1 /* $NetBSD: in6_src.c,v 1.6 2001/03/30 11:08:57 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 "opt_inet.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/malloc.h> 73 #include <sys/mbuf.h> 74 #include <sys/protosw.h> 75 #include <sys/socket.h> 76 #include <sys/socketvar.h> 77 #include <sys/ioctl.h> 78 #include <sys/errno.h> 79 #include <sys/time.h> 80 #include <sys/proc.h> 81 82 #include <net/if.h> 83 #include <net/route.h> 84 85 #include <netinet/in.h> 86 #include <netinet/in_var.h> 87 #include <netinet/in_systm.h> 88 #include <netinet/ip.h> 89 #include <netinet/in_pcb.h> 90 #include <netinet6/in6_var.h> 91 #include <netinet/ip6.h> 92 #include <netinet6/in6_pcb.h> 93 #include <netinet6/ip6_var.h> 94 #include <netinet6/nd6.h> 95 #ifdef ENABLE_DEFAULT_SCOPE 96 #include <netinet6/scope6_var.h> 97 #endif 98 99 #include <net/net_osdep.h> 100 101 #include "loop.h" 102 extern struct ifnet loif[NLOOP]; 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 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst)) { 244 RTFREE(ro->ro_rt); 245 ro->ro_rt = (struct rtentry *)0; 246 } 247 if (ro->ro_rt == (struct rtentry *)0 || 248 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 249 struct sockaddr_in6 *sa6; 250 251 /* No route yet, so try to acquire one */ 252 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 253 sa6 = (struct sockaddr_in6 *)&ro->ro_dst; 254 sa6->sin6_family = AF_INET6; 255 sa6->sin6_len = sizeof(struct sockaddr_in6); 256 sa6->sin6_addr = *dst; 257 sa6->sin6_scope_id = dstsock->sin6_scope_id; 258 if (IN6_IS_ADDR_MULTICAST(dst)) { 259 ro->ro_rt = rtalloc1(&((struct route *)ro) 260 ->ro_dst, 0); 261 } else { 262 rtalloc((struct route *)ro); 263 } 264 } 265 266 /* 267 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 268 * the address. But we don't know why it does so. 269 * It is necessary to ensure the scope even for lo0 270 * so doesn't check out IFF_LOOPBACK. 271 */ 272 273 if (ro->ro_rt) { 274 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); 275 if (ia6 == 0) /* xxx scope error ?*/ 276 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 277 } 278 #if 0 279 /* 280 * xxx The followings are necessary? (kazu) 281 * I don't think so. 282 * It's for SO_DONTROUTE option in IPv4.(jinmei) 283 */ 284 if (ia6 == 0) { 285 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 286 287 sin6->sin6_addr = *dst; 288 289 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 290 if (ia6 == 0) 291 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 292 if (ia6 == 0) 293 return(0); 294 return(&satosin6(&ia6->ia_addr)->sin6_addr); 295 } 296 #endif /* 0 */ 297 if (ia6 == 0) { 298 *errorp = EHOSTUNREACH; /* no route */ 299 return(0); 300 } 301 return(&satosin6(&ia6->ia_addr)->sin6_addr); 302 } 303 304 *errorp = EADDRNOTAVAIL; 305 return(0); 306 } 307 308 /* 309 * Default hop limit selection. The precedence is as follows: 310 * 1. Hoplimit value specified via ioctl. 311 * 2. (If the outgoing interface is detected) the current 312 * hop limit of the interface specified by router advertisement. 313 * 3. The system default hoplimit. 314 */ 315 int 316 in6_selecthlim(in6p, ifp) 317 struct in6pcb *in6p; 318 struct ifnet *ifp; 319 { 320 if (in6p && in6p->in6p_hops >= 0) 321 return(in6p->in6p_hops); 322 else if (ifp) 323 return(nd_ifinfo[ifp->if_index].chlim); 324 else 325 return(ip6_defhlim); 326 } 327 328 /* 329 * Find an empty port and set it to the specified PCB. 330 */ 331 int 332 in6_pcbsetport(laddr, in6p) 333 struct in6_addr *laddr; 334 struct in6pcb *in6p; 335 { 336 struct socket *so = in6p->in6p_socket; 337 struct in6pcb *head = in6p->in6p_head; 338 u_int16_t last_port, lport = 0; 339 int wild = 0; 340 void *t; 341 u_int16_t min, max; 342 struct proc *p = curproc; /* XXX */ 343 344 /* XXX: this is redundant when called from in6_pcbbind */ 345 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 && 346 ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 || 347 (so->so_options & SO_ACCEPTCONN) == 0)) 348 wild = IN6PLOOKUP_WILDCARD; 349 350 if (in6p->in6p_flags & IN6P_LOWPORT) { 351 #ifndef IPNOPRIVPORTS 352 if (p == 0 || (suser(p->p_ucred, &p->p_acflag) != 0)) 353 return (EACCES); 354 #endif 355 min = ip6_lowportmin; 356 max = ip6_lowportmax; 357 } else { 358 min = ip6_anonportmin; 359 max = ip6_anonportmax; 360 } 361 362 /* value out of range */ 363 if (head->in6p_lport < min) 364 head->in6p_lport = min; 365 else if (head->in6p_lport > max) 366 head->in6p_lport = min; 367 last_port = head->in6p_lport; 368 goto startover; /*to randomize*/ 369 for (;;) { 370 lport = htons(head->in6p_lport); 371 if (IN6_IS_ADDR_V4MAPPED(laddr)) { 372 #if 0 373 t = in_pcblookup_bind(&tcbtable, 374 (struct in_addr *)&in6p->in6p_laddr.s6_addr32[3], 375 lport); 376 #else 377 t = NULL; 378 #endif 379 } else { 380 t = in6_pcblookup(head, &zeroin6_addr, 0, laddr, 381 lport, wild); 382 } 383 if (t == 0) 384 break; 385 startover: 386 if (head->in6p_lport >= max) 387 head->in6p_lport = min; 388 else 389 head->in6p_lport++; 390 if (head->in6p_lport == last_port) 391 return (EADDRINUSE); 392 } 393 394 in6p->in6p_lport = lport; 395 return(0); /* success */ 396 } 397 398 /* 399 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 400 * If the address scope of is link-local, embed the interface index in the 401 * address. The routine determines our precedence 402 * between advanced API scope/interface specification and basic API 403 * specification. 404 * 405 * this function should be nuked in the future, when we get rid of 406 * embedded scopeid thing. 407 * 408 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 409 * there can be multiple interfaces that belong to a particular scope zone 410 * (in specification, we have 1:N mapping between a scope zone and interfaces). 411 * we may want to change the function to return something other than ifp. 412 */ 413 int 414 in6_embedscope(in6, sin6, in6p, ifpp) 415 struct in6_addr *in6; 416 const struct sockaddr_in6 *sin6; 417 struct in6pcb *in6p; 418 struct ifnet **ifpp; 419 { 420 struct ifnet *ifp = NULL; 421 u_int32_t scopeid; 422 423 *in6 = sin6->sin6_addr; 424 scopeid = sin6->sin6_scope_id; 425 if (ifpp) 426 *ifpp = NULL; 427 428 /* 429 * don't try to read sin6->sin6_addr beyond here, since the caller may 430 * ask us to overwrite existing sockaddr_in6 431 */ 432 433 #ifdef ENABLE_DEFAULT_SCOPE 434 if (scopeid == 0) 435 scopeid = scope6_addr2default(in6); 436 #endif 437 438 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 439 struct in6_pktinfo *pi; 440 441 /* 442 * KAME assumption: link id == interface id 443 */ 444 445 if (in6p && in6p->in6p_outputopts && 446 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 447 pi->ipi6_ifindex) { 448 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 449 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 450 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 451 in6p->in6p_moptions && 452 in6p->in6p_moptions->im6o_multicast_ifp) { 453 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 454 in6->s6_addr16[1] = htons(ifp->if_index); 455 } else if (scopeid) { 456 /* boundary check */ 457 if (scopeid < 0 || if_index < scopeid) 458 return ENXIO; /* XXX EINVAL? */ 459 ifp = ifindex2ifnet[scopeid]; 460 /*XXX assignment to 16bit from 32bit variable */ 461 in6->s6_addr16[1] = htons(scopeid & 0xffff); 462 } 463 464 if (ifpp) 465 *ifpp = ifp; 466 } 467 468 return 0; 469 } 470 471 /* 472 * generate standard sockaddr_in6 from embedded form. 473 * touches sin6_addr and sin6_scope_id only. 474 * 475 * this function should be nuked in the future, when we get rid of 476 * embedded scopeid thing. 477 */ 478 int 479 in6_recoverscope(sin6, in6, ifp) 480 struct sockaddr_in6 *sin6; 481 const struct in6_addr *in6; 482 struct ifnet *ifp; 483 { 484 u_int32_t scopeid; 485 486 sin6->sin6_addr = *in6; 487 488 /* 489 * don't try to read *in6 beyond here, since the caller may 490 * ask us to overwrite existing sockaddr_in6 491 */ 492 493 sin6->sin6_scope_id = 0; 494 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 495 /* 496 * KAME assumption: link id == interface id 497 */ 498 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 499 if (scopeid) { 500 /* sanity check */ 501 if (scopeid < 0 || if_index < scopeid) 502 return ENXIO; 503 if (ifp && ifp->if_index != scopeid) 504 return ENXIO; 505 sin6->sin6_addr.s6_addr16[1] = 0; 506 sin6->sin6_scope_id = scopeid; 507 } 508 } 509 510 return 0; 511 } 512 513 /* 514 * just clear the embedded scope identifer. 515 * XXX: currently used for bsdi4 only as a supplement function. 516 */ 517 void 518 in6_clearscope(addr) 519 struct in6_addr *addr; 520 { 521 if (IN6_IS_SCOPE_LINKLOCAL(addr)) 522 addr->s6_addr16[1] = 0; 523 } 524