunk);
                tsn = ntohl(chunk->dp.tsn);
                sid = ntohs(chunk->dp.sid);
                mid = (uint32_t)(ntohs(chunk->dp.ssn));
                fsn = tsn;
                ppid = chunk->dp.ppid;
        }
        if ((size_t)chk_length == clen) {
                /*
                 * Need to send an abort since we had a empty data chunk.
                 */
                op_err = sctp_generate_no_user_data_cause(tsn);
                stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_16;
                sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                *abort_flag = 1;
                return (0);
        }
        if ((chk_flags & SCTP_DATA_SACK_IMMEDIATELY) == SCTP_DATA_SACK_IMMEDIATELY) {
                asoc->send_sack = 1;
        }
        ordered = ((chk_flags & SCTP_DATA_UNORDERED) == 0);
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                sctp_log_map(tsn, asoc->cumulative_tsn, asoc->highest_tsn_inside_map, SCTP_MAP_TSN_ENTERS);
        }
        if (stcb == NULL) {
                return (0);
        }
        SCTP_LTRACE_CHK(stcb->sctp_ep, stcb, chk_type, tsn);
        if (SCTP_TSN_GE(asoc->cumulative_tsn, tsn)) {
                /* It is a duplicate */
                SCTP_STAT_INCR(sctps_recvdupdata);
                if (asoc->numduptsns < SCTP_MAX_DUP_TSNS) {
                        /* Record a dup for the next outbound sack */
                        asoc->dup_tsns[asoc->numduptsns] = tsn;
                        asoc->numduptsns++;
                }
                asoc->send_sack = 1;
                return (0);
        }
        /* Calculate the number of TSN's between the base and this TSN */
        SCTP_CALC_TSN_TO_GAP(gap, tsn, asoc->mapping_array_base_tsn);
        if (gap >= (SCTP_MAPPING_ARRAY << 3)) {
                /* Can't hold the bit in the mapping at max array, toss it */
                return (0);
        }
        if (gap >= (uint32_t)(asoc->mapping_array_size << 3)) {
                SCTP_TCB_LOCK_ASSERT(stcb);
                if (sctp_expand_mapping_array(asoc, gap)) {
                        /* Can't expand, drop it */
                        return (0);
                }
        }
        if (SCTP_TSN_GT(tsn, *high_tsn)) {
                *high_tsn = tsn;
        }
        /* See if we have received this one already */
        if (SCTP_IS_TSN_PRESENT(asoc->mapping_array, gap) ||
            SCTP_IS_TSN_PRESENT(asoc->nr_mapping_array, gap)) {
                SCTP_STAT_INCR(sctps_recvdupdata);
                if (asoc->numduptsns < SCTP_MAX_DUP_TSNS) {
                        /* Record a dup for the next outbound sack */
                        asoc->dup_tsns[asoc->numduptsns] = tsn;
                        asoc->numduptsns++;
                }
                asoc->send_sack = 1;
                return (0);
        }
        /*
         * Check to see about the GONE flag, duplicates would cause a sack
         * to be sent up above
         */
        if (((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) ||
            (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_ALLGONE) ||
            (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET))) {
                /*
                 * wait a minute, this guy is gone, there is no longer a
                 * receiver. Send peer an ABORT!
                 */
                op_err = sctp_generate_cause(SCTP_CAUSE_OUT_OF_RESC, "");
                sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                *abort_flag = 1;
                return (0);
        }
        /*
         * Now before going further we see if there is room. If NOT then we
         * MAY let one through only IF this TSN is the one we are waiting
         * for on a partial delivery API.
         */

        /* Is the stream valid? */
        if (sid >= asoc->streamincnt) {
                struct sctp_error_invalid_stream *cause;

                op_err = sctp_get_mbuf_for_msg(sizeof(struct sctp_error_invalid_stream),
                    0, M_NOWAIT, 1, MT_DATA);
                if (op_err != NULL) {
                        /* add some space up front so prepend will work well */
                        SCTP_BUF_RESV_UF(op_err, sizeof(struct sctp_chunkhdr));
                        cause = mtod(op_err, struct sctp_error_invalid_stream *);
                        /*
                         * Error causes are just param's and this one has
                         * two back to back phdr, one with the error type
                         * and size, the other with the streamid and a rsvd
                         */
                        SCTP_BUF_LEN(op_err) = sizeof(struct sctp_error_invalid_stream);
                        cause->cause.code = htons(SCTP_CAUSE_INVALID_STREAM);
                        cause->cause.length = htons(sizeof(struct sctp_error_invalid_stream));
                        cause->stream_id = htons(sid);
                        cause->reserved = htons(0);
                        sctp_queue_op_err(stcb, op_err);
                }
                SCTP_STAT_INCR(sctps_badsid);
                SCTP_TCB_LOCK_ASSERT(stcb);
                SCTP_SET_TSN_PRESENT(asoc->nr_mapping_array, gap);
                if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_nr_map)) {
                        asoc->highest_tsn_inside_nr_map = tsn;
                }
                if (tsn == (asoc->cumulative_tsn + 1)) {
                        /* Update cum-ack */
                        asoc->cumulative_tsn = tsn;
                }
                return (0);
        }
        /*
         * If its a fragmented message, lets see if we can find the control
         * on the reassembly queues.
         */
        if ((chk_type == SCTP_IDATA) &&
            ((chk_flags & SCTP_DATA_FIRST_FRAG) == 0) &&
            (fsn == 0)) {
                /*
                 * The first *must* be fsn 0, and other (middle/end) pieces
                 * can *not* be fsn 0. XXX: This can happen in case of a
                 * wrap around. Ignore is for now.
                 */
                SCTP_SNPRINTF(msg, sizeof(msg), "FSN zero for MID=%8.8x, but flags=%2.2x", mid, chk_flags);
                goto err_out;
        }
        control = sctp_find_reasm_entry(&asoc->strmin[sid], mid, ordered, asoc->idata_supported);
        SCTPDBG(SCTP_DEBUG_XXX, "chunk_flags:0x%x look for control on queues %p\n",
            chk_flags, control);
        if ((chk_flags & SCTP_DATA_NOT_FRAG) != SCTP_DATA_NOT_FRAG) {
                /* See if we can find the re-assembly entity */
                if (control != NULL) {
                        /* We found something, does it belong? */
                        if (ordered && (mid != control->mid)) {
                                SCTP_SNPRINTF(msg, sizeof(msg), "Reassembly problem (MID=%8.8x)", mid);
                err_out:
                                op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_17;
                                sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                                *abort_flag = 1;
                                return (0);
                        }
                        if (ordered && ((control->sinfo_flags >> 8) & SCTP_DATA_UNORDERED)) {
                                /*
                                 * We can't have a switched order with an
                                 * unordered chunk
                                 */
                                SCTP_SNPRINTF(msg, sizeof(msg),
                                    "All fragments of a user message must be ordered or unordered (TSN=%8.8x)",
                                    tsn);
                                goto err_out;
                        }
                        if (!ordered && (((control->sinfo_flags >> 8) & SCTP_DATA_UNORDERED) == 0)) {
                                /*
                                 * We can't have a switched unordered with a
                                 * ordered chunk
                                 */
                                SCTP_SNPRINTF(msg, sizeof(msg),
                                    "All fragments of a user message must be ordered or unordered (TSN=%8.8x)",
                                    tsn);
                                goto err_out;
                        }
                }
        } else {
                /*
                 * Its a complete segment. Lets validate we don't have a
                 * re-assembly going on with the same Stream/Seq (for
                 * ordered) or in the same Stream for unordered.
                 */
                if (control != NULL) {
                        if (ordered || asoc->idata_supported) {
                                SCTPDBG(SCTP_DEBUG_XXX, "chunk_flags: 0x%x dup detected on MID: %u\n",
                                    chk_flags, mid);
                                SCTP_SNPRINTF(msg, sizeof(msg), "Duplicate MID=%8.8x detected.", mid);
                                goto err_out;
                        } else {
                                if ((control->first_frag_seen) &&
                                    (tsn == control->fsn_included + 1) &&
                                    (control->end_added == 0)) {
                                        SCTP_SNPRINTF(msg, sizeof(msg),
                                            "Illegal message sequence, missing end for MID: %8.8x",
                                            control->fsn_included);
                                        goto err_out;
                                } else {
                                        control = NULL;
                                }
                        }
                }
        }
        /* now do the tests */
        if (((asoc->cnt_on_all_streams +
            asoc->cnt_on_reasm_queue +
            asoc->cnt_msg_on_sb) >= SCTP_BASE_SYSCTL(sctp_max_chunks_on_queue)) ||
            (((int)asoc->my_rwnd) <= 0)) {
                /*
                 * When we have NO room in the rwnd we check to make sure
                 * the reader is doing its job...
                 */
                if (SCTP_SBAVAIL(&stcb->sctp_socket->so_rcv) > 0) {
                        /* some to read, wake-up */
                        sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
                }
                /* now is it in the mapping array of what we have accepted? */
                if (chk_type == SCTP_DATA) {
                        if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_map) &&
                            SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_nr_map)) {
                                /* Nope not in the valid range dump it */
                dump_packet:
                                sctp_set_rwnd(stcb, asoc);
                                if ((asoc->cnt_on_all_streams +
                                    asoc->cnt_on_reasm_queue +
                                    asoc->cnt_msg_on_sb) >= SCTP_BASE_SYSCTL(sctp_max_chunks_on_queue)) {
                                        SCTP_STAT_INCR(sctps_datadropchklmt);
                                } else {
                                        SCTP_STAT_INCR(sctps_datadroprwnd);
                                }
                                *break_flag = 1;
                                return (0);
                        }
                } else {
                        if (control == NULL) {
                                goto dump_packet;
                        }
                        if (SCTP_TSN_GT(fsn, control->top_fsn)) {
                                goto dump_packet;
                        }
                }
        }
#ifdef SCTP_ASOCLOG_OF_TSNS
        SCTP_TCB_LOCK_ASSERT(stcb);
        if (asoc->tsn_in_at >= SCTP_TSN_LOG_SIZE) {
                asoc->tsn_in_at = 0;
                asoc->tsn_in_wrapped = 1;
        }
        asoc->in_tsnlog[asoc->tsn_in_at].tsn = tsn;
        asoc->in_tsnlog[asoc->tsn_in_at].strm = sid;
        asoc->in_tsnlog[asoc->tsn_in_at].seq = mid;
        asoc->in_tsnlog[asoc->tsn_in_at].sz = chk_length;
        asoc->in_tsnlog[asoc->tsn_in_at].flgs = chunk_flags;
        asoc->in_tsnlog[asoc->tsn_in_at].stcb = (void *)stcb;
        asoc->in_tsnlog[asoc->tsn_in_at].in_pos = asoc->tsn_in_at;
        asoc->in_tsnlog[asoc->tsn_in_at].in_out = 1;
        asoc->tsn_in_at++;
#endif
        /*
         * Before we continue lets validate that we are not being fooled by
         * an evil attacker. We can only have Nk chunks based on our TSN
         * spread allowed by the mapping array N * 8 bits, so there is no
         * way our stream sequence numbers could have wrapped. We of course
         * only validate the FIRST fragment so the bit must be set.
         */
        if ((chk_flags & SCTP_DATA_FIRST_FRAG) &&
            (TAILQ_EMPTY(&asoc->resetHead)) &&
            (chk_flags & SCTP_DATA_UNORDERED) == 0 &&
            SCTP_MID_GE(asoc->idata_supported, asoc->strmin[sid].last_mid_delivered, mid)) {
                /* The incoming sseq is behind where we last delivered? */
                SCTPDBG(SCTP_DEBUG_INDATA1, "EVIL/Broken-Dup S-SEQ: %u delivered: %u from peer, Abort!\n",
                    mid, asoc->strmin[sid].last_mid_delivered);

                if (asoc->idata_supported) {
                        SCTP_SNPRINTF(msg, sizeof(msg), "Delivered MID=%8.8x, got TSN=%8.8x, SID=%4.4x, MID=%8.8x",
                            asoc->strmin[sid].last_mid_delivered,
                            tsn,
                            sid,
                            mid);
                } else {
                        SCTP_SNPRINTF(msg, sizeof(msg), "Delivered SSN=%4.4x, got TSN=%8.8x, SID=%4.4x, SSN=%4.4x",
                            (uint16_t)asoc->strmin[sid].last_mid_delivered,
                            tsn,
                            sid,
                            (uint16_t)mid);
                }
                op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_18;
                sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                *abort_flag = 1;
                return (0);
        }
        if (chk_type == SCTP_IDATA) {
                the_len = (chk_length - sizeof(struct sctp_idata_chunk));
        } else {
                the_len = (chk_length - sizeof(struct sctp_data_chunk));
        }
        if (last_chunk == 0) {
                if (chk_type == SCTP_IDATA) {
                        dmbuf = SCTP_M_COPYM(*m,
                            (offset + sizeof(struct sctp_idata_chunk)),
                            the_len, M_NOWAIT);
                } else {
                        dmbuf = SCTP_M_COPYM(*m,
                            (offset + sizeof(struct sctp_data_chunk)),
                            the_len, M_NOWAIT);
                }
#ifdef SCTP_MBUF_LOGGING
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MBUF_LOGGING_ENABLE) {
                        sctp_log_mbc(dmbuf, SCTP_MBUF_ICOPY);
                }
#endif
        } else {
                /* We can steal the last chunk */
                int l_len;

                dmbuf = *m;
                /* lop off the top part */
                if (chk_type == SCTP_IDATA) {
                        m_adj(dmbuf, (offset + sizeof(struct sctp_idata_chunk)));
                } else {
                        m_adj(dmbuf, (offset + sizeof(struct sctp_data_chunk)));
                }
                if (SCTP_BUF_NEXT(dmbuf) == NULL) {
                        l_len = SCTP_BUF_LEN(dmbuf);
                } else {
                        /*
                         * need to count up the size hopefully does not hit
                         * this to often :-0
                         */
                        struct mbuf *lat;

                        l_len = 0;
                        for (lat = dmbuf; lat; lat = SCTP_BUF_NEXT(lat)) {
                                l_len += SCTP_BUF_LEN(lat);
                        }
                }
                if (l_len > the_len) {
                        /* Trim the end round bytes off  too */
                        m_adj(dmbuf, -(l_len - the_len));
                }
        }
        if (dmbuf == NULL) {
                SCTP_STAT_INCR(sctps_nomem);
                return (0);
        }
        /*
         * Now no matter what, we need a control, get one if we don't have
         * one (we may have gotten it above when we found the message was
         * fragmented
         */
        if (control == NULL) {
                sctp_alloc_a_readq(stcb, control);
                sctp_build_readq_entry_mac(control, stcb, asoc->context, net, tsn,
                    ppid,
                    sid,
                    chk_flags,
                    NULL, fsn, mid);
                if (control == NULL) {
                        SCTP_STAT_INCR(sctps_nomem);
                        return (0);
                }
                if ((chk_flags & SCTP_DATA_NOT_FRAG) == SCTP_DATA_NOT_FRAG) {
                        struct mbuf *mm;

                        control->data = dmbuf;
                        control->tail_mbuf = NULL;
                        for (mm = control->data; mm; mm = mm->m_next) {
                                control->length += SCTP_BUF_LEN(mm);
                                if (SCTP_BUF_NEXT(mm) == NULL) {
                                        control->tail_mbuf = mm;
                                }
                        }
                        control->end_added = 1;
                        control->last_frag_seen = 1;
                        control->first_frag_seen = 1;
                        control->fsn_included = fsn;
                        control->top_fsn = fsn;
                }
                created_control = 1;
        }
        SCTPDBG(SCTP_DEBUG_XXX, "chunk_flags: 0x%x ordered: %d MID: %u control: %p\n",
            chk_flags, ordered, mid, control);
        if ((chk_flags & SCTP_DATA_NOT_FRAG) == SCTP_DATA_NOT_FRAG &&
            TAILQ_EMPTY(&asoc->resetHead) &&
            ((ordered == 0) ||
            (SCTP_MID_EQ(asoc->idata_supported, asoc->strmin[sid].last_mid_delivered + 1, mid) &&
            TAILQ_EMPTY(&asoc->strmin[sid].inqueue)))) {
                /* Candidate for express delivery */
                /*
                 * Its not fragmented, No PD-API is up, Nothing in the
                 * delivery queue, Its un-ordered OR ordered and the next to
                 * deliver AND nothing else is stuck on the stream queue,
                 * And there is room for it in the socket buffer. Lets just
                 * stuff it up the buffer....
                 */
                SCTP_SET_TSN_PRESENT(asoc->nr_mapping_array, gap);
                if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_nr_map)) {
                        asoc->highest_tsn_inside_nr_map = tsn;
                }
                SCTPDBG(SCTP_DEBUG_XXX, "Injecting control: %p to be read (MID: %u)\n",
                    control, mid);

                sctp_add_to_readq(stcb->sctp_ep, stcb,
                    control, &stcb->sctp_socket->so_rcv,
                    1, SCTP_READ_LOCK_NOT_HELD, SCTP_SO_NOT_LOCKED);

                if ((chk_flags & SCTP_DATA_UNORDERED) == 0) {
                        /* for ordered, bump what we delivered */
                        asoc->strmin[sid].last_mid_delivered++;
                }
                SCTP_STAT_INCR(sctps_recvexpress);
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                        sctp_log_strm_del_alt(stcb, tsn, mid, sid,
                            SCTP_STR_LOG_FROM_EXPRS_DEL);
                }
                control = NULL;
                goto finish_express_del;
        }

        /* Now will we need a chunk too? */
        if ((chk_flags & SCTP_DATA_NOT_FRAG) != SCTP_DATA_NOT_FRAG) {
                sctp_alloc_a_chunk(stcb, chk);
                if (chk == NULL) {
                        /* No memory so we drop the chunk */
                        SCTP_STAT_INCR(sctps_nomem);
                        if (last_chunk == 0) {
                                /* we copied it, free the copy */
                                sctp_m_freem(dmbuf);
                        }
                        return (0);
                }
                chk->rec.data.tsn = tsn;
                chk->no_fr_allowed = 0;
                chk->rec.data.fsn = fsn;
                chk->rec.data.mid = mid;
                chk->rec.data.sid = sid;
                chk->rec.data.ppid = ppid;
                chk->rec.data.context = stcb->asoc.context;
                chk->rec.data.doing_fast_retransmit = 0;
                chk->rec.data.rcv_flags = chk_flags;
                chk->asoc = asoc;
                chk->send_size = the_len;
                chk->whoTo = net;
                SCTPDBG(SCTP_DEBUG_XXX, "Building ck: %p for control: %p to be read (MID: %u)\n",
                    chk,
                    control, mid);
                atomic_add_int(&net->ref_count, 1);
                chk->data = dmbuf;
        }
        /* Set the appropriate TSN mark */
        if (SCTP_BASE_SYSCTL(sctp_do_drain) == 0) {
                SCTP_SET_TSN_PRESENT(asoc->nr_mapping_array, gap);
                if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_nr_map)) {
                        asoc->highest_tsn_inside_nr_map = tsn;
                }
        } else {
                SCTP_SET_TSN_PRESENT(asoc->mapping_array, gap);
                if (SCTP_TSN_GT(tsn, asoc->highest_tsn_inside_map)) {
                        asoc->highest_tsn_inside_map = tsn;
                }
        }
        /* Now is it complete (i.e. not fragmented)? */
        if ((chk_flags & SCTP_DATA_NOT_FRAG) == SCTP_DATA_NOT_FRAG) {
                /*
                 * Special check for when streams are resetting. We could be
                 * more smart about this and check the actual stream to see
                 * if it is not being reset.. that way we would not create a
                 * HOLB when amongst streams being reset and those not being
                 * reset.
                 *
                 */
                if (((liste = TAILQ_FIRST(&asoc->resetHead)) != NULL) &&
                    SCTP_TSN_GT(tsn, liste->tsn)) {
                        /*
                         * yep its past where we need to reset... go ahead
                         * and queue it.
                         */
                        if (TAILQ_EMPTY(&asoc->pending_reply_queue)) {
                                /* first one on */
                                TAILQ_INSERT_TAIL(&asoc->pending_reply_queue, control, next);
                        } else {
                                struct sctp_queued_to_read *lcontrol, *nlcontrol;
                                unsigned char inserted = 0;

                                TAILQ_FOREACH_SAFE(lcontrol, &asoc->pending_reply_queue, next, nlcontrol) {
                                        if (SCTP_TSN_GT(control->sinfo_tsn, lcontrol->sinfo_tsn)) {
                                                continue;
                                        } else {
                                                /* found it */
                                                TAILQ_INSERT_BEFORE(lcontrol, control, next);
                                                inserted = 1;
                                                break;
                                        }
                                }
                                if (inserted == 0) {
                                        /*
                                         * must be put at end, use prevP
                                         * (all setup from loop) to setup
                                         * nextP.
                                         */
                                        TAILQ_INSERT_TAIL(&asoc->pending_reply_queue, control, next);
                                }
                        }
                        goto finish_express_del;
                }
                if (chk_flags & SCTP_DATA_UNORDERED) {
                        /* queue directly into socket buffer */
                        SCTPDBG(SCTP_DEBUG_XXX, "Unordered data to be read control: %p MID: %u\n",
                            control, mid);
                        sctp_mark_non_revokable(asoc, control->sinfo_tsn);
                        sctp_add_to_readq(stcb->sctp_ep, stcb,
                            control,
                            &stcb->sctp_socket->so_rcv, 1,
                            SCTP_READ_LOCK_NOT_HELD, SCTP_SO_NOT_LOCKED);

                } else {
                        SCTPDBG(SCTP_DEBUG_XXX, "Queue control: %p for reordering MID: %u\n", control,
                            mid);
                        sctp_queue_data_to_stream(stcb, asoc, control, abort_flag, &need_reasm_check);
                        if (*abort_flag) {
                                if (last_chunk) {
                                        *m = NULL;
                                }
                                return (0);
                        }
                }
                goto finish_express_del;
        }
        /* If we reach here its a reassembly */
        need_reasm_check = 1;
        SCTPDBG(SCTP_DEBUG_XXX,
            "Queue data to stream for reasm control: %p MID: %u\n",
            control, mid);
        sctp_queue_data_for_reasm(stcb, asoc, control, chk, created_control, abort_flag, tsn);
        if (*abort_flag) {
                /*
                 * the assoc is now gone and chk was put onto the reasm
                 * queue, which has all been freed.
                 */
                if (last_chunk) {
                        *m = NULL;
                }
                return (0);
        }
finish_express_del:
        /* Here we tidy up things */
        if (tsn == (asoc->cumulative_tsn + 1)) {
                /* Update cum-ack */
                asoc->cumulative_tsn = tsn;
        }
        if (last_chunk) {
                *m = NULL;
        }
        if (ordered) {
                SCTP_STAT_INCR_COUNTER64(sctps_inorderchunks);
        } else {
                SCTP_STAT_INCR_COUNTER64(sctps_inunorderchunks);
        }
        SCTP_STAT_INCR(sctps_recvdata);
        /* Set it present please */
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_STR_LOGGING_ENABLE) {
                sctp_log_strm_del_alt(stcb, tsn, mid, sid, SCTP_STR_LOG_FROM_MARK_TSN);
        }
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                sctp_log_map(asoc->mapping_array_base_tsn, asoc->cumulative_tsn,
                    asoc->highest_tsn_inside_map, SCTP_MAP_PREPARE_SLIDE);
        }
        if (need_reasm_check) {
                (void)sctp_deliver_reasm_check(stcb, asoc, &asoc->strmin[sid], SCTP_READ_LOCK_NOT_HELD);
                need_reasm_check = 0;
        }
        /* check the special flag for stream resets */
        if (((liste = TAILQ_FIRST(&asoc->resetHead)) != NULL) &&
            SCTP_TSN_GE(asoc->cumulative_tsn, liste->tsn)) {
                /*
                 * we have finished working through the backlogged TSN's now
                 * time to reset streams. 1: call reset function. 2: free
                 * pending_reply space 3: distribute any chunks in
                 * pending_reply_queue.
                 */
                sctp_reset_in_stream(stcb, liste->number_entries, liste->list_of_streams);
                TAILQ_REMOVE(&asoc->resetHead, liste, next_resp);
                sctp_send_deferred_reset_response(stcb, liste, SCTP_STREAM_RESET_RESULT_PERFORMED);
                SCTP_FREE(liste, SCTP_M_STRESET);
                /* sa_ignore FREED_MEMORY */
                liste = TAILQ_FIRST(&asoc->resetHead);
                if (TAILQ_EMPTY(&asoc->resetHead)) {
                        /* All can be removed */
                        TAILQ_FOREACH_SAFE(control, &asoc->pending_reply_queue, next, ncontrol) {
                                TAILQ_REMOVE(&asoc->pending_reply_queue, control, next);
                                strm = &asoc->strmin[control->sinfo_stream];
                                sctp_queue_data_to_stream(stcb, asoc, control, abort_flag, &need_reasm_check);
                                if (*abort_flag) {
                                        return (0);
                                }
                                if (need_reasm_check) {
                                        (void)sctp_deliver_reasm_check(stcb, asoc, strm, SCTP_READ_LOCK_NOT_HELD);
                                        need_reasm_check = 0;
                                }
                        }
                } else {
                        TAILQ_FOREACH_SAFE(control, &asoc->pending_reply_queue, next, ncontrol) {
                                if (SCTP_TSN_GT(control->sinfo_tsn, liste->tsn)) {
                                        break;
                                }
                                /*
                                 * if control->sinfo_tsn is <= liste->tsn we
                                 * can process it which is the NOT of
                                 * control->sinfo_tsn > liste->tsn
                                 */
                                TAILQ_REMOVE(&asoc->pending_reply_queue, control, next);
                                strm = &asoc->strmin[control->sinfo_stream];
                                sctp_queue_data_to_stream(stcb, asoc, control, abort_flag, &need_reasm_check);
                                if (*abort_flag) {
                                        return (0);
                                }
                                if (need_reasm_check) {
                                        (void)sctp_deliver_reasm_check(stcb, asoc, strm, SCTP_READ_LOCK_NOT_HELD);
                                        need_reasm_check = 0;
                                }
                        }
                }
        }
        return (1);
}

static const int8_t sctp_map_lookup_tab[256] = {
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 4,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 5,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 4,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 6,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 4,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 5,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 4,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 7,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 4,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 5,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 4,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 6,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 4,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 5,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 4,
        0, 1, 0, 2, 0, 1, 0, 3,
        0, 1, 0, 2, 0, 1, 0, 8
};

void
sctp_slide_mapping_arrays(struct sctp_tcb *stcb)
{
        /*
         * Now we also need to check the mapping array in a couple of ways.
         * 1) Did we move the cum-ack point?
         *
         * When you first glance at this you might think that all entries
         * that make up the position of the cum-ack would be in the
         * nr-mapping array only.. i.e. things up to the cum-ack are always
         * deliverable. Thats true with one exception, when its a fragmented
         * message we may not deliver the data until some threshold (or all
         * of it) is in place. So we must OR the nr_mapping_array and
         * mapping_array to get a true picture of the cum-ack.
         */
        struct sctp_association *asoc;
        int at;
        uint8_t val;
        int slide_from, slide_end, lgap, distance;
        uint32_t old_cumack, old_base, old_highest, highest_tsn;

        asoc = &stcb->asoc;

        old_cumack = asoc->cumulative_tsn;
        old_base = asoc->mapping_array_base_tsn;
        old_highest = asoc->highest_tsn_inside_map;
        /*
         * We could probably improve this a small bit by calculating the
         * offset of the current cum-ack as the starting point.
         */
        at = 0;
        for (slide_from = 0; slide_from < stcb->asoc.mapping_array_size; slide_from++) {
                val = asoc->nr_mapping_array[slide_from] | asoc->mapping_array[slide_from];
                if (val == 0xff) {
                        at += 8;
                } else {
                        /* there is a 0 bit */
                        at += sctp_map_lookup_tab[val];
                        break;
                }
        }
        asoc->cumulative_tsn = asoc->mapping_array_base_tsn + (at - 1);

        if (SCTP_TSN_GT(asoc->cumulative_tsn, asoc->highest_tsn_inside_map) &&
            SCTP_TSN_GT(asoc->cumulative_tsn, asoc->highest_tsn_inside_nr_map)) {
#ifdef INVARIANTS
                panic("huh, cumack 0x%x greater than high-tsn 0x%x in map",
                    asoc->cumulative_tsn, asoc->highest_tsn_inside_map);
#else
                SCTP_PRINTF("huh, cumack 0x%x greater than high-tsn 0x%x in map - should panic?\n",
                    asoc->cumulative_tsn, asoc->highest_tsn_inside_map);
                sctp_print_mapping_array(asoc);
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                        sctp_log_map(0, 6, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
                }
                asoc->highest_tsn_inside_map = asoc->cumulative_tsn;
                asoc->highest_tsn_inside_nr_map = asoc->cumulative_tsn;
#endif
        }
        if (SCTP_TSN_GT(asoc->highest_tsn_inside_nr_map, asoc->highest_tsn_inside_map)) {
                highest_tsn = asoc->highest_tsn_inside_nr_map;
        } else {
                highest_tsn = asoc->highest_tsn_inside_map;
        }
        if ((asoc->cumulative_tsn == highest_tsn) && (at >= 8)) {
                /* The complete array was completed by a single FR */
                /* highest becomes the cum-ack */
                int clr;
#ifdef INVARIANTS
                unsigned int i;
#endif

                /* clear the array */
                clr = ((at + 7) >> 3);
                if (clr > asoc->mapping_array_size) {
                        clr = asoc->mapping_array_size;
                }
                memset(asoc->mapping_array, 0, clr);
                memset(asoc->nr_mapping_array, 0, clr);
#ifdef INVARIANTS
                for (i = 0; i < asoc->mapping_array_size; i++) {
                        if ((asoc->mapping_array[i]) || (asoc->nr_mapping_array[i])) {
                                SCTP_PRINTF("Error Mapping array's not clean at clear\n");
                                sctp_print_mapping_array(asoc);
                        }
                }
#endif
                asoc->mapping_array_base_tsn = asoc->cumulative_tsn + 1;
                asoc->highest_tsn_inside_nr_map = asoc->highest_tsn_inside_map = asoc->cumulative_tsn;
        } else if (at >= 8) {
                /* we can slide the mapping array down */
                /* slide_from holds where we hit the first NON 0xff byte */

                /*
                 * now calculate the ceiling of the move using our highest
                 * TSN value
                 */
                SCTP_CALC_TSN_TO_GAP(lgap, highest_tsn, asoc->mapping_array_base_tsn);
                slide_end = (lgap >> 3);
                if (slide_end < slide_from) {
                        sctp_print_mapping_array(asoc);
#ifdef INVARIANTS
                        panic("impossible slide");
#else
                        SCTP_PRINTF("impossible slide lgap: %x slide_end: %x slide_from: %x? at: %d\n",
                            lgap, slide_end, slide_from, at);
                        return;
#endif
                }
                if (slide_end > asoc->mapping_array_size) {
#ifdef INVARIANTS
                        panic("would overrun buffer");
#else
                        SCTP_PRINTF("Gak, would have overrun map end: %d slide_end: %d\n",
                            asoc->mapping_array_size, slide_end);
                        slide_end = asoc->mapping_array_size;
#endif
                }
                distance = (slide_end - slide_from) + 1;
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                        sctp_log_map(old_base, old_cumack, old_highest,
                            SCTP_MAP_PREPARE_SLIDE);
                        sctp_log_map((uint32_t)slide_from, (uint32_t)slide_end,
                            (uint32_t)lgap, SCTP_MAP_SLIDE_FROM);
                }
                if (distance + slide_from > asoc->mapping_array_size ||
                    distance < 0) {
                        /*
                         * Here we do NOT slide forward the array so that
                         * hopefully when more data comes in to fill it up
                         * we will be able to slide it forward. Really I
                         * don't think this should happen :-0
                         */
                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                                sctp_log_map((uint32_t)distance, (uint32_t)slide_from,
                                    (uint32_t)asoc->mapping_array_size,
                                    SCTP_MAP_SLIDE_NONE);
                        }
                } else {
                        int ii;

                        for (ii = 0; ii < distance; ii++) {
                                asoc->mapping_array[ii] = asoc->mapping_array[slide_from + ii];
                                asoc->nr_mapping_array[ii] = asoc->nr_mapping_array[slide_from + ii];
                        }
                        for (ii = distance; ii < asoc->mapping_array_size; ii++) {
                                asoc->mapping_array[ii] = 0;
                                asoc->nr_mapping_array[ii] = 0;
                        }
                        if (asoc->highest_tsn_inside_map + 1 == asoc->mapping_array_base_tsn) {
                                asoc->highest_tsn_inside_map += (slide_from << 3);
                        }
                        if (asoc->highest_tsn_inside_nr_map + 1 == asoc->mapping_array_base_tsn) {
                                asoc->highest_tsn_inside_nr_map += (slide_from << 3);
                        }
                        asoc->mapping_array_base_tsn += (slide_from << 3);
                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                                sctp_log_map(asoc->mapping_array_base_tsn,
                                    asoc->cumulative_tsn, asoc->highest_tsn_inside_map,
                                    SCTP_MAP_SLIDE_RESULT);
                        }
                }
        }
}

void
sctp_sack_check(struct sctp_tcb *stcb, int was_a_gap)
{
        struct sctp_association *asoc;
        uint32_t highest_tsn;
        int is_a_gap;

        sctp_slide_mapping_arrays(stcb);
        asoc = &stcb->asoc;
        if (SCTP_TSN_GT(asoc->highest_tsn_inside_nr_map, asoc->highest_tsn_inside_map)) {
                highest_tsn = asoc->highest_tsn_inside_nr_map;
        } else {
                highest_tsn = asoc->highest_tsn_inside_map;
        }
        /* Is there a gap now? */
        is_a_gap = SCTP_TSN_GT(highest_tsn, stcb->asoc.cumulative_tsn);

        /*
         * Now we need to see if we need to queue a sack or just start the
         * timer (if allowed).
         */
        if (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_SENT) {
                /*
                 * Ok special case, in SHUTDOWN-SENT case. here we maker
                 * sure SACK timer is off and instead send a SHUTDOWN and a
                 * SACK
                 */
                if (SCTP_OS_TIMER_PENDING(&stcb->asoc.dack_timer.timer)) {
                        sctp_timer_stop(SCTP_TIMER_TYPE_RECV,
                            stcb->sctp_ep, stcb, NULL,
                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_19);
                }
                sctp_send_shutdown(stcb,
                    ((stcb->asoc.alternate) ? stcb->asoc.alternate : stcb->asoc.primary_destination));
                if (is_a_gap) {
                        sctp_send_sack(stcb, SCTP_SO_NOT_LOCKED);
                }
        } else {
                /*
                 * CMT DAC algorithm: increase number of packets received
                 * since last ack
                 */
                stcb->asoc.cmt_dac_pkts_rcvd++;

                if ((stcb->asoc.send_sack == 1) ||      /* We need to send a
                                                         * SACK */
                    ((was_a_gap) && (is_a_gap == 0)) || /* was a gap, but no
                                                         * longer is one */
                    (stcb->asoc.numduptsns) ||  /* we have dup's */
                    (is_a_gap) ||       /* is still a gap */
                    (stcb->asoc.delayed_ack == 0) ||    /* Delayed sack disabled */
                    (stcb->asoc.data_pkts_seen >= stcb->asoc.sack_freq)) {      /* hit limit of pkts */
                        if ((stcb->asoc.sctp_cmt_on_off > 0) &&
                            (SCTP_BASE_SYSCTL(sctp_cmt_use_dac)) &&
                            (stcb->asoc.send_sack == 0) &&
                            (stcb->asoc.numduptsns == 0) &&
                            (stcb->asoc.delayed_ack) &&
                            (!SCTP_OS_TIMER_PENDING(&stcb->asoc.dack_timer.timer))) {
                                /*
                                 * CMT DAC algorithm: With CMT, delay acks
                                 * even in the face of reordering.
                                 * Therefore, if acks that do not have to be
                                 * sent because of the above reasons, will
                                 * be delayed. That is, acks that would have
                                 * been sent due to gap reports will be
                                 * delayed with DAC. Start the delayed ack
                                 * timer.
                                 */
                                sctp_timer_start(SCTP_TIMER_TYPE_RECV,
                                    stcb->sctp_ep, stcb, NULL);
                        } else {
                                /*
                                 * Ok we must build a SACK since the timer
                                 * is pending, we got our first packet OR
                                 * there are gaps or duplicates.
                                 */
                                sctp_timer_stop(SCTP_TIMER_TYPE_RECV, stcb->sctp_ep, stcb, NULL,
                                    SCTP_FROM_SCTP_INDATA + SCTP_LOC_20);
                                sctp_send_sack(stcb, SCTP_SO_NOT_LOCKED);
                        }
                } else {
                        if (!SCTP_OS_TIMER_PENDING(&stcb->asoc.dack_timer.timer)) {
                                sctp_timer_start(SCTP_TIMER_TYPE_RECV,
                                    stcb->sctp_ep, stcb, NULL);
                        }
                }
        }
}

int
sctp_process_data(struct mbuf **mm, int iphlen, int *offset, int length,
    struct sctp_inpcb *inp, struct sctp_tcb *stcb,
    struct sctp_nets *net, uint32_t *high_tsn)
{
        struct sctp_chunkhdr *ch, chunk_buf;
        struct sctp_association *asoc;
        int num_chunks = 0;     /* number of control chunks processed */
        int stop_proc = 0;
        int break_flag, last_chunk;
        int abort_flag = 0, was_a_gap;
        struct mbuf *m;
        uint32_t highest_tsn;
        uint16_t chk_length;

        /* set the rwnd */
        sctp_set_rwnd(stcb, &stcb->asoc);

        m = *mm;
        SCTP_TCB_LOCK_ASSERT(stcb);
        asoc = &stcb->asoc;
        if (SCTP_TSN_GT(asoc->highest_tsn_inside_nr_map, asoc->highest_tsn_inside_map)) {
                highest_tsn = asoc->highest_tsn_inside_nr_map;
        } else {
                highest_tsn = asoc->highest_tsn_inside_map;
        }
        was_a_gap = SCTP_TSN_GT(highest_tsn, stcb->asoc.cumulative_tsn);
        /*
         * setup where we got the last DATA packet from for any SACK that
         * may need to go out. Don't bump the net. This is done ONLY when a
         * chunk is assigned.
         */
        asoc->last_data_chunk_from = net;

        /*-
         * Now before we proceed we must figure out if this is a wasted
         * cluster... i.e. it is a small packet sent in and yet the driver
         * underneath allocated a full cluster for it. If so we must copy it
         * to a smaller mbuf and free up the cluster mbuf. This will help
         * with cluster starvation.
         */
        if (SCTP_BUF_LEN(m) < (long)MLEN && SCTP_BUF_NEXT(m) == NULL) {
                /* we only handle mbufs that are singletons.. not chains */
                m = sctp_get_mbuf_for_msg(SCTP_BUF_LEN(m), 0, M_NOWAIT, 1, MT_DATA);
                if (m) {
                        /* ok lets see if we can copy the data up */
                        caddr_t *from, *to;

                        /* get the pointers and copy */
                        to = mtod(m, caddr_t *);
                        from = mtod((*mm), caddr_t *);
                        memcpy(to, from, SCTP_BUF_LEN((*mm)));
                        /* copy the length and free up the old */
                        SCTP_BUF_LEN(m) = SCTP_BUF_LEN((*mm));
                        sctp_m_freem(*mm);
                        /* success, back copy */
                        *mm = m;
                } else {
                        /* We are in trouble in the mbuf world .. yikes */
                        m = *mm;
                }
        }
        /* get pointer to the first chunk header */
        ch = (struct sctp_chunkhdr *)sctp_m_getptr(m, *offset,
            sizeof(struct sctp_chunkhdr),
            (uint8_t *)&chunk_buf);
        if (ch == NULL) {
                return (1);
        }
        /*
         * process all DATA chunks...
         */
        *high_tsn = asoc->cumulative_tsn;
        break_flag = 0;
        asoc->data_pkts_seen++;
        while (stop_proc == 0) {
                /* validate chunk length */
                chk_length = ntohs(ch->chunk_length);
                if (length - *offset < chk_length) {
                        /* all done, mutulated chunk */
                        stop_proc = 1;
                        continue;
                }
                if ((asoc->idata_supported == 1) &&
                    (ch->chunk_type == SCTP_DATA)) {
                        struct mbuf *op_err;
                        char msg[SCTP_DIAG_INFO_LEN];

                        SCTP_SNPRINTF(msg, sizeof(msg), "%s", "DATA chunk received when I-DATA was negotiated");
                        op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_21;
                        sctp_abort_an_association(inp, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                        return (2);
                }
                if ((asoc->idata_supported == 0) &&
                    (ch->chunk_type == SCTP_IDATA)) {
                        struct mbuf *op_err;
                        char msg[SCTP_DIAG_INFO_LEN];

                        SCTP_SNPRINTF(msg, sizeof(msg), "%s", "I-DATA chunk received when DATA was negotiated");
                        op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_22;
                        sctp_abort_an_association(inp, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                        return (2);
                }
                if ((ch->chunk_type == SCTP_DATA) ||
                    (ch->chunk_type == SCTP_IDATA)) {
                        uint16_t clen;

                        if (ch->chunk_type == SCTP_DATA) {
                                clen = sizeof(struct sctp_data_chunk);
                        } else {
                                clen = sizeof(struct sctp_idata_chunk);
                        }
                        if (chk_length < clen) {
                                /*
                                 * Need to send an abort since we had a
                                 * invalid data chunk.
                                 */
                                struct mbuf *op_err;
                                char msg[SCTP_DIAG_INFO_LEN];

                                SCTP_SNPRINTF(msg, sizeof(msg), "%s chunk of length %u",
                                    ch->chunk_type == SCTP_DATA ? "DATA" : "I-DATA",
                                    chk_length);
                                op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_23;
                                sctp_abort_an_association(inp, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                                return (2);
                        }
#ifdef SCTP_AUDITING_ENABLED
                        sctp_audit_log(0xB1, 0);
#endif
                        if (SCTP_SIZE32(chk_length) == (length - *offset)) {
                                last_chunk = 1;
                        } else {
                                last_chunk = 0;
                        }
                        if (sctp_process_a_data_chunk(stcb, asoc, mm, *offset,
                            chk_length, net, high_tsn, &abort_flag, &break_flag,
                            last_chunk, ch->chunk_type)) {
                                num_chunks++;
                        }
                        if (abort_flag)
                                return (2);

                        if (break_flag) {
                                /*
                                 * Set because of out of rwnd space and no
                                 * drop rep space left.
                                 */
                                stop_proc = 1;
                                continue;
                        }
                } else {
                        /* not a data chunk in the data region */
                        switch (ch->chunk_type) {
                        case SCTP_INITIATION:
                        case SCTP_INITIATION_ACK:
                        case SCTP_SELECTIVE_ACK:
                        case SCTP_NR_SELECTIVE_ACK:
                        case SCTP_HEARTBEAT_REQUEST:
                        case SCTP_HEARTBEAT_ACK:
                        case SCTP_ABORT_ASSOCIATION:
                        case SCTP_SHUTDOWN:
                        case SCTP_SHUTDOWN_ACK:
                        case SCTP_OPERATION_ERROR:
                        case SCTP_COOKIE_ECHO:
                        case SCTP_COOKIE_ACK:
                        case SCTP_ECN_ECHO:
                        case SCTP_ECN_CWR:
                        case SCTP_SHUTDOWN_COMPLETE:
                        case SCTP_AUTHENTICATION:
                        case SCTP_ASCONF_ACK:
                        case SCTP_PACKET_DROPPED:
                        case SCTP_STREAM_RESET:
                        case SCTP_FORWARD_CUM_TSN:
                        case SCTP_ASCONF:
                                {
                                        /*
                                         * Now, what do we do with KNOWN
                                         * chunks that are NOT in the right
                                         * place?
                                         *
                                         * For now, I do nothing but ignore
                                         * them. We may later want to add
                                         * sysctl stuff to switch out and do
                                         * either an ABORT() or possibly
                                         * process them.
                                         */
                                        struct mbuf *op_err;
                                        char msg[SCTP_DIAG_INFO_LEN];

                                        SCTP_SNPRINTF(msg, sizeof(msg), "DATA chunk followed by chunk of type %2.2x",
                                            ch->chunk_type);
                                        op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                        sctp_abort_an_association(inp, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                                        return (2);
                                }
                        default:
                                /*
                                 * Unknown chunk type: use bit rules after
                                 * checking length
                                 */
                                if (chk_length < sizeof(struct sctp_chunkhdr)) {
                                        /*
                                         * Need to send an abort since we
                                         * had a invalid chunk.
                                         */
                                        struct mbuf *op_err;
                                        char msg[SCTP_DIAG_INFO_LEN];

                                        SCTP_SNPRINTF(msg, sizeof(msg), "Chunk of length %u", chk_length);
                                        op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_24;
                                        sctp_abort_an_association(inp, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                                        return (2);
                                }
                                if (ch->chunk_type & 0x40) {
                                        /* Add a error report to the queue */
                                        struct mbuf *op_err;
                                        struct sctp_gen_error_cause *cause;

                                        op_err = sctp_get_mbuf_for_msg(sizeof(struct sctp_gen_error_cause),
                                            0, M_NOWAIT, 1, MT_DATA);
                                        if (op_err != NULL) {
                                                cause = mtod(op_err, struct sctp_gen_error_cause *);
                                                cause->code = htons(SCTP_CAUSE_UNRECOG_CHUNK);
                                                cause->length = htons((uint16_t)(chk_length + sizeof(struct sctp_gen_error_cause)));
                                                SCTP_BUF_LEN(op_err) = sizeof(struct sctp_gen_error_cause);
                                                SCTP_BUF_NEXT(op_err) = SCTP_M_COPYM(m, *offset, chk_length, M_NOWAIT);
                                                if (SCTP_BUF_NEXT(op_err) != NULL) {
                                                        sctp_queue_op_err(stcb, op_err);
                                                } else {
                                                        sctp_m_freem(op_err);
                                                }
                                        }
                                }
                                if ((ch->chunk_type & 0x80) == 0) {
                                        /* discard the rest of this packet */
                                        stop_proc = 1;
                                }       /* else skip this bad chunk and
                                         * continue... */
                                break;
                        }       /* switch of chunk type */
                }
                *offset += SCTP_SIZE32(chk_length);
                if ((*offset >= length) || stop_proc) {
                        /* no more data left in the mbuf chain */
                        stop_proc = 1;
                        continue;
                }
                ch = (struct sctp_chunkhdr *)sctp_m_getptr(m, *offset,
                    sizeof(struct sctp_chunkhdr),
                    (uint8_t *)&chunk_buf);
                if (ch == NULL) {
                        *offset = length;
                        stop_proc = 1;
                        continue;
                }
        }
        if (break_flag) {
                /*
                 * we need to report rwnd overrun drops.
                 */
                sctp_send_packet_dropped(stcb, net, *mm, length, iphlen, 0);
        }
        if (num_chunks) {
                /*
                 * Did we get data, if so update the time for auto-close and
                 * give peer credit for being alive.
                 */
                SCTP_STAT_INCR(sctps_recvpktwithdata);
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
                        sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
                            stcb->asoc.overall_error_count,
                            0,
                            SCTP_FROM_SCTP_INDATA,
                            __LINE__);
                }
                stcb->asoc.overall_error_count = 0;
                (void)SCTP_GETTIME_TIMEVAL(&stcb->asoc.time_last_rcvd);
        }
        /* now service all of the reassm queue if needed */
        if (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_SENT) {
                /* Assure that we ack right away */
                stcb->asoc.send_sack = 1;
        }
        /* Start a sack timer or QUEUE a SACK for sending */
        sctp_sack_check(stcb, was_a_gap);
        return (0);
}

static int
sctp_process_segment_range(struct sctp_tcb *stcb, struct sctp_tmit_chunk **p_tp1, uint32_t last_tsn,
    uint16_t frag_strt, uint16_t frag_end, int nr_sacking,
    int *num_frs,
    uint32_t *biggest_newly_acked_tsn,
    uint32_t *this_sack_lowest_newack,
    int *rto_ok)
{
        struct sctp_tmit_chunk *tp1;
        unsigned int theTSN;
        int j, wake_him = 0, circled = 0;

        /* Recover the tp1 we last saw */
        tp1 = *p_tp1;
        if (tp1 == NULL) {
                tp1 = TAILQ_FIRST(&stcb->asoc.sent_queue);
        }
        for (j = frag_strt; j <= frag_end; j++) {
                theTSN = j + last_tsn;
                while (tp1) {
                        if (tp1->rec.data.doing_fast_retransmit)
                                (*num_frs) += 1;

                        /*-
                         * CMT: CUCv2 algorithm. For each TSN being
                         * processed from the sent queue, track the
                         * next expected pseudo-cumack, or
                         * rtx_pseudo_cumack, if required. Separate
                         * cumack trackers for first transmissions,
                         * and retransmissions.
                         */
                        if ((tp1->sent < SCTP_DATAGRAM_RESEND) &&
                            (tp1->whoTo->find_pseudo_cumack == 1) &&
                            (tp1->snd_count == 1)) {
                                tp1->whoTo->pseudo_cumack = tp1->rec.data.tsn;
                                tp1->whoTo->find_pseudo_cumack = 0;
                        }
                        if ((tp1->sent < SCTP_DATAGRAM_RESEND) &&
                            (tp1->whoTo->find_rtx_pseudo_cumack == 1) &&
                            (tp1->snd_count > 1)) {
                                tp1->whoTo->rtx_pseudo_cumack = tp1->rec.data.tsn;
                                tp1->whoTo->find_rtx_pseudo_cumack = 0;
                        }
                        if (tp1->rec.data.tsn == theTSN) {
                                if (tp1->sent != SCTP_DATAGRAM_UNSENT) {
                                        /*-
                                         * must be held until
                                         * cum-ack passes
                                         */
                                        if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                                /*-
                                                 * If it is less than RESEND, it is
                                                 * now no-longer in flight.
                                                 * Higher values may already be set
                                                 * via previous Gap Ack Blocks...
                                                 * i.e. ACKED or RESEND.
                                                 */
                                                if (SCTP_TSN_GT(tp1->rec.data.tsn,
                                                    *biggest_newly_acked_tsn)) {
                                                        *biggest_newly_acked_tsn = tp1->rec.data.tsn;
                                                }
                                                /*-
                                                 * CMT: SFR algo (and HTNA) - set
                                                 * saw_newack to 1 for dest being
                                                 * newly acked. update
                                                 * this_sack_highest_newack if
                                                 * appropriate.
                                                 */
                                                if (tp1->rec.data.chunk_was_revoked == 0)
                                                        tp1->whoTo->saw_newack = 1;

                                                if (SCTP_TSN_GT(tp1->rec.data.tsn,
                                                    tp1->whoTo->this_sack_highest_newack)) {
                                                        tp1->whoTo->this_sack_highest_newack =
                                                            tp1->rec.data.tsn;
                                                }
                                                /*-
                                                 * CMT DAC algo: also update
                                                 * this_sack_lowest_newack
                                                 */
                                                if (*this_sack_lowest_newack == 0) {
                                                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                                                                sctp_log_sack(*this_sack_lowest_newack,
                                                                    last_tsn,
                                                                    tp1->rec.data.tsn,
                                                                    0,
                                                                    0,
                                                                    SCTP_LOG_TSN_ACKED);
                                                        }
                                                        *this_sack_lowest_newack = tp1->rec.data.tsn;
                                                }
                                                /*-
                                                 * CMT: CUCv2 algorithm. If (rtx-)pseudo-cumack for corresp
                                                 * dest is being acked, then we have a new (rtx-)pseudo-cumack. Set
                                                 * new_(rtx_)pseudo_cumack to TRUE so that the cwnd for this dest can be
                                                 * updated. Also trigger search for the next expected (rtx-)pseudo-cumack.
                                                 * Separate pseudo_cumack trackers for first transmissions and
                                                 * retransmissions.
                                                 */
                                                if (tp1->rec.data.tsn == tp1->whoTo->pseudo_cumack) {
                                                        if (tp1->rec.data.chunk_was_revoked == 0) {
                                                                tp1->whoTo->new_pseudo_cumack = 1;
                                                        }
                                                        tp1->whoTo->find_pseudo_cumack = 1;
                                                }
                                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
                                                        sctp_log_cwnd(stcb, tp1->whoTo, tp1->rec.data.tsn, SCTP_CWND_LOG_FROM_SACK);
                                                }
                                                if (tp1->rec.data.tsn == tp1->whoTo->rtx_pseudo_cumack) {
                                                        if (tp1->rec.data.chunk_was_revoked == 0) {
                                                                tp1->whoTo->new_pseudo_cumack = 1;
                                                        }
                                                        tp1->whoTo->find_rtx_pseudo_cumack = 1;
                                                }
                                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                                                        sctp_log_sack(*biggest_newly_acked_tsn,
                                                            last_tsn,
                                                            tp1->rec.data.tsn,
                                                            frag_strt,
                                                            frag_end,
                                                            SCTP_LOG_TSN_ACKED);
                                                }
                                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                                        sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_GAP,
                                                            tp1->whoTo->flight_size,
                                                            tp1->book_size,
                                                            (uint32_t)(uintptr_t)tp1->whoTo,
                                                            tp1->rec.data.tsn);
                                                }
                                                sctp_flight_size_decrease(tp1);
                                                if (stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) {
                                                        (*stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) (tp1->whoTo,
                                                            tp1);
                                                }
                                                sctp_total_flight_decrease(stcb, tp1);

                                                tp1->whoTo->net_ack += tp1->send_size;
                                                if (tp1->snd_count < 2) {
                                                        /*-
                                                         * True non-retransmitted chunk
                                                         */
                                                        tp1->whoTo->net_ack2 += tp1->send_size;

                                                        /*-
                                                         * update RTO too ?
                                                         */
                                                        if (tp1->do_rtt) {
                                                                if (*rto_ok &&
                                                                    sctp_calculate_rto(stcb,
                                                                    &stcb->asoc,
                                                                    tp1->whoTo,
                                                                    &tp1->sent_rcv_time,
                                                                    SCTP_RTT_FROM_DATA)) {
                                                                        *rto_ok = 0;
                                                                }
                                                                if (tp1->whoTo->rto_needed == 0) {
                                                                        tp1->whoTo->rto_needed = 1;
                                                                }
                                                                tp1->do_rtt = 0;
                                                        }
                                                }
                                        }
                                        if (tp1->sent <= SCTP_DATAGRAM_RESEND) {
                                                if (SCTP_TSN_GT(tp1->rec.data.tsn,
                                                    stcb->asoc.this_sack_highest_gap)) {
                                                        stcb->asoc.this_sack_highest_gap =
                                                            tp1->rec.data.tsn;
                                                }
                                                if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                                                        sctp_ucount_decr(stcb->asoc.sent_queue_retran_cnt);
#ifdef SCTP_AUDITING_ENABLED
                                                        sctp_audit_log(0xB2,
                                                            (stcb->asoc.sent_queue_retran_cnt & 0x000000ff));
#endif
                                                }
                                        }
                                        /*-
                                         * All chunks NOT UNSENT fall through here and are marked
                                         * (leave PR-SCTP ones that are to skip alone though)
                                         */
                                        if ((tp1->sent != SCTP_FORWARD_TSN_SKIP) &&
                                            (tp1->sent != SCTP_DATAGRAM_NR_ACKED)) {
                                                tp1->sent = SCTP_DATAGRAM_MARKED;
                                        }
                                        if (tp1->rec.data.chunk_was_revoked) {
                                                /* deflate the cwnd */
                                                tp1->whoTo->cwnd -= tp1->book_size;
                                                tp1->rec.data.chunk_was_revoked = 0;
                                        }
                                        /* NR Sack code here */
                                        if (nr_sacking &&
                                            (tp1->sent != SCTP_DATAGRAM_NR_ACKED)) {
                                                if (stcb->asoc.strmout[tp1->rec.data.sid].chunks_on_queues > 0) {
                                                        stcb->asoc.strmout[tp1->rec.data.sid].chunks_on_queues--;
#ifdef INVARIANTS
                                                } else {
                                                        panic("No chunks on the queues for sid %u.", tp1->rec.data.sid);
#endif
                                                }
                                                if ((stcb->asoc.strmout[tp1->rec.data.sid].chunks_on_queues == 0) &&
                                                    (stcb->asoc.strmout[tp1->rec.data.sid].state == SCTP_STREAM_RESET_PENDING) &&
                                                    TAILQ_EMPTY(&stcb->asoc.strmout[tp1->rec.data.sid].outqueue)) {
                                                        stcb->asoc.trigger_reset = 1;
                                                }
                                                tp1->sent = SCTP_DATAGRAM_NR_ACKED;
                                                if (tp1->data) {
                                                        /*
                                                         * sa_ignore
                                                         * NO_NULL_CHK
                                                         */
                                                        sctp_free_bufspace(stcb, &stcb->asoc, tp1, 1);
                                                        sctp_m_freem(tp1->data);
                                                        tp1->data = NULL;
                                                }
                                                wake_him++;
                                        }
                                }
                                break;
                        }       /* if (tp1->tsn == theTSN) */
                        if (SCTP_TSN_GT(tp1->rec.data.tsn, theTSN)) {
                                break;
                        }
                        tp1 = TAILQ_NEXT(tp1, sctp_next);
                        if ((tp1 == NULL) && (circled == 0)) {
                                circled++;
                                tp1 = TAILQ_FIRST(&stcb->asoc.sent_queue);
                        }
                }               /* end while (tp1) */
                if (tp1 == NULL) {
                        circled = 0;
                        tp1 = TAILQ_FIRST(&stcb->asoc.sent_queue);
                }
                /* In case the fragments were not in order we must reset */
        }                       /* end for (j = fragStart */
        *p_tp1 = tp1;
        return (wake_him);      /* Return value only used for nr-sack */
}

static int
sctp_handle_segments(struct mbuf *m, int *offset, struct sctp_tcb *stcb, struct sctp_association *asoc,
    uint32_t last_tsn, uint32_t *biggest_tsn_acked,
    uint32_t *biggest_newly_acked_tsn, uint32_t *this_sack_lowest_newack,
    int num_seg, int num_nr_seg, int *rto_ok)
{
        struct sctp_gap_ack_block *frag, block;
        struct sctp_tmit_chunk *tp1;
        int i;
        int num_frs = 0;
        int chunk_freed;
        int non_revocable;
        uint16_t frag_strt, frag_end, prev_frag_end;

        tp1 = TAILQ_FIRST(&asoc->sent_queue);
        prev_frag_end = 0;
        chunk_freed = 0;

        for (i = 0; i < (num_seg + num_nr_seg); i++) {
                if (i == num_seg) {
                        prev_frag_end = 0;
                        tp1 = TAILQ_FIRST(&asoc->sent_queue);
                }
                frag = (struct sctp_gap_ack_block *)sctp_m_getptr(m, *offset,
                    sizeof(struct sctp_gap_ack_block), (uint8_t *)&block);
                *offset += sizeof(block);
                if (frag == NULL) {
                        return (chunk_freed);
                }
                frag_strt = ntohs(frag->start);
                frag_end = ntohs(frag->end);

                if (frag_strt > frag_end) {
                        /* This gap report is malformed, skip it. */
                        continue;
                }
                if (frag_strt <= prev_frag_end) {
                        /* This gap report is not in order, so restart. */
                        tp1 = TAILQ_FIRST(&asoc->sent_queue);
                }
                if (SCTP_TSN_GT((last_tsn + frag_end), *biggest_tsn_acked)) {
                        *biggest_tsn_acked = last_tsn + frag_end;
                }
                if (i < num_seg) {
                        non_revocable = 0;
                } else {
                        non_revocable = 1;
                }
                if (sctp_process_segment_range(stcb, &tp1, last_tsn, frag_strt, frag_end,
                    non_revocable, &num_frs, biggest_newly_acked_tsn,
                    this_sack_lowest_newack, rto_ok)) {
                        chunk_freed = 1;
                }
                prev_frag_end = frag_end;
        }
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                if (num_frs)
                        sctp_log_fr(*biggest_tsn_acked,
                            *biggest_newly_acked_tsn,
                            last_tsn, SCTP_FR_LOG_BIGGEST_TSNS);
        }
        return (chunk_freed);
}

static void
sctp_check_for_revoked(struct sctp_tcb *stcb,
    struct sctp_association *asoc, uint32_t cumack,
    uint32_t biggest_tsn_acked)
{
        struct sctp_tmit_chunk *tp1;

        TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                if (SCTP_TSN_GT(tp1->rec.data.tsn, cumack)) {
                        /*
                         * ok this guy is either ACK or MARKED. If it is
                         * ACKED it has been previously acked but not this
                         * time i.e. revoked.  If it is MARKED it was ACK'ed
                         * again.
                         */
                        if (SCTP_TSN_GT(tp1->rec.data.tsn, biggest_tsn_acked)) {
                                break;
                        }
                        if (tp1->sent == SCTP_DATAGRAM_ACKED) {
                                /* it has been revoked */
                                tp1->sent = SCTP_DATAGRAM_SENT;
                                tp1->rec.data.chunk_was_revoked = 1;
                                /*
                                 * We must add this stuff back in to assure
                                 * timers and such get started.
                                 */
                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                        sctp_misc_ints(SCTP_FLIGHT_LOG_UP_REVOKE,
                                            tp1->whoTo->flight_size,
                                            tp1->book_size,
                                            (uint32_t)(uintptr_t)tp1->whoTo,
                                            tp1->rec.data.tsn);
                                }
                                sctp_flight_size_increase(tp1);
                                sctp_total_flight_increase(stcb, tp1);
                                /*
                                 * We inflate the cwnd to compensate for our
                                 * artificial inflation of the flight_size.
                                 */
                                tp1->whoTo->cwnd += tp1->book_size;
                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                                        sctp_log_sack(asoc->last_acked_seq,
                                            cumack,
                                            tp1->rec.data.tsn,
                                            0,
                                            0,
                                            SCTP_LOG_TSN_REVOKED);
                                }
                        } else if (tp1->sent == SCTP_DATAGRAM_MARKED) {
                                /* it has been re-acked in this SACK */
                                tp1->sent = SCTP_DATAGRAM_ACKED;
                        }
                }
                if (tp1->sent == SCTP_DATAGRAM_UNSENT)
                        break;
        }
}

static void
sctp_strike_gap_ack_chunks(struct sctp_tcb *stcb, struct sctp_association *asoc,
    uint32_t biggest_tsn_acked, uint32_t biggest_tsn_newly_acked, uint32_t this_sack_lowest_newack, int accum_moved)
{
        struct sctp_tmit_chunk *tp1;
        int strike_flag = 0;
        struct timeval now;
        uint32_t sending_seq;
        struct sctp_nets *net;
        int num_dests_sacked = 0;

        /*
         * select the sending_seq, this is either the next thing ready to be
         * sent but not transmitted, OR, the next seq we assign.
         */
        tp1 = TAILQ_FIRST(&stcb->asoc.send_queue);
        if (tp1 == NULL) {
                sending_seq = asoc->sending_seq;
        } else {
                sending_seq = tp1->rec.data.tsn;
        }

        /* CMT DAC algo: finding out if SACK is a mixed SACK */
        if ((asoc->sctp_cmt_on_off > 0) &&
            SCTP_BASE_SYSCTL(sctp_cmt_use_dac)) {
                TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                        if (net->saw_newack)
                                num_dests_sacked++;
                }
        }
        if (stcb->asoc.prsctp_supported) {
                (void)SCTP_GETTIME_TIMEVAL(&now);
        }
        TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                strike_flag = 0;
                if (tp1->no_fr_allowed) {
                        /* this one had a timeout or something */
                        continue;
                }
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                        if (tp1->sent < SCTP_DATAGRAM_RESEND)
                                sctp_log_fr(biggest_tsn_newly_acked,
                                    tp1->rec.data.tsn,
                                    tp1->sent,
                                    SCTP_FR_LOG_CHECK_STRIKE);
                }
                if (SCTP_TSN_GT(tp1->rec.data.tsn, biggest_tsn_acked) ||
                    tp1->sent == SCTP_DATAGRAM_UNSENT) {
                        /* done */
                        break;
                }
                if (stcb->asoc.prsctp_supported) {
                        if ((PR_SCTP_TTL_ENABLED(tp1->flags)) && tp1->sent < SCTP_DATAGRAM_ACKED) {
                                /* Is it expired? */
                                if (timevalcmp(&now, &tp1->rec.data.timetodrop, >)) {
                                        /* Yes so drop it */
                                        if (tp1->data != NULL) {
                                                (void)sctp_release_pr_sctp_chunk(stcb, tp1, 1,
                                                    SCTP_SO_NOT_LOCKED);
                                        }
                                        continue;
                                }
                        }
                }
                if (SCTP_TSN_GT(tp1->rec.data.tsn, asoc->this_sack_highest_gap) &&
                    !(accum_moved && asoc->fast_retran_loss_recovery)) {
                        /* we are beyond the tsn in the sack  */
                        break;
                }
                if (tp1->sent >= SCTP_DATAGRAM_RESEND) {
                        /* either a RESEND, ACKED, or MARKED */
                        /* skip */
                        if (tp1->sent == SCTP_FORWARD_TSN_SKIP) {
                                /* Continue strikin FWD-TSN chunks */
                                tp1->rec.data.fwd_tsn_cnt++;
                        }
                        continue;
                }
                /*
                 * CMT : SFR algo (covers part of DAC and HTNA as well)
                 */
                if (tp1->whoTo && tp1->whoTo->saw_newack == 0) {
                        /*
                         * No new acks were received for data sent to this
                         * dest. Therefore, according to the SFR algo for
                         * CMT, no data sent to this dest can be marked for
                         * FR using this SACK.
                         */
                        continue;
                } else if (tp1->whoTo &&
                            SCTP_TSN_GT(tp1->rec.data.tsn,
                            tp1->whoTo->this_sack_highest_newack) &&
                    !(accum_moved && asoc->fast_retran_loss_recovery)) {
                        /*
                         * CMT: New acks were received for data sent to this
                         * dest. But no new acks were seen for data sent
                         * after tp1. Therefore, according to the SFR algo
                         * for CMT, tp1 cannot be marked for FR using this
                         * SACK. This step covers part of the DAC algo and
                         * the HTNA algo as well.
                         */
                        continue;
                }
                /*
                 * Here we check to see if we were have already done a FR
                 * and if so we see if the biggest TSN we saw in the sack is
                 * smaller than the recovery point. If so we don't strike
                 * the tsn... otherwise we CAN strike the TSN.
                 */
                /*
                 * @@@ JRI: Check for CMT if (accum_moved &&
                 * asoc->fast_retran_loss_recovery && (sctp_cmt_on_off ==
                 * 0)) {
                 */
                if (accum_moved && asoc->fast_retran_loss_recovery) {
                        /*
                         * Strike the TSN if in fast-recovery and cum-ack
                         * moved.
                         */
                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                sctp_log_fr(biggest_tsn_newly_acked,
                                    tp1->rec.data.tsn,
                                    tp1->sent,
                                    SCTP_FR_LOG_STRIKE_CHUNK);
                        }
                        if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                tp1->sent++;
                        }
                        if ((asoc->sctp_cmt_on_off > 0) &&
                            SCTP_BASE_SYSCTL(sctp_cmt_use_dac)) {
                                /*
                                 * CMT DAC algorithm: If SACK flag is set to
                                 * 0, then lowest_newack test will not pass
                                 * because it would have been set to the
                                 * cumack earlier. If not already to be
                                 * rtx'd, If not a mixed sack and if tp1 is
                                 * not between two sacked TSNs, then mark by
                                 * one more. NOTE that we are marking by one
                                 * additional time since the SACK DAC flag
                                 * indicates that two packets have been
                                 * received after this missing TSN.
                                 */
                                if ((tp1->sent < SCTP_DATAGRAM_RESEND) && (num_dests_sacked == 1) &&
                                    SCTP_TSN_GT(this_sack_lowest_newack, tp1->rec.data.tsn)) {
                                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                                sctp_log_fr(16 + num_dests_sacked,
                                                    tp1->rec.data.tsn,
                                                    tp1->sent,
                                                    SCTP_FR_LOG_STRIKE_CHUNK);
                                        }
                                        tp1->sent++;
                                }
                        }
                } else if ((tp1->rec.data.doing_fast_retransmit) &&
                    (asoc->sctp_cmt_on_off == 0)) {
                        /*
                         * For those that have done a FR we must take
                         * special consideration if we strike. I.e the
                         * biggest_newly_acked must be higher than the
                         * sending_seq at the time we did the FR.
                         */
                        if (
#ifdef SCTP_FR_TO_ALTERNATE
                        /*
                         * If FR's go to new networks, then we must only do
                         * this for singly homed asoc's. However if the FR's
                         * go to the same network (Armando's work) then its
                         * ok to FR multiple times.
                         */
                            (asoc->numnets < 2)
#else
                            (1)
#endif
                            ) {
                                if (SCTP_TSN_GE(biggest_tsn_newly_acked,
                                    tp1->rec.data.fast_retran_tsn)) {
                                        /*
                                         * Strike the TSN, since this ack is
                                         * beyond where things were when we
                                         * did a FR.
                                         */
                                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                                sctp_log_fr(biggest_tsn_newly_acked,
                                                    tp1->rec.data.tsn,
                                                    tp1->sent,
                                                    SCTP_FR_LOG_STRIKE_CHUNK);
                                        }
                                        if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                                tp1->sent++;
                                        }
                                        strike_flag = 1;
                                        if ((asoc->sctp_cmt_on_off > 0) &&
                                            SCTP_BASE_SYSCTL(sctp_cmt_use_dac)) {
                                                /*
                                                 * CMT DAC algorithm: If
                                                 * SACK flag is set to 0,
                                                 * then lowest_newack test
                                                 * will not pass because it
                                                 * would have been set to
                                                 * the cumack earlier. If
                                                 * not already to be rtx'd,
                                                 * If not a mixed sack and
                                                 * if tp1 is not between two
                                                 * sacked TSNs, then mark by
                                                 * one more. NOTE that we
                                                 * are marking by one
                                                 * additional time since the
                                                 * SACK DAC flag indicates
                                                 * that two packets have
                                                 * been received after this
                                                 * missing TSN.
                                                 */
                                                if ((tp1->sent < SCTP_DATAGRAM_RESEND) &&
                                                    (num_dests_sacked == 1) &&
                                                    SCTP_TSN_GT(this_sack_lowest_newack,
                                                    tp1->rec.data.tsn)) {
                                                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                                                sctp_log_fr(32 + num_dests_sacked,
                                                                    tp1->rec.data.tsn,
                                                                    tp1->sent,
                                                                    SCTP_FR_LOG_STRIKE_CHUNK);
                                                        }
                                                        if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                                                tp1->sent++;
                                                        }
                                                }
                                        }
                                }
                        }
                        /*
                         * JRI: TODO: remove code for HTNA algo. CMT's SFR
                         * algo covers HTNA.
                         */
                } else if (SCTP_TSN_GT(tp1->rec.data.tsn,
                    biggest_tsn_newly_acked)) {
                        /*
                         * We don't strike these: This is the  HTNA
                         * algorithm i.e. we don't strike If our TSN is
                         * larger than the Highest TSN Newly Acked.
                         */
                        ;
                } else {
                        /* Strike the TSN */
                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                sctp_log_fr(biggest_tsn_newly_acked,
                                    tp1->rec.data.tsn,
                                    tp1->sent,
                                    SCTP_FR_LOG_STRIKE_CHUNK);
                        }
                        if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                tp1->sent++;
                        }
                        if ((asoc->sctp_cmt_on_off > 0) &&
                            SCTP_BASE_SYSCTL(sctp_cmt_use_dac)) {
                                /*
                                 * CMT DAC algorithm: If SACK flag is set to
                                 * 0, then lowest_newack test will not pass
                                 * because it would have been set to the
                                 * cumack earlier. If not already to be
                                 * rtx'd, If not a mixed sack and if tp1 is
                                 * not between two sacked TSNs, then mark by
                                 * one more. NOTE that we are marking by one
                                 * additional time since the SACK DAC flag
                                 * indicates that two packets have been
                                 * received after this missing TSN.
                                 */
                                if ((tp1->sent < SCTP_DATAGRAM_RESEND) && (num_dests_sacked == 1) &&
                                    SCTP_TSN_GT(this_sack_lowest_newack, tp1->rec.data.tsn)) {
                                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                                sctp_log_fr(48 + num_dests_sacked,
                                                    tp1->rec.data.tsn,
                                                    tp1->sent,
                                                    SCTP_FR_LOG_STRIKE_CHUNK);
                                        }
                                        tp1->sent++;
                                }
                        }
                }
                if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                        struct sctp_nets *alt;

                        /* fix counts and things */
                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_RSND,
                                    (tp1->whoTo ? (tp1->whoTo->flight_size) : 0),
                                    tp1->book_size,
                                    (uint32_t)(uintptr_t)tp1->whoTo,
                                    tp1->rec.data.tsn);
                        }
                        if (tp1->whoTo) {
                                tp1->whoTo->net_ack++;
                                sctp_flight_size_decrease(tp1);
                                if (stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) {
                                        (*stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) (tp1->whoTo,
                                            tp1);
                                }
                        }

                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_RWND_ENABLE) {
                                sctp_log_rwnd(SCTP_INCREASE_PEER_RWND,
                                    asoc->peers_rwnd, tp1->send_size, SCTP_BASE_SYSCTL(sctp_peer_chunk_oh));
                        }
                        /* add back to the rwnd */
                        asoc->peers_rwnd += (tp1->send_size + SCTP_BASE_SYSCTL(sctp_peer_chunk_oh));

                        /* remove from the total flight */
                        sctp_total_flight_decrease(stcb, tp1);

                        if ((stcb->asoc.prsctp_supported) &&
                            (PR_SCTP_RTX_ENABLED(tp1->flags))) {
                                /*
                                 * Has it been retransmitted tv_sec times? -
                                 * we store the retran count there.
                                 */
                                if (tp1->snd_count > tp1->rec.data.timetodrop.tv_sec) {
                                        /* Yes, so drop it */
                                        if (tp1->data != NULL) {
                                                (void)sctp_release_pr_sctp_chunk(stcb, tp1, 1,
                                                    SCTP_SO_NOT_LOCKED);
                                        }
                                        /* Make sure to flag we had a FR */
                                        if (tp1->whoTo != NULL) {
                                                tp1->whoTo->net_ack++;
                                        }
                                        continue;
                                }
                        }
                        /*
                         * SCTP_PRINTF("OK, we are now ready to FR this
                         * guy\n");
                         */
                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                sctp_log_fr(tp1->rec.data.tsn, tp1->snd_count,
                                    0, SCTP_FR_MARKED);
                        }
                        if (strike_flag) {
                                /* This is a subsequent FR */
                                SCTP_STAT_INCR(sctps_sendmultfastretrans);
                        }
                        sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
                        if (asoc->sctp_cmt_on_off > 0) {
                                /*
                                 * CMT: Using RTX_SSTHRESH policy for CMT.
                                 * If CMT is being used, then pick dest with
                                 * largest ssthresh for any retransmission.
                                 */
                                tp1->no_fr_allowed = 1;
                                alt = tp1->whoTo;
                                /* sa_ignore NO_NULL_CHK */
                                if (asoc->sctp_cmt_pf > 0) {
                                        /*
                                         * JRS 5/18/07 - If CMT PF is on,
                                         * use the PF version of
                                         * find_alt_net()
                                         */
                                        alt = sctp_find_alternate_net(stcb, alt, 2);
                                } else {
                                        /*
                                         * JRS 5/18/07 - If only CMT is on,
                                         * use the CMT version of
                                         * find_alt_net()
                                         */
                                        /* sa_ignore NO_NULL_CHK */
                                        alt = sctp_find_alternate_net(stcb, alt, 1);
                                }
                                if (alt == NULL) {
                                        alt = tp1->whoTo;
                                }
                                /*
                                 * CUCv2: If a different dest is picked for
                                 * the retransmission, then new
                                 * (rtx-)pseudo_cumack needs to be tracked
                                 * for orig dest. Let CUCv2 track new (rtx-)
                                 * pseudo-cumack always.
                                 */
                                if (tp1->whoTo) {
                                        tp1->whoTo->find_pseudo_cumack = 1;
                                        tp1->whoTo->find_rtx_pseudo_cumack = 1;
                                }
                        } else {        /* CMT is OFF */
#ifdef SCTP_FR_TO_ALTERNATE
                                /* Can we find an alternate? */
                                alt = sctp_find_alternate_net(stcb, tp1->whoTo, 0);
#else
                                /*
                                 * default behavior is to NOT retransmit
                                 * FR's to an alternate. Armando Caro's
                                 * paper details why.
                                 */
                                alt = tp1->whoTo;
#endif
                        }

                        tp1->rec.data.doing_fast_retransmit = 1;
                        /* mark the sending seq for possible subsequent FR's */
                        /*
                         * SCTP_PRINTF("Marking TSN for FR new value %x\n",
                         * (uint32_t)tpi->rec.data.tsn);
                         */
                        if (TAILQ_EMPTY(&asoc->send_queue)) {
                                /*
                                 * If the queue of send is empty then its
                                 * the next sequence number that will be
                                 * assigned so we subtract one from this to
                                 * get the one we last sent.
                                 */
                                tp1->rec.data.fast_retran_tsn = sending_seq;
                        } else {
                                /*
                                 * If there are chunks on the send queue
                                 * (unsent data that has made it from the
                                 * stream queues but not out the door, we
                                 * take the first one (which will have the
                                 * lowest TSN) and subtract one to get the
                                 * one we last sent.
                                 */
                                struct sctp_tmit_chunk *ttt;

                                ttt = TAILQ_FIRST(&asoc->send_queue);
                                tp1->rec.data.fast_retran_tsn =
                                    ttt->rec.data.tsn;
                        }

                        if (tp1->do_rtt) {
                                /*
                                 * this guy had a RTO calculation pending on
                                 * it, cancel it
                                 */
                                if ((tp1->whoTo != NULL) &&
                                    (tp1->whoTo->rto_needed == 0)) {
                                        tp1->whoTo->rto_needed = 1;
                                }
                                tp1->do_rtt = 0;
                        }
                        if (alt != tp1->whoTo) {
                                /* yes, there is an alternate. */
                                sctp_free_remote_addr(tp1->whoTo);
                                /* sa_ignore FREED_MEMORY */
                                tp1->whoTo = alt;
                                atomic_add_int(&alt->ref_count, 1);
                        }
                }
        }
}

struct sctp_tmit_chunk *
sctp_try_advance_peer_ack_point(struct sctp_tcb *stcb,
    struct sctp_association *asoc)
{
        struct sctp_tmit_chunk *tp1, *tp2, *a_adv = NULL;
        struct timeval now;
        int now_filled = 0;

        if (asoc->prsctp_supported == 0) {
                return (NULL);
        }
        TAILQ_FOREACH_SAFE(tp1, &asoc->sent_queue, sctp_next, tp2) {
                if (tp1->sent != SCTP_FORWARD_TSN_SKIP &&
                    tp1->sent != SCTP_DATAGRAM_RESEND &&
                    tp1->sent != SCTP_DATAGRAM_NR_ACKED) {
                        /* no chance to advance, out of here */
                        break;
                }
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_TRY_ADVANCE) {
                        if ((tp1->sent == SCTP_FORWARD_TSN_SKIP) ||
                            (tp1->sent == SCTP_DATAGRAM_NR_ACKED)) {
                                sctp_misc_ints(SCTP_FWD_TSN_CHECK,
                                    asoc->advanced_peer_ack_point,
                                    tp1->rec.data.tsn, 0, 0);
                        }
                }
                if (!PR_SCTP_ENABLED(tp1->flags)) {
                        /*
                         * We can't fwd-tsn past any that are reliable aka
                         * retransmitted until the asoc fails.
                         */
                        break;
                }
                if (!now_filled) {
                        (void)SCTP_GETTIME_TIMEVAL(&now);
                        now_filled = 1;
                }
                /*
                 * now we got a chunk which is marked for another
                 * retransmission to a PR-stream but has run out its chances
                 * already maybe OR has been marked to skip now. Can we skip
                 * it if its a resend?
                 */
                if (tp1->sent == SCTP_DATAGRAM_RESEND &&
                    (PR_SCTP_TTL_ENABLED(tp1->flags))) {
                        /*
                         * Now is this one marked for resend and its time is
                         * now up?
                         */
                        if (timevalcmp(&now, &tp1->rec.data.timetodrop, >)) {
                                /* Yes so drop it */
                                if (tp1->data) {
                                        (void)sctp_release_pr_sctp_chunk(stcb, tp1,
                                            1, SCTP_SO_NOT_LOCKED);
                                }
                        } else {
                                /*
                                 * No, we are done when hit one for resend
                                 * whos time as not expired.
                                 */
                                break;
                        }
                }
                /*
                 * Ok now if this chunk is marked to drop it we can clean up
                 * the chunk, advance our peer ack point and we can check
                 * the next chunk.
                 */
                if ((tp1->sent == SCTP_FORWARD_TSN_SKIP) ||
                    (tp1->sent == SCTP_DATAGRAM_NR_ACKED)) {
                        /* advance PeerAckPoint goes forward */
                        if (SCTP_TSN_GT(tp1->rec.data.tsn, asoc->advanced_peer_ack_point)) {
                                asoc->advanced_peer_ack_point = tp1->rec.data.tsn;
                                a_adv = tp1;
                        } else if (tp1->rec.data.tsn == asoc->advanced_peer_ack_point) {
                                /* No update but we do save the chk */
                                a_adv = tp1;
                        }
                } else {
                        /*
                         * If it is still in RESEND we can advance no
                         * further
                         */
                        break;
                }
        }
        return (a_adv);
}

static int
sctp_fs_audit(struct sctp_association *asoc)
{
        struct sctp_tmit_chunk *chk;
        int inflight = 0, resend = 0, inbetween = 0, acked = 0, above = 0;
        int ret;
#ifndef INVARIANTS
        int entry_flight, entry_cnt;
#endif

        ret = 0;
#ifndef INVARIANTS
        entry_flight = asoc->total_flight;
        entry_cnt = asoc->total_flight_count;
#endif
        if (asoc->pr_sctp_cnt >= asoc->sent_queue_cnt)
                return (0);

        TAILQ_FOREACH(chk, &asoc->sent_queue, sctp_next) {
                if (chk->sent < SCTP_DATAGRAM_RESEND) {
                        SCTP_PRINTF("Chk TSN: %u size: %d inflight cnt: %d\n",
                            chk->rec.data.tsn,
                            chk->send_size,
                            chk->snd_count);
                        inflight++;
                } else if (chk->sent == SCTP_DATAGRAM_RESEND) {
                        resend++;
                } else if (chk->sent < SCTP_DATAGRAM_ACKED) {
                        inbetween++;
                } else if (chk->sent > SCTP_DATAGRAM_ACKED) {
                        above++;
                } else {
                        acked++;
                }
        }

        if ((inflight > 0) || (inbetween > 0)) {
#ifdef INVARIANTS
                panic("Flight size-express incorrect F: %d I: %d R: %d Ab: %d ACK: %d",
                    inflight, inbetween, resend, above, acked);
#else
                SCTP_PRINTF("asoc->total_flight: %d cnt: %d\n",
                    entry_flight, entry_cnt);
                SCTP_PRINTF("Flight size-express incorrect F: %d I: %d R: %d Ab: %d ACK: %d\n",
                    inflight, inbetween, resend, above, acked);
                ret = 1;
#endif
        }
        return (ret);
}

static void
sctp_window_probe_recovery(struct sctp_tcb *stcb,
    struct sctp_association *asoc,
    struct sctp_tmit_chunk *tp1)
{
        tp1->window_probe = 0;
        if ((tp1->sent >= SCTP_DATAGRAM_ACKED) || (tp1->data == NULL)) {
                /* TSN's skipped we do NOT move back. */
                sctp_misc_ints(SCTP_FLIGHT_LOG_DWN_WP_FWD,
                    tp1->whoTo ? tp1->whoTo->flight_size : 0,
                    tp1->book_size,
                    (uint32_t)(uintptr_t)tp1->whoTo,
                    tp1->rec.data.tsn);
                return;
        }
        /* First setup this by shrinking flight */
        if (stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) {
                (*stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) (tp1->whoTo,
                    tp1);
        }
        sctp_flight_size_decrease(tp1);
        sctp_total_flight_decrease(stcb, tp1);
        /* Now mark for resend */
        tp1->sent = SCTP_DATAGRAM_RESEND;
        sctp_ucount_incr(asoc->sent_queue_retran_cnt);

        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_WP,
                    tp1->whoTo->flight_size,
                    tp1->book_size,
                    (uint32_t)(uintptr_t)tp1->whoTo,
                    tp1->rec.data.tsn);
        }
}

void
sctp_express_handle_sack(struct sctp_tcb *stcb, uint32_t cumack,
    uint32_t rwnd, int *abort_now, int ecne_seen)
{
        struct sctp_nets *net;
        struct sctp_association *asoc;
        struct sctp_tmit_chunk *tp1, *tp2;
        uint32_t old_rwnd;
        int win_probe_recovery = 0;
        int win_probe_recovered = 0;
        int j, done_once = 0;
        int rto_ok = 1;
        uint32_t send_s;

        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_SACK_ARRIVALS_ENABLE) {
                sctp_misc_ints(SCTP_SACK_LOG_EXPRESS, cumack,
                    rwnd, stcb->asoc.last_acked_seq, stcb->asoc.peers_rwnd);
        }
        SCTP_TCB_LOCK_ASSERT(stcb);
#ifdef SCTP_ASOCLOG_OF_TSNS
        stcb->asoc.cumack_log[stcb->asoc.cumack_log_at] = cumack;
        stcb->asoc.cumack_log_at++;
        if (stcb->asoc.cumack_log_at > SCTP_TSN_LOG_SIZE) {
                stcb->asoc.cumack_log_at = 0;
        }
#endif
        asoc = &stcb->asoc;
        old_rwnd = asoc->peers_rwnd;
        if (SCTP_TSN_GT(asoc->last_acked_seq, cumack)) {
                /* old ack */
                return;
        } else if (asoc->last_acked_seq == cumack) {
                /* Window update sack */
                asoc->peers_rwnd = sctp_sbspace_sub(rwnd,
                    (uint32_t)(asoc->total_flight + (asoc->total_flight_count * SCTP_BASE_SYSCTL(sctp_peer_chunk_oh))));
                if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                        /* SWS sender side engages */
                        asoc->peers_rwnd = 0;
                }
                if (asoc->peers_rwnd > old_rwnd) {
                        goto again;
                }
                return;
        }

        /* First setup for CC stuff */
        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                if (SCTP_TSN_GT(cumack, net->cwr_window_tsn)) {
                        /* Drag along the window_tsn for cwr's */
                        net->cwr_window_tsn = cumack;
                }
                net->prev_cwnd = net->cwnd;
                net->net_ack = 0;
                net->net_ack2 = 0;

                /*
                 * CMT: Reset CUC and Fast recovery algo variables before
                 * SACK processing
                 */
                net->new_pseudo_cumack = 0;
                net->will_exit_fast_recovery = 0;
                if (stcb->asoc.cc_functions.sctp_cwnd_prepare_net_for_sack) {
                        (*stcb->asoc.cc_functions.sctp_cwnd_prepare_net_for_sack) (stcb, net);
                }
        }
        if (!TAILQ_EMPTY(&asoc->sent_queue)) {
                tp1 = TAILQ_LAST(&asoc->sent_queue,
                    sctpchunk_listhead);
                send_s = tp1->rec.data.tsn + 1;
        } else {
                send_s = asoc->sending_seq;
        }
        if (SCTP_TSN_GE(cumack, send_s)) {
                struct mbuf *op_err;
                char msg[SCTP_DIAG_INFO_LEN];

                *abort_now = 1;
                /* XXX */
                SCTP_SNPRINTF(msg, sizeof(msg),
                    "Cum ack %8.8x greater or equal than TSN %8.8x",
                    cumack, send_s);
                op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_25;
                sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                return;
        }
        asoc->this_sack_highest_gap = cumack;
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
                sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
                    stcb->asoc.overall_error_count,
                    0,
                    SCTP_FROM_SCTP_INDATA,
                    __LINE__);
        }
        stcb->asoc.overall_error_count = 0;
        if (SCTP_TSN_GT(cumack, asoc->last_acked_seq)) {
                /* process the new consecutive TSN first */
                TAILQ_FOREACH_SAFE(tp1, &asoc->sent_queue, sctp_next, tp2) {
                        if (SCTP_TSN_GE(cumack, tp1->rec.data.tsn)) {
                                if (tp1->sent == SCTP_DATAGRAM_UNSENT) {
                                        SCTP_PRINTF("Warning, an unsent is now acked?\n");
                                }
                                if (tp1->sent < SCTP_DATAGRAM_ACKED) {
                                        /*
                                         * If it is less than ACKED, it is
                                         * now no-longer in flight. Higher
                                         * values may occur during marking
                                         */
                                        if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                                        sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_CA,
                                                            tp1->whoTo->flight_size,
                                                            tp1->book_size,
                                                            (uint32_t)(uintptr_t)tp1->whoTo,
                                                            tp1->rec.data.tsn);
                                                }
                                                sctp_flight_size_decrease(tp1);
                                                if (stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) {
                                                        (*stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) (tp1->whoTo,
                                                            tp1);
                                                }
                                                /* sa_ignore NO_NULL_CHK */
                                                sctp_total_flight_decrease(stcb, tp1);
                                        }
                                        tp1->whoTo->net_ack += tp1->send_size;
                                        if (tp1->snd_count < 2) {
                                                /*
                                                 * True non-retransmitted
                                                 * chunk
                                                 */
                                                tp1->whoTo->net_ack2 +=
                                                    tp1->send_size;

                                                /* update RTO too? */
                                                if (tp1->do_rtt) {
                                                        if (rto_ok &&
                                                            sctp_calculate_rto(stcb,
                                                            &stcb->asoc,
                                                            tp1->whoTo,
                                                            &tp1->sent_rcv_time,
                                                            SCTP_RTT_FROM_DATA)) {
                                                                rto_ok = 0;
                                                        }
                                                        if (tp1->whoTo->rto_needed == 0) {
                                                                tp1->whoTo->rto_needed = 1;
                                                        }
                                                        tp1->do_rtt = 0;
                                                }
                                        }
                                        /*
                                         * CMT: CUCv2 algorithm. From the
                                         * cumack'd TSNs, for each TSN being
                                         * acked for the first time, set the
                                         * following variables for the
                                         * corresp destination.
                                         * new_pseudo_cumack will trigger a
                                         * cwnd update.
                                         * find_(rtx_)pseudo_cumack will
                                         * trigger search for the next
                                         * expected (rtx-)pseudo-cumack.
                                         */
                                        tp1->whoTo->new_pseudo_cumack = 1;
                                        tp1->whoTo->find_pseudo_cumack = 1;
                                        tp1->whoTo->find_rtx_pseudo_cumack = 1;
                                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
                                                /* sa_ignore NO_NULL_CHK */
                                                sctp_log_cwnd(stcb, tp1->whoTo, tp1->rec.data.tsn, SCTP_CWND_LOG_FROM_SACK);
                                        }
                                }
                                if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                                        sctp_ucount_decr(asoc->sent_queue_retran_cnt);
                                }
                                if (tp1->rec.data.chunk_was_revoked) {
                                        /* deflate the cwnd */
                                        tp1->whoTo->cwnd -= tp1->book_size;
                                        tp1->rec.data.chunk_was_revoked = 0;
                                }
                                if (tp1->sent != SCTP_DATAGRAM_NR_ACKED) {
                                        if (asoc->strmout[tp1->rec.data.sid].chunks_on_queues > 0) {
                                                asoc->strmout[tp1->rec.data.sid].chunks_on_queues--;
#ifdef INVARIANTS
                                        } else {
                                                panic("No chunks on the queues for sid %u.", tp1->rec.data.sid);
#endif
                                        }
                                }
                                if ((asoc->strmout[tp1->rec.data.sid].chunks_on_queues == 0) &&
                                    (asoc->strmout[tp1->rec.data.sid].state == SCTP_STREAM_RESET_PENDING) &&
                                    TAILQ_EMPTY(&asoc->strmout[tp1->rec.data.sid].outqueue)) {
                                        asoc->trigger_reset = 1;
                                }
                                TAILQ_REMOVE(&asoc->sent_queue, tp1, sctp_next);
                                if (tp1->data) {
                                        /* sa_ignore NO_NULL_CHK */
                                        sctp_free_bufspace(stcb, asoc, tp1, 1);
                                        sctp_m_freem(tp1->data);
                                        tp1->data = NULL;
                                }
                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                                        sctp_log_sack(asoc->last_acked_seq,
                                            cumack,
                                            tp1->rec.data.tsn,
                                            0,
                                            0,
                                            SCTP_LOG_FREE_SENT);
                                }
                                asoc->sent_queue_cnt--;
                                sctp_free_a_chunk(stcb, tp1, SCTP_SO_NOT_LOCKED);
                        } else {
                                break;
                        }
                }
        }
        /* sa_ignore NO_NULL_CHK */
        if (stcb->sctp_socket) {
                SOCKBUF_LOCK(&stcb->sctp_socket->so_snd);
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_WAKE_LOGGING_ENABLE) {
                        /* sa_ignore NO_NULL_CHK */
                        sctp_wakeup_log(stcb, 1, SCTP_WAKESND_FROM_SACK);
                }
                sctp_sowwakeup_locked(stcb->sctp_ep, stcb->sctp_socket);
        } else {
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_WAKE_LOGGING_ENABLE) {
                        sctp_wakeup_log(stcb, 1, SCTP_NOWAKE_FROM_SACK);
                }
        }

        /* JRS - Use the congestion control given in the CC module */
        if ((asoc->last_acked_seq != cumack) && (ecne_seen == 0)) {
                TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                        if (net->net_ack2 > 0) {
                                /*
                                 * Karn's rule applies to clearing error
                                 * count, this is optional.
                                 */
                                net->error_count = 0;
                                if ((net->dest_state & SCTP_ADDR_REACHABLE) == 0) {
                                        /* addr came good */
                                        net->dest_state |= SCTP_ADDR_REACHABLE;
                                        sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_UP, stcb,
                                            0, (void *)net, SCTP_SO_NOT_LOCKED);
                                }
                                if (net == stcb->asoc.primary_destination) {
                                        if (stcb->asoc.alternate) {
                                                /*
                                                 * release the alternate,
                                                 * primary is good
                                                 */
                                                sctp_free_remote_addr(stcb->asoc.alternate);
                                                stcb->asoc.alternate = NULL;
                                        }
                                }
                                if (net->dest_state & SCTP_ADDR_PF) {
                                        net->dest_state &= ~SCTP_ADDR_PF;
                                        sctp_timer_stop(SCTP_TIMER_TYPE_HEARTBEAT,
                                            stcb->sctp_ep, stcb, net,
                                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_26);
                                        sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb, net);
                                        asoc->cc_functions.sctp_cwnd_update_exit_pf(stcb, net);
                                        /* Done with this net */
                                        net->net_ack = 0;
                                }
                                /* restore any doubled timers */
                                net->RTO = (net->lastsa >> SCTP_RTT_SHIFT) + net->lastsv;
                                if (net->RTO < stcb->asoc.minrto) {
                                        net->RTO = stcb->asoc.minrto;
                                }
                                if (net->RTO > stcb->asoc.maxrto) {
                                        net->RTO = stcb->asoc.maxrto;
                                }
                        }
                }
                asoc->cc_functions.sctp_cwnd_update_after_sack(stcb, asoc, 1, 0, 0);
        }
        asoc->last_acked_seq = cumack;

        if (TAILQ_EMPTY(&asoc->sent_queue)) {
                /* nothing left in-flight */
                TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                        net->flight_size = 0;
                        net->partial_bytes_acked = 0;
                }
                asoc->total_flight = 0;
                asoc->total_flight_count = 0;
        }

        /* RWND update */
        asoc->peers_rwnd = sctp_sbspace_sub(rwnd,
            (uint32_t)(asoc->total_flight + (asoc->total_flight_count * SCTP_BASE_SYSCTL(sctp_peer_chunk_oh))));
        if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                /* SWS sender side engages */
                asoc->peers_rwnd = 0;
        }
        if (asoc->peers_rwnd > old_rwnd) {
                win_probe_recovery = 1;
        }
        /* Now assure a timer where data is queued at */
again:
        j = 0;
        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                if (win_probe_recovery && (net->window_probe)) {
                        win_probe_recovered = 1;
                        /*
                         * Find first chunk that was used with window probe
                         * and clear the sent
                         */
                        /* sa_ignore FREED_MEMORY */
                        TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                                if (tp1->window_probe) {
                                        /* move back to data send queue */
                                        sctp_window_probe_recovery(stcb, asoc, tp1);
                                        break;
                                }
                        }
                }
                if (net->flight_size) {
                        j++;
                        sctp_timer_start(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep, stcb, net);
                        if (net->window_probe) {
                                net->window_probe = 0;
                        }
                } else {
                        if (net->window_probe) {
                                /*
                                 * In window probes we must assure a timer
                                 * is still running there
                                 */
                                net->window_probe = 0;
                                if (!SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                                        sctp_timer_start(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep, stcb, net);
                                }
                        } else if (SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                                sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                                    stcb, net,
                                    SCTP_FROM_SCTP_INDATA + SCTP_LOC_27);
                        }
                }
        }
        if ((j == 0) &&
            (!TAILQ_EMPTY(&asoc->sent_queue)) &&
            (asoc->sent_queue_retran_cnt == 0) &&
            (win_probe_recovered == 0) &&
            (done_once == 0)) {
                /*
                 * huh, this should not happen unless all packets are
                 * PR-SCTP and marked to skip of course.
                 */
                if (sctp_fs_audit(asoc)) {
                        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                                net->flight_size = 0;
                        }
                        asoc->total_flight = 0;
                        asoc->total_flight_count = 0;
                        asoc->sent_queue_retran_cnt = 0;
                        TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                                if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                        sctp_flight_size_increase(tp1);
                                        sctp_total_flight_increase(stcb, tp1);
                                } else if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                                        sctp_ucount_incr(asoc->sent_queue_retran_cnt);
                                }
                        }
                }
                done_once = 1;
                goto again;
        }
        /**********************************/
        /* Now what about shutdown issues */
        /**********************************/
        if (TAILQ_EMPTY(&asoc->send_queue) && TAILQ_EMPTY(&asoc->sent_queue)) {
                /* nothing left on sendqueue.. consider done */
                /* clean up */
                if ((asoc->stream_queue_cnt == 1) &&
                    ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) ||
                    (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_RECEIVED)) &&
                    ((*asoc->ss_functions.sctp_ss_is_user_msgs_incomplete) (stcb, asoc))) {
                        SCTP_ADD_SUBSTATE(stcb, SCTP_STATE_PARTIAL_MSG_LEFT);
                }
                if (((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) ||
                    (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_RECEIVED)) &&
                    (asoc->stream_queue_cnt == 1) &&
                    (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT)) {
                        struct mbuf *op_err;

                        *abort_now = 1;
                        /* XXX */
                        op_err = sctp_generate_cause(SCTP_CAUSE_USER_INITIATED_ABT, "");
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_28;
                        sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                        return;
                }
                if ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) &&
                    (asoc->stream_queue_cnt == 0)) {
                        struct sctp_nets *netp;

                        if ((SCTP_GET_STATE(stcb) == SCTP_STATE_OPEN) ||
                            (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_RECEIVED)) {
                                SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                        }
                        SCTP_SET_STATE(stcb, SCTP_STATE_SHUTDOWN_SENT);
                        sctp_stop_timers_for_shutdown(stcb);
                        if (asoc->alternate) {
                                netp = asoc->alternate;
                        } else {
                                netp = asoc->primary_destination;
                        }
                        sctp_send_shutdown(stcb, netp);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWN,
                            stcb->sctp_ep, stcb, netp);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNGUARD,
                            stcb->sctp_ep, stcb, NULL);
                } else if ((SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_RECEIVED) &&
                    (asoc->stream_queue_cnt == 0)) {
                        struct sctp_nets *netp;

                        SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                        SCTP_SET_STATE(stcb, SCTP_STATE_SHUTDOWN_ACK_SENT);
                        sctp_stop_timers_for_shutdown(stcb);
                        if (asoc->alternate) {
                                netp = asoc->alternate;
                        } else {
                                netp = asoc->primary_destination;
                        }
                        sctp_send_shutdown_ack(stcb, netp);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNACK,
                            stcb->sctp_ep, stcb, netp);
                }
        }
        /*********************************************/
        /* Here we perform PR-SCTP procedures        */
        /* (section 4.2)                             */
        /*********************************************/
        /* C1. update advancedPeerAckPoint */
        if (SCTP_TSN_GT(cumack, asoc->advanced_peer_ack_point)) {
                asoc->advanced_peer_ack_point = cumack;
        }
        /* PR-Sctp issues need to be addressed too */
        if ((asoc->prsctp_supported) && (asoc->pr_sctp_cnt > 0)) {
                struct sctp_tmit_chunk *lchk;
                uint32_t old_adv_peer_ack_point;

                old_adv_peer_ack_point = asoc->advanced_peer_ack_point;
                lchk = sctp_try_advance_peer_ack_point(stcb, asoc);
                /* C3. See if we need to send a Fwd-TSN */
                if (SCTP_TSN_GT(asoc->advanced_peer_ack_point, cumack)) {
                        /*
                         * ISSUE with ECN, see FWD-TSN processing.
                         */
                        if (SCTP_TSN_GT(asoc->advanced_peer_ack_point, old_adv_peer_ack_point)) {
                                send_forward_tsn(stcb, asoc);
                        } else if (lchk) {
                                /* try to FR fwd-tsn's that get lost too */
                                if (lchk->rec.data.fwd_tsn_cnt >= 3) {
                                        send_forward_tsn(stcb, asoc);
                                }
                        }
                }
                for (; lchk != NULL; lchk = TAILQ_NEXT(lchk, sctp_next)) {
                        if (lchk->whoTo != NULL) {
                                break;
                        }
                }
                if (lchk != NULL) {
                        /* Assure a timer is up */
                        sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                            stcb->sctp_ep, stcb, lchk->whoTo);
                }
        }
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_RWND_LOGGING_ENABLE) {
                sctp_misc_ints(SCTP_SACK_RWND_UPDATE,
                    rwnd,
                    stcb->asoc.peers_rwnd,
                    stcb->asoc.total_flight,
                    stcb->asoc.total_output_queue_size);
        }
}

void
sctp_handle_sack(struct mbuf *m, int offset_seg, int offset_dup,
    struct sctp_tcb *stcb,
    uint16_t num_seg, uint16_t num_nr_seg, uint16_t num_dup,
    int *abort_now, uint8_t flags,
    uint32_t cum_ack, uint32_t rwnd, int ecne_seen)
{
        struct sctp_association *asoc;
        struct sctp_tmit_chunk *tp1, *tp2;
        uint32_t last_tsn, biggest_tsn_acked, biggest_tsn_newly_acked, this_sack_lowest_newack;
        uint16_t wake_him = 0;
        uint32_t send_s = 0;
        long j;
        int accum_moved = 0;
        int will_exit_fast_recovery = 0;
        uint32_t a_rwnd, old_rwnd;
        int win_probe_recovery = 0;
        int win_probe_recovered = 0;
        struct sctp_nets *net = NULL;
        int done_once;
        int rto_ok = 1;
        uint8_t reneged_all = 0;
        uint8_t cmt_dac_flag;

        /*
         * we take any chance we can to service our queues since we cannot
         * get awoken when the socket is read from :<
         */
        /*
         * Now perform the actual SACK handling: 1) Verify that it is not an
         * old sack, if so discard. 2) If there is nothing left in the send
         * queue (cum-ack is equal to last acked) then you have a duplicate
         * too, update any rwnd change and verify no timers are running.
         * then return. 3) Process any new consecutive data i.e. cum-ack
         * moved process these first and note that it moved. 4) Process any
         * sack blocks. 5) Drop any acked from the queue. 6) Check for any
         * revoked blocks and mark. 7) Update the cwnd. 8) Nothing left,
         * sync up flightsizes and things, stop all timers and also check
         * for shutdown_pending state. If so then go ahead and send off the
         * shutdown. If in shutdown recv, send off the shutdown-ack and
         * start that timer, Ret. 9) Strike any non-acked things and do FR
         * procedure if needed being sure to set the FR flag. 10) Do pr-sctp
         * procedures. 11) Apply any FR penalties. 12) Assure we will SACK
         * if in shutdown_recv state.
         */
        SCTP_TCB_LOCK_ASSERT(stcb);
        /* CMT DAC algo */
        this_sack_lowest_newack = 0;
        SCTP_STAT_INCR(sctps_slowpath_sack);
        last_tsn = cum_ack;
        cmt_dac_flag = flags & SCTP_SACK_CMT_DAC;
#ifdef SCTP_ASOCLOG_OF_TSNS
        stcb->asoc.cumack_log[stcb->asoc.cumack_log_at] = cum_ack;
        stcb->asoc.cumack_log_at++;
        if (stcb->asoc.cumack_log_at > SCTP_TSN_LOG_SIZE) {
                stcb->asoc.cumack_log_at = 0;
        }
#endif
        a_rwnd = rwnd;

        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_SACK_ARRIVALS_ENABLE) {
                sctp_misc_ints(SCTP_SACK_LOG_NORMAL, cum_ack,
                    rwnd, stcb->asoc.last_acked_seq, stcb->asoc.peers_rwnd);
        }

        old_rwnd = stcb->asoc.peers_rwnd;
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
                sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
                    stcb->asoc.overall_error_count,
                    0,
                    SCTP_FROM_SCTP_INDATA,
                    __LINE__);
        }
        stcb->asoc.overall_error_count = 0;
        asoc = &stcb->asoc;
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                sctp_log_sack(asoc->last_acked_seq,
                    cum_ack,
                    0,
                    num_seg,
                    num_dup,
                    SCTP_LOG_NEW_SACK);
        }
        if ((num_dup) && (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE)) {
                uint16_t i;
                uint32_t *dupdata, dblock;

                for (i = 0; i < num_dup; i++) {
                        dupdata = (uint32_t *)sctp_m_getptr(m, offset_dup + i * sizeof(uint32_t),
                            sizeof(uint32_t), (uint8_t *)&dblock);
                        if (dupdata == NULL) {
                                break;
                        }
                        sctp_log_fr(*dupdata, 0, 0, SCTP_FR_DUPED);
                }
        }
        /* reality check */
        if (!TAILQ_EMPTY(&asoc->sent_queue)) {
                tp1 = TAILQ_LAST(&asoc->sent_queue,
                    sctpchunk_listhead);
                send_s = tp1->rec.data.tsn + 1;
        } else {
                tp1 = NULL;
                send_s = asoc->sending_seq;
        }
        if (SCTP_TSN_GE(cum_ack, send_s)) {
                struct mbuf *op_err;
                char msg[SCTP_DIAG_INFO_LEN];

                /*
                 * no way, we have not even sent this TSN out yet. Peer is
                 * hopelessly messed up with us.
                 */
                SCTP_PRINTF("NEW cum_ack:%x send_s:%x is smaller or equal\n",
                    cum_ack, send_s);
                if (tp1) {
                        SCTP_PRINTF("Got send_s from tsn:%x + 1 of tp1: %p\n",
                            tp1->rec.data.tsn, (void *)tp1);
                }
hopeless_peer:
                *abort_now = 1;
                /* XXX */
                SCTP_SNPRINTF(msg, sizeof(msg),
                    "Cum ack %8.8x greater or equal than TSN %8.8x",
                    cum_ack, send_s);
                op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_29;
                sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                return;
        }
        /**********************/
        /* 1) check the range */
        /**********************/
        if (SCTP_TSN_GT(asoc->last_acked_seq, last_tsn)) {
                /* acking something behind */
                return;
        }

        /* update the Rwnd of the peer */
        if (TAILQ_EMPTY(&asoc->sent_queue) &&
            TAILQ_EMPTY(&asoc->send_queue) &&
            (asoc->stream_queue_cnt == 0)) {
                /* nothing left on send/sent and strmq */
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_RWND_ENABLE) {
                        sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                            asoc->peers_rwnd, 0, 0, a_rwnd);
                }
                asoc->peers_rwnd = a_rwnd;
                if (asoc->sent_queue_retran_cnt) {
                        asoc->sent_queue_retran_cnt = 0;
                }
                if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                        /* SWS sender side engages */
                        asoc->peers_rwnd = 0;
                }
                /* stop any timers */
                TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                        sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                            stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_30);
                        net->partial_bytes_acked = 0;
                        net->flight_size = 0;
                }
                asoc->total_flight = 0;
                asoc->total_flight_count = 0;
                return;
        }
        /*
         * We init netAckSz and netAckSz2 to 0. These are used to track 2
         * things. The total byte count acked is tracked in netAckSz AND
         * netAck2 is used to track the total bytes acked that are un-
         * ambiguous and were never retransmitted. We track these on a per
         * destination address basis.
         */
        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                if (SCTP_TSN_GT(cum_ack, net->cwr_window_tsn)) {
                        /* Drag along the window_tsn for cwr's */
                        net->cwr_window_tsn = cum_ack;
                }
                net->prev_cwnd = net->cwnd;
                net->net_ack = 0;
                net->net_ack2 = 0;

                /*
                 * CMT: Reset CUC and Fast recovery algo variables before
                 * SACK processing
                 */
                net->new_pseudo_cumack = 0;
                net->will_exit_fast_recovery = 0;
                if (stcb->asoc.cc_functions.sctp_cwnd_prepare_net_for_sack) {
                        (*stcb->asoc.cc_functions.sctp_cwnd_prepare_net_for_sack) (stcb, net);
                }

                /*
                 * CMT: SFR algo (and HTNA) - this_sack_highest_newack has
                 * to be greater than the cumack. Also reset saw_newack to 0
                 * for all dests.
                 */
                net->saw_newack = 0;
                net->this_sack_highest_newack = last_tsn;
        }
        /* process the new consecutive TSN first */
        TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                if (SCTP_TSN_GE(last_tsn, tp1->rec.data.tsn)) {
                        if (tp1->sent != SCTP_DATAGRAM_UNSENT) {
                                accum_moved = 1;
                                if (tp1->sent < SCTP_DATAGRAM_ACKED) {
                                        /*
                                         * If it is less than ACKED, it is
                                         * now no-longer in flight. Higher
                                         * values may occur during marking
                                         */
                                        if ((tp1->whoTo->dest_state &
                                            SCTP_ADDR_UNCONFIRMED) &&
                                            (tp1->snd_count < 2)) {
                                                /*
                                                 * If there was no retran
                                                 * and the address is
                                                 * un-confirmed and we sent
                                                 * there and are now
                                                 * sacked.. its confirmed,
                                                 * mark it so.
                                                 */
                                                tp1->whoTo->dest_state &=
                                                    ~SCTP_ADDR_UNCONFIRMED;
                                        }
                                        if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                                        sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_CA,
                                                            tp1->whoTo->flight_size,
                                                            tp1->book_size,
                                                            (uint32_t)(uintptr_t)tp1->whoTo,
                                                            tp1->rec.data.tsn);
                                                }
                                                sctp_flight_size_decrease(tp1);
                                                sctp_total_flight_decrease(stcb, tp1);
                                                if (stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) {
                                                        (*stcb->asoc.cc_functions.sctp_cwnd_update_tsn_acknowledged) (tp1->whoTo,
                                                            tp1);
                                                }
                                        }
                                        tp1->whoTo->net_ack += tp1->send_size;

                                        /* CMT SFR and DAC algos */
                                        this_sack_lowest_newack = tp1->rec.data.tsn;
                                        tp1->whoTo->saw_newack = 1;

                                        if (tp1->snd_count < 2) {
                                                /*
                                                 * True non-retransmitted
                                                 * chunk
                                                 */
                                                tp1->whoTo->net_ack2 +=
                                                    tp1->send_size;

                                                /* update RTO too? */
                                                if (tp1->do_rtt) {
                                                        if (rto_ok &&
                                                            sctp_calculate_rto(stcb,
                                                            &stcb->asoc,
                                                            tp1->whoTo,
                                                            &tp1->sent_rcv_time,
                                                            SCTP_RTT_FROM_DATA)) {
                                                                rto_ok = 0;
                                                        }
                                                        if (tp1->whoTo->rto_needed == 0) {
                                                                tp1->whoTo->rto_needed = 1;
                                                        }
                                                        tp1->do_rtt = 0;
                                                }
                                        }
                                        /*
                                         * CMT: CUCv2 algorithm. From the
                                         * cumack'd TSNs, for each TSN being
                                         * acked for the first time, set the
                                         * following variables for the
                                         * corresp destination.
                                         * new_pseudo_cumack will trigger a
                                         * cwnd update.
                                         * find_(rtx_)pseudo_cumack will
                                         * trigger search for the next
                                         * expected (rtx-)pseudo-cumack.
                                         */
                                        tp1->whoTo->new_pseudo_cumack = 1;
                                        tp1->whoTo->find_pseudo_cumack = 1;
                                        tp1->whoTo->find_rtx_pseudo_cumack = 1;
                                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                                                sctp_log_sack(asoc->last_acked_seq,
                                                    cum_ack,
                                                    tp1->rec.data.tsn,
                                                    0,
                                                    0,
                                                    SCTP_LOG_TSN_ACKED);
                                        }
                                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
                                                sctp_log_cwnd(stcb, tp1->whoTo, tp1->rec.data.tsn, SCTP_CWND_LOG_FROM_SACK);
                                        }
                                }
                                if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                                        sctp_ucount_decr(asoc->sent_queue_retran_cnt);
#ifdef SCTP_AUDITING_ENABLED
                                        sctp_audit_log(0xB3,
                                            (asoc->sent_queue_retran_cnt & 0x000000ff));
#endif
                                }
                                if (tp1->rec.data.chunk_was_revoked) {
                                        /* deflate the cwnd */
                                        tp1->whoTo->cwnd -= tp1->book_size;
                                        tp1->rec.data.chunk_was_revoked = 0;
                                }
                                if (tp1->sent != SCTP_DATAGRAM_NR_ACKED) {
                                        tp1->sent = SCTP_DATAGRAM_ACKED;
                                }
                        }
                } else {
                        break;
                }
        }
        biggest_tsn_newly_acked = biggest_tsn_acked = last_tsn;
        /* always set this up to cum-ack */
        asoc->this_sack_highest_gap = last_tsn;

        if ((num_seg > 0) || (num_nr_seg > 0)) {
                /*
                 * thisSackHighestGap will increase while handling NEW
                 * segments this_sack_highest_newack will increase while
                 * handling NEWLY ACKED chunks. this_sack_lowest_newack is
                 * used for CMT DAC algo. saw_newack will also change.
                 */
                if (sctp_handle_segments(m, &offset_seg, stcb, asoc, last_tsn, &biggest_tsn_acked,
                    &biggest_tsn_newly_acked, &this_sack_lowest_newack,
                    num_seg, num_nr_seg, &rto_ok)) {
                        wake_him++;
                }
                /*
                 * validate the biggest_tsn_acked in the gap acks if strict
                 * adherence is wanted.
                 */
                if (SCTP_TSN_GE(biggest_tsn_acked, send_s)) {
                        /*
                         * peer is either confused or we are under attack.
                         * We must abort.
                         */
                        SCTP_PRINTF("Hopeless peer! biggest_tsn_acked:%x largest seq:%x\n",
                            biggest_tsn_acked, send_s);
                        goto hopeless_peer;
                }
        }
        /*******************************************/
        /* cancel ALL T3-send timer if accum moved */
        /*******************************************/
        if (asoc->sctp_cmt_on_off > 0) {
                TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                        if (net->new_pseudo_cumack)
                                sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                                    stcb, net,
                                    SCTP_FROM_SCTP_INDATA + SCTP_LOC_31);
                }
        } else {
                if (accum_moved) {
                        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                                sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                                    stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_32);
                        }
                }
        }
        /********************************************/
        /* drop the acked chunks from the sentqueue */
        /********************************************/
        asoc->last_acked_seq = cum_ack;

        TAILQ_FOREACH_SAFE(tp1, &asoc->sent_queue, sctp_next, tp2) {
                if (SCTP_TSN_GT(tp1->rec.data.tsn, cum_ack)) {
                        break;
                }
                if (tp1->sent != SCTP_DATAGRAM_NR_ACKED) {
                        if (asoc->strmout[tp1->rec.data.sid].chunks_on_queues > 0) {
                                asoc->strmout[tp1->rec.data.sid].chunks_on_queues--;
#ifdef INVARIANTS
                        } else {
                                panic("No chunks on the queues for sid %u.", tp1->rec.data.sid);
#endif
                        }
                }
                if ((asoc->strmout[tp1->rec.data.sid].chunks_on_queues == 0) &&
                    (asoc->strmout[tp1->rec.data.sid].state == SCTP_STREAM_RESET_PENDING) &&
                    TAILQ_EMPTY(&asoc->strmout[tp1->rec.data.sid].outqueue)) {
                        asoc->trigger_reset = 1;
                }
                TAILQ_REMOVE(&asoc->sent_queue, tp1, sctp_next);
                if (PR_SCTP_ENABLED(tp1->flags)) {
                        if (asoc->pr_sctp_cnt != 0)
                                asoc->pr_sctp_cnt--;
                }
                asoc->sent_queue_cnt--;
                if (tp1->data) {
                        /* sa_ignore NO_NULL_CHK */
                        sctp_free_bufspace(stcb, asoc, tp1, 1);
                        sctp_m_freem(tp1->data);
                        tp1->data = NULL;
                        if (asoc->prsctp_supported && PR_SCTP_BUF_ENABLED(tp1->flags)) {
                                asoc->sent_queue_cnt_removeable--;
                        }
                }
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_LOGGING_ENABLE) {
                        sctp_log_sack(asoc->last_acked_seq,
                            cum_ack,
                            tp1->rec.data.tsn,
                            0,
                            0,
                            SCTP_LOG_FREE_SENT);
                }
                sctp_free_a_chunk(stcb, tp1, SCTP_SO_NOT_LOCKED);
                wake_him++;
        }
        if (TAILQ_EMPTY(&asoc->sent_queue) && (asoc->total_flight > 0)) {
#ifdef INVARIANTS
                panic("Warning flight size is positive and should be 0");
#else
                SCTP_PRINTF("Warning flight size incorrect should be 0 is %d\n",
                    asoc->total_flight);
#endif
                asoc->total_flight = 0;
        }

        /* sa_ignore NO_NULL_CHK */
        if ((wake_him) && (stcb->sctp_socket)) {
                SOCKBUF_LOCK(&stcb->sctp_socket->so_snd);
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_WAKE_LOGGING_ENABLE) {
                        sctp_wakeup_log(stcb, wake_him, SCTP_WAKESND_FROM_SACK);
                }
                sctp_sowwakeup_locked(stcb->sctp_ep, stcb->sctp_socket);
        } else {
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_WAKE_LOGGING_ENABLE) {
                        sctp_wakeup_log(stcb, wake_him, SCTP_NOWAKE_FROM_SACK);
                }
        }

        if (asoc->fast_retran_loss_recovery && accum_moved) {
                if (SCTP_TSN_GE(asoc->last_acked_seq, asoc->fast_recovery_tsn)) {
                        /* Setup so we will exit RFC2582 fast recovery */
                        will_exit_fast_recovery = 1;
                }
        }
        /*
         * Check for revoked fragments:
         *
         * if Previous sack - Had no frags then we can't have any revoked if
         * Previous sack - Had frag's then - If we now have frags aka
         * num_seg > 0 call sctp_check_for_revoked() to tell if peer revoked
         * some of them. else - The peer revoked all ACKED fragments, since
         * we had some before and now we have NONE.
         */

        if (num_seg) {
                sctp_check_for_revoked(stcb, asoc, cum_ack, biggest_tsn_acked);
                asoc->saw_sack_with_frags = 1;
        } else if (asoc->saw_sack_with_frags) {
                int cnt_revoked = 0;

                /* Peer revoked all dg's marked or acked */
                TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                        if (tp1->sent == SCTP_DATAGRAM_ACKED) {
                                tp1->sent = SCTP_DATAGRAM_SENT;
                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                        sctp_misc_ints(SCTP_FLIGHT_LOG_UP_REVOKE,
                                            tp1->whoTo->flight_size,
                                            tp1->book_size,
                                            (uint32_t)(uintptr_t)tp1->whoTo,
                                            tp1->rec.data.tsn);
                                }
                                sctp_flight_size_increase(tp1);
                                sctp_total_flight_increase(stcb, tp1);
                                tp1->rec.data.chunk_was_revoked = 1;
                                /*
                                 * To ensure that this increase in
                                 * flightsize, which is artificial, does not
                                 * throttle the sender, we also increase the
                                 * cwnd artificially.
                                 */
                                tp1->whoTo->cwnd += tp1->book_size;
                                cnt_revoked++;
                        }
                }
                if (cnt_revoked) {
                        reneged_all = 1;
                }
                asoc->saw_sack_with_frags = 0;
        }
        if (num_nr_seg > 0)
                asoc->saw_sack_with_nr_frags = 1;
        else
                asoc->saw_sack_with_nr_frags = 0;

        /* JRS - Use the congestion control given in the CC module */
        if (ecne_seen == 0) {
                TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                        if (net->net_ack2 > 0) {
                                /*
                                 * Karn's rule applies to clearing error
                                 * count, this is optional.
                                 */
                                net->error_count = 0;
                                if ((net->dest_state & SCTP_ADDR_REACHABLE) == 0) {
                                        /* addr came good */
                                        net->dest_state |= SCTP_ADDR_REACHABLE;
                                        sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_UP, stcb,
                                            0, (void *)net, SCTP_SO_NOT_LOCKED);
                                }

                                if (net == stcb->asoc.primary_destination) {
                                        if (stcb->asoc.alternate) {
                                                /*
                                                 * release the alternate,
                                                 * primary is good
                                                 */
                                                sctp_free_remote_addr(stcb->asoc.alternate);
                                                stcb->asoc.alternate = NULL;
                                        }
                                }

                                if (net->dest_state & SCTP_ADDR_PF) {
                                        net->dest_state &= ~SCTP_ADDR_PF;
                                        sctp_timer_stop(SCTP_TIMER_TYPE_HEARTBEAT,
                                            stcb->sctp_ep, stcb, net,
                                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_33);
                                        sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb, net);
                                        asoc->cc_functions.sctp_cwnd_update_exit_pf(stcb, net);
                                        /* Done with this net */
                                        net->net_ack = 0;
                                }
                                /* restore any doubled timers */
                                net->RTO = (net->lastsa >> SCTP_RTT_SHIFT) + net->lastsv;
                                if (net->RTO < stcb->asoc.minrto) {
                                        net->RTO = stcb->asoc.minrto;
                                }
                                if (net->RTO > stcb->asoc.maxrto) {
                                        net->RTO = stcb->asoc.maxrto;
                                }
                        }
                }
                asoc->cc_functions.sctp_cwnd_update_after_sack(stcb, asoc, accum_moved, reneged_all, will_exit_fast_recovery);
        }

        if (TAILQ_EMPTY(&asoc->sent_queue)) {
                /* nothing left in-flight */
                TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                        /* stop all timers */
                        sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                            stcb, net,
                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_34);
                        net->flight_size = 0;
                        net->partial_bytes_acked = 0;
                }
                asoc->total_flight = 0;
                asoc->total_flight_count = 0;
        }

        /**********************************/
        /* Now what about shutdown issues */
        /**********************************/
        if (TAILQ_EMPTY(&asoc->send_queue) && TAILQ_EMPTY(&asoc->sent_queue)) {
                /* nothing left on sendqueue.. consider done */
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_RWND_ENABLE) {
                        sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                            asoc->peers_rwnd, 0, 0, a_rwnd);
                }
                asoc->peers_rwnd = a_rwnd;
                if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                        /* SWS sender side engages */
                        asoc->peers_rwnd = 0;
                }
                /* clean up */
                if ((asoc->stream_queue_cnt == 1) &&
                    ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) ||
                    (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_RECEIVED)) &&
                    ((*asoc->ss_functions.sctp_ss_is_user_msgs_incomplete) (stcb, asoc))) {
                        SCTP_ADD_SUBSTATE(stcb, SCTP_STATE_PARTIAL_MSG_LEFT);
                }
                if (((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) ||
                    (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_RECEIVED)) &&
                    (asoc->stream_queue_cnt == 1) &&
                    (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT)) {
                        struct mbuf *op_err;

                        *abort_now = 1;
                        /* XXX */
                        op_err = sctp_generate_cause(SCTP_CAUSE_USER_INITIATED_ABT, "");
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_35;
                        sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                        return;
                }
                if ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) &&
                    (asoc->stream_queue_cnt == 0)) {
                        struct sctp_nets *netp;

                        if ((SCTP_GET_STATE(stcb) == SCTP_STATE_OPEN) ||
                            (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_RECEIVED)) {
                                SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                        }
                        SCTP_SET_STATE(stcb, SCTP_STATE_SHUTDOWN_SENT);
                        sctp_stop_timers_for_shutdown(stcb);
                        if (asoc->alternate) {
                                netp = asoc->alternate;
                        } else {
                                netp = asoc->primary_destination;
                        }
                        sctp_send_shutdown(stcb, netp);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWN,
                            stcb->sctp_ep, stcb, netp);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNGUARD,
                            stcb->sctp_ep, stcb, NULL);
                        return;
                } else if ((SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_RECEIVED) &&
                    (asoc->stream_queue_cnt == 0)) {
                        struct sctp_nets *netp;

                        SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                        SCTP_SET_STATE(stcb, SCTP_STATE_SHUTDOWN_ACK_SENT);
                        sctp_stop_timers_for_shutdown(stcb);
                        if (asoc->alternate) {
                                netp = asoc->alternate;
                        } else {
                                netp = asoc->primary_destination;
                        }
                        sctp_send_shutdown_ack(stcb, netp);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNACK,
                            stcb->sctp_ep, stcb, netp);
                        return;
                }
        }
        /*
         * Now here we are going to recycle net_ack for a different use...
         * HEADS UP.
         */
        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                net->net_ack = 0;
        }

        /*
         * CMT DAC algorithm: If SACK DAC flag was 0, then no extra marking
         * to be done. Setting this_sack_lowest_newack to the cum_ack will
         * automatically ensure that.
         */
        if ((asoc->sctp_cmt_on_off > 0) &&
            SCTP_BASE_SYSCTL(sctp_cmt_use_dac) &&
            (cmt_dac_flag == 0)) {
                this_sack_lowest_newack = cum_ack;
        }
        if ((num_seg > 0) || (num_nr_seg > 0)) {
                sctp_strike_gap_ack_chunks(stcb, asoc, biggest_tsn_acked,
                    biggest_tsn_newly_acked, this_sack_lowest_newack, accum_moved);
        }
        /* JRS - Use the congestion control given in the CC module */
        asoc->cc_functions.sctp_cwnd_update_after_fr(stcb, asoc);

        /* Now are we exiting loss recovery ? */
        if (will_exit_fast_recovery) {
                /* Ok, we must exit fast recovery */
                asoc->fast_retran_loss_recovery = 0;
        }
        if ((asoc->sat_t3_loss_recovery) &&
            SCTP_TSN_GE(asoc->last_acked_seq, asoc->sat_t3_recovery_tsn)) {
                /* end satellite t3 loss recovery */
                asoc->sat_t3_loss_recovery = 0;
        }
        /*
         * CMT Fast recovery
         */
        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                if (net->will_exit_fast_recovery) {
                        /* Ok, we must exit fast recovery */
                        net->fast_retran_loss_recovery = 0;
                }
        }

        /* Adjust and set the new rwnd value */
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_RWND_ENABLE) {
                sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                    asoc->peers_rwnd, asoc->total_flight, (asoc->total_flight_count * SCTP_BASE_SYSCTL(sctp_peer_chunk_oh)), a_rwnd);
        }
        asoc->peers_rwnd = sctp_sbspace_sub(a_rwnd,
            (uint32_t)(asoc->total_flight + (asoc->total_flight_count * SCTP_BASE_SYSCTL(sctp_peer_chunk_oh))));
        if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                /* SWS sender side engages */
                asoc->peers_rwnd = 0;
        }
        if (asoc->peers_rwnd > old_rwnd) {
                win_probe_recovery = 1;
        }

        /*
         * Now we must setup so we have a timer up for anyone with
         * outstanding data.
         */
        done_once = 0;
again:
        j = 0;
        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                if (win_probe_recovery && (net->window_probe)) {
                        win_probe_recovered = 1;
                        /*-
                         * Find first chunk that was used with
                         * window probe and clear the event. Put
                         * it back into the send queue as if has
                         * not been sent.
                         */
                        TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                                if (tp1->window_probe) {
                                        sctp_window_probe_recovery(stcb, asoc, tp1);
                                        break;
                                }
                        }
                }
                if (net->flight_size) {
                        j++;
                        if (!SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                                sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                                    stcb->sctp_ep, stcb, net);
                        }
                        if (net->window_probe) {
                                net->window_probe = 0;
                        }
                } else {
                        if (net->window_probe) {
                                /*
                                 * In window probes we must assure a timer
                                 * is still running there
                                 */
                                if (!SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                                        sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                                            stcb->sctp_ep, stcb, net);
                                }
                        } else if (SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                                sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                                    stcb, net,
                                    SCTP_FROM_SCTP_INDATA + SCTP_LOC_36);
                        }
                }
        }
        if ((j == 0) &&
            (!TAILQ_EMPTY(&asoc->sent_queue)) &&
            (asoc->sent_queue_retran_cnt == 0) &&
            (win_probe_recovered == 0) &&
            (done_once == 0)) {
                /*
                 * huh, this should not happen unless all packets are
                 * PR-SCTP and marked to skip of course.
                 */
                if (sctp_fs_audit(asoc)) {
                        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                                net->flight_size = 0;
                        }
                        asoc->total_flight = 0;
                        asoc->total_flight_count = 0;
                        asoc->sent_queue_retran_cnt = 0;
                        TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                                if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                        sctp_flight_size_increase(tp1);
                                        sctp_total_flight_increase(stcb, tp1);
                                } else if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                                        sctp_ucount_incr(asoc->sent_queue_retran_cnt);
                                }
                        }
                }
                done_once = 1;
                goto again;
        }
        /*********************************************/
        /* Here we perform PR-SCTP procedures        */
        /* (section 4.2)                             */
        /*********************************************/
        /* C1. update advancedPeerAckPoint */
        if (SCTP_TSN_GT(cum_ack, asoc->advanced_peer_ack_point)) {
                asoc->advanced_peer_ack_point = cum_ack;
        }
        /* C2. try to further move advancedPeerAckPoint ahead */
        if ((asoc->prsctp_supported) && (asoc->pr_sctp_cnt > 0)) {
                struct sctp_tmit_chunk *lchk;
                uint32_t old_adv_peer_ack_point;

                old_adv_peer_ack_point = asoc->advanced_peer_ack_point;
                lchk = sctp_try_advance_peer_ack_point(stcb, asoc);
                /* C3. See if we need to send a Fwd-TSN */
                if (SCTP_TSN_GT(asoc->advanced_peer_ack_point, cum_ack)) {
                        /*
                         * ISSUE with ECN, see FWD-TSN processing.
                         */
                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LOG_TRY_ADVANCE) {
                                sctp_misc_ints(SCTP_FWD_TSN_CHECK,
                                    0xee, cum_ack, asoc->advanced_peer_ack_point,
                                    old_adv_peer_ack_point);
                        }
                        if (SCTP_TSN_GT(asoc->advanced_peer_ack_point, old_adv_peer_ack_point)) {
                                send_forward_tsn(stcb, asoc);
                        } else if (lchk) {
                                /* try to FR fwd-tsn's that get lost too */
                                if (lchk->rec.data.fwd_tsn_cnt >= 3) {
                                        send_forward_tsn(stcb, asoc);
                                }
                        }
                }
                for (; lchk != NULL; lchk = TAILQ_NEXT(lchk, sctp_next)) {
                        if (lchk->whoTo != NULL) {
                                break;
                        }
                }
                if (lchk != NULL) {
                        /* Assure a timer is up */
                        sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                            stcb->sctp_ep, stcb, lchk->whoTo);
                }
        }
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_SACK_RWND_LOGGING_ENABLE) {
                sctp_misc_ints(SCTP_SACK_RWND_UPDATE,
                    a_rwnd,
                    stcb->asoc.peers_rwnd,
                    stcb->asoc.total_flight,
                    stcb->asoc.total_output_queue_size);
        }
}

void
sctp_update_acked(struct sctp_tcb *stcb, struct sctp_shutdown_chunk *cp, int *abort_flag)
{
        /* Copy cum-ack */
        uint32_t cum_ack, a_rwnd;

        cum_ack = ntohl(cp->cumulative_tsn_ack);
        /* Arrange so a_rwnd does NOT change */
        a_rwnd = stcb->asoc.peers_rwnd + stcb->asoc.total_flight;

        /* Now call the express sack handling */
        sctp_express_handle_sack(stcb, cum_ack, a_rwnd, abort_flag, 0);
}

static void
sctp_kick_prsctp_reorder_queue(struct sctp_tcb *stcb,
    struct sctp_stream_in *strmin)
{
        struct sctp_queued_to_read *control, *ncontrol;
        struct sctp_association *asoc;
        uint32_t mid;
        int need_reasm_check = 0;

        KASSERT(stcb != NULL, ("stcb == NULL"));
        SCTP_TCB_LOCK_ASSERT(stcb);
        SCTP_INP_READ_LOCK_ASSERT(stcb->sctp_ep);

        asoc = &stcb->asoc;
        mid = strmin->last_mid_delivered;
        /*
         * First deliver anything prior to and including the stream no that
         * came in.
         */
        TAILQ_FOREACH_SAFE(control, &strmin->inqueue, next_instrm, ncontrol) {
                if (SCTP_MID_GE(asoc->idata_supported, mid, control->mid)) {
                        /* this is deliverable now */
                        if (((control->sinfo_flags >> 8) & SCTP_DATA_NOT_FRAG) == SCTP_DATA_NOT_FRAG) {
                                if (control->on_strm_q) {
                                        if (control->on_strm_q == SCTP_ON_ORDERED) {
                                                TAILQ_REMOVE(&strmin->inqueue, control, next_instrm);
                                        } else if (control->on_strm_q == SCTP_ON_UNORDERED) {
                                                TAILQ_REMOVE(&strmin->uno_inqueue, control, next_instrm);
#ifdef INVARIANTS
                                        } else {
                                                panic("strmin: %p ctl: %p unknown %d",
                                                    strmin, control, control->on_strm_q);
#endif
                                        }
                                        control->on_strm_q = 0;
                                }
                                /* subtract pending on streams */
                                if (asoc->size_on_all_streams >= control->length) {
                                        asoc->size_on_all_streams -= control->length;
                                } else {
#ifdef INVARIANTS
                                        panic("size_on_all_streams = %u smaller than control length %u", asoc->size_on_all_streams, control->length);
#else
                                        asoc->size_on_all_streams = 0;
#endif
                                }
                                sctp_ucount_decr(asoc->cnt_on_all_streams);
                                /* deliver it to at least the delivery-q */
                                if (stcb->sctp_socket) {
                                        sctp_mark_non_revokable(asoc, control->sinfo_tsn);
                                        sctp_add_to_readq(stcb->sctp_ep, stcb, control,
                                            &stcb->sctp_socket->so_rcv, 1,
                                            SCTP_READ_LOCK_HELD, SCTP_SO_NOT_LOCKED);
                                }
                        } else {
                                /* Its a fragmented message */
                                if (control->first_frag_seen) {
                                        /*
                                         * Make it so this is next to
                                         * deliver, we restore later
                                         */
                                        strmin->last_mid_delivered = control->mid - 1;
                                        need_reasm_check = 1;
                                        break;
                                }
                        }
                } else {
                        /* no more delivery now. */
                        break;
                }
        }
        if (need_reasm_check) {
                int ret;

                ret = sctp_deliver_reasm_check(stcb, &stcb->asoc, strmin, SCTP_READ_LOCK_HELD);
                if (SCTP_MID_GT(asoc->idata_supported, mid, strmin->last_mid_delivered)) {
                        /* Restore the next to deliver unless we are ahead */
                        strmin->last_mid_delivered = mid;
                }
                if (ret == 0) {
                        /* Left the front Partial one on */
                        return;
                }
                need_reasm_check = 0;
        }
        /*
         * now we must deliver things in queue the normal way  if any are
         * now ready.
         */
        mid = strmin->last_mid_delivered + 1;
        TAILQ_FOREACH_SAFE(control, &strmin->inqueue, next_instrm, ncontrol) {
                if (SCTP_MID_EQ(asoc->idata_supported, mid, control->mid)) {
                        if (((control->sinfo_flags >> 8) & SCTP_DATA_NOT_FRAG) == SCTP_DATA_NOT_FRAG) {
                                /* this is deliverable now */
                                if (control->on_strm_q) {
                                        if (control->on_strm_q == SCTP_ON_ORDERED) {
                                                TAILQ_REMOVE(&strmin->inqueue, control, next_instrm);
                                        } else if (control->on_strm_q == SCTP_ON_UNORDERED) {
                                                TAILQ_REMOVE(&strmin->uno_inqueue, control, next_instrm);
#ifdef INVARIANTS
                                        } else {
                                                panic("strmin: %p ctl: %p unknown %d",
                                                    strmin, control, control->on_strm_q);
#endif
                                        }
                                        control->on_strm_q = 0;
                                }
                                /* subtract pending on streams */
                                if (asoc->size_on_all_streams >= control->length) {
                                        asoc->size_on_all_streams -= control->length;
                                } else {
#ifdef INVARIANTS
                                        panic("size_on_all_streams = %u smaller than control length %u", asoc->size_on_all_streams, control->length);
#else
                                        asoc->size_on_all_streams = 0;
#endif
                                }
                                sctp_ucount_decr(asoc->cnt_on_all_streams);
                                /* deliver it to at least the delivery-q */
                                strmin->last_mid_delivered = control->mid;
                                if (stcb->sctp_socket) {
                                        sctp_mark_non_revokable(asoc, control->sinfo_tsn);
                                        sctp_add_to_readq(stcb->sctp_ep, stcb, control,
                                            &stcb->sctp_socket->so_rcv, 1,
                                            SCTP_READ_LOCK_HELD, SCTP_SO_NOT_LOCKED);
                                }
                                mid = strmin->last_mid_delivered + 1;
                        } else {
                                /* Its a fragmented message */
                                if (control->first_frag_seen) {
                                        /*
                                         * Make it so this is next to
                                         * deliver
                                         */
                                        strmin->last_mid_delivered = control->mid - 1;
                                        need_reasm_check = 1;
                                        break;
                                }
                        }
                } else {
                        break;
                }
        }
        if (need_reasm_check) {
                (void)sctp_deliver_reasm_check(stcb, &stcb->asoc, strmin, SCTP_READ_LOCK_HELD);
        }
}

static void
sctp_flush_reassm_for_str_seq(struct sctp_tcb *stcb,
    struct sctp_association *asoc, struct sctp_stream_in *strm,
    struct sctp_queued_to_read *control, int ordered, uint32_t cumtsn)
{
        struct sctp_tmit_chunk *chk, *nchk;

        /*
         * For now large messages held on the stream reasm that are complete
         * will be tossed too. We could in theory do more work to spin
         * through and stop after dumping one msg aka seeing the start of a
         * new msg at the head, and call the delivery function... to see if
         * it can be delivered... But for now we just dump everything on the
         * queue.
         */

        KASSERT(stcb != NULL, ("stcb == NULL"));
        SCTP_TCB_LOCK_ASSERT(stcb);
        SCTP_INP_READ_LOCK_ASSERT(stcb->sctp_ep);

        if (!asoc->idata_supported && !ordered &&
            control->first_frag_seen &&
            SCTP_TSN_GT(control->fsn_included, cumtsn)) {
                return;
        }
        TAILQ_FOREACH_SAFE(chk, &control->reasm, sctp_next, nchk) {
                /* Purge hanging chunks */
                if (!asoc->idata_supported && !ordered) {
                        if (SCTP_TSN_GT(chk->rec.data.tsn, cumtsn)) {
                                break;
                        }
                }
                TAILQ_REMOVE(&control->reasm, chk, sctp_next);
                if (asoc->size_on_reasm_queue >= chk->send_size) {
                        asoc->size_on_reasm_queue -= chk->send_size;
                } else {
#ifdef INVARIANTS
                        panic("size_on_reasm_queue = %u smaller than chunk length %u", asoc->size_on_reasm_queue, chk->send_size);
#else
                        asoc->size_on_reasm_queue = 0;
#endif
                }
                sctp_ucount_decr(asoc->cnt_on_reasm_queue);
                if (chk->data) {
                        sctp_m_freem(chk->data);
                        chk->data = NULL;
                }
                sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
        }
        if (!TAILQ_EMPTY(&control->reasm)) {
                KASSERT(!asoc->idata_supported,
                    ("Reassembly queue not empty for I-DATA"));
                KASSERT(!ordered,
                    ("Reassembly queue not empty for ordered data"));
                if (control->data) {
                        sctp_m_freem(control->data);
                        control->data = NULL;
                }
                control->fsn_included = 0xffffffff;
                control->first_frag_seen = 0;
                control->last_frag_seen = 0;
                if (control->on_read_q) {
                        /*
                         * We have to purge it from there, hopefully this
                         * will work :-)
                         */
                        TAILQ_REMOVE(&stcb->sctp_ep->read_queue, control, next);
                        control->on_read_q = 0;
                }
                chk = TAILQ_FIRST(&control->reasm);
                if (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                        TAILQ_REMOVE(&control->reasm, chk, sctp_next);
                        sctp_add_chk_to_control(control, strm, stcb, asoc,
                            chk, SCTP_READ_LOCK_HELD);
                }
                sctp_deliver_reasm_check(stcb, asoc, strm, SCTP_READ_LOCK_HELD);
                return;
        }
        if (control->on_strm_q == SCTP_ON_ORDERED) {
                TAILQ_REMOVE(&strm->inqueue, control, next_instrm);
                if (asoc->size_on_all_streams >= control->length) {
                        asoc->size_on_all_streams -= control->length;
                } else {
#ifdef INVARIANTS
                        panic("size_on_all_streams = %u smaller than control length %u", asoc->size_on_all_streams, control->length);
#else
                        asoc->size_on_all_streams = 0;
#endif
                }
                sctp_ucount_decr(asoc->cnt_on_all_streams);
                control->on_strm_q = 0;
        } else if (control->on_strm_q == SCTP_ON_UNORDERED) {
                TAILQ_REMOVE(&strm->uno_inqueue, control, next_instrm);
                control->on_strm_q = 0;
#ifdef INVARIANTS
        } else if (control->on_strm_q) {
                panic("strm: %p ctl: %p unknown %d",
                    strm, control, control->on_strm_q);
#endif
        }
        control->on_strm_q = 0;
        if (control->on_read_q == 0) {
                sctp_free_remote_addr(control->whoFrom);
                if (control->data) {
                        sctp_m_freem(control->data);
                        control->data = NULL;
                }
                sctp_free_a_readq(stcb, control);
        }
}

void
sctp_handle_forward_tsn(struct sctp_tcb *stcb,
    struct sctp_forward_tsn_chunk *fwd,
    int *abort_flag, struct mbuf *m, int offset)
{
        /* The pr-sctp fwd tsn */
        /*
         * here we will perform all the data receiver side steps for
         * processing FwdTSN, as required in by pr-sctp draft:
         *
         * Assume we get FwdTSN(x):
         *
         * 1) update local cumTSN to x 2) try to further advance cumTSN to x
         * + others we have 3) examine and update re-ordering queue on
         * pr-in-streams 4) clean up re-assembly queue 5) Send a sack to
         * report where we are.
         */
        struct sctp_association *asoc;
        uint32_t new_cum_tsn, gap;
        unsigned int i, fwd_sz, m_size;
        struct sctp_stream_in *strm;
        struct sctp_queued_to_read *control, *ncontrol;

        asoc = &stcb->asoc;
        if ((fwd_sz = ntohs(fwd->ch.chunk_length)) < sizeof(struct sctp_forward_tsn_chunk)) {
                SCTPDBG(SCTP_DEBUG_INDATA1,
                    "Bad size too small/big fwd-tsn\n");
                return;
        }
        m_size = (stcb->asoc.mapping_array_size << 3);
        /*************************************************************/
        /* 1. Here we update local cumTSN and shift the bitmap array */
        /*************************************************************/
        new_cum_tsn = ntohl(fwd->new_cumulative_tsn);

        if (SCTP_TSN_GE(asoc->cumulative_tsn, new_cum_tsn)) {
                /* Already got there ... */
                return;
        }
        /*
         * now we know the new TSN is more advanced, let's find the actual
         * gap
         */
        SCTP_CALC_TSN_TO_GAP(gap, new_cum_tsn, asoc->mapping_array_base_tsn);
        asoc->cumulative_tsn = new_cum_tsn;
        if (gap >= m_size) {
                if ((long)gap > sctp_sbspace(&stcb->asoc, &stcb->sctp_socket->so_rcv)) {
                        struct mbuf *op_err;
                        char msg[SCTP_DIAG_INFO_LEN];

                        /*
                         * out of range (of single byte chunks in the rwnd I
                         * give out). This must be an attacker.
                         */
                        *abort_flag = 1;
                        SCTP_SNPRINTF(msg, sizeof(msg),
                            "New cum ack %8.8x too high, highest TSN %8.8x",
                            new_cum_tsn, asoc->highest_tsn_inside_map);
                        op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_37;
                        sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                        return;
                }
                SCTP_STAT_INCR(sctps_fwdtsn_map_over);

                memset(stcb->asoc.mapping_array, 0, stcb->asoc.mapping_array_size);
                asoc->mapping_array_base_tsn = new_cum_tsn + 1;
                asoc->highest_tsn_inside_map = new_cum_tsn;

                memset(stcb->asoc.nr_mapping_array, 0, stcb->asoc.mapping_array_size);
                asoc->highest_tsn_inside_nr_map = new_cum_tsn;

                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
                        sctp_log_map(0, 3, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
                }
        } else {
                SCTP_TCB_LOCK_ASSERT(stcb);
                for (i = 0; i <= gap; i++) {
                        if (!SCTP_IS_TSN_PRESENT(asoc->mapping_array, i) &&
                            !SCTP_IS_TSN_PRESENT(asoc->nr_mapping_array, i)) {
                                SCTP_SET_TSN_PRESENT(asoc->nr_mapping_array, i);
                                if (SCTP_TSN_GT(asoc->mapping_array_base_tsn + i, asoc->highest_tsn_inside_nr_map)) {
                                        asoc->highest_tsn_inside_nr_map = asoc->mapping_array_base_tsn + i;
                                }
                        }
                }
        }
        /*************************************************************/
        /* 2. Clear up re-assembly queue                             */
        /*************************************************************/

        /* This is now done as part of clearing up the stream/seq */
        if (asoc->idata_supported == 0) {
                uint16_t sid;

                /* Flush all the un-ordered data based on cum-tsn */
                SCTP_INP_READ_LOCK(stcb->sctp_ep);
                for (sid = 0; sid < asoc->streamincnt; sid++) {
                        strm = &asoc->strmin[sid];
                        if (!TAILQ_EMPTY(&strm->uno_inqueue)) {
                                sctp_flush_reassm_for_str_seq(stcb, asoc, strm, TAILQ_FIRST(&strm->uno_inqueue), 0, new_cum_tsn);
                        }
                }
                SCTP_INP_READ_UNLOCK(stcb->sctp_ep);
        }
        /*******************************************************/
        /* 3. Update the PR-stream re-ordering queues and fix  */
        /* delivery issues as needed.                       */
        /*******************************************************/
        fwd_sz -= sizeof(*fwd);
        if (m && fwd_sz) {
                /* New method. */
                unsigned int num_str;
                uint32_t mid;
                uint16_t sid;
                uint16_t ordered, flags;
                struct sctp_strseq *stseq, strseqbuf;
                struct sctp_strseq_mid *stseq_m, strseqbuf_m;

                offset += sizeof(*fwd);

                SCTP_INP_READ_LOCK(stcb->sctp_ep);
                if (asoc->idata_supported) {
                        num_str = fwd_sz / sizeof(struct sctp_strseq_mid);
                } else {
                        num_str = fwd_sz / sizeof(struct sctp_strseq);
                }
                for (i = 0; i < num_str; i++) {
                        if (asoc->idata_supported) {
                                stseq_m = (struct sctp_strseq_mid *)sctp_m_getptr(m, offset,
                                    sizeof(struct sctp_strseq_mid),
                                    (uint8_t *)&strseqbuf_m);
                                offset += sizeof(struct sctp_strseq_mid);
                                if (stseq_m == NULL) {
                                        break;
                                }
                                sid = ntohs(stseq_m->sid);
                                mid = ntohl(stseq_m->mid);
                                flags = ntohs(stseq_m->flags);
                                if (flags & PR_SCTP_UNORDERED_FLAG) {
                                        ordered = 0;
                                } else {
                                        ordered = 1;
                                }
                        } else {
                                stseq = (struct sctp_strseq *)sctp_m_getptr(m, offset,
                                    sizeof(struct sctp_strseq),
                                    (uint8_t *)&strseqbuf);
                                offset += sizeof(struct sctp_strseq);
                                if (stseq == NULL) {
                                        break;
                                }
                                sid = ntohs(stseq->sid);
                                mid = (uint32_t)ntohs(stseq->ssn);
                                ordered = 1;
                        }
                        /* Convert */

                        /* now process */

                        /*
                         * Ok we now look for the stream/seq on the read
                         * queue where its not all delivered. If we find it
                         * we transmute the read entry into a PDI_ABORTED.
                         */
                        if (sid >= asoc->streamincnt) {
                                /* screwed up streams, stop!  */
                                break;
                        }
                        if ((asoc->str_of_pdapi == sid) &&
                            (asoc->ssn_of_pdapi == mid)) {
                                /*
                                 * If this is the one we were partially
                                 * delivering now then we no longer are.
                                 * Note this will change with the reassembly
                                 * re-write.
                                 */
                                asoc->fragmented_delivery_inprogress = 0;
                        }
                        strm = &asoc->strmin[sid];
                        if (ordered) {
                                TAILQ_FOREACH_SAFE(control, &strm->inqueue, next_instrm, ncontrol) {
                                        if (SCTP_MID_GE(asoc->idata_supported, mid, control->mid)) {
                                                sctp_flush_reassm_for_str_seq(stcb, asoc, strm, control, ordered, new_cum_tsn);
                                        }
                                }
                        } else {
                                if (asoc->idata_supported) {
                                        TAILQ_FOREACH_SAFE(control, &strm->uno_inqueue, next_instrm, ncontrol) {
                                                if (SCTP_MID_GE(asoc->idata_supported, mid, control->mid)) {
                                                        sctp_flush_reassm_for_str_seq(stcb, asoc, strm, control, ordered, new_cum_tsn);
                                                }
                                        }
                                } else {
                                        if (!TAILQ_EMPTY(&strm->uno_inqueue)) {
                                                sctp_flush_reassm_for_str_seq(stcb, asoc, strm, TAILQ_FIRST(&strm->uno_inqueue), ordered, new_cum_tsn);
                                        }
                                }
                        }
                        TAILQ_FOREACH(control, &stcb->sctp_ep->read_queue, next) {
                                if ((control->sinfo_stream == sid) &&
                                    (SCTP_MID_EQ(asoc->idata_supported, control->mid, mid))) {
                                        control->pdapi_aborted = 1;
                                        control->end_added = 1;
                                        if (control->on_strm_q == SCTP_ON_ORDERED) {
                                                TAILQ_REMOVE(&strm->inqueue, control, next_instrm);
                                                if (asoc->size_on_all_streams >= control->length) {
                                                        asoc->size_on_all_streams -= control->length;
                                                } else {
#ifdef INVARIANTS
                                                        panic("size_on_all_streams = %u smaller than control length %u", asoc->size_on_all_streams, control->length);
#else
                                                        asoc->size_on_all_streams = 0;
#endif
                                                }
                                                sctp_ucount_decr(asoc->cnt_on_all_streams);
                                        } else if (control->on_strm_q == SCTP_ON_UNORDERED) {
                                                TAILQ_REMOVE(&strm->uno_inqueue, control, next_instrm);
#ifdef INVARIANTS
                                        } else if (control->on_strm_q) {
                                                panic("strm: %p ctl: %p unknown %d",
                                                    strm, control, control->on_strm_q);
#endif
                                        }
                                        control->on_strm_q = 0;
                                        sctp_ulp_notify(SCTP_NOTIFY_PARTIAL_DELVIERY_INDICATION,
                                            stcb,
                                            SCTP_PARTIAL_DELIVERY_ABORTED,
                                            (void *)control,
                                            SCTP_SO_NOT_LOCKED);
                                        break;
                                } else if ((control->sinfo_stream == sid) &&
                                    SCTP_MID_GT(asoc->idata_supported, control->mid, mid)) {
                                        /* We are past our victim SSN */
                                        break;
                                }
                        }
                        if (SCTP_MID_GT(asoc->idata_supported, mid, strm->last_mid_delivered)) {
                                /* Update the sequence number */
                                strm->last_mid_delivered = mid;
                        }
                        /* now kick the stream the new way */
                        /* sa_ignore NO_NULL_CHK */
                        sctp_kick_prsctp_reorder_queue(stcb, strm);
                }
                SCTP_INP_READ_UNLOCK(stcb->sctp_ep);
        }
        /*
         * Now slide thing forward.
         */
        sctp_slide_mapping_arrays(stcb);
}