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 "resolved-link.h"
  27
  28 static void link_address_add_rrs(LinkAddress *a);
  29
  30 int link_new(Manager *m, Link **ret, int ifindex) {
  31         _cleanup_(link_freep) Link *l = NULL;
  32         int r;
  33
  34         assert(m);
  35         assert(ifindex > 0);
  36
  37         r = hashmap_ensure_allocated(&m->links, NULL, NULL);
  38         if (r < 0)
  39                 return r;
  40
  41         l = new0(Link, 1);
  42         if (!l)
  43                 return -ENOMEM;
  44
  45         l->ifindex = ifindex;
  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) && (l->flags & IFF_MULTICAST) && l->manager->use_llmnr) {
  97                 if (!l->llmnr_ipv4_scope) {
  98                         r = dns_scope_new(l->manager, &l->llmnr_ipv4_scope, l, DNS_PROTOCOL_LLMNR, AF_INET);
  99                         if (r < 0)
 100                                 log_warning("Failed to allocate LLMNR IPv4 scope: %s", strerror(-r));
 101                 }
 102         } else
 103                 l->llmnr_ipv4_scope = dns_scope_free(l->llmnr_ipv4_scope);
 104
 105         if (link_relevant(l, AF_INET6) && (l->flags & IFF_MULTICAST) && l->manager->use_llmnr) {
 106                 if (!l->llmnr_ipv6_scope) {
 107                         r = dns_scope_new(l->manager, &l->llmnr_ipv6_scope, l, DNS_PROTOCOL_LLMNR, AF_INET6);
 108                         if (r < 0)
 109                                 log_warning("Failed to allocate LLMNR IPv6 scope: %s", strerror(-r));
 110                 }
 111         } else
 112                 l->llmnr_ipv6_scope = dns_scope_free(l->llmnr_ipv6_scope);
 113 }
 114
 115 static void link_add_rrs(Link *l) {
 116         LinkAddress *a;
 117
 118         LIST_FOREACH(addresses, a, l->addresses)
 119                 link_address_add_rrs(a);
 120 }
 121
 122 int link_update_rtnl(Link *l, sd_rtnl_message *m) {
 123         const char *n = NULL;
 124         int r;
 125
 126         assert(l);
 127         assert(m);
 128
 129         r = sd_rtnl_message_link_get_flags(m, &l->flags);
 130         if (r < 0)
 131                 return r;
 132
 133         sd_rtnl_message_read_u32(m, IFLA_MTU, &l->mtu);
 134
 135         if (sd_rtnl_message_read_string(m, IFLA_IFNAME, &n) >= 0) {
 136                 strncpy(l->name, n, sizeof(l->name));
 137                 char_array_0(l->name);
 138         }
 139
 140         link_allocate_scopes(l);
 141         link_add_rrs(l);
 142
 143         return 0;
 144 }
 145
 146 static int link_update_dns_servers(Link *l) {
 147         _cleanup_strv_free_ char **nameservers = NULL;
 148         char **nameserver;
 149         DnsServer *s, *nx;
 150         int r;
 151
 152         assert(l);
 153
 154         LIST_FOREACH(servers, s, l->dns_servers)
 155                 s->marked = true;
 156
 157         r = sd_network_get_dns(l->ifindex, &nameservers);
 158         if (r < 0)
 159                 goto clear;
 160
 161         STRV_FOREACH(nameserver, nameservers) {
 162                 union in_addr_union a;
 163                 int family;
 164
 165                 r = in_addr_from_string_auto(*nameserver, &family, &a);
 166                 if (r < 0)
 167                         goto clear;
 168
 169                 s = link_find_dns_server(l, family, &a);
 170                 if (s)
 171                         s->marked = false;
 172                 else {
 173                         r = dns_server_new(l->manager, NULL, l, family, &a);
 174                         if (r < 0)
 175                                 goto clear;
 176                 }
 177         }
 178
 179         LIST_FOREACH_SAFE(servers, s, nx, l->dns_servers)
 180                 if (s->marked)
 181                         dns_server_free(s);
 182
 183         return 0;
 184
 185 clear:
 186         while (l->dns_servers)
 187                 dns_server_free(l->dns_servers);
 188
 189         return r;
 190 }
 191
 192 int link_update_monitor(Link *l) {
 193         assert(l);
 194
 195         link_update_dns_servers(l);
 196         link_allocate_scopes(l);
 197         link_add_rrs(l);
 198
 199         return 0;
 200 }
 201
 202 bool link_relevant(Link *l, int family) {
 203         _cleanup_free_ char *state = NULL;
 204         LinkAddress *a;
 205
 206         assert(l);
 207
 208         /* A link is relevant if it isn't a loopback device and has at
 209          * least one relevant IP address */
 210
 211         if (l->flags & IFF_LOOPBACK)
 212                 return false;
 213
 214         sd_network_get_link_operational_state(l->ifindex, &state);
 215         if (state && !STR_IN_SET(state, "unknown", "degraded", "routable"))
 216                 return false;
 217
 218         LIST_FOREACH(addresses, a, l->addresses)
 219                 if (a->family == family && link_address_relevant(a))
 220                         return true;
 221
 222         return false;
 223 }
 224
 225 LinkAddress *link_find_address(Link *l, int family, const union in_addr_union *in_addr) {
 226         LinkAddress *a;
 227
 228         assert(l);
 229
 230         LIST_FOREACH(addresses, a, l->addresses)
 231                 if (a->family == family && in_addr_equal(family, &a->in_addr, in_addr))
 232                         return a;
 233
 234         return NULL;
 235 }
 236
 237 DnsServer* link_find_dns_server(Link *l, int family, const union in_addr_union *in_addr) {
 238         DnsServer *s;
 239
 240         assert(l);
 241
 242         LIST_FOREACH(servers, s, l->dns_servers)
 243                 if (s->family == family && in_addr_equal(family, &s->address, in_addr))
 244                         return s;
 245         return NULL;
 246 }
 247
 248 DnsServer *link_get_dns_server(Link *l) {
 249         assert(l);
 250
 251         if (!l->current_dns_server)
 252                 l->current_dns_server = l->dns_servers;
 253
 254         return l->current_dns_server;
 255 }
 256
 257 void link_next_dns_server(Link *l) {
 258         assert(l);
 259
 260         /* Switch to the next DNS server */
 261
 262         if (!l->current_dns_server) {
 263                 l->current_dns_server = l->dns_servers;
 264                 if (l->current_dns_server)
 265                         return;
 266         }
 267
 268         if (!l->current_dns_server)
 269                 return;
 270
 271         if (l->current_dns_server->servers_next) {
 272                 l->current_dns_server = l->current_dns_server->servers_next;
 273                 return;
 274         }
 275
 276         l->current_dns_server = l->dns_servers;
 277 }
 278
 279 int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr) {
 280         LinkAddress *a;
 281
 282         assert(l);
 283         assert(in_addr);
 284
 285         a = new0(LinkAddress, 1);
 286         if (!a)
 287                 return -ENOMEM;
 288
 289         a->family = family;
 290         a->in_addr = *in_addr;
 291
 292         a->link = l;
 293         LIST_PREPEND(addresses, l->addresses, a);
 294
 295         if (ret)
 296                 *ret = a;
 297
 298         return 0;
 299 }
 300
 301 LinkAddress *link_address_free(LinkAddress *a) {
 302         if (!a)
 303                 return NULL;
 304
 305         if (a->link) {
 306                 LIST_REMOVE(addresses, a->link->addresses, a);
 307
 308                 if (a->llmnr_address_rr) {
 309
 310                         if (a->family == AF_INET && a->link->llmnr_ipv4_scope)
 311                                 dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr);
 312                         else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope)
 313                                 dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr);
 314
 315                         dns_resource_record_unref(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                         dns_resource_record_unref(a->llmnr_ptr_rr);
 325                 }
 326         }
 327
 328         free(a);
 329         return NULL;
 330 }
 331
 332 static void link_address_add_rrs(LinkAddress *a) {
 333         int r;
 334
 335         assert(a);
 336
 337         if (a->family == AF_INET && a->link->llmnr_ipv4_scope) {
 338
 339                 if (!a->link->manager->host_ipv4_key) {
 340                         a->link->manager->host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->hostname);
 341                         if (!a->link->manager->host_ipv4_key) {
 342                                 r = -ENOMEM;
 343                                 goto fail;
 344                         }
 345                 }
 346
 347                 if (!a->llmnr_address_rr) {
 348                         a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv4_key);
 349                         if (!a->llmnr_address_rr) {
 350                                 r = -ENOMEM;
 351                                 goto fail;
 352                         }
 353
 354                         a->llmnr_address_rr->a.in_addr = a->in_addr.in;
 355                         a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL;
 356                 }
 357
 358                 if (!a->llmnr_ptr_rr) {
 359                         r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname);
 360                         if (r < 0)
 361                                 goto fail;
 362
 363                         a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL;
 364                 }
 365
 366                 if (link_address_relevant(a)) {
 367                         r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr);
 368                         if (r < 0)
 369                                 goto fail;
 370
 371                         r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr);
 372                         if (r < 0)
 373                                 goto fail;
 374                 } else {
 375                         dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr);
 376                         dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr);
 377                 }
 378         }
 379
 380         if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope) {
 381
 382                 if (!a->link->manager->host_ipv6_key) {
 383                         a->link->manager->host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->hostname);
 384                         if (!a->link->manager->host_ipv6_key) {
 385                                 r = -ENOMEM;
 386                                 goto fail;
 387                         }
 388                 }
 389
 390                 if (!a->llmnr_address_rr) {
 391                         a->llmnr_address_rr = dns_resource_record_new(a->link->manager->host_ipv6_key);
 392                         if (!a->llmnr_address_rr) {
 393                                 r = -ENOMEM;
 394                                 goto fail;
 395                         }
 396
 397                         a->llmnr_address_rr->aaaa.in6_addr = a->in_addr.in6;
 398                         a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL;
 399                 }
 400
 401                 if (!a->llmnr_ptr_rr) {
 402                         r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->hostname);
 403                         if (r < 0)
 404                                 goto fail;
 405
 406                         a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL;
 407                 }
 408
 409                 if (link_address_relevant(a)) {
 410                         r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr);
 411                         if (r < 0)
 412                                 goto fail;
 413
 414                         r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr);
 415                         if (r < 0)
 416                                 goto fail;
 417                 } else {
 418                         dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr);
 419                         dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr);
 420                 }
 421         }
 422
 423         return;
 424
 425 fail:
 426         log_debug("Failed to update address RRs: %s", strerror(-r));
 427 }
 428
 429 int link_address_update_rtnl(LinkAddress *a, sd_rtnl_message *m) {
 430         int r;
 431         assert(a);
 432         assert(m);
 433
 434         r = sd_rtnl_message_addr_get_flags(m, &a->flags);
 435         if (r < 0)
 436                 return r;
 437
 438         sd_rtnl_message_addr_get_scope(m, &a->scope);
 439
 440         link_allocate_scopes(a->link);
 441         link_add_rrs(a->link);
 442
 443         return 0;
 444 }
 445
 446 bool link_address_relevant(LinkAddress *a) {
 447         assert(a);
 448
 449         if (a->flags & IFA_F_DEPRECATED)
 450                 return false;
 451
 452         if (IN_SET(a->scope, RT_SCOPE_HOST, RT_SCOPE_NOWHERE))
 453                 return false;
 454
 455         return true;
 456 }