gweb/gresolv.c

   1 /*
   2  *
   3  *  Resolver library with GLib integration
   4  *
   5  *  Copyright (C) 2009-2012  Intel Corporation. All rights reserved.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License version 2 as
   9  *  published by the Free Software Foundation.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <errno.h>
  27 #include <unistd.h>
  28 #include <stdarg.h>
  29 #include <string.h>
  30 #include <stdlib.h>
  31 #include <resolv.h>
  32 #include <sys/types.h>
  33 #include <sys/socket.h>
  34 #include <netdb.h>
  35 #include <arpa/inet.h>
  36 #include <arpa/nameser.h>
  37 #include <net/if.h>
  38
  39 #include "gresolv.h"
  40
  41 struct sort_result {
  42         int precedence;
  43         int src_scope;
  44         int dst_scope;
  45         int src_label;
  46         int dst_label;
  47         gboolean reachable;
  48         union {
  49                 struct sockaddr sa;
  50                 struct sockaddr_in sin;
  51                 struct sockaddr_in6 sin6;
  52         } src;
  53         union {
  54                 struct sockaddr sa;
  55                 struct sockaddr_in sin;
  56                 struct sockaddr_in6 sin6;
  57         } dst;
  58 };
  59
  60 struct resolv_query;
  61
  62 struct resolv_lookup {
  63         GResolv *resolv;
  64         guint id;
  65
  66         int nr_results;
  67         struct sort_result *results;
  68
  69         struct resolv_query *ipv4_query;
  70         struct resolv_query *ipv6_query;
  71
  72         guint ipv4_status;
  73         guint ipv6_status;
  74
  75         GResolvResultFunc result_func;
  76         gpointer result_data;
  77 };
  78
  79 struct resolv_query {
  80         GResolv *resolv;
  81
  82         guint timeout;
  83
  84         uint16_t msgid;
  85
  86         struct resolv_lookup *lookup;
  87 };
  88
  89 struct resolv_nameserver {
  90         GResolv *resolv;
  91
  92         char *address;
  93         uint16_t port;
  94         unsigned long flags;
  95
  96         GIOChannel *udp_channel;
  97         guint udp_watch;
  98 };
  99
 100 struct _GResolv {
 101         int ref_count;
 102
 103         int result_family;
 104
 105         guint next_lookup_id;
 106         GQueue *lookup_queue;
 107         GQueue *query_queue;
 108
 109         int index;
 110         GList *nameserver_list;
 111
 112         struct __res_state res;
 113
 114         GResolvDebugFunc debug_func;
 115         gpointer debug_data;
 116 };
 117
 118 static inline void debug(GResolv *resolv, const char *format, ...)
 119 {
 120         char str[256];
 121         va_list ap;
 122
 123         if (resolv->debug_func == NULL)
 124                 return;
 125
 126         va_start(ap, format);
 127
 128         if (vsnprintf(str, sizeof(str), format, ap) > 0)
 129                 resolv->debug_func(str, resolv->debug_data);
 130
 131         va_end(ap);
 132 }
 133
 134 static void destroy_query(struct resolv_query *query)
 135 {
 136         if (query->timeout > 0)
 137                 g_source_remove(query->timeout);
 138
 139         g_free(query);
 140 }
 141
 142 static void destroy_lookup(struct resolv_lookup *lookup)
 143 {
 144         if (lookup->ipv4_query != NULL) {
 145                 g_queue_remove(lookup->resolv->query_queue,
 146                                                 lookup->ipv4_query);
 147                 destroy_query(lookup->ipv4_query);
 148         }
 149
 150         if (lookup->ipv6_query != NULL) {
 151                 g_queue_remove(lookup->resolv->query_queue,
 152                                                 lookup->ipv6_query);
 153                 destroy_query(lookup->ipv6_query);
 154         }
 155
 156         g_free(lookup->results);
 157         g_free(lookup);
 158 }
 159
 160 static void find_srcaddr(struct sort_result *res)
 161 {
 162         socklen_t sl = sizeof(res->src);
 163         int fd;
 164
 165         fd = socket(res->dst.sa.sa_family, SOCK_DGRAM | SOCK_CLOEXEC,
 166                         IPPROTO_IP);
 167         if (fd < 0)
 168                 return;
 169
 170         if (connect(fd, &res->dst.sa, sizeof(res->dst)) < 0) {
 171                 close(fd);
 172                 return;
 173         }
 174
 175         if (getsockname(fd, &res->src.sa, &sl) < 0) {
 176                 close(fd);
 177                 return;
 178         }
 179
 180         res->reachable = TRUE;
 181         close(fd);
 182 }
 183
 184 struct gai_table
 185 {
 186         unsigned char addr[NS_IN6ADDRSZ];
 187         int mask;
 188         int value;
 189 };
 190
 191 static const struct gai_table gai_labels[] = {
 192         {
 193                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 194                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
 195                 .mask = 128,
 196                 .value = 0,
 197         }, {
 198                 .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 199                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 200                 .mask = 16,
 201                 .value = 2,
 202         }, {
 203                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 204                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 205                 .mask = 96,
 206                 .value = 3,
 207         }, {
 208                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 209                           0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 },
 210                 .mask = 96,
 211                 .value = 4,
 212         }, {
 213                 /* Variations from RFC 3484, matching glibc behaviour */
 214                 .addr = { 0xfe, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 215                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 216                 .mask = 10,
 217                 .value = 5,
 218         }, {
 219                 .addr = { 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 220                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 221                 .mask = 7,
 222                 .value = 6,
 223         }, {
 224                 .addr = { 0x20, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 225                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 226                 .mask = 32,
 227                 .value = 7,
 228         }, {
 229                 /* catch-all */
 230                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 231                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 232                 .mask = 0,
 233                 .value = 1,
 234         }
 235 };
 236
 237 static const struct gai_table gai_precedences[] = {
 238         {
 239                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 240                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
 241                 .mask = 128,
 242                 .value = 50,
 243         }, {
 244                 .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 245                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 246                 .mask = 16,
 247                 .value = 30,
 248         }, {
 249                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 250                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 251                 .mask = 96,
 252                 .value = 20,
 253         }, {
 254                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 255                           0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 },
 256                 .mask = 96,
 257                 .value = 10,
 258         }, {
 259                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 260                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 261                 .mask = 0,
 262                 .value = 40,
 263         }
 264 };
 265
 266 static unsigned char v4mapped[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 267                                     0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 };
 268
 269 static gboolean mask_compare(const unsigned char *one,
 270                                         const unsigned char *two, int mask)
 271 {
 272         if (mask > 8) {
 273                 if (memcmp(one, two, mask / 8))
 274                         return FALSE;
 275                 one += mask / 8;
 276                 two += mask / 8;
 277                 mask %= 8;
 278         }
 279
 280         if (mask && ((*one ^ *two) >> (8 - mask)))
 281                 return FALSE;
 282
 283         return TRUE;
 284 }
 285
 286 static int match_gai_table(struct sockaddr *sa, const struct gai_table *tbl)
 287 {
 288         struct sockaddr_in *sin = (void *)sa;
 289         struct sockaddr_in6 *sin6 = (void *)sa;
 290         void *addr;
 291
 292         if (sa->sa_family == AF_INET) {
 293                 addr = v4mapped;
 294                 memcpy(v4mapped+12, &sin->sin_addr, NS_INADDRSZ);
 295         } else
 296                 addr = &sin6->sin6_addr;
 297
 298         while (1) {
 299                 if (mask_compare(addr, tbl->addr, tbl->mask))
 300                         return tbl->value;
 301                 tbl++;
 302         }
 303 }
 304
 305 #define DQUAD(_a,_b,_c,_d) ( ((_a)<<24) | ((_b)<<16) | ((_c)<<8) | (_d) )
 306 #define V4MATCH(addr, a,b,c,d, m) ( ((addr) ^ DQUAD(a,b,c,d)) >> (32 - (m)) )
 307
 308 #define RFC3484_SCOPE_LINK      2
 309 #define RFC3484_SCOPE_SITE      5
 310 #define RFC3484_SCOPE_GLOBAL    14
 311
 312 static int addr_scope(struct sockaddr *sa)
 313 {
 314         if (sa->sa_family == AF_INET) {
 315                 struct sockaddr_in *sin = (void *)sa;
 316                 guint32 addr = ntohl(sin->sin_addr.s_addr);
 317
 318                 if (V4MATCH(addr, 169,254,0,0, 16) ||
 319                                         V4MATCH(addr, 127,0,0,0, 8))
 320                         return RFC3484_SCOPE_LINK;
 321
 322                 /* Site-local */
 323                 if (V4MATCH(addr, 10,0,0,0, 8) ||
 324                                 V4MATCH(addr, 172,16,0,0, 12) ||
 325                                 V4MATCH(addr, 192,168,0,0, 16))
 326                         return RFC3484_SCOPE_SITE;
 327
 328                 /* Global */
 329                 return RFC3484_SCOPE_GLOBAL;
 330         } else {
 331                 struct sockaddr_in6 *sin6 = (void *)sa;
 332
 333                 /* Multicast addresses have a 4-bit scope field */
 334                 if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
 335                         return sin6->sin6_addr.s6_addr[1] & 0xf;
 336
 337                 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) ||
 338                                 IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
 339                         return RFC3484_SCOPE_LINK;
 340
 341                 if (IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr))
 342                         return RFC3484_SCOPE_SITE;
 343
 344                 return RFC3484_SCOPE_GLOBAL;
 345         }
 346 }
 347
 348 static int rfc3484_compare(const void *__one, const void *__two)
 349 {
 350         const struct sort_result *one = __one;
 351         const struct sort_result *two = __two;
 352
 353         /* Rule 1: Avoid unusable destinations */
 354         if (one->reachable && !two->reachable)
 355                 return -1;
 356         else if (two->reachable && !one->reachable)
 357                 return 1;
 358
 359         /* Rule 2: Prefer matching scope */
 360         if (one->dst_scope == one->src_scope &&
 361                                 two->dst_scope != two->src_scope)
 362                 return -1;
 363         else if (two->dst_scope == two->src_scope &&
 364                                 one->dst_scope != one->src_scope)
 365                 return 1;
 366
 367         /* Rule 3: Avoid deprecated addresses */
 368
 369         /* Rule 4: Prefer home addresses */
 370
 371         /* Rule 5: Prefer matching label */
 372         if (one->dst_label == one->src_label &&
 373                                 two->dst_label != two->src_label)
 374                 return -1;
 375         else if (two->dst_label == two->src_label &&
 376                                 one->dst_label != one->src_label)
 377                 return 1;
 378
 379         /* Rule 6: Prefer higher precedence */
 380         if (one->precedence > two->precedence)
 381                 return -1;
 382         else if (two->precedence > one->precedence)
 383                 return 1;
 384
 385         /* Rule 7: Prefer native transport */
 386
 387         /* Rule 8: Prefer smaller scope */
 388         if (one->dst_scope != two->dst_scope)
 389                 return one->dst_scope - two->dst_scope;
 390
 391         /* Rule 9: Use longest matching prefix */
 392         if (one->dst.sa.sa_family == AF_INET) {
 393                 /*
 394                  * Rule 9 is meaningless and counterproductive for Legacy IP
 395                  * unless perhaps we can tell that it's actually on the local
 396                  * subnet. But we don't (yet) have local interface config
 397                  * information, so do nothing here for Legacy IP for now.
 398                  */
 399         } else {
 400                 int i;
 401
 402                 for (i = 0; i < 4; i++) {
 403                         guint32 cmp_one, cmp_two;
 404
 405                         cmp_one = one->src.sin6.sin6_addr.s6_addr32[i] ^
 406                                         one->dst.sin6.sin6_addr.s6_addr32[i];
 407                         cmp_two = two->src.sin6.sin6_addr.s6_addr32[i] ^
 408                                         two->dst.sin6.sin6_addr.s6_addr32[i];
 409
 410                         if (!cmp_two && !cmp_one)
 411                                 continue;
 412
 413                         if (cmp_one && !cmp_two)
 414                                 return 1;
 415                         if (cmp_two && !cmp_one)
 416                                 return -1;
 417
 418                         /* g_bit_storage() is effectively fls() */
 419                         cmp_one = g_bit_storage(ntohl(cmp_one));
 420                         cmp_two = g_bit_storage(ntohl(cmp_two));
 421
 422                         if (cmp_one == cmp_two)
 423                                 break;
 424
 425                         return cmp_one - cmp_two;
 426                 }
 427         }
 428
 429
 430         /* Rule 10: Otherwise, leave the order unchanged */
 431         if (one < two)
 432                 return -1;
 433         else
 434                 return 1;
 435 }
 436
 437 static void rfc3484_sort_results(struct resolv_lookup *lookup)
 438 {
 439         int i;
 440
 441         for (i = 0; i < lookup->nr_results; i++) {
 442                 struct sort_result *res = &lookup->results[i];
 443                 find_srcaddr(res);
 444                 res->precedence = match_gai_table(&res->dst.sa,
 445                                                         gai_precedences);
 446                 res->dst_label = match_gai_table(&res->dst.sa, gai_labels);
 447                 res->src_label = match_gai_table(&res->src.sa, gai_labels);
 448                 res->dst_scope = addr_scope(&res->dst.sa);
 449                 res->src_scope = addr_scope(&res->src.sa);
 450         }
 451
 452         qsort(lookup->results, lookup->nr_results,
 453                         sizeof(struct sort_result), rfc3484_compare);
 454 }
 455
 456 static void sort_and_return_results(struct resolv_lookup *lookup)
 457 {
 458         char buf[INET6_ADDRSTRLEN + 1];
 459         GResolvResultStatus status;
 460         char **results = g_try_new0(char *, lookup->nr_results + 1);
 461         int i, n = 0;
 462
 463         if (!results)
 464                 return;
 465
 466         memset(buf, 0, INET6_ADDRSTRLEN + 1);
 467
 468         rfc3484_sort_results(lookup);
 469
 470         for (i = 0; i < lookup->nr_results; i++) {
 471                 if (lookup->results[i].dst.sa.sa_family == AF_INET) {
 472                         if (inet_ntop(AF_INET,
 473                                         &lookup->results[i].dst.sin.sin_addr,
 474                                         buf, sizeof(buf) - 1) == NULL)
 475                                 continue;
 476                 } else if (lookup->results[i].dst.sa.sa_family == AF_INET6) {
 477                         if (inet_ntop(AF_INET6,
 478                                         &lookup->results[i].dst.sin6.sin6_addr,
 479                                         buf, sizeof(buf) - 1) == NULL)
 480                                 continue;
 481                 } else
 482                         continue;
 483
 484                 results[n++] = strdup(buf);
 485         }
 486
 487         results[n++] = NULL;
 488
 489         if (lookup->resolv->result_family == AF_INET)
 490                 status = lookup->ipv4_status;
 491         else if (lookup->resolv->result_family == AF_INET6)
 492                 status = lookup->ipv6_status;
 493         else {
 494                 if (lookup->ipv6_status == G_RESOLV_RESULT_STATUS_SUCCESS)
 495                         status = lookup->ipv6_status;
 496                 else
 497                         status = lookup->ipv4_status;
 498         }
 499
 500         g_queue_remove(lookup->resolv->lookup_queue, lookup);
 501
 502         lookup->result_func(status, results, lookup->result_data);
 503
 504         g_strfreev(results);
 505         destroy_lookup(lookup);
 506 }
 507
 508 static gboolean query_timeout(gpointer user_data)
 509 {
 510         struct resolv_query *query = user_data;
 511         struct resolv_lookup *lookup = query->lookup;
 512         GResolv *resolv = query->resolv;
 513
 514         query->timeout = 0;
 515
 516         if (query == lookup->ipv4_query) {
 517                 lookup->ipv4_status = G_RESOLV_RESULT_STATUS_NO_RESPONSE;
 518                 lookup->ipv4_query = NULL;
 519         } else if (query == lookup->ipv6_query) {
 520                 lookup->ipv6_status = G_RESOLV_RESULT_STATUS_NO_RESPONSE;
 521                 lookup->ipv6_query = NULL;
 522         }
 523
 524         g_queue_remove(resolv->query_queue, query);
 525
 526         if (lookup->ipv4_query == NULL && lookup->ipv6_query == NULL)
 527                 sort_and_return_results(lookup);
 528
 529         destroy_query(query);
 530
 531         return FALSE;
 532 }
 533
 534 static void free_nameserver(struct resolv_nameserver *nameserver)
 535 {
 536         if (nameserver == NULL)
 537                 return;
 538
 539         if (nameserver->udp_watch > 0)
 540                 g_source_remove(nameserver->udp_watch);
 541
 542         if (nameserver->udp_channel != NULL)
 543                 g_io_channel_unref(nameserver->udp_channel);
 544
 545         g_free(nameserver->address);
 546         g_free(nameserver);
 547 }
 548
 549 static void flush_nameservers(GResolv *resolv)
 550 {
 551         GList *list;
 552
 553         for (list = g_list_first(resolv->nameserver_list);
 554                                         list; list = g_list_next(list))
 555                 free_nameserver(list->data);
 556
 557         g_list_free(resolv->nameserver_list);
 558         resolv->nameserver_list = NULL;
 559 }
 560
 561 static int send_query(GResolv *resolv, const unsigned char *buf, int len)
 562 {
 563         GList *list;
 564
 565         if (resolv->nameserver_list == NULL)
 566                 return -ENOENT;
 567
 568         for (list = g_list_first(resolv->nameserver_list);
 569                                         list; list = g_list_next(list)) {
 570                 struct resolv_nameserver *nameserver = list->data;
 571                 int sk, sent;
 572
 573                 if (nameserver->udp_channel == NULL)
 574                         continue;
 575
 576                 sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
 577
 578                 sent = send(sk, buf, len, 0);
 579                 if (sent < 0)
 580                         continue;
 581         }
 582
 583         return 0;
 584 }
 585
 586 static gint compare_lookup_id(gconstpointer a, gconstpointer b)
 587 {
 588         const struct resolv_lookup *lookup = a;
 589         guint id = GPOINTER_TO_UINT(b);
 590
 591         if (lookup->id < id)
 592                 return -1;
 593
 594         if (lookup->id > id)
 595                 return 1;
 596
 597         return 0;
 598 }
 599
 600 static gint compare_query_msgid(gconstpointer a, gconstpointer b)
 601 {
 602         const struct resolv_query *query = a;
 603         uint16_t msgid = GPOINTER_TO_UINT(b);
 604
 605         if (query->msgid < msgid)
 606                 return -1;
 607
 608         if (query->msgid > msgid)
 609                 return 1;
 610
 611         return 0;
 612 }
 613
 614 static void add_result(struct resolv_lookup *lookup, int family,
 615                                                         const void *data)
 616 {
 617         int n = lookup->nr_results++;
 618         lookup->results = g_try_realloc(lookup->results,
 619                                         sizeof(struct sort_result) * (n + 1));
 620         if (lookup->results == NULL)
 621                 return;
 622
 623         memset(&lookup->results[n], 0, sizeof(struct sort_result));
 624
 625         lookup->results[n].dst.sa.sa_family = family;
 626         if (family == AF_INET)
 627                 memcpy(&lookup->results[n].dst.sin.sin_addr,
 628                                                 data, NS_INADDRSZ);
 629         else
 630                 memcpy(&lookup->results[n].dst.sin6.sin6_addr,
 631                                                 data, NS_IN6ADDRSZ);
 632 }
 633
 634 static void parse_response(struct resolv_nameserver *nameserver,
 635                                         const unsigned char *buf, int len)
 636 {
 637         GResolv *resolv = nameserver->resolv;
 638         GResolvResultStatus status;
 639         struct resolv_query *query;
 640         struct resolv_lookup *lookup;
 641         GList *list;
 642         ns_msg msg;
 643         ns_rr rr;
 644         int i, rcode, count;
 645
 646         debug(resolv, "response from %s", nameserver->address);
 647
 648         ns_initparse(buf, len, &msg);
 649
 650         rcode = ns_msg_getflag(msg, ns_f_rcode);
 651         count = ns_msg_count(msg, ns_s_an);
 652
 653         debug(resolv, "msg id: 0x%04x rcode: %d count: %d",
 654                                         ns_msg_id(msg), rcode, count);
 655
 656         switch (rcode) {
 657         case ns_r_noerror:
 658                 status = G_RESOLV_RESULT_STATUS_SUCCESS;
 659                 break;
 660         case ns_r_formerr:
 661                 status = G_RESOLV_RESULT_STATUS_FORMAT_ERROR;
 662                 break;
 663         case ns_r_servfail:
 664                 status = G_RESOLV_RESULT_STATUS_SERVER_FAILURE;
 665                 break;
 666         case ns_r_nxdomain:
 667                 status = G_RESOLV_RESULT_STATUS_NAME_ERROR;
 668                 break;
 669         case ns_r_notimpl:
 670                 status = G_RESOLV_RESULT_STATUS_NOT_IMPLEMENTED;
 671                 break;
 672         case ns_r_refused:
 673                 status = G_RESOLV_RESULT_STATUS_REFUSED;
 674                 break;
 675         default:
 676                 status = G_RESOLV_RESULT_STATUS_ERROR;
 677                 break;
 678         }
 679
 680         list = g_queue_find_custom(resolv->query_queue,
 681                         GUINT_TO_POINTER(ns_msg_id(msg)), compare_query_msgid);
 682         if (!list)
 683                 return;
 684
 685         query = list->data;
 686         lookup = query->lookup;
 687
 688         if (query == lookup->ipv6_query) {
 689                 lookup->ipv6_status = status;
 690                 lookup->ipv6_query = NULL;
 691         } else if (query == lookup->ipv4_query) {
 692                 lookup->ipv4_status = status;
 693                 lookup->ipv4_query = NULL;
 694         }
 695
 696         for (i = 0; i < count; i++) {
 697                 ns_parserr(&msg, ns_s_an, i, &rr);
 698
 699                 if (ns_rr_class(rr) != ns_c_in)
 700                         continue;
 701
 702                 g_assert(offsetof(struct sockaddr_in, sin_addr) ==
 703                                 offsetof(struct sockaddr_in6, sin6_flowinfo));
 704
 705                 if (ns_rr_type(rr) == ns_t_a &&
 706                                         ns_rr_rdlen(rr) == NS_INADDRSZ) {
 707                         add_result(lookup, AF_INET, ns_rr_rdata(rr));
 708                 } else if (ns_rr_type(rr) == ns_t_aaaa &&
 709                                         ns_rr_rdlen(rr) == NS_IN6ADDRSZ) {
 710                         add_result(lookup, AF_INET6, ns_rr_rdata(rr));
 711                 }
 712         }
 713
 714         g_queue_remove(resolv->query_queue, query);
 715
 716         if (lookup->ipv4_query == NULL && lookup->ipv6_query == NULL)
 717                 sort_and_return_results(lookup);
 718
 719         destroy_query(query);
 720 }
 721
 722 static gboolean received_udp_data(GIOChannel *channel, GIOCondition cond,
 723                                                         gpointer user_data)
 724 {
 725         struct resolv_nameserver *nameserver = user_data;
 726         unsigned char buf[4096];
 727         int sk, len;
 728
 729         if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
 730                 nameserver->udp_watch = 0;
 731                 return FALSE;
 732         }
 733
 734         sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
 735
 736         len = recv(sk, buf, sizeof(buf), 0);
 737         if (len < 12)
 738                 return TRUE;
 739
 740         parse_response(nameserver, buf, len);
 741
 742         return TRUE;
 743 }
 744
 745 static int connect_udp_channel(struct resolv_nameserver *nameserver)
 746 {
 747         struct addrinfo hints, *rp;
 748         char portnr[6];
 749         int err, sk;
 750
 751         memset(&hints, 0, sizeof(hints));
 752         hints.ai_family = AF_UNSPEC;
 753         hints.ai_socktype = SOCK_DGRAM;
 754         hints.ai_flags = AI_PASSIVE | AI_NUMERICSERV | AI_NUMERICHOST;
 755
 756         sprintf(portnr, "%d", nameserver->port);
 757         err = getaddrinfo(nameserver->address, portnr, &hints, &rp);
 758         if (err)
 759                 return -EINVAL;
 760
 761         /*
 762          * Do not blindly copy this code elsewhere; it doesn't loop over the
 763          * results using ->ai_next as it should. That's OK in *this* case
 764          * because it was a numeric lookup; we *know* there's only one.
 765          */
 766         if (!rp)
 767                 return -EINVAL;
 768
 769         sk = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
 770         if (sk < 0) {
 771                 freeaddrinfo(rp);
 772                 return -EIO;
 773         }
 774
 775         /*
 776          * If nameserver points to localhost ip, their is no need to
 777          * bind the socket on any interface.
 778          */
 779         if (nameserver->resolv->index > 0 &&
 780                         strncmp(nameserver->address, "127.0.0.1", 9) != 0) {
 781                 char interface[IF_NAMESIZE];
 782
 783                 memset(interface, 0, IF_NAMESIZE);
 784                 if (if_indextoname(nameserver->resolv->index,
 785                                                 interface) != NULL) {
 786                         if (setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE,
 787                                                 interface, IF_NAMESIZE) < 0) {
 788                                 close(sk);
 789                                 freeaddrinfo(rp);
 790                                 return -EIO;
 791                         }
 792                 }
 793         }
 794
 795         if (connect(sk, rp->ai_addr, rp->ai_addrlen) < 0) {
 796                 close(sk);
 797                 freeaddrinfo(rp);
 798                 return -EIO;
 799         }
 800
 801         freeaddrinfo(rp);
 802
 803         nameserver->udp_channel = g_io_channel_unix_new(sk);
 804         if (nameserver->udp_channel == NULL) {
 805                 close(sk);
 806                 return -ENOMEM;
 807         }
 808
 809         g_io_channel_set_close_on_unref(nameserver->udp_channel, TRUE);
 810
 811         nameserver->udp_watch = g_io_add_watch(nameserver->udp_channel,
 812                                 G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP,
 813                                 received_udp_data, nameserver);
 814
 815         return 0;
 816 }
 817
 818 GResolv *g_resolv_new(int index)
 819 {
 820         GResolv *resolv;
 821
 822         if (index < 0)
 823                 return NULL;
 824
 825         resolv = g_try_new0(GResolv, 1);
 826         if (resolv == NULL)
 827                 return NULL;
 828
 829         resolv->ref_count = 1;
 830
 831         resolv->result_family = AF_UNSPEC;
 832
 833         resolv->next_lookup_id = 1;
 834
 835         resolv->query_queue = g_queue_new();
 836         if (resolv->query_queue == NULL) {
 837                 g_free(resolv);
 838                 return NULL;
 839         }
 840
 841         resolv->lookup_queue = g_queue_new();
 842         if (resolv->lookup_queue == NULL) {
 843                 g_queue_free(resolv->query_queue);
 844                 g_free(resolv);
 845                 return NULL;
 846         }
 847
 848         resolv->index = index;
 849         resolv->nameserver_list = NULL;
 850
 851         res_ninit(&resolv->res);
 852
 853         return resolv;
 854 }
 855
 856 GResolv *g_resolv_ref(GResolv *resolv)
 857 {
 858         if (resolv == NULL)
 859                 return NULL;
 860
 861         __sync_fetch_and_add(&resolv->ref_count, 1);
 862
 863         return resolv;
 864 }
 865
 866 void g_resolv_unref(GResolv *resolv)
 867 {
 868         struct resolv_query *query;
 869
 870         if (resolv == NULL)
 871                 return;
 872
 873         if (__sync_fetch_and_sub(&resolv->ref_count, 1) != 1)
 874                 return;
 875
 876         while ((query = g_queue_pop_head(resolv->query_queue)))
 877                 destroy_query(query);
 878
 879         g_queue_free(resolv->query_queue);
 880         g_queue_free(resolv->lookup_queue);
 881
 882         flush_nameservers(resolv);
 883
 884         res_nclose(&resolv->res);
 885
 886         g_free(resolv);
 887 }
 888
 889 void g_resolv_set_debug(GResolv *resolv, GResolvDebugFunc func,
 890                                                 gpointer user_data)
 891 {
 892         if (resolv == NULL)
 893                 return;
 894
 895         resolv->debug_func = func;
 896         resolv->debug_data = user_data;
 897 }
 898
 899 gboolean g_resolv_add_nameserver(GResolv *resolv, const char *address,
 900                                         uint16_t port, unsigned long flags)
 901 {
 902         struct resolv_nameserver *nameserver;
 903
 904         if (resolv == NULL)
 905                 return FALSE;
 906
 907         nameserver = g_try_new0(struct resolv_nameserver, 1);
 908         if (nameserver == NULL)
 909                 return FALSE;
 910
 911         nameserver->address = g_strdup(address);
 912         nameserver->port = port;
 913         nameserver->flags = flags;
 914         nameserver->resolv = resolv;
 915
 916         if (connect_udp_channel(nameserver) < 0) {
 917                 free_nameserver(nameserver);
 918                 return FALSE;
 919         }
 920
 921         resolv->nameserver_list = g_list_append(resolv->nameserver_list,
 922                                                                 nameserver);
 923
 924         debug(resolv, "setting nameserver %s", address);
 925
 926         return TRUE;
 927 }
 928
 929 void g_resolv_flush_nameservers(GResolv *resolv)
 930 {
 931         if (resolv == NULL)
 932                 return;
 933
 934         flush_nameservers(resolv);
 935 }
 936
 937 static gint add_query(struct resolv_lookup *lookup, const char *hostname, int type)
 938 {
 939         struct resolv_query *query = g_try_new0(struct resolv_query, 1);
 940         unsigned char buf[4096];
 941         int len;
 942
 943         if (query == NULL)
 944                 return -ENOMEM;
 945
 946         len = res_mkquery(ns_o_query, hostname, ns_c_in, type,
 947                                         NULL, 0, NULL, buf, sizeof(buf));
 948
 949         query->msgid = buf[0] << 8 | buf[1];
 950
 951         if (send_query(lookup->resolv, buf, len) < 0) {
 952                 g_free(query);
 953                 return -EIO;
 954         }
 955
 956         query->resolv = lookup->resolv;
 957         query->lookup = lookup;
 958
 959         g_queue_push_tail(lookup->resolv->query_queue, query);
 960
 961         query->timeout = g_timeout_add_seconds(5, query_timeout, query);
 962
 963         if (type == ns_t_aaaa)
 964                 lookup->ipv6_query = query;
 965         else
 966                 lookup->ipv4_query = query;
 967
 968         return 0;
 969 }
 970
 971 guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
 972                                 GResolvResultFunc func, gpointer user_data)
 973 {
 974         struct resolv_lookup *lookup;
 975
 976         debug(resolv, "lookup hostname %s", hostname);
 977
 978         if (resolv == NULL)
 979                 return 0;
 980
 981         if (resolv->nameserver_list == NULL) {
 982                 int i;
 983
 984                 for (i = 0; i < resolv->res.nscount; i++) {
 985                         char buf[100];
 986                         int family = resolv->res.nsaddr_list[i].sin_family;
 987                         void *sa_addr = &resolv->res.nsaddr_list[i].sin_addr;
 988
 989                         if (family != AF_INET &&
 990                                         resolv->res._u._ext.nsaddrs[i]) {
 991                                 family = AF_INET6;
 992                                 sa_addr = &resolv->res._u._ext.nsaddrs[i]->sin6_addr;
 993                         }
 994
 995                         if (family != AF_INET && family != AF_INET6)
 996                                 continue;
 997
 998                         if (inet_ntop(family, sa_addr, buf, sizeof(buf)))
 999                                 g_resolv_add_nameserver(resolv, buf, 53, 0);
1000                 }
1001
1002                 if (resolv->nameserver_list == NULL)
1003                         g_resolv_add_nameserver(resolv, "127.0.0.1", 53, 0);
1004         }
1005
1006         lookup = g_try_new0(struct resolv_lookup, 1);
1007         if (lookup == NULL)
1008                 return 0;
1009
1010         lookup->resolv = resolv;
1011         lookup->result_func = func;
1012         lookup->result_data = user_data;
1013         lookup->id = resolv->next_lookup_id++;
1014
1015         if (resolv->result_family != AF_INET6) {
1016                 if (add_query(lookup, hostname, ns_t_a)) {
1017                         g_free(lookup);
1018                         return -EIO;
1019                 }
1020         }
1021
1022         if (resolv->result_family != AF_INET) {
1023                 if (add_query(lookup, hostname, ns_t_aaaa)) {
1024                         if (resolv->result_family != AF_INET6) {
1025                                 destroy_query(lookup->ipv4_query);
1026                                 g_queue_remove(resolv->query_queue,
1027                                                 lookup->ipv4_query);
1028                         }
1029
1030                         g_free(lookup);
1031                         return -EIO;
1032                 }
1033         }
1034
1035         g_queue_push_tail(resolv->lookup_queue, lookup);
1036         return lookup->id;
1037 }
1038
1039 gboolean g_resolv_cancel_lookup(GResolv *resolv, guint id)
1040 {
1041         GList *list;
1042
1043         list = g_queue_find_custom(resolv->lookup_queue,
1044                                 GUINT_TO_POINTER(id), compare_lookup_id);
1045
1046         if (list == NULL)
1047                 return FALSE;
1048
1049         g_queue_remove(resolv->lookup_queue, list->data);
1050         destroy_lookup(list->data);
1051
1052         return TRUE;
1053 }
1054
1055 gboolean g_resolv_set_address_family(GResolv *resolv, int family)
1056 {
1057         if (resolv == NULL)
1058                 return FALSE;
1059
1060         if (family != AF_UNSPEC && family != AF_INET && family != AF_INET6)
1061                 return FALSE;
1062
1063         resolv->result_family = family;
1064
1065         return TRUE;
1066 }