src/network/networkd-dhcp-server.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <netinet/in.h>
   4 #include <linux/if_arp.h>
   5 #include <linux/if.h>
   6
   7 #include "sd-dhcp-server.h"
   8
   9 #include "dhcp-protocol.h"
  10 #include "fd-util.h"
  11 #include "fileio.h"
  12 #include "network-common.h"
  13 #include "networkd-address.h"
  14 #include "networkd-dhcp-server-bus.h"
  15 #include "networkd-dhcp-server-static-lease.h"
  16 #include "networkd-dhcp-server.h"
  17 #include "networkd-link.h"
  18 #include "networkd-manager.h"
  19 #include "networkd-network.h"
  20 #include "networkd-queue.h"
  21 #include "networkd-route-util.h"
  22 #include "parse-util.h"
  23 #include "path-util.h"
  24 #include "socket-netlink.h"
  25 #include "string-table.h"
  26 #include "string-util.h"
  27 #include "strv.h"
  28
  29 static bool link_dhcp4_server_enabled(Link *link) {
  30         assert(link);
  31
  32         if (link->flags & IFF_LOOPBACK)
  33                 return false;
  34
  35         if (!link->network)
  36                 return false;
  37
  38         if (link->iftype == ARPHRD_CAN)
  39                 return false;
  40
  41         return link->network->dhcp_server;
  42 }
  43
  44 int network_adjust_dhcp_server(Network *network, Set **addresses) {
  45         int r;
  46
  47         assert(network);
  48         assert(addresses);
  49
  50         if (!network->dhcp_server)
  51                 return 0;
  52
  53         if (network->bond) {
  54                 log_warning("%s: DHCPServer= is enabled for bond slave. Disabling DHCP server.",
  55                             network->filename);
  56                 network->dhcp_server = false;
  57                 return 0;
  58         }
  59
  60         assert(network->dhcp_server_address_prefixlen <= 32);
  61
  62         if (network->dhcp_server_address_prefixlen == 0) {
  63                 Address *address;
  64
  65                 /* If the server address is not specified, then find suitable static address. */
  66
  67                 ORDERED_HASHMAP_FOREACH(address, network->addresses_by_section) {
  68                         assert(!section_is_invalid(address->section));
  69
  70                         if (address->family != AF_INET)
  71                                 continue;
  72
  73                         if (in4_addr_is_localhost(&address->in_addr.in))
  74                                 continue;
  75
  76                         if (in4_addr_is_link_local(&address->in_addr.in))
  77                                 continue;
  78
  79                         if (in4_addr_is_set(&address->in_addr_peer.in))
  80                                 continue;
  81
  82                         /* TODO: check if the prefix length is small enough for the pool. */
  83
  84                         network->dhcp_server_address = address;
  85                         break;
  86                 }
  87                 if (!network->dhcp_server_address) {
  88                         log_warning("%s: DHCPServer= is enabled, but no suitable static address configured. "
  89                                     "Disabling DHCP server.",
  90                                     network->filename);
  91                         network->dhcp_server = false;
  92                         return 0;
  93                 }
  94
  95         } else {
  96                 _cleanup_(address_unrefp) Address *a = NULL;
  97                 Address *existing;
  98                 unsigned line;
  99
 100                 /* TODO: check if the prefix length is small enough for the pool. */
 101
 102                 /* If an address is explicitly specified, then check if the corresponding [Address] section
 103                  * is configured, and add one if not. */
 104
 105                 existing = set_get(*addresses,
 106                                    &(Address) {
 107                                            .family = AF_INET,
 108                                            .in_addr.in = network->dhcp_server_address_in_addr,
 109                                            .prefixlen = network->dhcp_server_address_prefixlen,
 110                                    });
 111                 if (existing) {
 112                         /* Corresponding [Address] section already exists. */
 113                         network->dhcp_server_address = existing;
 114                         return 0;
 115                 }
 116
 117                 r = ordered_hashmap_by_section_find_unused_line(network->addresses_by_section, network->filename, &line);
 118                 if (r < 0)
 119                         return log_warning_errno(r, "%s: Failed to find unused line number for DHCP server address: %m",
 120                                                  network->filename);
 121
 122                 r = address_new_static(network, network->filename, line, &a);
 123                 if (r < 0)
 124                         return log_warning_errno(r, "%s: Failed to add new static address object for DHCP server: %m",
 125                                                  network->filename);
 126
 127                 a->family = AF_INET;
 128                 a->prefixlen = network->dhcp_server_address_prefixlen;
 129                 a->in_addr.in = network->dhcp_server_address_in_addr;
 130                 a->requested_as_null = !in4_addr_is_set(&network->dhcp_server_address_in_addr);
 131
 132                 r = address_section_verify(a);
 133                 if (r < 0)
 134                         return r;
 135
 136                 r = set_ensure_put(addresses, &address_hash_ops, a);
 137                 if (r < 0)
 138                         return log_oom();
 139                 assert(r > 0);
 140
 141                 network->dhcp_server_address = TAKE_PTR(a);
 142         }
 143
 144         return 0;
 145 }
 146
 147 static int link_start_dhcp4_server(Link *link) {
 148         int r;
 149
 150         assert(link);
 151         assert(link->manager);
 152
 153         if (!link->dhcp_server)
 154                 return 0; /* Not configured yet. */
 155
 156         if (!link_has_carrier(link))
 157                 return 0;
 158
 159         /* TODO: Maybe, also check the system time is synced. If the system does not have RTC battery, then
 160          * the realtime clock in not usable in the early boot stage, and all saved leases may be wrongly
 161          * handled as expired and dropped. */
 162         if (!sd_dhcp_server_is_in_relay_mode(link->dhcp_server) &&
 163             !link->manager->persistent_storage_is_ready)
 164                 return 0;
 165
 166         r = sd_dhcp_server_start(link->dhcp_server);
 167         if (r < 0)
 168                 return r;
 169
 170         log_link_debug(link, "Offering DHCPv4 leases");
 171         return 0;
 172 }
 173
 174 void manager_toggle_dhcp4_server_state(Manager *manager, bool start) {
 175         Link *link;
 176         int r;
 177
 178         assert(manager);
 179
 180         HASHMAP_FOREACH(link, manager->links_by_index) {
 181                 if (!link->dhcp_server)
 182                         continue;
 183                 if (sd_dhcp_server_is_in_relay_mode(link->dhcp_server))
 184                         continue;
 185
 186                 if (start)
 187                         r = link_start_dhcp4_server(link);
 188                 else
 189                         r = sd_dhcp_server_stop(link->dhcp_server);
 190                 if (r < 0)
 191                         log_link_debug_errno(link, r, "Failed to %s DHCP server, ignoring: %m",
 192                                              start ? "start" : "stop");
 193         }
 194 }
 195
 196 static int dhcp_server_find_uplink(Link *link, Link **ret) {
 197         assert(link);
 198
 199         if (link->network->dhcp_server_uplink_name)
 200                 return link_get_by_name(link->manager, link->network->dhcp_server_uplink_name, ret);
 201
 202         if (link->network->dhcp_server_uplink_index > 0)
 203                 return link_get_by_index(link->manager, link->network->dhcp_server_uplink_index, ret);
 204
 205         if (link->network->dhcp_server_uplink_index == UPLINK_INDEX_AUTO) {
 206                 /* It is not necessary to propagate error in automatic selection. */
 207                 if (manager_find_uplink(link->manager, AF_INET, link, ret) < 0)
 208                         *ret = NULL;
 209                 return 0;
 210         }
 211
 212         *ret = NULL;
 213         return 0;
 214 }
 215
 216 static int link_push_uplink_to_dhcp_server(
 217                 Link *link,
 218                 sd_dhcp_lease_server_type_t what,
 219                 sd_dhcp_server *s) {
 220
 221         _cleanup_free_ struct in_addr *addresses = NULL;
 222         bool use_dhcp_lease_data = true;
 223         size_t n_addresses = 0;
 224
 225         assert(link);
 226
 227         if (!link->network)
 228                 return 0;
 229         assert(link->network);
 230
 231         log_link_debug(link, "Copying %s from link", dhcp_lease_server_type_to_string(what));
 232
 233         switch (what) {
 234
 235         case SD_DHCP_LEASE_DNS:
 236                 /* For DNS we have a special case. We the data configured explicitly locally along with the
 237                  * data from the DHCP lease. */
 238
 239                 for (unsigned i = 0; i < link->network->n_dns; i++) {
 240                         struct in_addr ia;
 241
 242                         /* Only look for IPv4 addresses */
 243                         if (link->network->dns[i]->family != AF_INET)
 244                                 continue;
 245
 246                         ia = link->network->dns[i]->address.in;
 247
 248                         /* Never propagate obviously borked data */
 249                         if (in4_addr_is_null(&ia) || in4_addr_is_localhost(&ia))
 250                                 continue;
 251
 252                         if (!GREEDY_REALLOC(addresses, n_addresses + 1))
 253                                 return log_oom();
 254
 255                         addresses[n_addresses++] = ia;
 256                 }
 257
 258                 use_dhcp_lease_data = link->network->dhcp_use_dns;
 259                 break;
 260
 261         case SD_DHCP_LEASE_NTP: {
 262                 /* For NTP things are similar, but for NTP hostnames can be configured too, which we cannot
 263                  * propagate via DHCP. Hence let's only propagate those which are IP addresses. */
 264
 265                 STRV_FOREACH(i, link->network->ntp) {
 266                         union in_addr_union ia;
 267
 268                         if (in_addr_from_string(AF_INET, *i, &ia) < 0)
 269                                 continue;
 270
 271                         /* Never propagate obviously borked data */
 272                         if (in4_addr_is_null(&ia.in) || in4_addr_is_localhost(&ia.in))
 273                                 continue;
 274
 275                         if (!GREEDY_REALLOC(addresses, n_addresses + 1))
 276                                 return log_oom();
 277
 278                         addresses[n_addresses++] = ia.in;
 279                 }
 280
 281                 use_dhcp_lease_data = link->network->dhcp_use_ntp;
 282                 break;
 283         }
 284
 285         case SD_DHCP_LEASE_SIP:
 286
 287                 /* For SIP we don't allow explicit, local configuration, but there's control whether to use the data */
 288                 use_dhcp_lease_data = link->network->dhcp_use_sip;
 289                 break;
 290
 291         case SD_DHCP_LEASE_POP3:
 292         case SD_DHCP_LEASE_SMTP:
 293         case SD_DHCP_LEASE_LPR:
 294                 /* For the other server types we currently do not allow local configuration of server data,
 295                  * since there are typically no local consumers of the data. */
 296                 break;
 297
 298         default:
 299                 assert_not_reached();
 300         }
 301
 302         if (use_dhcp_lease_data && link->dhcp_lease) {
 303                 const struct in_addr *da;
 304
 305                 int n = sd_dhcp_lease_get_servers(link->dhcp_lease, what, &da);
 306                 if (n > 0) {
 307                         if (!GREEDY_REALLOC(addresses, n_addresses + n))
 308                                 return log_oom();
 309
 310                         for (int j = 0; j < n; j++)
 311                                 if (in4_addr_is_non_local(&da[j]))
 312                                         addresses[n_addresses++] = da[j];
 313                 }
 314         }
 315
 316         if (n_addresses <= 0)
 317                 return 0;
 318
 319         return sd_dhcp_server_set_servers(s, what, addresses, n_addresses);
 320 }
 321
 322 static int dhcp4_server_parse_dns_server_string_and_warn(
 323                 const char *string,
 324                 struct in_addr **addresses,
 325                 size_t *n_addresses) {
 326
 327         for (;;) {
 328                 _cleanup_free_ char *word = NULL, *server_name = NULL;
 329                 union in_addr_union address;
 330                 int family, r, ifindex = 0;
 331
 332                 r = extract_first_word(&string, &word, NULL, 0);
 333                 if (r < 0)
 334                         return r;
 335                 if (r == 0)
 336                         break;
 337
 338                 r = in_addr_ifindex_name_from_string_auto(word, &family, &address, &ifindex, &server_name);
 339                 if (r < 0) {
 340                         log_warning_errno(r, "Failed to parse DNS server address '%s', ignoring: %m", word);
 341                         continue;
 342                 }
 343
 344                 /* Only look for IPv4 addresses */
 345                 if (family != AF_INET)
 346                         continue;
 347
 348                 /* Never propagate obviously borked data */
 349                 if (in4_addr_is_null(&address.in) || in4_addr_is_localhost(&address.in))
 350                         continue;
 351
 352                 if (!GREEDY_REALLOC(*addresses, *n_addresses + 1))
 353                         return log_oom();
 354
 355                 (*addresses)[(*n_addresses)++] = address.in;
 356         }
 357
 358         return 0;
 359 }
 360
 361 static int dhcp4_server_set_dns_from_resolve_conf(Link *link) {
 362         _cleanup_free_ struct in_addr *addresses = NULL;
 363         _cleanup_fclose_ FILE *f = NULL;
 364         size_t n_addresses = 0;
 365         int r;
 366
 367         f = fopen(PRIVATE_UPLINK_RESOLV_CONF, "re");
 368         if (!f) {
 369                 if (errno == ENOENT)
 370                         return 0;
 371
 372                 return log_warning_errno(errno, "Failed to open " PRIVATE_UPLINK_RESOLV_CONF ": %m");
 373         }
 374
 375         for (;;) {
 376                 _cleanup_free_ char *line = NULL;
 377                 const char *a;
 378
 379                 r = read_stripped_line(f, LONG_LINE_MAX, &line);
 380                 if (r < 0)
 381                         return log_error_errno(r, "Failed to read " PRIVATE_UPLINK_RESOLV_CONF ": %m");
 382                 if (r == 0)
 383                         break;
 384
 385                 if (IN_SET(*line, '#', ';', 0))
 386                         continue;
 387
 388                 a = first_word(line, "nameserver");
 389                 if (!a)
 390                         continue;
 391
 392                 r = dhcp4_server_parse_dns_server_string_and_warn(a, &addresses, &n_addresses);
 393                 if (r < 0)
 394                         log_warning_errno(r, "Failed to parse DNS server address '%s', ignoring.", a);
 395         }
 396
 397         if (n_addresses <= 0)
 398                 return 0;
 399
 400         return sd_dhcp_server_set_dns(link->dhcp_server, addresses, n_addresses);
 401 }
 402
 403 static int dhcp4_server_configure(Link *link) {
 404         bool acquired_uplink = false;
 405         sd_dhcp_option *p;
 406         DHCPStaticLease *static_lease;
 407         Link *uplink = NULL;
 408         Address *address;
 409         bool bind_to_interface;
 410         int r;
 411
 412         assert(link);
 413         assert(link->network);
 414         assert(link->network->dhcp_server_address);
 415
 416         log_link_debug(link, "Configuring DHCP Server.");
 417
 418         if (link->dhcp_server)
 419                 return -EBUSY;
 420
 421         r = sd_dhcp_server_new(&link->dhcp_server, link->ifindex);
 422         if (r < 0)
 423                 return r;
 424
 425         r = sd_dhcp_server_attach_event(link->dhcp_server, link->manager->event, 0);
 426         if (r < 0)
 427                 return r;
 428
 429         r = sd_dhcp_server_set_callback(link->dhcp_server, dhcp_server_callback, link);
 430         if (r < 0)
 431                 return log_link_warning_errno(link, r, "Failed to set callback for DHCPv4 server instance: %m");
 432
 433         r = address_get(link, link->network->dhcp_server_address, &address);
 434         if (r < 0)
 435                 return log_link_error_errno(link, r, "Failed to find suitable address for DHCPv4 server instance: %m");
 436
 437         /* use the server address' subnet as the pool */
 438         r = sd_dhcp_server_configure_pool(link->dhcp_server, &address->in_addr.in, address->prefixlen,
 439                                           link->network->dhcp_server_pool_offset, link->network->dhcp_server_pool_size);
 440         if (r < 0)
 441                 return log_link_error_errno(link, r, "Failed to configure address pool for DHCPv4 server instance: %m");
 442
 443         if (link->network->dhcp_server_max_lease_time_usec > 0) {
 444                 r = sd_dhcp_server_set_max_lease_time(link->dhcp_server, link->network->dhcp_server_max_lease_time_usec);
 445                 if (r < 0)
 446                         return log_link_error_errno(link, r, "Failed to set maximum lease time for DHCPv4 server instance: %m");
 447         }
 448
 449         if (link->network->dhcp_server_default_lease_time_usec > 0) {
 450                 r = sd_dhcp_server_set_default_lease_time(link->dhcp_server, link->network->dhcp_server_default_lease_time_usec);
 451                 if (r < 0)
 452                         return log_link_error_errno(link, r, "Failed to set default lease time for DHCPv4 server instance: %m");
 453         }
 454
 455         r = sd_dhcp_server_set_ipv6_only_preferred_usec(link->dhcp_server, link->network->dhcp_server_ipv6_only_preferred_usec);
 456         if (r < 0)
 457                 return log_link_error_errno(link, r, "Failed to set IPv6 only preferred time for DHCPv4 server instance: %m");
 458
 459         r = sd_dhcp_server_set_boot_server_address(link->dhcp_server, &link->network->dhcp_server_boot_server_address);
 460         if (r < 0)
 461                 return log_link_warning_errno(link, r, "Failed to set boot server address for DHCPv4 server instance: %m");
 462
 463         r = sd_dhcp_server_set_boot_server_name(link->dhcp_server, link->network->dhcp_server_boot_server_name);
 464         if (r < 0)
 465                 return log_link_warning_errno(link, r, "Failed to set boot server name for DHCPv4 server instance: %m");
 466
 467         r = sd_dhcp_server_set_boot_filename(link->dhcp_server, link->network->dhcp_server_boot_filename);
 468         if (r < 0)
 469                 return log_link_warning_errno(link, r, "Failed to set boot filename for DHCPv4 server instance: %m");
 470
 471         r = sd_dhcp_server_set_rapid_commit(link->dhcp_server, link->network->dhcp_server_rapid_commit);
 472         if (r < 0)
 473                 return log_link_warning_errno(link, r, "Failed to %s Rapid Commit support for DHCPv4 server instance: %m",
 474                                               enable_disable(link->network->dhcp_server_rapid_commit));
 475
 476         for (sd_dhcp_lease_server_type_t type = 0; type < _SD_DHCP_LEASE_SERVER_TYPE_MAX; type++) {
 477
 478                 if (!link->network->dhcp_server_emit[type].emit)
 479                         continue;
 480
 481                 if (link->network->dhcp_server_emit[type].n_addresses > 0)
 482                         /* Explicitly specified servers to emit */
 483                         r = sd_dhcp_server_set_servers(
 484                                         link->dhcp_server,
 485                                         type,
 486                                         link->network->dhcp_server_emit[type].addresses,
 487                                         link->network->dhcp_server_emit[type].n_addresses);
 488                 else {
 489                         /* Emission is requested, but nothing explicitly configured. Let's find a suitable upling */
 490                         if (!acquired_uplink) {
 491                                 (void) dhcp_server_find_uplink(link, &uplink);
 492                                 acquired_uplink = true;
 493                         }
 494
 495                         if (uplink && uplink->network)
 496                                 r = link_push_uplink_to_dhcp_server(uplink, type, link->dhcp_server);
 497                         else if (type == SD_DHCP_LEASE_DNS)
 498                                 r = dhcp4_server_set_dns_from_resolve_conf(link);
 499                         else {
 500                                 log_link_debug(link,
 501                                                "Not emitting %s on link, couldn't find suitable uplink.",
 502                                                dhcp_lease_server_type_to_string(type));
 503                                 continue;
 504                         }
 505                 }
 506
 507                 if (r < 0)
 508                         log_link_warning_errno(link, r,
 509                                                "Failed to set %s for DHCP server, ignoring: %m",
 510                                                dhcp_lease_server_type_to_string(type));
 511         }
 512
 513         if (link->network->dhcp_server_emit_router) {
 514                 r = sd_dhcp_server_set_router(link->dhcp_server, &link->network->dhcp_server_router);
 515                 if (r < 0)
 516                         return log_link_error_errno(link, r, "Failed to set router address for DHCP server: %m");
 517         }
 518
 519         r = sd_dhcp_server_set_relay_target(link->dhcp_server, &link->network->dhcp_server_relay_target);
 520         if (r < 0)
 521                 return log_link_error_errno(link, r, "Failed to set relay target for DHCP server: %m");
 522
 523         bind_to_interface = sd_dhcp_server_is_in_relay_mode(link->dhcp_server) ? false : link->network->dhcp_server_bind_to_interface;
 524         r = sd_dhcp_server_set_bind_to_interface(link->dhcp_server, bind_to_interface);
 525         if (r < 0)
 526                 return log_link_error_errno(link, r, "Failed to set interface binding for DHCP server: %m");
 527
 528         r = sd_dhcp_server_set_relay_agent_information(link->dhcp_server, link->network->dhcp_server_relay_agent_circuit_id, link->network->dhcp_server_relay_agent_remote_id);
 529         if (r < 0)
 530                 return log_link_error_errno(link, r, "Failed to set agent circuit/remote id for DHCP server: %m");
 531
 532         if (link->network->dhcp_server_emit_timezone) {
 533                 _cleanup_free_ char *buffer = NULL;
 534                 const char *tz = NULL;
 535
 536                 if (link->network->dhcp_server_timezone)
 537                         tz = link->network->dhcp_server_timezone;
 538                 else {
 539                         r = get_timezone(&buffer);
 540                         if (r < 0)
 541                                 log_link_warning_errno(link, r, "Failed to determine timezone, not sending timezone: %m");
 542                         else
 543                                 tz = buffer;
 544                 }
 545
 546                 if (tz) {
 547                         r = sd_dhcp_server_set_timezone(link->dhcp_server, tz);
 548                         if (r < 0)
 549                                 return log_link_error_errno(link, r, "Failed to set timezone for DHCP server: %m");
 550                 }
 551         }
 552
 553         ORDERED_HASHMAP_FOREACH(p, link->network->dhcp_server_send_options) {
 554                 r = sd_dhcp_server_add_option(link->dhcp_server, p);
 555                 if (r == -EEXIST)
 556                         continue;
 557                 if (r < 0)
 558                         return log_link_error_errno(link, r, "Failed to set DHCPv4 option: %m");
 559         }
 560
 561         ORDERED_HASHMAP_FOREACH(p, link->network->dhcp_server_send_vendor_options) {
 562                 r = sd_dhcp_server_add_vendor_option(link->dhcp_server, p);
 563                 if (r == -EEXIST)
 564                         continue;
 565                 if (r < 0)
 566                         return log_link_error_errno(link, r, "Failed to set DHCPv4 option: %m");
 567         }
 568
 569         HASHMAP_FOREACH(static_lease, link->network->dhcp_static_leases_by_section) {
 570                 r = sd_dhcp_server_set_static_lease(link->dhcp_server, &static_lease->address, static_lease->client_id, static_lease->client_id_size);
 571                 if (r < 0)
 572                         return log_link_error_errno(link, r, "Failed to set DHCPv4 static lease for DHCP server: %m");
 573         }
 574
 575         if (!sd_dhcp_server_is_in_relay_mode(link->dhcp_server)) {
 576                 _cleanup_free_ char *lease_file = path_join("/var/lib/systemd/network/dhcp-server-lease/", link->ifname);
 577                 if (!lease_file)
 578                         return log_oom();
 579
 580                 r = sd_dhcp_server_set_lease_file(link->dhcp_server, lease_file);
 581                 if (r < 0)
 582                         log_link_warning_errno(link, r, "Failed to load DHCPv4 server leases, ignoring: %m");
 583         }
 584
 585         r = link_start_dhcp4_server(link);
 586         if (r < 0)
 587                 return log_link_error_errno(link, r, "Could not start DHCPv4 server instance: %m");
 588
 589         return 0;
 590 }
 591
 592 static bool dhcp_server_is_ready_to_configure(Link *link) {
 593         Link *uplink = NULL;
 594         Address *a;
 595
 596         assert(link);
 597         assert(link->network);
 598         assert(link->network->dhcp_server_address);
 599
 600         if (!link_is_ready_to_configure(link, /* allow_unmanaged = */ false))
 601                 return false;
 602
 603         if (!link_has_carrier(link))
 604                 return false;
 605
 606         if (!link->static_addresses_configured)
 607                 return false;
 608
 609         if (address_get(link, link->network->dhcp_server_address, &a) < 0)
 610                 return false;
 611
 612         if (!address_is_ready(a))
 613                 return false;
 614
 615         if (dhcp_server_find_uplink(link, &uplink) < 0)
 616                 return false;
 617
 618         if (uplink && !uplink->network)
 619                 return false;
 620
 621         return true;
 622 }
 623
 624 static int dhcp_server_process_request(Request *req, Link *link, void *userdata) {
 625         int r;
 626
 627         assert(link);
 628
 629         if (!dhcp_server_is_ready_to_configure(link))
 630                 return 0;
 631
 632         r = dhcp4_server_configure(link);
 633         if (r < 0)
 634                 return log_link_warning_errno(link, r, "Failed to configure DHCP server: %m");
 635
 636         return 1;
 637 }
 638
 639 int link_request_dhcp_server(Link *link) {
 640         int r;
 641
 642         assert(link);
 643
 644         if (!link_dhcp4_server_enabled(link))
 645                 return 0;
 646
 647         if (link->dhcp_server)
 648                 return 0;
 649
 650         log_link_debug(link, "Requesting DHCP server.");
 651         r = link_queue_request(link, REQUEST_TYPE_DHCP_SERVER, dhcp_server_process_request, NULL);
 652         if (r < 0)
 653                 return log_link_warning_errno(link, r, "Failed to request configuration of DHCP server: %m");
 654
 655         return 0;
 656 }
 657
 658 int config_parse_dhcp_server_relay_agent_suboption(
 659                 const char *unit,
 660                 const char *filename,
 661                 unsigned line,
 662                 const char *section,
 663                 unsigned section_line,
 664                 const char *lvalue,
 665                 int ltype,
 666                 const char *rvalue,
 667                 void *data,
 668                 void *userdata) {
 669
 670         char **suboption_value = data;
 671         char* p;
 672
 673         assert(filename);
 674         assert(lvalue);
 675         assert(rvalue);
 676
 677         if (isempty(rvalue)) {
 678                 *suboption_value = mfree(*suboption_value);
 679                 return 0;
 680         }
 681
 682         p = startswith(rvalue, "string:");
 683         if (!p) {
 684                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 685                            "Failed to parse %s=%s'. Invalid format, ignoring.", lvalue, rvalue);
 686                 return 0;
 687         }
 688         return free_and_strdup(suboption_value, empty_to_null(p));
 689 }
 690
 691 int config_parse_dhcp_server_emit(
 692                 const char *unit,
 693                 const char *filename,
 694                 unsigned line,
 695                 const char *section,
 696                 unsigned section_line,
 697                 const char *lvalue,
 698                 int ltype,
 699                 const char *rvalue,
 700                 void *data,
 701                 void *userdata) {
 702
 703         NetworkDHCPServerEmitAddress *emit = ASSERT_PTR(data);
 704
 705         assert(rvalue);
 706
 707         if (isempty(rvalue)) {
 708                 emit->addresses = mfree(emit->addresses);
 709                 emit->n_addresses = 0;
 710                 return 0;
 711         }
 712
 713         for (const char *p = rvalue;;) {
 714                 _cleanup_free_ char *w = NULL;
 715                 union in_addr_union a;
 716                 int r;
 717
 718                 r = extract_first_word(&p, &w, NULL, 0);
 719                 if (r == -ENOMEM)
 720                         return log_oom();
 721                 if (r < 0) {
 722                         log_syntax(unit, LOG_WARNING, filename, line, r,
 723                                    "Failed to extract word, ignoring: %s", rvalue);
 724                         return 0;
 725                 }
 726                 if (r == 0)
 727                         return 0;
 728
 729                 if (streq(w, "_server_address"))
 730                         a = IN_ADDR_NULL; /* null address will be converted to the server address. */
 731                 else {
 732                         r = in_addr_from_string(AF_INET, w, &a);
 733                         if (r < 0) {
 734                                 log_syntax(unit, LOG_WARNING, filename, line, r,
 735                                            "Failed to parse %s= address '%s', ignoring: %m", lvalue, w);
 736                                 continue;
 737                         }
 738
 739                         if (in4_addr_is_null(&a.in)) {
 740                                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 741                                            "Found a null address in %s=, ignoring.", lvalue);
 742                                 continue;
 743                         }
 744                 }
 745
 746                 if (!GREEDY_REALLOC(emit->addresses, emit->n_addresses + 1))
 747                         return log_oom();
 748
 749                 emit->addresses[emit->n_addresses++] = a.in;
 750         }
 751 }
 752
 753 int config_parse_dhcp_server_address(
 754                 const char *unit,
 755                 const char *filename,
 756                 unsigned line,
 757                 const char *section,
 758                 unsigned section_line,
 759                 const char *lvalue,
 760                 int ltype,
 761                 const char *rvalue,
 762                 void *data,
 763                 void *userdata) {
 764
 765         Network *network = ASSERT_PTR(userdata);
 766         union in_addr_union a;
 767         unsigned char prefixlen;
 768         int r;
 769
 770         assert(filename);
 771         assert(lvalue);
 772         assert(rvalue);
 773
 774         if (isempty(rvalue)) {
 775                 network->dhcp_server_address_in_addr = (struct in_addr) {};
 776                 network->dhcp_server_address_prefixlen = 0;
 777                 return 0;
 778         }
 779
 780         r = in_addr_prefix_from_string(rvalue, AF_INET, &a, &prefixlen);
 781         if (r < 0) {
 782                 log_syntax(unit, LOG_WARNING, filename, line, r,
 783                            "Failed to parse %s=, ignoring assignment: %s", lvalue, rvalue);
 784                 return 0;
 785         }
 786         if (in4_addr_is_localhost(&a.in) || in4_addr_is_link_local(&a.in)) {
 787                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 788                            "DHCP server address cannot be a localhost or link-local address, "
 789                            "ignoring assignment: %s", rvalue);
 790                 return 0;
 791         }
 792
 793         network->dhcp_server_address_in_addr = a.in;
 794         network->dhcp_server_address_prefixlen = prefixlen;
 795         return 0;
 796 }
 797
 798 int config_parse_dhcp_server_ipv6_only_preferred(
 799                 const char *unit,
 800                 const char *filename,
 801                 unsigned line,
 802                 const char *section,
 803                 unsigned section_line,
 804                 const char *lvalue,
 805                 int ltype,
 806                 const char *rvalue,
 807                 void *data,
 808                 void *userdata) {
 809
 810         usec_t t, *usec = ASSERT_PTR(data);
 811         int r;
 812
 813         assert(filename);
 814         assert(section);
 815         assert(lvalue);
 816         assert(rvalue);
 817
 818         if (isempty(rvalue)) {
 819                 *usec = 0;
 820                 return 0;
 821         }
 822
 823         r = parse_sec(rvalue, &t);
 824         if (r < 0) {
 825                 log_syntax(unit, LOG_WARNING, filename, line, r,
 826                            "Failed to parse [%s] %s=, ignoring assignment: %s", section, lvalue, rvalue);
 827                 return 0;
 828         }
 829
 830         if (t < MIN_V6ONLY_WAIT_USEC && !network_test_mode_enabled()) {
 831                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 832                            "Invalid [%s] %s=, ignoring assignment: %s", section, lvalue, rvalue);
 833                 return 0;
 834         }
 835
 836         *usec = t;
 837         return 0;
 838 }