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
  72 #include <sys/param.h>
  73 #include <sys/jail.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
  88 #include <net/if.h>
  89 #include <net/if_types.h>
  90 #include <net/route.h>
  91
  92 #include <netinet/in.h>
  93 #include <netinet/in_pcb.h>
  94 #include <netinet/in_systm.h>
  95 #include <netinet/in_var.h>
  96 #include <netinet/ip.h>
  97 #include <netinet/ip_icmp.h>
  98 #include <netinet/ip6.h>
  99 #include <netinet/icmp_var.h>
 100 #include <netinet/icmp6.h>
 101 #include <netinet/ip_var.h>
 102 #include <netinet/udp.h>
 103 #include <netinet/udp_var.h>
 104
 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                 V_ipsec6stat.in_polvio++;
 140                 return;
 141         }
 142 #endif /* IPSEC */
 143 #ifdef MAC
 144         if (mac_inpcb_check_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_INC(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 ifnet *ifp;
 173         struct ip6_hdr *ip6;
 174         struct udphdr *uh;
 175         struct inpcb *inp;
 176         struct udpcb *up;
 177         int off = *offp;
 178         int plen, ulen;
 179         struct sockaddr_in6 fromsa;
 180
 181         ifp = m->m_pkthdr.rcvif;
 182         ip6 = mtod(m, struct ip6_hdr *);
 183
 184         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 185                 /* XXX send icmp6 host/port unreach? */
 186                 m_freem(m);
 187                 return (IPPROTO_DONE);
 188         }
 189
 190 #ifndef PULLDOWN_TEST
 191         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
 192         ip6 = mtod(m, struct ip6_hdr *);
 193         uh = (struct udphdr *)((caddr_t)ip6 + off);
 194 #else
 195         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 196         if (!uh)
 197                 return (IPPROTO_DONE);
 198 #endif
 199
 200         UDPSTAT_INC(udps_ipackets);
 201
 202         /*
 203          * Destination port of 0 is illegal, based on RFC768.
 204          */
 205         if (uh->uh_dport == 0)
 206                 goto badunlocked;
 207
 208         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
 209         ulen = ntohs((u_short)uh->uh_ulen);
 210
 211         if (plen != ulen) {
 212                 UDPSTAT_INC(udps_badlen);
 213                 goto badunlocked;
 214         }
 215
 216         /*
 217          * Checksum extended UDP header and data.
 218          */
 219         if (uh->uh_sum == 0) {
 220                 UDPSTAT_INC(udps_nosum);
 221                 goto badunlocked;
 222         }
 223         if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
 224                 UDPSTAT_INC(udps_badsum);
 225                 goto badunlocked;
 226         }
 227
 228         /*
 229          * Construct sockaddr format source address.
 230          */
 231         init_sin6(&fromsa, m);
 232         fromsa.sin6_port = uh->uh_sport;
 233
 234         INP_INFO_RLOCK(&V_udbinfo);
 235         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 236                 struct inpcb *last;
 237                 struct ip6_moptions *imo;
 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->inp_lport != uh->uh_dport)
 259                                 continue;
 260                         if (inp->inp_fport != 0 &&
 261                             inp->inp_fport != uh->uh_sport)
 262                                 continue;
 263                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 264                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
 265                                                         &ip6->ip6_dst))
 266                                         continue;
 267                         }
 268                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 269                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
 270                                                         &ip6->ip6_src) ||
 271                                     inp->inp_fport != uh->uh_sport)
 272                                         continue;
 273                         }
 274
 275                         /*
 276                          * Handle socket delivery policy for any-source
 277                          * and source-specific multicast. [RFC3678]
 278                          */
 279                         imo = inp->in6p_moptions;
 280                         if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 281                                 struct sockaddr_in6      mcaddr;
 282                                 int                      blocked;
 283
 284                                 INP_RLOCK(inp);
 285
 286                                 bzero(&mcaddr, sizeof(struct sockaddr_in6));
 287                                 mcaddr.sin6_len = sizeof(struct sockaddr_in6);
 288                                 mcaddr.sin6_family = AF_INET6;
 289                                 mcaddr.sin6_addr = ip6->ip6_dst;
 290
 291                                 blocked = im6o_mc_filter(imo, ifp,
 292                                         (struct sockaddr *)&mcaddr,
 293                                         (struct sockaddr *)&fromsa);
 294                                 if (blocked != MCAST_PASS) {
 295                                         if (blocked == MCAST_NOTGMEMBER)
 296                                                 IP6STAT_INC(ip6s_notmember);
 297                                         if (blocked == MCAST_NOTSMEMBER ||
 298                                             blocked == MCAST_MUTED)
 299                                                 UDPSTAT_INC(udps_filtermcast);
 300                                         INP_RUNLOCK(inp); /* XXX */
 301                                         continue;
 302                                 }
 303
 304                                 INP_RUNLOCK(inp);
 305                         }
 306                         if (last != NULL) {
 307                                 struct mbuf *n;
 308
 309                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
 310                                         INP_RLOCK(last);
 311                                         up = intoudpcb(last);
 312                                         if (up->u_tun_func == NULL) {
 313                                                 udp6_append(last, n, off, &fromsa);
 314                                         } else {
 315                                                 /*
 316                                                  * Engage the tunneling
 317                                                  * protocol we will have to
 318                                                  * leave the info_lock up,
 319                                                  * since we are hunting
 320                                                  * through multiple UDP's.
 321                                                  *
 322                                                  */
 323                                                 (*up->u_tun_func)(n, off, last);
 324                                         }
 325                                         INP_RUNLOCK(last);
 326                                 }
 327                         }
 328                         last = inp;
 329                         /*
 330                          * Don't look for additional matches if this one does
 331                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 332                          * socket options set.  This heuristic avoids
 333                          * searching through all pcbs in the common case of a
 334                          * non-shared port.  It assumes that an application
 335                          * will never clear these options after setting them.
 336                          */
 337                         if ((last->inp_socket->so_options &
 338                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 339                                 break;
 340                 }
 341
 342                 if (last == NULL) {
 343                         /*
 344                          * No matching pcb found; discard datagram.  (No need
 345                          * to send an ICMP Port Unreachable for a broadcast
 346                          * or multicast datgram.)
 347                          */
 348                         UDPSTAT_INC(udps_noport);
 349                         UDPSTAT_INC(udps_noportmcast);
 350                         goto badheadlocked;
 351                 }
 352                 INP_RLOCK(last);
 353                 INP_INFO_RUNLOCK(&V_udbinfo);
 354                 up = intoudpcb(last);
 355                 if (up->u_tun_func == NULL) {
 356                         udp6_append(last, m, off, &fromsa);
 357                 } else {
 358                         /*
 359                          * Engage the tunneling protocol.
 360                          */
 361                         (*up->u_tun_func)(m, off, last);
 362                 }
 363                 INP_RUNLOCK(last);
 364                 return (IPPROTO_DONE);
 365         }
 366         /*
 367          * Locate pcb for datagram.
 368          */
 369         inp = in6_pcblookup_hash(&V_udbinfo, &ip6->ip6_src, uh->uh_sport,
 370             &ip6->ip6_dst, uh->uh_dport, 1, m->m_pkthdr.rcvif);
 371         if (inp == NULL) {
 372                 if (udp_log_in_vain) {
 373                         char ip6bufs[INET6_ADDRSTRLEN];
 374                         char ip6bufd[INET6_ADDRSTRLEN];
 375
 376                         log(LOG_INFO,
 377                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
 378                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 379                             ntohs(uh->uh_dport),
 380                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
 381                             ntohs(uh->uh_sport));
 382                 }
 383                 UDPSTAT_INC(udps_noport);
 384                 if (m->m_flags & M_MCAST) {
 385                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
 386                         UDPSTAT_INC(udps_noportmcast);
 387                         goto badheadlocked;
 388                 }
 389                 INP_INFO_RUNLOCK(&V_udbinfo);
 390                 if (V_udp_blackhole)
 391                         goto badunlocked;
 392                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
 393                         goto badunlocked;
 394                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
 395                 return (IPPROTO_DONE);
 396         }
 397         INP_RLOCK(inp);
 398         INP_INFO_RUNLOCK(&V_udbinfo);
 399         up = intoudpcb(inp);
 400         if (up->u_tun_func == NULL) {
 401                 udp6_append(inp, m, off, &fromsa);
 402         } else {
 403                 /*
 404                  * Engage the tunneling protocol.
 405                  */
 406
 407                 (*up->u_tun_func)(m, off, inp);
 408         }
 409         INP_RUNLOCK(inp);
 410         return (IPPROTO_DONE);
 411
 412 badheadlocked:
 413         INP_INFO_RUNLOCK(&V_udbinfo);
 414 badunlocked:
 415         if (m)
 416                 m_freem(m);
 417         return (IPPROTO_DONE);
 418 }
 419
 420 void
 421 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 422 {
 423         struct udphdr uh;
 424         struct ip6_hdr *ip6;
 425         struct mbuf *m;
 426         int off = 0;
 427         struct ip6ctlparam *ip6cp = NULL;
 428         const struct sockaddr_in6 *sa6_src = NULL;
 429         void *cmdarg;
 430         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 431         struct udp_portonly {
 432                 u_int16_t uh_sport;
 433                 u_int16_t uh_dport;
 434         } *uhp;
 435
 436         if (sa->sa_family != AF_INET6 ||
 437             sa->sa_len != sizeof(struct sockaddr_in6))
 438                 return;
 439
 440         if ((unsigned)cmd >= PRC_NCMDS)
 441                 return;
 442         if (PRC_IS_REDIRECT(cmd))
 443                 notify = in6_rtchange, d = NULL;
 444         else if (cmd == PRC_HOSTDEAD)
 445                 d = NULL;
 446         else if (inet6ctlerrmap[cmd] == 0)
 447                 return;
 448
 449         /* if the parameter is from icmp6, decode it. */
 450         if (d != NULL) {
 451                 ip6cp = (struct ip6ctlparam *)d;
 452                 m = ip6cp->ip6c_m;
 453                 ip6 = ip6cp->ip6c_ip6;
 454                 off = ip6cp->ip6c_off;
 455                 cmdarg = ip6cp->ip6c_cmdarg;
 456                 sa6_src = ip6cp->ip6c_src;
 457         } else {
 458                 m = NULL;
 459                 ip6 = NULL;
 460                 cmdarg = NULL;
 461                 sa6_src = &sa6_any;
 462         }
 463
 464         if (ip6) {
 465                 /*
 466                  * XXX: We assume that when IPV6 is non NULL,
 467                  * M and OFF are valid.
 468                  */
 469
 470                 /* Check if we can safely examine src and dst ports. */
 471                 if (m->m_pkthdr.len < off + sizeof(*uhp))
 472                         return;
 473
 474                 bzero(&uh, sizeof(uh));
 475                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
 476
 477                 (void) in6_pcbnotify(&V_udbinfo, sa, uh.uh_dport,
 478                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
 479                     cmdarg, notify);
 480         } else
 481                 (void) in6_pcbnotify(&V_udbinfo, sa, 0,
 482                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
 483 }
 484
 485 static int
 486 udp6_getcred(SYSCTL_HANDLER_ARGS)
 487 {
 488         struct xucred xuc;
 489         struct sockaddr_in6 addrs[2];
 490         struct inpcb *inp;
 491         int error;
 492
 493         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 494         if (error)
 495                 return (error);
 496
 497         if (req->newlen != sizeof(addrs))
 498                 return (EINVAL);
 499         if (req->oldlen != sizeof(struct xucred))
 500                 return (EINVAL);
 501         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 502         if (error)
 503                 return (error);
 504         if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
 505             (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
 506                 return (error);
 507         }
 508         INP_INFO_RLOCK(&V_udbinfo);
 509         inp = in6_pcblookup_hash(&V_udbinfo, &addrs[1].sin6_addr,
 510             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port, 1,
 511             NULL);
 512         if (inp != NULL) {
 513                 INP_RLOCK(inp);
 514                 INP_INFO_RUNLOCK(&V_udbinfo);
 515                 if (inp->inp_socket == NULL)
 516                         error = ENOENT;
 517                 if (error == 0)
 518                         error = cr_canseesocket(req->td->td_ucred,
 519                             inp->inp_socket);
 520                 if (error == 0)
 521                         cru2x(inp->inp_cred, &xuc);
 522                 INP_RUNLOCK(inp);
 523         } else {
 524                 INP_INFO_RUNLOCK(&V_udbinfo);
 525                 error = ENOENT;
 526         }
 527         if (error == 0)
 528                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 529         return (error);
 530 }
 531
 532 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
 533     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
 534
 535 static int
 536 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
 537     struct mbuf *control, struct thread *td)
 538 {
 539         u_int32_t ulen = m->m_pkthdr.len;
 540         u_int32_t plen = sizeof(struct udphdr) + ulen;
 541         struct ip6_hdr *ip6;
 542         struct udphdr *udp6;
 543         struct in6_addr *laddr, *faddr, in6a;
 544         struct sockaddr_in6 *sin6 = NULL;
 545         struct ifnet *oifp = NULL;
 546         int scope_ambiguous = 0;
 547         u_short fport;
 548         int error = 0;
 549         struct ip6_pktopts *optp, opt;
 550         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 551         int flags;
 552         struct sockaddr_in6 tmp;
 553
 554         INP_WLOCK_ASSERT(inp);
 555
 556         if (addr6) {
 557                 /* addr6 has been validated in udp6_send(). */
 558                 sin6 = (struct sockaddr_in6 *)addr6;
 559
 560                 /* protect *sin6 from overwrites */
 561                 tmp = *sin6;
 562                 sin6 = &tmp;
 563
 564                 /*
 565                  * Application should provide a proper zone ID or the use of
 566                  * default zone IDs should be enabled.  Unfortunately, some
 567                  * applications do not behave as it should, so we need a
 568                  * workaround.  Even if an appropriate ID is not determined,
 569                  * we'll see if we can determine the outgoing interface.  If we
 570                  * can, determine the zone ID based on the interface below.
 571                  */
 572                 if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
 573                         scope_ambiguous = 1;
 574                 if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
 575                         return (error);
 576         }
 577
 578         if (control) {
 579                 if ((error = ip6_setpktopts(control, &opt,
 580                     inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
 581                         goto release;
 582                 optp = &opt;
 583         } else
 584                 optp = inp->in6p_outputopts;
 585
 586         if (sin6) {
 587                 faddr = &sin6->sin6_addr;
 588
 589                 /*
 590                  * IPv4 version of udp_output calls in_pcbconnect in this case,
 591                  * which needs splnet and affects performance.
 592                  * Since we saw no essential reason for calling in_pcbconnect,
 593                  * we get rid of such kind of logic, and call in6_selectsrc
 594                  * and in6_pcbsetport in order to fill in the local address
 595                  * and the local port.
 596                  */
 597                 if (sin6->sin6_port == 0) {
 598                         error = EADDRNOTAVAIL;
 599                         goto release;
 600                 }
 601
 602                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 603                         /* how about ::ffff:0.0.0.0 case? */
 604                         error = EISCONN;
 605                         goto release;
 606                 }
 607
 608                 fport = sin6->sin6_port; /* allow 0 port */
 609
 610                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 611                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 612                                 /*
 613                                  * I believe we should explicitly discard the
 614                                  * packet when mapped addresses are disabled,
 615                                  * rather than send the packet as an IPv6 one.
 616                                  * If we chose the latter approach, the packet
 617                                  * might be sent out on the wire based on the
 618                                  * default route, the situation which we'd
 619                                  * probably want to avoid.
 620                                  * (20010421 jinmei@kame.net)
 621                                  */
 622                                 error = EINVAL;
 623                                 goto release;
 624                         }
 625                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 626                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 627                                 /*
 628                                  * when remote addr is an IPv4-mapped address,
 629                                  * local addr should not be an IPv6 address,
 630                                  * since you cannot determine how to map IPv6
 631                                  * source address to IPv4.
 632                                  */
 633                                 error = EINVAL;
 634                                 goto release;
 635                         }
 636
 637                         af = AF_INET;
 638                 }
 639
 640                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 641                         error = in6_selectsrc(sin6, optp, inp, NULL,
 642                             td->td_ucred, &oifp, &in6a);
 643                         if (error)
 644                                 goto release;
 645                         if (oifp && scope_ambiguous &&
 646                             (error = in6_setscope(&sin6->sin6_addr,
 647                             oifp, NULL))) {
 648                                 goto release;
 649                         }
 650                         laddr = &in6a;
 651                 } else
 652                         laddr = &inp->in6p_laddr;       /* XXX */
 653                 if (laddr == NULL) {
 654                         if (error == 0)
 655                                 error = EADDRNOTAVAIL;
 656                         goto release;
 657                 }
 658                 if (inp->inp_lport == 0 &&
 659                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0)
 660                         goto release;
 661         } else {
 662                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 663                         error = ENOTCONN;
 664                         goto release;
 665                 }
 666                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 667                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 668                                 /*
 669                                  * XXX: this case would happen when the
 670                                  * application sets the V6ONLY flag after
 671                                  * connecting the foreign address.
 672                                  * Such applications should be fixed,
 673                                  * so we bark here.
 674                                  */
 675                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 676                                     "option was set for a connected socket\n");
 677                                 error = EINVAL;
 678                                 goto release;
 679                         } else
 680                                 af = AF_INET;
 681                 }
 682                 laddr = &inp->in6p_laddr;
 683                 faddr = &inp->in6p_faddr;
 684                 fport = inp->inp_fport;
 685         }
 686
 687         if (af == AF_INET)
 688                 hlen = sizeof(struct ip);
 689
 690         /*
 691          * Calculate data length and get a mbuf
 692          * for UDP and IP6 headers.
 693          */
 694         M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
 695         if (m == 0) {
 696                 error = ENOBUFS;
 697                 goto release;
 698         }
 699
 700         /*
 701          * Stuff checksum and output datagram.
 702          */
 703         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 704         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
 705         udp6->uh_dport = fport;
 706         if (plen <= 0xffff)
 707                 udp6->uh_ulen = htons((u_short)plen);
 708         else
 709                 udp6->uh_ulen = 0;
 710         udp6->uh_sum = 0;
 711
 712         switch (af) {
 713         case AF_INET6:
 714                 ip6 = mtod(m, struct ip6_hdr *);
 715                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
 716                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 717                 ip6->ip6_vfc    |= IPV6_VERSION;
 718 #if 0                           /* ip6_plen will be filled in ip6_output. */
 719                 ip6->ip6_plen   = htons((u_short)plen);
 720 #endif
 721                 ip6->ip6_nxt    = IPPROTO_UDP;
 722                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 723                 ip6->ip6_src    = *laddr;
 724                 ip6->ip6_dst    = *faddr;
 725
 726                 if ((udp6->uh_sum = in6_cksum(m, IPPROTO_UDP,
 727                                 sizeof(struct ip6_hdr), plen)) == 0) {
 728                         udp6->uh_sum = 0xffff;
 729                 }
 730
 731                 flags = 0;
 732
 733                 UDPSTAT_INC(udps_opackets);
 734                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 735                     NULL, inp);
 736                 break;
 737         case AF_INET:
 738                 error = EAFNOSUPPORT;
 739                 goto release;
 740         }
 741         goto releaseopt;
 742
 743 release:
 744         m_freem(m);
 745
 746 releaseopt:
 747         if (control) {
 748                 ip6_clearpktopts(&opt, -1);
 749                 m_freem(control);
 750         }
 751         return (error);
 752 }
 753
 754 static void
 755 udp6_abort(struct socket *so)
 756 {
 757         struct inpcb *inp;
 758
 759         inp = sotoinpcb(so);
 760         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 761
 762 #ifdef INET
 763         if (inp->inp_vflag & INP_IPV4) {
 764                 struct pr_usrreqs *pru;
 765
 766                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 767                 (*pru->pru_abort)(so);
 768                 return;
 769         }
 770 #endif
 771
 772         INP_INFO_WLOCK(&V_udbinfo);
 773         INP_WLOCK(inp);
 774         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 775                 in6_pcbdisconnect(inp);
 776                 inp->in6p_laddr = in6addr_any;
 777                 soisdisconnected(so);
 778         }
 779         INP_WUNLOCK(inp);
 780         INP_INFO_WUNLOCK(&V_udbinfo);
 781 }
 782
 783 static int
 784 udp6_attach(struct socket *so, int proto, struct thread *td)
 785 {
 786         struct inpcb *inp;
 787         int error;
 788
 789         inp = sotoinpcb(so);
 790         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 791
 792         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 793                 error = soreserve(so, udp_sendspace, udp_recvspace);
 794                 if (error)
 795                         return (error);
 796         }
 797         INP_INFO_WLOCK(&V_udbinfo);
 798         error = in_pcballoc(so, &V_udbinfo);
 799         if (error) {
 800                 INP_INFO_WUNLOCK(&V_udbinfo);
 801                 return (error);
 802         }
 803         inp = (struct inpcb *)so->so_pcb;
 804         inp->inp_vflag |= INP_IPV6;
 805         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 806                 inp->inp_vflag |= INP_IPV4;
 807         inp->in6p_hops = -1;    /* use kernel default */
 808         inp->in6p_cksum = -1;   /* just to be sure */
 809         /*
 810          * XXX: ugly!!
 811          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 812          * because the socket may be bound to an IPv6 wildcard address,
 813          * which may match an IPv4-mapped IPv6 address.
 814          */
 815         inp->inp_ip_ttl = V_ip_defttl;
 816
 817         error = udp_newudpcb(inp);
 818         if (error) {
 819                 in_pcbdetach(inp);
 820                 in_pcbfree(inp);
 821                 INP_INFO_WUNLOCK(&V_udbinfo);
 822                 return (error);
 823         }
 824         INP_WUNLOCK(inp);
 825         INP_INFO_WUNLOCK(&V_udbinfo);
 826         return (0);
 827 }
 828
 829 static int
 830 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 831 {
 832         struct inpcb *inp;
 833         int error;
 834
 835         inp = sotoinpcb(so);
 836         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 837
 838         INP_INFO_WLOCK(&V_udbinfo);
 839         INP_WLOCK(inp);
 840         inp->inp_vflag &= ~INP_IPV4;
 841         inp->inp_vflag |= INP_IPV6;
 842         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 843                 struct sockaddr_in6 *sin6_p;
 844
 845                 sin6_p = (struct sockaddr_in6 *)nam;
 846
 847                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 848                         inp->inp_vflag |= INP_IPV4;
 849                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 850                         struct sockaddr_in sin;
 851
 852                         in6_sin6_2_sin(&sin, sin6_p);
 853                         inp->inp_vflag |= INP_IPV4;
 854                         inp->inp_vflag &= ~INP_IPV6;
 855                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 856                             td->td_ucred);
 857                         goto out;
 858                 }
 859         }
 860
 861         error = in6_pcbbind(inp, nam, td->td_ucred);
 862 out:
 863         INP_WUNLOCK(inp);
 864         INP_INFO_WUNLOCK(&V_udbinfo);
 865         return (error);
 866 }
 867
 868 static void
 869 udp6_close(struct socket *so)
 870 {
 871         struct inpcb *inp;
 872
 873         inp = sotoinpcb(so);
 874         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
 875
 876 #ifdef INET
 877         if (inp->inp_vflag & INP_IPV4) {
 878                 struct pr_usrreqs *pru;
 879
 880                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 881                 (*pru->pru_disconnect)(so);
 882                 return;
 883         }
 884 #endif
 885         INP_INFO_WLOCK(&V_udbinfo);
 886         INP_WLOCK(inp);
 887         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 888                 in6_pcbdisconnect(inp);
 889                 inp->in6p_laddr = in6addr_any;
 890                 soisdisconnected(so);
 891         }
 892         INP_WUNLOCK(inp);
 893         INP_INFO_WUNLOCK(&V_udbinfo);
 894 }
 895
 896 static int
 897 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 898 {
 899         struct inpcb *inp;
 900         struct sockaddr_in6 *sin6;
 901         int error;
 902
 903         inp = sotoinpcb(so);
 904         sin6 = (struct sockaddr_in6 *)nam;
 905         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
 906
 907         INP_INFO_WLOCK(&V_udbinfo);
 908         INP_WLOCK(inp);
 909         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0 &&
 910             IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
 911                 struct sockaddr_in sin;
 912
 913                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 914                         error = EISCONN;
 915                         goto out;
 916                 }
 917                 in6_sin6_2_sin(&sin, sin6);
 918                 error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
 919                 if (error != 0)
 920                         goto out;
 921                 error = in_pcbconnect(inp, (struct sockaddr *)&sin,
 922                     td->td_ucred);
 923                 if (error == 0) {
 924                         inp->inp_vflag |= INP_IPV4;
 925                         inp->inp_vflag &= ~INP_IPV6;
 926                         soisconnected(so);
 927                 }
 928                 goto out;
 929         }
 930         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 931                 error = EISCONN;
 932                 goto out;
 933         }
 934         error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
 935         if (error != 0)
 936                 goto out;
 937         error = in6_pcbconnect(inp, nam, td->td_ucred);
 938         if (error == 0) {
 939                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 940                         /* should be non mapped addr */
 941                         inp->inp_vflag &= ~INP_IPV4;
 942                         inp->inp_vflag |= INP_IPV6;
 943                 }
 944                 soisconnected(so);
 945         }
 946 out:
 947         INP_WUNLOCK(inp);
 948         INP_INFO_WUNLOCK(&V_udbinfo);
 949         return (error);
 950 }
 951
 952 static void
 953 udp6_detach(struct socket *so)
 954 {
 955         struct inpcb *inp;
 956         struct udpcb *up;
 957
 958         inp = sotoinpcb(so);
 959         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
 960
 961         INP_INFO_WLOCK(&V_udbinfo);
 962         INP_WLOCK(inp);
 963         up = intoudpcb(inp);
 964         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 965         in_pcbdetach(inp);
 966         in_pcbfree(inp);
 967         INP_INFO_WUNLOCK(&V_udbinfo);
 968         udp_discardcb(up);
 969 }
 970
 971 static int
 972 udp6_disconnect(struct socket *so)
 973 {
 974         struct inpcb *inp;
 975         int error;
 976
 977         inp = sotoinpcb(so);
 978         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
 979
 980         INP_INFO_WLOCK(&V_udbinfo);
 981         INP_WLOCK(inp);
 982
 983 #ifdef INET
 984         if (inp->inp_vflag & INP_IPV4) {
 985                 struct pr_usrreqs *pru;
 986
 987                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 988                 error = (*pru->pru_disconnect)(so);
 989                 goto out;
 990         }
 991 #endif
 992
 993         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 994                 error = ENOTCONN;
 995                 goto out;
 996         }
 997
 998         in6_pcbdisconnect(inp);
 999         inp->in6p_laddr = in6addr_any;
1000         SOCK_LOCK(so);
1001         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1002         SOCK_UNLOCK(so);
1003 out:
1004         INP_WUNLOCK(inp);
1005         INP_INFO_WUNLOCK(&V_udbinfo);
1006         return (0);
1007 }
1008
1009 static int
1010 udp6_send(struct socket *so, int flags, struct mbuf *m,
1011     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1012 {
1013         struct inpcb *inp;
1014         int error = 0;
1015
1016         inp = sotoinpcb(so);
1017         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1018
1019         INP_INFO_WLOCK(&V_udbinfo);
1020         INP_WLOCK(inp);
1021         if (addr) {
1022                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1023                         error = EINVAL;
1024                         goto bad;
1025                 }
1026                 if (addr->sa_family != AF_INET6) {
1027                         error = EAFNOSUPPORT;
1028                         goto bad;
1029                 }
1030         }
1031
1032 #ifdef INET
1033         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1034                 int hasv4addr;
1035                 struct sockaddr_in6 *sin6 = 0;
1036
1037                 if (addr == 0)
1038                         hasv4addr = (inp->inp_vflag & INP_IPV4);
1039                 else {
1040                         sin6 = (struct sockaddr_in6 *)addr;
1041                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1042                             ? 1 : 0;
1043                 }
1044                 if (hasv4addr) {
1045                         struct pr_usrreqs *pru;
1046
1047                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
1048                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
1049                                 /*
1050                                  * When remote addr is IPv4-mapped address,
1051                                  * local addr should not be an IPv6 address;
1052                                  * since you cannot determine how to map IPv6
1053                                  * source address to IPv4.
1054                                  */
1055                                 error = EINVAL;
1056                                 goto out;
1057                         }
1058
1059                         /*
1060                          * XXXRW: We release UDP-layer locks before calling
1061                          * udp_send() in order to avoid recursion.  However,
1062                          * this does mean there is a short window where inp's
1063                          * fields are unstable.  Could this lead to a
1064                          * potential race in which the factors causing us to
1065                          * select the UDPv4 output routine are invalidated?
1066                          */
1067                         INP_WUNLOCK(inp);
1068                         INP_INFO_WUNLOCK(&V_udbinfo);
1069                         if (sin6)
1070                                 in6_sin6_2_sin_in_sock(addr);
1071                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1072                         /* addr will just be freed in sendit(). */
1073                         return ((*pru->pru_send)(so, flags, m, addr, control,
1074                             td));
1075                 }
1076         }
1077 #endif
1078 #ifdef MAC
1079         mac_inpcb_create_mbuf(inp, m);
1080 #endif
1081         error = udp6_output(inp, m, addr, control, td);
1082 out:
1083         INP_WUNLOCK(inp);
1084         INP_INFO_WUNLOCK(&V_udbinfo);
1085         return (error);
1086
1087 bad:
1088         INP_WUNLOCK(inp);
1089         INP_INFO_WUNLOCK(&V_udbinfo);
1090         m_freem(m);
1091         return (error);
1092 }
1093
1094 struct pr_usrreqs udp6_usrreqs = {
1095         .pru_abort =            udp6_abort,
1096         .pru_attach =           udp6_attach,
1097         .pru_bind =             udp6_bind,
1098         .pru_connect =          udp6_connect,
1099         .pru_control =          in6_control,
1100         .pru_detach =           udp6_detach,
1101         .pru_disconnect =       udp6_disconnect,
1102         .pru_peeraddr =         in6_mapped_peeraddr,
1103         .pru_send =             udp6_send,
1104         .pru_shutdown =         udp_shutdown,
1105         .pru_sockaddr =         in6_mapped_sockaddr,
1106         .pru_soreceive =        soreceive_dgram,
1107         .pru_sosend =           sosend_dgram,
1108         .pru_sosetlabel =       in_pcbsosetlabel,
1109         .pru_close =            udp6_close
1110 };