bsd/netinet6/in6_src.c

   1 /*      $KAME: in6_src.c,v 1.10 2000/03/28 09:02:23 k-sugyou Exp $      */
   2
   3 /*
   4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the project nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * Copyright (c) 1982, 1986, 1991, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 3. All advertising materials mentioning features or use of this software
  45  *    must display the following acknowledgement:
  46  *      This product includes software developed by the University of
  47  *      California, Berkeley and its contributors.
  48  * 4. Neither the name of the University nor the names of its contributors
  49  *    may be used to endorse or promote products derived from this software
  50  *    without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  62  * SUCH DAMAGE.
  63  *
  64  *      @(#)in_pcb.c    8.2 (Berkeley) 1/4/94
  65  */
  66
  67 /* for MIP6 */
  68 #if (defined(__FreeBSD__) && __FreeBSD__ >= 3) || defined(__NetBSD__)
  69 #include "opt_inet.h"
  70 #endif
  71
  72 #ifdef __NetBSD__
  73 #include "opt_ipsec.h"
  74 #endif
  75
  76 #include <sys/param.h>
  77 #include <sys/systm.h>
  78 #include <sys/malloc.h>
  79 #include <sys/mbuf.h>
  80 #include <sys/protosw.h>
  81 #include <sys/socket.h>
  82 #include <sys/socketvar.h>
  83 #if !(defined(__FreeBSD__) && __FreeBSD__ >= 4)
  84 #include <sys/ioctl.h>
  85 #endif
  86 #include <sys/errno.h>
  87 #include <sys/time.h>
  88 #include <sys/proc.h>
  89
  90 #include <net/if.h>
  91 #include <net/route.h>
  92
  93 #include <netinet/in.h>
  94 #include <netinet/in_var.h>
  95 #include <netinet/in_systm.h>
  96 #include <netinet/ip.h>
  97 #include <netinet/in_pcb.h>
  98 #include <netinet6/in6_var.h>
  99 #include <netinet/ip6.h>
 100 #if !(defined(__OpenBSD__) || (defined(__bsdi__) && _BSDI_VERSION >= 199802))
 101 #include <netinet6/in6_pcb.h>
 102 #endif
 103 #include <netinet6/ip6_var.h>
 104 #include <netinet6/nd6.h>
 105
 106 #include <net/net_osdep.h>
 107
 108 #ifndef __bsdi__
 109 #include "loop.h"
 110 #endif
 111 #if defined(__NetBSD__) || defined(__OpenBSD__)
 112 extern struct ifnet loif[NLOOP];
 113 #endif
 114
 115 #if MIP6
 116 #include <netinet6/mip6.h>
 117 #include <netinet6/mip6_common.h>
 118
 119 extern struct nd_prefix *(*mip6_get_home_prefix_hook) __P((void));
 120 #endif
 121
 122 /*
 123  * Return an IPv6 address, which is the most appropriate for given
 124  * destination and user specified options.
 125  * If necessary, this function lookups the routing table and return
 126  * an entry to the caller for later use.
 127  */
 128 struct in6_addr *
 129 in6_selectsrc(dstsock, opts, mopts, ro, laddr, errorp)
 130         struct sockaddr_in6 *dstsock;
 131         struct ip6_pktopts *opts;
 132         struct ip6_moptions *mopts;
 133         struct route_in6 *ro;
 134         struct in6_addr *laddr;
 135         int *errorp;
 136 {
 137         struct in6_addr *dst;
 138         struct in6_ifaddr *ia6 = 0;
 139         struct in6_pktinfo *pi = NULL;
 140
 141         dst = &dstsock->sin6_addr;
 142         *errorp = 0;
 143
 144         /*
 145          * If the source address is explicitly specified by the caller,
 146          * use it.
 147          */
 148         if (opts && (pi = opts->ip6po_pktinfo) &&
 149             !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr))
 150                 return(&pi->ipi6_addr);
 151
 152         /*
 153          * If the source address is not specified but the socket(if any)
 154          * is already bound, use the bound address.
 155          */
 156         if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr))
 157                 return(laddr);
 158
 159         /*
 160          * If the caller doesn't specify the source address but
 161          * the outgoing interface, use an address associated with
 162          * the interface.
 163          */
 164         if (pi && pi->ipi6_ifindex) {
 165                 /* XXX boundary check is assumed to be already done. */
 166                 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex],
 167                                        dst);
 168                 if (ia6 == 0) {
 169                         *errorp = EADDRNOTAVAIL;
 170                         return(0);
 171                 }
 172                 return(&satosin6(&ia6->ia_addr)->sin6_addr);
 173         }
 174
 175         /*
 176          * If the destination address is a link-local unicast address or
 177          * a multicast address, and if the outgoing interface is specified
 178          * by the sin6_scope_id filed, use an address associated with the
 179          * interface.
 180          * XXX: We're now trying to define more specific semantics of
 181          *      sin6_scope_id field, so this part will be rewritten in
 182          *      the near future.
 183          */
 184         if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) &&
 185             dstsock->sin6_scope_id) {
 186                 /*
 187                  * I'm not sure if boundary check for scope_id is done
 188                  * somewhere...
 189                  */
 190                 if (dstsock->sin6_scope_id < 0 ||
 191                     if_index < dstsock->sin6_scope_id) {
 192                         *errorp = ENXIO; /* XXX: better error? */
 193                         return(0);
 194                 }
 195                 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id],
 196                                        dst);
 197                 if (ia6 == 0) {
 198                         *errorp = EADDRNOTAVAIL;
 199                         return(0);
 200                 }
 201                 return(&satosin6(&ia6->ia_addr)->sin6_addr);
 202         }
 203
 204         /*
 205          * If the destination address is a multicast address and
 206          * the outgoing interface for the address is specified
 207          * by the caller, use an address associated with the interface.
 208          * There is a sanity check here; if the destination has node-local
 209          * scope, the outgoing interfacde should be a loopback address.
 210          * Even if the outgoing interface is not specified, we also
 211          * choose a loopback interface as the outgoing interface.
 212          */
 213         if (IN6_IS_ADDR_MULTICAST(dst)) {
 214                 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL;
 215 #ifdef __bsdi__
 216 #if _BSDI_VERSION >= 199802
 217                 extern struct ifnet *loifp;
 218 #else
 219                 extern struct ifnet loif;
 220                 struct ifnet *loifp = &loif;
 221 #endif
 222 #endif
 223
 224                 if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) {
 225 #ifdef __bsdi__
 226                         ifp = loifp;
 227 #else
 228                         ifp = &loif[0];
 229 #endif
 230                 }
 231
 232                 if (ifp) {
 233                         ia6 = in6_ifawithscope(ifp, dst);
 234                         if (ia6 == 0) {
 235                                 *errorp = EADDRNOTAVAIL;
 236                                 return(0);
 237                         }
 238                         return(&satosin6(&ia6->ia_addr)->sin6_addr);
 239                 }
 240         }
 241
 242         /*
 243          * If the next hop address for the packet is specified
 244          * by caller, use an address associated with the route
 245          * to the next hop.
 246          */
 247         {
 248                 struct sockaddr_in6 *sin6_next;
 249                 struct rtentry *rt;
 250
 251                 if (opts && opts->ip6po_nexthop) {
 252                         sin6_next = satosin6(opts->ip6po_nexthop);
 253                         rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL);
 254                         if (rt) {
 255                                 ia6 = in6_ifawithscope(rt->rt_ifp, dst);
 256                                 if (ia6 == 0)
 257                                         ia6 = ifatoia6(rt->rt_ifa);
 258                         }
 259                         if (ia6 == 0) {
 260                                 *errorp = EADDRNOTAVAIL;
 261                                 return(0);
 262                         }
 263                         return(&satosin6(&ia6->ia_addr)->sin6_addr);
 264                 }
 265         }
 266
 267 #if MIP6
 268         /*
 269          * This is needed to assure that the Home Address is used for
 270          * outgoing packets when not at home. We can't choose any other
 271          * address if we want to keep connections up during movement.
 272          */
 273         if (mip6_get_home_prefix_hook) {        /* Only Mobile Node */
 274                 struct nd_prefix *pr;
 275                 if ((pr = (*mip6_get_home_prefix_hook)()) &&
 276                     !IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr)) {
 277                         if (in6_addrscope(dst) ==
 278                             in6_addrscope(&pr->ndpr_addr)) {
 279 #if MIP6_DEBUG
 280                                 /* Noisy but useful */
 281                                 mip6_debug("%s: Local address %s is chosen "
 282                                            "for pcb to dest %s.\n",
 283                                            __FUNCTION__,
 284                                            ip6_sprintf(&pr->ndpr_addr),
 285                                            ip6_sprintf(dst));
 286 #endif
 287                                 return(&pr->ndpr_addr);
 288                         }
 289                 }
 290         }
 291 #endif /* MIP6 */
 292
 293         /*
 294          * If route is known or can be allocated now,
 295          * our src addr is taken from the i/f, else punt.
 296          */
 297         if (ro) {
 298                 if (ro->ro_rt &&
 299                     !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst)) {
 300                         RTFREE(ro->ro_rt);
 301                         ro->ro_rt = (struct rtentry *)0;
 302                 }
 303                 if (ro->ro_rt == (struct rtentry *)0 ||
 304                     ro->ro_rt->rt_ifp == (struct ifnet *)0) {
 305                         /* No route yet, so try to acquire one */
 306                         bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
 307                         ro->ro_dst.sin6_family = AF_INET6;
 308                         ro->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
 309                         ro->ro_dst.sin6_addr = *dst;
 310                         if (IN6_IS_ADDR_MULTICAST(dst)) {
 311 #if defined( __FreeBSD__) || defined (__APPLE__)
 312                                 ro->ro_rt = rtalloc1(&((struct route *)ro)
 313                                                      ->ro_dst, 0, 0UL);
 314 #else
 315                                 ro->ro_rt = rtalloc1(&((struct route *)ro)
 316                                                      ->ro_dst, 0);
 317 #endif /*__FreeBSD__*/
 318                         } else {
 319 #ifdef __bsdi__  /* bsdi needs rtcalloc to make a host route */
 320                                 rtcalloc((struct route *)ro);
 321 #else
 322                                 rtalloc((struct route *)ro);
 323 #endif
 324                         }
 325                 }
 326
 327                 /*
 328                  * in_pcbconnect() checks out IFF_LOOPBACK to skip using
 329                  * the address. But we don't know why it does so.
 330                  * It is necessary to ensure the scope even for lo0
 331                  * so doesn't check out IFF_LOOPBACK.
 332                  */
 333
 334                 if (ro->ro_rt) {
 335                         ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst);
 336                         if (ia6 == 0) /* xxx scope error ?*/
 337                                 ia6 = ifatoia6(ro->ro_rt->rt_ifa);
 338                 }
 339 #if 0
 340                 /*
 341                  * xxx The followings are necessary? (kazu)
 342                  * I don't think so.
 343                  * It's for SO_DONTROUTE option in IPv4.(jinmei)
 344                  */
 345                 if (ia6 == 0) {
 346                         struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0};
 347
 348                         sin6->sin6_addr = *dst;
 349
 350                         ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6)));
 351                         if (ia6 == 0)
 352                                 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6)));
 353                         if (ia6 == 0)
 354                                 return(0);
 355                         return(&satosin6(&ia6->ia_addr)->sin6_addr);
 356                 }
 357 #endif /* 0 */
 358                 if (ia6 == 0) {
 359                         *errorp = EHOSTUNREACH; /* no route */
 360                         return(0);
 361                 }
 362                 return(&satosin6(&ia6->ia_addr)->sin6_addr);
 363         }
 364
 365         *errorp = EADDRNOTAVAIL;
 366         return(0);
 367 }
 368
 369 /*
 370  * Default hop limit selection. The precedence is as follows:
 371  * 1. Hoplimit value specified via ioctl.
 372  * 2. (If the outgoing interface is detected) the current
 373  *     hop limit of the interface specified by router advertisement.
 374  * 3. The system default hoplimit.
 375 */
 376 #if HAVE_NRL_INPCB
 377 #define in6pcb          inpcb
 378 #define in6p_hops       inp_hops
 379 #endif
 380 int
 381 in6_selecthlim(in6p, ifp)
 382         struct in6pcb *in6p;
 383         struct ifnet *ifp;
 384 {
 385         if (in6p && in6p->in6p_hops >= 0)
 386                 return(in6p->in6p_hops);
 387         else if (ifp)
 388                 return(nd_ifinfo[ifp->if_index].chlim);
 389         else
 390                 return(ip6_defhlim);
 391 }
 392 #if HAVE_NRL_INPCB
 393 #undef in6pcb
 394 #undef in6p_hops
 395 #endif
 396
 397 #if !(defined(__FreeBSD__) && __FreeBSD__ >= 3) && !defined(__OpenBSD__) && !defined(__APPLE__)
 398 /*
 399  * Find an empty port and set it to the specified PCB.
 400  */
 401 #if HAVE_NRL_INPCB      /* XXX: I really hate such ugly macros...(jinmei) */
 402 #define in6pcb          inpcb
 403 #define in6p_socket     inp_socket
 404 #define in6p_lport      inp_lport
 405 #define in6p_head       inp_head
 406 #define in6p_flags      inp_flags
 407 #define IN6PLOOKUP_WILDCARD INPLOOKUP_WILDCARD
 408 #endif
 409 int
 410 in6_pcbsetport(laddr, in6p)
 411         struct in6_addr *laddr;
 412         struct in6pcb *in6p;
 413 {
 414         struct socket *so = in6p->in6p_socket;
 415         struct in6pcb *head = in6p->in6p_head;
 416         u_int16_t last_port, lport = 0;
 417         int wild = 0;
 418         void *t;
 419         u_int16_t min, max;
 420 #ifdef __NetBSD__
 421         struct proc *p = curproc;               /* XXX */
 422 #endif
 423
 424         /* XXX: this is redundant when called from in6_pcbbind */
 425         if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 &&
 426            ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 ||
 427             (so->so_options & SO_ACCEPTCONN) == 0))
 428                 wild = IN6PLOOKUP_WILDCARD;
 429
 430         if (in6p->in6p_flags & IN6P_LOWPORT) {
 431 #ifdef __NetBSD__
 432                 if (p == 0 || (suser(p->p_ucred, &p->p_acflag) != 0))
 433                         return (EACCES);
 434 #else
 435                 if ((so->so_state & SS_PRIV) == 0)
 436                         return (EACCES);
 437 #endif
 438                 min = IPV6PORT_RESERVEDMIN;
 439                 max = IPV6PORT_RESERVEDMAX;
 440         } else {
 441                 min = IPV6PORT_ANONMIN;
 442                 max = IPV6PORT_ANONMAX;
 443         }
 444
 445         /* value out of range */
 446         if (head->in6p_lport < min)
 447                 head->in6p_lport = min;
 448         else if (head->in6p_lport > max)
 449                 head->in6p_lport = min;
 450         last_port = head->in6p_lport;
 451         goto startover; /*to randomize*/
 452         for (;;) {
 453                 lport = htons(head->in6p_lport);
 454                 if (IN6_IS_ADDR_V4MAPPED(laddr)) {
 455 #if 0
 456                         t = in_pcblookup_bind(&tcbtable,
 457                                               (struct in_addr *)&in6p->in6p_laddr.s6_addr32[3],
 458                                               lport);
 459 #else
 460                         t = NULL;
 461 #endif
 462                 } else {
 463 #if HAVE_NRL_INPCB
 464                         /* XXX: ugly cast... */
 465                         t = in_pcblookup(head, (struct in_addr *)&zeroin6_addr,
 466                                          0, (struct in_addr *)laddr,
 467                                          lport, wild | INPLOOKUP_IPV6);
 468 #else
 469                         t = in6_pcblookup(head, &zeroin6_addr, 0, laddr,
 470                                           lport, wild);
 471 #endif
 472                 }
 473                 if (t == 0)
 474                         break;
 475           startover:
 476                 if (head->in6p_lport >= max)
 477                         head->in6p_lport = min;
 478                 else
 479                         head->in6p_lport++;
 480                 if (head->in6p_lport == last_port)
 481                         return (EADDRINUSE);
 482         }
 483
 484         in6p->in6p_lport = lport;
 485         return(0);              /* success */
 486 }
 487 #if HAVE_NRL_INPCB
 488 #undef in6pcb
 489 #undef in6p_socket
 490 #undef in6p_lport
 491 #undef in6p_head
 492 #undef in6p_flags
 493 #undef IN6PLOOKUP_WILDCARD
 494 #endif
 495 #endif /* !FreeBSD3 && !OpenBSD*/