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
 143         INP_LOCK_ASSERT(inp);
 144
 145 #ifdef IPSEC
 146         /* Check AH/ESP integrity. */
 147         if (ipsec6_in_reject(n, inp)) {
 148                 m_freem(n);
 149                 IPSEC6STAT_INC(ips_in_polvio);
 150                 return;
 151         }
 152 #endif /* IPSEC */
 153 #ifdef MAC
 154         if (mac_inpcb_check_deliver(inp, n) != 0) {
 155                 m_freem(n);
 156                 return;
 157         }
 158 #endif
 159         opts = NULL;
 160         if (inp->inp_flags & INP_CONTROLOPTS ||
 161             inp->inp_socket->so_options & SO_TIMESTAMP)
 162                 ip6_savecontrol(inp, n, &opts);
 163         m_adj(n, off + sizeof(struct udphdr));
 164
 165         so = inp->inp_socket;
 166         SOCKBUF_LOCK(&so->so_rcv);
 167         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
 168             opts) == 0) {
 169                 SOCKBUF_UNLOCK(&so->so_rcv);
 170                 m_freem(n);
 171                 if (opts)
 172                         m_freem(opts);
 173                 UDPSTAT_INC(udps_fullsock);
 174         } else
 175                 sorwakeup_locked(so);
 176 }
 177
 178 int
 179 udp6_input(struct mbuf **mp, int *offp, int proto)
 180 {
 181         struct mbuf *m = *mp;
 182         struct ifnet *ifp;
 183         struct ip6_hdr *ip6;
 184         struct udphdr *uh;
 185         struct inpcb *inp;
 186         struct inpcbinfo *pcbinfo;
 187         struct udpcb *up;
 188         int off = *offp;
 189         int cscov_partial;
 190         int plen, ulen;
 191         struct sockaddr_in6 fromsa;
 192         struct m_tag *fwd_tag;
 193         uint16_t uh_sum;
 194         uint8_t nxt;
 195
 196         ifp = m->m_pkthdr.rcvif;
 197         ip6 = mtod(m, struct ip6_hdr *);
 198
 199         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 200                 /* XXX send icmp6 host/port unreach? */
 201                 m_freem(m);
 202                 return (IPPROTO_DONE);
 203         }
 204
 205 #ifndef PULLDOWN_TEST
 206         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
 207         ip6 = mtod(m, struct ip6_hdr *);
 208         uh = (struct udphdr *)((caddr_t)ip6 + off);
 209 #else
 210         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 211         if (!uh)
 212                 return (IPPROTO_DONE);
 213 #endif
 214
 215         UDPSTAT_INC(udps_ipackets);
 216
 217         /*
 218          * Destination port of 0 is illegal, based on RFC768.
 219          */
 220         if (uh->uh_dport == 0)
 221                 goto badunlocked;
 222
 223         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
 224         ulen = ntohs((u_short)uh->uh_ulen);
 225
 226         nxt = ip6->ip6_nxt;
 227         cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
 228         if (nxt == IPPROTO_UDPLITE) {
 229                 /* Zero means checksum over the complete packet. */
 230                 if (ulen == 0)
 231                         ulen = plen;
 232                 if (ulen == plen)
 233                         cscov_partial = 0;
 234                 if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
 235                         /* XXX: What is the right UDPLite MIB counter? */
 236                         goto badunlocked;
 237                 }
 238                 if (uh->uh_sum == 0) {
 239                         /* XXX: What is the right UDPLite MIB counter? */
 240                         goto badunlocked;
 241                 }
 242         } else {
 243                 if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
 244                         UDPSTAT_INC(udps_badlen);
 245                         goto badunlocked;
 246                 }
 247                 if (uh->uh_sum == 0) {
 248                         UDPSTAT_INC(udps_nosum);
 249                         goto badunlocked;
 250                 }
 251         }
 252
 253         if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
 254             !cscov_partial) {
 255                 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 256                         uh_sum = m->m_pkthdr.csum_data;
 257                 else
 258                         uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
 259                             m->m_pkthdr.csum_data);
 260                 uh_sum ^= 0xffff;
 261         } else
 262                 uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);
 263
 264         if (uh_sum != 0) {
 265                 UDPSTAT_INC(udps_badsum);
 266                 goto badunlocked;
 267         }
 268
 269         /*
 270          * Construct sockaddr format source address.
 271          */
 272         init_sin6(&fromsa, m);
 273         fromsa.sin6_port = uh->uh_sport;
 274
 275         pcbinfo = get_inpcbinfo(nxt);
 276         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 277                 struct inpcb *last;
 278                 struct inpcbhead *pcblist;
 279                 struct ip6_moptions *imo;
 280
 281                 INP_INFO_RLOCK(pcbinfo);
 282                 /*
 283                  * In the event that laddr should be set to the link-local
 284                  * address (this happens in RIPng), the multicast address
 285                  * specified in the received packet will not match laddr.  To
 286                  * handle this situation, matching is relaxed if the
 287                  * receiving interface is the same as one specified in the
 288                  * socket and if the destination multicast address matches
 289                  * one of the multicast groups specified in the socket.
 290                  */
 291
 292                 /*
 293                  * KAME note: traditionally we dropped udpiphdr from mbuf
 294                  * here.  We need udphdr for IPsec processing so we do that
 295                  * later.
 296                  */
 297                 pcblist = get_pcblist(nxt);
 298                 last = NULL;
 299                 LIST_FOREACH(inp, pcblist, inp_list) {
 300                         if ((inp->inp_vflag & INP_IPV6) == 0)
 301                                 continue;
 302                         if (inp->inp_lport != uh->uh_dport)
 303                                 continue;
 304                         if (inp->inp_fport != 0 &&
 305                             inp->inp_fport != uh->uh_sport)
 306                                 continue;
 307                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 308                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
 309                                                         &ip6->ip6_dst))
 310                                         continue;
 311                         }
 312                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 313                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
 314                                                         &ip6->ip6_src) ||
 315                                     inp->inp_fport != uh->uh_sport)
 316                                         continue;
 317                         }
 318
 319                         /*
 320                          * XXXRW: Because we weren't holding either the inpcb
 321                          * or the hash lock when we checked for a match
 322                          * before, we should probably recheck now that the
 323                          * inpcb lock is (supposed to be) held.
 324                          */
 325
 326                         /*
 327                          * Handle socket delivery policy for any-source
 328                          * and source-specific multicast. [RFC3678]
 329                          */
 330                         imo = inp->in6p_moptions;
 331                         if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 332                                 struct sockaddr_in6      mcaddr;
 333                                 int                      blocked;
 334
 335                                 INP_RLOCK(inp);
 336
 337                                 bzero(&mcaddr, sizeof(struct sockaddr_in6));
 338                                 mcaddr.sin6_len = sizeof(struct sockaddr_in6);
 339                                 mcaddr.sin6_family = AF_INET6;
 340                                 mcaddr.sin6_addr = ip6->ip6_dst;
 341
 342                                 blocked = im6o_mc_filter(imo, ifp,
 343                                         (struct sockaddr *)&mcaddr,
 344                                         (struct sockaddr *)&fromsa);
 345                                 if (blocked != MCAST_PASS) {
 346                                         if (blocked == MCAST_NOTGMEMBER)
 347                                                 IP6STAT_INC(ip6s_notmember);
 348                                         if (blocked == MCAST_NOTSMEMBER ||
 349                                             blocked == MCAST_MUTED)
 350                                                 UDPSTAT_INC(udps_filtermcast);
 351                                         INP_RUNLOCK(inp); /* XXX */
 352                                         continue;
 353                                 }
 354
 355                                 INP_RUNLOCK(inp);
 356                         }
 357                         if (last != NULL) {
 358                                 struct mbuf *n;
 359
 360                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
 361                                         INP_RLOCK(last);
 362                                         up = intoudpcb(last);
 363                                         if (up->u_tun_func == NULL) {
 364                                                 udp6_append(last, n, off, &fromsa);
 365                                         } else {
 366                                                 /*
 367                                                  * Engage the tunneling
 368                                                  * protocol we will have to
 369                                                  * leave the info_lock up,
 370                                                  * since we are hunting
 371                                                  * through multiple UDP's.
 372                                                  *
 373                                                  */
 374                                                 (*up->u_tun_func)(n, off, last);
 375                                         }
 376                                         INP_RUNLOCK(last);
 377                                 }
 378                         }
 379                         last = inp;
 380                         /*
 381                          * Don't look for additional matches if this one does
 382                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 383                          * socket options set.  This heuristic avoids
 384                          * searching through all pcbs in the common case of a
 385                          * non-shared port.  It assumes that an application
 386                          * will never clear these options after setting them.
 387                          */
 388                         if ((last->inp_socket->so_options &
 389                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 390                                 break;
 391                 }
 392
 393                 if (last == NULL) {
 394                         /*
 395                          * No matching pcb found; discard datagram.  (No need
 396                          * to send an ICMP Port Unreachable for a broadcast
 397                          * or multicast datgram.)
 398                          */
 399                         UDPSTAT_INC(udps_noport);
 400                         UDPSTAT_INC(udps_noportmcast);
 401                         goto badheadlocked;
 402                 }
 403                 INP_RLOCK(last);
 404                 INP_INFO_RUNLOCK(pcbinfo);
 405                 up = intoudpcb(last);
 406                 UDP_PROBE(receive, NULL, last, ip6, last, uh);
 407                 if (up->u_tun_func == NULL) {
 408                         udp6_append(last, m, off, &fromsa);
 409                 } else {
 410                         /*
 411                          * Engage the tunneling protocol.
 412                          */
 413                         (*up->u_tun_func)(m, off, last);
 414                 }
 415                 INP_RUNLOCK(last);
 416                 return (IPPROTO_DONE);
 417         }
 418         /*
 419          * Locate pcb for datagram.
 420          */
 421
 422         /*
 423          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 424          */
 425         if ((m->m_flags & M_IP6_NEXTHOP) &&
 426             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 427                 struct sockaddr_in6 *next_hop6;
 428
 429                 next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
 430
 431                 /*
 432                  * Transparently forwarded. Pretend to be the destination.
 433                  * Already got one like this?
 434                  */
 435                 inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
 436                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 437                     INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
 438                 if (!inp) {
 439                         /*
 440                          * It's new.  Try to find the ambushing socket.
 441                          * Because we've rewritten the destination address,
 442                          * any hardware-generated hash is ignored.
 443                          */
 444                         inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
 445                             uh->uh_sport, &next_hop6->sin6_addr,
 446                             next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
 447                             uh->uh_dport, INPLOOKUP_WILDCARD |
 448                             INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
 449                 }
 450                 /* Remove the tag from the packet. We don't need it anymore. */
 451                 m_tag_delete(m, fwd_tag);
 452                 m->m_flags &= ~M_IP6_NEXTHOP;
 453         } else
 454                 inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
 455                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 456                     INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
 457                     m->m_pkthdr.rcvif, m);
 458         if (inp == NULL) {
 459                 if (udp_log_in_vain) {
 460                         char ip6bufs[INET6_ADDRSTRLEN];
 461                         char ip6bufd[INET6_ADDRSTRLEN];
 462
 463                         log(LOG_INFO,
 464                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
 465                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 466                             ntohs(uh->uh_dport),
 467                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
 468                             ntohs(uh->uh_sport));
 469                 }
 470                 UDPSTAT_INC(udps_noport);
 471                 if (m->m_flags & M_MCAST) {
 472                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
 473                         UDPSTAT_INC(udps_noportmcast);
 474                         goto badunlocked;
 475                 }
 476                 if (V_udp_blackhole)
 477                         goto badunlocked;
 478                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
 479                         goto badunlocked;
 480                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
 481                 return (IPPROTO_DONE);
 482         }
 483         INP_RLOCK_ASSERT(inp);
 484         up = intoudpcb(inp);
 485         if (cscov_partial) {
 486                 if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
 487                         INP_RUNLOCK(inp);
 488                         m_freem(m);
 489                         return (IPPROTO_DONE);
 490                 }
 491         }
 492         UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
 493         if (up->u_tun_func == NULL) {
 494                 udp6_append(inp, m, off, &fromsa);
 495         } else {
 496                 /*
 497                  * Engage the tunneling protocol.
 498                  */
 499
 500                 (*up->u_tun_func)(m, off, inp);
 501         }
 502         INP_RUNLOCK(inp);
 503         return (IPPROTO_DONE);
 504
 505 badheadlocked:
 506         INP_INFO_RUNLOCK(pcbinfo);
 507 badunlocked:
 508         if (m)
 509                 m_freem(m);
 510         return (IPPROTO_DONE);
 511 }
 512
 513 static void
 514 udp6_common_ctlinput(int cmd, struct sockaddr *sa, void *d,
 515     struct inpcbinfo *pcbinfo)
 516 {
 517         struct udphdr uh;
 518         struct ip6_hdr *ip6;
 519         struct mbuf *m;
 520         int off = 0;
 521         struct ip6ctlparam *ip6cp = NULL;
 522         const struct sockaddr_in6 *sa6_src = NULL;
 523         void *cmdarg;
 524         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 525         struct udp_portonly {
 526                 u_int16_t uh_sport;
 527                 u_int16_t uh_dport;
 528         } *uhp;
 529
 530         if (sa->sa_family != AF_INET6 ||
 531             sa->sa_len != sizeof(struct sockaddr_in6))
 532                 return;
 533
 534         if ((unsigned)cmd >= PRC_NCMDS)
 535                 return;
 536         if (PRC_IS_REDIRECT(cmd))
 537                 notify = in6_rtchange, d = NULL;
 538         else if (cmd == PRC_HOSTDEAD)
 539                 d = NULL;
 540         else if (inet6ctlerrmap[cmd] == 0)
 541                 return;
 542
 543         /* if the parameter is from icmp6, decode it. */
 544         if (d != NULL) {
 545                 ip6cp = (struct ip6ctlparam *)d;
 546                 m = ip6cp->ip6c_m;
 547                 ip6 = ip6cp->ip6c_ip6;
 548                 off = ip6cp->ip6c_off;
 549                 cmdarg = ip6cp->ip6c_cmdarg;
 550                 sa6_src = ip6cp->ip6c_src;
 551         } else {
 552                 m = NULL;
 553                 ip6 = NULL;
 554                 cmdarg = NULL;
 555                 sa6_src = &sa6_any;
 556         }
 557
 558         if (ip6) {
 559                 /*
 560                  * XXX: We assume that when IPV6 is non NULL,
 561                  * M and OFF are valid.
 562                  */
 563
 564                 /* Check if we can safely examine src and dst ports. */
 565                 if (m->m_pkthdr.len < off + sizeof(*uhp))
 566                         return;
 567
 568                 bzero(&uh, sizeof(uh));
 569                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
 570
 571                 (void)in6_pcbnotify(pcbinfo, sa, uh.uh_dport,
 572                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
 573                     cmdarg, notify);
 574         } else
 575                 (void)in6_pcbnotify(pcbinfo, sa, 0,
 576                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
 577 }
 578
 579 void
 580 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 581 {
 582
 583         return (udp6_common_ctlinput(cmd, sa, d, &V_udbinfo));
 584 }
 585
 586 void
 587 udplite6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 588 {
 589
 590         return (udp6_common_ctlinput(cmd, sa, d, &V_ulitecbinfo));
 591 }
 592
 593 static int
 594 udp6_getcred(SYSCTL_HANDLER_ARGS)
 595 {
 596         struct xucred xuc;
 597         struct sockaddr_in6 addrs[2];
 598         struct inpcb *inp;
 599         int error;
 600
 601         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 602         if (error)
 603                 return (error);
 604
 605         if (req->newlen != sizeof(addrs))
 606                 return (EINVAL);
 607         if (req->oldlen != sizeof(struct xucred))
 608                 return (EINVAL);
 609         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 610         if (error)
 611                 return (error);
 612         if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
 613             (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
 614                 return (error);
 615         }
 616         inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
 617             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
 618             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 619         if (inp != NULL) {
 620                 INP_RLOCK_ASSERT(inp);
 621                 if (inp->inp_socket == NULL)
 622                         error = ENOENT;
 623                 if (error == 0)
 624                         error = cr_canseesocket(req->td->td_ucred,
 625                             inp->inp_socket);
 626                 if (error == 0)
 627                         cru2x(inp->inp_cred, &xuc);
 628                 INP_RUNLOCK(inp);
 629         } else
 630                 error = ENOENT;
 631         if (error == 0)
 632                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 633         return (error);
 634 }
 635
 636 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
 637     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
 638
 639 static int
 640 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
 641     struct mbuf *control, struct thread *td)
 642 {
 643         u_int32_t ulen = m->m_pkthdr.len;
 644         u_int32_t plen = sizeof(struct udphdr) + ulen;
 645         struct ip6_hdr *ip6;
 646         struct udphdr *udp6;
 647         struct in6_addr *laddr, *faddr, in6a;
 648         struct sockaddr_in6 *sin6 = NULL;
 649         struct ifnet *oifp = NULL;
 650         int cscov_partial = 0;
 651         int scope_ambiguous = 0;
 652         u_short fport;
 653         int error = 0;
 654         uint8_t nxt;
 655         uint16_t cscov = 0;
 656         struct ip6_pktopts *optp, opt;
 657         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 658         int flags;
 659         struct sockaddr_in6 tmp;
 660
 661         INP_WLOCK_ASSERT(inp);
 662         INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
 663
 664         if (addr6) {
 665                 /* addr6 has been validated in udp6_send(). */
 666                 sin6 = (struct sockaddr_in6 *)addr6;
 667
 668                 /* protect *sin6 from overwrites */
 669                 tmp = *sin6;
 670                 sin6 = &tmp;
 671
 672                 /*
 673                  * Application should provide a proper zone ID or the use of
 674                  * default zone IDs should be enabled.  Unfortunately, some
 675                  * applications do not behave as it should, so we need a
 676                  * workaround.  Even if an appropriate ID is not determined,
 677                  * we'll see if we can determine the outgoing interface.  If we
 678                  * can, determine the zone ID based on the interface below.
 679                  */
 680                 if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
 681                         scope_ambiguous = 1;
 682                 if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
 683                         return (error);
 684         }
 685
 686         if (control) {
 687                 if ((error = ip6_setpktopts(control, &opt,
 688                     inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
 689                         goto release;
 690                 optp = &opt;
 691         } else
 692                 optp = inp->in6p_outputopts;
 693
 694         if (sin6) {
 695                 faddr = &sin6->sin6_addr;
 696
 697                 /*
 698                  * Since we saw no essential reason for calling in_pcbconnect,
 699                  * we get rid of such kind of logic, and call in6_selectsrc
 700                  * and in6_pcbsetport in order to fill in the local address
 701                  * and the local port.
 702                  */
 703                 if (sin6->sin6_port == 0) {
 704                         error = EADDRNOTAVAIL;
 705                         goto release;
 706                 }
 707
 708                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 709                         /* how about ::ffff:0.0.0.0 case? */
 710                         error = EISCONN;
 711                         goto release;
 712                 }
 713
 714                 fport = sin6->sin6_port; /* allow 0 port */
 715
 716                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 717                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 718                                 /*
 719                                  * I believe we should explicitly discard the
 720                                  * packet when mapped addresses are disabled,
 721                                  * rather than send the packet as an IPv6 one.
 722                                  * If we chose the latter approach, the packet
 723                                  * might be sent out on the wire based on the
 724                                  * default route, the situation which we'd
 725                                  * probably want to avoid.
 726                                  * (20010421 jinmei@kame.net)
 727                                  */
 728                                 error = EINVAL;
 729                                 goto release;
 730                         }
 731                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 732                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 733                                 /*
 734                                  * when remote addr is an IPv4-mapped address,
 735                                  * local addr should not be an IPv6 address,
 736                                  * since you cannot determine how to map IPv6
 737                                  * source address to IPv4.
 738                                  */
 739                                 error = EINVAL;
 740                                 goto release;
 741                         }
 742
 743                         af = AF_INET;
 744                 }
 745
 746                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 747                         error = in6_selectsrc(sin6, optp, inp, NULL,
 748                             td->td_ucred, &oifp, &in6a);
 749                         if (error)
 750                                 goto release;
 751                         if (oifp && scope_ambiguous &&
 752                             (error = in6_setscope(&sin6->sin6_addr,
 753                             oifp, NULL))) {
 754                                 goto release;
 755                         }
 756                         laddr = &in6a;
 757                 } else
 758                         laddr = &inp->in6p_laddr;       /* XXX */
 759                 if (laddr == NULL) {
 760                         if (error == 0)
 761                                 error = EADDRNOTAVAIL;
 762                         goto release;
 763                 }
 764                 if (inp->inp_lport == 0 &&
 765                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
 766                         /* Undo an address bind that may have occurred. */
 767                         inp->in6p_laddr = in6addr_any;
 768                         goto release;
 769                 }
 770         } else {
 771                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 772                         error = ENOTCONN;
 773                         goto release;
 774                 }
 775                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 776                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 777                                 /*
 778                                  * XXX: this case would happen when the
 779                                  * application sets the V6ONLY flag after
 780                                  * connecting the foreign address.
 781                                  * Such applications should be fixed,
 782                                  * so we bark here.
 783                                  */
 784                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 785                                     "option was set for a connected socket\n");
 786                                 error = EINVAL;
 787                                 goto release;
 788                         } else
 789                                 af = AF_INET;
 790                 }
 791                 laddr = &inp->in6p_laddr;
 792                 faddr = &inp->in6p_faddr;
 793                 fport = inp->inp_fport;
 794         }
 795
 796         if (af == AF_INET)
 797                 hlen = sizeof(struct ip);
 798
 799         /*
 800          * Calculate data length and get a mbuf
 801          * for UDP and IP6 headers.
 802          */
 803         M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
 804         if (m == 0) {
 805                 error = ENOBUFS;
 806                 goto release;
 807         }
 808
 809         /*
 810          * Stuff checksum and output datagram.
 811          */
 812         nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
 813             IPPROTO_UDP : IPPROTO_UDPLITE;
 814         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 815         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
 816         udp6->uh_dport = fport;
 817         if (nxt == IPPROTO_UDPLITE) {
 818                 struct udpcb *up;
 819
 820                 up = intoudpcb(inp);
 821                 cscov = up->u_txcslen;
 822                 if (cscov >= plen)
 823                         cscov = 0;
 824                 udp6->uh_ulen = htons(cscov);
 825                 /*
 826                  * For UDP-Lite, checksum coverage length of zero means
 827                  * the entire UDPLite packet is covered by the checksum.
 828                  */
 829                 cscov_partial = (cscov == 0) ? 0 : 1;
 830         } else if (plen <= 0xffff)
 831                 udp6->uh_ulen = htons((u_short)plen);
 832         else
 833                 udp6->uh_ulen = 0;
 834         udp6->uh_sum = 0;
 835
 836         switch (af) {
 837         case AF_INET6:
 838                 ip6 = mtod(m, struct ip6_hdr *);
 839                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
 840                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 841                 ip6->ip6_vfc    |= IPV6_VERSION;
 842                 ip6->ip6_plen   = htons((u_short)plen);
 843                 ip6->ip6_nxt    = nxt;
 844                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 845                 ip6->ip6_src    = *laddr;
 846                 ip6->ip6_dst    = *faddr;
 847
 848                 if (cscov_partial) {
 849                         if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
 850                             sizeof(struct ip6_hdr), plen, cscov)) == 0)
 851                                 udp6->uh_sum = 0xffff;
 852                 } else {
 853                         udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
 854                         m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
 855                         m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 856                 }
 857
 858                 flags = 0;
 859
 860                 UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
 861                 UDPSTAT_INC(udps_opackets);
 862                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 863                     NULL, inp);
 864                 break;
 865         case AF_INET:
 866                 error = EAFNOSUPPORT;
 867                 goto release;
 868         }
 869         goto releaseopt;
 870
 871 release:
 872         m_freem(m);
 873
 874 releaseopt:
 875         if (control) {
 876                 ip6_clearpktopts(&opt, -1);
 877                 m_freem(control);
 878         }
 879         return (error);
 880 }
 881
 882 static void
 883 udp6_abort(struct socket *so)
 884 {
 885         struct inpcb *inp;
 886         struct inpcbinfo *pcbinfo;
 887
 888         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 889         inp = sotoinpcb(so);
 890         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 891
 892 #ifdef INET
 893         if (inp->inp_vflag & INP_IPV4) {
 894                 struct pr_usrreqs *pru;
 895
 896                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 897                 (*pru->pru_abort)(so);
 898                 return;
 899         }
 900 #endif
 901
 902         INP_WLOCK(inp);
 903         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 904                 INP_HASH_WLOCK(pcbinfo);
 905                 in6_pcbdisconnect(inp);
 906                 inp->in6p_laddr = in6addr_any;
 907                 INP_HASH_WUNLOCK(pcbinfo);
 908                 soisdisconnected(so);
 909         }
 910         INP_WUNLOCK(inp);
 911 }
 912
 913 static int
 914 udp6_attach(struct socket *so, int proto, struct thread *td)
 915 {
 916         struct inpcb *inp;
 917         struct inpcbinfo *pcbinfo;
 918         int error;
 919
 920         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 921         inp = sotoinpcb(so);
 922         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 923
 924         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 925                 error = soreserve(so, udp_sendspace, udp_recvspace);
 926                 if (error)
 927                         return (error);
 928         }
 929         INP_INFO_WLOCK(pcbinfo);
 930         error = in_pcballoc(so, pcbinfo);
 931         if (error) {
 932                 INP_INFO_WUNLOCK(pcbinfo);
 933                 return (error);
 934         }
 935         inp = (struct inpcb *)so->so_pcb;
 936         inp->inp_vflag |= INP_IPV6;
 937         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 938                 inp->inp_vflag |= INP_IPV4;
 939         inp->in6p_hops = -1;    /* use kernel default */
 940         inp->in6p_cksum = -1;   /* just to be sure */
 941         /*
 942          * XXX: ugly!!
 943          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 944          * because the socket may be bound to an IPv6 wildcard address,
 945          * which may match an IPv4-mapped IPv6 address.
 946          */
 947         inp->inp_ip_ttl = V_ip_defttl;
 948
 949         error = udp_newudpcb(inp);
 950         if (error) {
 951                 in_pcbdetach(inp);
 952                 in_pcbfree(inp);
 953                 INP_INFO_WUNLOCK(pcbinfo);
 954                 return (error);
 955         }
 956         INP_WUNLOCK(inp);
 957         INP_INFO_WUNLOCK(pcbinfo);
 958         return (0);
 959 }
 960
 961 static int
 962 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 963 {
 964         struct inpcb *inp;
 965         struct inpcbinfo *pcbinfo;
 966         int error;
 967
 968         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 969         inp = sotoinpcb(so);
 970         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 971
 972         INP_WLOCK(inp);
 973         INP_HASH_WLOCK(pcbinfo);
 974         inp->inp_vflag &= ~INP_IPV4;
 975         inp->inp_vflag |= INP_IPV6;
 976         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 977                 struct sockaddr_in6 *sin6_p;
 978
 979                 sin6_p = (struct sockaddr_in6 *)nam;
 980
 981                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 982                         inp->inp_vflag |= INP_IPV4;
 983 #ifdef INET
 984                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 985                         struct sockaddr_in sin;
 986
 987                         in6_sin6_2_sin(&sin, sin6_p);
 988                         inp->inp_vflag |= INP_IPV4;
 989                         inp->inp_vflag &= ~INP_IPV6;
 990                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 991                             td->td_ucred);
 992                         goto out;
 993                 }
 994 #endif
 995         }
 996
 997         error = in6_pcbbind(inp, nam, td->td_ucred);
 998 #ifdef INET
 999 out:
1000 #endif
1001         INP_HASH_WUNLOCK(pcbinfo);
1002         INP_WUNLOCK(inp);
1003         return (error);
1004 }
1005
1006 static void
1007 udp6_close(struct socket *so)
1008 {
1009         struct inpcb *inp;
1010         struct inpcbinfo *pcbinfo;
1011
1012         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1013         inp = sotoinpcb(so);
1014         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
1015
1016 #ifdef INET
1017         if (inp->inp_vflag & INP_IPV4) {
1018                 struct pr_usrreqs *pru;
1019
1020                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1021                 (*pru->pru_disconnect)(so);
1022                 return;
1023         }
1024 #endif
1025         INP_WLOCK(inp);
1026         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1027                 INP_HASH_WLOCK(pcbinfo);
1028                 in6_pcbdisconnect(inp);
1029                 inp->in6p_laddr = in6addr_any;
1030                 INP_HASH_WUNLOCK(pcbinfo);
1031                 soisdisconnected(so);
1032         }
1033         INP_WUNLOCK(inp);
1034 }
1035
1036 static int
1037 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1038 {
1039         struct inpcb *inp;
1040         struct inpcbinfo *pcbinfo;
1041         struct sockaddr_in6 *sin6;
1042         int error;
1043
1044         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1045         inp = sotoinpcb(so);
1046         sin6 = (struct sockaddr_in6 *)nam;
1047         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
1048
1049         /*
1050          * XXXRW: Need to clarify locking of v4/v6 flags.
1051          */
1052         INP_WLOCK(inp);
1053 #ifdef INET
1054         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
1055                 struct sockaddr_in sin;
1056
1057                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
1058                         error = EINVAL;
1059                         goto out;
1060                 }
1061                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1062                         error = EISCONN;
1063                         goto out;
1064                 }
1065                 in6_sin6_2_sin(&sin, sin6);
1066                 inp->inp_vflag |= INP_IPV4;
1067                 inp->inp_vflag &= ~INP_IPV6;
1068                 error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
1069                 if (error != 0)
1070                         goto out;
1071                 INP_HASH_WLOCK(pcbinfo);
1072                 error = in_pcbconnect(inp, (struct sockaddr *)&sin,
1073                     td->td_ucred);
1074                 INP_HASH_WUNLOCK(pcbinfo);
1075                 if (error == 0)
1076                         soisconnected(so);
1077                 goto out;
1078         }
1079 #endif
1080         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1081                 error = EISCONN;
1082                 goto out;
1083         }
1084         inp->inp_vflag &= ~INP_IPV4;
1085         inp->inp_vflag |= INP_IPV6;
1086         error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1087         if (error != 0)
1088                 goto out;
1089         INP_HASH_WLOCK(pcbinfo);
1090         error = in6_pcbconnect(inp, nam, td->td_ucred);
1091         INP_HASH_WUNLOCK(pcbinfo);
1092         if (error == 0)
1093                 soisconnected(so);
1094 out:
1095         INP_WUNLOCK(inp);
1096         return (error);
1097 }
1098
1099 static void
1100 udp6_detach(struct socket *so)
1101 {
1102         struct inpcb *inp;
1103         struct inpcbinfo *pcbinfo;
1104         struct udpcb *up;
1105
1106         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1107         inp = sotoinpcb(so);
1108         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1109
1110         INP_INFO_WLOCK(pcbinfo);
1111         INP_WLOCK(inp);
1112         up = intoudpcb(inp);
1113         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1114         in_pcbdetach(inp);
1115         in_pcbfree(inp);
1116         INP_INFO_WUNLOCK(pcbinfo);
1117         udp_discardcb(up);
1118 }
1119
1120 static int
1121 udp6_disconnect(struct socket *so)
1122 {
1123         struct inpcb *inp;
1124         struct inpcbinfo *pcbinfo;
1125         int error;
1126
1127         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1128         inp = sotoinpcb(so);
1129         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1130
1131 #ifdef INET
1132         if (inp->inp_vflag & INP_IPV4) {
1133                 struct pr_usrreqs *pru;
1134
1135                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1136                 (void)(*pru->pru_disconnect)(so);
1137                 return (0);
1138         }
1139 #endif
1140
1141         INP_WLOCK(inp);
1142
1143         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1144                 error = ENOTCONN;
1145                 goto out;
1146         }
1147
1148         INP_HASH_WLOCK(pcbinfo);
1149         in6_pcbdisconnect(inp);
1150         inp->in6p_laddr = in6addr_any;
1151         INP_HASH_WUNLOCK(pcbinfo);
1152         SOCK_LOCK(so);
1153         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1154         SOCK_UNLOCK(so);
1155 out:
1156         INP_WUNLOCK(inp);
1157         return (0);
1158 }
1159
1160 static int
1161 udp6_send(struct socket *so, int flags, struct mbuf *m,
1162     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1163 {
1164         struct inpcb *inp;
1165         struct inpcbinfo *pcbinfo;
1166         int error = 0;
1167
1168         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1169         inp = sotoinpcb(so);
1170         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1171
1172         INP_WLOCK(inp);
1173         if (addr) {
1174                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1175                         error = EINVAL;
1176                         goto bad;
1177                 }
1178                 if (addr->sa_family != AF_INET6) {
1179                         error = EAFNOSUPPORT;
1180                         goto bad;
1181                 }
1182         }
1183
1184 #ifdef INET
1185         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1186                 int hasv4addr;
1187                 struct sockaddr_in6 *sin6 = 0;
1188
1189                 if (addr == 0)
1190                         hasv4addr = (inp->inp_vflag & INP_IPV4);
1191                 else {
1192                         sin6 = (struct sockaddr_in6 *)addr;
1193                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1194                             ? 1 : 0;
1195                 }
1196                 if (hasv4addr) {
1197                         struct pr_usrreqs *pru;
1198
1199                         /*
1200                          * XXXRW: We release UDP-layer locks before calling
1201                          * udp_send() in order to avoid recursion.  However,
1202                          * this does mean there is a short window where inp's
1203                          * fields are unstable.  Could this lead to a
1204                          * potential race in which the factors causing us to
1205                          * select the UDPv4 output routine are invalidated?
1206                          */
1207                         INP_WUNLOCK(inp);
1208                         if (sin6)
1209                                 in6_sin6_2_sin_in_sock(addr);
1210                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1211                         /* addr will just be freed in sendit(). */
1212                         return ((*pru->pru_send)(so, flags, m, addr, control,
1213                             td));
1214                 }
1215         }
1216 #endif
1217 #ifdef MAC
1218         mac_inpcb_create_mbuf(inp, m);
1219 #endif
1220         INP_HASH_WLOCK(pcbinfo);
1221         error = udp6_output(inp, m, addr, control, td);
1222         INP_HASH_WUNLOCK(pcbinfo);
1223 #ifdef INET
1224 #endif
1225         INP_WUNLOCK(inp);
1226         return (error);
1227
1228 bad:
1229         INP_WUNLOCK(inp);
1230         m_freem(m);
1231         return (error);
1232 }
1233
1234 struct pr_usrreqs udp6_usrreqs = {
1235         .pru_abort =            udp6_abort,
1236         .pru_attach =           udp6_attach,
1237         .pru_bind =             udp6_bind,
1238         .pru_connect =          udp6_connect,
1239         .pru_control =          in6_control,
1240         .pru_detach =           udp6_detach,
1241         .pru_disconnect =       udp6_disconnect,
1242         .pru_peeraddr =         in6_mapped_peeraddr,
1243         .pru_send =             udp6_send,
1244         .pru_shutdown =         udp_shutdown,
1245         .pru_sockaddr =         in6_mapped_sockaddr,
1246         .pru_soreceive =        soreceive_dgram,
1247         .pru_sosend =           sosend_dgram,
1248         .pru_sosetlabel =       in_pcbsosetlabel,
1249         .pru_close =            udp6_close
1250 };