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->use_llmnr) {
  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->use_llmnr) {
 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         LIST_FOREACH(servers, s, l->dns_servers)
 154                 s->marked = true;
 155
 156         r = sd_network_get_dns(l->ifindex, &nameservers);
 157         if (r < 0)
 158                 goto clear;
 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, 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 DnsServer *link_get_dns_server(Link *l) {
 252         assert(l);
 253
 254         if (!l->current_dns_server)
 255                 l->current_dns_server = l->dns_servers;
 256
 257         return l->current_dns_server;
 258 }
 259
 260 void link_next_dns_server(Link *l) {
 261         assert(l);
 262
 263         /* Switch to the next DNS server */
 264
 265         if (!l->current_dns_server) {
 266                 l->current_dns_server = l->dns_servers;
 267                 if (l->current_dns_server)
 268                         return;
 269         }
 270
 271         if (!l->current_dns_server)
 272                 return;
 273
 274         if (l->current_dns_server->servers_next) {
 275                 l->current_dns_server = l->current_dns_server->servers_next;
 276                 return;
 277         }
 278
 279         l->current_dns_server = l->dns_servers;
 280 }
 281
 282 int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr) {
 283         LinkAddress *a;
 284
 285         assert(l);
 286         assert(in_addr);
 287
 288         a = new0(LinkAddress, 1);
 289         if (!a)
 290                 return -ENOMEM;
 291
 292         a->family = family;
 293         a->in_addr = *in_addr;
 294
 295         a->link = l;
 296         LIST_PREPEND(addresses, l->addresses, a);
 297
 298         if (ret)
 299                 *ret = a;
 300
 301         return 0;
 302 }
 303
 304 LinkAddress *link_address_free(LinkAddress *a) {
 305         if (!a)
 306                 return NULL;
 307
 308         if (a->link) {
 309                 LIST_REMOVE(addresses, a->link->addresses, a);
 310
 311                 if (a->llmnr_address_rr) {
 312                         if (a->family == AF_INET && a->link->llmnr_ipv4_scope)
 313                                 dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr);
 314                         else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope)
 315                                 dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr);
 316                 }
 317
 318                 if (a->llmnr_ptr_rr) {
 319                         if (a->family == AF_INET && a->link->llmnr_ipv4_scope)
 320                                 dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr);
 321                         else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope)
 322                                 dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr);
 323                 }
 324         }
 325
 326         dns_resource_record_unref(a->llmnr_address_rr);
 327         dns_resource_record_unref(a->llmnr_ptr_rr);
 328
 329         free(a);
 330         return NULL;
 331 }
 332
 333 void link_address_add_rrs(LinkAddress *a, bool force_remove) {
 334         int r;
 335
 336         assert(a);
 337
 338         if (a->family == AF_INET) {
 339
 340                 if (!force_remove && link_address_relevant(a) && a->link->llmnr_ipv4_scope) {
 341                         if (!a->link->manager->host_ipv4_key) {
 342                                 a->link->manager->host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->hostname);
 343                                 if (!a->link->manager->host_ipv4_key) {
 344                                         r = -ENOMEM;
 345                                         goto fail;
 346                                 }
 347                         }
 348
 349                         if (!a->llmnr_address_rr) {
 350                                 a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv4_key);
 351                                 if (!a->llmnr_address_rr) {
 352                                         r = -ENOMEM;
 353                                         goto fail;
 354                                 }
 355
 356                                 a->llmnr_address_rr->a.in_addr = a->in_addr.in;
 357                                 a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL;
 358                         }
 359
 360                         if (!a->llmnr_ptr_rr) {
 361                                 r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname);
 362                                 if (r < 0)
 363                                         goto fail;
 364
 365                                 a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL;
 366                         }
 367
 368                         r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_address_rr, true);
 369                         if (r < 0)
 370                                 log_warning("Failed tp add A record to LLMNR zone: %s", strerror(-r));
 371
 372                         r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_ptr_rr, false);
 373                         if (r < 0)
 374                                 log_warning("Failed tp add IPv6 PTR record to LLMNR zone: %s", strerror(-r));
 375                 } else {
 376                         if (a->llmnr_address_rr) {
 377                                 if (a->link->llmnr_ipv4_scope)
 378                                         dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr);
 379                                 a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr);
 380                         }
 381
 382                         if (a->llmnr_ptr_rr) {
 383                                 if (a->link->llmnr_ipv4_scope)
 384                                         dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr);
 385                                 a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr);
 386                         }
 387                 }
 388         }
 389
 390         if (a->family == AF_INET6) {
 391
 392                 if (!force_remove && link_address_relevant(a) && a->link->llmnr_ipv6_scope) {
 393                         if (!a->link->manager->host_ipv6_key) {
 394                                 a->link->manager->host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->hostname);
 395                                 if (!a->link->manager->host_ipv6_key) {
 396                                         r = -ENOMEM;
 397                                         goto fail;
 398                                 }
 399                         }
 400
 401                         if (!a->llmnr_address_rr) {
 402                                 a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv6_key);
 403                                 if (!a->llmnr_address_rr) {
 404                                         r = -ENOMEM;
 405                                         goto fail;
 406                                 }
 407
 408                                 a->llmnr_address_rr->aaaa.in6_addr = a->in_addr.in6;
 409                                 a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL;
 410                         }
 411
 412                         if (!a->llmnr_ptr_rr) {
 413                                 r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname);
 414                                 if (r < 0)
 415                                         goto fail;
 416
 417                                 a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL;
 418                         }
 419
 420                         r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_address_rr, true);
 421                         if (r < 0)
 422                                 log_warning("Failed to add AAAA record to LLMNR zone: %s", strerror(-r));
 423
 424                         r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_ptr_rr, false);
 425                         if (r < 0)
 426                                 log_warning("Failed to add IPv6 PTR record to LLMNR zone: %s", strerror(-r));
 427                 } else {
 428                         if (a->llmnr_address_rr) {
 429                                 if (a->link->llmnr_ipv6_scope)
 430                                         dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr);
 431                                 a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr);
 432                         }
 433
 434                         if (a->llmnr_ptr_rr) {
 435                                 if (a->link->llmnr_ipv6_scope)
 436                                         dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr);
 437                                 a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr);
 438                         }
 439                 }
 440         }
 441
 442         return;
 443
 444 fail:
 445         log_debug("Failed to update address RRs: %s", strerror(-r));
 446 }
 447
 448 int link_address_update_rtnl(LinkAddress *a, sd_rtnl_message *m) {
 449         int r;
 450         assert(a);
 451         assert(m);
 452
 453         r = sd_rtnl_message_addr_get_flags(m, &a->flags);
 454         if (r < 0)
 455                 return r;
 456
 457         sd_rtnl_message_addr_get_scope(m, &a->scope);
 458
 459         link_allocate_scopes(a->link);
 460         link_add_rrs(a->link, false);
 461
 462         return 0;
 463 }
 464
 465 bool link_address_relevant(LinkAddress *a) {
 466         assert(a);
 467
 468         if (a->flags & IFA_F_DEPRECATED)
 469                 return false;
 470
 471         if (IN_SET(a->scope, RT_SCOPE_HOST, RT_SCOPE_NOWHERE))
 472                 return false;
 473
 474         return true;
 475 }