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/kernel.h>
  75 #include <sys/lock.h>
  76 #include <sys/mbuf.h>
  77 #include <sys/priv.h>
  78 #include <sys/proc.h>
  79 #include <sys/protosw.h>
  80 #include <sys/signalvar.h>
  81 #include <sys/socket.h>
  82 #include <sys/socketvar.h>
  83 #include <sys/sx.h>
  84 #include <sys/sysctl.h>
  85 #include <sys/syslog.h>
  86 #include <sys/systm.h>
  87 #include <sys/vimage.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         INIT_VNET_INET(inp->inp_vnet);
 131         struct socket *so;
 132         struct mbuf *opts;
 133
 134         INP_LOCK_ASSERT(inp);
 135
 136 #ifdef IPSEC
 137         /* Check AH/ESP integrity. */
 138         if (ipsec6_in_reject(n, inp)) {
 139                 INIT_VNET_IPSEC(inp->inp_vnet);
 140                 m_freem(n);
 141                 V_ipsec6stat.in_polvio++;
 142                 return;
 143         }
 144 #endif /* IPSEC */
 145 #ifdef MAC
 146         if (mac_inpcb_check_deliver(inp, n) != 0) {
 147                 m_freem(n);
 148                 return;
 149         }
 150 #endif
 151         opts = NULL;
 152         if (inp->in6p_flags & IN6P_CONTROLOPTS ||
 153             inp->inp_socket->so_options & SO_TIMESTAMP)
 154                 ip6_savecontrol(inp, n, &opts);
 155         m_adj(n, off + sizeof(struct udphdr));
 156
 157         so = inp->inp_socket;
 158         SOCKBUF_LOCK(&so->so_rcv);
 159         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
 160             opts) == 0) {
 161                 SOCKBUF_UNLOCK(&so->so_rcv);
 162                 m_freem(n);
 163                 if (opts)
 164                         m_freem(opts);
 165                 V_udpstat.udps_fullsock++;
 166         } else
 167                 sorwakeup_locked(so);
 168 }
 169
 170 int
 171 udp6_input(struct mbuf **mp, int *offp, int proto)
 172 {
 173         INIT_VNET_INET(curvnet);
 174         INIT_VNET_INET6(curvnet);
 175         struct mbuf *m = *mp;
 176         struct ip6_hdr *ip6;
 177         struct udphdr *uh;
 178         struct inpcb *inp;
 179         int off = *offp;
 180         int plen, ulen;
 181         struct sockaddr_in6 fromsa;
 182
 183         ip6 = mtod(m, struct ip6_hdr *);
 184
 185         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 186                 /* XXX send icmp6 host/port unreach? */
 187                 m_freem(m);
 188                 return (IPPROTO_DONE);
 189         }
 190
 191 #ifndef PULLDOWN_TEST
 192         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
 193         ip6 = mtod(m, struct ip6_hdr *);
 194         uh = (struct udphdr *)((caddr_t)ip6 + off);
 195 #else
 196         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 197         if (!uh)
 198                 return (IPPROTO_DONE);
 199 #endif
 200
 201         V_udpstat.udps_ipackets++;
 202
 203         /*
 204          * Destination port of 0 is illegal, based on RFC768.
 205          */
 206         if (uh->uh_dport == 0)
 207                 goto badunlocked;
 208
 209         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
 210         ulen = ntohs((u_short)uh->uh_ulen);
 211
 212         if (plen != ulen) {
 213                 V_udpstat.udps_badlen++;
 214                 goto badunlocked;
 215         }
 216
 217         /*
 218          * Checksum extended UDP header and data.
 219          */
 220         if (uh->uh_sum == 0) {
 221                 V_udpstat.udps_nosum++;
 222                 goto badunlocked;
 223         }
 224         if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
 225                 V_udpstat.udps_badsum++;
 226                 goto badunlocked;
 227         }
 228
 229         /*
 230          * Construct sockaddr format source address.
 231          */
 232         init_sin6(&fromsa, m);
 233         fromsa.sin6_port = uh->uh_sport;
 234
 235         INP_INFO_RLOCK(&V_udbinfo);
 236         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 237                 struct inpcb *last;
 238
 239                 /*
 240                  * In the event that laddr should be set to the link-local
 241                  * address (this happens in RIPng), the multicast address
 242                  * specified in the received packet will not match laddr.  To
 243                  * handle this situation, matching is relaxed if the
 244                  * receiving interface is the same as one specified in the
 245                  * socket and if the destination multicast address matches
 246                  * one of the multicast groups specified in the socket.
 247                  */
 248
 249                 /*
 250                  * KAME note: traditionally we dropped udpiphdr from mbuf
 251                  * here.  We need udphdr for IPsec processing so we do that
 252                  * later.
 253                  */
 254                 last = NULL;
 255                 LIST_FOREACH(inp, &V_udb, inp_list) {
 256                         if ((inp->inp_vflag & INP_IPV6) == 0)
 257                                 continue;
 258                         if (inp->in6p_lport != uh->uh_dport)
 259                                 continue;
 260                         /*
 261                          * XXX: Do not check source port of incoming datagram
 262                          * unless inp_connect() has been called to bind the
 263                          * fport part of the 4-tuple; the source could be
 264                          * trying to talk to us with an ephemeral port.
 265                          */
 266                         if (inp->inp_fport != 0 &&
 267                             inp->inp_fport != uh->uh_sport)
 268                                 continue;
 269                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 270                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
 271                                                         &ip6->ip6_dst))
 272                                         continue;
 273                         }
 274                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 275                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
 276                                                         &ip6->ip6_src) ||
 277                                     inp->in6p_fport != uh->uh_sport)
 278                                         continue;
 279                         }
 280
 281                         if (last != NULL) {
 282                                 struct mbuf *n;
 283
 284                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
 285                                         INP_RLOCK(last);
 286                                         udp6_append(last, n, off, &fromsa);
 287                                         INP_RUNLOCK(last);
 288                                 }
 289                         }
 290                         last = inp;
 291                         /*
 292                          * Don't look for additional matches if this one does
 293                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 294                          * socket options set.  This heuristic avoids
 295                          * searching through all pcbs in the common case of a
 296                          * non-shared port.  It assumes that an application
 297                          * will never clear these options after setting them.
 298                          */
 299                         if ((last->inp_socket->so_options &
 300                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 301                                 break;
 302                 }
 303
 304                 if (last == NULL) {
 305                         /*
 306                          * No matching pcb found; discard datagram.  (No need
 307                          * to send an ICMP Port Unreachable for a broadcast
 308                          * or multicast datgram.)
 309                          */
 310                         V_udpstat.udps_noport++;
 311                         V_udpstat.udps_noportmcast++;
 312                         goto badheadlocked;
 313                 }
 314                 INP_RLOCK(last);
 315                 INP_INFO_RUNLOCK(&V_udbinfo);
 316                 udp6_append(last, m, off, &fromsa);
 317                 INP_RUNLOCK(last);
 318                 return (IPPROTO_DONE);
 319         }
 320         /*
 321          * Locate pcb for datagram.
 322          */
 323         inp = in6_pcblookup_hash(&V_udbinfo, &ip6->ip6_src, uh->uh_sport,
 324             &ip6->ip6_dst, uh->uh_dport, 1, m->m_pkthdr.rcvif);
 325         if (inp == NULL) {
 326                 if (udp_log_in_vain) {
 327                         char ip6bufs[INET6_ADDRSTRLEN];
 328                         char ip6bufd[INET6_ADDRSTRLEN];
 329
 330                         log(LOG_INFO,
 331                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
 332                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 333                             ntohs(uh->uh_dport),
 334                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
 335                             ntohs(uh->uh_sport));
 336                 }
 337                 V_udpstat.udps_noport++;
 338                 if (m->m_flags & M_MCAST) {
 339                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
 340                         V_udpstat.udps_noportmcast++;
 341                         goto badheadlocked;
 342                 }
 343                 INP_INFO_RUNLOCK(&V_udbinfo);
 344                 if (V_udp_blackhole)
 345                         goto badunlocked;
 346                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
 347                         goto badunlocked;
 348                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
 349                 return (IPPROTO_DONE);
 350         }
 351         INP_RLOCK(inp);
 352         INP_INFO_RUNLOCK(&V_udbinfo);
 353         udp6_append(inp, m, off, &fromsa);
 354         INP_RUNLOCK(inp);
 355         return (IPPROTO_DONE);
 356
 357 badheadlocked:
 358         INP_INFO_RUNLOCK(&V_udbinfo);
 359 badunlocked:
 360         if (m)
 361                 m_freem(m);
 362         return (IPPROTO_DONE);
 363 }
 364
 365 void
 366 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 367 {
 368         INIT_VNET_INET(curvnet);
 369         struct udphdr uh;
 370         struct ip6_hdr *ip6;
 371         struct mbuf *m;
 372         int off = 0;
 373         struct ip6ctlparam *ip6cp = NULL;
 374         const struct sockaddr_in6 *sa6_src = NULL;
 375         void *cmdarg;
 376         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 377         struct udp_portonly {
 378                 u_int16_t uh_sport;
 379                 u_int16_t uh_dport;
 380         } *uhp;
 381
 382         if (sa->sa_family != AF_INET6 ||
 383             sa->sa_len != sizeof(struct sockaddr_in6))
 384                 return;
 385
 386         if ((unsigned)cmd >= PRC_NCMDS)
 387                 return;
 388         if (PRC_IS_REDIRECT(cmd))
 389                 notify = in6_rtchange, d = NULL;
 390         else if (cmd == PRC_HOSTDEAD)
 391                 d = NULL;
 392         else if (inet6ctlerrmap[cmd] == 0)
 393                 return;
 394
 395         /* if the parameter is from icmp6, decode it. */
 396         if (d != NULL) {
 397                 ip6cp = (struct ip6ctlparam *)d;
 398                 m = ip6cp->ip6c_m;
 399                 ip6 = ip6cp->ip6c_ip6;
 400                 off = ip6cp->ip6c_off;
 401                 cmdarg = ip6cp->ip6c_cmdarg;
 402                 sa6_src = ip6cp->ip6c_src;
 403         } else {
 404                 m = NULL;
 405                 ip6 = NULL;
 406                 cmdarg = NULL;
 407                 sa6_src = &sa6_any;
 408         }
 409
 410         if (ip6) {
 411                 /*
 412                  * XXX: We assume that when IPV6 is non NULL,
 413                  * M and OFF are valid.
 414                  */
 415
 416                 /* Check if we can safely examine src and dst ports. */
 417                 if (m->m_pkthdr.len < off + sizeof(*uhp))
 418                         return;
 419
 420                 bzero(&uh, sizeof(uh));
 421                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
 422
 423                 (void) in6_pcbnotify(&V_udbinfo, sa, uh.uh_dport,
 424                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
 425                     cmdarg, notify);
 426         } else
 427                 (void) in6_pcbnotify(&V_udbinfo, sa, 0,
 428                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
 429 }
 430
 431 static int
 432 udp6_getcred(SYSCTL_HANDLER_ARGS)
 433 {
 434         INIT_VNET_INET(curvnet);
 435         INIT_VNET_INET6(curvnet);
 436         struct xucred xuc;
 437         struct sockaddr_in6 addrs[2];
 438         struct inpcb *inp;
 439         int error;
 440
 441         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 442         if (error)
 443                 return (error);
 444
 445         if (req->newlen != sizeof(addrs))
 446                 return (EINVAL);
 447         if (req->oldlen != sizeof(struct xucred))
 448                 return (EINVAL);
 449         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 450         if (error)
 451                 return (error);
 452         if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
 453             (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
 454                 return (error);
 455         }
 456         INP_INFO_RLOCK(&V_udbinfo);
 457         inp = in6_pcblookup_hash(&V_udbinfo, &addrs[1].sin6_addr,
 458             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port, 1,
 459             NULL);
 460         if (inp != NULL) {
 461                 INP_RLOCK(inp);
 462                 INP_INFO_RUNLOCK(&V_udbinfo);
 463                 if (inp->inp_socket == NULL)
 464                         error = ENOENT;
 465                 if (error == 0)
 466                         error = cr_canseesocket(req->td->td_ucred,
 467                             inp->inp_socket);
 468                 if (error == 0)
 469                         cru2x(inp->inp_cred, &xuc);
 470                 INP_RUNLOCK(inp);
 471         } else {
 472                 INP_INFO_RUNLOCK(&V_udbinfo);
 473                 error = ENOENT;
 474         }
 475         if (error == 0)
 476                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 477         return (error);
 478 }
 479
 480 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
 481     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
 482
 483 static int
 484 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
 485     struct mbuf *control, struct thread *td)
 486 {
 487         INIT_VNET_INET(curvnet);
 488         INIT_VNET_INET6(curvnet);
 489         u_int32_t ulen = m->m_pkthdr.len;
 490         u_int32_t plen = sizeof(struct udphdr) + ulen;
 491         struct ip6_hdr *ip6;
 492         struct udphdr *udp6;
 493         struct in6_addr *laddr, *faddr;
 494         struct sockaddr_in6 *sin6 = NULL;
 495         struct ifnet *oifp = NULL;
 496         int scope_ambiguous = 0;
 497         u_short fport;
 498         int error = 0;
 499         struct ip6_pktopts *optp, opt;
 500         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 501         int flags;
 502         struct sockaddr_in6 tmp;
 503
 504         INP_WLOCK_ASSERT(inp);
 505
 506         if (addr6) {
 507                 /* addr6 has been validated in udp6_send(). */
 508                 sin6 = (struct sockaddr_in6 *)addr6;
 509
 510                 /* protect *sin6 from overwrites */
 511                 tmp = *sin6;
 512                 sin6 = &tmp;
 513
 514                 /*
 515                  * Application should provide a proper zone ID or the use of
 516                  * default zone IDs should be enabled.  Unfortunately, some
 517                  * applications do not behave as it should, so we need a
 518                  * workaround.  Even if an appropriate ID is not determined,
 519                  * we'll see if we can determine the outgoing interface.  If we
 520                  * can, determine the zone ID based on the interface below.
 521                  */
 522                 if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
 523                         scope_ambiguous = 1;
 524                 if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
 525                         return (error);
 526         }
 527
 528         if (control) {
 529                 if ((error = ip6_setpktopts(control, &opt,
 530                     inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
 531                         goto release;
 532                 optp = &opt;
 533         } else
 534                 optp = inp->in6p_outputopts;
 535
 536         if (sin6) {
 537                 faddr = &sin6->sin6_addr;
 538
 539                 /*
 540                  * IPv4 version of udp_output calls in_pcbconnect in this case,
 541                  * which needs splnet and affects performance.
 542                  * Since we saw no essential reason for calling in_pcbconnect,
 543                  * we get rid of such kind of logic, and call in6_selectsrc
 544                  * and in6_pcbsetport in order to fill in the local address
 545                  * and the local port.
 546                  */
 547                 if (sin6->sin6_port == 0) {
 548                         error = EADDRNOTAVAIL;
 549                         goto release;
 550                 }
 551
 552                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 553                         /* how about ::ffff:0.0.0.0 case? */
 554                         error = EISCONN;
 555                         goto release;
 556                 }
 557
 558                 fport = sin6->sin6_port; /* allow 0 port */
 559
 560                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 561                         if ((inp->in6p_flags & IN6P_IPV6_V6ONLY)) {
 562                                 /*
 563                                  * I believe we should explicitly discard the
 564                                  * packet when mapped addresses are disabled,
 565                                  * rather than send the packet as an IPv6 one.
 566                                  * If we chose the latter approach, the packet
 567                                  * might be sent out on the wire based on the
 568                                  * default route, the situation which we'd
 569                                  * probably want to avoid.
 570                                  * (20010421 jinmei@kame.net)
 571                                  */
 572                                 error = EINVAL;
 573                                 goto release;
 574                         }
 575                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 576                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 577                                 /*
 578                                  * when remote addr is an IPv4-mapped address,
 579                                  * local addr should not be an IPv6 address,
 580                                  * since you cannot determine how to map IPv6
 581                                  * source address to IPv4.
 582                                  */
 583                                 error = EINVAL;
 584                                 goto release;
 585                         }
 586
 587                         af = AF_INET;
 588                 }
 589
 590                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 591                         laddr = in6_selectsrc(sin6, optp, inp, NULL,
 592                             td->td_ucred, &oifp, &error);
 593                         if (oifp && scope_ambiguous &&
 594                             (error = in6_setscope(&sin6->sin6_addr,
 595                             oifp, NULL))) {
 596                                 goto release;
 597                         }
 598                 } else
 599                         laddr = &inp->in6p_laddr;       /* XXX */
 600                 if (laddr == NULL) {
 601                         if (error == 0)
 602                                 error = EADDRNOTAVAIL;
 603                         goto release;
 604                 }
 605                 if (inp->in6p_lport == 0 &&
 606                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0)
 607                         goto release;
 608         } else {
 609                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 610                         error = ENOTCONN;
 611                         goto release;
 612                 }
 613                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 614                         if ((inp->in6p_flags & IN6P_IPV6_V6ONLY)) {
 615                                 /*
 616                                  * XXX: this case would happen when the
 617                                  * application sets the V6ONLY flag after
 618                                  * connecting the foreign address.
 619                                  * Such applications should be fixed,
 620                                  * so we bark here.
 621                                  */
 622                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 623                                     "option was set for a connected socket\n");
 624                                 error = EINVAL;
 625                                 goto release;
 626                         } else
 627                                 af = AF_INET;
 628                 }
 629                 laddr = &inp->in6p_laddr;
 630                 faddr = &inp->in6p_faddr;
 631                 fport = inp->in6p_fport;
 632         }
 633
 634         if (af == AF_INET)
 635                 hlen = sizeof(struct ip);
 636
 637         /*
 638          * Calculate data length and get a mbuf
 639          * for UDP and IP6 headers.
 640          */
 641         M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
 642         if (m == 0) {
 643                 error = ENOBUFS;
 644                 goto release;
 645         }
 646
 647         /*
 648          * Stuff checksum and output datagram.
 649          */
 650         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 651         udp6->uh_sport = inp->in6p_lport; /* lport is always set in the PCB */
 652         udp6->uh_dport = fport;
 653         if (plen <= 0xffff)
 654                 udp6->uh_ulen = htons((u_short)plen);
 655         else
 656                 udp6->uh_ulen = 0;
 657         udp6->uh_sum = 0;
 658
 659         switch (af) {
 660         case AF_INET6:
 661                 ip6 = mtod(m, struct ip6_hdr *);
 662                 ip6->ip6_flow   = inp->in6p_flowinfo & IPV6_FLOWINFO_MASK;
 663                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 664                 ip6->ip6_vfc    |= IPV6_VERSION;
 665 #if 0                           /* ip6_plen will be filled in ip6_output. */
 666                 ip6->ip6_plen   = htons((u_short)plen);
 667 #endif
 668                 ip6->ip6_nxt    = IPPROTO_UDP;
 669                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 670                 ip6->ip6_src    = *laddr;
 671                 ip6->ip6_dst    = *faddr;
 672
 673                 if ((udp6->uh_sum = in6_cksum(m, IPPROTO_UDP,
 674                                 sizeof(struct ip6_hdr), plen)) == 0) {
 675                         udp6->uh_sum = 0xffff;
 676                 }
 677
 678                 flags = 0;
 679
 680                 V_udpstat.udps_opackets++;
 681                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 682                     NULL, inp);
 683                 break;
 684         case AF_INET:
 685                 error = EAFNOSUPPORT;
 686                 goto release;
 687         }
 688         goto releaseopt;
 689
 690 release:
 691         m_freem(m);
 692
 693 releaseopt:
 694         if (control) {
 695                 ip6_clearpktopts(&opt, -1);
 696                 m_freem(control);
 697         }
 698         return (error);
 699 }
 700
 701 static void
 702 udp6_abort(struct socket *so)
 703 {
 704         INIT_VNET_INET(so->so_vnet);
 705         struct inpcb *inp;
 706
 707         inp = sotoinpcb(so);
 708         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 709
 710 #ifdef INET
 711         if (inp->inp_vflag & INP_IPV4) {
 712                 struct pr_usrreqs *pru;
 713
 714                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 715                 (*pru->pru_abort)(so);
 716                 return;
 717         }
 718 #endif
 719
 720         INP_INFO_WLOCK(&V_udbinfo);
 721         INP_WLOCK(inp);
 722         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 723                 in6_pcbdisconnect(inp);
 724                 inp->in6p_laddr = in6addr_any;
 725                 soisdisconnected(so);
 726         }
 727         INP_WUNLOCK(inp);
 728         INP_INFO_WUNLOCK(&V_udbinfo);
 729 }
 730
 731 static int
 732 udp6_attach(struct socket *so, int proto, struct thread *td)
 733 {
 734         INIT_VNET_INET(so->so_vnet);
 735         struct inpcb *inp;
 736         int error;
 737
 738         inp = sotoinpcb(so);
 739         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 740
 741         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 742                 error = soreserve(so, udp_sendspace, udp_recvspace);
 743                 if (error)
 744                         return (error);
 745         }
 746         INP_INFO_WLOCK(&V_udbinfo);
 747         error = in_pcballoc(so, &V_udbinfo);
 748         if (error) {
 749                 INP_INFO_WUNLOCK(&V_udbinfo);
 750                 return (error);
 751         }
 752         inp = (struct inpcb *)so->so_pcb;
 753         INP_INFO_WUNLOCK(&V_udbinfo);
 754         inp->inp_vflag |= INP_IPV6;
 755         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 756                 inp->inp_vflag |= INP_IPV4;
 757         inp->in6p_hops = -1;    /* use kernel default */
 758         inp->in6p_cksum = -1;   /* just to be sure */
 759         /*
 760          * XXX: ugly!!
 761          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 762          * because the socket may be bound to an IPv6 wildcard address,
 763          * which may match an IPv4-mapped IPv6 address.
 764          */
 765         inp->inp_ip_ttl = V_ip_defttl;
 766         INP_WUNLOCK(inp);
 767         return (0);
 768 }
 769
 770 static int
 771 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 772 {
 773         INIT_VNET_INET(so->so_vnet);
 774         struct inpcb *inp;
 775         int error;
 776
 777         inp = sotoinpcb(so);
 778         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 779
 780         INP_INFO_WLOCK(&V_udbinfo);
 781         INP_WLOCK(inp);
 782         inp->inp_vflag &= ~INP_IPV4;
 783         inp->inp_vflag |= INP_IPV6;
 784         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 785                 struct sockaddr_in6 *sin6_p;
 786
 787                 sin6_p = (struct sockaddr_in6 *)nam;
 788
 789                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 790                         inp->inp_vflag |= INP_IPV4;
 791                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 792                         struct sockaddr_in sin;
 793
 794                         in6_sin6_2_sin(&sin, sin6_p);
 795                         inp->inp_vflag |= INP_IPV4;
 796                         inp->inp_vflag &= ~INP_IPV6;
 797                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 798                             td->td_ucred);
 799                         goto out;
 800                 }
 801         }
 802
 803         error = in6_pcbbind(inp, nam, td->td_ucred);
 804 out:
 805         INP_WUNLOCK(inp);
 806         INP_INFO_WUNLOCK(&V_udbinfo);
 807         return (error);
 808 }
 809
 810 static void
 811 udp6_close(struct socket *so)
 812 {
 813         INIT_VNET_INET(so->so_vnet);
 814         struct inpcb *inp;
 815
 816         inp = sotoinpcb(so);
 817         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
 818
 819 #ifdef INET
 820         if (inp->inp_vflag & INP_IPV4) {
 821                 struct pr_usrreqs *pru;
 822
 823                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 824                 (*pru->pru_disconnect)(so);
 825                 return;
 826         }
 827 #endif
 828         INP_INFO_WLOCK(&V_udbinfo);
 829         INP_WLOCK(inp);
 830         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 831                 in6_pcbdisconnect(inp);
 832                 inp->in6p_laddr = in6addr_any;
 833                 soisdisconnected(so);
 834         }
 835         INP_WUNLOCK(inp);
 836         INP_INFO_WUNLOCK(&V_udbinfo);
 837 }
 838
 839 static int
 840 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 841 {
 842         INIT_VNET_INET(so->so_vnet);
 843         struct inpcb *inp;
 844         int error;
 845
 846         inp = sotoinpcb(so);
 847         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
 848
 849         INP_INFO_WLOCK(&V_udbinfo);
 850         INP_WLOCK(inp);
 851         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 852                 struct sockaddr_in6 *sin6_p;
 853
 854                 sin6_p = (struct sockaddr_in6 *)nam;
 855                 if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 856                         struct sockaddr_in sin;
 857
 858                         if (inp->inp_faddr.s_addr != INADDR_ANY) {
 859                                 error = EISCONN;
 860                                 goto out;
 861                         }
 862                         in6_sin6_2_sin(&sin, sin6_p);
 863                         error = in_pcbconnect(inp, (struct sockaddr *)&sin,
 864                             td->td_ucred);
 865                         if (error == 0) {
 866                                 inp->inp_vflag |= INP_IPV4;
 867                                 inp->inp_vflag &= ~INP_IPV6;
 868                                 soisconnected(so);
 869                         }
 870                         goto out;
 871                 }
 872         }
 873         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 874                 error = EISCONN;
 875                 goto out;
 876         }
 877         error = in6_pcbconnect(inp, nam, td->td_ucred);
 878         if (error == 0) {
 879                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 880                         /* should be non mapped addr */
 881                         inp->inp_vflag &= ~INP_IPV4;
 882                         inp->inp_vflag |= INP_IPV6;
 883                 }
 884                 soisconnected(so);
 885         }
 886 out:
 887         INP_WUNLOCK(inp);
 888         INP_INFO_WUNLOCK(&V_udbinfo);
 889         return (error);
 890 }
 891
 892 static void
 893 udp6_detach(struct socket *so)
 894 {
 895         INIT_VNET_INET(so->so_vnet);
 896         struct inpcb *inp;
 897
 898         inp = sotoinpcb(so);
 899         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
 900
 901         INP_INFO_WLOCK(&V_udbinfo);
 902         INP_WLOCK(inp);
 903         in6_pcbdetach(inp);
 904         in6_pcbfree(inp);
 905         INP_INFO_WUNLOCK(&V_udbinfo);
 906 }
 907
 908 static int
 909 udp6_disconnect(struct socket *so)
 910 {
 911         INIT_VNET_INET(so->so_vnet);
 912         struct inpcb *inp;
 913         int error;
 914
 915         inp = sotoinpcb(so);
 916         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
 917
 918         INP_INFO_WLOCK(&V_udbinfo);
 919         INP_WLOCK(inp);
 920
 921 #ifdef INET
 922         if (inp->inp_vflag & INP_IPV4) {
 923                 struct pr_usrreqs *pru;
 924
 925                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 926                 error = (*pru->pru_disconnect)(so);
 927                 goto out;
 928         }
 929 #endif
 930
 931         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 932                 error = ENOTCONN;
 933                 goto out;
 934         }
 935
 936         in6_pcbdisconnect(inp);
 937         inp->in6p_laddr = in6addr_any;
 938         SOCK_LOCK(so);
 939         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
 940         SOCK_UNLOCK(so);
 941 out:
 942         INP_WUNLOCK(inp);
 943         INP_INFO_WUNLOCK(&V_udbinfo);
 944         return (0);
 945 }
 946
 947 static int
 948 udp6_send(struct socket *so, int flags, struct mbuf *m,
 949     struct sockaddr *addr, struct mbuf *control, struct thread *td)
 950 {
 951         INIT_VNET_INET(so->so_vnet);
 952         struct inpcb *inp;
 953         int error = 0;
 954
 955         inp = sotoinpcb(so);
 956         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
 957
 958         INP_INFO_WLOCK(&V_udbinfo);
 959         INP_WLOCK(inp);
 960         if (addr) {
 961                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
 962                         error = EINVAL;
 963                         goto bad;
 964                 }
 965                 if (addr->sa_family != AF_INET6) {
 966                         error = EAFNOSUPPORT;
 967                         goto bad;
 968                 }
 969         }
 970
 971 #ifdef INET
 972         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 973                 int hasv4addr;
 974                 struct sockaddr_in6 *sin6 = 0;
 975
 976                 if (addr == 0)
 977                         hasv4addr = (inp->inp_vflag & INP_IPV4);
 978                 else {
 979                         sin6 = (struct sockaddr_in6 *)addr;
 980                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
 981                             ? 1 : 0;
 982                 }
 983                 if (hasv4addr) {
 984                         struct pr_usrreqs *pru;
 985
 986                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 987                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 988                                 /*
 989                                  * When remote addr is IPv4-mapped address,
 990                                  * local addr should not be an IPv6 address;
 991                                  * since you cannot determine how to map IPv6
 992                                  * source address to IPv4.
 993                                  */
 994                                 error = EINVAL;
 995                                 goto out;
 996                         }
 997
 998                         /*
 999                          * XXXRW: We release UDP-layer locks before calling
1000                          * udp_send() in order to avoid recursion.  However,
1001                          * this does mean there is a short window where inp's
1002                          * fields are unstable.  Could this lead to a
1003                          * potential race in which the factors causing us to
1004                          * select the UDPv4 output routine are invalidated?
1005                          */
1006                         INP_WUNLOCK(inp);
1007                         INP_INFO_WUNLOCK(&V_udbinfo);
1008                         if (sin6)
1009                                 in6_sin6_2_sin_in_sock(addr);
1010                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1011                         /* addr will just be freed in sendit(). */
1012                         return ((*pru->pru_send)(so, flags, m, addr, control,
1013                             td));
1014                 }
1015         }
1016 #endif
1017 #ifdef MAC
1018         mac_inpcb_create_mbuf(inp, m);
1019 #endif
1020         error = udp6_output(inp, m, addr, control, td);
1021 out:
1022         INP_WUNLOCK(inp);
1023         INP_INFO_WUNLOCK(&V_udbinfo);
1024         return (error);
1025
1026 bad:
1027         INP_WUNLOCK(inp);
1028         INP_INFO_WUNLOCK(&V_udbinfo);
1029         m_freem(m);
1030         return (error);
1031 }
1032
1033 struct pr_usrreqs udp6_usrreqs = {
1034         .pru_abort =            udp6_abort,
1035         .pru_attach =           udp6_attach,
1036         .pru_bind =             udp6_bind,
1037         .pru_connect =          udp6_connect,
1038         .pru_control =          in6_control,
1039         .pru_detach =           udp6_detach,
1040         .pru_disconnect =       udp6_disconnect,
1041         .pru_peeraddr =         in6_mapped_peeraddr,
1042         .pru_send =             udp6_send,
1043         .pru_shutdown =         udp_shutdown,
1044         .pru_sockaddr =         in6_mapped_sockaddr,
1045         .pru_soreceive =        soreceive_dgram,
1046         .pru_sosend =           sosend_dgram,
1047         .pru_sosetlabel =       in_pcbsosetlabel,
1048         .pru_close =            udp6_close
1049 };