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 #ifdef IPFIREWALL_FORWARD
 186         struct m_tag *fwd_tag;
 187 #endif
 188
 189         ifp = m->m_pkthdr.rcvif;
 190         ip6 = mtod(m, struct ip6_hdr *);
 191
 192         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 193                 /* XXX send icmp6 host/port unreach? */
 194                 m_freem(m);
 195                 return (IPPROTO_DONE);
 196         }
 197
 198 #ifndef PULLDOWN_TEST
 199         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
 200         ip6 = mtod(m, struct ip6_hdr *);
 201         uh = (struct udphdr *)((caddr_t)ip6 + off);
 202 #else
 203         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 204         if (!uh)
 205                 return (IPPROTO_DONE);
 206 #endif
 207
 208         UDPSTAT_INC(udps_ipackets);
 209
 210         /*
 211          * Destination port of 0 is illegal, based on RFC768.
 212          */
 213         if (uh->uh_dport == 0)
 214                 goto badunlocked;
 215
 216         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
 217         ulen = ntohs((u_short)uh->uh_ulen);
 218
 219         if (plen != ulen) {
 220                 UDPSTAT_INC(udps_badlen);
 221                 goto badunlocked;
 222         }
 223
 224         /*
 225          * Checksum extended UDP header and data.
 226          */
 227         if (uh->uh_sum == 0) {
 228                 UDPSTAT_INC(udps_nosum);
 229                 goto badunlocked;
 230         }
 231         if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
 232                 UDPSTAT_INC(udps_badsum);
 233                 goto badunlocked;
 234         }
 235
 236         /*
 237          * Construct sockaddr format source address.
 238          */
 239         init_sin6(&fromsa, m);
 240         fromsa.sin6_port = uh->uh_sport;
 241
 242         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 243                 struct inpcb *last;
 244                 struct ip6_moptions *imo;
 245
 246                 INP_INFO_RLOCK(&V_udbinfo);
 247                 /*
 248                  * In the event that laddr should be set to the link-local
 249                  * address (this happens in RIPng), the multicast address
 250                  * specified in the received packet will not match laddr.  To
 251                  * handle this situation, matching is relaxed if the
 252                  * receiving interface is the same as one specified in the
 253                  * socket and if the destination multicast address matches
 254                  * one of the multicast groups specified in the socket.
 255                  */
 256
 257                 /*
 258                  * KAME note: traditionally we dropped udpiphdr from mbuf
 259                  * here.  We need udphdr for IPsec processing so we do that
 260                  * later.
 261                  */
 262                 last = NULL;
 263                 LIST_FOREACH(inp, &V_udb, inp_list) {
 264                         if ((inp->inp_vflag & INP_IPV6) == 0)
 265                                 continue;
 266                         if (inp->inp_lport != uh->uh_dport)
 267                                 continue;
 268                         if (inp->inp_fport != 0 &&
 269                             inp->inp_fport != uh->uh_sport)
 270                                 continue;
 271                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 272                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
 273                                                         &ip6->ip6_dst))
 274                                         continue;
 275                         }
 276                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 277                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
 278                                                         &ip6->ip6_src) ||
 279                                     inp->inp_fport != uh->uh_sport)
 280                                         continue;
 281                         }
 282
 283                         /*
 284                          * XXXRW: Because we weren't holding either the inpcb
 285                          * or the hash lock when we checked for a match
 286                          * before, we should probably recheck now that the
 287                          * inpcb lock is (supposed to be) held.
 288                          */
 289
 290                         /*
 291                          * Handle socket delivery policy for any-source
 292                          * and source-specific multicast. [RFC3678]
 293                          */
 294                         imo = inp->in6p_moptions;
 295                         if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 296                                 struct sockaddr_in6      mcaddr;
 297                                 int                      blocked;
 298
 299                                 INP_RLOCK(inp);
 300
 301                                 bzero(&mcaddr, sizeof(struct sockaddr_in6));
 302                                 mcaddr.sin6_len = sizeof(struct sockaddr_in6);
 303                                 mcaddr.sin6_family = AF_INET6;
 304                                 mcaddr.sin6_addr = ip6->ip6_dst;
 305
 306                                 blocked = im6o_mc_filter(imo, ifp,
 307                                         (struct sockaddr *)&mcaddr,
 308                                         (struct sockaddr *)&fromsa);
 309                                 if (blocked != MCAST_PASS) {
 310                                         if (blocked == MCAST_NOTGMEMBER)
 311                                                 IP6STAT_INC(ip6s_notmember);
 312                                         if (blocked == MCAST_NOTSMEMBER ||
 313                                             blocked == MCAST_MUTED)
 314                                                 UDPSTAT_INC(udps_filtermcast);
 315                                         INP_RUNLOCK(inp); /* XXX */
 316                                         continue;
 317                                 }
 318
 319                                 INP_RUNLOCK(inp);
 320                         }
 321                         if (last != NULL) {
 322                                 struct mbuf *n;
 323
 324                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
 325                                         INP_RLOCK(last);
 326                                         up = intoudpcb(last);
 327                                         if (up->u_tun_func == NULL) {
 328                                                 udp6_append(last, n, off, &fromsa);
 329                                         } else {
 330                                                 /*
 331                                                  * Engage the tunneling
 332                                                  * protocol we will have to
 333                                                  * leave the info_lock up,
 334                                                  * since we are hunting
 335                                                  * through multiple UDP's.
 336                                                  *
 337                                                  */
 338                                                 (*up->u_tun_func)(n, off, last);
 339                                         }
 340                                         INP_RUNLOCK(last);
 341                                 }
 342                         }
 343                         last = inp;
 344                         /*
 345                          * Don't look for additional matches if this one does
 346                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 347                          * socket options set.  This heuristic avoids
 348                          * searching through all pcbs in the common case of a
 349                          * non-shared port.  It assumes that an application
 350                          * will never clear these options after setting them.
 351                          */
 352                         if ((last->inp_socket->so_options &
 353                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 354                                 break;
 355                 }
 356
 357                 if (last == NULL) {
 358                         /*
 359                          * No matching pcb found; discard datagram.  (No need
 360                          * to send an ICMP Port Unreachable for a broadcast
 361                          * or multicast datgram.)
 362                          */
 363                         UDPSTAT_INC(udps_noport);
 364                         UDPSTAT_INC(udps_noportmcast);
 365                         goto badheadlocked;
 366                 }
 367                 INP_RLOCK(last);
 368                 INP_INFO_RUNLOCK(&V_udbinfo);
 369                 up = intoudpcb(last);
 370                 if (up->u_tun_func == NULL) {
 371                         udp6_append(last, m, off, &fromsa);
 372                 } else {
 373                         /*
 374                          * Engage the tunneling protocol.
 375                          */
 376                         (*up->u_tun_func)(m, off, last);
 377                 }
 378                 INP_RUNLOCK(last);
 379                 return (IPPROTO_DONE);
 380         }
 381         /*
 382          * Locate pcb for datagram.
 383          */
 384 #ifdef IPFIREWALL_FORWARD
 385         /*
 386          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 387          */
 388         fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 389         if (fwd_tag != NULL) {
 390                 struct sockaddr_in6 *next_hop6;
 391
 392                 next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
 393
 394                 /*
 395                  * Transparently forwarded. Pretend to be the destination.
 396                  * Already got one like this?
 397                  */
 398                 inp = in6_pcblookup_mbuf(&V_udbinfo,
 399                     &ip6->ip6_src, uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 400                     INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
 401                 if (!inp) {
 402                         /*
 403                          * It's new.  Try to find the ambushing socket.
 404                          * Because we've rewritten the destination address,
 405                          * any hardware-generated hash is ignored.
 406                          */
 407                         inp = in6_pcblookup(&V_udbinfo, &ip6->ip6_src,
 408                             uh->uh_sport, &next_hop6->sin6_addr,
 409                             next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
 410                             uh->uh_dport, INPLOOKUP_WILDCARD |
 411                             INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
 412                 }
 413                 /* Remove the tag from the packet. We don't need it anymore. */
 414                 m_tag_delete(m, fwd_tag);
 415         } else
 416 #endif /* IPFIREWALL_FORWARD */
 417                 inp = in6_pcblookup_mbuf(&V_udbinfo, &ip6->ip6_src,
 418                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 419                     INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
 420                     m->m_pkthdr.rcvif, m);
 421         if (inp == NULL) {
 422                 if (udp_log_in_vain) {
 423                         char ip6bufs[INET6_ADDRSTRLEN];
 424                         char ip6bufd[INET6_ADDRSTRLEN];
 425
 426                         log(LOG_INFO,
 427                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
 428                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 429                             ntohs(uh->uh_dport),
 430                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
 431                             ntohs(uh->uh_sport));
 432                 }
 433                 UDPSTAT_INC(udps_noport);
 434                 if (m->m_flags & M_MCAST) {
 435                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
 436                         UDPSTAT_INC(udps_noportmcast);
 437                         goto badunlocked;
 438                 }
 439                 if (V_udp_blackhole)
 440                         goto badunlocked;
 441                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
 442                         goto badunlocked;
 443                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
 444                 return (IPPROTO_DONE);
 445         }
 446         INP_RLOCK_ASSERT(inp);
 447         up = intoudpcb(inp);
 448         if (up->u_tun_func == NULL) {
 449                 udp6_append(inp, m, off, &fromsa);
 450         } else {
 451                 /*
 452                  * Engage the tunneling protocol.
 453                  */
 454
 455                 (*up->u_tun_func)(m, off, inp);
 456         }
 457         INP_RUNLOCK(inp);
 458         return (IPPROTO_DONE);
 459
 460 badheadlocked:
 461         INP_INFO_RUNLOCK(&V_udbinfo);
 462 badunlocked:
 463         if (m)
 464                 m_freem(m);
 465         return (IPPROTO_DONE);
 466 }
 467
 468 void
 469 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 470 {
 471         struct udphdr uh;
 472         struct ip6_hdr *ip6;
 473         struct mbuf *m;
 474         int off = 0;
 475         struct ip6ctlparam *ip6cp = NULL;
 476         const struct sockaddr_in6 *sa6_src = NULL;
 477         void *cmdarg;
 478         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 479         struct udp_portonly {
 480                 u_int16_t uh_sport;
 481                 u_int16_t uh_dport;
 482         } *uhp;
 483
 484         if (sa->sa_family != AF_INET6 ||
 485             sa->sa_len != sizeof(struct sockaddr_in6))
 486                 return;
 487
 488         if ((unsigned)cmd >= PRC_NCMDS)
 489                 return;
 490         if (PRC_IS_REDIRECT(cmd))
 491                 notify = in6_rtchange, d = NULL;
 492         else if (cmd == PRC_HOSTDEAD)
 493                 d = NULL;
 494         else if (inet6ctlerrmap[cmd] == 0)
 495                 return;
 496
 497         /* if the parameter is from icmp6, decode it. */
 498         if (d != NULL) {
 499                 ip6cp = (struct ip6ctlparam *)d;
 500                 m = ip6cp->ip6c_m;
 501                 ip6 = ip6cp->ip6c_ip6;
 502                 off = ip6cp->ip6c_off;
 503                 cmdarg = ip6cp->ip6c_cmdarg;
 504                 sa6_src = ip6cp->ip6c_src;
 505         } else {
 506                 m = NULL;
 507                 ip6 = NULL;
 508                 cmdarg = NULL;
 509                 sa6_src = &sa6_any;
 510         }
 511
 512         if (ip6) {
 513                 /*
 514                  * XXX: We assume that when IPV6 is non NULL,
 515                  * M and OFF are valid.
 516                  */
 517
 518                 /* Check if we can safely examine src and dst ports. */
 519                 if (m->m_pkthdr.len < off + sizeof(*uhp))
 520                         return;
 521
 522                 bzero(&uh, sizeof(uh));
 523                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
 524
 525                 (void) in6_pcbnotify(&V_udbinfo, sa, uh.uh_dport,
 526                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
 527                     cmdarg, notify);
 528         } else
 529                 (void) in6_pcbnotify(&V_udbinfo, sa, 0,
 530                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
 531 }
 532
 533 static int
 534 udp6_getcred(SYSCTL_HANDLER_ARGS)
 535 {
 536         struct xucred xuc;
 537         struct sockaddr_in6 addrs[2];
 538         struct inpcb *inp;
 539         int error;
 540
 541         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 542         if (error)
 543                 return (error);
 544
 545         if (req->newlen != sizeof(addrs))
 546                 return (EINVAL);
 547         if (req->oldlen != sizeof(struct xucred))
 548                 return (EINVAL);
 549         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 550         if (error)
 551                 return (error);
 552         if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
 553             (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
 554                 return (error);
 555         }
 556         inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
 557             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
 558             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 559         if (inp != NULL) {
 560                 INP_RLOCK_ASSERT(inp);
 561                 if (inp->inp_socket == NULL)
 562                         error = ENOENT;
 563                 if (error == 0)
 564                         error = cr_canseesocket(req->td->td_ucred,
 565                             inp->inp_socket);
 566                 if (error == 0)
 567                         cru2x(inp->inp_cred, &xuc);
 568                 INP_RUNLOCK(inp);
 569         } else
 570                 error = ENOENT;
 571         if (error == 0)
 572                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 573         return (error);
 574 }
 575
 576 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
 577     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
 578
 579 static int
 580 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
 581     struct mbuf *control, struct thread *td)
 582 {
 583         u_int32_t ulen = m->m_pkthdr.len;
 584         u_int32_t plen = sizeof(struct udphdr) + ulen;
 585         struct ip6_hdr *ip6;
 586         struct udphdr *udp6;
 587         struct in6_addr *laddr, *faddr, in6a;
 588         struct sockaddr_in6 *sin6 = NULL;
 589         struct ifnet *oifp = NULL;
 590         int scope_ambiguous = 0;
 591         u_short fport;
 592         int error = 0;
 593         struct ip6_pktopts *optp, opt;
 594         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 595         int flags;
 596         struct sockaddr_in6 tmp;
 597
 598         INP_WLOCK_ASSERT(inp);
 599         INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
 600
 601         if (addr6) {
 602                 /* addr6 has been validated in udp6_send(). */
 603                 sin6 = (struct sockaddr_in6 *)addr6;
 604
 605                 /* protect *sin6 from overwrites */
 606                 tmp = *sin6;
 607                 sin6 = &tmp;
 608
 609                 /*
 610                  * Application should provide a proper zone ID or the use of
 611                  * default zone IDs should be enabled.  Unfortunately, some
 612                  * applications do not behave as it should, so we need a
 613                  * workaround.  Even if an appropriate ID is not determined,
 614                  * we'll see if we can determine the outgoing interface.  If we
 615                  * can, determine the zone ID based on the interface below.
 616                  */
 617                 if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
 618                         scope_ambiguous = 1;
 619                 if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
 620                         return (error);
 621         }
 622
 623         if (control) {
 624                 if ((error = ip6_setpktopts(control, &opt,
 625                     inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
 626                         goto release;
 627                 optp = &opt;
 628         } else
 629                 optp = inp->in6p_outputopts;
 630
 631         if (sin6) {
 632                 faddr = &sin6->sin6_addr;
 633
 634                 /*
 635                  * IPv4 version of udp_output calls in_pcbconnect in this case,
 636                  * which needs splnet and affects performance.
 637                  * Since we saw no essential reason for calling in_pcbconnect,
 638                  * we get rid of such kind of logic, and call in6_selectsrc
 639                  * and in6_pcbsetport in order to fill in the local address
 640                  * and the local port.
 641                  */
 642                 if (sin6->sin6_port == 0) {
 643                         error = EADDRNOTAVAIL;
 644                         goto release;
 645                 }
 646
 647                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 648                         /* how about ::ffff:0.0.0.0 case? */
 649                         error = EISCONN;
 650                         goto release;
 651                 }
 652
 653                 fport = sin6->sin6_port; /* allow 0 port */
 654
 655                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 656                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 657                                 /*
 658                                  * I believe we should explicitly discard the
 659                                  * packet when mapped addresses are disabled,
 660                                  * rather than send the packet as an IPv6 one.
 661                                  * If we chose the latter approach, the packet
 662                                  * might be sent out on the wire based on the
 663                                  * default route, the situation which we'd
 664                                  * probably want to avoid.
 665                                  * (20010421 jinmei@kame.net)
 666                                  */
 667                                 error = EINVAL;
 668                                 goto release;
 669                         }
 670                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 671                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 672                                 /*
 673                                  * when remote addr is an IPv4-mapped address,
 674                                  * local addr should not be an IPv6 address,
 675                                  * since you cannot determine how to map IPv6
 676                                  * source address to IPv4.
 677                                  */
 678                                 error = EINVAL;
 679                                 goto release;
 680                         }
 681
 682                         af = AF_INET;
 683                 }
 684
 685                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 686                         error = in6_selectsrc(sin6, optp, inp, NULL,
 687                             td->td_ucred, &oifp, &in6a);
 688                         if (error)
 689                                 goto release;
 690                         if (oifp && scope_ambiguous &&
 691                             (error = in6_setscope(&sin6->sin6_addr,
 692                             oifp, NULL))) {
 693                                 goto release;
 694                         }
 695                         laddr = &in6a;
 696                 } else
 697                         laddr = &inp->in6p_laddr;       /* XXX */
 698                 if (laddr == NULL) {
 699                         if (error == 0)
 700                                 error = EADDRNOTAVAIL;
 701                         goto release;
 702                 }
 703                 if (inp->inp_lport == 0 &&
 704                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
 705                         /* Undo an address bind that may have occurred. */
 706                         inp->in6p_laddr = in6addr_any;
 707                         goto release;
 708                 }
 709         } else {
 710                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 711                         error = ENOTCONN;
 712                         goto release;
 713                 }
 714                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 715                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 716                                 /*
 717                                  * XXX: this case would happen when the
 718                                  * application sets the V6ONLY flag after
 719                                  * connecting the foreign address.
 720                                  * Such applications should be fixed,
 721                                  * so we bark here.
 722                                  */
 723                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 724                                     "option was set for a connected socket\n");
 725                                 error = EINVAL;
 726                                 goto release;
 727                         } else
 728                                 af = AF_INET;
 729                 }
 730                 laddr = &inp->in6p_laddr;
 731                 faddr = &inp->in6p_faddr;
 732                 fport = inp->inp_fport;
 733         }
 734
 735         if (af == AF_INET)
 736                 hlen = sizeof(struct ip);
 737
 738         /*
 739          * Calculate data length and get a mbuf
 740          * for UDP and IP6 headers.
 741          */
 742         M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
 743         if (m == 0) {
 744                 error = ENOBUFS;
 745                 goto release;
 746         }
 747
 748         /*
 749          * Stuff checksum and output datagram.
 750          */
 751         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 752         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
 753         udp6->uh_dport = fport;
 754         if (plen <= 0xffff)
 755                 udp6->uh_ulen = htons((u_short)plen);
 756         else
 757                 udp6->uh_ulen = 0;
 758         udp6->uh_sum = 0;
 759
 760         switch (af) {
 761         case AF_INET6:
 762                 ip6 = mtod(m, struct ip6_hdr *);
 763                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
 764                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 765                 ip6->ip6_vfc    |= IPV6_VERSION;
 766 #if 0                           /* ip6_plen will be filled in ip6_output. */
 767                 ip6->ip6_plen   = htons((u_short)plen);
 768 #endif
 769                 ip6->ip6_nxt    = IPPROTO_UDP;
 770                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 771                 ip6->ip6_src    = *laddr;
 772                 ip6->ip6_dst    = *faddr;
 773
 774                 if ((udp6->uh_sum = in6_cksum(m, IPPROTO_UDP,
 775                                 sizeof(struct ip6_hdr), plen)) == 0) {
 776                         udp6->uh_sum = 0xffff;
 777                 }
 778
 779                 flags = 0;
 780
 781                 UDPSTAT_INC(udps_opackets);
 782                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 783                     NULL, inp);
 784                 break;
 785         case AF_INET:
 786                 error = EAFNOSUPPORT;
 787                 goto release;
 788         }
 789         goto releaseopt;
 790
 791 release:
 792         m_freem(m);
 793
 794 releaseopt:
 795         if (control) {
 796                 ip6_clearpktopts(&opt, -1);
 797                 m_freem(control);
 798         }
 799         return (error);
 800 }
 801
 802 static void
 803 udp6_abort(struct socket *so)
 804 {
 805         struct inpcb *inp;
 806
 807         inp = sotoinpcb(so);
 808         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 809
 810 #ifdef INET
 811         if (inp->inp_vflag & INP_IPV4) {
 812                 struct pr_usrreqs *pru;
 813
 814                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 815                 (*pru->pru_abort)(so);
 816                 return;
 817         }
 818 #endif
 819
 820         INP_WLOCK(inp);
 821         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 822                 INP_HASH_WLOCK(&V_udbinfo);
 823                 in6_pcbdisconnect(inp);
 824                 inp->in6p_laddr = in6addr_any;
 825                 INP_HASH_WUNLOCK(&V_udbinfo);
 826                 soisdisconnected(so);
 827         }
 828         INP_WUNLOCK(inp);
 829 }
 830
 831 static int
 832 udp6_attach(struct socket *so, int proto, struct thread *td)
 833 {
 834         struct inpcb *inp;
 835         int error;
 836
 837         inp = sotoinpcb(so);
 838         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 839
 840         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 841                 error = soreserve(so, udp_sendspace, udp_recvspace);
 842                 if (error)
 843                         return (error);
 844         }
 845         INP_INFO_WLOCK(&V_udbinfo);
 846         error = in_pcballoc(so, &V_udbinfo);
 847         if (error) {
 848                 INP_INFO_WUNLOCK(&V_udbinfo);
 849                 return (error);
 850         }
 851         inp = (struct inpcb *)so->so_pcb;
 852         inp->inp_vflag |= INP_IPV6;
 853         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 854                 inp->inp_vflag |= INP_IPV4;
 855         inp->in6p_hops = -1;    /* use kernel default */
 856         inp->in6p_cksum = -1;   /* just to be sure */
 857         /*
 858          * XXX: ugly!!
 859          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 860          * because the socket may be bound to an IPv6 wildcard address,
 861          * which may match an IPv4-mapped IPv6 address.
 862          */
 863         inp->inp_ip_ttl = V_ip_defttl;
 864
 865         error = udp_newudpcb(inp);
 866         if (error) {
 867                 in_pcbdetach(inp);
 868                 in_pcbfree(inp);
 869                 INP_INFO_WUNLOCK(&V_udbinfo);
 870                 return (error);
 871         }
 872         INP_WUNLOCK(inp);
 873         INP_INFO_WUNLOCK(&V_udbinfo);
 874         return (0);
 875 }
 876
 877 static int
 878 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 879 {
 880         struct inpcb *inp;
 881         int error;
 882
 883         inp = sotoinpcb(so);
 884         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 885
 886         INP_WLOCK(inp);
 887         INP_HASH_WLOCK(&V_udbinfo);
 888         inp->inp_vflag &= ~INP_IPV4;
 889         inp->inp_vflag |= INP_IPV6;
 890         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 891                 struct sockaddr_in6 *sin6_p;
 892
 893                 sin6_p = (struct sockaddr_in6 *)nam;
 894
 895                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 896                         inp->inp_vflag |= INP_IPV4;
 897 #ifdef INET
 898                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 899                         struct sockaddr_in sin;
 900
 901                         in6_sin6_2_sin(&sin, sin6_p);
 902                         inp->inp_vflag |= INP_IPV4;
 903                         inp->inp_vflag &= ~INP_IPV6;
 904                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 905                             td->td_ucred);
 906                         goto out;
 907                 }
 908 #endif
 909         }
 910
 911         error = in6_pcbbind(inp, nam, td->td_ucred);
 912 #ifdef INET
 913 out:
 914 #endif
 915         INP_HASH_WUNLOCK(&V_udbinfo);
 916         INP_WUNLOCK(inp);
 917         return (error);
 918 }
 919
 920 static void
 921 udp6_close(struct socket *so)
 922 {
 923         struct inpcb *inp;
 924
 925         inp = sotoinpcb(so);
 926         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
 927
 928 #ifdef INET
 929         if (inp->inp_vflag & INP_IPV4) {
 930                 struct pr_usrreqs *pru;
 931
 932                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 933                 (*pru->pru_disconnect)(so);
 934                 return;
 935         }
 936 #endif
 937         INP_WLOCK(inp);
 938         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 939                 INP_HASH_WLOCK(&V_udbinfo);
 940                 in6_pcbdisconnect(inp);
 941                 inp->in6p_laddr = in6addr_any;
 942                 INP_HASH_WUNLOCK(&V_udbinfo);
 943                 soisdisconnected(so);
 944         }
 945         INP_WUNLOCK(inp);
 946 }
 947
 948 static int
 949 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 950 {
 951         struct inpcb *inp;
 952         struct sockaddr_in6 *sin6;
 953         int error;
 954
 955         inp = sotoinpcb(so);
 956         sin6 = (struct sockaddr_in6 *)nam;
 957         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
 958
 959         /*
 960          * XXXRW: Need to clarify locking of v4/v6 flags.
 961          */
 962         INP_WLOCK(inp);
 963 #ifdef INET
 964         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
 965                 struct sockaddr_in sin;
 966
 967                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
 968                         error = EINVAL;
 969                         goto out;
 970                 }
 971                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 972                         error = EISCONN;
 973                         goto out;
 974                 }
 975                 in6_sin6_2_sin(&sin, sin6);
 976                 inp->inp_vflag |= INP_IPV4;
 977                 inp->inp_vflag &= ~INP_IPV6;
 978                 error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
 979                 if (error != 0)
 980                         goto out;
 981                 INP_HASH_WLOCK(&V_udbinfo);
 982                 error = in_pcbconnect(inp, (struct sockaddr *)&sin,
 983                     td->td_ucred);
 984                 INP_HASH_WUNLOCK(&V_udbinfo);
 985                 if (error == 0)
 986                         soisconnected(so);
 987                 goto out;
 988         }
 989 #endif
 990         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 991                 error = EISCONN;
 992                 goto out;
 993         }
 994         inp->inp_vflag &= ~INP_IPV4;
 995         inp->inp_vflag |= INP_IPV6;
 996         error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
 997         if (error != 0)
 998                 goto out;
 999         INP_HASH_WLOCK(&V_udbinfo);
1000         error = in6_pcbconnect(inp, nam, td->td_ucred);
1001         INP_HASH_WUNLOCK(&V_udbinfo);
1002         if (error == 0)
1003                 soisconnected(so);
1004 out:
1005         INP_WUNLOCK(inp);
1006         return (error);
1007 }
1008
1009 static void
1010 udp6_detach(struct socket *so)
1011 {
1012         struct inpcb *inp;
1013         struct udpcb *up;
1014
1015         inp = sotoinpcb(so);
1016         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1017
1018         INP_INFO_WLOCK(&V_udbinfo);
1019         INP_WLOCK(inp);
1020         up = intoudpcb(inp);
1021         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1022         in_pcbdetach(inp);
1023         in_pcbfree(inp);
1024         INP_INFO_WUNLOCK(&V_udbinfo);
1025         udp_discardcb(up);
1026 }
1027
1028 static int
1029 udp6_disconnect(struct socket *so)
1030 {
1031         struct inpcb *inp;
1032         int error;
1033
1034         inp = sotoinpcb(so);
1035         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1036
1037 #ifdef INET
1038         if (inp->inp_vflag & INP_IPV4) {
1039                 struct pr_usrreqs *pru;
1040
1041                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1042                 (void)(*pru->pru_disconnect)(so);
1043                 return (0);
1044         }
1045 #endif
1046
1047         INP_WLOCK(inp);
1048
1049         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1050                 error = ENOTCONN;
1051                 goto out;
1052         }
1053
1054         INP_HASH_WLOCK(&V_udbinfo);
1055         in6_pcbdisconnect(inp);
1056         inp->in6p_laddr = in6addr_any;
1057         INP_HASH_WUNLOCK(&V_udbinfo);
1058         SOCK_LOCK(so);
1059         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1060         SOCK_UNLOCK(so);
1061 out:
1062         INP_WUNLOCK(inp);
1063         return (0);
1064 }
1065
1066 static int
1067 udp6_send(struct socket *so, int flags, struct mbuf *m,
1068     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1069 {
1070         struct inpcb *inp;
1071         int error = 0;
1072
1073         inp = sotoinpcb(so);
1074         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1075
1076         INP_WLOCK(inp);
1077         if (addr) {
1078                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1079                         error = EINVAL;
1080                         goto bad;
1081                 }
1082                 if (addr->sa_family != AF_INET6) {
1083                         error = EAFNOSUPPORT;
1084                         goto bad;
1085                 }
1086         }
1087
1088 #ifdef INET
1089         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1090                 int hasv4addr;
1091                 struct sockaddr_in6 *sin6 = 0;
1092
1093                 if (addr == 0)
1094                         hasv4addr = (inp->inp_vflag & INP_IPV4);
1095                 else {
1096                         sin6 = (struct sockaddr_in6 *)addr;
1097                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1098                             ? 1 : 0;
1099                 }
1100                 if (hasv4addr) {
1101                         struct pr_usrreqs *pru;
1102
1103                         /*
1104                          * XXXRW: We release UDP-layer locks before calling
1105                          * udp_send() in order to avoid recursion.  However,
1106                          * this does mean there is a short window where inp's
1107                          * fields are unstable.  Could this lead to a
1108                          * potential race in which the factors causing us to
1109                          * select the UDPv4 output routine are invalidated?
1110                          */
1111                         INP_WUNLOCK(inp);
1112                         if (sin6)
1113                                 in6_sin6_2_sin_in_sock(addr);
1114                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1115                         /* addr will just be freed in sendit(). */
1116                         return ((*pru->pru_send)(so, flags, m, addr, control,
1117                             td));
1118                 }
1119         }
1120 #endif
1121 #ifdef MAC
1122         mac_inpcb_create_mbuf(inp, m);
1123 #endif
1124         INP_HASH_WLOCK(&V_udbinfo);
1125         error = udp6_output(inp, m, addr, control, td);
1126         INP_HASH_WUNLOCK(&V_udbinfo);
1127 #ifdef INET
1128 #endif
1129         INP_WUNLOCK(inp);
1130         return (error);
1131
1132 bad:
1133         INP_WUNLOCK(inp);
1134         m_freem(m);
1135         return (error);
1136 }
1137
1138 struct pr_usrreqs udp6_usrreqs = {
1139         .pru_abort =            udp6_abort,
1140         .pru_attach =           udp6_attach,
1141         .pru_bind =             udp6_bind,
1142         .pru_connect =          udp6_connect,
1143         .pru_control =          in6_control,
1144         .pru_detach =           udp6_detach,
1145         .pru_disconnect =       udp6_disconnect,
1146         .pru_peeraddr =         in6_mapped_peeraddr,
1147         .pru_send =             udp6_send,
1148         .pru_shutdown =         udp_shutdown,
1149         .pru_sockaddr =         in6_mapped_sockaddr,
1150         .pru_soreceive =        soreceive_dgram,
1151         .pru_sosend =           sosend_dgram,
1152         .pru_sosetlabel =       in_pcbsosetlabel,
1153         .pru_close =            udp6_close
1154 };