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, 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
  46         r = hashmap_put(m->links, INT_TO_PTR(ifindex), l);
  47         if (r < 0)
  48                 return r;
  49
  50         l->manager = m;
  51
  52         if (ret)
  53                 *ret = l;
  54         l = NULL;
  55
  56         return 0;
  57 }
  58
  59 Link *link_free(Link *l) {
  60
  61         if (!l)
  62                 return NULL;
  63
  64         while (l->addresses)
  65                 link_address_free(l->addresses);
  66
  67         if (l->manager)
  68                 hashmap_remove(l->manager->links, INT_TO_PTR(l->ifindex));
  69
  70         dns_scope_free(l->unicast_scope);
  71         dns_scope_free(l->llmnr_ipv4_scope);
  72         dns_scope_free(l->llmnr_ipv6_scope);
  73
  74         while (l->dns_servers)
  75                 dns_server_free(l->dns_servers);
  76
  77         free(l);
  78         return NULL;
  79 }
  80
  81 static void link_allocate_scopes(Link *l) {
  82         int r;
  83
  84         assert(l);
  85
  86         if (l->dns_servers) {
  87                 if (!l->unicast_scope) {
  88                         r = dns_scope_new(l->manager, &l->unicast_scope, l, DNS_PROTOCOL_DNS, AF_UNSPEC);
  89                         if (r < 0)
  90                                 log_warning("Failed to allocate DNS scope: %s", strerror(-r));
  91                 }
  92         } else
  93                 l->unicast_scope = dns_scope_free(l->unicast_scope);
  94
  95         if (link_relevant(l, AF_INET) && l->manager->llmnr_support != SUPPORT_NO) {
  96                 if (!l->llmnr_ipv4_scope) {
  97                         r = dns_scope_new(l->manager, &l->llmnr_ipv4_scope, l, DNS_PROTOCOL_LLMNR, AF_INET);
  98                         if (r < 0)
  99                                 log_warning("Failed to allocate LLMNR IPv4 scope: %s", strerror(-r));
 100                 }
 101         } else
 102                 l->llmnr_ipv4_scope = dns_scope_free(l->llmnr_ipv4_scope);
 103
 104         if (link_relevant(l, AF_INET6) && l->manager->llmnr_support != SUPPORT_NO) {
 105                 if (!l->llmnr_ipv6_scope) {
 106                         r = dns_scope_new(l->manager, &l->llmnr_ipv6_scope, l, DNS_PROTOCOL_LLMNR, AF_INET6);
 107                         if (r < 0)
 108                                 log_warning("Failed to allocate LLMNR IPv6 scope: %s", strerror(-r));
 109                 }
 110         } else
 111                 l->llmnr_ipv6_scope = dns_scope_free(l->llmnr_ipv6_scope);
 112 }
 113
 114 void link_add_rrs(Link *l, bool force_remove) {
 115         LinkAddress *a;
 116
 117         LIST_FOREACH(addresses, a, l->addresses)
 118                 link_address_add_rrs(a, force_remove);
 119 }
 120
 121 int link_update_rtnl(Link *l, sd_rtnl_message *m) {
 122         const char *n = NULL;
 123         int r;
 124
 125         assert(l);
 126         assert(m);
 127
 128         r = sd_rtnl_message_link_get_flags(m, &l->flags);
 129         if (r < 0)
 130                 return r;
 131
 132         sd_rtnl_message_read_u32(m, IFLA_MTU, &l->mtu);
 133
 134         if (sd_rtnl_message_read_string(m, IFLA_IFNAME, &n) >= 0) {
 135                 strncpy(l->name, n, sizeof(l->name));
 136                 char_array_0(l->name);
 137         }
 138
 139         link_allocate_scopes(l);
 140         link_add_rrs(l, false);
 141
 142         return 0;
 143 }
 144
 145 static int link_update_dns_servers(Link *l) {
 146         _cleanup_strv_free_ char **nameservers = NULL;
 147         char **nameserver;
 148         DnsServer *s, *nx;
 149         int r;
 150
 151         assert(l);
 152
 153         r = sd_network_get_dns(l->ifindex, &nameservers);
 154         if (r < 0)
 155                 goto clear;
 156
 157         LIST_FOREACH(servers, s, l->dns_servers)
 158                 s->marked = true;
 159
 160         STRV_FOREACH(nameserver, nameservers) {
 161                 union in_addr_union a;
 162                 int family;
 163
 164                 r = in_addr_from_string_auto(*nameserver, &family, &a);
 165                 if (r < 0)
 166                         goto clear;
 167
 168                 s = link_find_dns_server(l, family, &a);
 169                 if (s)
 170                         s->marked = false;
 171                 else {
 172                         r = dns_server_new(l->manager, NULL, DNS_SERVER_LINK, l, family, &a);
 173                         if (r < 0)
 174                                 goto clear;
 175                 }
 176         }
 177
 178         LIST_FOREACH_SAFE(servers, s, nx, l->dns_servers)
 179                 if (s->marked)
 180                         dns_server_free(s);
 181
 182         return 0;
 183
 184 clear:
 185         while (l->dns_servers)
 186                 dns_server_free(l->dns_servers);
 187
 188         return r;
 189 }
 190
 191 int link_update_monitor(Link *l) {
 192         assert(l);
 193
 194         link_update_dns_servers(l);
 195         link_allocate_scopes(l);
 196         link_add_rrs(l, false);
 197
 198         return 0;
 199 }
 200
 201 bool link_relevant(Link *l, int family) {
 202         _cleanup_free_ char *state = NULL;
 203         LinkAddress *a;
 204
 205         assert(l);
 206
 207         /* A link is relevant if it isn't a loopback or pointopoint
 208          * device, has a link beat, can do multicast and has at least
 209          * one relevant IP address */
 210
 211         if (l->flags & (IFF_LOOPBACK|IFF_POINTOPOINT|IFF_DORMANT))
 212                 return false;
 213
 214         if ((l->flags & (IFF_UP|IFF_LOWER_UP|IFF_MULTICAST)) != (IFF_UP|IFF_LOWER_UP|IFF_MULTICAST))
 215                 return false;
 216
 217         sd_network_get_link_operational_state(l->ifindex, &state);
 218         if (state && !STR_IN_SET(state, "unknown", "degraded", "routable"))
 219                 return false;
 220
 221         LIST_FOREACH(addresses, a, l->addresses)
 222                 if (a->family == family && link_address_relevant(a))
 223                         return true;
 224
 225         return false;
 226 }
 227
 228 LinkAddress *link_find_address(Link *l, int family, const union in_addr_union *in_addr) {
 229         LinkAddress *a;
 230
 231         assert(l);
 232
 233         LIST_FOREACH(addresses, a, l->addresses)
 234                 if (a->family == family && in_addr_equal(family, &a->in_addr, in_addr))
 235                         return a;
 236
 237         return NULL;
 238 }
 239
 240 DnsServer* link_find_dns_server(Link *l, int family, const union in_addr_union *in_addr) {
 241         DnsServer *s;
 242
 243         assert(l);
 244
 245         LIST_FOREACH(servers, s, l->dns_servers)
 246                 if (s->family == family && in_addr_equal(family, &s->address, in_addr))
 247                         return s;
 248         return NULL;
 249 }
 250
 251 static DnsServer* link_set_dns_server(Link *l, DnsServer *s) {
 252         assert(l);
 253
 254         if (l->current_dns_server == s)
 255                 return s;
 256
 257         if (s) {
 258                 _cleanup_free_ char *ip = NULL;
 259
 260                 in_addr_to_string(s->family, &s->address, &ip);
 261                 log_info("Switching to DNS server %s for interface %s.", strna(ip), l->name);
 262         } else
 263                 log_info("No DNS server set for interface %s.", l->name);
 264
 265         l->current_dns_server = s;
 266         return s;
 267 }
 268
 269 DnsServer *link_get_dns_server(Link *l) {
 270         assert(l);
 271
 272         if (!l->current_dns_server)
 273                 link_set_dns_server(l, l->dns_servers);
 274
 275         return l->current_dns_server;
 276 }
 277
 278 void link_next_dns_server(Link *l) {
 279         assert(l);
 280
 281         if (!l->current_dns_server)
 282                 return;
 283
 284         if (l->current_dns_server->servers_next) {
 285                 link_set_dns_server(l, l->current_dns_server->servers_next);
 286                 return;
 287         }
 288
 289         link_set_dns_server(l, l->dns_servers);
 290 }
 291
 292 int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr) {
 293         LinkAddress *a;
 294
 295         assert(l);
 296         assert(in_addr);
 297
 298         a = new0(LinkAddress, 1);
 299         if (!a)
 300                 return -ENOMEM;
 301
 302         a->family = family;
 303         a->in_addr = *in_addr;
 304
 305         a->link = l;
 306         LIST_PREPEND(addresses, l->addresses, a);
 307
 308         if (ret)
 309                 *ret = a;
 310
 311         return 0;
 312 }
 313
 314 LinkAddress *link_address_free(LinkAddress *a) {
 315         if (!a)
 316                 return NULL;
 317
 318         if (a->link) {
 319                 LIST_REMOVE(addresses, a->link->addresses, a);
 320
 321                 if (a->llmnr_address_rr) {
 322                         if (a->family == AF_INET && a->link->llmnr_ipv4_scope)
 323                                 dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr);
 324                         else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope)
 325                                 dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr);
 326                 }
 327
 328                 if (a->llmnr_ptr_rr) {
 329                         if (a->family == AF_INET && a->link->llmnr_ipv4_scope)
 330                                 dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr);
 331                         else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope)
 332                                 dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr);
 333                 }
 334         }
 335
 336         dns_resource_record_unref(a->llmnr_address_rr);
 337         dns_resource_record_unref(a->llmnr_ptr_rr);
 338
 339         free(a);
 340         return NULL;
 341 }
 342
 343 void link_address_add_rrs(LinkAddress *a, bool force_remove) {
 344         int r;
 345
 346         assert(a);
 347
 348         if (a->family == AF_INET) {
 349
 350                 if (!force_remove &&
 351                     link_address_relevant(a) &&
 352                     a->link->llmnr_ipv4_scope &&
 353                     a->link->manager->llmnr_support == SUPPORT_YES) {
 354
 355                         if (!a->link->manager->host_ipv4_key) {
 356                                 a->link->manager->host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->hostname);
 357                                 if (!a->link->manager->host_ipv4_key) {
 358                                         r = -ENOMEM;
 359                                         goto fail;
 360                                 }
 361                         }
 362
 363                         if (!a->llmnr_address_rr) {
 364                                 a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv4_key);
 365                                 if (!a->llmnr_address_rr) {
 366                                         r = -ENOMEM;
 367                                         goto fail;
 368                                 }
 369
 370                                 a->llmnr_address_rr->a.in_addr = a->in_addr.in;
 371                                 a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL;
 372                         }
 373
 374                         if (!a->llmnr_ptr_rr) {
 375                                 r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname);
 376                                 if (r < 0)
 377                                         goto fail;
 378
 379                                 a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL;
 380                         }
 381
 382                         r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_address_rr, true);
 383                         if (r < 0)
 384                                 log_warning("Failed tp add A record to LLMNR zone: %s", strerror(-r));
 385
 386                         r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_ptr_rr, false);
 387                         if (r < 0)
 388                                 log_warning("Failed tp add IPv6 PTR record to LLMNR zone: %s", strerror(-r));
 389                 } else {
 390                         if (a->llmnr_address_rr) {
 391                                 if (a->link->llmnr_ipv4_scope)
 392                                         dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr);
 393                                 a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr);
 394                         }
 395
 396                         if (a->llmnr_ptr_rr) {
 397                                 if (a->link->llmnr_ipv4_scope)
 398                                         dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr);
 399                                 a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr);
 400                         }
 401                 }
 402         }
 403
 404         if (a->family == AF_INET6) {
 405
 406                 if (!force_remove &&
 407                     link_address_relevant(a) &&
 408                     a->link->llmnr_ipv6_scope &&
 409                     a->link->manager->llmnr_support == SUPPORT_YES) {
 410
 411                         if (!a->link->manager->host_ipv6_key) {
 412                                 a->link->manager->host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->hostname);
 413                                 if (!a->link->manager->host_ipv6_key) {
 414                                         r = -ENOMEM;
 415                                         goto fail;
 416                                 }
 417                         }
 418
 419                         if (!a->llmnr_address_rr) {
 420                                 a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv6_key);
 421                                 if (!a->llmnr_address_rr) {
 422                                         r = -ENOMEM;
 423                                         goto fail;
 424                                 }
 425
 426                                 a->llmnr_address_rr->aaaa.in6_addr = a->in_addr.in6;
 427                                 a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL;
 428                         }
 429
 430                         if (!a->llmnr_ptr_rr) {
 431                                 r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname);
 432                                 if (r < 0)
 433                                         goto fail;
 434
 435                                 a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL;
 436                         }
 437
 438                         r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_address_rr, true);
 439                         if (r < 0)
 440                                 log_warning("Failed to add AAAA record to LLMNR zone: %s", strerror(-r));
 441
 442                         r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_ptr_rr, false);
 443                         if (r < 0)
 444                                 log_warning("Failed to add IPv6 PTR record to LLMNR zone: %s", strerror(-r));
 445                 } else {
 446                         if (a->llmnr_address_rr) {
 447                                 if (a->link->llmnr_ipv6_scope)
 448                                         dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr);
 449                                 a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr);
 450                         }
 451
 452                         if (a->llmnr_ptr_rr) {
 453                                 if (a->link->llmnr_ipv6_scope)
 454                                         dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr);
 455                                 a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr);
 456                         }
 457                 }
 458         }
 459
 460         return;
 461
 462 fail:
 463         log_debug("Failed to update address RRs: %s", strerror(-r));
 464 }
 465
 466 int link_address_update_rtnl(LinkAddress *a, sd_rtnl_message *m) {
 467         int r;
 468         assert(a);
 469         assert(m);
 470
 471         r = sd_rtnl_message_addr_get_flags(m, &a->flags);
 472         if (r < 0)
 473                 return r;
 474
 475         sd_rtnl_message_addr_get_scope(m, &a->scope);
 476
 477         link_allocate_scopes(a->link);
 478         link_add_rrs(a->link, false);
 479
 480         return 0;
 481 }
 482
 483 bool link_address_relevant(LinkAddress *a) {
 484         assert(a);
 485
 486         if (a->flags & IFA_F_DEPRECATED)
 487                 return false;
 488
 489         if (IN_SET(a->scope, RT_SCOPE_HOST, RT_SCOPE_NOWHERE))
 490                 return false;
 491
 492         return true;
 493 }