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 #define debug(resolv, format, arg...)                           \
 119         _debug(resolv, __FILE__, __func__, format, ## arg)
 120
 121 static void _debug(GResolv *resolv, const char *file, const char *caller,
 122                                                 const char *format, ...)
 123 {
 124         char str[256];
 125         va_list ap;
 126         int len;
 127
 128         if (resolv->debug_func == NULL)
 129                 return;
 130
 131         va_start(ap, format);
 132
 133         if ((len = snprintf(str, sizeof(str), "%s:%s() resolv %p ",
 134                                                 file, caller, resolv)) > 0) {
 135                 if (vsnprintf(str + len, sizeof(str) - len, format, ap) > 0)
 136                         resolv->debug_func(str, resolv->debug_data);
 137         }
 138
 139         va_end(ap);
 140 }
 141
 142 static void destroy_query(struct resolv_query *query)
 143 {
 144         if (query->timeout > 0)
 145                 g_source_remove(query->timeout);
 146
 147         g_free(query);
 148 }
 149
 150 static void destroy_lookup(struct resolv_lookup *lookup)
 151 {
 152         if (lookup->ipv4_query != NULL) {
 153                 g_queue_remove(lookup->resolv->query_queue,
 154                                                 lookup->ipv4_query);
 155                 destroy_query(lookup->ipv4_query);
 156         }
 157
 158         if (lookup->ipv6_query != NULL) {
 159                 g_queue_remove(lookup->resolv->query_queue,
 160                                                 lookup->ipv6_query);
 161                 destroy_query(lookup->ipv6_query);
 162         }
 163
 164         g_free(lookup->results);
 165         g_free(lookup);
 166 }
 167
 168 static void find_srcaddr(struct sort_result *res)
 169 {
 170         socklen_t sl = sizeof(res->src);
 171         int fd;
 172
 173         fd = socket(res->dst.sa.sa_family, SOCK_DGRAM | SOCK_CLOEXEC,
 174                         IPPROTO_IP);
 175         if (fd < 0)
 176                 return;
 177
 178         if (connect(fd, &res->dst.sa, sizeof(res->dst)) < 0) {
 179                 close(fd);
 180                 return;
 181         }
 182
 183         if (getsockname(fd, &res->src.sa, &sl) < 0) {
 184                 close(fd);
 185                 return;
 186         }
 187
 188         res->reachable = TRUE;
 189         close(fd);
 190 }
 191
 192 struct gai_table
 193 {
 194         unsigned char addr[NS_IN6ADDRSZ];
 195         int mask;
 196         int value;
 197 };
 198
 199 static const struct gai_table gai_labels[] = {
 200         {
 201                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 202                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
 203                 .mask = 128,
 204                 .value = 0,
 205         }, {
 206                 .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 207                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 208                 .mask = 16,
 209                 .value = 2,
 210         }, {
 211                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 212                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 213                 .mask = 96,
 214                 .value = 3,
 215         }, {
 216                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 217                           0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 },
 218                 .mask = 96,
 219                 .value = 4,
 220         }, {
 221                 /* Variations from RFC 3484, matching glibc behaviour */
 222                 .addr = { 0xfe, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 223                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 224                 .mask = 10,
 225                 .value = 5,
 226         }, {
 227                 .addr = { 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 228                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 229                 .mask = 7,
 230                 .value = 6,
 231         }, {
 232                 .addr = { 0x20, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 233                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 234                 .mask = 32,
 235                 .value = 7,
 236         }, {
 237                 /* catch-all */
 238                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 239                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 240                 .mask = 0,
 241                 .value = 1,
 242         }
 243 };
 244
 245 static const struct gai_table gai_precedences[] = {
 246         {
 247                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 248                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
 249                 .mask = 128,
 250                 .value = 50,
 251         }, {
 252                 .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 253                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 254                 .mask = 16,
 255                 .value = 30,
 256         }, {
 257                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 258                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 259                 .mask = 96,
 260                 .value = 20,
 261         }, {
 262                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 263                           0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 },
 264                 .mask = 96,
 265                 .value = 10,
 266         }, {
 267                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 268                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 269                 .mask = 0,
 270                 .value = 40,
 271         }
 272 };
 273
 274 static unsigned char v4mapped[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 275                                     0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 };
 276
 277 static gboolean mask_compare(const unsigned char *one,
 278                                         const unsigned char *two, int mask)
 279 {
 280         if (mask > 8) {
 281                 if (memcmp(one, two, mask / 8))
 282                         return FALSE;
 283                 one += mask / 8;
 284                 two += mask / 8;
 285                 mask %= 8;
 286         }
 287
 288         if (mask && ((*one ^ *two) >> (8 - mask)))
 289                 return FALSE;
 290
 291         return TRUE;
 292 }
 293
 294 static int match_gai_table(struct sockaddr *sa, const struct gai_table *tbl)
 295 {
 296         struct sockaddr_in *sin = (void *)sa;
 297         struct sockaddr_in6 *sin6 = (void *)sa;
 298         void *addr;
 299
 300         if (sa->sa_family == AF_INET) {
 301                 addr = v4mapped;
 302                 memcpy(v4mapped+12, &sin->sin_addr, NS_INADDRSZ);
 303         } else
 304                 addr = &sin6->sin6_addr;
 305
 306         while (1) {
 307                 if (mask_compare(addr, tbl->addr, tbl->mask))
 308                         return tbl->value;
 309                 tbl++;
 310         }
 311 }
 312
 313 #define DQUAD(_a,_b,_c,_d) ( ((_a)<<24) | ((_b)<<16) | ((_c)<<8) | (_d) )
 314 #define V4MATCH(addr, a,b,c,d, m) ( ((addr) ^ DQUAD(a,b,c,d)) >> (32 - (m)) )
 315
 316 #define RFC3484_SCOPE_LINK      2
 317 #define RFC3484_SCOPE_SITE      5
 318 #define RFC3484_SCOPE_GLOBAL    14
 319
 320 static int addr_scope(struct sockaddr *sa)
 321 {
 322         if (sa->sa_family == AF_INET) {
 323                 struct sockaddr_in *sin = (void *)sa;
 324                 guint32 addr = ntohl(sin->sin_addr.s_addr);
 325
 326                 if (V4MATCH(addr, 169,254,0,0, 16) ||
 327                                         V4MATCH(addr, 127,0,0,0, 8))
 328                         return RFC3484_SCOPE_LINK;
 329
 330                 /* Site-local */
 331                 if (V4MATCH(addr, 10,0,0,0, 8) ||
 332                                 V4MATCH(addr, 172,16,0,0, 12) ||
 333                                 V4MATCH(addr, 192,168,0,0, 16))
 334                         return RFC3484_SCOPE_SITE;
 335
 336                 /* Global */
 337                 return RFC3484_SCOPE_GLOBAL;
 338         } else {
 339                 struct sockaddr_in6 *sin6 = (void *)sa;
 340
 341                 /* Multicast addresses have a 4-bit scope field */
 342                 if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
 343                         return sin6->sin6_addr.s6_addr[1] & 0xf;
 344
 345                 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) ||
 346                                 IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
 347                         return RFC3484_SCOPE_LINK;
 348
 349                 if (IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr))
 350                         return RFC3484_SCOPE_SITE;
 351
 352                 return RFC3484_SCOPE_GLOBAL;
 353         }
 354 }
 355
 356 static int rfc3484_compare(const void *__one, const void *__two)
 357 {
 358         const struct sort_result *one = __one;
 359         const struct sort_result *two = __two;
 360
 361         /* Rule 1: Avoid unusable destinations */
 362         if (one->reachable && !two->reachable)
 363                 return -1;
 364         else if (two->reachable && !one->reachable)
 365                 return 1;
 366
 367         /* Rule 2: Prefer matching scope */
 368         if (one->dst_scope == one->src_scope &&
 369                                 two->dst_scope != two->src_scope)
 370                 return -1;
 371         else if (two->dst_scope == two->src_scope &&
 372                                 one->dst_scope != one->src_scope)
 373                 return 1;
 374
 375         /* Rule 3: Avoid deprecated addresses */
 376
 377         /* Rule 4: Prefer home addresses */
 378
 379         /* Rule 5: Prefer matching label */
 380         if (one->dst_label == one->src_label &&
 381                                 two->dst_label != two->src_label)
 382                 return -1;
 383         else if (two->dst_label == two->src_label &&
 384                                 one->dst_label != one->src_label)
 385                 return 1;
 386
 387         /* Rule 6: Prefer higher precedence */
 388         if (one->precedence > two->precedence)
 389                 return -1;
 390         else if (two->precedence > one->precedence)
 391                 return 1;
 392
 393         /* Rule 7: Prefer native transport */
 394
 395         /* Rule 8: Prefer smaller scope */
 396         if (one->dst_scope != two->dst_scope)
 397                 return one->dst_scope - two->dst_scope;
 398
 399         /* Rule 9: Use longest matching prefix */
 400         if (one->dst.sa.sa_family == AF_INET) {
 401                 /*
 402                  * Rule 9 is meaningless and counterproductive for Legacy IP
 403                  * unless perhaps we can tell that it's actually on the local
 404                  * subnet. But we don't (yet) have local interface config
 405                  * information, so do nothing here for Legacy IP for now.
 406                  */
 407         } else {
 408                 int i;
 409
 410                 for (i = 0; i < 4; i++) {
 411                         guint32 cmp_one, cmp_two;
 412
 413                         cmp_one = one->src.sin6.sin6_addr.s6_addr32[i] ^
 414                                         one->dst.sin6.sin6_addr.s6_addr32[i];
 415                         cmp_two = two->src.sin6.sin6_addr.s6_addr32[i] ^
 416                                         two->dst.sin6.sin6_addr.s6_addr32[i];
 417
 418                         if (!cmp_two && !cmp_one)
 419                                 continue;
 420
 421                         if (cmp_one && !cmp_two)
 422                                 return 1;
 423                         if (cmp_two && !cmp_one)
 424                                 return -1;
 425
 426                         /* g_bit_storage() is effectively fls() */
 427                         cmp_one = g_bit_storage(ntohl(cmp_one));
 428                         cmp_two = g_bit_storage(ntohl(cmp_two));
 429
 430                         if (cmp_one == cmp_two)
 431                                 break;
 432
 433                         return cmp_one - cmp_two;
 434                 }
 435         }
 436
 437
 438         /* Rule 10: Otherwise, leave the order unchanged */
 439         if (one < two)
 440                 return -1;
 441         else
 442                 return 1;
 443 }
 444
 445 static void rfc3484_sort_results(struct resolv_lookup *lookup)
 446 {
 447         int i;
 448
 449         for (i = 0; i < lookup->nr_results; i++) {
 450                 struct sort_result *res = &lookup->results[i];
 451                 find_srcaddr(res);
 452                 res->precedence = match_gai_table(&res->dst.sa,
 453                                                         gai_precedences);
 454                 res->dst_label = match_gai_table(&res->dst.sa, gai_labels);
 455                 res->src_label = match_gai_table(&res->src.sa, gai_labels);
 456                 res->dst_scope = addr_scope(&res->dst.sa);
 457                 res->src_scope = addr_scope(&res->src.sa);
 458         }
 459
 460         qsort(lookup->results, lookup->nr_results,
 461                         sizeof(struct sort_result), rfc3484_compare);
 462 }
 463
 464 static void sort_and_return_results(struct resolv_lookup *lookup)
 465 {
 466         char buf[INET6_ADDRSTRLEN + 1];
 467         GResolvResultStatus status;
 468         char **results = g_try_new0(char *, lookup->nr_results + 1);
 469         int i, n = 0;
 470
 471         if (!results)
 472                 return;
 473
 474         memset(buf, 0, INET6_ADDRSTRLEN + 1);
 475
 476         rfc3484_sort_results(lookup);
 477
 478         for (i = 0; i < lookup->nr_results; i++) {
 479                 if (lookup->results[i].dst.sa.sa_family == AF_INET) {
 480                         if (inet_ntop(AF_INET,
 481                                         &lookup->results[i].dst.sin.sin_addr,
 482                                         buf, sizeof(buf) - 1) == NULL)
 483                                 continue;
 484                 } else if (lookup->results[i].dst.sa.sa_family == AF_INET6) {
 485                         if (inet_ntop(AF_INET6,
 486                                         &lookup->results[i].dst.sin6.sin6_addr,
 487                                         buf, sizeof(buf) - 1) == NULL)
 488                                 continue;
 489                 } else
 490                         continue;
 491
 492                 results[n++] = strdup(buf);
 493         }
 494
 495         results[n++] = NULL;
 496
 497         if (lookup->resolv->result_family == AF_INET)
 498                 status = lookup->ipv4_status;
 499         else if (lookup->resolv->result_family == AF_INET6)
 500                 status = lookup->ipv6_status;
 501         else {
 502                 if (lookup->ipv6_status == G_RESOLV_RESULT_STATUS_SUCCESS)
 503                         status = lookup->ipv6_status;
 504                 else
 505                         status = lookup->ipv4_status;
 506         }
 507
 508         g_queue_remove(lookup->resolv->lookup_queue, lookup);
 509
 510         lookup->result_func(status, results, lookup->result_data);
 511
 512         g_strfreev(results);
 513         destroy_lookup(lookup);
 514 }
 515
 516 static gboolean query_timeout(gpointer user_data)
 517 {
 518         struct resolv_query *query = user_data;
 519         struct resolv_lookup *lookup = query->lookup;
 520         GResolv *resolv = query->resolv;
 521
 522         query->timeout = 0;
 523
 524         if (query == lookup->ipv4_query) {
 525                 lookup->ipv4_status = G_RESOLV_RESULT_STATUS_NO_RESPONSE;
 526                 lookup->ipv4_query = NULL;
 527         } else if (query == lookup->ipv6_query) {
 528                 lookup->ipv6_status = G_RESOLV_RESULT_STATUS_NO_RESPONSE;
 529                 lookup->ipv6_query = NULL;
 530         }
 531
 532         g_queue_remove(resolv->query_queue, query);
 533
 534         if (lookup->ipv4_query == NULL && lookup->ipv6_query == NULL)
 535                 sort_and_return_results(lookup);
 536
 537         destroy_query(query);
 538
 539         return FALSE;
 540 }
 541
 542 static void free_nameserver(struct resolv_nameserver *nameserver)
 543 {
 544         if (nameserver == NULL)
 545                 return;
 546
 547         if (nameserver->udp_watch > 0)
 548                 g_source_remove(nameserver->udp_watch);
 549
 550         if (nameserver->udp_channel != NULL)
 551                 g_io_channel_unref(nameserver->udp_channel);
 552
 553         g_free(nameserver->address);
 554         g_free(nameserver);
 555 }
 556
 557 static void flush_nameservers(GResolv *resolv)
 558 {
 559         GList *list;
 560
 561         for (list = g_list_first(resolv->nameserver_list);
 562                                         list; list = g_list_next(list))
 563                 free_nameserver(list->data);
 564
 565         g_list_free(resolv->nameserver_list);
 566         resolv->nameserver_list = NULL;
 567 }
 568
 569 static int send_query(GResolv *resolv, const unsigned char *buf, int len)
 570 {
 571         GList *list;
 572
 573         if (resolv->nameserver_list == NULL)
 574                 return -ENOENT;
 575
 576         for (list = g_list_first(resolv->nameserver_list);
 577                                         list; list = g_list_next(list)) {
 578                 struct resolv_nameserver *nameserver = list->data;
 579                 int sk, sent;
 580
 581                 if (nameserver->udp_channel == NULL)
 582                         continue;
 583
 584                 sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
 585
 586                 sent = send(sk, buf, len, 0);
 587                 if (sent < 0)
 588                         continue;
 589         }
 590
 591         return 0;
 592 }
 593
 594 static gint compare_lookup_id(gconstpointer a, gconstpointer b)
 595 {
 596         const struct resolv_lookup *lookup = a;
 597         guint id = GPOINTER_TO_UINT(b);
 598
 599         if (lookup->id < id)
 600                 return -1;
 601
 602         if (lookup->id > id)
 603                 return 1;
 604
 605         return 0;
 606 }
 607
 608 static gint compare_query_msgid(gconstpointer a, gconstpointer b)
 609 {
 610         const struct resolv_query *query = a;
 611         uint16_t msgid = GPOINTER_TO_UINT(b);
 612
 613         if (query->msgid < msgid)
 614                 return -1;
 615
 616         if (query->msgid > msgid)
 617                 return 1;
 618
 619         return 0;
 620 }
 621
 622 static void add_result(struct resolv_lookup *lookup, int family,
 623                                                         const void *data)
 624 {
 625         int n = lookup->nr_results++;
 626         lookup->results = g_try_realloc(lookup->results,
 627                                         sizeof(struct sort_result) * (n + 1));
 628         if (lookup->results == NULL)
 629                 return;
 630
 631         memset(&lookup->results[n], 0, sizeof(struct sort_result));
 632
 633         lookup->results[n].dst.sa.sa_family = family;
 634         if (family == AF_INET)
 635                 memcpy(&lookup->results[n].dst.sin.sin_addr,
 636                                                 data, NS_INADDRSZ);
 637         else
 638                 memcpy(&lookup->results[n].dst.sin6.sin6_addr,
 639                                                 data, NS_IN6ADDRSZ);
 640 }
 641
 642 static void parse_response(struct resolv_nameserver *nameserver,
 643                                         const unsigned char *buf, int len)
 644 {
 645         GResolv *resolv = nameserver->resolv;
 646         GResolvResultStatus status;
 647         struct resolv_query *query;
 648         struct resolv_lookup *lookup;
 649         GList *list;
 650         ns_msg msg;
 651         ns_rr rr;
 652         int i, rcode, count;
 653
 654         debug(resolv, "response from %s", nameserver->address);
 655
 656         ns_initparse(buf, len, &msg);
 657
 658         rcode = ns_msg_getflag(msg, ns_f_rcode);
 659         count = ns_msg_count(msg, ns_s_an);
 660
 661         debug(resolv, "msg id: 0x%04x rcode: %d count: %d",
 662                                         ns_msg_id(msg), rcode, count);
 663
 664         switch (rcode) {
 665         case ns_r_noerror:
 666                 status = G_RESOLV_RESULT_STATUS_SUCCESS;
 667                 break;
 668         case ns_r_formerr:
 669                 status = G_RESOLV_RESULT_STATUS_FORMAT_ERROR;
 670                 break;
 671         case ns_r_servfail:
 672                 status = G_RESOLV_RESULT_STATUS_SERVER_FAILURE;
 673                 break;
 674         case ns_r_nxdomain:
 675                 status = G_RESOLV_RESULT_STATUS_NAME_ERROR;
 676                 break;
 677         case ns_r_notimpl:
 678                 status = G_RESOLV_RESULT_STATUS_NOT_IMPLEMENTED;
 679                 break;
 680         case ns_r_refused:
 681                 status = G_RESOLV_RESULT_STATUS_REFUSED;
 682                 break;
 683         default:
 684                 status = G_RESOLV_RESULT_STATUS_ERROR;
 685                 break;
 686         }
 687
 688         list = g_queue_find_custom(resolv->query_queue,
 689                         GUINT_TO_POINTER(ns_msg_id(msg)), compare_query_msgid);
 690         if (!list)
 691                 return;
 692
 693         query = list->data;
 694         lookup = query->lookup;
 695
 696         if (query == lookup->ipv6_query) {
 697                 lookup->ipv6_status = status;
 698                 lookup->ipv6_query = NULL;
 699         } else if (query == lookup->ipv4_query) {
 700                 lookup->ipv4_status = status;
 701                 lookup->ipv4_query = NULL;
 702         }
 703
 704         for (i = 0; i < count; i++) {
 705                 ns_parserr(&msg, ns_s_an, i, &rr);
 706
 707                 if (ns_rr_class(rr) != ns_c_in)
 708                         continue;
 709
 710                 g_assert(offsetof(struct sockaddr_in, sin_addr) ==
 711                                 offsetof(struct sockaddr_in6, sin6_flowinfo));
 712
 713                 if (ns_rr_type(rr) == ns_t_a &&
 714                                         ns_rr_rdlen(rr) == NS_INADDRSZ) {
 715                         add_result(lookup, AF_INET, ns_rr_rdata(rr));
 716                 } else if (ns_rr_type(rr) == ns_t_aaaa &&
 717                                         ns_rr_rdlen(rr) == NS_IN6ADDRSZ) {
 718                         add_result(lookup, AF_INET6, ns_rr_rdata(rr));
 719                 }
 720         }
 721
 722         g_queue_remove(resolv->query_queue, query);
 723
 724         if (lookup->ipv4_query == NULL && lookup->ipv6_query == NULL)
 725                 sort_and_return_results(lookup);
 726
 727         destroy_query(query);
 728 }
 729
 730 static gboolean received_udp_data(GIOChannel *channel, GIOCondition cond,
 731                                                         gpointer user_data)
 732 {
 733         struct resolv_nameserver *nameserver = user_data;
 734         unsigned char buf[4096];
 735         int sk, len;
 736
 737         if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
 738                 nameserver->udp_watch = 0;
 739                 return FALSE;
 740         }
 741
 742         sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
 743
 744         len = recv(sk, buf, sizeof(buf), 0);
 745         if (len < 12)
 746                 return TRUE;
 747
 748         parse_response(nameserver, buf, len);
 749
 750         return TRUE;
 751 }
 752
 753 static int connect_udp_channel(struct resolv_nameserver *nameserver)
 754 {
 755         struct addrinfo hints, *rp;
 756         char portnr[6];
 757         int err, sk;
 758
 759         memset(&hints, 0, sizeof(hints));
 760         hints.ai_family = AF_UNSPEC;
 761         hints.ai_socktype = SOCK_DGRAM;
 762         hints.ai_flags = AI_PASSIVE | AI_NUMERICSERV | AI_NUMERICHOST;
 763
 764         sprintf(portnr, "%d", nameserver->port);
 765         err = getaddrinfo(nameserver->address, portnr, &hints, &rp);
 766         if (err)
 767                 return -EINVAL;
 768
 769         /*
 770          * Do not blindly copy this code elsewhere; it doesn't loop over the
 771          * results using ->ai_next as it should. That's OK in *this* case
 772          * because it was a numeric lookup; we *know* there's only one.
 773          */
 774         if (!rp)
 775                 return -EINVAL;
 776
 777         sk = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
 778         if (sk < 0) {
 779                 freeaddrinfo(rp);
 780                 return -EIO;
 781         }
 782
 783         /*
 784          * If nameserver points to localhost ip, their is no need to
 785          * bind the socket on any interface.
 786          */
 787         if (nameserver->resolv->index > 0 &&
 788                         strncmp(nameserver->address, "127.0.0.1", 9) != 0) {
 789                 char interface[IF_NAMESIZE];
 790
 791                 memset(interface, 0, IF_NAMESIZE);
 792                 if (if_indextoname(nameserver->resolv->index,
 793                                                 interface) != NULL) {
 794                         if (setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE,
 795                                                 interface, IF_NAMESIZE) < 0) {
 796                                 close(sk);
 797                                 freeaddrinfo(rp);
 798                                 return -EIO;
 799                         }
 800                 }
 801         }
 802
 803         if (connect(sk, rp->ai_addr, rp->ai_addrlen) < 0) {
 804                 close(sk);
 805                 freeaddrinfo(rp);
 806                 return -EIO;
 807         }
 808
 809         freeaddrinfo(rp);
 810
 811         nameserver->udp_channel = g_io_channel_unix_new(sk);
 812         if (nameserver->udp_channel == NULL) {
 813                 close(sk);
 814                 return -ENOMEM;
 815         }
 816
 817         g_io_channel_set_close_on_unref(nameserver->udp_channel, TRUE);
 818
 819         nameserver->udp_watch = g_io_add_watch(nameserver->udp_channel,
 820                                 G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP,
 821                                 received_udp_data, nameserver);
 822
 823         return 0;
 824 }
 825
 826 GResolv *g_resolv_new(int index)
 827 {
 828         GResolv *resolv;
 829
 830         if (index < 0)
 831                 return NULL;
 832
 833         resolv = g_try_new0(GResolv, 1);
 834         if (resolv == NULL)
 835                 return NULL;
 836
 837         resolv->ref_count = 1;
 838
 839         resolv->result_family = AF_UNSPEC;
 840
 841         resolv->next_lookup_id = 1;
 842
 843         resolv->query_queue = g_queue_new();
 844         if (resolv->query_queue == NULL) {
 845                 g_free(resolv);
 846                 return NULL;
 847         }
 848
 849         resolv->lookup_queue = g_queue_new();
 850         if (resolv->lookup_queue == NULL) {
 851                 g_queue_free(resolv->query_queue);
 852                 g_free(resolv);
 853                 return NULL;
 854         }
 855
 856         resolv->index = index;
 857         resolv->nameserver_list = NULL;
 858
 859         res_ninit(&resolv->res);
 860
 861         return resolv;
 862 }
 863
 864 GResolv *g_resolv_ref(GResolv *resolv)
 865 {
 866         if (resolv == NULL)
 867                 return NULL;
 868
 869         __sync_fetch_and_add(&resolv->ref_count, 1);
 870
 871         return resolv;
 872 }
 873
 874 void g_resolv_unref(GResolv *resolv)
 875 {
 876         struct resolv_query *query;
 877         struct resolv_lookup *lookup;
 878
 879         if (resolv == NULL)
 880                 return;
 881
 882         if (__sync_fetch_and_sub(&resolv->ref_count, 1) != 1)
 883                 return;
 884
 885         while ((lookup = g_queue_pop_head(resolv->lookup_queue)))
 886                 destroy_lookup(lookup);
 887
 888         while ((query = g_queue_pop_head(resolv->query_queue)))
 889                 destroy_query(query);
 890
 891         g_queue_free(resolv->query_queue);
 892         g_queue_free(resolv->lookup_queue);
 893
 894         flush_nameservers(resolv);
 895
 896         res_nclose(&resolv->res);
 897
 898         g_free(resolv);
 899 }
 900
 901 void g_resolv_set_debug(GResolv *resolv, GResolvDebugFunc func,
 902                                                 gpointer user_data)
 903 {
 904         if (resolv == NULL)
 905                 return;
 906
 907         resolv->debug_func = func;
 908         resolv->debug_data = user_data;
 909 }
 910
 911 gboolean g_resolv_add_nameserver(GResolv *resolv, const char *address,
 912                                         uint16_t port, unsigned long flags)
 913 {
 914         struct resolv_nameserver *nameserver;
 915
 916         if (resolv == NULL)
 917                 return FALSE;
 918
 919         nameserver = g_try_new0(struct resolv_nameserver, 1);
 920         if (nameserver == NULL)
 921                 return FALSE;
 922
 923         nameserver->address = g_strdup(address);
 924         nameserver->port = port;
 925         nameserver->flags = flags;
 926         nameserver->resolv = resolv;
 927
 928         if (connect_udp_channel(nameserver) < 0) {
 929                 free_nameserver(nameserver);
 930                 return FALSE;
 931         }
 932
 933         resolv->nameserver_list = g_list_append(resolv->nameserver_list,
 934                                                                 nameserver);
 935
 936         debug(resolv, "setting nameserver %s", address);
 937
 938         return TRUE;
 939 }
 940
 941 void g_resolv_flush_nameservers(GResolv *resolv)
 942 {
 943         if (resolv == NULL)
 944                 return;
 945
 946         flush_nameservers(resolv);
 947 }
 948
 949 static gint add_query(struct resolv_lookup *lookup, const char *hostname, int type)
 950 {
 951         struct resolv_query *query = g_try_new0(struct resolv_query, 1);
 952         unsigned char buf[4096];
 953         int len;
 954
 955         if (query == NULL)
 956                 return -ENOMEM;
 957
 958         len = res_mkquery(ns_o_query, hostname, ns_c_in, type,
 959                                         NULL, 0, NULL, buf, sizeof(buf));
 960
 961         query->msgid = buf[0] << 8 | buf[1];
 962
 963         if (send_query(lookup->resolv, buf, len) < 0) {
 964                 g_free(query);
 965                 return -EIO;
 966         }
 967
 968         query->resolv = lookup->resolv;
 969         query->lookup = lookup;
 970
 971         g_queue_push_tail(lookup->resolv->query_queue, query);
 972
 973         query->timeout = g_timeout_add_seconds(5, query_timeout, query);
 974
 975         if (type == ns_t_aaaa)
 976                 lookup->ipv6_query = query;
 977         else
 978                 lookup->ipv4_query = query;
 979
 980         return 0;
 981 }
 982
 983 guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
 984                                 GResolvResultFunc func, gpointer user_data)
 985 {
 986         struct resolv_lookup *lookup;
 987
 988         debug(resolv, "lookup hostname %s", hostname);
 989
 990         if (resolv == NULL)
 991                 return 0;
 992
 993         if (resolv->nameserver_list == NULL) {
 994                 int i;
 995
 996                 for (i = 0; i < resolv->res.nscount; i++) {
 997                         char buf[100];
 998                         int family = resolv->res.nsaddr_list[i].sin_family;
 999                         void *sa_addr = &resolv->res.nsaddr_list[i].sin_addr;
1000
1001                         if (family != AF_INET &&
1002                                         resolv->res._u._ext.nsaddrs[i]) {
1003                                 family = AF_INET6;
1004                                 sa_addr = &resolv->res._u._ext.nsaddrs[i]->sin6_addr;
1005                         }
1006
1007                         if (family != AF_INET && family != AF_INET6)
1008                                 continue;
1009
1010                         if (inet_ntop(family, sa_addr, buf, sizeof(buf)))
1011                                 g_resolv_add_nameserver(resolv, buf, 53, 0);
1012                 }
1013
1014                 if (resolv->nameserver_list == NULL)
1015                         g_resolv_add_nameserver(resolv, "127.0.0.1", 53, 0);
1016         }
1017
1018         lookup = g_try_new0(struct resolv_lookup, 1);
1019         if (lookup == NULL)
1020                 return 0;
1021
1022         lookup->resolv = resolv;
1023         lookup->result_func = func;
1024         lookup->result_data = user_data;
1025         lookup->id = resolv->next_lookup_id++;
1026
1027         if (resolv->result_family != AF_INET6) {
1028                 if (add_query(lookup, hostname, ns_t_a)) {
1029                         g_free(lookup);
1030                         return -EIO;
1031                 }
1032         }
1033
1034         if (resolv->result_family != AF_INET) {
1035                 if (add_query(lookup, hostname, ns_t_aaaa)) {
1036                         if (resolv->result_family != AF_INET6) {
1037                                 destroy_query(lookup->ipv4_query);
1038                                 g_queue_remove(resolv->query_queue,
1039                                                 lookup->ipv4_query);
1040                         }
1041
1042                         g_free(lookup);
1043                         return -EIO;
1044                 }
1045         }
1046
1047         g_queue_push_tail(resolv->lookup_queue, lookup);
1048         return lookup->id;
1049 }
1050
1051 gboolean g_resolv_cancel_lookup(GResolv *resolv, guint id)
1052 {
1053         GList *list;
1054
1055         list = g_queue_find_custom(resolv->lookup_queue,
1056                                 GUINT_TO_POINTER(id), compare_lookup_id);
1057
1058         if (list == NULL)
1059                 return FALSE;
1060
1061         g_queue_remove(resolv->lookup_queue, list->data);
1062         destroy_lookup(list->data);
1063
1064         return TRUE;
1065 }
1066
1067 gboolean g_resolv_set_address_family(GResolv *resolv, int family)
1068 {
1069         if (resolv == NULL)
1070                 return FALSE;
1071
1072         if (family != AF_UNSPEC && family != AF_INET && family != AF_INET6)
1073                 return FALSE;
1074
1075         resolv->result_family = family;
1076
1077         return TRUE;
1078 }