1 /* $KAME: name6.c,v 1.25 2000/06/26 16:44:40 itojun Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, 1998, and 1999 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 /* 32 * ++Copyright++ 1985, 1988, 1993 33 * - 34 * Copyright (c) 1985, 1988, 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 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 66 * 67 * Permission to use, copy, modify, and distribute this software for any 68 * purpose with or without fee is hereby granted, provided that the above 69 * copyright notice and this permission notice appear in all copies, and that 70 * the name of Digital Equipment Corporation not be used in advertising or 71 * publicity pertaining to distribution of the document or software without 72 * specific, written prior permission. 73 * 74 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 75 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 76 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 77 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 78 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 79 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 80 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 81 * SOFTWARE. 82 * - 83 * --Copyright-- 84 * 85 * $FreeBSD: src/lib/libc/net/name6.c,v 1.62 2007/07/31 16:09:41 bushman Exp $ 86 */ 87 88 /* 89 * Atsushi Onoe <onoe@sm.sony.co.jp> 90 */ 91 92 #include "namespace.h" 93 #include <sys/param.h> 94 #include <sys/socket.h> 95 #include <sys/time.h> 96 #include <sys/queue.h> 97 #include <netinet/in.h> 98 #ifdef INET6 99 #include <net/if.h> 100 #include <net/if_var.h> 101 #include <sys/sysctl.h> 102 #include <sys/ioctl.h> 103 #include <netinet6/in6_var.h> /* XXX */ 104 #endif 105 106 #include <arpa/inet.h> 107 #include <arpa/nameser.h> 108 109 #include <errno.h> 110 #include <netdb.h> 111 #include <resolv.h> 112 #include <stdio.h> 113 #include <stdlib.h> 114 #include <string.h> 115 #include <stdarg.h> 116 #include <nsswitch.h> 117 #include <unistd.h> 118 #include "un-namespace.h" 119 #include "netdb_private.h" 120 #include "res_private.h" 121 122 #ifndef MAXALIASES 123 #define MAXALIASES 10 124 #endif 125 #ifndef MAXADDRS 126 #define MAXADDRS 20 127 #endif 128 #ifndef MAXDNAME 129 #define MAXDNAME 1025 130 #endif 131 132 #ifdef INET6 133 #define ADDRLEN(af) ((af) == AF_INET6 ? sizeof(struct in6_addr) : \ 134 sizeof(struct in_addr)) 135 #else 136 #define ADDRLEN(af) sizeof(struct in_addr) 137 #endif 138 139 #define MAPADDR(ab, ina) \ 140 do { \ 141 memcpy(&(ab)->map_inaddr, ina, sizeof(struct in_addr)); \ 142 memset((ab)->map_zero, 0, sizeof((ab)->map_zero)); \ 143 memset((ab)->map_one, 0xff, sizeof((ab)->map_one)); \ 144 } while (0) 145 #define MAPADDRENABLED(flags) \ 146 (((flags) & AI_V4MAPPED) || \ 147 (((flags) & AI_V4MAPPED_CFG))) 148 149 union inx_addr { 150 struct in_addr in_addr; 151 #ifdef INET6 152 struct in6_addr in6_addr; 153 #endif 154 struct { 155 u_char mau_zero[10]; 156 u_char mau_one[2]; 157 struct in_addr mau_inaddr; 158 } map_addr_un; 159 #define map_zero map_addr_un.mau_zero 160 #define map_one map_addr_un.mau_one 161 #define map_inaddr map_addr_un.mau_inaddr 162 }; 163 164 struct policyqueue { 165 TAILQ_ENTRY(policyqueue) pc_entry; 166 #ifdef INET6 167 struct in6_addrpolicy pc_policy; 168 #endif 169 }; 170 TAILQ_HEAD(policyhead, policyqueue); 171 172 #define AIO_SRCFLAG_DEPRECATED 0x1 173 174 struct hp_order { 175 union { 176 struct sockaddr_storage aiou_ss; 177 struct sockaddr aiou_sa; 178 } aio_src_un; 179 #define aio_srcsa aio_src_un.aiou_sa 180 u_int32_t aio_srcflag; 181 int aio_srcscope; 182 int aio_dstscope; 183 struct policyqueue *aio_srcpolicy; 184 struct policyqueue *aio_dstpolicy; 185 union { 186 struct sockaddr_storage aiou_ss; 187 struct sockaddr aiou_sa; 188 } aio_un; 189 #define aio_sa aio_un.aiou_sa 190 int aio_matchlen; 191 char *aio_h_addr; 192 }; 193 194 static struct hostent *_hpcopy(struct hostent *, int *); 195 static struct hostent *_hpaddr(int, const char *, void *, int *); 196 #ifdef INET6 197 static struct hostent *_hpmerge(struct hostent *, struct hostent *, int *); 198 static struct hostent *_hpmapv6(struct hostent *, int *); 199 #endif 200 static struct hostent *_hpsort(struct hostent *, res_state); 201 202 static struct hostent *_hpreorder(struct hostent *); 203 static int get_addrselectpolicy(struct policyhead *); 204 static void free_addrselectpolicy(struct policyhead *); 205 static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 206 struct policyhead *); 207 static void set_source(struct hp_order *, struct policyhead *); 208 static int matchlen(struct sockaddr *, struct sockaddr *); 209 static int comp_dst(const void *, const void *); 210 static int gai_addr2scopetype(struct sockaddr *); 211 212 /* 213 * Functions defined in RFC2553 214 * getipnodebyname, getipnodebyaddr, freehostent 215 */ 216 217 struct hostent * 218 getipnodebyname(const char *name, int af, int flags, int *errp) 219 { 220 struct hostent *hp; 221 union inx_addr addrbuf; 222 res_state statp; 223 u_long options; 224 225 switch (af) { 226 case AF_INET: 227 #ifdef INET6 228 case AF_INET6: 229 #endif 230 break; 231 default: 232 *errp = NO_RECOVERY; 233 return NULL; 234 } 235 236 if (flags & AI_ADDRCONFIG) { 237 int s; 238 239 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 240 return NULL; 241 /* 242 * TODO: 243 * Note that implementation dependent test for address 244 * configuration should be done everytime called 245 * (or apropriate interval), 246 * because addresses will be dynamically assigned or deleted. 247 */ 248 _close(s); 249 } 250 251 #ifdef INET6 252 /* special case for literal address */ 253 if (inet_pton(AF_INET6, name, &addrbuf) == 1) { 254 if (af != AF_INET6) { 255 *errp = HOST_NOT_FOUND; 256 return NULL; 257 } 258 return _hpaddr(af, name, &addrbuf, errp); 259 } 260 #endif 261 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) { 262 if (af != AF_INET) { 263 if (MAPADDRENABLED(flags)) { 264 MAPADDR(&addrbuf, &addrbuf.in_addr); 265 } else { 266 *errp = HOST_NOT_FOUND; 267 return NULL; 268 } 269 } 270 return _hpaddr(af, name, &addrbuf, errp); 271 } 272 273 274 statp = __res_state(); 275 if ((statp->options & RES_INIT) == 0) { 276 if (res_ninit(statp) < 0) { 277 *errp = NETDB_INTERNAL; 278 return NULL; 279 } 280 } 281 282 options = statp->options; 283 statp->options &= ~RES_USE_INET6; 284 285 hp = gethostbyname2(name, af); 286 hp = _hpcopy(hp, errp); 287 288 #ifdef INET6 289 if (af == AF_INET6 && ((flags & AI_ALL) || hp == NULL) && 290 MAPADDRENABLED(flags)) { 291 struct hostent *hp2 = gethostbyname2(name, AF_INET); 292 if (hp == NULL) 293 if (hp2 == NULL) 294 *errp = statp->res_h_errno; 295 else 296 hp = _hpmapv6(hp2, errp); 297 else { 298 if (hp2 && strcmp(hp->h_name, hp2->h_name) == 0) { 299 struct hostent *hpb = hp; 300 hp = _hpmerge(hpb, hp2, errp); 301 freehostent(hpb); 302 } 303 } 304 } 305 #endif 306 307 if (hp == NULL) 308 *errp = statp->res_h_errno; 309 310 statp->options = options; 311 return _hpreorder(_hpsort(hp, statp)); 312 } 313 314 struct hostent * 315 getipnodebyaddr(const void *src, size_t len, int af, int *errp) 316 { 317 struct hostent *hp; 318 res_state statp; 319 u_long options; 320 321 #ifdef INET6 322 struct in6_addr addrbuf; 323 #else 324 struct in_addr addrbuf; 325 #endif 326 327 switch (af) { 328 case AF_INET: 329 if (len != sizeof(struct in_addr)) { 330 *errp = NO_RECOVERY; 331 return NULL; 332 } 333 if ((long)src & ~(sizeof(struct in_addr) - 1)) { 334 memcpy(&addrbuf, src, len); 335 src = &addrbuf; 336 } 337 if (((struct in_addr *)src)->s_addr == 0) 338 return NULL; 339 break; 340 #ifdef INET6 341 case AF_INET6: 342 if (len != sizeof(struct in6_addr)) { 343 *errp = NO_RECOVERY; 344 return NULL; 345 } 346 if ((long)src & ~(sizeof(struct in6_addr) / 2 - 1)) { /*XXX*/ 347 memcpy(&addrbuf, src, len); 348 src = &addrbuf; 349 } 350 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src)) 351 return NULL; 352 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src) 353 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) { 354 src = (char *)src + 355 (sizeof(struct in6_addr) - sizeof(struct in_addr)); 356 af = AF_INET; 357 len = sizeof(struct in_addr); 358 } 359 break; 360 #endif 361 default: 362 *errp = NO_RECOVERY; 363 return NULL; 364 } 365 366 statp = __res_state(); 367 if ((statp->options & RES_INIT) == 0) { 368 if (res_ninit(statp) < 0) { 369 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 370 return NULL; 371 } 372 } 373 374 options = statp->options; 375 statp->options &= ~RES_USE_INET6; 376 377 hp = gethostbyaddr(src, len, af); 378 if (hp == NULL) 379 *errp = statp->res_h_errno; 380 381 statp->options = options; 382 return (_hpcopy(hp, errp)); 383 } 384 385 void 386 freehostent(struct hostent *ptr) 387 { 388 free(ptr); 389 } 390 391 /* 392 * Private utility functions 393 */ 394 395 /* 396 * _hpcopy: allocate and copy hostent structure 397 */ 398 static struct hostent * 399 _hpcopy(struct hostent *hp, int *errp) 400 { 401 struct hostent *nhp; 402 char *cp, **pp; 403 int size, addrsize; 404 int nalias = 0, naddr = 0; 405 int al_off; 406 int i; 407 408 if (hp == NULL) 409 return hp; 410 411 /* count size to be allocated */ 412 size = sizeof(struct hostent); 413 if (hp->h_name != NULL) 414 size += strlen(hp->h_name) + 1; 415 if ((pp = hp->h_aliases) != NULL) { 416 for (i = 0; *pp != NULL; i++, pp++) { 417 if (**pp != '\0') { 418 size += strlen(*pp) + 1; 419 nalias++; 420 } 421 } 422 } 423 /* adjust alignment */ 424 size = ALIGN(size); 425 al_off = size; 426 size += sizeof(char *) * (nalias + 1); 427 addrsize = ALIGN(hp->h_length); 428 if ((pp = hp->h_addr_list) != NULL) { 429 while (*pp++ != NULL) 430 naddr++; 431 } 432 size += addrsize * naddr; 433 size += sizeof(char *) * (naddr + 1); 434 435 /* copy */ 436 if ((nhp = (struct hostent *)malloc(size)) == NULL) { 437 *errp = TRY_AGAIN; 438 return NULL; 439 } 440 cp = (char *)&nhp[1]; 441 if (hp->h_name != NULL) { 442 nhp->h_name = cp; 443 strcpy(cp, hp->h_name); 444 cp += strlen(cp) + 1; 445 } else 446 nhp->h_name = NULL; 447 nhp->h_aliases = (char **)((char *)nhp + al_off); 448 if ((pp = hp->h_aliases) != NULL) { 449 for (i = 0; *pp != NULL; pp++) { 450 if (**pp != '\0') { 451 nhp->h_aliases[i++] = cp; 452 strcpy(cp, *pp); 453 cp += strlen(cp) + 1; 454 } 455 } 456 } 457 nhp->h_aliases[nalias] = NULL; 458 cp = (char *)&nhp->h_aliases[nalias + 1]; 459 nhp->h_addrtype = hp->h_addrtype; 460 nhp->h_length = hp->h_length; 461 nhp->h_addr_list = (char **)cp; 462 if ((pp = hp->h_addr_list) != NULL) { 463 cp = (char *)&nhp->h_addr_list[naddr + 1]; 464 for (i = 0; *pp != NULL; pp++) { 465 nhp->h_addr_list[i++] = cp; 466 memcpy(cp, *pp, hp->h_length); 467 cp += addrsize; 468 } 469 } 470 nhp->h_addr_list[naddr] = NULL; 471 return nhp; 472 } 473 474 /* 475 * _hpaddr: construct hostent structure with one address 476 */ 477 static struct hostent * 478 _hpaddr(int af, const char *name, void *addr, int *errp) 479 { 480 struct hostent *hp, hpbuf; 481 char *addrs[2]; 482 483 hp = &hpbuf; 484 hp->h_name = (char *)name; 485 hp->h_aliases = NULL; 486 hp->h_addrtype = af; 487 hp->h_length = ADDRLEN(af); 488 hp->h_addr_list = addrs; 489 addrs[0] = (char *)addr; 490 addrs[1] = NULL; 491 return (_hpcopy(hp, errp)); 492 } 493 494 #ifdef INET6 495 /* 496 * _hpmerge: merge 2 hostent structure, arguments will be freed 497 */ 498 static struct hostent * 499 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp) 500 { 501 int i, j; 502 int naddr, nalias; 503 char **pp; 504 struct hostent *hp, hpbuf; 505 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1]; 506 union inx_addr addrbuf[MAXADDRS]; 507 508 if (hp1 == NULL) 509 return _hpcopy(hp2, errp); 510 if (hp2 == NULL) 511 return _hpcopy(hp1, errp); 512 513 #define HP(i) (i == 1 ? hp1 : hp2) 514 hp = &hpbuf; 515 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name); 516 hp->h_aliases = aliases; 517 nalias = 0; 518 for (i = 1; i <= 2; i++) { 519 if ((pp = HP(i)->h_aliases) == NULL) 520 continue; 521 for (; nalias < MAXALIASES && *pp != NULL; pp++) { 522 /* check duplicates */ 523 for (j = 0; j < nalias; j++) 524 if (strcasecmp(*pp, aliases[j]) == 0) 525 break; 526 if (j == nalias) 527 aliases[nalias++] = *pp; 528 } 529 } 530 aliases[nalias] = NULL; 531 if (hp1->h_length != hp2->h_length) { 532 hp->h_addrtype = AF_INET6; 533 hp->h_length = sizeof(struct in6_addr); 534 } else { 535 hp->h_addrtype = hp1->h_addrtype; 536 hp->h_length = hp1->h_length; 537 } 538 539 hp->h_addr_list = addrs; 540 naddr = 0; 541 for (i = 1; i <= 2; i++) { 542 if ((pp = HP(i)->h_addr_list) == NULL) 543 continue; 544 if (HP(i)->h_length == hp->h_length) { 545 while (naddr < MAXADDRS && *pp != NULL) 546 addrs[naddr++] = *pp++; 547 } else { 548 /* copy IPv4 addr as mapped IPv6 addr */ 549 while (naddr < MAXADDRS && *pp != NULL) { 550 MAPADDR(&addrbuf[naddr], *pp++); 551 addrs[naddr] = (char *)&addrbuf[naddr]; 552 naddr++; 553 } 554 } 555 } 556 addrs[naddr] = NULL; 557 return (_hpcopy(hp, errp)); 558 } 559 #endif 560 561 /* 562 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses 563 */ 564 #ifdef INET6 565 static struct hostent * 566 _hpmapv6(struct hostent *hp, int *errp) 567 { 568 struct hostent hp6; 569 570 if (hp == NULL) 571 return NULL; 572 if (hp->h_addrtype == AF_INET6) 573 return _hpcopy(hp, errp); 574 575 memset(&hp6, 0, sizeof(struct hostent)); 576 hp6.h_addrtype = AF_INET6; 577 hp6.h_length = sizeof(struct in6_addr); 578 return _hpmerge(&hp6, hp, errp); 579 } 580 #endif 581 582 /* 583 * _hpsort: sort address by sortlist 584 */ 585 static struct hostent * 586 _hpsort(struct hostent *hp, res_state statp) 587 { 588 int i, j, n; 589 u_char *ap, *sp, *mp, **pp; 590 char t; 591 char order[MAXADDRS]; 592 int nsort = statp->nsort; 593 594 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0) 595 return hp; 596 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) { 597 for (j = 0; j < nsort; j++) { 598 #ifdef INET6 599 if (statp->_u._ext.ext->sort_list[j].af != 600 hp->h_addrtype) 601 continue; 602 sp = (u_char *)&statp->_u._ext.ext->sort_list[j].addr; 603 mp = (u_char *)&statp->_u._ext.ext->sort_list[j].mask; 604 #else 605 sp = (u_char *)&statp->sort_list[j].addr; 606 mp = (u_char *)&statp->sort_list[j].mask; 607 #endif 608 for (n = 0; n < hp->h_length; n++) { 609 if ((ap[n] & mp[n]) != sp[n]) 610 break; 611 } 612 if (n == hp->h_length) 613 break; 614 } 615 order[i] = j; 616 } 617 n = i; 618 pp = (u_char **)hp->h_addr_list; 619 for (i = 0; i < n - 1; i++) { 620 for (j = i + 1; j < n; j++) { 621 if (order[i] > order[j]) { 622 ap = pp[i]; 623 pp[i] = pp[j]; 624 pp[j] = ap; 625 t = order[i]; 626 order[i] = order[j]; 627 order[j] = t; 628 } 629 } 630 } 631 return hp; 632 } 633 634 /* 635 * _hpreorder: sort address by default address selection 636 */ 637 static struct hostent * 638 _hpreorder(struct hostent *hp) 639 { 640 struct hp_order *aio; 641 int i, n; 642 char *ap; 643 struct sockaddr *sa; 644 struct policyhead policyhead; 645 646 if (hp == NULL) 647 return hp; 648 649 switch (hp->h_addrtype) { 650 case AF_INET: 651 #ifdef INET6 652 case AF_INET6: 653 #endif 654 break; 655 default: 656 free_addrselectpolicy(&policyhead); 657 return hp; 658 } 659 660 /* count the number of addrinfo elements for sorting. */ 661 for (n = 0; hp->h_addr_list[n] != NULL; n++) 662 ; 663 664 /* 665 * If the number is small enough, we can skip the reordering process. 666 */ 667 if (n <= 1) 668 return hp; 669 670 /* allocate a temporary array for sort and initialization of it. */ 671 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 672 return hp; /* give up reordering */ 673 memset(aio, 0, sizeof(*aio) * n); 674 675 /* retrieve address selection policy from the kernel */ 676 TAILQ_INIT(&policyhead); 677 if (!get_addrselectpolicy(&policyhead)) { 678 /* no policy is installed into kernel, we don't sort. */ 679 free(aio); 680 return hp; 681 } 682 683 for (i = 0; i < n; i++) { 684 ap = hp->h_addr_list[i]; 685 aio[i].aio_h_addr = ap; 686 sa = &aio[i].aio_sa; 687 switch (hp->h_addrtype) { 688 case AF_INET: 689 sa->sa_family = AF_INET; 690 sa->sa_len = sizeof(struct sockaddr_in); 691 memcpy(&((struct sockaddr_in *)sa)->sin_addr, ap, 692 sizeof(struct in_addr)); 693 break; 694 #ifdef INET6 695 case AF_INET6: 696 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) { 697 sa->sa_family = AF_INET; 698 sa->sa_len = sizeof(struct sockaddr_in); 699 memcpy(&((struct sockaddr_in *)sa)->sin_addr, 700 &ap[12], sizeof(struct in_addr)); 701 } else { 702 sa->sa_family = AF_INET6; 703 sa->sa_len = sizeof(struct sockaddr_in6); 704 memcpy(&((struct sockaddr_in6 *)sa)->sin6_addr, 705 ap, sizeof(struct in6_addr)); 706 } 707 break; 708 #endif 709 } 710 aio[i].aio_dstscope = gai_addr2scopetype(sa); 711 aio[i].aio_dstpolicy = match_addrselectpolicy(sa, &policyhead); 712 set_source(&aio[i], &policyhead); 713 } 714 715 /* perform sorting. */ 716 qsort(aio, n, sizeof(*aio), comp_dst); 717 718 /* reorder the h_addr_list. */ 719 for (i = 0; i < n; i++) 720 hp->h_addr_list[i] = aio[i].aio_h_addr; 721 722 /* cleanup and return */ 723 free(aio); 724 free_addrselectpolicy(&policyhead); 725 return hp; 726 } 727 728 static int 729 get_addrselectpolicy(struct policyhead *head) 730 { 731 #ifdef INET6 732 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 733 size_t l; 734 char *buf; 735 struct in6_addrpolicy *pol, *ep; 736 737 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) 738 return (0); 739 if ((buf = malloc(l)) == NULL) 740 return (0); 741 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) { 742 free(buf); 743 return (0); 744 } 745 746 ep = (struct in6_addrpolicy *)(buf + l); 747 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 748 struct policyqueue *new; 749 750 if ((new = malloc(sizeof(*new))) == NULL) { 751 free_addrselectpolicy(head); /* make the list empty */ 752 break; 753 } 754 new->pc_policy = *pol; 755 TAILQ_INSERT_TAIL(head, new, pc_entry); 756 } 757 758 free(buf); 759 return (1); 760 #else 761 return (0); 762 #endif 763 } 764 765 static void 766 free_addrselectpolicy(struct policyhead *head) 767 { 768 struct policyqueue *ent, *nent; 769 770 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 771 nent = TAILQ_NEXT(ent, pc_entry); 772 TAILQ_REMOVE(head, ent, pc_entry); 773 free(ent); 774 } 775 } 776 777 static struct policyqueue * 778 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 779 { 780 #ifdef INET6 781 struct policyqueue *ent, *bestent = NULL; 782 struct in6_addrpolicy *pol; 783 int matchlen, bestmatchlen = -1; 784 u_char *mp, *ep, *k, *p, m; 785 struct sockaddr_in6 key; 786 787 switch(addr->sa_family) { 788 case AF_INET6: 789 key = *(struct sockaddr_in6 *)addr; 790 break; 791 case AF_INET: 792 /* convert the address into IPv4-mapped IPv6 address. */ 793 memset(&key, 0, sizeof(key)); 794 key.sin6_family = AF_INET6; 795 key.sin6_len = sizeof(key); 796 key.sin6_addr.s6_addr[10] = 0xff; 797 key.sin6_addr.s6_addr[11] = 0xff; 798 memcpy(&key.sin6_addr.s6_addr[12], 799 &((struct sockaddr_in *)addr)->sin_addr, 4); 800 break; 801 default: 802 return(NULL); 803 } 804 805 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 806 pol = &ent->pc_policy; 807 matchlen = 0; 808 809 mp = (u_char *)&pol->addrmask.sin6_addr; 810 ep = mp + 16; /* XXX: scope field? */ 811 k = (u_char *)&key.sin6_addr; 812 p = (u_char *)&pol->addr.sin6_addr; 813 for (; mp < ep && *mp; mp++, k++, p++) { 814 m = *mp; 815 if ((*k & m) != *p) 816 goto next; /* not match */ 817 if (m == 0xff) /* short cut for a typical case */ 818 matchlen += 8; 819 else { 820 while (m >= 0x80) { 821 matchlen++; 822 m <<= 1; 823 } 824 } 825 } 826 827 /* matched. check if this is better than the current best. */ 828 if (matchlen > bestmatchlen) { 829 bestent = ent; 830 bestmatchlen = matchlen; 831 } 832 833 next: 834 continue; 835 } 836 837 return(bestent); 838 #else 839 return(NULL); 840 #endif 841 842 } 843 844 static void 845 set_source(struct hp_order *aio, struct policyhead *ph) 846 { 847 struct sockaddr_storage ss = aio->aio_un.aiou_ss; 848 socklen_t srclen; 849 int s; 850 851 /* set unspec ("no source is available"), just in case */ 852 aio->aio_srcsa.sa_family = AF_UNSPEC; 853 aio->aio_srcscope = -1; 854 855 switch(ss.ss_family) { 856 case AF_INET: 857 ((struct sockaddr_in *)&ss)->sin_port = htons(1); 858 break; 859 #ifdef INET6 860 case AF_INET6: 861 ((struct sockaddr_in6 *)&ss)->sin6_port = htons(1); 862 break; 863 #endif 864 default: /* ignore unsupported AFs explicitly */ 865 return; 866 } 867 868 /* open a socket to get the source address for the given dst */ 869 if ((s = _socket(ss.ss_family, SOCK_DGRAM, IPPROTO_UDP)) < 0) 870 return; /* give up */ 871 if (_connect(s, (struct sockaddr *)&ss, ss.ss_len) < 0) 872 goto cleanup; 873 srclen = ss.ss_len; 874 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 875 aio->aio_srcsa.sa_family = AF_UNSPEC; 876 goto cleanup; 877 } 878 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 879 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 880 aio->aio_matchlen = matchlen(&aio->aio_srcsa, (struct sockaddr *)&ss); 881 #ifdef INET6 882 if (ss.ss_family == AF_INET6) { 883 struct in6_ifreq ifr6; 884 u_int32_t flags6; 885 886 /* XXX: interface name should not be hardcoded */ 887 strncpy(ifr6.ifr_name, "lo0", sizeof(ifr6.ifr_name)); 888 memset(&ifr6, 0, sizeof(ifr6)); 889 memcpy(&ifr6.ifr_addr, &ss, ss.ss_len); 890 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 891 flags6 = ifr6.ifr_ifru.ifru_flags6; 892 if ((flags6 & IN6_IFF_DEPRECATED)) 893 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 894 } 895 } 896 #endif 897 898 cleanup: 899 _close(s); 900 return; 901 } 902 903 static int 904 matchlen(struct sockaddr *src, struct sockaddr *dst) 905 { 906 int match = 0; 907 u_char *s, *d; 908 u_char *lim, r; 909 int addrlen; 910 911 switch (src->sa_family) { 912 #ifdef INET6 913 case AF_INET6: 914 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 915 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 916 addrlen = sizeof(struct in6_addr); 917 lim = s + addrlen; 918 break; 919 #endif 920 case AF_INET: 921 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 922 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 923 addrlen = sizeof(struct in_addr); 924 lim = s + addrlen; 925 break; 926 default: 927 return(0); 928 } 929 930 while (s < lim) 931 if ((r = (*d++ ^ *s++)) != 0) { 932 while (r < addrlen * 8) { 933 match++; 934 r <<= 1; 935 } 936 break; 937 } else 938 match += 8; 939 return(match); 940 } 941 942 static int 943 comp_dst(const void *arg1, const void *arg2) 944 { 945 const struct hp_order *dst1 = arg1, *dst2 = arg2; 946 947 /* 948 * Rule 1: Avoid unusable destinations. 949 * XXX: we currently do not consider if an appropriate route exists. 950 */ 951 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 952 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 953 return(-1); 954 } 955 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 956 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 957 return(1); 958 } 959 960 /* Rule 2: Prefer matching scope. */ 961 if (dst1->aio_dstscope == dst1->aio_srcscope && 962 dst2->aio_dstscope != dst2->aio_srcscope) { 963 return(-1); 964 } 965 if (dst1->aio_dstscope != dst1->aio_srcscope && 966 dst2->aio_dstscope == dst2->aio_srcscope) { 967 return(1); 968 } 969 970 /* Rule 3: Avoid deprecated addresses. */ 971 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 972 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 973 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 974 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 975 return(-1); 976 } 977 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 978 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 979 return(1); 980 } 981 } 982 983 /* Rule 4: Prefer home addresses. */ 984 /* XXX: not implemented yet */ 985 986 /* Rule 5: Prefer matching label. */ 987 #ifdef INET6 988 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 989 dst1->aio_srcpolicy->pc_policy.label == 990 dst1->aio_dstpolicy->pc_policy.label && 991 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 992 dst2->aio_srcpolicy->pc_policy.label != 993 dst2->aio_dstpolicy->pc_policy.label)) { 994 return(-1); 995 } 996 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 997 dst2->aio_srcpolicy->pc_policy.label == 998 dst2->aio_dstpolicy->pc_policy.label && 999 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 1000 dst1->aio_srcpolicy->pc_policy.label != 1001 dst1->aio_dstpolicy->pc_policy.label)) { 1002 return(1); 1003 } 1004 #endif 1005 1006 /* Rule 6: Prefer higher precedence. */ 1007 #ifdef INET6 1008 if (dst1->aio_dstpolicy && 1009 (dst2->aio_dstpolicy == NULL || 1010 dst1->aio_dstpolicy->pc_policy.preced > 1011 dst2->aio_dstpolicy->pc_policy.preced)) { 1012 return(-1); 1013 } 1014 if (dst2->aio_dstpolicy && 1015 (dst1->aio_dstpolicy == NULL || 1016 dst2->aio_dstpolicy->pc_policy.preced > 1017 dst1->aio_dstpolicy->pc_policy.preced)) { 1018 return(1); 1019 } 1020 #endif 1021 1022 /* Rule 7: Prefer native transport. */ 1023 /* XXX: not implemented yet */ 1024 1025 /* Rule 8: Prefer smaller scope. */ 1026 if (dst1->aio_dstscope >= 0 && 1027 dst1->aio_dstscope < dst2->aio_dstscope) { 1028 return(-1); 1029 } 1030 if (dst2->aio_dstscope >= 0 && 1031 dst2->aio_dstscope < dst1->aio_dstscope) { 1032 return(1); 1033 } 1034 1035 /* 1036 * Rule 9: Use longest matching prefix. 1037 * We compare the match length in a same AF only. 1038 */ 1039 if (dst1->aio_sa.sa_family == dst2->aio_sa.sa_family) { 1040 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1041 return(-1); 1042 } 1043 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1044 return(1); 1045 } 1046 } 1047 1048 /* Rule 10: Otherwise, leave the order unchanged. */ 1049 return(-1); 1050 } 1051 1052 /* 1053 * Copy from scope.c. 1054 * XXX: we should standardize the functions and link them as standard 1055 * library. 1056 */ 1057 static int 1058 gai_addr2scopetype(struct sockaddr *sa) 1059 { 1060 #ifdef INET6 1061 struct sockaddr_in6 *sa6; 1062 #endif 1063 struct sockaddr_in *sa4; 1064 1065 switch(sa->sa_family) { 1066 #ifdef INET6 1067 case AF_INET6: 1068 sa6 = (struct sockaddr_in6 *)sa; 1069 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1070 /* just use the scope field of the multicast address */ 1071 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1072 } 1073 /* 1074 * Unicast addresses: map scope type to corresponding scope 1075 * value defined for multcast addresses. 1076 * XXX: hardcoded scope type values are bad... 1077 */ 1078 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1079 return(1); /* node local scope */ 1080 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1081 return(2); /* link-local scope */ 1082 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1083 return(5); /* site-local scope */ 1084 return(14); /* global scope */ 1085 break; 1086 #endif 1087 case AF_INET: 1088 /* 1089 * IPv4 pseudo scoping according to RFC 3484. 1090 */ 1091 sa4 = (struct sockaddr_in *)sa; 1092 /* IPv4 autoconfiguration addresses have link-local scope. */ 1093 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1094 ((u_char *)&sa4->sin_addr)[1] == 254) 1095 return(2); 1096 /* Private addresses have site-local scope. */ 1097 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1098 (((u_char *)&sa4->sin_addr)[0] == 172 && 1099 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1100 (((u_char *)&sa4->sin_addr)[0] == 192 && 1101 ((u_char *)&sa4->sin_addr)[1] == 168)) 1102 return(14); /* XXX: It should be 5 unless NAT */ 1103 /* Loopback addresses have link-local scope. */ 1104 if (((u_char *)&sa4->sin_addr)[0] == 127) 1105 return(2); 1106 return(14); 1107 break; 1108 default: 1109 errno = EAFNOSUPPORT; /* is this a good error? */ 1110 return(-1); 1111 } 1112 } 1113