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. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * - 61 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 62 * 63 * Permission to use, copy, modify, and distribute this software for any 64 * purpose with or without fee is hereby granted, provided that the above 65 * copyright notice and this permission notice appear in all copies, and that 66 * the name of Digital Equipment Corporation not be used in advertising or 67 * publicity pertaining to distribution of the document or software without 68 * specific, written prior permission. 69 * 70 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 71 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 72 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 73 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 74 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 75 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 76 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 77 * SOFTWARE. 78 * - 79 * --Copyright-- 80 * 81 * $FreeBSD: src/lib/libc/net/name6.c,v 1.62 2007/07/31 16:09:41 bushman Exp $ 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 <net/if_var.h> 97 #include <sys/sysctl.h> 98 #include <sys/ioctl.h> 99 #include <netinet6/in6_var.h> /* XXX */ 100 #endif 101 102 #include <arpa/inet.h> 103 #include <arpa/nameser.h> 104 105 #include <errno.h> 106 #include <netdb.h> 107 #include <resolv.h> 108 #include <stdio.h> 109 #include <stdlib.h> 110 #include <string.h> 111 #include <stdarg.h> 112 #include <nsswitch.h> 113 #include <unistd.h> 114 #include "un-namespace.h" 115 #include "netdb_private.h" 116 #include "res_private.h" 117 118 #ifndef MAXALIASES 119 #define MAXALIASES 10 120 #endif 121 #ifndef MAXADDRS 122 #define MAXADDRS 20 123 #endif 124 #ifndef MAXDNAME 125 #define MAXDNAME 1025 126 #endif 127 128 #ifdef INET6 129 #define ADDRLEN(af) ((af) == AF_INET6 ? sizeof(struct in6_addr) : \ 130 sizeof(struct in_addr)) 131 #else 132 #define ADDRLEN(af) sizeof(struct in_addr) 133 #endif 134 135 #define MAPADDR(ab, ina) \ 136 do { \ 137 memcpy(&(ab)->map_inaddr, ina, sizeof(struct in_addr)); \ 138 memset((ab)->map_zero, 0, sizeof((ab)->map_zero)); \ 139 memset((ab)->map_one, 0xff, sizeof((ab)->map_one)); \ 140 } while (0) 141 #define MAPADDRENABLED(flags) \ 142 (((flags) & AI_V4MAPPED) || \ 143 (((flags) & AI_V4MAPPED_CFG))) 144 145 union inx_addr { 146 struct in_addr in_addr; 147 #ifdef INET6 148 struct in6_addr in6_addr; 149 #endif 150 struct { 151 u_char mau_zero[10]; 152 u_char mau_one[2]; 153 struct in_addr mau_inaddr; 154 } map_addr_un; 155 #define map_zero map_addr_un.mau_zero 156 #define map_one map_addr_un.mau_one 157 #define map_inaddr map_addr_un.mau_inaddr 158 }; 159 160 struct policyqueue { 161 TAILQ_ENTRY(policyqueue) pc_entry; 162 #ifdef INET6 163 struct in6_addrpolicy pc_policy; 164 #endif 165 }; 166 TAILQ_HEAD(policyhead, policyqueue); 167 168 #define AIO_SRCFLAG_DEPRECATED 0x1 169 170 struct hp_order { 171 union { 172 struct sockaddr_storage aiou_ss; 173 struct sockaddr aiou_sa; 174 } aio_src_un; 175 #define aio_srcsa aio_src_un.aiou_sa 176 u_int32_t aio_srcflag; 177 int aio_srcscope; 178 int aio_dstscope; 179 struct policyqueue *aio_srcpolicy; 180 struct policyqueue *aio_dstpolicy; 181 union { 182 struct sockaddr_storage aiou_ss; 183 struct sockaddr aiou_sa; 184 } aio_un; 185 #define aio_sa aio_un.aiou_sa 186 int aio_matchlen; 187 char *aio_h_addr; 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 static struct hostent *_hpreorder(struct hostent *); 199 static int get_addrselectpolicy(struct policyhead *); 200 static void free_addrselectpolicy(struct policyhead *); 201 static struct policyqueue *match_addrselectpolicy(struct sockaddr *, 202 struct policyhead *); 203 static void set_source(struct hp_order *, struct policyhead *); 204 static int matchlen(struct sockaddr *, struct sockaddr *); 205 static int comp_dst(const void *, const void *); 206 static int gai_addr2scopetype(struct sockaddr *); 207 208 /* 209 * Functions defined in RFC2553 210 * getipnodebyname, getipnodebyaddr, freehostent 211 */ 212 213 struct hostent * 214 getipnodebyname(const char *name, int af, int flags, int *errp) 215 { 216 struct hostent *hp; 217 union inx_addr addrbuf; 218 res_state statp; 219 u_long options; 220 221 switch (af) { 222 case AF_INET: 223 #ifdef INET6 224 case AF_INET6: 225 #endif 226 break; 227 default: 228 *errp = NO_RECOVERY; 229 return NULL; 230 } 231 232 if (flags & AI_ADDRCONFIG) { 233 int s; 234 235 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0) 236 return NULL; 237 /* 238 * TODO: 239 * Note that implementation dependent test for address 240 * configuration should be done everytime called 241 * (or apropriate interval), 242 * because addresses will be dynamically assigned or deleted. 243 */ 244 _close(s); 245 } 246 247 #ifdef INET6 248 /* special case for literal address */ 249 if (inet_pton(AF_INET6, name, &addrbuf) == 1) { 250 if (af != AF_INET6) { 251 *errp = HOST_NOT_FOUND; 252 return NULL; 253 } 254 return _hpaddr(af, name, &addrbuf, errp); 255 } 256 #endif 257 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) { 258 if (af != AF_INET) { 259 if (MAPADDRENABLED(flags)) { 260 MAPADDR(&addrbuf, &addrbuf.in_addr); 261 } else { 262 *errp = HOST_NOT_FOUND; 263 return NULL; 264 } 265 } 266 return _hpaddr(af, name, &addrbuf, errp); 267 } 268 269 270 statp = __res_state(); 271 if ((statp->options & RES_INIT) == 0) { 272 if (res_ninit(statp) < 0) { 273 *errp = NETDB_INTERNAL; 274 return NULL; 275 } 276 } 277 278 options = statp->options; 279 statp->options &= ~RES_USE_INET6; 280 281 hp = gethostbyname2(name, af); 282 hp = _hpcopy(hp, errp); 283 284 #ifdef INET6 285 if (af == AF_INET6 && ((flags & AI_ALL) || hp == NULL) && 286 MAPADDRENABLED(flags)) { 287 struct hostent *hp2 = gethostbyname2(name, AF_INET); 288 if (hp == NULL) 289 if (hp2 == NULL) 290 *errp = statp->res_h_errno; 291 else 292 hp = _hpmapv6(hp2, errp); 293 else { 294 if (hp2 && strcmp(hp->h_name, hp2->h_name) == 0) { 295 struct hostent *hpb = hp; 296 hp = _hpmerge(hpb, hp2, errp); 297 freehostent(hpb); 298 } 299 } 300 } 301 #endif 302 303 if (hp == NULL) 304 *errp = statp->res_h_errno; 305 306 statp->options = options; 307 return _hpreorder(_hpsort(hp, statp)); 308 } 309 310 struct hostent * 311 getipnodebyaddr(const void *src, size_t len, int af, int *errp) 312 { 313 struct hostent *hp; 314 res_state statp; 315 u_long options; 316 317 #ifdef INET6 318 struct in6_addr addrbuf; 319 #else 320 struct in_addr addrbuf; 321 #endif 322 323 switch (af) { 324 case AF_INET: 325 if (len != sizeof(struct in_addr)) { 326 *errp = NO_RECOVERY; 327 return NULL; 328 } 329 if ((long)src & ~(sizeof(struct in_addr) - 1)) { 330 memcpy(&addrbuf, src, len); 331 src = &addrbuf; 332 } 333 if (((struct in_addr *)src)->s_addr == 0) 334 return NULL; 335 break; 336 #ifdef INET6 337 case AF_INET6: 338 if (len != sizeof(struct in6_addr)) { 339 *errp = NO_RECOVERY; 340 return NULL; 341 } 342 if ((long)src & ~(sizeof(struct in6_addr) / 2 - 1)) { /*XXX*/ 343 memcpy(&addrbuf, src, len); 344 src = &addrbuf; 345 } 346 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src)) 347 return NULL; 348 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src) 349 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) { 350 src = (char *)src + 351 (sizeof(struct in6_addr) - sizeof(struct in_addr)); 352 af = AF_INET; 353 len = sizeof(struct in_addr); 354 } 355 break; 356 #endif 357 default: 358 *errp = NO_RECOVERY; 359 return NULL; 360 } 361 362 statp = __res_state(); 363 if ((statp->options & RES_INIT) == 0) { 364 if (res_ninit(statp) < 0) { 365 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 366 return NULL; 367 } 368 } 369 370 options = statp->options; 371 statp->options &= ~RES_USE_INET6; 372 373 hp = gethostbyaddr(src, len, af); 374 if (hp == NULL) 375 *errp = statp->res_h_errno; 376 377 statp->options = options; 378 return (_hpcopy(hp, errp)); 379 } 380 381 void 382 freehostent(struct hostent *ptr) 383 { 384 free(ptr); 385 } 386 387 /* 388 * Private utility functions 389 */ 390 391 /* 392 * _hpcopy: allocate and copy hostent structure 393 */ 394 static struct hostent * 395 _hpcopy(struct hostent *hp, int *errp) 396 { 397 struct hostent *nhp; 398 char *cp, **pp; 399 int size, addrsize; 400 int nalias = 0, naddr = 0; 401 int al_off; 402 int i; 403 404 if (hp == NULL) 405 return hp; 406 407 /* count size to be allocated */ 408 size = sizeof(struct hostent); 409 if (hp->h_name != NULL) 410 size += strlen(hp->h_name) + 1; 411 if ((pp = hp->h_aliases) != NULL) { 412 for (i = 0; *pp != NULL; i++, pp++) { 413 if (**pp != '\0') { 414 size += strlen(*pp) + 1; 415 nalias++; 416 } 417 } 418 } 419 /* adjust alignment */ 420 size = ALIGN(size); 421 al_off = size; 422 size += sizeof(char *) * (nalias + 1); 423 addrsize = ALIGN(hp->h_length); 424 if ((pp = hp->h_addr_list) != NULL) { 425 while (*pp++ != NULL) 426 naddr++; 427 } 428 size += addrsize * naddr; 429 size += sizeof(char *) * (naddr + 1); 430 431 /* copy */ 432 if ((nhp = (struct hostent *)malloc(size)) == NULL) { 433 *errp = TRY_AGAIN; 434 return NULL; 435 } 436 cp = (char *)&nhp[1]; 437 if (hp->h_name != NULL) { 438 nhp->h_name = cp; 439 strcpy(cp, hp->h_name); 440 cp += strlen(cp) + 1; 441 } else 442 nhp->h_name = NULL; 443 nhp->h_aliases = (char **)((char *)nhp + al_off); 444 if ((pp = hp->h_aliases) != NULL) { 445 for (i = 0; *pp != NULL; pp++) { 446 if (**pp != '\0') { 447 nhp->h_aliases[i++] = cp; 448 strcpy(cp, *pp); 449 cp += strlen(cp) + 1; 450 } 451 } 452 } 453 nhp->h_aliases[nalias] = NULL; 454 cp = (char *)&nhp->h_aliases[nalias + 1]; 455 nhp->h_addrtype = hp->h_addrtype; 456 nhp->h_length = hp->h_length; 457 nhp->h_addr_list = (char **)cp; 458 if ((pp = hp->h_addr_list) != NULL) { 459 cp = (char *)&nhp->h_addr_list[naddr + 1]; 460 for (i = 0; *pp != NULL; pp++) { 461 nhp->h_addr_list[i++] = cp; 462 memcpy(cp, *pp, hp->h_length); 463 cp += addrsize; 464 } 465 } 466 nhp->h_addr_list[naddr] = NULL; 467 return nhp; 468 } 469 470 /* 471 * _hpaddr: construct hostent structure with one address 472 */ 473 static struct hostent * 474 _hpaddr(int af, const char *name, void *addr, int *errp) 475 { 476 struct hostent *hp, hpbuf; 477 char *addrs[2]; 478 479 hp = &hpbuf; 480 hp->h_name = (char *)name; 481 hp->h_aliases = NULL; 482 hp->h_addrtype = af; 483 hp->h_length = ADDRLEN(af); 484 hp->h_addr_list = addrs; 485 addrs[0] = (char *)addr; 486 addrs[1] = NULL; 487 return (_hpcopy(hp, errp)); 488 } 489 490 #ifdef INET6 491 /* 492 * _hpmerge: merge 2 hostent structure, arguments will be freed 493 */ 494 static struct hostent * 495 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp) 496 { 497 int i, j; 498 int naddr, nalias; 499 char **pp; 500 struct hostent *hp, hpbuf; 501 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1]; 502 union inx_addr addrbuf[MAXADDRS]; 503 504 if (hp1 == NULL) 505 return _hpcopy(hp2, errp); 506 if (hp2 == NULL) 507 return _hpcopy(hp1, errp); 508 509 #define HP(i) (i == 1 ? hp1 : hp2) 510 hp = &hpbuf; 511 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name); 512 hp->h_aliases = aliases; 513 nalias = 0; 514 for (i = 1; i <= 2; i++) { 515 if ((pp = HP(i)->h_aliases) == NULL) 516 continue; 517 for (; nalias < MAXALIASES && *pp != NULL; pp++) { 518 /* check duplicates */ 519 for (j = 0; j < nalias; j++) 520 if (strcasecmp(*pp, aliases[j]) == 0) 521 break; 522 if (j == nalias) 523 aliases[nalias++] = *pp; 524 } 525 } 526 aliases[nalias] = NULL; 527 if (hp1->h_length != hp2->h_length) { 528 hp->h_addrtype = AF_INET6; 529 hp->h_length = sizeof(struct in6_addr); 530 } else { 531 hp->h_addrtype = hp1->h_addrtype; 532 hp->h_length = hp1->h_length; 533 } 534 535 hp->h_addr_list = addrs; 536 naddr = 0; 537 for (i = 1; i <= 2; i++) { 538 if ((pp = HP(i)->h_addr_list) == NULL) 539 continue; 540 if (HP(i)->h_length == hp->h_length) { 541 while (naddr < MAXADDRS && *pp != NULL) 542 addrs[naddr++] = *pp++; 543 } else { 544 /* copy IPv4 addr as mapped IPv6 addr */ 545 while (naddr < MAXADDRS && *pp != NULL) { 546 MAPADDR(&addrbuf[naddr], *pp++); 547 addrs[naddr] = (char *)&addrbuf[naddr]; 548 naddr++; 549 } 550 } 551 } 552 addrs[naddr] = NULL; 553 return (_hpcopy(hp, errp)); 554 } 555 #endif 556 557 /* 558 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses 559 */ 560 #ifdef INET6 561 static struct hostent * 562 _hpmapv6(struct hostent *hp, int *errp) 563 { 564 struct hostent hp6; 565 566 if (hp == NULL) 567 return NULL; 568 if (hp->h_addrtype == AF_INET6) 569 return _hpcopy(hp, errp); 570 571 memset(&hp6, 0, sizeof(struct hostent)); 572 hp6.h_addrtype = AF_INET6; 573 hp6.h_length = sizeof(struct in6_addr); 574 return _hpmerge(&hp6, hp, errp); 575 } 576 #endif 577 578 /* 579 * _hpsort: sort address by sortlist 580 */ 581 static struct hostent * 582 _hpsort(struct hostent *hp, res_state statp) 583 { 584 int i, j, n; 585 u_char *ap, *sp, *mp, **pp; 586 char t; 587 char order[MAXADDRS]; 588 int nsort = statp->nsort; 589 590 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0) 591 return hp; 592 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) { 593 for (j = 0; j < nsort; j++) { 594 #ifdef INET6 595 if (statp->_u._ext.ext->sort_list[j].af != 596 hp->h_addrtype) 597 continue; 598 sp = (u_char *)&statp->_u._ext.ext->sort_list[j].addr; 599 mp = (u_char *)&statp->_u._ext.ext->sort_list[j].mask; 600 #else 601 sp = (u_char *)&statp->sort_list[j].addr; 602 mp = (u_char *)&statp->sort_list[j].mask; 603 #endif 604 for (n = 0; n < hp->h_length; n++) { 605 if ((ap[n] & mp[n]) != sp[n]) 606 break; 607 } 608 if (n == hp->h_length) 609 break; 610 } 611 order[i] = j; 612 } 613 n = i; 614 pp = (u_char **)hp->h_addr_list; 615 for (i = 0; i < n - 1; i++) { 616 for (j = i + 1; j < n; j++) { 617 if (order[i] > order[j]) { 618 ap = pp[i]; 619 pp[i] = pp[j]; 620 pp[j] = ap; 621 t = order[i]; 622 order[i] = order[j]; 623 order[j] = t; 624 } 625 } 626 } 627 return hp; 628 } 629 630 /* 631 * _hpreorder: sort address by default address selection 632 */ 633 static struct hostent * 634 _hpreorder(struct hostent *hp) 635 { 636 struct hp_order *aio; 637 int i, n; 638 char *ap; 639 struct sockaddr *sa; 640 struct policyhead policyhead; 641 642 if (hp == NULL) 643 return hp; 644 645 switch (hp->h_addrtype) { 646 case AF_INET: 647 #ifdef INET6 648 case AF_INET6: 649 #endif 650 break; 651 default: 652 free_addrselectpolicy(&policyhead); 653 return hp; 654 } 655 656 /* count the number of addrinfo elements for sorting. */ 657 for (n = 0; hp->h_addr_list[n] != NULL; n++) 658 ; 659 660 /* 661 * If the number is small enough, we can skip the reordering process. 662 */ 663 if (n <= 1) 664 return hp; 665 666 /* allocate a temporary array for sort and initialization of it. */ 667 if ((aio = malloc(sizeof(*aio) * n)) == NULL) 668 return hp; /* give up reordering */ 669 memset(aio, 0, sizeof(*aio) * n); 670 671 /* retrieve address selection policy from the kernel */ 672 TAILQ_INIT(&policyhead); 673 if (!get_addrselectpolicy(&policyhead)) { 674 /* no policy is installed into kernel, we don't sort. */ 675 free(aio); 676 return hp; 677 } 678 679 for (i = 0; i < n; i++) { 680 ap = hp->h_addr_list[i]; 681 aio[i].aio_h_addr = ap; 682 sa = &aio[i].aio_sa; 683 switch (hp->h_addrtype) { 684 case AF_INET: 685 sa->sa_family = AF_INET; 686 sa->sa_len = sizeof(struct sockaddr_in); 687 memcpy(&((struct sockaddr_in *)sa)->sin_addr, ap, 688 sizeof(struct in_addr)); 689 break; 690 #ifdef INET6 691 case AF_INET6: 692 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) { 693 sa->sa_family = AF_INET; 694 sa->sa_len = sizeof(struct sockaddr_in); 695 memcpy(&((struct sockaddr_in *)sa)->sin_addr, 696 &ap[12], sizeof(struct in_addr)); 697 } else { 698 sa->sa_family = AF_INET6; 699 sa->sa_len = sizeof(struct sockaddr_in6); 700 memcpy(&((struct sockaddr_in6 *)sa)->sin6_addr, 701 ap, sizeof(struct in6_addr)); 702 } 703 break; 704 #endif 705 } 706 aio[i].aio_dstscope = gai_addr2scopetype(sa); 707 aio[i].aio_dstpolicy = match_addrselectpolicy(sa, &policyhead); 708 set_source(&aio[i], &policyhead); 709 } 710 711 /* perform sorting. */ 712 qsort(aio, n, sizeof(*aio), comp_dst); 713 714 /* reorder the h_addr_list. */ 715 for (i = 0; i < n; i++) 716 hp->h_addr_list[i] = aio[i].aio_h_addr; 717 718 /* cleanup and return */ 719 free(aio); 720 free_addrselectpolicy(&policyhead); 721 return hp; 722 } 723 724 static int 725 get_addrselectpolicy(struct policyhead *head) 726 { 727 #ifdef INET6 728 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY }; 729 size_t l; 730 char *buf; 731 struct in6_addrpolicy *pol, *ep; 732 733 if (sysctl(mib, NELEM(mib), NULL, &l, NULL, 0) < 0) 734 return (0); 735 if ((buf = malloc(l)) == NULL) 736 return (0); 737 if (sysctl(mib, NELEM(mib), buf, &l, NULL, 0) < 0) { 738 free(buf); 739 return (0); 740 } 741 742 ep = (struct in6_addrpolicy *)(buf + l); 743 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) { 744 struct policyqueue *new; 745 746 if ((new = malloc(sizeof(*new))) == NULL) { 747 free_addrselectpolicy(head); /* make the list empty */ 748 break; 749 } 750 new->pc_policy = *pol; 751 TAILQ_INSERT_TAIL(head, new, pc_entry); 752 } 753 754 free(buf); 755 return (1); 756 #else 757 return (0); 758 #endif 759 } 760 761 static void 762 free_addrselectpolicy(struct policyhead *head) 763 { 764 struct policyqueue *ent, *nent; 765 766 for (ent = TAILQ_FIRST(head); ent; ent = nent) { 767 nent = TAILQ_NEXT(ent, pc_entry); 768 TAILQ_REMOVE(head, ent, pc_entry); 769 free(ent); 770 } 771 } 772 773 static struct policyqueue * 774 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head) 775 { 776 #ifdef INET6 777 struct policyqueue *ent, *bestent = NULL; 778 struct in6_addrpolicy *pol; 779 int matchlen, bestmatchlen = -1; 780 u_char *mp, *ep, *k, *p, m; 781 struct sockaddr_in6 key; 782 783 switch(addr->sa_family) { 784 case AF_INET6: 785 key = *(struct sockaddr_in6 *)addr; 786 break; 787 case AF_INET: 788 /* convert the address into IPv4-mapped IPv6 address. */ 789 memset(&key, 0, sizeof(key)); 790 key.sin6_family = AF_INET6; 791 key.sin6_len = sizeof(key); 792 key.sin6_addr.s6_addr[10] = 0xff; 793 key.sin6_addr.s6_addr[11] = 0xff; 794 memcpy(&key.sin6_addr.s6_addr[12], 795 &((struct sockaddr_in *)addr)->sin_addr, 4); 796 break; 797 default: 798 return(NULL); 799 } 800 801 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) { 802 pol = &ent->pc_policy; 803 matchlen = 0; 804 805 mp = (u_char *)&pol->addrmask.sin6_addr; 806 ep = mp + 16; /* XXX: scope field? */ 807 k = (u_char *)&key.sin6_addr; 808 p = (u_char *)&pol->addr.sin6_addr; 809 for (; mp < ep && *mp; mp++, k++, p++) { 810 m = *mp; 811 if ((*k & m) != *p) 812 goto next; /* not match */ 813 if (m == 0xff) /* short cut for a typical case */ 814 matchlen += 8; 815 else { 816 while (m >= 0x80) { 817 matchlen++; 818 m <<= 1; 819 } 820 } 821 } 822 823 /* matched. check if this is better than the current best. */ 824 if (matchlen > bestmatchlen) { 825 bestent = ent; 826 bestmatchlen = matchlen; 827 } 828 829 next: 830 continue; 831 } 832 833 return(bestent); 834 #else 835 return(NULL); 836 #endif 837 838 } 839 840 static void 841 set_source(struct hp_order *aio, struct policyhead *ph) 842 { 843 struct sockaddr_storage ss = aio->aio_un.aiou_ss; 844 socklen_t srclen; 845 int s; 846 847 /* set unspec ("no source is available"), just in case */ 848 aio->aio_srcsa.sa_family = AF_UNSPEC; 849 aio->aio_srcscope = -1; 850 851 switch(ss.ss_family) { 852 case AF_INET: 853 ((struct sockaddr_in *)&ss)->sin_port = htons(1); 854 break; 855 #ifdef INET6 856 case AF_INET6: 857 ((struct sockaddr_in6 *)&ss)->sin6_port = htons(1); 858 break; 859 #endif 860 default: /* ignore unsupported AFs explicitly */ 861 return; 862 } 863 864 /* open a socket to get the source address for the given dst */ 865 if ((s = _socket(ss.ss_family, SOCK_DGRAM, IPPROTO_UDP)) < 0) 866 return; /* give up */ 867 if (_connect(s, (struct sockaddr *)&ss, ss.ss_len) < 0) 868 goto cleanup; 869 srclen = ss.ss_len; 870 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) { 871 aio->aio_srcsa.sa_family = AF_UNSPEC; 872 goto cleanup; 873 } 874 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa); 875 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph); 876 aio->aio_matchlen = matchlen(&aio->aio_srcsa, (struct sockaddr *)&ss); 877 #ifdef INET6 878 if (ss.ss_family == AF_INET6) { 879 struct in6_ifreq ifr6; 880 u_int32_t flags6; 881 882 /* XXX: interface name should not be hardcoded */ 883 strncpy(ifr6.ifr_name, "lo0", sizeof(ifr6.ifr_name)); 884 memset(&ifr6, 0, sizeof(ifr6)); 885 memcpy(&ifr6.ifr_addr, &ss, ss.ss_len); 886 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) { 887 flags6 = ifr6.ifr_ifru.ifru_flags6; 888 if ((flags6 & IN6_IFF_DEPRECATED)) 889 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED; 890 } 891 } 892 #endif 893 894 cleanup: 895 _close(s); 896 return; 897 } 898 899 static int 900 matchlen(struct sockaddr *src, struct sockaddr *dst) 901 { 902 int match = 0; 903 u_char *s, *d; 904 u_char *lim, r; 905 int addrlen; 906 907 switch (src->sa_family) { 908 #ifdef INET6 909 case AF_INET6: 910 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr; 911 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr; 912 addrlen = sizeof(struct in6_addr); 913 lim = s + addrlen; 914 break; 915 #endif 916 case AF_INET: 917 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr; 918 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr; 919 addrlen = sizeof(struct in_addr); 920 lim = s + addrlen; 921 break; 922 default: 923 return(0); 924 } 925 926 while (s < lim) 927 if ((r = (*d++ ^ *s++)) != 0) { 928 while (r < addrlen * 8) { 929 match++; 930 r <<= 1; 931 } 932 break; 933 } else 934 match += 8; 935 return(match); 936 } 937 938 static int 939 comp_dst(const void *arg1, const void *arg2) 940 { 941 const struct hp_order *dst1 = arg1, *dst2 = arg2; 942 943 /* 944 * Rule 1: Avoid unusable destinations. 945 * XXX: we currently do not consider if an appropriate route exists. 946 */ 947 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 948 dst2->aio_srcsa.sa_family == AF_UNSPEC) { 949 return(-1); 950 } 951 if (dst1->aio_srcsa.sa_family == AF_UNSPEC && 952 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 953 return(1); 954 } 955 956 /* Rule 2: Prefer matching scope. */ 957 if (dst1->aio_dstscope == dst1->aio_srcscope && 958 dst2->aio_dstscope != dst2->aio_srcscope) { 959 return(-1); 960 } 961 if (dst1->aio_dstscope != dst1->aio_srcscope && 962 dst2->aio_dstscope == dst2->aio_srcscope) { 963 return(1); 964 } 965 966 /* Rule 3: Avoid deprecated addresses. */ 967 if (dst1->aio_srcsa.sa_family != AF_UNSPEC && 968 dst2->aio_srcsa.sa_family != AF_UNSPEC) { 969 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 970 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 971 return(-1); 972 } 973 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && 974 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { 975 return(1); 976 } 977 } 978 979 /* Rule 4: Prefer home addresses. */ 980 /* XXX: not implemented yet */ 981 982 /* Rule 5: Prefer matching label. */ 983 #ifdef INET6 984 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && 985 dst1->aio_srcpolicy->pc_policy.label == 986 dst1->aio_dstpolicy->pc_policy.label && 987 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || 988 dst2->aio_srcpolicy->pc_policy.label != 989 dst2->aio_dstpolicy->pc_policy.label)) { 990 return(-1); 991 } 992 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && 993 dst2->aio_srcpolicy->pc_policy.label == 994 dst2->aio_dstpolicy->pc_policy.label && 995 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || 996 dst1->aio_srcpolicy->pc_policy.label != 997 dst1->aio_dstpolicy->pc_policy.label)) { 998 return(1); 999 } 1000 #endif 1001 1002 /* Rule 6: Prefer higher precedence. */ 1003 #ifdef INET6 1004 if (dst1->aio_dstpolicy && 1005 (dst2->aio_dstpolicy == NULL || 1006 dst1->aio_dstpolicy->pc_policy.preced > 1007 dst2->aio_dstpolicy->pc_policy.preced)) { 1008 return(-1); 1009 } 1010 if (dst2->aio_dstpolicy && 1011 (dst1->aio_dstpolicy == NULL || 1012 dst2->aio_dstpolicy->pc_policy.preced > 1013 dst1->aio_dstpolicy->pc_policy.preced)) { 1014 return(1); 1015 } 1016 #endif 1017 1018 /* Rule 7: Prefer native transport. */ 1019 /* XXX: not implemented yet */ 1020 1021 /* Rule 8: Prefer smaller scope. */ 1022 if (dst1->aio_dstscope >= 0 && 1023 dst1->aio_dstscope < dst2->aio_dstscope) { 1024 return(-1); 1025 } 1026 if (dst2->aio_dstscope >= 0 && 1027 dst2->aio_dstscope < dst1->aio_dstscope) { 1028 return(1); 1029 } 1030 1031 /* 1032 * Rule 9: Use longest matching prefix. 1033 * We compare the match length in a same AF only. 1034 */ 1035 if (dst1->aio_sa.sa_family == dst2->aio_sa.sa_family) { 1036 if (dst1->aio_matchlen > dst2->aio_matchlen) { 1037 return(-1); 1038 } 1039 if (dst1->aio_matchlen < dst2->aio_matchlen) { 1040 return(1); 1041 } 1042 } 1043 1044 /* Rule 10: Otherwise, leave the order unchanged. */ 1045 return(-1); 1046 } 1047 1048 /* 1049 * Copy from scope.c. 1050 * XXX: we should standardize the functions and link them as standard 1051 * library. 1052 */ 1053 static int 1054 gai_addr2scopetype(struct sockaddr *sa) 1055 { 1056 #ifdef INET6 1057 struct sockaddr_in6 *sa6; 1058 #endif 1059 struct sockaddr_in *sa4; 1060 1061 switch(sa->sa_family) { 1062 #ifdef INET6 1063 case AF_INET6: 1064 sa6 = (struct sockaddr_in6 *)sa; 1065 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) { 1066 /* just use the scope field of the multicast address */ 1067 return(sa6->sin6_addr.s6_addr[2] & 0x0f); 1068 } 1069 /* 1070 * Unicast addresses: map scope type to corresponding scope 1071 * value defined for multcast addresses. 1072 * XXX: hardcoded scope type values are bad... 1073 */ 1074 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) 1075 return(1); /* node local scope */ 1076 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) 1077 return(2); /* link-local scope */ 1078 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr)) 1079 return(5); /* site-local scope */ 1080 return(14); /* global scope */ 1081 break; 1082 #endif 1083 case AF_INET: 1084 /* 1085 * IPv4 pseudo scoping according to RFC 3484. 1086 */ 1087 sa4 = (struct sockaddr_in *)sa; 1088 /* IPv4 autoconfiguration addresses have link-local scope. */ 1089 if (((u_char *)&sa4->sin_addr)[0] == 169 && 1090 ((u_char *)&sa4->sin_addr)[1] == 254) 1091 return(2); 1092 /* Private addresses have site-local scope. */ 1093 if (((u_char *)&sa4->sin_addr)[0] == 10 || 1094 (((u_char *)&sa4->sin_addr)[0] == 172 && 1095 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) || 1096 (((u_char *)&sa4->sin_addr)[0] == 192 && 1097 ((u_char *)&sa4->sin_addr)[1] == 168)) 1098 return(14); /* XXX: It should be 5 unless NAT */ 1099 /* Loopback addresses have link-local scope. */ 1100 if (((u_char *)&sa4->sin_addr)[0] == 127) 1101 return(2); 1102 return(14); 1103 break; 1104 default: 1105 errno = EAFNOSUPPORT; /* is this a good error? */ 1106 return(-1); 1107 } 1108 } 1109