1 /* $NetBSD: in6_src.c,v 1.18 2003/12/10 11:46:33 itojun Exp $ */ 2 /* $KAME: in6_src.c,v 1.36 2001/02/06 04:08:17 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1991, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94 62 */ 63 64 #include <sys/cdefs.h> 65 __KERNEL_RCSID(0, "$NetBSD: in6_src.c,v 1.18 2003/12/10 11:46:33 itojun Exp $"); 66 67 #include "opt_inet.h" 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/malloc.h> 72 #include <sys/mbuf.h> 73 #include <sys/protosw.h> 74 #include <sys/socket.h> 75 #include <sys/socketvar.h> 76 #include <sys/ioctl.h> 77 #include <sys/errno.h> 78 #include <sys/time.h> 79 #include <sys/proc.h> 80 81 #include <net/if.h> 82 #include <net/route.h> 83 84 #include <netinet/in.h> 85 #include <netinet/in_var.h> 86 #include <netinet/in_systm.h> 87 #include <netinet/ip.h> 88 #include <netinet/in_pcb.h> 89 #include <netinet6/in6_var.h> 90 #include <netinet/ip6.h> 91 #include <netinet6/in6_pcb.h> 92 #include <netinet6/ip6_var.h> 93 #include <netinet6/nd6.h> 94 #ifdef ENABLE_DEFAULT_SCOPE 95 #include <netinet6/scope6_var.h> 96 #endif 97 98 #include <net/net_osdep.h> 99 100 #include "loop.h" 101 extern struct ifnet loif[NLOOP]; 102 103 /* 104 * Return an IPv6 address, which is the most appropriate for a given 105 * destination and user specified options. 106 * If necessary, this function lookups the routing table and returns 107 * an entry to the caller for later use. 108 */ 109 struct in6_addr * 110 in6_selectsrc(dstsock, opts, mopts, ro, laddr, errorp) 111 struct sockaddr_in6 *dstsock; 112 struct ip6_pktopts *opts; 113 struct ip6_moptions *mopts; 114 struct route_in6 *ro; 115 struct in6_addr *laddr; 116 int *errorp; 117 { 118 struct in6_addr *dst; 119 struct in6_ifaddr *ia6 = 0; 120 struct in6_pktinfo *pi = NULL; 121 122 dst = &dstsock->sin6_addr; 123 *errorp = 0; 124 125 /* 126 * If the source address is explicitly specified by the caller, 127 * use it. 128 */ 129 if (opts && (pi = opts->ip6po_pktinfo) && 130 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) 131 return (&pi->ipi6_addr); 132 133 /* 134 * If the source address is not specified but the socket(if any) 135 * is already bound, use the bound address. 136 */ 137 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) 138 return (laddr); 139 140 /* 141 * If the caller doesn't specify the source address but 142 * the outgoing interface, use an address associated with 143 * the interface. 144 */ 145 if (pi && pi->ipi6_ifindex) { 146 /* XXX boundary check is assumed to be already done. */ 147 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex], 148 dst); 149 if (ia6 == 0) { 150 *errorp = EADDRNOTAVAIL; 151 return (0); 152 } 153 return (&satosin6(&ia6->ia_addr)->sin6_addr); 154 } 155 156 /* 157 * If the destination address is a link-local unicast address or 158 * a multicast address, and if the outgoing interface is specified 159 * by the sin6_scope_id filed, use an address associated with the 160 * interface. 161 * XXX: We're now trying to define more specific semantics of 162 * sin6_scope_id field, so this part will be rewritten in 163 * the near future. 164 */ 165 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) && 166 dstsock->sin6_scope_id) { 167 /* 168 * I'm not sure if boundary check for scope_id is done 169 * somewhere... 170 */ 171 if (dstsock->sin6_scope_id < 0 || 172 if_indexlim <= dstsock->sin6_scope_id || 173 !ifindex2ifnet[dstsock->sin6_scope_id]) { 174 *errorp = ENXIO; /* XXX: better error? */ 175 return (0); 176 } 177 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id], 178 dst); 179 if (ia6 == 0) { 180 *errorp = EADDRNOTAVAIL; 181 return (0); 182 } 183 return (&satosin6(&ia6->ia_addr)->sin6_addr); 184 } 185 186 /* 187 * If the destination address is a multicast address and 188 * the outgoing interface for the address is specified 189 * by the caller, use an address associated with the interface. 190 * There is a sanity check here; if the destination has node-local 191 * scope, the outgoing interfacde should be a loopback address. 192 * Even if the outgoing interface is not specified, we also 193 * choose a loopback interface as the outgoing interface. 194 */ 195 if (IN6_IS_ADDR_MULTICAST(dst)) { 196 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 197 198 if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) { 199 ifp = &loif[0]; 200 } 201 202 if (ifp) { 203 ia6 = in6_ifawithscope(ifp, dst); 204 if (ia6 == 0) { 205 *errorp = EADDRNOTAVAIL; 206 return (0); 207 } 208 return (&satosin6(&ia6->ia_addr)->sin6_addr); 209 } 210 } 211 212 /* 213 * If the next hop address for the packet is specified 214 * by caller, use an address associated with the route 215 * to the next hop. 216 */ 217 { 218 struct sockaddr_in6 *sin6_next; 219 struct rtentry *rt; 220 221 if (opts && opts->ip6po_nexthop) { 222 sin6_next = satosin6(opts->ip6po_nexthop); 223 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); 224 if (rt) { 225 ia6 = in6_ifawithscope(rt->rt_ifp, dst); 226 if (ia6 == 0) 227 ia6 = ifatoia6(rt->rt_ifa); 228 } 229 if (ia6 == 0) { 230 *errorp = EADDRNOTAVAIL; 231 return (0); 232 } 233 return (&satosin6(&ia6->ia_addr)->sin6_addr); 234 } 235 } 236 237 /* 238 * If route is known or can be allocated now, 239 * our src addr is taken from the i/f, else punt. 240 * Note that we should check the address family of the 241 * cached destination, in case of sharing the cache with IPv4. 242 */ 243 if (ro) { 244 if (ro->ro_rt && 245 (ro->ro_dst.sin6_family != AF_INET6 || 246 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst))) { 247 RTFREE(ro->ro_rt); 248 ro->ro_rt = (struct rtentry *)0; 249 } 250 if (ro->ro_rt == (struct rtentry *)0 || 251 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 252 struct sockaddr_in6 *sa6; 253 254 /* No route yet, so try to acquire one */ 255 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 256 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 257 sa6->sin6_family = AF_INET6; 258 sa6->sin6_len = sizeof(struct sockaddr_in6); 259 sa6->sin6_addr = *dst; 260 sa6->sin6_scope_id = dstsock->sin6_scope_id; 261 if (IN6_IS_ADDR_MULTICAST(dst)) { 262 ro->ro_rt = rtalloc1(&((struct route *)ro) 263 ->ro_dst, 0); 264 } else { 265 rtalloc((struct route *)ro); 266 } 267 } 268 269 /* 270 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 271 * the address. But we don't know why it does so. 272 * It is necessary to ensure the scope even for lo0 273 * so doesn't check out IFF_LOOPBACK. 274 */ 275 276 if (ro->ro_rt) { 277 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); 278 if (ia6 == 0) /* xxx scope error ?*/ 279 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 280 } 281 #if 0 282 /* 283 * xxx The followings are necessary? (kazu) 284 * I don't think so. 285 * It's for SO_DONTROUTE option in IPv4.(jinmei) 286 */ 287 if (ia6 == 0) { 288 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 289 290 sin6->sin6_addr = *dst; 291 292 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 293 if (ia6 == 0) 294 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 295 if (ia6 == 0) 296 return (0); 297 return (&satosin6(&ia6->ia_addr)->sin6_addr); 298 } 299 #endif /* 0 */ 300 if (ia6 == 0) { 301 *errorp = EHOSTUNREACH; /* no route */ 302 return (0); 303 } 304 return (&satosin6(&ia6->ia_addr)->sin6_addr); 305 } 306 307 *errorp = EADDRNOTAVAIL; 308 return (0); 309 } 310 311 /* 312 * Default hop limit selection. The precedence is as follows: 313 * 1. Hoplimit value specified via ioctl. 314 * 2. (If the outgoing interface is detected) the current 315 * hop limit of the interface specified by router advertisement. 316 * 3. The system default hoplimit. 317 */ 318 int 319 in6_selecthlim(in6p, ifp) 320 struct in6pcb *in6p; 321 struct ifnet *ifp; 322 { 323 if (in6p && in6p->in6p_af != AF_INET6) 324 return (-1); 325 326 if (in6p && in6p->in6p_hops >= 0) 327 return (in6p->in6p_hops); 328 else if (ifp) 329 return (ND_IFINFO(ifp)->chlim); 330 else 331 return (ip6_defhlim); 332 } 333 334 /* 335 * Find an empty port and set it to the specified PCB. 336 */ 337 int 338 in6_pcbsetport(laddr, in6p, p) 339 struct in6_addr *laddr; 340 struct in6pcb *in6p; 341 struct proc *p; 342 { 343 struct socket *so = in6p->in6p_socket; 344 struct inpcbtable *table = in6p->in6p_table; 345 int cnt; 346 u_int16_t min, max; 347 u_int16_t lport, *lastport; 348 int wild = 0; 349 void *t; 350 351 if (in6p->in6p_af != AF_INET6) 352 return (EINVAL); 353 354 /* XXX: this is redundant when called from in6_pcbbind */ 355 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 && 356 ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 || 357 (so->so_options & SO_ACCEPTCONN) == 0)) 358 wild = 1; 359 360 if (in6p->in6p_flags & IN6P_LOWPORT) { 361 #ifndef IPNOPRIVPORTS 362 if (p == 0 || (suser(p->p_ucred, &p->p_acflag) != 0)) 363 return (EACCES); 364 #endif 365 min = ip6_lowportmin; 366 max = ip6_lowportmax; 367 lastport = &table->inpt_lastlow; 368 } else { 369 min = ip6_anonportmin; 370 max = ip6_anonportmax; 371 lastport = &table->inpt_lastport; 372 } 373 if (min > max) { /* sanity check */ 374 u_int16_t swp; 375 376 swp = min; 377 min = max; 378 max = swp; 379 } 380 381 lport = *lastport - 1; 382 for (cnt = max - min + 1; cnt; cnt--, lport--) { 383 if (lport < min || lport > max) 384 lport = max; 385 #ifdef INET 386 if (IN6_IS_ADDR_V4MAPPED(laddr)) { 387 t = in_pcblookup_port(table, 388 *(struct in_addr *)&in6p->in6p_laddr.s6_addr32[3], 389 lport, wild); 390 } else 391 #endif 392 { 393 t = in6_pcblookup_port(table, laddr, lport, wild); 394 } 395 if (t == 0) 396 goto found; 397 } 398 399 return (EAGAIN); 400 401 found: 402 in6p->in6p_flags |= IN6P_ANONPORT; 403 *lastport = lport; 404 in6p->in6p_lport = htons(lport); 405 in6_pcbstate(in6p, IN6P_BOUND); 406 return (0); /* success */ 407 } 408 409 /* 410 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 411 * If the address scope of is link-local, embed the interface index in the 412 * address. The routine determines our precedence 413 * between advanced API scope/interface specification and basic API 414 * specification. 415 * 416 * this function should be nuked in the future, when we get rid of 417 * embedded scopeid thing. 418 * 419 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 420 * there can be multiple interfaces that belong to a particular scope zone 421 * (in specification, we have 1:N mapping between a scope zone and interfaces). 422 * we may want to change the function to return something other than ifp. 423 */ 424 int 425 in6_embedscope(in6, sin6, in6p, ifpp) 426 struct in6_addr *in6; 427 const struct sockaddr_in6 *sin6; 428 struct in6pcb *in6p; 429 struct ifnet **ifpp; 430 { 431 struct ifnet *ifp = NULL; 432 u_int32_t scopeid; 433 434 *in6 = sin6->sin6_addr; 435 scopeid = sin6->sin6_scope_id; 436 if (ifpp) 437 *ifpp = NULL; 438 439 /* 440 * don't try to read sin6->sin6_addr beyond here, since the caller may 441 * ask us to overwrite existing sockaddr_in6 442 */ 443 444 #ifdef ENABLE_DEFAULT_SCOPE 445 if (scopeid == 0) 446 scopeid = scope6_addr2default(in6); 447 #endif 448 449 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 450 struct in6_pktinfo *pi; 451 452 /* 453 * KAME assumption: link id == interface id 454 */ 455 456 if (in6p && in6p->in6p_outputopts && 457 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 458 pi->ipi6_ifindex) { 459 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 460 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 461 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 462 in6p->in6p_moptions && 463 in6p->in6p_moptions->im6o_multicast_ifp) { 464 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 465 in6->s6_addr16[1] = htons(ifp->if_index); 466 } else if (scopeid) { 467 /* boundary check */ 468 if (scopeid < 0 || if_indexlim <= scopeid || 469 !ifindex2ifnet[scopeid]) 470 return ENXIO; /* XXX EINVAL? */ 471 ifp = ifindex2ifnet[scopeid]; 472 /* XXX assignment to 16bit from 32bit variable */ 473 in6->s6_addr16[1] = htons(scopeid & 0xffff); 474 } 475 476 if (ifpp) 477 *ifpp = ifp; 478 } 479 480 return 0; 481 } 482 483 /* 484 * generate standard sockaddr_in6 from embedded form. 485 * touches sin6_addr and sin6_scope_id only. 486 * 487 * this function should be nuked in the future, when we get rid of 488 * embedded scopeid thing. 489 */ 490 int 491 in6_recoverscope(sin6, in6, ifp) 492 struct sockaddr_in6 *sin6; 493 const struct in6_addr *in6; 494 struct ifnet *ifp; 495 { 496 u_int32_t scopeid; 497 498 sin6->sin6_addr = *in6; 499 500 /* 501 * don't try to read *in6 beyond here, since the caller may 502 * ask us to overwrite existing sockaddr_in6 503 */ 504 505 sin6->sin6_scope_id = 0; 506 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 507 /* 508 * KAME assumption: link id == interface id 509 */ 510 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 511 if (scopeid) { 512 /* sanity check */ 513 if (scopeid < 0 || if_indexlim <= scopeid || 514 !ifindex2ifnet[scopeid]) 515 return ENXIO; 516 if (ifp && ifp->if_index != scopeid) 517 return ENXIO; 518 sin6->sin6_addr.s6_addr16[1] = 0; 519 sin6->sin6_scope_id = scopeid; 520 } 521 } 522 523 return 0; 524 } 525 526 /* 527 * just clear the embedded scope identifer. 528 */ 529 void 530 in6_clearscope(addr) 531 struct in6_addr *addr; 532 { 533 if (IN6_IS_SCOPE_LINKLOCAL(addr)) 534 addr->s6_addr16[1] = 0; 535 } 536