src/network.c

   1 /*
   2         libloc - A library to determine the location of someone on the Internet
   3
   4         Copyright (C) 2017 IPFire Development Team <info@ipfire.org>
   5
   6         This library is free software; you can redistribute it and/or
   7         modify it under the terms of the GNU Lesser General Public
   8         License as published by the Free Software Foundation; either
   9         version 2.1 of the License, or (at your option) any later version.
  10
  11         This library 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 GNU
  14         Lesser General Public License for more details.
  15 */
  16
  17 #include <arpa/inet.h>
  18 #include <assert.h>
  19 #include <errno.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23
  24 #ifdef HAVE_ENDIAN_H
  25 #  include <endian.h>
  26 #endif
  27
  28 #include <loc/libloc.h>
  29 #include <loc/compat.h>
  30 #include <loc/country.h>
  31 #include <loc/network.h>
  32 #include <loc/network-list.h>
  33 #include <loc/private.h>
  34
  35 struct loc_network {
  36         struct loc_ctx* ctx;
  37         int refcount;
  38
  39         int family;
  40         struct in6_addr first_address;
  41         struct in6_addr last_address;
  42         unsigned int prefix;
  43
  44         char country_code[3];
  45         uint32_t asn;
  46         enum loc_network_flags flags;
  47 };
  48
  49 static int valid_prefix(struct in6_addr* address, unsigned int prefix) {
  50         // The prefix cannot be larger than 128 bits
  51         if (prefix > 128)
  52                 return 1;
  53
  54         // And the prefix cannot be zero
  55         if (prefix == 0)
  56                 return 1;
  57
  58         // For IPv4-mapped addresses the prefix has to be 96 or lager
  59         if (IN6_IS_ADDR_V4MAPPED(address) && prefix <= 96)
  60                 return 1;
  61
  62         return 0;
  63 }
  64
  65 static struct in6_addr prefix_to_bitmask(unsigned int prefix) {
  66         struct in6_addr bitmask;
  67
  68         for (unsigned int i = 0; i < 16; i++)
  69                 bitmask.s6_addr[i] = 0;
  70
  71         for (int i = prefix, j = 0; i > 0; i -= 8, j++) {
  72                 if (i >= 8)
  73                         bitmask.s6_addr[j] = 0xff;
  74                 else
  75                         bitmask.s6_addr[j] = 0xff << (8 - i);
  76         }
  77
  78         return bitmask;
  79 }
  80
  81 static struct in6_addr make_first_address(const struct in6_addr* address, const struct in6_addr* bitmask) {
  82         struct in6_addr a;
  83
  84         // Perform bitwise AND
  85         for (unsigned int i = 0; i < 4; i++)
  86                 a.s6_addr32[i] = address->s6_addr32[i] & bitmask->s6_addr32[i];
  87
  88         return a;
  89 }
  90
  91 static struct in6_addr make_last_address(const struct in6_addr* address, const struct in6_addr* bitmask) {
  92         struct in6_addr a;
  93
  94         // Perform bitwise OR
  95         for (unsigned int i = 0; i < 4; i++)
  96                 a.s6_addr32[i] = address->s6_addr32[i] | ~bitmask->s6_addr32[i];
  97
  98         return a;
  99 }
 100
 101 static struct in6_addr address_increment(const struct in6_addr* address) {
 102         struct in6_addr a = *address;
 103
 104         for (int octet = 15; octet >= 0; octet--) {
 105                 if (a.s6_addr[octet] < 255) {
 106                         a.s6_addr[octet]++;
 107                         break;
 108                 } else {
 109                         a.s6_addr[octet] = 0;
 110                 }
 111         }
 112
 113         return a;
 114 }
 115
 116 LOC_EXPORT int loc_network_new(struct loc_ctx* ctx, struct loc_network** network,
 117                 struct in6_addr* address, unsigned int prefix) {
 118         // Address cannot be unspecified
 119         if (IN6_IS_ADDR_UNSPECIFIED(address)) {
 120                 DEBUG(ctx, "Start address is unspecified\n");
 121                 return -EINVAL;
 122         }
 123
 124         // Address cannot be loopback
 125         if (IN6_IS_ADDR_LOOPBACK(address)) {
 126                 DEBUG(ctx, "Start address is loopback address\n");
 127                 return -EINVAL;
 128         }
 129
 130         // Address cannot be link-local
 131         if (IN6_IS_ADDR_LINKLOCAL(address)) {
 132                 DEBUG(ctx, "Start address cannot be link-local\n");
 133                 return -EINVAL;
 134         }
 135
 136         // Address cannot be site-local
 137         if (IN6_IS_ADDR_SITELOCAL(address)) {
 138                 DEBUG(ctx, "Start address cannot be site-local\n");
 139                 return -EINVAL;
 140         }
 141
 142         // Validate the prefix
 143         if (valid_prefix(address, prefix) != 0) {
 144                 DEBUG(ctx, "Invalid prefix: %u\n", prefix);
 145                 return -EINVAL;
 146         }
 147
 148         struct loc_network* n = calloc(1, sizeof(*n));
 149         if (!n)
 150                 return -ENOMEM;
 151
 152         n->ctx = loc_ref(ctx);
 153         n->refcount = 1;
 154
 155         // Store the prefix
 156         n->prefix = prefix;
 157
 158         // Convert the prefix into a bitmask
 159         struct in6_addr bitmask = prefix_to_bitmask(n->prefix);
 160
 161         // Store the first and last address in the network
 162         n->first_address = make_first_address(address, &bitmask);
 163         n->last_address = make_last_address(&n->first_address, &bitmask);
 164
 165         // Set family
 166         if (IN6_IS_ADDR_V4MAPPED(&n->first_address))
 167                 n->family = AF_INET;
 168         else
 169                 n->family = AF_INET6;
 170
 171         DEBUG(n->ctx, "Network allocated at %p\n", n);
 172         *network = n;
 173         return 0;
 174 }
 175
 176 LOC_EXPORT int loc_network_new_from_string(struct loc_ctx* ctx, struct loc_network** network,
 177                 const char* address_string) {
 178         struct in6_addr first_address;
 179         char* prefix_string;
 180         unsigned int prefix = 128;
 181         int r = -EINVAL;
 182
 183         DEBUG(ctx, "Attempting to parse network %s\n", address_string);
 184
 185         // Make a copy of the string to work on it
 186         char* buffer = strdup(address_string);
 187         address_string = prefix_string = buffer;
 188
 189         // Split address and prefix
 190         address_string = strsep(&prefix_string, "/");
 191
 192         DEBUG(ctx, "  Split into address = %s, prefix = %s\n", address_string, prefix_string);
 193
 194         // Parse the address
 195         r = loc_parse_address(ctx, address_string, &first_address);
 196         if (r) {
 197                 DEBUG(ctx, "The address could not be parsed\n");
 198                 goto FAIL;
 199         }
 200
 201         // If a prefix was given, we will try to parse it
 202         if (prefix_string) {
 203                 // Convert prefix to integer
 204                 prefix = strtol(prefix_string, NULL, 10);
 205
 206                 if (!prefix) {
 207                         DEBUG(ctx, "The prefix was not parsable: %s\n", prefix_string);
 208                         goto FAIL;
 209                 }
 210
 211                 // Map the prefix to IPv6 if needed
 212                 if (IN6_IS_ADDR_V4MAPPED(&first_address))
 213                         prefix += 96;
 214         }
 215
 216 FAIL:
 217         // Free temporary buffer
 218         free(buffer);
 219
 220         // Exit if the parsing was unsuccessful
 221         if (r)
 222                 return r;
 223
 224         // Create a new network
 225         return loc_network_new(ctx, network, &first_address, prefix);
 226 }
 227
 228 LOC_EXPORT struct loc_network* loc_network_ref(struct loc_network* network) {
 229         network->refcount++;
 230
 231         return network;
 232 }
 233
 234 static void loc_network_free(struct loc_network* network) {
 235         DEBUG(network->ctx, "Releasing network at %p\n", network);
 236
 237         loc_unref(network->ctx);
 238         free(network);
 239 }
 240
 241 LOC_EXPORT struct loc_network* loc_network_unref(struct loc_network* network) {
 242         if (!network)
 243                 return NULL;
 244
 245         if (--network->refcount > 0)
 246                 return network;
 247
 248         loc_network_free(network);
 249         return NULL;
 250 }
 251
 252 static int format_ipv6_address(const struct in6_addr* address, char* string, size_t length) {
 253         const char* ret = inet_ntop(AF_INET6, address, string, length);
 254         if (!ret)
 255                 return -1;
 256
 257         return 0;
 258 }
 259
 260 static int format_ipv4_address(const struct in6_addr* address, char* string, size_t length) {
 261         struct in_addr ipv4_address;
 262         ipv4_address.s_addr = address->s6_addr32[3];
 263
 264         const char* ret = inet_ntop(AF_INET, &ipv4_address, string, length);
 265         if (!ret)
 266                 return -1;
 267
 268         return 0;
 269 }
 270
 271 LOC_EXPORT char* loc_network_str(struct loc_network* network) {
 272         int r;
 273         const size_t length = INET6_ADDRSTRLEN + 4;
 274
 275         char* string = malloc(length);
 276         if (!string)
 277                 return NULL;
 278
 279         unsigned int prefix = network->prefix;
 280
 281         switch (network->family) {
 282                 case AF_INET6:
 283                         r = format_ipv6_address(&network->first_address, string, length);
 284                         break;
 285
 286                 case AF_INET:
 287                         r = format_ipv4_address(&network->first_address, string, length);
 288                         prefix -= 96;
 289                         break;
 290
 291                 default:
 292                         r = -1;
 293                         break;
 294         }
 295
 296         if (r) {
 297                 ERROR(network->ctx, "Could not convert network to string: %s\n", strerror(errno));
 298                 free(string);
 299
 300                 return NULL;
 301         }
 302
 303         // Append prefix
 304         sprintf(string + strlen(string), "/%u", prefix);
 305
 306         return string;
 307 }
 308
 309 LOC_EXPORT int loc_network_address_family(struct loc_network* network) {
 310         return network->family;
 311 }
 312
 313 LOC_EXPORT unsigned int loc_network_prefix(struct loc_network* network) {
 314         switch (network->family) {
 315                 case AF_INET6:
 316                         return network->prefix;
 317
 318                 case AF_INET:
 319                         return network->prefix - 96;
 320         }
 321
 322         return 0;
 323 }
 324
 325 static char* loc_network_format_address(struct loc_network* network, const struct in6_addr* address) {
 326         const size_t length = INET6_ADDRSTRLEN;
 327
 328         char* string = malloc(length);
 329         if (!string)
 330                 return NULL;
 331
 332         int r = 0;
 333
 334         switch (network->family) {
 335                 case AF_INET6:
 336                         r = format_ipv6_address(address, string, length);
 337                         break;
 338
 339                 case AF_INET:
 340                         r = format_ipv4_address(address, string, length);
 341                         break;
 342
 343                 default:
 344                         r = -1;
 345                         break;
 346         }
 347
 348         if (r) {
 349                 ERROR(network->ctx, "Could not format IP address to string: %s\n", strerror(errno));
 350                 free(string);
 351
 352                 return NULL;
 353         }
 354
 355         return string;
 356 }
 357
 358 LOC_EXPORT const struct in6_addr* loc_network_get_first_address(struct loc_network* network) {
 359         return &network->first_address;
 360 }
 361
 362 LOC_EXPORT char* loc_network_format_first_address(struct loc_network* network) {
 363         return loc_network_format_address(network, &network->first_address);
 364 }
 365
 366 LOC_EXPORT const struct in6_addr* loc_network_get_last_address(struct loc_network* network) {
 367         return &network->last_address;
 368 }
 369
 370 LOC_EXPORT char* loc_network_format_last_address(struct loc_network* network) {
 371         return loc_network_format_address(network, &network->last_address);
 372 }
 373
 374 LOC_EXPORT int loc_network_match_address(struct loc_network* network, const struct in6_addr* address) {
 375         // Address must be larger than the start address
 376         if (in6_addr_cmp(&network->first_address, address) > 0)
 377                 return 1;
 378
 379         // Address must be smaller than the last address
 380         if (in6_addr_cmp(&network->last_address, address) < 0)
 381                 return 1;
 382
 383         // The address is inside this network
 384         return 0;
 385 }
 386
 387 LOC_EXPORT const char* loc_network_get_country_code(struct loc_network* network) {
 388         return network->country_code;
 389 }
 390
 391 LOC_EXPORT int loc_network_set_country_code(struct loc_network* network, const char* country_code) {
 392         // Set empty country code
 393         if (!country_code || !*country_code) {
 394                 *network->country_code = '\0';
 395                 return 0;
 396         }
 397
 398         // Check country code
 399         if (!loc_country_code_is_valid(country_code))
 400                 return -EINVAL;
 401
 402         loc_country_code_copy(network->country_code, country_code);
 403
 404         return 0;
 405 }
 406
 407 LOC_EXPORT int loc_network_match_country_code(struct loc_network* network, const char* country_code) {
 408         // Check country code
 409         if (!loc_country_code_is_valid(country_code))
 410                 return -EINVAL;
 411
 412         return (network->country_code[0] == country_code[0])
 413                 && (network->country_code[1] == country_code[1]);
 414 }
 415
 416 LOC_EXPORT uint32_t loc_network_get_asn(struct loc_network* network) {
 417         return network->asn;
 418 }
 419
 420 LOC_EXPORT int loc_network_set_asn(struct loc_network* network, uint32_t asn) {
 421         network->asn = asn;
 422
 423         return 0;
 424 }
 425
 426 LOC_EXPORT int loc_network_match_asn(struct loc_network* network, uint32_t asn) {
 427         return network->asn == asn;
 428 }
 429
 430 LOC_EXPORT int loc_network_has_flag(struct loc_network* network, uint32_t flag) {
 431         return network->flags & flag;
 432 }
 433
 434 LOC_EXPORT int loc_network_set_flag(struct loc_network* network, uint32_t flag) {
 435         network->flags |= flag;
 436
 437         return 0;
 438 }
 439
 440 LOC_EXPORT int loc_network_match_flag(struct loc_network* network, uint32_t flag) {
 441         return loc_network_has_flag(network, flag);
 442 }
 443
 444 LOC_EXPORT int loc_network_cmp(struct loc_network* self, struct loc_network* other) {
 445         // Compare family
 446         if (self->family > other->family)
 447                 return 1;
 448         else if (self->family < other->family)
 449                 return -1;
 450
 451         // Compare address
 452         int r = in6_addr_cmp(&self->first_address, &other->first_address);
 453         if (r)
 454                 return r;
 455
 456         // Compare prefix
 457         if (self->prefix > other->prefix)
 458                 return 1;
 459         else if (self->prefix < other->prefix)
 460                 return -1;
 461
 462         // Both networks are equal
 463         return 0;
 464 }
 465
 466 LOC_EXPORT int loc_network_gt(struct loc_network* self, struct loc_network* other) {
 467         // Families must match
 468         if (self->family != other->family)
 469                 return -1;
 470
 471         int r = in6_addr_cmp(&self->first_address, &other->first_address);
 472
 473         switch (r) {
 474                 // Smaller
 475                 case -1:
 476                         return 0;
 477
 478                 // Larger
 479                 case 1:
 480                         return 1;
 481
 482                 default:
 483                         break;
 484         }
 485
 486         if (self->prefix > other->prefix)
 487                 return 1;
 488
 489         // Dunno
 490         return 0;
 491 }
 492
 493 LOC_EXPORT int loc_network_overlaps(struct loc_network* self, struct loc_network* other) {
 494         if (loc_network_match_address(self, &other->first_address) == 0)
 495                 return 1;
 496
 497         if (loc_network_match_address(self, &other->last_address) == 0)
 498                 return 1;
 499
 500         if (loc_network_match_address(other, &self->first_address) == 0)
 501                 return 1;
 502
 503         if (loc_network_match_address(other, &self->last_address) == 0)
 504                 return 1;
 505
 506         return 0;
 507 }
 508
 509 LOC_EXPORT int loc_network_is_subnet(struct loc_network* self, struct loc_network* other) {
 510         // Check family
 511         if (self->family != other->family)
 512                 return 0;
 513
 514         // The prefix must be smaller (this avoids the more complex comparisons later)
 515         if (self->prefix > other->prefix)
 516                 return 0;
 517
 518         // If the start address of the other network is smaller than this network,
 519         // it cannot be a subnet.
 520         if (in6_addr_cmp(&self->first_address, &other->first_address) > 0)
 521                 return 0;
 522
 523         // If the end address of the other network is greater than this network,
 524         // it cannot be a subnet.
 525         if (in6_addr_cmp(&self->last_address, &other->last_address) < 0)
 526                 return 0;
 527
 528         return 1;
 529 }
 530
 531 LOC_EXPORT int loc_network_subnets(struct loc_network* network,
 532                 struct loc_network** subnet1, struct loc_network** subnet2) {
 533         int r;
 534         *subnet1 = NULL;
 535         *subnet2 = NULL;
 536
 537         // New prefix length
 538         unsigned int prefix = network->prefix + 1;
 539
 540         // Check if the new prefix is valid
 541         if (valid_prefix(&network->first_address, prefix))
 542                 return -1;
 543
 544         // Create the first half of the network
 545         r = loc_network_new(network->ctx, subnet1, &network->first_address, prefix);
 546         if (r)
 547                 return r;
 548
 549         // The next subnet starts after the first one
 550         struct in6_addr first_address = address_increment(&(*subnet1)->last_address);
 551
 552         // Create the second half of the network
 553         r = loc_network_new(network->ctx, subnet2, &first_address, prefix);
 554         if (r)
 555                 return r;
 556
 557         // Copy country code
 558         const char* country_code = loc_network_get_country_code(network);
 559         if (country_code) {
 560                 loc_network_set_country_code(*subnet1, country_code);
 561                 loc_network_set_country_code(*subnet2, country_code);
 562         }
 563
 564         // Copy ASN
 565         uint32_t asn = loc_network_get_asn(network);
 566         if (asn) {
 567                 loc_network_set_asn(*subnet1, asn);
 568                 loc_network_set_asn(*subnet2, asn);
 569         }
 570
 571         return 0;
 572 }
 573
 574 static int __loc_network_exclude(struct loc_network* network,
 575                 struct loc_network* other, struct loc_network_list* list) {
 576         struct loc_network* subnet1 = NULL;
 577         struct loc_network* subnet2 = NULL;
 578
 579         int r = loc_network_subnets(network, &subnet1, &subnet2);
 580         if (r)
 581                 goto ERROR;
 582
 583         if (loc_network_cmp(other, subnet1) == 0) {
 584                 r = loc_network_list_push(list, subnet2);
 585                 if (r)
 586                         goto ERROR;
 587
 588         } else if (loc_network_cmp(other, subnet2) == 0) {
 589                 r = loc_network_list_push(list, subnet1);
 590                 if (r)
 591                         goto ERROR;
 592
 593         } else  if (loc_network_is_subnet(subnet1, other)) {
 594                 r = loc_network_list_push(list, subnet2);
 595                 if (r)
 596                         goto ERROR;
 597
 598                 r = __loc_network_exclude(subnet1, other, list);
 599                 if (r)
 600                         goto ERROR;
 601
 602         } else if (loc_network_is_subnet(subnet2, other)) {
 603                 r = loc_network_list_push(list, subnet1);
 604                 if (r)
 605                         goto ERROR;
 606
 607                 r = __loc_network_exclude(subnet2, other, list);
 608                 if (r)
 609                         goto ERROR;
 610
 611         } else {
 612                 ERROR(network->ctx, "We should never get here\n");
 613                 r = 1;
 614                 goto ERROR;
 615         }
 616
 617 ERROR:
 618         if (subnet1)
 619                 loc_network_unref(subnet1);
 620
 621         if (subnet2)
 622                 loc_network_unref(subnet2);
 623
 624         return r;
 625 }
 626
 627 static int __loc_network_exclude_to_list(struct loc_network* self,
 628                 struct loc_network* other, struct loc_network_list* list) {
 629         // Family must match
 630         if (self->family != other->family) {
 631                 DEBUG(self->ctx, "Family mismatch\n");
 632
 633                 return 1;
 634         }
 635
 636         // Other must be a subnet of self
 637         if (!loc_network_is_subnet(self, other)) {
 638                 DEBUG(self->ctx, "Network %p is not contained in network %p\n", other, self);
 639
 640                 return 1;
 641         }
 642
 643         // We cannot perform this operation if both networks equal
 644         if (loc_network_cmp(self, other) == 0) {
 645                 DEBUG(self->ctx, "Networks %p and %p are equal\n", self, other);
 646
 647                 return 1;
 648         }
 649
 650         return __loc_network_exclude(self, other, list);
 651 }
 652
 653 LOC_EXPORT struct loc_network_list* loc_network_exclude(
 654                 struct loc_network* self, struct loc_network* other) {
 655         struct loc_network_list* list;
 656
 657 #ifdef ENABLE_DEBUG
 658         char* n1 = loc_network_str(self);
 659         char* n2 = loc_network_str(other);
 660
 661         DEBUG(self->ctx, "Returning %s excluding %s...\n", n1, n2);
 662
 663         free(n1);
 664         free(n2);
 665 #endif
 666
 667         // Create a new list with the result
 668         int r = loc_network_list_new(self->ctx, &list);
 669         if (r) {
 670                 ERROR(self->ctx, "Could not create network list: %d\n", r);
 671
 672                 return NULL;
 673         }
 674
 675         r = __loc_network_exclude_to_list(self, other, list);
 676         if (r) {
 677                 loc_network_list_unref(list);
 678
 679                 return NULL;
 680         }
 681
 682         // Return the result
 683         return list;
 684 }
 685
 686 LOC_EXPORT struct loc_network_list* loc_network_exclude_list(
 687                 struct loc_network* network, struct loc_network_list* list) {
 688         struct loc_network_list* to_check;
 689
 690         // Create a new list with all networks to look at
 691         int r = loc_network_list_new(network->ctx, &to_check);
 692         if (r)
 693                 return NULL;
 694
 695         struct loc_network* subnet = NULL;
 696         struct loc_network_list* subnets = NULL;
 697
 698         for (unsigned int i = 0; i < loc_network_list_size(list); i++) {
 699                 subnet = loc_network_list_get(list, i);
 700
 701                 // Find all excluded networks
 702                 if (!loc_network_list_contains(to_check, subnet)) {
 703                         r = __loc_network_exclude_to_list(network, subnet, to_check);
 704                         if (r) {
 705                                 loc_network_list_unref(to_check);
 706                                 loc_network_unref(subnet);
 707
 708                                 return NULL;
 709                         }
 710                 }
 711
 712                 // Cleanup
 713                 loc_network_unref(subnet);
 714         }
 715
 716         r = loc_network_list_new(network->ctx, &subnets);
 717         if (r) {
 718                 loc_network_list_unref(to_check);
 719                 return NULL;
 720         }
 721
 722         while (!loc_network_list_empty(to_check)) {
 723                 struct loc_network* subnet_to_check = loc_network_list_pop(to_check);
 724
 725                 // Marks whether this subnet passed all checks
 726                 int passed = 1;
 727
 728                 for (unsigned int i = 0; i < loc_network_list_size(list); i++) {
 729                         subnet = loc_network_list_get(list, i);
 730
 731                         // Drop this subnet if is is already in list
 732                         if (loc_network_cmp(subnet_to_check, subnet) == 0) {
 733                                 passed = 0;
 734                                 loc_network_unref(subnet);
 735                                 break;
 736                         }
 737
 738                         // Drop this subnet if is a subnet of another subnet
 739                         if (loc_network_is_subnet(subnet_to_check, subnet)) {
 740                                 passed = 0;
 741                                 loc_network_unref(subnet);
 742                                 break;
 743                         }
 744
 745                         // Break it down if it overlaps
 746                         if (loc_network_overlaps(subnet_to_check, subnet)) {
 747                                 passed = 0;
 748
 749                                 struct loc_network_list* excluded = loc_network_exclude(subnet_to_check, subnet);
 750                                 if (excluded) {
 751                                         loc_network_list_merge(to_check, excluded);
 752                                         loc_network_list_unref(excluded);
 753                                 }
 754
 755                                 loc_network_unref(subnet);
 756                                 break;
 757                         }
 758
 759                         loc_network_unref(subnet);
 760                 }
 761
 762                 if (passed) {
 763                         r = loc_network_list_push(subnets, subnet_to_check);
 764                 }
 765
 766                 loc_network_unref(subnet_to_check);
 767         }
 768
 769         loc_network_list_unref(to_check);
 770
 771         // Sort the result
 772         loc_network_list_sort(subnets);
 773
 774         return subnets;
 775 }
 776
 777 LOC_EXPORT int loc_network_to_database_v1(struct loc_network* network, struct loc_database_network_v1* dbobj) {
 778         // Add country code
 779         loc_country_code_copy(dbobj->country_code, network->country_code);
 780
 781         // Add ASN
 782         dbobj->asn = htobe32(network->asn);
 783
 784         // Flags
 785         dbobj->flags = htobe16(network->flags);
 786
 787         return 0;
 788 }
 789
 790 LOC_EXPORT int loc_network_new_from_database_v1(struct loc_ctx* ctx, struct loc_network** network,
 791                 struct in6_addr* address, unsigned int prefix, const struct loc_database_network_v1* dbobj) {
 792         char country_code[3] = "\0\0";
 793
 794         int r = loc_network_new(ctx, network, address, prefix);
 795         if (r) {
 796                 ERROR(ctx, "Could not allocate a new network: %s", strerror(-r));
 797                 return r;
 798         }
 799
 800         // Import country code
 801         loc_country_code_copy(country_code, dbobj->country_code);
 802
 803         r = loc_network_set_country_code(*network, country_code);
 804         if (r) {
 805                 ERROR(ctx, "Could not set country code: %s\n", country_code);
 806                 return r;
 807         }
 808
 809         // Import ASN
 810         uint32_t asn = be32toh(dbobj->asn);
 811         r = loc_network_set_asn(*network, asn);
 812         if (r) {
 813                 ERROR(ctx, "Could not set ASN: %d\n", asn);
 814                 return r;
 815         }
 816
 817         // Import flags
 818         int flags = be16toh(dbobj->flags);
 819         r = loc_network_set_flag(*network, flags);
 820         if (r) {
 821                 ERROR(ctx, "Could not set flags: %d\n", flags);
 822                 return r;
 823         }
 824
 825         return 0;
 826 }
 827
 828 struct loc_network_tree {
 829         struct loc_ctx* ctx;
 830         int refcount;
 831
 832         struct loc_network_tree_node* root;
 833 };
 834
 835 struct loc_network_tree_node {
 836         struct loc_ctx* ctx;
 837         int refcount;
 838
 839         struct loc_network_tree_node* zero;
 840         struct loc_network_tree_node* one;
 841
 842         struct loc_network* network;
 843 };
 844
 845 int loc_network_tree_new(struct loc_ctx* ctx, struct loc_network_tree** tree) {
 846         struct loc_network_tree* t = calloc(1, sizeof(*t));
 847         if (!t)
 848                 return -ENOMEM;
 849
 850         t->ctx = loc_ref(ctx);
 851         t->refcount = 1;
 852
 853         // Create the root node
 854         int r = loc_network_tree_node_new(ctx, &t->root);
 855         if (r) {
 856                 loc_network_tree_unref(t);
 857                 return r;
 858         }
 859
 860         DEBUG(t->ctx, "Network tree allocated at %p\n", t);
 861         *tree = t;
 862         return 0;
 863 }
 864
 865 struct loc_network_tree_node* loc_network_tree_get_root(struct loc_network_tree* tree) {
 866         return loc_network_tree_node_ref(tree->root);
 867 }
 868
 869 static struct loc_network_tree_node* loc_network_tree_get_node(struct loc_network_tree_node* node, int path) {
 870         struct loc_network_tree_node** n;
 871
 872         if (path == 0)
 873                 n = &node->zero;
 874         else
 875                 n = &node->one;
 876
 877         // If the desired node doesn't exist, yet, we will create it
 878         if (*n == NULL) {
 879                 int r = loc_network_tree_node_new(node->ctx, n);
 880                 if (r)
 881                         return NULL;
 882         }
 883
 884         return *n;
 885 }
 886
 887 static struct loc_network_tree_node* loc_network_tree_get_path(struct loc_network_tree* tree, const struct in6_addr* address, unsigned int prefix) {
 888         struct loc_network_tree_node* node = tree->root;
 889
 890         for (unsigned int i = 0; i < prefix; i++) {
 891                 // Check if the ith bit is one or zero
 892                 node = loc_network_tree_get_node(node, in6_addr_get_bit(address, i));
 893         }
 894
 895         return node;
 896 }
 897
 898 static int __loc_network_tree_walk(struct loc_ctx* ctx, struct loc_network_tree_node* node,
 899                 int(*filter_callback)(struct loc_network* network, void* data),
 900                 int(*callback)(struct loc_network* network, void* data), void* data) {
 901         int r;
 902
 903         // Finding a network ends the walk here
 904         if (node->network) {
 905                 if (filter_callback) {
 906                         int f = filter_callback(node->network, data);
 907                         if (f < 0)
 908                                 return f;
 909
 910                         // Skip network if filter function returns value greater than zero
 911                         if (f > 0)
 912                                 return 0;
 913                 }
 914
 915                 r = callback(node->network, data);
 916                 if (r)
 917                         return r;
 918         }
 919
 920         // Walk down on the left side of the tree first
 921         if (node->zero) {
 922                 r = __loc_network_tree_walk(ctx, node->zero, filter_callback, callback, data);
 923                 if (r)
 924                         return r;
 925         }
 926
 927         // Then walk on the other side
 928         if (node->one) {
 929                 r = __loc_network_tree_walk(ctx, node->one, filter_callback, callback, data);
 930                 if (r)
 931                         return r;
 932         }
 933
 934         return 0;
 935 }
 936
 937 int loc_network_tree_walk(struct loc_network_tree* tree,
 938                 int(*filter_callback)(struct loc_network* network, void* data),
 939                 int(*callback)(struct loc_network* network, void* data), void* data) {
 940         return __loc_network_tree_walk(tree->ctx, tree->root, filter_callback, callback, data);
 941 }
 942
 943 static void loc_network_tree_free(struct loc_network_tree* tree) {
 944         DEBUG(tree->ctx, "Releasing network tree at %p\n", tree);
 945
 946         loc_network_tree_node_unref(tree->root);
 947
 948         loc_unref(tree->ctx);
 949         free(tree);
 950 }
 951
 952 struct loc_network_tree* loc_network_tree_unref(struct loc_network_tree* tree) {
 953         if (--tree->refcount > 0)
 954                 return tree;
 955
 956         loc_network_tree_free(tree);
 957         return NULL;
 958 }
 959
 960 static int __loc_network_tree_dump(struct loc_network* network, void* data) {
 961         DEBUG(network->ctx, "Dumping network at %p\n", network);
 962
 963         char* s = loc_network_str(network);
 964         if (!s)
 965                 return 1;
 966
 967         INFO(network->ctx, "%s\n", s);
 968         free(s);
 969
 970         return 0;
 971 }
 972
 973 int loc_network_tree_dump(struct loc_network_tree* tree) {
 974         DEBUG(tree->ctx, "Dumping network tree at %p\n", tree);
 975
 976         return loc_network_tree_walk(tree, NULL, __loc_network_tree_dump, NULL);
 977 }
 978
 979 int loc_network_tree_add_network(struct loc_network_tree* tree, struct loc_network* network) {
 980         DEBUG(tree->ctx, "Adding network %p to tree %p\n", network, tree);
 981
 982         struct loc_network_tree_node* node = loc_network_tree_get_path(tree,
 983                         &network->first_address, network->prefix);
 984         if (!node) {
 985                 ERROR(tree->ctx, "Could not find a node\n");
 986                 return -ENOMEM;
 987         }
 988
 989         // Check if node has not been set before
 990         if (node->network) {
 991                 DEBUG(tree->ctx, "There is already a network at this path\n");
 992                 return -EBUSY;
 993         }
 994
 995         // Point node to the network
 996         node->network = loc_network_ref(network);
 997
 998         return 0;
 999 }
1000
1001 static int __loc_network_tree_count(struct loc_network* network, void* data) {
1002         size_t* counter = (size_t*)data;
1003
1004         // Increase the counter for each network
1005         counter++;
1006
1007         return 0;
1008 }
1009
1010 size_t loc_network_tree_count_networks(struct loc_network_tree* tree) {
1011         size_t counter = 0;
1012
1013         int r = loc_network_tree_walk(tree, NULL, __loc_network_tree_count, &counter);
1014         if (r)
1015                 return r;
1016
1017         return counter;
1018 }
1019
1020 static size_t __loc_network_tree_count_nodes(struct loc_network_tree_node* node) {
1021         size_t counter = 1;
1022
1023         if (node->zero)
1024                 counter += __loc_network_tree_count_nodes(node->zero);
1025
1026         if (node->one)
1027                 counter += __loc_network_tree_count_nodes(node->one);
1028
1029         return counter;
1030 }
1031
1032 size_t loc_network_tree_count_nodes(struct loc_network_tree* tree) {
1033         return __loc_network_tree_count_nodes(tree->root);
1034 }
1035
1036 int loc_network_tree_node_new(struct loc_ctx* ctx, struct loc_network_tree_node** node) {
1037         struct loc_network_tree_node* n = calloc(1, sizeof(*n));
1038         if (!n)
1039                 return -ENOMEM;
1040
1041         n->ctx = loc_ref(ctx);
1042         n->refcount = 1;
1043
1044         n->zero = n->one = NULL;
1045
1046         DEBUG(n->ctx, "Network node allocated at %p\n", n);
1047         *node = n;
1048         return 0;
1049 }
1050
1051 struct loc_network_tree_node* loc_network_tree_node_ref(struct loc_network_tree_node* node) {
1052         if (node)
1053                 node->refcount++;
1054
1055         return node;
1056 }
1057
1058 static void loc_network_tree_node_free(struct loc_network_tree_node* node) {
1059         DEBUG(node->ctx, "Releasing network node at %p\n", node);
1060
1061         if (node->network)
1062                 loc_network_unref(node->network);
1063
1064         if (node->zero)
1065                 loc_network_tree_node_unref(node->zero);
1066
1067         if (node->one)
1068                 loc_network_tree_node_unref(node->one);
1069
1070         loc_unref(node->ctx);
1071         free(node);
1072 }
1073
1074 struct loc_network_tree_node* loc_network_tree_node_unref(struct loc_network_tree_node* node) {
1075         if (!node)
1076                 return NULL;
1077
1078         if (--node->refcount > 0)
1079                 return node;
1080
1081         loc_network_tree_node_free(node);
1082         return NULL;
1083 }
1084
1085 struct loc_network_tree_node* loc_network_tree_node_get(struct loc_network_tree_node* node, unsigned int index) {
1086         if (index == 0)
1087                 node = node->zero;
1088         else
1089                 node = node->one;
1090
1091         if (!node)
1092                 return NULL;
1093
1094         return loc_network_tree_node_ref(node);
1095 }
1096
1097 int loc_network_tree_node_is_leaf(struct loc_network_tree_node* node) {
1098         return (!!node->network);
1099 }
1100
1101 struct loc_network* loc_network_tree_node_get_network(struct loc_network_tree_node* node) {
1102         return loc_network_ref(node->network);
1103 }