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_rss.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_var.h>
  98 #include <net/if_types.h>
  99 #include <net/route.h>
 100
 101 #include <netinet/in.h>
 102 #include <netinet/in_kdtrace.h>
 103 #include <netinet/in_pcb.h>
 104 #include <netinet/in_systm.h>
 105 #include <netinet/in_var.h>
 106 #include <netinet/ip.h>
 107 #include <netinet/ip_icmp.h>
 108 #include <netinet/ip6.h>
 109 #include <netinet/icmp_var.h>
 110 #include <netinet/icmp6.h>
 111 #include <netinet/ip_var.h>
 112 #include <netinet/udp.h>
 113 #include <netinet/udp_var.h>
 114 #include <netinet/udplite.h>
 115 #include <netinet/in_rss.h>
 116
 117 #include <netinet6/ip6protosw.h>
 118 #include <netinet6/ip6_var.h>
 119 #include <netinet6/in6_pcb.h>
 120 #include <netinet6/udp6_var.h>
 121 #include <netinet6/scope6_var.h>
 122
 123 #ifdef IPSEC
 124 #include <netipsec/ipsec.h>
 125 #include <netipsec/ipsec6.h>
 126 #endif /* IPSEC */
 127
 128 #include <security/mac/mac_framework.h>
 129
 130 /*
 131  * UDP protocol implementation.
 132  * Per RFC 768, August, 1980.
 133  */
 134
 135 extern struct protosw   inetsw[];
 136 static void             udp6_detach(struct socket *so);
 137
 138 static void
 139 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
 140     struct sockaddr_in6 *fromsa)
 141 {
 142         struct socket *so;
 143         struct mbuf *opts;
 144         struct udpcb *up;
 145
 146         INP_LOCK_ASSERT(inp);
 147
 148         /*
 149          * Engage the tunneling protocol.
 150          */
 151         up = intoudpcb(inp);
 152         if (up->u_tun_func != NULL) {
 153                 (*up->u_tun_func)(n, off, inp, (struct sockaddr *)fromsa,
 154                     up->u_tun_ctx);
 155                 return;
 156         }
 157 #ifdef IPSEC
 158         /* Check AH/ESP integrity. */
 159         if (ipsec6_in_reject(n, inp)) {
 160                 m_freem(n);
 161                 return;
 162         }
 163 #endif /* IPSEC */
 164 #ifdef MAC
 165         if (mac_inpcb_check_deliver(inp, n) != 0) {
 166                 m_freem(n);
 167                 return;
 168         }
 169 #endif
 170         opts = NULL;
 171         if (inp->inp_flags & INP_CONTROLOPTS ||
 172             inp->inp_socket->so_options & SO_TIMESTAMP)
 173                 ip6_savecontrol(inp, n, &opts);
 174         m_adj(n, off + sizeof(struct udphdr));
 175
 176         so = inp->inp_socket;
 177         SOCKBUF_LOCK(&so->so_rcv);
 178         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
 179             opts) == 0) {
 180                 SOCKBUF_UNLOCK(&so->so_rcv);
 181                 m_freem(n);
 182                 if (opts)
 183                         m_freem(opts);
 184                 UDPSTAT_INC(udps_fullsock);
 185         } else
 186                 sorwakeup_locked(so);
 187 }
 188
 189 int
 190 udp6_input(struct mbuf **mp, int *offp, int proto)
 191 {
 192         struct mbuf *m = *mp;
 193         struct ifnet *ifp;
 194         struct ip6_hdr *ip6;
 195         struct udphdr *uh;
 196         struct inpcb *inp;
 197         struct inpcbinfo *pcbinfo;
 198         struct udpcb *up;
 199         int off = *offp;
 200         int cscov_partial;
 201         int plen, ulen;
 202         struct sockaddr_in6 fromsa;
 203         struct m_tag *fwd_tag;
 204         uint16_t uh_sum;
 205         uint8_t nxt;
 206
 207         ifp = m->m_pkthdr.rcvif;
 208         ip6 = mtod(m, struct ip6_hdr *);
 209
 210 #ifndef PULLDOWN_TEST
 211         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
 212         ip6 = mtod(m, struct ip6_hdr *);
 213         uh = (struct udphdr *)((caddr_t)ip6 + off);
 214 #else
 215         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 216         if (!uh)
 217                 return (IPPROTO_DONE);
 218 #endif
 219
 220         UDPSTAT_INC(udps_ipackets);
 221
 222         /*
 223          * Destination port of 0 is illegal, based on RFC768.
 224          */
 225         if (uh->uh_dport == 0)
 226                 goto badunlocked;
 227
 228         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
 229         ulen = ntohs((u_short)uh->uh_ulen);
 230
 231         nxt = ip6->ip6_nxt;
 232         cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
 233         if (nxt == IPPROTO_UDPLITE) {
 234                 /* Zero means checksum over the complete packet. */
 235                 if (ulen == 0)
 236                         ulen = plen;
 237                 if (ulen == plen)
 238                         cscov_partial = 0;
 239                 if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
 240                         /* XXX: What is the right UDPLite MIB counter? */
 241                         goto badunlocked;
 242                 }
 243                 if (uh->uh_sum == 0) {
 244                         /* XXX: What is the right UDPLite MIB counter? */
 245                         goto badunlocked;
 246                 }
 247         } else {
 248                 if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
 249                         UDPSTAT_INC(udps_badlen);
 250                         goto badunlocked;
 251                 }
 252                 if (uh->uh_sum == 0) {
 253                         UDPSTAT_INC(udps_nosum);
 254                         goto badunlocked;
 255                 }
 256         }
 257
 258         if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
 259             !cscov_partial) {
 260                 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 261                         uh_sum = m->m_pkthdr.csum_data;
 262                 else
 263                         uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
 264                             m->m_pkthdr.csum_data);
 265                 uh_sum ^= 0xffff;
 266         } else
 267                 uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);
 268
 269         if (uh_sum != 0) {
 270                 UDPSTAT_INC(udps_badsum);
 271                 goto badunlocked;
 272         }
 273
 274         /*
 275          * Construct sockaddr format source address.
 276          */
 277         init_sin6(&fromsa, m);
 278         fromsa.sin6_port = uh->uh_sport;
 279
 280         pcbinfo = get_inpcbinfo(nxt);
 281         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 282                 struct inpcb *last;
 283                 struct inpcbhead *pcblist;
 284                 struct ip6_moptions *imo;
 285
 286                 INP_INFO_RLOCK(pcbinfo);
 287                 /*
 288                  * In the event that laddr should be set to the link-local
 289                  * address (this happens in RIPng), the multicast address
 290                  * specified in the received packet will not match laddr.  To
 291                  * handle this situation, matching is relaxed if the
 292                  * receiving interface is the same as one specified in the
 293                  * socket and if the destination multicast address matches
 294                  * one of the multicast groups specified in the socket.
 295                  */
 296
 297                 /*
 298                  * KAME note: traditionally we dropped udpiphdr from mbuf
 299                  * here.  We need udphdr for IPsec processing so we do that
 300                  * later.
 301                  */
 302                 pcblist = get_pcblist(nxt);
 303                 last = NULL;
 304                 LIST_FOREACH(inp, pcblist, inp_list) {
 305                         if ((inp->inp_vflag & INP_IPV6) == 0)
 306                                 continue;
 307                         if (inp->inp_lport != uh->uh_dport)
 308                                 continue;
 309                         if (inp->inp_fport != 0 &&
 310                             inp->inp_fport != uh->uh_sport)
 311                                 continue;
 312                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 313                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
 314                                                         &ip6->ip6_dst))
 315                                         continue;
 316                         }
 317                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 318                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
 319                                                         &ip6->ip6_src) ||
 320                                     inp->inp_fport != uh->uh_sport)
 321                                         continue;
 322                         }
 323
 324                         /*
 325                          * XXXRW: Because we weren't holding either the inpcb
 326                          * or the hash lock when we checked for a match
 327                          * before, we should probably recheck now that the
 328                          * inpcb lock is (supposed to be) held.
 329                          */
 330
 331                         /*
 332                          * Handle socket delivery policy for any-source
 333                          * and source-specific multicast. [RFC3678]
 334                          */
 335                         imo = inp->in6p_moptions;
 336                         if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 337                                 struct sockaddr_in6      mcaddr;
 338                                 int                      blocked;
 339
 340                                 INP_RLOCK(inp);
 341
 342                                 bzero(&mcaddr, sizeof(struct sockaddr_in6));
 343                                 mcaddr.sin6_len = sizeof(struct sockaddr_in6);
 344                                 mcaddr.sin6_family = AF_INET6;
 345                                 mcaddr.sin6_addr = ip6->ip6_dst;
 346
 347                                 blocked = im6o_mc_filter(imo, ifp,
 348                                         (struct sockaddr *)&mcaddr,
 349                                         (struct sockaddr *)&fromsa);
 350                                 if (blocked != MCAST_PASS) {
 351                                         if (blocked == MCAST_NOTGMEMBER)
 352                                                 IP6STAT_INC(ip6s_notmember);
 353                                         if (blocked == MCAST_NOTSMEMBER ||
 354                                             blocked == MCAST_MUTED)
 355                                                 UDPSTAT_INC(udps_filtermcast);
 356                                         INP_RUNLOCK(inp); /* XXX */
 357                                         continue;
 358                                 }
 359
 360                                 INP_RUNLOCK(inp);
 361                         }
 362                         if (last != NULL) {
 363                                 struct mbuf *n;
 364
 365                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
 366                                         INP_RLOCK(last);
 367                                         UDP_PROBE(receive, NULL, last, ip6,
 368                                             last, uh);
 369                                         udp6_append(last, n, off, &fromsa);
 370                                         INP_RUNLOCK(last);
 371                                 }
 372                         }
 373                         last = inp;
 374                         /*
 375                          * Don't look for additional matches if this one does
 376                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 377                          * socket options set.  This heuristic avoids
 378                          * searching through all pcbs in the common case of a
 379                          * non-shared port.  It assumes that an application
 380                          * will never clear these options after setting them.
 381                          */
 382                         if ((last->inp_socket->so_options &
 383                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 384                                 break;
 385                 }
 386
 387                 if (last == NULL) {
 388                         /*
 389                          * No matching pcb found; discard datagram.  (No need
 390                          * to send an ICMP Port Unreachable for a broadcast
 391                          * or multicast datgram.)
 392                          */
 393                         UDPSTAT_INC(udps_noport);
 394                         UDPSTAT_INC(udps_noportmcast);
 395                         goto badheadlocked;
 396                 }
 397                 INP_RLOCK(last);
 398                 INP_INFO_RUNLOCK(pcbinfo);
 399                 UDP_PROBE(receive, NULL, last, ip6, last, uh);
 400                 udp6_append(last, m, off, &fromsa);
 401                 INP_RUNLOCK(last);
 402                 return (IPPROTO_DONE);
 403         }
 404         /*
 405          * Locate pcb for datagram.
 406          */
 407
 408         /*
 409          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 410          */
 411         if ((m->m_flags & M_IP6_NEXTHOP) &&
 412             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 413                 struct sockaddr_in6 *next_hop6;
 414
 415                 next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
 416
 417                 /*
 418                  * Transparently forwarded. Pretend to be the destination.
 419                  * Already got one like this?
 420                  */
 421                 inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
 422                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 423                     INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
 424                 if (!inp) {
 425                         /*
 426                          * It's new.  Try to find the ambushing socket.
 427                          * Because we've rewritten the destination address,
 428                          * any hardware-generated hash is ignored.
 429                          */
 430                         inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
 431                             uh->uh_sport, &next_hop6->sin6_addr,
 432                             next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
 433                             uh->uh_dport, INPLOOKUP_WILDCARD |
 434                             INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
 435                 }
 436                 /* Remove the tag from the packet. We don't need it anymore. */
 437                 m_tag_delete(m, fwd_tag);
 438                 m->m_flags &= ~M_IP6_NEXTHOP;
 439         } else
 440                 inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
 441                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 442                     INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
 443                     m->m_pkthdr.rcvif, m);
 444         if (inp == NULL) {
 445                 if (udp_log_in_vain) {
 446                         char ip6bufs[INET6_ADDRSTRLEN];
 447                         char ip6bufd[INET6_ADDRSTRLEN];
 448
 449                         log(LOG_INFO,
 450                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
 451                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 452                             ntohs(uh->uh_dport),
 453                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
 454                             ntohs(uh->uh_sport));
 455                 }
 456                 UDPSTAT_INC(udps_noport);
 457                 if (m->m_flags & M_MCAST) {
 458                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
 459                         UDPSTAT_INC(udps_noportmcast);
 460                         goto badunlocked;
 461                 }
 462                 if (V_udp_blackhole)
 463                         goto badunlocked;
 464                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
 465                         goto badunlocked;
 466                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
 467                 return (IPPROTO_DONE);
 468         }
 469         INP_RLOCK_ASSERT(inp);
 470         up = intoudpcb(inp);
 471         if (cscov_partial) {
 472                 if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
 473                         INP_RUNLOCK(inp);
 474                         m_freem(m);
 475                         return (IPPROTO_DONE);
 476                 }
 477         }
 478         UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
 479         udp6_append(inp, m, off, &fromsa);
 480         INP_RUNLOCK(inp);
 481         return (IPPROTO_DONE);
 482
 483 badheadlocked:
 484         INP_INFO_RUNLOCK(pcbinfo);
 485 badunlocked:
 486         if (m)
 487                 m_freem(m);
 488         return (IPPROTO_DONE);
 489 }
 490
 491 static void
 492 udp6_common_ctlinput(int cmd, struct sockaddr *sa, void *d,
 493     struct inpcbinfo *pcbinfo)
 494 {
 495         struct udphdr uh;
 496         struct ip6_hdr *ip6;
 497         struct mbuf *m;
 498         int off = 0;
 499         struct ip6ctlparam *ip6cp = NULL;
 500         const struct sockaddr_in6 *sa6_src = NULL;
 501         void *cmdarg;
 502         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 503         struct udp_portonly {
 504                 u_int16_t uh_sport;
 505                 u_int16_t uh_dport;
 506         } *uhp;
 507
 508         if (sa->sa_family != AF_INET6 ||
 509             sa->sa_len != sizeof(struct sockaddr_in6))
 510                 return;
 511
 512         if ((unsigned)cmd >= PRC_NCMDS)
 513                 return;
 514         if (PRC_IS_REDIRECT(cmd))
 515                 notify = in6_rtchange, d = NULL;
 516         else if (cmd == PRC_HOSTDEAD)
 517                 d = NULL;
 518         else if (inet6ctlerrmap[cmd] == 0)
 519                 return;
 520
 521         /* if the parameter is from icmp6, decode it. */
 522         if (d != NULL) {
 523                 ip6cp = (struct ip6ctlparam *)d;
 524                 m = ip6cp->ip6c_m;
 525                 ip6 = ip6cp->ip6c_ip6;
 526                 off = ip6cp->ip6c_off;
 527                 cmdarg = ip6cp->ip6c_cmdarg;
 528                 sa6_src = ip6cp->ip6c_src;
 529         } else {
 530                 m = NULL;
 531                 ip6 = NULL;
 532                 cmdarg = NULL;
 533                 sa6_src = &sa6_any;
 534         }
 535
 536         if (ip6) {
 537                 /*
 538                  * XXX: We assume that when IPV6 is non NULL,
 539                  * M and OFF are valid.
 540                  */
 541
 542                 /* Check if we can safely examine src and dst ports. */
 543                 if (m->m_pkthdr.len < off + sizeof(*uhp))
 544                         return;
 545
 546                 bzero(&uh, sizeof(uh));
 547                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
 548
 549                 (void)in6_pcbnotify(pcbinfo, sa, uh.uh_dport,
 550                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
 551                     cmdarg, notify);
 552         } else
 553                 (void)in6_pcbnotify(pcbinfo, sa, 0,
 554                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
 555 }
 556
 557 void
 558 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 559 {
 560
 561         return (udp6_common_ctlinput(cmd, sa, d, &V_udbinfo));
 562 }
 563
 564 void
 565 udplite6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 566 {
 567
 568         return (udp6_common_ctlinput(cmd, sa, d, &V_ulitecbinfo));
 569 }
 570
 571 static int
 572 udp6_getcred(SYSCTL_HANDLER_ARGS)
 573 {
 574         struct xucred xuc;
 575         struct sockaddr_in6 addrs[2];
 576         struct inpcb *inp;
 577         int error;
 578
 579         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 580         if (error)
 581                 return (error);
 582
 583         if (req->newlen != sizeof(addrs))
 584                 return (EINVAL);
 585         if (req->oldlen != sizeof(struct xucred))
 586                 return (EINVAL);
 587         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 588         if (error)
 589                 return (error);
 590         if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
 591             (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
 592                 return (error);
 593         }
 594         inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
 595             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
 596             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 597         if (inp != NULL) {
 598                 INP_RLOCK_ASSERT(inp);
 599                 if (inp->inp_socket == NULL)
 600                         error = ENOENT;
 601                 if (error == 0)
 602                         error = cr_canseesocket(req->td->td_ucred,
 603                             inp->inp_socket);
 604                 if (error == 0)
 605                         cru2x(inp->inp_cred, &xuc);
 606                 INP_RUNLOCK(inp);
 607         } else
 608                 error = ENOENT;
 609         if (error == 0)
 610                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 611         return (error);
 612 }
 613
 614 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
 615     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
 616
 617 static int
 618 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
 619     struct mbuf *control, struct thread *td)
 620 {
 621         u_int32_t ulen = m->m_pkthdr.len;
 622         u_int32_t plen = sizeof(struct udphdr) + ulen;
 623         struct ip6_hdr *ip6;
 624         struct udphdr *udp6;
 625         struct in6_addr *laddr, *faddr, in6a;
 626         struct sockaddr_in6 *sin6 = NULL;
 627         struct ifnet *oifp = NULL;
 628         int cscov_partial = 0;
 629         int scope_ambiguous = 0;
 630         u_short fport;
 631         int error = 0;
 632         uint8_t nxt;
 633         uint16_t cscov = 0;
 634         struct ip6_pktopts *optp, opt;
 635         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 636         int flags;
 637         struct sockaddr_in6 tmp;
 638
 639         INP_WLOCK_ASSERT(inp);
 640         INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
 641
 642         if (addr6) {
 643                 /* addr6 has been validated in udp6_send(). */
 644                 sin6 = (struct sockaddr_in6 *)addr6;
 645
 646                 /* protect *sin6 from overwrites */
 647                 tmp = *sin6;
 648                 sin6 = &tmp;
 649
 650                 /*
 651                  * Application should provide a proper zone ID or the use of
 652                  * default zone IDs should be enabled.  Unfortunately, some
 653                  * applications do not behave as it should, so we need a
 654                  * workaround.  Even if an appropriate ID is not determined,
 655                  * we'll see if we can determine the outgoing interface.  If we
 656                  * can, determine the zone ID based on the interface below.
 657                  */
 658                 if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
 659                         scope_ambiguous = 1;
 660                 if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
 661                         return (error);
 662         }
 663
 664         if (control) {
 665                 if ((error = ip6_setpktopts(control, &opt,
 666                     inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
 667                         goto release;
 668                 optp = &opt;
 669         } else
 670                 optp = inp->in6p_outputopts;
 671
 672         if (sin6) {
 673                 faddr = &sin6->sin6_addr;
 674
 675                 /*
 676                  * Since we saw no essential reason for calling in_pcbconnect,
 677                  * we get rid of such kind of logic, and call in6_selectsrc
 678                  * and in6_pcbsetport in order to fill in the local address
 679                  * and the local port.
 680                  */
 681                 if (sin6->sin6_port == 0) {
 682                         error = EADDRNOTAVAIL;
 683                         goto release;
 684                 }
 685
 686                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 687                         /* how about ::ffff:0.0.0.0 case? */
 688                         error = EISCONN;
 689                         goto release;
 690                 }
 691
 692                 fport = sin6->sin6_port; /* allow 0 port */
 693
 694                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 695                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 696                                 /*
 697                                  * I believe we should explicitly discard the
 698                                  * packet when mapped addresses are disabled,
 699                                  * rather than send the packet as an IPv6 one.
 700                                  * If we chose the latter approach, the packet
 701                                  * might be sent out on the wire based on the
 702                                  * default route, the situation which we'd
 703                                  * probably want to avoid.
 704                                  * (20010421 jinmei@kame.net)
 705                                  */
 706                                 error = EINVAL;
 707                                 goto release;
 708                         }
 709                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 710                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 711                                 /*
 712                                  * when remote addr is an IPv4-mapped address,
 713                                  * local addr should not be an IPv6 address,
 714                                  * since you cannot determine how to map IPv6
 715                                  * source address to IPv4.
 716                                  */
 717                                 error = EINVAL;
 718                                 goto release;
 719                         }
 720
 721                         af = AF_INET;
 722                 }
 723
 724                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 725                         error = in6_selectsrc(sin6, optp, inp, NULL,
 726                             td->td_ucred, &oifp, &in6a);
 727                         if (error)
 728                                 goto release;
 729                         if (oifp && scope_ambiguous &&
 730                             (error = in6_setscope(&sin6->sin6_addr,
 731                             oifp, NULL))) {
 732                                 goto release;
 733                         }
 734                         laddr = &in6a;
 735                 } else
 736                         laddr = &inp->in6p_laddr;       /* XXX */
 737                 if (laddr == NULL) {
 738                         if (error == 0)
 739                                 error = EADDRNOTAVAIL;
 740                         goto release;
 741                 }
 742                 if (inp->inp_lport == 0 &&
 743                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
 744                         /* Undo an address bind that may have occurred. */
 745                         inp->in6p_laddr = in6addr_any;
 746                         goto release;
 747                 }
 748         } else {
 749                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 750                         error = ENOTCONN;
 751                         goto release;
 752                 }
 753                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 754                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 755                                 /*
 756                                  * XXX: this case would happen when the
 757                                  * application sets the V6ONLY flag after
 758                                  * connecting the foreign address.
 759                                  * Such applications should be fixed,
 760                                  * so we bark here.
 761                                  */
 762                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 763                                     "option was set for a connected socket\n");
 764                                 error = EINVAL;
 765                                 goto release;
 766                         } else
 767                                 af = AF_INET;
 768                 }
 769                 laddr = &inp->in6p_laddr;
 770                 faddr = &inp->in6p_faddr;
 771                 fport = inp->inp_fport;
 772         }
 773
 774         if (af == AF_INET)
 775                 hlen = sizeof(struct ip);
 776
 777         /*
 778          * Calculate data length and get a mbuf
 779          * for UDP and IP6 headers.
 780          */
 781         M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
 782         if (m == 0) {
 783                 error = ENOBUFS;
 784                 goto release;
 785         }
 786
 787         /*
 788          * Stuff checksum and output datagram.
 789          */
 790         nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
 791             IPPROTO_UDP : IPPROTO_UDPLITE;
 792         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 793         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
 794         udp6->uh_dport = fport;
 795         if (nxt == IPPROTO_UDPLITE) {
 796                 struct udpcb *up;
 797
 798                 up = intoudpcb(inp);
 799                 cscov = up->u_txcslen;
 800                 if (cscov >= plen)
 801                         cscov = 0;
 802                 udp6->uh_ulen = htons(cscov);
 803                 /*
 804                  * For UDP-Lite, checksum coverage length of zero means
 805                  * the entire UDPLite packet is covered by the checksum.
 806                  */
 807                 cscov_partial = (cscov == 0) ? 0 : 1;
 808         } else if (plen <= 0xffff)
 809                 udp6->uh_ulen = htons((u_short)plen);
 810         else
 811                 udp6->uh_ulen = 0;
 812         udp6->uh_sum = 0;
 813
 814         switch (af) {
 815         case AF_INET6:
 816                 ip6 = mtod(m, struct ip6_hdr *);
 817                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
 818                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 819                 ip6->ip6_vfc    |= IPV6_VERSION;
 820                 ip6->ip6_plen   = htons((u_short)plen);
 821                 ip6->ip6_nxt    = nxt;
 822                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 823                 ip6->ip6_src    = *laddr;
 824                 ip6->ip6_dst    = *faddr;
 825
 826                 if (cscov_partial) {
 827                         if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
 828                             sizeof(struct ip6_hdr), plen, cscov)) == 0)
 829                                 udp6->uh_sum = 0xffff;
 830                 } else {
 831                         udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
 832                         m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
 833                         m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 834                 }
 835
 836                 /*
 837                  * XXX for now assume UDP is 2-tuple.
 838                  * Later on this may become configurable as 4-tuple;
 839                  * we should support that.
 840                  *
 841                  * XXX .. and we should likely cache this in the inpcb.
 842                  */
 843 #ifdef  RSS
 844                 m->m_pkthdr.flowid = rss_hash_ip6_2tuple(faddr, laddr);
 845                 M_HASHTYPE_SET(m, M_HASHTYPE_RSS_IPV6);
 846 #endif
 847                 flags = 0;
 848
 849 #ifdef  RSS
 850                 /*
 851                  * Don't override with the inp cached flowid.
 852                  *
 853                  * Until the whole UDP path is vetted, it may actually
 854                  * be incorrect.
 855                  */
 856                 flags |= IP_NODEFAULTFLOWID;
 857 #endif
 858
 859                 UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
 860                 UDPSTAT_INC(udps_opackets);
 861                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 862                     NULL, inp);
 863                 break;
 864         case AF_INET:
 865                 error = EAFNOSUPPORT;
 866                 goto release;
 867         }
 868         goto releaseopt;
 869
 870 release:
 871         m_freem(m);
 872
 873 releaseopt:
 874         if (control) {
 875                 ip6_clearpktopts(&opt, -1);
 876                 m_freem(control);
 877         }
 878         return (error);
 879 }
 880
 881 static void
 882 udp6_abort(struct socket *so)
 883 {
 884         struct inpcb *inp;
 885         struct inpcbinfo *pcbinfo;
 886
 887         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 888         inp = sotoinpcb(so);
 889         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 890
 891 #ifdef INET
 892         if (inp->inp_vflag & INP_IPV4) {
 893                 struct pr_usrreqs *pru;
 894
 895                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 896                 (*pru->pru_abort)(so);
 897                 return;
 898         }
 899 #endif
 900
 901         INP_WLOCK(inp);
 902         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 903                 INP_HASH_WLOCK(pcbinfo);
 904                 in6_pcbdisconnect(inp);
 905                 inp->in6p_laddr = in6addr_any;
 906                 INP_HASH_WUNLOCK(pcbinfo);
 907                 soisdisconnected(so);
 908         }
 909         INP_WUNLOCK(inp);
 910 }
 911
 912 static int
 913 udp6_attach(struct socket *so, int proto, struct thread *td)
 914 {
 915         struct inpcb *inp;
 916         struct inpcbinfo *pcbinfo;
 917         int error;
 918
 919         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 920         inp = sotoinpcb(so);
 921         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 922
 923         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 924                 error = soreserve(so, udp_sendspace, udp_recvspace);
 925                 if (error)
 926                         return (error);
 927         }
 928         INP_INFO_WLOCK(pcbinfo);
 929         error = in_pcballoc(so, pcbinfo);
 930         if (error) {
 931                 INP_INFO_WUNLOCK(pcbinfo);
 932                 return (error);
 933         }
 934         inp = (struct inpcb *)so->so_pcb;
 935         inp->inp_vflag |= INP_IPV6;
 936         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 937                 inp->inp_vflag |= INP_IPV4;
 938         inp->in6p_hops = -1;    /* use kernel default */
 939         inp->in6p_cksum = -1;   /* just to be sure */
 940         /*
 941          * XXX: ugly!!
 942          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 943          * because the socket may be bound to an IPv6 wildcard address,
 944          * which may match an IPv4-mapped IPv6 address.
 945          */
 946         inp->inp_ip_ttl = V_ip_defttl;
 947
 948         error = udp_newudpcb(inp);
 949         if (error) {
 950                 in_pcbdetach(inp);
 951                 in_pcbfree(inp);
 952                 INP_INFO_WUNLOCK(pcbinfo);
 953                 return (error);
 954         }
 955         INP_WUNLOCK(inp);
 956         INP_INFO_WUNLOCK(pcbinfo);
 957         return (0);
 958 }
 959
 960 static int
 961 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 962 {
 963         struct inpcb *inp;
 964         struct inpcbinfo *pcbinfo;
 965         int error;
 966
 967         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 968         inp = sotoinpcb(so);
 969         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 970
 971         INP_WLOCK(inp);
 972         INP_HASH_WLOCK(pcbinfo);
 973         inp->inp_vflag &= ~INP_IPV4;
 974         inp->inp_vflag |= INP_IPV6;
 975         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 976                 struct sockaddr_in6 *sin6_p;
 977
 978                 sin6_p = (struct sockaddr_in6 *)nam;
 979
 980                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 981                         inp->inp_vflag |= INP_IPV4;
 982 #ifdef INET
 983                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 984                         struct sockaddr_in sin;
 985
 986                         in6_sin6_2_sin(&sin, sin6_p);
 987                         inp->inp_vflag |= INP_IPV4;
 988                         inp->inp_vflag &= ~INP_IPV6;
 989                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 990                             td->td_ucred);
 991                         goto out;
 992                 }
 993 #endif
 994         }
 995
 996         error = in6_pcbbind(inp, nam, td->td_ucred);
 997 #ifdef INET
 998 out:
 999 #endif
1000         INP_HASH_WUNLOCK(pcbinfo);
1001         INP_WUNLOCK(inp);
1002         return (error);
1003 }
1004
1005 static void
1006 udp6_close(struct socket *so)
1007 {
1008         struct inpcb *inp;
1009         struct inpcbinfo *pcbinfo;
1010
1011         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1012         inp = sotoinpcb(so);
1013         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
1014
1015 #ifdef INET
1016         if (inp->inp_vflag & INP_IPV4) {
1017                 struct pr_usrreqs *pru;
1018
1019                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1020                 (*pru->pru_disconnect)(so);
1021                 return;
1022         }
1023 #endif
1024         INP_WLOCK(inp);
1025         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1026                 INP_HASH_WLOCK(pcbinfo);
1027                 in6_pcbdisconnect(inp);
1028                 inp->in6p_laddr = in6addr_any;
1029                 INP_HASH_WUNLOCK(pcbinfo);
1030                 soisdisconnected(so);
1031         }
1032         INP_WUNLOCK(inp);
1033 }
1034
1035 static int
1036 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1037 {
1038         struct inpcb *inp;
1039         struct inpcbinfo *pcbinfo;
1040         struct sockaddr_in6 *sin6;
1041         int error;
1042
1043         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1044         inp = sotoinpcb(so);
1045         sin6 = (struct sockaddr_in6 *)nam;
1046         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
1047
1048         /*
1049          * XXXRW: Need to clarify locking of v4/v6 flags.
1050          */
1051         INP_WLOCK(inp);
1052 #ifdef INET
1053         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
1054                 struct sockaddr_in sin;
1055
1056                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
1057                         error = EINVAL;
1058                         goto out;
1059                 }
1060                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1061                         error = EISCONN;
1062                         goto out;
1063                 }
1064                 in6_sin6_2_sin(&sin, sin6);
1065                 inp->inp_vflag |= INP_IPV4;
1066                 inp->inp_vflag &= ~INP_IPV6;
1067                 error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
1068                 if (error != 0)
1069                         goto out;
1070                 INP_HASH_WLOCK(pcbinfo);
1071                 error = in_pcbconnect(inp, (struct sockaddr *)&sin,
1072                     td->td_ucred);
1073                 INP_HASH_WUNLOCK(pcbinfo);
1074                 if (error == 0)
1075                         soisconnected(so);
1076                 goto out;
1077         }
1078 #endif
1079         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1080                 error = EISCONN;
1081                 goto out;
1082         }
1083         inp->inp_vflag &= ~INP_IPV4;
1084         inp->inp_vflag |= INP_IPV6;
1085         error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1086         if (error != 0)
1087                 goto out;
1088         INP_HASH_WLOCK(pcbinfo);
1089         error = in6_pcbconnect(inp, nam, td->td_ucred);
1090         INP_HASH_WUNLOCK(pcbinfo);
1091         if (error == 0)
1092                 soisconnected(so);
1093 out:
1094         INP_WUNLOCK(inp);
1095         return (error);
1096 }
1097
1098 static void
1099 udp6_detach(struct socket *so)
1100 {
1101         struct inpcb *inp;
1102         struct inpcbinfo *pcbinfo;
1103         struct udpcb *up;
1104
1105         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1106         inp = sotoinpcb(so);
1107         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1108
1109         INP_INFO_WLOCK(pcbinfo);
1110         INP_WLOCK(inp);
1111         up = intoudpcb(inp);
1112         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1113         in_pcbdetach(inp);
1114         in_pcbfree(inp);
1115         INP_INFO_WUNLOCK(pcbinfo);
1116         udp_discardcb(up);
1117 }
1118
1119 static int
1120 udp6_disconnect(struct socket *so)
1121 {
1122         struct inpcb *inp;
1123         struct inpcbinfo *pcbinfo;
1124         int error;
1125
1126         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1127         inp = sotoinpcb(so);
1128         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1129
1130 #ifdef INET
1131         if (inp->inp_vflag & INP_IPV4) {
1132                 struct pr_usrreqs *pru;
1133
1134                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1135                 (void)(*pru->pru_disconnect)(so);
1136                 return (0);
1137         }
1138 #endif
1139
1140         INP_WLOCK(inp);
1141
1142         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1143                 error = ENOTCONN;
1144                 goto out;
1145         }
1146
1147         INP_HASH_WLOCK(pcbinfo);
1148         in6_pcbdisconnect(inp);
1149         inp->in6p_laddr = in6addr_any;
1150         INP_HASH_WUNLOCK(pcbinfo);
1151         SOCK_LOCK(so);
1152         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1153         SOCK_UNLOCK(so);
1154 out:
1155         INP_WUNLOCK(inp);
1156         return (0);
1157 }
1158
1159 static int
1160 udp6_send(struct socket *so, int flags, struct mbuf *m,
1161     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1162 {
1163         struct inpcb *inp;
1164         struct inpcbinfo *pcbinfo;
1165         int error = 0;
1166
1167         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1168         inp = sotoinpcb(so);
1169         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1170
1171         INP_WLOCK(inp);
1172         if (addr) {
1173                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1174                         error = EINVAL;
1175                         goto bad;
1176                 }
1177                 if (addr->sa_family != AF_INET6) {
1178                         error = EAFNOSUPPORT;
1179                         goto bad;
1180                 }
1181         }
1182
1183 #ifdef INET
1184         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1185                 int hasv4addr;
1186                 struct sockaddr_in6 *sin6 = 0;
1187
1188                 if (addr == 0)
1189                         hasv4addr = (inp->inp_vflag & INP_IPV4);
1190                 else {
1191                         sin6 = (struct sockaddr_in6 *)addr;
1192                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1193                             ? 1 : 0;
1194                 }
1195                 if (hasv4addr) {
1196                         struct pr_usrreqs *pru;
1197
1198                         /*
1199                          * XXXRW: We release UDP-layer locks before calling
1200                          * udp_send() in order to avoid recursion.  However,
1201                          * this does mean there is a short window where inp's
1202                          * fields are unstable.  Could this lead to a
1203                          * potential race in which the factors causing us to
1204                          * select the UDPv4 output routine are invalidated?
1205                          */
1206                         INP_WUNLOCK(inp);
1207                         if (sin6)
1208                                 in6_sin6_2_sin_in_sock(addr);
1209                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1210                         /* addr will just be freed in sendit(). */
1211                         return ((*pru->pru_send)(so, flags, m, addr, control,
1212                             td));
1213                 }
1214         }
1215 #endif
1216 #ifdef MAC
1217         mac_inpcb_create_mbuf(inp, m);
1218 #endif
1219         INP_HASH_WLOCK(pcbinfo);
1220         error = udp6_output(inp, m, addr, control, td);
1221         INP_HASH_WUNLOCK(pcbinfo);
1222 #ifdef INET
1223 #endif
1224         INP_WUNLOCK(inp);
1225         return (error);
1226
1227 bad:
1228         INP_WUNLOCK(inp);
1229         m_freem(m);
1230         return (error);
1231 }
1232
1233 struct pr_usrreqs udp6_usrreqs = {
1234         .pru_abort =            udp6_abort,
1235         .pru_attach =           udp6_attach,
1236         .pru_bind =             udp6_bind,
1237         .pru_connect =          udp6_connect,
1238         .pru_control =          in6_control,
1239         .pru_detach =           udp6_detach,
1240         .pru_disconnect =       udp6_disconnect,
1241         .pru_peeraddr =         in6_mapped_peeraddr,
1242         .pru_send =             udp6_send,
1243         .pru_shutdown =         udp_shutdown,
1244         .pru_sockaddr =         in6_mapped_sockaddr,
1245         .pru_soreceive =        soreceive_dgram,
1246         .pru_sosend =           sosend_dgram,
1247         .pru_sosetlabel =       in_pcbsosetlabel,
1248         .pru_close =            udp6_close
1249 };