1 /* $NetBSD: in6_src.c,v 1.10 2002/01/22 03:53:56 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. All advertising materials mentioning features or use of this software 46 * must display the following acknowledgement: 47 * This product includes software developed by the University of 48 * California, Berkeley and its contributors. 49 * 4. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94 66 */ 67 68 #include <sys/cdefs.h> 69 __KERNEL_RCSID(0, "$NetBSD: in6_src.c,v 1.10 2002/01/22 03:53:56 itojun Exp $"); 70 71 #include "opt_inet.h" 72 73 #include <sys/param.h> 74 #include <sys/systm.h> 75 #include <sys/malloc.h> 76 #include <sys/mbuf.h> 77 #include <sys/protosw.h> 78 #include <sys/socket.h> 79 #include <sys/socketvar.h> 80 #include <sys/ioctl.h> 81 #include <sys/errno.h> 82 #include <sys/time.h> 83 #include <sys/proc.h> 84 85 #include <net/if.h> 86 #include <net/route.h> 87 88 #include <netinet/in.h> 89 #include <netinet/in_var.h> 90 #include <netinet/in_systm.h> 91 #include <netinet/ip.h> 92 #include <netinet/in_pcb.h> 93 #include <netinet6/in6_var.h> 94 #include <netinet/ip6.h> 95 #include <netinet6/in6_pcb.h> 96 #include <netinet6/ip6_var.h> 97 #include <netinet6/nd6.h> 98 #ifdef ENABLE_DEFAULT_SCOPE 99 #include <netinet6/scope6_var.h> 100 #endif 101 102 #include <net/net_osdep.h> 103 104 #include "loop.h" 105 extern struct ifnet loif[NLOOP]; 106 107 /* 108 * Return an IPv6 address, which is the most appropriate for a given 109 * destination and user specified options. 110 * If necessary, this function lookups the routing table and returns 111 * an entry to the caller for later use. 112 */ 113 struct in6_addr * 114 in6_selectsrc(dstsock, opts, mopts, ro, laddr, errorp) 115 struct sockaddr_in6 *dstsock; 116 struct ip6_pktopts *opts; 117 struct ip6_moptions *mopts; 118 struct route_in6 *ro; 119 struct in6_addr *laddr; 120 int *errorp; 121 { 122 struct in6_addr *dst; 123 struct in6_ifaddr *ia6 = 0; 124 struct in6_pktinfo *pi = NULL; 125 126 dst = &dstsock->sin6_addr; 127 *errorp = 0; 128 129 /* 130 * If the source address is explicitly specified by the caller, 131 * use it. 132 */ 133 if (opts && (pi = opts->ip6po_pktinfo) && 134 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) 135 return(&pi->ipi6_addr); 136 137 /* 138 * If the source address is not specified but the socket(if any) 139 * is already bound, use the bound address. 140 */ 141 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) 142 return(laddr); 143 144 /* 145 * If the caller doesn't specify the source address but 146 * the outgoing interface, use an address associated with 147 * the interface. 148 */ 149 if (pi && pi->ipi6_ifindex) { 150 /* XXX boundary check is assumed to be already done. */ 151 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex], 152 dst); 153 if (ia6 == 0) { 154 *errorp = EADDRNOTAVAIL; 155 return(0); 156 } 157 return(&satosin6(&ia6->ia_addr)->sin6_addr); 158 } 159 160 /* 161 * If the destination address is a link-local unicast address or 162 * a multicast address, and if the outgoing interface is specified 163 * by the sin6_scope_id filed, use an address associated with the 164 * interface. 165 * XXX: We're now trying to define more specific semantics of 166 * sin6_scope_id field, so this part will be rewritten in 167 * the near future. 168 */ 169 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) && 170 dstsock->sin6_scope_id) { 171 /* 172 * I'm not sure if boundary check for scope_id is done 173 * somewhere... 174 */ 175 if (dstsock->sin6_scope_id < 0 || 176 if_index < dstsock->sin6_scope_id) { 177 *errorp = ENXIO; /* XXX: better error? */ 178 return(0); 179 } 180 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id], 181 dst); 182 if (ia6 == 0) { 183 *errorp = EADDRNOTAVAIL; 184 return(0); 185 } 186 return(&satosin6(&ia6->ia_addr)->sin6_addr); 187 } 188 189 /* 190 * If the destination address is a multicast address and 191 * the outgoing interface for the address is specified 192 * by the caller, use an address associated with the interface. 193 * There is a sanity check here; if the destination has node-local 194 * scope, the outgoing interfacde should be a loopback address. 195 * Even if the outgoing interface is not specified, we also 196 * choose a loopback interface as the outgoing interface. 197 */ 198 if (IN6_IS_ADDR_MULTICAST(dst)) { 199 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 200 201 if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) { 202 ifp = &loif[0]; 203 } 204 205 if (ifp) { 206 ia6 = in6_ifawithscope(ifp, dst); 207 if (ia6 == 0) { 208 *errorp = EADDRNOTAVAIL; 209 return(0); 210 } 211 return(&satosin6(&ia6->ia_addr)->sin6_addr); 212 } 213 } 214 215 /* 216 * If the next hop address for the packet is specified 217 * by caller, use an address associated with the route 218 * to the next hop. 219 */ 220 { 221 struct sockaddr_in6 *sin6_next; 222 struct rtentry *rt; 223 224 if (opts && opts->ip6po_nexthop) { 225 sin6_next = satosin6(opts->ip6po_nexthop); 226 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); 227 if (rt) { 228 ia6 = in6_ifawithscope(rt->rt_ifp, dst); 229 if (ia6 == 0) 230 ia6 = ifatoia6(rt->rt_ifa); 231 } 232 if (ia6 == 0) { 233 *errorp = EADDRNOTAVAIL; 234 return(0); 235 } 236 return(&satosin6(&ia6->ia_addr)->sin6_addr); 237 } 238 } 239 240 /* 241 * If route is known or can be allocated now, 242 * our src addr is taken from the i/f, else punt. 243 * Note that we should check the address family of the 244 * cached destination, in case of sharing the cache with IPv4. 245 */ 246 if (ro) { 247 if (ro->ro_rt && 248 (ro->ro_dst.sin6_family != AF_INET6 || 249 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst))) { 250 RTFREE(ro->ro_rt); 251 ro->ro_rt = (struct rtentry *)0; 252 } 253 if (ro->ro_rt == (struct rtentry *)0 || 254 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 255 struct sockaddr_in6 *sa6; 256 257 /* No route yet, so try to acquire one */ 258 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 259 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 260 sa6->sin6_family = AF_INET6; 261 sa6->sin6_len = sizeof(struct sockaddr_in6); 262 sa6->sin6_addr = *dst; 263 sa6->sin6_scope_id = dstsock->sin6_scope_id; 264 if (IN6_IS_ADDR_MULTICAST(dst)) { 265 ro->ro_rt = rtalloc1(&((struct route *)ro) 266 ->ro_dst, 0); 267 } else { 268 rtalloc((struct route *)ro); 269 } 270 } 271 272 /* 273 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 274 * the address. But we don't know why it does so. 275 * It is necessary to ensure the scope even for lo0 276 * so doesn't check out IFF_LOOPBACK. 277 */ 278 279 if (ro->ro_rt) { 280 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); 281 if (ia6 == 0) /* xxx scope error ?*/ 282 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 283 } 284 #if 0 285 /* 286 * xxx The followings are necessary? (kazu) 287 * I don't think so. 288 * It's for SO_DONTROUTE option in IPv4.(jinmei) 289 */ 290 if (ia6 == 0) { 291 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 292 293 sin6->sin6_addr = *dst; 294 295 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 296 if (ia6 == 0) 297 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 298 if (ia6 == 0) 299 return(0); 300 return(&satosin6(&ia6->ia_addr)->sin6_addr); 301 } 302 #endif /* 0 */ 303 if (ia6 == 0) { 304 *errorp = EHOSTUNREACH; /* no route */ 305 return(0); 306 } 307 return(&satosin6(&ia6->ia_addr)->sin6_addr); 308 } 309 310 *errorp = EADDRNOTAVAIL; 311 return(0); 312 } 313 314 /* 315 * Default hop limit selection. The precedence is as follows: 316 * 1. Hoplimit value specified via ioctl. 317 * 2. (If the outgoing interface is detected) the current 318 * hop limit of the interface specified by router advertisement. 319 * 3. The system default hoplimit. 320 */ 321 int 322 in6_selecthlim(in6p, ifp) 323 struct in6pcb *in6p; 324 struct ifnet *ifp; 325 { 326 if (in6p && in6p->in6p_hops >= 0) 327 return(in6p->in6p_hops); 328 else if (ifp) 329 return(nd_ifinfo[ifp->if_index].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) 339 struct in6_addr *laddr; 340 struct in6pcb *in6p; 341 { 342 struct socket *so = in6p->in6p_socket; 343 struct in6pcb *head = in6p->in6p_head; 344 u_int16_t last_port, lport = 0; 345 int wild = 0; 346 void *t; 347 u_int16_t min, max; 348 349 /* XXX: this is redundant when called from in6_pcbbind */ 350 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 && 351 ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 || 352 (so->so_options & SO_ACCEPTCONN) == 0)) 353 wild = IN6PLOOKUP_WILDCARD; 354 355 if (in6p->in6p_flags & IN6P_LOWPORT) { 356 #ifndef IPNOPRIVPORTS 357 struct proc *p = curproc; /* XXX */ 358 359 if (p == 0 || (suser(p->p_ucred, &p->p_acflag) != 0)) 360 return (EACCES); 361 #endif 362 min = ip6_lowportmin; 363 max = ip6_lowportmax; 364 } else { 365 min = ip6_anonportmin; 366 max = ip6_anonportmax; 367 } 368 369 /* value out of range */ 370 if (head->in6p_lport < min) 371 head->in6p_lport = min; 372 else if (head->in6p_lport > max) 373 head->in6p_lport = min; 374 last_port = head->in6p_lport; 375 goto startover; /*to randomize*/ 376 for (;;) { 377 lport = htons(head->in6p_lport); 378 if (IN6_IS_ADDR_V4MAPPED(laddr)) { 379 #if 0 380 t = in_pcblookup_bind(&tcbtable, 381 (struct in_addr *)&in6p->in6p_laddr.s6_addr32[3], 382 lport); 383 #else 384 t = NULL; 385 #endif 386 } else { 387 t = in6_pcblookup(head, &zeroin6_addr, 0, laddr, 388 lport, wild); 389 } 390 if (t == 0) 391 break; 392 startover: 393 if (head->in6p_lport >= max) 394 head->in6p_lport = min; 395 else 396 head->in6p_lport++; 397 if (head->in6p_lport == last_port) 398 return (EADDRINUSE); 399 } 400 401 in6p->in6p_lport = lport; 402 return(0); /* success */ 403 } 404 405 /* 406 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 407 * If the address scope of is link-local, embed the interface index in the 408 * address. The routine determines our precedence 409 * between advanced API scope/interface specification and basic API 410 * specification. 411 * 412 * this function should be nuked in the future, when we get rid of 413 * embedded scopeid thing. 414 * 415 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 416 * there can be multiple interfaces that belong to a particular scope zone 417 * (in specification, we have 1:N mapping between a scope zone and interfaces). 418 * we may want to change the function to return something other than ifp. 419 */ 420 int 421 in6_embedscope(in6, sin6, in6p, ifpp) 422 struct in6_addr *in6; 423 const struct sockaddr_in6 *sin6; 424 struct in6pcb *in6p; 425 struct ifnet **ifpp; 426 { 427 struct ifnet *ifp = NULL; 428 u_int32_t scopeid; 429 430 *in6 = sin6->sin6_addr; 431 scopeid = sin6->sin6_scope_id; 432 if (ifpp) 433 *ifpp = NULL; 434 435 /* 436 * don't try to read sin6->sin6_addr beyond here, since the caller may 437 * ask us to overwrite existing sockaddr_in6 438 */ 439 440 #ifdef ENABLE_DEFAULT_SCOPE 441 if (scopeid == 0) 442 scopeid = scope6_addr2default(in6); 443 #endif 444 445 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 446 struct in6_pktinfo *pi; 447 448 /* 449 * KAME assumption: link id == interface id 450 */ 451 452 if (in6p && in6p->in6p_outputopts && 453 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 454 pi->ipi6_ifindex) { 455 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 456 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 457 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 458 in6p->in6p_moptions && 459 in6p->in6p_moptions->im6o_multicast_ifp) { 460 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 461 in6->s6_addr16[1] = htons(ifp->if_index); 462 } else if (scopeid) { 463 /* boundary check */ 464 if (scopeid < 0 || if_index < scopeid) 465 return ENXIO; /* XXX EINVAL? */ 466 ifp = ifindex2ifnet[scopeid]; 467 /* XXX assignment to 16bit from 32bit variable */ 468 in6->s6_addr16[1] = htons(scopeid & 0xffff); 469 } 470 471 if (ifpp) 472 *ifpp = ifp; 473 } 474 475 return 0; 476 } 477 478 /* 479 * generate standard sockaddr_in6 from embedded form. 480 * touches sin6_addr and sin6_scope_id only. 481 * 482 * this function should be nuked in the future, when we get rid of 483 * embedded scopeid thing. 484 */ 485 int 486 in6_recoverscope(sin6, in6, ifp) 487 struct sockaddr_in6 *sin6; 488 const struct in6_addr *in6; 489 struct ifnet *ifp; 490 { 491 u_int32_t scopeid; 492 493 sin6->sin6_addr = *in6; 494 495 /* 496 * don't try to read *in6 beyond here, since the caller may 497 * ask us to overwrite existing sockaddr_in6 498 */ 499 500 sin6->sin6_scope_id = 0; 501 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 502 /* 503 * KAME assumption: link id == interface id 504 */ 505 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 506 if (scopeid) { 507 /* sanity check */ 508 if (scopeid < 0 || if_index < scopeid) 509 return ENXIO; 510 if (ifp && ifp->if_index != scopeid) 511 return ENXIO; 512 sin6->sin6_addr.s6_addr16[1] = 0; 513 sin6->sin6_scope_id = scopeid; 514 } 515 } 516 517 return 0; 518 } 519 520 /* 521 * just clear the embedded scope identifer. 522 * XXX: currently used for bsdi4 only as a supplement function. 523 */ 524 void 525 in6_clearscope(addr) 526 struct in6_addr *addr; 527 { 528 if (IN6_IS_SCOPE_LINKLOCAL(addr)) 529 addr->s6_addr16[1] = 0; 530 } 531