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                 IPSEC6STAT_INC(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                  * IPv4 version of udp_output calls in_pcbconnect in this case,
 646                  * which needs splnet and affects performance.
 647                  * Since we saw no essential reason for calling in_pcbconnect,
 648                  * we get rid of such kind of logic, and call in6_selectsrc
 649                  * and in6_pcbsetport in order to fill in the local address
 650                  * and the local port.
 651                  */
 652                 if (sin6->sin6_port == 0) {
 653                         error = EADDRNOTAVAIL;
 654                         goto release;
 655                 }
 656
 657                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 658                         /* how about ::ffff:0.0.0.0 case? */
 659                         error = EISCONN;
 660                         goto release;
 661                 }
 662
 663                 fport = sin6->sin6_port; /* allow 0 port */
 664
 665                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 666                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 667                                 /*
 668                                  * I believe we should explicitly discard the
 669                                  * packet when mapped addresses are disabled,
 670                                  * rather than send the packet as an IPv6 one.
 671                                  * If we chose the latter approach, the packet
 672                                  * might be sent out on the wire based on the
 673                                  * default route, the situation which we'd
 674                                  * probably want to avoid.
 675                                  * (20010421 jinmei@kame.net)
 676                                  */
 677                                 error = EINVAL;
 678                                 goto release;
 679                         }
 680                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 681                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 682                                 /*
 683                                  * when remote addr is an IPv4-mapped address,
 684                                  * local addr should not be an IPv6 address,
 685                                  * since you cannot determine how to map IPv6
 686                                  * source address to IPv4.
 687                                  */
 688                                 error = EINVAL;
 689                                 goto release;
 690                         }
 691
 692                         af = AF_INET;
 693                 }
 694
 695                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 696                         error = in6_selectsrc(sin6, optp, inp, NULL,
 697                             td->td_ucred, &oifp, &in6a);
 698                         if (error)
 699                                 goto release;
 700                         if (oifp && scope_ambiguous &&
 701                             (error = in6_setscope(&sin6->sin6_addr,
 702                             oifp, NULL))) {
 703                                 goto release;
 704                         }
 705                         laddr = &in6a;
 706                 } else
 707                         laddr = &inp->in6p_laddr;       /* XXX */
 708                 if (laddr == NULL) {
 709                         if (error == 0)
 710                                 error = EADDRNOTAVAIL;
 711                         goto release;
 712                 }
 713                 if (inp->inp_lport == 0 &&
 714                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
 715                         /* Undo an address bind that may have occurred. */
 716                         inp->in6p_laddr = in6addr_any;
 717                         goto release;
 718                 }
 719         } else {
 720                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 721                         error = ENOTCONN;
 722                         goto release;
 723                 }
 724                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 725                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 726                                 /*
 727                                  * XXX: this case would happen when the
 728                                  * application sets the V6ONLY flag after
 729                                  * connecting the foreign address.
 730                                  * Such applications should be fixed,
 731                                  * so we bark here.
 732                                  */
 733                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 734                                     "option was set for a connected socket\n");
 735                                 error = EINVAL;
 736                                 goto release;
 737                         } else
 738                                 af = AF_INET;
 739                 }
 740                 laddr = &inp->in6p_laddr;
 741                 faddr = &inp->in6p_faddr;
 742                 fport = inp->inp_fport;
 743         }
 744
 745         if (af == AF_INET)
 746                 hlen = sizeof(struct ip);
 747
 748         /*
 749          * Calculate data length and get a mbuf
 750          * for UDP and IP6 headers.
 751          */
 752         M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
 753         if (m == 0) {
 754                 error = ENOBUFS;
 755                 goto release;
 756         }
 757
 758         /*
 759          * Stuff checksum and output datagram.
 760          */
 761         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 762         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
 763         udp6->uh_dport = fport;
 764         if (plen <= 0xffff)
 765                 udp6->uh_ulen = htons((u_short)plen);
 766         else
 767                 udp6->uh_ulen = 0;
 768         udp6->uh_sum = 0;
 769
 770         switch (af) {
 771         case AF_INET6:
 772                 ip6 = mtod(m, struct ip6_hdr *);
 773                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
 774                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 775                 ip6->ip6_vfc    |= IPV6_VERSION;
 776 #if 0                           /* ip6_plen will be filled in ip6_output. */
 777                 ip6->ip6_plen   = htons((u_short)plen);
 778 #endif
 779                 ip6->ip6_nxt    = IPPROTO_UDP;
 780                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 781                 ip6->ip6_src    = *laddr;
 782                 ip6->ip6_dst    = *faddr;
 783
 784                 udp6->uh_sum = in6_cksum_pseudo(ip6, plen, IPPROTO_UDP, 0);
 785                 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
 786                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 787
 788                 flags = 0;
 789
 790                 UDPSTAT_INC(udps_opackets);
 791                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 792                     NULL, inp);
 793                 break;
 794         case AF_INET:
 795                 error = EAFNOSUPPORT;
 796                 goto release;
 797         }
 798         goto releaseopt;
 799
 800 release:
 801         m_freem(m);
 802
 803 releaseopt:
 804         if (control) {
 805                 ip6_clearpktopts(&opt, -1);
 806                 m_freem(control);
 807         }
 808         return (error);
 809 }
 810
 811 static void
 812 udp6_abort(struct socket *so)
 813 {
 814         struct inpcb *inp;
 815
 816         inp = sotoinpcb(so);
 817         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 818
 819 #ifdef INET
 820         if (inp->inp_vflag & INP_IPV4) {
 821                 struct pr_usrreqs *pru;
 822
 823                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 824                 (*pru->pru_abort)(so);
 825                 return;
 826         }
 827 #endif
 828
 829         INP_WLOCK(inp);
 830         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 831                 INP_HASH_WLOCK(&V_udbinfo);
 832                 in6_pcbdisconnect(inp);
 833                 inp->in6p_laddr = in6addr_any;
 834                 INP_HASH_WUNLOCK(&V_udbinfo);
 835                 soisdisconnected(so);
 836         }
 837         INP_WUNLOCK(inp);
 838 }
 839
 840 static int
 841 udp6_attach(struct socket *so, int proto, struct thread *td)
 842 {
 843         struct inpcb *inp;
 844         int error;
 845
 846         inp = sotoinpcb(so);
 847         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 848
 849         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 850                 error = soreserve(so, udp_sendspace, udp_recvspace);
 851                 if (error)
 852                         return (error);
 853         }
 854         INP_INFO_WLOCK(&V_udbinfo);
 855         error = in_pcballoc(so, &V_udbinfo);
 856         if (error) {
 857                 INP_INFO_WUNLOCK(&V_udbinfo);
 858                 return (error);
 859         }
 860         inp = (struct inpcb *)so->so_pcb;
 861         inp->inp_vflag |= INP_IPV6;
 862         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 863                 inp->inp_vflag |= INP_IPV4;
 864         inp->in6p_hops = -1;    /* use kernel default */
 865         inp->in6p_cksum = -1;   /* just to be sure */
 866         /*
 867          * XXX: ugly!!
 868          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 869          * because the socket may be bound to an IPv6 wildcard address,
 870          * which may match an IPv4-mapped IPv6 address.
 871          */
 872         inp->inp_ip_ttl = V_ip_defttl;
 873
 874         error = udp_newudpcb(inp);
 875         if (error) {
 876                 in_pcbdetach(inp);
 877                 in_pcbfree(inp);
 878                 INP_INFO_WUNLOCK(&V_udbinfo);
 879                 return (error);
 880         }
 881         INP_WUNLOCK(inp);
 882         INP_INFO_WUNLOCK(&V_udbinfo);
 883         return (0);
 884 }
 885
 886 static int
 887 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 888 {
 889         struct inpcb *inp;
 890         int error;
 891
 892         inp = sotoinpcb(so);
 893         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 894
 895         INP_WLOCK(inp);
 896         INP_HASH_WLOCK(&V_udbinfo);
 897         inp->inp_vflag &= ~INP_IPV4;
 898         inp->inp_vflag |= INP_IPV6;
 899         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 900                 struct sockaddr_in6 *sin6_p;
 901
 902                 sin6_p = (struct sockaddr_in6 *)nam;
 903
 904                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 905                         inp->inp_vflag |= INP_IPV4;
 906 #ifdef INET
 907                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 908                         struct sockaddr_in sin;
 909
 910                         in6_sin6_2_sin(&sin, sin6_p);
 911                         inp->inp_vflag |= INP_IPV4;
 912                         inp->inp_vflag &= ~INP_IPV6;
 913                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 914                             td->td_ucred);
 915                         goto out;
 916                 }
 917 #endif
 918         }
 919
 920         error = in6_pcbbind(inp, nam, td->td_ucred);
 921 #ifdef INET
 922 out:
 923 #endif
 924         INP_HASH_WUNLOCK(&V_udbinfo);
 925         INP_WUNLOCK(inp);
 926         return (error);
 927 }
 928
 929 static void
 930 udp6_close(struct socket *so)
 931 {
 932         struct inpcb *inp;
 933
 934         inp = sotoinpcb(so);
 935         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
 936
 937 #ifdef INET
 938         if (inp->inp_vflag & INP_IPV4) {
 939                 struct pr_usrreqs *pru;
 940
 941                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 942                 (*pru->pru_disconnect)(so);
 943                 return;
 944         }
 945 #endif
 946         INP_WLOCK(inp);
 947         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 948                 INP_HASH_WLOCK(&V_udbinfo);
 949                 in6_pcbdisconnect(inp);
 950                 inp->in6p_laddr = in6addr_any;
 951                 INP_HASH_WUNLOCK(&V_udbinfo);
 952                 soisdisconnected(so);
 953         }
 954         INP_WUNLOCK(inp);
 955 }
 956
 957 static int
 958 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 959 {
 960         struct inpcb *inp;
 961         struct sockaddr_in6 *sin6;
 962         int error;
 963
 964         inp = sotoinpcb(so);
 965         sin6 = (struct sockaddr_in6 *)nam;
 966         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
 967
 968         /*
 969          * XXXRW: Need to clarify locking of v4/v6 flags.
 970          */
 971         INP_WLOCK(inp);
 972 #ifdef INET
 973         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
 974                 struct sockaddr_in sin;
 975
 976                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
 977                         error = EINVAL;
 978                         goto out;
 979                 }
 980                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 981                         error = EISCONN;
 982                         goto out;
 983                 }
 984                 in6_sin6_2_sin(&sin, sin6);
 985                 inp->inp_vflag |= INP_IPV4;
 986                 inp->inp_vflag &= ~INP_IPV6;
 987                 error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
 988                 if (error != 0)
 989                         goto out;
 990                 INP_HASH_WLOCK(&V_udbinfo);
 991                 error = in_pcbconnect(inp, (struct sockaddr *)&sin,
 992                     td->td_ucred);
 993                 INP_HASH_WUNLOCK(&V_udbinfo);
 994                 if (error == 0)
 995                         soisconnected(so);
 996                 goto out;
 997         }
 998 #endif
 999         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1000                 error = EISCONN;
1001                 goto out;
1002         }
1003         inp->inp_vflag &= ~INP_IPV4;
1004         inp->inp_vflag |= INP_IPV6;
1005         error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1006         if (error != 0)
1007                 goto out;
1008         INP_HASH_WLOCK(&V_udbinfo);
1009         error = in6_pcbconnect(inp, nam, td->td_ucred);
1010         INP_HASH_WUNLOCK(&V_udbinfo);
1011         if (error == 0)
1012                 soisconnected(so);
1013 out:
1014         INP_WUNLOCK(inp);
1015         return (error);
1016 }
1017
1018 static void
1019 udp6_detach(struct socket *so)
1020 {
1021         struct inpcb *inp;
1022         struct udpcb *up;
1023
1024         inp = sotoinpcb(so);
1025         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1026
1027         INP_INFO_WLOCK(&V_udbinfo);
1028         INP_WLOCK(inp);
1029         up = intoudpcb(inp);
1030         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1031         in_pcbdetach(inp);
1032         in_pcbfree(inp);
1033         INP_INFO_WUNLOCK(&V_udbinfo);
1034         udp_discardcb(up);
1035 }
1036
1037 static int
1038 udp6_disconnect(struct socket *so)
1039 {
1040         struct inpcb *inp;
1041         int error;
1042
1043         inp = sotoinpcb(so);
1044         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1045
1046 #ifdef INET
1047         if (inp->inp_vflag & INP_IPV4) {
1048                 struct pr_usrreqs *pru;
1049
1050                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1051                 (void)(*pru->pru_disconnect)(so);
1052                 return (0);
1053         }
1054 #endif
1055
1056         INP_WLOCK(inp);
1057
1058         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1059                 error = ENOTCONN;
1060                 goto out;
1061         }
1062
1063         INP_HASH_WLOCK(&V_udbinfo);
1064         in6_pcbdisconnect(inp);
1065         inp->in6p_laddr = in6addr_any;
1066         INP_HASH_WUNLOCK(&V_udbinfo);
1067         SOCK_LOCK(so);
1068         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1069         SOCK_UNLOCK(so);
1070 out:
1071         INP_WUNLOCK(inp);
1072         return (0);
1073 }
1074
1075 static int
1076 udp6_send(struct socket *so, int flags, struct mbuf *m,
1077     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1078 {
1079         struct inpcb *inp;
1080         int error = 0;
1081
1082         inp = sotoinpcb(so);
1083         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1084
1085         INP_WLOCK(inp);
1086         if (addr) {
1087                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1088                         error = EINVAL;
1089                         goto bad;
1090                 }
1091                 if (addr->sa_family != AF_INET6) {
1092                         error = EAFNOSUPPORT;
1093                         goto bad;
1094                 }
1095         }
1096
1097 #ifdef INET
1098         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1099                 int hasv4addr;
1100                 struct sockaddr_in6 *sin6 = 0;
1101
1102                 if (addr == 0)
1103                         hasv4addr = (inp->inp_vflag & INP_IPV4);
1104                 else {
1105                         sin6 = (struct sockaddr_in6 *)addr;
1106                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1107                             ? 1 : 0;
1108                 }
1109                 if (hasv4addr) {
1110                         struct pr_usrreqs *pru;
1111
1112                         /*
1113                          * XXXRW: We release UDP-layer locks before calling
1114                          * udp_send() in order to avoid recursion.  However,
1115                          * this does mean there is a short window where inp's
1116                          * fields are unstable.  Could this lead to a
1117                          * potential race in which the factors causing us to
1118                          * select the UDPv4 output routine are invalidated?
1119                          */
1120                         INP_WUNLOCK(inp);
1121                         if (sin6)
1122                                 in6_sin6_2_sin_in_sock(addr);
1123                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1124                         /* addr will just be freed in sendit(). */
1125                         return ((*pru->pru_send)(so, flags, m, addr, control,
1126                             td));
1127                 }
1128         }
1129 #endif
1130 #ifdef MAC
1131         mac_inpcb_create_mbuf(inp, m);
1132 #endif
1133         INP_HASH_WLOCK(&V_udbinfo);
1134         error = udp6_output(inp, m, addr, control, td);
1135         INP_HASH_WUNLOCK(&V_udbinfo);
1136 #ifdef INET
1137 #endif
1138         INP_WUNLOCK(inp);
1139         return (error);
1140
1141 bad:
1142         INP_WUNLOCK(inp);
1143         m_freem(m);
1144         return (error);
1145 }
1146
1147 struct pr_usrreqs udp6_usrreqs = {
1148         .pru_abort =            udp6_abort,
1149         .pru_attach =           udp6_attach,
1150         .pru_bind =             udp6_bind,
1151         .pru_connect =          udp6_connect,
1152         .pru_control =          in6_control,
1153         .pru_detach =           udp6_detach,
1154         .pru_disconnect =       udp6_disconnect,
1155         .pru_peeraddr =         in6_mapped_peeraddr,
1156         .pru_send =             udp6_send,
1157         .pru_shutdown =         udp_shutdown,
1158         .pru_sockaddr =         in6_mapped_sockaddr,
1159         .pru_soreceive =        soreceive_dgram,
1160         .pru_sosend =           sosend_dgram,
1161         .pru_sosetlabel =       in_pcbsosetlabel,
1162         .pru_close =            udp6_close
1163 };