sys/netinet6/udp6_usrreq.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: udp6_usrreq.c,v 1.27 2001/05/21 05:45:10 jinmei Exp $
  30  *      $KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei Exp $
  31  */
  32
  33 /*-
  34  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
  35  *      The Regents of the University of California.
  36  * All rights reserved.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 4. Neither the name of the University nor the names of its contributors
  47  *    may be used to endorse or promote products derived from this software
  48  *    without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  60  * SUCH DAMAGE.
  61  *
  62  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
  63  */
  64
  65 #include <sys/cdefs.h>
  66 __FBSDID("$FreeBSD$");
  67
  68 #include "opt_inet.h"
  69 #include "opt_inet6.h"
  70 #include "opt_ipsec.h"
  71 #include "opt_mac.h"
  72
  73 #include <sys/param.h>
  74 #include <sys/jail.h>
  75 #include <sys/kernel.h>
  76 #include <sys/lock.h>
  77 #include <sys/mbuf.h>
  78 #include <sys/priv.h>
  79 #include <sys/proc.h>
  80 #include <sys/protosw.h>
  81 #include <sys/signalvar.h>
  82 #include <sys/socket.h>
  83 #include <sys/socketvar.h>
  84 #include <sys/sx.h>
  85 #include <sys/sysctl.h>
  86 #include <sys/syslog.h>
  87 #include <sys/systm.h>
  88
  89 #include <net/if.h>
  90 #include <net/if_types.h>
  91 #include <net/route.h>
  92
  93 #include <netinet/in.h>
  94 #include <netinet/in_pcb.h>
  95 #include <netinet/in_systm.h>
  96 #include <netinet/in_var.h>
  97 #include <netinet/ip.h>
  98 #include <netinet/ip_icmp.h>
  99 #include <netinet/ip6.h>
 100 #include <netinet/icmp_var.h>
 101 #include <netinet/icmp6.h>
 102 #include <netinet/ip_var.h>
 103 #include <netinet/udp.h>
 104 #include <netinet/udp_var.h>
 105 #include <netinet6/ip6protosw.h>
 106 #include <netinet6/ip6_var.h>
 107 #include <netinet6/in6_pcb.h>
 108 #include <netinet6/udp6_var.h>
 109 #include <netinet6/scope6_var.h>
 110
 111 #ifdef IPSEC
 112 #include <netipsec/ipsec.h>
 113 #include <netipsec/ipsec6.h>
 114 #endif /* IPSEC */
 115
 116 #include <security/mac/mac_framework.h>
 117
 118 /*
 119  * UDP protocol implementation.
 120  * Per RFC 768, August, 1980.
 121  */
 122
 123 extern struct protosw   inetsw[];
 124 static void             udp6_detach(struct socket *so);
 125
 126 static void
 127 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
 128     struct sockaddr_in6 *fromsa)
 129 {
 130         struct socket *so;
 131         struct mbuf *opts;
 132
 133         INP_LOCK_ASSERT(inp);
 134
 135 #ifdef IPSEC
 136         /* Check AH/ESP integrity. */
 137         if (ipsec6_in_reject(n, inp)) {
 138                 m_freem(n);
 139                 ipsec6stat.in_polvio++;
 140                 return;
 141         }
 142 #endif /* IPSEC */
 143 #ifdef MAC
 144         if (mac_check_inpcb_deliver(inp, n) != 0) {
 145                 m_freem(n);
 146                 return;
 147         }
 148 #endif
 149         opts = NULL;
 150         if (inp->inp_flags & INP_CONTROLOPTS ||
 151             inp->inp_socket->so_options & SO_TIMESTAMP)
 152                 ip6_savecontrol(inp, n, &opts);
 153         m_adj(n, off + sizeof(struct udphdr));
 154
 155         so = inp->inp_socket;
 156         SOCKBUF_LOCK(&so->so_rcv);
 157         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
 158             opts) == 0) {
 159                 SOCKBUF_UNLOCK(&so->so_rcv);
 160                 m_freem(n);
 161                 if (opts)
 162                         m_freem(opts);
 163                 udpstat.udps_fullsock++;
 164         } else
 165                 sorwakeup_locked(so);
 166 }
 167
 168 int
 169 udp6_input(struct mbuf **mp, int *offp, int proto)
 170 {
 171         struct mbuf *m = *mp;
 172         struct ip6_hdr *ip6;
 173         struct udphdr *uh;
 174         struct inpcb *inp;
 175         int off = *offp;
 176         int plen, ulen;
 177         struct sockaddr_in6 fromsa;
 178
 179         ip6 = mtod(m, struct ip6_hdr *);
 180
 181         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 182                 /* XXX send icmp6 host/port unreach? */
 183                 m_freem(m);
 184                 return (IPPROTO_DONE);
 185         }
 186
 187 #ifndef PULLDOWN_TEST
 188         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
 189         ip6 = mtod(m, struct ip6_hdr *);
 190         uh = (struct udphdr *)((caddr_t)ip6 + off);
 191 #else
 192         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 193         if (!uh)
 194                 return (IPPROTO_DONE);
 195 #endif
 196
 197         udpstat.udps_ipackets++;
 198
 199         /*
 200          * Destination port of 0 is illegal, based on RFC768.
 201          */
 202         if (uh->uh_dport == 0)
 203                 goto badunlocked;
 204
 205         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
 206         ulen = ntohs((u_short)uh->uh_ulen);
 207
 208         if (plen != ulen) {
 209                 udpstat.udps_badlen++;
 210                 goto badunlocked;
 211         }
 212
 213         /*
 214          * Checksum extended UDP header and data.
 215          */
 216         if (uh->uh_sum == 0) {
 217                 udpstat.udps_nosum++;
 218                 goto badunlocked;
 219         }
 220         if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
 221                 udpstat.udps_badsum++;
 222                 goto badunlocked;
 223         }
 224
 225         /*
 226          * Construct sockaddr format source address.
 227          */
 228         init_sin6(&fromsa, m);
 229         fromsa.sin6_port = uh->uh_sport;
 230
 231         INP_INFO_RLOCK(&udbinfo);
 232         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 233                 struct inpcb *last;
 234
 235                 /*
 236                  * In the event that laddr should be set to the link-local
 237                  * address (this happens in RIPng), the multicast address
 238                  * specified in the received packet will not match laddr.  To
 239                  * handle this situation, matching is relaxed if the
 240                  * receiving interface is the same as one specified in the
 241                  * socket and if the destination multicast address matches
 242                  * one of the multicast groups specified in the socket.
 243                  */
 244
 245                 /*
 246                  * KAME note: traditionally we dropped udpiphdr from mbuf
 247                  * here.  We need udphdr for IPsec processing so we do that
 248                  * later.
 249                  */
 250                 last = NULL;
 251                 LIST_FOREACH(inp, &udb, inp_list) {
 252                         if ((inp->inp_vflag & INP_IPV6) == 0)
 253                                 continue;
 254                         if (inp->inp_lport != uh->uh_dport)
 255                                 continue;
 256                         /*
 257                          * XXX: Do not check source port of incoming datagram
 258                          * unless inp_connect() has been called to bind the
 259                          * fport part of the 4-tuple; the source could be
 260                          * trying to talk to us with an ephemeral port.
 261                          */
 262                         if (inp->inp_fport != 0 &&
 263                             inp->inp_fport != uh->uh_sport)
 264                                 continue;
 265                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 266                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
 267                                                         &ip6->ip6_dst))
 268                                         continue;
 269                         }
 270                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 271                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
 272                                                         &ip6->ip6_src) ||
 273                                     inp->inp_fport != uh->uh_sport)
 274                                         continue;
 275                         }
 276
 277                         if (last != NULL) {
 278                                 struct mbuf *n;
 279
 280                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
 281                                         INP_RLOCK(last);
 282                                         udp6_append(last, n, off, &fromsa);
 283                                         INP_RUNLOCK(last);
 284                                 }
 285                         }
 286                         last = inp;
 287                         /*
 288                          * Don't look for additional matches if this one does
 289                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 290                          * socket options set.  This heuristic avoids
 291                          * searching through all pcbs in the common case of a
 292                          * non-shared port.  It assumes that an application
 293                          * will never clear these options after setting them.
 294                          */
 295                         if ((last->inp_socket->so_options &
 296                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 297                                 break;
 298                 }
 299
 300                 if (last == NULL) {
 301                         /*
 302                          * No matching pcb found; discard datagram.  (No need
 303                          * to send an ICMP Port Unreachable for a broadcast
 304                          * or multicast datgram.)
 305                          */
 306                         udpstat.udps_noport++;
 307                         udpstat.udps_noportmcast++;
 308                         goto badheadlocked;
 309                 }
 310                 INP_RLOCK(last);
 311                 INP_INFO_RUNLOCK(&udbinfo);
 312                 udp6_append(last, m, off, &fromsa);
 313                 INP_RUNLOCK(last);
 314                 return (IPPROTO_DONE);
 315         }
 316         /*
 317          * Locate pcb for datagram.
 318          */
 319         inp = in6_pcblookup_hash(&udbinfo, &ip6->ip6_src, uh->uh_sport,
 320             &ip6->ip6_dst, uh->uh_dport, 1, m->m_pkthdr.rcvif);
 321         if (inp == NULL) {
 322                 if (udp_log_in_vain) {
 323                         char ip6bufs[INET6_ADDRSTRLEN];
 324                         char ip6bufd[INET6_ADDRSTRLEN];
 325
 326                         log(LOG_INFO,
 327                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
 328                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 329                             ntohs(uh->uh_dport),
 330                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
 331                             ntohs(uh->uh_sport));
 332                 }
 333                 udpstat.udps_noport++;
 334                 if (m->m_flags & M_MCAST) {
 335                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
 336                         udpstat.udps_noportmcast++;
 337                         goto badheadlocked;
 338                 }
 339                 INP_INFO_RUNLOCK(&udbinfo);
 340                 if (udp_blackhole)
 341                         goto badunlocked;
 342                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
 343                         goto badunlocked;
 344                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
 345                 return (IPPROTO_DONE);
 346         }
 347         INP_RLOCK(inp);
 348         INP_INFO_RUNLOCK(&udbinfo);
 349         udp6_append(inp, m, off, &fromsa);
 350         INP_RUNLOCK(inp);
 351         return (IPPROTO_DONE);
 352
 353 badheadlocked:
 354         INP_INFO_RUNLOCK(&udbinfo);
 355 badunlocked:
 356         if (m)
 357                 m_freem(m);
 358         return (IPPROTO_DONE);
 359 }
 360
 361 void
 362 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 363 {
 364         struct udphdr uh;
 365         struct ip6_hdr *ip6;
 366         struct mbuf *m;
 367         int off = 0;
 368         struct ip6ctlparam *ip6cp = NULL;
 369         const struct sockaddr_in6 *sa6_src = NULL;
 370         void *cmdarg;
 371         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 372         struct udp_portonly {
 373                 u_int16_t uh_sport;
 374                 u_int16_t uh_dport;
 375         } *uhp;
 376
 377         if (sa->sa_family != AF_INET6 ||
 378             sa->sa_len != sizeof(struct sockaddr_in6))
 379                 return;
 380
 381         if ((unsigned)cmd >= PRC_NCMDS)
 382                 return;
 383         if (PRC_IS_REDIRECT(cmd))
 384                 notify = in6_rtchange, d = NULL;
 385         else if (cmd == PRC_HOSTDEAD)
 386                 d = NULL;
 387         else if (inet6ctlerrmap[cmd] == 0)
 388                 return;
 389
 390         /* if the parameter is from icmp6, decode it. */
 391         if (d != NULL) {
 392                 ip6cp = (struct ip6ctlparam *)d;
 393                 m = ip6cp->ip6c_m;
 394                 ip6 = ip6cp->ip6c_ip6;
 395                 off = ip6cp->ip6c_off;
 396                 cmdarg = ip6cp->ip6c_cmdarg;
 397                 sa6_src = ip6cp->ip6c_src;
 398         } else {
 399                 m = NULL;
 400                 ip6 = NULL;
 401                 cmdarg = NULL;
 402                 sa6_src = &sa6_any;
 403         }
 404
 405         if (ip6) {
 406                 /*
 407                  * XXX: We assume that when IPV6 is non NULL,
 408                  * M and OFF are valid.
 409                  */
 410
 411                 /* Check if we can safely examine src and dst ports. */
 412                 if (m->m_pkthdr.len < off + sizeof(*uhp))
 413                         return;
 414
 415                 bzero(&uh, sizeof(uh));
 416                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
 417
 418                 (void) in6_pcbnotify(&udbinfo, sa, uh.uh_dport,
 419                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
 420                     cmdarg, notify);
 421         } else
 422                 (void) in6_pcbnotify(&udbinfo, sa, 0,
 423                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
 424 }
 425
 426 static int
 427 udp6_getcred(SYSCTL_HANDLER_ARGS)
 428 {
 429         struct xucred xuc;
 430         struct sockaddr_in6 addrs[2];
 431         struct inpcb *inp;
 432         int error;
 433
 434         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 435         if (error)
 436                 return (error);
 437
 438         if (req->newlen != sizeof(addrs))
 439                 return (EINVAL);
 440         if (req->oldlen != sizeof(struct xucred))
 441                 return (EINVAL);
 442         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 443         if (error)
 444                 return (error);
 445         if ((error = sa6_embedscope(&addrs[0], ip6_use_defzone)) != 0 ||
 446             (error = sa6_embedscope(&addrs[1], ip6_use_defzone)) != 0) {
 447                 return (error);
 448         }
 449         INP_INFO_RLOCK(&udbinfo);
 450         inp = in6_pcblookup_hash(&udbinfo, &addrs[1].sin6_addr,
 451             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port, 1,
 452             NULL);
 453         if (inp != NULL) {
 454                 INP_RLOCK(inp);
 455                 INP_INFO_RUNLOCK(&udbinfo);
 456                 if (inp->inp_socket == NULL)
 457                         error = ENOENT;
 458                 if (error == 0)
 459                         error = cr_canseesocket(req->td->td_ucred,
 460                             inp->inp_socket);
 461                 if (error == 0)
 462                         cru2x(inp->inp_cred, &xuc);
 463                 INP_RUNLOCK(inp);
 464         } else {
 465                 INP_INFO_RUNLOCK(&udbinfo);
 466                 error = ENOENT;
 467         }
 468         if (error == 0)
 469                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 470         return (error);
 471 }
 472
 473 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
 474     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
 475
 476 static int
 477 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
 478     struct mbuf *control, struct thread *td)
 479 {
 480         u_int32_t ulen = m->m_pkthdr.len;
 481         u_int32_t plen = sizeof(struct udphdr) + ulen;
 482         struct ip6_hdr *ip6;
 483         struct udphdr *udp6;
 484         struct in6_addr *laddr, *faddr;
 485         struct sockaddr_in6 *sin6 = NULL;
 486         struct ifnet *oifp = NULL;
 487         int scope_ambiguous = 0;
 488         u_short fport;
 489         int error = 0;
 490         struct ip6_pktopts *optp, opt;
 491         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 492         int flags;
 493         struct sockaddr_in6 tmp;
 494
 495         INP_WLOCK_ASSERT(inp);
 496
 497         if (addr6) {
 498                 /* addr6 has been validated in udp6_send(). */
 499                 sin6 = (struct sockaddr_in6 *)addr6;
 500
 501                 /* protect *sin6 from overwrites */
 502                 tmp = *sin6;
 503                 sin6 = &tmp;
 504
 505                 /*
 506                  * Application should provide a proper zone ID or the use of
 507                  * default zone IDs should be enabled.  Unfortunately, some
 508                  * applications do not behave as it should, so we need a
 509                  * workaround.  Even if an appropriate ID is not determined,
 510                  * we'll see if we can determine the outgoing interface.  If we
 511                  * can, determine the zone ID based on the interface below.
 512                  */
 513                 if (sin6->sin6_scope_id == 0 && !ip6_use_defzone)
 514                         scope_ambiguous = 1;
 515                 if ((error = sa6_embedscope(sin6, ip6_use_defzone)) != 0)
 516                         return (error);
 517         }
 518
 519         if (control) {
 520                 if ((error = ip6_setpktopts(control, &opt,
 521                     inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
 522                         goto release;
 523                 optp = &opt;
 524         } else
 525                 optp = inp->in6p_outputopts;
 526
 527         if (sin6) {
 528                 faddr = &sin6->sin6_addr;
 529
 530                 /*
 531                  * IPv4 version of udp_output calls in_pcbconnect in this case,
 532                  * which needs splnet and affects performance.
 533                  * Since we saw no essential reason for calling in_pcbconnect,
 534                  * we get rid of such kind of logic, and call in6_selectsrc
 535                  * and in6_pcbsetport in order to fill in the local address
 536                  * and the local port.
 537                  */
 538                 if (sin6->sin6_port == 0) {
 539                         error = EADDRNOTAVAIL;
 540                         goto release;
 541                 }
 542
 543                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 544                         /* how about ::ffff:0.0.0.0 case? */
 545                         error = EISCONN;
 546                         goto release;
 547                 }
 548
 549                 fport = sin6->sin6_port; /* allow 0 port */
 550
 551                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 552                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 553                                 /*
 554                                  * I believe we should explicitly discard the
 555                                  * packet when mapped addresses are disabled,
 556                                  * rather than send the packet as an IPv6 one.
 557                                  * If we chose the latter approach, the packet
 558                                  * might be sent out on the wire based on the
 559                                  * default route, the situation which we'd
 560                                  * probably want to avoid.
 561                                  * (20010421 jinmei@kame.net)
 562                                  */
 563                                 error = EINVAL;
 564                                 goto release;
 565                         }
 566                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 567                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 568                                 /*
 569                                  * when remote addr is an IPv4-mapped address,
 570                                  * local addr should not be an IPv6 address,
 571                                  * since you cannot determine how to map IPv6
 572                                  * source address to IPv4.
 573                                  */
 574                                 error = EINVAL;
 575                                 goto release;
 576                         }
 577
 578                         af = AF_INET;
 579                 }
 580
 581                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 582                         laddr = in6_selectsrc(sin6, optp, inp, NULL,
 583                             td->td_ucred, &oifp, &error);
 584                         if (oifp && scope_ambiguous &&
 585                             (error = in6_setscope(&sin6->sin6_addr,
 586                             oifp, NULL))) {
 587                                 goto release;
 588                         }
 589                 } else
 590                         laddr = &inp->in6p_laddr;       /* XXX */
 591                 if (laddr == NULL) {
 592                         if (error == 0)
 593                                 error = EADDRNOTAVAIL;
 594                         goto release;
 595                 }
 596                 if (inp->inp_lport == 0 &&
 597                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0)
 598                         goto release;
 599         } else {
 600                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 601                         error = ENOTCONN;
 602                         goto release;
 603                 }
 604                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 605                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 606                                 /*
 607                                  * XXX: this case would happen when the
 608                                  * application sets the V6ONLY flag after
 609                                  * connecting the foreign address.
 610                                  * Such applications should be fixed,
 611                                  * so we bark here.
 612                                  */
 613                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 614                                     "option was set for a connected socket\n");
 615                                 error = EINVAL;
 616                                 goto release;
 617                         } else
 618                                 af = AF_INET;
 619                 }
 620                 laddr = &inp->in6p_laddr;
 621                 faddr = &inp->in6p_faddr;
 622                 fport = inp->inp_fport;
 623         }
 624
 625         if (af == AF_INET)
 626                 hlen = sizeof(struct ip);
 627
 628         /*
 629          * Calculate data length and get a mbuf
 630          * for UDP and IP6 headers.
 631          */
 632         M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
 633         if (m == 0) {
 634                 error = ENOBUFS;
 635                 goto release;
 636         }
 637
 638         /*
 639          * Stuff checksum and output datagram.
 640          */
 641         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 642         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
 643         udp6->uh_dport = fport;
 644         if (plen <= 0xffff)
 645                 udp6->uh_ulen = htons((u_short)plen);
 646         else
 647                 udp6->uh_ulen = 0;
 648         udp6->uh_sum = 0;
 649
 650         switch (af) {
 651         case AF_INET6:
 652                 ip6 = mtod(m, struct ip6_hdr *);
 653                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
 654                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 655                 ip6->ip6_vfc    |= IPV6_VERSION;
 656 #if 0                           /* ip6_plen will be filled in ip6_output. */
 657                 ip6->ip6_plen   = htons((u_short)plen);
 658 #endif
 659                 ip6->ip6_nxt    = IPPROTO_UDP;
 660                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 661                 ip6->ip6_src    = *laddr;
 662                 ip6->ip6_dst    = *faddr;
 663
 664                 if ((udp6->uh_sum = in6_cksum(m, IPPROTO_UDP,
 665                                 sizeof(struct ip6_hdr), plen)) == 0) {
 666                         udp6->uh_sum = 0xffff;
 667                 }
 668
 669                 flags = 0;
 670
 671                 udpstat.udps_opackets++;
 672                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 673                     NULL, inp);
 674                 break;
 675         case AF_INET:
 676                 error = EAFNOSUPPORT;
 677                 goto release;
 678         }
 679         goto releaseopt;
 680
 681 release:
 682         m_freem(m);
 683
 684 releaseopt:
 685         if (control) {
 686                 ip6_clearpktopts(&opt, -1);
 687                 m_freem(control);
 688         }
 689         return (error);
 690 }
 691
 692 static void
 693 udp6_abort(struct socket *so)
 694 {
 695         struct inpcb *inp;
 696
 697         inp = sotoinpcb(so);
 698         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 699
 700 #ifdef INET
 701         if (inp->inp_vflag & INP_IPV4) {
 702                 struct pr_usrreqs *pru;
 703
 704                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 705                 (*pru->pru_abort)(so);
 706                 return;
 707         }
 708 #endif
 709
 710         INP_INFO_WLOCK(&udbinfo);
 711         INP_WLOCK(inp);
 712         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 713                 in6_pcbdisconnect(inp);
 714                 inp->in6p_laddr = in6addr_any;
 715                 soisdisconnected(so);
 716         }
 717         INP_WUNLOCK(inp);
 718         INP_INFO_WUNLOCK(&udbinfo);
 719 }
 720
 721 static int
 722 udp6_attach(struct socket *so, int proto, struct thread *td)
 723 {
 724         struct inpcb *inp;
 725         int error;
 726
 727         inp = sotoinpcb(so);
 728         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 729
 730         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 731                 error = soreserve(so, udp_sendspace, udp_recvspace);
 732                 if (error)
 733                         return (error);
 734         }
 735         INP_INFO_WLOCK(&udbinfo);
 736         error = in_pcballoc(so, &udbinfo);
 737         if (error) {
 738                 INP_INFO_WUNLOCK(&udbinfo);
 739                 return (error);
 740         }
 741         inp = (struct inpcb *)so->so_pcb;
 742         INP_INFO_WUNLOCK(&udbinfo);
 743         inp->inp_vflag |= INP_IPV6;
 744         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 745                 inp->inp_vflag |= INP_IPV4;
 746         inp->in6p_hops = -1;    /* use kernel default */
 747         inp->in6p_cksum = -1;   /* just to be sure */
 748         /*
 749          * XXX: ugly!!
 750          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 751          * because the socket may be bound to an IPv6 wildcard address,
 752          * which may match an IPv4-mapped IPv6 address.
 753          */
 754         inp->inp_ip_ttl = ip_defttl;
 755         INP_WUNLOCK(inp);
 756         return (0);
 757 }
 758
 759 static int
 760 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 761 {
 762         struct inpcb *inp;
 763         int error;
 764
 765         inp = sotoinpcb(so);
 766         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 767
 768         INP_INFO_WLOCK(&udbinfo);
 769         INP_WLOCK(inp);
 770         inp->inp_vflag &= ~INP_IPV4;
 771         inp->inp_vflag |= INP_IPV6;
 772         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 773                 struct sockaddr_in6 *sin6_p;
 774
 775                 sin6_p = (struct sockaddr_in6 *)nam;
 776
 777                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 778                         inp->inp_vflag |= INP_IPV4;
 779                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 780                         struct sockaddr_in sin;
 781
 782                         in6_sin6_2_sin(&sin, sin6_p);
 783                         inp->inp_vflag |= INP_IPV4;
 784                         inp->inp_vflag &= ~INP_IPV6;
 785                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 786                             td->td_ucred);
 787                         goto out;
 788                 }
 789         }
 790
 791         error = in6_pcbbind(inp, nam, td->td_ucred);
 792 out:
 793         INP_WUNLOCK(inp);
 794         INP_INFO_WUNLOCK(&udbinfo);
 795         return (error);
 796 }
 797
 798 static void
 799 udp6_close(struct socket *so)
 800 {
 801         struct inpcb *inp;
 802
 803         inp = sotoinpcb(so);
 804         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
 805
 806 #ifdef INET
 807         if (inp->inp_vflag & INP_IPV4) {
 808                 struct pr_usrreqs *pru;
 809
 810                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 811                 (*pru->pru_disconnect)(so);
 812                 return;
 813         }
 814 #endif
 815         INP_INFO_WLOCK(&udbinfo);
 816         INP_WLOCK(inp);
 817         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 818                 in6_pcbdisconnect(inp);
 819                 inp->in6p_laddr = in6addr_any;
 820                 soisdisconnected(so);
 821         }
 822         INP_WUNLOCK(inp);
 823         INP_INFO_WUNLOCK(&udbinfo);
 824 }
 825
 826 static int
 827 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 828 {
 829         struct inpcb *inp;
 830         struct sockaddr_in6 *sin6;
 831         int error;
 832
 833         inp = sotoinpcb(so);
 834         sin6 = (struct sockaddr_in6 *)nam;
 835         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
 836
 837         INP_INFO_WLOCK(&udbinfo);
 838         INP_WLOCK(inp);
 839         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0 &&
 840             IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
 841                 struct sockaddr_in sin;
 842
 843                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 844                         error = EISCONN;
 845                         goto out;
 846                 }
 847                 in6_sin6_2_sin(&sin, sin6);
 848                 error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
 849                 if (error != 0)
 850                         goto out;
 851                 error = in_pcbconnect(inp, (struct sockaddr *)&sin,
 852                     td->td_ucred);
 853                 if (error == 0) {
 854                         inp->inp_vflag |= INP_IPV4;
 855                         inp->inp_vflag &= ~INP_IPV6;
 856                         soisconnected(so);
 857                 }
 858                 goto out;
 859         }
 860         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 861                 error = EISCONN;
 862                 goto out;
 863         }
 864         error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
 865         if (error != 0)
 866                 goto out;
 867         error = in6_pcbconnect(inp, nam, td->td_ucred);
 868         if (error == 0) {
 869                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 870                         /* should be non mapped addr */
 871                         inp->inp_vflag &= ~INP_IPV4;
 872                         inp->inp_vflag |= INP_IPV6;
 873                 }
 874                 soisconnected(so);
 875         }
 876 out:
 877         INP_WUNLOCK(inp);
 878         INP_INFO_WUNLOCK(&udbinfo);
 879         return (error);
 880 }
 881
 882 static void
 883 udp6_detach(struct socket *so)
 884 {
 885         struct inpcb *inp;
 886
 887         inp = sotoinpcb(so);
 888         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
 889
 890         INP_INFO_WLOCK(&udbinfo);
 891         INP_WLOCK(inp);
 892         in_pcbdetach(inp);
 893         in_pcbfree(inp);
 894         INP_INFO_WUNLOCK(&udbinfo);
 895 }
 896
 897 static int
 898 udp6_disconnect(struct socket *so)
 899 {
 900         struct inpcb *inp;
 901         int error;
 902
 903         inp = sotoinpcb(so);
 904         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
 905
 906         INP_INFO_WLOCK(&udbinfo);
 907         INP_WLOCK(inp);
 908
 909 #ifdef INET
 910         if (inp->inp_vflag & INP_IPV4) {
 911                 struct pr_usrreqs *pru;
 912
 913                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 914                 error = (*pru->pru_disconnect)(so);
 915                 goto out;
 916         }
 917 #endif
 918
 919         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 920                 error = ENOTCONN;
 921                 goto out;
 922         }
 923
 924         in6_pcbdisconnect(inp);
 925         inp->in6p_laddr = in6addr_any;
 926         SOCK_LOCK(so);
 927         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
 928         SOCK_UNLOCK(so);
 929 out:
 930         INP_WUNLOCK(inp);
 931         INP_INFO_WUNLOCK(&udbinfo);
 932         return (0);
 933 }
 934
 935 static int
 936 udp6_send(struct socket *so, int flags, struct mbuf *m,
 937     struct sockaddr *addr, struct mbuf *control, struct thread *td)
 938 {
 939         struct inpcb *inp;
 940         int error = 0;
 941
 942         inp = sotoinpcb(so);
 943         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
 944
 945         INP_INFO_WLOCK(&udbinfo);
 946         INP_WLOCK(inp);
 947         if (addr) {
 948                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
 949                         error = EINVAL;
 950                         goto bad;
 951                 }
 952                 if (addr->sa_family != AF_INET6) {
 953                         error = EAFNOSUPPORT;
 954                         goto bad;
 955                 }
 956         }
 957
 958 #ifdef INET
 959         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 960                 int hasv4addr;
 961                 struct sockaddr_in6 *sin6 = 0;
 962
 963                 if (addr == 0)
 964                         hasv4addr = (inp->inp_vflag & INP_IPV4);
 965                 else {
 966                         sin6 = (struct sockaddr_in6 *)addr;
 967                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
 968                             ? 1 : 0;
 969                 }
 970                 if (hasv4addr) {
 971                         struct pr_usrreqs *pru;
 972
 973                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 974                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 975                                 /*
 976                                  * When remote addr is IPv4-mapped address,
 977                                  * local addr should not be an IPv6 address;
 978                                  * since you cannot determine how to map IPv6
 979                                  * source address to IPv4.
 980                                  */
 981                                 error = EINVAL;
 982                                 goto out;
 983                         }
 984
 985                         /*
 986                          * XXXRW: We release UDP-layer locks before calling
 987                          * udp_send() in order to avoid recursion.  However,
 988                          * this does mean there is a short window where inp's
 989                          * fields are unstable.  Could this lead to a
 990                          * potential race in which the factors causing us to
 991                          * select the UDPv4 output routine are invalidated?
 992                          */
 993                         INP_WUNLOCK(inp);
 994                         INP_INFO_WUNLOCK(&udbinfo);
 995                         if (sin6)
 996                                 in6_sin6_2_sin_in_sock(addr);
 997                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 998                         /* addr will just be freed in sendit(). */
 999                         return ((*pru->pru_send)(so, flags, m, addr, control,
1000                             td));
1001                 }
1002         }
1003 #endif
1004 #ifdef MAC
1005         mac_create_mbuf_from_inpcb(inp, m);
1006 #endif
1007         error = udp6_output(inp, m, addr, control, td);
1008 out:
1009         INP_WUNLOCK(inp);
1010         INP_INFO_WUNLOCK(&udbinfo);
1011         return (error);
1012
1013 bad:
1014         INP_WUNLOCK(inp);
1015         INP_INFO_WUNLOCK(&udbinfo);
1016         m_freem(m);
1017         return (error);
1018 }
1019
1020 struct pr_usrreqs udp6_usrreqs = {
1021         .pru_abort =            udp6_abort,
1022         .pru_attach =           udp6_attach,
1023         .pru_bind =             udp6_bind,
1024         .pru_connect =          udp6_connect,
1025         .pru_control =          in6_control,
1026         .pru_detach =           udp6_detach,
1027         .pru_disconnect =       udp6_disconnect,
1028         .pru_peeraddr =         in6_mapped_peeraddr,
1029         .pru_send =             udp6_send,
1030         .pru_shutdown =         udp_shutdown,
1031         .pru_sockaddr =         in6_mapped_sockaddr,
1032         .pru_sosend =           sosend_dgram,
1033         .pru_sosetlabel =       in_pcbsosetlabel,
1034         .pru_close =            udp6_close
1035 };