1 /* $FreeBSD: src/sys/netinet6/in6_src.c,v 1.1.2.3 2002/02/26 18:02:06 ume Exp $ */ 2 /* $DragonFly: src/sys/netinet6/in6_src.c,v 1.7 2004/05/20 18:30:36 cpressey Exp $ */ 3 /* $KAME: in6_src.c,v 1.37 2001/03/29 05:34:31 itojun Exp $ */ 4 5 /* 6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * Copyright (c) 1982, 1986, 1991, 1993 36 * The Regents of the University of California. All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. All advertising materials mentioning features or use of this software 47 * must display the following acknowledgement: 48 * This product includes software developed by the University of 49 * California, Berkeley and its contributors. 50 * 4. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 * 66 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94 67 */ 68 69 #include "opt_inet.h" 70 #include "opt_inet6.h" 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/malloc.h> 75 #include <sys/mbuf.h> 76 #include <sys/protosw.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/errno.h> 80 #include <sys/time.h> 81 #include <sys/proc.h> 82 83 #include <net/if.h> 84 #include <net/route.h> 85 86 #include <netinet/in.h> 87 #include <netinet/in_var.h> 88 #include <netinet/in_systm.h> 89 #include <netinet/ip.h> 90 #include <netinet/in_pcb.h> 91 #include <netinet6/in6_var.h> 92 #include <netinet/ip6.h> 93 #include <netinet6/in6_pcb.h> 94 #include <netinet6/ip6_var.h> 95 #include <netinet6/nd6.h> 96 #ifdef ENABLE_DEFAULT_SCOPE 97 #include <netinet6/scope6_var.h> 98 #endif 99 100 #include <net/net_osdep.h> 101 102 #include "use_loop.h" 103 104 /* 105 * Return an IPv6 address, which is the most appropriate for a given 106 * destination and user specified options. 107 * If necessary, this function lookups the routing table and returns 108 * an entry to the caller for later use. 109 */ 110 struct in6_addr * 111 in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 112 struct ip6_moptions *mopts, struct route_in6 *ro, 113 struct in6_addr *laddr, int *errorp) 114 { 115 struct in6_addr *dst; 116 struct in6_ifaddr *ia6 = 0; 117 struct in6_pktinfo *pi = NULL; 118 119 dst = &dstsock->sin6_addr; 120 *errorp = 0; 121 122 /* 123 * If the source address is explicitly specified by the caller, 124 * use it. 125 */ 126 if (opts && (pi = opts->ip6po_pktinfo) && 127 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) 128 return(&pi->ipi6_addr); 129 130 /* 131 * If the source address is not specified but the socket(if any) 132 * is already bound, use the bound address. 133 */ 134 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) 135 return(laddr); 136 137 /* 138 * If the caller doesn't specify the source address but 139 * the outgoing interface, use an address associated with 140 * the interface. 141 */ 142 if (pi && pi->ipi6_ifindex) { 143 /* XXX boundary check is assumed to be already done. */ 144 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex], 145 dst); 146 if (ia6 == 0) { 147 *errorp = EADDRNOTAVAIL; 148 return(0); 149 } 150 return(&satosin6(&ia6->ia_addr)->sin6_addr); 151 } 152 153 /* 154 * If the destination address is a link-local unicast address or 155 * a multicast address, and if the outgoing interface is specified 156 * by the sin6_scope_id filed, use an address associated with the 157 * interface. 158 * XXX: We're now trying to define more specific semantics of 159 * sin6_scope_id field, so this part will be rewritten in 160 * the near future. 161 */ 162 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) && 163 dstsock->sin6_scope_id) { 164 /* 165 * I'm not sure if boundary check for scope_id is done 166 * somewhere... 167 */ 168 if (dstsock->sin6_scope_id < 0 || 169 if_index < dstsock->sin6_scope_id) { 170 *errorp = ENXIO; /* XXX: better error? */ 171 return(0); 172 } 173 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id], 174 dst); 175 if (ia6 == 0) { 176 *errorp = EADDRNOTAVAIL; 177 return(0); 178 } 179 return(&satosin6(&ia6->ia_addr)->sin6_addr); 180 } 181 182 /* 183 * If the destination address is a multicast address and 184 * the outgoing interface for the address is specified 185 * by the caller, use an address associated with the interface. 186 * There is a sanity check here; if the destination has node-local 187 * scope, the outgoing interfacde should be a loopback address. 188 * Even if the outgoing interface is not specified, we also 189 * choose a loopback interface as the outgoing interface. 190 */ 191 if (IN6_IS_ADDR_MULTICAST(dst)) { 192 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 193 194 if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) { 195 ifp = &loif[0]; 196 } 197 198 if (ifp) { 199 ia6 = in6_ifawithscope(ifp, dst); 200 if (ia6 == 0) { 201 *errorp = EADDRNOTAVAIL; 202 return(0); 203 } 204 return(&satosin6(&ia6->ia_addr)->sin6_addr); 205 } 206 } 207 208 /* 209 * If the next hop address for the packet is specified 210 * by caller, use an address associated with the route 211 * to the next hop. 212 */ 213 { 214 struct sockaddr_in6 *sin6_next; 215 struct rtentry *rt; 216 217 if (opts && opts->ip6po_nexthop) { 218 sin6_next = satosin6(opts->ip6po_nexthop); 219 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); 220 if (rt) { 221 ia6 = in6_ifawithscope(rt->rt_ifp, dst); 222 if (ia6 == 0) 223 ia6 = ifatoia6(rt->rt_ifa); 224 } 225 if (ia6 == 0) { 226 *errorp = EADDRNOTAVAIL; 227 return(0); 228 } 229 return(&satosin6(&ia6->ia_addr)->sin6_addr); 230 } 231 } 232 233 /* 234 * If route is known or can be allocated now, 235 * our src addr is taken from the i/f, else punt. 236 */ 237 if (ro) { 238 if (ro->ro_rt && 239 (!(ro->ro_rt->rt_flags & RTF_UP) || 240 satosin6(&ro->ro_dst)->sin6_family != AF_INET6 || 241 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 242 dst))) { 243 RTFREE(ro->ro_rt); 244 ro->ro_rt = (struct rtentry *)0; 245 } 246 if (ro->ro_rt == (struct rtentry *)0 || 247 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 248 struct sockaddr_in6 *sa6; 249 250 /* No route yet, so try to acquire one */ 251 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 252 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 253 sa6->sin6_family = AF_INET6; 254 sa6->sin6_len = sizeof(struct sockaddr_in6); 255 sa6->sin6_addr = *dst; 256 sa6->sin6_scope_id = dstsock->sin6_scope_id; 257 if (IN6_IS_ADDR_MULTICAST(dst)) { 258 ro->ro_rt = rtalloc1(&((struct route *)ro) 259 ->ro_dst, 0, 0UL); 260 } else { 261 rtalloc((struct route *)ro); 262 } 263 } 264 265 /* 266 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 267 * the address. But we don't know why it does so. 268 * It is necessary to ensure the scope even for lo0 269 * so doesn't check out IFF_LOOPBACK. 270 */ 271 272 if (ro->ro_rt) { 273 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); 274 if (ia6 == 0) /* xxx scope error ?*/ 275 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 276 } 277 #if 0 278 /* 279 * xxx The followings are necessary? (kazu) 280 * I don't think so. 281 * It's for SO_DONTROUTE option in IPv4.(jinmei) 282 */ 283 if (ia6 == 0) { 284 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 285 286 sin6->sin6_addr = *dst; 287 288 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 289 if (ia6 == 0) 290 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 291 if (ia6 == 0) 292 return(0); 293 return(&satosin6(&ia6->ia_addr)->sin6_addr); 294 } 295 #endif /* 0 */ 296 if (ia6 == 0) { 297 *errorp = EHOSTUNREACH; /* no route */ 298 return(0); 299 } 300 return(&satosin6(&ia6->ia_addr)->sin6_addr); 301 } 302 303 *errorp = EADDRNOTAVAIL; 304 return(0); 305 } 306 307 /* 308 * Default hop limit selection. The precedence is as follows: 309 * 1. Hoplimit value specified via ioctl. 310 * 2. (If the outgoing interface is detected) the current 311 * hop limit of the interface specified by router advertisement. 312 * 3. The system default hoplimit. 313 */ 314 int 315 in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp) 316 { 317 if (in6p && in6p->in6p_hops >= 0) 318 return(in6p->in6p_hops); 319 else if (ifp) 320 return(nd_ifinfo[ifp->if_index].chlim); 321 else 322 return(ip6_defhlim); 323 } 324 325 /* 326 * XXX: this is borrowed from in6_pcbbind(). If possible, we should 327 * share this function by all *bsd*... 328 */ 329 int 330 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct thread *td) 331 { 332 struct socket *so = inp->inp_socket; 333 u_int16_t lport = 0, first, last, *lastport; 334 int count, error = 0, wild = 0; 335 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; 336 337 /* XXX: this is redundant when called from in6_pcbbind */ 338 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0) 339 wild = INPLOOKUP_WILDCARD; 340 341 inp->inp_flags |= INP_ANONPORT; 342 343 if (inp->inp_flags & INP_HIGHPORT) { 344 first = ipport_hifirstauto; /* sysctl */ 345 last = ipport_hilastauto; 346 lastport = &pcbinfo->lasthi; 347 } else if (inp->inp_flags & INP_LOWPORT) { 348 if ((error = suser(td)) != 0) 349 return error; 350 first = ipport_lowfirstauto; /* 1023 */ 351 last = ipport_lowlastauto; /* 600 */ 352 lastport = &pcbinfo->lastlow; 353 } else { 354 first = ipport_firstauto; /* sysctl */ 355 last = ipport_lastauto; 356 lastport = &pcbinfo->lastport; 357 } 358 /* 359 * Simple check to ensure all ports are not used up causing 360 * a deadlock here. 361 * 362 * We split the two cases (up and down) so that the direction 363 * is not being tested on each round of the loop. 364 */ 365 if (first > last) { 366 /* 367 * counting down 368 */ 369 count = first - last; 370 371 do { 372 if (count-- < 0) { /* completely used? */ 373 /* 374 * Undo any address bind that may have 375 * occurred above. 376 */ 377 inp->in6p_laddr = in6addr_any; 378 return (EAGAIN); 379 } 380 --*lastport; 381 if (*lastport > first || *lastport < last) 382 *lastport = first; 383 lport = htons(*lastport); 384 } while (in6_pcblookup_local(pcbinfo, 385 &inp->in6p_laddr, lport, wild)); 386 } else { 387 /* 388 * counting up 389 */ 390 count = last - first; 391 392 do { 393 if (count-- < 0) { /* completely used? */ 394 /* 395 * Undo any address bind that may have 396 * occurred above. 397 */ 398 inp->in6p_laddr = in6addr_any; 399 return (EAGAIN); 400 } 401 ++*lastport; 402 if (*lastport < first || *lastport > last) 403 *lastport = first; 404 lport = htons(*lastport); 405 } while (in6_pcblookup_local(pcbinfo, 406 &inp->in6p_laddr, lport, wild)); 407 } 408 409 inp->inp_lport = lport; 410 if (in_pcbinsporthash(inp) != 0) { 411 inp->in6p_laddr = in6addr_any; 412 inp->inp_lport = 0; 413 return (EAGAIN); 414 } 415 416 return(0); 417 } 418 419 /* 420 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 421 * If the address scope of is link-local, embed the interface index in the 422 * address. The routine determines our precedence 423 * between advanced API scope/interface specification and basic API 424 * specification. 425 * 426 * this function should be nuked in the future, when we get rid of 427 * embedded scopeid thing. 428 * 429 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 430 * there can be multiple interfaces that belong to a particular scope zone 431 * (in specification, we have 1:N mapping between a scope zone and interfaces). 432 * we may want to change the function to return something other than ifp. 433 */ 434 int 435 in6_embedscope(struct in6_addr *in6, 436 const struct sockaddr_in6 *sin6, 437 #ifdef HAVE_NRL_INPCB 438 struct inpcb *in6p, 439 #define in6p_outputopts inp_outputopts6 440 #define in6p_moptions inp_moptions6 441 #else 442 struct in6pcb *in6p, 443 #endif 444 struct ifnet **ifpp) 445 { 446 struct ifnet *ifp = NULL; 447 u_int32_t scopeid; 448 449 *in6 = sin6->sin6_addr; 450 scopeid = sin6->sin6_scope_id; 451 if (ifpp) 452 *ifpp = NULL; 453 454 /* 455 * don't try to read sin6->sin6_addr beyond here, since the caller may 456 * ask us to overwrite existing sockaddr_in6 457 */ 458 459 #ifdef ENABLE_DEFAULT_SCOPE 460 if (scopeid == 0) 461 scopeid = scope6_addr2default(in6); 462 #endif 463 464 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 465 struct in6_pktinfo *pi; 466 467 /* 468 * KAME assumption: link id == interface id 469 */ 470 471 if (in6p && in6p->in6p_outputopts && 472 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 473 pi->ipi6_ifindex) { 474 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 475 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 476 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 477 in6p->in6p_moptions && 478 in6p->in6p_moptions->im6o_multicast_ifp) { 479 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 480 in6->s6_addr16[1] = htons(ifp->if_index); 481 } else if (scopeid) { 482 /* boundary check */ 483 if (scopeid < 0 || if_index < scopeid) 484 return ENXIO; /* XXX EINVAL? */ 485 ifp = ifindex2ifnet[scopeid]; 486 /*XXX assignment to 16bit from 32bit variable */ 487 in6->s6_addr16[1] = htons(scopeid & 0xffff); 488 } 489 490 if (ifpp) 491 *ifpp = ifp; 492 } 493 494 return 0; 495 } 496 #ifdef HAVE_NRL_INPCB 497 #undef in6p_outputopts 498 #undef in6p_moptions 499 #endif 500 501 /* 502 * generate standard sockaddr_in6 from embedded form. 503 * touches sin6_addr and sin6_scope_id only. 504 * 505 * this function should be nuked in the future, when we get rid of 506 * embedded scopeid thing. 507 */ 508 int 509 in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6, 510 struct ifnet *ifp) 511 { 512 u_int32_t scopeid; 513 514 sin6->sin6_addr = *in6; 515 516 /* 517 * don't try to read *in6 beyond here, since the caller may 518 * ask us to overwrite existing sockaddr_in6 519 */ 520 521 sin6->sin6_scope_id = 0; 522 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 523 /* 524 * KAME assumption: link id == interface id 525 */ 526 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 527 if (scopeid) { 528 /* sanity check */ 529 if (scopeid < 0 || if_index < scopeid) 530 return ENXIO; 531 if (ifp && ifp->if_index != scopeid) 532 return ENXIO; 533 sin6->sin6_addr.s6_addr16[1] = 0; 534 sin6->sin6_scope_id = scopeid; 535 } 536 } 537 538 return 0; 539 } 540 541 /* 542 * just clear the embedded scope identifer. 543 * XXX: currently used for bsdi4 only as a supplement function. 544 */ 545 void 546 in6_clearscope(struct in6_addr *addr) 547 { 548 if (IN6_IS_SCOPE_LINKLOCAL(addr)) 549 addr->s6_addr16[1] = 0; 550 } 551