src/resolve/resolved-link.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2014 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <net/if.h>
  23
  24 #include "sd-network.h"
  25 #include "strv.h"
  26 #include "missing.h"
  27 #include "resolved-link.h"
  28
  29 int link_new(Manager *m, Link **ret, int ifindex) {
  30         _cleanup_(link_freep) Link *l = NULL;
  31         int r;
  32
  33         assert(m);
  34         assert(ifindex > 0);
  35
  36         r = hashmap_ensure_allocated(&m->links, NULL);
  37         if (r < 0)
  38                 return r;
  39
  40         l = new0(Link, 1);
  41         if (!l)
  42                 return -ENOMEM;
  43
  44         l->ifindex = ifindex;
  45         l->llmnr_support = SUPPORT_YES;
  46
  47         r = hashmap_put(m->links, INT_TO_PTR(ifindex), l);
  48         if (r < 0)
  49                 return r;
  50
  51         l->manager = m;
  52
  53         if (ret)
  54                 *ret = l;
  55         l = NULL;
  56
  57         return 0;
  58 }
  59
  60 Link *link_free(Link *l) {
  61
  62         if (!l)
  63                 return NULL;
  64
  65         while (l->addresses)
  66                 link_address_free(l->addresses);
  67
  68         if (l->manager)
  69                 hashmap_remove(l->manager->links, INT_TO_PTR(l->ifindex));
  70
  71         dns_scope_free(l->unicast_scope);
  72         dns_scope_free(l->llmnr_ipv4_scope);
  73         dns_scope_free(l->llmnr_ipv6_scope);
  74
  75         while (l->dns_servers)
  76                 dns_server_free(l->dns_servers);
  77
  78         free(l);
  79         return NULL;
  80 }
  81
  82 static void link_allocate_scopes(Link *l) {
  83         int r;
  84
  85         assert(l);
  86
  87         if (l->dns_servers) {
  88                 if (!l->unicast_scope) {
  89                         r = dns_scope_new(l->manager, &l->unicast_scope, l, DNS_PROTOCOL_DNS, AF_UNSPEC);
  90                         if (r < 0)
  91                                 log_warning("Failed to allocate DNS scope: %s", strerror(-r));
  92                 }
  93         } else
  94                 l->unicast_scope = dns_scope_free(l->unicast_scope);
  95
  96         if (link_relevant(l, AF_INET) &&
  97             l->llmnr_support != SUPPORT_NO &&
  98             l->manager->llmnr_support != SUPPORT_NO) {
  99                 if (!l->llmnr_ipv4_scope) {
 100                         r = dns_scope_new(l->manager, &l->llmnr_ipv4_scope, l, DNS_PROTOCOL_LLMNR, AF_INET);
 101                         if (r < 0)
 102                                 log_warning("Failed to allocate LLMNR IPv4 scope: %s", strerror(-r));
 103                 }
 104         } else
 105                 l->llmnr_ipv4_scope = dns_scope_free(l->llmnr_ipv4_scope);
 106
 107         if (link_relevant(l, AF_INET6) &&
 108             l->llmnr_support != SUPPORT_NO &&
 109             l->manager->llmnr_support != SUPPORT_NO &&
 110             socket_ipv6_is_supported()) {
 111                 if (!l->llmnr_ipv6_scope) {
 112                         r = dns_scope_new(l->manager, &l->llmnr_ipv6_scope, l, DNS_PROTOCOL_LLMNR, AF_INET6);
 113                         if (r < 0)
 114                                 log_warning("Failed to allocate LLMNR IPv6 scope: %s", strerror(-r));
 115                 }
 116         } else
 117                 l->llmnr_ipv6_scope = dns_scope_free(l->llmnr_ipv6_scope);
 118 }
 119
 120 void link_add_rrs(Link *l, bool force_remove) {
 121         LinkAddress *a;
 122
 123         LIST_FOREACH(addresses, a, l->addresses)
 124                 link_address_add_rrs(a, force_remove);
 125 }
 126
 127 int link_update_rtnl(Link *l, sd_rtnl_message *m) {
 128         const char *n = NULL;
 129         int r;
 130
 131         assert(l);
 132         assert(m);
 133
 134         r = sd_rtnl_message_link_get_flags(m, &l->flags);
 135         if (r < 0)
 136                 return r;
 137
 138         sd_rtnl_message_read_u32(m, IFLA_MTU, &l->mtu);
 139
 140         if (sd_rtnl_message_read_string(m, IFLA_IFNAME, &n) >= 0) {
 141                 strncpy(l->name, n, sizeof(l->name)-1);
 142                 char_array_0(l->name);
 143         }
 144
 145         link_allocate_scopes(l);
 146         link_add_rrs(l, false);
 147
 148         return 0;
 149 }
 150
 151 static int link_update_dns_servers(Link *l) {
 152         _cleanup_strv_free_ char **nameservers = NULL;
 153         char **nameserver;
 154         DnsServer *s, *nx;
 155         int r;
 156
 157         assert(l);
 158
 159         r = sd_network_link_get_dns(l->ifindex, &nameservers);
 160         if (r < 0)
 161                 goto clear;
 162
 163         LIST_FOREACH(servers, s, l->dns_servers)
 164                 s->marked = true;
 165
 166         STRV_FOREACH(nameserver, nameservers) {
 167                 union in_addr_union a;
 168                 int family;
 169
 170                 r = in_addr_from_string_auto(*nameserver, &family, &a);
 171                 if (r < 0)
 172                         goto clear;
 173
 174                 s = link_find_dns_server(l, family, &a);
 175                 if (s)
 176                         s->marked = false;
 177                 else {
 178                         r = dns_server_new(l->manager, NULL, DNS_SERVER_LINK, l, family, &a);
 179                         if (r < 0)
 180                                 goto clear;
 181                 }
 182         }
 183
 184         LIST_FOREACH_SAFE(servers, s, nx, l->dns_servers)
 185                 if (s->marked)
 186                         dns_server_free(s);
 187
 188         return 0;
 189
 190 clear:
 191         while (l->dns_servers)
 192                 dns_server_free(l->dns_servers);
 193
 194         return r;
 195 }
 196
 197 static int link_update_llmnr_support(Link *l) {
 198         _cleanup_free_ char *b = NULL;
 199         int r;
 200
 201         assert(l);
 202
 203         r = sd_network_link_get_llmnr(l->ifindex, &b);
 204         if (r < 0)
 205                 goto clear;
 206
 207         r = parse_boolean(b);
 208         if (r < 0) {
 209                 if (streq(b, "resolve"))
 210                         l->llmnr_support = SUPPORT_RESOLVE;
 211                 else
 212                         goto clear;
 213
 214         } else if (r > 0)
 215                 l->llmnr_support = SUPPORT_YES;
 216         else
 217                 l->llmnr_support = SUPPORT_NO;
 218
 219         return 0;
 220
 221 clear:
 222         l->llmnr_support = SUPPORT_YES;
 223         return r;
 224 }
 225
 226 static int link_update_domains(Link *l) {
 227         int r;
 228
 229         if (!l->unicast_scope)
 230                 return 0;
 231
 232         strv_free(l->unicast_scope->domains);
 233         l->unicast_scope->domains = NULL;
 234
 235         r = sd_network_link_get_domains(l->ifindex,
 236                                         &l->unicast_scope->domains);
 237         if (r < 0)
 238                 return r;
 239
 240         return 0;
 241 }
 242
 243 int link_update_monitor(Link *l) {
 244         assert(l);
 245
 246         link_update_dns_servers(l);
 247         link_update_llmnr_support(l);
 248         link_allocate_scopes(l);
 249         link_update_domains(l);
 250         link_add_rrs(l, false);
 251
 252         return 0;
 253 }
 254
 255 bool link_relevant(Link *l, int family) {
 256         _cleanup_free_ char *state = NULL;
 257         LinkAddress *a;
 258
 259         assert(l);
 260
 261         /* A link is relevant if it isn't a loopback or pointopoint
 262          * device, has a link beat, can do multicast and has at least
 263          * one relevant IP address */
 264
 265         if (l->flags & (IFF_LOOPBACK|IFF_POINTOPOINT|IFF_DORMANT))
 266                 return false;
 267
 268         if ((l->flags & (IFF_UP|IFF_LOWER_UP|IFF_MULTICAST)) != (IFF_UP|IFF_LOWER_UP|IFF_MULTICAST))
 269                 return false;
 270
 271         sd_network_link_get_operational_state(l->ifindex, &state);
 272         if (state && !STR_IN_SET(state, "unknown", "degraded", "routable"))
 273                 return false;
 274
 275         LIST_FOREACH(addresses, a, l->addresses)
 276                 if (a->family == family && link_address_relevant(a))
 277                         return true;
 278
 279         return false;
 280 }
 281
 282 LinkAddress *link_find_address(Link *l, int family, const union in_addr_union *in_addr) {
 283         LinkAddress *a;
 284
 285         assert(l);
 286
 287         LIST_FOREACH(addresses, a, l->addresses)
 288                 if (a->family == family && in_addr_equal(family, &a->in_addr, in_addr))
 289                         return a;
 290
 291         return NULL;
 292 }
 293
 294 DnsServer* link_find_dns_server(Link *l, int family, const union in_addr_union *in_addr) {
 295         DnsServer *s;
 296
 297         assert(l);
 298
 299         LIST_FOREACH(servers, s, l->dns_servers)
 300                 if (s->family == family && in_addr_equal(family, &s->address, in_addr))
 301                         return s;
 302         return NULL;
 303 }
 304
 305 DnsServer* link_set_dns_server(Link *l, DnsServer *s) {
 306         assert(l);
 307
 308         if (l->current_dns_server == s)
 309                 return s;
 310
 311         if (s) {
 312                 _cleanup_free_ char *ip = NULL;
 313
 314                 in_addr_to_string(s->family, &s->address, &ip);
 315                 log_info("Switching to DNS server %s for interface %s.", strna(ip), l->name);
 316         }
 317
 318         l->current_dns_server = s;
 319
 320         if (l->unicast_scope)
 321                 dns_cache_flush(&l->unicast_scope->cache);
 322
 323         return s;
 324 }
 325
 326 DnsServer *link_get_dns_server(Link *l) {
 327         assert(l);
 328
 329         if (!l->current_dns_server)
 330                 link_set_dns_server(l, l->dns_servers);
 331
 332         return l->current_dns_server;
 333 }
 334
 335 void link_next_dns_server(Link *l) {
 336         assert(l);
 337
 338         if (!l->current_dns_server)
 339                 return;
 340
 341         if (l->current_dns_server->servers_next) {
 342                 link_set_dns_server(l, l->current_dns_server->servers_next);
 343                 return;
 344         }
 345
 346         link_set_dns_server(l, l->dns_servers);
 347 }
 348
 349 int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr) {
 350         LinkAddress *a;
 351
 352         assert(l);
 353         assert(in_addr);
 354
 355         a = new0(LinkAddress, 1);
 356         if (!a)
 357                 return -ENOMEM;
 358
 359         a->family = family;
 360         a->in_addr = *in_addr;
 361
 362         a->link = l;
 363         LIST_PREPEND(addresses, l->addresses, a);
 364
 365         if (ret)
 366                 *ret = a;
 367
 368         return 0;
 369 }
 370
 371 LinkAddress *link_address_free(LinkAddress *a) {
 372         if (!a)
 373                 return NULL;
 374
 375         if (a->link) {
 376                 LIST_REMOVE(addresses, a->link->addresses, a);
 377
 378                 if (a->llmnr_address_rr) {
 379                         if (a->family == AF_INET && a->link->llmnr_ipv4_scope)
 380                                 dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr);
 381                         else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope)
 382                                 dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr);
 383                 }
 384
 385                 if (a->llmnr_ptr_rr) {
 386                         if (a->family == AF_INET && a->link->llmnr_ipv4_scope)
 387                                 dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr);
 388                         else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope)
 389                                 dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr);
 390                 }
 391         }
 392
 393         dns_resource_record_unref(a->llmnr_address_rr);
 394         dns_resource_record_unref(a->llmnr_ptr_rr);
 395
 396         free(a);
 397         return NULL;
 398 }
 399
 400 void link_address_add_rrs(LinkAddress *a, bool force_remove) {
 401         int r;
 402
 403         assert(a);
 404
 405         if (a->family == AF_INET) {
 406
 407                 if (!force_remove &&
 408                     link_address_relevant(a) &&
 409                     a->link->llmnr_ipv4_scope &&
 410                     a->link->llmnr_support == SUPPORT_YES &&
 411                     a->link->manager->llmnr_support == SUPPORT_YES) {
 412
 413                         if (!a->link->manager->host_ipv4_key) {
 414                                 a->link->manager->host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->hostname);
 415                                 if (!a->link->manager->host_ipv4_key) {
 416                                         r = -ENOMEM;
 417                                         goto fail;
 418                                 }
 419                         }
 420
 421                         if (!a->llmnr_address_rr) {
 422                                 a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv4_key);
 423                                 if (!a->llmnr_address_rr) {
 424                                         r = -ENOMEM;
 425                                         goto fail;
 426                                 }
 427
 428                                 a->llmnr_address_rr->a.in_addr = a->in_addr.in;
 429                                 a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL;
 430                         }
 431
 432                         if (!a->llmnr_ptr_rr) {
 433                                 r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname);
 434                                 if (r < 0)
 435                                         goto fail;
 436
 437                                 a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL;
 438                         }
 439
 440                         r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_address_rr, true);
 441                         if (r < 0)
 442                                 log_warning("Failed to add A record to LLMNR zone: %s", strerror(-r));
 443
 444                         r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_ptr_rr, false);
 445                         if (r < 0)
 446                                 log_warning("Failed to add IPv6 PTR record to LLMNR zone: %s", strerror(-r));
 447                 } else {
 448                         if (a->llmnr_address_rr) {
 449                                 if (a->link->llmnr_ipv4_scope)
 450                                         dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr);
 451                                 a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr);
 452                         }
 453
 454                         if (a->llmnr_ptr_rr) {
 455                                 if (a->link->llmnr_ipv4_scope)
 456                                         dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr);
 457                                 a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr);
 458                         }
 459                 }
 460         }
 461
 462         if (a->family == AF_INET6) {
 463
 464                 if (!force_remove &&
 465                     link_address_relevant(a) &&
 466                     a->link->llmnr_ipv6_scope &&
 467                     a->link->llmnr_support == SUPPORT_YES &&
 468                     a->link->manager->llmnr_support == SUPPORT_YES) {
 469
 470                         if (!a->link->manager->host_ipv6_key) {
 471                                 a->link->manager->host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->hostname);
 472                                 if (!a->link->manager->host_ipv6_key) {
 473                                         r = -ENOMEM;
 474                                         goto fail;
 475                                 }
 476                         }
 477
 478                         if (!a->llmnr_address_rr) {
 479                                 a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv6_key);
 480                                 if (!a->llmnr_address_rr) {
 481                                         r = -ENOMEM;
 482                                         goto fail;
 483                                 }
 484
 485                                 a->llmnr_address_rr->aaaa.in6_addr = a->in_addr.in6;
 486                                 a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL;
 487                         }
 488
 489                         if (!a->llmnr_ptr_rr) {
 490                                 r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname);
 491                                 if (r < 0)
 492                                         goto fail;
 493
 494                                 a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL;
 495                         }
 496
 497                         r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_address_rr, true);
 498                         if (r < 0)
 499                                 log_warning("Failed to add AAAA record to LLMNR zone: %s", strerror(-r));
 500
 501                         r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_ptr_rr, false);
 502                         if (r < 0)
 503                                 log_warning("Failed to add IPv6 PTR record to LLMNR zone: %s", strerror(-r));
 504                 } else {
 505                         if (a->llmnr_address_rr) {
 506                                 if (a->link->llmnr_ipv6_scope)
 507                                         dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr);
 508                                 a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr);
 509                         }
 510
 511                         if (a->llmnr_ptr_rr) {
 512                                 if (a->link->llmnr_ipv6_scope)
 513                                         dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr);
 514                                 a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr);
 515                         }
 516                 }
 517         }
 518
 519         return;
 520
 521 fail:
 522         log_debug("Failed to update address RRs: %s", strerror(-r));
 523 }
 524
 525 int link_address_update_rtnl(LinkAddress *a, sd_rtnl_message *m) {
 526         int r;
 527         assert(a);
 528         assert(m);
 529
 530         r = sd_rtnl_message_addr_get_flags(m, &a->flags);
 531         if (r < 0)
 532                 return r;
 533
 534         sd_rtnl_message_addr_get_scope(m, &a->scope);
 535
 536         link_allocate_scopes(a->link);
 537         link_add_rrs(a->link, false);
 538
 539         return 0;
 540 }
 541
 542 bool link_address_relevant(LinkAddress *a) {
 543         assert(a);
 544
 545         if (a->flags & (IFA_F_DEPRECATED|IFA_F_TENTATIVE))
 546                 return false;
 547
 548         if (IN_SET(a->scope, RT_SCOPE_HOST, RT_SCOPE_NOWHERE))
 549                 return false;
 550
 551         return true;
 552 }