1 /* $FreeBSD$ */ 2 /* $KAME: in6_src.c,v 1.27 2000/06/21 08:07:13 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 "opt_inet.h" 69 #include "opt_inet6.h" 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/mbuf.h> 74 #include <sys/protosw.h> 75 #include <sys/socket.h> 76 #include <sys/socketvar.h> 77 #include <sys/errno.h> 78 #include <sys/time.h> 79 80 #include <net/if.h> 81 #include <net/route.h> 82 83 #include <netinet/in.h> 84 #include <netinet/in_var.h> 85 #include <netinet/in_systm.h> 86 #include <netinet/ip.h> 87 #include <netinet/in_pcb.h> 88 #include <netinet6/in6_var.h> 89 #include <netinet/ip6.h> 90 #include <netinet6/in6_pcb.h> 91 #include <netinet6/ip6_var.h> 92 #include <netinet6/nd6.h> 93 #ifdef ENABLE_DEFAULT_SCOPE 94 #include <netinet6/scope6_var.h> 95 #endif 96 97 #include <net/net_osdep.h> 98 99 #include "loop.h" 100 101 /* 102 * Return an IPv6 address, which is the most appropriate for given 103 * destination and user specified options. 104 * If necessary, this function lookups the routing table and return 105 * an entry to the caller for later use. 106 */ 107 struct in6_addr * 108 in6_selectsrc(dstsock, opts, mopts, ro, laddr, errorp) 109 struct sockaddr_in6 *dstsock; 110 struct ip6_pktopts *opts; 111 struct ip6_moptions *mopts; 112 struct route_in6 *ro; 113 struct in6_addr *laddr; 114 int *errorp; 115 { 116 struct in6_addr *dst; 117 struct in6_ifaddr *ia6 = 0; 118 struct in6_pktinfo *pi = NULL; 119 120 dst = &dstsock->sin6_addr; 121 *errorp = 0; 122 123 /* 124 * If the source address is explicitly specified by the caller, 125 * use it. 126 */ 127 if (opts && (pi = opts->ip6po_pktinfo) && 128 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) 129 return(&pi->ipi6_addr); 130 131 /* 132 * If the source address is not specified but the socket(if any) 133 * is already bound, use the bound address. 134 */ 135 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) 136 return(laddr); 137 138 /* 139 * If the caller doesn't specify the source address but 140 * the outgoing interface, use an address associated with 141 * the interface. 142 */ 143 if (pi && pi->ipi6_ifindex) { 144 /* XXX boundary check is assumed to be already done. */ 145 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex], 146 dst); 147 if (ia6 == 0) { 148 *errorp = EADDRNOTAVAIL; 149 return(0); 150 } 151 return(&satosin6(&ia6->ia_addr)->sin6_addr); 152 } 153 154 /* 155 * If the destination address is a link-local unicast address or 156 * a multicast address, and if the outgoing interface is specified 157 * by the sin6_scope_id filed, use an address associated with the 158 * interface. 159 * XXX: We're now trying to define more specific semantics of 160 * sin6_scope_id field, so this part will be rewritten in 161 * the near future. 162 */ 163 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) && 164 dstsock->sin6_scope_id) { 165 /* 166 * I'm not sure if boundary check for scope_id is done 167 * somewhere... 168 */ 169 if (dstsock->sin6_scope_id < 0 || 170 if_index < dstsock->sin6_scope_id) { 171 *errorp = ENXIO; /* XXX: better error? */ 172 return(0); 173 } 174 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id], 175 dst); 176 if (ia6 == 0) { 177 *errorp = EADDRNOTAVAIL; 178 return(0); 179 } 180 return(&satosin6(&ia6->ia_addr)->sin6_addr); 181 } 182 183 /* 184 * If the destination address is a multicast address and 185 * the outgoing interface for the address is specified 186 * by the caller, use an address associated with the interface. 187 * There is a sanity check here; if the destination has node-local 188 * scope, the outgoing interfacde should be a loopback address. 189 * Even if the outgoing interface is not specified, we also 190 * choose a loopback interface as the outgoing interface. 191 */ 192 if (IN6_IS_ADDR_MULTICAST(dst)) { 193 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 194 195 if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) { 196 ifp = &loif[0]; 197 } 198 199 if (ifp) { 200 ia6 = in6_ifawithscope(ifp, dst); 201 if (ia6 == 0) { 202 *errorp = EADDRNOTAVAIL; 203 return(0); 204 } 205 return(&satosin6(&ia6->ia_addr)->sin6_addr); 206 } 207 } 208 209 /* 210 * If the next hop address for the packet is specified 211 * by caller, use an address associated with the route 212 * to the next hop. 213 */ 214 { 215 struct sockaddr_in6 *sin6_next; 216 struct rtentry *rt; 217 218 if (opts && opts->ip6po_nexthop) { 219 sin6_next = satosin6(opts->ip6po_nexthop); 220 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); 221 if (rt) { 222 ia6 = in6_ifawithscope(rt->rt_ifp, dst); 223 if (ia6 == 0) 224 ia6 = ifatoia6(rt->rt_ifa); 225 } 226 if (ia6 == 0) { 227 *errorp = EADDRNOTAVAIL; 228 return(0); 229 } 230 return(&satosin6(&ia6->ia_addr)->sin6_addr); 231 } 232 } 233 234 /* 235 * If route is known or can be allocated now, 236 * our src addr is taken from the i/f, else punt. 237 */ 238 if (ro) { 239 if (ro->ro_rt && 240 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst)) { 241 RTFREE(ro->ro_rt); 242 ro->ro_rt = (struct rtentry *)0; 243 } 244 if (ro->ro_rt == (struct rtentry *)0 || 245 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 246 /* No route yet, so try to acquire one */ 247 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 248 ro->ro_dst.sin6_family = AF_INET6; 249 ro->ro_dst.sin6_len = sizeof(struct sockaddr_in6); 250 ro->ro_dst.sin6_addr = *dst; 251 ro->ro_dst.sin6_scope_id = dstsock->sin6_scope_id; 252 if (IN6_IS_ADDR_MULTICAST(dst)) { 253 ro->ro_rt = rtalloc1(&((struct route *)ro) 254 ->ro_dst, 0, 0UL); 255 } else { 256 rtalloc((struct route *)ro); 257 } 258 } 259 260 /* 261 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 262 * the address. But we don't know why it does so. 263 * It is necessary to ensure the scope even for lo0 264 * so doesn't check out IFF_LOOPBACK. 265 */ 266 267 if (ro->ro_rt) { 268 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); 269 if (ia6 == 0) /* xxx scope error ?*/ 270 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 271 } 272 #if 0 273 /* 274 * xxx The followings are necessary? (kazu) 275 * I don't think so. 276 * It's for SO_DONTROUTE option in IPv4.(jinmei) 277 */ 278 if (ia6 == 0) { 279 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 280 281 sin6->sin6_addr = *dst; 282 283 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 284 if (ia6 == 0) 285 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 286 if (ia6 == 0) 287 return(0); 288 return(&satosin6(&ia6->ia_addr)->sin6_addr); 289 } 290 #endif /* 0 */ 291 if (ia6 == 0) { 292 *errorp = EHOSTUNREACH; /* no route */ 293 return(0); 294 } 295 return(&satosin6(&ia6->ia_addr)->sin6_addr); 296 } 297 298 *errorp = EADDRNOTAVAIL; 299 return(0); 300 } 301 302 /* 303 * Default hop limit selection. The precedence is as follows: 304 * 1. Hoplimit value specified via ioctl. 305 * 2. (If the outgoing interface is detected) the current 306 * hop limit of the interface specified by router advertisement. 307 * 3. The system default hoplimit. 308 */ 309 int 310 in6_selecthlim(in6p, ifp) 311 struct in6pcb *in6p; 312 struct ifnet *ifp; 313 { 314 if (in6p && in6p->in6p_hops >= 0) 315 return(in6p->in6p_hops); 316 else if (ifp) 317 return(nd_ifinfo[ifp->if_index].chlim); 318 else 319 return(ip6_defhlim); 320 } 321 322 /* 323 * XXX: this is borrowed from in6_pcbbind(). If possible, we should 324 * share this function by all *bsd*... 325 */ 326 int 327 in6_pcbsetport(laddr, inp, p) 328 struct in6_addr *laddr; 329 struct inpcb *inp; 330 struct proc *p; 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 (p && (error = suser(p))) 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_pcbinshash(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(in6, sin6, in6p, ifpp) 436 struct in6_addr *in6; 437 const struct sockaddr_in6 *sin6; 438 #ifdef HAVE_NRL_INPCB 439 struct inpcb *in6p; 440 #define in6p_outputopts inp_outputopts6 441 #define in6p_moptions inp_moptions6 442 #else 443 struct in6pcb *in6p; 444 #endif 445 struct ifnet **ifpp; 446 { 447 struct ifnet *ifp = NULL; 448 u_int32_t scopeid; 449 450 *in6 = sin6->sin6_addr; 451 scopeid = sin6->sin6_scope_id; 452 if (ifpp) 453 *ifpp = NULL; 454 455 /* 456 * don't try to read sin6->sin6_addr beyond here, since the caller may 457 * ask us to overwrite existing sockaddr_in6 458 */ 459 460 #ifdef ENABLE_DEFAULT_SCOPE 461 if (scopeid == 0) 462 scopeid = scope6_addr2default(in6); 463 #endif 464 465 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 466 struct in6_pktinfo *pi; 467 468 /* 469 * KAME assumption: link id == interface id 470 */ 471 472 if (in6p && in6p->in6p_outputopts && 473 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 474 pi->ipi6_ifindex) { 475 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 476 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 477 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 478 in6p->in6p_moptions && 479 in6p->in6p_moptions->im6o_multicast_ifp) { 480 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 481 in6->s6_addr16[1] = htons(ifp->if_index); 482 } else if (scopeid) { 483 /* boundary check */ 484 if (scopeid < 0 || if_index < scopeid) 485 return ENXIO; /* XXX EINVAL? */ 486 ifp = ifindex2ifnet[scopeid]; 487 /*XXX assignment to 16bit from 32bit variable */ 488 in6->s6_addr16[1] = htons(scopeid & 0xffff); 489 } 490 491 if (ifpp) 492 *ifpp = ifp; 493 } 494 495 return 0; 496 } 497 #ifdef HAVE_NRL_INPCB 498 #undef in6p_outputopts 499 #undef in6p_moptions 500 #endif 501 502 /* 503 * generate standard sockaddr_in6 from embedded form. 504 * touches sin6_addr and sin6_scope_id only. 505 * 506 * this function should be nuked in the future, when we get rid of 507 * embedded scopeid thing. 508 */ 509 int 510 in6_recoverscope(sin6, in6, ifp) 511 struct sockaddr_in6 *sin6; 512 const struct in6_addr *in6; 513 struct ifnet *ifp; 514 { 515 u_int32_t scopeid; 516 517 sin6->sin6_addr = *in6; 518 519 /* 520 * don't try to read *in6 beyond here, since the caller may 521 * ask us to overwrite existing sockaddr_in6 522 */ 523 524 sin6->sin6_scope_id = 0; 525 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 526 /* 527 * KAME assumption: link id == interface id 528 */ 529 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 530 if (scopeid) { 531 /* sanity check */ 532 if (scopeid < 0 || if_index < scopeid) 533 return ENXIO; 534 #ifndef FAKE_LOOPBACK_IF 535 if (ifp && (ifp->if_flags & IFF_LOOPBACK) == 0 && 536 ifp->if_index != scopeid) { 537 return ENXIO; 538 } 539 #else 540 if (ifp && ifp->if_index != scopeid) 541 return ENXIO; 542 #endif 543 sin6->sin6_addr.s6_addr16[1] = 0; 544 sin6->sin6_scope_id = scopeid; 545 } 546 } 547 548 return 0; 549 } 550