1 /* $NetBSD: in6_src.c,v 1.16 2003/08/07 16:33:26 agc 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 1.16 2003/08/07 16:33:26 agc 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_index < dstsock->sin6_scope_id) { 173 *errorp = ENXIO; /* XXX: better error? */ 174 return (0); 175 } 176 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id], 177 dst); 178 if (ia6 == 0) { 179 *errorp = EADDRNOTAVAIL; 180 return (0); 181 } 182 return (&satosin6(&ia6->ia_addr)->sin6_addr); 183 } 184 185 /* 186 * If the destination address is a multicast address and 187 * the outgoing interface for the address is specified 188 * by the caller, use an address associated with the interface. 189 * There is a sanity check here; if the destination has node-local 190 * scope, the outgoing interfacde should be a loopback address. 191 * Even if the outgoing interface is not specified, we also 192 * choose a loopback interface as the outgoing interface. 193 */ 194 if (IN6_IS_ADDR_MULTICAST(dst)) { 195 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 196 197 if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) { 198 ifp = &loif[0]; 199 } 200 201 if (ifp) { 202 ia6 = in6_ifawithscope(ifp, dst); 203 if (ia6 == 0) { 204 *errorp = EADDRNOTAVAIL; 205 return (0); 206 } 207 return (&satosin6(&ia6->ia_addr)->sin6_addr); 208 } 209 } 210 211 /* 212 * If the next hop address for the packet is specified 213 * by caller, use an address associated with the route 214 * to the next hop. 215 */ 216 { 217 struct sockaddr_in6 *sin6_next; 218 struct rtentry *rt; 219 220 if (opts && opts->ip6po_nexthop) { 221 sin6_next = satosin6(opts->ip6po_nexthop); 222 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); 223 if (rt) { 224 ia6 = in6_ifawithscope(rt->rt_ifp, dst); 225 if (ia6 == 0) 226 ia6 = ifatoia6(rt->rt_ifa); 227 } 228 if (ia6 == 0) { 229 *errorp = EADDRNOTAVAIL; 230 return (0); 231 } 232 return (&satosin6(&ia6->ia_addr)->sin6_addr); 233 } 234 } 235 236 /* 237 * If route is known or can be allocated now, 238 * our src addr is taken from the i/f, else punt. 239 * Note that we should check the address family of the 240 * cached destination, in case of sharing the cache with IPv4. 241 */ 242 if (ro) { 243 if (ro->ro_rt && 244 (ro->ro_dst.sin6_family != AF_INET6 || 245 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst))) { 246 RTFREE(ro->ro_rt); 247 ro->ro_rt = (struct rtentry *)0; 248 } 249 if (ro->ro_rt == (struct rtentry *)0 || 250 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 251 struct sockaddr_in6 *sa6; 252 253 /* No route yet, so try to acquire one */ 254 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 255 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 256 sa6->sin6_family = AF_INET6; 257 sa6->sin6_len = sizeof(struct sockaddr_in6); 258 sa6->sin6_addr = *dst; 259 sa6->sin6_scope_id = dstsock->sin6_scope_id; 260 if (IN6_IS_ADDR_MULTICAST(dst)) { 261 ro->ro_rt = rtalloc1(&((struct route *)ro) 262 ->ro_dst, 0); 263 } else { 264 rtalloc((struct route *)ro); 265 } 266 } 267 268 /* 269 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 270 * the address. But we don't know why it does so. 271 * It is necessary to ensure the scope even for lo0 272 * so doesn't check out IFF_LOOPBACK. 273 */ 274 275 if (ro->ro_rt) { 276 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); 277 if (ia6 == 0) /* xxx scope error ?*/ 278 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 279 } 280 #if 0 281 /* 282 * xxx The followings are necessary? (kazu) 283 * I don't think so. 284 * It's for SO_DONTROUTE option in IPv4.(jinmei) 285 */ 286 if (ia6 == 0) { 287 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 288 289 sin6->sin6_addr = *dst; 290 291 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 292 if (ia6 == 0) 293 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 294 if (ia6 == 0) 295 return (0); 296 return (&satosin6(&ia6->ia_addr)->sin6_addr); 297 } 298 #endif /* 0 */ 299 if (ia6 == 0) { 300 *errorp = EHOSTUNREACH; /* no route */ 301 return (0); 302 } 303 return (&satosin6(&ia6->ia_addr)->sin6_addr); 304 } 305 306 *errorp = EADDRNOTAVAIL; 307 return (0); 308 } 309 310 /* 311 * Default hop limit selection. The precedence is as follows: 312 * 1. Hoplimit value specified via ioctl. 313 * 2. (If the outgoing interface is detected) the current 314 * hop limit of the interface specified by router advertisement. 315 * 3. The system default hoplimit. 316 */ 317 int 318 in6_selecthlim(in6p, ifp) 319 struct in6pcb *in6p; 320 struct ifnet *ifp; 321 { 322 if (in6p && in6p->in6p_hops >= 0) 323 return (in6p->in6p_hops); 324 else if (ifp) 325 return (ND_IFINFO(ifp)->chlim); 326 else 327 return (ip6_defhlim); 328 } 329 330 /* 331 * Find an empty port and set it to the specified PCB. 332 */ 333 int 334 in6_pcbsetport(laddr, in6p, p) 335 struct in6_addr *laddr; 336 struct in6pcb *in6p; 337 struct proc *p; 338 { 339 struct socket *so = in6p->in6p_socket; 340 struct in6pcb *head = in6p->in6p_head; 341 u_int16_t last_port, lport = 0; 342 int wild = 0; 343 void *t; 344 u_int16_t min, max; 345 346 /* XXX: this is redundant when called from in6_pcbbind */ 347 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 && 348 ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 || 349 (so->so_options & SO_ACCEPTCONN) == 0)) 350 wild = IN6PLOOKUP_WILDCARD; 351 352 if (in6p->in6p_flags & IN6P_LOWPORT) { 353 #ifndef IPNOPRIVPORTS 354 if (p == 0 || (suser(p->p_ucred, &p->p_acflag) != 0)) 355 return (EACCES); 356 #endif 357 min = ip6_lowportmin; 358 max = ip6_lowportmax; 359 } else { 360 min = ip6_anonportmin; 361 max = ip6_anonportmax; 362 } 363 364 /* value out of range */ 365 if (head->in6p_lport < min) 366 head->in6p_lport = min; 367 else if (head->in6p_lport > max) 368 head->in6p_lport = min; 369 last_port = head->in6p_lport; 370 goto startover; /*to randomize*/ 371 for (;;) { 372 lport = htons(head->in6p_lport); 373 if (IN6_IS_ADDR_V4MAPPED(laddr)) { 374 #if 0 375 t = in_pcblookup_bind(&tcbtable, 376 (struct in_addr *)&in6p->in6p_laddr.s6_addr32[3], 377 lport); 378 #else 379 t = NULL; 380 #endif 381 } else { 382 t = in6_pcblookup(head, &zeroin6_addr, 0, laddr, 383 lport, wild); 384 } 385 if (t == 0) 386 break; 387 startover: 388 if (head->in6p_lport >= max) 389 head->in6p_lport = min; 390 else 391 head->in6p_lport++; 392 if (head->in6p_lport == last_port) 393 return (EADDRINUSE); 394 } 395 396 in6p->in6p_lport = lport; 397 return (0); /* success */ 398 } 399 400 /* 401 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 402 * If the address scope of is link-local, embed the interface index in the 403 * address. The routine determines our precedence 404 * between advanced API scope/interface specification and basic API 405 * specification. 406 * 407 * this function should be nuked in the future, when we get rid of 408 * embedded scopeid thing. 409 * 410 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 411 * there can be multiple interfaces that belong to a particular scope zone 412 * (in specification, we have 1:N mapping between a scope zone and interfaces). 413 * we may want to change the function to return something other than ifp. 414 */ 415 int 416 in6_embedscope(in6, sin6, in6p, ifpp) 417 struct in6_addr *in6; 418 const struct sockaddr_in6 *sin6; 419 struct in6pcb *in6p; 420 struct ifnet **ifpp; 421 { 422 struct ifnet *ifp = NULL; 423 u_int32_t scopeid; 424 425 *in6 = sin6->sin6_addr; 426 scopeid = sin6->sin6_scope_id; 427 if (ifpp) 428 *ifpp = NULL; 429 430 /* 431 * don't try to read sin6->sin6_addr beyond here, since the caller may 432 * ask us to overwrite existing sockaddr_in6 433 */ 434 435 #ifdef ENABLE_DEFAULT_SCOPE 436 if (scopeid == 0) 437 scopeid = scope6_addr2default(in6); 438 #endif 439 440 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 441 struct in6_pktinfo *pi; 442 443 /* 444 * KAME assumption: link id == interface id 445 */ 446 447 if (in6p && in6p->in6p_outputopts && 448 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 449 pi->ipi6_ifindex) { 450 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 451 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 452 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 453 in6p->in6p_moptions && 454 in6p->in6p_moptions->im6o_multicast_ifp) { 455 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 456 in6->s6_addr16[1] = htons(ifp->if_index); 457 } else if (scopeid) { 458 /* boundary check */ 459 if (scopeid < 0 || if_index < scopeid) 460 return ENXIO; /* XXX EINVAL? */ 461 ifp = ifindex2ifnet[scopeid]; 462 /* XXX assignment to 16bit from 32bit variable */ 463 in6->s6_addr16[1] = htons(scopeid & 0xffff); 464 } 465 466 if (ifpp) 467 *ifpp = ifp; 468 } 469 470 return 0; 471 } 472 473 /* 474 * generate standard sockaddr_in6 from embedded form. 475 * touches sin6_addr and sin6_scope_id only. 476 * 477 * this function should be nuked in the future, when we get rid of 478 * embedded scopeid thing. 479 */ 480 int 481 in6_recoverscope(sin6, in6, ifp) 482 struct sockaddr_in6 *sin6; 483 const struct in6_addr *in6; 484 struct ifnet *ifp; 485 { 486 u_int32_t scopeid; 487 488 sin6->sin6_addr = *in6; 489 490 /* 491 * don't try to read *in6 beyond here, since the caller may 492 * ask us to overwrite existing sockaddr_in6 493 */ 494 495 sin6->sin6_scope_id = 0; 496 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 497 /* 498 * KAME assumption: link id == interface id 499 */ 500 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 501 if (scopeid) { 502 /* sanity check */ 503 if (scopeid < 0 || if_index < scopeid) 504 return ENXIO; 505 if (ifp && ifp->if_index != scopeid) 506 return ENXIO; 507 sin6->sin6_addr.s6_addr16[1] = 0; 508 sin6->sin6_scope_id = scopeid; 509 } 510 } 511 512 return 0; 513 } 514 515 /* 516 * just clear the embedded scope identifer. 517 */ 518 void 519 in6_clearscope(addr) 520 struct in6_addr *addr; 521 { 522 if (IN6_IS_SCOPE_LINKLOCAL(addr)) 523 addr->s6_addr16[1] = 0; 524 } 525