1 /* $KAME: name6.c,v 1.25 2000/06/26 16:44:40 itojun Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-3-Clause 5 * 6 * Copyright (C) 1995, 1996, 1997, 1998, and 1999 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 * ++Copyright++ 1985, 1988, 1993 35 * - 36 * Copyright (c) 1985, 1988, 1993 37 * The Regents of the University of California. All rights reserved. 38 * 39 * Redistribution and use in source and binary forms, with or without 40 * modification, are permitted provided that the following conditions 41 * are met: 42 * 1. Redistributions of source code must retain the above copyright 43 * notice, this list of conditions and the following disclaimer. 44 * 2. Redistributions in binary form must reproduce the above copyright 45 * notice, this list of conditions and the following disclaimer in the 46 * documentation and/or other materials provided with the distribution. 47 * 3. Neither the name of the University nor the names of its contributors 48 * may be used to endorse or promote products derived from this software 49 * without specific prior written permission. 50 * 51 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 52 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 53 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 54 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 55 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 56 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 57 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 58 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 59 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 60 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 61 * SUCH DAMAGE. 62 * - 63 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 64 * 65 * Permission to use, copy, modify, and distribute this software for any 66 * purpose with or without fee is hereby granted, provided that the above 67 * copyright notice and this permission notice appear in all copies, and that 68 * the name of Digital Equipment Corporation not be used in advertising or 69 * publicity pertaining to distribution of the document or software without 70 * specific, written prior permission. 71 * 72 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 73 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 74 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 75 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 76 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 77 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 78 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 79 * SOFTWARE. 80 * - 81 * --Copyright-- 82 */ 83 84 /* 85 * Atsushi Onoe <onoe@sm.sony.co.jp> 86 */ 87 88 #include "namespace.h" 89 #include <sys/param.h> 90 #include <sys/socket.h> 91 #include <sys/time.h> 92 #include <sys/queue.h> 93 #include <netinet/in.h> 94 #ifdef INET6 95 #include <net/if.h> 96 #include <sys/sysctl.h> 97 #include <sys/ioctl.h> 98 #include <netinet6/in6_var.h> /* XXX */ 99 #endif 100 101 #include <arpa/inet.h> 102 #include <arpa/nameser.h> 103 104 #include <errno.h> 105 #include <netdb.h> 106 #include <resolv.h> 107 #include <stdio.h> 108 #include <stdlib.h> 109 #include <string.h> 110 #include <stdarg.h> 111 #include <nsswitch.h> 112 #include <unistd.h> 113 #include "un-namespace.h" 114 #include "netdb_private.h" 115 #include "res_private.h" 116 117 #ifndef MAXALIASES 118 #define MAXALIASES 10 119 #endif 120 #ifndef MAXADDRS 121 #define MAXADDRS 20 122 #endif 123 #ifndef MAXDNAME 124 #define MAXDNAME 1025 125 #endif 126 127 #ifdef INET6 128 #define ADDRLEN(af) ((af) == AF_INET6 ? sizeof(struct in6_addr) : \ 129 sizeof(struct in_addr)) 130 #else 131 #define ADDRLEN(af) sizeof(struct in_addr) 132 #endif 133 134 #define MAPADDR(ab, ina) \ 135 do { \ 136 memcpy(&(ab)->map_inaddr, ina, sizeof(struct in_addr)); \ 137 memset((ab)->map_zero, 0, sizeof((ab)->map_zero)); \ 138 memset((ab)->map_one, 0xff, sizeof((ab)->map_one)); \ 139 } while (0) 140 #define MAPADDRENABLED(flags) \ 141 (((flags) & AI_V4MAPPED) || \ 142 (((flags) & AI_V4MAPPED_CFG))) 143 144 union inx_addr { 145 struct in_addr in_addr; 146 #ifdef INET6 147 struct in6_addr in6_addr; 148 #endif 149 struct { 150 u_char mau_zero[10]; 151 u_char mau_one[2]; 152 struct in_addr mau_inaddr; 153 } map_addr_un; 154 #define map_zero map_addr_un.mau_zero 155 #define map_one map_addr_un.mau_one 156 #define map_inaddr map_addr_un.mau_inaddr 157 }; 158 159 struct policyqueue { 160 TAILQ_ENTRY(policyqueue) pc_entry; 161 #ifdef INET6 162 struct in6_addrpolicy pc_policy; 163 #endif 164 }; 165 TAILQ_HEAD(policyhead, policyqueue); 166 167 #define AIO_SRCFLAG_DEPRECATED 0x1 168 169 struct hp_order { 170 union { 171 struct sockaddr_storage aiou_ss; 172 struct sockaddr aiou_sa; 173 } aio_src_un; 174 #define aio_srcsa aio_src_un.aiou_sa 175 u_int32_t aio_srcflag; 176 int aio_srcscope; 177 int aio_dstscope; 178 struct policyqueue *aio_srcpolicy; 179 struct policyqueue *aio_dstpolicy; 180 union { 181 struct sockaddr_storage aiou_ss; 182 struct sockaddr aiou_sa; 183 } aio_un; 184 #define aio_sa aio_un.aiou_sa 185 int aio_matchlen; 186 char *aio_h_addr; 187 int aio_initial_sequence; 188 }; 189 190 static struct hostent *_hpcopy(struct hostent *, int *); 191 static struct hostent *_hpaddr(int, const char *, void *, int *); 192 #ifdef INET6 193 static struct hostent *_hpmerge(struct hostent *, struct hostent *, int *); 194 static struct hostent *_hpmapv6(struct hostent *, int *); 195 #endif 196 static struct hostent *_hpsort(struct hostent *, res_state); 197 198 #ifdef INET6 199 static struct hostent *_hpreorder(struct hostent *); 200 static int get_addrselectpolicy(struct policyhead *); 201 static void free_addrselectpolicy(struct policyhead *); 202 static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 203 struct policyhead *); 204 static void set_source(struct hp_order *, struct policyhead *); 205 static int matchlen(struct sockaddr *, struct sockaddr *); 206 static int comp_dst(const void *, const void *); 207 static int gai_addr2scopetype(struct sockaddr *); 208 #endif 209 210 /* 211 * Functions defined in RFC2553 212 * getipnodebyname, getipnodebyaddr, freehostent 213 */ 214 215 struct hostent * 216 getipnodebyname(const char *name, int af, int flags, int *errp) 217 { 218 struct hostent *hp; 219 union inx_addr addrbuf; 220 res_state statp; 221 u_long options; 222 223 switch (af) { 224 case AF_INET: 225 #ifdef INET6 226 case AF_INET6: 227 #endif 228 break; 229 default: 230 *errp = NO_RECOVERY; 231 return NULL; 232 } 233 234 if (flags & AI_ADDRCONFIG) { 235 int s; 236 237 if ((s = _socket(af, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) 238 return NULL; 239 /* 240 * TODO: 241 * Note that implementation dependent test for address 242 * configuration should be done every time called 243 * (or appropriate interval), 244 * because addresses will be dynamically assigned or deleted. 245 */ 246 _close(s); 247 } 248 249 #ifdef INET6 250 /* special case for literal address */ 251 if (inet_pton(AF_INET6, name, &addrbuf) == 1) { 252 if (af != AF_INET6) { 253 *errp = HOST_NOT_FOUND; 254 return NULL; 255 } 256 return _hpaddr(af, name, &addrbuf, errp); 257 } 258 #endif 259 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) { 260 if (af != AF_INET) { 261 if (MAPADDRENABLED(flags)) { 262 MAPADDR(&addrbuf, &addrbuf.in_addr); 263 } else { 264 *errp = HOST_NOT_FOUND; 265 return NULL; 266 } 267 } 268 return _hpaddr(af, name, &addrbuf, errp); 269 } 270 271 272 statp = __res_state(); 273 if ((statp->options & RES_INIT) == 0) { 274 if (res_ninit(statp) < 0) { 275 *errp = NETDB_INTERNAL; 276 return NULL; 277 } 278 } 279 280 options = statp->options; 281 statp->options &= ~RES_USE_INET6; 282 283 hp = gethostbyname2(name, af); 284 hp = _hpcopy(hp, errp); 285 #ifdef INET6 286 if (af == AF_INET6) 287 hp = _hpreorder(hp); 288 289 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 _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 (rounddown2((long)src, sizeof(struct in_addr))) { 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 (rounddown2((long)src, sizeof(struct in6_addr) / 2)) { 347 /* XXX */ 348 memcpy(&addrbuf, src, len); 349 src = &addrbuf; 350 } 351 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src)) 352 return NULL; 353 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src) 354 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) { 355 src = (char *)src + 356 (sizeof(struct in6_addr) - sizeof(struct in_addr)); 357 af = AF_INET; 358 len = sizeof(struct in_addr); 359 } 360 break; 361 #endif 362 default: 363 *errp = NO_RECOVERY; 364 return NULL; 365 } 366 367 statp = __res_state(); 368 if ((statp->options & RES_INIT) == 0) { 369 if (res_ninit(statp) < 0) { 370 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 371 return NULL; 372 } 373 } 374 375 options = statp->options; 376 statp->options &= ~RES_USE_INET6; 377 378 hp = gethostbyaddr(src, len, af); 379 if (hp == NULL) 380 *errp = statp->res_h_errno; 381 382 statp->options = options; 383 return (_hpcopy(hp, errp)); 384 } 385 386 void 387 freehostent(struct hostent *ptr) 388 { 389 free(ptr); 390 } 391 392 /* 393 * Private utility functions 394 */ 395 396 /* 397 * _hpcopy: allocate and copy hostent structure 398 */ 399 static struct hostent * 400 _hpcopy(struct hostent *hp, int *errp) 401 { 402 struct hostent *nhp; 403 char *cp, **pp; 404 int size, addrsize; 405 int nalias = 0, naddr = 0; 406 int al_off; 407 int i; 408 409 if (hp == NULL) 410 return hp; 411 412 /* count size to be allocated */ 413 size = sizeof(struct hostent); 414 if (hp->h_name != NULL) 415 size += strlen(hp->h_name) + 1; 416 if ((pp = hp->h_aliases) != NULL) { 417 for (i = 0; *pp != NULL; i++, pp++) { 418 if (**pp != '\0') { 419 size += strlen(*pp) + 1; 420 nalias++; 421 } 422 } 423 } 424 /* adjust alignment */ 425 size = ALIGN(size); 426 al_off = size; 427 size += sizeof(char *) * (nalias + 1); 428 addrsize = ALIGN(hp->h_length); 429 if ((pp = hp->h_addr_list) != NULL) { 430 while (*pp++ != NULL) 431 naddr++; 432 } 433 size += addrsize * naddr; 434 size += sizeof(char *) * (naddr + 1); 435 436 /* copy */ 437 if ((nhp = (struct hostent *)malloc(size)) == NULL) { 438 *errp = TRY_AGAIN; 439 return NULL; 440 } 441 cp = (char *)&nhp[1]; 442 if (hp->h_name != NULL) { 443 nhp->h_name = cp; 444 strcpy(cp, hp->h_name); 445 cp += strlen(cp) + 1; 446 } else 447 nhp->h_name = NULL; 448 nhp->h_aliases = (char **)((char *)nhp + al_off); 449 if ((pp = hp->h_aliases) != NULL) { 450 for (i = 0; *pp != NULL; pp++) { 451 if (**pp != '\0') { 452 nhp->h_aliases[i++] = cp; 453 strcpy(cp, *pp); 454 cp += strlen(cp) + 1; 455 } 456 } 457 } 458 nhp->h_aliases[nalias] = NULL; 459 cp = (char *)&nhp->h_aliases[nalias + 1]; 460 nhp->h_addrtype = hp->h_addrtype; 461 nhp->h_length = hp->h_length; 462 nhp->h_addr_list = (char **)cp; 463 if ((pp = hp->h_addr_list) != NULL) { 464 cp = (char *)&nhp->h_addr_list[naddr + 1]; 465 for (i = 0; *pp != NULL; pp++) { 466 nhp->h_addr_list[i++] = cp; 467 memcpy(cp, *pp, hp->h_length); 468 cp += addrsize; 469 } 470 } 471 nhp->h_addr_list[naddr] = NULL; 472 return nhp; 473 } 474 475 /* 476 * _hpaddr: construct hostent structure with one address 477 */ 478 static struct hostent * 479 _hpaddr(int af, const char *name, void *addr, int *errp) 480 { 481 struct hostent *hp, hpbuf; 482 char *addrs[2]; 483 484 hp = &hpbuf; 485 hp->h_name = (char *)name; 486 hp->h_aliases = NULL; 487 hp->h_addrtype = af; 488 hp->h_length = ADDRLEN(af); 489 hp->h_addr_list = addrs; 490 addrs[0] = (char *)addr; 491 addrs[1] = NULL; 492 return (_hpcopy(hp, errp)); 493 } 494 495 #ifdef INET6 496 /* 497 * _hpmerge: merge 2 hostent structure, arguments will be freed 498 */ 499 static struct hostent * 500 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp) 501 { 502 int i, j; 503 int naddr, nalias; 504 char **pp; 505 struct hostent *hp, hpbuf; 506 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1]; 507 union inx_addr addrbuf[MAXADDRS]; 508 509 if (hp1 == NULL) 510 return _hpcopy(hp2, errp); 511 if (hp2 == NULL) 512 return _hpcopy(hp1, errp); 513 514 #define HP(i) (i == 1 ? hp1 : hp2) 515 hp = &hpbuf; 516 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name); 517 hp->h_aliases = aliases; 518 nalias = 0; 519 for (i = 1; i <= 2; i++) { 520 if ((pp = HP(i)->h_aliases) == NULL) 521 continue; 522 for (; nalias < MAXALIASES && *pp != NULL; pp++) { 523 /* check duplicates */ 524 for (j = 0; j < nalias; j++) 525 if (strcasecmp(*pp, aliases[j]) == 0) 526 break; 527 if (j == nalias) 528 aliases[nalias++] = *pp; 529 } 530 } 531 aliases[nalias] = NULL; 532 if (hp1->h_length != hp2->h_length) { 533 hp->h_addrtype = AF_INET6; 534 hp->h_length = sizeof(struct in6_addr); 535 } else { 536 hp->h_addrtype = hp1->h_addrtype; 537 hp->h_length = hp1->h_length; 538 } 539 540 hp->h_addr_list = addrs; 541 naddr = 0; 542 for (i = 1; i <= 2; i++) { 543 if ((pp = HP(i)->h_addr_list) == NULL) 544 continue; 545 if (HP(i)->h_length == hp->h_length) { 546 while (naddr < MAXADDRS && *pp != NULL) 547 addrs[naddr++] = *pp++; 548 } else { 549 /* copy IPv4 addr as mapped IPv6 addr */ 550 while (naddr < MAXADDRS && *pp != NULL) { 551 MAPADDR(&addrbuf[naddr], *pp++); 552 addrs[naddr] = (char *)&addrbuf[naddr]; 553 naddr++; 554 } 555 } 556 } 557 addrs[naddr] = NULL; 558 return (_hpcopy(hp, errp)); 559 } 560 #endif 561 562 /* 563 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses 564 */ 565 #ifdef INET6 566 static struct hostent * 567 _hpmapv6(struct hostent *hp, int *errp) 568 { 569 struct hostent hp6; 570 571 if (hp == NULL) 572 return NULL; 573 if (hp->h_addrtype == AF_INET6) 574 return _hpcopy(hp, errp); 575 576 memset(&hp6, 0, sizeof(struct hostent)); 577 hp6.h_addrtype = AF_INET6; 578 hp6.h_length = sizeof(struct in6_addr); 579 return _hpmerge(&hp6, hp, errp); 580 } 581 #endif 582 583 /* 584 * _hpsort: sort address by sortlist 585 */ 586 static struct hostent * 587 _hpsort(struct hostent *hp, res_state statp) 588 { 589 int i, j, n; 590 u_char *ap, *sp, *mp, **pp; 591 char t; 592 char order[MAXADDRS]; 593 int nsort = statp->nsort; 594 595 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0) 596 return hp; 597 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) { 598 for (j = 0; j < nsort; j++) { 599 #ifdef INET6 600 if (statp->_u._ext.ext->sort_list[j].af != 601 hp->h_addrtype) 602 continue; 603 sp = (u_char *)&statp->_u._ext.ext->sort_list[j].addr; 604 mp = (u_char *)&statp->_u._ext.ext->sort_list[j].mask; 605 #else 606 sp = (u_char *)&statp->sort_list[j].addr; 607 mp = (u_char *)&statp->sort_list[j].mask; 608 #endif 609 for (n = 0; n < hp->h_length; n++) { 610 if ((ap[n] & mp[n]) != sp[n]) 611 break; 612 } 613 if (n == hp->h_length) 614 break; 615 } 616 order[i] = j; 617 } 618 n = i; 619 pp = (u_char **)hp->h_addr_list; 620 for (i = 0; i < n - 1; i++) { 621 for (j = i + 1; j < n; j++) { 622 if (order[i] > order[j]) { 623 ap = pp[i]; 624 pp[i] = pp[j]; 625 pp[j] = ap; 626 t = order[i]; 627 order[i] = order[j]; 628 order[j] = t; 629 } 630 } 631 } 632 return hp; 633 } 634 635 #ifdef INET6 636 /* 637 * _hpreorder: sort address by default address selection 638 */ 639 static struct hostent * 640 _hpreorder(struct hostent *hp) 641 { 642 struct hp_order *aio; 643 int i, n; 644 char *ap; 645 struct sockaddr *sa; 646 struct policyhead policyhead; 647 648 if (hp == NULL) 649 return hp; 650 651 switch (hp->h_addrtype) { 652 case AF_INET: 653 #ifdef INET6 654 case AF_INET6: 655 #endif 656 break; 657 default: 658 return hp; 659 } 660 661 /* count the number of addrinfo elements for sorting. */ 662 for (n = 0; hp->h_addr_list[n] != NULL; n++) 663 ; 664 665 /* 666 * If the number is small enough, we can skip the reordering process. 667 */ 668 if (n <= 1) 669 return hp; 670 671 /* allocate a temporary array for sort and initialization of it. */ 672 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 673 return hp; /* give up reordering */ 674 memset(aio, 0, sizeof(*aio) * n); 675 676 /* retrieve address selection policy from the kernel */ 677 TAILQ_INIT(&policyhead); 678 if (!get_addrselectpolicy(&policyhead)) { 679 /* no policy is installed into kernel, we don't sort. */ 680 free(aio); 681 return hp; 682 } 683 684 for (i = 0; i < n; i++) { 685 ap = hp->h_addr_list[i]; 686 aio[i].aio_h_addr = ap; 687 sa = &aio[i].aio_sa; 688 switch (hp->h_addrtype) { 689 case AF_INET: 690 sa->sa_family = AF_INET; 691 sa->sa_len = sizeof(struct sockaddr_in); 692 memcpy(&((struct sockaddr_in *)sa)->sin_addr, ap, 693 sizeof(struct in_addr)); 694 break; 695 #ifdef INET6 696 case AF_INET6: 697 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) { 698 sa->sa_family = AF_INET; 699 sa->sa_len = sizeof(struct sockaddr_in); 700 memcpy(&((struct sockaddr_in *)sa)->sin_addr, 701 &ap[12], sizeof(struct in_addr)); 702 } else { 703 sa->sa_family = AF_INET6; 704 sa->sa_len = sizeof(struct sockaddr_in6); 705 memcpy(&((struct sockaddr_in6 *)sa)->sin6_addr, 706 ap, sizeof(struct in6_addr)); 707 } 708 break; 709 #endif 710 } 711 aio[i].aio_dstscope = gai_addr2scopetype(sa); 712 aio[i].aio_dstpolicy = match_addrselectpolicy(sa, &policyhead); 713 set_source(&aio[i], &policyhead); 714 aio[i].aio_initial_sequence = i; 715 } 716 717 /* perform sorting. */ 718 qsort(aio, n, sizeof(*aio), comp_dst); 719 720 /* reorder the h_addr_list. */ 721 for (i = 0; i < n; i++) 722 hp->h_addr_list[i] = aio[i].aio_h_addr; 723 724 /* cleanup and return */ 725 free(aio); 726 free_addrselectpolicy(&policyhead); 727 return hp; 728 } 729 730 static int 731 get_addrselectpolicy(struct policyhead *head) 732 { 733 #ifdef INET6 734 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 735 size_t l; 736 char *buf; 737 struct in6_addrpolicy *pol, *ep; 738 739 if (sysctl(mib, nitems(mib), NULL, &l, NULL, 0) < 0) 740 return (0); 741 if ((buf = malloc(l)) == NULL) 742 return (0); 743 if (sysctl(mib, nitems(mib), buf, &l, NULL, 0) < 0) { 744 free(buf); 745 return (0); 746 } 747 748 ep = (struct in6_addrpolicy *)(buf + l); 749 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 750 struct policyqueue *new; 751 752 if ((new = malloc(sizeof(*new))) == NULL) { 753 free_addrselectpolicy(head); /* make the list empty */ 754 break; 755 } 756 new->pc_policy = *pol; 757 TAILQ_INSERT_TAIL(head, new, pc_entry); 758 } 759 760 free(buf); 761 return (1); 762 #else 763 return (0); 764 #endif 765 } 766 767 static void 768 free_addrselectpolicy(struct policyhead *head) 769 { 770 struct policyqueue *ent, *nent; 771 772 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 773 nent = TAILQ_NEXT(ent, pc_entry); 774 TAILQ_REMOVE(head, ent, pc_entry); 775 free(ent); 776 } 777 } 778 779 static struct policyqueue * 780 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 781 { 782 #ifdef INET6 783 struct policyqueue *ent, *bestent = NULL; 784 struct in6_addrpolicy *pol; 785 int matchlen, bestmatchlen = -1; 786 u_char *mp, *ep, *k, *p, m; 787 struct sockaddr_in6 key; 788 789 switch(addr->sa_family) { 790 case AF_INET6: 791 key = *(struct sockaddr_in6 *)addr; 792 break; 793 case AF_INET: 794 /* convert the address into IPv4-mapped IPv6 address. */ 795 memset(&key, 0, sizeof(key)); 796 key.sin6_family = AF_INET6; 797 key.sin6_len = sizeof(key); 798 _map_v4v6_address( 799 (char *)&((struct sockaddr_in *)addr)->sin_addr, 800 (char *)&key.sin6_addr); 801 break; 802 default: 803 return(NULL); 804 } 805 806 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 807 pol = &ent->pc_policy; 808 matchlen = 0; 809 810 mp = (u_char *)&pol->addrmask.sin6_addr; 811 ep = mp + 16; /* XXX: scope field? */ 812 k = (u_char *)&key.sin6_addr; 813 p = (u_char *)&pol->addr.sin6_addr; 814 for (; mp < ep && *mp; mp++, k++, p++) { 815 m = *mp; 816 if ((*k & m) != *p) 817 goto next; /* not match */ 818 if (m == 0xff) /* short cut for a typical case */ 819 matchlen += 8; 820 else { 821 while (m >= 0x80) { 822 matchlen++; 823 m <<= 1; 824 } 825 } 826 } 827 828 /* matched. check if this is better than the current best. */ 829 if (matchlen > bestmatchlen) { 830 bestent = ent; 831 bestmatchlen = matchlen; 832 } 833 834 next: 835 continue; 836 } 837 838 return(bestent); 839 #else 840 return(NULL); 841 #endif 842 843 } 844 845 static void 846 set_source(struct hp_order *aio, struct policyhead *ph) 847 { 848 struct sockaddr_storage ss = aio->aio_un.aiou_ss; 849 socklen_t srclen; 850 int s; 851 852 /* set unspec ("no source is available"), just in case */ 853 aio->aio_srcsa.sa_family = AF_UNSPEC; 854 aio->aio_srcscope = -1; 855 856 switch(ss.ss_family) { 857 case AF_INET: 858 ((struct sockaddr_in *)&ss)->sin_port = htons(1); 859 break; 860 #ifdef INET6 861 case AF_INET6: 862 ((struct sockaddr_in6 *)&ss)->sin6_port = htons(1); 863 break; 864 #endif 865 default: /* ignore unsupported AFs explicitly */ 866 return; 867 } 868 869 /* open a socket to get the source address for the given dst */ 870 if ((s = _socket(ss.ss_family, SOCK_DGRAM | SOCK_CLOEXEC, 871 IPPROTO_UDP)) < 0) 872 return; /* give up */ 873 if (_connect(s, (struct sockaddr *)&ss, ss.ss_len) < 0) 874 goto cleanup; 875 srclen = ss.ss_len; 876 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 877 aio->aio_srcsa.sa_family = AF_UNSPEC; 878 goto cleanup; 879 } 880 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 881 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 882 aio->aio_matchlen = matchlen(&aio->aio_srcsa, (struct sockaddr *)&ss); 883 #ifdef INET6 884 if (ss.ss_family == AF_INET6) { 885 struct in6_ifreq ifr6; 886 u_int32_t flags6; 887 888 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 & 0x80) == 0) { 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 1050 /* 1051 * Note that qsort is unstable; so, we can't return zero and 1052 * expect the order to be unchanged. 1053 * That also means we can't depend on the current position of 1054 * dst2 being after dst1. We must enforce the initial order 1055 * with an explicit compare on the original position. 1056 * The qsort specification requires that "When the same objects 1057 * (consisting of width bytes, irrespective of their current 1058 * positions in the array) are passed more than once to the 1059 * comparison function, the results shall be consistent with one 1060 * another." 1061 * In other words, If A < B, then we must also return B > A. 1062 */ 1063 if (dst2->aio_initial_sequence < dst1->aio_initial_sequence) 1064 return(1); 1065 1066 return(-1); 1067 } 1068 1069 /* 1070 * Copy from scope.c. 1071 * XXX: we should standardize the functions and link them as standard 1072 * library. 1073 */ 1074 static int 1075 gai_addr2scopetype(struct sockaddr *sa) 1076 { 1077 #ifdef INET6 1078 struct sockaddr_in6 *sa6; 1079 #endif 1080 struct sockaddr_in *sa4; 1081 1082 switch(sa->sa_family) { 1083 #ifdef INET6 1084 case AF_INET6: 1085 sa6 = (struct sockaddr_in6 *)sa; 1086 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1087 /* just use the scope field of the multicast address */ 1088 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1089 } 1090 /* 1091 * Unicast addresses: map scope type to corresponding scope 1092 * value defined for multcast addresses. 1093 * XXX: hardcoded scope type values are bad... 1094 */ 1095 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1096 return(1); /* node local scope */ 1097 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1098 return(2); /* link-local scope */ 1099 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1100 return(5); /* site-local scope */ 1101 return(14); /* global scope */ 1102 break; 1103 #endif 1104 case AF_INET: 1105 /* 1106 * IPv4 pseudo scoping according to RFC 3484. 1107 */ 1108 sa4 = (struct sockaddr_in *)sa; 1109 /* IPv4 autoconfiguration addresses have link-local scope. */ 1110 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1111 ((u_char *)&sa4->sin_addr)[1] == 254) 1112 return(2); 1113 /* Private addresses have site-local scope. */ 1114 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1115 (((u_char *)&sa4->sin_addr)[0] == 172 && 1116 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1117 (((u_char *)&sa4->sin_addr)[0] == 192 && 1118 ((u_char *)&sa4->sin_addr)[1] == 168)) 1119 return(14); /* XXX: It should be 5 unless NAT */ 1120 /* Loopback addresses have link-local scope. */ 1121 if (((u_char *)&sa4->sin_addr)[0] == 127) 1122 return(2); 1123 return(14); 1124 break; 1125 default: 1126 errno = EAFNOSUPPORT; /* is this a good error? */ 1127 return(-1); 1128 } 1129 } 1130 #endif 1131