sys/netinet6/udp6_usrreq.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * Copyright (c) 2010-2011 Juniper Networks, Inc.
   4  * Copyright (c) 2014 Kevin Lo
   5  * All rights reserved.
   6  *
   7  * Portions of this software were developed by Robert N. M. Watson under
   8  * contract to Juniper Networks, Inc.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the project nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      $KAME: udp6_usrreq.c,v 1.27 2001/05/21 05:45:10 jinmei Exp $
  35  *      $KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei Exp $
  36  */
  37
  38 /*-
  39  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
  40  *      The Regents of the University of California.
  41  * All rights reserved.
  42  *
  43  * Redistribution and use in source and binary forms, with or without
  44  * modification, are permitted provided that the following conditions
  45  * are met:
  46  * 1. Redistributions of source code must retain the above copyright
  47  *    notice, this list of conditions and the following disclaimer.
  48  * 2. Redistributions in binary form must reproduce the above copyright
  49  *    notice, this list of conditions and the following disclaimer in the
  50  *    documentation and/or other materials provided with the distribution.
  51  * 4. Neither the name of the University nor the names of its contributors
  52  *    may be used to endorse or promote products derived from this software
  53  *    without specific prior written permission.
  54  *
  55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  65  * SUCH DAMAGE.
  66  *
  67  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
  68  */
  69
  70 #include <sys/cdefs.h>
  71 __FBSDID("$FreeBSD$");
  72
  73 #include "opt_inet.h"
  74 #include "opt_inet6.h"
  75 #include "opt_ipfw.h"
  76 #include "opt_ipsec.h"
  77 #include "opt_kdtrace.h"
  78
  79 #include <sys/param.h>
  80 #include <sys/jail.h>
  81 #include <sys/kernel.h>
  82 #include <sys/lock.h>
  83 #include <sys/mbuf.h>
  84 #include <sys/priv.h>
  85 #include <sys/proc.h>
  86 #include <sys/protosw.h>
  87 #include <sys/sdt.h>
  88 #include <sys/signalvar.h>
  89 #include <sys/socket.h>
  90 #include <sys/socketvar.h>
  91 #include <sys/sx.h>
  92 #include <sys/sysctl.h>
  93 #include <sys/syslog.h>
  94 #include <sys/systm.h>
  95
  96 #include <net/if.h>
  97 #include <net/if_types.h>
  98 #include <net/route.h>
  99
 100 #include <netinet/in.h>
 101 #include <netinet/in_kdtrace.h>
 102 #include <netinet/in_pcb.h>
 103 #include <netinet/in_systm.h>
 104 #include <netinet/in_var.h>
 105 #include <netinet/ip.h>
 106 #include <netinet/ip_icmp.h>
 107 #include <netinet/ip6.h>
 108 #include <netinet/icmp_var.h>
 109 #include <netinet/icmp6.h>
 110 #include <netinet/ip_var.h>
 111 #include <netinet/udp.h>
 112 #include <netinet/udp_var.h>
 113 #include <netinet/udplite.h>
 114
 115 #include <netinet6/ip6protosw.h>
 116 #include <netinet6/ip6_var.h>
 117 #include <netinet6/in6_pcb.h>
 118 #include <netinet6/udp6_var.h>
 119 #include <netinet6/scope6_var.h>
 120
 121 #ifdef IPSEC
 122 #include <netipsec/ipsec.h>
 123 #include <netipsec/ipsec6.h>
 124 #endif /* IPSEC */
 125
 126 #include <security/mac/mac_framework.h>
 127
 128 /*
 129  * UDP protocol implementation.
 130  * Per RFC 768, August, 1980.
 131  */
 132
 133 extern struct protosw   inetsw[];
 134 static void             udp6_detach(struct socket *so);
 135
 136 static void
 137 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
 138     struct sockaddr_in6 *fromsa)
 139 {
 140         struct socket *so;
 141         struct mbuf *opts;
 142         struct udpcb *up;
 143
 144         INP_LOCK_ASSERT(inp);
 145
 146         /*
 147          * Engage the tunneling protocol.
 148          */
 149         up = intoudpcb(inp);
 150         if (up->u_tun_func != NULL) {
 151                 (*up->u_tun_func)(n, off, inp, (struct sockaddr *)fromsa,
 152                     up->u_tun_ctx);
 153                 return;
 154         }
 155 #ifdef IPSEC
 156         /* Check AH/ESP integrity. */
 157         if (ipsec6_in_reject(n, inp)) {
 158                 m_freem(n);
 159                 IPSEC6STAT_INC(ips_in_polvio);
 160                 return;
 161         }
 162 #endif /* IPSEC */
 163 #ifdef MAC
 164         if (mac_inpcb_check_deliver(inp, n) != 0) {
 165                 m_freem(n);
 166                 return;
 167         }
 168 #endif
 169         opts = NULL;
 170         if (inp->inp_flags & INP_CONTROLOPTS ||
 171             inp->inp_socket->so_options & SO_TIMESTAMP)
 172                 ip6_savecontrol(inp, n, &opts);
 173         m_adj(n, off + sizeof(struct udphdr));
 174
 175         so = inp->inp_socket;
 176         SOCKBUF_LOCK(&so->so_rcv);
 177         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
 178             opts) == 0) {
 179                 SOCKBUF_UNLOCK(&so->so_rcv);
 180                 m_freem(n);
 181                 if (opts)
 182                         m_freem(opts);
 183                 UDPSTAT_INC(udps_fullsock);
 184         } else
 185                 sorwakeup_locked(so);
 186 }
 187
 188 int
 189 udp6_input(struct mbuf **mp, int *offp, int proto)
 190 {
 191         struct mbuf *m = *mp;
 192         struct ifnet *ifp;
 193         struct ip6_hdr *ip6;
 194         struct udphdr *uh;
 195         struct inpcb *inp;
 196         struct inpcbinfo *pcbinfo;
 197         struct udpcb *up;
 198         int off = *offp;
 199         int cscov_partial;
 200         int plen, ulen;
 201         struct sockaddr_in6 fromsa;
 202         struct m_tag *fwd_tag;
 203         uint16_t uh_sum;
 204         uint8_t nxt;
 205
 206         ifp = m->m_pkthdr.rcvif;
 207         ip6 = mtod(m, struct ip6_hdr *);
 208
 209         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 210                 /* XXX send icmp6 host/port unreach? */
 211                 m_freem(m);
 212                 return (IPPROTO_DONE);
 213         }
 214
 215 #ifndef PULLDOWN_TEST
 216         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
 217         ip6 = mtod(m, struct ip6_hdr *);
 218         uh = (struct udphdr *)((caddr_t)ip6 + off);
 219 #else
 220         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 221         if (!uh)
 222                 return (IPPROTO_DONE);
 223 #endif
 224
 225         UDPSTAT_INC(udps_ipackets);
 226
 227         /*
 228          * Destination port of 0 is illegal, based on RFC768.
 229          */
 230         if (uh->uh_dport == 0)
 231                 goto badunlocked;
 232
 233         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
 234         ulen = ntohs((u_short)uh->uh_ulen);
 235
 236         nxt = ip6->ip6_nxt;
 237         cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
 238         if (nxt == IPPROTO_UDPLITE) {
 239                 /* Zero means checksum over the complete packet. */
 240                 if (ulen == 0)
 241                         ulen = plen;
 242                 if (ulen == plen)
 243                         cscov_partial = 0;
 244                 if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
 245                         /* XXX: What is the right UDPLite MIB counter? */
 246                         goto badunlocked;
 247                 }
 248                 if (uh->uh_sum == 0) {
 249                         /* XXX: What is the right UDPLite MIB counter? */
 250                         goto badunlocked;
 251                 }
 252         } else {
 253                 if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
 254                         UDPSTAT_INC(udps_badlen);
 255                         goto badunlocked;
 256                 }
 257                 if (uh->uh_sum == 0) {
 258                         UDPSTAT_INC(udps_nosum);
 259                         goto badunlocked;
 260                 }
 261         }
 262
 263         if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
 264             !cscov_partial) {
 265                 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 266                         uh_sum = m->m_pkthdr.csum_data;
 267                 else
 268                         uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
 269                             m->m_pkthdr.csum_data);
 270                 uh_sum ^= 0xffff;
 271         } else
 272                 uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);
 273
 274         if (uh_sum != 0) {
 275                 UDPSTAT_INC(udps_badsum);
 276                 goto badunlocked;
 277         }
 278
 279         /*
 280          * Construct sockaddr format source address.
 281          */
 282         init_sin6(&fromsa, m);
 283         fromsa.sin6_port = uh->uh_sport;
 284
 285         pcbinfo = get_inpcbinfo(nxt);
 286         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 287                 struct inpcb *last;
 288                 struct inpcbhead *pcblist;
 289                 struct ip6_moptions *imo;
 290
 291                 INP_INFO_RLOCK(pcbinfo);
 292                 /*
 293                  * In the event that laddr should be set to the link-local
 294                  * address (this happens in RIPng), the multicast address
 295                  * specified in the received packet will not match laddr.  To
 296                  * handle this situation, matching is relaxed if the
 297                  * receiving interface is the same as one specified in the
 298                  * socket and if the destination multicast address matches
 299                  * one of the multicast groups specified in the socket.
 300                  */
 301
 302                 /*
 303                  * KAME note: traditionally we dropped udpiphdr from mbuf
 304                  * here.  We need udphdr for IPsec processing so we do that
 305                  * later.
 306                  */
 307                 pcblist = get_pcblist(nxt);
 308                 last = NULL;
 309                 LIST_FOREACH(inp, pcblist, inp_list) {
 310                         if ((inp->inp_vflag & INP_IPV6) == 0)
 311                                 continue;
 312                         if (inp->inp_lport != uh->uh_dport)
 313                                 continue;
 314                         if (inp->inp_fport != 0 &&
 315                             inp->inp_fport != uh->uh_sport)
 316                                 continue;
 317                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 318                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
 319                                                         &ip6->ip6_dst))
 320                                         continue;
 321                         }
 322                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 323                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
 324                                                         &ip6->ip6_src) ||
 325                                     inp->inp_fport != uh->uh_sport)
 326                                         continue;
 327                         }
 328
 329                         /*
 330                          * XXXRW: Because we weren't holding either the inpcb
 331                          * or the hash lock when we checked for a match
 332                          * before, we should probably recheck now that the
 333                          * inpcb lock is (supposed to be) held.
 334                          */
 335
 336                         /*
 337                          * Handle socket delivery policy for any-source
 338                          * and source-specific multicast. [RFC3678]
 339                          */
 340                         imo = inp->in6p_moptions;
 341                         if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 342                                 struct sockaddr_in6      mcaddr;
 343                                 int                      blocked;
 344
 345                                 INP_RLOCK(inp);
 346
 347                                 bzero(&mcaddr, sizeof(struct sockaddr_in6));
 348                                 mcaddr.sin6_len = sizeof(struct sockaddr_in6);
 349                                 mcaddr.sin6_family = AF_INET6;
 350                                 mcaddr.sin6_addr = ip6->ip6_dst;
 351
 352                                 blocked = im6o_mc_filter(imo, ifp,
 353                                         (struct sockaddr *)&mcaddr,
 354                                         (struct sockaddr *)&fromsa);
 355                                 if (blocked != MCAST_PASS) {
 356                                         if (blocked == MCAST_NOTGMEMBER)
 357                                                 IP6STAT_INC(ip6s_notmember);
 358                                         if (blocked == MCAST_NOTSMEMBER ||
 359                                             blocked == MCAST_MUTED)
 360                                                 UDPSTAT_INC(udps_filtermcast);
 361                                         INP_RUNLOCK(inp); /* XXX */
 362                                         continue;
 363                                 }
 364
 365                                 INP_RUNLOCK(inp);
 366                         }
 367                         if (last != NULL) {
 368                                 struct mbuf *n;
 369
 370                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
 371                                         INP_RLOCK(last);
 372                                         UDP_PROBE(receive, NULL, last, ip6,
 373                                             last, uh);
 374                                         udp6_append(last, n, off, &fromsa);
 375                                         INP_RUNLOCK(last);
 376                                 }
 377                         }
 378                         last = inp;
 379                         /*
 380                          * Don't look for additional matches if this one does
 381                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 382                          * socket options set.  This heuristic avoids
 383                          * searching through all pcbs in the common case of a
 384                          * non-shared port.  It assumes that an application
 385                          * will never clear these options after setting them.
 386                          */
 387                         if ((last->inp_socket->so_options &
 388                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 389                                 break;
 390                 }
 391
 392                 if (last == NULL) {
 393                         /*
 394                          * No matching pcb found; discard datagram.  (No need
 395                          * to send an ICMP Port Unreachable for a broadcast
 396                          * or multicast datgram.)
 397                          */
 398                         UDPSTAT_INC(udps_noport);
 399                         UDPSTAT_INC(udps_noportmcast);
 400                         goto badheadlocked;
 401                 }
 402                 INP_RLOCK(last);
 403                 INP_INFO_RUNLOCK(pcbinfo);
 404                 UDP_PROBE(receive, NULL, last, ip6, last, uh);
 405                 udp6_append(last, m, off, &fromsa);
 406                 INP_RUNLOCK(last);
 407                 return (IPPROTO_DONE);
 408         }
 409         /*
 410          * Locate pcb for datagram.
 411          */
 412
 413         /*
 414          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 415          */
 416         if ((m->m_flags & M_IP6_NEXTHOP) &&
 417             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 418                 struct sockaddr_in6 *next_hop6;
 419
 420                 next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
 421
 422                 /*
 423                  * Transparently forwarded. Pretend to be the destination.
 424                  * Already got one like this?
 425                  */
 426                 inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
 427                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 428                     INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
 429                 if (!inp) {
 430                         /*
 431                          * It's new.  Try to find the ambushing socket.
 432                          * Because we've rewritten the destination address,
 433                          * any hardware-generated hash is ignored.
 434                          */
 435                         inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
 436                             uh->uh_sport, &next_hop6->sin6_addr,
 437                             next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
 438                             uh->uh_dport, INPLOOKUP_WILDCARD |
 439                             INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
 440                 }
 441                 /* Remove the tag from the packet. We don't need it anymore. */
 442                 m_tag_delete(m, fwd_tag);
 443                 m->m_flags &= ~M_IP6_NEXTHOP;
 444         } else
 445                 inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
 446                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 447                     INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
 448                     m->m_pkthdr.rcvif, m);
 449         if (inp == NULL) {
 450                 if (udp_log_in_vain) {
 451                         char ip6bufs[INET6_ADDRSTRLEN];
 452                         char ip6bufd[INET6_ADDRSTRLEN];
 453
 454                         log(LOG_INFO,
 455                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
 456                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 457                             ntohs(uh->uh_dport),
 458                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
 459                             ntohs(uh->uh_sport));
 460                 }
 461                 UDPSTAT_INC(udps_noport);
 462                 if (m->m_flags & M_MCAST) {
 463                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
 464                         UDPSTAT_INC(udps_noportmcast);
 465                         goto badunlocked;
 466                 }
 467                 if (V_udp_blackhole)
 468                         goto badunlocked;
 469                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
 470                         goto badunlocked;
 471                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
 472                 return (IPPROTO_DONE);
 473         }
 474         INP_RLOCK_ASSERT(inp);
 475         up = intoudpcb(inp);
 476         if (cscov_partial) {
 477                 if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
 478                         INP_RUNLOCK(inp);
 479                         m_freem(m);
 480                         return (IPPROTO_DONE);
 481                 }
 482         }
 483         UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
 484         udp6_append(inp, m, off, &fromsa);
 485         INP_RUNLOCK(inp);
 486         return (IPPROTO_DONE);
 487
 488 badheadlocked:
 489         INP_INFO_RUNLOCK(pcbinfo);
 490 badunlocked:
 491         if (m)
 492                 m_freem(m);
 493         return (IPPROTO_DONE);
 494 }
 495
 496 static void
 497 udp6_common_ctlinput(int cmd, struct sockaddr *sa, void *d,
 498     struct inpcbinfo *pcbinfo)
 499 {
 500         struct udphdr uh;
 501         struct ip6_hdr *ip6;
 502         struct mbuf *m;
 503         int off = 0;
 504         struct ip6ctlparam *ip6cp = NULL;
 505         const struct sockaddr_in6 *sa6_src = NULL;
 506         void *cmdarg;
 507         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 508         struct udp_portonly {
 509                 u_int16_t uh_sport;
 510                 u_int16_t uh_dport;
 511         } *uhp;
 512
 513         if (sa->sa_family != AF_INET6 ||
 514             sa->sa_len != sizeof(struct sockaddr_in6))
 515                 return;
 516
 517         if ((unsigned)cmd >= PRC_NCMDS)
 518                 return;
 519         if (PRC_IS_REDIRECT(cmd))
 520                 notify = in6_rtchange, d = NULL;
 521         else if (cmd == PRC_HOSTDEAD)
 522                 d = NULL;
 523         else if (inet6ctlerrmap[cmd] == 0)
 524                 return;
 525
 526         /* if the parameter is from icmp6, decode it. */
 527         if (d != NULL) {
 528                 ip6cp = (struct ip6ctlparam *)d;
 529                 m = ip6cp->ip6c_m;
 530                 ip6 = ip6cp->ip6c_ip6;
 531                 off = ip6cp->ip6c_off;
 532                 cmdarg = ip6cp->ip6c_cmdarg;
 533                 sa6_src = ip6cp->ip6c_src;
 534         } else {
 535                 m = NULL;
 536                 ip6 = NULL;
 537                 cmdarg = NULL;
 538                 sa6_src = &sa6_any;
 539         }
 540
 541         if (ip6) {
 542                 /*
 543                  * XXX: We assume that when IPV6 is non NULL,
 544                  * M and OFF are valid.
 545                  */
 546
 547                 /* Check if we can safely examine src and dst ports. */
 548                 if (m->m_pkthdr.len < off + sizeof(*uhp))
 549                         return;
 550
 551                 bzero(&uh, sizeof(uh));
 552                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
 553
 554                 (void)in6_pcbnotify(pcbinfo, sa, uh.uh_dport,
 555                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
 556                     cmdarg, notify);
 557         } else
 558                 (void)in6_pcbnotify(pcbinfo, sa, 0,
 559                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
 560 }
 561
 562 void
 563 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 564 {
 565
 566         return (udp6_common_ctlinput(cmd, sa, d, &V_udbinfo));
 567 }
 568
 569 void
 570 udplite6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 571 {
 572
 573         return (udp6_common_ctlinput(cmd, sa, d, &V_ulitecbinfo));
 574 }
 575
 576 static int
 577 udp6_getcred(SYSCTL_HANDLER_ARGS)
 578 {
 579         struct xucred xuc;
 580         struct sockaddr_in6 addrs[2];
 581         struct inpcb *inp;
 582         int error;
 583
 584         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 585         if (error)
 586                 return (error);
 587
 588         if (req->newlen != sizeof(addrs))
 589                 return (EINVAL);
 590         if (req->oldlen != sizeof(struct xucred))
 591                 return (EINVAL);
 592         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 593         if (error)
 594                 return (error);
 595         if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
 596             (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
 597                 return (error);
 598         }
 599         inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
 600             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
 601             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 602         if (inp != NULL) {
 603                 INP_RLOCK_ASSERT(inp);
 604                 if (inp->inp_socket == NULL)
 605                         error = ENOENT;
 606                 if (error == 0)
 607                         error = cr_canseesocket(req->td->td_ucred,
 608                             inp->inp_socket);
 609                 if (error == 0)
 610                         cru2x(inp->inp_cred, &xuc);
 611                 INP_RUNLOCK(inp);
 612         } else
 613                 error = ENOENT;
 614         if (error == 0)
 615                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 616         return (error);
 617 }
 618
 619 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
 620     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
 621
 622 static int
 623 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
 624     struct mbuf *control, struct thread *td)
 625 {
 626         u_int32_t ulen = m->m_pkthdr.len;
 627         u_int32_t plen = sizeof(struct udphdr) + ulen;
 628         struct ip6_hdr *ip6;
 629         struct udphdr *udp6;
 630         struct in6_addr *laddr, *faddr, in6a;
 631         struct sockaddr_in6 *sin6 = NULL;
 632         struct ifnet *oifp = NULL;
 633         int cscov_partial = 0;
 634         int scope_ambiguous = 0;
 635         u_short fport;
 636         int error = 0;
 637         uint8_t nxt;
 638         uint16_t cscov = 0;
 639         struct ip6_pktopts *optp, opt;
 640         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 641         int flags;
 642         struct sockaddr_in6 tmp;
 643
 644         INP_WLOCK_ASSERT(inp);
 645         INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
 646
 647         if (addr6) {
 648                 /* addr6 has been validated in udp6_send(). */
 649                 sin6 = (struct sockaddr_in6 *)addr6;
 650
 651                 /* protect *sin6 from overwrites */
 652                 tmp = *sin6;
 653                 sin6 = &tmp;
 654
 655                 /*
 656                  * Application should provide a proper zone ID or the use of
 657                  * default zone IDs should be enabled.  Unfortunately, some
 658                  * applications do not behave as it should, so we need a
 659                  * workaround.  Even if an appropriate ID is not determined,
 660                  * we'll see if we can determine the outgoing interface.  If we
 661                  * can, determine the zone ID based on the interface below.
 662                  */
 663                 if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
 664                         scope_ambiguous = 1;
 665                 if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
 666                         return (error);
 667         }
 668
 669         if (control) {
 670                 if ((error = ip6_setpktopts(control, &opt,
 671                     inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
 672                         goto release;
 673                 optp = &opt;
 674         } else
 675                 optp = inp->in6p_outputopts;
 676
 677         if (sin6) {
 678                 faddr = &sin6->sin6_addr;
 679
 680                 /*
 681                  * Since we saw no essential reason for calling in_pcbconnect,
 682                  * we get rid of such kind of logic, and call in6_selectsrc
 683                  * and in6_pcbsetport in order to fill in the local address
 684                  * and the local port.
 685                  */
 686                 if (sin6->sin6_port == 0) {
 687                         error = EADDRNOTAVAIL;
 688                         goto release;
 689                 }
 690
 691                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 692                         /* how about ::ffff:0.0.0.0 case? */
 693                         error = EISCONN;
 694                         goto release;
 695                 }
 696
 697                 fport = sin6->sin6_port; /* allow 0 port */
 698
 699                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 700                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 701                                 /*
 702                                  * I believe we should explicitly discard the
 703                                  * packet when mapped addresses are disabled,
 704                                  * rather than send the packet as an IPv6 one.
 705                                  * If we chose the latter approach, the packet
 706                                  * might be sent out on the wire based on the
 707                                  * default route, the situation which we'd
 708                                  * probably want to avoid.
 709                                  * (20010421 jinmei@kame.net)
 710                                  */
 711                                 error = EINVAL;
 712                                 goto release;
 713                         }
 714                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 715                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 716                                 /*
 717                                  * when remote addr is an IPv4-mapped address,
 718                                  * local addr should not be an IPv6 address,
 719                                  * since you cannot determine how to map IPv6
 720                                  * source address to IPv4.
 721                                  */
 722                                 error = EINVAL;
 723                                 goto release;
 724                         }
 725
 726                         af = AF_INET;
 727                 }
 728
 729                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 730                         error = in6_selectsrc(sin6, optp, inp, NULL,
 731                             td->td_ucred, &oifp, &in6a);
 732                         if (error)
 733                                 goto release;
 734                         if (oifp && scope_ambiguous &&
 735                             (error = in6_setscope(&sin6->sin6_addr,
 736                             oifp, NULL))) {
 737                                 goto release;
 738                         }
 739                         laddr = &in6a;
 740                 } else
 741                         laddr = &inp->in6p_laddr;       /* XXX */
 742                 if (laddr == NULL) {
 743                         if (error == 0)
 744                                 error = EADDRNOTAVAIL;
 745                         goto release;
 746                 }
 747                 if (inp->inp_lport == 0 &&
 748                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
 749                         /* Undo an address bind that may have occurred. */
 750                         inp->in6p_laddr = in6addr_any;
 751                         goto release;
 752                 }
 753         } else {
 754                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 755                         error = ENOTCONN;
 756                         goto release;
 757                 }
 758                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 759                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 760                                 /*
 761                                  * XXX: this case would happen when the
 762                                  * application sets the V6ONLY flag after
 763                                  * connecting the foreign address.
 764                                  * Such applications should be fixed,
 765                                  * so we bark here.
 766                                  */
 767                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 768                                     "option was set for a connected socket\n");
 769                                 error = EINVAL;
 770                                 goto release;
 771                         } else
 772                                 af = AF_INET;
 773                 }
 774                 laddr = &inp->in6p_laddr;
 775                 faddr = &inp->in6p_faddr;
 776                 fport = inp->inp_fport;
 777         }
 778
 779         if (af == AF_INET)
 780                 hlen = sizeof(struct ip);
 781
 782         /*
 783          * Calculate data length and get a mbuf
 784          * for UDP and IP6 headers.
 785          */
 786         M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
 787         if (m == 0) {
 788                 error = ENOBUFS;
 789                 goto release;
 790         }
 791
 792         /*
 793          * Stuff checksum and output datagram.
 794          */
 795         nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
 796             IPPROTO_UDP : IPPROTO_UDPLITE;
 797         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 798         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
 799         udp6->uh_dport = fport;
 800         if (nxt == IPPROTO_UDPLITE) {
 801                 struct udpcb *up;
 802
 803                 up = intoudpcb(inp);
 804                 cscov = up->u_txcslen;
 805                 if (cscov >= plen)
 806                         cscov = 0;
 807                 udp6->uh_ulen = htons(cscov);
 808                 /*
 809                  * For UDP-Lite, checksum coverage length of zero means
 810                  * the entire UDPLite packet is covered by the checksum.
 811                  */
 812                 cscov_partial = (cscov == 0) ? 0 : 1;
 813         } else if (plen <= 0xffff)
 814                 udp6->uh_ulen = htons((u_short)plen);
 815         else
 816                 udp6->uh_ulen = 0;
 817         udp6->uh_sum = 0;
 818
 819         switch (af) {
 820         case AF_INET6:
 821                 ip6 = mtod(m, struct ip6_hdr *);
 822                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
 823                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 824                 ip6->ip6_vfc    |= IPV6_VERSION;
 825                 ip6->ip6_plen   = htons((u_short)plen);
 826                 ip6->ip6_nxt    = nxt;
 827                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 828                 ip6->ip6_src    = *laddr;
 829                 ip6->ip6_dst    = *faddr;
 830
 831                 if (cscov_partial) {
 832                         if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
 833                             sizeof(struct ip6_hdr), plen, cscov)) == 0)
 834                                 udp6->uh_sum = 0xffff;
 835                 } else {
 836                         udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
 837                         m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
 838                         m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 839                 }
 840
 841                 flags = 0;
 842
 843                 UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
 844                 UDPSTAT_INC(udps_opackets);
 845                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 846                     NULL, inp);
 847                 break;
 848         case AF_INET:
 849                 error = EAFNOSUPPORT;
 850                 goto release;
 851         }
 852         goto releaseopt;
 853
 854 release:
 855         m_freem(m);
 856
 857 releaseopt:
 858         if (control) {
 859                 ip6_clearpktopts(&opt, -1);
 860                 m_freem(control);
 861         }
 862         return (error);
 863 }
 864
 865 static void
 866 udp6_abort(struct socket *so)
 867 {
 868         struct inpcb *inp;
 869         struct inpcbinfo *pcbinfo;
 870
 871         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 872         inp = sotoinpcb(so);
 873         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 874
 875 #ifdef INET
 876         if (inp->inp_vflag & INP_IPV4) {
 877                 struct pr_usrreqs *pru;
 878
 879                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 880                 (*pru->pru_abort)(so);
 881                 return;
 882         }
 883 #endif
 884
 885         INP_WLOCK(inp);
 886         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 887                 INP_HASH_WLOCK(pcbinfo);
 888                 in6_pcbdisconnect(inp);
 889                 inp->in6p_laddr = in6addr_any;
 890                 INP_HASH_WUNLOCK(pcbinfo);
 891                 soisdisconnected(so);
 892         }
 893         INP_WUNLOCK(inp);
 894 }
 895
 896 static int
 897 udp6_attach(struct socket *so, int proto, struct thread *td)
 898 {
 899         struct inpcb *inp;
 900         struct inpcbinfo *pcbinfo;
 901         int error;
 902
 903         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 904         inp = sotoinpcb(so);
 905         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 906
 907         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 908                 error = soreserve(so, udp_sendspace, udp_recvspace);
 909                 if (error)
 910                         return (error);
 911         }
 912         INP_INFO_WLOCK(pcbinfo);
 913         error = in_pcballoc(so, pcbinfo);
 914         if (error) {
 915                 INP_INFO_WUNLOCK(pcbinfo);
 916                 return (error);
 917         }
 918         inp = (struct inpcb *)so->so_pcb;
 919         inp->inp_vflag |= INP_IPV6;
 920         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 921                 inp->inp_vflag |= INP_IPV4;
 922         inp->in6p_hops = -1;    /* use kernel default */
 923         inp->in6p_cksum = -1;   /* just to be sure */
 924         /*
 925          * XXX: ugly!!
 926          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 927          * because the socket may be bound to an IPv6 wildcard address,
 928          * which may match an IPv4-mapped IPv6 address.
 929          */
 930         inp->inp_ip_ttl = V_ip_defttl;
 931
 932         error = udp_newudpcb(inp);
 933         if (error) {
 934                 in_pcbdetach(inp);
 935                 in_pcbfree(inp);
 936                 INP_INFO_WUNLOCK(pcbinfo);
 937                 return (error);
 938         }
 939         INP_WUNLOCK(inp);
 940         INP_INFO_WUNLOCK(pcbinfo);
 941         return (0);
 942 }
 943
 944 static int
 945 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 946 {
 947         struct inpcb *inp;
 948         struct inpcbinfo *pcbinfo;
 949         int error;
 950
 951         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 952         inp = sotoinpcb(so);
 953         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 954
 955         INP_WLOCK(inp);
 956         INP_HASH_WLOCK(pcbinfo);
 957         inp->inp_vflag &= ~INP_IPV4;
 958         inp->inp_vflag |= INP_IPV6;
 959         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 960                 struct sockaddr_in6 *sin6_p;
 961
 962                 sin6_p = (struct sockaddr_in6 *)nam;
 963
 964                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 965                         inp->inp_vflag |= INP_IPV4;
 966 #ifdef INET
 967                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 968                         struct sockaddr_in sin;
 969
 970                         in6_sin6_2_sin(&sin, sin6_p);
 971                         inp->inp_vflag |= INP_IPV4;
 972                         inp->inp_vflag &= ~INP_IPV6;
 973                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 974                             td->td_ucred);
 975                         goto out;
 976                 }
 977 #endif
 978         }
 979
 980         error = in6_pcbbind(inp, nam, td->td_ucred);
 981 #ifdef INET
 982 out:
 983 #endif
 984         INP_HASH_WUNLOCK(pcbinfo);
 985         INP_WUNLOCK(inp);
 986         return (error);
 987 }
 988
 989 static void
 990 udp6_close(struct socket *so)
 991 {
 992         struct inpcb *inp;
 993         struct inpcbinfo *pcbinfo;
 994
 995         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 996         inp = sotoinpcb(so);
 997         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
 998
 999 #ifdef INET
1000         if (inp->inp_vflag & INP_IPV4) {
1001                 struct pr_usrreqs *pru;
1002
1003                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1004                 (*pru->pru_disconnect)(so);
1005                 return;
1006         }
1007 #endif
1008         INP_WLOCK(inp);
1009         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1010                 INP_HASH_WLOCK(pcbinfo);
1011                 in6_pcbdisconnect(inp);
1012                 inp->in6p_laddr = in6addr_any;
1013                 INP_HASH_WUNLOCK(pcbinfo);
1014                 soisdisconnected(so);
1015         }
1016         INP_WUNLOCK(inp);
1017 }
1018
1019 static int
1020 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1021 {
1022         struct inpcb *inp;
1023         struct inpcbinfo *pcbinfo;
1024         struct sockaddr_in6 *sin6;
1025         int error;
1026
1027         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1028         inp = sotoinpcb(so);
1029         sin6 = (struct sockaddr_in6 *)nam;
1030         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
1031
1032         /*
1033          * XXXRW: Need to clarify locking of v4/v6 flags.
1034          */
1035         INP_WLOCK(inp);
1036 #ifdef INET
1037         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
1038                 struct sockaddr_in sin;
1039
1040                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
1041                         error = EINVAL;
1042                         goto out;
1043                 }
1044                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1045                         error = EISCONN;
1046                         goto out;
1047                 }
1048                 in6_sin6_2_sin(&sin, sin6);
1049                 inp->inp_vflag |= INP_IPV4;
1050                 inp->inp_vflag &= ~INP_IPV6;
1051                 error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
1052                 if (error != 0)
1053                         goto out;
1054                 INP_HASH_WLOCK(pcbinfo);
1055                 error = in_pcbconnect(inp, (struct sockaddr *)&sin,
1056                     td->td_ucred);
1057                 INP_HASH_WUNLOCK(pcbinfo);
1058                 if (error == 0)
1059                         soisconnected(so);
1060                 goto out;
1061         }
1062 #endif
1063         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1064                 error = EISCONN;
1065                 goto out;
1066         }
1067         inp->inp_vflag &= ~INP_IPV4;
1068         inp->inp_vflag |= INP_IPV6;
1069         error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1070         if (error != 0)
1071                 goto out;
1072         INP_HASH_WLOCK(pcbinfo);
1073         error = in6_pcbconnect(inp, nam, td->td_ucred);
1074         INP_HASH_WUNLOCK(pcbinfo);
1075         if (error == 0)
1076                 soisconnected(so);
1077 out:
1078         INP_WUNLOCK(inp);
1079         return (error);
1080 }
1081
1082 static void
1083 udp6_detach(struct socket *so)
1084 {
1085         struct inpcb *inp;
1086         struct inpcbinfo *pcbinfo;
1087         struct udpcb *up;
1088
1089         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1090         inp = sotoinpcb(so);
1091         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1092
1093         INP_INFO_WLOCK(pcbinfo);
1094         INP_WLOCK(inp);
1095         up = intoudpcb(inp);
1096         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1097         in_pcbdetach(inp);
1098         in_pcbfree(inp);
1099         INP_INFO_WUNLOCK(pcbinfo);
1100         udp_discardcb(up);
1101 }
1102
1103 static int
1104 udp6_disconnect(struct socket *so)
1105 {
1106         struct inpcb *inp;
1107         struct inpcbinfo *pcbinfo;
1108         int error;
1109
1110         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1111         inp = sotoinpcb(so);
1112         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1113
1114 #ifdef INET
1115         if (inp->inp_vflag & INP_IPV4) {
1116                 struct pr_usrreqs *pru;
1117
1118                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1119                 (void)(*pru->pru_disconnect)(so);
1120                 return (0);
1121         }
1122 #endif
1123
1124         INP_WLOCK(inp);
1125
1126         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1127                 error = ENOTCONN;
1128                 goto out;
1129         }
1130
1131         INP_HASH_WLOCK(pcbinfo);
1132         in6_pcbdisconnect(inp);
1133         inp->in6p_laddr = in6addr_any;
1134         INP_HASH_WUNLOCK(pcbinfo);
1135         SOCK_LOCK(so);
1136         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1137         SOCK_UNLOCK(so);
1138 out:
1139         INP_WUNLOCK(inp);
1140         return (0);
1141 }
1142
1143 static int
1144 udp6_send(struct socket *so, int flags, struct mbuf *m,
1145     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1146 {
1147         struct inpcb *inp;
1148         struct inpcbinfo *pcbinfo;
1149         int error = 0;
1150
1151         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1152         inp = sotoinpcb(so);
1153         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1154
1155         INP_WLOCK(inp);
1156         if (addr) {
1157                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1158                         error = EINVAL;
1159                         goto bad;
1160                 }
1161                 if (addr->sa_family != AF_INET6) {
1162                         error = EAFNOSUPPORT;
1163                         goto bad;
1164                 }
1165         }
1166
1167 #ifdef INET
1168         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1169                 int hasv4addr;
1170                 struct sockaddr_in6 *sin6 = 0;
1171
1172                 if (addr == 0)
1173                         hasv4addr = (inp->inp_vflag & INP_IPV4);
1174                 else {
1175                         sin6 = (struct sockaddr_in6 *)addr;
1176                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1177                             ? 1 : 0;
1178                 }
1179                 if (hasv4addr) {
1180                         struct pr_usrreqs *pru;
1181
1182                         /*
1183                          * XXXRW: We release UDP-layer locks before calling
1184                          * udp_send() in order to avoid recursion.  However,
1185                          * this does mean there is a short window where inp's
1186                          * fields are unstable.  Could this lead to a
1187                          * potential race in which the factors causing us to
1188                          * select the UDPv4 output routine are invalidated?
1189                          */
1190                         INP_WUNLOCK(inp);
1191                         if (sin6)
1192                                 in6_sin6_2_sin_in_sock(addr);
1193                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1194                         /* addr will just be freed in sendit(). */
1195                         return ((*pru->pru_send)(so, flags, m, addr, control,
1196                             td));
1197                 }
1198         }
1199 #endif
1200 #ifdef MAC
1201         mac_inpcb_create_mbuf(inp, m);
1202 #endif
1203         INP_HASH_WLOCK(pcbinfo);
1204         error = udp6_output(inp, m, addr, control, td);
1205         INP_HASH_WUNLOCK(pcbinfo);
1206 #ifdef INET
1207 #endif
1208         INP_WUNLOCK(inp);
1209         return (error);
1210
1211 bad:
1212         INP_WUNLOCK(inp);
1213         m_freem(m);
1214         return (error);
1215 }
1216
1217 struct pr_usrreqs udp6_usrreqs = {
1218         .pru_abort =            udp6_abort,
1219         .pru_attach =           udp6_attach,
1220         .pru_bind =             udp6_bind,
1221         .pru_connect =          udp6_connect,
1222         .pru_control =          in6_control,
1223         .pru_detach =           udp6_detach,
1224         .pru_disconnect =       udp6_disconnect,
1225         .pru_peeraddr =         in6_mapped_peeraddr,
1226         .pru_send =             udp6_send,
1227         .pru_shutdown =         udp_shutdown,
1228         .pru_sockaddr =         in6_mapped_sockaddr,
1229         .pru_soreceive =        soreceive_dgram,
1230         .pru_sosend =           sosend_dgram,
1231         .pru_sosetlabel =       in_pcbsosetlabel,
1232         .pru_close =            udp6_close
1233 };