src/network/networkd-ndisc.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 /***
   3   Copyright © 2014 Intel Corporation. All rights reserved.
   4 ***/
   5
   6 #include <arpa/inet.h>
   7 #include <netinet/icmp6.h>
   8 #include <linux/if.h>
   9
  10 #include "sd-ndisc.h"
  11
  12 #include "missing_network.h"
  13 #include "networkd-address-generation.h"
  14 #include "networkd-address.h"
  15 #include "networkd-dhcp6.h"
  16 #include "networkd-manager.h"
  17 #include "networkd-ndisc.h"
  18 #include "networkd-queue.h"
  19 #include "networkd-route.h"
  20 #include "networkd-state-file.h"
  21 #include "string-table.h"
  22 #include "string-util.h"
  23 #include "strv.h"
  24
  25 #define NDISC_DNSSL_MAX 64U
  26 #define NDISC_RDNSS_MAX 64U
  27
  28 bool link_ipv6_accept_ra_enabled(Link *link) {
  29         assert(link);
  30
  31         if (!socket_ipv6_is_supported())
  32                 return false;
  33
  34         if (link->flags & IFF_LOOPBACK)
  35                 return false;
  36
  37         if (!link->network)
  38                 return false;
  39
  40         if (!link_ipv6ll_enabled(link))
  41                 return false;
  42
  43         assert(link->network->ipv6_accept_ra >= 0);
  44         return link->network->ipv6_accept_ra;
  45 }
  46
  47 void network_adjust_ipv6_accept_ra(Network *network) {
  48         assert(network);
  49
  50         if (!FLAGS_SET(network->link_local, ADDRESS_FAMILY_IPV6)) {
  51                 if (network->ipv6_accept_ra > 0)
  52                         log_warning("%s: IPv6AcceptRA= is enabled but IPv6 link local addressing is disabled or not supported. "
  53                                     "Disabling IPv6AcceptRA=.", network->filename);
  54                 network->ipv6_accept_ra = false;
  55         }
  56
  57         if (network->ipv6_accept_ra < 0)
  58                 /* default to accept RA if ip_forward is disabled and ignore RA if ip_forward is enabled */
  59                 network->ipv6_accept_ra = !FLAGS_SET(network->ip_forward, ADDRESS_FAMILY_IPV6);
  60
  61         /* When RouterAllowList=, PrefixAllowList= or RouteAllowList= are specified, then
  62          * RouterDenyList=, PrefixDenyList= or RouteDenyList= are ignored, respectively. */
  63         if (!set_isempty(network->ndisc_allow_listed_router))
  64                 network->ndisc_deny_listed_router = set_free_free(network->ndisc_deny_listed_router);
  65         if (!set_isempty(network->ndisc_allow_listed_prefix))
  66                 network->ndisc_deny_listed_prefix = set_free_free(network->ndisc_deny_listed_prefix);
  67         if (!set_isempty(network->ndisc_allow_listed_route_prefix))
  68                 network->ndisc_deny_listed_route_prefix = set_free_free(network->ndisc_deny_listed_route_prefix);
  69 }
  70
  71 static int ndisc_remove(Link *link, struct in6_addr *router) {
  72         bool updated = false;
  73         NDiscDNSSL *dnssl;
  74         NDiscRDNSS *rdnss;
  75         Address *address;
  76         Route *route;
  77         int k, r = 0;
  78
  79         assert(link);
  80
  81         SET_FOREACH(route, link->routes) {
  82                 if (route->source != NETWORK_CONFIG_SOURCE_NDISC)
  83                         continue;
  84                 if (!route_is_marked(route))
  85                         continue;
  86                 if (router && !in6_addr_equal(router, &route->provider.in6))
  87                         continue;
  88
  89                 k = route_remove(route);
  90                 if (k < 0)
  91                         r = k;
  92
  93                 route_cancel_request(route);
  94         }
  95
  96         SET_FOREACH(address, link->addresses) {
  97                 if (address->source != NETWORK_CONFIG_SOURCE_NDISC)
  98                         continue;
  99                 if (!address_is_marked(address))
 100                         continue;
 101                 if (router && !in6_addr_equal(router, &address->provider.in6))
 102                         continue;
 103
 104                 k = address_remove(address);
 105                 if (k < 0)
 106                         r = k;
 107
 108                 address_cancel_request(address);
 109         }
 110
 111         SET_FOREACH(rdnss, link->ndisc_rdnss) {
 112                 if (!rdnss->marked)
 113                         continue;
 114                 if (router && !in6_addr_equal(router, &rdnss->router))
 115                         continue;
 116
 117                 free(set_remove(link->ndisc_rdnss, rdnss));
 118                 updated = true;
 119         }
 120
 121         SET_FOREACH(dnssl, link->ndisc_dnssl) {
 122                 if (!dnssl->marked)
 123                         continue;
 124                 if (router && !in6_addr_equal(router, &dnssl->router))
 125                         continue;
 126
 127                 free(set_remove(link->ndisc_dnssl, dnssl));
 128                 updated = true;
 129         }
 130
 131         if (updated)
 132                 link_dirty(link);
 133
 134         return r;
 135 }
 136
 137 static int ndisc_check_ready(Link *link);
 138
 139 static int ndisc_address_ready_callback(Address *address) {
 140         Address *a;
 141
 142         assert(address);
 143         assert(address->link);
 144
 145         SET_FOREACH(a, address->link->addresses)
 146                 if (a->source == NETWORK_CONFIG_SOURCE_NDISC)
 147                         a->callback = NULL;
 148
 149         return ndisc_check_ready(address->link);
 150 }
 151
 152 static int ndisc_check_ready(Link *link) {
 153         bool found = false, ready = false;
 154         Address *address;
 155         int r;
 156
 157         assert(link);
 158
 159         if (link->ndisc_messages > 0) {
 160                 log_link_debug(link, "%s(): SLAAC addresses and routes are not set.", __func__);
 161                 return 0;
 162         }
 163
 164         SET_FOREACH(address, link->addresses) {
 165                 if (address->source != NETWORK_CONFIG_SOURCE_NDISC)
 166                         continue;
 167
 168                 found = true;
 169
 170                 if (address_is_ready(address)) {
 171                         ready = true;
 172                         break;
 173                 }
 174         }
 175
 176         if (found && !ready) {
 177                 SET_FOREACH(address, link->addresses)
 178                         if (address->source == NETWORK_CONFIG_SOURCE_NDISC)
 179                                 address->callback = ndisc_address_ready_callback;
 180
 181                 log_link_debug(link, "%s(): no SLAAC address is ready.", __func__);
 182                 return 0;
 183         }
 184
 185         link->ndisc_configured = true;
 186         log_link_debug(link, "SLAAC addresses and routes set.");
 187
 188         r = ndisc_remove(link, NULL);
 189         if (r < 0)
 190                 return r;
 191
 192         link_check_ready(link);
 193         return 0;
 194 }
 195
 196 static int ndisc_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
 197         int r;
 198
 199         assert(link);
 200         assert(link->ndisc_messages > 0);
 201
 202         link->ndisc_messages--;
 203
 204         r = route_configure_handler_internal(rtnl, m, link, "Could not set NDisc route");
 205         if (r <= 0)
 206                 return r;
 207
 208         r = ndisc_check_ready(link);
 209         if (r < 0)
 210                 link_enter_failed(link);
 211
 212         return 1;
 213 }
 214
 215 static int ndisc_request_route(Route *in, Link *link, sd_ndisc_router *rt) {
 216         _cleanup_(route_freep) Route *route = in;
 217         struct in6_addr router;
 218         Route *existing;
 219         int r;
 220
 221         assert(route);
 222         assert(link);
 223         assert(rt);
 224
 225         r = sd_ndisc_router_get_address(rt, &router);
 226         if (r < 0)
 227                 return r;
 228
 229         route->source = NETWORK_CONFIG_SOURCE_NDISC;
 230         route->provider.in6 = router;
 231         if (!route->table_set)
 232                 route->table = link_get_ipv6_accept_ra_route_table(link);
 233         if (!route->priority_set)
 234                 route->priority = link->network->ipv6_accept_ra_route_metric;
 235         if (!route->protocol_set)
 236                 route->protocol = RTPROT_RA;
 237
 238         if (route_get(NULL, link, route, &existing) < 0)
 239                 link->ndisc_configured = false;
 240         else
 241                 route_unmark(existing);
 242
 243         return link_request_route(link, TAKE_PTR(route), true, &link->ndisc_messages,
 244                                   ndisc_route_handler, NULL);
 245 }
 246
 247 static int ndisc_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
 248         int r;
 249
 250         assert(link);
 251         assert(link->ndisc_messages > 0);
 252
 253         link->ndisc_messages--;
 254
 255         r = address_configure_handler_internal(rtnl, m, link, "Could not set NDisc address");
 256         if (r <= 0)
 257                 return r;
 258
 259         r = ndisc_check_ready(link);
 260         if (r < 0)
 261                 link_enter_failed(link);
 262
 263         return 1;
 264 }
 265
 266 static int ndisc_request_address(Address *in, Link *link, sd_ndisc_router *rt) {
 267         _cleanup_(address_freep) Address *address = in;
 268         struct in6_addr router;
 269         Address *existing;
 270         int r;
 271
 272         assert(address);
 273         assert(link);
 274         assert(rt);
 275
 276         r = sd_ndisc_router_get_address(rt, &router);
 277         if (r < 0)
 278                 return r;
 279
 280         address->source = NETWORK_CONFIG_SOURCE_NDISC;
 281         address->provider.in6 = router;
 282
 283         if (address_get(link, address, &existing) < 0)
 284                 link->ndisc_configured = false;
 285         else
 286                 address_unmark(existing);
 287
 288         return link_request_address(link, TAKE_PTR(address), true, &link->ndisc_messages,
 289                                  ndisc_address_handler, NULL);
 290 }
 291
 292 static int ndisc_router_process_default(Link *link, sd_ndisc_router *rt) {
 293         _cleanup_(route_freep) Route *route = NULL;
 294         usec_t lifetime_usec, timestamp_usec;
 295         struct in6_addr gateway;
 296         uint16_t lifetime_sec;
 297         unsigned preference;
 298         uint32_t mtu = 0;
 299         int r;
 300
 301         assert(link);
 302         assert(rt);
 303
 304         r = sd_ndisc_router_get_lifetime(rt, &lifetime_sec);
 305         if (r < 0)
 306                 return log_link_error_errno(link, r, "Failed to get gateway lifetime from RA: %m");
 307
 308         if (lifetime_sec == 0) /* not a default router */
 309                 return 0;
 310
 311         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &timestamp_usec);
 312         if (r < 0)
 313                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 314
 315         lifetime_usec = usec_add(timestamp_usec, lifetime_sec * USEC_PER_SEC);
 316
 317         r = sd_ndisc_router_get_address(rt, &gateway);
 318         if (r < 0)
 319                 return log_link_error_errno(link, r, "Failed to get gateway address from RA: %m");
 320
 321         if (link_get_ipv6_address(link, &gateway, NULL) >= 0) {
 322                 if (DEBUG_LOGGING) {
 323                         _cleanup_free_ char *buffer = NULL;
 324
 325                         (void) in6_addr_to_string(&gateway, &buffer);
 326                         log_link_debug(link, "No NDisc route added, gateway %s matches local address",
 327                                        strna(buffer));
 328                 }
 329                 return 0;
 330         }
 331
 332         r = sd_ndisc_router_get_preference(rt, &preference);
 333         if (r < 0)
 334                 return log_link_error_errno(link, r, "Failed to get default router preference from RA: %m");
 335
 336         if (link->network->ipv6_accept_ra_use_mtu) {
 337                 r = sd_ndisc_router_get_mtu(rt, &mtu);
 338                 if (r < 0 && r != -ENODATA)
 339                         return log_link_error_errno(link, r, "Failed to get default router MTU from RA: %m");
 340         }
 341
 342         r = route_new(&route);
 343         if (r < 0)
 344                 return log_oom();
 345
 346         route->family = AF_INET6;
 347         route->pref = preference;
 348         route->gw_family = AF_INET6;
 349         route->gw.in6 = gateway;
 350         route->lifetime_usec = lifetime_usec;
 351         route->mtu = mtu;
 352
 353         r = ndisc_request_route(TAKE_PTR(route), link, rt);
 354         if (r < 0)
 355                 return log_link_error_errno(link, r, "Could not request default route: %m");
 356
 357         Route *route_gw;
 358         HASHMAP_FOREACH(route_gw, link->network->routes_by_section) {
 359                 if (!route_gw->gateway_from_dhcp_or_ra)
 360                         continue;
 361
 362                 if (route_gw->gw_family != AF_INET6)
 363                         continue;
 364
 365                 r = route_dup(route_gw, &route);
 366                 if (r < 0)
 367                         return r;
 368
 369                 route->gw.in6 = gateway;
 370                 if (!route->pref_set)
 371                         route->pref = preference;
 372                 route->lifetime_usec = lifetime_usec;
 373                 if (route->mtu == 0)
 374                         route->mtu = mtu;
 375
 376                 r = ndisc_request_route(TAKE_PTR(route), link, rt);
 377                 if (r < 0)
 378                         return log_link_error_errno(link, r, "Could not request gateway: %m");
 379         }
 380
 381         return 0;
 382 }
 383
 384 static int ndisc_router_process_autonomous_prefix(Link *link, sd_ndisc_router *rt) {
 385         uint32_t lifetime_valid_sec, lifetime_preferred_sec;
 386         usec_t lifetime_valid_usec, lifetime_preferred_usec, timestamp_usec;
 387         _cleanup_set_free_ Set *addresses = NULL;
 388         struct in6_addr prefix, *a;
 389         unsigned prefixlen;
 390         int r;
 391
 392         assert(link);
 393         assert(link->network);
 394         assert(rt);
 395
 396         if (!link->network->ipv6_accept_ra_use_autonomous_prefix)
 397                 return 0;
 398
 399         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &timestamp_usec);
 400         if (r < 0)
 401                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 402
 403         r = sd_ndisc_router_prefix_get_address(rt, &prefix);
 404         if (r < 0)
 405                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
 406
 407         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
 408         if (r < 0)
 409                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
 410
 411         /* ndisc_generate_addresses() below requires the prefix length <= 64. */
 412         if (prefixlen > 64) {
 413                 _cleanup_free_ char *buf = NULL;
 414
 415                 (void) in6_addr_prefix_to_string(&prefix, prefixlen, &buf);
 416                 log_link_debug(link, "Prefix is longer than 64, ignoring autonomous prefix %s.", strna(buf));
 417                 return 0;
 418         }
 419
 420         r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_valid_sec);
 421         if (r < 0)
 422                 return log_link_error_errno(link, r, "Failed to get prefix valid lifetime: %m");
 423
 424         if (lifetime_valid_sec == 0) {
 425                 log_link_debug(link, "Ignoring prefix as its valid lifetime is zero.");
 426                 return 0;
 427         }
 428
 429         r = sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred_sec);
 430         if (r < 0)
 431                 return log_link_error_errno(link, r, "Failed to get prefix preferred lifetime: %m");
 432
 433         /* The preferred lifetime is never greater than the valid lifetime */
 434         if (lifetime_preferred_sec > lifetime_valid_sec)
 435                 return 0;
 436
 437         lifetime_valid_usec = usec_add(lifetime_valid_sec * USEC_PER_SEC, timestamp_usec);
 438         lifetime_preferred_usec = usec_add(lifetime_preferred_sec * USEC_PER_SEC, timestamp_usec);
 439
 440         r = ndisc_generate_addresses(link, &prefix, prefixlen, &addresses);
 441         if (r < 0)
 442                 return log_link_error_errno(link, r, "Failed to generate SLAAC addresses: %m");
 443
 444         SET_FOREACH(a, addresses) {
 445                 _cleanup_(address_freep) Address *address = NULL;
 446                 Address *e;
 447
 448                 r = address_new(&address);
 449                 if (r < 0)
 450                         return log_oom();
 451
 452                 address->family = AF_INET6;
 453                 address->in_addr.in6 = *a;
 454                 address->prefixlen = prefixlen;
 455                 address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR;
 456                 address->lifetime_valid_usec = lifetime_valid_usec;
 457                 address->lifetime_preferred_usec = lifetime_preferred_usec;
 458
 459                 /* See RFC4862, section 5.5.3.e. But the following logic is deviated from RFC4862 by
 460                  * honoring all valid lifetimes to improve the reaction of SLAAC to renumbering events.
 461                  * See draft-ietf-6man-slaac-renum-02, section 4.2. */
 462                 r = address_get(link, address, &e);
 463                 if (r > 0) {
 464                         /* If the address is already assigned, but not valid anymore, then refuse to
 465                          * update the address, and it will be removed. */
 466                         if (e->lifetime_valid_usec < timestamp_usec)
 467                                 continue;
 468                 }
 469
 470                 r = ndisc_request_address(TAKE_PTR(address), link, rt);
 471                 if (r < 0)
 472                         return log_link_error_errno(link, r, "Could not request SLAAC address: %m");
 473         }
 474
 475         return 0;
 476 }
 477
 478 static int ndisc_router_process_onlink_prefix(Link *link, sd_ndisc_router *rt) {
 479         _cleanup_(route_freep) Route *route = NULL;
 480         usec_t timestamp_usec;
 481         uint32_t lifetime_sec;
 482         unsigned prefixlen;
 483         int r;
 484
 485         assert(link);
 486         assert(link->network);
 487         assert(rt);
 488
 489         if (!link->network->ipv6_accept_ra_use_onlink_prefix)
 490                 return 0;
 491
 492         r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_sec);
 493         if (r < 0)
 494                 return log_link_error_errno(link, r, "Failed to get prefix lifetime: %m");
 495
 496         if (lifetime_sec == 0)
 497                 return 0;
 498
 499         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &timestamp_usec);
 500         if (r < 0)
 501                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 502
 503         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
 504         if (r < 0)
 505                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
 506
 507         r = route_new(&route);
 508         if (r < 0)
 509                 return log_oom();
 510
 511         route->family = AF_INET6;
 512         route->flags = RTM_F_PREFIX;
 513         route->dst_prefixlen = prefixlen;
 514         route->lifetime_usec = usec_add(timestamp_usec, lifetime_sec * USEC_PER_SEC);
 515
 516         r = sd_ndisc_router_prefix_get_address(rt, &route->dst.in6);
 517         if (r < 0)
 518                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
 519
 520         r = ndisc_request_route(TAKE_PTR(route), link, rt);
 521         if (r < 0)
 522                 return log_link_error_errno(link, r, "Could not request prefix route: %m");;
 523
 524         return 0;
 525 }
 526
 527 static int ndisc_router_process_prefix(Link *link, sd_ndisc_router *rt) {
 528         unsigned prefixlen;
 529         struct in6_addr a;
 530         uint8_t flags;
 531         int r;
 532
 533         assert(link);
 534         assert(link->network);
 535         assert(rt);
 536
 537         r = sd_ndisc_router_prefix_get_address(rt, &a);
 538         if (r < 0)
 539                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
 540
 541         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
 542         if (r < 0)
 543                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
 544
 545         if (in6_prefix_is_filtered(&a, prefixlen, link->network->ndisc_allow_listed_prefix, link->network->ndisc_deny_listed_prefix)) {
 546                 if (DEBUG_LOGGING) {
 547                         _cleanup_free_ char *b = NULL;
 548
 549                         (void) in6_addr_prefix_to_string(&a, prefixlen, &b);
 550                         if (!set_isempty(link->network->ndisc_allow_listed_prefix))
 551                                 log_link_debug(link, "Prefix '%s' is not in allow list, ignoring", strna(b));
 552                         else
 553                                 log_link_debug(link, "Prefix '%s' is in deny list, ignoring", strna(b));
 554                 }
 555                 return 0;
 556         }
 557
 558         r = sd_ndisc_router_prefix_get_flags(rt, &flags);
 559         if (r < 0)
 560                 return log_link_error_errno(link, r, "Failed to get RA prefix flags: %m");
 561
 562         if (FLAGS_SET(flags, ND_OPT_PI_FLAG_ONLINK)) {
 563                 r = ndisc_router_process_onlink_prefix(link, rt);
 564                 if (r < 0)
 565                         return r;
 566         }
 567
 568         if (FLAGS_SET(flags, ND_OPT_PI_FLAG_AUTO)) {
 569                 r = ndisc_router_process_autonomous_prefix(link, rt);
 570                 if (r < 0)
 571                         return r;
 572         }
 573
 574         return 0;
 575 }
 576
 577 static int ndisc_router_process_route(Link *link, sd_ndisc_router *rt) {
 578         _cleanup_(route_freep) Route *route = NULL;
 579         unsigned preference, prefixlen;
 580         struct in6_addr gateway, dst;
 581         uint32_t lifetime_sec;
 582         usec_t timestamp_usec;
 583         int r;
 584
 585         assert(link);
 586
 587         r = sd_ndisc_router_route_get_lifetime(rt, &lifetime_sec);
 588         if (r < 0)
 589                 return log_link_error_errno(link, r, "Failed to get route lifetime from RA: %m");
 590
 591         if (lifetime_sec == 0)
 592                 return 0;
 593
 594         r = sd_ndisc_router_route_get_address(rt, &dst);
 595         if (r < 0)
 596                 return log_link_error_errno(link, r, "Failed to get route destination address: %m");
 597
 598         r = sd_ndisc_router_route_get_prefixlen(rt, &prefixlen);
 599         if (r < 0)
 600                 return log_link_error_errno(link, r, "Failed to get route prefix length: %m");
 601
 602         if (in6_prefix_is_filtered(&dst, prefixlen, link->network->ndisc_allow_listed_route_prefix, link->network->ndisc_deny_listed_route_prefix)) {
 603                 if (DEBUG_LOGGING) {
 604                         _cleanup_free_ char *buf = NULL;
 605
 606                         (void) in6_addr_prefix_to_string(&dst, prefixlen, &buf);
 607                         if (!set_isempty(link->network->ndisc_allow_listed_route_prefix))
 608                                 log_link_debug(link, "Route prefix '%s' is not in allow list, ignoring", strna(buf));
 609                         else
 610                                 log_link_debug(link, "Route prefix '%s' is in deny list, ignoring", strna(buf));
 611                 }
 612                 return 0;
 613         }
 614
 615         r = sd_ndisc_router_get_address(rt, &gateway);
 616         if (r < 0)
 617                 return log_link_error_errno(link, r, "Failed to get gateway address from RA: %m");
 618
 619         if (link_get_ipv6_address(link, &gateway, NULL) >= 0) {
 620                 if (DEBUG_LOGGING) {
 621                         _cleanup_free_ char *buf = NULL;
 622
 623                         (void) in6_addr_to_string(&gateway, &buf);
 624                         log_link_debug(link, "Advertised route gateway %s is local to the link, ignoring route", strna(buf));
 625                 }
 626                 return 0;
 627         }
 628
 629         r = sd_ndisc_router_route_get_preference(rt, &preference);
 630         if (r < 0)
 631                 return log_link_error_errno(link, r, "Failed to get default router preference from RA: %m");
 632
 633         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &timestamp_usec);
 634         if (r < 0)
 635                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 636
 637         r = route_new(&route);
 638         if (r < 0)
 639                 return log_oom();
 640
 641         route->family = AF_INET6;
 642         route->pref = preference;
 643         route->gw.in6 = gateway;
 644         route->gw_family = AF_INET6;
 645         route->dst.in6 = dst;
 646         route->dst_prefixlen = prefixlen;
 647         route->lifetime_usec = usec_add(timestamp_usec, lifetime_sec * USEC_PER_SEC);
 648
 649         r = ndisc_request_route(TAKE_PTR(route), link, rt);
 650         if (r < 0)
 651                 return log_link_error_errno(link, r, "Could not request additional route: %m");
 652
 653         return 0;
 654 }
 655
 656 static void ndisc_rdnss_hash_func(const NDiscRDNSS *x, struct siphash *state) {
 657         siphash24_compress(&x->address, sizeof(x->address), state);
 658 }
 659
 660 static int ndisc_rdnss_compare_func(const NDiscRDNSS *a, const NDiscRDNSS *b) {
 661         return memcmp(&a->address, &b->address, sizeof(a->address));
 662 }
 663
 664 DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
 665                 ndisc_rdnss_hash_ops,
 666                 NDiscRDNSS,
 667                 ndisc_rdnss_hash_func,
 668                 ndisc_rdnss_compare_func,
 669                 free);
 670
 671 static int ndisc_router_process_rdnss(Link *link, sd_ndisc_router *rt) {
 672         usec_t lifetime_usec, timestamp_usec;
 673         uint32_t lifetime_sec;
 674         const struct in6_addr *a;
 675         struct in6_addr router;
 676         bool updated = false;
 677         int n, r;
 678
 679         assert(link);
 680         assert(link->network);
 681         assert(rt);
 682
 683         if (!link->network->ipv6_accept_ra_use_dns)
 684                 return 0;
 685
 686         r = sd_ndisc_router_get_address(rt, &router);
 687         if (r < 0)
 688                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
 689
 690         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &timestamp_usec);
 691         if (r < 0)
 692                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 693
 694         r = sd_ndisc_router_rdnss_get_lifetime(rt, &lifetime_sec);
 695         if (r < 0)
 696                 return log_link_error_errno(link, r, "Failed to get RDNSS lifetime: %m");
 697
 698         if (lifetime_sec == 0)
 699                 return 0;
 700
 701         lifetime_usec = usec_add(timestamp_usec, lifetime_sec * USEC_PER_SEC);
 702
 703         n = sd_ndisc_router_rdnss_get_addresses(rt, &a);
 704         if (n < 0)
 705                 return log_link_error_errno(link, n, "Failed to get RDNSS addresses: %m");
 706
 707         if (n >= (int) NDISC_RDNSS_MAX) {
 708                 log_link_warning(link, "Too many RDNSS records per link. Only first %i records will be used.", NDISC_RDNSS_MAX);
 709                 n = NDISC_RDNSS_MAX;
 710         }
 711
 712         for (int j = 0; j < n; j++) {
 713                 _cleanup_free_ NDiscRDNSS *x = NULL;
 714                 NDiscRDNSS *rdnss, d = {
 715                         .address = a[j],
 716                 };
 717
 718                 rdnss = set_get(link->ndisc_rdnss, &d);
 719                 if (rdnss) {
 720                         rdnss->marked = false;
 721                         rdnss->router = router;
 722                         rdnss->lifetime_usec = lifetime_usec;
 723                         continue;
 724                 }
 725
 726                 x = new(NDiscRDNSS, 1);
 727                 if (!x)
 728                         return log_oom();
 729
 730                 *x = (NDiscRDNSS) {
 731                         .address = a[j],
 732                         .router = router,
 733                         .lifetime_usec = lifetime_usec,
 734                 };
 735
 736                 r = set_ensure_consume(&link->ndisc_rdnss, &ndisc_rdnss_hash_ops, TAKE_PTR(x));
 737                 if (r < 0)
 738                         return log_oom();
 739                 assert(r > 0);
 740
 741                 updated = true;
 742         }
 743
 744         if (updated)
 745                 link_dirty(link);
 746
 747         return 0;
 748 }
 749
 750 static void ndisc_dnssl_hash_func(const NDiscDNSSL *x, struct siphash *state) {
 751         siphash24_compress_string(NDISC_DNSSL_DOMAIN(x), state);
 752 }
 753
 754 static int ndisc_dnssl_compare_func(const NDiscDNSSL *a, const NDiscDNSSL *b) {
 755         return strcmp(NDISC_DNSSL_DOMAIN(a), NDISC_DNSSL_DOMAIN(b));
 756 }
 757
 758 DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
 759                 ndisc_dnssl_hash_ops,
 760                 NDiscDNSSL,
 761                 ndisc_dnssl_hash_func,
 762                 ndisc_dnssl_compare_func,
 763                 free);
 764
 765 static int ndisc_router_process_dnssl(Link *link, sd_ndisc_router *rt) {
 766         _cleanup_strv_free_ char **l = NULL;
 767         usec_t lifetime_usec, timestamp_usec;
 768         struct in6_addr router;
 769         uint32_t lifetime_sec;
 770         bool updated = false;
 771         char **j;
 772         int r;
 773
 774         assert(link);
 775         assert(link->network);
 776         assert(rt);
 777
 778         if (link->network->ipv6_accept_ra_use_domains == DHCP_USE_DOMAINS_NO)
 779                 return 0;
 780
 781         r = sd_ndisc_router_get_address(rt, &router);
 782         if (r < 0)
 783                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
 784
 785         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &timestamp_usec);
 786         if (r < 0)
 787                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 788
 789         r = sd_ndisc_router_dnssl_get_lifetime(rt, &lifetime_sec);
 790         if (r < 0)
 791                 return log_link_error_errno(link, r, "Failed to get DNSSL lifetime: %m");
 792
 793         if (lifetime_sec == 0)
 794                 return 0;
 795
 796         lifetime_usec = usec_add(timestamp_usec, lifetime_sec * USEC_PER_SEC);
 797
 798         r = sd_ndisc_router_dnssl_get_domains(rt, &l);
 799         if (r < 0)
 800                 return log_link_error_errno(link, r, "Failed to get DNSSL addresses: %m");
 801
 802         if (strv_length(l) >= NDISC_DNSSL_MAX) {
 803                 log_link_warning(link, "Too many DNSSL records per link. Only first %i records will be used.", NDISC_DNSSL_MAX);
 804                 STRV_FOREACH(j, l + NDISC_DNSSL_MAX)
 805                         *j = mfree(*j);
 806         }
 807
 808         STRV_FOREACH(j, l) {
 809                 _cleanup_free_ NDiscDNSSL *s = NULL;
 810                 NDiscDNSSL *dnssl;
 811
 812                 s = malloc0(ALIGN(sizeof(NDiscDNSSL)) + strlen(*j) + 1);
 813                 if (!s)
 814                         return log_oom();
 815
 816                 strcpy(NDISC_DNSSL_DOMAIN(s), *j);
 817
 818                 dnssl = set_get(link->ndisc_dnssl, s);
 819                 if (dnssl) {
 820                         dnssl->marked = false;
 821                         dnssl->router = router;
 822                         dnssl->lifetime_usec = lifetime_usec;
 823                         continue;
 824                 }
 825
 826                 s->router = router;
 827                 s->lifetime_usec = lifetime_usec;
 828
 829                 r = set_ensure_consume(&link->ndisc_dnssl, &ndisc_dnssl_hash_ops, TAKE_PTR(s));
 830                 if (r < 0)
 831                         return log_oom();
 832                 assert(r > 0);
 833
 834                 updated = true;
 835         }
 836
 837         if (updated)
 838                 link_dirty(link);
 839
 840         return 0;
 841 }
 842
 843 static int ndisc_router_process_options(Link *link, sd_ndisc_router *rt) {
 844         int r;
 845
 846         assert(link);
 847         assert(link->network);
 848         assert(rt);
 849
 850         for (r = sd_ndisc_router_option_rewind(rt); ; r = sd_ndisc_router_option_next(rt)) {
 851                 uint8_t type;
 852
 853                 if (r < 0)
 854                         return log_link_error_errno(link, r, "Failed to iterate through options: %m");
 855                 if (r == 0) /* EOF */
 856                         return 0;
 857
 858                 r = sd_ndisc_router_option_get_type(rt, &type);
 859                 if (r < 0)
 860                         return log_link_error_errno(link, r, "Failed to get RA option type: %m");
 861
 862                 switch (type) {
 863
 864                 case SD_NDISC_OPTION_PREFIX_INFORMATION:
 865                         r = ndisc_router_process_prefix(link, rt);
 866                         if (r < 0)
 867                                 return r;
 868                         break;
 869
 870                 case SD_NDISC_OPTION_ROUTE_INFORMATION:
 871                         r = ndisc_router_process_route(link, rt);
 872                         if (r < 0)
 873                                 return r;
 874                         break;
 875
 876                 case SD_NDISC_OPTION_RDNSS:
 877                         r = ndisc_router_process_rdnss(link, rt);
 878                         if (r < 0)
 879                                 return r;
 880                         break;
 881
 882                 case SD_NDISC_OPTION_DNSSL:
 883                         r = ndisc_router_process_dnssl(link, rt);
 884                         if (r < 0)
 885                                 return r;
 886                         break;
 887                 }
 888         }
 889 }
 890
 891 static void ndisc_mark(Link *link, const struct in6_addr *router) {
 892         NDiscRDNSS *rdnss;
 893         NDiscDNSSL *dnssl;
 894
 895         assert(link);
 896         assert(router);
 897
 898         link_mark_addresses(link, NETWORK_CONFIG_SOURCE_NDISC, router);
 899         link_mark_routes(link, NETWORK_CONFIG_SOURCE_NDISC, router);
 900
 901         SET_FOREACH(rdnss, link->ndisc_rdnss)
 902                 if (in6_addr_equal(&rdnss->router, router))
 903                         rdnss->marked = true;
 904
 905         SET_FOREACH(dnssl, link->ndisc_dnssl)
 906                 if (in6_addr_equal(&dnssl->router, router))
 907                         dnssl->marked = true;
 908 }
 909
 910 static int ndisc_start_dhcp6_client(Link *link, sd_ndisc_router *rt) {
 911         int r;
 912
 913         assert(link);
 914         assert(link->network);
 915
 916         switch (link->network->ipv6_accept_ra_start_dhcp6_client) {
 917         case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO:
 918                 return 0;
 919
 920         case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES: {
 921                 uint64_t flags;
 922
 923                 r = sd_ndisc_router_get_flags(rt, &flags);
 924                 if (r < 0)
 925                         return log_link_warning_errno(link, r, "Failed to get RA flags: %m");
 926
 927                 if ((flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER)) == 0)
 928                         return 0;
 929
 930                 /* (re)start DHCPv6 client in stateful or stateless mode according to RA flags.
 931                  * Note, if both managed and other information bits are set, then ignore other
 932                  * information bit. See RFC 4861. */
 933                 r = dhcp6_start_on_ra(link, !(flags & ND_RA_FLAG_MANAGED));
 934                 break;
 935         }
 936         case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS:
 937                 /* When IPv6AcceptRA.DHCPv6Client=always, start dhcp6 client in managed mode
 938                  * even if the router flags have neither M nor O flags. */
 939                 r = dhcp6_start_on_ra(link, /* information_request = */ false);
 940                 break;
 941
 942         default:
 943                 assert_not_reached();
 944         }
 945
 946         if (r < 0)
 947                 return log_link_error_errno(link, r, "Could not acquire DHCPv6 lease on NDisc request: %m");
 948
 949         log_link_debug(link, "Acquiring DHCPv6 lease on NDisc request");
 950         return 0;
 951 }
 952
 953 static int ndisc_router_handler(Link *link, sd_ndisc_router *rt) {
 954         struct in6_addr router;
 955         int r;
 956
 957         assert(link);
 958         assert(link->network);
 959         assert(link->manager);
 960         assert(rt);
 961
 962         r = sd_ndisc_router_get_address(rt, &router);
 963         if (r < 0)
 964                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
 965
 966         if (in6_prefix_is_filtered(&router, 128, link->network->ndisc_allow_listed_router, link->network->ndisc_deny_listed_router)) {
 967                 if (DEBUG_LOGGING) {
 968                         _cleanup_free_ char *buf = NULL;
 969
 970                         (void) in6_addr_to_string(&router, &buf);
 971                         if (!set_isempty(link->network->ndisc_allow_listed_router))
 972                                 log_link_debug(link, "Router '%s' is not in allow list, ignoring", strna(buf));
 973                         else
 974                                 log_link_debug(link, "Router '%s' is in deny list, ignoring", strna(buf));
 975                 }
 976                 return 0;
 977         }
 978
 979         ndisc_mark(link, &router);
 980
 981         r = ndisc_start_dhcp6_client(link, rt);
 982         if (r < 0)
 983                 return r;
 984
 985         r = ndisc_router_process_default(link, rt);
 986         if (r < 0)
 987                 return r;
 988
 989         r = ndisc_router_process_options(link, rt);
 990         if (r < 0)
 991                 return r;
 992
 993         if (link->ndisc_messages == 0) {
 994                 link->ndisc_configured = true;
 995
 996                 r = ndisc_remove(link, &router);
 997                 if (r < 0)
 998                         return r;
 999         } else
1000                 log_link_debug(link, "Setting SLAAC addresses and router.");
1001
1002         if (!link->ndisc_configured)
1003                 link_set_state(link, LINK_STATE_CONFIGURING);
1004
1005         link_check_ready(link);
1006         return 0;
1007 }
1008
1009 static void ndisc_handler(sd_ndisc *nd, sd_ndisc_event_t event, sd_ndisc_router *rt, void *userdata) {
1010         Link *link = userdata;
1011         int r;
1012
1013         assert(link);
1014
1015         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
1016                 return;
1017
1018         switch (event) {
1019
1020         case SD_NDISC_EVENT_ROUTER:
1021                 r = ndisc_router_handler(link, rt);
1022                 if (r < 0) {
1023                         link_enter_failed(link);
1024                         return;
1025                 }
1026                 break;
1027
1028         case SD_NDISC_EVENT_TIMEOUT:
1029                 log_link_debug(link, "NDisc handler get timeout event");
1030                 if (link->ndisc_messages == 0) {
1031                         link->ndisc_configured = true;
1032                         link_check_ready(link);
1033                 }
1034                 break;
1035         default:
1036                 assert_not_reached();
1037         }
1038 }
1039
1040 int ndisc_configure(Link *link) {
1041         int r;
1042
1043         assert(link);
1044
1045         if (!link_ipv6_accept_ra_enabled(link))
1046                 return 0;
1047
1048         if (link->ndisc)
1049                 return -EBUSY; /* Already configured. */
1050
1051         r = sd_ndisc_new(&link->ndisc);
1052         if (r < 0)
1053                 return r;
1054
1055         r = sd_ndisc_attach_event(link->ndisc, link->manager->event, 0);
1056         if (r < 0)
1057                 return r;
1058
1059         r = sd_ndisc_set_mac(link->ndisc, &link->hw_addr.ether);
1060         if (r < 0)
1061                 return r;
1062
1063         r = sd_ndisc_set_ifindex(link->ndisc, link->ifindex);
1064         if (r < 0)
1065                 return r;
1066
1067         r = sd_ndisc_set_callback(link->ndisc, ndisc_handler, link);
1068         if (r < 0)
1069                 return r;
1070
1071         return 0;
1072 }
1073
1074 int ndisc_start(Link *link) {
1075         assert(link);
1076
1077         if (!link->ndisc || !link->dhcp6_client)
1078                 return 0;
1079
1080         if (!link_has_carrier(link))
1081                 return 0;
1082
1083         if (in6_addr_is_null(&link->ipv6ll_address))
1084                 return 0;
1085
1086         log_link_debug(link, "Discovering IPv6 routers");
1087
1088         return sd_ndisc_start(link->ndisc);
1089 }
1090
1091 void ndisc_vacuum(Link *link) {
1092         NDiscRDNSS *r;
1093         NDiscDNSSL *d;
1094         usec_t time_now;
1095
1096         assert(link);
1097
1098         /* Removes all RDNSS and DNSSL entries whose validity time has passed */
1099
1100         time_now = now(clock_boottime_or_monotonic());
1101
1102         SET_FOREACH(r, link->ndisc_rdnss)
1103                 if (r->lifetime_usec < time_now)
1104                         free(set_remove(link->ndisc_rdnss, r));
1105
1106         SET_FOREACH(d, link->ndisc_dnssl)
1107                 if (d->lifetime_usec < time_now)
1108                         free(set_remove(link->ndisc_dnssl, d));
1109 }
1110
1111 void ndisc_flush(Link *link) {
1112         assert(link);
1113
1114         /* Removes all RDNSS and DNSSL entries, without exception */
1115
1116         link->ndisc_rdnss = set_free(link->ndisc_rdnss);
1117         link->ndisc_dnssl = set_free(link->ndisc_dnssl);
1118 }
1119
1120 static const char* const ipv6_accept_ra_start_dhcp6_client_table[_IPV6_ACCEPT_RA_START_DHCP6_CLIENT_MAX] = {
1121         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO]     = "no",
1122         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS] = "always",
1123         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES]    = "yes",
1124 };
1125
1126 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING_WITH_BOOLEAN(ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client, IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES);
1127
1128 DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_use_domains, dhcp_use_domains, DHCPUseDomains,
1129                          "Failed to parse UseDomains= setting");
1130 DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_start_dhcp6_client, ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client,
1131                          "Failed to parse DHCPv6Client= setting");