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 1.13 2006/12/29 18:02:56 victor 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/jail.h> 75 #include <sys/malloc.h> 76 #include <sys/mbuf.h> 77 #include <sys/protosw.h> 78 #include <sys/socket.h> 79 #include <sys/socketvar.h> 80 #include <sys/errno.h> 81 #include <sys/time.h> 82 #include <sys/proc.h> 83 84 #include <net/if.h> 85 #include <net/route.h> 86 87 #include <netinet/in.h> 88 #include <netinet/in_var.h> 89 #include <netinet/in_systm.h> 90 #include <netinet/ip.h> 91 #include <netinet/in_pcb.h> 92 #include <netinet6/in6_var.h> 93 #include <netinet/ip6.h> 94 #include <netinet6/in6_pcb.h> 95 #include <netinet6/ip6_var.h> 96 #include <netinet6/nd6.h> 97 #ifdef ENABLE_DEFAULT_SCOPE 98 #include <netinet6/scope6_var.h> 99 #endif 100 101 #include <net/net_osdep.h> 102 103 #include "use_loop.h" 104 105 /* 106 * Return an IPv6 address, which is the most appropriate for a given 107 * destination and user specified options. 108 * If necessary, this function lookups the routing table and returns 109 * an entry to the caller for later use. 110 */ 111 struct in6_addr * 112 in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, 113 struct ip6_moptions *mopts, struct route_in6 *ro, 114 struct in6_addr *laddr, int *errorp, struct thread *td) 115 { 116 struct sockaddr_in6 jsin6; 117 struct ucred *cred = NULL; 118 struct in6_addr *dst; 119 struct in6_ifaddr *ia6 = 0; 120 struct in6_pktinfo *pi = NULL; 121 int jailed = 0; 122 123 if (td && td->td_proc && td->td_proc->p_ucred) 124 cred = td->td_proc->p_ucred; 125 if (cred && cred->cr_prison) 126 jailed = 1; 127 jsin6.sin6_family = AF_INET6; 128 dst = &dstsock->sin6_addr; 129 *errorp = 0; 130 131 /* 132 * If the source address is explicitly specified by the caller, 133 * use it. 134 */ 135 if (opts && (pi = opts->ip6po_pktinfo) && 136 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { 137 jsin6.sin6_addr = pi->ipi6_addr; 138 if (jailed && !jailed_ip(cred->cr_prison, 139 (struct sockaddr *)&jsin6)) { 140 return(0); 141 } else { 142 return (&pi->ipi6_addr); 143 } 144 } 145 146 /* 147 * If the source address is not specified but the socket(if any) 148 * is already bound, use the bound address. 149 */ 150 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) { 151 jsin6.sin6_addr = *laddr; 152 if (jailed && !jailed_ip(cred->cr_prison, 153 (struct sockaddr *)&jsin6)) { 154 return(0); 155 } else { 156 return (laddr); 157 } 158 } 159 160 /* 161 * If the caller doesn't specify the source address but 162 * the outgoing interface, use an address associated with 163 * the interface. 164 */ 165 if (pi && pi->ipi6_ifindex) { 166 /* XXX boundary check is assumed to be already done. */ 167 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex], 168 dst); 169 170 if (ia6 && jailed) { 171 jsin6.sin6_addr = (&ia6->ia_addr)->sin6_addr; 172 if (!jailed_ip(cred->cr_prison, 173 (struct sockaddr *)&jsin6)) 174 ia6 = 0; 175 } 176 177 if (ia6 == 0) { 178 *errorp = EADDRNOTAVAIL; 179 return (0); 180 } 181 return (&satosin6(&ia6->ia_addr)->sin6_addr); 182 } 183 184 /* 185 * If the destination address is a link-local unicast address or 186 * a multicast address, and if the outgoing interface is specified 187 * by the sin6_scope_id filed, use an address associated with the 188 * interface. 189 * XXX: We're now trying to define more specific semantics of 190 * sin6_scope_id field, so this part will be rewritten in 191 * the near future. 192 */ 193 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) && 194 dstsock->sin6_scope_id) { 195 /* 196 * I'm not sure if boundary check for scope_id is done 197 * somewhere... 198 */ 199 if (dstsock->sin6_scope_id < 0 || 200 if_index < dstsock->sin6_scope_id) { 201 *errorp = ENXIO; /* XXX: better error? */ 202 return (0); 203 } 204 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id], 205 dst); 206 207 if (ia6 && jailed) { 208 jsin6.sin6_addr = (&ia6->ia_addr)->sin6_addr; 209 if (!jailed_ip(cred->cr_prison, 210 (struct sockaddr *)&jsin6)) 211 ia6 = 0; 212 } 213 214 if (ia6 == 0) { 215 *errorp = EADDRNOTAVAIL; 216 return (0); 217 } 218 return (&satosin6(&ia6->ia_addr)->sin6_addr); 219 } 220 221 /* 222 * If the destination address is a multicast address and 223 * the outgoing interface for the address is specified 224 * by the caller, use an address associated with the interface. 225 * There is a sanity check here; if the destination has node-local 226 * scope, the outgoing interfacde should be a loopback address. 227 * Even if the outgoing interface is not specified, we also 228 * choose a loopback interface as the outgoing interface. 229 */ 230 if (!jailed && IN6_IS_ADDR_MULTICAST(dst)) { 231 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 232 233 if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) { 234 ifp = &loif[0]; 235 } 236 237 if (ifp) { 238 ia6 = in6_ifawithscope(ifp, dst); 239 if (ia6 == 0) { 240 *errorp = EADDRNOTAVAIL; 241 return (0); 242 } 243 return (&satosin6(&ia6->ia_addr)->sin6_addr); 244 } 245 } 246 247 /* 248 * If the next hop address for the packet is specified 249 * by caller, use an address associated with the route 250 * to the next hop. 251 */ 252 { 253 struct sockaddr_in6 *sin6_next; 254 struct rtentry *rt; 255 256 if (opts && opts->ip6po_nexthop) { 257 sin6_next = satosin6(opts->ip6po_nexthop); 258 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); 259 if (rt) { 260 ia6 = in6_ifawithscope(rt->rt_ifp, dst); 261 if (ia6 == 0) 262 ia6 = ifatoia6(rt->rt_ifa); 263 } 264 if (ia6 && jailed) { 265 jsin6.sin6_addr = (&ia6->ia_addr)->sin6_addr; 266 if (!jailed_ip(cred->cr_prison, 267 (struct sockaddr *)&jsin6)) 268 ia6 = 0; 269 } 270 271 if (ia6 == 0) { 272 *errorp = EADDRNOTAVAIL; 273 return (0); 274 } 275 return (&satosin6(&ia6->ia_addr)->sin6_addr); 276 } 277 } 278 279 /* 280 * If route is known or can be allocated now, 281 * our src addr is taken from the i/f, else punt. 282 */ 283 if (ro) { 284 if (ro->ro_rt && 285 (!(ro->ro_rt->rt_flags & RTF_UP) || 286 satosin6(&ro->ro_dst)->sin6_family != AF_INET6 || 287 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, 288 dst))) { 289 RTFREE(ro->ro_rt); 290 ro->ro_rt = NULL; 291 } 292 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) { 293 struct sockaddr_in6 *sa6; 294 295 /* No route yet, so try to acquire one */ 296 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 297 sa6 = &ro->ro_dst; 298 sa6->sin6_family = AF_INET6; 299 sa6->sin6_len = sizeof(struct sockaddr_in6); 300 sa6->sin6_addr = *dst; 301 sa6->sin6_scope_id = dstsock->sin6_scope_id; 302 if (!jailed && IN6_IS_ADDR_MULTICAST(dst)) { 303 ro->ro_rt = 304 rtpurelookup((struct sockaddr *)&ro->ro_dst); 305 } else { 306 rtalloc((struct route *)ro); 307 } 308 } 309 310 /* 311 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 312 * the address. But we don't know why it does so. 313 * It is necessary to ensure the scope even for lo0 314 * so doesn't check out IFF_LOOPBACK. 315 */ 316 317 if (ro->ro_rt) { 318 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); 319 if (ia6 && jailed) { 320 jsin6.sin6_addr = (&ia6->ia_addr)->sin6_addr; 321 if (!jailed_ip(cred->cr_prison, 322 (struct sockaddr *)&jsin6)) 323 ia6 = 0; 324 } 325 326 if (ia6 == 0) /* xxx scope error ?*/ 327 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 328 329 if (ia6 && jailed) { 330 jsin6.sin6_addr = (&ia6->ia_addr)->sin6_addr; 331 if (!jailed_ip(cred->cr_prison, 332 (struct sockaddr *)&jsin6)) 333 ia6 = 0; 334 } 335 } 336 #if 0 337 /* 338 * xxx The followings are necessary? (kazu) 339 * I don't think so. 340 * It's for SO_DONTROUTE option in IPv4.(jinmei) 341 */ 342 if (ia6 == 0) { 343 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 344 345 sin6->sin6_addr = *dst; 346 347 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 348 if (ia6 == 0) 349 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 350 if (ia6 == 0) 351 return (0); 352 return (&satosin6(&ia6->ia_addr)->sin6_addr); 353 } 354 #endif /* 0 */ 355 if (ia6 == 0) { 356 *errorp = EHOSTUNREACH; /* no route */ 357 return (0); 358 } 359 return (&satosin6(&ia6->ia_addr)->sin6_addr); 360 } 361 362 *errorp = EADDRNOTAVAIL; 363 return (0); 364 } 365 366 /* 367 * Default hop limit selection. The precedence is as follows: 368 * 1. Hoplimit value specified via ioctl. 369 * 2. (If the outgoing interface is detected) the current 370 * hop limit of the interface specified by router advertisement. 371 * 3. The system default hoplimit. 372 */ 373 int 374 in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp) 375 { 376 if (in6p && in6p->in6p_hops >= 0) 377 return (in6p->in6p_hops); 378 else if (ifp) 379 return (ND_IFINFO(ifp)->chlim); 380 else 381 return (ip6_defhlim); 382 } 383 384 /* 385 * XXX: this is borrowed from in6_pcbbind(). If possible, we should 386 * share this function by all *bsd*... 387 */ 388 int 389 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct thread *td) 390 { 391 struct socket *so = inp->inp_socket; 392 u_int16_t lport = 0, first, last, *lastport; 393 int count, error = 0, wild = 0; 394 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; 395 struct ucred *cred = NULL; 396 397 /* XXX: this is redundant when called from in6_pcbbind */ 398 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0) 399 wild = INPLOOKUP_WILDCARD; 400 if (td->td_proc && td->td_proc->p_ucred) 401 cred = td->td_proc->p_ucred; 402 403 inp->inp_flags |= INP_ANONPORT; 404 405 if (inp->inp_flags & INP_HIGHPORT) { 406 first = ipport_hifirstauto; /* sysctl */ 407 last = ipport_hilastauto; 408 lastport = &pcbinfo->lasthi; 409 } else if (inp->inp_flags & INP_LOWPORT) { 410 if ((error = suser(td)) != 0) 411 return error; 412 first = ipport_lowfirstauto; /* 1023 */ 413 last = ipport_lowlastauto; /* 600 */ 414 lastport = &pcbinfo->lastlow; 415 } else { 416 first = ipport_firstauto; /* sysctl */ 417 last = ipport_lastauto; 418 lastport = &pcbinfo->lastport; 419 } 420 /* 421 * Simple check to ensure all ports are not used up causing 422 * a deadlock here. 423 * 424 * We split the two cases (up and down) so that the direction 425 * is not being tested on each round of the loop. 426 */ 427 if (first > last) { 428 /* 429 * counting down 430 */ 431 count = first - last; 432 433 do { 434 if (count-- < 0) { /* completely used? */ 435 /* 436 * Undo any address bind that may have 437 * occurred above. 438 */ 439 inp->in6p_laddr = kin6addr_any; 440 return (EAGAIN); 441 } 442 --*lastport; 443 if (*lastport > first || *lastport < last) 444 *lastport = first; 445 lport = htons(*lastport); 446 } while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr, 447 lport, wild, cred)); 448 } else { 449 /* 450 * counting up 451 */ 452 count = last - first; 453 454 do { 455 if (count-- < 0) { /* completely used? */ 456 /* 457 * Undo any address bind that may have 458 * occurred above. 459 */ 460 inp->in6p_laddr = kin6addr_any; 461 return (EAGAIN); 462 } 463 ++*lastport; 464 if (*lastport < first || *lastport > last) 465 *lastport = first; 466 lport = htons(*lastport); 467 } while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr, 468 lport, wild, cred)); 469 } 470 471 inp->inp_lport = lport; 472 if (in_pcbinsporthash(inp) != 0) { 473 inp->in6p_laddr = kin6addr_any; 474 inp->inp_lport = 0; 475 return (EAGAIN); 476 } 477 478 return (0); 479 } 480 481 /* 482 * generate kernel-internal form (scopeid embedded into s6_addr16[1]). 483 * If the address scope of is link-local, embed the interface index in the 484 * address. The routine determines our precedence 485 * between advanced API scope/interface specification and basic API 486 * specification. 487 * 488 * this function should be nuked in the future, when we get rid of 489 * embedded scopeid thing. 490 * 491 * XXX actually, it is over-specification to return ifp against sin6_scope_id. 492 * there can be multiple interfaces that belong to a particular scope zone 493 * (in specification, we have 1:N mapping between a scope zone and interfaces). 494 * we may want to change the function to return something other than ifp. 495 */ 496 int 497 in6_embedscope(struct in6_addr *in6, 498 const struct sockaddr_in6 *sin6, 499 #ifdef HAVE_NRL_INPCB 500 struct inpcb *in6p, 501 #define in6p_outputopts inp_outputopts6 502 #define in6p_moptions inp_moptions6 503 #else 504 struct in6pcb *in6p, 505 #endif 506 struct ifnet **ifpp) 507 { 508 struct ifnet *ifp = NULL; 509 u_int32_t scopeid; 510 511 *in6 = sin6->sin6_addr; 512 scopeid = sin6->sin6_scope_id; 513 if (ifpp) 514 *ifpp = NULL; 515 516 /* 517 * don't try to read sin6->sin6_addr beyond here, since the caller may 518 * ask us to overwrite existing sockaddr_in6 519 */ 520 521 #ifdef ENABLE_DEFAULT_SCOPE 522 if (scopeid == 0) 523 scopeid = scope6_addr2default(in6); 524 #endif 525 526 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 527 struct in6_pktinfo *pi; 528 529 /* 530 * KAME assumption: link id == interface id 531 */ 532 533 if (in6p && in6p->in6p_outputopts && 534 (pi = in6p->in6p_outputopts->ip6po_pktinfo) && 535 pi->ipi6_ifindex) { 536 ifp = ifindex2ifnet[pi->ipi6_ifindex]; 537 in6->s6_addr16[1] = htons(pi->ipi6_ifindex); 538 } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && 539 in6p->in6p_moptions && 540 in6p->in6p_moptions->im6o_multicast_ifp) { 541 ifp = in6p->in6p_moptions->im6o_multicast_ifp; 542 in6->s6_addr16[1] = htons(ifp->if_index); 543 } else if (scopeid) { 544 /* boundary check */ 545 if (scopeid < 0 || if_index < scopeid) 546 return ENXIO; /* XXX EINVAL? */ 547 ifp = ifindex2ifnet[scopeid]; 548 /*XXX assignment to 16bit from 32bit variable */ 549 in6->s6_addr16[1] = htons(scopeid & 0xffff); 550 } 551 552 if (ifpp) 553 *ifpp = ifp; 554 } 555 556 return 0; 557 } 558 #ifdef HAVE_NRL_INPCB 559 #undef in6p_outputopts 560 #undef in6p_moptions 561 #endif 562 563 /* 564 * generate standard sockaddr_in6 from embedded form. 565 * touches sin6_addr and sin6_scope_id only. 566 * 567 * this function should be nuked in the future, when we get rid of 568 * embedded scopeid thing. 569 */ 570 int 571 in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6, 572 struct ifnet *ifp) 573 { 574 u_int32_t scopeid; 575 576 sin6->sin6_addr = *in6; 577 578 /* 579 * don't try to read *in6 beyond here, since the caller may 580 * ask us to overwrite existing sockaddr_in6 581 */ 582 583 sin6->sin6_scope_id = 0; 584 if (IN6_IS_SCOPE_LINKLOCAL(in6)) { 585 /* 586 * KAME assumption: link id == interface id 587 */ 588 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]); 589 if (scopeid) { 590 /* sanity check */ 591 if (scopeid < 0 || if_index < scopeid) 592 return ENXIO; 593 if (ifp && ifp->if_index != scopeid) 594 return ENXIO; 595 sin6->sin6_addr.s6_addr16[1] = 0; 596 sin6->sin6_scope_id = scopeid; 597 } 598 } 599 600 return 0; 601 } 602 603 /* 604 * just clear the embedded scope identifer. 605 * XXX: currently used for bsdi4 only as a supplement function. 606 */ 607 void 608 in6_clearscope(struct in6_addr *addr) 609 { 610 if (IN6_IS_SCOPE_LINKLOCAL(addr)) 611 addr->s6_addr16[1] = 0; 612 } 613