contrib/bind-9.2.4rc7/lib/lwres/getipnode.c

   1 /*
   2  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1999-2003  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: getipnode.c,v 1.30.2.6 2004/03/09 06:12:33 marka Exp $ */
  19
  20 #include <config.h>
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include <lwres/lwres.h>
  27 #include <lwres/net.h>
  28 #include <lwres/netdb.h>        /* XXX #include <netdb.h> */
  29
  30 #include "assert_p.h"
  31
  32 #ifndef INADDRSZ
  33 #define INADDRSZ 4
  34 #endif
  35 #ifndef IN6ADDRSZ
  36 #define IN6ADDRSZ 16
  37 #endif
  38
  39 #ifdef LWRES_PLATFORM_NEEDIN6ADDRANY
  40 LIBLWRES_EXTERNAL_DATA const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
  41 #endif
  42
  43 #ifndef IN6_IS_ADDR_V4COMPAT
  44 static const unsigned char in6addr_compat[12] = {
  45         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  46 };
  47 #define IN6_IS_ADDR_V4COMPAT(x) (!memcmp((x)->s6_addr, in6addr_compat, 12) && \
  48                                  ((x)->s6_addr[12] != 0 || \
  49                                   (x)->s6_addr[13] != 0 || \
  50                                   (x)->s6_addr[14] != 0 || \
  51                                    ((x)->s6_addr[15] != 0 && \
  52                                     (x)->s6_addr[15] != 1)))
  53 #endif
  54 #ifndef IN6_IS_ADDR_V4MAPPED
  55 #define IN6_IS_ADDR_V4MAPPED(x) (!memcmp((x)->s6_addr, in6addr_mapped, 12))
  56 #endif
  57
  58 static const unsigned char in6addr_mapped[12] = {
  59         0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0xff, 0xff
  60 };
  61
  62 /***
  63  ***    Forward declarations.
  64  ***/
  65
  66 static int
  67 scan_interfaces(int *, int *);
  68
  69 static struct hostent *
  70 copyandmerge(struct hostent *, struct hostent *, int, int *);
  71
  72 static struct hostent *
  73 hostfromaddr(lwres_gnbaresponse_t *addr, int af, const void *src);
  74
  75 static struct hostent *
  76 hostfromname(lwres_gabnresponse_t *name, int af);
  77
  78 /***
  79  ***    Public functions.
  80  ***/
  81
  82 /*
  83  *      AI_V4MAPPED + AF_INET6
  84  *      If no IPv6 address then a query for IPv4 and map returned values.
  85  *
  86  *      AI_ALL + AI_V4MAPPED + AF_INET6
  87  *      Return IPv6 and IPv4 mapped.
  88  *
  89  *      AI_ADDRCONFIG
  90  *      Only return IPv6 / IPv4 address if there is an interface of that
  91  *      type active.
  92  */
  93
  94 struct hostent *
  95 lwres_getipnodebyname(const char *name, int af, int flags, int *error_num) {
  96         int have_v4 = 1, have_v6 = 1;
  97         struct in_addr in4;
  98         struct in6_addr in6;
  99         struct hostent he, *he1 = NULL, *he2 = NULL, *he3 = NULL;
 100         int v4 = 0, v6 = 0;
 101         int tmp_err;
 102         lwres_context_t *lwrctx = NULL;
 103         lwres_gabnresponse_t *by = NULL;
 104         int n;
 105
 106         /*
 107          * If we care about active interfaces then check.
 108          */
 109         if ((flags & AI_ADDRCONFIG) != 0)
 110                 if (scan_interfaces(&have_v4, &have_v6) == -1) {
 111                         *error_num = NO_RECOVERY;
 112                         return (NULL);
 113                 }
 114
 115         /* Check for literal address. */
 116         if ((v4 = lwres_net_pton(AF_INET, name, &in4)) != 1)
 117                 v6 = lwres_net_pton(AF_INET6, name, &in6);
 118
 119         /*
 120          * Impossible combination?
 121          */
 122         if ((af == AF_INET6 && (flags & AI_V4MAPPED) == 0 && v4 == 1) ||
 123             (af == AF_INET && v6 == 1) ||
 124             (have_v4 == 0 && v4 == 1) ||
 125             (have_v6 == 0 && v6 == 1) ||
 126             (have_v4 == 0 && af == AF_INET) ||
 127             (have_v6 == 0 && af == AF_INET6 &&
 128              (((flags & AI_V4MAPPED) != 0 && have_v4) ||
 129               (flags & AI_V4MAPPED) == 0))) {
 130                 *error_num = HOST_NOT_FOUND;
 131                 return (NULL);
 132         }
 133
 134         /*
 135          * Literal address?
 136          */
 137         if (v4 == 1 || v6 == 1) {
 138                 char *addr_list[2];
 139                 char *aliases[1];
 140                 char mappedname[sizeof("::ffff:123.123.123.123")];
 141                 union {
 142                         const char *const_name;
 143                         char *deconst_name;
 144                 } u;
 145
 146                 u.const_name = name;
 147                 if (v4 == 1 && af == AF_INET6) {
 148                         strcpy(mappedname, "::ffff:");
 149                         lwres_net_ntop(AF_INET, (char *)&in4,
 150                                        mappedname + sizeof("::ffff:") - 1,
 151                                        sizeof(mappedname) - sizeof("::ffff:")
 152                                        + 1);
 153                         he.h_name = mappedname;
 154                 } else
 155                         he.h_name = u.deconst_name;
 156                 he.h_addr_list = addr_list;
 157                 he.h_addr_list[0] = (v4 == 1) ? (char *)&in4 : (char *)&in6;
 158                 he.h_addr_list[1] = NULL;
 159                 he.h_aliases = aliases;
 160                 he.h_aliases[0] = NULL;
 161                 he.h_length = (v4 == 1) ? INADDRSZ : IN6ADDRSZ;
 162                 he.h_addrtype = (v4 == 1) ? AF_INET : AF_INET6;
 163                 return (copyandmerge(&he, NULL, af, error_num));
 164         }
 165
 166         n = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0);
 167         if (n != 0) {
 168                 *error_num = NO_RECOVERY;
 169                 goto cleanup;
 170         }
 171         (void) lwres_conf_parse(lwrctx, lwres_resolv_conf);
 172         tmp_err = NO_RECOVERY;
 173         if (have_v6 && af == AF_INET6) {
 174
 175                 n = lwres_getaddrsbyname(lwrctx, name, LWRES_ADDRTYPE_V6, &by);
 176                 if (n == 0) {
 177                         he1 = hostfromname(by, AF_INET6);
 178                         lwres_gabnresponse_free(lwrctx, &by);
 179                         if (he1 == NULL) {
 180                                 *error_num = NO_RECOVERY;
 181                                 goto cleanup;
 182                         }
 183                 } else {
 184                         tmp_err = HOST_NOT_FOUND;
 185                 }
 186         }
 187
 188         if (have_v4 &&
 189             ((af == AF_INET) ||
 190              (af == AF_INET6 && (flags & AI_V4MAPPED) != 0 &&
 191               (he1 == NULL || (flags & AI_ALL) != 0)))) {
 192                 n = lwres_getaddrsbyname(lwrctx, name, LWRES_ADDRTYPE_V4, &by);
 193                 if (n == 0) {
 194                         he2 = hostfromname(by, AF_INET);
 195                         lwres_gabnresponse_free(lwrctx, &by);
 196                         if (he2 == NULL) {
 197                                 *error_num = NO_RECOVERY;
 198                                 goto cleanup;
 199                         }
 200                 } else if (he1 == NULL) {
 201                         if (n == LWRES_R_NOTFOUND)
 202                                 *error_num = HOST_NOT_FOUND;
 203                         else
 204                                 *error_num = NO_RECOVERY;
 205                         goto cleanup;
 206                 }
 207         } else
 208                 *error_num = tmp_err;
 209
 210         he3 = copyandmerge(he1, he2, af, error_num);
 211
 212  cleanup:
 213         if (he1 != NULL)
 214                 lwres_freehostent(he1);
 215         if (he2 != NULL)
 216                 lwres_freehostent(he2);
 217         if (lwrctx != NULL) {
 218                 lwres_conf_clear(lwrctx);
 219                 lwres_context_destroy(&lwrctx);
 220         }
 221         return (he3);
 222 }
 223
 224 struct hostent *
 225 lwres_getipnodebyaddr(const void *src, size_t len, int af, int *error_num) {
 226         struct hostent *he1, *he2;
 227         lwres_context_t *lwrctx = NULL;
 228         lwres_gnbaresponse_t *by = NULL;
 229         lwres_result_t n;
 230         union {
 231                 const void *konst;
 232                 struct in6_addr *in6;
 233         } u;
 234
 235         /*
 236          * Sanity checks.
 237          */
 238         if (src == NULL) {
 239                 *error_num = NO_RECOVERY;
 240                 return (NULL);
 241         }
 242
 243         switch (af) {
 244         case AF_INET:
 245                 if (len != (unsigned int)INADDRSZ) {
 246                         *error_num = NO_RECOVERY;
 247                         return (NULL);
 248                 }
 249                 break;
 250         case AF_INET6:
 251                 if (len != (unsigned int)IN6ADDRSZ) {
 252                         *error_num = NO_RECOVERY;
 253                         return (NULL);
 254                 }
 255                 break;
 256         default:
 257                 *error_num = NO_RECOVERY;
 258                 return (NULL);
 259         }
 260
 261         /*
 262          * The de-"const"-ing game is done because at least one
 263          * vendor's system (RedHat 6.0) defines the IN6_IS_ADDR_*
 264          * macros in such a way that they discard the const with
 265          * internal casting, and gcc ends up complaining.  Rather
 266          * than replacing their own (possibly optimized) definitions
 267          * with our own, cleanly discarding the const is the easiest
 268          * thing to do.
 269          */
 270         u.konst = src;
 271
 272         /*
 273          * Look up IPv4 and IPv4 mapped/compatible addresses.
 274          */
 275         if ((af == AF_INET6 && IN6_IS_ADDR_V4COMPAT(u.in6)) ||
 276             (af == AF_INET6 && IN6_IS_ADDR_V4MAPPED(u.in6)) ||
 277             (af == AF_INET)) {
 278                 const unsigned char *cp = src;
 279
 280                 if (af == AF_INET6)
 281                         cp += 12;
 282                 n = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0);
 283                 if (n == LWRES_R_SUCCESS)
 284                         (void) lwres_conf_parse(lwrctx, lwres_resolv_conf);
 285                 if (n == LWRES_R_SUCCESS)
 286                         n = lwres_getnamebyaddr(lwrctx, LWRES_ADDRTYPE_V4,
 287                                                 INADDRSZ, cp, &by);
 288                 if (n != LWRES_R_SUCCESS) {
 289                         lwres_conf_clear(lwrctx);
 290                         lwres_context_destroy(&lwrctx);
 291                         if (n == LWRES_R_NOTFOUND)
 292                                 *error_num = HOST_NOT_FOUND;
 293                         else
 294                                 *error_num = NO_RECOVERY;
 295                         return (NULL);
 296                 }
 297                 he1 = hostfromaddr(by, AF_INET, cp);
 298                 lwres_gnbaresponse_free(lwrctx, &by);
 299                 lwres_conf_clear(lwrctx);
 300                 lwres_context_destroy(&lwrctx);
 301                 if (af != AF_INET6)
 302                         return (he1);
 303
 304                 /*
 305                  * Convert from AF_INET to AF_INET6.
 306                  */
 307                 he2 = copyandmerge(he1, NULL, af, error_num);
 308                 lwres_freehostent(he1);
 309                 if (he2 == NULL)
 310                         return (NULL);
 311                 /*
 312                  * Restore original address.
 313                  */
 314                 memcpy(he2->h_addr, src, len);
 315                 return (he2);
 316         }
 317
 318         /*
 319          * Lookup IPv6 address.
 320          */
 321         if (memcmp(src, &in6addr_any, IN6ADDRSZ) == 0) {
 322                 *error_num = HOST_NOT_FOUND;
 323                 return (NULL);
 324         }
 325
 326         n = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0);
 327         if (n == LWRES_R_SUCCESS)
 328                 (void) lwres_conf_parse(lwrctx, lwres_resolv_conf);
 329         if (n == LWRES_R_SUCCESS)
 330                 n = lwres_getnamebyaddr(lwrctx, LWRES_ADDRTYPE_V6, IN6ADDRSZ,
 331                                         src, &by);
 332         if (n != 0) {
 333                 *error_num = HOST_NOT_FOUND;
 334                 return (NULL);
 335         }
 336         he1 = hostfromaddr(by, AF_INET6, src);
 337         lwres_gnbaresponse_free(lwrctx, &by);
 338         if (he1 == NULL)
 339                 *error_num = NO_RECOVERY;
 340         lwres_context_destroy(&lwrctx);
 341         return (he1);
 342 }
 343
 344 void
 345 lwres_freehostent(struct hostent *he) {
 346         char **cpp;
 347         int names = 1;
 348         int addresses = 1;
 349
 350         free(he->h_name);
 351
 352         cpp = he->h_addr_list;
 353         while (*cpp != NULL) {
 354                 free(*cpp);
 355                 *cpp = NULL;
 356                 cpp++;
 357                 addresses++;
 358         }
 359
 360         cpp = he->h_aliases;
 361         while (*cpp != NULL) {
 362                 free(*cpp);
 363                 cpp++;
 364                 names++;
 365         }
 366
 367         free(he->h_aliases);
 368         free(he->h_addr_list);
 369         free(he);
 370 }
 371
 372 /*
 373  * Private
 374  */
 375
 376 /*
 377  * Scan the interface table and set have_v4 and have_v6 depending
 378  * upon whether there are IPv4 and IPv6 interface addresses.
 379  *
 380  * Returns:
 381  *      0 on success
 382  *      -1 on failure.
 383  */
 384
 385 static int
 386 scan_interfaces(int *have_v4, int *have_v6) {
 387 #if 1
 388         *have_v4 = *have_v6 = 1;
 389         return (0);
 390 #else
 391         struct ifconf ifc;
 392         struct ifreq ifreq;
 393         struct in_addr in4;
 394         struct in6_addr in6;
 395         char *buf = NULL, *cp, *cplim;
 396         static int bufsiz = 4095;
 397         int s, cpsize, n;
 398
 399         /*
 400          * Set to zero.  Used as loop terminators below.
 401          */
 402         *have_v4 = *have_v6 = 0;
 403
 404         /*
 405          * Get interface list from system.
 406          */
 407         if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
 408                 goto err_ret;
 409
 410         /*
 411          * Grow buffer until large enough to contain all interface
 412          * descriptions.
 413          */
 414         for (;;) {
 415                 buf = malloc(bufsiz);
 416                 if (buf == NULL)
 417                         goto err_ret;
 418                 ifc.ifc_len = bufsiz;
 419                 ifc.ifc_buf = buf;
 420 #ifdef IRIX_EMUL_IOCTL_SIOCGIFCONF
 421                 /*
 422                  * This is a fix for IRIX OS in which the call to ioctl with
 423                  * the flag SIOCGIFCONF may not return an entry for all the
 424                  * interfaces like most flavors of Unix.
 425                  */
 426                 if (emul_ioctl(&ifc) >= 0)
 427                         break;
 428 #else
 429                 if ((n = ioctl(s, SIOCGIFCONF, (char *)&ifc)) != -1) {
 430                         /*
 431                          * Some OS's just return what will fit rather
 432                          * than set EINVAL if the buffer is too small
 433                          * to fit all the interfaces in.  If
 434                          * ifc.ifc_len is too near to the end of the
 435                          * buffer we will grow it just in case and
 436                          * retry.
 437                          */
 438                         if (ifc.ifc_len + 2 * sizeof(ifreq) < bufsiz)
 439                                 break;
 440                 }
 441 #endif
 442                 if ((n == -1) && errno != EINVAL)
 443                         goto err_ret;
 444
 445                 if (bufsiz > 1000000)
 446                         goto err_ret;
 447
 448                 free(buf);
 449                 bufsiz += 4096;
 450         }
 451
 452         /*
 453          * Parse system's interface list.
 454          */
 455         cplim = buf + ifc.ifc_len;    /* skip over if's with big ifr_addr's */
 456         for (cp = buf;
 457              (*have_v4 == 0 || *have_v6 == 0) && cp < cplim;
 458              cp += cpsize) {
 459                 memcpy(&ifreq, cp, sizeof ifreq);
 460 #ifdef LWRES_PLATFORM_HAVESALEN
 461 #ifdef FIX_ZERO_SA_LEN
 462                 if (ifreq.ifr_addr.sa_len == 0)
 463                         ifreq.ifr_addr.sa_len = IN6ADDRSZ;
 464 #endif
 465 #ifdef HAVE_MINIMUM_IFREQ
 466                 cpsize = sizeof ifreq;
 467                 if (ifreq.ifr_addr.sa_len > sizeof (struct sockaddr))
 468                         cpsize += (int)ifreq.ifr_addr.sa_len -
 469                                 (int)(sizeof(struct sockaddr));
 470 #else
 471                 cpsize = sizeof ifreq.ifr_name + ifreq.ifr_addr.sa_len;
 472 #endif /* HAVE_MINIMUM_IFREQ */
 473 #elif defined SIOCGIFCONF_ADDR
 474                 cpsize = sizeof ifreq;
 475 #else
 476                 cpsize = sizeof ifreq.ifr_name;
 477                 /* XXX maybe this should be a hard error? */
 478                 if (ioctl(s, SIOCGIFADDR, (char *)&ifreq) < 0)
 479                         continue;
 480 #endif /* LWRES_PLATFORM_HAVESALEN */
 481                 switch (ifreq.ifr_addr.sa_family) {
 482                 case AF_INET:
 483                         if (*have_v4 == 0) {
 484                                 memcpy(&in4,
 485                                        &((struct sockaddr_in *)
 486                                        &ifreq.ifr_addr)->sin_addr,
 487                                        sizeof(in4));
 488                                 if (in4.s_addr == INADDR_ANY)
 489                                         break;
 490                                 n = ioctl(s, SIOCGIFFLAGS, (char *)&ifreq);
 491                                 if (n < 0)
 492                                         break;
 493                                 if ((ifreq.ifr_flags & IFF_UP) == 0)
 494                                         break;
 495                                 *have_v4 = 1;
 496                         }
 497                         break;
 498                 case AF_INET6:
 499                         if (*have_v6 == 0) {
 500                                 memcpy(&in6,
 501                                        &((struct sockaddr_in6 *)
 502                                        &ifreq.ifr_addr)->sin6_addr,
 503                                        sizeof(in6));
 504                                 if (memcmp(&in6, &in6addr_any,
 505                                            sizeof(in6)) == 0)
 506                                         break;
 507                                 n = ioctl(s, SIOCGIFFLAGS, (char *)&ifreq);
 508                                 if (n < 0)
 509                                         break;
 510                                 if ((ifreq.ifr_flags & IFF_UP) == 0)
 511                                         break;
 512                                 *have_v6 = 1;
 513                         }
 514                         break;
 515                 }
 516         }
 517         if (buf != NULL)
 518                 free(buf);
 519         close(s);
 520         return (0);
 521  err_ret:
 522         if (buf != NULL)
 523                 free(buf);
 524         if (s != -1)
 525                 close(s);
 526         return (-1);
 527 #endif
 528 }
 529
 530 static struct hostent *
 531 copyandmerge(struct hostent *he1, struct hostent *he2, int af, int *error_num)
 532 {
 533         struct hostent *he = NULL;
 534         int addresses = 1;      /* NULL terminator */
 535         int names = 1;          /* NULL terminator */
 536         int len = 0;
 537         char **cpp, **npp;
 538
 539         /*
 540          * Work out array sizes.
 541          */
 542         if (he1 != NULL) {
 543                 cpp = he1->h_addr_list;
 544                 while (*cpp != NULL) {
 545                         addresses++;
 546                         cpp++;
 547                 }
 548                 cpp = he1->h_aliases;
 549                 while (*cpp != NULL) {
 550                         names++;
 551                         cpp++;
 552                 }
 553         }
 554
 555         if (he2 != NULL) {
 556                 cpp = he2->h_addr_list;
 557                 while (*cpp != NULL) {
 558                         addresses++;
 559                         cpp++;
 560                 }
 561                 if (he1 == NULL) {
 562                         cpp = he2->h_aliases;
 563                         while (*cpp != NULL) {
 564                                 names++;
 565                                 cpp++;
 566                         }
 567                 }
 568         }
 569
 570         if (addresses == 1) {
 571                 *error_num = NO_ADDRESS;
 572                 return (NULL);
 573         }
 574
 575         he = malloc(sizeof *he);
 576         if (he == NULL)
 577                 goto no_recovery;
 578
 579         he->h_addr_list = malloc(sizeof(char *) * (addresses));
 580         if (he->h_addr_list == NULL)
 581                 goto cleanup0;
 582         memset(he->h_addr_list, 0, sizeof(char *) * (addresses));
 583
 584         /*
 585          * Copy addresses.
 586          */
 587         npp = he->h_addr_list;
 588         if (he1 != NULL) {
 589                 cpp = he1->h_addr_list;
 590                 while (*cpp != NULL) {
 591                         *npp = malloc((af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
 592                         if (*npp == NULL)
 593                                 goto cleanup1;
 594                         /*
 595                          * Convert to mapped if required.
 596                          */
 597                         if (af == AF_INET6 && he1->h_addrtype == AF_INET) {
 598                                 memcpy(*npp, in6addr_mapped,
 599                                        sizeof in6addr_mapped);
 600                                 memcpy(*npp + sizeof in6addr_mapped, *cpp,
 601                                        INADDRSZ);
 602                         } else {
 603                                 memcpy(*npp, *cpp,
 604                                        (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
 605                         }
 606                         cpp++;
 607                         npp++;
 608                 }
 609         }
 610
 611         if (he2 != NULL) {
 612                 cpp = he2->h_addr_list;
 613                 while (*cpp != NULL) {
 614                         *npp = malloc((af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
 615                         if (*npp == NULL)
 616                                 goto cleanup1;
 617                         /*
 618                          * Convert to mapped if required.
 619                          */
 620                         if (af == AF_INET6 && he2->h_addrtype == AF_INET) {
 621                                 memcpy(*npp, in6addr_mapped,
 622                                        sizeof in6addr_mapped);
 623                                 memcpy(*npp + sizeof in6addr_mapped, *cpp,
 624                                        INADDRSZ);
 625                         } else {
 626                                 memcpy(*npp, *cpp,
 627                                        (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
 628                         }
 629                         cpp++;
 630                         npp++;
 631                 }
 632         }
 633
 634         he->h_aliases = malloc(sizeof(char *) * (names));
 635         if (he->h_aliases == NULL)
 636                 goto cleanup1;
 637         memset(he->h_aliases, 0, sizeof(char *) * (names));
 638
 639         /*
 640          * Copy aliases.
 641          */
 642         npp = he->h_aliases;
 643         cpp = (he1 != NULL) ? he1->h_aliases : he2->h_aliases;
 644         while (*cpp != NULL) {
 645                 len = strlen (*cpp) + 1;
 646                 *npp = malloc(len);
 647                 if (*npp == NULL)
 648                         goto cleanup2;
 649                 strcpy(*npp, *cpp);
 650                 npp++;
 651                 cpp++;
 652         }
 653
 654         /*
 655          * Copy hostname.
 656          */
 657         he->h_name = malloc(strlen((he1 != NULL) ?
 658                             he1->h_name : he2->h_name) + 1);
 659         if (he->h_name == NULL)
 660                 goto cleanup2;
 661         strcpy(he->h_name, (he1 != NULL) ? he1->h_name : he2->h_name);
 662
 663         /*
 664          * Set address type and length.
 665          */
 666         he->h_addrtype = af;
 667         he->h_length = (af == AF_INET) ? INADDRSZ : IN6ADDRSZ;
 668         return (he);
 669
 670  cleanup2:
 671         cpp = he->h_aliases;
 672         while (*cpp != NULL) {
 673                 free(*cpp);
 674                 cpp++;
 675         }
 676         free(he->h_aliases);
 677
 678  cleanup1:
 679         cpp = he->h_addr_list;
 680         while (*cpp != NULL) {
 681                 free(*cpp);
 682                 *cpp = NULL;
 683                 cpp++;
 684         }
 685         free(he->h_addr_list);
 686
 687  cleanup0:
 688         free(he);
 689
 690  no_recovery:
 691         *error_num = NO_RECOVERY;
 692         return (NULL);
 693 }
 694
 695 static struct hostent *
 696 hostfromaddr(lwres_gnbaresponse_t *addr, int af, const void *src) {
 697         struct hostent *he;
 698         int i;
 699
 700         he = malloc(sizeof *he);
 701         if (he == NULL)
 702                 goto cleanup;
 703         memset(he, 0, sizeof(*he));
 704
 705         /*
 706          * Set family and length.
 707          */
 708         he->h_addrtype = af;
 709         switch (af) {
 710         case AF_INET:
 711                 he->h_length = INADDRSZ;
 712                 break;
 713         case AF_INET6:
 714                 he->h_length = IN6ADDRSZ;
 715                 break;
 716         default:
 717                 INSIST(0);
 718         }
 719
 720         /*
 721          * Copy name.
 722          */
 723         he->h_name = strdup(addr->realname);
 724         if (he->h_name == NULL)
 725                 goto cleanup;
 726
 727         /*
 728          * Copy aliases.
 729          */
 730         he->h_aliases = malloc(sizeof(char *) * (addr->naliases + 1));
 731         if (he->h_aliases == NULL)
 732                 goto cleanup;
 733         for (i = 0 ; i < addr->naliases; i++) {
 734                 he->h_aliases[i] = strdup(addr->aliases[i]);
 735                 if (he->h_aliases[i] == NULL)
 736                         goto cleanup;
 737         }
 738         he->h_aliases[i] = NULL;
 739
 740         /*
 741          * Copy address.
 742          */
 743         he->h_addr_list = malloc(sizeof(char *) * 2);
 744         if (he->h_addr_list == NULL)
 745                 goto cleanup;
 746         he->h_addr_list[0] = malloc(he->h_length);
 747         if (he->h_addr_list[0] == NULL)
 748                 goto cleanup;
 749         memcpy(he->h_addr_list[0], src, he->h_length);
 750         he->h_addr_list[1] = NULL;
 751         return (he);
 752
 753  cleanup:
 754         if (he != NULL && he->h_addr_list != NULL) {
 755                 for (i = 0; he->h_addr_list[i] != NULL; i++)
 756                         free(he->h_addr_list[i]);
 757                 free(he->h_addr_list);
 758         }
 759         if (he != NULL && he->h_aliases != NULL) {
 760                 for (i = 0; he->h_aliases[i] != NULL; i++)
 761                         free(he->h_aliases[i]);
 762                 free(he->h_aliases);
 763         }
 764         if (he != NULL && he->h_name != NULL)
 765                 free(he->h_name);
 766         if (he != NULL)
 767                 free(he);
 768         return (NULL);
 769 }
 770
 771 static struct hostent *
 772 hostfromname(lwres_gabnresponse_t *name, int af) {
 773         struct hostent *he;
 774         int i;
 775         lwres_addr_t *addr;
 776
 777         he = malloc(sizeof *he);
 778         if (he == NULL)
 779                 goto cleanup;
 780         memset(he, 0, sizeof(*he));
 781
 782         /*
 783          * Set family and length.
 784          */
 785         he->h_addrtype = af;
 786         switch (af) {
 787         case AF_INET:
 788                 he->h_length = INADDRSZ;
 789                 break;
 790         case AF_INET6:
 791                 he->h_length = IN6ADDRSZ;
 792                 break;
 793         default:
 794                 INSIST(0);
 795         }
 796
 797         /*
 798          * Copy name.
 799          */
 800         he->h_name = strdup(name->realname);
 801         if (he->h_name == NULL)
 802                 goto cleanup;
 803
 804         /*
 805          * Copy aliases.
 806          */
 807         he->h_aliases = malloc(sizeof(char *) * (name->naliases + 1));
 808         for (i = 0 ; i < name->naliases; i++) {
 809                 he->h_aliases[i] = strdup(name->aliases[i]);
 810                 if (he->h_aliases[i] == NULL)
 811                         goto cleanup;
 812         }
 813         he->h_aliases[i] = NULL;
 814
 815         /*
 816          * Copy addresses.
 817          */
 818         he->h_addr_list = malloc(sizeof(char *) * (name->naddrs + 1));
 819         addr = LWRES_LIST_HEAD(name->addrs);
 820         i = 0;
 821         while (addr != NULL) {
 822                 he->h_addr_list[i] = malloc(he->h_length);
 823                 if (he->h_addr_list[i] == NULL)
 824                         goto cleanup;
 825                 memcpy(he->h_addr_list[i], addr->address, he->h_length);
 826                 addr = LWRES_LIST_NEXT(addr, link);
 827                 i++;
 828         }
 829         he->h_addr_list[i] = NULL;
 830         return (he);
 831
 832  cleanup:
 833         if (he != NULL && he->h_addr_list != NULL) {
 834                 for (i = 0; he->h_addr_list[i] != NULL; i++)
 835                         free(he->h_addr_list[i]);
 836                 free(he->h_addr_list);
 837         }
 838         if (he != NULL && he->h_aliases != NULL) {
 839                 for (i = 0; he->h_aliases[i] != NULL; i++)
 840                         free(he->h_aliases[i]);
 841                 free(he->h_aliases);
 842         }
 843         if (he != NULL && he->h_name != NULL)
 844                 free(he->h_name);
 845         if (he != NULL)
 846                 free(he);
 847         return (NULL);
 848 }