1 /* $NetBSD: in6_src.c,v 1.2 2000/07/07 15:54:19 itojun Exp $ */ 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 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 given 106 * destination and user specified options. 107 * If necessary, this function lookups the routing table and return 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 /* No route yet, so try to acquire one */ 250 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 251 ro->ro_dst.sin6_family = AF_INET6; 252 ro->ro_dst.sin6_len = sizeof(struct sockaddr_in6); 253 ro->ro_dst.sin6_addr = *dst; 254 ro->ro_dst.sin6_scope_id = dstsock->sin6_scope_id; 255 if (IN6_IS_ADDR_MULTICAST(dst)) { 256 ro->ro_rt = rtalloc1(&((struct route *)ro) 257 ->ro_dst, 0); 258 } else { 259 rtalloc((struct route *)ro); 260 } 261 } 262 263 /* 264 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 265 * the address. But we don't know why it does so. 266 * It is necessary to ensure the scope even for lo0 267 * so doesn't check out IFF_LOOPBACK. 268 */ 269 270 if (ro->ro_rt) { 271 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); 272 if (ia6 == 0) /* xxx scope error ?*/ 273 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 274 } 275 #if 0 276 /* 277 * xxx The followings are necessary? (kazu) 278 * I don't think so. 279 * It's for SO_DONTROUTE option in IPv4.(jinmei) 280 */ 281 if (ia6 == 0) { 282 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 283 284 sin6->sin6_addr = *dst; 285 286 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 287 if (ia6 == 0) 288 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 289 if (ia6 == 0) 290 return(0); 291 return(&satosin6(&ia6->ia_addr)->sin6_addr); 292 } 293 #endif /* 0 */ 294 if (ia6 == 0) { 295 *errorp = EHOSTUNREACH; /* no route */ 296 return(0); 297 } 298 return(&satosin6(&ia6->ia_addr)->sin6_addr); 299 } 300 301 *errorp = EADDRNOTAVAIL; 302 return(0); 303 } 304 305 /* 306 * Default hop limit selection. The precedence is as follows: 307 * 1. Hoplimit value specified via ioctl. 308 * 2. (If the outgoing interface is detected) the current 309 * hop limit of the interface specified by router advertisement. 310 * 3. The system default hoplimit. 311 */ 312 int 313 in6_selecthlim(in6p, ifp) 314 struct in6pcb *in6p; 315 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 * Find an empty port and set it to the specified PCB. 327 */ 328 int 329 in6_pcbsetport(laddr, in6p) 330 struct in6_addr *laddr; 331 struct in6pcb *in6p; 332 { 333 struct socket *so = in6p->in6p_socket; 334 struct in6pcb *head = in6p->in6p_head; 335 u_int16_t last_port, lport = 0; 336 int wild = 0; 337 void *t; 338 u_int16_t min, max; 339 struct proc *p = curproc; /* XXX */ 340 341 /* XXX: this is redundant when called from in6_pcbbind */ 342 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 && 343 ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 || 344 (so->so_options & SO_ACCEPTCONN) == 0)) 345 wild = IN6PLOOKUP_WILDCARD; 346 347 if (in6p->in6p_flags & IN6P_LOWPORT) { 348 if (p == 0 || (suser(p->p_ucred, &p->p_acflag) != 0)) 349 return (EACCES); 350 min = IPV6PORT_RESERVEDMIN; 351 max = IPV6PORT_RESERVEDMAX; 352 } else { 353 min = IPV6PORT_ANONMIN; 354 max = IPV6PORT_ANONMAX; 355 } 356 357 /* value out of range */ 358 if (head->in6p_lport < min) 359 head->in6p_lport = min; 360 else if (head->in6p_lport > max) 361 head->in6p_lport = min; 362 last_port = head->in6p_lport; 363 goto startover; /*to randomize*/ 364 for (;;) { 365 lport = htons(head->in6p_lport); 366 if (IN6_IS_ADDR_V4MAPPED(laddr)) { 367 #if 0 368 t = in_pcblookup_bind(&tcbtable, 369 (struct in_addr *)&in6p->in6p_laddr.s6_addr32[3], 370 lport); 371 #else 372 t = NULL; 373 #endif 374 } else { 375 t = in6_pcblookup(head, &zeroin6_addr, 0, laddr, 376 lport, wild); 377 } 378 if (t == 0) 379 break; 380 startover: 381 if (head->in6p_lport >= max) 382 head->in6p_lport = min; 383 else 384 head->in6p_lport++; 385 if (head->in6p_lport == last_port) 386 return (EADDRINUSE); 387 } 388 389 in6p->in6p_lport = lport; 390 return(0); /* success */ 391 } 392 393 /* 394 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 395 * If the address scope of is link-local, embed the interface index in the 396 * address. The routine determines our precedence 397 * between advanced API scope/interface specification and basic API 398 * specification. 399 * 400 * this function should be nuked in the future, when we get rid of 401 * embedded scopeid thing. 402 * 403 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 404 * there can be multiple interfaces that belong to a particular scope zone 405 * (in specification, we have 1:N mapping between a scope zone and interfaces). 406 * we may want to change the function to return something other than ifp. 407 */ 408 int 409 in6_embedscope(in6, sin6, in6p, ifpp) 410 struct in6_addr *in6; 411 const struct sockaddr_in6 *sin6; 412 struct in6pcb *in6p; 413 struct ifnet **ifpp; 414 { 415 struct ifnet *ifp = NULL; 416 u_int32_t scopeid; 417 418 *in6 = sin6->sin6_addr; 419 scopeid = sin6->sin6_scope_id; 420 if (ifpp) 421 *ifpp = NULL; 422 423 /* 424 * don't try to read sin6->sin6_addr beyond here, since the caller may 425 * ask us to overwrite existing sockaddr_in6 426 */ 427 428 #ifdef ENABLE_DEFAULT_SCOPE 429 if (scopeid == 0) 430 scopeid = scope6_addr2default(in6); 431 #endif 432 433 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 434 struct in6_pktinfo *pi; 435 436 /* 437 * KAME assumption: link id == interface id 438 */ 439 440 if (in6p && in6p->in6p_outputopts && 441 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 442 pi->ipi6_ifindex) { 443 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 444 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 445 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 446 in6p->in6p_moptions && 447 in6p->in6p_moptions->im6o_multicast_ifp) { 448 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 449 in6->s6_addr16[1] = htons(ifp->if_index); 450 } else if (scopeid) { 451 /* boundary check */ 452 if (scopeid < 0 || if_index < scopeid) 453 return ENXIO; /* XXX EINVAL? */ 454 ifp = ifindex2ifnet[scopeid]; 455 /*XXX assignment to 16bit from 32bit variable */ 456 in6->s6_addr16[1] = htons(scopeid & 0xffff); 457 } 458 459 if (ifpp) 460 *ifpp = ifp; 461 } 462 463 return 0; 464 } 465 466 /* 467 * generate standard sockaddr_in6 from embedded form. 468 * touches sin6_addr and sin6_scope_id only. 469 * 470 * this function should be nuked in the future, when we get rid of 471 * embedded scopeid thing. 472 */ 473 int 474 in6_recoverscope(sin6, in6, ifp) 475 struct sockaddr_in6 *sin6; 476 const struct in6_addr *in6; 477 struct ifnet *ifp; 478 { 479 u_int32_t scopeid; 480 481 sin6->sin6_addr = *in6; 482 483 /* 484 * don't try to read *in6 beyond here, since the caller may 485 * ask us to overwrite existing sockaddr_in6 486 */ 487 488 sin6->sin6_scope_id = 0; 489 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 490 /* 491 * KAME assumption: link id == interface id 492 */ 493 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 494 if (scopeid) { 495 /* sanity check */ 496 if (scopeid < 0 || if_index < scopeid) 497 return ENXIO; 498 #ifndef FAKE_LOOPBACK_IF 499 if (ifp && (ifp->if_flags & IFF_LOOPBACK) == 0 && 500 ifp->if_index != scopeid) { 501 return ENXIO; 502 } 503 #else 504 if (ifp && ifp->if_index != scopeid) 505 return ENXIO; 506 #endif 507 sin6->sin6_addr.s6_addr16[1] = 0; 508 sin6->sin6_scope_id = scopeid; 509 } 510 } 511 512 return 0; 513 } 514