Modules/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  * GAI_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 GAI_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 GAI_ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN GAI_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 RFC2133 is silent about which error
  37  *   code must be returned for which situation.
  38  * - PF_UNSPEC case would be handled in getipnodebyname() with the AI_ALL flag.
  39  */
  40
  41 #if 0
  42 #include <sys/types.h>
  43 #include <sys/param.h>
  44 #include <sys/sysctl.h>
  45 #include <sys/socket.h>
  46 #include <netinet/in.h>
  47 #include <arpa/inet.h>
  48 #include <arpa/nameser.h>
  49 #include <netdb.h>
  50 #include <resolv.h>
  51 #include <string.h>
  52 #include <stdlib.h>
  53 #include <stddef.h>
  54 #include <ctype.h>
  55 #include <unistd.h>
  56
  57 #include "addrinfo.h"
  58 #endif
  59
  60 #if defined(__KAME__) && defined(ENABLE_IPV6)
  61 # define FAITH
  62 #endif
  63
  64 #define SUCCESS 0
  65 #define GAI_ANY 0
  66 #define YES 1
  67 #define NO  0
  68
  69 #ifdef FAITH
  70 static int translate = NO;
  71 static struct in6_addr faith_prefix = IN6ADDR_GAI_ANY_INIT;
  72 #endif
  73
  74 static const char in_addrany[] = { 0, 0, 0, 0 };
  75 static const char in6_addrany[] = {
  76         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  77 };
  78 static const char in_loopback[] = { 127, 0, 0, 1 };
  79 static const char in6_loopback[] = {
  80         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
  81 };
  82
  83 struct sockinet {
  84         u_char  si_len;
  85         u_char  si_family;
  86         u_short si_port;
  87 };
  88
  89 static struct gai_afd {
  90         int a_af;
  91         int a_addrlen;
  92         int a_socklen;
  93         int a_off;
  94         const char *a_addrany;
  95         const char *a_loopback;
  96 } gai_afdl [] = {
  97 #ifdef ENABLE_IPV6
  98 #define N_INET6 0
  99         {PF_INET6, sizeof(struct in6_addr),
 100          sizeof(struct sockaddr_in6),
 101          offsetof(struct sockaddr_in6, sin6_addr),
 102          in6_addrany, in6_loopback},
 103 #define N_INET  1
 104 #else
 105 #define N_INET  0
 106 #endif
 107         {PF_INET, sizeof(struct in_addr),
 108          sizeof(struct sockaddr_in),
 109          offsetof(struct sockaddr_in, sin_addr),
 110          in_addrany, in_loopback},
 111         {0, 0, 0, 0, NULL, NULL},
 112 };
 113
 114 #ifdef ENABLE_IPV6
 115 #define PTON_MAX        16
 116 #else
 117 #define PTON_MAX        4
 118 #endif
 119
 120 #ifndef IN_MULTICAST
 121 #define IN_MULTICAST(i)     (((i) & 0xf0000000U) == 0xe0000000U)
 122 #endif
 123
 124 #ifndef IN_EXPERIMENTAL
 125 #define IN_EXPERIMENTAL(i)  (((i) & 0xe0000000U) == 0xe0000000U)
 126 #endif
 127
 128 #ifndef IN_LOOPBACKNET
 129 #define IN_LOOPBACKNET      127
 130 #endif
 131
 132 static int get_name Py_PROTO((const char *, struct gai_afd *,
 133                           struct addrinfo **, char *, struct addrinfo *,
 134                           int));
 135 static int get_addr Py_PROTO((const char *, int, struct addrinfo **,
 136                         struct addrinfo *, int));
 137 static int str_isnumber Py_PROTO((const char *));
 138
 139 static char *ai_errlist[] = {
 140         "success.",
 141         "address family for hostname not supported.",   /* EAI_ADDRFAMILY */
 142         "temporary failure in name resolution.",        /* EAI_AGAIN      */
 143         "invalid value for ai_flags.",                  /* EAI_BADFLAGS   */
 144         "non-recoverable failure in name resolution.",  /* EAI_FAIL       */
 145         "ai_family not supported.",                     /* EAI_FAMILY     */
 146         "memory allocation failure.",                   /* EAI_MEMORY     */
 147         "no address associated with hostname.",         /* EAI_NODATA     */
 148         "hostname nor servname provided, or not known.",/* EAI_NONAME     */
 149         "servname not supported for ai_socktype.",      /* EAI_SERVICE    */
 150         "ai_socktype not supported.",                   /* EAI_SOCKTYPE   */
 151         "system error returned in errno.",              /* EAI_SYSTEM     */
 152         "invalid value for hints.",                     /* EAI_BADHINTS   */
 153         "resolved protocol is unknown.",                /* EAI_PROTOCOL   */
 154         "unknown error.",                               /* EAI_MAX        */
 155 };
 156
 157 #define GET_CANONNAME(ai, str) \
 158 if (pai->ai_flags & AI_CANONNAME) {\
 159         if (((ai)->ai_canonname = (char *)malloc(strlen(str) + 1)) != NULL) {\
 160                 strcpy((ai)->ai_canonname, (str));\
 161         } else {\
 162                 error = EAI_MEMORY;\
 163                 goto free;\
 164         }\
 165 }
 166
 167 #ifdef HAVE_SOCKADDR_SA_LEN
 168 #define GET_AI(ai, gai_afd, addr, port) {\
 169         char *p;\
 170         if (((ai) = (struct addrinfo *)malloc(sizeof(struct addrinfo) +\
 171                                               ((gai_afd)->a_socklen)))\
 172             == NULL) goto free;\
 173         memcpy(ai, pai, sizeof(struct addrinfo));\
 174         (ai)->ai_addr = (struct sockaddr *)((ai) + 1);\
 175         memset((ai)->ai_addr, 0, (gai_afd)->a_socklen);\
 176         (ai)->ai_addr->sa_len = (ai)->ai_addrlen = (gai_afd)->a_socklen;\
 177         (ai)->ai_addr->sa_family = (ai)->ai_family = (gai_afd)->a_af;\
 178         ((struct sockinet *)(ai)->ai_addr)->si_port = port;\
 179         p = (char *)((ai)->ai_addr);\
 180         memcpy(p + (gai_afd)->a_off, (addr), (gai_afd)->a_addrlen);\
 181 }
 182 #else
 183 #define GET_AI(ai, gai_afd, addr, port) {\
 184         char *p;\
 185         if (((ai) = (struct addrinfo *)malloc(sizeof(struct addrinfo) +\
 186                                               ((gai_afd)->a_socklen)))\
 187             == NULL) goto free;\
 188         memcpy(ai, pai, sizeof(struct addrinfo));\
 189         (ai)->ai_addr = (struct sockaddr *)((ai) + 1);\
 190         memset((ai)->ai_addr, 0, (gai_afd)->a_socklen);\
 191         (ai)->ai_addrlen = (gai_afd)->a_socklen;\
 192         (ai)->ai_addr->sa_family = (ai)->ai_family = (gai_afd)->a_af;\
 193         ((struct sockinet *)(ai)->ai_addr)->si_port = port;\
 194         p = (char *)((ai)->ai_addr);\
 195         memcpy(p + (gai_afd)->a_off, (addr), (gai_afd)->a_addrlen);\
 196 }
 197 #endif
 198
 199 #define ERR(err) { error = (err); goto bad; }
 200
 201 char *
 202 gai_strerror(int ecode)
 203 {
 204         if (ecode < 0 || ecode > EAI_MAX)
 205                 ecode = EAI_MAX;
 206         return ai_errlist[ecode];
 207 }
 208
 209 void
 210 freeaddrinfo(struct addrinfo *ai)
 211 {
 212         struct addrinfo *next;
 213
 214         do {
 215                 next = ai->ai_next;
 216                 if (ai->ai_canonname)
 217                         free(ai->ai_canonname);
 218                 /* no need to free(ai->ai_addr) */
 219                 free(ai);
 220         } while ((ai = next) != NULL);
 221 }
 222
 223 static int
 224 str_isnumber(const char *p)
 225 {
 226         unsigned char *q = (unsigned char *)p;
 227         while (*q) {
 228                 if (! isdigit(*q))
 229                         return NO;
 230                 q++;
 231         }
 232         return YES;
 233 }
 234
 235 int
 236 getaddrinfo(const char*hostname, const char*servname,
 237             const struct addrinfo *hints, struct addrinfo **res)
 238 {
 239         struct addrinfo sentinel;
 240         struct addrinfo *top = NULL;
 241         struct addrinfo *cur;
 242         int i, error = 0;
 243         char pton[PTON_MAX];
 244         struct addrinfo ai;
 245         struct addrinfo *pai;
 246         u_short port;
 247
 248 #ifdef FAITH
 249         static int firsttime = 1;
 250
 251         if (firsttime) {
 252                 /* translator hack */
 253                 {
 254                         char *q = getenv("GAI");
 255                         if (q && inet_pton(AF_INET6, q, &faith_prefix) == 1)
 256                                 translate = YES;
 257                 }
 258                 firsttime = 0;
 259         }
 260 #endif
 261
 262         /* initialize file static vars */
 263         sentinel.ai_next = NULL;
 264         cur = &sentinel;
 265         pai = &ai;
 266         pai->ai_flags = 0;
 267         pai->ai_family = PF_UNSPEC;
 268         pai->ai_socktype = GAI_ANY;
 269         pai->ai_protocol = GAI_ANY;
 270         pai->ai_addrlen = 0;
 271         pai->ai_canonname = NULL;
 272         pai->ai_addr = NULL;
 273         pai->ai_next = NULL;
 274         port = GAI_ANY;
 275
 276         if (hostname == NULL && servname == NULL)
 277                 return EAI_NONAME;
 278         if (hints) {
 279                 /* error check for hints */
 280                 if (hints->ai_addrlen || hints->ai_canonname ||
 281                     hints->ai_addr || hints->ai_next)
 282                         ERR(EAI_BADHINTS); /* xxx */
 283                 if (hints->ai_flags & ~AI_MASK)
 284                         ERR(EAI_BADFLAGS);
 285                 switch (hints->ai_family) {
 286                 case PF_UNSPEC:
 287                 case PF_INET:
 288 #ifdef ENABLE_IPV6
 289                 case PF_INET6:
 290 #endif
 291                         break;
 292                 default:
 293                         ERR(EAI_FAMILY);
 294                 }
 295                 memcpy(pai, hints, sizeof(*pai));
 296                 switch (pai->ai_socktype) {
 297                 case GAI_ANY:
 298                         switch (pai->ai_protocol) {
 299                         case GAI_ANY:
 300                                 break;
 301                         case IPPROTO_UDP:
 302                                 pai->ai_socktype = SOCK_DGRAM;
 303                                 break;
 304                         case IPPROTO_TCP:
 305                                 pai->ai_socktype = SOCK_STREAM;
 306                                 break;
 307                         default:
 308                                 pai->ai_socktype = SOCK_RAW;
 309                                 break;
 310                         }
 311                         break;
 312                 case SOCK_RAW:
 313                         break;
 314                 case SOCK_DGRAM:
 315                         if (pai->ai_protocol != IPPROTO_UDP &&
 316                             pai->ai_protocol != GAI_ANY)
 317                                 ERR(EAI_BADHINTS);      /*xxx*/
 318                         pai->ai_protocol = IPPROTO_UDP;
 319                         break;
 320                 case SOCK_STREAM:
 321                         if (pai->ai_protocol != IPPROTO_TCP &&
 322                             pai->ai_protocol != GAI_ANY)
 323                                 ERR(EAI_BADHINTS);      /*xxx*/
 324                         pai->ai_protocol = IPPROTO_TCP;
 325                         break;
 326                 default:
 327                         ERR(EAI_SOCKTYPE);
 328                         /* unreachable */
 329                 }
 330         }
 331
 332         /*
 333          * service port
 334          */
 335         if (servname) {
 336                 if (str_isnumber(servname)) {
 337                         if (pai->ai_socktype == GAI_ANY) {
 338                                 /* caller accept *GAI_ANY* socktype */
 339                                 pai->ai_socktype = SOCK_DGRAM;
 340                                 pai->ai_protocol = IPPROTO_UDP;
 341                         }
 342                         port = htons((u_short)atoi(servname));
 343                 } else {
 344                         struct servent *sp;
 345                         char *proto;
 346
 347                         proto = NULL;
 348                         switch (pai->ai_socktype) {
 349                         case GAI_ANY:
 350                                 proto = NULL;
 351                                 break;
 352                         case SOCK_DGRAM:
 353                                 proto = "udp";
 354                                 break;
 355                         case SOCK_STREAM:
 356                                 proto = "tcp";
 357                                 break;
 358                         default:
 359                                 fprintf(stderr, "panic!\n");
 360                                 break;
 361                         }
 362                         if ((sp = getservbyname(servname, proto)) == NULL)
 363                                 ERR(EAI_SERVICE);
 364                         port = sp->s_port;
 365                         if (pai->ai_socktype == GAI_ANY) {
 366                                 if (strcmp(sp->s_proto, "udp") == 0) {
 367                                         pai->ai_socktype = SOCK_DGRAM;
 368                                         pai->ai_protocol = IPPROTO_UDP;
 369                                 } else if (strcmp(sp->s_proto, "tcp") == 0) {
 370                                         pai->ai_socktype = SOCK_STREAM;
 371                                         pai->ai_protocol = IPPROTO_TCP;
 372                                 } else
 373                                         ERR(EAI_PROTOCOL);      /*xxx*/
 374                         }
 375                 }
 376         }
 377
 378         /*
 379          * hostname == NULL.
 380          * passive socket -> anyaddr (0.0.0.0 or ::)
 381          * non-passive socket -> localhost (127.0.0.1 or ::1)
 382          */
 383         if (hostname == NULL) {
 384                 struct gai_afd *gai_afd;
 385
 386                 for (gai_afd = &gai_afdl[0]; gai_afd->a_af; gai_afd++) {
 387                         if (!(pai->ai_family == PF_UNSPEC
 388                            || pai->ai_family == gai_afd->a_af)) {
 389                                 continue;
 390                         }
 391
 392                         if (pai->ai_flags & AI_PASSIVE) {
 393                                 GET_AI(cur->ai_next, gai_afd, gai_afd->a_addrany, port);
 394                                 /* xxx meaningless?
 395                                  * GET_CANONNAME(cur->ai_next, "anyaddr");
 396                                  */
 397                         } else {
 398                                 GET_AI(cur->ai_next, gai_afd, gai_afd->a_loopback,
 399                                         port);
 400                                 /* xxx meaningless?
 401                                  * GET_CANONNAME(cur->ai_next, "localhost");
 402                                  */
 403                         }
 404                         cur = cur->ai_next;
 405                 }
 406                 top = sentinel.ai_next;
 407                 if (top)
 408                         goto good;
 409                 else
 410                         ERR(EAI_FAMILY);
 411         }
 412
 413         /* hostname as numeric name */
 414         for (i = 0; gai_afdl[i].a_af; i++) {
 415                 if (inet_pton(gai_afdl[i].a_af, hostname, pton)) {
 416                         u_long v4a;
 417 #ifdef ENABLE_IPV6
 418                         u_char pfx;
 419 #endif
 420
 421                         switch (gai_afdl[i].a_af) {
 422                         case AF_INET:
 423                                 v4a = ((struct in_addr *)pton)->s_addr;
 424                                 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
 425                                         pai->ai_flags &= ~AI_CANONNAME;
 426                                 v4a >>= IN_CLASSA_NSHIFT;
 427                                 if (v4a == 0 || v4a == IN_LOOPBACKNET)
 428                                         pai->ai_flags &= ~AI_CANONNAME;
 429                                 break;
 430 #ifdef ENABLE_IPV6
 431                         case AF_INET6:
 432                                 pfx = ((struct in6_addr *)pton)->s6_addr8[0];
 433                                 if (pfx == 0 || pfx == 0xfe || pfx == 0xff)
 434                                         pai->ai_flags &= ~AI_CANONNAME;
 435                                 break;
 436 #endif
 437                         }
 438
 439                         if (pai->ai_family == gai_afdl[i].a_af ||
 440                             pai->ai_family == PF_UNSPEC) {
 441                                 if (! (pai->ai_flags & AI_CANONNAME)) {
 442                                         GET_AI(top, &gai_afdl[i], pton, port);
 443                                         goto good;
 444                                 }
 445                                 /*
 446                                  * if AI_CANONNAME and if reverse lookup
 447                                  * fail, return ai anyway to pacify
 448                                  * calling application.
 449                                  *
 450                                  * XXX getaddrinfo() is a name->address
 451                                  * translation function, and it looks strange
 452                                  * that we do addr->name translation here.
 453                                  */
 454                                 get_name(pton, &gai_afdl[i], &top, pton, pai, port);
 455                                 goto good;
 456                         } else
 457                                 ERR(EAI_FAMILY);        /*xxx*/
 458                 }
 459         }
 460
 461         if (pai->ai_flags & AI_NUMERICHOST)
 462                 ERR(EAI_NONAME);
 463
 464         /* hostname as alphabetical name */
 465         error = get_addr(hostname, pai->ai_family, &top, pai, port);
 466         if (error == 0) {
 467                 if (top) {
 468  good:
 469                         *res = top;
 470                         return SUCCESS;
 471                 } else
 472                         error = EAI_FAIL;
 473         }
 474  free:
 475         if (top)
 476                 freeaddrinfo(top);
 477  bad:
 478         *res = NULL;
 479         return error;
 480 }
 481
 482 static int
 483 get_name(addr, gai_afd, res, numaddr, pai, port0)
 484         const char *addr;
 485         struct gai_afd *gai_afd;
 486         struct addrinfo **res;
 487         char *numaddr;
 488         struct addrinfo *pai;
 489         int port0;
 490 {
 491         u_short port = port0 & 0xffff;
 492         struct hostent *hp;
 493         struct addrinfo *cur;
 494         int error = 0;
 495 #ifdef ENABLE_IPV6
 496         int h_error;
 497 #endif
 498
 499 #ifdef ENABLE_IPV6
 500         hp = getipnodebyaddr(addr, gai_afd->a_addrlen, gai_afd->a_af, &h_error);
 501 #else
 502         hp = gethostbyaddr(addr, gai_afd->a_addrlen, AF_INET);
 503 #endif
 504         if (hp && hp->h_name && hp->h_name[0] && hp->h_addr_list[0]) {
 505                 GET_AI(cur, gai_afd, hp->h_addr_list[0], port);
 506                 GET_CANONNAME(cur, hp->h_name);
 507         } else
 508                 GET_AI(cur, gai_afd, numaddr, port);
 509
 510 #ifdef ENABLE_IPV6
 511         if (hp)
 512                 freehostent(hp);
 513 #endif
 514         *res = cur;
 515         return SUCCESS;
 516  free:
 517         if (cur)
 518                 freeaddrinfo(cur);
 519 #ifdef ENABLE_IPV6
 520         if (hp)
 521                 freehostent(hp);
 522 #endif
 523  /* bad: */
 524         *res = NULL;
 525         return error;
 526 }
 527
 528 static int
 529 get_addr(hostname, af, res, pai, port0)
 530         const char *hostname;
 531         int af;
 532         struct addrinfo **res;
 533         struct addrinfo *pai;
 534         int port0;
 535 {
 536         u_short port = port0 & 0xffff;
 537         struct addrinfo sentinel;
 538         struct hostent *hp;
 539         struct addrinfo *top, *cur;
 540         struct gai_afd *gai_afd;
 541         int i, error = 0, h_error;
 542         char *ap;
 543
 544         top = NULL;
 545         sentinel.ai_next = NULL;
 546         cur = &sentinel;
 547 #ifdef ENABLE_IPV6
 548         if (af == AF_UNSPEC) {
 549                 hp = getipnodebyname(hostname, AF_INET6,
 550                                 AI_ADDRCONFIG|AI_ALL|AI_V4MAPPED, &h_error);
 551         } else
 552                 hp = getipnodebyname(hostname, af, AI_ADDRCONFIG, &h_error);
 553 #else
 554         hp = gethostbyname(hostname);
 555         h_error = h_errno;
 556 #endif
 557         if (hp == NULL) {
 558                 switch (h_error) {
 559                 case HOST_NOT_FOUND:
 560                 case NO_DATA:
 561                         error = EAI_NODATA;
 562                         break;
 563                 case TRY_AGAIN:
 564                         error = EAI_AGAIN;
 565                         break;
 566                 case NO_RECOVERY:
 567                 default:
 568                         error = EAI_FAIL;
 569                         break;
 570                 }
 571                 goto free;
 572         }
 573
 574         if ((hp->h_name == NULL) || (hp->h_name[0] == 0) ||
 575             (hp->h_addr_list[0] == NULL)) {
 576                 error = EAI_FAIL;
 577                 goto free;
 578         }
 579
 580         for (i = 0; (ap = hp->h_addr_list[i]) != NULL; i++) {
 581                 switch (af) {
 582 #ifdef ENABLE_IPV6
 583                 case AF_INET6:
 584                         gai_afd = &gai_afdl[N_INET6];
 585                         break;
 586 #endif
 587 #ifndef ENABLE_IPV6
 588                 default:        /* AF_UNSPEC */
 589 #endif
 590                 case AF_INET:
 591                         gai_afd = &gai_afdl[N_INET];
 592                         break;
 593 #ifdef ENABLE_IPV6
 594                 default:        /* AF_UNSPEC */
 595                         if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) {
 596                                 ap += sizeof(struct in6_addr) -
 597                                         sizeof(struct in_addr);
 598                                 gai_afd = &gai_afdl[N_INET];
 599                         } else
 600                                 gai_afd = &gai_afdl[N_INET6];
 601                         break;
 602 #endif
 603                 }
 604 #ifdef FAITH
 605                 if (translate && gai_afd->a_af == AF_INET) {
 606                         struct in6_addr *in6;
 607
 608                         GET_AI(cur->ai_next, &gai_afdl[N_INET6], ap, port);
 609                         in6 = &((struct sockaddr_in6 *)cur->ai_next->ai_addr)->sin6_addr;
 610                         memcpy(&in6->s6_addr32[0], &faith_prefix,
 611                             sizeof(struct in6_addr) - sizeof(struct in_addr));
 612                         memcpy(&in6->s6_addr32[3], ap, sizeof(struct in_addr));
 613                 } else
 614 #endif /* FAITH */
 615                 GET_AI(cur->ai_next, gai_afd, ap, port);
 616                 if (cur == &sentinel) {
 617                         top = cur->ai_next;
 618                         GET_CANONNAME(top, hp->h_name);
 619                 }
 620                 cur = cur->ai_next;
 621         }
 622 #ifdef ENABLE_IPV6
 623         freehostent(hp);
 624 #endif
 625         *res = top;
 626         return SUCCESS;
 627  free:
 628         if (top)
 629                 freeaddrinfo(top);
 630 #ifdef ENABLE_IPV6
 631         if (hp)
 632                 freehostent(hp);
 633 #endif
 634 /* bad: */
 635         *res = NULL;
 636         return error;
 637 }