1 /* $FreeBSD$ */ 2 /* $KAME: in6_src.c,v 1.37 2001/03/29 05:34:31 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/malloc.h> 74 #include <sys/mbuf.h> 75 #include <sys/protosw.h> 76 #include <sys/socket.h> 77 #include <sys/socketvar.h> 78 #include <sys/errno.h> 79 #include <sys/time.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 /* 101 * Return an IPv6 address, which is the most appropriate for a given 102 * destination and user specified options. 103 * If necessary, this function lookups the routing table and returns 104 * an entry to the caller for later use. 105 */ 106 struct in6_addr * 107 in6_selectsrc(dstsock, opts, mopts, ro, laddr, errorp) 108 struct sockaddr_in6 *dstsock; 109 struct ip6_pktopts *opts; 110 struct ip6_moptions *mopts; 111 struct route_in6 *ro; 112 struct in6_addr *laddr; 113 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(ifnet_byindex(pi->ipi6_ifindex), dst); 145 if (ia6 == 0) { 146 *errorp = EADDRNOTAVAIL; 147 return(0); 148 } 149 return(&satosin6(&ia6->ia_addr)->sin6_addr); 150 } 151 152 /* 153 * If the destination address is a link-local unicast address or 154 * a multicast address, and if the outgoing interface is specified 155 * by the sin6_scope_id filed, use an address associated with the 156 * interface. 157 * XXX: We're now trying to define more specific semantics of 158 * sin6_scope_id field, so this part will be rewritten in 159 * the near future. 160 */ 161 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) && 162 dstsock->sin6_scope_id) { 163 /* 164 * I'm not sure if boundary check for scope_id is done 165 * somewhere... 166 */ 167 if (dstsock->sin6_scope_id < 0 || 168 if_index < dstsock->sin6_scope_id) { 169 *errorp = ENXIO; /* XXX: better error? */ 170 return(0); 171 } 172 ia6 = in6_ifawithscope(ifnet_byindex(dstsock->sin6_scope_id), 173 dst); 174 if (ia6 == 0) { 175 *errorp = EADDRNOTAVAIL; 176 return(0); 177 } 178 return(&satosin6(&ia6->ia_addr)->sin6_addr); 179 } 180 181 /* 182 * If the destination address is a multicast address and 183 * the outgoing interface for the address is specified 184 * by the caller, use an address associated with the interface. 185 * There is a sanity check here; if the destination has node-local 186 * scope, the outgoing interfacde should be a loopback address. 187 * Even if the outgoing interface is not specified, we also 188 * choose a loopback interface as the outgoing interface. 189 */ 190 if (IN6_IS_ADDR_MULTICAST(dst)) { 191 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 192 193 if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) { 194 ifp = &loif[0]; 195 } 196 197 if (ifp) { 198 ia6 = in6_ifawithscope(ifp, dst); 199 if (ia6 == 0) { 200 *errorp = EADDRNOTAVAIL; 201 return(0); 202 } 203 return(&satosin6(&ia6->ia_addr)->sin6_addr); 204 } 205 } 206 207 /* 208 * If the next hop address for the packet is specified 209 * by caller, use an address associated with the route 210 * to the next hop. 211 */ 212 { 213 struct sockaddr_in6 *sin6_next; 214 struct rtentry *rt; 215 216 if (opts && opts->ip6po_nexthop) { 217 sin6_next = satosin6(opts->ip6po_nexthop); 218 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); 219 if (rt) { 220 ia6 = in6_ifawithscope(rt->rt_ifp, dst); 221 if (ia6 == 0) 222 ia6 = ifatoia6(rt->rt_ifa); 223 } 224 if (ia6 == 0) { 225 *errorp = EADDRNOTAVAIL; 226 return(0); 227 } 228 return(&satosin6(&ia6->ia_addr)->sin6_addr); 229 } 230 } 231 232 /* 233 * If route is known or can be allocated now, 234 * our src addr is taken from the i/f, else punt. 235 */ 236 if (ro) { 237 if (ro->ro_rt && 238 (!(ro->ro_rt->rt_flags & RTF_UP) || 239 satosin6(&ro->ro_dst)->sin6_family != AF_INET6 || 240 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 241 dst))) { 242 RTFREE(ro->ro_rt); 243 ro->ro_rt = (struct rtentry *)0; 244 } 245 if (ro->ro_rt == (struct rtentry *)0 || 246 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 247 struct sockaddr_in6 *sa6; 248 249 /* No route yet, so try to acquire one */ 250 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 251 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 252 sa6->sin6_family = AF_INET6; 253 sa6->sin6_len = sizeof(struct sockaddr_in6); 254 sa6->sin6_addr = *dst; 255 sa6->sin6_scope_id = dstsock->sin6_scope_id; 256 if (IN6_IS_ADDR_MULTICAST(dst)) { 257 ro->ro_rt = rtalloc1(&((struct route *)ro) 258 ->ro_dst, 0, 0UL); 259 } else { 260 rtalloc((struct route *)ro); 261 } 262 } 263 264 /* 265 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 266 * the address. But we don't know why it does so. 267 * It is necessary to ensure the scope even for lo0 268 * so doesn't check out IFF_LOOPBACK. 269 */ 270 271 if (ro->ro_rt) { 272 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); 273 if (ia6 == 0) /* xxx scope error ?*/ 274 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 275 } 276 #if 0 277 /* 278 * xxx The followings are necessary? (kazu) 279 * I don't think so. 280 * It's for SO_DONTROUTE option in IPv4.(jinmei) 281 */ 282 if (ia6 == 0) { 283 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 284 285 sin6->sin6_addr = *dst; 286 287 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 288 if (ia6 == 0) 289 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 290 if (ia6 == 0) 291 return(0); 292 return(&satosin6(&ia6->ia_addr)->sin6_addr); 293 } 294 #endif /* 0 */ 295 if (ia6 == 0) { 296 *errorp = EHOSTUNREACH; /* no route */ 297 return(0); 298 } 299 return(&satosin6(&ia6->ia_addr)->sin6_addr); 300 } 301 302 *errorp = EADDRNOTAVAIL; 303 return(0); 304 } 305 306 /* 307 * Default hop limit selection. The precedence is as follows: 308 * 1. Hoplimit value specified via ioctl. 309 * 2. (If the outgoing interface is detected) the current 310 * hop limit of the interface specified by router advertisement. 311 * 3. The system default hoplimit. 312 */ 313 int 314 in6_selecthlim(in6p, ifp) 315 struct in6pcb *in6p; 316 struct ifnet *ifp; 317 { 318 if (in6p && in6p->in6p_hops >= 0) 319 return(in6p->in6p_hops); 320 else if (ifp) 321 return(nd_ifinfo[ifp->if_index].chlim); 322 else 323 return(ip6_defhlim); 324 } 325 326 /* 327 * XXX: this is borrowed from in6_pcbbind(). If possible, we should 328 * share this function by all *bsd*... 329 */ 330 int 331 in6_pcbsetport(laddr, inp, td) 332 struct in6_addr *laddr; 333 struct inpcb *inp; 334 struct thread *td; 335 { 336 struct socket *so = inp->inp_socket; 337 u_int16_t lport = 0, first, last, *lastport; 338 int count, error = 0, wild = 0; 339 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; 340 341 /* XXX: this is redundant when called from in6_pcbbind */ 342 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0) 343 wild = INPLOOKUP_WILDCARD; 344 345 inp->inp_flags |= INP_ANONPORT; 346 347 if (inp->inp_flags & INP_HIGHPORT) { 348 first = ipport_hifirstauto; /* sysctl */ 349 last = ipport_hilastauto; 350 lastport = &pcbinfo->lasthi; 351 } else if (inp->inp_flags & INP_LOWPORT) { 352 if (td && (error = suser(td))) 353 return error; 354 first = ipport_lowfirstauto; /* 1023 */ 355 last = ipport_lowlastauto; /* 600 */ 356 lastport = &pcbinfo->lastlow; 357 } else { 358 first = ipport_firstauto; /* sysctl */ 359 last = ipport_lastauto; 360 lastport = &pcbinfo->lastport; 361 } 362 /* 363 * Simple check to ensure all ports are not used up causing 364 * a deadlock here. 365 * 366 * We split the two cases (up and down) so that the direction 367 * is not being tested on each round of the loop. 368 */ 369 if (first > last) { 370 /* 371 * counting down 372 */ 373 count = first - last; 374 375 do { 376 if (count-- < 0) { /* completely used? */ 377 /* 378 * Undo any address bind that may have 379 * occurred above. 380 */ 381 inp->in6p_laddr = in6addr_any; 382 return (EAGAIN); 383 } 384 --*lastport; 385 if (*lastport > first || *lastport < last) 386 *lastport = first; 387 lport = htons(*lastport); 388 } while (in6_pcblookup_local(pcbinfo, 389 &inp->in6p_laddr, lport, wild)); 390 } else { 391 /* 392 * counting up 393 */ 394 count = last - first; 395 396 do { 397 if (count-- < 0) { /* completely used? */ 398 /* 399 * Undo any address bind that may have 400 * occurred above. 401 */ 402 inp->in6p_laddr = in6addr_any; 403 return (EAGAIN); 404 } 405 ++*lastport; 406 if (*lastport < first || *lastport > last) 407 *lastport = first; 408 lport = htons(*lastport); 409 } while (in6_pcblookup_local(pcbinfo, 410 &inp->in6p_laddr, lport, wild)); 411 } 412 413 inp->inp_lport = lport; 414 if (in_pcbinshash(inp) != 0) { 415 inp->in6p_laddr = in6addr_any; 416 inp->inp_lport = 0; 417 return (EAGAIN); 418 } 419 420 return(0); 421 } 422 423 /* 424 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 425 * If the address scope of is link-local, embed the interface index in the 426 * address. The routine determines our precedence 427 * between advanced API scope/interface specification and basic API 428 * specification. 429 * 430 * this function should be nuked in the future, when we get rid of 431 * embedded scopeid thing. 432 * 433 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 434 * there can be multiple interfaces that belong to a particular scope zone 435 * (in specification, we have 1:N mapping between a scope zone and interfaces). 436 * we may want to change the function to return something other than ifp. 437 */ 438 int 439 in6_embedscope(in6, sin6, in6p, ifpp) 440 struct in6_addr *in6; 441 const struct sockaddr_in6 *sin6; 442 #ifdef HAVE_NRL_INPCB 443 struct inpcb *in6p; 444 #define in6p_outputopts inp_outputopts6 445 #define in6p_moptions inp_moptions6 446 #else 447 struct in6pcb *in6p; 448 #endif 449 struct ifnet **ifpp; 450 { 451 struct ifnet *ifp = NULL; 452 u_int32_t scopeid; 453 454 *in6 = sin6->sin6_addr; 455 scopeid = sin6->sin6_scope_id; 456 if (ifpp) 457 *ifpp = NULL; 458 459 /* 460 * don't try to read sin6->sin6_addr beyond here, since the caller may 461 * ask us to overwrite existing sockaddr_in6 462 */ 463 464 #ifdef ENABLE_DEFAULT_SCOPE 465 if (scopeid == 0) 466 scopeid = scope6_addr2default(in6); 467 #endif 468 469 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 470 struct in6_pktinfo *pi; 471 472 /* 473 * KAME assumption: link id == interface id 474 */ 475 476 if (in6p && in6p->in6p_outputopts && 477 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 478 pi->ipi6_ifindex) { 479 ifp = ifnet_byindex(pi->ipi6_ifindex); 480 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 481 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 482 in6p->in6p_moptions && 483 in6p->in6p_moptions->im6o_multicast_ifp) { 484 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 485 in6->s6_addr16[1] = htons(ifp->if_index); 486 } else if (scopeid) { 487 /* boundary check */ 488 if (scopeid < 0 || if_index < scopeid) 489 return ENXIO; /* XXX EINVAL? */ 490 ifp = ifnet_byindex(scopeid); 491 /*XXX assignment to 16bit from 32bit variable */ 492 in6->s6_addr16[1] = htons(scopeid & 0xffff); 493 } 494 495 if (ifpp) 496 *ifpp = ifp; 497 } 498 499 return 0; 500 } 501 #ifdef HAVE_NRL_INPCB 502 #undef in6p_outputopts 503 #undef in6p_moptions 504 #endif 505 506 /* 507 * generate standard sockaddr_in6 from embedded form. 508 * touches sin6_addr and sin6_scope_id only. 509 * 510 * this function should be nuked in the future, when we get rid of 511 * embedded scopeid thing. 512 */ 513 int 514 in6_recoverscope(sin6, in6, ifp) 515 struct sockaddr_in6 *sin6; 516 const struct in6_addr *in6; 517 struct ifnet *ifp; 518 { 519 u_int32_t scopeid; 520 521 sin6->sin6_addr = *in6; 522 523 /* 524 * don't try to read *in6 beyond here, since the caller may 525 * ask us to overwrite existing sockaddr_in6 526 */ 527 528 sin6->sin6_scope_id = 0; 529 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 530 /* 531 * KAME assumption: link id == interface id 532 */ 533 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 534 if (scopeid) { 535 /* sanity check */ 536 if (scopeid < 0 || if_index < scopeid) 537 return ENXIO; 538 if (ifp && ifp->if_index != scopeid) 539 return ENXIO; 540 sin6->sin6_addr.s6_addr16[1] = 0; 541 sin6->sin6_scope_id = scopeid; 542 } 543 } 544 545 return 0; 546 } 547 548 /* 549 * just clear the embedded scope identifer. 550 * XXX: currently used for bsdi4 only as a supplement function. 551 */ 552 void 553 in6_clearscope(addr) 554 struct in6_addr *addr; 555 { 556 if (IN6_IS_SCOPE_LINKLOCAL(addr)) 557 addr->s6_addr16[1] = 0; 558 } 559