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 #include <sys/vimage.h>
  89
  90 #include <net/if.h>
  91 #include <net/if_types.h>
  92 #include <net/route.h>
  93
  94 #include <netinet/in.h>
  95 #include <netinet/in_pcb.h>
  96 #include <netinet/in_systm.h>
  97 #include <netinet/in_var.h>
  98 #include <netinet/ip.h>
  99 #include <netinet/ip_icmp.h>
 100 #include <netinet/ip6.h>
 101 #include <netinet/icmp_var.h>
 102 #include <netinet/icmp6.h>
 103 #include <netinet/ip_var.h>
 104 #include <netinet/udp.h>
 105 #include <netinet/udp_var.h>
 106 #include <netinet/vinet.h>
 107
 108 #include <netinet6/ip6protosw.h>
 109 #include <netinet6/ip6_var.h>
 110 #include <netinet6/in6_pcb.h>
 111 #include <netinet6/udp6_var.h>
 112 #include <netinet6/scope6_var.h>
 113 #include <netinet6/vinet6.h>
 114
 115 #ifdef IPSEC
 116 #include <netipsec/ipsec.h>
 117 #include <netipsec/ipsec6.h>
 118 #endif /* IPSEC */
 119
 120 #include <security/mac/mac_framework.h>
 121
 122 /*
 123  * UDP protocol implementation.
 124  * Per RFC 768, August, 1980.
 125  */
 126
 127 extern struct protosw   inetsw[];
 128 static void             udp6_detach(struct socket *so);
 129
 130 static void
 131 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
 132     struct sockaddr_in6 *fromsa)
 133 {
 134         INIT_VNET_INET(inp->inp_vnet);
 135         struct socket *so;
 136         struct mbuf *opts;
 137
 138         INP_LOCK_ASSERT(inp);
 139
 140 #ifdef IPSEC
 141         /* Check AH/ESP integrity. */
 142         if (ipsec6_in_reject(n, inp)) {
 143                 INIT_VNET_IPSEC(inp->inp_vnet);
 144                 m_freem(n);
 145                 V_ipsec6stat.in_polvio++;
 146                 return;
 147         }
 148 #endif /* IPSEC */
 149 #ifdef MAC
 150         if (mac_inpcb_check_deliver(inp, n) != 0) {
 151                 m_freem(n);
 152                 return;
 153         }
 154 #endif
 155         opts = NULL;
 156         if (inp->inp_flags & INP_CONTROLOPTS ||
 157             inp->inp_socket->so_options & SO_TIMESTAMP)
 158                 ip6_savecontrol(inp, n, &opts);
 159         m_adj(n, off + sizeof(struct udphdr));
 160
 161         so = inp->inp_socket;
 162         SOCKBUF_LOCK(&so->so_rcv);
 163         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
 164             opts) == 0) {
 165                 SOCKBUF_UNLOCK(&so->so_rcv);
 166                 m_freem(n);
 167                 if (opts)
 168                         m_freem(opts);
 169                 V_udpstat.udps_fullsock++;
 170         } else
 171                 sorwakeup_locked(so);
 172 }
 173
 174 int
 175 udp6_input(struct mbuf **mp, int *offp, int proto)
 176 {
 177         INIT_VNET_INET(curvnet);
 178         INIT_VNET_INET6(curvnet);
 179         struct mbuf *m = *mp;
 180         struct ip6_hdr *ip6;
 181         struct udphdr *uh;
 182         struct inpcb *inp;
 183         int off = *offp;
 184         int plen, ulen;
 185         struct sockaddr_in6 fromsa;
 186
 187         ip6 = mtod(m, struct ip6_hdr *);
 188
 189         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 190                 /* XXX send icmp6 host/port unreach? */
 191                 m_freem(m);
 192                 return (IPPROTO_DONE);
 193         }
 194
 195 #ifndef PULLDOWN_TEST
 196         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
 197         ip6 = mtod(m, struct ip6_hdr *);
 198         uh = (struct udphdr *)((caddr_t)ip6 + off);
 199 #else
 200         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 201         if (!uh)
 202                 return (IPPROTO_DONE);
 203 #endif
 204
 205         V_udpstat.udps_ipackets++;
 206
 207         /*
 208          * Destination port of 0 is illegal, based on RFC768.
 209          */
 210         if (uh->uh_dport == 0)
 211                 goto badunlocked;
 212
 213         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
 214         ulen = ntohs((u_short)uh->uh_ulen);
 215
 216         if (plen != ulen) {
 217                 V_udpstat.udps_badlen++;
 218                 goto badunlocked;
 219         }
 220
 221         /*
 222          * Checksum extended UDP header and data.
 223          */
 224         if (uh->uh_sum == 0) {
 225                 V_udpstat.udps_nosum++;
 226                 goto badunlocked;
 227         }
 228         if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
 229                 V_udpstat.udps_badsum++;
 230                 goto badunlocked;
 231         }
 232
 233         /*
 234          * Construct sockaddr format source address.
 235          */
 236         init_sin6(&fromsa, m);
 237         fromsa.sin6_port = uh->uh_sport;
 238
 239         INP_INFO_RLOCK(&V_udbinfo);
 240         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 241                 struct inpcb *last;
 242
 243                 /*
 244                  * In the event that laddr should be set to the link-local
 245                  * address (this happens in RIPng), the multicast address
 246                  * specified in the received packet will not match laddr.  To
 247                  * handle this situation, matching is relaxed if the
 248                  * receiving interface is the same as one specified in the
 249                  * socket and if the destination multicast address matches
 250                  * one of the multicast groups specified in the socket.
 251                  */
 252
 253                 /*
 254                  * KAME note: traditionally we dropped udpiphdr from mbuf
 255                  * here.  We need udphdr for IPsec processing so we do that
 256                  * later.
 257                  */
 258                 last = NULL;
 259                 LIST_FOREACH(inp, &V_udb, inp_list) {
 260                         if ((inp->inp_vflag & INP_IPV6) == 0)
 261                                 continue;
 262                         if (inp->inp_lport != uh->uh_dport)
 263                                 continue;
 264                         /*
 265                          * XXX: Do not check source port of incoming datagram
 266                          * unless inp_connect() has been called to bind the
 267                          * fport part of the 4-tuple; the source could be
 268                          * trying to talk to us with an ephemeral port.
 269                          */
 270                         if (inp->inp_fport != 0 &&
 271                             inp->inp_fport != uh->uh_sport)
 272                                 continue;
 273                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 274                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
 275                                                         &ip6->ip6_dst))
 276                                         continue;
 277                         }
 278                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 279                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
 280                                                         &ip6->ip6_src) ||
 281                                     inp->inp_fport != uh->uh_sport)
 282                                         continue;
 283                         }
 284
 285                         if (last != NULL) {
 286                                 struct mbuf *n;
 287
 288                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
 289                                         INP_RLOCK(last);
 290                                         udp6_append(last, n, off, &fromsa);
 291                                         INP_RUNLOCK(last);
 292                                 }
 293                         }
 294                         last = inp;
 295                         /*
 296                          * Don't look for additional matches if this one does
 297                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 298                          * socket options set.  This heuristic avoids
 299                          * searching through all pcbs in the common case of a
 300                          * non-shared port.  It assumes that an application
 301                          * will never clear these options after setting them.
 302                          */
 303                         if ((last->inp_socket->so_options &
 304                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 305                                 break;
 306                 }
 307
 308                 if (last == NULL) {
 309                         /*
 310                          * No matching pcb found; discard datagram.  (No need
 311                          * to send an ICMP Port Unreachable for a broadcast
 312                          * or multicast datgram.)
 313                          */
 314                         V_udpstat.udps_noport++;
 315                         V_udpstat.udps_noportmcast++;
 316                         goto badheadlocked;
 317                 }
 318                 INP_RLOCK(last);
 319                 INP_INFO_RUNLOCK(&V_udbinfo);
 320                 udp6_append(last, m, off, &fromsa);
 321                 INP_RUNLOCK(last);
 322                 return (IPPROTO_DONE);
 323         }
 324         /*
 325          * Locate pcb for datagram.
 326          */
 327         inp = in6_pcblookup_hash(&V_udbinfo, &ip6->ip6_src, uh->uh_sport,
 328             &ip6->ip6_dst, uh->uh_dport, 1, m->m_pkthdr.rcvif);
 329         if (inp == NULL) {
 330                 if (udp_log_in_vain) {
 331                         char ip6bufs[INET6_ADDRSTRLEN];
 332                         char ip6bufd[INET6_ADDRSTRLEN];
 333
 334                         log(LOG_INFO,
 335                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
 336                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 337                             ntohs(uh->uh_dport),
 338                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
 339                             ntohs(uh->uh_sport));
 340                 }
 341                 V_udpstat.udps_noport++;
 342                 if (m->m_flags & M_MCAST) {
 343                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
 344                         V_udpstat.udps_noportmcast++;
 345                         goto badheadlocked;
 346                 }
 347                 INP_INFO_RUNLOCK(&V_udbinfo);
 348                 if (V_udp_blackhole)
 349                         goto badunlocked;
 350                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
 351                         goto badunlocked;
 352                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
 353                 return (IPPROTO_DONE);
 354         }
 355         INP_RLOCK(inp);
 356         INP_INFO_RUNLOCK(&V_udbinfo);
 357         udp6_append(inp, m, off, &fromsa);
 358         INP_RUNLOCK(inp);
 359         return (IPPROTO_DONE);
 360
 361 badheadlocked:
 362         INP_INFO_RUNLOCK(&V_udbinfo);
 363 badunlocked:
 364         if (m)
 365                 m_freem(m);
 366         return (IPPROTO_DONE);
 367 }
 368
 369 void
 370 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 371 {
 372         INIT_VNET_INET(curvnet);
 373         struct udphdr uh;
 374         struct ip6_hdr *ip6;
 375         struct mbuf *m;
 376         int off = 0;
 377         struct ip6ctlparam *ip6cp = NULL;
 378         const struct sockaddr_in6 *sa6_src = NULL;
 379         void *cmdarg;
 380         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 381         struct udp_portonly {
 382                 u_int16_t uh_sport;
 383                 u_int16_t uh_dport;
 384         } *uhp;
 385
 386         if (sa->sa_family != AF_INET6 ||
 387             sa->sa_len != sizeof(struct sockaddr_in6))
 388                 return;
 389
 390         if ((unsigned)cmd >= PRC_NCMDS)
 391                 return;
 392         if (PRC_IS_REDIRECT(cmd))
 393                 notify = in6_rtchange, d = NULL;
 394         else if (cmd == PRC_HOSTDEAD)
 395                 d = NULL;
 396         else if (inet6ctlerrmap[cmd] == 0)
 397                 return;
 398
 399         /* if the parameter is from icmp6, decode it. */
 400         if (d != NULL) {
 401                 ip6cp = (struct ip6ctlparam *)d;
 402                 m = ip6cp->ip6c_m;
 403                 ip6 = ip6cp->ip6c_ip6;
 404                 off = ip6cp->ip6c_off;
 405                 cmdarg = ip6cp->ip6c_cmdarg;
 406                 sa6_src = ip6cp->ip6c_src;
 407         } else {
 408                 m = NULL;
 409                 ip6 = NULL;
 410                 cmdarg = NULL;
 411                 sa6_src = &sa6_any;
 412         }
 413
 414         if (ip6) {
 415                 /*
 416                  * XXX: We assume that when IPV6 is non NULL,
 417                  * M and OFF are valid.
 418                  */
 419
 420                 /* Check if we can safely examine src and dst ports. */
 421                 if (m->m_pkthdr.len < off + sizeof(*uhp))
 422                         return;
 423
 424                 bzero(&uh, sizeof(uh));
 425                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
 426
 427                 (void) in6_pcbnotify(&V_udbinfo, sa, uh.uh_dport,
 428                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
 429                     cmdarg, notify);
 430         } else
 431                 (void) in6_pcbnotify(&V_udbinfo, sa, 0,
 432                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
 433 }
 434
 435 static int
 436 udp6_getcred(SYSCTL_HANDLER_ARGS)
 437 {
 438         INIT_VNET_INET(curvnet);
 439         INIT_VNET_INET6(curvnet);
 440         struct xucred xuc;
 441         struct sockaddr_in6 addrs[2];
 442         struct inpcb *inp;
 443         int error;
 444
 445         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 446         if (error)
 447                 return (error);
 448
 449         if (req->newlen != sizeof(addrs))
 450                 return (EINVAL);
 451         if (req->oldlen != sizeof(struct xucred))
 452                 return (EINVAL);
 453         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 454         if (error)
 455                 return (error);
 456         if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
 457             (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
 458                 return (error);
 459         }
 460         INP_INFO_RLOCK(&V_udbinfo);
 461         inp = in6_pcblookup_hash(&V_udbinfo, &addrs[1].sin6_addr,
 462             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port, 1,
 463             NULL);
 464         if (inp != NULL) {
 465                 INP_RLOCK(inp);
 466                 INP_INFO_RUNLOCK(&V_udbinfo);
 467                 if (inp->inp_socket == NULL)
 468                         error = ENOENT;
 469                 if (error == 0)
 470                         error = cr_canseesocket(req->td->td_ucred,
 471                             inp->inp_socket);
 472                 if (error == 0)
 473                         cru2x(inp->inp_cred, &xuc);
 474                 INP_RUNLOCK(inp);
 475         } else {
 476                 INP_INFO_RUNLOCK(&V_udbinfo);
 477                 error = ENOENT;
 478         }
 479         if (error == 0)
 480                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 481         return (error);
 482 }
 483
 484 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
 485     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
 486
 487 static int
 488 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
 489     struct mbuf *control, struct thread *td)
 490 {
 491         INIT_VNET_INET(curvnet);
 492         INIT_VNET_INET6(curvnet);
 493         u_int32_t ulen = m->m_pkthdr.len;
 494         u_int32_t plen = sizeof(struct udphdr) + ulen;
 495         struct ip6_hdr *ip6;
 496         struct udphdr *udp6;
 497         struct in6_addr *laddr, *faddr;
 498         struct sockaddr_in6 *sin6 = NULL;
 499         struct ifnet *oifp = NULL;
 500         int scope_ambiguous = 0;
 501         u_short fport;
 502         int error = 0;
 503         struct ip6_pktopts *optp, opt;
 504         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 505         int flags;
 506         struct sockaddr_in6 tmp;
 507
 508         INP_WLOCK_ASSERT(inp);
 509
 510         if (addr6) {
 511                 /* addr6 has been validated in udp6_send(). */
 512                 sin6 = (struct sockaddr_in6 *)addr6;
 513
 514                 /* protect *sin6 from overwrites */
 515                 tmp = *sin6;
 516                 sin6 = &tmp;
 517
 518                 /*
 519                  * Application should provide a proper zone ID or the use of
 520                  * default zone IDs should be enabled.  Unfortunately, some
 521                  * applications do not behave as it should, so we need a
 522                  * workaround.  Even if an appropriate ID is not determined,
 523                  * we'll see if we can determine the outgoing interface.  If we
 524                  * can, determine the zone ID based on the interface below.
 525                  */
 526                 if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
 527                         scope_ambiguous = 1;
 528                 if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
 529                         return (error);
 530         }
 531
 532         if (control) {
 533                 if ((error = ip6_setpktopts(control, &opt,
 534                     inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
 535                         goto release;
 536                 optp = &opt;
 537         } else
 538                 optp = inp->in6p_outputopts;
 539
 540         if (sin6) {
 541                 faddr = &sin6->sin6_addr;
 542
 543                 /*
 544                  * IPv4 version of udp_output calls in_pcbconnect in this case,
 545                  * which needs splnet and affects performance.
 546                  * Since we saw no essential reason for calling in_pcbconnect,
 547                  * we get rid of such kind of logic, and call in6_selectsrc
 548                  * and in6_pcbsetport in order to fill in the local address
 549                  * and the local port.
 550                  */
 551                 if (sin6->sin6_port == 0) {
 552                         error = EADDRNOTAVAIL;
 553                         goto release;
 554                 }
 555
 556                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 557                         /* how about ::ffff:0.0.0.0 case? */
 558                         error = EISCONN;
 559                         goto release;
 560                 }
 561
 562                 fport = sin6->sin6_port; /* allow 0 port */
 563
 564                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 565                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 566                                 /*
 567                                  * I believe we should explicitly discard the
 568                                  * packet when mapped addresses are disabled,
 569                                  * rather than send the packet as an IPv6 one.
 570                                  * If we chose the latter approach, the packet
 571                                  * might be sent out on the wire based on the
 572                                  * default route, the situation which we'd
 573                                  * probably want to avoid.
 574                                  * (20010421 jinmei@kame.net)
 575                                  */
 576                                 error = EINVAL;
 577                                 goto release;
 578                         }
 579                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 580                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 581                                 /*
 582                                  * when remote addr is an IPv4-mapped address,
 583                                  * local addr should not be an IPv6 address,
 584                                  * since you cannot determine how to map IPv6
 585                                  * source address to IPv4.
 586                                  */
 587                                 error = EINVAL;
 588                                 goto release;
 589                         }
 590
 591                         af = AF_INET;
 592                 }
 593
 594                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 595                         laddr = in6_selectsrc(sin6, optp, inp, NULL,
 596                             td->td_ucred, &oifp, &error);
 597                         if (oifp && scope_ambiguous &&
 598                             (error = in6_setscope(&sin6->sin6_addr,
 599                             oifp, NULL))) {
 600                                 goto release;
 601                         }
 602                 } else
 603                         laddr = &inp->in6p_laddr;       /* XXX */
 604                 if (laddr == NULL) {
 605                         if (error == 0)
 606                                 error = EADDRNOTAVAIL;
 607                         goto release;
 608                 }
 609                 if (inp->inp_lport == 0 &&
 610                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0)
 611                         goto release;
 612         } else {
 613                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 614                         error = ENOTCONN;
 615                         goto release;
 616                 }
 617                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 618                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 619                                 /*
 620                                  * XXX: this case would happen when the
 621                                  * application sets the V6ONLY flag after
 622                                  * connecting the foreign address.
 623                                  * Such applications should be fixed,
 624                                  * so we bark here.
 625                                  */
 626                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 627                                     "option was set for a connected socket\n");
 628                                 error = EINVAL;
 629                                 goto release;
 630                         } else
 631                                 af = AF_INET;
 632                 }
 633                 laddr = &inp->in6p_laddr;
 634                 faddr = &inp->in6p_faddr;
 635                 fport = inp->inp_fport;
 636         }
 637
 638         if (af == AF_INET)
 639                 hlen = sizeof(struct ip);
 640
 641         /*
 642          * Calculate data length and get a mbuf
 643          * for UDP and IP6 headers.
 644          */
 645         M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
 646         if (m == 0) {
 647                 error = ENOBUFS;
 648                 goto release;
 649         }
 650
 651         /*
 652          * Stuff checksum and output datagram.
 653          */
 654         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 655         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
 656         udp6->uh_dport = fport;
 657         if (plen <= 0xffff)
 658                 udp6->uh_ulen = htons((u_short)plen);
 659         else
 660                 udp6->uh_ulen = 0;
 661         udp6->uh_sum = 0;
 662
 663         switch (af) {
 664         case AF_INET6:
 665                 ip6 = mtod(m, struct ip6_hdr *);
 666                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
 667                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 668                 ip6->ip6_vfc    |= IPV6_VERSION;
 669 #if 0                           /* ip6_plen will be filled in ip6_output. */
 670                 ip6->ip6_plen   = htons((u_short)plen);
 671 #endif
 672                 ip6->ip6_nxt    = IPPROTO_UDP;
 673                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 674                 ip6->ip6_src    = *laddr;
 675                 ip6->ip6_dst    = *faddr;
 676
 677                 if ((udp6->uh_sum = in6_cksum(m, IPPROTO_UDP,
 678                                 sizeof(struct ip6_hdr), plen)) == 0) {
 679                         udp6->uh_sum = 0xffff;
 680                 }
 681
 682                 flags = 0;
 683
 684                 V_udpstat.udps_opackets++;
 685                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 686                     NULL, inp);
 687                 break;
 688         case AF_INET:
 689                 error = EAFNOSUPPORT;
 690                 goto release;
 691         }
 692         goto releaseopt;
 693
 694 release:
 695         m_freem(m);
 696
 697 releaseopt:
 698         if (control) {
 699                 ip6_clearpktopts(&opt, -1);
 700                 m_freem(control);
 701         }
 702         return (error);
 703 }
 704
 705 static void
 706 udp6_abort(struct socket *so)
 707 {
 708         INIT_VNET_INET(so->so_vnet);
 709         struct inpcb *inp;
 710
 711         inp = sotoinpcb(so);
 712         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 713
 714 #ifdef INET
 715         if (inp->inp_vflag & INP_IPV4) {
 716                 struct pr_usrreqs *pru;
 717
 718                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 719                 (*pru->pru_abort)(so);
 720                 return;
 721         }
 722 #endif
 723
 724         INP_INFO_WLOCK(&V_udbinfo);
 725         INP_WLOCK(inp);
 726         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 727                 in6_pcbdisconnect(inp);
 728                 inp->in6p_laddr = in6addr_any;
 729                 soisdisconnected(so);
 730         }
 731         INP_WUNLOCK(inp);
 732         INP_INFO_WUNLOCK(&V_udbinfo);
 733 }
 734
 735 static int
 736 udp6_attach(struct socket *so, int proto, struct thread *td)
 737 {
 738         INIT_VNET_INET(so->so_vnet);
 739         struct inpcb *inp;
 740         int error;
 741
 742         inp = sotoinpcb(so);
 743         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 744
 745         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 746                 error = soreserve(so, udp_sendspace, udp_recvspace);
 747                 if (error)
 748                         return (error);
 749         }
 750         INP_INFO_WLOCK(&V_udbinfo);
 751         error = in_pcballoc(so, &V_udbinfo);
 752         if (error) {
 753                 INP_INFO_WUNLOCK(&V_udbinfo);
 754                 return (error);
 755         }
 756         inp = (struct inpcb *)so->so_pcb;
 757         INP_INFO_WUNLOCK(&V_udbinfo);
 758         inp->inp_vflag |= INP_IPV6;
 759         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 760                 inp->inp_vflag |= INP_IPV4;
 761         inp->in6p_hops = -1;    /* use kernel default */
 762         inp->in6p_cksum = -1;   /* just to be sure */
 763         /*
 764          * XXX: ugly!!
 765          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 766          * because the socket may be bound to an IPv6 wildcard address,
 767          * which may match an IPv4-mapped IPv6 address.
 768          */
 769         inp->inp_ip_ttl = V_ip_defttl;
 770         INP_WUNLOCK(inp);
 771         return (0);
 772 }
 773
 774 static int
 775 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 776 {
 777         INIT_VNET_INET(so->so_vnet);
 778         struct inpcb *inp;
 779         int error;
 780
 781         inp = sotoinpcb(so);
 782         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 783
 784         INP_INFO_WLOCK(&V_udbinfo);
 785         INP_WLOCK(inp);
 786         inp->inp_vflag &= ~INP_IPV4;
 787         inp->inp_vflag |= INP_IPV6;
 788         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 789                 struct sockaddr_in6 *sin6_p;
 790
 791                 sin6_p = (struct sockaddr_in6 *)nam;
 792
 793                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 794                         inp->inp_vflag |= INP_IPV4;
 795                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 796                         struct sockaddr_in sin;
 797
 798                         in6_sin6_2_sin(&sin, sin6_p);
 799                         inp->inp_vflag |= INP_IPV4;
 800                         inp->inp_vflag &= ~INP_IPV6;
 801                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 802                             td->td_ucred);
 803                         goto out;
 804                 }
 805         }
 806
 807         error = in6_pcbbind(inp, nam, td->td_ucred);
 808 out:
 809         INP_WUNLOCK(inp);
 810         INP_INFO_WUNLOCK(&V_udbinfo);
 811         return (error);
 812 }
 813
 814 static void
 815 udp6_close(struct socket *so)
 816 {
 817         INIT_VNET_INET(so->so_vnet);
 818         struct inpcb *inp;
 819
 820         inp = sotoinpcb(so);
 821         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
 822
 823 #ifdef INET
 824         if (inp->inp_vflag & INP_IPV4) {
 825                 struct pr_usrreqs *pru;
 826
 827                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 828                 (*pru->pru_disconnect)(so);
 829                 return;
 830         }
 831 #endif
 832         INP_INFO_WLOCK(&V_udbinfo);
 833         INP_WLOCK(inp);
 834         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 835                 in6_pcbdisconnect(inp);
 836                 inp->in6p_laddr = in6addr_any;
 837                 soisdisconnected(so);
 838         }
 839         INP_WUNLOCK(inp);
 840         INP_INFO_WUNLOCK(&V_udbinfo);
 841 }
 842
 843 static int
 844 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 845 {
 846         INIT_VNET_INET(so->so_vnet);
 847         struct inpcb *inp;
 848         int error;
 849
 850         inp = sotoinpcb(so);
 851         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
 852
 853         INP_INFO_WLOCK(&V_udbinfo);
 854         INP_WLOCK(inp);
 855         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 856                 struct sockaddr_in6 *sin6_p;
 857
 858                 sin6_p = (struct sockaddr_in6 *)nam;
 859                 if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 860                         struct sockaddr_in sin;
 861
 862                         if (inp->inp_faddr.s_addr != INADDR_ANY) {
 863                                 error = EISCONN;
 864                                 goto out;
 865                         }
 866                         in6_sin6_2_sin(&sin, sin6_p);
 867                         if (td && jailed(td->td_ucred))
 868                                 if (prison_remote_ip4(td->td_ucred,
 869                                     &sin.sin_addr) != 0) {
 870                                         error = EAFNOSUPPORT;
 871                                         goto out;
 872                                 }
 873                         error = in_pcbconnect(inp, (struct sockaddr *)&sin,
 874                             td->td_ucred);
 875                         if (error == 0) {
 876                                 inp->inp_vflag |= INP_IPV4;
 877                                 inp->inp_vflag &= ~INP_IPV6;
 878                                 soisconnected(so);
 879                         }
 880                         goto out;
 881                 }
 882         }
 883         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 884                 error = EISCONN;
 885                 goto out;
 886         }
 887         if (td && jailed(td->td_ucred)) {
 888                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
 889                 if (prison_remote_ip6(td->td_ucred, &sin6->sin6_addr) != 0) {
 890                         error = EAFNOSUPPORT;
 891                         goto out;
 892                 }
 893         }
 894         error = in6_pcbconnect(inp, nam, td->td_ucred);
 895         if (error == 0) {
 896                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 897                         /* should be non mapped addr */
 898                         inp->inp_vflag &= ~INP_IPV4;
 899                         inp->inp_vflag |= INP_IPV6;
 900                 }
 901                 soisconnected(so);
 902         }
 903 out:
 904         INP_WUNLOCK(inp);
 905         INP_INFO_WUNLOCK(&V_udbinfo);
 906         return (error);
 907 }
 908
 909 static void
 910 udp6_detach(struct socket *so)
 911 {
 912         INIT_VNET_INET(so->so_vnet);
 913         struct inpcb *inp;
 914
 915         inp = sotoinpcb(so);
 916         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
 917
 918         INP_INFO_WLOCK(&V_udbinfo);
 919         INP_WLOCK(inp);
 920         in_pcbdetach(inp);
 921         in_pcbfree(inp);
 922         INP_INFO_WUNLOCK(&V_udbinfo);
 923 }
 924
 925 static int
 926 udp6_disconnect(struct socket *so)
 927 {
 928         INIT_VNET_INET(so->so_vnet);
 929         struct inpcb *inp;
 930         int error;
 931
 932         inp = sotoinpcb(so);
 933         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
 934
 935         INP_INFO_WLOCK(&V_udbinfo);
 936         INP_WLOCK(inp);
 937
 938 #ifdef INET
 939         if (inp->inp_vflag & INP_IPV4) {
 940                 struct pr_usrreqs *pru;
 941
 942                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 943                 error = (*pru->pru_disconnect)(so);
 944                 goto out;
 945         }
 946 #endif
 947
 948         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 949                 error = ENOTCONN;
 950                 goto out;
 951         }
 952
 953         in6_pcbdisconnect(inp);
 954         inp->in6p_laddr = in6addr_any;
 955         SOCK_LOCK(so);
 956         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
 957         SOCK_UNLOCK(so);
 958 out:
 959         INP_WUNLOCK(inp);
 960         INP_INFO_WUNLOCK(&V_udbinfo);
 961         return (0);
 962 }
 963
 964 static int
 965 udp6_send(struct socket *so, int flags, struct mbuf *m,
 966     struct sockaddr *addr, struct mbuf *control, struct thread *td)
 967 {
 968         INIT_VNET_INET(so->so_vnet);
 969         struct inpcb *inp;
 970         int error = 0;
 971
 972         inp = sotoinpcb(so);
 973         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
 974
 975         INP_INFO_WLOCK(&V_udbinfo);
 976         INP_WLOCK(inp);
 977         if (addr) {
 978                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
 979                         error = EINVAL;
 980                         goto bad;
 981                 }
 982                 if (addr->sa_family != AF_INET6) {
 983                         error = EAFNOSUPPORT;
 984                         goto bad;
 985                 }
 986         }
 987
 988 #ifdef INET
 989         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 990                 int hasv4addr;
 991                 struct sockaddr_in6 *sin6 = 0;
 992
 993                 if (addr == 0)
 994                         hasv4addr = (inp->inp_vflag & INP_IPV4);
 995                 else {
 996                         sin6 = (struct sockaddr_in6 *)addr;
 997                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
 998                             ? 1 : 0;
 999                 }
1000                 if (hasv4addr) {
1001                         struct pr_usrreqs *pru;
1002
1003                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
1004                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
1005                                 /*
1006                                  * When remote addr is IPv4-mapped address,
1007                                  * local addr should not be an IPv6 address;
1008                                  * since you cannot determine how to map IPv6
1009                                  * source address to IPv4.
1010                                  */
1011                                 error = EINVAL;
1012                                 goto out;
1013                         }
1014
1015                         /*
1016                          * XXXRW: We release UDP-layer locks before calling
1017                          * udp_send() in order to avoid recursion.  However,
1018                          * this does mean there is a short window where inp's
1019                          * fields are unstable.  Could this lead to a
1020                          * potential race in which the factors causing us to
1021                          * select the UDPv4 output routine are invalidated?
1022                          */
1023                         INP_WUNLOCK(inp);
1024                         INP_INFO_WUNLOCK(&V_udbinfo);
1025                         if (sin6)
1026                                 in6_sin6_2_sin_in_sock(addr);
1027                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1028                         /* addr will just be freed in sendit(). */
1029                         return ((*pru->pru_send)(so, flags, m, addr, control,
1030                             td));
1031                 }
1032         }
1033 #endif
1034 #ifdef MAC
1035         mac_inpcb_create_mbuf(inp, m);
1036 #endif
1037         error = udp6_output(inp, m, addr, control, td);
1038 out:
1039         INP_WUNLOCK(inp);
1040         INP_INFO_WUNLOCK(&V_udbinfo);
1041         return (error);
1042
1043 bad:
1044         INP_WUNLOCK(inp);
1045         INP_INFO_WUNLOCK(&V_udbinfo);
1046         m_freem(m);
1047         return (error);
1048 }
1049
1050 struct pr_usrreqs udp6_usrreqs = {
1051         .pru_abort =            udp6_abort,
1052         .pru_attach =           udp6_attach,
1053         .pru_bind =             udp6_bind,
1054         .pru_connect =          udp6_connect,
1055         .pru_control =          in6_control,
1056         .pru_detach =           udp6_detach,
1057         .pru_disconnect =       udp6_disconnect,
1058         .pru_peeraddr =         in6_mapped_peeraddr,
1059         .pru_send =             udp6_send,
1060         .pru_shutdown =         udp_shutdown,
1061         .pru_sockaddr =         in6_mapped_sockaddr,
1062         .pru_soreceive =        soreceive_dgram,
1063         .pru_sosend =           sosend_dgram,
1064         .pru_sosetlabel =       in_pcbsosetlabel,
1065         .pru_close =            udp6_close
1066 };