contrib/bind-9.5.2/lib/bind/irs/gethostent.c

   1 /*
   2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (c) 1996-1999 by 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
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 #if !defined(LINT) && !defined(CODECENTER)
  19 static const char rcsid[] = "$Id: gethostent.c,v 1.8 2006/01/10 05:06:00 marka Exp $";
  20 #endif
  21
  22 /* Imports */
  23
  24 #include "port_before.h"
  25
  26 #if !defined(__BIND_NOSTATIC)
  27
  28 #include <sys/types.h>
  29 #include <sys/param.h>
  30 #include <sys/socket.h>
  31 #include <sys/ioctl.h>
  32 #include <netinet/in.h>
  33 #include <net/if.h>
  34 #include <arpa/inet.h>
  35 #include <arpa/nameser.h>
  36
  37 #include <ctype.h>
  38 #include <errno.h>
  39 #include <stdlib.h>
  40 #include <netdb.h>
  41 #include <resolv.h>
  42 #include <stdio.h>
  43 #include <string.h>
  44 #include <unistd.h>
  45
  46 #include <irs.h>
  47 #include <isc/memcluster.h>
  48
  49 #include "port_after.h"
  50
  51 #include "irs_p.h"
  52 #include "irs_data.h"
  53
  54 /* Definitions */
  55
  56 struct pvt {
  57         char *          aliases[1];
  58         char *          addrs[2];
  59         char            addr[NS_IN6ADDRSZ];
  60         char            name[NS_MAXDNAME + 1];
  61         struct hostent  host;
  62 };
  63
  64 /* Forward */
  65
  66 static struct net_data *init(void);
  67 static void             freepvt(struct net_data *);
  68 static struct hostent  *fakeaddr(const char *, int, struct net_data *);
  69
  70
  71 /* Public */
  72
  73 struct hostent *
  74 gethostbyname(const char *name) {
  75         struct net_data *net_data = init();
  76
  77         return (gethostbyname_p(name, net_data));
  78 }
  79
  80 struct hostent *
  81 gethostbyname2(const char *name, int af) {
  82         struct net_data *net_data = init();
  83
  84         return (gethostbyname2_p(name, af, net_data));
  85 }
  86
  87 struct hostent *
  88 gethostbyaddr(const char *addr, int len, int af) {
  89         struct net_data *net_data = init();
  90
  91         return (gethostbyaddr_p(addr, len, af, net_data));
  92 }
  93
  94 struct hostent *
  95 gethostent() {
  96         struct net_data *net_data = init();
  97
  98         return (gethostent_p(net_data));
  99 }
 100
 101 void
 102 sethostent(int stayopen) {
 103         struct net_data *net_data = init();
 104         sethostent_p(stayopen, net_data);
 105 }
 106
 107
 108 void
 109 endhostent() {
 110         struct net_data *net_data = init();
 111         endhostent_p(net_data);
 112 }
 113
 114 /* Shared private. */
 115
 116 struct hostent *
 117 gethostbyname_p(const char *name, struct net_data *net_data) {
 118         struct hostent *hp;
 119
 120         if (!net_data)
 121                 return (NULL);
 122
 123         if (net_data->res->options & RES_USE_INET6) {
 124                 hp = gethostbyname2_p(name, AF_INET6, net_data);
 125                 if (hp)
 126                         return (hp);
 127         }
 128         return (gethostbyname2_p(name, AF_INET, net_data));
 129 }
 130
 131 struct hostent *
 132 gethostbyname2_p(const char *name, int af, struct net_data *net_data) {
 133         struct irs_ho *ho;
 134         char tmp[NS_MAXDNAME];
 135         struct hostent *hp;
 136         const char *cp;
 137         char **hap;
 138
 139         if (!net_data || !(ho = net_data->ho))
 140                 return (NULL);
 141         if (net_data->ho_stayopen && net_data->ho_last &&
 142             net_data->ho_last->h_addrtype == af) {
 143                 if (ns_samename(name, net_data->ho_last->h_name) == 1)
 144                         return (net_data->ho_last);
 145                 for (hap = net_data->ho_last->h_aliases; hap && *hap; hap++)
 146                         if (ns_samename(name, *hap) == 1)
 147                                 return (net_data->ho_last);
 148         }
 149         if (!strchr(name, '.') && (cp = res_hostalias(net_data->res, name,
 150                                                       tmp, sizeof tmp)))
 151                 name = cp;
 152         if ((hp = fakeaddr(name, af, net_data)) != NULL)
 153                 return (hp);
 154         net_data->ho_last = (*ho->byname2)(ho, name, af);
 155         if (!net_data->ho_stayopen)
 156                 endhostent();
 157         return (net_data->ho_last);
 158 }
 159
 160 struct hostent *
 161 gethostbyaddr_p(const char *addr, int len, int af, struct net_data *net_data) {
 162         struct irs_ho *ho;
 163         char **hap;
 164
 165         if (!net_data || !(ho = net_data->ho))
 166                 return (NULL);
 167         if (net_data->ho_stayopen && net_data->ho_last &&
 168             net_data->ho_last->h_length == len)
 169                 for (hap = net_data->ho_last->h_addr_list;
 170                      hap && *hap;
 171                      hap++)
 172                         if (!memcmp(addr, *hap, len))
 173                                 return (net_data->ho_last);
 174         net_data->ho_last = (*ho->byaddr)(ho, addr, len, af);
 175         if (!net_data->ho_stayopen)
 176                 endhostent();
 177         return (net_data->ho_last);
 178 }
 179
 180
 181 struct hostent *
 182 gethostent_p(struct net_data *net_data) {
 183         struct irs_ho *ho;
 184         struct hostent *hp;
 185
 186         if (!net_data || !(ho = net_data->ho))
 187                 return (NULL);
 188         while ((hp = (*ho->next)(ho)) != NULL &&
 189                hp->h_addrtype == AF_INET6 &&
 190                (net_data->res->options & RES_USE_INET6) == 0U)
 191                 continue;
 192         net_data->ho_last = hp;
 193         return (net_data->ho_last);
 194 }
 195
 196
 197 void
 198 sethostent_p(int stayopen, struct net_data *net_data) {
 199         struct irs_ho *ho;
 200
 201         if (!net_data || !(ho = net_data->ho))
 202                 return;
 203         freepvt(net_data);
 204         (*ho->rewind)(ho);
 205         net_data->ho_stayopen = (stayopen != 0);
 206         if (stayopen == 0)
 207                 net_data_minimize(net_data);
 208 }
 209
 210 void
 211 endhostent_p(struct net_data *net_data) {
 212         struct irs_ho *ho;
 213
 214         if ((net_data != NULL) && ((ho = net_data->ho) != NULL))
 215                 (*ho->minimize)(ho);
 216 }
 217
 218 #ifndef IN6_IS_ADDR_V4COMPAT
 219 static const unsigned char in6addr_compat[12] = {
 220         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 221 #define IN6_IS_ADDR_V4COMPAT(x) (!memcmp((x)->s6_addr, in6addr_compat, 12) && \
 222                                  ((x)->s6_addr[12] != 0 || \
 223                                   (x)->s6_addr[13] != 0 || \
 224                                   (x)->s6_addr[14] != 0 || \
 225                                    ((x)->s6_addr[15] != 0 && \
 226                                     (x)->s6_addr[15] != 1)))
 227 #endif
 228 #ifndef IN6_IS_ADDR_V4MAPPED
 229 #define IN6_IS_ADDR_V4MAPPED(x) (!memcmp((x)->s6_addr, in6addr_mapped, 12))
 230 #endif
 231
 232 static const unsigned char in6addr_mapped[12] = {
 233         0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0xff, 0xff };
 234
 235 static int scan_interfaces(int *, int *);
 236 static struct hostent *copyandmerge(struct hostent *, struct hostent *, int, int *);
 237
 238 /*%
 239  *      Public functions
 240  */
 241
 242 /*%
 243  *      AI_V4MAPPED + AF_INET6
 244  *      If no IPv6 address then a query for IPv4 and map returned values.
 245  *
 246  *      AI_ALL + AI_V4MAPPED + AF_INET6
 247  *      Return IPv6 and IPv4 mapped.
 248  *
 249  *      AI_ADDRCONFIG
 250  *      Only return IPv6 / IPv4 address if there is an interface of that
 251  *      type active.
 252  */
 253
 254 struct hostent *
 255 getipnodebyname(const char *name, int af, int flags, int *error_num) {
 256         int have_v4 = 1, have_v6 = 1;
 257         struct in_addr in4;
 258         struct in6_addr in6;
 259         struct hostent he, *he1 = NULL, *he2 = NULL, *he3;
 260         int v4 = 0, v6 = 0;
 261         struct net_data *net_data = init();
 262         u_long options;
 263         int tmp_err;
 264
 265         if (net_data == NULL) {
 266                 *error_num = NO_RECOVERY;
 267                 return (NULL);
 268         }
 269
 270         /* If we care about active interfaces then check. */
 271         if ((flags & AI_ADDRCONFIG) != 0)
 272                 if (scan_interfaces(&have_v4, &have_v6) == -1) {
 273                         *error_num = NO_RECOVERY;
 274                         return (NULL);
 275                 }
 276
 277         /* Check for literal address. */
 278         if ((v4 = inet_pton(AF_INET, name, &in4)) != 1)
 279                 v6 = inet_pton(AF_INET6, name, &in6);
 280
 281         /* Impossible combination? */
 282
 283         if ((af == AF_INET6 && (flags & AI_V4MAPPED) == 0 && v4 == 1) ||
 284             (af == AF_INET && v6 == 1) ||
 285             (have_v4 == 0 && v4 == 1) ||
 286             (have_v6 == 0 && v6 == 1) ||
 287             (have_v4 == 0 && af == AF_INET) ||
 288             (have_v6 == 0 && af == AF_INET6)) {
 289                 *error_num = HOST_NOT_FOUND;
 290                 return (NULL);
 291         }
 292
 293         /* Literal address? */
 294         if (v4 == 1 || v6 == 1) {
 295                 char *addr_list[2];
 296                 char *aliases[1];
 297
 298                 DE_CONST(name, he.h_name);
 299                 he.h_addr_list = addr_list;
 300                 he.h_addr_list[0] = (v4 == 1) ? (char *)&in4 : (char *)&in6;
 301                 he.h_addr_list[1] = NULL;
 302                 he.h_aliases = aliases;
 303                 he.h_aliases[0] = NULL;
 304                 he.h_length = (v4 == 1) ? INADDRSZ : IN6ADDRSZ;
 305                 he.h_addrtype = (v4 == 1) ? AF_INET : AF_INET6;
 306                 return (copyandmerge(&he, NULL, af, error_num));
 307         }
 308
 309         options = net_data->res->options;
 310         net_data->res->options &= ~RES_USE_INET6;
 311
 312         tmp_err = NO_RECOVERY;
 313         if (have_v6 && af == AF_INET6) {
 314                 he2 = gethostbyname2_p(name, AF_INET6, net_data);
 315                 if (he2 != NULL) {
 316                         he1 = copyandmerge(he2, NULL, af, error_num);
 317                         if (he1 == NULL)
 318                                 return (NULL);
 319                         he2 = NULL;
 320                 } else {
 321                         tmp_err = net_data->res->res_h_errno;
 322                 }
 323         }
 324
 325         if (have_v4 &&
 326             ((af == AF_INET) ||
 327              (af == AF_INET6 && (flags & AI_V4MAPPED) != 0 &&
 328               (he1 == NULL || (flags & AI_ALL) != 0)))) {
 329                 he2 = gethostbyname2_p(name, AF_INET, net_data);
 330                 if (he1 == NULL && he2 == NULL) {
 331                         *error_num = net_data->res->res_h_errno;
 332                         return (NULL);
 333                 }
 334         } else
 335                 *error_num = tmp_err;
 336
 337         net_data->res->options = options;
 338
 339         he3 = copyandmerge(he1, he2, af, error_num);
 340
 341         if (he1 != NULL)
 342                 freehostent(he1);
 343         return (he3);
 344 }
 345
 346 struct hostent *
 347 getipnodebyaddr(const void *src, size_t len, int af, int *error_num) {
 348         struct hostent *he1, *he2;
 349         struct net_data *net_data = init();
 350
 351         /* Sanity Checks. */
 352         if (src == NULL) {
 353                 *error_num = NO_RECOVERY;
 354                 return (NULL);
 355         }
 356
 357         switch (af) {
 358         case AF_INET:
 359                 if (len != (size_t)INADDRSZ) {
 360                         *error_num = NO_RECOVERY;
 361                         return (NULL);
 362                 }
 363                 break;
 364         case AF_INET6:
 365                 if (len != (size_t)IN6ADDRSZ) {
 366                         *error_num = NO_RECOVERY;
 367                         return (NULL);
 368                 }
 369                 break;
 370         default:
 371                 *error_num = NO_RECOVERY;
 372                 return (NULL);
 373         }
 374
 375         /*
 376          * Lookup IPv4 and IPv4 mapped/compatible addresses
 377          */
 378         if ((af == AF_INET6 &&
 379              IN6_IS_ADDR_V4COMPAT((const struct in6_addr *)src)) ||
 380             (af == AF_INET6 &&
 381              IN6_IS_ADDR_V4MAPPED((const struct in6_addr *)src)) ||
 382             (af == AF_INET)) {
 383                 const char *cp = src;
 384
 385                 if (af == AF_INET6)
 386                         cp += 12;
 387                 he1 = gethostbyaddr_p(cp, 4, AF_INET, net_data);
 388                 if (he1 == NULL) {
 389                         *error_num = net_data->res->res_h_errno;
 390                         return (NULL);
 391                 }
 392                 he2 = copyandmerge(he1, NULL, af, error_num);
 393                 if (he2 == NULL)
 394                         return (NULL);
 395                 /*
 396                  * Restore original address if mapped/compatible.
 397                  */
 398                 if (af == AF_INET6)
 399                         memcpy(he1->h_addr, src, len);
 400                 return (he2);
 401         }
 402
 403         /*
 404          * Lookup IPv6 address.
 405          */
 406         if (memcmp((const struct in6_addr *)src, &in6addr_any, 16) == 0) {
 407                 *error_num = HOST_NOT_FOUND;
 408                 return (NULL);
 409         }
 410
 411         he1 = gethostbyaddr_p(src, 16, AF_INET6, net_data);
 412         if (he1 == NULL) {
 413                 *error_num = net_data->res->res_h_errno;
 414                 return (NULL);
 415         }
 416         return (copyandmerge(he1, NULL, af, error_num));
 417 }
 418
 419 void
 420 freehostent(struct hostent *he) {
 421         char **cpp;
 422         int names = 1;
 423         int addresses = 1;
 424
 425         memput(he->h_name, strlen(he->h_name) + 1);
 426
 427         cpp = he->h_addr_list;
 428         while (*cpp != NULL) {
 429                 memput(*cpp, (he->h_addrtype == AF_INET) ?
 430                              INADDRSZ : IN6ADDRSZ);
 431                 *cpp = NULL;
 432                 cpp++;
 433                 addresses++;
 434         }
 435
 436         cpp = he->h_aliases;
 437         while (*cpp != NULL) {
 438                 memput(*cpp, strlen(*cpp) + 1);
 439                 cpp++;
 440                 names++;
 441         }
 442
 443         memput(he->h_aliases, sizeof(char *) * (names));
 444         memput(he->h_addr_list, sizeof(char *) * (addresses));
 445         memput(he, sizeof *he);
 446 }
 447
 448 /*%
 449  * Private
 450  */
 451
 452 /*%
 453  * Scan the interface table and set have_v4 and have_v6 depending
 454  * upon whether there are IPv4 and IPv6 interface addresses.
 455  *
 456  * Returns:
 457  *      0 on success
 458  *      -1 on failure.
 459  */
 460
 461 #if defined(SIOCGLIFCONF) && defined(SIOCGLIFADDR) && \
 462     !defined(IRIX_EMUL_IOCTL_SIOCGIFCONF)
 463
 464 #ifdef __hpux
 465 #define lifc_len iflc_len
 466 #define lifc_buf iflc_buf
 467 #define lifc_req iflc_req
 468 #define LIFCONF if_laddrconf
 469 #else
 470 #define SETFAMILYFLAGS
 471 #define LIFCONF lifconf
 472 #endif
 473
 474 #ifdef __hpux
 475 #define lifr_addr iflr_addr
 476 #define lifr_name iflr_name
 477 #define lifr_dstaddr iflr_dstaddr
 478 #define lifr_flags iflr_flags
 479 #define ss_family sa_family
 480 #define LIFREQ if_laddrreq
 481 #else
 482 #define LIFREQ lifreq
 483 #endif
 484
 485 static void
 486 scan_interfaces6(int *have_v4, int *have_v6) {
 487         struct LIFCONF lifc;
 488         struct LIFREQ lifreq;
 489         struct in_addr in4;
 490         struct in6_addr in6;
 491         char *buf = NULL, *cp, *cplim;
 492         static unsigned int bufsiz = 4095;
 493         int s, cpsize, n;
 494
 495         /* Get interface list from system. */
 496         if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) == -1)
 497                 goto cleanup;
 498
 499         /*
 500          * Grow buffer until large enough to contain all interface
 501          * descriptions.
 502          */
 503         for (;;) {
 504                 buf = memget(bufsiz);
 505                 if (buf == NULL)
 506                         goto cleanup;
 507 #ifdef SETFAMILYFLAGS
 508                 lifc.lifc_family = AF_UNSPEC;   /*%< request all families */
 509                 lifc.lifc_flags = 0;
 510 #endif
 511                 lifc.lifc_len = bufsiz;
 512                 lifc.lifc_buf = buf;
 513                 if ((n = ioctl(s, SIOCGLIFCONF, (char *)&lifc)) != -1) {
 514                         /*
 515                          * Some OS's just return what will fit rather
 516                          * than set EINVAL if the buffer is too small
 517                          * to fit all the interfaces in.  If
 518                          * lifc.lifc_len is too near to the end of the
 519                          * buffer we will grow it just in case and
 520                          * retry.
 521                          */
 522                         if (lifc.lifc_len + 2 * sizeof(lifreq) < bufsiz)
 523                                 break;
 524                 }
 525                 if ((n == -1) && errno != EINVAL)
 526                         goto cleanup;
 527
 528                 if (bufsiz > 1000000)
 529                         goto cleanup;
 530
 531                 memput(buf, bufsiz);
 532                 bufsiz += 4096;
 533         }
 534
 535         /* Parse system's interface list. */
 536         cplim = buf + lifc.lifc_len;    /*%< skip over if's with big ifr_addr's */
 537         for (cp = buf;
 538              (*have_v4 == 0 || *have_v6 == 0) && cp < cplim;
 539              cp += cpsize) {
 540                 memcpy(&lifreq, cp, sizeof lifreq);
 541 #ifdef HAVE_SA_LEN
 542 #ifdef FIX_ZERO_SA_LEN
 543                 if (lifreq.lifr_addr.sa_len == 0)
 544                         lifreq.lifr_addr.sa_len = 16;
 545 #endif
 546 #ifdef HAVE_MINIMUM_IFREQ
 547                 cpsize = sizeof lifreq;
 548                 if (lifreq.lifr_addr.sa_len > sizeof (struct sockaddr))
 549                         cpsize += (int)lifreq.lifr_addr.sa_len -
 550                                 (int)(sizeof (struct sockaddr));
 551 #else
 552                 cpsize = sizeof lifreq.lifr_name + lifreq.lifr_addr.sa_len;
 553 #endif /* HAVE_MINIMUM_IFREQ */
 554 #elif defined SIOCGIFCONF_ADDR
 555                 cpsize = sizeof lifreq;
 556 #else
 557                 cpsize = sizeof lifreq.lifr_name;
 558                 /* XXX maybe this should be a hard error? */
 559                 if (ioctl(s, SIOCGLIFADDR, (char *)&lifreq) < 0)
 560                         continue;
 561 #endif
 562                 switch (lifreq.lifr_addr.ss_family) {
 563                 case AF_INET:
 564                         if (*have_v4 == 0) {
 565                                 memcpy(&in4,
 566                                        &((struct sockaddr_in *)
 567                                        &lifreq.lifr_addr)->sin_addr,
 568                                        sizeof in4);
 569                                 if (in4.s_addr == INADDR_ANY)
 570                                         break;
 571                                 n = ioctl(s, SIOCGLIFFLAGS, (char *)&lifreq);
 572                                 if (n < 0)
 573                                         break;
 574                                 if ((lifreq.lifr_flags & IFF_UP) == 0)
 575                                         break;
 576                                 *have_v4 = 1;
 577                         }
 578                         break;
 579                 case AF_INET6:
 580                         if (*have_v6 == 0) {
 581                                 memcpy(&in6,
 582                                        &((struct sockaddr_in6 *)
 583                                        &lifreq.lifr_addr)->sin6_addr, sizeof in6);
 584                                 if (memcmp(&in6, &in6addr_any, sizeof in6) == 0)
 585                                         break;
 586                                 n = ioctl(s, SIOCGLIFFLAGS, (char *)&lifreq);
 587                                 if (n < 0)
 588                                         break;
 589                                 if ((lifreq.lifr_flags & IFF_UP) == 0)
 590                                         break;
 591                                 *have_v6 = 1;
 592                         }
 593                         break;
 594                 }
 595         }
 596         if (buf != NULL)
 597                 memput(buf, bufsiz);
 598         close(s);
 599         /* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
 600         return;
 601  cleanup:
 602         if (buf != NULL)
 603                 memput(buf, bufsiz);
 604         if (s != -1)
 605                 close(s);
 606         /* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
 607         return;
 608 }
 609 #endif
 610
 611 #if ( defined(__linux__) || defined(__linux) || defined(LINUX) )
 612 #ifndef IF_NAMESIZE
 613 # ifdef IFNAMSIZ
 614 #  define IF_NAMESIZE  IFNAMSIZ
 615 # else
 616 #  define IF_NAMESIZE 16
 617 # endif
 618 #endif
 619 static void
 620 scan_linux6(int *have_v6) {
 621         FILE *proc = NULL;
 622         char address[33];
 623         char name[IF_NAMESIZE+1];
 624         int ifindex, prefix, flag3, flag4;
 625
 626         proc = fopen("/proc/net/if_inet6", "r");
 627         if (proc == NULL)
 628                 return;
 629
 630         if (fscanf(proc, "%32[a-f0-9] %x %x %x %x %16s\n",
 631                    address, &ifindex, &prefix, &flag3, &flag4, name) == 6)
 632                 *have_v6 = 1;
 633         fclose(proc);
 634         return;
 635 }
 636 #endif
 637
 638 static int
 639 scan_interfaces(int *have_v4, int *have_v6) {
 640         struct ifconf ifc;
 641         union {
 642                 char _pad[256];         /*%< leave space for IPv6 addresses */
 643                 struct ifreq ifreq;
 644         } u;
 645         struct in_addr in4;
 646         struct in6_addr in6;
 647         char *buf = NULL, *cp, *cplim;
 648         static unsigned int bufsiz = 4095;
 649         int s, n;
 650         size_t cpsize;
 651
 652         /* Set to zero.  Used as loop terminators below. */
 653         *have_v4 = *have_v6 = 0;
 654
 655 #if defined(SIOCGLIFCONF) && defined(SIOCGLIFADDR) && \
 656     !defined(IRIX_EMUL_IOCTL_SIOCGIFCONF)
 657         /*
 658          * Try to scan the interfaces using IPv6 ioctls().
 659          */
 660         scan_interfaces6(have_v4, have_v6);
 661         if (*have_v4 != 0 && *have_v6 != 0)
 662                 return (0);
 663 #endif
 664 #ifdef __linux
 665         scan_linux6(have_v6);
 666 #endif
 667
 668         /* Get interface list from system. */
 669         if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
 670                 goto err_ret;
 671
 672         /*
 673          * Grow buffer until large enough to contain all interface
 674          * descriptions.
 675          */
 676         for (;;) {
 677                 buf = memget(bufsiz);
 678                 if (buf == NULL)
 679                         goto err_ret;
 680                 ifc.ifc_len = bufsiz;
 681                 ifc.ifc_buf = buf;
 682 #ifdef IRIX_EMUL_IOCTL_SIOCGIFCONF
 683                 /*
 684                  * This is a fix for IRIX OS in which the call to ioctl with
 685                  * the flag SIOCGIFCONF may not return an entry for all the
 686                  * interfaces like most flavors of Unix.
 687                  */
 688                 if (emul_ioctl(&ifc) >= 0)
 689                         break;
 690 #else
 691                 if ((n = ioctl(s, SIOCGIFCONF, (char *)&ifc)) != -1) {
 692                         /*
 693                          * Some OS's just return what will fit rather
 694                          * than set EINVAL if the buffer is too small
 695                          * to fit all the interfaces in.  If
 696                          * ifc.ifc_len is too near to the end of the
 697                          * buffer we will grow it just in case and
 698                          * retry.
 699                          */
 700                         if (ifc.ifc_len + 2 * sizeof(u.ifreq) < bufsiz)
 701                                 break;
 702                 }
 703 #endif
 704                 if ((n == -1) && errno != EINVAL)
 705                         goto err_ret;
 706
 707                 if (bufsiz > 1000000)
 708                         goto err_ret;
 709
 710                 memput(buf, bufsiz);
 711                 bufsiz += 4096;
 712         }
 713
 714         /* Parse system's interface list. */
 715         cplim = buf + ifc.ifc_len;    /*%< skip over if's with big ifr_addr's */
 716         for (cp = buf;
 717              (*have_v4 == 0 || *have_v6 == 0) && cp < cplim;
 718              cp += cpsize) {
 719                 memcpy(&u.ifreq, cp, sizeof u.ifreq);
 720 #ifdef HAVE_SA_LEN
 721 #ifdef FIX_ZERO_SA_LEN
 722                 if (u.ifreq.ifr_addr.sa_len == 0)
 723                         u.ifreq.ifr_addr.sa_len = 16;
 724 #endif
 725 #ifdef HAVE_MINIMUM_IFREQ
 726                 cpsize = sizeof u.ifreq;
 727                 if (u.ifreq.ifr_addr.sa_len > sizeof (struct sockaddr))
 728                         cpsize += (int)u.ifreq.ifr_addr.sa_len -
 729                                 (int)(sizeof (struct sockaddr));
 730 #else
 731                 cpsize = sizeof u.ifreq.ifr_name + u.ifreq.ifr_addr.sa_len;
 732 #endif /* HAVE_MINIMUM_IFREQ */
 733                 if (cpsize > sizeof u.ifreq && cpsize <= sizeof u)
 734                         memcpy(&u.ifreq, cp, cpsize);
 735 #elif defined SIOCGIFCONF_ADDR
 736                 cpsize = sizeof u.ifreq;
 737 #else
 738                 cpsize = sizeof u.ifreq.ifr_name;
 739                 /* XXX maybe this should be a hard error? */
 740                 if (ioctl(s, SIOCGIFADDR, (char *)&u.ifreq) < 0)
 741                         continue;
 742 #endif
 743                 switch (u.ifreq.ifr_addr.sa_family) {
 744                 case AF_INET:
 745                         if (*have_v4 == 0) {
 746                                 memcpy(&in4,
 747                                        &((struct sockaddr_in *)
 748                                        &u.ifreq.ifr_addr)->sin_addr,
 749                                        sizeof in4);
 750                                 if (in4.s_addr == INADDR_ANY)
 751                                         break;
 752                                 n = ioctl(s, SIOCGIFFLAGS, (char *)&u.ifreq);
 753                                 if (n < 0)
 754                                         break;
 755                                 if ((u.ifreq.ifr_flags & IFF_UP) == 0)
 756                                         break;
 757                                 *have_v4 = 1;
 758                         }
 759                         break;
 760                 case AF_INET6:
 761                         if (*have_v6 == 0) {
 762                                 memcpy(&in6,
 763                                        &((struct sockaddr_in6 *)
 764                                        &u.ifreq.ifr_addr)->sin6_addr,
 765                                        sizeof in6);
 766                                 if (memcmp(&in6, &in6addr_any, sizeof in6) == 0)
 767                                         break;
 768                                 n = ioctl(s, SIOCGIFFLAGS, (char *)&u.ifreq);
 769                                 if (n < 0)
 770                                         break;
 771                                 if ((u.ifreq.ifr_flags & IFF_UP) == 0)
 772                                         break;
 773                                 *have_v6 = 1;
 774                         }
 775                         break;
 776                 }
 777         }
 778         if (buf != NULL)
 779                 memput(buf, bufsiz);
 780         close(s);
 781         /* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
 782         return (0);
 783  err_ret:
 784         if (buf != NULL)
 785                 memput(buf, bufsiz);
 786         if (s != -1)
 787                 close(s);
 788         /* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
 789         return (-1);
 790 }
 791
 792 static struct hostent *
 793 copyandmerge(struct hostent *he1, struct hostent *he2, int af, int *error_num) {
 794         struct hostent *he = NULL;
 795         int addresses = 1;      /*%< NULL terminator */
 796         int names = 1;          /*%< NULL terminator */
 797         int len = 0;
 798         char **cpp, **npp;
 799
 800         /*
 801          * Work out array sizes;
 802          */
 803         if (he1 != NULL) {
 804                 cpp = he1->h_addr_list;
 805                 while (*cpp != NULL) {
 806                         addresses++;
 807                         cpp++;
 808                 }
 809                 cpp = he1->h_aliases;
 810                 while (*cpp != NULL) {
 811                         names++;
 812                         cpp++;
 813                 }
 814         }
 815
 816         if (he2 != NULL) {
 817                 cpp = he2->h_addr_list;
 818                 while (*cpp != NULL) {
 819                         addresses++;
 820                         cpp++;
 821                 }
 822                 if (he1 == NULL) {
 823                         cpp = he2->h_aliases;
 824                         while (*cpp != NULL) {
 825                                 names++;
 826                                 cpp++;
 827                         }
 828                 }
 829         }
 830
 831         if (addresses == 1) {
 832                 *error_num = NO_ADDRESS;
 833                 return (NULL);
 834         }
 835
 836         he = memget(sizeof *he);
 837         if (he == NULL)
 838                 goto no_recovery;
 839
 840         he->h_addr_list = memget(sizeof(char *) * (addresses));
 841         if (he->h_addr_list == NULL)
 842                 goto cleanup0;
 843         memset(he->h_addr_list, 0, sizeof(char *) * (addresses));
 844
 845         /* copy addresses */
 846         npp = he->h_addr_list;
 847         if (he1 != NULL) {
 848                 cpp = he1->h_addr_list;
 849                 while (*cpp != NULL) {
 850                         *npp = memget((af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
 851                         if (*npp == NULL)
 852                                 goto cleanup1;
 853                         /* convert to mapped if required */
 854                         if (af == AF_INET6 && he1->h_addrtype == AF_INET) {
 855                                 memcpy(*npp, in6addr_mapped,
 856                                        sizeof in6addr_mapped);
 857                                 memcpy(*npp + sizeof in6addr_mapped, *cpp,
 858                                        INADDRSZ);
 859                         } else {
 860                                 memcpy(*npp, *cpp,
 861                                        (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
 862                         }
 863                         cpp++;
 864                         npp++;
 865                 }
 866         }
 867
 868         if (he2 != NULL) {
 869                 cpp = he2->h_addr_list;
 870                 while (*cpp != NULL) {
 871                         *npp = memget((af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
 872                         if (*npp == NULL)
 873                                 goto cleanup1;
 874                         /* convert to mapped if required */
 875                         if (af == AF_INET6 && he2->h_addrtype == AF_INET) {
 876                                 memcpy(*npp, in6addr_mapped,
 877                                        sizeof in6addr_mapped);
 878                                 memcpy(*npp + sizeof in6addr_mapped, *cpp,
 879                                        INADDRSZ);
 880                         } else {
 881                                 memcpy(*npp, *cpp,
 882                                        (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
 883                         }
 884                         cpp++;
 885                         npp++;
 886                 }
 887         }
 888
 889         he->h_aliases = memget(sizeof(char *) * (names));
 890         if (he->h_aliases == NULL)
 891                 goto cleanup1;
 892         memset(he->h_aliases, 0, sizeof(char *) * (names));
 893
 894         /* copy aliases */
 895         npp = he->h_aliases;
 896         cpp = (he1 != NULL) ? he1->h_aliases : he2->h_aliases;
 897         while (*cpp != NULL) {
 898                 len = strlen (*cpp) + 1;
 899                 *npp = memget(len);
 900                 if (*npp == NULL)
 901                         goto cleanup2;
 902                 strcpy(*npp, *cpp);
 903                 npp++;
 904                 cpp++;
 905         }
 906
 907         /* copy hostname */
 908         he->h_name = memget(strlen((he1 != NULL) ?
 909                             he1->h_name : he2->h_name) + 1);
 910         if (he->h_name == NULL)
 911                 goto cleanup2;
 912         strcpy(he->h_name, (he1 != NULL) ? he1->h_name : he2->h_name);
 913
 914         /* set address type and length */
 915         he->h_addrtype = af;
 916         he->h_length = (af == AF_INET) ? INADDRSZ : IN6ADDRSZ;
 917         return(he);
 918
 919  cleanup2:
 920         cpp = he->h_aliases;
 921         while (*cpp != NULL) {
 922                 memput(*cpp, strlen(*cpp) + 1);
 923                 cpp++;
 924         }
 925         memput(he->h_aliases, sizeof(char *) * (names));
 926
 927  cleanup1:
 928         cpp = he->h_addr_list;
 929         while (*cpp != NULL) {
 930                 memput(*cpp, (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
 931                 *cpp = NULL;
 932                 cpp++;
 933         }
 934         memput(he->h_addr_list, sizeof(char *) * (addresses));
 935
 936  cleanup0:
 937         memput(he, sizeof *he);
 938
 939  no_recovery:
 940         *error_num = NO_RECOVERY;
 941         return (NULL);
 942 }
 943
 944 static struct net_data *
 945 init() {
 946         struct net_data *net_data;
 947
 948         if (!(net_data = net_data_init(NULL)))
 949                 goto error;
 950         if (!net_data->ho) {
 951                 net_data->ho = (*net_data->irs->ho_map)(net_data->irs);
 952                 if (!net_data->ho || !net_data->res) {
 953   error:
 954                         errno = EIO;
 955                         if (net_data && net_data->res)
 956                                 RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
 957                         return (NULL);
 958                 }
 959
 960                 (*net_data->ho->res_set)(net_data->ho, net_data->res, NULL);
 961         }
 962
 963         return (net_data);
 964 }
 965
 966 static void
 967 freepvt(struct net_data *net_data) {
 968         if (net_data->ho_data) {
 969                 free(net_data->ho_data);
 970                 net_data->ho_data = NULL;
 971         }
 972 }
 973
 974 static struct hostent *
 975 fakeaddr(const char *name, int af, struct net_data *net_data) {
 976         struct pvt *pvt;
 977
 978         freepvt(net_data);
 979         net_data->ho_data = malloc(sizeof (struct pvt));
 980         if (!net_data->ho_data) {
 981                 errno = ENOMEM;
 982                 RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
 983                 return (NULL);
 984         }
 985         pvt = net_data->ho_data;
 986 #ifndef __bsdi__
 987         /*
 988          * Unlike its forebear(inet_aton), our friendly inet_pton() is strict
 989          * in its interpretation of its input, and it will only return "1" if
 990          * the input string is a formally valid(and thus unambiguous with
 991          * respect to host names) internet address specification for this AF.
 992          *
 993          * This means "telnet 0xdeadbeef" and "telnet 127.1" are dead now.
 994          */
 995         if (inet_pton(af, name, pvt->addr) != 1) {
 996 #else
 997         /* BSDI XXX
 998          * We put this back to inet_aton -- we really want the old behavior
 999          * Long live 127.1...
1000          */
1001         if ((af != AF_INET ||
1002             inet_aton(name, (struct in_addr *)pvt->addr) != 1) &&
1003             inet_pton(af, name, pvt->addr) != 1) {
1004 #endif
1005                 RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
1006                 return (NULL);
1007         }
1008         strncpy(pvt->name, name, NS_MAXDNAME);
1009         pvt->name[NS_MAXDNAME] = '\0';
1010         if (af == AF_INET && (net_data->res->options & RES_USE_INET6) != 0U) {
1011                 map_v4v6_address(pvt->addr, pvt->addr);
1012                 af = AF_INET6;
1013         }
1014         pvt->host.h_addrtype = af;
1015         switch(af) {
1016         case AF_INET:
1017                 pvt->host.h_length = NS_INADDRSZ;
1018                 break;
1019         case AF_INET6:
1020                 pvt->host.h_length = NS_IN6ADDRSZ;
1021                 break;
1022         default:
1023                 errno = EAFNOSUPPORT;
1024                 RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
1025                 return (NULL);
1026         }
1027         pvt->host.h_name = pvt->name;
1028         pvt->host.h_aliases = pvt->aliases;
1029         pvt->aliases[0] = NULL;
1030         pvt->addrs[0] = (char *)pvt->addr;
1031         pvt->addrs[1] = NULL;
1032         pvt->host.h_addr_list = pvt->addrs;
1033         RES_SET_H_ERRNO(net_data->res, NETDB_SUCCESS);
1034         return (&pvt->host);
1035 }
1036
1037 #ifdef grot     /*%< for future use in gethostbyaddr(), for "SUNSECURITY" */
1038         struct hostent *rhp;
1039         char **haddr;
1040         u_long old_options;
1041         char hname2[MAXDNAME+1];
1042
1043         if (af == AF_INET) {
1044             /*
1045              * turn off search as the name should be absolute,
1046              * 'localhost' should be matched by defnames
1047              */
1048             strncpy(hname2, hp->h_name, MAXDNAME);
1049             hname2[MAXDNAME] = '\0';
1050             old_options = net_data->res->options;
1051             net_data->res->options &= ~RES_DNSRCH;
1052             net_data->res->options |= RES_DEFNAMES;
1053             if (!(rhp = gethostbyname(hname2))) {
1054                 net_data->res->options = old_options;
1055                 RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
1056                 return (NULL);
1057             }
1058             net_data->res->options = old_options;
1059             for (haddr = rhp->h_addr_list; *haddr; haddr++)
1060                 if (!memcmp(*haddr, addr, INADDRSZ))
1061                         break;
1062             if (!*haddr) {
1063                 RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
1064                 return (NULL);
1065             }
1066         }
1067 #endif /* grot */
1068 #endif /*__BIND_NOSTATIC*/
1069
1070 /*! \file */