gweb/gresolv.c

   1 /*
   2  *
   3  *  Resolver library with GLib integration
   4  *
   5  *  Copyright (C) 2009-2010  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
  38 #include "gresolv.h"
  39
  40 struct sort_result {
  41         int precedence;
  42         int src_scope;
  43         int dst_scope;
  44         int src_label;
  45         int dst_label;
  46         gboolean reachable;
  47         union {
  48                 struct sockaddr sa;
  49                 struct sockaddr_in sin;
  50                 struct sockaddr_in6 sin6;
  51         } src;
  52         union {
  53                 struct sockaddr sa;
  54                 struct sockaddr_in sin;
  55                 struct sockaddr_in6 sin6;
  56         } dst;
  57 };
  58
  59 struct resolv_query;
  60
  61 struct resolv_lookup {
  62         GResolv *resolv;
  63         guint id;
  64
  65         int nr_results;
  66         struct sort_result *results;
  67
  68         struct resolv_query *ipv4_query;
  69         struct resolv_query *ipv6_query;
  70
  71         guint ipv4_status;
  72         guint ipv6_status;
  73
  74         GResolvResultFunc result_func;
  75         gpointer result_data;
  76 };
  77
  78 struct resolv_query {
  79         GResolv *resolv;
  80
  81         guint timeout;
  82
  83         uint16_t msgid;
  84
  85         struct resolv_lookup *lookup;
  86 };
  87
  88 struct resolv_nameserver {
  89         GResolv *resolv;
  90
  91         char *address;
  92         uint16_t port;
  93         unsigned long flags;
  94
  95         GIOChannel *udp_channel;
  96         guint udp_watch;
  97 };
  98
  99 struct _GResolv {
 100         gint ref_count;
 101
 102         int result_family;
 103
 104         guint next_lookup_id;
 105         GQueue *lookup_queue;
 106         GQueue *query_queue;
 107
 108         int index;
 109         GList *nameserver_list;
 110
 111         struct __res_state res;
 112
 113         GResolvDebugFunc debug_func;
 114         gpointer debug_data;
 115 };
 116
 117 static inline void debug(GResolv *resolv, const char *format, ...)
 118 {
 119         char str[256];
 120         va_list ap;
 121
 122         if (resolv->debug_func == NULL)
 123                 return;
 124
 125         va_start(ap, format);
 126
 127         if (vsnprintf(str, sizeof(str), format, ap) > 0)
 128                 resolv->debug_func(str, resolv->debug_data);
 129
 130         va_end(ap);
 131 }
 132
 133 static void destroy_query(struct resolv_query *query)
 134 {
 135         if (query->timeout > 0)
 136                 g_source_remove(query->timeout);
 137
 138         g_free(query);
 139 }
 140
 141 static void destroy_lookup(struct resolv_lookup *lookup)
 142 {
 143         if (lookup->ipv4_query != NULL) {
 144                 g_queue_remove(lookup->resolv->query_queue,
 145                                                 lookup->ipv4_query);
 146                 destroy_query(lookup->ipv4_query);
 147         }
 148
 149         if (lookup->ipv6_query != NULL) {
 150                 g_queue_remove(lookup->resolv->query_queue,
 151                                                 lookup->ipv6_query);
 152                 destroy_query(lookup->ipv6_query);
 153         }
 154
 155         g_free(lookup->results);
 156         g_free(lookup);
 157 }
 158
 159 static void find_srcaddr(struct sort_result *res)
 160 {
 161         socklen_t sl = sizeof(res->src);
 162         int fd;
 163
 164         fd = socket(res->dst.sa.sa_family, SOCK_DGRAM, IPPROTO_IP);
 165         if (fd < 0)
 166                 return;
 167
 168         if (connect(fd, &res->dst.sa, sizeof(res->dst)) < 0) {
 169                 close(fd);
 170                 return;
 171         }
 172
 173         if (getsockname(fd, &res->src.sa, &sl) < 0) {
 174                 close(fd);
 175                 return;
 176         }
 177
 178         res->reachable = TRUE;
 179         close(fd);
 180 }
 181
 182 struct gai_table
 183 {
 184         unsigned char addr[NS_IN6ADDRSZ];
 185         int mask;
 186         int value;
 187 };
 188
 189 static const struct gai_table gai_labels[] = {
 190         {
 191                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 192                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
 193                 .mask = 128,
 194                 .value = 0,
 195         }, {
 196                 .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 197                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 198                 .mask = 16,
 199                 .value = 2,
 200         }, {
 201                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 202                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 203                 .mask = 96,
 204                 .value = 3,
 205         }, {
 206                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 207                           0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 },
 208                 .mask = 96,
 209                 .value = 4,
 210         }, {
 211                 /* Variations from RFC 3484, matching glibc behaviour */
 212                 .addr = { 0xfe, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 213                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 214                 .mask = 10,
 215                 .value = 5,
 216         }, {
 217                 .addr = { 0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 218                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 219                 .mask = 7,
 220                 .value = 6,
 221         }, {
 222                 .addr = { 0x20, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 223                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 224                 .mask = 32,
 225                 .value = 7,
 226         }, {
 227                 /* catch-all */
 228                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 229                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 230                 .mask = 0,
 231                 .value = 1,
 232         }
 233 };
 234
 235 static const struct gai_table gai_precedences[] = {
 236         {
 237                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 238                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
 239                 .mask = 128,
 240                 .value = 50,
 241         }, {
 242                 .addr = { 0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 243                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 244                 .mask = 16,
 245                 .value = 30,
 246         }, {
 247                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 248                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 249                 .mask = 96,
 250                 .value = 20,
 251         }, {
 252                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 253                           0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 },
 254                 .mask = 96,
 255                 .value = 10,
 256         }, {
 257                 .addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 258                           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
 259                 .mask = 0,
 260                 .value = 40,
 261         }
 262 };
 263
 264 static unsigned char v4mapped[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 265                                     0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00 };
 266
 267 static gboolean mask_compare(const unsigned char *one,
 268                                         const unsigned char *two, int mask)
 269 {
 270         if (mask > 8) {
 271                 if (memcmp(one, two, mask / 8))
 272                         return FALSE;
 273                 one += mask / 8;
 274                 two += mask / 8;
 275                 mask %= 8;
 276         }
 277
 278         if (mask && ((*one ^ *two) >> (8 - mask)))
 279                 return FALSE;
 280
 281         return TRUE;
 282 }
 283
 284 static int match_gai_table(struct sockaddr *sa, const struct gai_table *tbl)
 285 {
 286         struct sockaddr_in *sin = (void *)sa;
 287         struct sockaddr_in6 *sin6 = (void *)sa;
 288         void *addr;
 289
 290         if (sa->sa_family == AF_INET) {
 291                 addr = v4mapped;
 292                 memcpy(v4mapped+12, &sin->sin_addr, NS_INADDRSZ);
 293         } else
 294                 addr = &sin6->sin6_addr;
 295
 296         while (1) {
 297                 if (mask_compare(addr, tbl->addr, tbl->mask))
 298                         return tbl->value;
 299                 tbl++;
 300         }
 301 }
 302
 303 #define DQUAD(_a,_b,_c,_d) ( ((_a)<<24) | ((_b)<<16) | ((_c)<<8) | (_d) )
 304 #define V4MATCH(addr, a,b,c,d, m) ( ((addr) ^ DQUAD(a,b,c,d)) >> (32 - (m)) )
 305
 306 #define RFC3484_SCOPE_LINK      2
 307 #define RFC3484_SCOPE_SITE      5
 308 #define RFC3484_SCOPE_GLOBAL    14
 309
 310 static int addr_scope(struct sockaddr *sa)
 311 {
 312         if (sa->sa_family == AF_INET) {
 313                 struct sockaddr_in *sin = (void *)sa;
 314                 guint32 addr = ntohl(sin->sin_addr.s_addr);
 315
 316                 if (V4MATCH(addr, 169,254,0,0, 16) ||
 317                                         V4MATCH(addr, 127,0,0,0, 8))
 318                         return RFC3484_SCOPE_LINK;
 319
 320                 /* Site-local */
 321                 if (V4MATCH(addr, 10,0,0,0, 8) ||
 322                                 V4MATCH(addr, 172,16,0,0, 12) ||
 323                                 V4MATCH(addr, 192,168,0,0, 16))
 324                         return RFC3484_SCOPE_SITE;
 325
 326                 /* Global */
 327                 return RFC3484_SCOPE_GLOBAL;
 328         } else {
 329                 struct sockaddr_in6 *sin6 = (void *)sa;
 330
 331                 /* Multicast addresses have a 4-bit scope field */
 332                 if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
 333                         return sin6->sin6_addr.s6_addr[1] & 0xf;
 334
 335                 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) ||
 336                                 IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
 337                         return RFC3484_SCOPE_LINK;
 338
 339                 if (IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr))
 340                         return RFC3484_SCOPE_SITE;
 341
 342                 return RFC3484_SCOPE_GLOBAL;
 343         }
 344 }
 345
 346 static int rfc3484_compare(const void *__one, const void *__two)
 347 {
 348         const struct sort_result *one = __one;
 349         const struct sort_result *two = __two;
 350
 351         /* Rule 1: Avoid unusable destinations */
 352         if (one->reachable && !two->reachable)
 353                 return -1;
 354         else if (two->reachable && !one->reachable)
 355                 return 1;
 356
 357         /* Rule 2: Prefer matching scope */
 358         if (one->dst_scope == one->src_scope &&
 359                                 two->dst_scope != two->src_scope)
 360                 return -1;
 361         else if (two->dst_scope == two->src_scope &&
 362                                 one->dst_scope != one->src_scope)
 363                 return 1;
 364
 365         /* Rule 3: Avoid deprecated addresses */
 366
 367         /* Rule 4: Prefer home addresses */
 368
 369         /* Rule 5: Prefer matching label */
 370         if (one->dst_label == one->src_label &&
 371                                 two->dst_label != two->src_label)
 372                 return -1;
 373         else if (two->dst_label == two->src_label &&
 374                                 one->dst_label != one->src_label)
 375                 return 1;
 376
 377         /* Rule 6: Prefer higher precedence */
 378         if (one->precedence > two->precedence)
 379                 return -1;
 380         else if (two->precedence > one->precedence)
 381                 return 1;
 382
 383         /* Rule 7: Prefer native transport */
 384
 385         /* Rule 8: Prefer smaller scope */
 386         if (one->dst_scope != two->dst_scope)
 387                 return one->dst_scope - two->dst_scope;
 388
 389         /* Rule 9: Use longest matching prefix */
 390         if (one->dst.sa.sa_family == AF_INET) {
 391                 /*
 392                  * Rule 9 is meaningless and counterproductive for Legacy IP
 393                  * unless perhaps we can tell that it's actually on the local
 394                  * subnet. But we don't (yet) have local interface config
 395                  * information, so do nothing here for Legacy IP for now.
 396                  */
 397         } else {
 398                 int i;
 399
 400                 for (i = 0; i < 4; i++) {
 401                         guint32 cmp_one, cmp_two;
 402
 403                         cmp_one = one->src.sin6.sin6_addr.s6_addr32[i] ^
 404                                         one->dst.sin6.sin6_addr.s6_addr32[i];
 405                         cmp_two = two->src.sin6.sin6_addr.s6_addr32[i] ^
 406                                         two->dst.sin6.sin6_addr.s6_addr32[i];
 407
 408                         if (!cmp_two && !cmp_one)
 409                                 continue;
 410
 411                         if (cmp_one && !cmp_two)
 412                                 return 1;
 413                         if (cmp_two && !cmp_one)
 414                                 return -1;
 415
 416                         /* g_bit_storage() is effectively fls() */
 417                         cmp_one = g_bit_storage(ntohl(cmp_one));
 418                         cmp_two = g_bit_storage(ntohl(cmp_two));
 419
 420                         if (cmp_one == cmp_two)
 421                                 break;
 422
 423                         return cmp_one - cmp_two;
 424                 }
 425         }
 426
 427
 428         /* Rule 10: Otherwise, leave the order unchanged */
 429         if (one < two)
 430                 return -1;
 431         else
 432                 return 1;
 433 }
 434
 435 static void rfc3484_sort_results(struct resolv_lookup *lookup)
 436 {
 437         int i;
 438
 439         for (i = 0; i < lookup->nr_results; i++) {
 440                 struct sort_result *res = &lookup->results[i];
 441                 find_srcaddr(res);
 442                 res->precedence = match_gai_table(&res->dst.sa,
 443                                                         gai_precedences);
 444                 res->dst_label = match_gai_table(&res->dst.sa, gai_labels);
 445                 res->src_label = match_gai_table(&res->src.sa, gai_labels);
 446                 res->dst_scope = addr_scope(&res->dst.sa);
 447                 res->src_scope = addr_scope(&res->src.sa);
 448         }
 449
 450         qsort(lookup->results, lookup->nr_results,
 451                         sizeof(struct sort_result), rfc3484_compare);
 452 }
 453
 454 static void sort_and_return_results(struct resolv_lookup *lookup)
 455 {
 456         char buf[INET6_ADDRSTRLEN + 1];
 457         GResolvResultStatus status;
 458         char **results = g_try_new0(char *, lookup->nr_results + 1);
 459         int i, n = 0;
 460
 461         if (!results)
 462                 return;
 463
 464         memset(buf, 0, INET6_ADDRSTRLEN + 1);
 465
 466         rfc3484_sort_results(lookup);
 467
 468         for (i = 0; i < lookup->nr_results; i++) {
 469                 if (lookup->results[i].dst.sa.sa_family == AF_INET) {
 470                         if (inet_ntop(AF_INET,
 471                                         &lookup->results[i].dst.sin.sin_addr,
 472                                         buf, sizeof(buf) - 1) == NULL)
 473                                 continue;
 474                 } else if (lookup->results[i].dst.sa.sa_family == AF_INET6) {
 475                         if (inet_ntop(AF_INET6,
 476                                         &lookup->results[i].dst.sin6.sin6_addr,
 477                                         buf, sizeof(buf) - 1) == NULL)
 478                                 continue;
 479                 } else
 480                         continue;
 481
 482                 results[n++] = strdup(buf);
 483         }
 484
 485         results[n++] = NULL;
 486
 487         status = lookup->ipv4_status;
 488
 489         if (status == G_RESOLV_RESULT_STATUS_SUCCESS)
 490                 status = lookup->ipv6_status;
 491
 492         lookup->result_func(status, results, lookup->result_data);
 493
 494         g_strfreev(results);
 495         g_queue_remove(lookup->resolv->lookup_queue, lookup);
 496         destroy_lookup(lookup);
 497 }
 498
 499 static gboolean query_timeout(gpointer user_data)
 500 {
 501         struct resolv_query *query = user_data;
 502         struct resolv_lookup *lookup = query->lookup;
 503         GResolv *resolv = query->resolv;
 504
 505         query->timeout = 0;
 506
 507         if (query == lookup->ipv4_query) {
 508                 lookup->ipv4_status = G_RESOLV_RESULT_STATUS_NO_RESPONSE;
 509                 lookup->ipv4_query = NULL;
 510         } else if (query == lookup->ipv6_query) {
 511                 lookup->ipv6_status = G_RESOLV_RESULT_STATUS_NO_RESPONSE;
 512                 lookup->ipv6_query = NULL;
 513         }
 514
 515         if (lookup->ipv4_query == NULL && lookup->ipv4_query == NULL)
 516                 sort_and_return_results(lookup);
 517
 518         destroy_query(query);
 519         g_queue_remove(resolv->query_queue, query);
 520
 521         return FALSE;
 522 }
 523
 524 static void free_nameserver(struct resolv_nameserver *nameserver)
 525 {
 526         if (nameserver == NULL)
 527                 return;
 528
 529         if (nameserver->udp_watch > 0)
 530                 g_source_remove(nameserver->udp_watch);
 531
 532         if (nameserver->udp_channel != NULL)
 533                 g_io_channel_unref(nameserver->udp_channel);
 534
 535         g_free(nameserver->address);
 536         g_free(nameserver);
 537 }
 538
 539 static void flush_nameservers(GResolv *resolv)
 540 {
 541         GList *list;
 542
 543         for (list = g_list_first(resolv->nameserver_list);
 544                                         list; list = g_list_next(list))
 545                 free_nameserver(list->data);
 546
 547         g_list_free(resolv->nameserver_list);
 548         resolv->nameserver_list = NULL;
 549 }
 550
 551 static int send_query(GResolv *resolv, const unsigned char *buf, int len)
 552 {
 553         GList *list;
 554
 555         if (resolv->nameserver_list == NULL)
 556                 return -ENOENT;
 557
 558         for (list = g_list_first(resolv->nameserver_list);
 559                                         list; list = g_list_next(list)) {
 560                 struct resolv_nameserver *nameserver = list->data;
 561                 int sk, sent;
 562
 563                 if (nameserver->udp_channel == NULL)
 564                         continue;
 565
 566                 sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
 567
 568                 sent = send(sk, buf, len, 0);
 569                 if (sent < 0)
 570                         continue;
 571         }
 572
 573         return 0;
 574 }
 575
 576 static gint compare_lookup_id(gconstpointer a, gconstpointer b)
 577 {
 578         const struct resolv_lookup *lookup = a;
 579         guint id = GPOINTER_TO_UINT(b);
 580
 581         if (lookup->id < id)
 582                 return -1;
 583
 584         if (lookup->id > id)
 585                 return 1;
 586
 587         return 0;
 588 }
 589
 590 static gint compare_query_msgid(gconstpointer a, gconstpointer b)
 591 {
 592         const struct resolv_query *query = a;
 593         uint16_t msgid = GPOINTER_TO_UINT(b);
 594
 595         if (query->msgid < msgid)
 596                 return -1;
 597
 598         if (query->msgid > msgid)
 599                 return 1;
 600
 601         return 0;
 602 }
 603
 604 static void add_result(struct resolv_lookup *lookup, int family,
 605                                                         const void *data)
 606 {
 607         int n = lookup->nr_results++;
 608         lookup->results = g_realloc(lookup->results,
 609                                         sizeof(struct sort_result) * (n + 1));
 610
 611         memset(&lookup->results[n], 0, sizeof(struct sort_result));
 612
 613         lookup->results[n].dst.sa.sa_family = family;
 614         if (family == AF_INET)
 615                 memcpy(&lookup->results[n].dst.sin.sin_addr,
 616                                                 data, NS_INADDRSZ);
 617         else
 618                 memcpy(&lookup->results[n].dst.sin6.sin6_addr,
 619                                                 data, NS_IN6ADDRSZ);
 620 }
 621
 622 static void parse_response(struct resolv_nameserver *nameserver,
 623                                         const unsigned char *buf, int len)
 624 {
 625         GResolv *resolv = nameserver->resolv;
 626         GResolvResultStatus status;
 627         struct resolv_query *query;
 628         struct resolv_lookup *lookup;
 629         GList *list;
 630         ns_msg msg;
 631         ns_rr rr;
 632         int i, rcode, count;
 633
 634         debug(resolv, "response from %s", nameserver->address);
 635
 636         ns_initparse(buf, len, &msg);
 637
 638         rcode = ns_msg_getflag(msg, ns_f_rcode);
 639         count = ns_msg_count(msg, ns_s_an);
 640
 641         debug(resolv, "msg id: 0x%04x rcode: %d count: %d",
 642                                         ns_msg_id(msg), rcode, count);
 643
 644         switch (rcode) {
 645         case 0:
 646                 status = G_RESOLV_RESULT_STATUS_SUCCESS;
 647                 break;
 648         case 1:
 649                 status = G_RESOLV_RESULT_STATUS_FORMAT_ERROR;
 650                 break;
 651         case 2:
 652                 status = G_RESOLV_RESULT_STATUS_SERVER_FAILURE;
 653                 break;
 654         case 3:
 655                 status = G_RESOLV_RESULT_STATUS_NAME_ERROR;
 656                 break;
 657         case 4:
 658                 status = G_RESOLV_RESULT_STATUS_NOT_IMPLEMENTED;
 659                 break;
 660         case 5:
 661                 status = G_RESOLV_RESULT_STATUS_REFUSED;
 662                 break;
 663         default:
 664                 status = G_RESOLV_RESULT_STATUS_ERROR;
 665                 break;
 666         }
 667
 668         list = g_queue_find_custom(resolv->query_queue,
 669                         GUINT_TO_POINTER(ns_msg_id(msg)), compare_query_msgid);
 670         if (!list)
 671                 return;
 672
 673         query = list->data;
 674         lookup = query->lookup;
 675
 676         if (query == lookup->ipv6_query) {
 677                 lookup->ipv6_status = status;
 678                 lookup->ipv6_query = NULL;
 679         } else if (query == lookup->ipv4_query) {
 680                 lookup->ipv4_status = status;
 681                 lookup->ipv4_query = NULL;
 682         }
 683
 684         for (i = 0; i < count; i++) {
 685                 ns_parserr(&msg, ns_s_an, i, &rr);
 686
 687                 if (ns_rr_class(rr) != ns_c_in)
 688                         continue;
 689
 690                 g_assert(offsetof(struct sockaddr_in, sin_addr) ==
 691                                 offsetof(struct sockaddr_in6, sin6_flowinfo));
 692
 693                 if (ns_rr_type(rr) == ns_t_a &&
 694                                         ns_rr_rdlen(rr) == NS_INADDRSZ) {
 695                         add_result(lookup, AF_INET, ns_rr_rdata(rr));
 696                 } else if (ns_rr_type(rr) == ns_t_aaaa &&
 697                                         ns_rr_rdlen(rr) == NS_IN6ADDRSZ) {
 698                         add_result(lookup, AF_INET6, ns_rr_rdata(rr));
 699                 }
 700         }
 701
 702         if (lookup->ipv4_query == NULL && lookup->ipv6_query == NULL)
 703                 sort_and_return_results(lookup);
 704
 705         destroy_query(query);
 706         g_queue_remove(resolv->query_queue, query);
 707 }
 708
 709 static gboolean received_udp_data(GIOChannel *channel, GIOCondition cond,
 710                                                         gpointer user_data)
 711 {
 712         struct resolv_nameserver *nameserver = user_data;
 713         unsigned char buf[4096];
 714         int sk, len;
 715
 716         if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
 717                 nameserver->udp_watch = 0;
 718                 return FALSE;
 719         }
 720
 721         sk = g_io_channel_unix_get_fd(nameserver->udp_channel);
 722
 723         len = recv(sk, buf, sizeof(buf), 0);
 724         if (len < 12)
 725                 return TRUE;
 726
 727         parse_response(nameserver, buf, len);
 728
 729         return TRUE;
 730 }
 731
 732 static int connect_udp_channel(struct resolv_nameserver *nameserver)
 733 {
 734         struct addrinfo hints, *rp;
 735         char portnr[6];
 736         int err, sk;
 737
 738         memset(&hints, 0, sizeof(hints));
 739         hints.ai_family = AF_UNSPEC;
 740         hints.ai_socktype = SOCK_DGRAM;
 741         hints.ai_flags = AI_PASSIVE | AI_NUMERICSERV | AI_NUMERICHOST;
 742
 743         sprintf(portnr, "%d", nameserver->port);
 744         err = getaddrinfo(nameserver->address, portnr, &hints, &rp);
 745         if (err)
 746                 return -EINVAL;
 747
 748         /*
 749          * Do not blindly copy this code elsewhere; it doesn't loop over the
 750          * results using ->ai_next as it should. That's OK in *this* case
 751          * because it was a numeric lookup; we *know* there's only one.
 752          */
 753         if (!rp)
 754                 return -EINVAL;
 755
 756         sk = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
 757         if (sk < 0) {
 758                 freeaddrinfo(rp);
 759                 return -EIO;
 760         }
 761
 762         if (connect(sk, rp->ai_addr, rp->ai_addrlen) < 0) {
 763                 close(sk);
 764                 freeaddrinfo(rp);
 765                 return -EIO;
 766         }
 767
 768         freeaddrinfo(rp);
 769
 770         nameserver->udp_channel = g_io_channel_unix_new(sk);
 771         if (nameserver->udp_channel == NULL) {
 772                 close(sk);
 773                 return -ENOMEM;
 774         }
 775
 776         g_io_channel_set_close_on_unref(nameserver->udp_channel, TRUE);
 777
 778         nameserver->udp_watch = g_io_add_watch(nameserver->udp_channel,
 779                                 G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP,
 780                                 received_udp_data, nameserver);
 781
 782         return 0;
 783 }
 784
 785 GResolv *g_resolv_new(int index)
 786 {
 787         GResolv *resolv;
 788
 789         if (index < 0)
 790                 return NULL;
 791
 792         resolv = g_try_new0(GResolv, 1);
 793         if (resolv == NULL)
 794                 return NULL;
 795
 796         resolv->ref_count = 1;
 797
 798         resolv->result_family = AF_UNSPEC;
 799
 800         resolv->next_lookup_id = 1;
 801
 802         resolv->query_queue = g_queue_new();
 803         if (resolv->query_queue == NULL) {
 804                 g_free(resolv);
 805                 return NULL;
 806         }
 807
 808         resolv->lookup_queue = g_queue_new();
 809         if (resolv->lookup_queue == NULL) {
 810                 g_queue_free(resolv->query_queue);
 811                 g_free(resolv);
 812                 return NULL;
 813         }
 814
 815         resolv->index = index;
 816         resolv->nameserver_list = NULL;
 817
 818         res_ninit(&resolv->res);
 819
 820         return resolv;
 821 }
 822
 823 GResolv *g_resolv_ref(GResolv *resolv)
 824 {
 825         if (resolv == NULL)
 826                 return NULL;
 827
 828         g_atomic_int_inc(&resolv->ref_count);
 829
 830         return resolv;
 831 }
 832
 833 void g_resolv_unref(GResolv *resolv)
 834 {
 835         struct resolv_query *query;
 836
 837         if (resolv == NULL)
 838                 return;
 839
 840         if (g_atomic_int_dec_and_test(&resolv->ref_count) == FALSE)
 841                 return;
 842
 843         while ((query = g_queue_pop_head(resolv->query_queue)))
 844                 destroy_query(query);
 845
 846         g_queue_free(resolv->query_queue);
 847         g_queue_free(resolv->lookup_queue);
 848
 849         flush_nameservers(resolv);
 850
 851         res_nclose(&resolv->res);
 852
 853         g_free(resolv);
 854 }
 855
 856 void g_resolv_set_debug(GResolv *resolv, GResolvDebugFunc func,
 857                                                 gpointer user_data)
 858 {
 859         if (resolv == NULL)
 860                 return;
 861
 862         resolv->debug_func = func;
 863         resolv->debug_data = user_data;
 864 }
 865
 866 gboolean g_resolv_add_nameserver(GResolv *resolv, const char *address,
 867                                         uint16_t port, unsigned long flags)
 868 {
 869         struct resolv_nameserver *nameserver;
 870
 871         if (resolv == NULL)
 872                 return FALSE;
 873
 874         nameserver = g_try_new0(struct resolv_nameserver, 1);
 875         if (nameserver == NULL)
 876                 return FALSE;
 877
 878         nameserver->address = g_strdup(address);
 879         nameserver->port = port;
 880         nameserver->flags = flags;
 881
 882         if (connect_udp_channel(nameserver) < 0) {
 883                 free_nameserver(nameserver);
 884                 return FALSE;
 885         }
 886
 887         nameserver->resolv = resolv;
 888
 889         resolv->nameserver_list = g_list_append(resolv->nameserver_list,
 890                                                                 nameserver);
 891
 892         debug(resolv, "setting nameserver %s", address);
 893
 894         return TRUE;
 895 }
 896
 897 void g_resolv_flush_nameservers(GResolv *resolv)
 898 {
 899         if (resolv == NULL)
 900                 return;
 901
 902         flush_nameservers(resolv);
 903 }
 904
 905 static gint add_query(struct resolv_lookup *lookup, const char *hostname, int type)
 906 {
 907         struct resolv_query *query = g_try_new0(struct resolv_query, 1);
 908         unsigned char buf[4096];
 909         int len;
 910
 911         if (query == NULL)
 912                 return -ENOMEM;
 913
 914         len = res_mkquery(ns_o_query, hostname, ns_c_in, type,
 915                                         NULL, 0, NULL, buf, sizeof(buf));
 916
 917         query->msgid = buf[0] << 8 | buf[1];
 918
 919         if (send_query(lookup->resolv, buf, len) < 0) {
 920                 g_free(query);
 921                 return -EIO;
 922         }
 923
 924         query->resolv = lookup->resolv;
 925         query->lookup = lookup;
 926
 927         g_queue_push_tail(lookup->resolv->query_queue, query);
 928
 929         query->timeout = g_timeout_add_seconds(5, query_timeout, query);
 930
 931         if (type == ns_t_aaaa)
 932                 lookup->ipv6_query = query;
 933         else
 934                 lookup->ipv4_query = query;
 935
 936         return 0;
 937 }
 938
 939 guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
 940                                 GResolvResultFunc func, gpointer user_data)
 941 {
 942         struct resolv_lookup *lookup;
 943
 944         debug(resolv, "lookup hostname %s", hostname);
 945
 946         if (resolv == NULL)
 947                 return 0;
 948
 949         if (resolv->nameserver_list == NULL) {
 950                 int i;
 951
 952                 for (i = 0; i < resolv->res.nscount; i++) {
 953                         char buf[100];
 954                         int family = resolv->res.nsaddr_list[i].sin_family;
 955                         void *sa_addr = &resolv->res.nsaddr_list[i].sin_addr;
 956
 957                         if (family != AF_INET &&
 958                                         resolv->res._u._ext.nsaddrs[i]) {
 959                                 family = AF_INET6;
 960                                 sa_addr = &resolv->res._u._ext.nsaddrs[i]->sin6_addr;
 961                         }
 962
 963                         if (family != AF_INET && family != AF_INET6)
 964                                 continue;
 965
 966                         if (inet_ntop(family, sa_addr, buf, sizeof(buf)))
 967                                 g_resolv_add_nameserver(resolv, buf, 53, 0);
 968                 }
 969
 970                 if (resolv->nameserver_list == NULL)
 971                         g_resolv_add_nameserver(resolv, "127.0.0.1", 53, 0);
 972         }
 973
 974         lookup = g_try_new0(struct resolv_lookup, 1);
 975         if (lookup == NULL)
 976                 return 0;
 977
 978         lookup->resolv = resolv;
 979         lookup->result_func = func;
 980         lookup->result_data = user_data;
 981         lookup->id = resolv->next_lookup_id++;
 982
 983         if (resolv->result_family != AF_INET6) {
 984                 if (add_query(lookup, hostname, ns_t_a)) {
 985                         g_free(lookup);
 986                         return -EIO;
 987                 }
 988         }
 989
 990         if (resolv->result_family != AF_INET) {
 991                 if (add_query(lookup, hostname, ns_t_aaaa)) {
 992                         if (resolv->result_family != AF_INET6) {
 993                                 destroy_query(lookup->ipv4_query);
 994                                 g_queue_remove(resolv->query_queue,
 995                                                 lookup->ipv4_query);
 996                         }
 997
 998                         g_free(lookup);
 999                         return -EIO;
1000                 }
1001         }
1002
1003         g_queue_push_tail(resolv->lookup_queue, lookup);
1004         return lookup->id;
1005 }
1006
1007 gboolean g_resolv_cancel_lookup(GResolv *resolv, guint id)
1008 {
1009         GList *list;
1010
1011         list = g_queue_find_custom(resolv->lookup_queue,
1012                                 GUINT_TO_POINTER(id), compare_lookup_id);
1013
1014         if (list == NULL)
1015                 return FALSE;
1016
1017         destroy_lookup(list->data);
1018         g_queue_remove(resolv->query_queue, list->data);
1019
1020         return TRUE;
1021 }
1022
1023 gboolean g_resolv_set_address_family(GResolv *resolv, int family)
1024 {
1025         if (resolv == NULL)
1026                 return FALSE;
1027
1028         if (family != AF_UNSPEC && family != AF_INET && family != AF_INET6)
1029                 return FALSE;
1030
1031         resolv->result_family = family;
1032
1033         return TRUE;
1034 }