sys/netinet/ip_encap.c

   1 /*      $KAME: ip_encap.c,v 1.73 2001/10/02 08:30:58 itojun 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  * My grandfather said that there's a devil inside tunnelling technology...
  33  *
  34  * We have surprisingly many protocols that want packets with IP protocol
  35  * #4 or #41.  Here's a list of protocols that want protocol #41:
  36  *      RFC1933 configured tunnel
  37  *      RFC1933 automatic tunnel
  38  *      RFC2401 IPsec tunnel
  39  *      RFC2473 IPv6 generic packet tunnelling
  40  *      RFC2529 6over4 tunnel
  41  *      RFC3056 6to4 tunnel
  42  *      isatap tunnel
  43  *      mobile-ip6 (uses RFC2473)
  44  * Here's a list of protocol that want protocol #4:
  45  *      RFC1853 IPv4-in-IPv4 tunnelling
  46  *      RFC2003 IPv4 encapsulation within IPv4
  47  *      RFC2344 reverse tunnelling for mobile-ip4
  48  *      RFC2401 IPsec tunnel
  49  * Well, what can I say.  They impose different en/decapsulation mechanism
  50  * from each other, so they need separate protocol handler.  The only one
  51  * we can easily determine by protocol # is IPsec, which always has
  52  * AH/ESP/IPComp header right after outer IP header.
  53  *
  54  * So, clearly good old protosw does not work for protocol #4 and #41.
  55  * The code will let you match protocol via src/dst address pair.
  56  */
  57 /* XXX is M_NETADDR correct? */
  58
  59 /*
  60  * With USE_RADIX the code will use radix table for tunnel lookup, for
  61  * tunnels registered with encap_attach() with a addr/mask pair.
  62  * Faster on machines with thousands of tunnel registerations (= interfaces).
  63  *
  64  * The code assumes that radix table code can handle non-continuous netmask,
  65  * as it will pass radix table memory region with (src + dst) sockaddr pair.
  66  *
  67  * FreeBSD is excluded here as they make max_keylen a static variable, and
  68  * thus forbid definition of radix table other than proper domains.
  69  *
  70  * !!!!!!!
  71  * !!NOTE: dom_maxrtkey assumes USE_RADIX is defined.
  72  * !!!!!!!
  73  */
  74 #define USE_RADIX
  75
  76 #include <sys/cdefs.h>
  77 __KERNEL_RCSID(0, "$NetBSD: ip_encap.c,v 1.37 2009/04/18 14:58:05 tsutsui Exp $");
  78
  79 #include "opt_mrouting.h"
  80 #include "opt_inet.h"
  81
  82 #include <sys/param.h>
  83 #include <sys/systm.h>
  84 #include <sys/socket.h>
  85 #include <sys/sockio.h>
  86 #include <sys/mbuf.h>
  87 #include <sys/errno.h>
  88 #include <sys/protosw.h>
  89 #include <sys/queue.h>
  90
  91 #include <net/if.h>
  92 #include <net/route.h>
  93
  94 #include <netinet/in.h>
  95 #include <netinet/in_systm.h>
  96 #include <netinet/ip.h>
  97 #include <netinet/ip_var.h>
  98 #include <netinet/ip_encap.h>
  99 #ifdef MROUTING
 100 #include <netinet/ip_mroute.h>
 101 #endif /* MROUTING */
 102
 103 #ifdef INET6
 104 #include <netinet/ip6.h>
 105 #include <netinet6/ip6_var.h>
 106 #include <netinet6/ip6protosw.h>
 107 #include <netinet6/in6_var.h>
 108 #include <netinet6/in6_pcb.h>
 109 #include <netinet/icmp6.h>
 110 #endif
 111
 112 #include <machine/stdarg.h>
 113
 114 #include <net/net_osdep.h>
 115
 116 enum direction { INBOUND, OUTBOUND };
 117
 118 #ifdef INET
 119 static struct encaptab *encap4_lookup(struct mbuf *, int, int, enum direction);
 120 #endif
 121 #ifdef INET6
 122 static struct encaptab *encap6_lookup(struct mbuf *, int, int, enum direction);
 123 #endif
 124 static int encap_add(struct encaptab *);
 125 static int encap_remove(struct encaptab *);
 126 static int encap_afcheck(int, const struct sockaddr *, const struct sockaddr *);
 127 #ifdef USE_RADIX
 128 static struct radix_node_head *encap_rnh(int);
 129 static int mask_matchlen(const struct sockaddr *);
 130 #endif
 131 #ifndef USE_RADIX
 132 static int mask_match(const struct encaptab *, const struct sockaddr *,
 133                 const struct sockaddr *);
 134 #endif
 135 static void encap_fillarg(struct mbuf *, const struct encaptab *);
 136
 137 LIST_HEAD(, encaptab) encaptab = LIST_HEAD_INITIALIZER(&encaptab);
 138
 139 #ifdef USE_RADIX
 140 extern int max_keylen;  /* radix.c */
 141 struct radix_node_head *encap_head[2];  /* 0 for AF_INET, 1 for AF_INET6 */
 142 #endif
 143
 144 void
 145 encap_init(void)
 146 {
 147         static int initialized = 0;
 148
 149         if (initialized)
 150                 return;
 151         initialized++;
 152 #if 0
 153         /*
 154          * we cannot use LIST_INIT() here, since drivers may want to call
 155          * encap_attach(), on driver attach.  encap_init() will be called
 156          * on AF_INET{,6} initialization, which happens after driver
 157          * initialization - using LIST_INIT() here can nuke encap_attach()
 158          * from drivers.
 159          */
 160         LIST_INIT(&encaptab);
 161 #endif
 162
 163 #ifdef USE_RADIX
 164         /*
 165          * initialize radix lookup table when the radix subsystem is inited.
 166          */
 167         rn_delayedinit((void *)&encap_head[0],
 168             sizeof(struct sockaddr_pack) << 3);
 169 #ifdef INET6
 170         rn_delayedinit((void *)&encap_head[1],
 171             sizeof(struct sockaddr_pack) << 3);
 172 #endif
 173 #endif
 174 }
 175
 176 #ifdef INET
 177 static struct encaptab *
 178 encap4_lookup(struct mbuf *m, int off, int proto, enum direction dir)
 179 {
 180         struct ip *ip;
 181         struct ip_pack4 pack;
 182         struct encaptab *ep, *match;
 183         int prio, matchprio;
 184 #ifdef USE_RADIX
 185         struct radix_node_head *rnh = encap_rnh(AF_INET);
 186         struct radix_node *rn;
 187 #endif
 188
 189 #ifdef DIAGNOSTIC
 190         if (m->m_len < sizeof(*ip))
 191                 panic("encap4_lookup");
 192 #endif
 193         ip = mtod(m, struct ip *);
 194
 195         memset(&pack, 0, sizeof(pack));
 196         pack.p.sp_len = sizeof(pack);
 197         pack.mine.sin_family = pack.yours.sin_family = AF_INET;
 198         pack.mine.sin_len = pack.yours.sin_len = sizeof(struct sockaddr_in);
 199         if (dir == INBOUND) {
 200                 pack.mine.sin_addr = ip->ip_dst;
 201                 pack.yours.sin_addr = ip->ip_src;
 202         } else {
 203                 pack.mine.sin_addr = ip->ip_src;
 204                 pack.yours.sin_addr = ip->ip_dst;
 205         }
 206
 207         match = NULL;
 208         matchprio = 0;
 209
 210 #ifdef USE_RADIX
 211         rn = rnh->rnh_matchaddr((void *)&pack, rnh);
 212         if (rn && (rn->rn_flags & RNF_ROOT) == 0) {
 213                 match = (struct encaptab *)rn;
 214                 matchprio = mask_matchlen(match->srcmask) +
 215                     mask_matchlen(match->dstmask);
 216         }
 217 #endif
 218
 219         LIST_FOREACH(ep, &encaptab, chain) {
 220                 if (ep->af != AF_INET)
 221                         continue;
 222                 if (ep->proto >= 0 && ep->proto != proto)
 223                         continue;
 224                 if (ep->func)
 225                         prio = (*ep->func)(m, off, proto, ep->arg);
 226                 else {
 227 #ifdef USE_RADIX
 228                         continue;
 229 #else
 230                         prio = mask_match(ep, (struct sockaddr *)&pack.mine,
 231                             (struct sockaddr *)&pack.yours);
 232 #endif
 233                 }
 234
 235                 /*
 236                  * We prioritize the matches by using bit length of the
 237                  * matches.  mask_match() and user-supplied matching function
 238                  * should return the bit length of the matches (for example,
 239                  * if both src/dst are matched for IPv4, 64 should be returned).
 240                  * 0 or negative return value means "it did not match".
 241                  *
 242                  * The question is, since we have two "mask" portion, we
 243                  * cannot really define total order between entries.
 244                  * For example, which of these should be preferred?
 245                  * mask_match() returns 48 (32 + 16) for both of them.
 246                  *      src=3ffe::/16, dst=3ffe:501::/32
 247                  *      src=3ffe:501::/32, dst=3ffe::/16
 248                  *
 249                  * We need to loop through all the possible candidates
 250                  * to get the best match - the search takes O(n) for
 251                  * n attachments (i.e. interfaces).
 252                  *
 253                  * For radix-based lookup, I guess source takes precedence.
 254                  * See rn_{refines,lexobetter} for the correct answer.
 255                  */
 256                 if (prio <= 0)
 257                         continue;
 258                 if (prio > matchprio) {
 259                         matchprio = prio;
 260                         match = ep;
 261                 }
 262         }
 263
 264         return match;
 265 #undef s
 266 #undef d
 267 }
 268
 269 void
 270 encap4_input(struct mbuf *m, ...)
 271 {
 272         int off, proto;
 273         va_list ap;
 274         const struct protosw *psw;
 275         struct encaptab *match;
 276
 277         va_start(ap, m);
 278         off = va_arg(ap, int);
 279         proto = va_arg(ap, int);
 280         va_end(ap);
 281
 282         match = encap4_lookup(m, off, proto, INBOUND);
 283
 284         if (match) {
 285                 /* found a match, "match" has the best one */
 286                 psw = match->psw;
 287                 if (psw && psw->pr_input) {
 288                         encap_fillarg(m, match);
 289                         (*psw->pr_input)(m, off, proto);
 290                 } else
 291                         m_freem(m);
 292                 return;
 293         }
 294
 295         /* last resort: inject to raw socket */
 296         rip_input(m, off, proto);
 297 }
 298 #endif
 299
 300 #ifdef INET6
 301 static struct encaptab *
 302 encap6_lookup(struct mbuf *m, int off, int proto, enum direction dir)
 303 {
 304         struct ip6_hdr *ip6;
 305         struct ip_pack6 pack;
 306         int prio, matchprio;
 307         struct encaptab *ep, *match;
 308 #ifdef USE_RADIX
 309         struct radix_node_head *rnh = encap_rnh(AF_INET6);
 310         struct radix_node *rn;
 311 #endif
 312
 313 #ifdef DIAGNOSTIC
 314         if (m->m_len < sizeof(*ip6))
 315                 panic("encap6_lookup");
 316 #endif
 317         ip6 = mtod(m, struct ip6_hdr *);
 318
 319         memset(&pack, 0, sizeof(pack));
 320         pack.p.sp_len = sizeof(pack);
 321         pack.mine.sin6_family = pack.yours.sin6_family = AF_INET6;
 322         pack.mine.sin6_len = pack.yours.sin6_len = sizeof(struct sockaddr_in6);
 323         if (dir == INBOUND) {
 324                 pack.mine.sin6_addr = ip6->ip6_dst;
 325                 pack.yours.sin6_addr = ip6->ip6_src;
 326         } else {
 327                 pack.mine.sin6_addr = ip6->ip6_src;
 328                 pack.yours.sin6_addr = ip6->ip6_dst;
 329         }
 330
 331         match = NULL;
 332         matchprio = 0;
 333
 334 #ifdef USE_RADIX
 335         rn = rnh->rnh_matchaddr((void *)&pack, rnh);
 336         if (rn && (rn->rn_flags & RNF_ROOT) == 0) {
 337                 match = (struct encaptab *)rn;
 338                 matchprio = mask_matchlen(match->srcmask) +
 339                     mask_matchlen(match->dstmask);
 340         }
 341 #endif
 342
 343         LIST_FOREACH(ep, &encaptab, chain) {
 344                 if (ep->af != AF_INET6)
 345                         continue;
 346                 if (ep->proto >= 0 && ep->proto != proto)
 347                         continue;
 348                 if (ep->func)
 349                         prio = (*ep->func)(m, off, proto, ep->arg);
 350                 else {
 351 #ifdef USE_RADIX
 352                         continue;
 353 #else
 354                         prio = mask_match(ep, (struct sockaddr *)&pack.mine,
 355                             (struct sockaddr *)&pack.yours);
 356 #endif
 357                 }
 358
 359                 /* see encap4_lookup() for issues here */
 360                 if (prio <= 0)
 361                         continue;
 362                 if (prio > matchprio) {
 363                         matchprio = prio;
 364                         match = ep;
 365                 }
 366         }
 367
 368         return match;
 369 #undef s
 370 #undef d
 371 }
 372
 373 int
 374 encap6_input(struct mbuf **mp, int *offp, int proto)
 375 {
 376         struct mbuf *m = *mp;
 377         const struct ip6protosw *psw;
 378         struct encaptab *match;
 379
 380         match = encap6_lookup(m, *offp, proto, INBOUND);
 381
 382         if (match) {
 383                 /* found a match */
 384                 psw = (const struct ip6protosw *)match->psw;
 385                 if (psw && psw->pr_input) {
 386                         encap_fillarg(m, match);
 387                         return (*psw->pr_input)(mp, offp, proto);
 388                 } else {
 389                         m_freem(m);
 390                         return IPPROTO_DONE;
 391                 }
 392         }
 393
 394         /* last resort: inject to raw socket */
 395         return rip6_input(mp, offp, proto);
 396 }
 397 #endif
 398
 399 static int
 400 encap_add(struct encaptab *ep)
 401 {
 402 #ifdef USE_RADIX
 403         struct radix_node_head *rnh = encap_rnh(ep->af);
 404 #endif
 405         int error = 0;
 406
 407         LIST_INSERT_HEAD(&encaptab, ep, chain);
 408 #ifdef USE_RADIX
 409         if (!ep->func && rnh) {
 410                 if (!rnh->rnh_addaddr((void *)ep->addrpack,
 411                     (void *)ep->maskpack, rnh, ep->nodes)) {
 412                         error = EEXIST;
 413                         goto fail;
 414                 }
 415         }
 416 #endif
 417         return error;
 418
 419  fail:
 420         LIST_REMOVE(ep, chain);
 421         return error;
 422 }
 423
 424 static int
 425 encap_remove(struct encaptab *ep)
 426 {
 427 #ifdef USE_RADIX
 428         struct radix_node_head *rnh = encap_rnh(ep->af);
 429 #endif
 430         int error = 0;
 431
 432         LIST_REMOVE(ep, chain);
 433 #ifdef USE_RADIX
 434         if (!ep->func && rnh) {
 435                 if (!rnh->rnh_deladdr((void *)ep->addrpack,
 436                     (void *)ep->maskpack, rnh))
 437                         error = ESRCH;
 438         }
 439 #endif
 440         return error;
 441 }
 442
 443 static int
 444 encap_afcheck(int af, const struct sockaddr *sp, const struct sockaddr *dp)
 445 {
 446         if (sp && dp) {
 447                 if (sp->sa_len != dp->sa_len)
 448                         return EINVAL;
 449                 if (af != sp->sa_family || af != dp->sa_family)
 450                         return EINVAL;
 451         } else if (!sp && !dp)
 452                 ;
 453         else
 454                 return EINVAL;
 455
 456         switch (af) {
 457         case AF_INET:
 458                 if (sp && sp->sa_len != sizeof(struct sockaddr_in))
 459                         return EINVAL;
 460                 if (dp && dp->sa_len != sizeof(struct sockaddr_in))
 461                         return EINVAL;
 462                 break;
 463 #ifdef INET6
 464         case AF_INET6:
 465                 if (sp && sp->sa_len != sizeof(struct sockaddr_in6))
 466                         return EINVAL;
 467                 if (dp && dp->sa_len != sizeof(struct sockaddr_in6))
 468                         return EINVAL;
 469                 break;
 470 #endif
 471         default:
 472                 return EAFNOSUPPORT;
 473         }
 474
 475         return 0;
 476 }
 477
 478 /*
 479  * sp (src ptr) is always my side, and dp (dst ptr) is always remote side.
 480  * length of mask (sm and dm) is assumed to be same as sp/dp.
 481  * Return value will be necessary as input (cookie) for encap_detach().
 482  */
 483 const struct encaptab *
 484 encap_attach(int af, int proto,
 485     const struct sockaddr *sp, const struct sockaddr *sm,
 486     const struct sockaddr *dp, const struct sockaddr *dm,
 487     const struct protosw *psw, void *arg)
 488 {
 489         struct encaptab *ep;
 490         int error;
 491         int s;
 492         size_t l;
 493         struct ip_pack4 *pack4;
 494 #ifdef INET6
 495         struct ip_pack6 *pack6;
 496 #endif
 497
 498         s = splsoftnet();
 499         /* sanity check on args */
 500         error = encap_afcheck(af, sp, dp);
 501         if (error)
 502                 goto fail;
 503
 504         /* check if anyone have already attached with exactly same config */
 505         LIST_FOREACH(ep, &encaptab, chain) {
 506                 if (ep->af != af)
 507                         continue;
 508                 if (ep->proto != proto)
 509                         continue;
 510                 if (ep->func)
 511                         continue;
 512 #ifdef DIAGNOSTIC
 513                 if (!ep->src || !ep->dst || !ep->srcmask || !ep->dstmask)
 514                         panic("null pointers in encaptab");
 515 #endif
 516                 if (ep->src->sa_len != sp->sa_len ||
 517                     memcmp(ep->src, sp, sp->sa_len) != 0 ||
 518                     memcmp(ep->srcmask, sm, sp->sa_len) != 0)
 519                         continue;
 520                 if (ep->dst->sa_len != dp->sa_len ||
 521                     memcmp(ep->dst, dp, dp->sa_len) != 0 ||
 522                     memcmp(ep->dstmask, dm, dp->sa_len) != 0)
 523                         continue;
 524
 525                 error = EEXIST;
 526                 goto fail;
 527         }
 528
 529         switch (af) {
 530         case AF_INET:
 531                 l = sizeof(*pack4);
 532                 break;
 533 #ifdef INET6
 534         case AF_INET6:
 535                 l = sizeof(*pack6);
 536                 break;
 537 #endif
 538         default:
 539                 goto fail;
 540         }
 541
 542         /* M_NETADDR ok? */
 543         ep = malloc(sizeof(*ep), M_NETADDR, M_NOWAIT|M_ZERO);
 544         if (ep == NULL) {
 545                 error = ENOBUFS;
 546                 goto fail;
 547         }
 548         ep->addrpack = malloc(l, M_NETADDR, M_NOWAIT|M_ZERO);
 549         if (ep->addrpack == NULL) {
 550                 error = ENOBUFS;
 551                 goto gc;
 552         }
 553         ep->maskpack = malloc(l, M_NETADDR, M_NOWAIT|M_ZERO);
 554         if (ep->maskpack == NULL) {
 555                 error = ENOBUFS;
 556                 goto gc;
 557         }
 558
 559         ep->af = af;
 560         ep->proto = proto;
 561         ep->addrpack->sa_len = l & 0xff;
 562         ep->maskpack->sa_len = l & 0xff;
 563         switch (af) {
 564         case AF_INET:
 565                 pack4 = (struct ip_pack4 *)ep->addrpack;
 566                 ep->src = (struct sockaddr *)&pack4->mine;
 567                 ep->dst = (struct sockaddr *)&pack4->yours;
 568                 pack4 = (struct ip_pack4 *)ep->maskpack;
 569                 ep->srcmask = (struct sockaddr *)&pack4->mine;
 570                 ep->dstmask = (struct sockaddr *)&pack4->yours;
 571                 break;
 572 #ifdef INET6
 573         case AF_INET6:
 574                 pack6 = (struct ip_pack6 *)ep->addrpack;
 575                 ep->src = (struct sockaddr *)&pack6->mine;
 576                 ep->dst = (struct sockaddr *)&pack6->yours;
 577                 pack6 = (struct ip_pack6 *)ep->maskpack;
 578                 ep->srcmask = (struct sockaddr *)&pack6->mine;
 579                 ep->dstmask = (struct sockaddr *)&pack6->yours;
 580                 break;
 581 #endif
 582         }
 583
 584         memcpy(ep->src, sp, sp->sa_len);
 585         memcpy(ep->srcmask, sm, sp->sa_len);
 586         memcpy(ep->dst, dp, dp->sa_len);
 587         memcpy(ep->dstmask, dm, dp->sa_len);
 588         ep->psw = psw;
 589         ep->arg = arg;
 590
 591         error = encap_add(ep);
 592         if (error)
 593                 goto gc;
 594
 595         error = 0;
 596         splx(s);
 597         return ep;
 598
 599 gc:
 600         if (ep->addrpack)
 601                 free(ep->addrpack, M_NETADDR);
 602         if (ep->maskpack)
 603                 free(ep->maskpack, M_NETADDR);
 604         if (ep)
 605                 free(ep, M_NETADDR);
 606 fail:
 607         splx(s);
 608         return NULL;
 609 }
 610
 611 const struct encaptab *
 612 encap_attach_func(int af, int proto,
 613     int (*func)(struct mbuf *, int, int, void *),
 614     const struct protosw *psw, void *arg)
 615 {
 616         struct encaptab *ep;
 617         int error;
 618         int s;
 619
 620         s = splsoftnet();
 621         /* sanity check on args */
 622         if (!func) {
 623                 error = EINVAL;
 624                 goto fail;
 625         }
 626
 627         error = encap_afcheck(af, NULL, NULL);
 628         if (error)
 629                 goto fail;
 630
 631         ep = malloc(sizeof(*ep), M_NETADDR, M_NOWAIT);  /*XXX*/
 632         if (ep == NULL) {
 633                 error = ENOBUFS;
 634                 goto fail;
 635         }
 636         memset(ep, 0, sizeof(*ep));
 637
 638         ep->af = af;
 639         ep->proto = proto;
 640         ep->func = func;
 641         ep->psw = psw;
 642         ep->arg = arg;
 643
 644         error = encap_add(ep);
 645         if (error)
 646                 goto fail;
 647
 648         error = 0;
 649         splx(s);
 650         return ep;
 651
 652 fail:
 653         splx(s);
 654         return NULL;
 655 }
 656
 657 /* XXX encap4_ctlinput() is necessary if we set DF=1 on outer IPv4 header */
 658
 659 #ifdef INET6
 660 void *
 661 encap6_ctlinput(int cmd, const struct sockaddr *sa, void *d0)
 662 {
 663         void *d = d0;
 664         struct ip6_hdr *ip6;
 665         struct mbuf *m;
 666         int off;
 667         struct ip6ctlparam *ip6cp = NULL;
 668         int nxt;
 669         struct encaptab *ep;
 670         const struct ip6protosw *psw;
 671
 672         if (sa->sa_family != AF_INET6 ||
 673             sa->sa_len != sizeof(struct sockaddr_in6))
 674                 return NULL;
 675
 676         if ((unsigned)cmd >= PRC_NCMDS)
 677                 return NULL;
 678         if (cmd == PRC_HOSTDEAD)
 679                 d = NULL;
 680         else if (cmd == PRC_MSGSIZE)
 681                 ; /* special code is present, see below */
 682         else if (inet6ctlerrmap[cmd] == 0)
 683                 return NULL;
 684
 685         /* if the parameter is from icmp6, decode it. */
 686         if (d != NULL) {
 687                 ip6cp = (struct ip6ctlparam *)d;
 688                 m = ip6cp->ip6c_m;
 689                 ip6 = ip6cp->ip6c_ip6;
 690                 off = ip6cp->ip6c_off;
 691                 nxt = ip6cp->ip6c_nxt;
 692
 693                 if (ip6 && cmd == PRC_MSGSIZE) {
 694                         int valid = 0;
 695                         struct encaptab *match;
 696
 697                         /*
 698                         * Check to see if we have a valid encap configuration.
 699                         */
 700                         match = encap6_lookup(m, off, nxt, OUTBOUND);
 701                         if (match)
 702                                 valid++;
 703
 704                         /*
 705                         * Depending on the value of "valid" and routing table
 706                         * size (mtudisc_{hi,lo}wat), we will:
 707                         * - recalcurate the new MTU and create the
 708                         *   corresponding routing entry, or
 709                         * - ignore the MTU change notification.
 710                         */
 711                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
 712                 }
 713         } else {
 714                 m = NULL;
 715                 ip6 = NULL;
 716                 nxt = -1;
 717         }
 718
 719         /* inform all listeners */
 720         LIST_FOREACH(ep, &encaptab, chain) {
 721                 if (ep->af != AF_INET6)
 722                         continue;
 723                 if (ep->proto >= 0 && ep->proto != nxt)
 724                         continue;
 725
 726                 /* should optimize by looking at address pairs */
 727
 728                 /* XXX need to pass ep->arg or ep itself to listeners */
 729                 psw = (const struct ip6protosw *)ep->psw;
 730                 if (psw && psw->pr_ctlinput)
 731                         (*psw->pr_ctlinput)(cmd, sa, d);
 732         }
 733
 734         rip6_ctlinput(cmd, sa, d0);
 735         return NULL;
 736 }
 737 #endif
 738
 739 int
 740 encap_detach(const struct encaptab *cookie)
 741 {
 742         const struct encaptab *ep = cookie;
 743         struct encaptab *p;
 744         int error;
 745
 746         LIST_FOREACH(p, &encaptab, chain) {
 747                 if (p == ep) {
 748                         error = encap_remove(p);
 749                         if (error)
 750                                 return error;
 751                         if (!ep->func) {
 752                                 free(p->addrpack, M_NETADDR);
 753                                 free(p->maskpack, M_NETADDR);
 754                         }
 755                         free(p, M_NETADDR);     /*XXX*/
 756                         return 0;
 757                 }
 758         }
 759
 760         return ENOENT;
 761 }
 762
 763 #ifdef USE_RADIX
 764 static struct radix_node_head *
 765 encap_rnh(int af)
 766 {
 767
 768         switch (af) {
 769         case AF_INET:
 770                 return encap_head[0];
 771 #ifdef INET6
 772         case AF_INET6:
 773                 return encap_head[1];
 774 #endif
 775         default:
 776                 return NULL;
 777         }
 778 }
 779
 780 static int
 781 mask_matchlen(const struct sockaddr *sa)
 782 {
 783         const char *p, *ep;
 784         int l;
 785
 786         p = (const char *)sa;
 787         ep = p + sa->sa_len;
 788         p += 2; /* sa_len + sa_family */
 789
 790         l = 0;
 791         while (p < ep) {
 792                 l += (*p ? 8 : 0);      /* estimate */
 793                 p++;
 794         }
 795         return l;
 796 }
 797 #endif
 798
 799 #ifndef USE_RADIX
 800 static int
 801 mask_match(const struct encaptab *ep,
 802            const struct sockaddr *sp,
 803            const struct sockaddr *dp)
 804 {
 805         struct sockaddr_storage s;
 806         struct sockaddr_storage d;
 807         int i;
 808         const u_int8_t *p, *q;
 809         u_int8_t *r;
 810         int matchlen;
 811
 812 #ifdef DIAGNOSTIC
 813         if (ep->func)
 814                 panic("wrong encaptab passed to mask_match");
 815 #endif
 816         if (sp->sa_len > sizeof(s) || dp->sa_len > sizeof(d))
 817                 return 0;
 818         if (sp->sa_family != ep->af || dp->sa_family != ep->af)
 819                 return 0;
 820         if (sp->sa_len != ep->src->sa_len || dp->sa_len != ep->dst->sa_len)
 821                 return 0;
 822
 823         matchlen = 0;
 824
 825         p = (const u_int8_t *)sp;
 826         q = (const u_int8_t *)ep->srcmask;
 827         r = (u_int8_t *)&s;
 828         for (i = 0 ; i < sp->sa_len; i++) {
 829                 r[i] = p[i] & q[i];
 830                 /* XXX estimate */
 831                 matchlen += (q[i] ? 8 : 0);
 832         }
 833
 834         p = (const u_int8_t *)dp;
 835         q = (const u_int8_t *)ep->dstmask;
 836         r = (u_int8_t *)&d;
 837         for (i = 0 ; i < dp->sa_len; i++) {
 838                 r[i] = p[i] & q[i];
 839                 /* XXX rough estimate */
 840                 matchlen += (q[i] ? 8 : 0);
 841         }
 842
 843         /* need to overwrite len/family portion as we don't compare them */
 844         s.ss_len = sp->sa_len;
 845         s.ss_family = sp->sa_family;
 846         d.ss_len = dp->sa_len;
 847         d.ss_family = dp->sa_family;
 848
 849         if (memcmp(&s, ep->src, ep->src->sa_len) == 0 &&
 850             memcmp(&d, ep->dst, ep->dst->sa_len) == 0) {
 851                 return matchlen;
 852         } else
 853                 return 0;
 854 }
 855 #endif
 856
 857 static void
 858 encap_fillarg(struct mbuf *m, const struct encaptab *ep)
 859 {
 860         struct m_tag *mtag;
 861
 862         mtag = m_tag_get(PACKET_TAG_ENCAP, sizeof(void *), M_NOWAIT);
 863         if (mtag) {
 864                 *(void **)(mtag + 1) = ep->arg;
 865                 m_tag_prepend(m, mtag);
 866         }
 867 }
 868
 869 void *
 870 encap_getarg(struct mbuf *m)
 871 {
 872         void *p;
 873         struct m_tag *mtag;
 874
 875         p = NULL;
 876         mtag = m_tag_find(m, PACKET_TAG_ENCAP, NULL);
 877         if (mtag != NULL) {
 878                 p = *(void **)(mtag + 1);
 879                 m_tag_delete(m, mtag);
 880         }
 881         return p;
 882 }