bsd/netinet6/udp6_output.c

   1 /*
   2  * Copyright (c) 2000-2019 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29
  30 /*      $FreeBSD: src/sys/netinet6/udp6_output.c,v 1.1.2.3 2001/08/31 13:49:58 jlemon Exp $     */
  31 /*      $KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei Exp $    */
  32
  33 /*
  34  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
  35  * All rights reserved.
  36  *
  37  * Redistribution and use in source and binary forms, with or without
  38  * modification, are permitted provided that the following conditions
  39  * are met:
  40  * 1. Redistributions of source code must retain the above copyright
  41  *    notice, this list of conditions and the following disclaimer.
  42  * 2. Redistributions in binary form must reproduce the above copyright
  43  *    notice, this list of conditions and the following disclaimer in the
  44  *    documentation and/or other materials provided with the distribution.
  45  * 3. Neither the name of the project nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  */
  61
  62 /*
  63  * Copyright (c) 1982, 1986, 1989, 1993
  64  *      The Regents of the University of California.  All rights reserved.
  65  *
  66  * Redistribution and use in source and binary forms, with or without
  67  * modification, are permitted provided that the following conditions
  68  * are met:
  69  * 1. Redistributions of source code must retain the above copyright
  70  *    notice, this list of conditions and the following disclaimer.
  71  * 2. Redistributions in binary form must reproduce the above copyright
  72  *    notice, this list of conditions and the following disclaimer in the
  73  *    documentation and/or other materials provided with the distribution.
  74  * 3. All advertising materials mentioning features or use of this software
  75  *    must display the following acknowledgement:
  76  *      This product includes software developed by the University of
  77  *      California, Berkeley and its contributors.
  78  * 4. Neither the name of the University nor the names of its contributors
  79  *    may be used to endorse or promote products derived from this software
  80  *    without specific prior written permission.
  81  *
  82  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  83  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  84  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  85  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  86  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  87  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  88  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  89  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  90  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  91  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  92  * SUCH DAMAGE.
  93  *
  94  *      @(#)udp_var.h   8.1 (Berkeley) 6/10/93
  95  */
  96
  97 #include <sys/param.h>
  98 #include <sys/malloc.h>
  99 #include <sys/mbuf.h>
 100 #include <sys/protosw.h>
 101 #include <sys/socket.h>
 102 #include <sys/socketvar.h>
 103 #include <sys/sysctl.h>
 104 #include <sys/errno.h>
 105 #include <sys/stat.h>
 106 #include <sys/systm.h>
 107 #include <sys/proc.h>
 108 #include <sys/syslog.h>
 109
 110 #include <machine/endian.h>
 111
 112 #include <net/if.h>
 113 #include <net/route.h>
 114 #include <net/if_types.h>
 115 #include <net/ntstat.h>
 116
 117 #include <netinet/in.h>
 118 #include <netinet/in_var.h>
 119 #include <netinet/in_systm.h>
 120 #include <netinet/in_tclass.h>
 121 #include <netinet/ip.h>
 122 #include <netinet/ip_var.h>
 123 #include <netinet/in_pcb.h>
 124 #include <netinet/udp.h>
 125 #include <netinet/udp_var.h>
 126 #include <netinet/ip6.h>
 127 #include <netinet6/ip6_var.h>
 128 #include <netinet6/in6_pcb.h>
 129 #include <netinet6/udp6_var.h>
 130 #include <netinet/icmp6.h>
 131 #include <netinet6/ip6protosw.h>
 132
 133 #if NECP
 134 #include <net/necp.h>
 135 #endif /* NECP */
 136
 137 #include <net/net_osdep.h>
 138
 139 #if CONTENT_FILTER
 140 #include <net/content_filter.h>
 141 #endif /* CONTENT_FILTER */
 142
 143 /*
 144  * UDP protocol inplementation.
 145  * Per RFC 768, August, 1980.
 146  */
 147 extern int soreserveheadroom;
 148
 149 int
 150 udp6_output(struct in6pcb *in6p, struct mbuf *m, struct sockaddr *addr6,
 151     struct mbuf *control, struct proc *p)
 152 {
 153         u_int32_t ulen = m->m_pkthdr.len;
 154         u_int32_t plen = sizeof(struct udphdr) + ulen;
 155         struct ip6_hdr *ip6;
 156         struct udphdr *udp6;
 157         struct in6_addr *laddr, *faddr;
 158         u_short fport;
 159         int error = 0;
 160         struct ip6_pktopts opt, *optp = NULL;
 161         struct ip6_moptions *im6o;
 162         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 163         int flags;
 164         struct sockaddr_in6 tmp;
 165         struct  in6_addr storage;
 166         int sotc = SO_TC_UNSPEC;
 167         int netsvctype = _NET_SERVICE_TYPE_UNSPEC;
 168         struct ip6_out_args ip6oa;
 169         struct flowadv *adv = &ip6oa.ip6oa_flowadv;
 170         struct socket *so = in6p->in6p_socket;
 171         struct route_in6 ro;
 172         int flowadv = 0;
 173 #if CONTENT_FILTER
 174         struct m_tag *cfil_tag = NULL;
 175         bool cfil_faddr_use = false;
 176         uint32_t cfil_so_state_change_cnt = 0;
 177         struct sockaddr *cfil_faddr = NULL;
 178         struct sockaddr_in6 *cfil_sin6 = NULL;
 179 #endif
 180
 181         bzero(&ip6oa, sizeof(ip6oa));
 182         ip6oa.ip6oa_boundif = IFSCOPE_NONE;
 183         ip6oa.ip6oa_flags = IP6OAF_SELECT_SRCIF;
 184
 185         /* Enable flow advisory only when connected */
 186         flowadv = (so->so_state & SS_ISCONNECTED) ? 1 : 0;
 187
 188         if (flowadv && INP_WAIT_FOR_IF_FEEDBACK(in6p)) {
 189                 error = ENOBUFS;
 190                 goto release;
 191         }
 192
 193         if (in6p->inp_flags & INP_BOUND_IF) {
 194                 ip6oa.ip6oa_boundif = in6p->inp_boundifp->if_index;
 195                 ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF;
 196         }
 197         if (INP_NO_CELLULAR(in6p)) {
 198                 ip6oa.ip6oa_flags |= IP6OAF_NO_CELLULAR;
 199         }
 200         if (INP_NO_EXPENSIVE(in6p)) {
 201                 ip6oa.ip6oa_flags |= IP6OAF_NO_EXPENSIVE;
 202         }
 203         if (INP_NO_CONSTRAINED(in6p)) {
 204                 ip6oa.ip6oa_flags |= IP6OAF_NO_CONSTRAINED;
 205         }
 206         if (INP_AWDL_UNRESTRICTED(in6p)) {
 207                 ip6oa.ip6oa_flags |= IP6OAF_AWDL_UNRESTRICTED;
 208         }
 209         if (INP_INTCOPROC_ALLOWED(in6p)) {
 210                 ip6oa.ip6oa_flags |= IP6OAF_INTCOPROC_ALLOWED;
 211         }
 212
 213 #if CONTENT_FILTER
 214         /*
 215          * If socket is subject to UDP Content Filter and no addr is passed in,
 216          * retrieve CFIL saved state from mbuf and use it if necessary.
 217          */
 218         if (so->so_cfil_db && !addr6) {
 219                 cfil_tag = cfil_udp_get_socket_state(m, &cfil_so_state_change_cnt, NULL, &cfil_faddr);
 220                 if (cfil_tag) {
 221                         cfil_sin6 = (struct sockaddr_in6 *)(void *)cfil_faddr;
 222                         if ((so->so_state_change_cnt != cfil_so_state_change_cnt) &&
 223                             (in6p->in6p_fport != cfil_sin6->sin6_port ||
 224                             !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &cfil_sin6->sin6_addr))) {
 225                                 /*
 226                                  * Socket is connected but socket state and dest addr/port changed.
 227                                  * We need to use the saved faddr info.
 228                                  */
 229                                 cfil_faddr_use = true;
 230                         }
 231                 }
 232         }
 233 #endif
 234
 235         if (control) {
 236                 sotc = so_tc_from_control(control, &netsvctype);
 237                 if ((error = ip6_setpktopts(control, &opt,
 238                     NULL, IPPROTO_UDP)) != 0) {
 239                         goto release;
 240                 }
 241                 optp = &opt;
 242         } else {
 243                 optp = in6p->in6p_outputopts;
 244         }
 245
 246         if (sotc == SO_TC_UNSPEC) {
 247                 sotc = so->so_traffic_class;
 248                 netsvctype = so->so_netsvctype;
 249         }
 250         ip6oa.ip6oa_sotc = sotc;
 251         ip6oa.ip6oa_netsvctype = netsvctype;
 252
 253         if (addr6) {
 254                 /*
 255                  * IPv4 version of udp_output calls in_pcbconnect in this case,
 256                  * which has its costs.
 257                  *
 258                  * Since we saw no essential reason for calling in_pcbconnect,
 259                  * we get rid of such kind of logic, and call in6_selectsrc
 260                  * and in6_pcbsetport in order to fill in the local address
 261                  * and the local port.
 262                  */
 263                 struct sockaddr_in6 *sin6 =
 264                     (struct sockaddr_in6 *)(void *)addr6;
 265
 266                 if (sin6->sin6_port == 0) {
 267                         error = EADDRNOTAVAIL;
 268                         goto release;
 269                 }
 270
 271                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
 272                         /* how about ::ffff:0.0.0.0 case? */
 273                         error = EISCONN;
 274                         goto release;
 275                 }
 276
 277                 /* protect *sin6 from overwrites */
 278                 tmp = *sin6;
 279                 sin6 = &tmp;
 280
 281                 faddr = &sin6->sin6_addr;
 282                 fport = sin6->sin6_port; /* allow 0 port */
 283
 284                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 285                         if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY)) {
 286                                 /*
 287                                  * I believe we should explicitly discard the
 288                                  * packet when mapped addresses are disabled,
 289                                  * rather than send the packet as an IPv6 one.
 290                                  * If we chose the latter approach, the packet
 291                                  * might be sent out on the wire based on the
 292                                  * default route, the situation which we'd
 293                                  * probably want to avoid.
 294                                  * (20010421 jinmei@kame.net)
 295                                  */
 296                                 error = EINVAL;
 297                                 goto release;
 298                         } else {
 299                                 af = AF_INET;
 300                         }
 301                 }
 302
 303                 /* KAME hack: embed scopeid */
 304                 if (in6_embedscope(&sin6->sin6_addr, sin6, in6p, NULL,
 305                     optp) != 0) {
 306                         error = EINVAL;
 307                         goto release;
 308                 }
 309
 310                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 311                         laddr = in6_selectsrc(sin6, optp,
 312                             in6p, &in6p->in6p_route, NULL, &storage,
 313                             ip6oa.ip6oa_boundif, &error);
 314                 } else {
 315                         laddr = &in6p->in6p_laddr;      /* XXX */
 316                 }
 317                 if (laddr == NULL) {
 318                         if (error == 0) {
 319                                 error = EADDRNOTAVAIL;
 320                         }
 321                         goto release;
 322                 }
 323                 if (in6p->in6p_lport == 0 &&
 324                     (error = in6_pcbsetport(laddr, in6p, p, 0)) != 0) {
 325                         goto release;
 326                 }
 327         } else {
 328                 if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
 329                         error = ENOTCONN;
 330                         goto release;
 331                 }
 332                 laddr = &in6p->in6p_laddr;
 333                 faddr = &in6p->in6p_faddr;
 334                 fport = in6p->in6p_fport;
 335 #if CONTENT_FILTER
 336                 if (cfil_faddr_use) {
 337                         faddr = &((struct sockaddr_in6 *)(void *)cfil_faddr)->sin6_addr;
 338                         fport = ((struct sockaddr_in6 *)(void *)cfil_faddr)->sin6_port;
 339
 340                         /* Do not use cached route */
 341                         ROUTE_RELEASE(&in6p->in6p_route);
 342                 }
 343 #endif
 344                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 345                         if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY)) {
 346                                 /*
 347                                  * XXX: this case would happen when the
 348                                  * application sets the V6ONLY flag after
 349                                  * connecting the foreign address.
 350                                  * Such applications should be fixed,
 351                                  * so we bark here.
 352                                  */
 353                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 354                                     "option was set for a connected socket\n");
 355                                 error = EINVAL;
 356                                 goto release;
 357                         } else {
 358                                 af = AF_INET;
 359                         }
 360                 }
 361         }
 362
 363         if (in6p->inp_flowhash == 0) {
 364                 in6p->inp_flowhash = inp_calc_flowhash(in6p);
 365         }
 366         /* update flowinfo - RFC 6437 */
 367         if (in6p->inp_flow == 0 && in6p->in6p_flags & IN6P_AUTOFLOWLABEL) {
 368                 in6p->inp_flow &= ~IPV6_FLOWLABEL_MASK;
 369                 in6p->inp_flow |=
 370                     (htonl(in6p->inp_flowhash) & IPV6_FLOWLABEL_MASK);
 371         }
 372
 373         if (af == AF_INET) {
 374                 hlen = sizeof(struct ip);
 375         }
 376
 377         if (fport == htons(53) && !(so->so_flags1 & SOF1_DNS_COUNTED)) {
 378                 so->so_flags1 |= SOF1_DNS_COUNTED;
 379                 INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_inet_dgram_dns);
 380         }
 381
 382         /*
 383          * Calculate data length and get a mbuf
 384          * for UDP and IP6 headers.
 385          */
 386         M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT, 1);
 387         if (m == 0) {
 388                 error = ENOBUFS;
 389                 goto release;
 390         }
 391
 392         /*
 393          * Stuff checksum and output datagram.
 394          */
 395         udp6 = (struct udphdr *)(void *)(mtod(m, caddr_t) + hlen);
 396         udp6->uh_sport = in6p->in6p_lport; /* lport is always set in the PCB */
 397         udp6->uh_dport = fport;
 398         if (plen <= 0xffff) {
 399                 udp6->uh_ulen = htons((u_short)plen);
 400         } else {
 401                 udp6->uh_ulen = 0;
 402         }
 403         udp6->uh_sum = 0;
 404
 405         switch (af) {
 406         case AF_INET6:
 407                 ip6 = mtod(m, struct ip6_hdr *);
 408                 ip6->ip6_flow   = in6p->inp_flow & IPV6_FLOWINFO_MASK;
 409                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 410                 ip6->ip6_vfc    |= IPV6_VERSION;
 411 #if 0           /* ip6_plen will be filled in ip6_output. */
 412                 ip6->ip6_plen   = htons((u_short)plen);
 413 #endif
 414                 ip6->ip6_nxt    = IPPROTO_UDP;
 415                 ip6->ip6_hlim   = in6_selecthlim(in6p, in6p->in6p_route.ro_rt ?
 416                     in6p->in6p_route.ro_rt->rt_ifp : NULL);
 417                 ip6->ip6_src    = *laddr;
 418                 ip6->ip6_dst    = *faddr;
 419
 420                 udp6->uh_sum = in6_pseudo(laddr, faddr,
 421                     htonl(plen + IPPROTO_UDP));
 422                 m->m_pkthdr.csum_flags = (CSUM_UDPIPV6 | CSUM_ZERO_INVERT);
 423                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 424
 425                 if (!IN6_IS_ADDR_UNSPECIFIED(laddr)) {
 426                         ip6oa.ip6oa_flags |= IP6OAF_BOUND_SRCADDR;
 427                 }
 428
 429                 flags = IPV6_OUTARGS;
 430
 431                 udp6stat.udp6s_opackets++;
 432
 433 #if NECP
 434                 {
 435                         necp_kernel_policy_id policy_id;
 436                         necp_kernel_policy_id skip_policy_id;
 437                         u_int32_t route_rule_id;
 438
 439                         /*
 440                          * We need a route to perform NECP route rule checks
 441                          */
 442                         if (net_qos_policy_restricted != 0 &&
 443                             ROUTE_UNUSABLE(&in6p->inp_route)) {
 444                                 struct sockaddr_in6 to;
 445                                 struct sockaddr_in6 from;
 446
 447                                 ROUTE_RELEASE(&in6p->inp_route);
 448
 449                                 bzero(&from, sizeof(struct sockaddr_in6));
 450                                 from.sin6_family = AF_INET6;
 451                                 from.sin6_len = sizeof(struct sockaddr_in6);
 452                                 from.sin6_addr = *laddr;
 453
 454                                 bzero(&to, sizeof(struct sockaddr_in6));
 455                                 to.sin6_family = AF_INET6;
 456                                 to.sin6_len = sizeof(struct sockaddr_in6);
 457                                 to.sin6_addr = *faddr;
 458
 459                                 in6p->inp_route.ro_dst.sa_family = AF_INET6;
 460                                 in6p->inp_route.ro_dst.sa_len = sizeof(struct sockaddr_in6);
 461                                 ((struct sockaddr_in6 *)(void *)&in6p->inp_route.ro_dst)->sin6_addr =
 462                                     *faddr;
 463
 464                                 rtalloc_scoped(&in6p->inp_route, ip6oa.ip6oa_boundif);
 465
 466                                 inp_update_necp_policy(in6p, (struct sockaddr *)&from,
 467                                     (struct sockaddr *)&to, ip6oa.ip6oa_boundif);
 468                                 in6p->inp_policyresult.results.qos_marking_gencount = 0;
 469                         }
 470
 471                         if (!necp_socket_is_allowed_to_send_recv_v6(in6p, in6p->in6p_lport, fport, laddr, faddr, NULL, &policy_id, &route_rule_id, &skip_policy_id)) {
 472                                 error = EHOSTUNREACH;
 473                                 goto release;
 474                         }
 475
 476                         necp_mark_packet_from_socket(m, in6p, policy_id, route_rule_id, skip_policy_id);
 477
 478                         if (net_qos_policy_restricted != 0) {
 479                                 necp_socket_update_qos_marking(in6p, in6p->in6p_route.ro_rt,
 480                                     NULL, route_rule_id);
 481                         }
 482                 }
 483 #endif /* NECP */
 484                 if ((so->so_flags1 & SOF1_QOSMARKING_ALLOWED)) {
 485                         ip6oa.ip6oa_flags |= IP6OAF_QOSMARKING_ALLOWED;
 486                 }
 487
 488 #if IPSEC
 489                 if (in6p->in6p_sp != NULL && ipsec_setsocket(m, so) != 0) {
 490                         error = ENOBUFS;
 491                         goto release;
 492                 }
 493 #endif /*IPSEC*/
 494
 495                 /* In case of IPv4-mapped address used in previous send */
 496                 if (ROUTE_UNUSABLE(&in6p->in6p_route) ||
 497                     rt_key(in6p->in6p_route.ro_rt)->sa_family != AF_INET6) {
 498                         ROUTE_RELEASE(&in6p->in6p_route);
 499                 }
 500
 501                 /* Copy the cached route and take an extra reference */
 502                 in6p_route_copyout(in6p, &ro);
 503
 504                 set_packet_service_class(m, so, sotc, PKT_SCF_IPV6);
 505
 506                 m->m_pkthdr.pkt_flowsrc = FLOWSRC_INPCB;
 507                 m->m_pkthdr.pkt_flowid = in6p->inp_flowhash;
 508                 m->m_pkthdr.pkt_proto = IPPROTO_UDP;
 509                 m->m_pkthdr.pkt_flags |= (PKTF_FLOW_ID | PKTF_FLOW_LOCALSRC);
 510                 if (flowadv) {
 511                         m->m_pkthdr.pkt_flags |= PKTF_FLOW_ADV;
 512                 }
 513                 m->m_pkthdr.tx_udp_pid = so->last_pid;
 514                 if (so->so_flags & SOF_DELEGATED) {
 515                         m->m_pkthdr.tx_udp_e_pid = so->e_pid;
 516                 } else {
 517                         m->m_pkthdr.tx_udp_e_pid = 0;
 518                 }
 519
 520                 im6o = in6p->in6p_moptions;
 521                 if (im6o != NULL) {
 522                         IM6O_LOCK(im6o);
 523                         IM6O_ADDREF_LOCKED(im6o);
 524                         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 525                             im6o->im6o_multicast_ifp != NULL) {
 526                                 in6p->in6p_last_outifp =
 527                                     im6o->im6o_multicast_ifp;
 528                         }
 529                         IM6O_UNLOCK(im6o);
 530                 }
 531
 532                 in6p->inp_sndinprog_cnt++;
 533
 534                 socket_unlock(so, 0);
 535                 error = ip6_output(m, optp, &ro, flags, im6o, NULL, &ip6oa);
 536                 m = NULL;
 537                 socket_lock(so, 0);
 538
 539                 if (im6o != NULL) {
 540                         IM6O_REMREF(im6o);
 541                 }
 542
 543                 if (error == 0 && nstat_collect) {
 544                         boolean_t cell, wifi, wired;
 545
 546                         if (in6p->in6p_route.ro_rt != NULL) {
 547                                 cell = IFNET_IS_CELLULAR(in6p->in6p_route.
 548                                     ro_rt->rt_ifp);
 549                                 wifi = (!cell && IFNET_IS_WIFI(in6p->in6p_route.
 550                                     ro_rt->rt_ifp));
 551                                 wired = (!wifi && IFNET_IS_WIRED(in6p->in6p_route.
 552                                     ro_rt->rt_ifp));
 553                         } else {
 554                                 cell = wifi = wired = FALSE;
 555                         }
 556                         INP_ADD_STAT(in6p, cell, wifi, wired, txpackets, 1);
 557                         INP_ADD_STAT(in6p, cell, wifi, wired, txbytes, ulen);
 558                         inp_set_activity_bitmap(in6p);
 559                 }
 560
 561                 if (flowadv && (adv->code == FADV_FLOW_CONTROLLED ||
 562                     adv->code == FADV_SUSPENDED)) {
 563                         /*
 564                          * Return an error to indicate
 565                          * that the packet has been dropped.
 566                          */
 567                         error = ENOBUFS;
 568                         inp_set_fc_state(in6p, adv->code);
 569                 }
 570
 571                 VERIFY(in6p->inp_sndinprog_cnt > 0);
 572                 if (--in6p->inp_sndinprog_cnt == 0) {
 573                         in6p->inp_flags &= ~(INP_FC_FEEDBACK);
 574                         if (in6p->inp_sndingprog_waiters > 0) {
 575                                 wakeup(&in6p->inp_sndinprog_cnt);
 576                         }
 577                 }
 578
 579                 if (ro.ro_rt != NULL) {
 580                         struct ifnet *outif = ro.ro_rt->rt_ifp;
 581
 582                         so->so_pktheadroom = P2ROUNDUP(
 583                                 sizeof(struct udphdr) +
 584                                 hlen +
 585                                 ifnet_hdrlen(outif) +
 586                                 ifnet_mbuf_packetpreamblelen(outif),
 587                                 sizeof(u_int32_t));
 588                 }
 589
 590                 /* Synchronize PCB cached route */
 591                 in6p_route_copyin(in6p, &ro);
 592
 593                 if (in6p->in6p_route.ro_rt != NULL) {
 594                         struct rtentry *rt = in6p->in6p_route.ro_rt;
 595                         struct ifnet *outif;
 596
 597                         if (rt->rt_flags & RTF_MULTICAST) {
 598                                 rt = NULL;      /* unusable */
 599                         }
 600 #if CONTENT_FILTER
 601                         /*
 602                          * Discard temporary route for cfil case
 603                          */
 604                         if (cfil_faddr_use) {
 605                                 rt = NULL;      /* unusable */
 606                         }
 607 #endif
 608
 609                         /*
 610                          * Always discard the cached route for unconnected
 611                          * socket or if it is a multicast route.
 612                          */
 613                         if (rt == NULL) {
 614                                 ROUTE_RELEASE(&in6p->in6p_route);
 615                         }
 616
 617                         /*
 618                          * If the destination route is unicast, update outif
 619                          * with that of the route interface used by IP.
 620                          */
 621                         if (rt != NULL) {
 622                                 /*
 623                                  * When an NECP IP tunnel policy forces the outbound interface,
 624                                  * ip6_output_list() informs the transport layer what is the actual
 625                                  * outgoing interface
 626                                  */
 627                                 if (ip6oa.ip6oa_flags & IP6OAF_BOUND_IF) {
 628                                         outif = ifindex2ifnet[ip6oa.ip6oa_boundif];
 629                                 } else {
 630                                         outif = rt->rt_ifp;
 631                                 }
 632                                 if (outif != NULL && outif != in6p->in6p_last_outifp) {
 633                                         in6p->in6p_last_outifp = outif;
 634
 635                                         so->so_pktheadroom = P2ROUNDUP(
 636                                                 sizeof(struct udphdr) +
 637                                                 hlen +
 638                                                 ifnet_hdrlen(outif) +
 639                                                 ifnet_mbuf_packetpreamblelen(outif),
 640                                                 sizeof(u_int32_t));
 641                                 }
 642                         }
 643                 } else {
 644                         ROUTE_RELEASE(&in6p->in6p_route);
 645                 }
 646
 647                 /*
 648                  * If output interface was cellular/expensive, and this
 649                  * socket is denied access to it, generate an event.
 650                  */
 651                 if (error != 0 && (ip6oa.ip6oa_retflags & IP6OARF_IFDENIED) &&
 652                     (INP_NO_CELLULAR(in6p) || INP_NO_EXPENSIVE(in6p) || INP_NO_CONSTRAINED(in6p))) {
 653                         soevent(in6p->inp_socket, (SO_FILT_HINT_LOCKED |
 654                             SO_FILT_HINT_IFDENIED));
 655                 }
 656                 break;
 657         case AF_INET:
 658                 error = EAFNOSUPPORT;
 659                 goto release;
 660         }
 661         goto releaseopt;
 662
 663 release:
 664         if (m != NULL) {
 665                 m_freem(m);
 666         }
 667
 668 releaseopt:
 669         if (control != NULL) {
 670                 if (optp == &opt) {
 671                         ip6_clearpktopts(optp, -1);
 672                 }
 673                 m_freem(control);
 674         }
 675 #if CONTENT_FILTER
 676         if (cfil_tag) {
 677                 m_tag_free(cfil_tag);
 678         }
 679 #endif
 680         return error;
 681 }