lib/libc/net/name6.c

   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 }