src/libsystemd-network/sd-dhcp-lease.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright © 2013 Intel Corporation. All rights reserved.
   4 ***/
   5
   6 #include <arpa/inet.h>
   7 #include <errno.h>
   8 #include <stdio.h>
   9 #include <stdio_ext.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12
  13 #include "sd-dhcp-lease.h"
  14
  15 #include "alloc-util.h"
  16 #include "dhcp-lease-internal.h"
  17 #include "dhcp-protocol.h"
  18 #include "dns-domain.h"
  19 #include "env-file.h"
  20 #include "fd-util.h"
  21 #include "fileio.h"
  22 #include "hexdecoct.h"
  23 #include "hostname-util.h"
  24 #include "in-addr-util.h"
  25 #include "network-internal.h"
  26 #include "parse-util.h"
  27 #include "stdio-util.h"
  28 #include "string-util.h"
  29 #include "strv.h"
  30 #include "tmpfile-util.h"
  31 #include "unaligned.h"
  32
  33 int sd_dhcp_lease_get_address(sd_dhcp_lease *lease, struct in_addr *addr) {
  34         assert_return(lease, -EINVAL);
  35         assert_return(addr, -EINVAL);
  36
  37         if (lease->address == 0)
  38                 return -ENODATA;
  39
  40         addr->s_addr = lease->address;
  41         return 0;
  42 }
  43
  44 int sd_dhcp_lease_get_broadcast(sd_dhcp_lease *lease, struct in_addr *addr) {
  45         assert_return(lease, -EINVAL);
  46         assert_return(addr, -EINVAL);
  47
  48         if (!lease->have_broadcast)
  49                 return -ENODATA;
  50
  51         addr->s_addr = lease->broadcast;
  52         return 0;
  53 }
  54
  55 int sd_dhcp_lease_get_lifetime(sd_dhcp_lease *lease, uint32_t *lifetime) {
  56         assert_return(lease, -EINVAL);
  57         assert_return(lifetime, -EINVAL);
  58
  59         if (lease->lifetime <= 0)
  60                 return -ENODATA;
  61
  62         *lifetime = lease->lifetime;
  63         return 0;
  64 }
  65
  66 int sd_dhcp_lease_get_t1(sd_dhcp_lease *lease, uint32_t *t1) {
  67         assert_return(lease, -EINVAL);
  68         assert_return(t1, -EINVAL);
  69
  70         if (lease->t1 <= 0)
  71                 return -ENODATA;
  72
  73         *t1 = lease->t1;
  74         return 0;
  75 }
  76
  77 int sd_dhcp_lease_get_t2(sd_dhcp_lease *lease, uint32_t *t2) {
  78         assert_return(lease, -EINVAL);
  79         assert_return(t2, -EINVAL);
  80
  81         if (lease->t2 <= 0)
  82                 return -ENODATA;
  83
  84         *t2 = lease->t2;
  85         return 0;
  86 }
  87
  88 int sd_dhcp_lease_get_mtu(sd_dhcp_lease *lease, uint16_t *mtu) {
  89         assert_return(lease, -EINVAL);
  90         assert_return(mtu, -EINVAL);
  91
  92         if (lease->mtu <= 0)
  93                 return -ENODATA;
  94
  95         *mtu = lease->mtu;
  96         return 0;
  97 }
  98
  99 int sd_dhcp_lease_get_dns(sd_dhcp_lease *lease, const struct in_addr **addr) {
 100         assert_return(lease, -EINVAL);
 101         assert_return(addr, -EINVAL);
 102
 103         if (lease->dns_size <= 0)
 104                 return -ENODATA;
 105
 106         *addr = lease->dns;
 107         return (int) lease->dns_size;
 108 }
 109
 110 int sd_dhcp_lease_get_ntp(sd_dhcp_lease *lease, const struct in_addr **addr) {
 111         assert_return(lease, -EINVAL);
 112         assert_return(addr, -EINVAL);
 113
 114         if (lease->ntp_size <= 0)
 115                 return -ENODATA;
 116
 117         *addr = lease->ntp;
 118         return (int) lease->ntp_size;
 119 }
 120
 121 int sd_dhcp_lease_get_domainname(sd_dhcp_lease *lease, const char **domainname) {
 122         assert_return(lease, -EINVAL);
 123         assert_return(domainname, -EINVAL);
 124
 125         if (!lease->domainname)
 126                 return -ENODATA;
 127
 128         *domainname = lease->domainname;
 129         return 0;
 130 }
 131
 132 int sd_dhcp_lease_get_hostname(sd_dhcp_lease *lease, const char **hostname) {
 133         assert_return(lease, -EINVAL);
 134         assert_return(hostname, -EINVAL);
 135
 136         if (!lease->hostname)
 137                 return -ENODATA;
 138
 139         *hostname = lease->hostname;
 140         return 0;
 141 }
 142
 143 int sd_dhcp_lease_get_root_path(sd_dhcp_lease *lease, const char **root_path) {
 144         assert_return(lease, -EINVAL);
 145         assert_return(root_path, -EINVAL);
 146
 147         if (!lease->root_path)
 148                 return -ENODATA;
 149
 150         *root_path = lease->root_path;
 151         return 0;
 152 }
 153
 154 int sd_dhcp_lease_get_router(sd_dhcp_lease *lease, const struct in_addr **addr) {
 155         assert_return(lease, -EINVAL);
 156         assert_return(addr, -EINVAL);
 157
 158         if (lease->router_size <= 0)
 159                 return -ENODATA;
 160
 161         *addr = lease->router;
 162         return (int) lease->router_size;
 163 }
 164
 165 int sd_dhcp_lease_get_netmask(sd_dhcp_lease *lease, struct in_addr *addr) {
 166         assert_return(lease, -EINVAL);
 167         assert_return(addr, -EINVAL);
 168
 169         if (!lease->have_subnet_mask)
 170                 return -ENODATA;
 171
 172         addr->s_addr = lease->subnet_mask;
 173         return 0;
 174 }
 175
 176 int sd_dhcp_lease_get_server_identifier(sd_dhcp_lease *lease, struct in_addr *addr) {
 177         assert_return(lease, -EINVAL);
 178         assert_return(addr, -EINVAL);
 179
 180         if (lease->server_address == 0)
 181                 return -ENODATA;
 182
 183         addr->s_addr = lease->server_address;
 184         return 0;
 185 }
 186
 187 int sd_dhcp_lease_get_next_server(sd_dhcp_lease *lease, struct in_addr *addr) {
 188         assert_return(lease, -EINVAL);
 189         assert_return(addr, -EINVAL);
 190
 191         if (lease->next_server == 0)
 192                 return -ENODATA;
 193
 194         addr->s_addr = lease->next_server;
 195         return 0;
 196 }
 197
 198 /*
 199  * The returned routes array must be freed by the caller.
 200  * Route objects have the same lifetime of the lease and must not be freed.
 201  */
 202 int sd_dhcp_lease_get_routes(sd_dhcp_lease *lease, sd_dhcp_route ***routes) {
 203         sd_dhcp_route **ret;
 204         unsigned i;
 205
 206         assert_return(lease, -EINVAL);
 207         assert_return(routes, -EINVAL);
 208
 209         if (lease->static_route_size <= 0)
 210                 return -ENODATA;
 211
 212         ret = new(sd_dhcp_route *, lease->static_route_size);
 213         if (!ret)
 214                 return -ENOMEM;
 215
 216         for (i = 0; i < lease->static_route_size; i++)
 217                 ret[i] = &lease->static_route[i];
 218
 219         *routes = ret;
 220         return (int) lease->static_route_size;
 221 }
 222
 223 int sd_dhcp_lease_get_search_domains(sd_dhcp_lease *lease, char ***domains) {
 224         size_t r;
 225
 226         assert_return(lease, -EINVAL);
 227         assert_return(domains, -EINVAL);
 228
 229         r = strv_length(lease->search_domains);
 230         if (r > 0) {
 231                 *domains = lease->search_domains;
 232                 return (int) r;
 233         }
 234
 235         return -ENODATA;
 236 }
 237
 238 int sd_dhcp_lease_get_vendor_specific(sd_dhcp_lease *lease, const void **data, size_t *data_len) {
 239         assert_return(lease, -EINVAL);
 240         assert_return(data, -EINVAL);
 241         assert_return(data_len, -EINVAL);
 242
 243         if (lease->vendor_specific_len <= 0)
 244                 return -ENODATA;
 245
 246         *data = lease->vendor_specific;
 247         *data_len = lease->vendor_specific_len;
 248         return 0;
 249 }
 250
 251 static sd_dhcp_lease *dhcp_lease_free(sd_dhcp_lease *lease) {
 252         assert(lease);
 253
 254         while (lease->private_options) {
 255                 struct sd_dhcp_raw_option *option = lease->private_options;
 256
 257                 LIST_REMOVE(options, lease->private_options, option);
 258
 259                 free(option->data);
 260                 free(option);
 261         }
 262
 263         free(lease->root_path);
 264         free(lease->router);
 265         free(lease->timezone);
 266         free(lease->hostname);
 267         free(lease->domainname);
 268         free(lease->dns);
 269         free(lease->ntp);
 270         free(lease->static_route);
 271         free(lease->client_id);
 272         free(lease->vendor_specific);
 273         strv_free(lease->search_domains);
 274         return mfree(lease);
 275 }
 276
 277 DEFINE_TRIVIAL_REF_UNREF_FUNC(sd_dhcp_lease, sd_dhcp_lease, dhcp_lease_free);
 278
 279 static int lease_parse_u32(const uint8_t *option, size_t len, uint32_t *ret, uint32_t min) {
 280         assert(option);
 281         assert(ret);
 282
 283         if (len != 4)
 284                 return -EINVAL;
 285
 286         *ret = unaligned_read_be32((be32_t*) option);
 287         if (*ret < min)
 288                 *ret = min;
 289
 290         return 0;
 291 }
 292
 293 static int lease_parse_u16(const uint8_t *option, size_t len, uint16_t *ret, uint16_t min) {
 294         assert(option);
 295         assert(ret);
 296
 297         if (len != 2)
 298                 return -EINVAL;
 299
 300         *ret = unaligned_read_be16((be16_t*) option);
 301         if (*ret < min)
 302                 *ret = min;
 303
 304         return 0;
 305 }
 306
 307 static int lease_parse_be32(const uint8_t *option, size_t len, be32_t *ret) {
 308         assert(option);
 309         assert(ret);
 310
 311         if (len != 4)
 312                 return -EINVAL;
 313
 314         memcpy(ret, option, 4);
 315         return 0;
 316 }
 317
 318 static int lease_parse_string(const uint8_t *option, size_t len, char **ret) {
 319         assert(option);
 320         assert(ret);
 321
 322         if (len <= 0)
 323                 *ret = mfree(*ret);
 324         else {
 325                 char *string;
 326
 327                 /*
 328                  * One trailing NUL byte is OK, we don't mind. See:
 329                  * https://github.com/systemd/systemd/issues/1337
 330                  */
 331                 if (memchr(option, 0, len - 1))
 332                         return -EINVAL;
 333
 334                 string = strndup((const char *) option, len);
 335                 if (!string)
 336                         return -ENOMEM;
 337
 338                 free_and_replace(*ret, string);
 339         }
 340
 341         return 0;
 342 }
 343
 344 static int lease_parse_domain(const uint8_t *option, size_t len, char **ret) {
 345         _cleanup_free_ char *name = NULL, *normalized = NULL;
 346         int r;
 347
 348         assert(option);
 349         assert(ret);
 350
 351         r = lease_parse_string(option, len, &name);
 352         if (r < 0)
 353                 return r;
 354         if (!name) {
 355                 *ret = mfree(*ret);
 356                 return 0;
 357         }
 358
 359         r = dns_name_normalize(name, 0, &normalized);
 360         if (r < 0)
 361                 return r;
 362
 363         if (is_localhost(normalized))
 364                 return -EINVAL;
 365
 366         if (dns_name_is_root(normalized))
 367                 return -EINVAL;
 368
 369         free_and_replace(*ret, normalized);
 370
 371         return 0;
 372 }
 373
 374 static int lease_parse_in_addrs(const uint8_t *option, size_t len, struct in_addr **ret, size_t *n_ret) {
 375         assert(option);
 376         assert(ret);
 377         assert(n_ret);
 378
 379         if (len <= 0) {
 380                 *ret = mfree(*ret);
 381                 *n_ret = 0;
 382         } else {
 383                 size_t n_addresses;
 384                 struct in_addr *addresses;
 385
 386                 if (len % 4 != 0)
 387                         return -EINVAL;
 388
 389                 n_addresses = len / 4;
 390
 391                 addresses = newdup(struct in_addr, option, n_addresses);
 392                 if (!addresses)
 393                         return -ENOMEM;
 394
 395                 free(*ret);
 396                 *ret = addresses;
 397                 *n_ret = n_addresses;
 398         }
 399
 400         return 0;
 401 }
 402
 403 static int lease_parse_routes(
 404                 const uint8_t *option, size_t len,
 405                 struct sd_dhcp_route **routes, size_t *routes_size, size_t *routes_allocated) {
 406
 407         struct in_addr addr;
 408
 409         assert(option || len <= 0);
 410         assert(routes);
 411         assert(routes_size);
 412         assert(routes_allocated);
 413
 414         if (len <= 0)
 415                 return 0;
 416
 417         if (len % 8 != 0)
 418                 return -EINVAL;
 419
 420         if (!GREEDY_REALLOC(*routes, *routes_allocated, *routes_size + (len / 8)))
 421                 return -ENOMEM;
 422
 423         while (len >= 8) {
 424                 struct sd_dhcp_route *route = *routes + *routes_size;
 425                 int r;
 426
 427                 route->option = SD_DHCP_OPTION_STATIC_ROUTE;
 428                 r = in4_addr_default_prefixlen((struct in_addr*) option, &route->dst_prefixlen);
 429                 if (r < 0) {
 430                         log_debug("Failed to determine destination prefix length from class based IP, ignoring");
 431                         continue;
 432                 }
 433
 434                 assert_se(lease_parse_be32(option, 4, &addr.s_addr) >= 0);
 435                 route->dst_addr = inet_makeaddr(inet_netof(addr), 0);
 436                 option += 4;
 437
 438                 assert_se(lease_parse_be32(option, 4, &route->gw_addr.s_addr) >= 0);
 439                 option += 4;
 440
 441                 len -= 8;
 442                 (*routes_size)++;
 443         }
 444
 445         return 0;
 446 }
 447
 448 /* parses RFC3442 Classless Static Route Option */
 449 static int lease_parse_classless_routes(
 450                 const uint8_t *option, size_t len,
 451                 struct sd_dhcp_route **routes, size_t *routes_size, size_t *routes_allocated) {
 452
 453         assert(option || len <= 0);
 454         assert(routes);
 455         assert(routes_size);
 456         assert(routes_allocated);
 457
 458         if (len <= 0)
 459                 return 0;
 460
 461         /* option format: (subnet-mask-width significant-subnet-octets gateway-ip)*  */
 462
 463         while (len > 0) {
 464                 uint8_t dst_octets;
 465                 struct sd_dhcp_route *route;
 466
 467                 if (!GREEDY_REALLOC(*routes, *routes_allocated, *routes_size + 1))
 468                         return -ENOMEM;
 469
 470                 route = *routes + *routes_size;
 471                 route->option = SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE;
 472
 473                 dst_octets = (*option == 0 ? 0 : ((*option - 1) / 8) + 1);
 474                 route->dst_prefixlen = *option;
 475                 option++;
 476                 len--;
 477
 478                 /* can't have more than 4 octets in IPv4 */
 479                 if (dst_octets > 4 || len < dst_octets)
 480                         return -EINVAL;
 481
 482                 route->dst_addr.s_addr = 0;
 483                 memcpy(&route->dst_addr.s_addr, option, dst_octets);
 484                 option += dst_octets;
 485                 len -= dst_octets;
 486
 487                 if (len < 4)
 488                         return -EINVAL;
 489
 490                 assert_se(lease_parse_be32(option, 4, &route->gw_addr.s_addr) >= 0);
 491                 option += 4;
 492                 len -= 4;
 493
 494                 (*routes_size)++;
 495         }
 496
 497         return 0;
 498 }
 499
 500 int dhcp_lease_parse_options(uint8_t code, uint8_t len, const void *option, void *userdata) {
 501         sd_dhcp_lease *lease = userdata;
 502         int r;
 503
 504         assert(lease);
 505
 506         switch(code) {
 507
 508         case SD_DHCP_OPTION_IP_ADDRESS_LEASE_TIME:
 509                 r = lease_parse_u32(option, len, &lease->lifetime, 1);
 510                 if (r < 0)
 511                         log_debug_errno(r, "Failed to parse lease time, ignoring: %m");
 512
 513                 break;
 514
 515         case SD_DHCP_OPTION_SERVER_IDENTIFIER:
 516                 r = lease_parse_be32(option, len, &lease->server_address);
 517                 if (r < 0)
 518                         log_debug_errno(r, "Failed to parse server identifier, ignoring: %m");
 519
 520                 break;
 521
 522         case SD_DHCP_OPTION_SUBNET_MASK:
 523                 r = lease_parse_be32(option, len, &lease->subnet_mask);
 524                 if (r < 0)
 525                         log_debug_errno(r, "Failed to parse subnet mask, ignoring: %m");
 526                 else
 527                         lease->have_subnet_mask = true;
 528                 break;
 529
 530         case SD_DHCP_OPTION_BROADCAST:
 531                 r = lease_parse_be32(option, len, &lease->broadcast);
 532                 if (r < 0)
 533                         log_debug_errno(r, "Failed to parse broadcast address, ignoring: %m");
 534                 else
 535                         lease->have_broadcast = true;
 536                 break;
 537
 538         case SD_DHCP_OPTION_ROUTER:
 539                 r = lease_parse_in_addrs(option, len, &lease->router, &lease->router_size);
 540                 if (r < 0)
 541                         log_debug_errno(r, "Failed to parse router addresses, ignoring: %m");
 542                 break;
 543
 544         case SD_DHCP_OPTION_DOMAIN_NAME_SERVER:
 545                 r = lease_parse_in_addrs(option, len, &lease->dns, &lease->dns_size);
 546                 if (r < 0)
 547                         log_debug_errno(r, "Failed to parse DNS server, ignoring: %m");
 548                 break;
 549
 550         case SD_DHCP_OPTION_NTP_SERVER:
 551                 r = lease_parse_in_addrs(option, len, &lease->ntp, &lease->ntp_size);
 552                 if (r < 0)
 553                         log_debug_errno(r, "Failed to parse NTP server, ignoring: %m");
 554                 break;
 555
 556         case SD_DHCP_OPTION_STATIC_ROUTE:
 557                 r = lease_parse_routes(option, len, &lease->static_route, &lease->static_route_size, &lease->static_route_allocated);
 558                 if (r < 0)
 559                         log_debug_errno(r, "Failed to parse static routes, ignoring: %m");
 560                 break;
 561
 562         case SD_DHCP_OPTION_INTERFACE_MTU:
 563                 r = lease_parse_u16(option, len, &lease->mtu, 68);
 564                 if (r < 0)
 565                         log_debug_errno(r, "Failed to parse MTU, ignoring: %m");
 566                 if (lease->mtu < DHCP_DEFAULT_MIN_SIZE) {
 567                         log_debug("MTU value of %" PRIu16 " too small. Using default MTU value of %d instead.", lease->mtu, DHCP_DEFAULT_MIN_SIZE);
 568                         lease->mtu = DHCP_DEFAULT_MIN_SIZE;
 569                 }
 570
 571                 break;
 572
 573         case SD_DHCP_OPTION_DOMAIN_NAME:
 574                 r = lease_parse_domain(option, len, &lease->domainname);
 575                 if (r < 0) {
 576                         log_debug_errno(r, "Failed to parse domain name, ignoring: %m");
 577                         return 0;
 578                 }
 579
 580                 break;
 581
 582         case SD_DHCP_OPTION_DOMAIN_SEARCH_LIST:
 583                 r = dhcp_lease_parse_search_domains(option, len, &lease->search_domains);
 584                 if (r < 0)
 585                         log_debug_errno(r, "Failed to parse Domain Search List, ignoring: %m");
 586                 break;
 587
 588         case SD_DHCP_OPTION_HOST_NAME:
 589                 r = lease_parse_domain(option, len, &lease->hostname);
 590                 if (r < 0) {
 591                         log_debug_errno(r, "Failed to parse host name, ignoring: %m");
 592                         return 0;
 593                 }
 594
 595                 break;
 596
 597         case SD_DHCP_OPTION_ROOT_PATH:
 598                 r = lease_parse_string(option, len, &lease->root_path);
 599                 if (r < 0)
 600                         log_debug_errno(r, "Failed to parse root path, ignoring: %m");
 601                 break;
 602
 603         case SD_DHCP_OPTION_RENEWAL_T1_TIME:
 604                 r = lease_parse_u32(option, len, &lease->t1, 1);
 605                 if (r < 0)
 606                         log_debug_errno(r, "Failed to parse T1 time, ignoring: %m");
 607                 break;
 608
 609         case SD_DHCP_OPTION_REBINDING_T2_TIME:
 610                 r = lease_parse_u32(option, len, &lease->t2, 1);
 611                 if (r < 0)
 612                         log_debug_errno(r, "Failed to parse T2 time, ignoring: %m");
 613                 break;
 614
 615         case SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE:
 616                 r = lease_parse_classless_routes(
 617                                 option, len,
 618                                 &lease->static_route,
 619                                 &lease->static_route_size,
 620                                 &lease->static_route_allocated);
 621                 if (r < 0)
 622                         log_debug_errno(r, "Failed to parse classless routes, ignoring: %m");
 623                 break;
 624
 625         case SD_DHCP_OPTION_NEW_TZDB_TIMEZONE: {
 626                 _cleanup_free_ char *tz = NULL;
 627
 628                 r = lease_parse_string(option, len, &tz);
 629                 if (r < 0) {
 630                         log_debug_errno(r, "Failed to parse timezone option, ignoring: %m");
 631                         return 0;
 632                 }
 633
 634                 if (!timezone_is_valid(tz, LOG_DEBUG)) {
 635                         log_debug_errno(r, "Timezone is not valid, ignoring: %m");
 636                         return 0;
 637                 }
 638
 639                 free_and_replace(lease->timezone, tz);
 640
 641                 break;
 642         }
 643
 644         case SD_DHCP_OPTION_VENDOR_SPECIFIC:
 645
 646                 if (len <= 0)
 647                         lease->vendor_specific = mfree(lease->vendor_specific);
 648                 else {
 649                         void *p;
 650
 651                         p = memdup(option, len);
 652                         if (!p)
 653                                 return -ENOMEM;
 654
 655                         free(lease->vendor_specific);
 656                         lease->vendor_specific = p;
 657                 }
 658
 659                 lease->vendor_specific_len = len;
 660                 break;
 661
 662         case SD_DHCP_OPTION_PRIVATE_BASE ... SD_DHCP_OPTION_PRIVATE_LAST:
 663                 r = dhcp_lease_insert_private_option(lease, code, option, len);
 664                 if (r < 0)
 665                         return r;
 666
 667                 break;
 668
 669         default:
 670                 log_debug("Ignoring option DHCP option %"PRIu8" while parsing.", code);
 671                 break;
 672         }
 673
 674         return 0;
 675 }
 676
 677 /* Parses compressed domain names. */
 678 int dhcp_lease_parse_search_domains(const uint8_t *option, size_t len, char ***domains) {
 679         _cleanup_strv_free_ char **names = NULL;
 680         size_t pos = 0, cnt = 0;
 681         int r;
 682
 683         assert(domains);
 684         assert_return(option && len > 0, -ENODATA);
 685
 686         while (pos < len) {
 687                 _cleanup_free_ char *name = NULL;
 688                 size_t n = 0, allocated = 0;
 689                 size_t jump_barrier = pos, next_chunk = 0;
 690                 bool first = true;
 691
 692                 for (;;) {
 693                         uint8_t c;
 694                         c = option[pos++];
 695
 696                         if (c == 0) {
 697                                 /* End of name */
 698                                 break;
 699                         } else if (c <= 63) {
 700                                 const char *label;
 701
 702                                 /* Literal label */
 703                                 label = (const char*) (option + pos);
 704                                 pos += c;
 705                                 if (pos >= len)
 706                                         return -EBADMSG;
 707
 708                                 if (!GREEDY_REALLOC(name, allocated, n + !first + DNS_LABEL_ESCAPED_MAX))
 709                                         return -ENOMEM;
 710
 711                                 if (first)
 712                                         first = false;
 713                                 else
 714                                         name[n++] = '.';
 715
 716                                 r = dns_label_escape(label, c, name + n, DNS_LABEL_ESCAPED_MAX);
 717                                 if (r < 0)
 718                                         return r;
 719
 720                                 n += r;
 721                         } else if ((c & 0xc0) == 0xc0) {
 722                                 /* Pointer */
 723
 724                                 uint8_t d;
 725                                 uint16_t ptr;
 726
 727                                 if (pos >= len)
 728                                         return -EBADMSG;
 729
 730                                 d = option[pos++];
 731                                 ptr = (uint16_t) (c & ~0xc0) << 8 | (uint16_t) d;
 732
 733                                 /* Jumps are limited to a "prior occurrence" (RFC-1035 4.1.4) */
 734                                 if (ptr >= jump_barrier)
 735                                         return -EBADMSG;
 736                                 jump_barrier = ptr;
 737
 738                                 /* Save current location so we don't end up re-parsing what's parsed so far. */
 739                                 if (next_chunk == 0)
 740                                         next_chunk = pos;
 741
 742                                 pos = ptr;
 743                         } else
 744                                 return -EBADMSG;
 745                 }
 746
 747                 if (!GREEDY_REALLOC(name, allocated, n + 1))
 748                         return -ENOMEM;
 749                 name[n] = 0;
 750
 751                 r = strv_extend(&names, name);
 752                 if (r < 0)
 753                         return r;
 754
 755                 cnt++;
 756
 757                 if (next_chunk != 0)
 758                       pos = next_chunk;
 759         }
 760
 761         *domains = TAKE_PTR(names);
 762
 763         return cnt;
 764 }
 765
 766 int dhcp_lease_insert_private_option(sd_dhcp_lease *lease, uint8_t tag, const void *data, uint8_t len) {
 767         struct sd_dhcp_raw_option *cur, *option;
 768
 769         assert(lease);
 770
 771         LIST_FOREACH(options, cur, lease->private_options) {
 772                 if (tag < cur->tag)
 773                         break;
 774                 if (tag == cur->tag) {
 775                         log_debug("Ignoring duplicate option, tagged %i.", tag);
 776                         return 0;
 777                 }
 778         }
 779
 780         option = new(struct sd_dhcp_raw_option, 1);
 781         if (!option)
 782                 return -ENOMEM;
 783
 784         option->tag = tag;
 785         option->length = len;
 786         option->data = memdup(data, len);
 787         if (!option->data) {
 788                 free(option);
 789                 return -ENOMEM;
 790         }
 791
 792         LIST_INSERT_BEFORE(options, lease->private_options, cur, option);
 793         return 0;
 794 }
 795
 796 int dhcp_lease_new(sd_dhcp_lease **ret) {
 797         sd_dhcp_lease *lease;
 798
 799         lease = new0(sd_dhcp_lease, 1);
 800         if (!lease)
 801                 return -ENOMEM;
 802
 803         lease->n_ref = 1;
 804
 805         *ret = lease;
 806         return 0;
 807 }
 808
 809 int dhcp_lease_save(sd_dhcp_lease *lease, const char *lease_file) {
 810         _cleanup_free_ char *temp_path = NULL;
 811         _cleanup_fclose_ FILE *f = NULL;
 812         struct sd_dhcp_raw_option *option;
 813         struct in_addr address;
 814         const struct in_addr *addresses;
 815         const void *client_id, *data;
 816         size_t client_id_len, data_len;
 817         char sbuf[INET_ADDRSTRLEN];
 818         const char *string;
 819         uint16_t mtu;
 820         _cleanup_free_ sd_dhcp_route **routes = NULL;
 821         char **search_domains = NULL;
 822         uint32_t t1, t2, lifetime;
 823         int r;
 824
 825         assert(lease);
 826         assert(lease_file);
 827
 828         r = fopen_temporary(lease_file, &f, &temp_path);
 829         if (r < 0)
 830                 goto fail;
 831
 832         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 833         (void) fchmod(fileno(f), 0644);
 834
 835         fprintf(f,
 836                 "# This is private data. Do not parse.\n");
 837
 838         r = sd_dhcp_lease_get_address(lease, &address);
 839         if (r >= 0)
 840                 fprintf(f, "ADDRESS=%s\n", inet_ntop(AF_INET, &address, sbuf, sizeof(sbuf)));
 841
 842         r = sd_dhcp_lease_get_netmask(lease, &address);
 843         if (r >= 0)
 844                 fprintf(f, "NETMASK=%s\n", inet_ntop(AF_INET, &address, sbuf, sizeof(sbuf)));
 845
 846         r = sd_dhcp_lease_get_router(lease, &addresses);
 847         if (r > 0) {
 848                 fputs("ROUTER=", f);
 849                 serialize_in_addrs(f, addresses, r, false, NULL);
 850                 fputc('\n', f);
 851         }
 852
 853         r = sd_dhcp_lease_get_server_identifier(lease, &address);
 854         if (r >= 0)
 855                 fprintf(f, "SERVER_ADDRESS=%s\n", inet_ntop(AF_INET, &address, sbuf, sizeof(sbuf)));
 856
 857         r = sd_dhcp_lease_get_next_server(lease, &address);
 858         if (r >= 0)
 859                 fprintf(f, "NEXT_SERVER=%s\n", inet_ntop(AF_INET, &address, sbuf, sizeof(sbuf)));
 860
 861         r = sd_dhcp_lease_get_broadcast(lease, &address);
 862         if (r >= 0)
 863                 fprintf(f, "BROADCAST=%s\n", inet_ntop(AF_INET, &address, sbuf, sizeof(sbuf)));
 864
 865         r = sd_dhcp_lease_get_mtu(lease, &mtu);
 866         if (r >= 0)
 867                 fprintf(f, "MTU=%" PRIu16 "\n", mtu);
 868
 869         r = sd_dhcp_lease_get_t1(lease, &t1);
 870         if (r >= 0)
 871                 fprintf(f, "T1=%" PRIu32 "\n", t1);
 872
 873         r = sd_dhcp_lease_get_t2(lease, &t2);
 874         if (r >= 0)
 875                 fprintf(f, "T2=%" PRIu32 "\n", t2);
 876
 877         r = sd_dhcp_lease_get_lifetime(lease, &lifetime);
 878         if (r >= 0)
 879                 fprintf(f, "LIFETIME=%" PRIu32 "\n", lifetime);
 880
 881         r = sd_dhcp_lease_get_dns(lease, &addresses);
 882         if (r > 0) {
 883                 fputs("DNS=", f);
 884                 serialize_in_addrs(f, addresses, r, false, NULL);
 885                 fputc('\n', f);
 886         }
 887
 888         r = sd_dhcp_lease_get_ntp(lease, &addresses);
 889         if (r > 0) {
 890                 fputs("NTP=", f);
 891                 serialize_in_addrs(f, addresses, r, false, NULL);
 892                 fputc('\n', f);
 893         }
 894
 895         r = sd_dhcp_lease_get_domainname(lease, &string);
 896         if (r >= 0)
 897                 fprintf(f, "DOMAINNAME=%s\n", string);
 898
 899         r = sd_dhcp_lease_get_search_domains(lease, &search_domains);
 900         if (r > 0) {
 901                 fputs("DOMAIN_SEARCH_LIST=", f);
 902                 fputstrv(f, search_domains, NULL, NULL);
 903                 fputc('\n', f);
 904         }
 905
 906         r = sd_dhcp_lease_get_hostname(lease, &string);
 907         if (r >= 0)
 908                 fprintf(f, "HOSTNAME=%s\n", string);
 909
 910         r = sd_dhcp_lease_get_root_path(lease, &string);
 911         if (r >= 0)
 912                 fprintf(f, "ROOT_PATH=%s\n", string);
 913
 914         r = sd_dhcp_lease_get_routes(lease, &routes);
 915         if (r > 0)
 916                 serialize_dhcp_routes(f, "ROUTES", routes, r);
 917
 918         r = sd_dhcp_lease_get_timezone(lease, &string);
 919         if (r >= 0)
 920                 fprintf(f, "TIMEZONE=%s\n", string);
 921
 922         r = sd_dhcp_lease_get_client_id(lease, &client_id, &client_id_len);
 923         if (r >= 0) {
 924                 _cleanup_free_ char *client_id_hex = NULL;
 925
 926                 client_id_hex = hexmem(client_id, client_id_len);
 927                 if (!client_id_hex) {
 928                         r = -ENOMEM;
 929                         goto fail;
 930                 }
 931                 fprintf(f, "CLIENTID=%s\n", client_id_hex);
 932         }
 933
 934         r = sd_dhcp_lease_get_vendor_specific(lease, &data, &data_len);
 935         if (r >= 0) {
 936                 _cleanup_free_ char *option_hex = NULL;
 937
 938                 option_hex = hexmem(data, data_len);
 939                 if (!option_hex) {
 940                         r = -ENOMEM;
 941                         goto fail;
 942                 }
 943                 fprintf(f, "VENDOR_SPECIFIC=%s\n", option_hex);
 944         }
 945
 946         LIST_FOREACH(options, option, lease->private_options) {
 947                 char key[STRLEN("OPTION_000")+1];
 948
 949                 xsprintf(key, "OPTION_%" PRIu8, option->tag);
 950                 r = serialize_dhcp_option(f, key, option->data, option->length);
 951                 if (r < 0)
 952                         goto fail;
 953         }
 954
 955         r = fflush_and_check(f);
 956         if (r < 0)
 957                 goto fail;
 958
 959         if (rename(temp_path, lease_file) < 0) {
 960                 r = -errno;
 961                 goto fail;
 962         }
 963
 964         return 0;
 965
 966 fail:
 967         if (temp_path)
 968                 (void) unlink(temp_path);
 969
 970         return log_error_errno(r, "Failed to save lease data %s: %m", lease_file);
 971 }
 972
 973 int dhcp_lease_load(sd_dhcp_lease **ret, const char *lease_file) {
 974
 975         _cleanup_(sd_dhcp_lease_unrefp) sd_dhcp_lease *lease = NULL;
 976         _cleanup_free_ char
 977                 *address = NULL,
 978                 *router = NULL,
 979                 *netmask = NULL,
 980                 *server_address = NULL,
 981                 *next_server = NULL,
 982                 *broadcast = NULL,
 983                 *dns = NULL,
 984                 *ntp = NULL,
 985                 *mtu = NULL,
 986                 *routes = NULL,
 987                 *domains = NULL,
 988                 *client_id_hex = NULL,
 989                 *vendor_specific_hex = NULL,
 990                 *lifetime = NULL,
 991                 *t1 = NULL,
 992                 *t2 = NULL,
 993                 *options[SD_DHCP_OPTION_PRIVATE_LAST - SD_DHCP_OPTION_PRIVATE_BASE + 1] = {};
 994
 995         int r, i;
 996
 997         assert(lease_file);
 998         assert(ret);
 999
1000         r = dhcp_lease_new(&lease);
1001         if (r < 0)
1002                 return r;
1003
1004         r = parse_env_file(NULL, lease_file,
1005                            "ADDRESS", &address,
1006                            "ROUTER", &router,
1007                            "NETMASK", &netmask,
1008                            "SERVER_IDENTIFIER", &server_address,
1009                            "NEXT_SERVER", &next_server,
1010                            "BROADCAST", &broadcast,
1011                            "DNS", &dns,
1012                            "NTP", &ntp,
1013                            "MTU", &mtu,
1014                            "DOMAINNAME", &lease->domainname,
1015                            "HOSTNAME", &lease->hostname,
1016                            "DOMAIN_SEARCH_LIST", &domains,
1017                            "ROOT_PATH", &lease->root_path,
1018                            "ROUTES", &routes,
1019                            "CLIENTID", &client_id_hex,
1020                            "TIMEZONE", &lease->timezone,
1021                            "VENDOR_SPECIFIC", &vendor_specific_hex,
1022                            "LIFETIME", &lifetime,
1023                            "T1", &t1,
1024                            "T2", &t2,
1025                            "OPTION_224", &options[0],
1026                            "OPTION_225", &options[1],
1027                            "OPTION_226", &options[2],
1028                            "OPTION_227", &options[3],
1029                            "OPTION_228", &options[4],
1030                            "OPTION_229", &options[5],
1031                            "OPTION_230", &options[6],
1032                            "OPTION_231", &options[7],
1033                            "OPTION_232", &options[8],
1034                            "OPTION_233", &options[9],
1035                            "OPTION_234", &options[10],
1036                            "OPTION_235", &options[11],
1037                            "OPTION_236", &options[12],
1038                            "OPTION_237", &options[13],
1039                            "OPTION_238", &options[14],
1040                            "OPTION_239", &options[15],
1041                            "OPTION_240", &options[16],
1042                            "OPTION_241", &options[17],
1043                            "OPTION_242", &options[18],
1044                            "OPTION_243", &options[19],
1045                            "OPTION_244", &options[20],
1046                            "OPTION_245", &options[21],
1047                            "OPTION_246", &options[22],
1048                            "OPTION_247", &options[23],
1049                            "OPTION_248", &options[24],
1050                            "OPTION_249", &options[25],
1051                            "OPTION_250", &options[26],
1052                            "OPTION_251", &options[27],
1053                            "OPTION_252", &options[28],
1054                            "OPTION_253", &options[29],
1055                            "OPTION_254", &options[30]);
1056         if (r < 0)
1057                 return r;
1058
1059         if (address) {
1060                 r = inet_pton(AF_INET, address, &lease->address);
1061                 if (r <= 0)
1062                         log_debug("Failed to parse address %s, ignoring.", address);
1063         }
1064
1065         if (router) {
1066                 r = deserialize_in_addrs(&lease->router, router);
1067                 if (r < 0)
1068                         log_debug_errno(r, "Failed to deserialize router addresses %s, ignoring: %m", router);
1069                 else
1070                         lease->router_size = r;
1071         }
1072
1073         if (netmask) {
1074                 r = inet_pton(AF_INET, netmask, &lease->subnet_mask);
1075                 if (r <= 0)
1076                         log_debug("Failed to parse netmask %s, ignoring.", netmask);
1077                 else
1078                         lease->have_subnet_mask = true;
1079         }
1080
1081         if (server_address) {
1082                 r = inet_pton(AF_INET, server_address, &lease->server_address);
1083                 if (r <= 0)
1084                         log_debug("Failed to parse server address %s, ignoring.", server_address);
1085         }
1086
1087         if (next_server) {
1088                 r = inet_pton(AF_INET, next_server, &lease->next_server);
1089                 if (r <= 0)
1090                         log_debug("Failed to parse next server %s, ignoring.", next_server);
1091         }
1092
1093         if (broadcast) {
1094                 r = inet_pton(AF_INET, broadcast, &lease->broadcast);
1095                 if (r <= 0)
1096                         log_debug("Failed to parse broadcast address %s, ignoring.", broadcast);
1097                 else
1098                         lease->have_broadcast = true;
1099         }
1100
1101         if (dns) {
1102                 r = deserialize_in_addrs(&lease->dns, dns);
1103                 if (r < 0)
1104                         log_debug_errno(r, "Failed to deserialize DNS servers %s, ignoring: %m", dns);
1105                 else
1106                         lease->dns_size = r;
1107         }
1108
1109         if (ntp) {
1110                 r = deserialize_in_addrs(&lease->ntp, ntp);
1111                 if (r < 0)
1112                         log_debug_errno(r, "Failed to deserialize NTP servers %s, ignoring: %m", ntp);
1113                 else
1114                         lease->ntp_size = r;
1115         }
1116
1117         if (mtu) {
1118                 r = safe_atou16(mtu, &lease->mtu);
1119                 if (r < 0)
1120                         log_debug_errno(r, "Failed to parse MTU %s, ignoring: %m", mtu);
1121         }
1122
1123         if (domains) {
1124                 _cleanup_strv_free_ char **a = NULL;
1125                 a = strv_split(domains, " ");
1126                 if (!a)
1127                         return -ENOMEM;
1128
1129                 if (!strv_isempty(a)) {
1130                         lease->search_domains = a;
1131                         a = NULL;
1132                 }
1133         }
1134
1135         if (routes) {
1136                 r = deserialize_dhcp_routes(
1137                                 &lease->static_route,
1138                                 &lease->static_route_size,
1139                                 &lease->static_route_allocated,
1140                                 routes);
1141                 if (r < 0)
1142                         log_debug_errno(r, "Failed to parse DHCP routes %s, ignoring: %m", routes);
1143         }
1144
1145         if (lifetime) {
1146                 r = safe_atou32(lifetime, &lease->lifetime);
1147                 if (r < 0)
1148                         log_debug_errno(r, "Failed to parse lifetime %s, ignoring: %m", lifetime);
1149         }
1150
1151         if (t1) {
1152                 r = safe_atou32(t1, &lease->t1);
1153                 if (r < 0)
1154                         log_debug_errno(r, "Failed to parse T1 %s, ignoring: %m", t1);
1155         }
1156
1157         if (t2) {
1158                 r = safe_atou32(t2, &lease->t2);
1159                 if (r < 0)
1160                         log_debug_errno(r, "Failed to parse T2 %s, ignoring: %m", t2);
1161         }
1162
1163         if (client_id_hex) {
1164                 r = unhexmem(client_id_hex, (size_t) -1, &lease->client_id, &lease->client_id_len);
1165                 if (r < 0)
1166                         log_debug_errno(r, "Failed to parse client ID %s, ignoring: %m", client_id_hex);
1167         }
1168
1169         if (vendor_specific_hex) {
1170                 r = unhexmem(vendor_specific_hex, (size_t) -1, &lease->vendor_specific, &lease->vendor_specific_len);
1171                 if (r < 0)
1172                         log_debug_errno(r, "Failed to parse vendor specific data %s, ignoring: %m", vendor_specific_hex);
1173         }
1174
1175         for (i = 0; i <= SD_DHCP_OPTION_PRIVATE_LAST - SD_DHCP_OPTION_PRIVATE_BASE; i++) {
1176                 _cleanup_free_ void *data = NULL;
1177                 size_t len;
1178
1179                 if (!options[i])
1180                         continue;
1181
1182                 r = unhexmem(options[i], (size_t) -1, &data, &len);
1183                 if (r < 0) {
1184                         log_debug_errno(r, "Failed to parse private DHCP option %s, ignoring: %m", options[i]);
1185                         continue;
1186                 }
1187
1188                 r = dhcp_lease_insert_private_option(lease, SD_DHCP_OPTION_PRIVATE_BASE + i, data, len);
1189                 if (r < 0)
1190                         return r;
1191         }
1192
1193         *ret = TAKE_PTR(lease);
1194
1195         return 0;
1196 }
1197
1198 int dhcp_lease_set_default_subnet_mask(sd_dhcp_lease *lease) {
1199         struct in_addr address, mask;
1200         int r;
1201
1202         assert(lease);
1203
1204         if (lease->address == 0)
1205                 return -ENODATA;
1206
1207         address.s_addr = lease->address;
1208
1209         /* fall back to the default subnet masks based on address class */
1210         r = in4_addr_default_subnet_mask(&address, &mask);
1211         if (r < 0)
1212                 return r;
1213
1214         lease->subnet_mask = mask.s_addr;
1215         lease->have_subnet_mask = true;
1216
1217         return 0;
1218 }
1219
1220 int sd_dhcp_lease_get_client_id(sd_dhcp_lease *lease, const void **client_id, size_t *client_id_len) {
1221         assert_return(lease, -EINVAL);
1222         assert_return(client_id, -EINVAL);
1223         assert_return(client_id_len, -EINVAL);
1224
1225         if (!lease->client_id)
1226                 return -ENODATA;
1227
1228         *client_id = lease->client_id;
1229         *client_id_len = lease->client_id_len;
1230
1231         return 0;
1232 }
1233
1234 int dhcp_lease_set_client_id(sd_dhcp_lease *lease, const void *client_id, size_t client_id_len) {
1235         assert_return(lease, -EINVAL);
1236         assert_return(client_id || client_id_len <= 0, -EINVAL);
1237
1238         if (client_id_len <= 0)
1239                 lease->client_id = mfree(lease->client_id);
1240         else {
1241                 void *p;
1242
1243                 p = memdup(client_id, client_id_len);
1244                 if (!p)
1245                         return -ENOMEM;
1246
1247                 free(lease->client_id);
1248                 lease->client_id = p;
1249                 lease->client_id_len = client_id_len;
1250         }
1251
1252         return 0;
1253 }
1254
1255 int sd_dhcp_lease_get_timezone(sd_dhcp_lease *lease, const char **tz) {
1256         assert_return(lease, -EINVAL);
1257         assert_return(tz, -EINVAL);
1258
1259         if (!lease->timezone)
1260                 return -ENODATA;
1261
1262         *tz = lease->timezone;
1263         return 0;
1264 }
1265
1266 int sd_dhcp_route_get_destination(sd_dhcp_route *route, struct in_addr *destination) {
1267         assert_return(route, -EINVAL);
1268         assert_return(destination, -EINVAL);
1269
1270         *destination = route->dst_addr;
1271         return 0;
1272 }
1273
1274 int sd_dhcp_route_get_destination_prefix_length(sd_dhcp_route *route, uint8_t *length) {
1275         assert_return(route, -EINVAL);
1276         assert_return(length, -EINVAL);
1277
1278         *length = route->dst_prefixlen;
1279         return 0;
1280 }
1281
1282 int sd_dhcp_route_get_gateway(sd_dhcp_route *route, struct in_addr *gateway) {
1283         assert_return(route, -EINVAL);
1284         assert_return(gateway, -EINVAL);
1285
1286         *gateway = route->gw_addr;
1287         return 0;
1288 }
1289
1290 int sd_dhcp_route_get_option(sd_dhcp_route *route) {
1291         assert_return(route, -EINVAL);
1292
1293         return route->option;
1294 }