/* $KAME: sctp6_usrreq.c,v 1.38 2005/08/24 08:08:56 suz Exp $ */
/* $NetBSD: sctp6_usrreq.c,v 1.27 2025/11/19 22:31:52 andvar Exp $ */

/*
 * Copyright (c) 2001, 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Cisco Systems, Inc.
 * 4. 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 CISCO SYSTEMS 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 CISCO SYSTEMS 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: sctp6_usrreq.c,v 1.27 2025/11/19 22:31:52 andvar Exp $");

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

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/malloc.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/errno.h>
#include <sys/stat.h>
#include <sys/systm.h>
#include <sys/syslog.h>
#include <sys/proc.h>
#include <net/if.h>
#include <net/route.h>
#include <net/if_types.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/sctp_pcb.h>
#include <netinet/sctp_header.h>
#include <netinet/sctp_var.h>
#include <netinet/sctputil.h>
#include <netinet/sctp_output.h>
#include <netinet/sctp_input.h>
#include <netinet/sctp_asconf.h>
#include <netinet/sctp_route.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet/icmp6.h>
#include <netinet6/sctp6_var.h>
#include <netinet6/ip6protosw.h>

#ifdef IPSEC
#include <netipsec/ipsec.h>
#include <netipsec/ipsec6.h>
#endif /*IPSEC*/

#if defined(NFAITH) && NFAITH > 0
#include <net/if_faith.h>
#endif

#if defined(HAVE_NRL_INPCB) || defined(__FreeBSD__)
#ifndef in6pcb
#define in6pcb          inpcb
#endif
#ifndef sotoin6pcb
#define sotoin6pcb      sotoinpcb
#endif
#endif

#ifdef SCTP_DEBUG
extern u_int32_t sctp_debug_on;
#endif

static  int sctp6_detach(struct socket *so);

extern int sctp_no_csum_on_loopback;

int
sctp6_input(struct mbuf **mp, int *offp, int proto)
{
        struct mbuf *m = *mp;
        struct ip6_hdr *ip6;
        struct sctphdr *sh;
        struct sctp_inpcb *in6p = NULL;
        struct sctp_nets *net;
        int refcount_up = 0;
        u_int32_t check, calc_check;
        struct inpcb *in6p_ip;
        struct sctp_chunkhdr *ch;
        struct mbuf *opts = NULL;
        int length, mlen, offset, iphlen;
        u_int8_t ecn_bits;
        struct sctp_tcb *stcb = NULL;
        int off = *offp;
        int s;

        ip6 = mtod(m, struct ip6_hdr *);
        /* Ensure that (sctphdr + sctp_chunkhdr) in a row. */
        IP6_EXTHDR_GET(sh, struct sctphdr *, m, off, sizeof(*sh) + sizeof(*ch));
        if (sh == NULL) {
                sctp_pegs[SCTP_HDR_DROPS]++;
                return IPPROTO_DONE;
        }
        ch = (struct sctp_chunkhdr *)((vaddr_t)sh + sizeof(struct sctphdr));

        iphlen = off;
        offset = iphlen + sizeof(*sh) + sizeof(*ch);

#if defined(NFAITH) && NFAITH > 0
        if (faithprefix(&ip6->ip6_dst))
                goto bad;
#endif /* NFAITH defined and > 0 */
        sctp_pegs[SCTP_INPKTS]++;
#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_INPUT1) {
                printf("V6 input gets a packet iphlen:%d pktlen:%d\n", iphlen, m->m_pkthdr.len);
        }
#endif
        if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
                /* No multi-cast support in SCTP */
                sctp_pegs[SCTP_IN_MCAST]++;
                goto bad;
        }
        /* destination port of 0 is illegal, based on RFC2960. */
        if (sh->dest_port == 0)
                goto bad;
        if ((sctp_no_csum_on_loopback == 0) ||
           (m_get_rcvif_NOMPSAFE(m) == NULL) ||
           (m_get_rcvif_NOMPSAFE(m)->if_type != IFT_LOOP)) {
                /* we do NOT validate things from the loopback if the
                 * sysctl is set to 1.
                 */
                check = sh->checksum;           /* save incoming checksum */
                if ((check == 0) && (sctp_no_csum_on_loopback)) {
                        /* special hook for where we got a local address
                         * somehow routed across a non IFT_LOOP type interface
                         */
                        if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &ip6->ip6_dst))
                                goto sctp_skip_csum;
                }
                sh->checksum = 0;               /* prepare for calc */
                calc_check = sctp_calculate_sum(m, &mlen, iphlen);
                if (calc_check != check) {
#ifdef SCTP_DEBUG
                        if (sctp_debug_on & SCTP_DEBUG_INPUT1) {
                                printf("Bad CSUM on SCTP packet calc_check:%x check:%x  m:%p mlen:%d iphlen:%d\n",
                                       calc_check, check, m,
                                       mlen, iphlen);
                        }
#endif
                        stcb = sctp_findassociation_addr(m, iphlen, offset - sizeof(*ch),
                                                         sh, ch, &in6p, &net);
                        /* in6p's ref-count increased && stcb locked */
                        if ((in6p) && (stcb)) {
                                sctp_send_packet_dropped(stcb, net, m, iphlen, 1);
                                sctp_chunk_output((struct sctp_inpcb *)in6p, stcb, 2);
                        } else if ((in6p != NULL) && (stcb == NULL)) {
                                refcount_up = 1;
                        }
                        sctp_pegs[SCTP_BAD_CSUM]++;
                        goto bad;
                }
                sh->checksum = calc_check;
        } else {
sctp_skip_csum:
                mlen = m->m_pkthdr.len;
        }
        net = NULL;
        /*
         * Locate pcb and tcb for datagram
         * sctp_findassociation_addr() wants IP/SCTP/first chunk header...
         */
#ifdef SCTP_DEBUG
        if (sctp_debug_on & SCTP_DEBUG_INPUT1) {
                printf("V6 Find the association\n");
        }
#endif
        stcb = sctp_findassociation_addr(m, iphlen, offset - sizeof(*ch),
            sh, ch, &in6p, &net);
        /* in6p's ref-count increased */
        if (in6p == NULL) {
                struct sctp_init_chunk *init_chk, chunk_buf;

                sctp_pegs[SCTP_NOPORTS]++;
                if (ch->chunk_type == SCTP_INITIATION) {
                        /* we do a trick here to get the INIT tag,
                         * dig in and get the tag from the INIT and
                         * put it in the common header.
                         */
                        init_chk = (struct sctp_init_chunk *)sctp_m_getptr(m,
                            iphlen + sizeof(*sh), sizeof(*init_chk),
                            (u_int8_t *)&chunk_buf);
                        sh->v_tag = init_chk->init.initiate_tag;
                }
                sctp_send_abort(m, iphlen, sh, 0, NULL);
                goto bad;
        } else if (stcb == NULL) {
                refcount_up = 1;
        }
        in6p_ip = (struct inpcb *)in6p;
#ifdef IPSEC
        /*
         * Check AH/ESP integrity.
         */
        if (ipsec_used && ipsec_in_reject(m, in6p_ip)) {
/* XXX */
#if 0
                /* FIX ME: need to find right stat */
                ipsec6stat.in_polvio++;
#endif
                goto bad;
        }
#endif /*IPSEC*/

        /*
         * Construct sockaddr format source address.
         * Stuff source address and datagram in user buffer.
         */
        if ((in6p->ip_inp.inp.inp_flags & INP_CONTROLOPTS)
#ifndef __OpenBSD__
            || (in6p->sctp_socket->so_options & SO_TIMESTAMP)
#endif
            ) {
#if defined(__FreeBSD__) || defined(__APPLE__)
#if (defined(SCTP_BASE_FREEBSD) && __FreeBSD_version < 501113) || defined(__APPLE__)
                ip6_savecontrol(in6p_ip, &opts, ip6, m);
#elif __FreeBSD_version >= 440000 || (defined(SCTP_BASE_FREEBSD) && __FreeBSD_version >= 501113)
                ip6_savecontrol(in6p_ip, m, &opts);
#else
                ip6_savecontrol(in6p_ip, m, &opts, NULL);
#endif
#elif defined(__NetBSD__)
                ip6_savecontrol(in6p_ip, &opts, ip6, m);
#else
                ip6_savecontrol(in6p_ip, m, &opts);
#endif
        }

        /*
         * CONTROL chunk processing
         */
        length = ntohs(ip6->ip6_plen) + iphlen;
        offset -= sizeof(*ch);
        ecn_bits = ((ntohl(ip6->ip6_flow) >> 20) & 0x000000ff);
        s = splsoftnet();
        (void)sctp_common_input_processing(&m, iphlen, offset, length, sh, ch,
            in6p, stcb, net, ecn_bits);
        /* inp's ref-count reduced && stcb unlocked */
        splx(s);
        /* XXX this stuff below gets moved to appropriate parts later... */
        m_freem(m);
        m_freem(opts);

        if ((in6p) && refcount_up){
                /* reduce ref-count */
                SCTP_INP_WLOCK(in6p);
                SCTP_INP_DECR_REF(in6p);
                SCTP_INP_WUNLOCK(in6p);
        }

        return IPPROTO_DONE;

bad:
        if (stcb) {
                SCTP_TCB_UNLOCK(stcb);
        }

        if ((in6p) && refcount_up){
                /* reduce ref-count */
                SCTP_INP_WLOCK(in6p);
                SCTP_INP_DECR_REF(in6p);
                SCTP_INP_WUNLOCK(in6p);
        }
        m_freem(m);
        m_freem(opts);
        return IPPROTO_DONE;
}


static void
sctp6_notify_mbuf(struct sctp_inpcb *inp,
                  struct icmp6_hdr *icmp6,
                  struct sctphdr *sh,
                  struct sctp_tcb *stcb,
                  struct sctp_nets *net)
{
        unsigned int nxtsz;

        if ((inp == NULL) || (stcb == NULL) || (net == NULL) ||
            (icmp6 == NULL) || (sh == NULL)) {
                goto out;
        }

        /* First do we even look at it? */
        if (ntohl(sh->v_tag) != (stcb->asoc.peer_vtag))
                goto out;

        if (icmp6->icmp6_type != ICMP6_PACKET_TOO_BIG) {
                /* not PACKET TO BIG */
                goto out;
        }
        /*
         * ok we need to look closely. We could even get smarter and
         * look at anyone that we sent to in case we get a different
         * ICMP that tells us there is no way to reach a host, but for
         * this impl, all we care about is MTU discovery.
         */
        nxtsz = ntohl(icmp6->icmp6_mtu);
        /* Stop any PMTU timer */
        sctp_timer_stop(SCTP_TIMER_TYPE_PATHMTURAISE, inp, stcb, NULL);

        /* Adjust destination size limit */
        if (net->mtu > nxtsz) {
                net->mtu = nxtsz;
        }
        /* now what about the ep? */
        if (stcb->asoc.smallest_mtu > nxtsz) {
                struct sctp_tmit_chunk *chk;
                struct sctp_stream_out *strm;
                /* Adjust that too */
                stcb->asoc.smallest_mtu = nxtsz;
                /* now off to subtract IP_DF flag if needed */

                TAILQ_FOREACH(chk, &stcb->asoc.send_queue, sctp_next) {
                        if ((chk->send_size+IP_HDR_SIZE) > nxtsz) {
                                chk->flags |= CHUNK_FLAGS_FRAGMENT_OK;
                        }
                }
                TAILQ_FOREACH(chk, &stcb->asoc.sent_queue, sctp_next) {
                        if ((chk->send_size+IP_HDR_SIZE) > nxtsz) {
                                /*
                                 * For this guy we also mark for immediate
                                 * resend since we sent to big of chunk
                                 */
                                chk->flags |= CHUNK_FLAGS_FRAGMENT_OK;
                                if (chk->sent != SCTP_DATAGRAM_RESEND)
                                        stcb->asoc.sent_queue_retran_cnt++;
                                chk->sent = SCTP_DATAGRAM_RESEND;
                                chk->rec.data.doing_fast_retransmit = 0;

                                chk->sent = SCTP_DATAGRAM_RESEND;
                                /* Clear any time so NO RTT is being done */
                                chk->sent_rcv_time.tv_sec = 0;
                                chk->sent_rcv_time.tv_usec = 0;
                                stcb->asoc.total_flight -= chk->send_size;
                                net->flight_size -= chk->send_size;
                        }
                }
                TAILQ_FOREACH(strm, &stcb->asoc.out_wheel, next_spoke) {
                        TAILQ_FOREACH(chk, &strm->outqueue, sctp_next) {
                                if ((chk->send_size+IP_HDR_SIZE) > nxtsz) {
                                        chk->flags |= CHUNK_FLAGS_FRAGMENT_OK;
                                }
                        }
                }
        }
        sctp_timer_start(SCTP_TIMER_TYPE_PATHMTURAISE, inp, stcb, NULL);
out:
        if (inp) {
                /* reduce inp's ref-count */
                SCTP_INP_WLOCK(inp);
                SCTP_INP_DECR_REF(inp);
                SCTP_INP_WUNLOCK(inp);
        }
        if (stcb) {
                SCTP_TCB_UNLOCK(stcb);
        }
}


void *
sctp6_ctlinput(int cmd, const struct sockaddr *pktdst, void *d)
{
        struct sctphdr sh;
        struct ip6ctlparam *ip6cp = NULL;
        int s, cm;

        if (pktdst->sa_family != AF_INET6 ||
            pktdst->sa_len != sizeof(struct sockaddr_in6))
                return NULL;

        if ((unsigned)cmd >= PRC_NCMDS)
                return NULL;
        if (PRC_IS_REDIRECT(cmd)) {
                d = NULL;
        } else if (inet6ctlerrmap[cmd] == 0) {
                return NULL;
        }

        /* if the parameter is from icmp6, decode it. */
        if (d != NULL) {
                ip6cp = (struct ip6ctlparam *)d;
        } else {
                ip6cp = (struct ip6ctlparam *)NULL;
        }

        if (ip6cp) {
                /*
                 * XXX: We assume that when IPV6 is non NULL,
                 * M and OFF are valid.
                 */
                /* check if we can safely examine src and dst ports */
                struct sctp_inpcb *inp;
                struct sctp_tcb *stcb;
                struct sctp_nets *net;
                struct sockaddr_in6 final;

                if (ip6cp->ip6c_m == NULL ||
                    (size_t)ip6cp->ip6c_m->m_pkthdr.len < (ip6cp->ip6c_off + sizeof(sh)))
                        return NULL;

                memset(&sh, 0, sizeof(sh));
                memset(&final, 0, sizeof(final));
                inp = NULL;
                net = NULL;
                m_copydata(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(sh),
                    (void *)&sh);
                ip6cp->ip6c_src->sin6_port = sh.src_port;
                final.sin6_len = sizeof(final);
                final.sin6_family = AF_INET6;
                final.sin6_addr = ((const struct sockaddr_in6 *)pktdst)->sin6_addr;
                final.sin6_port = sh.dest_port;
                s = splsoftnet();
                stcb = sctp_findassociation_addr_sa(sin6tosa(ip6cp->ip6c_src),
                                                    sin6tosa(&final),
                                                    &inp, &net, 1);
                /* inp's ref-count increased && stcb locked */
                if (stcb != NULL && inp && (inp->sctp_socket != NULL)) {
                        if (cmd == PRC_MSGSIZE) {
                                sctp6_notify_mbuf(inp,
                                                  ip6cp->ip6c_icmp6,
                                                  &sh,
                                                  stcb,
                                                  net);
                                /* inp's ref-count reduced && stcb unlocked */
                        } else {
                                if (cmd == PRC_HOSTDEAD) {
                                        cm = EHOSTUNREACH;
                                } else {
                                        cm = inet6ctlerrmap[cmd];
                                }
                                sctp_notify(inp, cm, &sh, sin6tosa(&final),
                                            stcb, net);
                                /* inp's ref-count reduced && stcb unlocked */
                        }
                } else {
                        if (PRC_IS_REDIRECT(cmd) && inp) {
                                in6pcb_rtchange((struct inpcb *)inp, inet6ctlerrmap[cmd]);
                        }
                        if (inp) {
                                /* reduce inp's ref-count */
                                SCTP_INP_WLOCK(inp);
                                SCTP_INP_DECR_REF(inp);
                                SCTP_INP_WUNLOCK(inp);
                        }
                        if (stcb) {
                                SCTP_TCB_UNLOCK(stcb);
                        }
                }
                splx(s);
        }
        return NULL;
}

/*
 * 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
 */
#ifdef __FreeBSD__
static int
sctp6_getcred(SYSCTL_HANDLER_ARGS)
{
        struct sockaddr_in6 addrs[2];
        struct sctp_inpcb *inp;
        struct sctp_nets *net;
        struct sctp_tcb *stcb;
        int error, s;

#if defined(__FreeBSD__) && __FreeBSD_version >= 500000
        error = suser(req->td);
#else
        error = suser(req->p);
#endif
        if (error)
                return (error);

        if (req->newlen != sizeof(addrs))
                return (EINVAL);
        if (req->oldlen != sizeof(struct ucred))
                return (EINVAL);
        error = SYSCTL_IN(req, addrs, sizeof(addrs));
        if (error)
                return (error);
        s = splsoftnet();

        stcb = sctp_findassociation_addr_sa(sin6tosa(&addrs[0]),
                                           sin6tosa(&addrs[1]),
                                           &inp, &net, 1);
        if (stcb == NULL || inp == NULL || inp->sctp_socket == NULL) {
                error = ENOENT;
                if (inp) {
                        SCTP_INP_WLOCK(inp);
                        SCTP_INP_DECR_REF(inp);
                        SCTP_INP_WUNLOCK(inp);
                }
                goto out;
        }
        error = SYSCTL_OUT(req, inp->sctp_socket->so_cred,
                           sizeof(struct ucred));

        SCTP_TCB_UNLOCK (stcb);
 out:
        splx(s);
        return (error);
}

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

#endif

/* This is the same as the sctp_abort() could be made common */
static int
sctp6_abort(struct socket *so)
{
        int s;
        struct sctp_inpcb *inp;

        KASSERT(solocked(so));

        s = splsoftnet();
        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp == 0)
                return EINVAL;  /* ??? possible? panic instead? */
        soisdisconnected(so);
        sctp_inpcb_free(inp, 1);
        splx(s);
        return 0;
}

static int
sctp6_attach(struct socket *so, int proto)
{
        struct in6pcb *inp6;
        int error;
        struct sctp_inpcb *inp;

        sosetlock(so);
        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp != NULL)
                return EINVAL;

        if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
                error = soreserve(so, sctp_sendspace, sctp_recvspace);
                if (error)
                        return error;
        }
        error = sctp_inpcb_alloc(so);
        if (error)
                return error;
        inp = (struct sctp_inpcb *)so->so_pcb;
        inp->sctp_flags |= SCTP_PCB_FLAGS_BOUND_V6;     /* I'm v6! */
        inp6 = (struct in6pcb *)inp;

        inp->inp_vflag |=  INP_IPV6;
        if (ip6_v6only) {
                inp6->in6p_flags |= IN6P_IPV6_V6ONLY;
        }
        so->so_send = sctp_sosend;

#ifdef IPSEC
        inp6->in6p_af = proto;
#endif
        inp6->in6p_hops = -1;           /* use kernel default */
        inp6->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->inp_ip_ttl = ip_defttl;
#endif
        /*
         * Hmm what about the IPSEC stuff that is missing here but
         * in sctp_attach()?
         */
        return 0;
}

static int
sctp6_bind(struct socket *so, struct sockaddr *nam, struct lwp *l)
{
        struct sctp_inpcb *inp;
        struct in6pcb *inp6;
        int error;

        KASSERT(solocked(so));

        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp == 0)
                return EINVAL;

        inp6 = (struct in6pcb *)inp;
        inp->inp_vflag &= ~INP_IPV4;
        inp->inp_vflag |= INP_IPV6;

        if (nam != NULL && (inp6->in6p_flags & IN6P_IPV6_V6ONLY) == 0) {
                if (nam->sa_family == AF_INET) {
                        /* binding v4 addr to v6 socket, so reset flags */
                        inp->inp_vflag |= INP_IPV4;
                        inp->inp_vflag &= ~INP_IPV6;
                } else {
                        struct sockaddr_in6 *sin6_p;
                        sin6_p = (struct sockaddr_in6 *)nam;

                        if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr)) {
                          inp->inp_vflag |= INP_IPV4;
                        }
                        else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
                                struct sockaddr_in sin;
                                in6_sin6_2_sin(&sin, sin6_p);
                                inp->inp_vflag |= INP_IPV4;
                                inp->inp_vflag &= ~INP_IPV6;
                                error = sctp_inpcb_bind(so, (struct sockaddr *)&sin, l);
                                return error;
                        }
                }
        } else if (nam != NULL) {
                /* IPV6_V6ONLY socket */
                if (nam->sa_family == AF_INET) {
                        /* can't bind v4 addr to v6 only socket! */
                        return EINVAL;
                } else {
                        struct sockaddr_in6 *sin6_p;
                        sin6_p = (struct sockaddr_in6 *)nam;

                        if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr))
                                /* can't bind v4-mapped addrs either! */
                                /* NOTE: we don't support SIIT */
                                return EINVAL;
                }
        }
        error = sctp_inpcb_bind(so, nam, l);
        return error;
}

/*This could be made common with sctp_detach() since they are identical */
static int
sctp6_detach(struct socket *so)
{
        struct sctp_inpcb *inp;

        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp == 0)
                return EINVAL;

        if (((so->so_options & SO_LINGER) && (so->so_linger == 0)) ||
            (so->so_rcv.sb_cc > 0))
                sctp_inpcb_free(inp, 1);
        else
                sctp_inpcb_free(inp, 0);
        return 0;
}

static int
sctp6_disconnect(struct socket *so)
{
        struct sctp_inpcb *inp;

        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp == NULL) {
                return (ENOTCONN);
        }
        if (inp->sctp_flags & SCTP_PCB_FLAGS_TCPTYPE) {
                if (LIST_EMPTY(&inp->sctp_asoc_list)) {
                        /* No connection */
                        return (ENOTCONN);
                } else {
                        int some_on_streamwheel = 0;
                        struct sctp_association *asoc;
                        struct sctp_tcb *stcb;

                        stcb = LIST_FIRST(&inp->sctp_asoc_list);
                        if (stcb == NULL) {
                                return (EINVAL);
                        }
                        asoc = &stcb->asoc;
                        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 queued to send, so I'm done... */
                                if ((SCTP_GET_STATE(asoc) !=
                                     SCTP_STATE_SHUTDOWN_SENT) &&
                                    (SCTP_GET_STATE(asoc) !=
                                     SCTP_STATE_SHUTDOWN_ACK_SENT)) {
                                        /* only send SHUTDOWN the first time */
#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_chunk_output(stcb->sctp_ep, stcb, 1);
                                        asoc->state = SCTP_STATE_SHUTDOWN_SENT;
                                        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 {
                                /*
                                 * we still got (or just got) data to send,
                                 * so set SHUTDOWN_PENDING
                                 */
                                /*
                                 * XXX sockets draft says that MSG_EOF should
                                 * be sent with no data.  currently, we will
                                 * allow user data to be sent first and move
                                 * to SHUTDOWN-PENDING
                                 */
                                asoc->state |= SCTP_STATE_SHUTDOWN_PENDING;
                        }
                        return (0);
                }
        } else {
                /* UDP model does not support this */
                return EOPNOTSUPP;
        }
}

static int
sctp6_recvoob(struct socket *so, struct mbuf *m, int flags)
{
        KASSERT(solocked(so));

        return EOPNOTSUPP;
}

static int
sctp6_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
           struct mbuf *control, struct lwp *l)
{
        struct sctp_inpcb *inp;
        struct in6pcb *inp6;
#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) {
                m_freem(control);
                control = NULL;
                m_freem(m);
                return EINVAL;
        }
        inp6 = (struct in6pcb *)inp;
        /* 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) &&
            (nam == NULL)) {
                goto connected_type;
        }
        if (nam == NULL) {
                m_freem(m);
                m_freem(control);
                control = NULL;
                return (EDESTADDRREQ);
        }

#ifdef INET
        sin6 = (struct sockaddr_in6 *)nam;
        /*
         * XXX XXX XXX Check sin6->sin6_len?
         */
        if (inp6->in6p_flags & IN6P_IPV6_V6ONLY) {
                /*
                 * if IPV6_V6ONLY flag, we discard datagrams
                 * destined to a v4 addr or v4-mapped addr
                 */
                if (nam->sa_family == AF_INET) {
                        return EINVAL;
                }
                if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                        return EINVAL;
                }
        }

        if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                if (!ip6_v6only) {
                        struct sockaddr_in sin;
                        /* convert v4-mapped into v4 addr and send */
                        in6_sin6_2_sin(&sin, sin6);
                        return sctp_send(so, m, (struct sockaddr *)&sin,
                            control, l);
                } else {
                        /* mapped addresses aren't enabled */
                        return EINVAL;
                }
        }
#endif /* INET */
 connected_type:
        /* now what about control */
        if (control) {
                if (inp->control) {
                        printf("huh? control set?\n");
                        m_freem(inp->control);
                        inp->control = NULL;
                }
                inp->control = control;
        }
        /* add it in possibly */
        if ((inp->pkt) &&
            (inp->pkt->m_flags & M_PKTHDR)) {
                struct mbuf *x;
                int c_len;

                c_len = 0;
                /* How big is it */
                for (x=m;x;x = x->m_next) {
                        c_len += x->m_len;
                }
                inp->pkt->m_pkthdr.len += c_len;
        }
        /* Place the data */
        if (inp->pkt) {
                inp->pkt_last->m_next = m;
                inp->pkt_last = m;
        } else {
                inp->pkt_last = inp->pkt = m;
        }
        if ((so->so_state & SS_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.
                 */
                int ret;
                ret = sctp_output(inp, inp->pkt , nam, inp->control, l, 0);
                inp->pkt = NULL;
                inp->control = NULL;
                return (ret);
        } else {
                return (0);
        }
}

static int
sctp6_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
{
        KASSERT(solocked(so));

        m_freem(m);
        m_freem(control);

        return EOPNOTSUPP;
}

static int
sctp6_connect(struct socket *so, struct sockaddr *nam, struct lwp *l)
{
        int error = 0;
        struct sctp_inpcb *inp;
        struct in6pcb *inp6;
        struct sctp_tcb *stcb;
#ifdef INET
        struct sockaddr_in6 *sin6;
        struct sockaddr_storage ss;
#endif /* INET */

        inp6 = (struct in6pcb *)so->so_pcb;
        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp == 0) {
                return (ECONNRESET);    /* I made the same as TCP since
                                         * we are not setup? */
        }
        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, l);
                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);
                return (EADDRINUSE);
        }

#ifdef INET
        sin6 = (struct sockaddr_in6 *)nam;

        /*
         * XXX XXX XXX Check sin6->sin6_len?
         */

        if (inp6->in6p_flags & IN6P_IPV6_V6ONLY) {
                /*
                 * if IPV6_V6ONLY flag, ignore connections
                 * destined to a v4 addr or v4-mapped addr
                 */
                if (nam->sa_family == AF_INET) {
                        SCTP_INP_RUNLOCK(inp);
                        SCTP_ASOC_CREATE_UNLOCK(inp);
                        return EINVAL;
                }
                if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                        SCTP_INP_RUNLOCK(inp);
                        SCTP_ASOC_CREATE_UNLOCK(inp);
                        return EINVAL;
                }
        }

        if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                if (!ip6_v6only) {
                        /* convert v4-mapped into v4 addr */
                        in6_sin6_2_sin((struct sockaddr_in *)&ss, sin6);
                        nam = (struct sockaddr *)&ss;
                } else {
                        /* mapped addresses aren't enabled */
                        SCTP_INP_RUNLOCK(inp);
                        SCTP_ASOC_CREATE_UNLOCK(inp);
                        return EINVAL;
                }
        }
#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_UNLOCK (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, nam, 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);
                return (EALREADY);
        }
        /* We are GOOD to go */
        stcb = sctp_aloc_assoc(inp, nam, 1, &error, 0);
        SCTP_ASOC_CREATE_UNLOCK(inp);
        if (stcb == NULL) {
                /* Gak! no memory */
                return (error);
        }
        if (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_TCPTYPE) {
                stcb->sctp_ep->sctp_flags |= SCTP_PCB_FLAGS_CONNECTED;
                /* Set the connected flag so we can queue data */
                soisconnecting(so);
        }
        stcb->asoc.state = SCTP_STATE_COOKIE_WAIT;
        SCTP_GETTIME_TIMEVAL(&stcb->asoc.time_entered);
        sctp_send_initiate(inp, stcb);
        SCTP_TCB_UNLOCK (stcb);
        return error;
}

static int
sctp6_connect2(struct socket *so, struct socket *so2)
{
        KASSERT(solocked(so));

        return EOPNOTSUPP;
}

static int
sctp6_getaddr(struct socket *so, struct sockaddr *nam)
{
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
        struct sctp_inpcb *inp;
        int error;

        /*
         * Do the malloc first in case it blocks.
         */
        memset(sin6, 0, sizeof(*sin6));
        sin6->sin6_family = AF_INET6;
        sin6->sin6_len = sizeof(*sin6);

        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp == NULL) {
                return ECONNRESET;
        }

        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;
                        const struct sockaddr_in6 *sin_a6;
                        struct sctp_nets *net;
                        int fnd;

                        stcb = LIST_FIRST(&inp->sctp_asoc_list);
                        if (stcb == NULL) {
                                goto notConn6;
                        }
                        fnd = 0;
                        sin_a6 = NULL;
                        TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
                                sin_a6 = (const struct sockaddr_in6 *)rtcache_getdst(&net->ro);
                                if (sin_a6->sin6_family == AF_INET6) {
                                        fnd = 1;
                                        break;
                                }
                        }
                        if ((!fnd) || (sin_a6 == NULL)) {
                                /* punt */
                                goto notConn6;
                        }
                        sin6->sin6_addr = sctp_ipv6_source_address_selection(
                            inp, stcb, &net->ro, net, 0);

                } else {
                        /* For the bound all case you get back 0 */
                notConn6:
                        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->ifa_addr->sa_family == AF_INET6) {
                                struct sockaddr_in6 *sin_a;
                                sin_a = (struct sockaddr_in6 *)laddr->ifa->ifa_addr;
                                sin6->sin6_addr = sin_a->sin6_addr;
                                fnd = 1;
                                break;
                        }
                }
                if (!fnd) {
                        return ENOENT;
                }
        }
        /* Scoping things for v6 */
        if ((error = sa6_recoverscope(sin6)) != 0)
                return (error);

        return (0);
}

static int
sctp6_peeraddr(struct socket *so, struct sockaddr *nam)
{
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
        int fnd, error;
        const struct sockaddr_in6 *sin_a6;
        struct sctp_inpcb *inp;
        struct sctp_tcb *stcb;
        struct sctp_nets *net;
        /*
         * Do the malloc first in case it blocks.
         */
        inp = (struct sctp_inpcb *)so->so_pcb;
        if ((inp->sctp_flags & SCTP_PCB_FLAGS_CONNECTED) == 0) {
                /* UDP type and listeners will drop out here */
                return (ENOTCONN);
        }
        memset(sin6, 0, sizeof(*sin6));
        sin6->sin6_family = AF_INET6;
        sin6->sin6_len = sizeof(*sin6);

        /* We must recapture incase we blocked */
        inp = (struct sctp_inpcb *)so->so_pcb;
        if (inp == NULL) {
                return ECONNRESET;
        }
        stcb = LIST_FIRST(&inp->sctp_asoc_list);
        if (stcb == NULL) {
                return ECONNRESET;
        }
        fnd = 0;
        TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
                sin_a6 = (const struct sockaddr_in6 *)rtcache_getdst(&net->ro);
                if (sin_a6->sin6_family == AF_INET6) {
                        fnd = 1;
                        sin6->sin6_port = stcb->rport;
                        sin6->sin6_addr = sin_a6->sin6_addr;
                        break;
                }
        }
        if (!fnd) {
                /* No IPv4 address */
                return ENOENT;
        }
        if ((error = sa6_recoverscope(sin6)) != 0)
                return (error);

        return (0);
}

static int
sctp6_sockaddr(struct socket *so, struct sockaddr *nam)
{
        struct in6pcb *inp6 = sotoin6pcb(so);
        int     error;

        if (inp6 == NULL)
                return EINVAL;

        /* allow v6 addresses precedence */
        error = sctp6_getaddr(so, nam);
        if (error) {
                /* try v4 next if v6 failed */
                error = sctp_sockaddr(so, nam);
                if (error) {
                        return (error);
                }

                /* if I'm V6ONLY, convert it to v4-mapped */
                if (inp6->in6p_flags & IN6P_IPV6_V6ONLY) {
                        struct sockaddr_in6 sin6;
                        in6_sin_2_v4mapsin6((struct sockaddr_in *)nam, &sin6);
                        memcpy(nam, &sin6, sizeof(struct sockaddr_in6));
                }
        }
        return (error);
}

#if 0
static int
sctp6_getpeeraddr(struct socket *so, struct sockaddr *nam)
{
        struct in6pcb *inp6 = sotoin6pcb(so);
        int     error;

        if (inp6 == NULL)
                return EINVAL;

        /* allow v6 addresses precedence */
        error = sctp6_peeraddr(so, nam);
        if (error) {
                /* try v4 next if v6 failed */
                error = sctp_peeraddr(so, nam);
                if (error) {
                        return (error);
                }
                /* if I'm V6ONLY, convert it to v4-mapped */
                if ((inp6->in6p_flags & IN6P_IPV6_V6ONLY)) {
                        struct sockaddr_in6 sin6;
                        in6_sin_2_v4mapsin6((struct sockaddr_in *)addr, &sin6);
                        memcpy(addr, &sin6, sizeof(struct sockaddr_in6));
                }
        }
        return error;
}
#endif

static int
sctp6_ioctl(struct socket *so, u_long cmd, void *nam, struct ifnet *ifp)
{
        int error = 0;
        int family;

        if (cmd == SIOCCONNECTX) {
                solock(so);
                error = sctp_do_connect_x(so, nam, curlwp, 0);
                sounlock(so);
        } else if (cmd == SIOCCONNECTXDEL) {
                solock(so);
                error = sctp_do_connect_x(so, nam, curlwp, 1);
                sounlock(so);
        } else {
                family = so->so_proto->pr_domain->dom_family;
                switch (family) {
#ifdef INET
                case PF_INET:
                        error = in_control(so, cmd, nam, ifp);
                        break;
#endif
#ifdef INET6
                case PF_INET6:
                        error = in6_control(so, cmd, nam, ifp);
                        break;
#endif
                default:
                        error = EAFNOSUPPORT;
                }
        }
        return (error);
}

static int
sctp6_accept(struct socket *so, struct sockaddr *nam)
{
        return sctp_accept(so, nam);
}

static int
sctp6_stat(struct socket *so, struct stat *ub)
{
        return 0;
}

static int
sctp6_listen(struct socket *so, struct lwp *l)
{
        return sctp_listen(so, l);
}

static int
sctp6_shutdown(struct socket *so)
{
        return sctp_shutdown(so);
}

static int
sctp6_rcvd(struct socket *so, int flags, struct lwp *l)
{
        KASSERT(solocked(so));

        return sctp_rcvd(so, flags, l);
}

static int
sctp6_purgeif(struct socket *so, struct ifnet *ifp)
{
        struct ifaddr *ifa;
        /* FIXME NOMPSAFE */
        IFADDR_READER_FOREACH(ifa, ifp) {
                if (ifa->ifa_addr->sa_family == PF_INET6) {
                        sctp_delete_ip_address(ifa);
                }
        }

#ifndef NET_MPSAFE
        mutex_enter(softnet_lock);
#endif
        in6_purgeif(ifp);
#ifndef NET_MPSAFE
        mutex_exit(softnet_lock);
#endif

        return 0;
}

PR_WRAP_USRREQS(sctp6)
#define sctp6_attach    sctp6_attach_wrapper
#define sctp6_detach    sctp6_detach_wrapper
#define sctp6_accept    sctp6_accept_wrapper
#define sctp6_bind      sctp6_bind_wrapper
#define sctp6_listen    sctp6_listen_wrapper
#define sctp6_connect   sctp6_connect_wrapper
#define sctp6_connect2  sctp6_connect2_wrapper
#define sctp6_disconnect        sctp6_disconnect_wrapper
#define sctp6_shutdown  sctp6_shutdown_wrapper
#define sctp6_abort     sctp6_abort_wrapper
#define sctp6_ioctl     sctp6_ioctl_wrapper
#define sctp6_stat      sctp6_stat_wrapper
#define sctp6_peeraddr  sctp6_peeraddr_wrapper
#define sctp6_sockaddr  sctp6_sockaddr_wrapper
#define sctp6_rcvd      sctp6_rcvd_wrapper
#define sctp6_recvoob   sctp6_recvoob_wrapper
#define sctp6_send      sctp6_send_wrapper
#define sctp6_sendoob   sctp6_sendoob_wrapper
#define sctp6_purgeif   sctp6_purgeif_wrapper

const struct pr_usrreqs sctp6_usrreqs = {
        .pr_attach      = sctp6_attach,
        .pr_detach      = sctp6_detach,
        .pr_accept      = sctp6_accept,
        .pr_bind        = sctp6_bind,
        .pr_listen      = sctp6_listen,
        .pr_connect     = sctp6_connect,
        .pr_connect2    = sctp6_connect2,
        .pr_disconnect  = sctp6_disconnect,
        .pr_shutdown    = sctp6_shutdown,
        .pr_abort       = sctp6_abort,
        .pr_ioctl       = sctp6_ioctl,
        .pr_stat        = sctp6_stat,
        .pr_peeraddr    = sctp6_peeraddr,
        .pr_sockaddr    = sctp6_sockaddr,
        .pr_rcvd        = sctp6_rcvd,
        .pr_recvoob     = sctp6_recvoob,
        .pr_send        = sctp6_send,
        .pr_sendoob     = sctp6_sendoob,
        .pr_purgeif     = sctp6_purgeif,
};