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 #include "opt_kdtrace.h"
  77
  78 #include <sys/param.h>
  79 #include <sys/jail.h>
  80 #include <sys/kernel.h>
  81 #include <sys/lock.h>
  82 #include <sys/mbuf.h>
  83 #include <sys/priv.h>
  84 #include <sys/proc.h>
  85 #include <sys/protosw.h>
  86 #include <sys/sdt.h>
  87 #include <sys/signalvar.h>
  88 #include <sys/socket.h>
  89 #include <sys/socketvar.h>
  90 #include <sys/sx.h>
  91 #include <sys/sysctl.h>
  92 #include <sys/syslog.h>
  93 #include <sys/systm.h>
  94
  95 #include <net/if.h>
  96 #include <net/if_types.h>
  97 #include <net/route.h>
  98
  99 #include <netinet/in.h>
 100 #include <netinet/in_kdtrace.h>
 101 #include <netinet/in_pcb.h>
 102 #include <netinet/in_systm.h>
 103 #include <netinet/in_var.h>
 104 #include <netinet/ip.h>
 105 #include <netinet/ip_icmp.h>
 106 #include <netinet/ip6.h>
 107 #include <netinet/icmp_var.h>
 108 #include <netinet/icmp6.h>
 109 #include <netinet/ip_var.h>
 110 #include <netinet/udp.h>
 111 #include <netinet/udp_var.h>
 112
 113 #include <netinet6/ip6protosw.h>
 114 #include <netinet6/ip6_var.h>
 115 #include <netinet6/in6_pcb.h>
 116 #include <netinet6/udp6_var.h>
 117 #include <netinet6/scope6_var.h>
 118
 119 #ifdef IPSEC
 120 #include <netipsec/ipsec.h>
 121 #include <netipsec/ipsec6.h>
 122 #endif /* IPSEC */
 123
 124 #include <security/mac/mac_framework.h>
 125
 126 /*
 127  * UDP protocol implementation.
 128  * Per RFC 768, August, 1980.
 129  */
 130
 131 extern struct protosw   inetsw[];
 132 static void             udp6_detach(struct socket *so);
 133
 134 static void
 135 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
 136     struct sockaddr_in6 *fromsa)
 137 {
 138         struct socket *so;
 139         struct mbuf *opts;
 140
 141         INP_LOCK_ASSERT(inp);
 142
 143 #ifdef IPSEC
 144         /* Check AH/ESP integrity. */
 145         if (ipsec6_in_reject(n, inp)) {
 146                 m_freem(n);
 147                 IPSEC6STAT_INC(ips_in_polvio);
 148                 return;
 149         }
 150 #endif /* IPSEC */
 151 #ifdef MAC
 152         if (mac_inpcb_check_deliver(inp, n) != 0) {
 153                 m_freem(n);
 154                 return;
 155         }
 156 #endif
 157         opts = NULL;
 158         if (inp->inp_flags & INP_CONTROLOPTS ||
 159             inp->inp_socket->so_options & SO_TIMESTAMP)
 160                 ip6_savecontrol(inp, n, &opts);
 161         m_adj(n, off + sizeof(struct udphdr));
 162
 163         so = inp->inp_socket;
 164         SOCKBUF_LOCK(&so->so_rcv);
 165         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
 166             opts) == 0) {
 167                 SOCKBUF_UNLOCK(&so->so_rcv);
 168                 m_freem(n);
 169                 if (opts)
 170                         m_freem(opts);
 171                 UDPSTAT_INC(udps_fullsock);
 172         } else
 173                 sorwakeup_locked(so);
 174 }
 175
 176 int
 177 udp6_input(struct mbuf **mp, int *offp, int proto)
 178 {
 179         struct mbuf *m = *mp;
 180         struct ifnet *ifp;
 181         struct ip6_hdr *ip6;
 182         struct udphdr *uh;
 183         struct inpcb *inp;
 184         struct udpcb *up;
 185         int off = *offp;
 186         int plen, ulen;
 187         struct sockaddr_in6 fromsa;
 188         struct m_tag *fwd_tag;
 189         uint16_t uh_sum;
 190
 191         ifp = m->m_pkthdr.rcvif;
 192         ip6 = mtod(m, struct ip6_hdr *);
 193
 194         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 195                 /* XXX send icmp6 host/port unreach? */
 196                 m_freem(m);
 197                 return (IPPROTO_DONE);
 198         }
 199
 200 #ifndef PULLDOWN_TEST
 201         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
 202         ip6 = mtod(m, struct ip6_hdr *);
 203         uh = (struct udphdr *)((caddr_t)ip6 + off);
 204 #else
 205         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 206         if (!uh)
 207                 return (IPPROTO_DONE);
 208 #endif
 209
 210         UDPSTAT_INC(udps_ipackets);
 211
 212         /*
 213          * Destination port of 0 is illegal, based on RFC768.
 214          */
 215         if (uh->uh_dport == 0)
 216                 goto badunlocked;
 217
 218         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
 219         ulen = ntohs((u_short)uh->uh_ulen);
 220
 221         if (plen != ulen) {
 222                 UDPSTAT_INC(udps_badlen);
 223                 goto badunlocked;
 224         }
 225
 226         /*
 227          * Checksum extended UDP header and data.
 228          */
 229         if (uh->uh_sum == 0) {
 230                 UDPSTAT_INC(udps_nosum);
 231                 goto badunlocked;
 232         }
 233
 234         if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) {
 235                 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 236                         uh_sum = m->m_pkthdr.csum_data;
 237                 else
 238                         uh_sum = in6_cksum_pseudo(ip6, ulen,
 239                             IPPROTO_UDP, m->m_pkthdr.csum_data);
 240                 uh_sum ^= 0xffff;
 241         } else
 242                 uh_sum = in6_cksum(m, IPPROTO_UDP, off, ulen);
 243
 244         if (uh_sum != 0) {
 245                 UDPSTAT_INC(udps_badsum);
 246                 goto badunlocked;
 247         }
 248
 249         /*
 250          * Construct sockaddr format source address.
 251          */
 252         init_sin6(&fromsa, m);
 253         fromsa.sin6_port = uh->uh_sport;
 254
 255         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 256                 struct inpcb *last;
 257                 struct ip6_moptions *imo;
 258
 259                 INP_INFO_RLOCK(&V_udbinfo);
 260                 /*
 261                  * In the event that laddr should be set to the link-local
 262                  * address (this happens in RIPng), the multicast address
 263                  * specified in the received packet will not match laddr.  To
 264                  * handle this situation, matching is relaxed if the
 265                  * receiving interface is the same as one specified in the
 266                  * socket and if the destination multicast address matches
 267                  * one of the multicast groups specified in the socket.
 268                  */
 269
 270                 /*
 271                  * KAME note: traditionally we dropped udpiphdr from mbuf
 272                  * here.  We need udphdr for IPsec processing so we do that
 273                  * later.
 274                  */
 275                 last = NULL;
 276                 LIST_FOREACH(inp, &V_udb, inp_list) {
 277                         if ((inp->inp_vflag & INP_IPV6) == 0)
 278                                 continue;
 279                         if (inp->inp_lport != uh->uh_dport)
 280                                 continue;
 281                         if (inp->inp_fport != 0 &&
 282                             inp->inp_fport != uh->uh_sport)
 283                                 continue;
 284                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 285                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
 286                                                         &ip6->ip6_dst))
 287                                         continue;
 288                         }
 289                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 290                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
 291                                                         &ip6->ip6_src) ||
 292                                     inp->inp_fport != uh->uh_sport)
 293                                         continue;
 294                         }
 295
 296                         /*
 297                          * XXXRW: Because we weren't holding either the inpcb
 298                          * or the hash lock when we checked for a match
 299                          * before, we should probably recheck now that the
 300                          * inpcb lock is (supposed to be) held.
 301                          */
 302
 303                         /*
 304                          * Handle socket delivery policy for any-source
 305                          * and source-specific multicast. [RFC3678]
 306                          */
 307                         imo = inp->in6p_moptions;
 308                         if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 309                                 struct sockaddr_in6      mcaddr;
 310                                 int                      blocked;
 311
 312                                 INP_RLOCK(inp);
 313
 314                                 bzero(&mcaddr, sizeof(struct sockaddr_in6));
 315                                 mcaddr.sin6_len = sizeof(struct sockaddr_in6);
 316                                 mcaddr.sin6_family = AF_INET6;
 317                                 mcaddr.sin6_addr = ip6->ip6_dst;
 318
 319                                 blocked = im6o_mc_filter(imo, ifp,
 320                                         (struct sockaddr *)&mcaddr,
 321                                         (struct sockaddr *)&fromsa);
 322                                 if (blocked != MCAST_PASS) {
 323                                         if (blocked == MCAST_NOTGMEMBER)
 324                                                 IP6STAT_INC(ip6s_notmember);
 325                                         if (blocked == MCAST_NOTSMEMBER ||
 326                                             blocked == MCAST_MUTED)
 327                                                 UDPSTAT_INC(udps_filtermcast);
 328                                         INP_RUNLOCK(inp); /* XXX */
 329                                         continue;
 330                                 }
 331
 332                                 INP_RUNLOCK(inp);
 333                         }
 334                         if (last != NULL) {
 335                                 struct mbuf *n;
 336
 337                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
 338                                         INP_RLOCK(last);
 339                                         up = intoudpcb(last);
 340                                         if (up->u_tun_func == NULL) {
 341                                                 udp6_append(last, n, off, &fromsa);
 342                                         } else {
 343                                                 /*
 344                                                  * Engage the tunneling
 345                                                  * protocol we will have to
 346                                                  * leave the info_lock up,
 347                                                  * since we are hunting
 348                                                  * through multiple UDP's.
 349                                                  *
 350                                                  */
 351                                                 (*up->u_tun_func)(n, off, last);
 352                                         }
 353                                         INP_RUNLOCK(last);
 354                                 }
 355                         }
 356                         last = inp;
 357                         /*
 358                          * Don't look for additional matches if this one does
 359                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 360                          * socket options set.  This heuristic avoids
 361                          * searching through all pcbs in the common case of a
 362                          * non-shared port.  It assumes that an application
 363                          * will never clear these options after setting them.
 364                          */
 365                         if ((last->inp_socket->so_options &
 366                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 367                                 break;
 368                 }
 369
 370                 if (last == NULL) {
 371                         /*
 372                          * No matching pcb found; discard datagram.  (No need
 373                          * to send an ICMP Port Unreachable for a broadcast
 374                          * or multicast datgram.)
 375                          */
 376                         UDPSTAT_INC(udps_noport);
 377                         UDPSTAT_INC(udps_noportmcast);
 378                         goto badheadlocked;
 379                 }
 380                 INP_RLOCK(last);
 381                 INP_INFO_RUNLOCK(&V_udbinfo);
 382                 up = intoudpcb(last);
 383                 UDP_PROBE(receive, NULL, last, ip6, last, uh);
 384                 if (up->u_tun_func == NULL) {
 385                         udp6_append(last, m, off, &fromsa);
 386                 } else {
 387                         /*
 388                          * Engage the tunneling protocol.
 389                          */
 390                         (*up->u_tun_func)(m, off, last);
 391                 }
 392                 INP_RUNLOCK(last);
 393                 return (IPPROTO_DONE);
 394         }
 395         /*
 396          * Locate pcb for datagram.
 397          */
 398
 399         /*
 400          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 401          */
 402         if ((m->m_flags & M_IP6_NEXTHOP) &&
 403             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 404                 struct sockaddr_in6 *next_hop6;
 405
 406                 next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
 407
 408                 /*
 409                  * Transparently forwarded. Pretend to be the destination.
 410                  * Already got one like this?
 411                  */
 412                 inp = in6_pcblookup_mbuf(&V_udbinfo,
 413                     &ip6->ip6_src, uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 414                     INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
 415                 if (!inp) {
 416                         /*
 417                          * It's new.  Try to find the ambushing socket.
 418                          * Because we've rewritten the destination address,
 419                          * any hardware-generated hash is ignored.
 420                          */
 421                         inp = in6_pcblookup(&V_udbinfo, &ip6->ip6_src,
 422                             uh->uh_sport, &next_hop6->sin6_addr,
 423                             next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
 424                             uh->uh_dport, INPLOOKUP_WILDCARD |
 425                             INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
 426                 }
 427                 /* Remove the tag from the packet. We don't need it anymore. */
 428                 m_tag_delete(m, fwd_tag);
 429                 m->m_flags &= ~M_IP6_NEXTHOP;
 430         } else
 431                 inp = in6_pcblookup_mbuf(&V_udbinfo, &ip6->ip6_src,
 432                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 433                     INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
 434                     m->m_pkthdr.rcvif, m);
 435         if (inp == NULL) {
 436                 if (udp_log_in_vain) {
 437                         char ip6bufs[INET6_ADDRSTRLEN];
 438                         char ip6bufd[INET6_ADDRSTRLEN];
 439
 440                         log(LOG_INFO,
 441                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
 442                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 443                             ntohs(uh->uh_dport),
 444                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
 445                             ntohs(uh->uh_sport));
 446                 }
 447                 UDPSTAT_INC(udps_noport);
 448                 if (m->m_flags & M_MCAST) {
 449                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
 450                         UDPSTAT_INC(udps_noportmcast);
 451                         goto badunlocked;
 452                 }
 453                 if (V_udp_blackhole)
 454                         goto badunlocked;
 455                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
 456                         goto badunlocked;
 457                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
 458                 return (IPPROTO_DONE);
 459         }
 460         INP_RLOCK_ASSERT(inp);
 461         up = intoudpcb(inp);
 462         UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
 463         if (up->u_tun_func == NULL) {
 464                 udp6_append(inp, m, off, &fromsa);
 465         } else {
 466                 /*
 467                  * Engage the tunneling protocol.
 468                  */
 469
 470                 (*up->u_tun_func)(m, off, inp);
 471         }
 472         INP_RUNLOCK(inp);
 473         return (IPPROTO_DONE);
 474
 475 badheadlocked:
 476         INP_INFO_RUNLOCK(&V_udbinfo);
 477 badunlocked:
 478         if (m)
 479                 m_freem(m);
 480         return (IPPROTO_DONE);
 481 }
 482
 483 void
 484 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 485 {
 486         struct udphdr uh;
 487         struct ip6_hdr *ip6;
 488         struct mbuf *m;
 489         int off = 0;
 490         struct ip6ctlparam *ip6cp = NULL;
 491         const struct sockaddr_in6 *sa6_src = NULL;
 492         void *cmdarg;
 493         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 494         struct udp_portonly {
 495                 u_int16_t uh_sport;
 496                 u_int16_t uh_dport;
 497         } *uhp;
 498
 499         if (sa->sa_family != AF_INET6 ||
 500             sa->sa_len != sizeof(struct sockaddr_in6))
 501                 return;
 502
 503         if ((unsigned)cmd >= PRC_NCMDS)
 504                 return;
 505         if (PRC_IS_REDIRECT(cmd))
 506                 notify = in6_rtchange, d = NULL;
 507         else if (cmd == PRC_HOSTDEAD)
 508                 d = NULL;
 509         else if (inet6ctlerrmap[cmd] == 0)
 510                 return;
 511
 512         /* if the parameter is from icmp6, decode it. */
 513         if (d != NULL) {
 514                 ip6cp = (struct ip6ctlparam *)d;
 515                 m = ip6cp->ip6c_m;
 516                 ip6 = ip6cp->ip6c_ip6;
 517                 off = ip6cp->ip6c_off;
 518                 cmdarg = ip6cp->ip6c_cmdarg;
 519                 sa6_src = ip6cp->ip6c_src;
 520         } else {
 521                 m = NULL;
 522                 ip6 = NULL;
 523                 cmdarg = NULL;
 524                 sa6_src = &sa6_any;
 525         }
 526
 527         if (ip6) {
 528                 /*
 529                  * XXX: We assume that when IPV6 is non NULL,
 530                  * M and OFF are valid.
 531                  */
 532
 533                 /* Check if we can safely examine src and dst ports. */
 534                 if (m->m_pkthdr.len < off + sizeof(*uhp))
 535                         return;
 536
 537                 bzero(&uh, sizeof(uh));
 538                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
 539
 540                 (void) in6_pcbnotify(&V_udbinfo, sa, uh.uh_dport,
 541                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
 542                     cmdarg, notify);
 543         } else
 544                 (void) in6_pcbnotify(&V_udbinfo, sa, 0,
 545                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
 546 }
 547
 548 static int
 549 udp6_getcred(SYSCTL_HANDLER_ARGS)
 550 {
 551         struct xucred xuc;
 552         struct sockaddr_in6 addrs[2];
 553         struct inpcb *inp;
 554         int error;
 555
 556         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 557         if (error)
 558                 return (error);
 559
 560         if (req->newlen != sizeof(addrs))
 561                 return (EINVAL);
 562         if (req->oldlen != sizeof(struct xucred))
 563                 return (EINVAL);
 564         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 565         if (error)
 566                 return (error);
 567         if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
 568             (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
 569                 return (error);
 570         }
 571         inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
 572             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
 573             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 574         if (inp != NULL) {
 575                 INP_RLOCK_ASSERT(inp);
 576                 if (inp->inp_socket == NULL)
 577                         error = ENOENT;
 578                 if (error == 0)
 579                         error = cr_canseesocket(req->td->td_ucred,
 580                             inp->inp_socket);
 581                 if (error == 0)
 582                         cru2x(inp->inp_cred, &xuc);
 583                 INP_RUNLOCK(inp);
 584         } else
 585                 error = ENOENT;
 586         if (error == 0)
 587                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 588         return (error);
 589 }
 590
 591 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
 592     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
 593
 594 static int
 595 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
 596     struct mbuf *control, struct thread *td)
 597 {
 598         u_int32_t ulen = m->m_pkthdr.len;
 599         u_int32_t plen = sizeof(struct udphdr) + ulen;
 600         struct ip6_hdr *ip6;
 601         struct udphdr *udp6;
 602         struct in6_addr *laddr, *faddr, in6a;
 603         struct sockaddr_in6 *sin6 = NULL;
 604         struct ifnet *oifp = NULL;
 605         int scope_ambiguous = 0;
 606         u_short fport;
 607         int error = 0;
 608         struct ip6_pktopts *optp, opt;
 609         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 610         int flags;
 611         struct sockaddr_in6 tmp;
 612
 613         INP_WLOCK_ASSERT(inp);
 614         INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
 615
 616         if (addr6) {
 617                 /* addr6 has been validated in udp6_send(). */
 618                 sin6 = (struct sockaddr_in6 *)addr6;
 619
 620                 /* protect *sin6 from overwrites */
 621                 tmp = *sin6;
 622                 sin6 = &tmp;
 623
 624                 /*
 625                  * Application should provide a proper zone ID or the use of
 626                  * default zone IDs should be enabled.  Unfortunately, some
 627                  * applications do not behave as it should, so we need a
 628                  * workaround.  Even if an appropriate ID is not determined,
 629                  * we'll see if we can determine the outgoing interface.  If we
 630                  * can, determine the zone ID based on the interface below.
 631                  */
 632                 if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
 633                         scope_ambiguous = 1;
 634                 if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
 635                         return (error);
 636         }
 637
 638         if (control) {
 639                 if ((error = ip6_setpktopts(control, &opt,
 640                     inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
 641                         goto release;
 642                 optp = &opt;
 643         } else
 644                 optp = inp->in6p_outputopts;
 645
 646         if (sin6) {
 647                 faddr = &sin6->sin6_addr;
 648
 649                 /*
 650                  * Since we saw no essential reason for calling in_pcbconnect,
 651                  * we get rid of such kind of logic, and call in6_selectsrc
 652                  * and in6_pcbsetport in order to fill in the local address
 653                  * and the local port.
 654                  */
 655                 if (sin6->sin6_port == 0) {
 656                         error = EADDRNOTAVAIL;
 657                         goto release;
 658                 }
 659
 660                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 661                         /* how about ::ffff:0.0.0.0 case? */
 662                         error = EISCONN;
 663                         goto release;
 664                 }
 665
 666                 fport = sin6->sin6_port; /* allow 0 port */
 667
 668                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 669                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 670                                 /*
 671                                  * I believe we should explicitly discard the
 672                                  * packet when mapped addresses are disabled,
 673                                  * rather than send the packet as an IPv6 one.
 674                                  * If we chose the latter approach, the packet
 675                                  * might be sent out on the wire based on the
 676                                  * default route, the situation which we'd
 677                                  * probably want to avoid.
 678                                  * (20010421 jinmei@kame.net)
 679                                  */
 680                                 error = EINVAL;
 681                                 goto release;
 682                         }
 683                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 684                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 685                                 /*
 686                                  * when remote addr is an IPv4-mapped address,
 687                                  * local addr should not be an IPv6 address,
 688                                  * since you cannot determine how to map IPv6
 689                                  * source address to IPv4.
 690                                  */
 691                                 error = EINVAL;
 692                                 goto release;
 693                         }
 694
 695                         af = AF_INET;
 696                 }
 697
 698                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 699                         error = in6_selectsrc(sin6, optp, inp, NULL,
 700                             td->td_ucred, &oifp, &in6a);
 701                         if (error)
 702                                 goto release;
 703                         if (oifp && scope_ambiguous &&
 704                             (error = in6_setscope(&sin6->sin6_addr,
 705                             oifp, NULL))) {
 706                                 goto release;
 707                         }
 708                         laddr = &in6a;
 709                 } else
 710                         laddr = &inp->in6p_laddr;       /* XXX */
 711                 if (laddr == NULL) {
 712                         if (error == 0)
 713                                 error = EADDRNOTAVAIL;
 714                         goto release;
 715                 }
 716                 if (inp->inp_lport == 0 &&
 717                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
 718                         /* Undo an address bind that may have occurred. */
 719                         inp->in6p_laddr = in6addr_any;
 720                         goto release;
 721                 }
 722         } else {
 723                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 724                         error = ENOTCONN;
 725                         goto release;
 726                 }
 727                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 728                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 729                                 /*
 730                                  * XXX: this case would happen when the
 731                                  * application sets the V6ONLY flag after
 732                                  * connecting the foreign address.
 733                                  * Such applications should be fixed,
 734                                  * so we bark here.
 735                                  */
 736                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 737                                     "option was set for a connected socket\n");
 738                                 error = EINVAL;
 739                                 goto release;
 740                         } else
 741                                 af = AF_INET;
 742                 }
 743                 laddr = &inp->in6p_laddr;
 744                 faddr = &inp->in6p_faddr;
 745                 fport = inp->inp_fport;
 746         }
 747
 748         if (af == AF_INET)
 749                 hlen = sizeof(struct ip);
 750
 751         /*
 752          * Calculate data length and get a mbuf
 753          * for UDP and IP6 headers.
 754          */
 755         M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
 756         if (m == 0) {
 757                 error = ENOBUFS;
 758                 goto release;
 759         }
 760
 761         /*
 762          * Stuff checksum and output datagram.
 763          */
 764         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 765         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
 766         udp6->uh_dport = fport;
 767         if (plen <= 0xffff)
 768                 udp6->uh_ulen = htons((u_short)plen);
 769         else
 770                 udp6->uh_ulen = 0;
 771         udp6->uh_sum = 0;
 772
 773         switch (af) {
 774         case AF_INET6:
 775                 ip6 = mtod(m, struct ip6_hdr *);
 776                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
 777                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 778                 ip6->ip6_vfc    |= IPV6_VERSION;
 779                 ip6->ip6_plen   = htons((u_short)plen);
 780                 ip6->ip6_nxt    = IPPROTO_UDP;
 781                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 782                 ip6->ip6_src    = *laddr;
 783                 ip6->ip6_dst    = *faddr;
 784
 785                 udp6->uh_sum = in6_cksum_pseudo(ip6, plen, IPPROTO_UDP, 0);
 786                 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
 787                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 788
 789                 flags = 0;
 790
 791                 UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
 792                 UDPSTAT_INC(udps_opackets);
 793                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 794                     NULL, inp);
 795                 break;
 796         case AF_INET:
 797                 error = EAFNOSUPPORT;
 798                 goto release;
 799         }
 800         goto releaseopt;
 801
 802 release:
 803         m_freem(m);
 804
 805 releaseopt:
 806         if (control) {
 807                 ip6_clearpktopts(&opt, -1);
 808                 m_freem(control);
 809         }
 810         return (error);
 811 }
 812
 813 static void
 814 udp6_abort(struct socket *so)
 815 {
 816         struct inpcb *inp;
 817
 818         inp = sotoinpcb(so);
 819         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 820
 821 #ifdef INET
 822         if (inp->inp_vflag & INP_IPV4) {
 823                 struct pr_usrreqs *pru;
 824
 825                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 826                 (*pru->pru_abort)(so);
 827                 return;
 828         }
 829 #endif
 830
 831         INP_WLOCK(inp);
 832         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 833                 INP_HASH_WLOCK(&V_udbinfo);
 834                 in6_pcbdisconnect(inp);
 835                 inp->in6p_laddr = in6addr_any;
 836                 INP_HASH_WUNLOCK(&V_udbinfo);
 837                 soisdisconnected(so);
 838         }
 839         INP_WUNLOCK(inp);
 840 }
 841
 842 static int
 843 udp6_attach(struct socket *so, int proto, struct thread *td)
 844 {
 845         struct inpcb *inp;
 846         int error;
 847
 848         inp = sotoinpcb(so);
 849         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 850
 851         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 852                 error = soreserve(so, udp_sendspace, udp_recvspace);
 853                 if (error)
 854                         return (error);
 855         }
 856         INP_INFO_WLOCK(&V_udbinfo);
 857         error = in_pcballoc(so, &V_udbinfo);
 858         if (error) {
 859                 INP_INFO_WUNLOCK(&V_udbinfo);
 860                 return (error);
 861         }
 862         inp = (struct inpcb *)so->so_pcb;
 863         inp->inp_vflag |= INP_IPV6;
 864         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 865                 inp->inp_vflag |= INP_IPV4;
 866         inp->in6p_hops = -1;    /* use kernel default */
 867         inp->in6p_cksum = -1;   /* just to be sure */
 868         /*
 869          * XXX: ugly!!
 870          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 871          * because the socket may be bound to an IPv6 wildcard address,
 872          * which may match an IPv4-mapped IPv6 address.
 873          */
 874         inp->inp_ip_ttl = V_ip_defttl;
 875
 876         error = udp_newudpcb(inp);
 877         if (error) {
 878                 in_pcbdetach(inp);
 879                 in_pcbfree(inp);
 880                 INP_INFO_WUNLOCK(&V_udbinfo);
 881                 return (error);
 882         }
 883         INP_WUNLOCK(inp);
 884         INP_INFO_WUNLOCK(&V_udbinfo);
 885         return (0);
 886 }
 887
 888 static int
 889 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 890 {
 891         struct inpcb *inp;
 892         int error;
 893
 894         inp = sotoinpcb(so);
 895         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 896
 897         INP_WLOCK(inp);
 898         INP_HASH_WLOCK(&V_udbinfo);
 899         inp->inp_vflag &= ~INP_IPV4;
 900         inp->inp_vflag |= INP_IPV6;
 901         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 902                 struct sockaddr_in6 *sin6_p;
 903
 904                 sin6_p = (struct sockaddr_in6 *)nam;
 905
 906                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 907                         inp->inp_vflag |= INP_IPV4;
 908 #ifdef INET
 909                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 910                         struct sockaddr_in sin;
 911
 912                         in6_sin6_2_sin(&sin, sin6_p);
 913                         inp->inp_vflag |= INP_IPV4;
 914                         inp->inp_vflag &= ~INP_IPV6;
 915                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 916                             td->td_ucred);
 917                         goto out;
 918                 }
 919 #endif
 920         }
 921
 922         error = in6_pcbbind(inp, nam, td->td_ucred);
 923 #ifdef INET
 924 out:
 925 #endif
 926         INP_HASH_WUNLOCK(&V_udbinfo);
 927         INP_WUNLOCK(inp);
 928         return (error);
 929 }
 930
 931 static void
 932 udp6_close(struct socket *so)
 933 {
 934         struct inpcb *inp;
 935
 936         inp = sotoinpcb(so);
 937         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
 938
 939 #ifdef INET
 940         if (inp->inp_vflag & INP_IPV4) {
 941                 struct pr_usrreqs *pru;
 942
 943                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 944                 (*pru->pru_disconnect)(so);
 945                 return;
 946         }
 947 #endif
 948         INP_WLOCK(inp);
 949         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 950                 INP_HASH_WLOCK(&V_udbinfo);
 951                 in6_pcbdisconnect(inp);
 952                 inp->in6p_laddr = in6addr_any;
 953                 INP_HASH_WUNLOCK(&V_udbinfo);
 954                 soisdisconnected(so);
 955         }
 956         INP_WUNLOCK(inp);
 957 }
 958
 959 static int
 960 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 961 {
 962         struct inpcb *inp;
 963         struct sockaddr_in6 *sin6;
 964         int error;
 965
 966         inp = sotoinpcb(so);
 967         sin6 = (struct sockaddr_in6 *)nam;
 968         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
 969
 970         /*
 971          * XXXRW: Need to clarify locking of v4/v6 flags.
 972          */
 973         INP_WLOCK(inp);
 974 #ifdef INET
 975         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
 976                 struct sockaddr_in sin;
 977
 978                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
 979                         error = EINVAL;
 980                         goto out;
 981                 }
 982                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 983                         error = EISCONN;
 984                         goto out;
 985                 }
 986                 in6_sin6_2_sin(&sin, sin6);
 987                 inp->inp_vflag |= INP_IPV4;
 988                 inp->inp_vflag &= ~INP_IPV6;
 989                 error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
 990                 if (error != 0)
 991                         goto out;
 992                 INP_HASH_WLOCK(&V_udbinfo);
 993                 error = in_pcbconnect(inp, (struct sockaddr *)&sin,
 994                     td->td_ucred);
 995                 INP_HASH_WUNLOCK(&V_udbinfo);
 996                 if (error == 0)
 997                         soisconnected(so);
 998                 goto out;
 999         }
1000 #endif
1001         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1002                 error = EISCONN;
1003                 goto out;
1004         }
1005         inp->inp_vflag &= ~INP_IPV4;
1006         inp->inp_vflag |= INP_IPV6;
1007         error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1008         if (error != 0)
1009                 goto out;
1010         INP_HASH_WLOCK(&V_udbinfo);
1011         error = in6_pcbconnect(inp, nam, td->td_ucred);
1012         INP_HASH_WUNLOCK(&V_udbinfo);
1013         if (error == 0)
1014                 soisconnected(so);
1015 out:
1016         INP_WUNLOCK(inp);
1017         return (error);
1018 }
1019
1020 static void
1021 udp6_detach(struct socket *so)
1022 {
1023         struct inpcb *inp;
1024         struct udpcb *up;
1025
1026         inp = sotoinpcb(so);
1027         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1028
1029         INP_INFO_WLOCK(&V_udbinfo);
1030         INP_WLOCK(inp);
1031         up = intoudpcb(inp);
1032         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1033         in_pcbdetach(inp);
1034         in_pcbfree(inp);
1035         INP_INFO_WUNLOCK(&V_udbinfo);
1036         udp_discardcb(up);
1037 }
1038
1039 static int
1040 udp6_disconnect(struct socket *so)
1041 {
1042         struct inpcb *inp;
1043         int error;
1044
1045         inp = sotoinpcb(so);
1046         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1047
1048 #ifdef INET
1049         if (inp->inp_vflag & INP_IPV4) {
1050                 struct pr_usrreqs *pru;
1051
1052                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1053                 (void)(*pru->pru_disconnect)(so);
1054                 return (0);
1055         }
1056 #endif
1057
1058         INP_WLOCK(inp);
1059
1060         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1061                 error = ENOTCONN;
1062                 goto out;
1063         }
1064
1065         INP_HASH_WLOCK(&V_udbinfo);
1066         in6_pcbdisconnect(inp);
1067         inp->in6p_laddr = in6addr_any;
1068         INP_HASH_WUNLOCK(&V_udbinfo);
1069         SOCK_LOCK(so);
1070         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1071         SOCK_UNLOCK(so);
1072 out:
1073         INP_WUNLOCK(inp);
1074         return (0);
1075 }
1076
1077 static int
1078 udp6_send(struct socket *so, int flags, struct mbuf *m,
1079     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1080 {
1081         struct inpcb *inp;
1082         int error = 0;
1083
1084         inp = sotoinpcb(so);
1085         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1086
1087         INP_WLOCK(inp);
1088         if (addr) {
1089                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1090                         error = EINVAL;
1091                         goto bad;
1092                 }
1093                 if (addr->sa_family != AF_INET6) {
1094                         error = EAFNOSUPPORT;
1095                         goto bad;
1096                 }
1097         }
1098
1099 #ifdef INET
1100         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1101                 int hasv4addr;
1102                 struct sockaddr_in6 *sin6 = 0;
1103
1104                 if (addr == 0)
1105                         hasv4addr = (inp->inp_vflag & INP_IPV4);
1106                 else {
1107                         sin6 = (struct sockaddr_in6 *)addr;
1108                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1109                             ? 1 : 0;
1110                 }
1111                 if (hasv4addr) {
1112                         struct pr_usrreqs *pru;
1113
1114                         /*
1115                          * XXXRW: We release UDP-layer locks before calling
1116                          * udp_send() in order to avoid recursion.  However,
1117                          * this does mean there is a short window where inp's
1118                          * fields are unstable.  Could this lead to a
1119                          * potential race in which the factors causing us to
1120                          * select the UDPv4 output routine are invalidated?
1121                          */
1122                         INP_WUNLOCK(inp);
1123                         if (sin6)
1124                                 in6_sin6_2_sin_in_sock(addr);
1125                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1126                         /* addr will just be freed in sendit(). */
1127                         return ((*pru->pru_send)(so, flags, m, addr, control,
1128                             td));
1129                 }
1130         }
1131 #endif
1132 #ifdef MAC
1133         mac_inpcb_create_mbuf(inp, m);
1134 #endif
1135         INP_HASH_WLOCK(&V_udbinfo);
1136         error = udp6_output(inp, m, addr, control, td);
1137         INP_HASH_WUNLOCK(&V_udbinfo);
1138 #ifdef INET
1139 #endif
1140         INP_WUNLOCK(inp);
1141         return (error);
1142
1143 bad:
1144         INP_WUNLOCK(inp);
1145         m_freem(m);
1146         return (error);
1147 }
1148
1149 struct pr_usrreqs udp6_usrreqs = {
1150         .pru_abort =            udp6_abort,
1151         .pru_attach =           udp6_attach,
1152         .pru_bind =             udp6_bind,
1153         .pru_connect =          udp6_connect,
1154         .pru_control =          in6_control,
1155         .pru_detach =           udp6_detach,
1156         .pru_disconnect =       udp6_disconnect,
1157         .pru_peeraddr =         in6_mapped_peeraddr,
1158         .pru_send =             udp6_send,
1159         .pru_shutdown =         udp_shutdown,
1160         .pru_sockaddr =         in6_mapped_sockaddr,
1161         .pru_soreceive =        soreceive_dgram,
1162         .pru_sosend =           sosend_dgram,
1163         .pru_sosetlabel =       in_pcbsosetlabel,
1164         .pru_close =            udp6_close
1165 };