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 void filter_bogus_addresses(struct in_addr *addresses, size_t *n) {
 375         size_t i, j;
 376
 377         /* Silently filter DNS/NTP servers supplied to us that do not make outside of the local scope. */
 378
 379         for (i = 0, j = 0; i < *n; i ++) {
 380
 381                 if (in4_addr_is_null(addresses+i) ||
 382                     in4_addr_is_localhost(addresses+i))
 383                         continue;
 384
 385                 addresses[j++] = addresses[i];
 386         }
 387
 388         *n = j;
 389 }
 390
 391 static int lease_parse_in_addrs(const uint8_t *option, size_t len, bool filter_bogus, struct in_addr **ret, size_t *n_ret) {
 392         assert(option);
 393         assert(ret);
 394         assert(n_ret);
 395
 396         if (len <= 0) {
 397                 *ret = mfree(*ret);
 398                 *n_ret = 0;
 399         } else {
 400                 size_t n_addresses;
 401                 struct in_addr *addresses;
 402
 403                 if (len % 4 != 0)
 404                         return -EINVAL;
 405
 406                 n_addresses = len / 4;
 407
 408                 addresses = newdup(struct in_addr, option, n_addresses);
 409                 if (!addresses)
 410                         return -ENOMEM;
 411
 412                 if (filter_bogus)
 413                         filter_bogus_addresses(addresses, &n_addresses);
 414
 415                 free(*ret);
 416                 *ret = addresses;
 417                 *n_ret = n_addresses;
 418         }
 419
 420         return 0;
 421 }
 422
 423 static int lease_parse_routes(
 424                 const uint8_t *option, size_t len,
 425                 struct sd_dhcp_route **routes, size_t *routes_size, size_t *routes_allocated) {
 426
 427         struct in_addr addr;
 428
 429         assert(option || len <= 0);
 430         assert(routes);
 431         assert(routes_size);
 432         assert(routes_allocated);
 433
 434         if (len <= 0)
 435                 return 0;
 436
 437         if (len % 8 != 0)
 438                 return -EINVAL;
 439
 440         if (!GREEDY_REALLOC(*routes, *routes_allocated, *routes_size + (len / 8)))
 441                 return -ENOMEM;
 442
 443         while (len >= 8) {
 444                 struct sd_dhcp_route *route = *routes + *routes_size;
 445                 int r;
 446
 447                 route->option = SD_DHCP_OPTION_STATIC_ROUTE;
 448                 r = in4_addr_default_prefixlen((struct in_addr*) option, &route->dst_prefixlen);
 449                 if (r < 0) {
 450                         log_debug("Failed to determine destination prefix length from class based IP, ignoring");
 451                         continue;
 452                 }
 453
 454                 assert_se(lease_parse_be32(option, 4, &addr.s_addr) >= 0);
 455                 route->dst_addr = inet_makeaddr(inet_netof(addr), 0);
 456                 option += 4;
 457
 458                 assert_se(lease_parse_be32(option, 4, &route->gw_addr.s_addr) >= 0);
 459                 option += 4;
 460
 461                 len -= 8;
 462                 (*routes_size)++;
 463         }
 464
 465         return 0;
 466 }
 467
 468 /* parses RFC3442 Classless Static Route Option */
 469 static int lease_parse_classless_routes(
 470                 const uint8_t *option, size_t len,
 471                 struct sd_dhcp_route **routes, size_t *routes_size, size_t *routes_allocated) {
 472
 473         assert(option || len <= 0);
 474         assert(routes);
 475         assert(routes_size);
 476         assert(routes_allocated);
 477
 478         if (len <= 0)
 479                 return 0;
 480
 481         /* option format: (subnet-mask-width significant-subnet-octets gateway-ip)*  */
 482
 483         while (len > 0) {
 484                 uint8_t dst_octets;
 485                 struct sd_dhcp_route *route;
 486
 487                 if (!GREEDY_REALLOC(*routes, *routes_allocated, *routes_size + 1))
 488                         return -ENOMEM;
 489
 490                 route = *routes + *routes_size;
 491                 route->option = SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE;
 492
 493                 dst_octets = (*option == 0 ? 0 : ((*option - 1) / 8) + 1);
 494                 route->dst_prefixlen = *option;
 495                 option++;
 496                 len--;
 497
 498                 /* can't have more than 4 octets in IPv4 */
 499                 if (dst_octets > 4 || len < dst_octets)
 500                         return -EINVAL;
 501
 502                 route->dst_addr.s_addr = 0;
 503                 memcpy(&route->dst_addr.s_addr, option, dst_octets);
 504                 option += dst_octets;
 505                 len -= dst_octets;
 506
 507                 if (len < 4)
 508                         return -EINVAL;
 509
 510                 assert_se(lease_parse_be32(option, 4, &route->gw_addr.s_addr) >= 0);
 511                 option += 4;
 512                 len -= 4;
 513
 514                 (*routes_size)++;
 515         }
 516
 517         return 0;
 518 }
 519
 520 int dhcp_lease_parse_options(uint8_t code, uint8_t len, const void *option, void *userdata) {
 521         sd_dhcp_lease *lease = userdata;
 522         int r;
 523
 524         assert(lease);
 525
 526         switch(code) {
 527
 528         case SD_DHCP_OPTION_IP_ADDRESS_LEASE_TIME:
 529                 r = lease_parse_u32(option, len, &lease->lifetime, 1);
 530                 if (r < 0)
 531                         log_debug_errno(r, "Failed to parse lease time, ignoring: %m");
 532
 533                 break;
 534
 535         case SD_DHCP_OPTION_SERVER_IDENTIFIER:
 536                 r = lease_parse_be32(option, len, &lease->server_address);
 537                 if (r < 0)
 538                         log_debug_errno(r, "Failed to parse server identifier, ignoring: %m");
 539
 540                 break;
 541
 542         case SD_DHCP_OPTION_SUBNET_MASK:
 543                 r = lease_parse_be32(option, len, &lease->subnet_mask);
 544                 if (r < 0)
 545                         log_debug_errno(r, "Failed to parse subnet mask, ignoring: %m");
 546                 else
 547                         lease->have_subnet_mask = true;
 548                 break;
 549
 550         case SD_DHCP_OPTION_BROADCAST:
 551                 r = lease_parse_be32(option, len, &lease->broadcast);
 552                 if (r < 0)
 553                         log_debug_errno(r, "Failed to parse broadcast address, ignoring: %m");
 554                 else
 555                         lease->have_broadcast = true;
 556                 break;
 557
 558         case SD_DHCP_OPTION_ROUTER:
 559                 r = lease_parse_in_addrs(option, len, false, &lease->router, &lease->router_size);
 560                 if (r < 0)
 561                         log_debug_errno(r, "Failed to parse router addresses, ignoring: %m");
 562                 break;
 563
 564         case SD_DHCP_OPTION_DOMAIN_NAME_SERVER:
 565                 r = lease_parse_in_addrs(option, len, true, &lease->dns, &lease->dns_size);
 566                 if (r < 0)
 567                         log_debug_errno(r, "Failed to parse DNS server, ignoring: %m");
 568                 break;
 569
 570         case SD_DHCP_OPTION_NTP_SERVER:
 571                 r = lease_parse_in_addrs(option, len, true, &lease->ntp, &lease->ntp_size);
 572                 if (r < 0)
 573                         log_debug_errno(r, "Failed to parse NTP server, ignoring: %m");
 574                 break;
 575
 576         case SD_DHCP_OPTION_STATIC_ROUTE:
 577                 r = lease_parse_routes(option, len, &lease->static_route, &lease->static_route_size, &lease->static_route_allocated);
 578                 if (r < 0)
 579                         log_debug_errno(r, "Failed to parse static routes, ignoring: %m");
 580                 break;
 581
 582         case SD_DHCP_OPTION_INTERFACE_MTU:
 583                 r = lease_parse_u16(option, len, &lease->mtu, 68);
 584                 if (r < 0)
 585                         log_debug_errno(r, "Failed to parse MTU, ignoring: %m");
 586                 if (lease->mtu < DHCP_DEFAULT_MIN_SIZE) {
 587                         log_debug("MTU value of %" PRIu16 " too small. Using default MTU value of %d instead.", lease->mtu, DHCP_DEFAULT_MIN_SIZE);
 588                         lease->mtu = DHCP_DEFAULT_MIN_SIZE;
 589                 }
 590
 591                 break;
 592
 593         case SD_DHCP_OPTION_DOMAIN_NAME:
 594                 r = lease_parse_domain(option, len, &lease->domainname);
 595                 if (r < 0) {
 596                         log_debug_errno(r, "Failed to parse domain name, ignoring: %m");
 597                         return 0;
 598                 }
 599
 600                 break;
 601
 602         case SD_DHCP_OPTION_DOMAIN_SEARCH_LIST:
 603                 r = dhcp_lease_parse_search_domains(option, len, &lease->search_domains);
 604                 if (r < 0)
 605                         log_debug_errno(r, "Failed to parse Domain Search List, ignoring: %m");
 606                 break;
 607
 608         case SD_DHCP_OPTION_HOST_NAME:
 609                 r = lease_parse_domain(option, len, &lease->hostname);
 610                 if (r < 0) {
 611                         log_debug_errno(r, "Failed to parse host name, ignoring: %m");
 612                         return 0;
 613                 }
 614
 615                 break;
 616
 617         case SD_DHCP_OPTION_ROOT_PATH:
 618                 r = lease_parse_string(option, len, &lease->root_path);
 619                 if (r < 0)
 620                         log_debug_errno(r, "Failed to parse root path, ignoring: %m");
 621                 break;
 622
 623         case SD_DHCP_OPTION_RENEWAL_T1_TIME:
 624                 r = lease_parse_u32(option, len, &lease->t1, 1);
 625                 if (r < 0)
 626                         log_debug_errno(r, "Failed to parse T1 time, ignoring: %m");
 627                 break;
 628
 629         case SD_DHCP_OPTION_REBINDING_T2_TIME:
 630                 r = lease_parse_u32(option, len, &lease->t2, 1);
 631                 if (r < 0)
 632                         log_debug_errno(r, "Failed to parse T2 time, ignoring: %m");
 633                 break;
 634
 635         case SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE:
 636                 r = lease_parse_classless_routes(
 637                                 option, len,
 638                                 &lease->static_route,
 639                                 &lease->static_route_size,
 640                                 &lease->static_route_allocated);
 641                 if (r < 0)
 642                         log_debug_errno(r, "Failed to parse classless routes, ignoring: %m");
 643                 break;
 644
 645         case SD_DHCP_OPTION_NEW_TZDB_TIMEZONE: {
 646                 _cleanup_free_ char *tz = NULL;
 647
 648                 r = lease_parse_string(option, len, &tz);
 649                 if (r < 0) {
 650                         log_debug_errno(r, "Failed to parse timezone option, ignoring: %m");
 651                         return 0;
 652                 }
 653
 654                 if (!timezone_is_valid(tz, LOG_DEBUG)) {
 655                         log_debug_errno(r, "Timezone is not valid, ignoring: %m");
 656                         return 0;
 657                 }
 658
 659                 free_and_replace(lease->timezone, tz);
 660
 661                 break;
 662         }
 663
 664         case SD_DHCP_OPTION_VENDOR_SPECIFIC:
 665
 666                 if (len <= 0)
 667                         lease->vendor_specific = mfree(lease->vendor_specific);
 668                 else {
 669                         void *p;
 670
 671                         p = memdup(option, len);
 672                         if (!p)
 673                                 return -ENOMEM;
 674
 675                         free(lease->vendor_specific);
 676                         lease->vendor_specific = p;
 677                 }
 678
 679                 lease->vendor_specific_len = len;
 680                 break;
 681
 682         case SD_DHCP_OPTION_PRIVATE_BASE ... SD_DHCP_OPTION_PRIVATE_LAST:
 683                 r = dhcp_lease_insert_private_option(lease, code, option, len);
 684                 if (r < 0)
 685                         return r;
 686
 687                 break;
 688
 689         default:
 690                 log_debug("Ignoring option DHCP option %"PRIu8" while parsing.", code);
 691                 break;
 692         }
 693
 694         return 0;
 695 }
 696
 697 /* Parses compressed domain names. */
 698 int dhcp_lease_parse_search_domains(const uint8_t *option, size_t len, char ***domains) {
 699         _cleanup_strv_free_ char **names = NULL;
 700         size_t pos = 0, cnt = 0;
 701         int r;
 702
 703         assert(domains);
 704         assert_return(option && len > 0, -ENODATA);
 705
 706         while (pos < len) {
 707                 _cleanup_free_ char *name = NULL;
 708                 size_t n = 0, allocated = 0;
 709                 size_t jump_barrier = pos, next_chunk = 0;
 710                 bool first = true;
 711
 712                 for (;;) {
 713                         uint8_t c;
 714                         c = option[pos++];
 715
 716                         if (c == 0) {
 717                                 /* End of name */
 718                                 break;
 719                         } else if (c <= 63) {
 720                                 const char *label;
 721
 722                                 /* Literal label */
 723                                 label = (const char*) (option + pos);
 724                                 pos += c;
 725                                 if (pos >= len)
 726                                         return -EBADMSG;
 727
 728                                 if (!GREEDY_REALLOC(name, allocated, n + !first + DNS_LABEL_ESCAPED_MAX))
 729                                         return -ENOMEM;
 730
 731                                 if (first)
 732                                         first = false;
 733                                 else
 734                                         name[n++] = '.';
 735
 736                                 r = dns_label_escape(label, c, name + n, DNS_LABEL_ESCAPED_MAX);
 737                                 if (r < 0)
 738                                         return r;
 739
 740                                 n += r;
 741                         } else if ((c & 0xc0) == 0xc0) {
 742                                 /* Pointer */
 743
 744                                 uint8_t d;
 745                                 uint16_t ptr;
 746
 747                                 if (pos >= len)
 748                                         return -EBADMSG;
 749
 750                                 d = option[pos++];
 751                                 ptr = (uint16_t) (c & ~0xc0) << 8 | (uint16_t) d;
 752
 753                                 /* Jumps are limited to a "prior occurrence" (RFC-1035 4.1.4) */
 754                                 if (ptr >= jump_barrier)
 755                                         return -EBADMSG;
 756                                 jump_barrier = ptr;
 757
 758                                 /* Save current location so we don't end up re-parsing what's parsed so far. */
 759                                 if (next_chunk == 0)
 760                                         next_chunk = pos;
 761
 762                                 pos = ptr;
 763                         } else
 764                                 return -EBADMSG;
 765                 }
 766
 767                 if (!GREEDY_REALLOC(name, allocated, n + 1))
 768                         return -ENOMEM;
 769                 name[n] = 0;
 770
 771                 r = strv_extend(&names, name);
 772                 if (r < 0)
 773                         return r;
 774
 775                 cnt++;
 776
 777                 if (next_chunk != 0)
 778                       pos = next_chunk;
 779         }
 780
 781         *domains = TAKE_PTR(names);
 782
 783         return cnt;
 784 }
 785
 786 int dhcp_lease_insert_private_option(sd_dhcp_lease *lease, uint8_t tag, const void *data, uint8_t len) {
 787         struct sd_dhcp_raw_option *cur, *option;
 788
 789         assert(lease);
 790
 791         LIST_FOREACH(options, cur, lease->private_options) {
 792                 if (tag < cur->tag)
 793                         break;
 794                 if (tag == cur->tag) {
 795                         log_debug("Ignoring duplicate option, tagged %i.", tag);
 796                         return 0;
 797                 }
 798         }
 799
 800         option = new(struct sd_dhcp_raw_option, 1);
 801         if (!option)
 802                 return -ENOMEM;
 803
 804         option->tag = tag;
 805         option->length = len;
 806         option->data = memdup(data, len);
 807         if (!option->data) {
 808                 free(option);
 809                 return -ENOMEM;
 810         }
 811
 812         LIST_INSERT_BEFORE(options, lease->private_options, cur, option);
 813         return 0;
 814 }
 815
 816 int dhcp_lease_new(sd_dhcp_lease **ret) {
 817         sd_dhcp_lease *lease;
 818
 819         lease = new0(sd_dhcp_lease, 1);
 820         if (!lease)
 821                 return -ENOMEM;
 822
 823         lease->n_ref = 1;
 824
 825         *ret = lease;
 826         return 0;
 827 }
 828
 829 int dhcp_lease_save(sd_dhcp_lease *lease, const char *lease_file) {
 830         _cleanup_free_ char *temp_path = NULL;
 831         _cleanup_fclose_ FILE *f = NULL;
 832         struct sd_dhcp_raw_option *option;
 833         struct in_addr address;
 834         const struct in_addr *addresses;
 835         const void *client_id, *data;
 836         size_t client_id_len, data_len;
 837         const char *string;
 838         uint16_t mtu;
 839         _cleanup_free_ sd_dhcp_route **routes = NULL;
 840         char **search_domains = NULL;
 841         uint32_t t1, t2, lifetime;
 842         int r;
 843
 844         assert(lease);
 845         assert(lease_file);
 846
 847         r = fopen_temporary(lease_file, &f, &temp_path);
 848         if (r < 0)
 849                 goto fail;
 850
 851         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 852         (void) fchmod(fileno(f), 0644);
 853
 854         fprintf(f,
 855                 "# This is private data. Do not parse.\n");
 856
 857         r = sd_dhcp_lease_get_address(lease, &address);
 858         if (r >= 0)
 859                 fprintf(f, "ADDRESS=%s\n", inet_ntoa(address));
 860
 861         r = sd_dhcp_lease_get_netmask(lease, &address);
 862         if (r >= 0)
 863                 fprintf(f, "NETMASK=%s\n", inet_ntoa(address));
 864
 865         r = sd_dhcp_lease_get_router(lease, &addresses);
 866         if (r > 0) {
 867                 fputs("ROUTER=", f);
 868                 serialize_in_addrs(f, addresses, r);
 869                 fputc('\n', f);
 870         }
 871
 872         r = sd_dhcp_lease_get_server_identifier(lease, &address);
 873         if (r >= 0)
 874                 fprintf(f, "SERVER_ADDRESS=%s\n", inet_ntoa(address));
 875
 876         r = sd_dhcp_lease_get_next_server(lease, &address);
 877         if (r >= 0)
 878                 fprintf(f, "NEXT_SERVER=%s\n", inet_ntoa(address));
 879
 880         r = sd_dhcp_lease_get_broadcast(lease, &address);
 881         if (r >= 0)
 882                 fprintf(f, "BROADCAST=%s\n", inet_ntoa(address));
 883
 884         r = sd_dhcp_lease_get_mtu(lease, &mtu);
 885         if (r >= 0)
 886                 fprintf(f, "MTU=%" PRIu16 "\n", mtu);
 887
 888         r = sd_dhcp_lease_get_t1(lease, &t1);
 889         if (r >= 0)
 890                 fprintf(f, "T1=%" PRIu32 "\n", t1);
 891
 892         r = sd_dhcp_lease_get_t2(lease, &t2);
 893         if (r >= 0)
 894                 fprintf(f, "T2=%" PRIu32 "\n", t2);
 895
 896         r = sd_dhcp_lease_get_lifetime(lease, &lifetime);
 897         if (r >= 0)
 898                 fprintf(f, "LIFETIME=%" PRIu32 "\n", lifetime);
 899
 900         r = sd_dhcp_lease_get_dns(lease, &addresses);
 901         if (r > 0) {
 902                 fputs("DNS=", f);
 903                 serialize_in_addrs(f, addresses, r);
 904                 fputc('\n', f);
 905         }
 906
 907         r = sd_dhcp_lease_get_ntp(lease, &addresses);
 908         if (r > 0) {
 909                 fputs("NTP=", f);
 910                 serialize_in_addrs(f, addresses, r);
 911                 fputc('\n', f);
 912         }
 913
 914         r = sd_dhcp_lease_get_domainname(lease, &string);
 915         if (r >= 0)
 916                 fprintf(f, "DOMAINNAME=%s\n", string);
 917
 918         r = sd_dhcp_lease_get_search_domains(lease, &search_domains);
 919         if (r > 0) {
 920                 fputs("DOMAIN_SEARCH_LIST=", f);
 921                 fputstrv(f, search_domains, NULL, NULL);
 922                 fputc('\n', f);
 923         }
 924
 925         r = sd_dhcp_lease_get_hostname(lease, &string);
 926         if (r >= 0)
 927                 fprintf(f, "HOSTNAME=%s\n", string);
 928
 929         r = sd_dhcp_lease_get_root_path(lease, &string);
 930         if (r >= 0)
 931                 fprintf(f, "ROOT_PATH=%s\n", string);
 932
 933         r = sd_dhcp_lease_get_routes(lease, &routes);
 934         if (r > 0)
 935                 serialize_dhcp_routes(f, "ROUTES", routes, r);
 936
 937         r = sd_dhcp_lease_get_timezone(lease, &string);
 938         if (r >= 0)
 939                 fprintf(f, "TIMEZONE=%s\n", string);
 940
 941         r = sd_dhcp_lease_get_client_id(lease, &client_id, &client_id_len);
 942         if (r >= 0) {
 943                 _cleanup_free_ char *client_id_hex = NULL;
 944
 945                 client_id_hex = hexmem(client_id, client_id_len);
 946                 if (!client_id_hex) {
 947                         r = -ENOMEM;
 948                         goto fail;
 949                 }
 950                 fprintf(f, "CLIENTID=%s\n", client_id_hex);
 951         }
 952
 953         r = sd_dhcp_lease_get_vendor_specific(lease, &data, &data_len);
 954         if (r >= 0) {
 955                 _cleanup_free_ char *option_hex = NULL;
 956
 957                 option_hex = hexmem(data, data_len);
 958                 if (!option_hex) {
 959                         r = -ENOMEM;
 960                         goto fail;
 961                 }
 962                 fprintf(f, "VENDOR_SPECIFIC=%s\n", option_hex);
 963         }
 964
 965         LIST_FOREACH(options, option, lease->private_options) {
 966                 char key[STRLEN("OPTION_000")+1];
 967
 968                 xsprintf(key, "OPTION_%" PRIu8, option->tag);
 969                 r = serialize_dhcp_option(f, key, option->data, option->length);
 970                 if (r < 0)
 971                         goto fail;
 972         }
 973
 974         r = fflush_and_check(f);
 975         if (r < 0)
 976                 goto fail;
 977
 978         if (rename(temp_path, lease_file) < 0) {
 979                 r = -errno;
 980                 goto fail;
 981         }
 982
 983         return 0;
 984
 985 fail:
 986         if (temp_path)
 987                 (void) unlink(temp_path);
 988
 989         return log_error_errno(r, "Failed to save lease data %s: %m", lease_file);
 990 }
 991
 992 int dhcp_lease_load(sd_dhcp_lease **ret, const char *lease_file) {
 993
 994         _cleanup_(sd_dhcp_lease_unrefp) sd_dhcp_lease *lease = NULL;
 995         _cleanup_free_ char
 996                 *address = NULL,
 997                 *router = NULL,
 998                 *netmask = NULL,
 999                 *server_address = NULL,
1000                 *next_server = NULL,
1001                 *broadcast = NULL,
1002                 *dns = NULL,
1003                 *ntp = NULL,
1004                 *mtu = NULL,
1005                 *routes = NULL,
1006                 *domains = NULL,
1007                 *client_id_hex = NULL,
1008                 *vendor_specific_hex = NULL,
1009                 *lifetime = NULL,
1010                 *t1 = NULL,
1011                 *t2 = NULL,
1012                 *options[SD_DHCP_OPTION_PRIVATE_LAST - SD_DHCP_OPTION_PRIVATE_BASE + 1] = {};
1013
1014         int r, i;
1015
1016         assert(lease_file);
1017         assert(ret);
1018
1019         r = dhcp_lease_new(&lease);
1020         if (r < 0)
1021                 return r;
1022
1023         r = parse_env_file(NULL, lease_file,
1024                            "ADDRESS", &address,
1025                            "ROUTER", &router,
1026                            "NETMASK", &netmask,
1027                            "SERVER_IDENTIFIER", &server_address,
1028                            "NEXT_SERVER", &next_server,
1029                            "BROADCAST", &broadcast,
1030                            "DNS", &dns,
1031                            "NTP", &ntp,
1032                            "MTU", &mtu,
1033                            "DOMAINNAME", &lease->domainname,
1034                            "HOSTNAME", &lease->hostname,
1035                            "DOMAIN_SEARCH_LIST", &domains,
1036                            "ROOT_PATH", &lease->root_path,
1037                            "ROUTES", &routes,
1038                            "CLIENTID", &client_id_hex,
1039                            "TIMEZONE", &lease->timezone,
1040                            "VENDOR_SPECIFIC", &vendor_specific_hex,
1041                            "LIFETIME", &lifetime,
1042                            "T1", &t1,
1043                            "T2", &t2,
1044                            "OPTION_224", &options[0],
1045                            "OPTION_225", &options[1],
1046                            "OPTION_226", &options[2],
1047                            "OPTION_227", &options[3],
1048                            "OPTION_228", &options[4],
1049                            "OPTION_229", &options[5],
1050                            "OPTION_230", &options[6],
1051                            "OPTION_231", &options[7],
1052                            "OPTION_232", &options[8],
1053                            "OPTION_233", &options[9],
1054                            "OPTION_234", &options[10],
1055                            "OPTION_235", &options[11],
1056                            "OPTION_236", &options[12],
1057                            "OPTION_237", &options[13],
1058                            "OPTION_238", &options[14],
1059                            "OPTION_239", &options[15],
1060                            "OPTION_240", &options[16],
1061                            "OPTION_241", &options[17],
1062                            "OPTION_242", &options[18],
1063                            "OPTION_243", &options[19],
1064                            "OPTION_244", &options[20],
1065                            "OPTION_245", &options[21],
1066                            "OPTION_246", &options[22],
1067                            "OPTION_247", &options[23],
1068                            "OPTION_248", &options[24],
1069                            "OPTION_249", &options[25],
1070                            "OPTION_250", &options[26],
1071                            "OPTION_251", &options[27],
1072                            "OPTION_252", &options[28],
1073                            "OPTION_253", &options[29],
1074                            "OPTION_254", &options[30]);
1075         if (r < 0)
1076                 return r;
1077
1078         if (address) {
1079                 r = inet_pton(AF_INET, address, &lease->address);
1080                 if (r <= 0)
1081                         log_debug("Failed to parse address %s, ignoring.", address);
1082         }
1083
1084         if (router) {
1085                 r = deserialize_in_addrs(&lease->router, router);
1086                 if (r < 0)
1087                         log_debug_errno(r, "Failed to deserialize router addresses %s, ignoring: %m", router);
1088                 else
1089                         lease->router_size = r;
1090         }
1091
1092         if (netmask) {
1093                 r = inet_pton(AF_INET, netmask, &lease->subnet_mask);
1094                 if (r <= 0)
1095                         log_debug("Failed to parse netmask %s, ignoring.", netmask);
1096                 else
1097                         lease->have_subnet_mask = true;
1098         }
1099
1100         if (server_address) {
1101                 r = inet_pton(AF_INET, server_address, &lease->server_address);
1102                 if (r <= 0)
1103                         log_debug("Failed to parse server address %s, ignoring.", server_address);
1104         }
1105
1106         if (next_server) {
1107                 r = inet_pton(AF_INET, next_server, &lease->next_server);
1108                 if (r <= 0)
1109                         log_debug("Failed to parse next server %s, ignoring.", next_server);
1110         }
1111
1112         if (broadcast) {
1113                 r = inet_pton(AF_INET, broadcast, &lease->broadcast);
1114                 if (r <= 0)
1115                         log_debug("Failed to parse broadcast address %s, ignoring.", broadcast);
1116                 else
1117                         lease->have_broadcast = true;
1118         }
1119
1120         if (dns) {
1121                 r = deserialize_in_addrs(&lease->dns, dns);
1122                 if (r < 0)
1123                         log_debug_errno(r, "Failed to deserialize DNS servers %s, ignoring: %m", dns);
1124                 else
1125                         lease->dns_size = r;
1126         }
1127
1128         if (ntp) {
1129                 r = deserialize_in_addrs(&lease->ntp, ntp);
1130                 if (r < 0)
1131                         log_debug_errno(r, "Failed to deserialize NTP servers %s, ignoring: %m", ntp);
1132                 else
1133                         lease->ntp_size = r;
1134         }
1135
1136         if (mtu) {
1137                 r = safe_atou16(mtu, &lease->mtu);
1138                 if (r < 0)
1139                         log_debug_errno(r, "Failed to parse MTU %s, ignoring: %m", mtu);
1140         }
1141
1142         if (domains) {
1143                 _cleanup_strv_free_ char **a = NULL;
1144                 a = strv_split(domains, " ");
1145                 if (!a)
1146                         return -ENOMEM;
1147
1148                 if (!strv_isempty(a)) {
1149                         lease->search_domains = a;
1150                         a = NULL;
1151                 }
1152         }
1153
1154         if (routes) {
1155                 r = deserialize_dhcp_routes(
1156                                 &lease->static_route,
1157                                 &lease->static_route_size,
1158                                 &lease->static_route_allocated,
1159                                 routes);
1160                 if (r < 0)
1161                         log_debug_errno(r, "Failed to parse DHCP routes %s, ignoring: %m", routes);
1162         }
1163
1164         if (lifetime) {
1165                 r = safe_atou32(lifetime, &lease->lifetime);
1166                 if (r < 0)
1167                         log_debug_errno(r, "Failed to parse lifetime %s, ignoring: %m", lifetime);
1168         }
1169
1170         if (t1) {
1171                 r = safe_atou32(t1, &lease->t1);
1172                 if (r < 0)
1173                         log_debug_errno(r, "Failed to parse T1 %s, ignoring: %m", t1);
1174         }
1175
1176         if (t2) {
1177                 r = safe_atou32(t2, &lease->t2);
1178                 if (r < 0)
1179                         log_debug_errno(r, "Failed to parse T2 %s, ignoring: %m", t2);
1180         }
1181
1182         if (client_id_hex) {
1183                 r = unhexmem(client_id_hex, (size_t) -1, &lease->client_id, &lease->client_id_len);
1184                 if (r < 0)
1185                         log_debug_errno(r, "Failed to parse client ID %s, ignoring: %m", client_id_hex);
1186         }
1187
1188         if (vendor_specific_hex) {
1189                 r = unhexmem(vendor_specific_hex, (size_t) -1, &lease->vendor_specific, &lease->vendor_specific_len);
1190                 if (r < 0)
1191                         log_debug_errno(r, "Failed to parse vendor specific data %s, ignoring: %m", vendor_specific_hex);
1192         }
1193
1194         for (i = 0; i <= SD_DHCP_OPTION_PRIVATE_LAST - SD_DHCP_OPTION_PRIVATE_BASE; i++) {
1195                 _cleanup_free_ void *data = NULL;
1196                 size_t len;
1197
1198                 if (!options[i])
1199                         continue;
1200
1201                 r = unhexmem(options[i], (size_t) -1, &data, &len);
1202                 if (r < 0) {
1203                         log_debug_errno(r, "Failed to parse private DHCP option %s, ignoring: %m", options[i]);
1204                         continue;
1205                 }
1206
1207                 r = dhcp_lease_insert_private_option(lease, SD_DHCP_OPTION_PRIVATE_BASE + i, data, len);
1208                 if (r < 0)
1209                         return r;
1210         }
1211
1212         *ret = TAKE_PTR(lease);
1213
1214         return 0;
1215 }
1216
1217 int dhcp_lease_set_default_subnet_mask(sd_dhcp_lease *lease) {
1218         struct in_addr address, mask;
1219         int r;
1220
1221         assert(lease);
1222
1223         if (lease->address == 0)
1224                 return -ENODATA;
1225
1226         address.s_addr = lease->address;
1227
1228         /* fall back to the default subnet masks based on address class */
1229         r = in4_addr_default_subnet_mask(&address, &mask);
1230         if (r < 0)
1231                 return r;
1232
1233         lease->subnet_mask = mask.s_addr;
1234         lease->have_subnet_mask = true;
1235
1236         return 0;
1237 }
1238
1239 int sd_dhcp_lease_get_client_id(sd_dhcp_lease *lease, const void **client_id, size_t *client_id_len) {
1240         assert_return(lease, -EINVAL);
1241         assert_return(client_id, -EINVAL);
1242         assert_return(client_id_len, -EINVAL);
1243
1244         if (!lease->client_id)
1245                 return -ENODATA;
1246
1247         *client_id = lease->client_id;
1248         *client_id_len = lease->client_id_len;
1249
1250         return 0;
1251 }
1252
1253 int dhcp_lease_set_client_id(sd_dhcp_lease *lease, const void *client_id, size_t client_id_len) {
1254         assert_return(lease, -EINVAL);
1255         assert_return(client_id || client_id_len <= 0, -EINVAL);
1256
1257         if (client_id_len <= 0)
1258                 lease->client_id = mfree(lease->client_id);
1259         else {
1260                 void *p;
1261
1262                 p = memdup(client_id, client_id_len);
1263                 if (!p)
1264                         return -ENOMEM;
1265
1266                 free(lease->client_id);
1267                 lease->client_id = p;
1268                 lease->client_id_len = client_id_len;
1269         }
1270
1271         return 0;
1272 }
1273
1274 int sd_dhcp_lease_get_timezone(sd_dhcp_lease *lease, const char **tz) {
1275         assert_return(lease, -EINVAL);
1276         assert_return(tz, -EINVAL);
1277
1278         if (!lease->timezone)
1279                 return -ENODATA;
1280
1281         *tz = lease->timezone;
1282         return 0;
1283 }
1284
1285 int sd_dhcp_route_get_destination(sd_dhcp_route *route, struct in_addr *destination) {
1286         assert_return(route, -EINVAL);
1287         assert_return(destination, -EINVAL);
1288
1289         *destination = route->dst_addr;
1290         return 0;
1291 }
1292
1293 int sd_dhcp_route_get_destination_prefix_length(sd_dhcp_route *route, uint8_t *length) {
1294         assert_return(route, -EINVAL);
1295         assert_return(length, -EINVAL);
1296
1297         *length = route->dst_prefixlen;
1298         return 0;
1299 }
1300
1301 int sd_dhcp_route_get_gateway(sd_dhcp_route *route, struct in_addr *gateway) {
1302         assert_return(route, -EINVAL);
1303         assert_return(gateway, -EINVAL);
1304
1305         *gateway = route->gw_addr;
1306         return 0;
1307 }
1308
1309 int sd_dhcp_route_get_option(sd_dhcp_route *route) {
1310         assert_return(route, -EINVAL);
1311
1312         return route->option;
1313 }