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 1.2 2003/06/17 04:28:52 dillon 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 "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(dstsock, opts, mopts, ro, laddr, errorp) 112 struct sockaddr_in6 *dstsock; 113 struct ip6_pktopts *opts; 114 struct ip6_moptions *mopts; 115 struct route_in6 *ro; 116 struct in6_addr *laddr; 117 int *errorp; 118 { 119 struct in6_addr *dst; 120 struct in6_ifaddr *ia6 = 0; 121 struct in6_pktinfo *pi = NULL; 122 123 dst = &dstsock->sin6_addr; 124 *errorp = 0; 125 126 /* 127 * If the source address is explicitly specified by the caller, 128 * use it. 129 */ 130 if (opts && (pi = opts->ip6po_pktinfo) && 131 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) 132 return(&pi->ipi6_addr); 133 134 /* 135 * If the source address is not specified but the socket(if any) 136 * is already bound, use the bound address. 137 */ 138 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) 139 return(laddr); 140 141 /* 142 * If the caller doesn't specify the source address but 143 * the outgoing interface, use an address associated with 144 * the interface. 145 */ 146 if (pi && pi->ipi6_ifindex) { 147 /* XXX boundary check is assumed to be already done. */ 148 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex], 149 dst); 150 if (ia6 == 0) { 151 *errorp = EADDRNOTAVAIL; 152 return(0); 153 } 154 return(&satosin6(&ia6->ia_addr)->sin6_addr); 155 } 156 157 /* 158 * If the destination address is a link-local unicast address or 159 * a multicast address, and if the outgoing interface is specified 160 * by the sin6_scope_id filed, use an address associated with the 161 * interface. 162 * XXX: We're now trying to define more specific semantics of 163 * sin6_scope_id field, so this part will be rewritten in 164 * the near future. 165 */ 166 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) && 167 dstsock->sin6_scope_id) { 168 /* 169 * I'm not sure if boundary check for scope_id is done 170 * somewhere... 171 */ 172 if (dstsock->sin6_scope_id < 0 || 173 if_index < 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 */ 241 if (ro) { 242 if (ro->ro_rt && 243 (!(ro->ro_rt->rt_flags & RTF_UP) || 244 satosin6(&ro->ro_dst)->sin6_family != AF_INET6 || 245 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 246 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, 0UL); 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_hops >= 0) 324 return(in6p->in6p_hops); 325 else if (ifp) 326 return(nd_ifinfo[ifp->if_index].chlim); 327 else 328 return(ip6_defhlim); 329 } 330 331 /* 332 * XXX: this is borrowed from in6_pcbbind(). If possible, we should 333 * share this function by all *bsd*... 334 */ 335 int 336 in6_pcbsetport(laddr, inp, p) 337 struct in6_addr *laddr; 338 struct inpcb *inp; 339 struct proc *p; 340 { 341 struct socket *so = inp->inp_socket; 342 u_int16_t lport = 0, first, last, *lastport; 343 int count, error = 0, wild = 0; 344 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; 345 346 /* XXX: this is redundant when called from in6_pcbbind */ 347 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0) 348 wild = INPLOOKUP_WILDCARD; 349 350 inp->inp_flags |= INP_ANONPORT; 351 352 if (inp->inp_flags & INP_HIGHPORT) { 353 first = ipport_hifirstauto; /* sysctl */ 354 last = ipport_hilastauto; 355 lastport = &pcbinfo->lasthi; 356 } else if (inp->inp_flags & INP_LOWPORT) { 357 if (p && (error = suser(p))) 358 return error; 359 first = ipport_lowfirstauto; /* 1023 */ 360 last = ipport_lowlastauto; /* 600 */ 361 lastport = &pcbinfo->lastlow; 362 } else { 363 first = ipport_firstauto; /* sysctl */ 364 last = ipport_lastauto; 365 lastport = &pcbinfo->lastport; 366 } 367 /* 368 * Simple check to ensure all ports are not used up causing 369 * a deadlock here. 370 * 371 * We split the two cases (up and down) so that the direction 372 * is not being tested on each round of the loop. 373 */ 374 if (first > last) { 375 /* 376 * counting down 377 */ 378 count = first - last; 379 380 do { 381 if (count-- < 0) { /* completely used? */ 382 /* 383 * Undo any address bind that may have 384 * occurred above. 385 */ 386 inp->in6p_laddr = in6addr_any; 387 return (EAGAIN); 388 } 389 --*lastport; 390 if (*lastport > first || *lastport < last) 391 *lastport = first; 392 lport = htons(*lastport); 393 } while (in6_pcblookup_local(pcbinfo, 394 &inp->in6p_laddr, lport, wild)); 395 } else { 396 /* 397 * counting up 398 */ 399 count = last - first; 400 401 do { 402 if (count-- < 0) { /* completely used? */ 403 /* 404 * Undo any address bind that may have 405 * occurred above. 406 */ 407 inp->in6p_laddr = in6addr_any; 408 return (EAGAIN); 409 } 410 ++*lastport; 411 if (*lastport < first || *lastport > last) 412 *lastport = first; 413 lport = htons(*lastport); 414 } while (in6_pcblookup_local(pcbinfo, 415 &inp->in6p_laddr, lport, wild)); 416 } 417 418 inp->inp_lport = lport; 419 if (in_pcbinshash(inp) != 0) { 420 inp->in6p_laddr = in6addr_any; 421 inp->inp_lport = 0; 422 return (EAGAIN); 423 } 424 425 return(0); 426 } 427 428 /* 429 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 430 * If the address scope of is link-local, embed the interface index in the 431 * address. The routine determines our precedence 432 * between advanced API scope/interface specification and basic API 433 * specification. 434 * 435 * this function should be nuked in the future, when we get rid of 436 * embedded scopeid thing. 437 * 438 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 439 * there can be multiple interfaces that belong to a particular scope zone 440 * (in specification, we have 1:N mapping between a scope zone and interfaces). 441 * we may want to change the function to return something other than ifp. 442 */ 443 int 444 in6_embedscope(in6, sin6, in6p, ifpp) 445 struct in6_addr *in6; 446 const struct sockaddr_in6 *sin6; 447 #ifdef HAVE_NRL_INPCB 448 struct inpcb *in6p; 449 #define in6p_outputopts inp_outputopts6 450 #define in6p_moptions inp_moptions6 451 #else 452 struct in6pcb *in6p; 453 #endif 454 struct ifnet **ifpp; 455 { 456 struct ifnet *ifp = NULL; 457 u_int32_t scopeid; 458 459 *in6 = sin6->sin6_addr; 460 scopeid = sin6->sin6_scope_id; 461 if (ifpp) 462 *ifpp = NULL; 463 464 /* 465 * don't try to read sin6->sin6_addr beyond here, since the caller may 466 * ask us to overwrite existing sockaddr_in6 467 */ 468 469 #ifdef ENABLE_DEFAULT_SCOPE 470 if (scopeid == 0) 471 scopeid = scope6_addr2default(in6); 472 #endif 473 474 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 475 struct in6_pktinfo *pi; 476 477 /* 478 * KAME assumption: link id == interface id 479 */ 480 481 if (in6p && in6p->in6p_outputopts && 482 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 483 pi->ipi6_ifindex) { 484 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 485 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 486 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 487 in6p->in6p_moptions && 488 in6p->in6p_moptions->im6o_multicast_ifp) { 489 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 490 in6->s6_addr16[1] = htons(ifp->if_index); 491 } else if (scopeid) { 492 /* boundary check */ 493 if (scopeid < 0 || if_index < scopeid) 494 return ENXIO; /* XXX EINVAL? */ 495 ifp = ifindex2ifnet[scopeid]; 496 /*XXX assignment to 16bit from 32bit variable */ 497 in6->s6_addr16[1] = htons(scopeid & 0xffff); 498 } 499 500 if (ifpp) 501 *ifpp = ifp; 502 } 503 504 return 0; 505 } 506 #ifdef HAVE_NRL_INPCB 507 #undef in6p_outputopts 508 #undef in6p_moptions 509 #endif 510 511 /* 512 * generate standard sockaddr_in6 from embedded form. 513 * touches sin6_addr and sin6_scope_id only. 514 * 515 * this function should be nuked in the future, when we get rid of 516 * embedded scopeid thing. 517 */ 518 int 519 in6_recoverscope(sin6, in6, ifp) 520 struct sockaddr_in6 *sin6; 521 const struct in6_addr *in6; 522 struct ifnet *ifp; 523 { 524 u_int32_t scopeid; 525 526 sin6->sin6_addr = *in6; 527 528 /* 529 * don't try to read *in6 beyond here, since the caller may 530 * ask us to overwrite existing sockaddr_in6 531 */ 532 533 sin6->sin6_scope_id = 0; 534 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 535 /* 536 * KAME assumption: link id == interface id 537 */ 538 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 539 if (scopeid) { 540 /* sanity check */ 541 if (scopeid < 0 || if_index < scopeid) 542 return ENXIO; 543 if (ifp && ifp->if_index != scopeid) 544 return ENXIO; 545 sin6->sin6_addr.s6_addr16[1] = 0; 546 sin6->sin6_scope_id = scopeid; 547 } 548 } 549 550 return 0; 551 } 552 553 /* 554 * just clear the embedded scope identifer. 555 * XXX: currently used for bsdi4 only as a supplement function. 556 */ 557 void 558 in6_clearscope(addr) 559 struct in6_addr *addr; 560 { 561 if (IN6_IS_SCOPE_LINKLOCAL(addr)) 562 addr->s6_addr16[1] = 0; 563 } 564