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  * All rights reserved.
   5  *
   6  * Portions of this software were developed by Robert N. M. Watson under
   7  * contract to Juniper Networks, Inc.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      $KAME: udp6_usrreq.c,v 1.27 2001/05/21 05:45:10 jinmei Exp $
  34  *      $KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei Exp $
  35  */
  36
  37 /*-
  38  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
  39  *      The Regents of the University of California.
  40  * All rights reserved.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  * 4. Neither the name of the University nor the names of its contributors
  51  *    may be used to endorse or promote products derived from this software
  52  *    without specific prior written permission.
  53  *
  54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  64  * SUCH DAMAGE.
  65  *
  66  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
  67  */
  68
  69 #include <sys/cdefs.h>
  70 __FBSDID("$FreeBSD$");
  71
  72 #include "opt_inet.h"
  73 #include "opt_inet6.h"
  74 #include "opt_ipfw.h"
  75 #include "opt_ipsec.h"
  76
  77 #include <sys/param.h>
  78 #include <sys/jail.h>
  79 #include <sys/kernel.h>
  80 #include <sys/lock.h>
  81 #include <sys/mbuf.h>
  82 #include <sys/priv.h>
  83 #include <sys/proc.h>
  84 #include <sys/protosw.h>
  85 #include <sys/signalvar.h>
  86 #include <sys/socket.h>
  87 #include <sys/socketvar.h>
  88 #include <sys/sx.h>
  89 #include <sys/sysctl.h>
  90 #include <sys/syslog.h>
  91 #include <sys/systm.h>
  92
  93 #include <net/if.h>
  94 #include <net/if_types.h>
  95 #include <net/route.h>
  96
  97 #include <netinet/in.h>
  98 #include <netinet/in_pcb.h>
  99 #include <netinet/in_systm.h>
 100 #include <netinet/in_var.h>
 101 #include <netinet/ip.h>
 102 #include <netinet/ip_icmp.h>
 103 #include <netinet/ip6.h>
 104 #include <netinet/icmp_var.h>
 105 #include <netinet/icmp6.h>
 106 #include <netinet/ip_var.h>
 107 #include <netinet/udp.h>
 108 #include <netinet/udp_var.h>
 109
 110 #include <netinet6/ip6protosw.h>
 111 #include <netinet6/ip6_var.h>
 112 #include <netinet6/in6_pcb.h>
 113 #include <netinet6/udp6_var.h>
 114 #include <netinet6/scope6_var.h>
 115
 116 #ifdef IPSEC
 117 #include <netipsec/ipsec.h>
 118 #include <netipsec/ipsec6.h>
 119 #endif /* IPSEC */
 120
 121 #include <security/mac/mac_framework.h>
 122
 123 /*
 124  * UDP protocol implementation.
 125  * Per RFC 768, August, 1980.
 126  */
 127
 128 extern struct protosw   inetsw[];
 129 static void             udp6_detach(struct socket *so);
 130
 131 static void
 132 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
 133     struct sockaddr_in6 *fromsa)
 134 {
 135         struct socket *so;
 136         struct mbuf *opts;
 137
 138         INP_LOCK_ASSERT(inp);
 139
 140 #ifdef IPSEC
 141         /* Check AH/ESP integrity. */
 142         if (ipsec6_in_reject(n, inp)) {
 143                 m_freem(n);
 144                 V_ipsec6stat.in_polvio++;
 145                 return;
 146         }
 147 #endif /* IPSEC */
 148 #ifdef MAC
 149         if (mac_inpcb_check_deliver(inp, n) != 0) {
 150                 m_freem(n);
 151                 return;
 152         }
 153 #endif
 154         opts = NULL;
 155         if (inp->inp_flags & INP_CONTROLOPTS ||
 156             inp->inp_socket->so_options & SO_TIMESTAMP)
 157                 ip6_savecontrol(inp, n, &opts);
 158         m_adj(n, off + sizeof(struct udphdr));
 159
 160         so = inp->inp_socket;
 161         SOCKBUF_LOCK(&so->so_rcv);
 162         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
 163             opts) == 0) {
 164                 SOCKBUF_UNLOCK(&so->so_rcv);
 165                 m_freem(n);
 166                 if (opts)
 167                         m_freem(opts);
 168                 UDPSTAT_INC(udps_fullsock);
 169         } else
 170                 sorwakeup_locked(so);
 171 }
 172
 173 int
 174 udp6_input(struct mbuf **mp, int *offp, int proto)
 175 {
 176         struct mbuf *m = *mp;
 177         struct ifnet *ifp;
 178         struct ip6_hdr *ip6;
 179         struct udphdr *uh;
 180         struct inpcb *inp;
 181         struct udpcb *up;
 182         int off = *offp;
 183         int plen, ulen;
 184         struct sockaddr_in6 fromsa;
 185         struct m_tag *fwd_tag;
 186         uint16_t uh_sum;
 187
 188         ifp = m->m_pkthdr.rcvif;
 189         ip6 = mtod(m, struct ip6_hdr *);
 190
 191         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 192                 /* XXX send icmp6 host/port unreach? */
 193                 m_freem(m);
 194                 return (IPPROTO_DONE);
 195         }
 196
 197 #ifndef PULLDOWN_TEST
 198         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
 199         ip6 = mtod(m, struct ip6_hdr *);
 200         uh = (struct udphdr *)((caddr_t)ip6 + off);
 201 #else
 202         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 203         if (!uh)
 204                 return (IPPROTO_DONE);
 205 #endif
 206
 207         UDPSTAT_INC(udps_ipackets);
 208
 209         /*
 210          * Destination port of 0 is illegal, based on RFC768.
 211          */
 212         if (uh->uh_dport == 0)
 213                 goto badunlocked;
 214
 215         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
 216         ulen = ntohs((u_short)uh->uh_ulen);
 217
 218         if (plen != ulen) {
 219                 UDPSTAT_INC(udps_badlen);
 220                 goto badunlocked;
 221         }
 222
 223         /*
 224          * Checksum extended UDP header and data.
 225          */
 226         if (uh->uh_sum == 0) {
 227                 UDPSTAT_INC(udps_nosum);
 228                 goto badunlocked;
 229         }
 230
 231         if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) {
 232                 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 233                         uh_sum = m->m_pkthdr.csum_data;
 234                 else
 235                         uh_sum = in6_cksum_pseudo(ip6, ulen,
 236                             IPPROTO_UDP, m->m_pkthdr.csum_data);
 237                 uh_sum ^= 0xffff;
 238         } else
 239                 uh_sum = in6_cksum(m, IPPROTO_UDP, off, ulen);
 240
 241         if (uh_sum != 0) {
 242                 UDPSTAT_INC(udps_badsum);
 243                 goto badunlocked;
 244         }
 245
 246         /*
 247          * Construct sockaddr format source address.
 248          */
 249         init_sin6(&fromsa, m);
 250         fromsa.sin6_port = uh->uh_sport;
 251
 252         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 253                 struct inpcb *last;
 254                 struct ip6_moptions *imo;
 255
 256                 INP_INFO_RLOCK(&V_udbinfo);
 257                 /*
 258                  * In the event that laddr should be set to the link-local
 259                  * address (this happens in RIPng), the multicast address
 260                  * specified in the received packet will not match laddr.  To
 261                  * handle this situation, matching is relaxed if the
 262                  * receiving interface is the same as one specified in the
 263                  * socket and if the destination multicast address matches
 264                  * one of the multicast groups specified in the socket.
 265                  */
 266
 267                 /*
 268                  * KAME note: traditionally we dropped udpiphdr from mbuf
 269                  * here.  We need udphdr for IPsec processing so we do that
 270                  * later.
 271                  */
 272                 last = NULL;
 273                 LIST_FOREACH(inp, &V_udb, inp_list) {
 274                         if ((inp->inp_vflag & INP_IPV6) == 0)
 275                                 continue;
 276                         if (inp->inp_lport != uh->uh_dport)
 277                                 continue;
 278                         if (inp->inp_fport != 0 &&
 279                             inp->inp_fport != uh->uh_sport)
 280                                 continue;
 281                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 282                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
 283                                                         &ip6->ip6_dst))
 284                                         continue;
 285                         }
 286                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 287                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
 288                                                         &ip6->ip6_src) ||
 289                                     inp->inp_fport != uh->uh_sport)
 290                                         continue;
 291                         }
 292
 293                         /*
 294                          * XXXRW: Because we weren't holding either the inpcb
 295                          * or the hash lock when we checked for a match
 296                          * before, we should probably recheck now that the
 297                          * inpcb lock is (supposed to be) held.
 298                          */
 299
 300                         /*
 301                          * Handle socket delivery policy for any-source
 302                          * and source-specific multicast. [RFC3678]
 303                          */
 304                         imo = inp->in6p_moptions;
 305                         if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 306                                 struct sockaddr_in6      mcaddr;
 307                                 int                      blocked;
 308
 309                                 INP_RLOCK(inp);
 310
 311                                 bzero(&mcaddr, sizeof(struct sockaddr_in6));
 312                                 mcaddr.sin6_len = sizeof(struct sockaddr_in6);
 313                                 mcaddr.sin6_family = AF_INET6;
 314                                 mcaddr.sin6_addr = ip6->ip6_dst;
 315
 316                                 blocked = im6o_mc_filter(imo, ifp,
 317                                         (struct sockaddr *)&mcaddr,
 318                                         (struct sockaddr *)&fromsa);
 319                                 if (blocked != MCAST_PASS) {
 320                                         if (blocked == MCAST_NOTGMEMBER)
 321                                                 IP6STAT_INC(ip6s_notmember);
 322                                         if (blocked == MCAST_NOTSMEMBER ||
 323                                             blocked == MCAST_MUTED)
 324                                                 UDPSTAT_INC(udps_filtermcast);
 325                                         INP_RUNLOCK(inp); /* XXX */
 326                                         continue;
 327                                 }
 328
 329                                 INP_RUNLOCK(inp);
 330                         }
 331                         if (last != NULL) {
 332                                 struct mbuf *n;
 333
 334                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
 335                                         INP_RLOCK(last);
 336                                         up = intoudpcb(last);
 337                                         if (up->u_tun_func == NULL) {
 338                                                 udp6_append(last, n, off, &fromsa);
 339                                         } else {
 340                                                 /*
 341                                                  * Engage the tunneling
 342                                                  * protocol we will have to
 343                                                  * leave the info_lock up,
 344                                                  * since we are hunting
 345                                                  * through multiple UDP's.
 346                                                  *
 347                                                  */
 348                                                 (*up->u_tun_func)(n, off, last);
 349                                         }
 350                                         INP_RUNLOCK(last);
 351                                 }
 352                         }
 353                         last = inp;
 354                         /*
 355                          * Don't look for additional matches if this one does
 356                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 357                          * socket options set.  This heuristic avoids
 358                          * searching through all pcbs in the common case of a
 359                          * non-shared port.  It assumes that an application
 360                          * will never clear these options after setting them.
 361                          */
 362                         if ((last->inp_socket->so_options &
 363                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 364                                 break;
 365                 }
 366
 367                 if (last == NULL) {
 368                         /*
 369                          * No matching pcb found; discard datagram.  (No need
 370                          * to send an ICMP Port Unreachable for a broadcast
 371                          * or multicast datgram.)
 372                          */
 373                         UDPSTAT_INC(udps_noport);
 374                         UDPSTAT_INC(udps_noportmcast);
 375                         goto badheadlocked;
 376                 }
 377                 INP_RLOCK(last);
 378                 INP_INFO_RUNLOCK(&V_udbinfo);
 379                 up = intoudpcb(last);
 380                 if (up->u_tun_func == NULL) {
 381                         udp6_append(last, m, off, &fromsa);
 382                 } else {
 383                         /*
 384                          * Engage the tunneling protocol.
 385                          */
 386                         (*up->u_tun_func)(m, off, last);
 387                 }
 388                 INP_RUNLOCK(last);
 389                 return (IPPROTO_DONE);
 390         }
 391         /*
 392          * Locate pcb for datagram.
 393          */
 394
 395         /*
 396          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 397          */
 398         if ((m->m_flags & M_IP6_NEXTHOP) &&
 399             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 400                 struct sockaddr_in6 *next_hop6;
 401
 402                 next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
 403
 404                 /*
 405                  * Transparently forwarded. Pretend to be the destination.
 406                  * Already got one like this?
 407                  */
 408                 inp = in6_pcblookup_mbuf(&V_udbinfo,
 409                     &ip6->ip6_src, uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 410                     INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
 411                 if (!inp) {
 412                         /*
 413                          * It's new.  Try to find the ambushing socket.
 414                          * Because we've rewritten the destination address,
 415                          * any hardware-generated hash is ignored.
 416                          */
 417                         inp = in6_pcblookup(&V_udbinfo, &ip6->ip6_src,
 418                             uh->uh_sport, &next_hop6->sin6_addr,
 419                             next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
 420                             uh->uh_dport, INPLOOKUP_WILDCARD |
 421                             INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
 422                 }
 423                 /* Remove the tag from the packet. We don't need it anymore. */
 424                 m_tag_delete(m, fwd_tag);
 425                 m->m_flags &= ~M_IP6_NEXTHOP;
 426         } else
 427                 inp = in6_pcblookup_mbuf(&V_udbinfo, &ip6->ip6_src,
 428                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 429                     INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
 430                     m->m_pkthdr.rcvif, m);
 431         if (inp == NULL) {
 432                 if (udp_log_in_vain) {
 433                         char ip6bufs[INET6_ADDRSTRLEN];
 434                         char ip6bufd[INET6_ADDRSTRLEN];
 435
 436                         log(LOG_INFO,
 437                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
 438                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 439                             ntohs(uh->uh_dport),
 440                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
 441                             ntohs(uh->uh_sport));
 442                 }
 443                 UDPSTAT_INC(udps_noport);
 444                 if (m->m_flags & M_MCAST) {
 445                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
 446                         UDPSTAT_INC(udps_noportmcast);
 447                         goto badunlocked;
 448                 }
 449                 if (V_udp_blackhole)
 450                         goto badunlocked;
 451                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
 452                         goto badunlocked;
 453                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
 454                 return (IPPROTO_DONE);
 455         }
 456         INP_RLOCK_ASSERT(inp);
 457         up = intoudpcb(inp);
 458         if (up->u_tun_func == NULL) {
 459                 udp6_append(inp, m, off, &fromsa);
 460         } else {
 461                 /*
 462                  * Engage the tunneling protocol.
 463                  */
 464
 465                 (*up->u_tun_func)(m, off, inp);
 466         }
 467         INP_RUNLOCK(inp);
 468         return (IPPROTO_DONE);
 469
 470 badheadlocked:
 471         INP_INFO_RUNLOCK(&V_udbinfo);
 472 badunlocked:
 473         if (m)
 474                 m_freem(m);
 475         return (IPPROTO_DONE);
 476 }
 477
 478 void
 479 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 480 {
 481         struct udphdr uh;
 482         struct ip6_hdr *ip6;
 483         struct mbuf *m;
 484         int off = 0;
 485         struct ip6ctlparam *ip6cp = NULL;
 486         const struct sockaddr_in6 *sa6_src = NULL;
 487         void *cmdarg;
 488         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 489         struct udp_portonly {
 490                 u_int16_t uh_sport;
 491                 u_int16_t uh_dport;
 492         } *uhp;
 493
 494         if (sa->sa_family != AF_INET6 ||
 495             sa->sa_len != sizeof(struct sockaddr_in6))
 496                 return;
 497
 498         if ((unsigned)cmd >= PRC_NCMDS)
 499                 return;
 500         if (PRC_IS_REDIRECT(cmd))
 501                 notify = in6_rtchange, d = NULL;
 502         else if (cmd == PRC_HOSTDEAD)
 503                 d = NULL;
 504         else if (inet6ctlerrmap[cmd] == 0)
 505                 return;
 506
 507         /* if the parameter is from icmp6, decode it. */
 508         if (d != NULL) {
 509                 ip6cp = (struct ip6ctlparam *)d;
 510                 m = ip6cp->ip6c_m;
 511                 ip6 = ip6cp->ip6c_ip6;
 512                 off = ip6cp->ip6c_off;
 513                 cmdarg = ip6cp->ip6c_cmdarg;
 514                 sa6_src = ip6cp->ip6c_src;
 515         } else {
 516                 m = NULL;
 517                 ip6 = NULL;
 518                 cmdarg = NULL;
 519                 sa6_src = &sa6_any;
 520         }
 521
 522         if (ip6) {
 523                 /*
 524                  * XXX: We assume that when IPV6 is non NULL,
 525                  * M and OFF are valid.
 526                  */
 527
 528                 /* Check if we can safely examine src and dst ports. */
 529                 if (m->m_pkthdr.len < off + sizeof(*uhp))
 530                         return;
 531
 532                 bzero(&uh, sizeof(uh));
 533                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
 534
 535                 (void) in6_pcbnotify(&V_udbinfo, sa, uh.uh_dport,
 536                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
 537                     cmdarg, notify);
 538         } else
 539                 (void) in6_pcbnotify(&V_udbinfo, sa, 0,
 540                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
 541 }
 542
 543 static int
 544 udp6_getcred(SYSCTL_HANDLER_ARGS)
 545 {
 546         struct xucred xuc;
 547         struct sockaddr_in6 addrs[2];
 548         struct inpcb *inp;
 549         int error;
 550
 551         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 552         if (error)
 553                 return (error);
 554
 555         if (req->newlen != sizeof(addrs))
 556                 return (EINVAL);
 557         if (req->oldlen != sizeof(struct xucred))
 558                 return (EINVAL);
 559         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 560         if (error)
 561                 return (error);
 562         if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
 563             (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
 564                 return (error);
 565         }
 566         inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
 567             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
 568             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 569         if (inp != NULL) {
 570                 INP_RLOCK_ASSERT(inp);
 571                 if (inp->inp_socket == NULL)
 572                         error = ENOENT;
 573                 if (error == 0)
 574                         error = cr_canseesocket(req->td->td_ucred,
 575                             inp->inp_socket);
 576                 if (error == 0)
 577                         cru2x(inp->inp_cred, &xuc);
 578                 INP_RUNLOCK(inp);
 579         } else
 580                 error = ENOENT;
 581         if (error == 0)
 582                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 583         return (error);
 584 }
 585
 586 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
 587     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
 588
 589 static int
 590 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
 591     struct mbuf *control, struct thread *td)
 592 {
 593         u_int32_t ulen = m->m_pkthdr.len;
 594         u_int32_t plen = sizeof(struct udphdr) + ulen;
 595         struct ip6_hdr *ip6;
 596         struct udphdr *udp6;
 597         struct in6_addr *laddr, *faddr, in6a;
 598         struct sockaddr_in6 *sin6 = NULL;
 599         struct ifnet *oifp = NULL;
 600         int scope_ambiguous = 0;
 601         u_short fport;
 602         int error = 0;
 603         struct ip6_pktopts *optp, opt;
 604         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 605         int flags;
 606         struct sockaddr_in6 tmp;
 607
 608         INP_WLOCK_ASSERT(inp);
 609         INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
 610
 611         if (addr6) {
 612                 /* addr6 has been validated in udp6_send(). */
 613                 sin6 = (struct sockaddr_in6 *)addr6;
 614
 615                 /* protect *sin6 from overwrites */
 616                 tmp = *sin6;
 617                 sin6 = &tmp;
 618
 619                 /*
 620                  * Application should provide a proper zone ID or the use of
 621                  * default zone IDs should be enabled.  Unfortunately, some
 622                  * applications do not behave as it should, so we need a
 623                  * workaround.  Even if an appropriate ID is not determined,
 624                  * we'll see if we can determine the outgoing interface.  If we
 625                  * can, determine the zone ID based on the interface below.
 626                  */
 627                 if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
 628                         scope_ambiguous = 1;
 629                 if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
 630                         return (error);
 631         }
 632
 633         if (control) {
 634                 if ((error = ip6_setpktopts(control, &opt,
 635                     inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
 636                         goto release;
 637                 optp = &opt;
 638         } else
 639                 optp = inp->in6p_outputopts;
 640
 641         if (sin6) {
 642                 faddr = &sin6->sin6_addr;
 643
 644                 /*
 645                  * Since we saw no essential reason for calling in_pcbconnect,
 646                  * we get rid of such kind of logic, and call in6_selectsrc
 647                  * and in6_pcbsetport in order to fill in the local address
 648                  * and the local port.
 649                  */
 650                 if (sin6->sin6_port == 0) {
 651                         error = EADDRNOTAVAIL;
 652                         goto release;
 653                 }
 654
 655                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 656                         /* how about ::ffff:0.0.0.0 case? */
 657                         error = EISCONN;
 658                         goto release;
 659                 }
 660
 661                 fport = sin6->sin6_port; /* allow 0 port */
 662
 663                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 664                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 665                                 /*
 666                                  * I believe we should explicitly discard the
 667                                  * packet when mapped addresses are disabled,
 668                                  * rather than send the packet as an IPv6 one.
 669                                  * If we chose the latter approach, the packet
 670                                  * might be sent out on the wire based on the
 671                                  * default route, the situation which we'd
 672                                  * probably want to avoid.
 673                                  * (20010421 jinmei@kame.net)
 674                                  */
 675                                 error = EINVAL;
 676                                 goto release;
 677                         }
 678                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 679                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 680                                 /*
 681                                  * when remote addr is an IPv4-mapped address,
 682                                  * local addr should not be an IPv6 address,
 683                                  * since you cannot determine how to map IPv6
 684                                  * source address to IPv4.
 685                                  */
 686                                 error = EINVAL;
 687                                 goto release;
 688                         }
 689
 690                         af = AF_INET;
 691                 }
 692
 693                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 694                         error = in6_selectsrc(sin6, optp, inp, NULL,
 695                             td->td_ucred, &oifp, &in6a);
 696                         if (error)
 697                                 goto release;
 698                         if (oifp && scope_ambiguous &&
 699                             (error = in6_setscope(&sin6->sin6_addr,
 700                             oifp, NULL))) {
 701                                 goto release;
 702                         }
 703                         laddr = &in6a;
 704                 } else
 705                         laddr = &inp->in6p_laddr;       /* XXX */
 706                 if (laddr == NULL) {
 707                         if (error == 0)
 708                                 error = EADDRNOTAVAIL;
 709                         goto release;
 710                 }
 711                 if (inp->inp_lport == 0 &&
 712                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
 713                         /* Undo an address bind that may have occurred. */
 714                         inp->in6p_laddr = in6addr_any;
 715                         goto release;
 716                 }
 717         } else {
 718                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 719                         error = ENOTCONN;
 720                         goto release;
 721                 }
 722                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 723                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 724                                 /*
 725                                  * XXX: this case would happen when the
 726                                  * application sets the V6ONLY flag after
 727                                  * connecting the foreign address.
 728                                  * Such applications should be fixed,
 729                                  * so we bark here.
 730                                  */
 731                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 732                                     "option was set for a connected socket\n");
 733                                 error = EINVAL;
 734                                 goto release;
 735                         } else
 736                                 af = AF_INET;
 737                 }
 738                 laddr = &inp->in6p_laddr;
 739                 faddr = &inp->in6p_faddr;
 740                 fport = inp->inp_fport;
 741         }
 742
 743         if (af == AF_INET)
 744                 hlen = sizeof(struct ip);
 745
 746         /*
 747          * Calculate data length and get a mbuf
 748          * for UDP and IP6 headers.
 749          */
 750         M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
 751         if (m == 0) {
 752                 error = ENOBUFS;
 753                 goto release;
 754         }
 755
 756         /*
 757          * Stuff checksum and output datagram.
 758          */
 759         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 760         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
 761         udp6->uh_dport = fport;
 762         if (plen <= 0xffff)
 763                 udp6->uh_ulen = htons((u_short)plen);
 764         else
 765                 udp6->uh_ulen = 0;
 766         udp6->uh_sum = 0;
 767
 768         switch (af) {
 769         case AF_INET6:
 770                 ip6 = mtod(m, struct ip6_hdr *);
 771                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
 772                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 773                 ip6->ip6_vfc    |= IPV6_VERSION;
 774 #if 0                           /* ip6_plen will be filled in ip6_output. */
 775                 ip6->ip6_plen   = htons((u_short)plen);
 776 #endif
 777                 ip6->ip6_nxt    = IPPROTO_UDP;
 778                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 779                 ip6->ip6_src    = *laddr;
 780                 ip6->ip6_dst    = *faddr;
 781
 782                 udp6->uh_sum = in6_cksum_pseudo(ip6, plen, IPPROTO_UDP, 0);
 783                 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
 784                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 785
 786                 flags = 0;
 787
 788                 UDPSTAT_INC(udps_opackets);
 789                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 790                     NULL, inp);
 791                 break;
 792         case AF_INET:
 793                 error = EAFNOSUPPORT;
 794                 goto release;
 795         }
 796         goto releaseopt;
 797
 798 release:
 799         m_freem(m);
 800
 801 releaseopt:
 802         if (control) {
 803                 ip6_clearpktopts(&opt, -1);
 804                 m_freem(control);
 805         }
 806         return (error);
 807 }
 808
 809 static void
 810 udp6_abort(struct socket *so)
 811 {
 812         struct inpcb *inp;
 813
 814         inp = sotoinpcb(so);
 815         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 816
 817 #ifdef INET
 818         if (inp->inp_vflag & INP_IPV4) {
 819                 struct pr_usrreqs *pru;
 820
 821                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 822                 (*pru->pru_abort)(so);
 823                 return;
 824         }
 825 #endif
 826
 827         INP_WLOCK(inp);
 828         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 829                 INP_HASH_WLOCK(&V_udbinfo);
 830                 in6_pcbdisconnect(inp);
 831                 inp->in6p_laddr = in6addr_any;
 832                 INP_HASH_WUNLOCK(&V_udbinfo);
 833                 soisdisconnected(so);
 834         }
 835         INP_WUNLOCK(inp);
 836 }
 837
 838 static int
 839 udp6_attach(struct socket *so, int proto, struct thread *td)
 840 {
 841         struct inpcb *inp;
 842         int error;
 843
 844         inp = sotoinpcb(so);
 845         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 846
 847         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 848                 error = soreserve(so, udp_sendspace, udp_recvspace);
 849                 if (error)
 850                         return (error);
 851         }
 852         INP_INFO_WLOCK(&V_udbinfo);
 853         error = in_pcballoc(so, &V_udbinfo);
 854         if (error) {
 855                 INP_INFO_WUNLOCK(&V_udbinfo);
 856                 return (error);
 857         }
 858         inp = (struct inpcb *)so->so_pcb;
 859         inp->inp_vflag |= INP_IPV6;
 860         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 861                 inp->inp_vflag |= INP_IPV4;
 862         inp->in6p_hops = -1;    /* use kernel default */
 863         inp->in6p_cksum = -1;   /* just to be sure */
 864         /*
 865          * XXX: ugly!!
 866          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 867          * because the socket may be bound to an IPv6 wildcard address,
 868          * which may match an IPv4-mapped IPv6 address.
 869          */
 870         inp->inp_ip_ttl = V_ip_defttl;
 871
 872         error = udp_newudpcb(inp);
 873         if (error) {
 874                 in_pcbdetach(inp);
 875                 in_pcbfree(inp);
 876                 INP_INFO_WUNLOCK(&V_udbinfo);
 877                 return (error);
 878         }
 879         INP_WUNLOCK(inp);
 880         INP_INFO_WUNLOCK(&V_udbinfo);
 881         return (0);
 882 }
 883
 884 static int
 885 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 886 {
 887         struct inpcb *inp;
 888         int error;
 889
 890         inp = sotoinpcb(so);
 891         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 892
 893         INP_WLOCK(inp);
 894         INP_HASH_WLOCK(&V_udbinfo);
 895         inp->inp_vflag &= ~INP_IPV4;
 896         inp->inp_vflag |= INP_IPV6;
 897         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 898                 struct sockaddr_in6 *sin6_p;
 899
 900                 sin6_p = (struct sockaddr_in6 *)nam;
 901
 902                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 903                         inp->inp_vflag |= INP_IPV4;
 904 #ifdef INET
 905                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 906                         struct sockaddr_in sin;
 907
 908                         in6_sin6_2_sin(&sin, sin6_p);
 909                         inp->inp_vflag |= INP_IPV4;
 910                         inp->inp_vflag &= ~INP_IPV6;
 911                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 912                             td->td_ucred);
 913                         goto out;
 914                 }
 915 #endif
 916         }
 917
 918         error = in6_pcbbind(inp, nam, td->td_ucred);
 919 #ifdef INET
 920 out:
 921 #endif
 922         INP_HASH_WUNLOCK(&V_udbinfo);
 923         INP_WUNLOCK(inp);
 924         return (error);
 925 }
 926
 927 static void
 928 udp6_close(struct socket *so)
 929 {
 930         struct inpcb *inp;
 931
 932         inp = sotoinpcb(so);
 933         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
 934
 935 #ifdef INET
 936         if (inp->inp_vflag & INP_IPV4) {
 937                 struct pr_usrreqs *pru;
 938
 939                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 940                 (*pru->pru_disconnect)(so);
 941                 return;
 942         }
 943 #endif
 944         INP_WLOCK(inp);
 945         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 946                 INP_HASH_WLOCK(&V_udbinfo);
 947                 in6_pcbdisconnect(inp);
 948                 inp->in6p_laddr = in6addr_any;
 949                 INP_HASH_WUNLOCK(&V_udbinfo);
 950                 soisdisconnected(so);
 951         }
 952         INP_WUNLOCK(inp);
 953 }
 954
 955 static int
 956 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 957 {
 958         struct inpcb *inp;
 959         struct sockaddr_in6 *sin6;
 960         int error;
 961
 962         inp = sotoinpcb(so);
 963         sin6 = (struct sockaddr_in6 *)nam;
 964         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
 965
 966         /*
 967          * XXXRW: Need to clarify locking of v4/v6 flags.
 968          */
 969         INP_WLOCK(inp);
 970 #ifdef INET
 971         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
 972                 struct sockaddr_in sin;
 973
 974                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
 975                         error = EINVAL;
 976                         goto out;
 977                 }
 978                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 979                         error = EISCONN;
 980                         goto out;
 981                 }
 982                 in6_sin6_2_sin(&sin, sin6);
 983                 inp->inp_vflag |= INP_IPV4;
 984                 inp->inp_vflag &= ~INP_IPV6;
 985                 error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
 986                 if (error != 0)
 987                         goto out;
 988                 INP_HASH_WLOCK(&V_udbinfo);
 989                 error = in_pcbconnect(inp, (struct sockaddr *)&sin,
 990                     td->td_ucred);
 991                 INP_HASH_WUNLOCK(&V_udbinfo);
 992                 if (error == 0)
 993                         soisconnected(so);
 994                 goto out;
 995         }
 996 #endif
 997         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 998                 error = EISCONN;
 999                 goto out;
1000         }
1001         inp->inp_vflag &= ~INP_IPV4;
1002         inp->inp_vflag |= INP_IPV6;
1003         error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1004         if (error != 0)
1005                 goto out;
1006         INP_HASH_WLOCK(&V_udbinfo);
1007         error = in6_pcbconnect(inp, nam, td->td_ucred);
1008         INP_HASH_WUNLOCK(&V_udbinfo);
1009         if (error == 0)
1010                 soisconnected(so);
1011 out:
1012         INP_WUNLOCK(inp);
1013         return (error);
1014 }
1015
1016 static void
1017 udp6_detach(struct socket *so)
1018 {
1019         struct inpcb *inp;
1020         struct udpcb *up;
1021
1022         inp = sotoinpcb(so);
1023         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1024
1025         INP_INFO_WLOCK(&V_udbinfo);
1026         INP_WLOCK(inp);
1027         up = intoudpcb(inp);
1028         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1029         in_pcbdetach(inp);
1030         in_pcbfree(inp);
1031         INP_INFO_WUNLOCK(&V_udbinfo);
1032         udp_discardcb(up);
1033 }
1034
1035 static int
1036 udp6_disconnect(struct socket *so)
1037 {
1038         struct inpcb *inp;
1039         int error;
1040
1041         inp = sotoinpcb(so);
1042         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1043
1044 #ifdef INET
1045         if (inp->inp_vflag & INP_IPV4) {
1046                 struct pr_usrreqs *pru;
1047
1048                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1049                 (void)(*pru->pru_disconnect)(so);
1050                 return (0);
1051         }
1052 #endif
1053
1054         INP_WLOCK(inp);
1055
1056         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1057                 error = ENOTCONN;
1058                 goto out;
1059         }
1060
1061         INP_HASH_WLOCK(&V_udbinfo);
1062         in6_pcbdisconnect(inp);
1063         inp->in6p_laddr = in6addr_any;
1064         INP_HASH_WUNLOCK(&V_udbinfo);
1065         SOCK_LOCK(so);
1066         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1067         SOCK_UNLOCK(so);
1068 out:
1069         INP_WUNLOCK(inp);
1070         return (0);
1071 }
1072
1073 static int
1074 udp6_send(struct socket *so, int flags, struct mbuf *m,
1075     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1076 {
1077         struct inpcb *inp;
1078         int error = 0;
1079
1080         inp = sotoinpcb(so);
1081         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1082
1083         INP_WLOCK(inp);
1084         if (addr) {
1085                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1086                         error = EINVAL;
1087                         goto bad;
1088                 }
1089                 if (addr->sa_family != AF_INET6) {
1090                         error = EAFNOSUPPORT;
1091                         goto bad;
1092                 }
1093         }
1094
1095 #ifdef INET
1096         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1097                 int hasv4addr;
1098                 struct sockaddr_in6 *sin6 = 0;
1099
1100                 if (addr == 0)
1101                         hasv4addr = (inp->inp_vflag & INP_IPV4);
1102                 else {
1103                         sin6 = (struct sockaddr_in6 *)addr;
1104                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1105                             ? 1 : 0;
1106                 }
1107                 if (hasv4addr) {
1108                         struct pr_usrreqs *pru;
1109
1110                         /*
1111                          * XXXRW: We release UDP-layer locks before calling
1112                          * udp_send() in order to avoid recursion.  However,
1113                          * this does mean there is a short window where inp's
1114                          * fields are unstable.  Could this lead to a
1115                          * potential race in which the factors causing us to
1116                          * select the UDPv4 output routine are invalidated?
1117                          */
1118                         INP_WUNLOCK(inp);
1119                         if (sin6)
1120                                 in6_sin6_2_sin_in_sock(addr);
1121                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1122                         /* addr will just be freed in sendit(). */
1123                         return ((*pru->pru_send)(so, flags, m, addr, control,
1124                             td));
1125                 }
1126         }
1127 #endif
1128 #ifdef MAC
1129         mac_inpcb_create_mbuf(inp, m);
1130 #endif
1131         INP_HASH_WLOCK(&V_udbinfo);
1132         error = udp6_output(inp, m, addr, control, td);
1133         INP_HASH_WUNLOCK(&V_udbinfo);
1134 #ifdef INET
1135 #endif
1136         INP_WUNLOCK(inp);
1137         return (error);
1138
1139 bad:
1140         INP_WUNLOCK(inp);
1141         m_freem(m);
1142         return (error);
1143 }
1144
1145 struct pr_usrreqs udp6_usrreqs = {
1146         .pru_abort =            udp6_abort,
1147         .pru_attach =           udp6_attach,
1148         .pru_bind =             udp6_bind,
1149         .pru_connect =          udp6_connect,
1150         .pru_control =          in6_control,
1151         .pru_detach =           udp6_detach,
1152         .pru_disconnect =       udp6_disconnect,
1153         .pru_peeraddr =         in6_mapped_peeraddr,
1154         .pru_send =             udp6_send,
1155         .pru_shutdown =         udp_shutdown,
1156         .pru_sockaddr =         in6_mapped_sockaddr,
1157         .pru_soreceive =        soreceive_dgram,
1158         .pru_sosend =           sosend_dgram,
1159         .pru_sosetlabel =       in_pcbsosetlabel,
1160         .pru_close =            udp6_close
1161 };