src/network/networkd-dhcp4.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <netinet/ether.h>
   4 #include <linux/if.h>
   5
   6 #include "alloc-util.h"
   7 #include "dhcp-lease-internal.h"
   8 #include "hostname-util.h"
   9 #include "parse-util.h"
  10 #include "netdev/vrf.h"
  11 #include "network-internal.h"
  12 #include "networkd-link.h"
  13 #include "networkd-manager.h"
  14 #include "networkd-network.h"
  15 #include "string-util.h"
  16 #include "sysctl-util.h"
  17
  18 static int dhcp4_route_handler(sd_netlink *rtnl, sd_netlink_message *m,
  19                                void *userdata) {
  20         Link *link = userdata;
  21         int r;
  22
  23         assert(link);
  24         assert(link->dhcp4_messages > 0);
  25
  26         link->dhcp4_messages--;
  27
  28         r = sd_netlink_message_get_errno(m);
  29         if (r < 0 && r != -EEXIST) {
  30                 log_link_error_errno(link, r, "Could not set DHCPv4 route: %m");
  31                 link_enter_failed(link);
  32         }
  33
  34         if (link->dhcp4_messages == 0) {
  35                 link->dhcp4_configured = true;
  36                 link_check_ready(link);
  37         }
  38
  39         return 1;
  40 }
  41
  42 static int route_scope_from_address(const Route *route, const struct in_addr *self_addr) {
  43         assert(route);
  44         assert(self_addr);
  45
  46         if (in_addr_is_localhost(AF_INET, &route->dst) ||
  47             (self_addr->s_addr && route->dst.in.s_addr == self_addr->s_addr))
  48                 return RT_SCOPE_HOST;
  49         else if (in4_addr_is_null(&route->gw.in))
  50                 return RT_SCOPE_LINK;
  51         else
  52                 return RT_SCOPE_UNIVERSE;
  53 }
  54
  55 static int link_set_dhcp_routes(Link *link) {
  56         _cleanup_free_ sd_dhcp_route **static_routes = NULL;
  57         bool classless_route = false, static_route = false;
  58         struct in_addr gateway, address;
  59         int r, n, i;
  60         uint32_t table;
  61
  62         assert(link);
  63
  64         if (!link->dhcp_lease) /* link went down while we configured the IP addresses? */
  65                 return 0;
  66
  67         if (!link->network) /* link went down while we configured the IP addresses? */
  68                 return 0;
  69
  70         if (!link->network->dhcp_use_routes)
  71                 return 0;
  72
  73         /* When the interface is part of an VRF use the VRFs routing table, unless
  74          * there is a another table specified. */
  75         table = link->network->dhcp_route_table;
  76         if (!link->network->dhcp_route_table_set && link->network->vrf != NULL)
  77                 table = VRF(link->network->vrf)->table;
  78
  79         r = sd_dhcp_lease_get_address(link->dhcp_lease, &address);
  80         if (r < 0)
  81                 return log_link_warning_errno(link, r, "DHCP error: could not get address: %m");
  82
  83         n = sd_dhcp_lease_get_routes(link->dhcp_lease, &static_routes);
  84         if (n == -ENODATA)
  85                 log_link_debug_errno(link, n, "DHCP: No routes received from DHCP server: %m");
  86         else if (n < 0)
  87                 log_link_debug_errno(link, n, "DHCP error: could not get routes: %m");
  88
  89         for (i = 0; i < n; i++) {
  90                 if (static_routes[i]->option == SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE)
  91                         classless_route = true;
  92
  93                 if (static_routes[i]->option == SD_DHCP_OPTION_STATIC_ROUTE)
  94                         static_route = true;
  95         }
  96
  97         for (i = 0; i < n; i++) {
  98                 _cleanup_(route_freep) Route *route = NULL;
  99
 100                 /* if the DHCP server returns both a Classless Static Routes option and a Static Routes option,
 101                    the DHCP client MUST ignore the Static Routes option. */
 102                 if (classless_route && static_routes[i]->option == SD_DHCP_OPTION_STATIC_ROUTE)
 103                         continue;
 104
 105                 r = route_new(&route);
 106                 if (r < 0)
 107                         return log_link_error_errno(link, r, "Could not allocate route: %m");
 108
 109                 route->family = AF_INET;
 110                 route->protocol = RTPROT_DHCP;
 111                 assert_se(sd_dhcp_route_get_gateway(static_routes[i], &route->gw.in) >= 0);
 112                 assert_se(sd_dhcp_route_get_destination(static_routes[i], &route->dst.in) >= 0);
 113                 assert_se(sd_dhcp_route_get_destination_prefix_length(static_routes[i], &route->dst_prefixlen) >= 0);
 114                 route->priority = link->network->dhcp_route_metric;
 115                 route->table = table;
 116                 route->scope = route_scope_from_address(route, &address);
 117
 118                 r = route_configure(route, link, dhcp4_route_handler);
 119                 if (r < 0)
 120                         return log_link_warning_errno(link, r, "Could not set host route: %m");
 121
 122                 link->dhcp4_messages++;
 123         }
 124
 125         r = sd_dhcp_lease_get_router(link->dhcp_lease, &gateway);
 126         if (r == -ENODATA)
 127                 log_link_info_errno(link, r, "DHCP: No gateway received from DHCP server: %m");
 128         else if (r < 0)
 129                 log_link_warning_errno(link, r, "DHCP error: could not get gateway: %m");
 130
 131         /* According to RFC 3442: If the DHCP server returns both a Classless Static Routes option and
 132            a Router option, the DHCP client MUST ignore the Router option. */
 133         if (classless_route && static_route)
 134                 log_link_warning(link, "Classless static routes received from DHCP server: ignoring static-route option and router option");
 135
 136         if (r >= 0 && !classless_route) {
 137                 _cleanup_(route_freep) Route *route = NULL;
 138                 _cleanup_(route_freep) Route *route_gw = NULL;
 139
 140                 r = route_new(&route);
 141                 if (r < 0)
 142                         return log_link_error_errno(link, r, "Could not allocate route: %m");
 143
 144                 route->protocol = RTPROT_DHCP;
 145
 146                 r = route_new(&route_gw);
 147                 if (r < 0)
 148                         return log_link_error_errno(link, r,  "Could not allocate route: %m");
 149
 150                 /* The dhcp netmask may mask out the gateway. Add an explicit
 151                  * route for the gw host so that we can route no matter the
 152                  * netmask or existing kernel route tables. */
 153                 route_gw->family = AF_INET;
 154                 route_gw->dst.in = gateway;
 155                 route_gw->dst_prefixlen = 32;
 156                 route_gw->prefsrc.in = address;
 157                 route_gw->scope = RT_SCOPE_LINK;
 158                 route_gw->protocol = RTPROT_DHCP;
 159                 route_gw->priority = link->network->dhcp_route_metric;
 160                 route_gw->table = table;
 161
 162                 r = route_configure(route_gw, link, dhcp4_route_handler);
 163                 if (r < 0)
 164                         return log_link_warning_errno(link, r, "Could not set host route: %m");
 165
 166                 link->dhcp4_messages++;
 167
 168                 route->family = AF_INET;
 169                 route->gw.in = gateway;
 170                 route->prefsrc.in = address;
 171                 route->priority = link->network->dhcp_route_metric;
 172                 route->table = table;
 173
 174                 r = route_configure(route, link, dhcp4_route_handler);
 175                 if (r < 0) {
 176                         log_link_warning_errno(link, r, "Could not set routes: %m");
 177                         link_enter_failed(link);
 178                         return r;
 179                 }
 180
 181                 link->dhcp4_messages++;
 182         }
 183
 184         return 0;
 185 }
 186
 187 static int dhcp_lease_lost(Link *link) {
 188         _cleanup_(address_freep) Address *address = NULL;
 189         struct in_addr addr;
 190         struct in_addr netmask;
 191         struct in_addr gateway;
 192         unsigned prefixlen = 0;
 193         int r;
 194
 195         assert(link);
 196         assert(link->dhcp_lease);
 197
 198         log_link_warning(link, "DHCP lease lost");
 199
 200         if (link->network->dhcp_use_routes) {
 201                 _cleanup_free_ sd_dhcp_route **routes = NULL;
 202                 int n, i;
 203
 204                 n = sd_dhcp_lease_get_routes(link->dhcp_lease, &routes);
 205                 if (n >= 0) {
 206                         for (i = 0; i < n; i++) {
 207                                 _cleanup_(route_freep) Route *route = NULL;
 208
 209                                 r = route_new(&route);
 210                                 if (r >= 0) {
 211                                         route->family = AF_INET;
 212                                         assert_se(sd_dhcp_route_get_gateway(routes[i], &route->gw.in) >= 0);
 213                                         assert_se(sd_dhcp_route_get_destination(routes[i], &route->dst.in) >= 0);
 214                                         assert_se(sd_dhcp_route_get_destination_prefix_length(routes[i], &route->dst_prefixlen) >= 0);
 215
 216                                         route_remove(route, link,
 217                                                      link_route_remove_handler);
 218                                 }
 219                         }
 220                 }
 221         }
 222
 223         r = address_new(&address);
 224         if (r >= 0) {
 225                 r = sd_dhcp_lease_get_router(link->dhcp_lease, &gateway);
 226                 if (r >= 0) {
 227                         _cleanup_(route_freep) Route *route_gw = NULL;
 228                         _cleanup_(route_freep) Route *route = NULL;
 229
 230                         r = route_new(&route_gw);
 231                         if (r >= 0) {
 232                                 route_gw->family = AF_INET;
 233                                 route_gw->dst.in = gateway;
 234                                 route_gw->dst_prefixlen = 32;
 235                                 route_gw->scope = RT_SCOPE_LINK;
 236
 237                                 route_remove(route_gw, link,
 238                                              link_route_remove_handler);
 239                         }
 240
 241                         r = route_new(&route);
 242                         if (r >= 0) {
 243                                 route->family = AF_INET;
 244                                 route->gw.in = gateway;
 245
 246                                 route_remove(route, link,
 247                                              link_route_remove_handler);
 248                         }
 249                 }
 250
 251                 r = sd_dhcp_lease_get_address(link->dhcp_lease, &addr);
 252                 if (r >= 0) {
 253                         r = sd_dhcp_lease_get_netmask(link->dhcp_lease, &netmask);
 254                         if (r >= 0)
 255                                 prefixlen = in4_addr_netmask_to_prefixlen(&netmask);
 256
 257                         address->family = AF_INET;
 258                         address->in_addr.in = addr;
 259                         address->prefixlen = prefixlen;
 260
 261                         address_remove(address, link, link_address_remove_handler);
 262                 }
 263         }
 264
 265         if (link->network->dhcp_use_mtu) {
 266                 uint16_t mtu;
 267
 268                 r = sd_dhcp_lease_get_mtu(link->dhcp_lease, &mtu);
 269                 if (r >= 0 && link->original_mtu != mtu) {
 270                         r = link_set_mtu(link, link->original_mtu);
 271                         if (r < 0) {
 272                                 log_link_warning(link,
 273                                                  "DHCP error: could not reset MTU");
 274                                 link_enter_failed(link);
 275                                 return r;
 276                         }
 277                 }
 278         }
 279
 280         if (link->network->dhcp_use_hostname) {
 281                 const char *hostname = NULL;
 282
 283                 if (link->network->dhcp_hostname)
 284                         hostname = link->network->dhcp_hostname;
 285                 else
 286                         (void) sd_dhcp_lease_get_hostname(link->dhcp_lease, &hostname);
 287
 288                 if (hostname) {
 289                         /* If a hostname was set due to the lease, then unset it now. */
 290                         r = manager_set_hostname(link->manager, NULL);
 291                         if (r < 0)
 292                                 log_link_warning_errno(link, r, "Failed to reset transient hostname: %m");
 293                 }
 294         }
 295
 296         link->dhcp_lease = sd_dhcp_lease_unref(link->dhcp_lease);
 297         link_dirty(link);
 298         link->dhcp4_configured = false;
 299
 300         return 0;
 301 }
 302
 303 static int dhcp4_address_handler(sd_netlink *rtnl, sd_netlink_message *m,
 304                                  void *userdata) {
 305         Link *link = userdata;
 306         int r;
 307
 308         assert(link);
 309
 310         r = sd_netlink_message_get_errno(m);
 311         if (r < 0 && r != -EEXIST) {
 312                 log_link_error_errno(link, r, "Could not set DHCPv4 address: %m");
 313                 link_enter_failed(link);
 314         } else if (r >= 0)
 315                 manager_rtnl_process_address(rtnl, m, link->manager);
 316
 317         link_set_dhcp_routes(link);
 318
 319         if (link->dhcp4_messages == 0) {
 320                 link->dhcp4_configured = true;
 321                 link_check_ready(link);
 322         }
 323
 324         return 1;
 325 }
 326
 327 static int dhcp4_update_address(Link *link,
 328                                 struct in_addr *address,
 329                                 struct in_addr *netmask,
 330                                 uint32_t lifetime) {
 331         _cleanup_(address_freep) Address *addr = NULL;
 332         unsigned prefixlen;
 333         int r;
 334
 335         assert(address);
 336         assert(netmask);
 337         assert(lifetime);
 338
 339         prefixlen = in4_addr_netmask_to_prefixlen(netmask);
 340
 341         r = address_new(&addr);
 342         if (r < 0)
 343                 return r;
 344
 345         addr->family = AF_INET;
 346         addr->in_addr.in.s_addr = address->s_addr;
 347         addr->cinfo.ifa_prefered = lifetime;
 348         addr->cinfo.ifa_valid = lifetime;
 349         addr->prefixlen = prefixlen;
 350         addr->broadcast.s_addr = address->s_addr | ~netmask->s_addr;
 351
 352         /* allow reusing an existing address and simply update its lifetime
 353          * in case it already exists */
 354         r = address_configure(addr, link, dhcp4_address_handler, true);
 355         if (r < 0)
 356                 return r;
 357
 358         return 0;
 359 }
 360
 361 static int dhcp_lease_renew(sd_dhcp_client *client, Link *link) {
 362         sd_dhcp_lease *lease;
 363         struct in_addr address;
 364         struct in_addr netmask;
 365         uint32_t lifetime = CACHE_INFO_INFINITY_LIFE_TIME;
 366         int r;
 367
 368         assert(link);
 369         assert(client);
 370         assert(link->network);
 371
 372         r = sd_dhcp_client_get_lease(client, &lease);
 373         if (r < 0)
 374                 return log_link_warning_errno(link, r, "DHCP error: no lease: %m");
 375
 376         sd_dhcp_lease_unref(link->dhcp_lease);
 377         link->dhcp4_configured = false;
 378         link->dhcp_lease = sd_dhcp_lease_ref(lease);
 379         link_dirty(link);
 380
 381         r = sd_dhcp_lease_get_address(lease, &address);
 382         if (r < 0)
 383                 return log_link_warning_errno(link, r, "DHCP error: no address: %m");
 384
 385         r = sd_dhcp_lease_get_netmask(lease, &netmask);
 386         if (r < 0)
 387                 return log_link_warning_errno(link, r, "DHCP error: no netmask: %m");
 388
 389         if (!link->network->dhcp_critical) {
 390                 r = sd_dhcp_lease_get_lifetime(link->dhcp_lease, &lifetime);
 391                 if (r < 0)
 392                         return log_link_warning_errno(link, r, "DHCP error: no lifetime: %m");
 393         }
 394
 395         r = dhcp4_update_address(link, &address, &netmask, lifetime);
 396         if (r < 0) {
 397                 log_link_warning_errno(link, r, "Could not update IP address: %m");
 398                 link_enter_failed(link);
 399                 return r;
 400         }
 401
 402         return 0;
 403 }
 404
 405 static int dhcp_lease_acquired(sd_dhcp_client *client, Link *link) {
 406         sd_dhcp_lease *lease;
 407         struct in_addr address;
 408         struct in_addr netmask;
 409         struct in_addr gateway;
 410         unsigned prefixlen;
 411         uint32_t lifetime = CACHE_INFO_INFINITY_LIFE_TIME;
 412         int r;
 413
 414         assert(client);
 415         assert(link);
 416
 417         r = sd_dhcp_client_get_lease(client, &lease);
 418         if (r < 0)
 419                 return log_link_error_errno(link, r, "DHCP error: No lease: %m");
 420
 421         r = sd_dhcp_lease_get_address(lease, &address);
 422         if (r < 0)
 423                 return log_link_error_errno(link, r, "DHCP error: No address: %m");
 424
 425         r = sd_dhcp_lease_get_netmask(lease, &netmask);
 426         if (r < 0)
 427                 return log_link_error_errno(link, r, "DHCP error: No netmask: %m");
 428
 429         prefixlen = in4_addr_netmask_to_prefixlen(&netmask);
 430
 431         r = sd_dhcp_lease_get_router(lease, &gateway);
 432         if (r < 0 && r != -ENODATA)
 433                 return log_link_error_errno(link, r, "DHCP error: Could not get gateway: %m");
 434
 435         if (r >= 0)
 436                 log_struct(LOG_INFO,
 437                            LOG_LINK_INTERFACE(link),
 438                            LOG_LINK_MESSAGE(link, "DHCPv4 address %u.%u.%u.%u/%u via %u.%u.%u.%u",
 439                                             ADDRESS_FMT_VAL(address),
 440                                             prefixlen,
 441                                             ADDRESS_FMT_VAL(gateway)),
 442                            "ADDRESS=%u.%u.%u.%u", ADDRESS_FMT_VAL(address),
 443                            "PREFIXLEN=%u", prefixlen,
 444                            "GATEWAY=%u.%u.%u.%u", ADDRESS_FMT_VAL(gateway));
 445         else
 446                 log_struct(LOG_INFO,
 447                            LOG_LINK_INTERFACE(link),
 448                            LOG_LINK_MESSAGE(link, "DHCPv4 address %u.%u.%u.%u/%u",
 449                                             ADDRESS_FMT_VAL(address),
 450                                             prefixlen),
 451                            "ADDRESS=%u.%u.%u.%u", ADDRESS_FMT_VAL(address),
 452                            "PREFIXLEN=%u", prefixlen);
 453
 454         link->dhcp_lease = sd_dhcp_lease_ref(lease);
 455         link_dirty(link);
 456
 457         if (link->network->dhcp_use_mtu) {
 458                 uint16_t mtu;
 459
 460                 r = sd_dhcp_lease_get_mtu(lease, &mtu);
 461                 if (r >= 0) {
 462                         r = link_set_mtu(link, mtu);
 463                         if (r < 0)
 464                                 log_link_error_errno(link, r, "Failed to set MTU to %" PRIu16 ": %m", mtu);
 465                 }
 466         }
 467
 468         if (link->network->dhcp_use_hostname) {
 469                 const char *dhcpname = NULL;
 470                 _cleanup_free_ char *hostname = NULL;
 471
 472                 if (link->network->dhcp_hostname)
 473                         dhcpname = link->network->dhcp_hostname;
 474                 else
 475                         (void) sd_dhcp_lease_get_hostname(lease, &dhcpname);
 476
 477                 if (dhcpname) {
 478                         r = shorten_overlong(dhcpname, &hostname);
 479                         if (r < 0)
 480                                 log_link_warning_errno(link, r, "Unable to shorten overlong DHCP hostname '%s', ignoring: %m", dhcpname);
 481                         if (r == 1)
 482                                 log_link_notice(link, "Overlong DCHP hostname received, shortened from '%s' to '%s'", dhcpname, hostname);
 483                 }
 484
 485                 if (hostname) {
 486                         r = manager_set_hostname(link->manager, hostname);
 487                         if (r < 0)
 488                                 log_link_error_errno(link, r, "Failed to set transient hostname to '%s': %m", hostname);
 489                 }
 490         }
 491
 492         if (link->network->dhcp_use_timezone) {
 493                 const char *tz = NULL;
 494
 495                 (void) sd_dhcp_lease_get_timezone(link->dhcp_lease, &tz);
 496
 497                 if (tz) {
 498                         r = manager_set_timezone(link->manager, tz);
 499                         if (r < 0)
 500                                 log_link_error_errno(link, r, "Failed to set timezone to '%s': %m", tz);
 501                 }
 502         }
 503
 504         if (!link->network->dhcp_critical) {
 505                 r = sd_dhcp_lease_get_lifetime(link->dhcp_lease, &lifetime);
 506                 if (r < 0)
 507                         return log_link_warning_errno(link, r, "DHCP error: no lifetime: %m");
 508         }
 509
 510         r = dhcp4_update_address(link, &address, &netmask, lifetime);
 511         if (r < 0) {
 512                 log_link_warning_errno(link, r, "Could not update IP address: %m");
 513                 link_enter_failed(link);
 514                 return r;
 515         }
 516
 517         return 0;
 518 }
 519 static void dhcp4_handler(sd_dhcp_client *client, int event, void *userdata) {
 520         Link *link = userdata;
 521         int r = 0;
 522
 523         assert(link);
 524         assert(link->network);
 525         assert(link->manager);
 526
 527         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
 528                 return;
 529
 530         switch (event) {
 531                 case SD_DHCP_CLIENT_EVENT_EXPIRED:
 532                 case SD_DHCP_CLIENT_EVENT_STOP:
 533                 case SD_DHCP_CLIENT_EVENT_IP_CHANGE:
 534                         if (link->network->dhcp_critical) {
 535                                 log_link_error(link, "DHCPv4 connection considered system critical, ignoring request to reconfigure it.");
 536                                 return;
 537                         }
 538
 539                         if (link->dhcp_lease) {
 540                                 r = dhcp_lease_lost(link);
 541                                 if (r < 0) {
 542                                         link_enter_failed(link);
 543                                         return;
 544                                 }
 545                         }
 546
 547                         if (event == SD_DHCP_CLIENT_EVENT_IP_CHANGE) {
 548                                 r = dhcp_lease_acquired(client, link);
 549                                 if (r < 0) {
 550                                         link_enter_failed(link);
 551                                         return;
 552                                 }
 553                         }
 554
 555                         break;
 556                 case SD_DHCP_CLIENT_EVENT_RENEW:
 557                         r = dhcp_lease_renew(client, link);
 558                         if (r < 0) {
 559                                 link_enter_failed(link);
 560                                 return;
 561                         }
 562                         break;
 563                 case SD_DHCP_CLIENT_EVENT_IP_ACQUIRE:
 564                         r = dhcp_lease_acquired(client, link);
 565                         if (r < 0) {
 566                                 link_enter_failed(link);
 567                                 return;
 568                         }
 569                         break;
 570                 default:
 571                         if (event < 0)
 572                                 log_link_warning_errno(link, event, "DHCP error: Client failed: %m");
 573                         else
 574                                 log_link_warning(link, "DHCP unknown event: %i", event);
 575                         break;
 576         }
 577
 578         return;
 579 }
 580
 581 static int dhcp4_set_hostname(Link *link) {
 582         _cleanup_free_ char *hostname = NULL;
 583         const char *hn;
 584         int r;
 585
 586         assert(link);
 587
 588         if (!link->network->dhcp_send_hostname)
 589                 hn = NULL;
 590         else if (link->network->dhcp_hostname)
 591                 hn = link->network->dhcp_hostname;
 592         else {
 593                 r = gethostname_strict(&hostname);
 594                 if (r < 0 && r != -ENXIO) /* ENXIO: no hostname set or hostname is "localhost" */
 595                         return r;
 596
 597                 hn = hostname;
 598         }
 599
 600         r = sd_dhcp_client_set_hostname(link->dhcp_client, hn);
 601         if (r == -EINVAL && hostname)
 602                 /* Ignore error when the machine's hostname is not suitable to send in DHCP packet. */
 603                 log_link_warning_errno(link, r, "DHCP4 CLIENT: Failed to set hostname from kernel hostname, ignoring: %m");
 604         else if (r < 0)
 605                 return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set hostname: %m");
 606
 607         return 0;
 608 }
 609
 610 static bool promote_secondaries_enabled(const char *ifname) {
 611         _cleanup_free_ char *promote_secondaries_sysctl = NULL;
 612         char *promote_secondaries_path;
 613         int r;
 614
 615         promote_secondaries_path = strjoina("net/ipv4/conf/", ifname, "/promote_secondaries");
 616         r = sysctl_read(promote_secondaries_path, &promote_secondaries_sysctl);
 617         if (r < 0) {
 618                 log_debug_errno(r, "Cannot read sysctl %s", promote_secondaries_path);
 619                 return false;
 620         }
 621
 622         truncate_nl(promote_secondaries_sysctl);
 623         r = parse_boolean(promote_secondaries_sysctl);
 624         if (r < 0)
 625                 log_warning_errno(r, "Cannot parse sysctl %s with content %s as boolean", promote_secondaries_path, promote_secondaries_sysctl);
 626         return r > 0;
 627 }
 628
 629 /* dhcp4_set_promote_secondaries will ensure this interface has
 630  * the "promote_secondaries" option in the kernel set. If this sysctl
 631  * is not set DHCP will work only as long as the IP address does not
 632  * changes between leases. The kernel will remove all secondary IP
 633  * addresses of an interface otherwise. The way systemd-network works
 634  * is that the new IP of a lease is added as a secondary IP and when
 635  * the primary one expires it relies on the kernel to promote the
 636  * secondary IP. See also https://github.com/systemd/systemd/issues/7163
 637  */
 638 int dhcp4_set_promote_secondaries(Link *link) {
 639         int r;
 640
 641         assert(link);
 642         assert(link->network);
 643         assert(link->network->dhcp & ADDRESS_FAMILY_IPV4);
 644
 645         /* check if the kernel has promote_secondaries enabled for our
 646          * interface. If it is not globally enabled or enabled for the
 647          * specific interface we must either enable it.
 648          */
 649         if (!(promote_secondaries_enabled("all") || promote_secondaries_enabled(link->ifname))) {
 650                 char *promote_secondaries_path = NULL;
 651
 652                 log_link_debug(link, "promote_secondaries is unset, setting it");
 653                 promote_secondaries_path = strjoina("net/ipv4/conf/", link->ifname, "/promote_secondaries");
 654                 r = sysctl_write(promote_secondaries_path, "1");
 655                 if (r < 0)
 656                         log_link_warning_errno(link, r, "cannot set sysctl %s to 1", promote_secondaries_path);
 657                 return r > 0;
 658         }
 659
 660         return 0;
 661 }
 662
 663 int dhcp4_set_client_identifier(Link *link) {
 664         int r;
 665
 666         assert(link);
 667         assert(link->network);
 668         assert(link->dhcp_client);
 669
 670         switch (link->network->dhcp_client_identifier) {
 671         case DHCP_CLIENT_ID_DUID: {
 672                 /* If configured, apply user specified DUID and IAID */
 673                 const DUID *duid = link_get_duid(link);
 674
 675                 if (duid->type == DUID_TYPE_LLT && duid->raw_data_len == 0)
 676                         r = sd_dhcp_client_set_iaid_duid_llt(link->dhcp_client,
 677                                                              link->network->iaid,
 678                                                              duid->llt_time);
 679                 else
 680                         r = sd_dhcp_client_set_iaid_duid(link->dhcp_client,
 681                                                          link->network->iaid,
 682                                                          duid->type,
 683                                                          duid->raw_data_len > 0 ? duid->raw_data : NULL,
 684                                                          duid->raw_data_len);
 685                 if (r < 0)
 686                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set IAID+DUID: %m");
 687                 break;
 688         }
 689         case DHCP_CLIENT_ID_DUID_ONLY: {
 690                 /* If configured, apply user specified DUID */
 691                 const DUID *duid = link_get_duid(link);
 692
 693                 if (duid->type == DUID_TYPE_LLT && duid->raw_data_len == 0)
 694                         r = sd_dhcp_client_set_duid_llt(link->dhcp_client,
 695                                                              duid->llt_time);
 696                 else
 697                         r = sd_dhcp_client_set_duid(link->dhcp_client,
 698                                                     duid->type,
 699                                                     duid->raw_data_len > 0 ? duid->raw_data : NULL,
 700                                                     duid->raw_data_len);
 701                 if (r < 0)
 702                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set DUID: %m");
 703                 break;
 704         }
 705         case DHCP_CLIENT_ID_MAC:
 706                 r = sd_dhcp_client_set_client_id(link->dhcp_client,
 707                                                  ARPHRD_ETHER,
 708                                                  (const uint8_t *) &link->mac,
 709                                                  sizeof(link->mac));
 710                 if (r < 0)
 711                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set client ID: %m");
 712                 break;
 713         default:
 714                 assert_not_reached("Unknown client identifier type.");
 715         }
 716
 717         return 0;
 718 }
 719
 720 int dhcp4_configure(Link *link) {
 721         int r;
 722
 723         assert(link);
 724         assert(link->network);
 725         assert(link->network->dhcp & ADDRESS_FAMILY_IPV4);
 726
 727         if (!link->dhcp_client) {
 728                 r = sd_dhcp_client_new(&link->dhcp_client, link->network->dhcp_anonymize);
 729                 if (r == -ENOMEM)
 730                         return log_oom();
 731                 if (r < 0)
 732                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to create DHCP4 client: %m");
 733         }
 734
 735         r = sd_dhcp_client_attach_event(link->dhcp_client, NULL, 0);
 736         if (r < 0)
 737                 return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to attach event: %m");
 738
 739         r = sd_dhcp_client_set_mac(link->dhcp_client,
 740                                    (const uint8_t *) &link->mac,
 741                                    sizeof (link->mac), ARPHRD_ETHER);
 742         if (r < 0)
 743                 return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set MAC address: %m");
 744
 745         r = sd_dhcp_client_set_ifindex(link->dhcp_client, link->ifindex);
 746         if (r < 0)
 747                 return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set ifindex: %m");
 748
 749         r = sd_dhcp_client_set_callback(link->dhcp_client, dhcp4_handler, link);
 750         if (r < 0)
 751                 return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set callback: %m");
 752
 753         r = sd_dhcp_client_set_request_broadcast(link->dhcp_client,
 754                                                  link->network->dhcp_broadcast);
 755         if (r < 0)
 756                 return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for broadcast: %m");
 757
 758         if (link->mtu) {
 759                 r = sd_dhcp_client_set_mtu(link->dhcp_client, link->mtu);
 760                 if (r < 0)
 761                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set MTU: %m");
 762         }
 763
 764         if (link->network->dhcp_use_mtu) {
 765                 r = sd_dhcp_client_set_request_option(link->dhcp_client,
 766                                                       SD_DHCP_OPTION_INTERFACE_MTU);
 767                 if (r < 0)
 768                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for MTU: %m");
 769         }
 770
 771         /* NOTE: even if this variable is called "use", it also "sends" PRL
 772          * options, maybe there should be a different configuration variable
 773          * to send or not route options?. */
 774         /* NOTE: when using Anonymize=yes, routes PRL options are sent
 775          * by default, so they don't need to be added here. */
 776         if (link->network->dhcp_use_routes && !link->network->dhcp_anonymize) {
 777                 r = sd_dhcp_client_set_request_option(link->dhcp_client,
 778                                                       SD_DHCP_OPTION_STATIC_ROUTE);
 779                 if (r < 0)
 780                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for static route: %m");
 781
 782                 r = sd_dhcp_client_set_request_option(link->dhcp_client,
 783                                                       SD_DHCP_OPTION_CLASSLESS_STATIC_ROUTE);
 784                 if (r < 0)
 785                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for classless static route: %m");
 786         }
 787
 788         if (link->network->dhcp_use_ntp) {
 789                 r = sd_dhcp_client_set_request_option(link->dhcp_client, SD_DHCP_OPTION_NTP_SERVER);
 790                 if (r < 0)
 791                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for NTP server: %m");
 792         }
 793
 794         if (link->network->dhcp_use_timezone) {
 795                 r = sd_dhcp_client_set_request_option(link->dhcp_client, SD_DHCP_OPTION_NEW_TZDB_TIMEZONE);
 796                 if (r < 0)
 797                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set request flag for timezone: %m");
 798         }
 799
 800         r = dhcp4_set_hostname(link);
 801         if (r < 0)
 802                 return r;
 803
 804         if (link->network->dhcp_vendor_class_identifier) {
 805                 r = sd_dhcp_client_set_vendor_class_identifier(link->dhcp_client,
 806                                                                link->network->dhcp_vendor_class_identifier);
 807                 if (r < 0)
 808                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set vendor class identifier: %m");
 809         }
 810
 811         if (link->network->dhcp_user_class) {
 812                 r = sd_dhcp_client_set_user_class(link->dhcp_client, (const char **) link->network->dhcp_user_class);
 813                 if (r < 0)
 814                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set user class: %m");
 815         }
 816
 817         if (link->network->dhcp_client_port) {
 818                 r = sd_dhcp_client_set_client_port(link->dhcp_client, link->network->dhcp_client_port);
 819                 if (r < 0)
 820                         return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set listen port: %m");
 821         }
 822
 823         return dhcp4_set_client_identifier(link);
 824 }