The Tcpdump Group git mirrors - libpcap/blob - Win32/Src/getaddrinfo.c

   1 /*
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator.
  32  *
  33  * Issues to be discussed:
  34  * - Thread safe-ness must be checked.
  35  * - Return values.  There are nonstandard return values defined and used
  36  *   in the source code.  This is because RFC2553 is silent about which error
  37  *   code must be returned for which situation.
  38  * Note:
  39  * - We use getipnodebyname() just for thread-safeness.  There's no intent
  40  *   to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to
  41  *   getipnodebyname().
  42  * - The code filters out AFs that are not supported by the kernel,
  43  *   when globbing NULL hostname (to loopback, or wildcard).  Is it the right
  44  *   thing to do?  What is the relationship with post-RFC2553 AI_ADDRCONFIG
  45  *   in ai_flags?
  46  */
  47
  48 #ifdef HAVE_CONFIG_H
  49 #include <config.h>
  50 #endif
  51
  52 #ifndef lint
  53 static const char rcsid[] _U_ =
  54      "@(#) $Header: /tcpdump/master/libpcap/Win32/Src/getaddrinfo.c,v 1.2.4.1 2008-09-15 23:38:45 guy Exp $";
  55 #endif
  56
  57 #include <pcap-stdinc.h>
  58 #if 0
  59 #include <sys/sysctl.h>
  60 #endif
  61 #ifndef __MINGW32__
  62 #include <arpa/nameser.h>
  63 #endif
  64 #include <string.h>
  65 #include <stdlib.h>
  66 #include <stddef.h>
  67 #include <ctype.h>
  68 #include <stdio.h>
  69 #include <errno.h>
  70
  71 #ifndef HAVE_PORTABLE_PROTOTYPE
  72 #include "cdecl_ext.h"
  73 #endif
  74
  75 #ifndef HAVE_U_INT32_T
  76 #include "bittypes.h"
  77 #endif
  78
  79 #ifndef HAVE_SOCKADDR_STORAGE
  80 #ifndef __MINGW32__
  81 #include "sockstorage.h"
  82 #endif
  83 #endif
  84
  85 #ifdef NEED_ADDRINFO_H
  86 #include "addrinfo.h"
  87 #ifdef WIN32
  88 #include "IP6_misc.h"
  89 #endif
  90 #endif
  91
  92
  93 #if defined(__KAME__) && defined(INET6)
  94 # define FAITH
  95 #endif
  96
  97 #define SUCCESS 0
  98 #define ANY 0
  99 #define YES 1
 100 #define NO  0
 101
 102 #ifdef FAITH
 103 static int translate = NO;
 104 static struct in6_addr faith_prefix = IN6ADDR_ANY_INIT;
 105 #endif
 106
 107 static const char in_addrany[] = { 0, 0, 0, 0 };
 108 static const char in6_addrany[] = {
 109         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 110 };
 111 static const char in_loopback[] = { 127, 0, 0, 1 };
 112 static const char in6_loopback[] = {
 113         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
 114 };
 115
 116 struct sockinet {
 117         u_char  si_len;
 118         u_char  si_family;
 119         u_short si_port;
 120         u_int32_t si_scope_id;
 121 };
 122
 123 static const struct afd {
 124         int a_af;
 125         int a_addrlen;
 126         int a_socklen;
 127         int a_off;
 128         const char *a_addrany;
 129         const char *a_loopback;
 130         int a_scoped;
 131 } afdl [] = {
 132 #ifdef INET6
 133         {PF_INET6, sizeof(struct in6_addr),
 134          sizeof(struct sockaddr_in6),
 135          offsetof(struct sockaddr_in6, sin6_addr),
 136          in6_addrany, in6_loopback, 1},
 137 #endif
 138         {PF_INET, sizeof(struct in_addr),
 139          sizeof(struct sockaddr_in),
 140          offsetof(struct sockaddr_in, sin_addr),
 141          in_addrany, in_loopback, 0},
 142         {0, 0, 0, 0, NULL, NULL, 0},
 143 };
 144
 145 struct explore {
 146         int e_af;
 147         int e_socktype;
 148         int e_protocol;
 149         const char *e_protostr;
 150         int e_wild;
 151 #define WILD_AF(ex)             ((ex)->e_wild & 0x01)
 152 #define WILD_SOCKTYPE(ex)       ((ex)->e_wild & 0x02)
 153 #define WILD_PROTOCOL(ex)       ((ex)->e_wild & 0x04)
 154 };
 155
 156 static const struct explore explore[] = {
 157 #if 0
 158         { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 },
 159 #endif
 160 #ifdef INET6
 161         { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
 162         { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
 163         { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
 164 #endif
 165         { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
 166         { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
 167         { PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
 168         { -1, 0, 0, NULL, 0 },
 169 };
 170
 171 #ifdef INET6
 172 #define PTON_MAX        16
 173 #else
 174 #define PTON_MAX        4
 175 #endif
 176
 177
 178 static int str_isnumber __P((const char *));
 179 static int explore_fqdn __P((const struct addrinfo *, const char *,
 180         const char *, struct addrinfo **));
 181 static int explore_null __P((const struct addrinfo *, const char *,
 182         const char *, struct addrinfo **));
 183 static int explore_numeric __P((const struct addrinfo *, const char *,
 184         const char *, struct addrinfo **));
 185 static int explore_numeric_scope __P((const struct addrinfo *, const char *,
 186         const char *, struct addrinfo **));
 187 static int get_name __P((const char *, const struct afd *, struct addrinfo **,
 188         char *, const struct addrinfo *, const char *));
 189 static int get_canonname __P((const struct addrinfo *,
 190         struct addrinfo *, const char *));
 191 static struct addrinfo *get_ai __P((const struct addrinfo *,
 192         const struct afd *, const char *));
 193 static int get_portmatch __P((const struct addrinfo *, const char *));
 194 static int get_port __P((struct addrinfo *, const char *, int));
 195 static const struct afd *find_afd __P((int));
 196
 197 static char *ai_errlist[] = {
 198         "Success",
 199         "Address family for hostname not supported",    /* EAI_ADDRFAMILY */
 200         "Temporary failure in name resolution",         /* EAI_AGAIN      */
 201         "Invalid value for ai_flags",                   /* EAI_BADFLAGS   */
 202         "Non-recoverable failure in name resolution",   /* EAI_FAIL       */
 203         "ai_family not supported",                      /* EAI_FAMILY     */
 204         "Memory allocation failure",                    /* EAI_MEMORY     */
 205         "No address associated with hostname",          /* EAI_NODATA     */
 206         "hostname nor servname provided, or not known", /* EAI_NONAME     */
 207         "servname not supported for ai_socktype",       /* EAI_SERVICE    */
 208         "ai_socktype not supported",                    /* EAI_SOCKTYPE   */
 209         "System error returned in errno",               /* EAI_SYSTEM     */
 210         "Invalid value for hints",                      /* EAI_BADHINTS   */
 211         "Resolved protocol is unknown",                 /* EAI_PROTOCOL   */
 212         "Unknown error",                                /* EAI_MAX        */
 213 };
 214
 215 /* XXX macros that make external reference is BAD. */
 216
 217 #define GET_AI(ai, afd, addr) \
 218 do { \
 219         /* external reference: pai, error, and label free */ \
 220         (ai) = get_ai(pai, (afd), (addr)); \
 221         if ((ai) == NULL) { \
 222                 error = EAI_MEMORY; \
 223                 goto free; \
 224         } \
 225 } while (0)
 226
 227 #define GET_PORT(ai, serv) \
 228 do { \
 229         /* external reference: error and label free */ \
 230         error = get_port((ai), (serv), 0); \
 231         if (error != 0) \
 232                 goto free; \
 233 } while (0)
 234
 235 #define GET_CANONNAME(ai, str) \
 236 do { \
 237         /* external reference: pai, error and label free */ \
 238         error = get_canonname(pai, (ai), (str)); \
 239         if (error != 0) \
 240                 goto free; \
 241 } while (0)
 242
 243 #define ERR(err) \
 244 do { \
 245         /* external reference: error, and label bad */ \
 246         error = (err); \
 247         goto bad; \
 248 } while (0)
 249
 250 #define MATCH_FAMILY(x, y, w) \
 251         ((x) == (y) || ((w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC)))
 252 #define MATCH(x, y, w) \
 253         ((x) == (y) || ((w) && ((x) == ANY || (y) == ANY)))
 254
 255 char *
 256 gai_strerror(ecode)
 257         int ecode;
 258 {
 259         if (ecode < 0 || ecode > EAI_MAX)
 260                 ecode = EAI_MAX;
 261         return ai_errlist[ecode];
 262 }
 263
 264 void
 265 freeaddrinfo(ai)
 266         struct addrinfo *ai;
 267 {
 268         struct addrinfo *next;
 269
 270         do {
 271                 next = ai->ai_next;
 272                 if (ai->ai_canonname)
 273                         free(ai->ai_canonname);
 274                 /* no need to free(ai->ai_addr) */
 275                 free(ai);
 276         } while ((ai = next) != NULL);
 277 }
 278
 279 static int
 280 str_isnumber(p)
 281         const char *p;
 282 {
 283         char *q = (char *)p;
 284         while (*q) {
 285                 if (! isdigit(*q))
 286                         return NO;
 287                 q++;
 288         }
 289         return YES;
 290 }
 291
 292 int
 293 getaddrinfo(hostname, servname, hints, res)
 294         const char *hostname, *servname;
 295         const struct addrinfo *hints;
 296         struct addrinfo **res;
 297 {
 298         struct addrinfo sentinel;
 299         struct addrinfo *cur;
 300         int error = 0;
 301         struct addrinfo ai;
 302         struct addrinfo ai0;
 303         struct addrinfo *pai;
 304         const struct afd *afd;
 305         const struct explore *ex;
 306
 307 #ifdef FAITH
 308         static int firsttime = 1;
 309
 310         if (firsttime) {
 311                 /* translator hack */
 312                 char *q = getenv("GAI");
 313                 if (q && inet_pton(AF_INET6, q, &faith_prefix) == 1)
 314                         translate = YES;
 315                 firsttime = 0;
 316         }
 317 #endif
 318
 319         sentinel.ai_next = NULL;
 320         cur = &sentinel;
 321         pai = &ai;
 322         pai->ai_flags = 0;
 323         pai->ai_family = PF_UNSPEC;
 324         pai->ai_socktype = ANY;
 325         pai->ai_protocol = ANY;
 326         pai->ai_addrlen = 0;
 327         pai->ai_canonname = NULL;
 328         pai->ai_addr = NULL;
 329         pai->ai_next = NULL;
 330
 331         if (hostname == NULL && servname == NULL)
 332                 return EAI_NONAME;
 333         if (hints) {
 334                 /* error check for hints */
 335                 if (hints->ai_addrlen || hints->ai_canonname ||
 336                     hints->ai_addr || hints->ai_next)
 337                         ERR(EAI_BADHINTS); /* xxx */
 338                 if (hints->ai_flags & ~AI_MASK)
 339                         ERR(EAI_BADFLAGS);
 340                 switch (hints->ai_family) {
 341                 case PF_UNSPEC:
 342                 case PF_INET:
 343 #ifdef INET6
 344                 case PF_INET6:
 345 #endif
 346                         break;
 347                 default:
 348                         ERR(EAI_FAMILY);
 349                 }
 350                 memcpy(pai, hints, sizeof(*pai));
 351
 352                 /*
 353                  * if both socktype/protocol are specified, check if they
 354                  * are meaningful combination.
 355                  */
 356                 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
 357                         for (ex = explore; ex->e_af >= 0; ex++) {
 358                                 if (pai->ai_family != ex->e_af)
 359                                         continue;
 360                                 if (ex->e_socktype == ANY)
 361                                         continue;
 362                                 if (ex->e_protocol == ANY)
 363                                         continue;
 364                                 if (pai->ai_socktype == ex->e_socktype
 365                                  && pai->ai_protocol != ex->e_protocol) {
 366                                         ERR(EAI_BADHINTS);
 367                                 }
 368                         }
 369                 }
 370         }
 371
 372         /*
 373          * check for special cases.  (1) numeric servname is disallowed if
 374          * socktype/protocol are left unspecified. (2) servname is disallowed
 375          * for raw and other inet{,6} sockets.
 376          */
 377         if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
 378 #ifdef PF_INET6
 379          || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
 380 #endif
 381             ) {
 382                 ai0 = *pai;
 383
 384                 if (pai->ai_family == PF_UNSPEC) {
 385 #ifdef PF_INET6
 386                         pai->ai_family = PF_INET6;
 387 #else
 388                         pai->ai_family = PF_INET;
 389 #endif
 390                 }
 391                 error = get_portmatch(pai, servname);
 392                 if (error)
 393                         ERR(error);
 394
 395                 *pai = ai0;
 396         }
 397
 398         ai0 = *pai;
 399
 400         /* NULL hostname, or numeric hostname */
 401         for (ex = explore; ex->e_af >= 0; ex++) {
 402                 *pai = ai0;
 403
 404                 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
 405                         continue;
 406                 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
 407                         continue;
 408                 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
 409                         continue;
 410
 411                 if (pai->ai_family == PF_UNSPEC)
 412                         pai->ai_family = ex->e_af;
 413                 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
 414                         pai->ai_socktype = ex->e_socktype;
 415                 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
 416                         pai->ai_protocol = ex->e_protocol;
 417
 418                 if (hostname == NULL)
 419                         error = explore_null(pai, hostname, servname, &cur->ai_next);
 420                 else
 421                         error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next);
 422
 423                 if (error)
 424                         goto free;
 425
 426                 while (cur && cur->ai_next)
 427                         cur = cur->ai_next;
 428         }
 429
 430         /*
 431          * XXX
 432          * If numreic representation of AF1 can be interpreted as FQDN
 433          * representation of AF2, we need to think again about the code below.
 434          */
 435         if (sentinel.ai_next)
 436                 goto good;
 437
 438         if (pai->ai_flags & AI_NUMERICHOST)
 439                 ERR(EAI_NONAME);
 440         if (hostname == NULL)
 441                 ERR(EAI_NONAME);
 442
 443         /*
 444          * hostname as alphabetical name.
 445          * we would like to prefer AF_INET6 than AF_INET, so we'll make a
 446          * outer loop by AFs.
 447          */
 448         for (afd = afdl; afd->a_af; afd++) {
 449                 *pai = ai0;
 450
 451                 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1))
 452                         continue;
 453
 454                 for (ex = explore; ex->e_af >= 0; ex++) {
 455                         *pai = ai0;
 456
 457                         if (pai->ai_family == PF_UNSPEC)
 458                                 pai->ai_family = afd->a_af;
 459
 460                         if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
 461                                 continue;
 462                         if (!MATCH(pai->ai_socktype, ex->e_socktype,
 463                                         WILD_SOCKTYPE(ex))) {
 464                                 continue;
 465                         }
 466                         if (!MATCH(pai->ai_protocol, ex->e_protocol,
 467                                         WILD_PROTOCOL(ex))) {
 468                                 continue;
 469                         }
 470
 471                         if (pai->ai_family == PF_UNSPEC)
 472                                 pai->ai_family = ex->e_af;
 473                         if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
 474                                 pai->ai_socktype = ex->e_socktype;
 475                         if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
 476                                 pai->ai_protocol = ex->e_protocol;
 477
 478                         error = explore_fqdn(pai, hostname, servname,
 479                                 &cur->ai_next);
 480
 481                         while (cur && cur->ai_next)
 482                                 cur = cur->ai_next;
 483                 }
 484         }
 485
 486         /* XXX */
 487         if (sentinel.ai_next)
 488                 error = 0;
 489
 490         if (error)
 491                 goto free;
 492         if (error == 0) {
 493                 if (sentinel.ai_next) {
 494  good:
 495                         *res = sentinel.ai_next;
 496                         return SUCCESS;
 497                 } else
 498                         error = EAI_FAIL;
 499         }
 500  free:
 501  bad:
 502         if (sentinel.ai_next)
 503                 freeaddrinfo(sentinel.ai_next);
 504         *res = NULL;
 505         return error;
 506 }
 507
 508 /*
 509  * FQDN hostname, DNS lookup
 510  */
 511 static int
 512 explore_fqdn(pai, hostname, servname, res)
 513         const struct addrinfo *pai;
 514         const char *hostname;
 515         const char *servname;
 516         struct addrinfo **res;
 517 {
 518         struct hostent *hp;
 519         int h_error;
 520         int af;
 521         char **aplist = NULL, *apbuf = NULL;
 522         char *ap;
 523         struct addrinfo sentinel, *cur;
 524         int i;
 525 #ifndef USE_GETIPNODEBY
 526         int naddrs;
 527 #endif
 528         const struct afd *afd;
 529         int error;
 530
 531         *res = NULL;
 532         sentinel.ai_next = NULL;
 533         cur = &sentinel;
 534
 535         /*
 536          * Do not filter unsupported AFs here.  We need to honor content of
 537          * databases (/etc/hosts, DNS and others).  Otherwise we cannot
 538          * replace gethostbyname() by getaddrinfo().
 539          */
 540
 541         /*
 542          * if the servname does not match socktype/protocol, ignore it.
 543          */
 544         if (get_portmatch(pai, servname) != 0)
 545                 return 0;
 546
 547         afd = find_afd(pai->ai_family);
 548
 549         /*
 550          * post-RFC2553: should look at (pai->ai_flags & AI_ADDRCONFIG)
 551          * rather than hardcoding it.  we may need to add AI_ADDRCONFIG
 552          * handling code by ourselves in case we don't have getipnodebyname().
 553          */
 554 #ifdef USE_GETIPNODEBY
 555         hp = getipnodebyname(hostname, pai->ai_family, AI_ADDRCONFIG, &h_error);
 556 #else
 557 #ifdef HAVE_GETHOSTBYNAME2
 558         hp = gethostbyname2(hostname, pai->ai_family);
 559 #else
 560         if (pai->ai_family != AF_INET)
 561                 return 0;
 562         hp = gethostbyname(hostname);
 563 #ifdef HAVE_H_ERRNO
 564         h_error = h_errno;
 565 #else
 566         h_error = EINVAL;
 567 #endif
 568 #endif /*HAVE_GETHOSTBYNAME2*/
 569 #endif /*USE_GETIPNODEBY*/
 570
 571         if (hp == NULL) {
 572                 switch (h_error) {
 573                 case HOST_NOT_FOUND:
 574                 case NO_DATA:
 575                         error = EAI_NODATA;
 576                         break;
 577                 case TRY_AGAIN:
 578                         error = EAI_AGAIN;
 579                         break;
 580                 case NO_RECOVERY:
 581                 case NETDB_INTERNAL:
 582                 default:
 583                         error = EAI_FAIL;
 584                         break;
 585                 }
 586         } else if ((hp->h_name == NULL) || (hp->h_name[0] == 0)
 587                         || (hp->h_addr_list[0] == NULL)) {
 588 #ifdef USE_GETIPNODEBY
 589                 freehostent(hp);
 590 #endif
 591                 hp = NULL;
 592                 error = EAI_FAIL;
 593         }
 594
 595         if (hp == NULL)
 596                 goto free;
 597
 598 #ifdef USE_GETIPNODEBY
 599         aplist = hp->h_addr_list;
 600 #else
 601         /*
 602          * hp will be overwritten if we use gethostbyname2().
 603          * always deep copy for simplification.
 604          */
 605         for (naddrs = 0; hp->h_addr_list[naddrs] != NULL; naddrs++)
 606                 ;
 607         naddrs++;
 608         aplist = (char **)malloc(sizeof(aplist[0]) * naddrs);
 609         apbuf = (char *)malloc(hp->h_length * naddrs);
 610         if (aplist == NULL || apbuf == NULL) {
 611                 error = EAI_MEMORY;
 612                 goto free;
 613         }
 614         memset(aplist, 0, sizeof(aplist[0]) * naddrs);
 615         for (i = 0; i < naddrs; i++) {
 616                 if (hp->h_addr_list[i] == NULL) {
 617                         aplist[i] = NULL;
 618                         continue;
 619                 }
 620                 memcpy(&apbuf[i * hp->h_length], hp->h_addr_list[i],
 621                         hp->h_length);
 622                 aplist[i] = &apbuf[i * hp->h_length];
 623         }
 624 #endif
 625
 626         for (i = 0; aplist[i] != NULL; i++) {
 627                 af = hp->h_addrtype;
 628                 ap = aplist[i];
 629 #ifdef AF_INET6
 630                 if (af == AF_INET6
 631                  && IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) {
 632                         af = AF_INET;
 633                         ap = ap + sizeof(struct in6_addr)
 634                                 - sizeof(struct in_addr);
 635                 }
 636 #endif
 637
 638                 if (af != pai->ai_family)
 639                         continue;
 640
 641                 if ((pai->ai_flags & AI_CANONNAME) == 0) {
 642                         GET_AI(cur->ai_next, afd, ap);
 643                         GET_PORT(cur->ai_next, servname);
 644                 } else {
 645                         /*
 646                          * if AI_CANONNAME and if reverse lookup
 647                          * fail, return ai anyway to pacify
 648                          * calling application.
 649                          *
 650                          * XXX getaddrinfo() is a name->address
 651                          * translation function, and it looks
 652                          * strange that we do addr->name
 653                          * translation here.
 654                          */
 655                         get_name(ap, afd, &cur->ai_next,
 656                                 ap, pai, servname);
 657                 }
 658
 659                 while (cur && cur->ai_next)
 660                         cur = cur->ai_next;
 661         }
 662
 663         *res = sentinel.ai_next;
 664         return 0;
 665
 666 free:
 667 #ifdef USE_GETIPNODEBY
 668         if (hp)
 669                 freehostent(hp);
 670 #endif
 671         if (aplist)
 672                 free(aplist);
 673         if (apbuf)
 674                 free(apbuf);
 675         if (sentinel.ai_next)
 676                 freeaddrinfo(sentinel.ai_next);
 677         return error;
 678 }
 679
 680 /*
 681  * hostname == NULL.
 682  * passive socket -> anyaddr (0.0.0.0 or ::)
 683  * non-passive socket -> localhost (127.0.0.1 or ::1)
 684  */
 685 static int
 686 explore_null(pai, hostname, servname, res)
 687         const struct addrinfo *pai;
 688         const char *hostname;
 689         const char *servname;
 690         struct addrinfo **res;
 691 {
 692         int s;
 693         const struct afd *afd;
 694         struct addrinfo *cur;
 695         struct addrinfo sentinel;
 696         int error;
 697
 698         *res = NULL;
 699         sentinel.ai_next = NULL;
 700         cur = &sentinel;
 701
 702         /*
 703          * filter out AFs that are not supported by the kernel
 704          * XXX errno?
 705          */
 706         s = socket(pai->ai_family, SOCK_DGRAM, 0);
 707         if (s < 0) {
 708                 if (errno != EMFILE)
 709                         return 0;
 710         } else
 711                 close(s);
 712
 713         /*
 714          * if the servname does not match socktype/protocol, ignore it.
 715          */
 716         if (get_portmatch(pai, servname) != 0)
 717                 return 0;
 718
 719         afd = find_afd(pai->ai_family);
 720
 721         if (pai->ai_flags & AI_PASSIVE) {
 722                 GET_AI(cur->ai_next, afd, afd->a_addrany);
 723                 /* xxx meaningless?
 724                  * GET_CANONNAME(cur->ai_next, "anyaddr");
 725                  */
 726                 GET_PORT(cur->ai_next, servname);
 727         } else {
 728                 GET_AI(cur->ai_next, afd, afd->a_loopback);
 729                 /* xxx meaningless?
 730                  * GET_CANONNAME(cur->ai_next, "localhost");
 731                  */
 732                 GET_PORT(cur->ai_next, servname);
 733         }
 734         cur = cur->ai_next;
 735
 736         *res = sentinel.ai_next;
 737         return 0;
 738
 739 free:
 740         if (sentinel.ai_next)
 741                 freeaddrinfo(sentinel.ai_next);
 742         return error;
 743 }
 744
 745 /*
 746  * numeric hostname
 747  */
 748 static int
 749 explore_numeric(pai, hostname, servname, res)
 750         const struct addrinfo *pai;
 751         const char *hostname;
 752         const char *servname;
 753         struct addrinfo **res;
 754 {
 755         const struct afd *afd;
 756         struct addrinfo *cur;
 757         struct addrinfo sentinel;
 758         int error;
 759         char pton[PTON_MAX];
 760         int flags;
 761
 762         *res = NULL;
 763         sentinel.ai_next = NULL;
 764         cur = &sentinel;
 765
 766         /*
 767          * if the servname does not match socktype/protocol, ignore it.
 768          */
 769         if (get_portmatch(pai, servname) != 0)
 770                 return 0;
 771
 772         afd = find_afd(pai->ai_family);
 773         flags = pai->ai_flags;
 774
 775         if (inet_pton(afd->a_af, hostname, pton) == 1) {
 776                 u_int32_t v4a;
 777 #ifdef INET6
 778                 u_char pfx;
 779 #endif
 780
 781                 switch (afd->a_af) {
 782                 case AF_INET:
 783                         v4a = (u_int32_t)ntohl(((struct in_addr *)pton)->s_addr);
 784                         if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
 785                                 flags &= ~AI_CANONNAME;
 786                         v4a >>= IN_CLASSA_NSHIFT;
 787                         if (v4a == 0 || v4a == IN_LOOPBACKNET)
 788                                 flags &= ~AI_CANONNAME;
 789                         break;
 790 #ifdef INET6
 791                 case AF_INET6:
 792                         pfx = ((struct in6_addr *)pton)->s6_addr[0];
 793                         if (pfx == 0 || pfx == 0xfe || pfx == 0xff)
 794                                 flags &= ~AI_CANONNAME;
 795                         break;
 796 #endif
 797                 }
 798
 799                 if (pai->ai_family == afd->a_af ||
 800                     pai->ai_family == PF_UNSPEC /*?*/) {
 801                         if ((flags & AI_CANONNAME) == 0) {
 802                                 GET_AI(cur->ai_next, afd, pton);
 803                                 GET_PORT(cur->ai_next, servname);
 804                         } else {
 805                                 /*
 806                                  * if AI_CANONNAME and if reverse lookup
 807                                  * fail, return ai anyway to pacify
 808                                  * calling application.
 809                                  *
 810                                  * XXX getaddrinfo() is a name->address
 811                                  * translation function, and it looks
 812                                  * strange that we do addr->name
 813                                  * translation here.
 814                                  */
 815                                 get_name(pton, afd, &cur->ai_next,
 816                                         pton, pai, servname);
 817                         }
 818                         while (cur && cur->ai_next)
 819                                 cur = cur->ai_next;
 820                 } else
 821                         ERR(EAI_FAMILY);        /*xxx*/
 822         }
 823
 824         *res = sentinel.ai_next;
 825         return 0;
 826
 827 free:
 828 bad:
 829         if (sentinel.ai_next)
 830                 freeaddrinfo(sentinel.ai_next);
 831         return error;
 832 }
 833
 834 /*
 835  * numeric hostname with scope
 836  */
 837 static int
 838 explore_numeric_scope(pai, hostname, servname, res)
 839         const struct addrinfo *pai;
 840         const char *hostname;
 841         const char *servname;
 842         struct addrinfo **res;
 843 {
 844 #ifndef SCOPE_DELIMITER
 845         return explore_numeric(pai, hostname, servname, res);
 846 #else
 847         const struct afd *afd;
 848         struct addrinfo *cur;
 849         int error;
 850         char *cp, *hostname2 = NULL;
 851         int scope;
 852         struct sockaddr_in6 *sin6;
 853
 854         /*
 855          * if the servname does not match socktype/protocol, ignore it.
 856          */
 857         if (get_portmatch(pai, servname) != 0)
 858                 return 0;
 859
 860         afd = find_afd(pai->ai_family);
 861         if (!afd->a_scoped)
 862                 return explore_numeric(pai, hostname, servname, res);
 863
 864         cp = strchr(hostname, SCOPE_DELIMITER);
 865         if (cp == NULL)
 866                 return explore_numeric(pai, hostname, servname, res);
 867
 868         /*
 869          * Handle special case of <scoped_address><delimiter><scope id>
 870          */
 871         hostname2 = strdup(hostname);
 872         if (hostname2 == NULL)
 873                 return EAI_MEMORY;
 874         /* terminate at the delimiter */
 875         hostname2[cp - hostname] = '\0';
 876
 877         cp++;
 878         switch (pai->ai_family) {
 879 #ifdef INET6
 880         case AF_INET6:
 881                 scope = if_nametoindex(cp);
 882                 if (scope == 0) {
 883                         free(hostname2);
 884                         return (EAI_NONAME);
 885                 }
 886                 break;
 887 #endif
 888         }
 889
 890         error = explore_numeric(pai, hostname2, servname, res);
 891         if (error == 0) {
 892                 for (cur = *res; cur; cur = cur->ai_next) {
 893                         if (cur->ai_family != AF_INET6)
 894                                 continue;
 895                         sin6 = (struct sockaddr_in6 *)cur->ai_addr;
 896                         if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) ||
 897                             IN6_IS_ADDR_MC_LINKLOCAL(&sin6->sin6_addr))
 898                                 sin6->sin6_scope_id = scope;
 899                 }
 900         }
 901
 902         free(hostname2);
 903
 904         return error;
 905 #endif
 906 }
 907
 908 static int
 909 get_name(addr, afd, res, numaddr, pai, servname)
 910         const char *addr;
 911         const struct afd *afd;
 912         struct addrinfo **res;
 913         char *numaddr;
 914         const struct addrinfo *pai;
 915         const char *servname;
 916 {
 917         struct hostent *hp = NULL;
 918         struct addrinfo *cur = NULL;
 919         int error = 0;
 920         char *ap = NULL, *cn = NULL;
 921 #ifdef USE_GETIPNODEBY
 922         int h_error;
 923
 924         hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
 925 #else
 926         hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
 927 #endif
 928         if (hp && hp->h_name && hp->h_name[0] && hp->h_addr_list[0]) {
 929 #ifdef USE_GETIPNODEBY
 930                 GET_AI(cur, afd, hp->h_addr_list[0]);
 931                 GET_PORT(cur, servname);
 932                 GET_CANONNAME(cur, hp->h_name);
 933 #else
 934                 /* hp will be damaged if we use gethostbyaddr() */
 935                 if ((ap = (char *)malloc(hp->h_length)) == NULL) {
 936                         error = EAI_MEMORY;
 937                         goto free;
 938                 }
 939                 memcpy(ap, hp->h_addr_list[0], hp->h_length);
 940                 if ((cn = strdup(hp->h_name)) == NULL) {
 941                         error = EAI_MEMORY;
 942                         goto free;
 943                 }
 944
 945                 GET_AI(cur, afd, ap);
 946                 GET_PORT(cur, servname);
 947                 GET_CANONNAME(cur, cn);
 948                 free(ap); ap = NULL;
 949                 free(cn); cn = NULL;
 950 #endif
 951         } else {
 952                 GET_AI(cur, afd, numaddr);
 953                 GET_PORT(cur, servname);
 954         }
 955
 956 #ifdef USE_GETIPNODEBY
 957         if (hp)
 958                 freehostent(hp);
 959 #endif
 960         *res = cur;
 961         return SUCCESS;
 962  free:
 963         if (cur)
 964                 freeaddrinfo(cur);
 965         if (ap)
 966                 free(ap);
 967         if (cn)
 968                 free(cn);
 969 #ifdef USE_GETIPNODEBY
 970         if (hp)
 971                 freehostent(hp);
 972 #endif
 973         *res = NULL;
 974         return error;
 975 }
 976
 977 static int
 978 get_canonname(pai, ai, str)
 979         const struct addrinfo *pai;
 980         struct addrinfo *ai;
 981         const char *str;
 982 {
 983         if ((pai->ai_flags & AI_CANONNAME) != 0) {
 984                 ai->ai_canonname = strdup(str);
 985                 if (ai->ai_canonname == NULL)
 986                         return EAI_MEMORY;
 987         }
 988         return 0;
 989 }
 990
 991 static struct addrinfo *
 992 get_ai(pai, afd, addr)
 993         const struct addrinfo *pai;
 994         const struct afd *afd;
 995         const char *addr;
 996 {
 997         char *p;
 998         struct addrinfo *ai;
 999
1000         ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
1001                 + (afd->a_socklen));
1002         if (ai == NULL)
1003                 return NULL;
1004
1005         memcpy(ai, pai, sizeof(struct addrinfo));
1006         ai->ai_addr = (struct sockaddr *)(ai + 1);
1007         memset(ai->ai_addr, 0, afd->a_socklen);
1008 #ifdef HAVE_SOCKADDR_SA_LEN
1009         ai->ai_addr->sa_len = afd->a_socklen;
1010 #endif
1011         ai->ai_addrlen = afd->a_socklen;
1012         ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
1013         p = (char *)(ai->ai_addr);
1014         memcpy(p + afd->a_off, addr, afd->a_addrlen);
1015         return ai;
1016 }
1017
1018 static int
1019 get_portmatch(ai, servname)
1020         const struct addrinfo *ai;
1021         const char *servname;
1022 {
1023
1024         /* get_port does not touch first argument. when matchonly == 1. */
1025         return get_port((struct addrinfo *)ai, servname, 1);
1026 }
1027
1028 static int
1029 get_port(ai, servname, matchonly)
1030         struct addrinfo *ai;
1031         const char *servname;
1032         int matchonly;
1033 {
1034         const char *proto;
1035         struct servent *sp;
1036         int port;
1037         int allownumeric;
1038
1039         if (servname == NULL)
1040                 return 0;
1041         switch (ai->ai_family) {
1042         case AF_INET:
1043 #ifdef AF_INET6
1044         case AF_INET6:
1045 #endif
1046                 break;
1047         default:
1048                 return 0;
1049         }
1050
1051         switch (ai->ai_socktype) {
1052         case SOCK_RAW:
1053                 return EAI_SERVICE;
1054         case SOCK_DGRAM:
1055         case SOCK_STREAM:
1056                 allownumeric = 1;
1057                 break;
1058         case ANY:
1059                 allownumeric = 0;
1060                 break;
1061         default:
1062                 return EAI_SOCKTYPE;
1063         }
1064
1065         if (str_isnumber(servname)) {
1066                 if (!allownumeric)
1067                         return EAI_SERVICE;
1068                 port = htons(atoi(servname));
1069                 if (port < 0 || port > 65535)
1070                         return EAI_SERVICE;
1071         } else {
1072                 switch (ai->ai_socktype) {
1073                 case SOCK_DGRAM:
1074                         proto = "udp";
1075                         break;
1076                 case SOCK_STREAM:
1077                         proto = "tcp";
1078                         break;
1079                 default:
1080                         proto = NULL;
1081                         break;
1082                 }
1083
1084                 if ((sp = getservbyname(servname, proto)) == NULL)
1085                         return EAI_SERVICE;
1086                 port = sp->s_port;
1087         }
1088
1089         if (!matchonly) {
1090                 switch (ai->ai_family) {
1091                 case AF_INET:
1092                         ((struct sockaddr_in *)ai->ai_addr)->sin_port = port;
1093                         break;
1094 #ifdef INET6
1095                 case AF_INET6:
1096                         ((struct sockaddr_in6 *)ai->ai_addr)->sin6_port = port;
1097                         break;
1098 #endif
1099                 }
1100         }
1101
1102         return 0;
1103 }
1104
1105 static const struct afd *
1106 find_afd(af)
1107         int af;
1108 {
1109         const struct afd *afd;
1110
1111         if (af == PF_UNSPEC)
1112                 return NULL;
1113         for (afd = afdl; afd->a_af; afd++) {
1114                 if (afd->a_af == af)
1115                         return afd;
1116         }
1117         return NULL;
1118 }