sys/netinet6/sctp6_usrreq.c

root/sys/netinet6/sctp6_usrreq.c
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
 * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
 * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * a) Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * b) Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the distribution.
 *
 * c) Neither the name of Cisco Systems, Inc. nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <netinet/sctp_os.h>
#ifdef INET6
#include <sys/proc.h>
#include <netinet/sctp_pcb.h>
#include <netinet/sctp_header.h>
#include <netinet/sctp_var.h>
#include <netinet6/sctp6_var.h>
#include <netinet/sctp_sysctl.h>
#include <netinet/sctp_output.h>
#include <netinet/sctp_uio.h>
#include <netinet/sctp_asconf.h>
#include <netinet/sctputil.h>
#include <netinet/sctp_indata.h>
#include <netinet/sctp_timer.h>
#include <netinet/sctp_auth.h>
#include <netinet/sctp_input.h>
#include <netinet/sctp_output.h>
#include <netinet/sctp_bsd_addr.h>
#include <netinet/sctp_crc32.h>
#include <netinet/icmp6.h>
#include <netinet/udp.h>

int
sctp6_input_with_port(struct mbuf **i_pak, int *offp, uint16_t port)
{
        struct mbuf *m;
        int iphlen;
        uint32_t vrf_id;
        uint8_t ecn_bits;
        struct sockaddr_in6 src, dst;
        struct ip6_hdr *ip6;
        struct sctphdr *sh;
        struct sctp_chunkhdr *ch;
        int length, offset;
        uint8_t compute_crc;
        uint32_t mflowid;
        uint8_t mflowtype;
        uint16_t fibnum;

        iphlen = *offp;
        if (SCTP_GET_PKT_VRFID(*i_pak, vrf_id)) {
                SCTP_RELEASE_PKT(*i_pak);
                return (IPPROTO_DONE);
        }
        m = SCTP_HEADER_TO_CHAIN(*i_pak);
#ifdef SCTP_MBUF_LOGGING
        /* Log in any input mbufs */
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MBUF_LOGGING_ENABLE) {
                sctp_log_mbc(m, SCTP_MBUF_INPUT);
        }
#endif
#ifdef SCTP_PACKET_LOGGING
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LAST_PACKET_TRACING) {
                sctp_packet_log(m);
        }
#endif
        SCTPDBG(SCTP_DEBUG_CRCOFFLOAD,
            "sctp6_input(): Packet of length %d received on %s with csum_flags 0x%b.\n",
            m->m_pkthdr.len,
            if_name(m->m_pkthdr.rcvif),
            (int)m->m_pkthdr.csum_flags, CSUM_BITS);
        mflowid = m->m_pkthdr.flowid;
        mflowtype = M_HASHTYPE_GET(m);
        fibnum = M_GETFIB(m);
        SCTP_STAT_INCR(sctps_recvpackets);
        SCTP_STAT_INCR_COUNTER64(sctps_inpackets);
        /* Get IP, SCTP, and first chunk header together in the first mbuf. */
        offset = iphlen + sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr);
        if (m->m_len < offset) {
                m = m_pullup(m, offset);
                if (m == NULL) {
                        SCTP_STAT_INCR(sctps_hdrops);
                        return (IPPROTO_DONE);
                }
        }
        ip6 = mtod(m, struct ip6_hdr *);
        sh = (struct sctphdr *)(mtod(m, caddr_t)+iphlen);
        ch = (struct sctp_chunkhdr *)((caddr_t)sh + sizeof(struct sctphdr));
        offset -= sizeof(struct sctp_chunkhdr);
        memset(&src, 0, sizeof(struct sockaddr_in6));
        src.sin6_family = AF_INET6;
        src.sin6_len = sizeof(struct sockaddr_in6);
        src.sin6_port = sh->src_port;
        src.sin6_addr = ip6->ip6_src;
        if (in6_setscope(&src.sin6_addr, m->m_pkthdr.rcvif, NULL) != 0) {
                goto out;
        }
        memset(&dst, 0, sizeof(struct sockaddr_in6));
        dst.sin6_family = AF_INET6;
        dst.sin6_len = sizeof(struct sockaddr_in6);
        dst.sin6_port = sh->dest_port;
        dst.sin6_addr = ip6->ip6_dst;
        if (in6_setscope(&dst.sin6_addr, m->m_pkthdr.rcvif, NULL) != 0) {
                goto out;
        }
        length = ntohs(ip6->ip6_plen) + iphlen;
        /* Validate mbuf chain length with IP payload length. */
        if (SCTP_HEADER_LEN(m) != length) {
                SCTPDBG(SCTP_DEBUG_INPUT1,
                    "sctp6_input() length:%d reported length:%d\n", length, SCTP_HEADER_LEN(m));
                SCTP_STAT_INCR(sctps_hdrops);
                goto out;
        }
        if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
                goto out;
        }
        ecn_bits = IPV6_TRAFFIC_CLASS(ip6);
        if (m->m_pkthdr.csum_flags & (CSUM_SCTP_VALID | CSUM_IP6_SCTP)) {
                /*
                 * Packet with CSUM_IP6_SCTP were sent from local host using
                 * checksum offloading. Checksum not required.
                 */
                SCTP_STAT_INCR(sctps_recvhwcrc);
                compute_crc = 0;
        } else {
                SCTP_STAT_INCR(sctps_recvswcrc);
                compute_crc = 1;
        }
        sctp_common_input_processing(&m, iphlen, offset, length,
            (struct sockaddr *)&src,
            (struct sockaddr *)&dst,
            sh, ch,
            compute_crc,
            ecn_bits,
            mflowtype, mflowid, fibnum,
            vrf_id, port);
out:
        if (m) {
                sctp_m_freem(m);
        }
        return (IPPROTO_DONE);
}

int
sctp6_input(struct mbuf **i_pak, int *offp, int proto SCTP_UNUSED)
{
        return (sctp6_input_with_port(i_pak, offp, 0));
}

void
sctp6_notify(struct sctp_inpcb *inp,
    struct sctp_tcb *stcb,
    struct sctp_nets *net,
    uint8_t icmp6_type,
    uint8_t icmp6_code,
    uint32_t next_mtu)
{
        int timer_stopped;

        switch (icmp6_type) {
        case ICMP6_DST_UNREACH:
                if ((icmp6_code == ICMP6_DST_UNREACH_NOROUTE) ||
                    (icmp6_code == ICMP6_DST_UNREACH_ADMIN) ||
                    (icmp6_code == ICMP6_DST_UNREACH_BEYONDSCOPE) ||
                    (icmp6_code == ICMP6_DST_UNREACH_ADDR)) {
                        /* Mark the net unreachable. */
                        if (net->dest_state & SCTP_ADDR_REACHABLE) {
                                /* Ok that destination is not reachable */
                                net->dest_state &= ~SCTP_ADDR_REACHABLE;
                                net->dest_state &= ~SCTP_ADDR_PF;
                                sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_DOWN,
                                    stcb, 0, (void *)net, SCTP_SO_NOT_LOCKED);
                        }
                }
                SCTP_TCB_UNLOCK(stcb);
                break;
        case ICMP6_PARAM_PROB:
                /* Treat it like an ABORT. */
                if (icmp6_code == ICMP6_PARAMPROB_NEXTHEADER) {
                        sctp_abort_notification(stcb, true, false, 0, NULL, SCTP_SO_NOT_LOCKED);
                        (void)sctp_free_assoc(inp, stcb, SCTP_NORMAL_PROC,
                            SCTP_FROM_SCTP_USRREQ + SCTP_LOC_2);
                } else {
                        SCTP_TCB_UNLOCK(stcb);
                }
                break;
        case ICMP6_PACKET_TOO_BIG:
                if (net->dest_state & SCTP_ADDR_NO_PMTUD) {
                        SCTP_TCB_UNLOCK(stcb);
                        break;
                }
                if (SCTP_OS_TIMER_PENDING(&net->pmtu_timer.timer)) {
                        timer_stopped = 1;
                        sctp_timer_stop(SCTP_TIMER_TYPE_PATHMTURAISE, inp, stcb, net,
                            SCTP_FROM_SCTP_USRREQ + SCTP_LOC_1);
                } else {
                        timer_stopped = 0;
                }
                /* Update the path MTU. */
                if (net->port) {
                        next_mtu -= sizeof(struct udphdr);
                }
                if (net->mtu > next_mtu) {
                        net->mtu = next_mtu;
                        if (net->port) {
                                sctp_hc_set_mtu(&net->ro._l_addr, inp->fibnum, next_mtu + sizeof(struct udphdr));
                        } else {
                                sctp_hc_set_mtu(&net->ro._l_addr, inp->fibnum, next_mtu);
                        }
                }
                /* Update the association MTU */
                if (stcb->asoc.smallest_mtu > next_mtu) {
                        sctp_pathmtu_adjustment(stcb, next_mtu, true);
                }
                /* Finally, start the PMTU timer if it was running before. */
                if (timer_stopped) {
                        sctp_timer_start(SCTP_TIMER_TYPE_PATHMTURAISE, inp, stcb, net);
                }
                SCTP_TCB_UNLOCK(stcb);
                break;
        default:
                SCTP_TCB_UNLOCK(stcb);
                break;
        }
}

void
sctp6_ctlinput(struct ip6ctlparam *ip6cp)
{
        struct sctp_inpcb *inp;
        struct sctp_tcb *stcb;
        struct sctp_nets *net;
        struct sctphdr sh;
        struct sockaddr_in6 src, dst;

        if (icmp6_errmap(ip6cp->ip6c_icmp6) == 0) {
                return;
        }

        /*
         * Check if we can safely examine the ports and the verification tag
         * of the SCTP common header.
         */
        if (ip6cp->ip6c_m->m_pkthdr.len <
            (int32_t)(ip6cp->ip6c_off + offsetof(struct sctphdr, checksum))) {
                return;
        }

        /* Copy out the port numbers and the verification tag. */
        memset(&sh, 0, sizeof(sh));
        m_copydata(ip6cp->ip6c_m,
            ip6cp->ip6c_off,
            sizeof(uint16_t) + sizeof(uint16_t) + sizeof(uint32_t),
            (caddr_t)&sh);
        memset(&src, 0, sizeof(struct sockaddr_in6));
        src.sin6_family = AF_INET6;
        src.sin6_len = sizeof(struct sockaddr_in6);
        src.sin6_port = sh.src_port;
        src.sin6_addr = ip6cp->ip6c_ip6->ip6_src;
        if (in6_setscope(&src.sin6_addr, ip6cp->ip6c_m->m_pkthdr.rcvif, NULL) != 0) {
                return;
        }
        memset(&dst, 0, sizeof(struct sockaddr_in6));
        dst.sin6_family = AF_INET6;
        dst.sin6_len = sizeof(struct sockaddr_in6);
        dst.sin6_port = sh.dest_port;
        dst.sin6_addr = ip6cp->ip6c_ip6->ip6_dst;
        if (in6_setscope(&dst.sin6_addr, ip6cp->ip6c_m->m_pkthdr.rcvif, NULL) != 0) {
                return;
        }
        inp = NULL;
        net = NULL;
        stcb = sctp_findassociation_addr_sa((struct sockaddr *)&dst,
            (struct sockaddr *)&src,
            &inp, &net, 1, SCTP_DEFAULT_VRFID);
        if ((stcb != NULL) &&
            (net != NULL) &&
            (inp != NULL)) {
                /* Check the verification tag */
                if (ntohl(sh.v_tag) != 0) {
                        /*
                         * This must be the verification tag used for
                         * sending out packets. We don't consider packets
                         * reflecting the verification tag.
                         */
                        if (ntohl(sh.v_tag) != stcb->asoc.peer_vtag) {
                                SCTP_TCB_UNLOCK(stcb);
                                return;
                        }
                } else {
                        if (ip6cp->ip6c_m->m_pkthdr.len >=
                            ip6cp->ip6c_off + sizeof(struct sctphdr) +
                            sizeof(struct sctp_chunkhdr) +
                            offsetof(struct sctp_init, a_rwnd)) {
                                /*
                                 * In this case we can check if we got an
                                 * INIT chunk and if the initiate tag
                                 * matches.
                                 */
                                uint32_t initiate_tag;
                                uint8_t chunk_type;

                                m_copydata(ip6cp->ip6c_m,
                                    ip6cp->ip6c_off +
                                    sizeof(struct sctphdr),
                                    sizeof(uint8_t),
                                    (caddr_t)&chunk_type);
                                m_copydata(ip6cp->ip6c_m,
                                    ip6cp->ip6c_off +
                                    sizeof(struct sctphdr) +
                                    sizeof(struct sctp_chunkhdr),
                                    sizeof(uint32_t),
                                    (caddr_t)&initiate_tag);
                                if ((chunk_type != SCTP_INITIATION) ||
                                    (ntohl(initiate_tag) != stcb->asoc.my_vtag)) {
                                        SCTP_TCB_UNLOCK(stcb);
                                        return;
                                }
                        } else {
                                SCTP_TCB_UNLOCK(stcb);
                                return;
                        }
                }
                sctp6_notify(inp, stcb, net,
                    ip6cp->ip6c_icmp6->icmp6_type,
                    ip6cp->ip6c_icmp6->icmp6_code,
                    ntohl(ip6cp->ip6c_icmp6->icmp6_mtu));
        } else {
                if ((stcb == NULL) && (inp != NULL)) {
                        /* reduce inp's ref-count */
                        SCTP_INP_WLOCK(inp);
                        SCTP_INP_DECR_REF(inp);
                        SCTP_INP_WUNLOCK(inp);
                }
                if (stcb) {
                        SCTP_TCB_UNLOCK(stcb);
                }
        }
}

/*
 * this routine can probably be collapsed into the one in sctp_userreq.c
 * since they do the same thing and now we lookup with a sockaddr
 */
static int
sctp6_getcred(SYSCTL_HANDLER_ARGS)
{
        struct xucred xuc;
        struct sockaddr_in6 addrs[2];
        struct sctp_inpcb *inp;
        struct sctp_nets *net;
        struct sctp_tcb *stcb;
        int error;
        uint32_t vrf_id;

        vrf_id = SCTP_DEFAULT_VRFID;

        if (req->newptr == NULL)
                return (EINVAL);
        error = priv_check(req->td, PRIV_NETINET_GETCRED);
        if (error)
                return (error);

        if (req->newlen != sizeof(addrs)) {
                SCTP_LTRACE_ERR_RET(NULL, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                return (EINVAL);
        }
        if (req->oldlen != sizeof(struct ucred)) {
                SCTP_LTRACE_ERR_RET(NULL, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                return (EINVAL);
        }
        error = SYSCTL_IN(req, addrs, sizeof(addrs));
        if (error)
                return (error);

        stcb = sctp_findassociation_addr_sa(sin6tosa(&addrs[1]),
            sin6tosa(&addrs[0]),
            &inp, &net, 1, vrf_id);
        if (stcb == NULL || inp == NULL || inp->sctp_socket == NULL) {
                if ((inp != NULL) && (stcb == NULL)) {
                        /* reduce ref-count */
                        SCTP_INP_WLOCK(inp);
                        SCTP_INP_DECR_REF(inp);
                        goto cred_can_cont;
                }
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, ENOENT);
                error = ENOENT;
                goto out;
        }
        SCTP_TCB_UNLOCK(stcb);
        /*
         * We use the write lock here, only since in the error leg we need
         * it. If we used RLOCK, then we would have to
         * wlock/decr/unlock/rlock. Which in theory could create a hole.
         * Better to use higher wlock.
         */
        SCTP_INP_WLOCK(inp);
cred_can_cont:
        error = cr_canseesocket(req->td->td_ucred, inp->sctp_socket);
        if (error) {
                SCTP_INP_WUNLOCK(inp);
                goto out;
        }
        cru2x(inp->sctp_socket->so_cred, &xuc);
        SCTP_INP_WUNLOCK(inp);
        error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
out:
        return (error);
}

SYSCTL_PROC(_net_inet6_sctp6, OID_AUTO, getcred,
    CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
    0, 0, sctp6_getcred, "S,ucred",
    "Get the ucred of a SCTP6 connection");

static int
sctp6_attach(struct socket *so, int proto SCTP_UNUSED, struct thread *p SCTP_UNUSED)
{
        int error;
        struct sctp_inpcb *inp;
        uint32_t vrf_id = SCTP_DEFAULT_VRFID;

        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp != NULL) {
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                return (EINVAL);
        }

        if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
                error = SCTP_SORESERVE(so, SCTP_BASE_SYSCTL(sctp_sendspace), SCTP_BASE_SYSCTL(sctp_recvspace));
                if (error)
                        return (error);
        }
        error = sctp_inpcb_alloc(so, vrf_id);
        if (error)
                return (error);
        inp = (struct sctp_inpcb *)so->so_pcb;
        SCTP_INP_WLOCK(inp);
        inp->sctp_flags |= SCTP_PCB_FLAGS_BOUND_V6;     /* I'm v6! */

        inp->ip_inp.inp.inp_vflag |= INP_IPV6;
        inp->ip_inp.inp.in6p_hops = -1; /* use kernel default */
        inp->ip_inp.inp.in6p_cksum = -1;        /* just to be sure */
#ifdef INET
        /*
         * XXX: ugly!! IPv4 TTL initialization is necessary for an IPv6
         * socket as well, because the socket may be bound to an IPv6
         * wildcard address, which may match an IPv4-mapped IPv6 address.
         */
        inp->ip_inp.inp.inp_ip_ttl = MODULE_GLOBAL(ip_defttl);
#endif
        SCTP_INP_WUNLOCK(inp);
        return (0);
}

static int
sctp6_bind(struct socket *so, struct sockaddr *addr, struct thread *p)
{
        struct sctp_inpcb *inp;
        int error;
        u_char vflagsav;

        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp == NULL) {
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                return (EINVAL);
        }

        if (addr) {
                switch (addr->sa_family) {
#ifdef INET
                case AF_INET:
                        if (addr->sa_len != sizeof(struct sockaddr_in)) {
                                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                                return (EINVAL);
                        }
                        break;
#endif
#ifdef INET6
                case AF_INET6:
                        if (addr->sa_len != sizeof(struct sockaddr_in6)) {
                                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                                return (EINVAL);
                        }
                        break;
#endif
                default:
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                        return (EINVAL);
                }
        }
        vflagsav = inp->ip_inp.inp.inp_vflag;
        inp->ip_inp.inp.inp_vflag &= ~INP_IPV4;
        inp->ip_inp.inp.inp_vflag |= INP_IPV6;
        if ((addr != NULL) && (SCTP_IPV6_V6ONLY(inp) == 0)) {
                switch (addr->sa_family) {
#ifdef INET
                case AF_INET:
                        /* binding v4 addr to v6 socket, so reset flags */
                        inp->ip_inp.inp.inp_vflag |= INP_IPV4;
                        inp->ip_inp.inp.inp_vflag &= ~INP_IPV6;
                        break;
#endif
#ifdef INET6
                case AF_INET6:
                        {
                                struct sockaddr_in6 *sin6_p;

                                sin6_p = (struct sockaddr_in6 *)addr;

                                if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr)) {
                                        inp->ip_inp.inp.inp_vflag |= INP_IPV4;
                                }
#ifdef INET
                                if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
                                        struct sockaddr_in sin;

                                        in6_sin6_2_sin(&sin, sin6_p);
                                        inp->ip_inp.inp.inp_vflag |= INP_IPV4;
                                        inp->ip_inp.inp.inp_vflag &= ~INP_IPV6;
                                        error = sctp_inpcb_bind(so, (struct sockaddr *)&sin, NULL, p);
                                        goto out;
                                }
#endif
                                break;
                        }
#endif
                default:
                        break;
                }
        } else if (addr != NULL) {
                struct sockaddr_in6 *sin6_p;

                /* IPV6_V6ONLY socket */
#ifdef INET
                if (addr->sa_family == AF_INET) {
                        /* can't bind v4 addr to v6 only socket! */
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                        error = EINVAL;
                        goto out;
                }
#endif
                sin6_p = (struct sockaddr_in6 *)addr;

                if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
                        /* can't bind v4-mapped addrs either! */
                        /* NOTE: we don't support SIIT */
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                        error = EINVAL;
                        goto out;
                }
        }
        error = sctp_inpcb_bind(so, addr, NULL, p);
out:
        if (error != 0)
                inp->ip_inp.inp.inp_vflag = vflagsav;
        return (error);
}

static void
sctp6_close(struct socket *so)
{
        sctp_close(so);
}

/* This could be made common with sctp_detach() since they are identical */

int
sctp_sendm(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
    struct mbuf *control, struct thread *p);

static int
sctp6_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
    struct mbuf *control, struct thread *p)
{
        struct sctp_inpcb *inp;

#ifdef INET
        struct sockaddr_in6 *sin6;
#endif                          /* INET */
        /* No SPL needed since sctp_output does this */

        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp == NULL) {
                if (control) {
                        SCTP_RELEASE_PKT(control);
                        control = NULL;
                }
                SCTP_RELEASE_PKT(m);
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                return (EINVAL);
        }
        /*
         * For the TCP model we may get a NULL addr, if we are a connected
         * socket thats ok.
         */
        if ((inp->sctp_flags & SCTP_PCB_FLAGS_CONNECTED) &&
            (addr == NULL)) {
                goto connected_type;
        }
        if (addr == NULL) {
                SCTP_RELEASE_PKT(m);
                if (control) {
                        SCTP_RELEASE_PKT(control);
                        control = NULL;
                }
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EDESTADDRREQ);
                return (EDESTADDRREQ);
        }
        switch (addr->sa_family) {
#ifdef INET
        case AF_INET:
                if (addr->sa_len != sizeof(struct sockaddr_in)) {
                        if (control) {
                                SCTP_RELEASE_PKT(control);
                                control = NULL;
                        }
                        SCTP_RELEASE_PKT(m);
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                        return (EINVAL);
                }
                break;
#endif
#ifdef INET6
        case AF_INET6:
                if (addr->sa_len != sizeof(struct sockaddr_in6)) {
                        if (control) {
                                SCTP_RELEASE_PKT(control);
                                control = NULL;
                        }
                        SCTP_RELEASE_PKT(m);
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                        return (EINVAL);
                }
                break;
#endif
        default:
                if (control) {
                        SCTP_RELEASE_PKT(control);
                        control = NULL;
                }
                SCTP_RELEASE_PKT(m);
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                return (EINVAL);
        }
#ifdef INET
        sin6 = (struct sockaddr_in6 *)addr;
        if (SCTP_IPV6_V6ONLY(inp)) {
                /*
                 * if IPV6_V6ONLY flag, we discard datagrams destined to a
                 * v4 addr or v4-mapped addr
                 */
                if (addr->sa_family == AF_INET) {
                        if (control) {
                                SCTP_RELEASE_PKT(control);
                                control = NULL;
                        }
                        SCTP_RELEASE_PKT(m);
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                        return (EINVAL);
                }
                if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                        if (control) {
                                SCTP_RELEASE_PKT(control);
                                control = NULL;
                        }
                        SCTP_RELEASE_PKT(m);
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                        return (EINVAL);
                }
        }
        if ((addr->sa_family == AF_INET6) &&
            IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                struct sockaddr_in sin;

                /* convert v4-mapped into v4 addr and send */
                in6_sin6_2_sin(&sin, sin6);
                return (sctp_sendm(so, flags, m, (struct sockaddr *)&sin, control, p));
        }
#endif                          /* INET */
connected_type:
        /* now what about control */
        if (control) {
                if (inp->control) {
                        SCTP_PRINTF("huh? control set?\n");
                        SCTP_RELEASE_PKT(inp->control);
                        inp->control = NULL;
                }
                inp->control = control;
        }
        /* Place the data */
        if (inp->pkt) {
                SCTP_BUF_NEXT(inp->pkt_last) = m;
                inp->pkt_last = m;
        } else {
                inp->pkt_last = inp->pkt = m;
        }
        if (
        /* FreeBSD and MacOSX uses a flag passed */
            ((flags & PRUS_MORETOCOME) == 0)
            ) {
                /*
                 * note with the current version this code will only be used
                 * by OpenBSD, NetBSD and FreeBSD have methods for
                 * re-defining sosend() to use sctp_sosend().  One can
                 * optionally switch back to this code (by changing back the
                 * definitions but this is not advisable.
                 */
                struct epoch_tracker et;
                int ret;

                NET_EPOCH_ENTER(et);
                ret = sctp_output(inp, inp->pkt, addr, inp->control, p, flags);
                NET_EPOCH_EXIT(et);
                inp->pkt = NULL;
                inp->control = NULL;
                return (ret);
        } else {
                return (0);
        }
}

static int
sctp6_connect(struct socket *so, struct sockaddr *addr, struct thread *p)
{
        struct epoch_tracker et;
        uint32_t vrf_id;
        int error = 0;
        struct sctp_inpcb *inp;
        struct sctp_tcb *stcb;
#ifdef INET
        struct sockaddr_in6 *sin6;
        union sctp_sockstore store;
#endif

        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp == NULL) {
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, ECONNRESET);
                return (ECONNRESET);    /* I made the same as TCP since we are
                                         * not setup? */
        }
        if (addr == NULL) {
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                return (EINVAL);
        }
        switch (addr->sa_family) {
#ifdef INET
        case AF_INET:
                if (addr->sa_len != sizeof(struct sockaddr_in)) {
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                        return (EINVAL);
                }
                break;
#endif
#ifdef INET6
        case AF_INET6:
                if (addr->sa_len != sizeof(struct sockaddr_in6)) {
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                        return (EINVAL);
                }
                break;
#endif
        default:
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                return (EINVAL);
        }

        vrf_id = inp->def_vrf_id;
        SCTP_ASOC_CREATE_LOCK(inp);
        SCTP_INP_RLOCK(inp);
        if ((inp->sctp_flags & SCTP_PCB_FLAGS_UNBOUND) ==
            SCTP_PCB_FLAGS_UNBOUND) {
                /* Bind a ephemeral port */
                SCTP_INP_RUNLOCK(inp);
                error = sctp6_bind(so, NULL, p);
                if (error) {
                        SCTP_ASOC_CREATE_UNLOCK(inp);

                        return (error);
                }
                SCTP_INP_RLOCK(inp);
        }
        if ((inp->sctp_flags & SCTP_PCB_FLAGS_TCPTYPE) &&
            (inp->sctp_flags & SCTP_PCB_FLAGS_CONNECTED)) {
                /* We are already connected AND the TCP model */
                SCTP_INP_RUNLOCK(inp);
                SCTP_ASOC_CREATE_UNLOCK(inp);
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EADDRINUSE);
                return (EADDRINUSE);
        }
#ifdef INET
        sin6 = (struct sockaddr_in6 *)addr;
        if (SCTP_IPV6_V6ONLY(inp)) {
                /*
                 * if IPV6_V6ONLY flag, ignore connections destined to a v4
                 * addr or v4-mapped addr
                 */
                if (addr->sa_family == AF_INET) {
                        SCTP_INP_RUNLOCK(inp);
                        SCTP_ASOC_CREATE_UNLOCK(inp);
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                        return (EINVAL);
                }
                if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                        SCTP_INP_RUNLOCK(inp);
                        SCTP_ASOC_CREATE_UNLOCK(inp);
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                        return (EINVAL);
                }
        }
        if ((addr->sa_family == AF_INET6) &&
            IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                /* convert v4-mapped into v4 addr */
                in6_sin6_2_sin(&store.sin, sin6);
                addr = &store.sa;
        }
#endif                          /* INET */
        /* Now do we connect? */
        if (inp->sctp_flags & SCTP_PCB_FLAGS_CONNECTED) {
                stcb = LIST_FIRST(&inp->sctp_asoc_list);
                if (stcb) {
                        SCTP_TCB_LOCK(stcb);
                }
                SCTP_INP_RUNLOCK(inp);
        } else {
                SCTP_INP_RUNLOCK(inp);
                SCTP_INP_WLOCK(inp);
                SCTP_INP_INCR_REF(inp);
                SCTP_INP_WUNLOCK(inp);
                stcb = sctp_findassociation_ep_addr(&inp, addr, NULL, NULL, NULL);
                if (stcb == NULL) {
                        SCTP_INP_WLOCK(inp);
                        SCTP_INP_DECR_REF(inp);
                        SCTP_INP_WUNLOCK(inp);
                }
        }

        if (stcb != NULL) {
                /* Already have or am bring up an association */
                SCTP_ASOC_CREATE_UNLOCK(inp);
                SCTP_TCB_UNLOCK(stcb);
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EALREADY);
                return (EALREADY);
        }
        /* We are GOOD to go */
        stcb = sctp_aloc_assoc_connected(inp, addr, &error, 0, 0, vrf_id,
            inp->sctp_ep.pre_open_stream_count,
            inp->sctp_ep.port, p,
            SCTP_INITIALIZE_AUTH_PARAMS);
        SCTP_ASOC_CREATE_UNLOCK(inp);
        if (stcb == NULL) {
                /* Gak! no memory */
                return (error);
        }
        SCTP_SET_STATE(stcb, SCTP_STATE_COOKIE_WAIT);
        (void)SCTP_GETTIME_TIMEVAL(&stcb->asoc.time_entered);
        NET_EPOCH_ENTER(et);
        sctp_send_initiate(inp, stcb, SCTP_SO_LOCKED);
        SCTP_TCB_UNLOCK(stcb);
        NET_EPOCH_EXIT(et);
        return (error);
}

static int
sctp6_getaddr(struct socket *so, struct sockaddr *sa)
{
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
        struct sctp_inpcb *inp;
        uint32_t vrf_id;
        struct sctp_ifa *sctp_ifa;
        int error;

        *sin6 = (struct sockaddr_in6 ){
                .sin6_len = sizeof(struct sockaddr_in6),
                .sin6_family = AF_INET6,
        };

        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp == NULL) {
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, ECONNRESET);
                return (ECONNRESET);
        }
        SCTP_INP_RLOCK(inp);
        sin6->sin6_port = inp->sctp_lport;
        if (inp->sctp_flags & SCTP_PCB_FLAGS_BOUNDALL) {
                /* For the bound all case you get back 0 */
                if (inp->sctp_flags & SCTP_PCB_FLAGS_CONNECTED) {
                        struct sctp_tcb *stcb;
                        struct sockaddr_in6 *sin_a6;
                        struct sctp_nets *net;
                        int fnd;

                        stcb = LIST_FIRST(&inp->sctp_asoc_list);
                        if (stcb == NULL) {
                                SCTP_INP_RUNLOCK(inp);
                                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, ENOENT);
                                return (ENOENT);
                        }
                        fnd = 0;
                        sin_a6 = NULL;
                        TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
                                sin_a6 = (struct sockaddr_in6 *)&net->ro._l_addr;
                                if (sin_a6 == NULL)
                                        /* this will make coverity happy */
                                        continue;

                                if (sin_a6->sin6_family == AF_INET6) {
                                        fnd = 1;
                                        break;
                                }
                        }
                        if ((!fnd) || (sin_a6 == NULL)) {
                                /* punt */
                                SCTP_INP_RUNLOCK(inp);
                                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, ENOENT);
                                return (ENOENT);
                        }
                        vrf_id = inp->def_vrf_id;
                        sctp_ifa = sctp_source_address_selection(inp, stcb, (sctp_route_t *)&net->ro, net, 0, vrf_id);
                        if (sctp_ifa) {
                                sin6->sin6_addr = sctp_ifa->address.sin6.sin6_addr;
                        }
                } else {
                        /* For the bound all case you get back 0 */
                        memset(&sin6->sin6_addr, 0, sizeof(sin6->sin6_addr));
                }
        } else {
                /* Take the first IPv6 address in the list */
                struct sctp_laddr *laddr;
                int fnd = 0;

                LIST_FOREACH(laddr, &inp->sctp_addr_list, sctp_nxt_addr) {
                        if (laddr->ifa->address.sa.sa_family == AF_INET6) {
                                struct sockaddr_in6 *sin_a;

                                sin_a = &laddr->ifa->address.sin6;
                                sin6->sin6_addr = sin_a->sin6_addr;
                                fnd = 1;
                                break;
                        }
                }
                if (!fnd) {
                        SCTP_INP_RUNLOCK(inp);
                        SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, ENOENT);
                        return (ENOENT);
                }
        }
        SCTP_INP_RUNLOCK(inp);
        /* Scoping things for v6 */
        if ((error = sa6_recoverscope(sin6)) != 0) {
                return (error);
        }

        return (0);
}

static int
sctp6_peeraddr(struct socket *so, struct sockaddr *sa)
{
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
        int fnd;
        struct sockaddr_in6 *sin_a6;
        struct sctp_inpcb *inp;
        struct sctp_tcb *stcb;
        struct sctp_nets *net;
        int error;

        *sin6 = (struct sockaddr_in6 ){
                .sin6_len = sizeof(struct sockaddr_in6),
                .sin6_family = AF_INET6,
        };

        inp = (struct sctp_inpcb *)so->so_pcb;
        if ((inp == NULL) ||
            ((inp->sctp_flags & SCTP_PCB_FLAGS_CONNECTED) == 0)) {
                /* UDP type and listeners will drop out here */
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, ENOTCONN);
                return (ENOTCONN);
        }
        SCTP_INP_RLOCK(inp);
        stcb = LIST_FIRST(&inp->sctp_asoc_list);
        if (stcb) {
                SCTP_TCB_LOCK(stcb);
        }
        SCTP_INP_RUNLOCK(inp);
        if (stcb == NULL) {
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, ECONNRESET);
                return (ECONNRESET);
        }
        fnd = 0;
        TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
                sin_a6 = (struct sockaddr_in6 *)&net->ro._l_addr;
                if (sin_a6->sin6_family == AF_INET6) {
                        fnd = 1;
                        sin6->sin6_port = stcb->rport;
                        sin6->sin6_addr = sin_a6->sin6_addr;
                        break;
                }
        }
        SCTP_TCB_UNLOCK(stcb);
        if (!fnd) {
                /* No IPv4 address */
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, ENOENT);
                return (ENOENT);
        }
        if ((error = sa6_recoverscope(sin6)) != 0) {
                SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, error);
                return (error);
        }

        return (0);
}

static int
sctp6_in6getaddr(struct socket *so, struct sockaddr *sa)
{
        struct inpcb *inp = sotoinpcb(so);
        int error;

        if (inp == NULL) {
                SCTP_LTRACE_ERR_RET(NULL, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                return (EINVAL);
        }

        /* allow v6 addresses precedence */
        error = sctp6_getaddr(so, sa);
#ifdef INET
        if (error) {
                struct sockaddr_in sin;

                /* try v4 next if v6 failed */
                error = sctp_ingetaddr(so, (struct sockaddr *)&sin);
                if (error)
                        return (error);
                in6_sin_2_v4mapsin6(&sin, (struct sockaddr_in6 *)sa);
        }
#endif
        return (error);
}

static int
sctp6_getpeeraddr(struct socket *so, struct sockaddr *sa)
{
        struct inpcb *inp = sotoinpcb(so);
        int error;

        if (inp == NULL) {
                SCTP_LTRACE_ERR_RET(NULL, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
                return (EINVAL);
        }

        /* allow v6 addresses precedence */
        error = sctp6_peeraddr(so, sa);
#ifdef INET
        if (error) {
                struct sockaddr_in sin;

                /* try v4 next if v6 failed */
                error = sctp_peeraddr(so, (struct sockaddr *)&sin);
                if (error)
                        return (error);
                in6_sin_2_v4mapsin6(&sin, (struct sockaddr_in6 *)sa);
        }
#endif
        return (error);
}

#define SCTP6_PROTOSW                                                   \
        .pr_protocol =  IPPROTO_SCTP,                                   \
        .pr_ctloutput = sctp_ctloutput,                                 \
        .pr_abort =     sctp_abort,                                     \
        .pr_accept =    sctp_accept,                                    \
        .pr_attach =    sctp6_attach,                                   \
        .pr_bind =      sctp6_bind,                                     \
        .pr_connect =   sctp6_connect,                                  \
        .pr_control =   in6_control,                                    \
        .pr_close =     sctp6_close,                                    \
        .pr_detach =    sctp6_close,                                    \
        .pr_disconnect = sctp_disconnect,                               \
        .pr_listen =    sctp_listen,                                    \
        .pr_peeraddr =  sctp6_getpeeraddr,                              \
        .pr_send =      sctp6_send,                                     \
        .pr_shutdown =  sctp_shutdown,                                  \
        .pr_sockaddr =  sctp6_in6getaddr,                               \
        .pr_sosend =    sctp_sosend,                                    \
        .pr_soreceive = sctp_soreceive

struct protosw sctp6_seqpacket_protosw = {
        .pr_type = SOCK_SEQPACKET,
        .pr_flags = PR_WANTRCVD,
        SCTP6_PROTOSW
};

struct protosw sctp6_stream_protosw = {
        .pr_type = SOCK_STREAM,
        .pr_flags = PR_CONNREQUIRED | PR_WANTRCVD,
        SCTP6_PROTOSW
};
#endif