root/sys/netinet/sctp_indata.c
/*      $NetBSD: sctp_indata.c,v 1.19 2025/11/19 22:31:51 andvar Exp $ */
/*      $KAME: sctp_indata.c,v 1.36 2005/03/06 16:04:17 itojun Exp $    */

/*
 * Copyright (C) 2002, 2003, 2004 Cisco Systems Inc,
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name of the project 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 PROJECT 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 PROJECT 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sctp_indata.c,v 1.19 2025/11/19 22:31:51 andvar Exp $");

#ifdef _KERNEL_OPT
#include "opt_ipsec.h"
#include "opt_inet.h"
#include "opt_sctp.h"
#endif /* _KERNEL_OPT */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/route.h>


#if defined(__FreeBSD__) && __FreeBSD_version >= 500000
#include <sys/limits.h>
#else
#include <machine/limits.h>
#endif
#include <machine/cpu.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#ifdef INET6
#include <netinet/ip6.h>
#endif /* INET6 */
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#ifdef INET6
#include <netinet6/ip6_var.h>
#endif /* INET6 */
#include <netinet/ip_icmp.h>
#include <netinet/icmp_var.h>
#include <netinet/sctp_var.h>
#include <netinet/sctp_pcb.h>
#include <netinet/sctp_header.h>
#include <netinet/sctputil.h>
#include <netinet/sctp_output.h>
#include <netinet/sctp_input.h>
#include <netinet/sctp_hashdriver.h>
#include <netinet/sctp_indata.h>
#include <netinet/sctp_uio.h>
#include <netinet/sctp_timer.h>
#ifdef IPSEC
#include <netipsec/ipsec.h>
#include <netipsec/key.h>
#endif /*IPSEC*/

#ifdef SCTP_DEBUG
extern u_int32_t sctp_debug_on;
#endif

/*
 * 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.
 */

extern int sctp_strict_sacks;

void
sctp_set_rwnd(struct sctp_tcb *stcb, struct sctp_association *asoc)
{
        u_int32_t calc, calc_w_oh;

#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_INDATA4) {
                printf("cc:%lu hiwat:%lu lowat:%lu mbcnt:%lu mbmax:%lu\n",
                       (u_long)stcb->sctp_socket->so_rcv.sb_cc,
                       (u_long)stcb->sctp_socket->so_rcv.sb_hiwat,
                       (u_long)stcb->sctp_socket->so_rcv.sb_lowat,
                       (u_long)stcb->sctp_socket->so_rcv.sb_mbcnt,
                       (u_long)stcb->sctp_socket->so_rcv.sb_mbmax);
                printf("Setting rwnd to: sb:%ld - (del:%d + reasm:%d str:%d)\n",
                       sctp_sbspace(&stcb->sctp_socket->so_rcv),
                       asoc->size_on_delivery_queue,
                       asoc->size_on_reasm_queue,
                       asoc->size_on_all_streams);
        }
#endif
        if (stcb->sctp_socket->so_rcv.sb_cc == 0 &&
            asoc->size_on_delivery_queue == 0 &&
            asoc->size_on_reasm_queue == 0 &&
            asoc->size_on_all_streams == 0) {
                /* Full rwnd granted */
                asoc->my_rwnd = uimax(stcb->sctp_socket->so_rcv.sb_hiwat,
                                    SCTP_MINIMAL_RWND);
                return;
        }
        /* get actual space */
        calc = (u_int32_t)sctp_sbspace(&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, (u_int32_t)asoc->size_on_delivery_queue);
        calc = sctp_sbspace_sub(calc, (u_int32_t)asoc->size_on_reasm_queue);
        calc = sctp_sbspace_sub(calc, (u_int32_t)asoc->size_on_all_streams);

        /* what is the overhead of all these rwnd's */
        calc_w_oh = sctp_sbspace_sub(calc, stcb->asoc.my_rwnd_control_len);

        asoc->my_rwnd = calc;
        if (calc_w_oh == 0) {
                /* If our overhead is greater than the advertised
                 * rwnd, we clamp the rwnd to 1. This lets us
                 * still accept inbound segments, but hopefully will
                 * shut the sender down when he finally gets the message.
                 */
                asoc->my_rwnd = 1;
        } else {
                /* SWS threshold */
                if (asoc->my_rwnd &&
                    (asoc->my_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_receiver)) {
                        /* SWS engaged, tell peer none left */
                        asoc->my_rwnd = 1;
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_INDATA4) {
                                printf(" - SWS zeros\n");
                        }
                } else {
                        if (sctp_debug_on & SCTP_DEBUG_INDATA4) {
                                printf("\n");
                        }
#endif
                }
        }
}

/*
 * Take a chk structure and build it into an mbuf. Hmm should we change things
 * so that instead we store the data side in a chunk?
 */
static struct mbuf *
sctp_build_ctl_nchunk(struct sctp_tcb *stcb, uint32_t tsn, uint32_t ppid,
    uint32_t context, uint16_t stream_no, uint16_t stream_seq, uint8_t flags)
{
        struct sctp_sndrcvinfo *outinfo;
        struct cmsghdr *cmh;
        struct mbuf *ret;

        if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_RECVDATAIOEVNT) == 0) {
                /* user does not want the sndrcv ctl */
                return (NULL);
        }

        MGETHDR(ret, M_DONTWAIT, MT_CONTROL);
        if (ret == NULL) {
                /* No space */
                return (ret);
        }
        /* We need a CMSG header followed by the struct  */
        cmh = mtod(ret, struct cmsghdr *);
        outinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmh);
        cmh->cmsg_level = IPPROTO_SCTP;
        cmh->cmsg_type = SCTP_SNDRCV;
        cmh->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
        outinfo->sinfo_stream = stream_no;
        outinfo->sinfo_ssn = stream_seq;
        if (flags & SCTP_DATA_UNORDERED) {
                outinfo->sinfo_flags = SCTP_UNORDERED;
        } else {
                outinfo->sinfo_flags = 0;
        }
        outinfo->sinfo_ppid = ppid;
        outinfo->sinfo_context = context;
        outinfo->sinfo_assoc_id = sctp_get_associd(stcb);
        outinfo->sinfo_tsn = tsn;
        outinfo->sinfo_cumtsn = stcb->asoc.cumulative_tsn;
        ret->m_len = cmh->cmsg_len;
        ret->m_pkthdr.len = ret->m_len;
        /*
         * We track how many control len's have gone upon the sb
         * and do not count these in the rwnd calculation.
         */
        stcb->asoc.my_rwnd_control_len +=
            CMSG_LEN(sizeof(struct sctp_sndrcvinfo));

        return (ret);
}

/*
 * Take a chk structure and build it into an mbuf.  Should we change things
 * so that instead we store the data side in a chunk?
 */
static
struct mbuf *
sctp_build_ctl(struct sctp_tcb *stcb, struct sctp_tmit_chunk *chk)
{
        struct sctp_sndrcvinfo *outinfo;
        struct cmsghdr *cmh;
        struct mbuf *ret;
        if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_RECVDATAIOEVNT) == 0) {
                /* user does not want the sndrcv ctl */
                return (NULL);
        }
        MGET(ret, M_DONTWAIT, MT_CONTROL);
        if (ret == NULL) {
                /* No space */
                return (ret);
        }

        /* We need a CMSG header followed by the struct  */
        cmh = mtod(ret, struct cmsghdr *);
        outinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmh);
        cmh->cmsg_level = IPPROTO_SCTP;
        cmh->cmsg_type = SCTP_SNDRCV;
        cmh->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
        outinfo->sinfo_stream = chk->rec.data.stream_number;
        outinfo->sinfo_ssn = chk->rec.data.stream_seq;
        if (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) {
                outinfo->sinfo_flags = SCTP_UNORDERED;
        } else {
                outinfo->sinfo_flags = 0;
        }
        outinfo->sinfo_ppid = chk->rec.data.payloadtype;
        outinfo->sinfo_context = chk->rec.data.context;
        outinfo->sinfo_assoc_id = sctp_get_associd(stcb);
        outinfo->sinfo_tsn = chk->rec.data.TSN_seq;
        outinfo->sinfo_cumtsn = stcb->asoc.cumulative_tsn;
        ret->m_len = cmh->cmsg_len;
        stcb->asoc.my_rwnd_control_len +=
            CMSG_LEN(sizeof(struct sctp_sndrcvinfo));

        return (ret);
}

int
sctp_deliver_data(struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct sctp_tmit_chunk *chk, int hold_locks)
{
        struct mbuf *control, *m;
        int free_it;
        struct sockaddr_in6 sin6;
        const struct sockaddr *to;

#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                printf("I am now in Deliver data! (%p)\n", chk);
        }
#endif
        /* get a write lock on the inp if not already */
        if (hold_locks == 0) {
                SCTP_TCB_UNLOCK(stcb);
                SCTP_INP_WLOCK(stcb->sctp_ep);
                SCTP_TCB_LOCK(stcb);
        }
        free_it = 0;
        /* We always add it to the queue */
        if (stcb && (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE)) {
                /* socket above is long gone */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("gone is gone!\n");
                }
#endif
                if (chk != NULL) {
                        sctp_m_freem(chk->data);
                        chk->data = NULL;
                        sctp_free_remote_addr(chk->whoTo);
                        SCTP_ZONE_FREE(sctppcbinfo.ipi_zone_chunk, chk);
                        sctppcbinfo.ipi_count_chunk--;
                        if ((int)sctppcbinfo.ipi_count_chunk < 0) {
                                panic("Chunk count is negative");
                        }
                        sctppcbinfo.ipi_gencnt_chunk++;
                }
                TAILQ_FOREACH(chk, &asoc->delivery_queue, sctp_next) {
                        asoc->size_on_delivery_queue -= chk->send_size;
                        asoc->cnt_on_delivery_queue--;
                        /*
                         * Lose the data pointer, since its in the socket buffer
                         */
                        sctp_m_freem(chk->data);
                        chk->data = NULL;
                        /* Now free the address and data */
                        sctp_free_remote_addr(chk->whoTo);
                        SCTP_ZONE_FREE(sctppcbinfo.ipi_zone_chunk, chk);
                        sctppcbinfo.ipi_count_chunk--;
                        if ((int)sctppcbinfo.ipi_count_chunk < 0) {
                                panic("Chunk count is negative");
                        }
                        sctppcbinfo.ipi_gencnt_chunk++;
                }
                if (hold_locks == 0) {
                        SCTP_INP_WUNLOCK(stcb->sctp_ep);
                }
                return (0);
        }
        if (chk != NULL) {
                TAILQ_INSERT_TAIL(&asoc->delivery_queue, chk, sctp_next);
                asoc->size_on_delivery_queue += chk->send_size;
                asoc->cnt_on_delivery_queue++;
        }
        if (asoc->fragmented_delivery_inprogress) {
                /*
                 * oh oh, fragmented delivery in progress
                 * return out of here.
                 */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("Fragmented delivery in progress?\n");
                }
#endif
                if (hold_locks == 0) {
                        SCTP_INP_WUNLOCK(stcb->sctp_ep);
                }
                return (0);
        }
        /* Now grab the first one  */
        chk = TAILQ_FIRST(&asoc->delivery_queue);
        if (chk == NULL) {
                /* Nothing in queue */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("Nothing in queue?\n");
                }
#endif
                asoc->size_on_delivery_queue = 0;
                asoc->cnt_on_delivery_queue = 0;
                if (hold_locks == 0) {
                        SCTP_INP_WUNLOCK(stcb->sctp_ep);
                }
                return (0);
        }

        if (stcb->sctp_socket->so_rcv.sb_cc >= stcb->sctp_socket->so_rcv.sb_hiwat) {
                /* Boy, there really is NO room */
                if (hold_locks == 0) {
                        SCTP_INP_WUNLOCK(stcb->sctp_ep);
                }
                return (0);
        }
#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                printf("Now to the delivery with chk(%p)!\n", chk);
        }
#endif
        /* XXX need to append PKTHDR to the socket buffer first */
        if ((chk->data->m_flags & M_PKTHDR) == 0) {
                MGETHDR(m, M_DONTWAIT, MT_DATA);
                if (m == NULL) {
                        /* no room! */
                        if (hold_locks == 0) {
                                SCTP_INP_WUNLOCK(stcb->sctp_ep);
                        }
                        return (0);
                }
                m->m_pkthdr.len = chk->send_size;
                m->m_len = 0;
                m->m_next = chk->data;
                chk->data = m;
        }
        if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                if (chk->data->m_next == NULL) {
                        /* hopefully we hit here most of the time */
                        chk->data->m_flags |= M_EOR;
                } else {
                        /* Add the flag to the LAST mbuf in the chain */
                        m = chk->data;
                        while (m->m_next != NULL) {
                                m = m->m_next;
                        }
                        m->m_flags |= M_EOR;
                }
        }

        if (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                struct sockaddr_in6 lsa6;

                control = sctp_build_ctl(stcb, chk);
                to = rtcache_getdst(&chk->whoTo->ro);
                if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_NEEDS_MAPPED_V4) &&
                    to->sa_family == AF_INET) {
                        const struct sockaddr_in *sin;

                        sin = (const struct sockaddr_in *)to;
                        in6_sin_2_v4mapsin6(sin, &sin6);
                        to = (struct sockaddr *)&sin6;
                }
                /* check and strip embedded scope junk */
                to = (const struct sockaddr *)sctp_recover_scope((const struct sockaddr_in6 *)to,
                    &lsa6);
                if (((const struct sockaddr_in *)to)->sin_port == 0) {
                        printf("Huh a, port is %d not net:%p %d?\n",
                               ((const struct sockaddr_in *)to)->sin_port,
                               chk->whoTo,
                               (int)(ntohs(stcb->rport)));
                        /*((struct sockaddr_in *)to)->sin_port = stcb->rport;*/
                        /* XXX */
                }
                if (sctp_sbspace(&stcb->sctp_socket->so_rcv) < (long)chk->send_size) {
                        /* Gak not enough room */
                        if (control) {
                                sctp_m_freem(control);
                                stcb->asoc.my_rwnd_control_len -=
                                    CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
                        }
                        goto skip;
                }
                if (!sbappendaddr_nocheck(&stcb->sctp_socket->so_rcv,
                    to, chk->data, control, stcb->asoc.my_vtag,
                    stcb->sctp_ep)) {
                        /* Gak not enough room */
                        if (control) {
                                sctp_m_freem(control);
                                stcb->asoc.my_rwnd_control_len -=
                                    CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
                        }
                } else {
                        if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_IN_TCPPOOL) == 0) {
                                if (sctp_add_to_socket_q(stcb->sctp_ep, stcb)) {
                                        stcb->asoc.my_rwnd_control_len +=
                                                sizeof(struct mbuf);
                                }
                        } else {
                                stcb->asoc.my_rwnd_control_len += sizeof(struct mbuf);
                        }
                        free_it = 1;
                }
        } else {
                /* append to a already started message. */
                if (sctp_sbspace(&stcb->sctp_socket->so_rcv) >=
                    (long)chk->send_size) {
                        sbappend(&stcb->sctp_socket->so_rcv, chk->data);
                        free_it = 1;
                }
        }
 skip:
        if (hold_locks == 0) {
                SCTP_INP_WUNLOCK(stcb->sctp_ep);
        }
        /* free up the one we inserted */
        if (free_it) {
                /* Pull it off the queue */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("Free_it true, doing tickle wakeup\n");
                }
#endif
                sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
                TAILQ_REMOVE(&asoc->delivery_queue, chk, sctp_next);
                asoc->size_on_delivery_queue -= chk->send_size;
                asoc->cnt_on_delivery_queue--;
                /* Lose the data pointer, since its in the socket buffer */
                chk->data = NULL;
                /* Now free the address and data */
                sctp_free_remote_addr(chk->whoTo);
                SCTP_ZONE_FREE(sctppcbinfo.ipi_zone_chunk, chk);
                sctppcbinfo.ipi_count_chunk--;
                if ((int)sctppcbinfo.ipi_count_chunk < 0) {
                        panic("Chunk count is negative");
                }
                sctppcbinfo.ipi_gencnt_chunk++;
        }
        return (free_it);
}

/*
 * We are delivering currently from the reassembly queue. We must continue to
 * deliver until we either:
 * 1) run out of space.
 * 2) run out of sequential TSN's
 * 3) hit the SCTP_DATA_LAST_FRAG flag.
 */
static void
sctp_service_reassembly(struct sctp_tcb *stcb, struct sctp_association *asoc, int hold_locks)
{
        const struct sockaddr *to;
        struct sockaddr_in6 sin6;
        struct sctp_tmit_chunk *chk, *at;
        struct mbuf *control, *m;
        u_int16_t nxt_todel;
        u_int16_t stream_no;
        int cntDel;
        cntDel = stream_no = 0;
        if (hold_locks == 0) {
                /*
                 * you always have the TCB lock, we need
                 * to have the inp write lock as well.
                 */
                SCTP_TCB_UNLOCK(stcb);
                SCTP_INP_WLOCK(stcb->sctp_ep);
                SCTP_TCB_LOCK(stcb);
        }
        if (stcb && (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE)) {
                /* socket above is long gone */
                asoc->fragmented_delivery_inprogress = 0;
                TAILQ_FOREACH(chk, &asoc->reasmqueue, sctp_next) {
                        asoc->size_on_delivery_queue -= chk->send_size;
                        asoc->cnt_on_delivery_queue--;
                        /*
                         * Lose the data pointer, since its in the socket buffer
                         */
                        sctp_m_freem(chk->data);
                        chk->data = NULL;
                        /* Now free the address and data */
                        sctp_free_remote_addr(chk->whoTo);
                        SCTP_ZONE_FREE(sctppcbinfo.ipi_zone_chunk, chk);
                        sctppcbinfo.ipi_count_chunk--;
                        if ((int)sctppcbinfo.ipi_count_chunk < 0) {
                                panic("Chunk count is negative");
                        }
                        sctppcbinfo.ipi_gencnt_chunk++;
                }
                if (hold_locks == 0) {
                        SCTP_INP_WUNLOCK(stcb->sctp_ep);
                }
                return;
        }
        do {
                if (stcb->sctp_socket->so_rcv.sb_cc >=
                    stcb->sctp_socket->so_rcv.sb_hiwat) {
                        if (cntDel) {
                                sctp_sorwakeup(stcb->sctp_ep,
                                               stcb->sctp_socket);
                        }
                        if (hold_locks == 0) {
                                SCTP_INP_WUNLOCK(stcb->sctp_ep);
                        }
                        return;
                }
                chk = TAILQ_FIRST(&asoc->reasmqueue);
                if (chk == NULL) {
                        if (cntDel) {
                                sctp_sorwakeup(stcb->sctp_ep,
                                               stcb->sctp_socket);
                        }
                        if (hold_locks == 0) {
                                SCTP_INP_WUNLOCK(stcb->sctp_ep);
                        }
                        return;
                }
                if (chk->rec.data.TSN_seq != (asoc->tsn_last_delivered + 1)) {
                        /* Can't deliver more :< */
                        if (cntDel) {
                                sctp_sorwakeup(stcb->sctp_ep,
                                               stcb->sctp_socket);
                        }
                        if (hold_locks == 0) {
                                SCTP_INP_WUNLOCK(stcb->sctp_ep);
                        }
                        return;
                }
                stream_no = chk->rec.data.stream_number;
                nxt_todel = asoc->strmin[stream_no].last_sequence_delivered + 1;
                if (nxt_todel != chk->rec.data.stream_seq &&
                    (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0) {
                        /*
                         * Not the next sequence to deliver in its stream OR
                         * unordered
                         */
                        if (cntDel) {
                                sctp_sorwakeup(stcb->sctp_ep,
                                               stcb->sctp_socket);
                        }
                        if (hold_locks == 0) {
                                SCTP_INP_WUNLOCK(stcb->sctp_ep);
                        }
                        return;
                }

                if ((chk->data->m_flags & M_PKTHDR) == 0) {
                        MGETHDR(m, M_DONTWAIT, MT_DATA);
                        if (m == NULL) {
                                /* no room! */
                                if (hold_locks == 0) {
                                        SCTP_INP_WUNLOCK(stcb->sctp_ep);
                                }
                                return;
                        }
                        m->m_pkthdr.len = chk->send_size;
                        m->m_len = 0;
                        m->m_next = chk->data;
                        chk->data = m;
                }
                if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                        if (chk->data->m_next == NULL) {
                                /* hopefully we hit here most of the time */
                                chk->data->m_flags |= M_EOR;
                        } else {
                                /* Add the flag to the LAST mbuf in the chain */
                                m = chk->data;
                                while (m->m_next != NULL) {
                                        m = m->m_next;
                                }
                                m->m_flags |= M_EOR;
                        }
                }
                if (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                        struct sockaddr_in6 lsa6;

                        control = sctp_build_ctl(stcb, chk);
                        to = rtcache_getdst(&chk->whoTo->ro);
                        if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_NEEDS_MAPPED_V4) &&
                            to->sa_family == AF_INET) {
                                const struct sockaddr_in *sin;

                                sin = satocsin(to);
                                in6_sin_2_v4mapsin6(sin, &sin6);
                                to = (struct sockaddr *)&sin6;
                        }
                        /* check and strip embedded scope junk */
                        to = (const struct sockaddr *)sctp_recover_scope((const struct sockaddr_in6 *)to,
                                                                   &lsa6);
                        if (((const struct sockaddr_in *)to)->sin_port == 0) {
                                printf("Huh b, port is %d not net:%p %d?\n",
                                       ((const struct sockaddr_in *)to)->sin_port,
                                       chk->whoTo,
                                       (int)(ntohs(stcb->rport)));
                                /*((struct sockaddr_in *)to)->sin_port = stcb->rport;*/
                                /* XXX */
                        }
                        if (sctp_sbspace(&stcb->sctp_socket->so_rcv) <
                            (long)chk->send_size) {
                                if (control) {
                                        sctp_m_freem(control);
                                        stcb->asoc.my_rwnd_control_len -=
                                                CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
                                }
                                sctp_sorwakeup(stcb->sctp_ep,
                                               stcb->sctp_socket);
                                if (hold_locks == 0) {
                                        SCTP_INP_WUNLOCK(stcb->sctp_ep);
                                }
                                return;
                        }
                        if (!sbappendaddr_nocheck(&stcb->sctp_socket->so_rcv,
                                                  to, chk->data, control, stcb->asoc.my_vtag,
                                                  stcb->sctp_ep)) {
                                /* Gak not enough room */
                                if (control) {
                                        sctp_m_freem(control);
                                        stcb->asoc.my_rwnd_control_len -=
                                                CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
                                }
                                sctp_sorwakeup(stcb->sctp_ep,
                                               stcb->sctp_socket);
                                if (hold_locks == 0) {
                                        SCTP_INP_WUNLOCK(stcb->sctp_ep);
                                }
                                return;
                        }
                        if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_IN_TCPPOOL) == 0) {
                                if (sctp_add_to_socket_q(stcb->sctp_ep, stcb)) {
                                        stcb->asoc.my_rwnd_control_len +=
                                                sizeof(struct mbuf);
                                }
                        } else {
                                stcb->asoc.my_rwnd_control_len += sizeof(struct mbuf);
                        }
                        cntDel++;
                } else {
                        if (sctp_sbspace(&stcb->sctp_socket->so_rcv) >=
                            (long)chk->send_size) {
                                sbappend(&stcb->sctp_socket->so_rcv, chk->data);
                                cntDel++;
                        } else {
                                /* out of space in the sb */
                                sctp_sorwakeup(stcb->sctp_ep,
                                               stcb->sctp_socket);
                                if (hold_locks == 0) {
                                        SCTP_INP_WUNLOCK(stcb->sctp_ep);
                                }
                                return;
                        }
                }
                /* pull it we did it */
                TAILQ_REMOVE(&asoc->reasmqueue, chk, sctp_next);
                if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                        asoc->fragmented_delivery_inprogress = 0;
                        if ((chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0) {
                                asoc->strmin[stream_no].last_sequence_delivered++;
                        }
                }
                asoc->tsn_last_delivered = chk->rec.data.TSN_seq;
                asoc->size_on_reasm_queue -= chk->send_size;
                asoc->cnt_on_reasm_queue--;
                /* free up the chk */
                sctp_free_remote_addr(chk->whoTo);
                chk->data = NULL;
                SCTP_ZONE_FREE(sctppcbinfo.ipi_zone_chunk, chk);
                sctppcbinfo.ipi_count_chunk--;
                if ((int)sctppcbinfo.ipi_count_chunk < 0) {
                        panic("Chunk count is negative");
                }
                sctppcbinfo.ipi_gencnt_chunk++;
                if (asoc->fragmented_delivery_inprogress == 0) {
                        /*
                         * Now lets see if we can deliver the next one on the
                         * stream
                         */
                        /*u_int16_t nxt_todel;*/
                        struct sctp_stream_in *strm;

                        strm = &asoc->strmin[stream_no];
                        nxt_todel = strm->last_sequence_delivered + 1;
                        chk = TAILQ_FIRST(&strm->inqueue);
                        if (chk && (nxt_todel == chk->rec.data.stream_seq)) {
                                while (chk != NULL) {
                                        /* all delivered */
                                        if (nxt_todel ==
                                            chk->rec.data.stream_seq) {
                                                at = TAILQ_NEXT(chk, sctp_next);
                                                TAILQ_REMOVE(&strm->inqueue,
                                                             chk, sctp_next);
                                                asoc->size_on_all_streams -=
                                                        chk->send_size;
                                                asoc->cnt_on_all_streams--;
                                                strm->last_sequence_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.
                                                 */
                                                sctp_deliver_data(stcb, asoc, chk, 1);
                                                chk = at;
                                        } else {
                                                break;
                                        }
                                        nxt_todel =
                                                strm->last_sequence_delivered + 1;
                                }
                        }
                        if (!TAILQ_EMPTY(&asoc->delivery_queue)) {
                                /* Here if deliver_data fails, we must break */
                                if (sctp_deliver_data(stcb, asoc, NULL, 1) == 0)
                                        break;
                        }
                        sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
                        if (hold_locks == 0) {
                                SCTP_INP_WUNLOCK(stcb->sctp_ep);
                        }
                        return;
                }
                chk = TAILQ_FIRST(&asoc->reasmqueue);
        } while (chk);
        if (cntDel) {
                sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
        }
        if (hold_locks == 0) {
                SCTP_INP_WUNLOCK(stcb->sctp_ep);
        }
}

/*
 * 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.
 * One big question still remains, what to do when the socket buffer is FULL??
 */
static void
sctp_queue_data_to_stream(struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct sctp_tmit_chunk *chk, int *abort_flag)
{
        struct sctp_stream_in *strm;
        struct sctp_tmit_chunk *at;
        int queue_needed;
        u_int16_t nxt_todel;
        struct mbuf *oper;

/*** FIX FIX FIX ???
 * Need to add code to deal with 16 bit seq wrap
 * without a TSN wrap for ordered delivery (maybe).
 * FIX FIX FIX ???
 */
        queue_needed = 1;
        asoc->size_on_all_streams += chk->send_size;
        asoc->cnt_on_all_streams++;
        strm = &asoc->strmin[chk->rec.data.stream_number];
        nxt_todel = strm->last_sequence_delivered + 1;
#ifdef SCTP_STR_LOGGING
        sctp_log_strm_del(chk, NULL, SCTP_STR_LOG_FROM_INTO_STRD);
#endif
#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                printf("queue to stream called for ssn:%u lastdel:%u nxt:%u\n",
                    (u_int)chk->rec.data.stream_seq,
                    (u_int)strm->last_sequence_delivered, (u_int)nxt_todel);
        }
#endif
        if (compare_with_wrap(strm->last_sequence_delivered,
            chk->rec.data.stream_seq, MAX_SEQ) ||
            (strm->last_sequence_delivered == chk->rec.data.stream_seq)) {
                /* The incoming sseq is behind where we last delivered? */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("Duplicate S-SEQ:%d delivered:%d from peer, Abort  association\n",
                            chk->rec.data.stream_seq,
                            strm->last_sequence_delivered);
                }
#endif
                /*
                 * throw it in the stream so it gets cleaned up in
                 * association destruction
                 */
                TAILQ_INSERT_HEAD(&strm->inqueue, chk, sctp_next);
                MGET(oper, M_DONTWAIT, MT_DATA);
                if (oper) {
                        struct sctp_paramhdr *ph;
                        u_int32_t *ippp;

                        oper->m_len = sizeof(struct sctp_paramhdr) +
                            sizeof(*ippp);
                        ph = mtod(oper, struct sctp_paramhdr *);
                        ph->param_type = htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                        ph->param_length = htons(oper->m_len);
                        ippp = (u_int32_t *)(ph + 1);
                        *ippp = htonl(0x00000001);
                }
                sctp_abort_an_association(stcb->sctp_ep, stcb,
                    SCTP_PEER_FAULTY, oper);

                *abort_flag = 1;
                return;

        }
        if (nxt_todel == chk->rec.data.stream_seq) {
                /* can be delivered right away */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("It's NEXT!\n");
                }
#endif
#ifdef SCTP_STR_LOGGING
                sctp_log_strm_del(chk, NULL, SCTP_STR_LOG_FROM_IMMED_DEL);
#endif
                queue_needed = 0;
                asoc->size_on_all_streams -= chk->send_size;
                asoc->cnt_on_all_streams--;
                strm->last_sequence_delivered++;
                sctp_deliver_data(stcb, asoc, chk, 0);
                chk = TAILQ_FIRST(&strm->inqueue);
                while (chk != NULL) {
                        /* all delivered */
                        nxt_todel = strm->last_sequence_delivered + 1;
                        if (nxt_todel == chk->rec.data.stream_seq) {
                                at = TAILQ_NEXT(chk, sctp_next);
                                TAILQ_REMOVE(&strm->inqueue, chk, sctp_next);
                                asoc->size_on_all_streams -= chk->send_size;
                                asoc->cnt_on_all_streams--;
                                strm->last_sequence_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.
                                 */
#ifdef SCTP_STR_LOGGING
                                sctp_log_strm_del(chk, NULL,
                                    SCTP_STR_LOG_FROM_IMMED_DEL);
#endif
                                sctp_deliver_data(stcb, asoc, chk, 0);
                                chk = at;
                                continue;
                        }
                        break;
                }
        }
        if (queue_needed) {
                /*
                 * Ok, we did not deliver this guy, find
                 * the correct place to put it on the queue.
                 */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("Queue Needed!\n");
                }
#endif
                if (TAILQ_EMPTY(&strm->inqueue)) {
                        /* Empty queue */
#ifdef SCTP_STR_LOGGING
                        sctp_log_strm_del(chk, NULL, SCTP_STR_LOG_FROM_INSERT_HD);
#endif
                        TAILQ_INSERT_HEAD(&strm->inqueue, chk, sctp_next);
                } else {
                        TAILQ_FOREACH(at, &strm->inqueue, sctp_next) {
                                if (compare_with_wrap(at->rec.data.stream_seq,
                                    chk->rec.data.stream_seq, MAX_SEQ)) {
                                        /*
                                         * one in queue is bigger than the new
                                         * one, insert before this one
                                         */
#ifdef SCTP_STR_LOGGING
                                        sctp_log_strm_del(chk, at,
                                            SCTP_STR_LOG_FROM_INSERT_MD);
#endif
                                        TAILQ_INSERT_BEFORE(at, chk, sctp_next);
                                        break;
                                } else if (at->rec.data.stream_seq ==
                                    chk->rec.data.stream_seq) {
                                        /*
                                         * 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!
                                         */

                                        sctp_m_freem(chk->data);
                                        chk->data = NULL;
                                        asoc->size_on_all_streams -= chk->send_size;
                                        asoc->cnt_on_all_streams--;
                                        sctp_pegs[SCTP_DUP_SSN_RCVD]++;
                                        sctp_free_remote_addr(chk->whoTo);
                                        SCTP_ZONE_FREE(sctppcbinfo.ipi_zone_chunk, chk);
                                        sctppcbinfo.ipi_count_chunk--;
                                        if ((int)sctppcbinfo.ipi_count_chunk <
                                            0) {
                                                panic("Chunk count is negative");
                                        }
                                        sctppcbinfo.ipi_gencnt_chunk++;
                                        return;
                                } else {
                                        if (TAILQ_NEXT(at, sctp_next) == NULL) {
                                                /*
                                                 * We are at the end, insert it
                                                 * after this one
                                                 */
#ifdef SCTP_STR_LOGGING
                                                sctp_log_strm_del(chk, at,
                                                    SCTP_STR_LOG_FROM_INSERT_TL);
#endif
                                                TAILQ_INSERT_AFTER(&strm->inqueue,
                                                    at, chk, sctp_next);
                                                break;
                                        }
                                }
                        }
                }
        } else {
                /* We delivered some chunks, wake them up */

#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("Doing WAKEUP!\n");
                }
#endif
                sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
        }
}

/*
 * Returns two things: You get the total size of the deliverable parts of the
 * first fragmented message on the reassembly queue. And you get a 1 back if
 * all of the message is ready or a 0 back if the message is still incomplete
 */
static int
sctp_is_all_msg_on_reasm(struct sctp_association *asoc, int *t_size)
{
        struct sctp_tmit_chunk *chk;
        u_int32_t tsn;

        *t_size = 0;
        chk = TAILQ_FIRST(&asoc->reasmqueue);
        if (chk == NULL) {
                /* nothing on the queue */
                return (0);
        }
        if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) == 0) {
                /* Not a first on the queue */
                return (0);
        }
        tsn = chk->rec.data.TSN_seq;
        while (chk) {
                if (tsn != chk->rec.data.TSN_seq) {
                        return (0);
                }
                *t_size += chk->send_size;
                if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                        return (1);
                }
                tsn++;
                chk = TAILQ_NEXT(chk, sctp_next);
        }
        return (0);
}

/*
 * 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_tmit_chunk *chk, int *abort_flag)
{
        struct mbuf *oper;
        u_int16_t nxt_todel;
        u_int32_t cum_ackp1, prev_tsn, post_tsn;
        int tsize;
        struct sctp_tmit_chunk *at, *prev, *next;

        prev = next = NULL;
        cum_ackp1 = asoc->tsn_last_delivered + 1;

        if (TAILQ_EMPTY(&asoc->reasmqueue)) {
                /* This is the first one on the queue */
                TAILQ_INSERT_HEAD(&asoc->reasmqueue, chk, sctp_next);
                /*
                 * we do not check for delivery of anything when
                 * only one fragment is here
                 */
                asoc->size_on_reasm_queue = chk->send_size;
                asoc->cnt_on_reasm_queue++;
                if (chk->rec.data.TSN_seq == cum_ackp1) {
                        if (asoc->fragmented_delivery_inprogress == 0  &&
                            (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) !=
                            SCTP_DATA_FIRST_FRAG) {
                                /*
                                 * An empty queue, no delivery inprogress, we
                                 * hit the next one and it does NOT have a
                                 * FIRST fragment mark.
                                 */
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                        printf("Gak, Evil plot, its not first, no fragmented delivery in progress\n");
                                }
#endif
                                MGET(oper, M_DONTWAIT, MT_DATA);
                                if (oper) {
                                        struct sctp_paramhdr *ph;
                                        u_int32_t *ippp;

                                        oper->m_len =
                                            sizeof(struct sctp_paramhdr) +
                                            sizeof(*ippp);
                                        ph = mtod(oper, struct sctp_paramhdr *);
                                        ph->param_type =
                                            htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                        ph->param_length = htons(oper->m_len);
                                        ippp = (u_int32_t *)(ph + 1);
                                        *ippp = htonl(0x10000001);
                                }
                                sctp_abort_an_association(stcb->sctp_ep, stcb,
                                    SCTP_PEER_FAULTY, oper);
                                *abort_flag = 1;
                        } else if (asoc->fragmented_delivery_inprogress &&
                            (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) == SCTP_DATA_FIRST_FRAG) {
                                /*
                                 * We are doing a partial delivery and the NEXT
                                 * chunk MUST be either the LAST or MIDDLE
                                 * fragment NOT a FIRST
                                 */
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                        printf("Gak, Evil plot, it IS a first and fragmented delivery in progress\n");
                                }
#endif
                                MGET(oper, M_DONTWAIT, MT_DATA);
                                if (oper) {
                                        struct sctp_paramhdr *ph;
                                        u_int32_t *ippp;

                                        oper->m_len =
                                            sizeof(struct sctp_paramhdr) +
                                            sizeof(*ippp);
                                        ph = mtod(oper, struct sctp_paramhdr *);
                                        ph->param_type =
                                            htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                        ph->param_length = htons(oper->m_len);
                                        ippp = (u_int32_t *)(ph + 1);
                                        *ippp = htonl(0x10000002);
                                }
                                sctp_abort_an_association(stcb->sctp_ep, stcb,
                                    SCTP_PEER_FAULTY, oper);
                                *abort_flag = 1;
                        } else if (asoc->fragmented_delivery_inprogress) {
                                /* Here we are ok with a MIDDLE or LAST piece */
                                if (chk->rec.data.stream_number !=
                                    asoc->str_of_pdapi) {
                                        /* Got to be the right STR No */
#ifdef SCTP_DEBUG
                                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                                printf("Gak, Evil plot, it IS not same stream number %d vs %d\n",
                                                    chk->rec.data.stream_number,
                                                    asoc->str_of_pdapi);
                                        }
#endif
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;
                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);
                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x10000003);
                                        }
                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);
                                        *abort_flag = 1;
                                } else if ((asoc->fragment_flags & SCTP_DATA_UNORDERED) !=
                                    SCTP_DATA_UNORDERED &&
                                    chk->rec.data.stream_seq !=
                                    asoc->ssn_of_pdapi) {
                                        /* Got to be the right STR Seq */
#ifdef SCTP_DEBUG
                                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                                printf("Gak, Evil plot, it IS not same stream seq %d vs %d\n",
                                                    chk->rec.data.stream_seq,
                                                    asoc->ssn_of_pdapi);
                                        }
#endif
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;
                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);
                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x10000004);
                                        }
                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);
                                        *abort_flag = 1;
                                }
                        }
                }
                return;
        }
        /* Find its place */
        at = TAILQ_FIRST(&asoc->reasmqueue);

        /* Grab the top flags */
        TAILQ_FOREACH(at, &asoc->reasmqueue, sctp_next) {
                if (compare_with_wrap(at->rec.data.TSN_seq,
                    chk->rec.data.TSN_seq, MAX_TSN)) {
                        /*
                         * one in queue is bigger than the new one, insert
                         * before this one
                         */
                        /* A check */
                        asoc->size_on_reasm_queue += chk->send_size;
                        asoc->cnt_on_reasm_queue++;
                        next = at;
                        TAILQ_INSERT_BEFORE(at, chk, sctp_next);
                        break;
                } else if (at->rec.data.TSN_seq == chk->rec.data.TSN_seq) {
                        /* 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!
                         */
                        sctp_m_freem(chk->data);
                        chk->data = NULL;
                        sctp_free_remote_addr(chk->whoTo);
                        SCTP_ZONE_FREE(sctppcbinfo.ipi_zone_chunk, chk);
                        sctppcbinfo.ipi_count_chunk--;
                        if ((int)sctppcbinfo.ipi_count_chunk < 0) {
                                panic("Chunk count is negative");
                        }
                        sctppcbinfo.ipi_gencnt_chunk++;
                        return;
                } else {
                        prev = at;
                        if (TAILQ_NEXT(at, sctp_next) == NULL) {
                                /*
                                 * We are at the end, insert it after this one
                                 */
                                /* check it first */
                                asoc->size_on_reasm_queue += chk->send_size;
                                asoc->cnt_on_reasm_queue++;
                                TAILQ_INSERT_AFTER(&asoc->reasmqueue, at, chk, sctp_next);
                                break;
                        }
                }
        }
        /* Now the audits */
        if (prev) {
                prev_tsn = chk->rec.data.TSN_seq - 1;
                if (prev_tsn == prev->rec.data.TSN_seq) {
                        /*
                         * Ok the one I am dropping onto the end
                         * is the NEXT. A bit of validation here.
                         */
                        if ((prev->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                            SCTP_DATA_FIRST_FRAG ||
                            (prev->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                            SCTP_DATA_MIDDLE_FRAG) {
                                /*
                                 * Insert chk MUST be a MIDDLE or LAST fragment
                                 */
                                if ((chk->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                                    SCTP_DATA_FIRST_FRAG) {
#ifdef SCTP_DEBUG
                                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                                printf("Prev check - It can be a midlle or last but not a first\n");
                                                printf("Gak, Evil plot, it's a FIRST!\n");
                                        }
#endif
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;

                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);

                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x10000005);
                                        }
                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);
                                        *abort_flag = 1;
                                        return;
                                }
                                if (chk->rec.data.stream_number !=
                                    prev->rec.data.stream_number) {
                                        /*
                                         * Huh, need the correct STR here, they
                                         * must be the same.
                                         */
#ifdef SCTP_DEBUG
                                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                                printf("Prev check - Gak, Evil plot, ssn:%d not the same as at:%d\n",
                                                    chk->rec.data.stream_number,
                                                    prev->rec.data.stream_number);
                                        }
#endif
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;

                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);
                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x10000006);
                                        }

                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);

                                        *abort_flag = 1;
                                        return;
                                }
                                if ((prev->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0 &&
                                    chk->rec.data.stream_seq !=
                                    prev->rec.data.stream_seq) {
                                        /*
                                         * Huh, need the correct STR here, they
                                         * must be the same.
                                         */
#ifdef SCTP_DEBUG
                                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                                printf("Prev check - Gak, Evil plot, sseq:%d not the same as at:%d\n",
                                                    chk->rec.data.stream_seq,
                                                    prev->rec.data.stream_seq);
                                        }
#endif
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;

                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);
                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x10000007);
                                        }

                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);

                                        *abort_flag = 1;
                                        return;
                                }
                        } else if ((prev->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                            SCTP_DATA_LAST_FRAG) {
                                /* Insert chk MUST be a FIRST */
                                if ((chk->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) !=
                                    SCTP_DATA_FIRST_FRAG) {
#ifdef SCTP_DEBUG
                                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                                printf("Prev check - Gak, evil plot, its not FIRST and it must be!\n");
                                        }
#endif
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;

                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);
                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x10000008);
                                        }

                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);

                                        *abort_flag = 1;
                                        return;
                                }
                        }
                }
        }

        if (next) {
                post_tsn = chk->rec.data.TSN_seq + 1;
                if (post_tsn == next->rec.data.TSN_seq) {
                        /*
                         * Ok the one I am inserting ahead of
                         * is my NEXT one. A bit of validation here.
                         */
                        if (next->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                                /* Insert chk MUST be a last fragment */
                                if ((chk->rec.data.rcv_flags&SCTP_DATA_FRAG_MASK)
                                   != SCTP_DATA_LAST_FRAG) {
#ifdef SCTP_DEBUG
                                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                                printf("Next chk - Next is FIRST, we must be LAST\n");
                                                printf("Gak, Evil plot, its not a last!\n");
                                        }
#endif
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;

                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);
                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x10000009);
                                        }

                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);

                                        *abort_flag = 1;
                                        return;
                                }
                        } else if ((next->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                            SCTP_DATA_MIDDLE_FRAG ||
                            (next->rec.data.rcv_flags&SCTP_DATA_FRAG_MASK) ==
                            SCTP_DATA_LAST_FRAG) {
                                /* Insert chk CAN be MIDDLE or FIRST NOT LAST */
                                if ((chk->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                                    SCTP_DATA_LAST_FRAG) {
#ifdef SCTP_DEBUG
                                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                                printf("Next chk - Next is a MIDDLE/LAST\n");
                                                printf("Gak, Evil plot, new prev chunk is a LAST\n");
                                        }
#endif
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;

                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);
                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x1000000a);
                                        }
                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);

                                        *abort_flag = 1;
                                        return;
                                }
                                if (chk->rec.data.stream_number !=
                                    next->rec.data.stream_number) {
                                        /*
                                         * Huh, need the correct STR here, they
                                         * must be the same.
                                         */
#ifdef SCTP_DEBUG
                                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                                printf("Next chk - Gak, Evil plot, ssn:%d not the same as at:%d\n",
                                                    chk->rec.data.stream_number,
                                                    next->rec.data.stream_number);
                                        }
#endif
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;

                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);
                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x1000000b);
                                        }

                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);

                                        *abort_flag = 1;
                                        return;
                                }
                                if ((next->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0 &&
                                    chk->rec.data.stream_seq !=
                                    next->rec.data.stream_seq) {
                                        /*
                                         * Huh, need the correct STR here, they
                                         * must be the same.
                                         */
#ifdef SCTP_DEBUG
                                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                                printf("Next chk - Gak, Evil plot, sseq:%d not the same as at:%d\n",
                                                    chk->rec.data.stream_seq,
                                                    next->rec.data.stream_seq);
                                        }
#endif
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;

                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);
                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x1000000c);
                                        }

                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);

                                        *abort_flag = 1;
                                        return;

                                }
                        }
                }
        }
        /*
         * now that we have all in there place we must check a number of
         * things to see if we can send data to the ULP.
         */
        /* we need to do some delivery, if we can */
        chk = TAILQ_FIRST(&asoc->reasmqueue);
        if (chk == NULL) {
                /* Huh? */
                asoc->size_on_reasm_queue = 0;
                asoc->cnt_on_reasm_queue = 0;
                return;
        }
        if (asoc->fragmented_delivery_inprogress == 0) {
                nxt_todel =
                    asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered + 1;
                if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) &&
                    (nxt_todel == chk->rec.data.stream_seq ||
                     (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED))) {
                        /*
                         * Yep the first one is here and its
                         * ok to deliver but should we?
                         */
                        if (TAILQ_EMPTY(&asoc->delivery_queue) &&
                            (sctp_is_all_msg_on_reasm(asoc, &tsize) ||
                             (asoc->size_on_reasm_queue >=
                              (stcb->sctp_socket->so_rcv.sb_hiwat >> 2) &&
                              tsize))) {
                                /*
                                 * Yes, we setup to
                                 * start reception, by backing down the TSN
                                 * just in case we can't deliver. If we
                                 */
                                asoc->fragmented_delivery_inprogress = 1;
                                asoc->tsn_last_delivered =
                                    chk->rec.data.TSN_seq - 1;
                                asoc->str_of_pdapi =
                                    chk->rec.data.stream_number;
                                asoc->ssn_of_pdapi = chk->rec.data.stream_seq;
                                asoc->fragment_flags = chk->rec.data.rcv_flags;
                                sctp_service_reassembly(stcb, asoc, 0);
                        }
                }
        } else {
                sctp_service_reassembly(stcb, asoc, 0);
        }
}

/*
 * This is an unfortunate routine. It checks to make sure a evil guy is not
 * stuffing us full of bad packet fragments. A broken peer could also do this
 * but this is doubtful. It is to bad I must worry about evil crackers sigh
 * :< more cycles.
 */
static int
sctp_does_chk_belong_to_reasm(struct sctp_association *asoc,
    struct sctp_tmit_chunk *chk)
{
        struct sctp_tmit_chunk *at;
        u_int32_t tsn_est;

        TAILQ_FOREACH(at, &asoc->reasmqueue, sctp_next) {
                if (compare_with_wrap(chk->rec.data.TSN_seq,
                    at->rec.data.TSN_seq, MAX_TSN)) {
                        /* is it one bigger? */
                        tsn_est = at->rec.data.TSN_seq + 1;
                        if (tsn_est == chk->rec.data.TSN_seq) {
                                /* yep. It better be a last then*/
                                if ((at->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) !=
                                    SCTP_DATA_LAST_FRAG) {
                                        /*
                                         * Ok this guy belongs next to a guy
                                         * that is NOT last, it should be a
                                         * middle/last, not a complete chunk.
                                         */
                                        return (1);
                                } else {
                                        /*
                                         * This guy is ok since its a LAST and
                                         * the new chunk is a fully self-
                                         * contained one.
                                         */
                                        return (0);
                                }
                        }
                } else if (chk->rec.data.TSN_seq == at->rec.data.TSN_seq) {
                        /* Software error since I have a dup? */
                        return (1);
                } else {
                        /*
                         * Ok, 'at' is larger than new chunk but does it
                         * need to be right before it.
                         */
                        tsn_est = chk->rec.data.TSN_seq + 1;
                        if (tsn_est == at->rec.data.TSN_seq) {
                                /* Yep, It better be a first */
                                if ((at->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) !=
                                    SCTP_DATA_FIRST_FRAG) {
                                        return (1);
                                } else {
                                        return (0);
                                }
                        }
                }
        }
        return (0);
}

extern unsigned int sctp_max_chunks_on_queue;
static int
sctp_process_a_data_chunk(struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct mbuf **m, int offset, struct sctp_data_chunk *ch, int chk_length,
    struct sctp_nets *net, u_int32_t *high_tsn, int *abort_flag,
    int *break_flag, int last_chunk)
{
        /* Process a data chunk */
        /*  struct sctp_tmit_chunk *chk;*/
        struct sctp_tmit_chunk *chk;
        u_int32_t tsn, gap;
        struct mbuf *dmbuf;
        int the_len;
        u_int16_t strmno, strmseq;
        struct mbuf *oper;

        chk = NULL;
        tsn = ntohl(ch->dp.tsn);
#ifdef SCTP_MAP_LOGGING
        sctp_log_map(0, tsn, asoc->cumulative_tsn, SCTP_MAP_PREPARE_SLIDE);
#endif
        if (compare_with_wrap(asoc->cumulative_tsn, tsn, MAX_TSN) ||
            asoc->cumulative_tsn == tsn) {
                /* It is a duplicate */
                sctp_pegs[SCTP_DUPTSN_RECVD]++;
                if (asoc->numduptsns < SCTP_MAX_DUP_TSNS) {
                        /* Record a dup for the next outbound sack */
                        asoc->dup_tsns[asoc->numduptsns] = tsn;
                        asoc->numduptsns++;
                }
                return (0);
        }
        /* Calculate the number of TSN's between the base and this TSN */
        if (tsn >= asoc->mapping_array_base_tsn) {
                gap  = tsn - asoc->mapping_array_base_tsn;
        } else {
                gap = (MAX_TSN - asoc->mapping_array_base_tsn) + tsn + 1;
        }
        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)) {
                if (sctp_expand_mapping_array(asoc)) {
                        /* Can't expand, drop it */
                        return (0);
                }
        }
        if (compare_with_wrap(tsn, *high_tsn, MAX_TSN)) {
                *high_tsn = tsn;
        }
        /* See if we have received this one already */
        if (SCTP_IS_TSN_PRESENT(asoc->mapping_array, gap)) {
                sctp_pegs[SCTP_DUPTSN_RECVD]++;
                if (asoc->numduptsns < SCTP_MAX_DUP_TSNS) {
                        /* Record a dup for the next outbound sack */
                        asoc->dup_tsns[asoc->numduptsns] = tsn;
                        asoc->numduptsns++;
                }
                if (!callout_pending(&asoc->dack_timer.timer)) {
                        /*
                         * By starting the timer we assure that we
                         * WILL sack at the end of the packet
                         * when sctp_sack_check gets called.
                         */
                        sctp_timer_start(SCTP_TIMER_TYPE_RECV, stcb->sctp_ep,
                            stcb, NULL);
                }
                return (0);
        }
        /*
         * Check to see about the GONE flag, duplicates would cause
         * a sack to be sent up above
         */
        if (stcb && (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE)) {
                /*
                 * wait a minute, this guy is gone, there is no
                 * longer a receiver. Send peer an ABORT!
                 */
                struct mbuf *op_err;
                op_err = sctp_generate_invmanparam(SCTP_CAUSE_OUT_OF_RESC);
                sctp_abort_an_association(stcb->sctp_ep, stcb, 0, op_err);
                *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.
         */

        /* now do the tests */
        if (((asoc->cnt_on_all_streams +
         asoc->cnt_on_delivery_queue +
         asoc->cnt_on_reasm_queue +
          asoc->cnt_msg_on_sb) > 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 (stcb->sctp_socket->so_rcv.sb_cc) {
                        /* 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 (compare_with_wrap(tsn,
                    asoc->highest_tsn_inside_map, MAX_TSN)) {

                        /* Nope not in the valid range dump it */
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                printf("My rwnd overrun1:tsn:%lx rwnd %lu sbspace:%ld delq:%d!\n",
                                    (u_long)tsn, (u_long)asoc->my_rwnd,
                                    sctp_sbspace(&stcb->sctp_socket->so_rcv),
                                    stcb->asoc.cnt_on_delivery_queue);
                        }
#endif
                        sctp_set_rwnd(stcb, asoc);
                        if ((asoc->cnt_on_all_streams +
                            asoc->cnt_on_delivery_queue +
                            asoc->cnt_on_reasm_queue +
                            asoc->cnt_msg_on_sb) > sctp_max_chunks_on_queue) {
                                sctp_pegs[SCTP_MSGC_DROP]++;
                        } else {
                                sctp_pegs[SCTP_RWND_DROPS]++;
                        }
                        *break_flag = 1;
                        return (0);
                }
        }
        strmno = ntohs(ch->dp.stream_id);
        if (strmno >= asoc->streamincnt) {
                struct sctp_paramhdr *phdr;
                struct mbuf *mb;

                MGETHDR(mb, M_DONTWAIT, MT_DATA);
                if (mb != NULL) {
                        /* add some space up front so prepend will work well */
                        mb->m_data += sizeof(struct sctp_chunkhdr);
                        phdr = mtod(mb, struct sctp_paramhdr *);
                        /*
                         * 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
                         */
                        mb->m_pkthdr.len = mb->m_len =
                            (sizeof(struct sctp_paramhdr) * 2);
                        phdr->param_type = htons(SCTP_CAUSE_INV_STRM);
                        phdr->param_length =
                            htons(sizeof(struct sctp_paramhdr) * 2);
                        phdr++;
                        /* We insert the stream in the type field */
                        phdr->param_type = ch->dp.stream_id;
                        /* And set the length to 0 for the rsvd field */
                        phdr->param_length = 0;
                        sctp_queue_op_err(stcb, mb);
                }
                sctp_pegs[SCTP_BAD_STRMNO]++;
                return (0);
        }
        /*
         * Before we continue lets validate that we are not
         * being fooled by an evil attacker. We can only
         * have 4k chunks based on our TSN spread allowed
         * by the mapping array 512 * 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.
         */
        strmseq = ntohs(ch->dp.stream_sequence);
        if ((ch->ch.chunk_flags & SCTP_DATA_FIRST_FRAG) &&
            (ch->ch.chunk_flags & SCTP_DATA_UNORDERED) == 0 &&
            (compare_with_wrap(asoc->strmin[strmno].last_sequence_delivered,
             strmseq, MAX_SEQ) ||
             asoc->strmin[strmno].last_sequence_delivered == strmseq)) {
                /* The incoming sseq is behind where we last delivered? */
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("EVIL/Broken-Dup S-SEQ:%d delivered:%d from peer, Abort!\n",
                            strmseq,
                            asoc->strmin[strmno].last_sequence_delivered);
                }
#endif
                /*
                 * throw it in the stream so it gets cleaned up in
                 * association destruction
                 */
                MGET(oper, M_DONTWAIT, MT_DATA);
                if (oper) {
                        struct sctp_paramhdr *ph;
                        u_int32_t *ippp;

                        oper->m_len = sizeof(struct sctp_paramhdr) +
                            sizeof(*ippp);
                        ph = mtod(oper, struct sctp_paramhdr *);
                        ph->param_type = htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                        ph->param_length = htons(oper->m_len);
                        ippp = (u_int32_t *)(ph + 1);
                        *ippp = htonl(0x20000001);
                }
                sctp_abort_an_association(stcb->sctp_ep, stcb, SCTP_PEER_FAULTY,
                    oper);
                sctp_pegs[SCTP_BAD_SSN_WRAP]++;
                *abort_flag = 1;
                return (0);
        }

        the_len = (chk_length-sizeof(struct sctp_data_chunk));
        if (last_chunk == 0) {
                dmbuf = sctp_m_copym(*m,
                    (offset + sizeof(struct sctp_data_chunk)),
                    the_len, M_DONTWAIT);
        } else {
                /* We can steal the last chunk */
                dmbuf = *m;
                /* lop off the top part */
                m_adj(dmbuf, (offset + sizeof(struct sctp_data_chunk)));
                if (dmbuf->m_pkthdr.len > the_len) {
                        /* Trim the end round bytes off  too */
                        m_adj(dmbuf, -(dmbuf->m_pkthdr.len-the_len));
                }
                sctp_pegs[SCTP_NO_COPY_IN]++;
        }
        if (dmbuf == NULL) {
                sctp_pegs[SCTP_DROP_NOMEMORY]++;
                return (0);
        }
        if ((ch->ch.chunk_flags & SCTP_DATA_NOT_FRAG) == SCTP_DATA_NOT_FRAG &&
            asoc->fragmented_delivery_inprogress == 0 &&
            TAILQ_EMPTY(&asoc->delivery_queue) &&
            ((ch->ch.chunk_flags & SCTP_DATA_UNORDERED) ||
             ((asoc->strmin[strmno].last_sequence_delivered + 1) == strmseq &&
              TAILQ_EMPTY(&asoc->strmin[strmno].inqueue))) &&
            ((long)(stcb->sctp_socket->so_rcv.sb_hiwat -
                    stcb->sctp_socket->so_rcv.sb_cc) >= (long)the_len)) {
                /* 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....
                 */

                struct mbuf *control, *mmm;
                struct sockaddr_in6 sin6;
                struct sockaddr_in6 lsa6;
                const struct sockaddr *to;

                /* It would be nice to avoid this copy if we could :< */
                control = sctp_build_ctl_nchunk(stcb, tsn,
                    ch->dp.protocol_id, 0, strmno, strmseq,
                    ch->ch.chunk_flags);
                /* XXX need to append PKTHDR to the socket buffer first */

                if ((dmbuf->m_flags & M_PKTHDR) == 0) {
                        struct mbuf *tmp;
                        MGETHDR(tmp, M_DONTWAIT, MT_DATA);
                        if (tmp == NULL) {

                                /* no room! */
                                if (control) {
                                        sctp_m_freem(control);
                                        stcb->asoc.my_rwnd_control_len -=
                                            CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
                                }

                                goto failed_express_del;
                        }
                        tmp->m_pkthdr.len = the_len;
                        tmp->m_len = 0;
                        tmp->m_next = dmbuf;
                        dmbuf = tmp;
                }
                to = rtcache_getdst(&net->ro);
                if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_NEEDS_MAPPED_V4) &&
                    to->sa_family == AF_INET) {
                        const struct sockaddr_in *sin;

                        sin = satocsin(to);
                        in6_sin_2_v4mapsin6(sin, &sin6);
                        to = (struct sockaddr *)&sin6;
                }

                /* check and strip embedded scope junk */
                to = (const struct sockaddr *)sctp_recover_scope((const struct sockaddr_in6 *)to,
                    &lsa6);
                if (((const struct sockaddr_in *)to)->sin_port == 0) {
                        printf("Huh c, port is %d not net:%p %d?\n",
                               ((const struct sockaddr_in *)to)->sin_port,
                               net,
                               (int)(ntohs(stcb->rport)));
                        /*((struct sockaddr_in *)to)->sin_port = stcb->rport;*/
                        /* XXX */
                }

                mmm = dmbuf;
                /* Mark the EOR */
                while (mmm->m_next != NULL) {
                        mmm = mmm->m_next;
                }
                mmm->m_flags |= M_EOR;
                if (compare_with_wrap(tsn, asoc->highest_tsn_inside_map, MAX_TSN)) {
                        /* we have a new high score */
                        asoc->highest_tsn_inside_map = tsn;
#ifdef SCTP_MAP_LOGGING
                        sctp_log_map(0, 1, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
#endif
                }
                SCTP_TCB_UNLOCK(stcb);
                SCTP_INP_WLOCK(stcb->sctp_ep);
                SCTP_TCB_LOCK(stcb);
                if (!sbappendaddr_nocheck(&stcb->sctp_socket->so_rcv, to, dmbuf,
                    control, stcb->asoc.my_vtag, stcb->sctp_ep)) {
                        if (control) {
                                sctp_m_freem(control);
                                stcb->asoc.my_rwnd_control_len -=
                                    CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
                        }
                        sctp_m_freem(dmbuf);
                        goto failed_express_del;
                }
                if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_IN_TCPPOOL) == 0) {
                        if (sctp_add_to_socket_q(stcb->sctp_ep, stcb)) {
                                stcb->asoc.my_rwnd_control_len += sizeof(struct mbuf);
                        }
                } else {
                        stcb->asoc.my_rwnd_control_len += sizeof(struct mbuf);
                }
                SCTP_INP_WUNLOCK(stcb->sctp_ep);
                sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
                if ((ch->ch.chunk_flags & SCTP_DATA_UNORDERED) == 0) {

                        /* for ordered, bump what we delivered */
                        asoc->strmin[strmno].last_sequence_delivered++;
                }
                sctp_pegs[SCTP_EXPRESS_ROUTE]++;
#ifdef SCTP_STR_LOGGING
                sctp_log_strm_del_alt(tsn, strmseq,
                    SCTP_STR_LOG_FROM_EXPRS_DEL);
#endif
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("Express Delivery succeeds\n");
                }
#endif
                goto finish_express_del;
        }

 failed_express_del:
        /* If we reach here this is a new chunk */
        chk = (struct sctp_tmit_chunk *)SCTP_ZONE_GET(sctppcbinfo.ipi_zone_chunk);
        if (chk == NULL) {
                /* No memory so we drop the chunk */
                sctp_pegs[SCTP_DROP_NOMEMORY]++;
                if (last_chunk == 0) {
                        /* we copied it, free the copy */
                        sctp_m_freem(dmbuf);
                }
                return (0);
        }
        sctppcbinfo.ipi_count_chunk++;
        sctppcbinfo.ipi_gencnt_chunk++;
        chk->rec.data.TSN_seq = tsn;
        chk->rec.data.stream_seq = strmseq;
        chk->rec.data.stream_number = strmno;
        chk->rec.data.payloadtype = ch->dp.protocol_id;
        chk->rec.data.context = 0;
        chk->rec.data.doing_fast_retransmit = 0;
        chk->rec.data.rcv_flags = ch->ch.chunk_flags;
        chk->asoc = asoc;
        chk->send_size = the_len;
        chk->whoTo = net;
        net->ref_count++;
        chk->data = dmbuf;


        /* Mark it as received */
        /* Now queue it where it belongs */
        if ((chk->rec.data.rcv_flags & SCTP_DATA_NOT_FRAG) ==
            SCTP_DATA_NOT_FRAG) {
                /* First a sanity check */
                if (asoc->fragmented_delivery_inprogress) {
                        /*
                         * Ok, we have a fragmented delivery in progress
                         * if this chunk is next to deliver OR belongs in
                         * our view to the reassembly, the peer is evil
                         * or broken.
                         */
                        u_int32_t estimate_tsn;
                        estimate_tsn = asoc->tsn_last_delivered + 1;
                        if (TAILQ_EMPTY(&asoc->reasmqueue) &&
                            (estimate_tsn == chk->rec.data.TSN_seq)) {
                                /* Evil/Broke peer */
                                MGET(oper, M_DONTWAIT, MT_DATA);
                                if (oper) {
                                        struct sctp_paramhdr *ph;
                                        u_int32_t *ippp;

                                        oper->m_len =
                                            sizeof(struct sctp_paramhdr) +
                                            sizeof(*ippp);
                                        ph = mtod(oper, struct sctp_paramhdr *);
                                        ph->param_type =
                                            htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                        ph->param_length = htons(oper->m_len);
                                        ippp = (u_int32_t *)(ph + 1);
                                        *ippp = htonl(0x20000002);
                                }
                                sctp_abort_an_association(stcb->sctp_ep, stcb,
                                    SCTP_PEER_FAULTY, oper);

                                *abort_flag = 1;
                                sctp_pegs[SCTP_DROP_FRAG]++;
                                return (0);
                        } else {
                                if (sctp_does_chk_belong_to_reasm(asoc, chk)) {
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;

                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);
                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x20000003);
                                        }
                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);

                                        *abort_flag = 1;
                                        sctp_pegs[SCTP_DROP_FRAG]++;
                                        return (0);
                                }
                        }
                } else {
                        if (!TAILQ_EMPTY(&asoc->reasmqueue)) {
                                /*
                                 * Reassembly queue is NOT empty
                                 * validate that this chk does not need to
                                 * be in reasembly queue. If it does then
                                 * our peer is broken or evil.
                                 */
                                if (sctp_does_chk_belong_to_reasm(asoc, chk)) {
                                        MGET(oper, M_DONTWAIT, MT_DATA);
                                        if (oper) {
                                                struct sctp_paramhdr *ph;
                                                u_int32_t *ippp;

                                                oper->m_len =
                                                    sizeof(struct sctp_paramhdr) +
                                                    sizeof(*ippp);
                                                ph = mtod(oper,
                                                    struct sctp_paramhdr *);
                                                ph->param_type =
                                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                                ph->param_length =
                                                    htons(oper->m_len);
                                                ippp = (u_int32_t *)(ph + 1);
                                                *ippp = htonl(0x20000004);
                                        }
                                        sctp_abort_an_association(stcb->sctp_ep,
                                            stcb, SCTP_PEER_FAULTY, oper);

                                        *abort_flag = 1;
                                        sctp_pegs[SCTP_DROP_FRAG]++;
                                        return (0);
                                }
                        }
                }
                if (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) {
                        /* queue directly into socket buffer */
                        sctp_deliver_data(stcb, asoc, chk, 0);
                        sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
                } else {
                        /* 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.
                         *
                         * We take complete messages that have a stream reset
                         * intervening (aka the TSN is after where our cum-ack needs
                         * to be) off and put them on a pending_reply_queue. The
                         * reassembly ones we do not have to worry about since
                         * they are all sorted and processed by TSN order. It
                         * is only the singletons I must worry about.
                         */
                        if ((asoc->pending_reply) &&
                           ((compare_with_wrap(tsn, ntohl(asoc->pending_reply->reset_at_tsn), MAX_TSN)) ||
                            (tsn == ntohl(asoc->pending_reply->reset_at_tsn)))
                                ) {
                                /* yep its past where we need to reset... go ahead and
                                 * queue it.
                                 */
                                TAILQ_INSERT_TAIL(&asoc->pending_reply_queue , chk, sctp_next);
                        } else {
                                sctp_queue_data_to_stream(stcb, asoc, chk, abort_flag);
                        }
                }
        } else {
                /* Into the re-assembly queue */
                sctp_queue_data_for_reasm(stcb, asoc, chk, abort_flag);
                if (*abort_flag) {
                        sctp_pegs[SCTP_DROP_FRAG]++;
                        return (0);
                }
        }
        if (compare_with_wrap(tsn, asoc->highest_tsn_inside_map, MAX_TSN)) {
                /* we have a new high score */
                asoc->highest_tsn_inside_map = tsn;
#ifdef SCTP_MAP_LOGGING
                sctp_log_map(0, 2, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
#endif
        }
 finish_express_del:
        if (last_chunk) {
                *m = NULL;
        }
        sctp_pegs[SCTP_PEG_TSNS_RCVD]++;
        /* Set it present please */
#ifdef SCTP_STR_LOGGING
        sctp_log_strm_del_alt(tsn, strmseq, SCTP_STR_LOG_FROM_MARK_TSN);
#endif
#ifdef SCTP_MAP_LOGGING
        sctp_log_map(asoc->mapping_array_base_tsn, asoc->cumulative_tsn,
                     asoc->highest_tsn_inside_map, SCTP_MAP_PREPARE_SLIDE);
#endif
        SCTP_SET_TSN_PRESENT(asoc->mapping_array, gap);
        return (1);
}

void
sctp_sack_check(struct sctp_tcb *stcb, int ok_to_sack, int was_a_gap, int *abort_flag)
{
        /*
         * Now we also need to check the mapping array in a couple of ways.
         * 1) Did we move the cum-ack point?
         */
        struct sctp_association *asoc;
        int i, at;
        int m_size, all_ones;
        int slide_from, slide_end, lgap, distance;
#ifdef SCTP_MAP_LOGGING
        uint32_t old_cumack, old_base, old_highest;
        unsigned char aux_array[64];
#endif

        asoc = &stcb->asoc;
        at = 0;

#ifdef SCTP_MAP_LOGGING
        old_cumack = asoc->cumulative_tsn;
        old_base = asoc->mapping_array_base_tsn;
        old_highest = asoc->highest_tsn_inside_map;
        if (asoc->mapping_array_size < 64)
                memcpy(aux_array, asoc->mapping_array,
                    asoc->mapping_array_size);
        else
                memcpy(aux_array, asoc->mapping_array, 64);
#endif

        /*
         * We could probably improve this a small bit by calculating the
         * offset of the current cum-ack as the starting point.
         */
        all_ones = 1;
        m_size = stcb->asoc.mapping_array_size << 3;
        for (i = 0; i < m_size; i++) {
                if (!SCTP_IS_TSN_PRESENT(asoc->mapping_array, i)) {
                        /*
                         * Ok we found the first place that we are
                         * missing a TSN.
                         */
                        at = i;
                        all_ones = 0;
                        asoc->cumulative_tsn = asoc->mapping_array_base_tsn +
                            (i - 1);
                        break;
                }
        }
        if (compare_with_wrap(asoc->cumulative_tsn,
                              asoc->highest_tsn_inside_map,
                              MAX_TSN)) {
                panic("huh, cumack greater than high-tsn in map");
        }
        if (all_ones ||
            (asoc->cumulative_tsn == asoc->highest_tsn_inside_map && at >= 8)) {
                /* The complete array was completed by a single FR */
                /* highest becomes the cum-ack */
                int clr;
                asoc->cumulative_tsn = asoc->highest_tsn_inside_map;
                /* clear the array */
                if (all_ones)
                        clr = asoc->mapping_array_size;
                else {
                        clr = (at >> 3) + 1;
                        /*
                         * this should be the allones case
                         * but just in case :>
                         */
                        if (clr > asoc->mapping_array_size)
                                clr = asoc->mapping_array_size;
                }
                memset(asoc->mapping_array, 0, clr);
                /* base becomes one ahead of the cum-ack */
                asoc->mapping_array_base_tsn = asoc->cumulative_tsn + 1;
#ifdef SCTP_MAP_LOGGING
                sctp_log_map(old_base, old_cumack, old_highest,
                    SCTP_MAP_PREPARE_SLIDE);
                sctp_log_map(asoc->mapping_array_base_tsn, asoc->cumulative_tsn,
                    asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_CLEARED);
#endif
        } else if (at >= 8) {
                /* we can slide the mapping array down */
                /* Calculate the new byte position we can move down */
                slide_from = at >> 3;
                /* now calculate the ceiling of the move using our highest TSN value */
                if (asoc->highest_tsn_inside_map >= asoc->mapping_array_base_tsn) {
                        lgap = asoc->highest_tsn_inside_map -
                            asoc->mapping_array_base_tsn;
                } else {
                        lgap = (MAX_TSN - asoc->mapping_array_base_tsn) +
                            asoc->highest_tsn_inside_map + 1;
                }
                slide_end = lgap >> 3;
                if (slide_end < slide_from) {
                        panic("impossible slide");
                }
                distance = (slide_end-slide_from) + 1;
#ifdef SCTP_MAP_LOGGING
                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);
#endif
                if (distance + slide_from > asoc->mapping_array_size ||
                    distance < 0) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                printf("Ugh bad addition.. you can't hrumpp!\n");
                        }
#endif
                        /*
                         * 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
                         */

#ifdef SCTP_MAP_LOGGING
                        sctp_log_map((uint32_t)distance, (uint32_t)slide_from,
                            (uint32_t)asoc->mapping_array_size,
                            SCTP_MAP_SLIDE_NONE);
#endif
                } else {
                        int ii;
                        for (ii = 0; ii < distance; ii++) {
                                asoc->mapping_array[ii] =
                                    asoc->mapping_array[slide_from + ii];
                        }
                        for (ii = distance;ii <= slide_end; ii++) {
                                asoc->mapping_array[ii] = 0;
                        }
                        asoc->mapping_array_base_tsn += (slide_from << 3);
#ifdef SCTP_MAP_LOGGING
                        sctp_log_map(asoc->mapping_array_base_tsn,
                            asoc->cumulative_tsn, asoc->highest_tsn_inside_map,
                            SCTP_MAP_SLIDE_RESULT);
#endif
                }
        }

        /* check the special flag for stream resets */
        if ((asoc->pending_reply) &&
           ((compare_with_wrap((asoc->cumulative_tsn+1), ntohl(asoc->pending_reply->reset_at_tsn), MAX_TSN)) ||
            ((asoc->cumulative_tsn+1) ==  ntohl(asoc->pending_reply->reset_at_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.
                 */
                struct sctp_tmit_chunk *chk;
                sctp_handle_stream_reset_response(stcb, asoc->pending_reply);
                free(asoc->pending_reply, M_PCB);
                asoc->pending_reply = NULL;
                chk = TAILQ_FIRST(&asoc->pending_reply_queue);
                while (chk) {
                        TAILQ_REMOVE(&asoc->pending_reply_queue, chk, sctp_next);
                        sctp_queue_data_to_stream(stcb, asoc, chk, abort_flag);
                        if (*abort_flag) {
                                return;
                        }
                        chk = TAILQ_FIRST(&asoc->pending_reply_queue);
                }
        }
        /*
         * Now we need to see if we need to queue a sack or just start
         * the timer (if allowed).
         */
        if (ok_to_sack) {
                if (SCTP_GET_STATE(asoc) == 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 (callout_pending(&stcb->asoc.dack_timer.timer)) {
                                sctp_timer_stop(SCTP_TIMER_TYPE_RECV,
                                    stcb->sctp_ep, stcb, NULL);
                        }
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_OUTPUT4) {
                                printf("%s:%d sends a shutdown\n",
                                       __FILE__,
                                       __LINE__
                                       );
                        }
#endif
                        sctp_send_shutdown(stcb, stcb->asoc.primary_destination);
                        sctp_send_sack(stcb);
                } else {
                        int is_a_gap;
                        /* is there a gap now ? */
                        is_a_gap = compare_with_wrap(stcb->asoc.highest_tsn_inside_map,
                            stcb->asoc.cumulative_tsn, MAX_TSN);
                        if ((stcb->asoc.first_ack_sent == 0) || /* First time we 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 */
                            (callout_pending(&stcb->asoc.dack_timer.timer)) /* timer was up . second packet */
                                ) {
                                /*
                                 * Ok we must build a SACK since the timer
                                 * is pending, we got our first packet OR
                                 * there are gaps or duplicates.
                                 */
                                stcb->asoc.first_ack_sent = 1;
                                sctp_send_sack(stcb);
                                /* The sending will stop the timer */
                        } else {
                                sctp_timer_start(SCTP_TIMER_TYPE_RECV,
                                    stcb->sctp_ep, stcb, NULL);
                        }
                }
        }
}

void
sctp_service_queues(struct sctp_tcb *stcb, struct sctp_association *asoc, int hold_locks)
{
        struct sctp_tmit_chunk *chk;
        int tsize, cntDel;
        u_int16_t nxt_todel;

        cntDel = 0;
        if (asoc->fragmented_delivery_inprogress) {
                sctp_service_reassembly(stcb, asoc, hold_locks);
        }
        /* Can we proceed further, i.e. the PD-API is complete */
        if (asoc->fragmented_delivery_inprogress) {
                /* no */
                return;
        }

        /*
         * Yes, reassembly delivery no longer in progress see if we
         * have some on the sb hold queue.
         */
        do {
                if (stcb->sctp_socket->so_rcv.sb_cc >= stcb->sctp_socket->so_rcv.sb_hiwat) {
                        if (cntDel == 0)
                                sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
                        break;
                }
                /* If deliver_data says no we must stop */
                if (sctp_deliver_data(stcb, asoc, (struct sctp_tmit_chunk *)NULL, hold_locks) == 0)
                        break;
                cntDel++;
                chk = TAILQ_FIRST(&asoc->delivery_queue);
        } while (chk);
        if (cntDel) {
                sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
        }
        /*
         * Now is there some other chunk I can deliver
         * from the reassembly queue.
         */
        chk = TAILQ_FIRST(&asoc->reasmqueue);
        if (chk == NULL) {
                asoc->size_on_reasm_queue = 0;
                asoc->cnt_on_reasm_queue = 0;
                return;
        }
        nxt_todel = asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered + 1;
        if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) &&
            ((nxt_todel == chk->rec.data.stream_seq) ||
             (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED))) {
                /*
                 * Yep the first one is here. We setup to
                 * start reception, by backing down the TSN
                 * just in case we can't deliver.
                 */

                /*
                 * Before we start though either all of the
                 * message should be here or 1/4 the socket buffer
                 * max or nothing on the delivery queue and something
                 * can be delivered.
                 */
                if (TAILQ_EMPTY(&asoc->delivery_queue) &&
                    (sctp_is_all_msg_on_reasm(asoc, &tsize) ||
                     (asoc->size_on_reasm_queue >=
                      (stcb->sctp_socket->so_rcv.sb_hiwat >> 2) && tsize))) {
                        asoc->fragmented_delivery_inprogress = 1;
                        asoc->tsn_last_delivered = chk->rec.data.TSN_seq-1;
                        asoc->str_of_pdapi = chk->rec.data.stream_number;
                        asoc->ssn_of_pdapi = chk->rec.data.stream_seq;
                        asoc->fragment_flags = chk->rec.data.rcv_flags;
                        sctp_service_reassembly(stcb, asoc, hold_locks);
                }
        }
}

int
sctp_process_data(struct mbuf **mm, int iphlen, int *offset, int length,
    struct sctphdr *sh, struct sctp_inpcb *inp, struct sctp_tcb *stcb,
    struct sctp_nets *net, u_int32_t *high_tsn)
{
        struct sctp_data_chunk *ch, chunk_buf;
        struct sctp_association *asoc;
        int num_chunks = 0;     /* number of control chunks processed */
        int chk_length, break_flag, last_chunk;
        int abort_flag = 0, was_a_gap = 0;
        struct mbuf *m;

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

        m = *mm;
        asoc = &stcb->asoc;
        if (compare_with_wrap(stcb->asoc.highest_tsn_inside_map,
            stcb->asoc.cumulative_tsn, MAX_TSN)) {
                /* there was a gap before this data was processed */
                was_a_gap = 1;
        }
        /*
         * 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 (m->m_len < (long)MHLEN && m->m_next == NULL) {
                /* we only handle mbufs that are singletons.. not chains */
                MGET(m, M_DONTWAIT, MT_DATA);
                if (m) {
                        /* ok lets see if we can copy the data up */
                        vaddr_t *from, *to;

                        if ((*mm)->m_flags & M_PKTHDR) {
                                /* got to copy the header first */
#ifdef __APPLE__
                                M_COPY_PKTHDR(m, (*mm));
#else
                                m_move_pkthdr(m, (*mm));
#endif
                        }
                        /* get the pointers and copy */
                        to = mtod(m, vaddr_t *);
                        from = mtod((*mm), vaddr_t *);
                        memcpy(to, from, (*mm)->m_len);
                        /* copy the length and free up the old */
                        m->m_len = (*mm)->m_len;
                        sctp_m_freem(*mm);
                        /* sucess, 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_data_chunk *)sctp_m_getptr(m, *offset,
            sizeof(chunk_buf), (u_int8_t *)&chunk_buf);
        if (ch == NULL) {
                printf(" ... its short\n");
                return (1);
        }
        /*
         * process all DATA chunks...
         */

#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_INPUT1) {
                printf("In process data off:%d length:%d iphlen:%d ch->type:%d\n",
                    *offset, length, iphlen, (int)ch->ch.chunk_type);
        }
#endif

        *high_tsn = asoc->cumulative_tsn;
        break_flag = 0;
        while (ch->ch.chunk_type == SCTP_DATA) {
                /* validate chunk length */
                chk_length = ntohs(ch->ch.chunk_length);
                if ((size_t)chk_length < sizeof(struct sctp_data_chunk) + 1 ||
                    length - *offset < chk_length) {
                        /*
                         * Need to send an abort since we had a invalid
                         * data chunk.
                         */
                        struct mbuf *op_err;
                        MGET(op_err, M_DONTWAIT, MT_DATA);
                        if (op_err) {
                                struct sctp_paramhdr *ph;
                                u_int32_t *ippp;

                                op_err->m_len = sizeof(struct sctp_paramhdr) +
                                    sizeof(*ippp);
                                ph = mtod(op_err, struct sctp_paramhdr *);
                                ph->param_type =
                                    htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                ph->param_length = htons(op_err->m_len);
                                ippp = (u_int32_t *)(ph + 1);
                                *ippp = htonl(0x30000001);
                        }
                        sctp_abort_association(inp, stcb, m, iphlen, sh,
                            op_err);
                        return (2);
                }
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INPUT1) {
                        printf("A chunk of len:%d to process (tot:%d)\n",
                            chk_length, length - *offset);
                }
#endif

#ifdef SCTP_AUDITING_ENABLED
                sctp_audit_log(0xB1, 0);
#endif
                if (SCTP_SIZE32(chk_length) == *offset - length) {
                        last_chunk = 1;
                } else {
                        last_chunk = 0;
                }
                if (sctp_process_a_data_chunk(stcb, asoc, mm, *offset, ch,
                    chk_length, net, high_tsn, &abort_flag, &break_flag,
                    last_chunk)) {
                        num_chunks++;
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_INPUT1) {
                                printf("Now incr num_chunks to %d\n",
                                    num_chunks);
                        }
#endif
                }
                if (abort_flag)
                        return (2);

                if (break_flag) {
                        /*
                         * Set because of out of rwnd space and no drop rep
                         * space left.
                         */
                        break;
                }

                *offset += SCTP_SIZE32(chk_length);
                if (*offset >= length) {
                        /* no more data left in the mbuf chain */
                        break;
                }
                ch = (struct sctp_data_chunk *)sctp_m_getptr(m, *offset,
                    sizeof(chunk_buf), (u_int8_t *)&chunk_buf);
                if (ch == NULL) {
                        *offset = length;
                        break;
                }
        } /* while */
        if (break_flag) {
                /*
                 * we need to report rwnd overrun drops.
                 */
                sctp_send_packet_dropped(stcb, net, *mm, 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_pegs[SCTP_DATA_DG_RECV]++;
                stcb->asoc.overall_error_count = 0;
                SCTP_GETTIME_TIMEVAL(&stcb->asoc.time_last_rcvd);
        }
        /* now service all of the reassm queue and delivery queue */
        sctp_service_queues(stcb, asoc, 0);
        if (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_SENT) {
                /*
                 * Assure that we ack right away by making
                 * sure that a d-ack timer is running. So the
                 * sack_check will send a sack.
                 */
                sctp_timer_start(SCTP_TIMER_TYPE_RECV, stcb->sctp_ep, stcb,
                    net);
        }
        /* Start a sack timer or QUEUE a SACK for sending */
        sctp_sack_check(stcb, 1, was_a_gap, &abort_flag);
        if (abort_flag)
                return (2);

        return (0);
}

static void
sctp_handle_segments(struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct sctp_sack_chunk *ch, u_long last_tsn, u_long *biggest_tsn_acked,
    u_long *biggest_newly_acked_tsn, int num_seg, int *ecn_seg_sums)
{
        /************************************************/
        /* process fragments and update sendqueue        */
        /************************************************/
        struct sctp_sack *sack;
        struct sctp_gap_ack_block *frag;
        struct sctp_tmit_chunk *tp1;
        int i;
        unsigned int j;
#ifdef SCTP_FR_LOGGING
        int num_frs=0;
#endif
        uint16_t frag_strt, frag_end, primary_flag_set;
        u_long last_frag_high;

        if (asoc->primary_destination->dest_state & SCTP_ADDR_SWITCH_PRIMARY) {
                primary_flag_set = 1;
        } else {
                primary_flag_set = 0;
        }

        sack = &ch->sack;
        frag = (struct sctp_gap_ack_block *)((vaddr_t)sack +
            sizeof(struct sctp_sack));
        tp1 = NULL;
        last_frag_high = 0;
        for (i = 0; i < num_seg; i++) {
                frag_strt = ntohs(frag->start);
                frag_end = ntohs(frag->end);
                /* some sanity checks on the fragment offsets */
                if (frag_strt > frag_end) {
                        /* this one is malformed, skip */
                        frag++;
                        continue;
                }
                if (compare_with_wrap((frag_end+last_tsn), *biggest_tsn_acked,
                    MAX_TSN))
                        *biggest_tsn_acked = frag_end+last_tsn;

                /* mark acked dgs and find out the highestTSN being acked */
                if (tp1 == NULL) {
                        tp1 = TAILQ_FIRST(&asoc->sent_queue);

                        /* save the locations of the last frags */
                        last_frag_high = frag_end + last_tsn;
                } else {
                        /*
                         * now lets see if we need to reset the queue
                         * due to a out-of-order SACK fragment
                         */
                        if (compare_with_wrap(frag_strt+last_tsn,
                            last_frag_high, MAX_TSN)) {
                                /*
                                 * if the new frag starts after the last TSN
                                 * frag covered, we are ok
                                 * and this one is beyond the last one
                                 */
                                ;
                        } else {
                                /*
                                 * ok, they have reset us, so we need to reset
                                 * the queue this will cause extra hunting but
                                 * hey, they chose the performance
                                 * hit when they failed to order there gaps..
                                 */
                                tp1 = TAILQ_FIRST(&asoc->sent_queue);
                        }
                        last_frag_high = frag_end + last_tsn;
                }
                for (j = frag_strt + last_tsn; j <= frag_end + last_tsn; j++) {
                        while (tp1) {
#ifdef SCTP_FR_LOGGING
                                if (tp1->rec.data.doing_fast_retransmit)
                                        num_frs++;
#endif

                                if (tp1->rec.data.TSN_seq == j) {
                                        if (tp1->sent != SCTP_DATAGRAM_UNSENT) {
                                                /* must be held until cum-ack passes */
                                                /* ECN Nonce: Add the nonce value to the sender's nonce sum */
                                                if (tp1->sent < SCTP_DATAGRAM_ACKED) {
                                                        /*
                                                         * If it is less than
                                                         * ACKED, it is now
                                                         * no-longer in flight.
                                                         * Higher values may
                                                         * already be set via
                                                         * previous Gap Ack
                                                         * Blocks...
                                                         * i.e. ACKED or MARKED.
                                                         */
                                                        if (compare_with_wrap(tp1->rec.data.TSN_seq,
                                                            *biggest_newly_acked_tsn,
                                                            MAX_TSN)) {
                                                                *biggest_newly_acked_tsn =
                                                                    tp1->rec.data.TSN_seq;
                                                        }
                                                        sctp_flight_size_decrease(tp1);

                                                        sctp_total_flight_decrease(stcb, tp1);

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

                                                                /* update RTO too? */
                                                                if (tp1->do_rtt) {
                                                                        tp1->whoTo->RTO =
                                                                            sctp_calculate_rto(stcb,
                                                                            asoc,
                                                                            tp1->whoTo,
                                                                            &tp1->sent_rcv_time);
                                                                        tp1->whoTo->rto_pending = 0;
                                                                        tp1->do_rtt = 0;
                                                                }
                                                        }
                                                }
                                                if (tp1->sent <= SCTP_DATAGRAM_RESEND &&
                                                    tp1->sent != SCTP_DATAGRAM_UNSENT &&
                                                    compare_with_wrap(tp1->rec.data.TSN_seq,
                                                    asoc->this_sack_highest_gap,
                                                    MAX_TSN)) {
                                                        asoc->this_sack_highest_gap =
                                                            tp1->rec.data.TSN_seq;
                                                        if (primary_flag_set) {
                                                                tp1->whoTo->cacc_saw_newack = 1;
                                                        }
                                                }
                                                if (tp1->sent == SCTP_DATAGRAM_RESEND) {
#ifdef SCTP_DEBUG
                                                        if (sctp_debug_on &
                                                            SCTP_DEBUG_INDATA3) {
                                                                printf("Hmm. one that is in RESEND that is now ACKED\n");
                                                        }
#endif
                                                        sctp_ucount_decr(asoc->sent_queue_retran_cnt);
#ifdef SCTP_AUDITING_ENABLED
                                                        sctp_audit_log(0xB2,
                                                            (asoc->sent_queue_retran_cnt & 0x000000ff));
#endif

                                                }
                                                (*ecn_seg_sums) += tp1->rec.data.ect_nonce;
                                                (*ecn_seg_sums) &= SCTP_SACK_NONCE_SUM;
                                                tp1->sent = SCTP_DATAGRAM_MARKED;
                                        }
                                        break;
                                } /* if (tp1->TSN_seq == j) */
                                if (compare_with_wrap(tp1->rec.data.TSN_seq, j,
                                    MAX_TSN))
                                        break;
                                tp1 = TAILQ_NEXT(tp1, sctp_next);
                        }/* end while (tp1) */
                }  /* end for (j = fragStart */
                frag++; /* next one */
        }
#ifdef SCTP_FR_LOGGING
        if (num_frs)
                sctp_log_fr(*biggest_tsn_acked, *biggest_newly_acked_tsn,
                    last_tsn, SCTP_FR_LOG_BIGGEST_TSNS);
#endif
}

static void
sctp_check_for_revoked(struct sctp_association *asoc, u_long cum_ack,
    u_long biggest_tsn_acked)
{
        struct sctp_tmit_chunk *tp1;
        int tot_revoked=0;

        tp1 = TAILQ_FIRST(&asoc->sent_queue);
        while (tp1) {
                if (compare_with_wrap(tp1->rec.data.TSN_seq, cum_ack,
                    MAX_TSN)) {
                        /*
                         * 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 (tp1->sent == SCTP_DATAGRAM_ACKED) {
                                /* it has been revoked */
                                /*
                                 * We do NOT add back to flight size here since
                                 * it is really NOT in flight. Resend (when/if
                                 * it occurs will add to flight size
                                 */
                                tp1->sent = SCTP_DATAGRAM_SENT;
                                tot_revoked++;
                        } else if (tp1->sent == SCTP_DATAGRAM_MARKED) {
                                /* it has been re-acked in this SACK */
                                tp1->sent = SCTP_DATAGRAM_ACKED;
                        }
                }
                if (compare_with_wrap(tp1->rec.data.TSN_seq, biggest_tsn_acked,
                    MAX_TSN)) {
                        /* above the sack */
                        break;
                }
                if (tp1->sent == SCTP_DATAGRAM_UNSENT)
                        break;
                tp1 = TAILQ_NEXT(tp1, sctp_next);
        }
        if (tot_revoked > 0) {
                /* Setup the ecn nonce re-sync point. We
                 * do this since once data is revoked
                 * we begin to retransmit things, which
                 * do NOT have the ECN bits set. This means
                 * we are now out of sync and must wait until
                 * we get back in sync with the peer to
                 * check ECN bits.
                 */
                tp1 = TAILQ_FIRST(&asoc->send_queue);
                if (tp1 == NULL) {
                        asoc->nonce_resync_tsn = asoc->sending_seq;
                } else {
                        asoc->nonce_resync_tsn = tp1->rec.data.TSN_seq;
                }
                asoc->nonce_wait_for_ecne = 0;
                asoc->nonce_sum_check = 0;
        }

}

extern int sctp_peer_chunk_oh;

static void
sctp_strike_gap_ack_chunks(struct sctp_tcb *stcb, struct sctp_association *asoc,
    u_long biggest_tsn_acked, int strike_enabled,
    u_long biggest_tsn_newly_acked, int accum_moved)
{
        struct sctp_tmit_chunk *tp1;
        int strike_flag=0;
        struct timeval now;
        int tot_retrans=0;
        u_int32_t sending_seq;
        int primary_switch_active = 0;
        int double_switch_active = 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_seq;
        }

        if (asoc->primary_destination->dest_state & SCTP_ADDR_SWITCH_PRIMARY) {
                primary_switch_active = 1;
        }
        if (asoc->primary_destination->dest_state & SCTP_ADDR_DOUBLE_SWITCH) {
                double_switch_active = 1;
        }
        if (stcb->asoc.peer_supports_prsctp ) {
                SCTP_GETTIME_TIMEVAL(&now);
        }
        tp1 = TAILQ_FIRST(&asoc->sent_queue);
        while (tp1) {
                strike_flag=0;
                if (compare_with_wrap(tp1->rec.data.TSN_seq, biggest_tsn_acked,
                    MAX_TSN) ||
                    tp1->sent == SCTP_DATAGRAM_UNSENT) {
                        /* done */
                        break;
                }
                if ((tp1->flags & (SCTP_PR_SCTP_ENABLED|SCTP_PR_SCTP_BUFFER)) ==
                    SCTP_PR_SCTP_ENABLED &&
                    tp1->sent < SCTP_DATAGRAM_ACKED) {
                        /* Is it expired? */
#ifndef __FreeBSD__
                        if (timercmp(&now, &tp1->rec.data.timetodrop, >))
#else
                        if (timevalcmp(&now, &tp1->rec.data.timetodrop, >))
#endif
                        {
                                /* Yes so drop it */
                                if (tp1->data != NULL) {
                                        sctp_release_pr_sctp_chunk(stcb, tp1,
                                            (SCTP_RESPONSE_TO_USER_REQ|SCTP_NOTIFY_DATAGRAM_SENT),
                                            &asoc->sent_queue);
                                }
                                tp1 = TAILQ_NEXT(tp1, sctp_next);
                                continue;
                        }
                }

                if (compare_with_wrap(tp1->rec.data.TSN_seq,
                    asoc->this_sack_highest_gap, MAX_TSN)) {
                        /* we are beyond the tsn in the sack  */
                        break;
                }
                if (tp1->sent >= SCTP_DATAGRAM_RESEND) {
                        /* either a RESEND, ACKED, or MARKED */
                        /* skip */
                        tp1 = TAILQ_NEXT(tp1, sctp_next);
                        continue;
                }
                if (primary_switch_active && (strike_enabled == 0)) {
                        if (tp1->whoTo != asoc->primary_destination) {
                                /*
                                 * We can only strike things on the primary if
                                 * the strike_enabled flag is clear
                                 */
                                tp1 = TAILQ_NEXT(tp1, sctp_next);
                                continue;
                        }
                } else if (primary_switch_active) {
                        if (tp1->whoTo->cacc_saw_newack == 0) {
                                /*
                                 * Only one was received but it was NOT
                                 * this one.
                                 */
                                tp1 = TAILQ_NEXT(tp1, sctp_next);
                                continue;
                        }
                }
                if (double_switch_active &&
                    (compare_with_wrap(asoc->primary_destination->next_tsn_at_change,
                    tp1->rec.data.TSN_seq, MAX_TSN))) {
                        /*
                         * With a double switch we do NOT mark unless we
                         * are beyond the switch point.
                         */
                        tp1 = TAILQ_NEXT(tp1, sctp_next);
                        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.
                 */
                if (accum_moved && asoc->fast_retran_loss_recovery) {
                        /*
                         * Strike the TSN if in fast-recovery and
                         * cum-ack moved.
                         */
                        tp1->sent++;
                } else if (tp1->rec.data.doing_fast_retransmit) {
                        /*
                         * 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.
                         */
#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.
                         */
                        if (asoc->numnets < 2)
#else
                        if (1)
#endif
                        {
                                if ((compare_with_wrap(biggest_tsn_newly_acked,
                                    tp1->rec.data.fast_retran_tsn, MAX_TSN)) ||
                                    (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.
                                         */
#ifdef SCTP_FR_LOGGING
                                        sctp_log_fr(biggest_tsn_newly_acked,
                                            tp1->rec.data.TSN_seq,
                                            tp1->rec.data.fast_retran_tsn,
                                            SCTP_FR_LOG_STRIKE_CHUNK);
#endif
                                        tp1->sent++;
                                        strike_flag=1;
                                }
                        }
                } else if (compare_with_wrap(tp1->rec.data.TSN_seq,
                    biggest_tsn_newly_acked, MAX_TSN)) {
                        /*
                         * 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 */
                        tp1->sent++;
                }
                if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                        /* Increment the count to resend */
                        struct sctp_nets *alt;

#ifdef SCTP_FR_LOGGING
                        sctp_log_fr(tp1->rec.data.TSN_seq, tp1->snd_count,
                            0, SCTP_FR_MARKED);
#endif
                        if (strike_flag) {
                                /* This is a subsequent FR */
                                sctp_pegs[SCTP_DUP_FR]++;
                        }
                        asoc->sent_queue_retran_cnt++;
#ifdef SCTP_FR_TO_ALTERNATE
                        /* Can we find an alternate? */
                        alt = sctp_find_alternate_net(stcb, tp1->whoTo);
#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;
                        tot_retrans++;
                        /* mark the sending seq for possible subsequent FR's */
                        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 - 1;
                        } 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_seq - 1;
                        }
                        if (tp1->do_rtt) {
                                /*
                                 * this guy had a RTO calculation pending on it,
                                 * cancel it
                                 */
                                tp1->whoTo->rto_pending = 0;
                                tp1->do_rtt = 0;
                        }
                        /* fix counts and things */

                        tp1->whoTo->net_ack++;
                        sctp_flight_size_decrease(tp1);
#ifdef SCTP_LOG_RWND
                        sctp_log_rwnd(SCTP_INCREASE_PEER_RWND,
                                      asoc->peers_rwnd , tp1->send_size, sctp_peer_chunk_oh);
#endif
                        /* add back to the rwnd */
                        asoc->peers_rwnd += (tp1->send_size + sctp_peer_chunk_oh);

                        /* remove from the total flight */
                        sctp_total_flight_decrease(stcb, tp1);
                        if (alt != tp1->whoTo) {
                                /* yes, there is an alternate. */
                                sctp_free_remote_addr(tp1->whoTo);
                                tp1->whoTo = alt;
                                alt->ref_count++;
                        }
                }
                tp1 = TAILQ_NEXT(tp1, sctp_next);
        } /* while (tp1) */

        if (tot_retrans > 0) {
                /* Setup the ecn nonce re-sync point. We
                 * do this since once we go to FR something
                 * we introduce a Karn's rule scenario and
                 * won't know the totals for the ECN bits.
                 */
                asoc->nonce_resync_tsn = sending_seq;
                asoc->nonce_wait_for_ecne = 0;
                asoc->nonce_sum_check = 0;
        }

}

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->peer_supports_prsctp == 0) {
                return (NULL);
        }
        tp1 = TAILQ_FIRST(&asoc->sent_queue);
        while (tp1) {
                if (tp1->sent != SCTP_FORWARD_TSN_SKIP &&
                    tp1->sent != SCTP_DATAGRAM_RESEND) {
                        /* no chance to advance, out of here */
                        break;
                }
                if ((tp1->flags & SCTP_PR_SCTP_ENABLED) == 0) {
                        /*
                         * We can't fwd-tsn past any that are reliable
                         * aka retransmitted until the asoc fails.
                         */
                        break;
                }
                if (!now_filled) {
                        SCTP_GETTIME_TIMEVAL(&now);
                        now_filled = 1;
                }
                tp2 = TAILQ_NEXT(tp1, sctp_next);
                /*
                 * 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 &&
                    (tp1->flags & SCTP_PR_SCTP_BUFFER) == 0) {
                        /*
                         * Now is this one marked for resend and its time
                         * is now up?
                         */
#ifndef __FreeBSD__
                        if (timercmp(&now, &tp1->rec.data.timetodrop, >))
#else
                        if (timevalcmp(&now, &tp1->rec.data.timetodrop, >))
#endif
                        {
                                /* Yes so drop it */
                                if (tp1->data) {
                                        sctp_release_pr_sctp_chunk(stcb, tp1,
                                            (SCTP_RESPONSE_TO_USER_REQ|SCTP_NOTIFY_DATAGRAM_SENT),
                                            &asoc->sent_queue);
                                }
                        } 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) {
                        /* advance PeerAckPoint goes forward */
                        asoc->advanced_peer_ack_point = tp1->rec.data.TSN_seq;
                        a_adv = tp1;
                        /*
                         * we don't want to de-queue it here. Just wait for the
                         * next peer SACK to come with a new cumTSN and then
                         * the chunk will be dropped in the normal fashion.
                         */
                        if (tp1->data) {
                                sctp_free_bufspace(stcb, asoc, tp1);
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_OUTPUT2) {
                                        printf("--total out:%lu total_mbuf_out:%lu\n",
                                            (u_long)asoc->total_output_queue_size,
                                            (u_long)asoc->total_output_mbuf_queue_size);
                                }
#endif
                                /*
                                 * Maybe there should be another notification
                                 * type
                                 */
                                sctp_ulp_notify(SCTP_NOTIFY_DG_FAIL, stcb,
                                    (SCTP_RESPONSE_TO_USER_REQ|SCTP_NOTIFY_DATAGRAM_SENT),
                                    tp1);
                                sctp_m_freem(tp1->data);
                                tp1->data = NULL;
                                sctp_sowwakeup(stcb->sctp_ep,
                                    stcb->sctp_socket);
                        }
                } else {
                        /* If it is still in RESEND we can advance no further */
                        break;
                }
                /*
                 * If we hit here we just dumped tp1, move to next
                 * tsn on sent queue.
                 */
                tp1 = tp2;
        }
        return (a_adv);
}

#ifdef SCTP_HIGH_SPEED
struct sctp_hs_raise_drop {
        int32_t cwnd;
        int32_t increase;
        int32_t drop_percent;
};

#define SCTP_HS_TABLE_SIZE 73

struct sctp_hs_raise_drop sctp_cwnd_adjust[SCTP_HS_TABLE_SIZE] = {
        {38,1,50},      /* 0   */
        {118,2,44},     /* 1   */
        {221,3,41},     /* 2   */
        {347,4,38},     /* 3   */
        {495,5,37},     /* 4   */
        {663,6,35},     /* 5   */
        {851,7,34},     /* 6   */
        {1058,8,33},    /* 7   */
        {1284,9,32},    /* 8   */
        {1529,10,31},   /* 9   */
        {1793,11,30},   /* 10  */
        {2076,12,29},   /* 11  */
        {2378,13,28},   /* 12  */
        {2699,14,28},   /* 13  */
        {3039,15,27},   /* 14  */
        {3399,16,27},   /* 15  */
        {3778,17,26},   /* 16  */
        {4177,18,26},   /* 17  */
        {4596,19,25},   /* 18  */
        {5036,20,25},   /* 19  */
        {5497,21,24},   /* 20  */
        {5979,22,24},   /* 21  */
        {6483,23,23},   /* 22  */
        {7009,24,23},   /* 23  */
        {7558,25,22},   /* 24  */
        {8130,26,22},   /* 25  */
        {8726,27,22},   /* 26  */
        {9346,28,21},   /* 27  */
        {9991,29,21},   /* 28  */
        {10661,30,21},  /* 29  */
        {11358,31,20},  /* 30  */
        {12082,32,20},  /* 31  */
        {12834,33,20},  /* 32  */
        {13614,34,19},  /* 33  */
        {14424,35,19},  /* 34  */
        {15265,36,19},  /* 35  */
        {16137,37,19},  /* 36  */
        {17042,38,18},  /* 37  */
        {17981,39,18},  /* 38  */
        {18955,40,18},  /* 39  */
        {19965,41,17},  /* 40  */
        {21013,42,17},  /* 41  */
        {22101,43,17},  /* 42  */
        {23230,44,17},  /* 43  */
        {24402,45,16},  /* 44  */
        {25618,46,16},  /* 45  */
        {26881,47,16},  /* 46  */
        {28193,48,16},  /* 47  */
        {29557,49,15},  /* 48  */
        {30975,50,15},  /* 49  */
        {32450,51,15},  /* 50  */
        {33986,52,15},  /* 51  */
        {35586,53,14},  /* 52  */
        {37253,54,14},  /* 53  */
        {38992,55,14},  /* 54  */
        {40808,56,14},  /* 55  */
        {42707,57,13},  /* 56  */
        {44694,58,13},  /* 57  */
        {46776,59,13},  /* 58  */
        {48961,60,13},  /* 59  */
        {51258,61,13},  /* 60  */
        {53677,62,12},  /* 61  */
        {56230,63,12},  /* 62  */
        {58932,64,12},  /* 63  */
        {61799,65,12},  /* 64  */
        {64851,66,11},  /* 65  */
        {68113,67,11},  /* 66  */
        {71617,68,11},  /* 67  */
        {75401,69,10},  /* 68  */
        {79517,70,10},  /* 69  */
        {84035,71,10},  /* 70  */
        {89053,72,10},  /* 71  */
        {94717,73,9}    /* 72  */
};

static void
sctp_hs_cwnd_increase(struct sctp_nets *net)
{
        int cur_val, i, indx, incr;

        cur_val = net->cwnd >> 10;
        indx = SCTP_HS_TABLE_SIZE - 1;

        if (cur_val < sctp_cwnd_adjust[0].cwnd) {
                /* normal mode */
                if (net->net_ack > net->mtu) {
                        net->cwnd += net->mtu;
#ifdef SCTP_CWND_LOGGING
                        sctp_log_cwnd(net, net->mtu, SCTP_CWND_LOG_FROM_SS);
#endif
                } else {
                        net->cwnd += net->net_ack;
#ifdef SCTP_CWND_LOGGING
                        sctp_log_cwnd(net, net->net_ack, SCTP_CWND_LOG_FROM_SS);
#endif
                }
        } else {
                for (i=net->last_hs_used; i<SCTP_HS_TABLE_SIZE; i++) {
                        if (cur_val < sctp_cwnd_adjust[i].cwnd) {
                                indx = i;
                                break;
                        }
                }
                net->last_hs_used = indx;
                incr = ((sctp_cwnd_adjust[indx].increase) << 10);
                net->cwnd += incr;
#ifdef SCTP_CWND_LOGGING
                sctp_log_cwnd(net, incr, SCTP_CWND_LOG_FROM_SS);
#endif
        }
}

static void
sctp_hs_cwnd_decrease(struct sctp_nets *net)
{
        int cur_val, i, indx;
#ifdef SCTP_CWND_LOGGING
        int old_cwnd = net->cwnd;
#endif

        cur_val = net->cwnd >> 10;
        indx = net->last_hs_used;
        if (cur_val < sctp_cwnd_adjust[0].cwnd) {
                /* normal mode */
                net->ssthresh = net->cwnd / 2;
                if (net->ssthresh < (net->mtu*2)) {
                        net->ssthresh = 2 * net->mtu;
                }
                net->cwnd = net->ssthresh;
#ifdef SCTP_CWND_LOGGING
                sctp_log_cwnd(net, (net->cwnd-old_cwnd), SCTP_CWND_LOG_FROM_FR);
#endif
        } else {
                /* drop by the proper amount */
                net->ssthresh = net->cwnd - (int)((net->cwnd / 100) *
                    sctp_cwnd_adjust[net->last_hs_used].drop_percent);
                net->cwnd = net->ssthresh;
                /* now where are we */
                indx = net->last_hs_used;
                cur_val = net->cwnd >> 10;
                /* reset where we are in the table */
                if (cur_val < sctp_cwnd_adjust[0].cwnd) {
                        /* feel out of hs */
                        net->last_hs_used = 0;
                } else {
                        for (i = indx; i >= 1; i--) {
                                if (cur_val > sctp_cwnd_adjust[i - 1].cwnd) {
                                        break;
                                }
                        }
                        net->last_hs_used = indx;
                }
        }
}
#endif

void
sctp_handle_sack(struct sctp_sack_chunk *ch, struct sctp_tcb *stcb,
    struct sctp_nets *net_from, int *abort_now)
{
        struct sctp_association *asoc;
        struct sctp_sack *sack;
        struct sctp_tmit_chunk *tp1, *tp2;
        u_long cum_ack, last_tsn, biggest_tsn_acked, biggest_tsn_newly_acked;
        uint16_t num_seg;
        unsigned int sack_length;
        uint32_t send_s;
        int some_on_streamwheel;
        int strike_enabled = 0, cnt_of_cacc = 0;
        int accum_moved = 0;
        int marking_allowed = 1;
        int will_exit_fast_recovery=0;
        u_int32_t a_rwnd;
        struct sctp_nets *net = NULL;
        int nonce_sum_flag, ecn_seg_sums=0;
        asoc = &stcb->asoc;

        /*
         * Handle the incoming sack on data I have been sending.
         */

        /*
         * we take any chance we can to service our queues since we
         * cannot get awoken when the socket is read from :<
         */
        asoc->overall_error_count = 0;

        if (asoc->sent_queue_retran_cnt) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("Handling SACK for asoc:%p retran:%d\n",
                               asoc, asoc->sent_queue_retran_cnt);
                }
#endif
        }

        sctp_service_queues(stcb, asoc, 0);

        /*
         * 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 consequtive 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.
         */

        sack_length = ntohs(ch->ch.chunk_length);
        if (sack_length < sizeof(struct sctp_sack_chunk)) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("Bad size on sack chunk .. to small\n");
                }
#endif
                return;
        }
        /* ECN Nonce */
        nonce_sum_flag = ch->ch.chunk_flags & SCTP_SACK_NONCE_SUM;
        sack = &ch->sack;
        cum_ack = last_tsn = ntohl(sack->cum_tsn_ack);
        num_seg = ntohs(sack->num_gap_ack_blks);

        /* reality check */
        if (TAILQ_EMPTY(&asoc->send_queue)) {
                send_s = asoc->sending_seq;
        } else {
                tp1 = TAILQ_FIRST(&asoc->send_queue);
                send_s = tp1->rec.data.TSN_seq;
        }

        if (sctp_strict_sacks) {
                if (cum_ack == send_s ||
                    compare_with_wrap(cum_ack, send_s, MAX_TSN)) {
                        struct mbuf *oper;
                        /*
                         * no way, we have not even sent this TSN out yet.
                         * Peer is hopelessly messed up with us.
                         */
                hopeless_peer:
                        *abort_now = 1;
                        /* XXX */
                        MGET(oper, M_DONTWAIT, MT_DATA);
                        if (oper) {
                                struct sctp_paramhdr *ph;
                                u_int32_t *ippp;

                                oper->m_len = sizeof(struct sctp_paramhdr) +
                                        sizeof(*ippp);
                                ph = mtod(oper, struct sctp_paramhdr *);
                                ph->param_type = htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                ph->param_length = htons(oper->m_len);
                                ippp = (u_int32_t *)(ph + 1);
                                *ippp = htonl(0x30000002);
                        }
                        sctp_abort_an_association(stcb->sctp_ep, stcb, SCTP_PEER_FAULTY, oper);
                        return;
                }
        }
        /* update the Rwnd of the peer */
        a_rwnd = (u_int32_t)ntohl(sack->a_rwnd);
        if (asoc->sent_queue_retran_cnt) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("cum_ack:%lx num_seg:%u last_acked_seq:%x\n",
                               cum_ack, (u_int)num_seg, asoc->last_acked_seq);
                }
#endif
        }
        if (compare_with_wrap(asoc->t3timeout_highest_marked, cum_ack, MAX_TSN)) {
                /* we are not allowed to mark for FR */
                marking_allowed = 0;
        }
        /**********************/
        /* 1) check the range */
        /**********************/
        if (compare_with_wrap(asoc->last_acked_seq, last_tsn, MAX_TSN)) {
                /* acking something behind */
                if (asoc->sent_queue_retran_cnt) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                printf("The cum-ack is behind us\n");
                        }
#endif
                }
                return;
        }

        if (TAILQ_EMPTY(&asoc->sent_queue)) {
                /* nothing left on sendqueue.. consider done */
#ifdef SCTP_LOG_RWND
                sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                                  asoc->peers_rwnd, 0, 0, a_rwnd);
#endif
                asoc->peers_rwnd = a_rwnd;
                if (asoc->sent_queue_retran_cnt) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                printf("Huh? retran set but none on queue\n");
                        }
#endif
                        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);
                        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-
         * amibguious and were never retransmitted. We track these on a
         * per destination address basis.
         */
        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                net->prev_cwnd = net->cwnd;
                net->net_ack = 0;
                net->net_ack2 = 0;
        }
        /* process the new consecutive TSN first */
        tp1 = TAILQ_FIRST(&asoc->sent_queue);
        while (tp1) {
                if (compare_with_wrap(last_tsn, tp1->rec.data.TSN_seq,
                                      MAX_TSN) ||
                    last_tsn == tp1->rec.data.TSN_seq) {
                        if (tp1->sent != SCTP_DATAGRAM_UNSENT) {
                                /* ECN Nonce: Add the nonce to the sender's nonce sum */
                                asoc->nonce_sum_expect_base += tp1->rec.data.ect_nonce;
                                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;
                                        }
                                        sctp_flight_size_decrease(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) {
                                                        tp1->whoTo->RTO =
                                                                sctp_calculate_rto(stcb,
                                                                                   asoc, tp1->whoTo,
                                                                                   &tp1->sent_rcv_time);
                                                        tp1->whoTo->rto_pending = 0;
                                                        tp1->do_rtt = 0;
                                                }
                                        }
                                }
                                if (tp1->sent == SCTP_DATAGRAM_RESEND) {
#ifdef SCTP_DEBUG
                                        if (sctp_debug_on & SCTP_DEBUG_INDATA3) {
                                                printf("Hmm. one that is in RESEND that is now ACKED\n");
                                        }
#endif
                                        sctp_ucount_decr(asoc->sent_queue_retran_cnt);
#ifdef SCTP_AUDITING_ENABLED
                                        sctp_audit_log(0xB3,
                                                       (asoc->sent_queue_retran_cnt & 0x000000ff));
#endif

                                }
                                tp1->sent = SCTP_DATAGRAM_ACKED;
                        }
                } else {
                        break;
                }
                tp1 = TAILQ_NEXT(tp1, sctp_next);
        }
        /*******************************************/
        /* cancel ALL T3-send timer if accum moved */
        /*******************************************/
        if (accum_moved) {
                TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                        sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                                        stcb, net);
                }
        }
        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 * sizeof(struct sctp_gap_ack_block) + sizeof(struct sctp_sack_chunk) > sack_length) {
                /* skip corrupt segments */
                strike_enabled = 0;
                goto skip_segments;
        }

        if (num_seg > 0) {
                if (asoc->primary_destination->dest_state &
                    SCTP_ADDR_SWITCH_PRIMARY) {
                        /* clear the nets CACC flags */
                        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                                net->cacc_saw_newack = 0;
                        }
                }
                /*
                 * thisSackHighestGap will increase while handling NEW segments
                 */

                sctp_handle_segments(stcb, asoc, ch, last_tsn,
                    &biggest_tsn_acked, &biggest_tsn_newly_acked,
                    num_seg, &ecn_seg_sums);

                if (sctp_strict_sacks) {
                        /* validate the biggest_tsn_acked in the gap acks
                         * if strict adherence is wanted.
                         */
                        if ((biggest_tsn_acked == send_s) ||
                            (compare_with_wrap(biggest_tsn_acked, send_s, MAX_TSN))) {
                                /*
                                 * peer is either confused or we are under
                                 * attack. We must abort.
                                 */
                                goto hopeless_peer;
                        }
                }

                if (asoc->primary_destination->dest_state &
                    SCTP_ADDR_SWITCH_PRIMARY) {
                        /* clear the nets CACC flags */
                        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                                if (net->cacc_saw_newack) {
                                        cnt_of_cacc++;
                                }
                        }
                }

        }

        if (cnt_of_cacc < 2) {
                strike_enabled = 1;
        } else {
                strike_enabled = 0;
        }
 skip_segments:
        /********************************************/
        /* drop the acked chunks from the sendqueue */
        /********************************************/
        asoc->last_acked_seq = cum_ack;
        if (asoc->primary_destination->dest_state & SCTP_ADDR_SWITCH_PRIMARY) {
                if ((cum_ack == asoc->primary_destination->next_tsn_at_change) ||
                    (compare_with_wrap(cum_ack,
                                       asoc->primary_destination->next_tsn_at_change, MAX_TSN))) {
                        struct sctp_nets *lnet;
                        /* Turn off the switch flag for ALL addresses */
                        TAILQ_FOREACH(lnet, &asoc->nets, sctp_next) {
                                asoc->primary_destination->dest_state &=
                                        ~(SCTP_ADDR_SWITCH_PRIMARY|SCTP_ADDR_DOUBLE_SWITCH);
                        }
                }
        }
        /* Drag along the t3 timeout point so we don't have a problem at wrap */
        if (marking_allowed) {
                asoc->t3timeout_highest_marked = cum_ack;
        }
        tp1 = TAILQ_FIRST(&asoc->sent_queue);
        do {
                if (compare_with_wrap(tp1->rec.data.TSN_seq, cum_ack,
                                      MAX_TSN)) {
                        break;
                }
                if (tp1->sent == SCTP_DATAGRAM_UNSENT) {
                        /* no more sent on list */
                        break;
                }
                tp2 = TAILQ_NEXT(tp1, sctp_next);
                TAILQ_REMOVE(&asoc->sent_queue, tp1, sctp_next);
                if (tp1->data) {
                        sctp_free_bufspace(stcb, asoc, tp1);
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_OUTPUT2) {
                                printf("--total out:%lu total_mbuf_out:%lu\n",
                                       (u_long)asoc->total_output_queue_size,
                                       (u_long)asoc->total_output_mbuf_queue_size);
                        }
#endif

                        sctp_m_freem(tp1->data);
                        if (tp1->flags & SCTP_PR_SCTP_BUFFER) {
                                asoc->sent_queue_cnt_removeable--;
                        }

                }
                tp1->data = NULL;
                asoc->sent_queue_cnt--;
                sctp_free_remote_addr(tp1->whoTo);
                sctppcbinfo.ipi_count_chunk--;
                asoc->chunks_on_out_queue--;

                if ((int)sctppcbinfo.ipi_count_chunk < 0) {
                        panic("Chunk count is going negative");
                }
                SCTP_ZONE_FREE(sctppcbinfo.ipi_zone_chunk, tp1);
                sctppcbinfo.ipi_gencnt_chunk++;
                sctp_sowwakeup(stcb->sctp_ep, stcb->sctp_socket);
                tp1 = tp2;
        } while (tp1 != NULL);


        if (asoc->fast_retran_loss_recovery && accum_moved) {
                if (compare_with_wrap(asoc->last_acked_seq,
                                      asoc->fast_recovery_tsn, MAX_TSN) ||
                    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 we hand
         * fragments in a previous segment. If we
         * had no previous fragments we cannot have
         * a revoke issue.
         */
        if (asoc->saw_sack_with_frags)
                sctp_check_for_revoked(asoc, cum_ack, biggest_tsn_acked);

        if (num_seg)
                asoc->saw_sack_with_frags = 1;
        else
                asoc->saw_sack_with_frags = 0;

        /******************************/
        /* update cwnd                */
        /******************************/
        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                /* if nothing was acked on this destination skip it */
                if (net->net_ack == 0)
                        continue;

                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_NOT_REACHABLE) ==
                            SCTP_ADDR_NOT_REACHABLE) {
                                /* addr came good */
                                net->dest_state &= ~SCTP_ADDR_NOT_REACHABLE;
                                net->dest_state |= SCTP_ADDR_REACHABLE;
                                sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_UP, stcb,
                                                SCTP_RECEIVED_SACK, (void *)net);
                                /* now was it the primary? if so restore */
                                if (net->dest_state & SCTP_ADDR_WAS_PRIMARY) {
                                        sctp_set_primary_addr(stcb, (struct sockaddr *)NULL, net);
                                }
                        }
                }

                if (asoc->fast_retran_loss_recovery &&
                    will_exit_fast_recovery == 0) {
                        /* If we are in loss recovery we skip any cwnd update */
                        sctp_pegs[SCTP_CWND_SKIP]++;
                        goto skip_cwnd_update;
                }
                if (accum_moved) {
                        /* If the cumulative ack moved we can proceed */
                        if (net->cwnd <= net->ssthresh) {
                                /* We are in slow start */
                                if (net->flight_size + net->net_ack >=
                                    net->cwnd ) {
#ifdef SCTP_HIGH_SPEED
                                        sctp_hs_cwnd_increase(net);
#else
                                        if (net->net_ack > net->mtu) {
                                                net->cwnd += net->mtu;
#ifdef SCTP_CWND_LOGGING
                                                sctp_log_cwnd(net, net->mtu,
                                                              SCTP_CWND_LOG_FROM_SS);
#endif

                                        } else {
                                                net->cwnd += net->net_ack;
#ifdef SCTP_CWND_LOGGING
                                                sctp_log_cwnd(net, net->net_ack,
                                                              SCTP_CWND_LOG_FROM_SS);
#endif

                                        }
#endif
                                        sctp_pegs[SCTP_CWND_SS]++;
                                } else {
                                        unsigned int dif;
                                        sctp_pegs[SCTP_CWND_NOUSE_SS]++;
                                        dif = net->cwnd - (net->flight_size +
                                                           net->net_ack);
#ifdef SCTP_CWND_LOGGING
/*                                      sctp_log_cwnd(net, net->net_ack,
                                        SCTP_CWND_LOG_NOADV_SS);*/
#endif
                                        if (dif > sctp_pegs[SCTP_CWND_DIFF_SA]) {
                                                sctp_pegs[SCTP_CWND_DIFF_SA] =
                                                        dif;
                                                sctp_pegs[SCTP_OQS_AT_SS] =
                                                        asoc->total_output_queue_size;
                                                sctp_pegs[SCTP_SQQ_AT_SS] =
                                                        asoc->sent_queue_cnt;
                                                sctp_pegs[SCTP_SQC_AT_SS] =
                                                        asoc->send_queue_cnt;
                                        }
                                }
                        } else {
                                /* We are in congestion avoidance */
                                if (net->flight_size + net->net_ack >=
                                    net->cwnd) {
                                        /*
                                         * add to pba only if we had a cwnd's
                                         * worth (or so) in flight OR the
                                         * burst limit was applied.
                                         */
                                        net->partial_bytes_acked +=
                                                net->net_ack;

                                        /*
                                         * Do we need to increase
                                         * (if pba is > cwnd)?
                                         */
                                        if (net->partial_bytes_acked >=
                                            net->cwnd) {
                                                if (net->cwnd <
                                                    net->partial_bytes_acked) {
                                                        net->partial_bytes_acked -=
                                                                net->cwnd;
                                                } else {
                                                        net->partial_bytes_acked =
                                                                0;
                                                }
                                                net->cwnd += net->mtu;
#ifdef SCTP_CWND_LOGGING
                                                sctp_log_cwnd(net, net->mtu,
                                                              SCTP_CWND_LOG_FROM_CA);
#endif
                                                sctp_pegs[SCTP_CWND_CA]++;
                                        }
                                } else {
                                        unsigned int dif;
                                        sctp_pegs[SCTP_CWND_NOUSE_CA]++;
#ifdef SCTP_CWND_LOGGING
/*                                      sctp_log_cwnd(net, net->net_ack,
                                        SCTP_CWND_LOG_NOADV_CA);
*/
#endif
                                        dif = net->cwnd - (net->flight_size +
                                                           net->net_ack);
                                        if (dif > sctp_pegs[SCTP_CWND_DIFF_CA]) {
                                                sctp_pegs[SCTP_CWND_DIFF_CA] =
                                                        dif;
                                                sctp_pegs[SCTP_OQS_AT_CA] =
                                                        asoc->total_output_queue_size;
                                                sctp_pegs[SCTP_SQQ_AT_CA] =
                                                        asoc->sent_queue_cnt;
                                                sctp_pegs[SCTP_SQC_AT_CA] =
                                                        asoc->send_queue_cnt;

                                        }

                                }
                        }
                } else {
                        sctp_pegs[SCTP_CWND_NOCUM]++;
                }
        skip_cwnd_update:
                /*
                 * NOW, according to Karn's rule do we need to restore the
                 * RTO timer back? Check our net_ack2. If not set then we
                 * have a ambiguity.. i.e. all data ack'd was sent to more
                 * than one place.
                 */

                if (net->net_ack2) {
                        /* restore any doubled timers */
                        net->RTO = ((net->lastsa >> 2) + net->lastsv) >> 1;
                        if (net->RTO < stcb->asoc.minrto) {
                                net->RTO = stcb->asoc.minrto;
                        }
                        if (net->RTO > stcb->asoc.maxrto) {
                                net->RTO = stcb->asoc.maxrto;
                        }
                }
                if (net->cwnd > sctp_pegs[SCTP_MAX_CWND]) {
                        sctp_pegs[SCTP_MAX_CWND] = net->cwnd;
                }
        }
        /**********************************/
        /* Now what about shutdown issues */
        /**********************************/
        some_on_streamwheel = 0;
        if (!TAILQ_EMPTY(&asoc->out_wheel)) {
                /* Check to see if some data queued */
                struct sctp_stream_out *outs;
                TAILQ_FOREACH(outs, &asoc->out_wheel, next_spoke) {
                        if (!TAILQ_EMPTY(&outs->outqueue)) {
                                some_on_streamwheel = 1;
                                break;
                        }
                }
        }
        if (TAILQ_EMPTY(&asoc->send_queue) && TAILQ_EMPTY(&asoc->sent_queue) &&
            some_on_streamwheel == 0) {
                /* nothing left on sendqueue.. consider done */
                /* stop all timers */
#ifdef SCTP_LOG_RWND
                sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                                  asoc->peers_rwnd, 0, 0,  a_rwnd);
#endif
                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;
                }
                /* stop any timers */
                TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                        sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                                        stcb, net);
                        net->flight_size = 0;
                        net->partial_bytes_acked = 0;
                }
                asoc->total_flight = 0;
                asoc->total_flight_count = 0;
                /* clean up */
                if (asoc->state & SCTP_STATE_SHUTDOWN_PENDING) {
                        asoc->state = SCTP_STATE_SHUTDOWN_SENT;
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_OUTPUT4) {
                                printf("%s:%d sends a shutdown\n",
                                       __FILE__,
                                       __LINE__
                                       );
                        }
#endif
                        sctp_send_shutdown(stcb,
                                           stcb->asoc.primary_destination);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWN,
                                         stcb->sctp_ep, stcb, asoc->primary_destination);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNGUARD,
                                         stcb->sctp_ep, stcb, asoc->primary_destination);
                } else if (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED) {
                        asoc->state = SCTP_STATE_SHUTDOWN_ACK_SENT;

                        sctp_send_shutdown_ack(stcb,
                                               stcb->asoc.primary_destination);

                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNACK,
                                         stcb->sctp_ep, stcb, asoc->primary_destination);
                }
                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;
        }
        if ((num_seg > 0) && marking_allowed) {
                sctp_strike_gap_ack_chunks(stcb, asoc, biggest_tsn_acked,
                                           strike_enabled, biggest_tsn_newly_acked, accum_moved);
        }

        /*********************************************/
        /* Here we perform PR-SCTP procedures        */
        /* (section 4.2)                             */
        /*********************************************/
        /* C1. update advancedPeerAckPoint */
        if (compare_with_wrap(cum_ack, asoc->advanced_peer_ack_point, MAX_TSN)) {
                asoc->advanced_peer_ack_point = cum_ack;
        }
        /* C2. try to further move advancedPeerAckPoint ahead */
        if (asoc->peer_supports_prsctp) {
                struct sctp_tmit_chunk *lchk;
                lchk = sctp_try_advance_peer_ack_point(stcb, asoc);
                /* C3. See if we need to send a Fwd-TSN */
                if (compare_with_wrap(asoc->advanced_peer_ack_point, cum_ack,
                                      MAX_TSN)) {
                        /*
                         * ISSUE with ECN, see FWD-TSN processing for notes
                         * on issues that will occur when the ECN NONCE stuff
                         * is put into SCTP for cross checking.
                         */
                        send_forward_tsn(stcb, asoc);

                        /* ECN Nonce: Disable Nonce Sum check when FWD TSN is sent and store resync tsn*/
                        asoc->nonce_sum_check = 0;
                        asoc->nonce_resync_tsn = asoc->advanced_peer_ack_point;
                        if (lchk) {
                                /* Assure a timer is up */
                                sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                                                 stcb->sctp_ep, stcb, lchk->whoTo);
                        }
                }
        }
        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                if (asoc->fast_retran_loss_recovery == 0) {
                        /* out of a RFC2582 Fast recovery window? */
                        if (net->net_ack > 0) {
                                /*
                                 * per section 7.2.3, are there
                                 * any destinations that had a fast
                                 * retransmit to them. If so what we
                                 * need to do is adjust ssthresh and
                                 * cwnd.
                                 */
                                struct sctp_tmit_chunk *lchk;
#ifdef  SCTP_HIGH_SPEED
                                sctp_hs_cwnd_decrease(net);
#else
#ifdef SCTP_CWND_LOGGING
                                int old_cwnd = net->cwnd;
#endif
                                net->ssthresh = net->cwnd / 2;
                                if (net->ssthresh < (net->mtu*2)) {
                                        net->ssthresh = 2 * net->mtu;
                                }
                                net->cwnd = net->ssthresh;
#ifdef SCTP_CWND_LOGGING
                                sctp_log_cwnd(net, (net->cwnd-old_cwnd),
                                              SCTP_CWND_LOG_FROM_FR);
#endif
#endif

                                lchk = TAILQ_FIRST(&asoc->send_queue);

                                net->partial_bytes_acked = 0;
                                /* Turn on fast recovery window */
                                asoc->fast_retran_loss_recovery = 1;
                                if (lchk == NULL) {
                                        /* Mark end of the window */
                                        asoc->fast_recovery_tsn = asoc->sending_seq - 1;
                                } else {
                                        asoc->fast_recovery_tsn = lchk->rec.data.TSN_seq - 1;
                                }


                                /* Disable Nonce Sum Checking and store the resync tsn*/
                                asoc->nonce_sum_check = 0;
                                asoc->nonce_resync_tsn = asoc->fast_recovery_tsn + 1;

                                sctp_timer_stop(SCTP_TIMER_TYPE_SEND,
                                                stcb->sctp_ep, stcb, net);
                                sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                                                 stcb->sctp_ep, stcb, net);
                        }
                } else if (net->net_ack > 0) {
                        /*
                         * Mark a peg that we WOULD have done a cwnd reduction
                         * but RFC2582 prevented this action.
                         */
                        sctp_pegs[SCTP_FR_INAWINDOW]++;
                }
        }


        /******************************************************************
         *  Here we do the stuff with ECN Nonce checking.
         *  We basically check to see if the nonce sum flag was incorrect
         *  or if resynchronization needs to be done. Also if we catch a
         *  misbehaving receiver we give him the kick.
         ******************************************************************/

        if (asoc->ecn_nonce_allowed) {
                if (asoc->nonce_sum_check) {
                        if (nonce_sum_flag != ((asoc->nonce_sum_expect_base + ecn_seg_sums) & SCTP_SACK_NONCE_SUM)) {
                                if (asoc->nonce_wait_for_ecne == 0) {
                                        struct sctp_tmit_chunk *lchk;
                                        lchk = TAILQ_FIRST(&asoc->send_queue);
                                        asoc->nonce_wait_for_ecne = 1;
                                        if (lchk) {
                                                asoc->nonce_wait_tsn = lchk->rec.data.TSN_seq;
                                        } else {
                                                asoc->nonce_wait_tsn = asoc->sending_seq;
                                        }
                                } else {
                                        if (compare_with_wrap(asoc->last_acked_seq, asoc->nonce_wait_tsn, MAX_TSN) ||
                                           (asoc->last_acked_seq == asoc->nonce_wait_tsn)) {
                                                /* Misbehaving peer. We need to react to this guy */
                                                printf("Mis-behaving peer detected\n");
                                                asoc->ecn_allowed = 0;
                                                asoc->ecn_nonce_allowed = 0;
                                        }
                                }
                        }
                } else {
                        /* See if Resynchronization Possible */
                        if (compare_with_wrap(asoc->last_acked_seq, asoc->nonce_resync_tsn, MAX_TSN)) {
                                asoc->nonce_sum_check = 1;
                                /* now we must calculate what the base
                                 * is. We do this based on two things, we know
                                 * the total's for all the segments gap-acked
                                 * in the SACK, its stored in ecn_seg_sums.
                                 * We also know the SACK's nonce sum, its
                                 * in nonce_sum_flag. So we can build a truth
                                 * table to back-calculate the new value of asoc->nonce_sum_expect_base:
                                 *
                                 *   SACK-flag-Value         Seg-Sums              Base
                                 *         0                    0                   0
                                 *         1                    0                   1
                                 *         0                    1                   1
                                 *         1                    1                   0
                                 */
                                asoc->nonce_sum_expect_base = (ecn_seg_sums ^ nonce_sum_flag) & SCTP_SACK_NONCE_SUM;
                        }
                }
        }
        /* 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) &&
            ((compare_with_wrap(asoc->last_acked_seq, asoc->sat_t3_recovery_tsn,
                                MAX_TSN) ||
              (asoc->last_acked_seq == asoc->sat_t3_recovery_tsn)))) {
                /* end satellite t3 loss recovery */
                asoc->sat_t3_loss_recovery = 0;
        }
        /* Adjust and set the new rwnd value */
#ifdef SCTP_LOG_RWND
        sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                          asoc->peers_rwnd,  asoc->total_flight, (asoc->sent_queue_cnt * sctp_peer_chunk_oh), a_rwnd);
#endif

        asoc->peers_rwnd = sctp_sbspace_sub(a_rwnd,
                                            (u_int32_t)(asoc->total_flight + (asoc->sent_queue_cnt * sctp_peer_chunk_oh)));
        if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                /* SWS sender side engages */
                asoc->peers_rwnd = 0;
        }
        /*
         * Now we must setup so we have a timer up for anyone with
         * outstanding data.
         */
        TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                struct sctp_tmit_chunk *chk;
                TAILQ_FOREACH(chk, &asoc->sent_queue, sctp_next) {
                        if (chk->whoTo == net &&
                            (chk->sent < SCTP_DATAGRAM_ACKED ||
                             chk->sent == SCTP_FORWARD_TSN_SKIP)) {
                                /*
                                 * Not ack'ed and still outstanding to this
                                 * destination or marked and must be
                                 * sacked after fwd-tsn sent.
                                 */
                                sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                                                 stcb->sctp_ep, stcb, net);
                                break;
                        }
                }
        }
}

void
sctp_update_acked(struct sctp_tcb *stcb, struct sctp_shutdown_chunk *cp,
    struct sctp_nets *netp, int *abort_flag)
{
        /* Mutate a shutdown into a SACK */
        struct sctp_sack_chunk sack;

        /* Copy cum-ack */
        sack.sack.cum_tsn_ack = cp->cumulative_tsn_ack;
        /* Arrange so a_rwnd does NOT change */
        sack.ch.chunk_type = SCTP_SELECTIVE_ACK;
        sack.ch.chunk_flags = 0;
        sack.ch.chunk_length = ntohs(sizeof(struct sctp_sack_chunk));
        sack.sack.a_rwnd =
            htonl(stcb->asoc.peers_rwnd + stcb->asoc.total_flight);
        /*
         * no gaps in this one. This may cause a temporal view to reneging,
         * but hopefully the second chunk is a true SACK in the packet and
         * will correct this view. One will come soon after no matter what
         * to fix this.
         */
        sack.sack.num_gap_ack_blks = 0;
        sack.sack.num_dup_tsns = 0;
        /* Now call the SACK processor */
        sctp_handle_sack(&sack, stcb, netp, abort_flag);
}

static void
sctp_kick_prsctp_reorder_queue(struct sctp_tcb *stcb,
    struct sctp_stream_in *strmin)
{
        struct sctp_tmit_chunk *chk, *nchk;
        struct sctp_association *asoc;
        int tt;

        asoc = &stcb->asoc;
        tt = strmin->last_sequence_delivered;
        /*
         * First deliver anything prior to and including the stream no that
         * came in
         */
        chk = TAILQ_FIRST(&strmin->inqueue);
        while (chk) {
                nchk = TAILQ_NEXT(chk, sctp_next);
                if (compare_with_wrap(tt, chk->rec.data.stream_seq, MAX_SEQ) ||
                    (tt == chk->rec.data.stream_seq)) {
                        /* this is deliverable now */
                        TAILQ_REMOVE(&strmin->inqueue, chk, sctp_next);
                        /* subtract pending on streams */
                        asoc->size_on_all_streams -= chk->send_size;
                        asoc->cnt_on_all_streams--;
                        /* deliver it to at least the delivery-q */
                        sctp_deliver_data(stcb, &stcb->asoc, chk, 0);
                } else {
                        /* no more delivery now. */
                        break;
                }
                chk = nchk;
        }
        /*
         * now we must deliver things in queue the normal way  if any
         * are now ready.
         */
        tt = strmin->last_sequence_delivered + 1;
        chk = TAILQ_FIRST(&strmin->inqueue);
        while (chk) {
                nchk = TAILQ_NEXT(chk, sctp_next);
                if (tt == chk->rec.data.stream_seq) {
                        /* this is deliverable now */
                        TAILQ_REMOVE(&strmin->inqueue, chk, sctp_next);
                        /* subtract pending on streams */
                        asoc->size_on_all_streams -= chk->send_size;
                        asoc->cnt_on_all_streams--;
                        /* deliver it to at least the delivery-q */
                        strmin->last_sequence_delivered =
                            chk->rec.data.stream_seq;
                        sctp_deliver_data(stcb, &stcb->asoc, chk, 0);
                        tt = strmin->last_sequence_delivered + 1;
                } else {
                        break;
                }
                chk = nchk;
        }

}

void
sctp_handle_forward_tsn(struct sctp_tcb *stcb,
    struct sctp_forward_tsn_chunk *fwd, int *abort_flag)
{
        /*
         * ISSUES that MUST be fixed for ECN! When we are the
         * sender of the forward TSN, when the SACK comes back
         * that acknowledges the FWD-TSN we must reset the
         * NONCE sum to match correctly. This will get quite
         * tricky since we may have sent more data interveneing and
         * must carefully account for what the SACK says on the
         * nonce and any gaps that are reported. This work
         * will NOT be done here, but I note it here since
         * it is really related to PR-SCTP and FWD-TSN's
         */

        /* 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_strseq *stseq;
        struct sctp_association *asoc;
        u_int32_t new_cum_tsn, gap, back_out_htsn;
        unsigned int i, cnt_gone, fwd_sz, cumack_set_flag, m_size;
        struct sctp_stream_in *strm;
        struct sctp_tmit_chunk *chk, *at;

        cumack_set_flag = 0;
        asoc = &stcb->asoc;
        cnt_gone = 0;
        if ((fwd_sz = ntohs(fwd->ch.chunk_length)) < sizeof(struct sctp_forward_tsn_chunk)) {
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("Bad size too small/big fwd-tsn\n");
                }
#endif
                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 (compare_with_wrap(asoc->cumulative_tsn, new_cum_tsn, MAX_TSN) ||
            asoc->cumulative_tsn == new_cum_tsn) {
                /* Already got there ... */
                return;
        }

        back_out_htsn = asoc->highest_tsn_inside_map;
        if (compare_with_wrap(new_cum_tsn, asoc->highest_tsn_inside_map,
            MAX_TSN)) {
                asoc->highest_tsn_inside_map = new_cum_tsn;
#ifdef SCTP_MAP_LOGGING
                        sctp_log_map(0, 0, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
#endif
        }
        /*
         * now we know the new TSN is more advanced, let's find the
         * actual gap
         */
        if ((compare_with_wrap(new_cum_tsn, asoc->mapping_array_base_tsn,
                               MAX_TSN)) ||
             (new_cum_tsn == asoc->mapping_array_base_tsn)) {
                gap = new_cum_tsn - asoc->mapping_array_base_tsn;
        } else {
                /* try to prevent underflow here */
                gap = new_cum_tsn + (MAX_TSN - asoc->mapping_array_base_tsn) + 1;
        }

        if (gap >= m_size) {
                asoc->highest_tsn_inside_map = back_out_htsn;
                if ((long)gap > sctp_sbspace(&stcb->sctp_socket->so_rcv)) {
                        /*
                         * out of range (of single byte chunks in the rwnd I
                         * give out)
                         * too questionable. better to drop it silently
                         */
                        return;
                }
                if (asoc->highest_tsn_inside_map >
                    asoc->mapping_array_base_tsn) {
                        gap = asoc->highest_tsn_inside_map -
                            asoc->mapping_array_base_tsn;
                } else {
                        gap = asoc->highest_tsn_inside_map +
                            (MAX_TSN - asoc->mapping_array_base_tsn) + 1;
                }
                cumack_set_flag = 1;
        }
        for (i = 0; i <= gap; i++) {
                SCTP_SET_TSN_PRESENT(asoc->mapping_array, i);
        }
        /*
         * Now after marking all, slide thing forward but no
         * sack please.
         */
        sctp_sack_check(stcb, 0, 0, abort_flag);
        if (*abort_flag)
                return;

        if (cumack_set_flag) {
                /*
                 * fwd-tsn went outside my gap array - not a
                 * common occurrence. Do the same thing we
                 * do when a cookie-echo arrives.
                 */
                asoc->highest_tsn_inside_map =  new_cum_tsn - 1;
                asoc->mapping_array_base_tsn = new_cum_tsn;
                asoc->cumulative_tsn = asoc->highest_tsn_inside_map;
#ifdef SCTP_MAP_LOGGING
                sctp_log_map(0, 3, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
#endif
                asoc->last_echo_tsn = asoc->highest_tsn_inside_map;
        }
        /*************************************************************/
        /* 2. Clear up re-assembly queue                             */
        /*************************************************************/

        /*
         * First service it if pd-api is up, just in case we can
         * progress it forward
         */
        if (asoc->fragmented_delivery_inprogress) {
                sctp_service_reassembly(stcb, asoc, 0);
        }
        if (!TAILQ_EMPTY(&asoc->reasmqueue)) {
                /* For each one on here see if we need to toss it */
                /*
                 * For now large messages held on the reasmqueue 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.
                 */
                chk = TAILQ_FIRST(&asoc->reasmqueue);
                while (chk) {
                        at = TAILQ_NEXT(chk, sctp_next);
                        if (compare_with_wrap(asoc->cumulative_tsn,
                            chk->rec.data.TSN_seq, MAX_TSN) ||
                            asoc->cumulative_tsn == chk->rec.data.TSN_seq) {
                                /* It needs to be tossed */
                                TAILQ_REMOVE(&asoc->reasmqueue, chk, sctp_next);
                                if (compare_with_wrap(chk->rec.data.TSN_seq,
                                    asoc->tsn_last_delivered, MAX_TSN)) {
                                        asoc->tsn_last_delivered =
                                            chk->rec.data.TSN_seq;
                                        asoc->str_of_pdapi =
                                            chk->rec.data.stream_number;
                                        asoc->ssn_of_pdapi =
                                            chk->rec.data.stream_seq;
                                        asoc->fragment_flags =
                                            chk->rec.data.rcv_flags;
                                }
                                asoc->size_on_reasm_queue -= chk->send_size;
                                asoc->cnt_on_reasm_queue--;
                                cnt_gone++;

                                /* Clear up any stream problem */
                                if ((chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) !=
                                    SCTP_DATA_UNORDERED &&
                                    (compare_with_wrap(chk->rec.data.stream_seq,
                                    asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered,
                                    MAX_SEQ))) {
                                        /*
                                         * We must dump forward this streams
                                         * sequence number if the chunk is not
                                         * unordered that is being skipped.
                                         * There is a chance that if the peer
                                         * does not include the last fragment
                                         * in its FWD-TSN we WILL have a problem
                                         * here since you would have a partial
                                         * chunk in queue that may not be
                                         * deliverable.
                                         * Also if a Partial delivery API as
                                         * started the user may get a partial
                                         * chunk. The next read returning a new
                                         * chunk... really ugly but I see no way
                                         * around it! Maybe a notify??
                                         */
                                        asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered =
                                            chk->rec.data.stream_seq;
                                }
                                sctp_m_freem(chk->data);
                                chk->data = NULL;
                                sctp_free_remote_addr(chk->whoTo);
                                SCTP_ZONE_FREE(sctppcbinfo.ipi_zone_chunk, chk);
                                sctppcbinfo.ipi_count_chunk--;
                                if ((int)sctppcbinfo.ipi_count_chunk < 0) {
                                        panic("Chunk count is negative");
                                }
                                sctppcbinfo.ipi_gencnt_chunk++;
                        } else {
                                /*
                                 * Ok we have gone beyond the end of the
                                 * fwd-tsn's mark. Some checks...
                                 */
                                if ((asoc->fragmented_delivery_inprogress) &&
                                    (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG)) {
                                        /* Special case PD-API is up and what we fwd-tsn'
                                         * over includes one that had the LAST_FRAG. We
                                         * no longer need to do the PD-API.
                                         */
                                        asoc->fragmented_delivery_inprogress = 0;
                                        sctp_ulp_notify(SCTP_NOTIFY_PARTIAL_DELVIERY_INDICATION,
                                            stcb, SCTP_PARTIAL_DELIVERY_ABORTED, (void *)NULL);

                                }
                                break;
                        }
                        chk = at;
                }
        }
        if (asoc->fragmented_delivery_inprogress) {
                /*
                 * Ok we removed cnt_gone chunks in the PD-API queue that
                 * were being delivered. So now we must turn off the
                 * flag.
                 */
                sctp_ulp_notify(SCTP_NOTIFY_PARTIAL_DELVIERY_INDICATION,
                    stcb, SCTP_PARTIAL_DELIVERY_ABORTED, (void *)NULL);
                asoc->fragmented_delivery_inprogress = 0;
        }
        /*************************************************************/
        /* 3. Update the PR-stream re-ordering queues                */
        /*************************************************************/
        stseq = (struct sctp_strseq *)((vaddr_t)fwd + sizeof(*fwd));
        fwd_sz -= sizeof(*fwd);
        {
                /* New method. */
                int num_str;
                num_str = fwd_sz/sizeof(struct sctp_strseq);
#ifdef SCTP_DEBUG
                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                        printf("Using NEW method, %d strseq's reported in FWD-TSN\n",
                            num_str);
                }
#endif
                for (i = 0; i < num_str; i++) {
                        u_int16_t st;
#if 0
                        unsigned char *xx;
                        /* Convert */
                        xx = (unsigned char *)&stseq[i];
#endif
                        st = ntohs(stseq[i].stream);
                        stseq[i].stream = st;
                        st = ntohs(stseq[i].sequence);
                        stseq[i].sequence = st;
                        /* now process */
                        if (stseq[i].stream > asoc->streamincnt) {
#ifdef SCTP_DEBUG
                                if (sctp_debug_on & SCTP_DEBUG_INDATA1) {
                                        printf("Bogus stream number %d "
                                            "streamincnt is %d\n",
                                            stseq[i].stream, asoc->streamincnt);
                                }
#endif
                                /*
                                 * It is arguable if we should continue. Since
                                 * the peer sent bogus stream info we may be in
                                 * deep trouble..
                                 * a return may be a better choice?
                                 */
                                continue;
                        }
                        strm = &asoc->strmin[stseq[i].stream];
                        if (compare_with_wrap(stseq[i].sequence,
                            strm->last_sequence_delivered, MAX_SEQ)) {
                                /* Update the sequence number */
                                strm->last_sequence_delivered =
                                    stseq[i].sequence;
                        }
                        /* now kick the stream the new way */
                        sctp_kick_prsctp_reorder_queue(stcb, strm);
                }
        }
}