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 "fd-util.h"
  20 #include "fileio.h"
  21 #include "hexdecoct.h"
  22 #include "hostname-util.h"
  23 #include "in-addr-util.h"
  24 #include "network-internal.h"
  25 #include "parse-util.h"
  26 #include "stdio-util.h"
  27 #include "string-util.h"
  28 #include "strv.h"
  29 #include "unaligned.h"
  30
  31 int sd_dhcp_lease_get_address(sd_dhcp_lease *lease, struct in_addr *addr) {
  32         assert_return(lease, -EINVAL);
  33         assert_return(addr, -EINVAL);
  34
  35         if (lease->address == 0)
  36                 return -ENODATA;
  37
  38         addr->s_addr = lease->address;
  39         return 0;
  40 }
  41
  42 int sd_dhcp_lease_get_broadcast(sd_dhcp_lease *lease, struct in_addr *addr) {
  43         assert_return(lease, -EINVAL);
  44         assert_return(addr, -EINVAL);
  45
  46         if (!lease->have_broadcast)
  47                 return -ENODATA;
  48
  49         addr->s_addr = lease->broadcast;
  50         return 0;
  51 }
  52
  53 int sd_dhcp_lease_get_lifetime(sd_dhcp_lease *lease, uint32_t *lifetime) {
  54         assert_return(lease, -EINVAL);
  55         assert_return(lifetime, -EINVAL);
  56
  57         if (lease->lifetime <= 0)
  58                 return -ENODATA;
  59
  60         *lifetime = lease->lifetime;
  61         return 0;
  62 }
  63
  64 int sd_dhcp_lease_get_t1(sd_dhcp_lease *lease, uint32_t *t1) {
  65         assert_return(lease, -EINVAL);
  66         assert_return(t1, -EINVAL);
  67
  68         if (lease->t1 <= 0)
  69                 return -ENODATA;
  70
  71         *t1 = lease->t1;
  72         return 0;
  73 }
  74
  75 int sd_dhcp_lease_get_t2(sd_dhcp_lease *lease, uint32_t *t2) {
  76         assert_return(lease, -EINVAL);
  77         assert_return(t2, -EINVAL);
  78
  79         if (lease->t2 <= 0)
  80                 return -ENODATA;
  81
  82         *t2 = lease->t2;
  83         return 0;
  84 }
  85
  86 int sd_dhcp_lease_get_mtu(sd_dhcp_lease *lease, uint16_t *mtu) {
  87         assert_return(lease, -EINVAL);
  88         assert_return(mtu, -EINVAL);
  89
  90         if (lease->mtu <= 0)
  91                 return -ENODATA;
  92
  93         *mtu = lease->mtu;
  94         return 0;
  95 }
  96
  97 int sd_dhcp_lease_get_dns(sd_dhcp_lease *lease, const struct in_addr **addr) {
  98         assert_return(lease, -EINVAL);
  99         assert_return(addr, -EINVAL);
 100
 101         if (lease->dns_size <= 0)
 102                 return -ENODATA;
 103
 104         *addr = lease->dns;
 105         return (int) lease->dns_size;
 106 }
 107
 108 int sd_dhcp_lease_get_ntp(sd_dhcp_lease *lease, const struct in_addr **addr) {
 109         assert_return(lease, -EINVAL);
 110         assert_return(addr, -EINVAL);
 111
 112         if (lease->ntp_size <= 0)
 113                 return -ENODATA;
 114
 115         *addr = lease->ntp;
 116         return (int) lease->ntp_size;
 117 }
 118
 119 int sd_dhcp_lease_get_domainname(sd_dhcp_lease *lease, const char **domainname) {
 120         assert_return(lease, -EINVAL);
 121         assert_return(domainname, -EINVAL);
 122
 123         if (!lease->domainname)
 124                 return -ENODATA;
 125
 126         *domainname = lease->domainname;
 127         return 0;
 128 }
 129
 130 int sd_dhcp_lease_get_hostname(sd_dhcp_lease *lease, const char **hostname) {
 131         assert_return(lease, -EINVAL);
 132         assert_return(hostname, -EINVAL);
 133
 134         if (!lease->hostname)
 135                 return -ENODATA;
 136
 137         *hostname = lease->hostname;
 138         return 0;
 139 }
 140
 141 int sd_dhcp_lease_get_root_path(sd_dhcp_lease *lease, const char **root_path) {
 142         assert_return(lease, -EINVAL);
 143         assert_return(root_path, -EINVAL);
 144
 145         if (!lease->root_path)
 146                 return -ENODATA;
 147
 148         *root_path = lease->root_path;
 149         return 0;
 150 }
 151
 152 int sd_dhcp_lease_get_router(sd_dhcp_lease *lease, struct in_addr *addr) {
 153         assert_return(lease, -EINVAL);
 154         assert_return(addr, -EINVAL);
 155
 156         if (lease->router == 0)
 157                 return -ENODATA;
 158
 159         addr->s_addr = lease->router;
 160         return 0;
 161 }
 162
 163 int sd_dhcp_lease_get_netmask(sd_dhcp_lease *lease, struct in_addr *addr) {
 164         assert_return(lease, -EINVAL);
 165         assert_return(addr, -EINVAL);
 166
 167         if (!lease->have_subnet_mask)
 168                 return -ENODATA;
 169
 170         addr->s_addr = lease->subnet_mask;
 171         return 0;
 172 }
 173
 174 int sd_dhcp_lease_get_server_identifier(sd_dhcp_lease *lease, struct in_addr *addr) {
 175         assert_return(lease, -EINVAL);
 176         assert_return(addr, -EINVAL);
 177
 178         if (lease->server_address == 0)
 179                 return -ENODATA;
 180
 181         addr->s_addr = lease->server_address;
 182         return 0;
 183 }
 184
 185 int sd_dhcp_lease_get_next_server(sd_dhcp_lease *lease, struct in_addr *addr) {
 186         assert_return(lease, -EINVAL);
 187         assert_return(addr, -EINVAL);
 188
 189         if (lease->next_server == 0)
 190                 return -ENODATA;
 191
 192         addr->s_addr = lease->next_server;
 193         return 0;
 194 }
 195
 196 /*
 197  * The returned routes array must be freed by the caller.
 198  * Route objects have the same lifetime of the lease and must not be freed.
 199  */
 200 int sd_dhcp_lease_get_routes(sd_dhcp_lease *lease, sd_dhcp_route ***routes) {
 201         sd_dhcp_route **ret;
 202         unsigned i;
 203
 204         assert_return(lease, -EINVAL);
 205         assert_return(routes, -EINVAL);
 206
 207         if (lease->static_route_size <= 0)
 208                 return -ENODATA;
 209
 210         ret = new(sd_dhcp_route *, lease->static_route_size);
 211         if (!ret)
 212                 return -ENOMEM;
 213
 214         for (i = 0; i < lease->static_route_size; i++)
 215                 ret[i] = &lease->static_route[i];
 216
 217         *routes = ret;
 218         return (int) lease->static_route_size;
 219 }
 220
 221 int sd_dhcp_lease_get_search_domains(sd_dhcp_lease *lease, char ***domains) {
 222         size_t r;
 223
 224         assert_return(lease, -EINVAL);
 225         assert_return(domains, -EINVAL);
 226
 227         r = strv_length(lease->search_domains);
 228         if (r > 0) {
 229                 *domains = lease->search_domains;
 230                 return (int) r;
 231         }
 232
 233         return -ENODATA;
 234 }
 235
 236 int sd_dhcp_lease_get_vendor_specific(sd_dhcp_lease *lease, const void **data, size_t *data_len) {
 237         assert_return(lease, -EINVAL);
 238         assert_return(data, -EINVAL);
 239         assert_return(data_len, -EINVAL);
 240
 241         if (lease->vendor_specific_len <= 0)
 242                 return -ENODATA;
 243
 244         *data = lease->vendor_specific;
 245         *data_len = lease->vendor_specific_len;
 246         return 0;
 247 }
 248
 249 static sd_dhcp_lease *dhcp_lease_free(sd_dhcp_lease *lease) {
 250         assert(lease);
 251
 252         while (lease->private_options) {
 253                 struct sd_dhcp_raw_option *option = lease->private_options;
 254
 255                 LIST_REMOVE(options, lease->private_options, option);
 256
 257                 free(option->data);
 258                 free(option);
 259         }
 260
 261         free(lease->root_path);
 262         free(lease->timezone);
 263         free(lease->hostname);
 264         free(lease->domainname);
 265         free(lease->dns);
 266         free(lease->ntp);
 267         free(lease->static_route);
 268         free(lease->client_id);
 269         free(lease->vendor_specific);
 270         strv_free(lease->search_domains);
 271         return mfree(lease);
 272 }
 273
 274 DEFINE_TRIVIAL_REF_UNREF_FUNC(sd_dhcp_lease, sd_dhcp_lease, dhcp_lease_free);
 275
 276 static int lease_parse_u32(const uint8_t *option, size_t len, uint32_t *ret, uint32_t min) {
 277         assert(option);
 278         assert(ret);
 279
 280         if (len != 4)
 281                 return -EINVAL;
 282
 283         *ret = unaligned_read_be32((be32_t*) option);
 284         if (*ret < min)
 285                 *ret = min;
 286
 287         return 0;
 288 }
 289
 290 static int lease_parse_u16(const uint8_t *option, size_t len, uint16_t *ret, uint16_t min) {
 291         assert(option);
 292         assert(ret);
 293
 294         if (len != 2)
 295                 return -EINVAL;
 296
 297         *ret = unaligned_read_be16((be16_t*) option);
 298         if (*ret < min)
 299                 *ret = min;
 300
 301         return 0;
 302 }
 303
 304 static int lease_parse_be32(const uint8_t *option, size_t len, be32_t *ret) {
 305         assert(option);
 306         assert(ret);
 307
 308         if (len != 4)
 309                 return -EINVAL;
 310
 311         memcpy(ret, option, 4);
 312         return 0;
 313 }
 314
 315 static int lease_parse_string(const uint8_t *option, size_t len, char **ret) {
 316         assert(option);
 317         assert(ret);
 318
 319         if (len <= 0)
 320                 *ret = mfree(*ret);
 321         else {
 322                 char *string;
 323
 324                 /*
 325                  * One trailing NUL byte is OK, we don't mind. See:
 326                  * https://github.com/systemd/systemd/issues/1337
 327                  */
 328                 if (memchr(option, 0, len - 1))
 329                         return -EINVAL;
 330
 331                 string = strndup((const char *) option, len);
 332                 if (!string)
 333                         return -ENOMEM;
 334
 335                 free_and_replace(*ret, string);
 336         }
 337
 338         return 0;
 339 }
 340
 341 static int lease_parse_domain(const uint8_t *option, size_t len, char **ret) {
 342         _cleanup_free_ char *name = NULL, *normalized = NULL;
 343         int r;
 344
 345         assert(option);
 346         assert(ret);
 347
 348         r = lease_parse_string(option, len, &name);
 349         if (r < 0)
 350                 return r;
 351         if (!name) {
 352                 *ret = mfree(*ret);
 353                 return 0;
 354         }
 355
 356         r = dns_name_normalize(name, &normalized);
 357         if (r < 0)
 358                 return r;
 359
 360         if (is_localhost(normalized))
 361                 return -EINVAL;
 362
 363         if (dns_name_is_root(normalized))
 364                 return -EINVAL;
 365
 366         free_and_replace(*ret, normalized);
 367
 368         return 0;
 369 }
 370
 371 static void filter_bogus_addresses(struct in_addr *addresses, size_t *n) {
 372         size_t i, j;
 373
 374         /* Silently filter DNS/NTP servers supplied to us that do not make outside of the local scope. */
 375
 376         for (i = 0, j = 0; i < *n; i ++) {
 377
 378                 if (in4_addr_is_null(addresses+i) ||
 379                     in4_addr_is_localhost(addresses+i))
 380                         continue;
 381
 382                 addresses[j++] = addresses[i];
 383         }
 384
 385         *n = j;
 386 }
 387
 388 static int lease_parse_in_addrs(const uint8_t *option, size_t len, struct in_addr **ret, size_t *n_ret) {
 389         assert(option);
 390         assert(ret);
 391         assert(n_ret);
 392
 393         if (len <= 0) {
 394                 *ret = mfree(*ret);
 395                 *n_ret = 0;
 396         } else {
 397                 size_t n_addresses;
 398                 struct in_addr *addresses;
 399
 400                 if (len % 4 != 0)
 401                         return -EINVAL;
 402
 403                 n_addresses = len / 4;
 404
 405                 addresses = newdup(struct in_addr, option, n_addresses);
 406                 if (!addresses)
 407                         return -ENOMEM;
 408
 409                 filter_bogus_addresses(addresses, &n_addresses);
 410
 411                 free(*ret);
 412                 *ret = addresses;
 413                 *n_ret = n_addresses;
 414         }
 415
 416         return 0;
 417 }
 418
 419 static int lease_parse_routes(
 420                 const uint8_t *option, size_t len,
 421                 struct sd_dhcp_route **routes, size_t *routes_size, size_t *routes_allocated) {
 422
 423         struct in_addr addr;
 424
 425         assert(option || len <= 0);
 426         assert(routes);
 427         assert(routes_size);
 428         assert(routes_allocated);
 429
 430         if (len <= 0)
 431                 return 0;
 432
 433         if (len % 8 != 0)
 434                 return -EINVAL;
 435
 436         if (!GREEDY_REALLOC(*routes, *routes_allocated, *routes_size + (len / 8)))
 437                 return -ENOMEM;
 438
 439         while (len >= 8) {
 440                 struct sd_dhcp_route *route = *routes + *routes_size;
 441                 int r;
 442
 443                 route->option = SD_DHCP_OPTION_STATIC_ROUTE;
 444                 r = in4_addr_default_prefixlen((struct in_addr*) option, &route->dst_prefixlen);
 445                 if (r < 0) {
 446                         log_debug("Failed to determine destination prefix length from class based IP, ignoring");
 447                         continue;
 448                 }
 449
 450                 assert_se(lease_parse_be32(option, 4, &addr.s_addr) >= 0);
 451                 route->dst_addr = inet_makeaddr(inet_netof(addr), 0);
 452                 option += 4;
 453
 454                 assert_se(lease_parse_be32(option, 4, &route->gw_addr.s_addr) >= 0);
 455                 option += 4;
 456
 457                 len -= 8;
 458                 (*routes_size)++;
 459         }
 460
 461         return 0;
 462 }
 463
 464 /* parses RFC3442 Classless Static Route Option */
 465 static int lease_parse_classless_routes(
 466                 const uint8_t *option, size_t len,
 467                 struct sd_dhcp_route **routes, size_t *routes_size, size_t *routes_allocated) {
 468
 469         assert(option || len <= 0);
 470         assert(routes);
 471         assert(routes_size);
 472         assert(routes_allocated);
 473
 474         if (len <= 0)
 475                 return 0;
 476
 477         /* option format: (subnet-mask-width significant-subnet-octets gateway-ip)*  */
 478
 479         while (len > 0) {
 480                 uint8_t dst_octets;
 481                 struct sd_dhcp_route *route;
 482
 483                 if (!GREEDY_REALLOC(*routes, *routes_allocated, *routes_size + 1))
 484                         return -ENOMEM;
 485
 486                 route = *routes + *routes_size;
 487                 route->option = SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE;
 488
 489                 dst_octets = (*option == 0 ? 0 : ((*option - 1) / 8) + 1);
 490                 route->dst_prefixlen = *option;
 491                 option++;
 492                 len--;
 493
 494                 /* can't have more than 4 octets in IPv4 */
 495                 if (dst_octets > 4 || len < dst_octets)
 496                         return -EINVAL;
 497
 498                 route->dst_addr.s_addr = 0;
 499                 memcpy(&route->dst_addr.s_addr, option, dst_octets);
 500                 option += dst_octets;
 501                 len -= dst_octets;
 502
 503                 if (len < 4)
 504                         return -EINVAL;
 505
 506                 assert_se(lease_parse_be32(option, 4, &route->gw_addr.s_addr) >= 0);
 507                 option += 4;
 508                 len -= 4;
 509
 510                 (*routes_size)++;
 511         }
 512
 513         return 0;
 514 }
 515
 516 int dhcp_lease_parse_options(uint8_t code, uint8_t len, const void *option, void *userdata) {
 517         sd_dhcp_lease *lease = userdata;
 518         int r;
 519
 520         assert(lease);
 521
 522         switch(code) {
 523
 524         case SD_DHCP_OPTION_IP_ADDRESS_LEASE_TIME:
 525                 r = lease_parse_u32(option, len, &lease->lifetime, 1);
 526                 if (r < 0)
 527                         log_debug_errno(r, "Failed to parse lease time, ignoring: %m");
 528
 529                 break;
 530
 531         case SD_DHCP_OPTION_SERVER_IDENTIFIER:
 532                 r = lease_parse_be32(option, len, &lease->server_address);
 533                 if (r < 0)
 534                         log_debug_errno(r, "Failed to parse server identifier, ignoring: %m");
 535
 536                 break;
 537
 538         case SD_DHCP_OPTION_SUBNET_MASK:
 539                 r = lease_parse_be32(option, len, &lease->subnet_mask);
 540                 if (r < 0)
 541                         log_debug_errno(r, "Failed to parse subnet mask, ignoring: %m");
 542                 else
 543                         lease->have_subnet_mask = true;
 544                 break;
 545
 546         case SD_DHCP_OPTION_BROADCAST:
 547                 r = lease_parse_be32(option, len, &lease->broadcast);
 548                 if (r < 0)
 549                         log_debug_errno(r, "Failed to parse broadcast address, ignoring: %m");
 550                 else
 551                         lease->have_broadcast = true;
 552                 break;
 553
 554         case SD_DHCP_OPTION_ROUTER:
 555                 if (len >= 4) {
 556                         r = lease_parse_be32(option, 4, &lease->router);
 557                         if (r < 0)
 558                                 log_debug_errno(r, "Failed to parse router address, ignoring: %m");
 559                 }
 560                 break;
 561
 562         case SD_DHCP_OPTION_DOMAIN_NAME_SERVER:
 563                 r = lease_parse_in_addrs(option, len, &lease->dns, &lease->dns_size);
 564                 if (r < 0)
 565                         log_debug_errno(r, "Failed to parse DNS server, ignoring: %m");
 566                 break;
 567
 568         case SD_DHCP_OPTION_NTP_SERVER:
 569                 r = lease_parse_in_addrs(option, len, &lease->ntp, &lease->ntp_size);
 570                 if (r < 0)
 571                         log_debug_errno(r, "Failed to parse NTP server, ignoring: %m");
 572                 break;
 573
 574         case SD_DHCP_OPTION_STATIC_ROUTE:
 575                 r = lease_parse_routes(option, len, &lease->static_route, &lease->static_route_size, &lease->static_route_allocated);
 576                 if (r < 0)
 577                         log_debug_errno(r, "Failed to parse static routes, ignoring: %m");
 578                 break;
 579
 580         case SD_DHCP_OPTION_INTERFACE_MTU:
 581                 r = lease_parse_u16(option, len, &lease->mtu, 68);
 582                 if (r < 0)
 583                         log_debug_errno(r, "Failed to parse MTU, ignoring: %m");
 584                 if (lease->mtu < DHCP_DEFAULT_MIN_SIZE) {
 585                         log_debug("MTU value of %" PRIu16 " too small. Using default MTU value of %d instead.", lease->mtu, DHCP_DEFAULT_MIN_SIZE);
 586                         lease->mtu = DHCP_DEFAULT_MIN_SIZE;
 587                 }
 588
 589                 break;
 590
 591         case SD_DHCP_OPTION_DOMAIN_NAME:
 592                 r = lease_parse_domain(option, len, &lease->domainname);
 593                 if (r < 0) {
 594                         log_debug_errno(r, "Failed to parse domain name, ignoring: %m");
 595                         return 0;
 596                 }
 597
 598                 break;
 599
 600         case SD_DHCP_OPTION_DOMAIN_SEARCH_LIST:
 601                 r = dhcp_lease_parse_search_domains(option, len, &lease->search_domains);
 602                 if (r < 0)
 603                         log_debug_errno(r, "Failed to parse Domain Search List, ignoring: %m");
 604                 break;
 605
 606         case SD_DHCP_OPTION_HOST_NAME:
 607                 r = lease_parse_domain(option, len, &lease->hostname);
 608                 if (r < 0) {
 609                         log_debug_errno(r, "Failed to parse host name, ignoring: %m");
 610                         return 0;
 611                 }
 612
 613                 break;
 614
 615         case SD_DHCP_OPTION_ROOT_PATH:
 616                 r = lease_parse_string(option, len, &lease->root_path);
 617                 if (r < 0)
 618                         log_debug_errno(r, "Failed to parse root path, ignoring: %m");
 619                 break;
 620
 621         case SD_DHCP_OPTION_RENEWAL_T1_TIME:
 622                 r = lease_parse_u32(option, len, &lease->t1, 1);
 623                 if (r < 0)
 624                         log_debug_errno(r, "Failed to parse T1 time, ignoring: %m");
 625                 break;
 626
 627         case SD_DHCP_OPTION_REBINDING_T2_TIME:
 628                 r = lease_parse_u32(option, len, &lease->t2, 1);
 629                 if (r < 0)
 630                         log_debug_errno(r, "Failed to parse T2 time, ignoring: %m");
 631                 break;
 632
 633         case SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE:
 634                 r = lease_parse_classless_routes(
 635                                 option, len,
 636                                 &lease->static_route,
 637                                 &lease->static_route_size,
 638                                 &lease->static_route_allocated);
 639                 if (r < 0)
 640                         log_debug_errno(r, "Failed to parse classless routes, ignoring: %m");
 641                 break;
 642
 643         case SD_DHCP_OPTION_NEW_TZDB_TIMEZONE: {
 644                 _cleanup_free_ char *tz = NULL;
 645
 646                 r = lease_parse_string(option, len, &tz);
 647                 if (r < 0) {
 648                         log_debug_errno(r, "Failed to parse timezone option, ignoring: %m");
 649                         return 0;
 650                 }
 651
 652                 if (!timezone_is_valid(tz, LOG_DEBUG)) {
 653                         log_debug_errno(r, "Timezone is not valid, ignoring: %m");
 654                         return 0;
 655                 }
 656
 657                 free_and_replace(lease->timezone, tz);
 658
 659                 break;
 660         }
 661
 662         case SD_DHCP_OPTION_VENDOR_SPECIFIC:
 663
 664                 if (len <= 0)
 665                         lease->vendor_specific = mfree(lease->vendor_specific);
 666                 else {
 667                         void *p;
 668
 669                         p = memdup(option, len);
 670                         if (!p)
 671                                 return -ENOMEM;
 672
 673                         free(lease->vendor_specific);
 674                         lease->vendor_specific = p;
 675                 }
 676
 677                 lease->vendor_specific_len = len;
 678                 break;
 679
 680         case SD_DHCP_OPTION_PRIVATE_BASE ... SD_DHCP_OPTION_PRIVATE_LAST:
 681                 r = dhcp_lease_insert_private_option(lease, code, option, len);
 682                 if (r < 0)
 683                         return r;
 684
 685                 break;
 686
 687         default:
 688                 log_debug("Ignoring option DHCP option %"PRIu8" while parsing.", code);
 689                 break;
 690         }
 691
 692         return 0;
 693 }
 694
 695 /* Parses compressed domain names. */
 696 int dhcp_lease_parse_search_domains(const uint8_t *option, size_t len, char ***domains) {
 697         _cleanup_strv_free_ char **names = NULL;
 698         size_t pos = 0, cnt = 0;
 699         int r;
 700
 701         assert(domains);
 702         assert_return(option && len > 0, -ENODATA);
 703
 704         while (pos < len) {
 705                 _cleanup_free_ char *name = NULL;
 706                 size_t n = 0, allocated = 0;
 707                 size_t jump_barrier = pos, next_chunk = 0;
 708                 bool first = true;
 709
 710                 for (;;) {
 711                         uint8_t c;
 712                         c = option[pos++];
 713
 714                         if (c == 0) {
 715                                 /* End of name */
 716                                 break;
 717                         } else if (c <= 63) {
 718                                 const char *label;
 719
 720                                 /* Literal label */
 721                                 label = (const char*) (option + pos);
 722                                 pos += c;
 723                                 if (pos >= len)
 724                                         return -EBADMSG;
 725
 726                                 if (!GREEDY_REALLOC(name, allocated, n + !first + DNS_LABEL_ESCAPED_MAX))
 727                                         return -ENOMEM;
 728
 729                                 if (first)
 730                                         first = false;
 731                                 else
 732                                         name[n++] = '.';
 733
 734                                 r = dns_label_escape(label, c, name + n, DNS_LABEL_ESCAPED_MAX);
 735                                 if (r < 0)
 736                                         return r;
 737
 738                                 n += r;
 739                         } else if ((c & 0xc0) == 0xc0) {
 740                                 /* Pointer */
 741
 742                                 uint8_t d;
 743                                 uint16_t ptr;
 744
 745                                 if (pos >= len)
 746                                         return -EBADMSG;
 747
 748                                 d = option[pos++];
 749                                 ptr = (uint16_t) (c & ~0xc0) << 8 | (uint16_t) d;
 750
 751                                 /* Jumps are limited to a "prior occurrence" (RFC-1035 4.1.4) */
 752                                 if (ptr >= jump_barrier)
 753                                         return -EBADMSG;
 754                                 jump_barrier = ptr;
 755
 756                                 /* Save current location so we don't end up re-parsing what's parsed so far. */
 757                                 if (next_chunk == 0)
 758                                         next_chunk = pos;
 759
 760                                 pos = ptr;
 761                         } else
 762                                 return -EBADMSG;
 763                 }
 764
 765                 if (!GREEDY_REALLOC(name, allocated, n + 1))
 766                         return -ENOMEM;
 767                 name[n] = 0;
 768
 769                 r = strv_extend(&names, name);
 770                 if (r < 0)
 771                         return r;
 772
 773                 cnt++;
 774
 775                 if (next_chunk != 0)
 776                       pos = next_chunk;
 777         }
 778
 779         *domains = TAKE_PTR(names);
 780
 781         return cnt;
 782 }
 783
 784 int dhcp_lease_insert_private_option(sd_dhcp_lease *lease, uint8_t tag, const void *data, uint8_t len) {
 785         struct sd_dhcp_raw_option *cur, *option;
 786
 787         assert(lease);
 788
 789         LIST_FOREACH(options, cur, lease->private_options) {
 790                 if (tag < cur->tag)
 791                         break;
 792                 if (tag == cur->tag) {
 793                         log_debug("Ignoring duplicate option, tagged %i.", tag);
 794                         return 0;
 795                 }
 796         }
 797
 798         option = new(struct sd_dhcp_raw_option, 1);
 799         if (!option)
 800                 return -ENOMEM;
 801
 802         option->tag = tag;
 803         option->length = len;
 804         option->data = memdup(data, len);
 805         if (!option->data) {
 806                 free(option);
 807                 return -ENOMEM;
 808         }
 809
 810         LIST_INSERT_BEFORE(options, lease->private_options, cur, option);
 811         return 0;
 812 }
 813
 814 int dhcp_lease_new(sd_dhcp_lease **ret) {
 815         sd_dhcp_lease *lease;
 816
 817         lease = new0(sd_dhcp_lease, 1);
 818         if (!lease)
 819                 return -ENOMEM;
 820
 821         lease->router = INADDR_ANY;
 822         lease->n_ref = 1;
 823
 824         *ret = lease;
 825         return 0;
 826 }
 827
 828 int dhcp_lease_save(sd_dhcp_lease *lease, const char *lease_file) {
 829         _cleanup_free_ char *temp_path = NULL;
 830         _cleanup_fclose_ FILE *f = NULL;
 831         struct sd_dhcp_raw_option *option;
 832         struct in_addr address;
 833         const struct in_addr *addresses;
 834         const void *client_id, *data;
 835         size_t client_id_len, data_len;
 836         const char *string;
 837         uint16_t mtu;
 838         _cleanup_free_ sd_dhcp_route **routes = NULL;
 839         char **search_domains = NULL;
 840         uint32_t t1, t2, lifetime;
 841         int r;
 842
 843         assert(lease);
 844         assert(lease_file);
 845
 846         r = fopen_temporary(lease_file, &f, &temp_path);
 847         if (r < 0)
 848                 goto fail;
 849
 850         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 851         (void) fchmod(fileno(f), 0644);
 852
 853         fprintf(f,
 854                 "# This is private data. Do not parse.\n");
 855
 856         r = sd_dhcp_lease_get_address(lease, &address);
 857         if (r >= 0)
 858                 fprintf(f, "ADDRESS=%s\n", inet_ntoa(address));
 859
 860         r = sd_dhcp_lease_get_netmask(lease, &address);
 861         if (r >= 0)
 862                 fprintf(f, "NETMASK=%s\n", inet_ntoa(address));
 863
 864         r = sd_dhcp_lease_get_router(lease, &address);
 865         if (r >= 0)
 866                 fprintf(f, "ROUTER=%s\n", inet_ntoa(address));
 867
 868         r = sd_dhcp_lease_get_server_identifier(lease, &address);
 869         if (r >= 0)
 870                 fprintf(f, "SERVER_ADDRESS=%s\n", inet_ntoa(address));
 871
 872         r = sd_dhcp_lease_get_next_server(lease, &address);
 873         if (r >= 0)
 874                 fprintf(f, "NEXT_SERVER=%s\n", inet_ntoa(address));
 875
 876         r = sd_dhcp_lease_get_broadcast(lease, &address);
 877         if (r >= 0)
 878                 fprintf(f, "BROADCAST=%s\n", inet_ntoa(address));
 879
 880         r = sd_dhcp_lease_get_mtu(lease, &mtu);
 881         if (r >= 0)
 882                 fprintf(f, "MTU=%" PRIu16 "\n", mtu);
 883
 884         r = sd_dhcp_lease_get_t1(lease, &t1);
 885         if (r >= 0)
 886                 fprintf(f, "T1=%" PRIu32 "\n", t1);
 887
 888         r = sd_dhcp_lease_get_t2(lease, &t2);
 889         if (r >= 0)
 890                 fprintf(f, "T2=%" PRIu32 "\n", t2);
 891
 892         r = sd_dhcp_lease_get_lifetime(lease, &lifetime);
 893         if (r >= 0)
 894                 fprintf(f, "LIFETIME=%" PRIu32 "\n", lifetime);
 895
 896         r = sd_dhcp_lease_get_dns(lease, &addresses);
 897         if (r > 0) {
 898                 fputs("DNS=", f);
 899                 serialize_in_addrs(f, addresses, r);
 900                 fputs("\n", f);
 901         }
 902
 903         r = sd_dhcp_lease_get_ntp(lease, &addresses);
 904         if (r > 0) {
 905                 fputs("NTP=", f);
 906                 serialize_in_addrs(f, addresses, r);
 907                 fputs("\n", f);
 908         }
 909
 910         r = sd_dhcp_lease_get_domainname(lease, &string);
 911         if (r >= 0)
 912                 fprintf(f, "DOMAINNAME=%s\n", string);
 913
 914         r = sd_dhcp_lease_get_search_domains(lease, &search_domains);
 915         if (r > 0) {
 916                 fputs("DOMAIN_SEARCH_LIST=", f);
 917                 fputstrv(f, search_domains, NULL, NULL);
 918                 fputs("\n", f);
 919         }
 920
 921         r = sd_dhcp_lease_get_hostname(lease, &string);
 922         if (r >= 0)
 923                 fprintf(f, "HOSTNAME=%s\n", string);
 924
 925         r = sd_dhcp_lease_get_root_path(lease, &string);
 926         if (r >= 0)
 927                 fprintf(f, "ROOT_PATH=%s\n", string);
 928
 929         r = sd_dhcp_lease_get_routes(lease, &routes);
 930         if (r > 0)
 931                 serialize_dhcp_routes(f, "ROUTES", routes, r);
 932
 933         r = sd_dhcp_lease_get_timezone(lease, &string);
 934         if (r >= 0)
 935                 fprintf(f, "TIMEZONE=%s\n", string);
 936
 937         r = sd_dhcp_lease_get_client_id(lease, &client_id, &client_id_len);
 938         if (r >= 0) {
 939                 _cleanup_free_ char *client_id_hex = NULL;
 940
 941                 client_id_hex = hexmem(client_id, client_id_len);
 942                 if (!client_id_hex) {
 943                         r = -ENOMEM;
 944                         goto fail;
 945                 }
 946                 fprintf(f, "CLIENTID=%s\n", client_id_hex);
 947         }
 948
 949         r = sd_dhcp_lease_get_vendor_specific(lease, &data, &data_len);
 950         if (r >= 0) {
 951                 _cleanup_free_ char *option_hex = NULL;
 952
 953                 option_hex = hexmem(data, data_len);
 954                 if (!option_hex) {
 955                         r = -ENOMEM;
 956                         goto fail;
 957                 }
 958                 fprintf(f, "VENDOR_SPECIFIC=%s\n", option_hex);
 959         }
 960
 961         LIST_FOREACH(options, option, lease->private_options) {
 962                 char key[STRLEN("OPTION_000")+1];
 963
 964                 xsprintf(key, "OPTION_%" PRIu8, option->tag);
 965                 r = serialize_dhcp_option(f, key, option->data, option->length);
 966                 if (r < 0)
 967                         goto fail;
 968         }
 969
 970         r = fflush_and_check(f);
 971         if (r < 0)
 972                 goto fail;
 973
 974         if (rename(temp_path, lease_file) < 0) {
 975                 r = -errno;
 976                 goto fail;
 977         }
 978
 979         return 0;
 980
 981 fail:
 982         if (temp_path)
 983                 (void) unlink(temp_path);
 984
 985         return log_error_errno(r, "Failed to save lease data %s: %m", lease_file);
 986 }
 987
 988 int dhcp_lease_load(sd_dhcp_lease **ret, const char *lease_file) {
 989
 990         _cleanup_(sd_dhcp_lease_unrefp) sd_dhcp_lease *lease = NULL;
 991         _cleanup_free_ char
 992                 *address = NULL,
 993                 *router = NULL,
 994                 *netmask = NULL,
 995                 *server_address = NULL,
 996                 *next_server = NULL,
 997                 *broadcast = NULL,
 998                 *dns = NULL,
 999                 *ntp = NULL,
1000                 *mtu = NULL,
1001                 *routes = NULL,
1002                 *domains = NULL,
1003                 *client_id_hex = NULL,
1004                 *vendor_specific_hex = NULL,
1005                 *lifetime = NULL,
1006                 *t1 = NULL,
1007                 *t2 = NULL,
1008                 *options[SD_DHCP_OPTION_PRIVATE_LAST - SD_DHCP_OPTION_PRIVATE_BASE + 1] = {};
1009
1010         int r, i;
1011
1012         assert(lease_file);
1013         assert(ret);
1014
1015         r = dhcp_lease_new(&lease);
1016         if (r < 0)
1017                 return r;
1018
1019         r = parse_env_file(NULL, lease_file,
1020                            "ADDRESS", &address,
1021                            "ROUTER", &router,
1022                            "NETMASK", &netmask,
1023                            "SERVER_IDENTIFIER", &server_address,
1024                            "NEXT_SERVER", &next_server,
1025                            "BROADCAST", &broadcast,
1026                            "DNS", &dns,
1027                            "NTP", &ntp,
1028                            "MTU", &mtu,
1029                            "DOMAINNAME", &lease->domainname,
1030                            "HOSTNAME", &lease->hostname,
1031                            "DOMAIN_SEARCH_LIST", &domains,
1032                            "ROOT_PATH", &lease->root_path,
1033                            "ROUTES", &routes,
1034                            "CLIENTID", &client_id_hex,
1035                            "TIMEZONE", &lease->timezone,
1036                            "VENDOR_SPECIFIC", &vendor_specific_hex,
1037                            "LIFETIME", &lifetime,
1038                            "T1", &t1,
1039                            "T2", &t2,
1040                            "OPTION_224", &options[0],
1041                            "OPTION_225", &options[1],
1042                            "OPTION_226", &options[2],
1043                            "OPTION_227", &options[3],
1044                            "OPTION_228", &options[4],
1045                            "OPTION_229", &options[5],
1046                            "OPTION_230", &options[6],
1047                            "OPTION_231", &options[7],
1048                            "OPTION_232", &options[8],
1049                            "OPTION_233", &options[9],
1050                            "OPTION_234", &options[10],
1051                            "OPTION_235", &options[11],
1052                            "OPTION_236", &options[12],
1053                            "OPTION_237", &options[13],
1054                            "OPTION_238", &options[14],
1055                            "OPTION_239", &options[15],
1056                            "OPTION_240", &options[16],
1057                            "OPTION_241", &options[17],
1058                            "OPTION_242", &options[18],
1059                            "OPTION_243", &options[19],
1060                            "OPTION_244", &options[20],
1061                            "OPTION_245", &options[21],
1062                            "OPTION_246", &options[22],
1063                            "OPTION_247", &options[23],
1064                            "OPTION_248", &options[24],
1065                            "OPTION_249", &options[25],
1066                            "OPTION_250", &options[26],
1067                            "OPTION_251", &options[27],
1068                            "OPTION_252", &options[28],
1069                            "OPTION_253", &options[29],
1070                            "OPTION_254", &options[30]);
1071         if (r < 0)
1072                 return r;
1073
1074         if (address) {
1075                 r = inet_pton(AF_INET, address, &lease->address);
1076                 if (r <= 0)
1077                         log_debug("Failed to parse address %s, ignoring.", address);
1078         }
1079
1080         if (router) {
1081                 r = inet_pton(AF_INET, router, &lease->router);
1082                 if (r <= 0)
1083                         log_debug("Failed to parse router %s, ignoring.", router);
1084         }
1085
1086         if (netmask) {
1087                 r = inet_pton(AF_INET, netmask, &lease->subnet_mask);
1088                 if (r <= 0)
1089                         log_debug("Failed to parse netmask %s, ignoring.", netmask);
1090                 else
1091                         lease->have_subnet_mask = true;
1092         }
1093
1094         if (server_address) {
1095                 r = inet_pton(AF_INET, server_address, &lease->server_address);
1096                 if (r <= 0)
1097                         log_debug("Failed to parse server address %s, ignoring.", server_address);
1098         }
1099
1100         if (next_server) {
1101                 r = inet_pton(AF_INET, next_server, &lease->next_server);
1102                 if (r <= 0)
1103                         log_debug("Failed to parse next server %s, ignoring.", next_server);
1104         }
1105
1106         if (broadcast) {
1107                 r = inet_pton(AF_INET, broadcast, &lease->broadcast);
1108                 if (r <= 0)
1109                         log_debug("Failed to parse broadcast address %s, ignoring.", broadcast);
1110                 else
1111                         lease->have_broadcast = true;
1112         }
1113
1114         if (dns) {
1115                 r = deserialize_in_addrs(&lease->dns, dns);
1116                 if (r < 0)
1117                         log_debug_errno(r, "Failed to deserialize DNS servers %s, ignoring: %m", dns);
1118                 else
1119                         lease->dns_size = r;
1120         }
1121
1122         if (ntp) {
1123                 r = deserialize_in_addrs(&lease->ntp, ntp);
1124                 if (r < 0)
1125                         log_debug_errno(r, "Failed to deserialize NTP servers %s, ignoring: %m", ntp);
1126                 else
1127                         lease->ntp_size = r;
1128         }
1129
1130         if (mtu) {
1131                 r = safe_atou16(mtu, &lease->mtu);
1132                 if (r < 0)
1133                         log_debug_errno(r, "Failed to parse MTU %s, ignoring: %m", mtu);
1134         }
1135
1136         if (domains) {
1137                 _cleanup_strv_free_ char **a = NULL;
1138                 a = strv_split(domains, " ");
1139                 if (!a)
1140                         return -ENOMEM;
1141
1142                 if (!strv_isempty(a)) {
1143                         lease->search_domains = a;
1144                         a = NULL;
1145                 }
1146         }
1147
1148         if (routes) {
1149                 r = deserialize_dhcp_routes(
1150                                 &lease->static_route,
1151                                 &lease->static_route_size,
1152                                 &lease->static_route_allocated,
1153                                 routes);
1154                 if (r < 0)
1155                         log_debug_errno(r, "Failed to parse DHCP routes %s, ignoring: %m", routes);
1156         }
1157
1158         if (lifetime) {
1159                 r = safe_atou32(lifetime, &lease->lifetime);
1160                 if (r < 0)
1161                         log_debug_errno(r, "Failed to parse lifetime %s, ignoring: %m", lifetime);
1162         }
1163
1164         if (t1) {
1165                 r = safe_atou32(t1, &lease->t1);
1166                 if (r < 0)
1167                         log_debug_errno(r, "Failed to parse T1 %s, ignoring: %m", t1);
1168         }
1169
1170         if (t2) {
1171                 r = safe_atou32(t2, &lease->t2);
1172                 if (r < 0)
1173                         log_debug_errno(r, "Failed to parse T2 %s, ignoring: %m", t2);
1174         }
1175
1176         if (client_id_hex) {
1177                 r = unhexmem(client_id_hex, (size_t) -1, &lease->client_id, &lease->client_id_len);
1178                 if (r < 0)
1179                         log_debug_errno(r, "Failed to parse client ID %s, ignoring: %m", client_id_hex);
1180         }
1181
1182         if (vendor_specific_hex) {
1183                 r = unhexmem(vendor_specific_hex, (size_t) -1, &lease->vendor_specific, &lease->vendor_specific_len);
1184                 if (r < 0)
1185                         log_debug_errno(r, "Failed to parse vendor specific data %s, ignoring: %m", vendor_specific_hex);
1186         }
1187
1188         for (i = 0; i <= SD_DHCP_OPTION_PRIVATE_LAST - SD_DHCP_OPTION_PRIVATE_BASE; i++) {
1189                 _cleanup_free_ void *data = NULL;
1190                 size_t len;
1191
1192                 if (!options[i])
1193                         continue;
1194
1195                 r = unhexmem(options[i], (size_t) -1, &data, &len);
1196                 if (r < 0) {
1197                         log_debug_errno(r, "Failed to parse private DHCP option %s, ignoring: %m", options[i]);
1198                         continue;
1199                 }
1200
1201                 r = dhcp_lease_insert_private_option(lease, SD_DHCP_OPTION_PRIVATE_BASE + i, data, len);
1202                 if (r < 0)
1203                         return r;
1204         }
1205
1206         *ret = TAKE_PTR(lease);
1207
1208         return 0;
1209 }
1210
1211 int dhcp_lease_set_default_subnet_mask(sd_dhcp_lease *lease) {
1212         struct in_addr address, mask;
1213         int r;
1214
1215         assert(lease);
1216
1217         if (lease->address == 0)
1218                 return -ENODATA;
1219
1220         address.s_addr = lease->address;
1221
1222         /* fall back to the default subnet masks based on address class */
1223         r = in4_addr_default_subnet_mask(&address, &mask);
1224         if (r < 0)
1225                 return r;
1226
1227         lease->subnet_mask = mask.s_addr;
1228         lease->have_subnet_mask = true;
1229
1230         return 0;
1231 }
1232
1233 int sd_dhcp_lease_get_client_id(sd_dhcp_lease *lease, const void **client_id, size_t *client_id_len) {
1234         assert_return(lease, -EINVAL);
1235         assert_return(client_id, -EINVAL);
1236         assert_return(client_id_len, -EINVAL);
1237
1238         if (!lease->client_id)
1239                 return -ENODATA;
1240
1241         *client_id = lease->client_id;
1242         *client_id_len = lease->client_id_len;
1243
1244         return 0;
1245 }
1246
1247 int dhcp_lease_set_client_id(sd_dhcp_lease *lease, const void *client_id, size_t client_id_len) {
1248         assert_return(lease, -EINVAL);
1249         assert_return(client_id || client_id_len <= 0, -EINVAL);
1250
1251         if (client_id_len <= 0)
1252                 lease->client_id = mfree(lease->client_id);
1253         else {
1254                 void *p;
1255
1256                 p = memdup(client_id, client_id_len);
1257                 if (!p)
1258                         return -ENOMEM;
1259
1260                 free(lease->client_id);
1261                 lease->client_id = p;
1262                 lease->client_id_len = client_id_len;
1263         }
1264
1265         return 0;
1266 }
1267
1268 int sd_dhcp_lease_get_timezone(sd_dhcp_lease *lease, const char **tz) {
1269         assert_return(lease, -EINVAL);
1270         assert_return(tz, -EINVAL);
1271
1272         if (!lease->timezone)
1273                 return -ENODATA;
1274
1275         *tz = lease->timezone;
1276         return 0;
1277 }
1278
1279 int sd_dhcp_route_get_destination(sd_dhcp_route *route, struct in_addr *destination) {
1280         assert_return(route, -EINVAL);
1281         assert_return(destination, -EINVAL);
1282
1283         *destination = route->dst_addr;
1284         return 0;
1285 }
1286
1287 int sd_dhcp_route_get_destination_prefix_length(sd_dhcp_route *route, uint8_t *length) {
1288         assert_return(route, -EINVAL);
1289         assert_return(length, -EINVAL);
1290
1291         *length = route->dst_prefixlen;
1292         return 0;
1293 }
1294
1295 int sd_dhcp_route_get_gateway(sd_dhcp_route *route, struct in_addr *gateway) {
1296         assert_return(route, -EINVAL);
1297         assert_return(gateway, -EINVAL);
1298
1299         *gateway = route->gw_addr;
1300         return 0;
1301 }