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 #include <linux/if_arp.h>
  10
  11 #include "sd-ndisc.h"
  12
  13 #include "missing_network.h"
  14 #include "networkd-address-generation.h"
  15 #include "networkd-address.h"
  16 #include "networkd-dhcp6.h"
  17 #include "networkd-manager.h"
  18 #include "networkd-ndisc.h"
  19 #include "networkd-queue.h"
  20 #include "networkd-route.h"
  21 #include "networkd-state-file.h"
  22 #include "string-table.h"
  23 #include "string-util.h"
  24 #include "strv.h"
  25
  26 #define NDISC_DNSSL_MAX 64U
  27 #define NDISC_RDNSS_MAX 64U
  28
  29 bool link_ipv6_accept_ra_enabled(Link *link) {
  30         assert(link);
  31
  32         if (!socket_ipv6_is_supported())
  33                 return false;
  34
  35         if (link->flags & IFF_LOOPBACK)
  36                 return false;
  37
  38         if (link->iftype == ARPHRD_CAN)
  39                 return false;
  40
  41         if (!link->network)
  42                 return false;
  43
  44         if (!link_may_have_ipv6ll(link))
  45                 return false;
  46
  47         assert(link->network->ipv6_accept_ra >= 0);
  48         return link->network->ipv6_accept_ra;
  49 }
  50
  51 void network_adjust_ipv6_accept_ra(Network *network) {
  52         assert(network);
  53
  54         if (!FLAGS_SET(network->link_local, ADDRESS_FAMILY_IPV6)) {
  55                 if (network->ipv6_accept_ra > 0)
  56                         log_warning("%s: IPv6AcceptRA= is enabled but IPv6 link-local addressing is disabled or not supported. "
  57                                     "Disabling IPv6AcceptRA=.", network->filename);
  58                 network->ipv6_accept_ra = false;
  59         }
  60
  61         if (network->ipv6_accept_ra < 0)
  62                 /* default to accept RA if ip_forward is disabled and ignore RA if ip_forward is enabled */
  63                 network->ipv6_accept_ra = !FLAGS_SET(network->ip_forward, ADDRESS_FAMILY_IPV6);
  64
  65         /* When RouterAllowList=, PrefixAllowList= or RouteAllowList= are specified, then
  66          * RouterDenyList=, PrefixDenyList= or RouteDenyList= are ignored, respectively. */
  67         if (!set_isempty(network->ndisc_allow_listed_router))
  68                 network->ndisc_deny_listed_router = set_free_free(network->ndisc_deny_listed_router);
  69         if (!set_isempty(network->ndisc_allow_listed_prefix))
  70                 network->ndisc_deny_listed_prefix = set_free_free(network->ndisc_deny_listed_prefix);
  71         if (!set_isempty(network->ndisc_allow_listed_route_prefix))
  72                 network->ndisc_deny_listed_route_prefix = set_free_free(network->ndisc_deny_listed_route_prefix);
  73 }
  74
  75 static int ndisc_remove(Link *link, struct in6_addr *router) {
  76         bool updated = false;
  77         NDiscDNSSL *dnssl;
  78         NDiscRDNSS *rdnss;
  79         Address *address;
  80         Route *route;
  81         int k, r = 0;
  82
  83         assert(link);
  84
  85         SET_FOREACH(route, link->routes) {
  86                 if (route->source != NETWORK_CONFIG_SOURCE_NDISC)
  87                         continue;
  88                 if (!route_is_marked(route))
  89                         continue;
  90                 if (router && !in6_addr_equal(router, &route->provider.in6))
  91                         continue;
  92
  93                 k = route_remove(route);
  94                 if (k < 0)
  95                         r = k;
  96
  97                 route_cancel_request(route, link);
  98         }
  99
 100         SET_FOREACH(address, link->addresses) {
 101                 if (address->source != NETWORK_CONFIG_SOURCE_NDISC)
 102                         continue;
 103                 if (!address_is_marked(address))
 104                         continue;
 105                 if (router && !in6_addr_equal(router, &address->provider.in6))
 106                         continue;
 107
 108                 k = address_remove(address);
 109                 if (k < 0)
 110                         r = k;
 111
 112                 address_cancel_request(address);
 113         }
 114
 115         SET_FOREACH(rdnss, link->ndisc_rdnss) {
 116                 if (!rdnss->marked)
 117                         continue;
 118                 if (router && !in6_addr_equal(router, &rdnss->router))
 119                         continue;
 120
 121                 free(set_remove(link->ndisc_rdnss, rdnss));
 122                 updated = true;
 123         }
 124
 125         SET_FOREACH(dnssl, link->ndisc_dnssl) {
 126                 if (!dnssl->marked)
 127                         continue;
 128                 if (router && !in6_addr_equal(router, &dnssl->router))
 129                         continue;
 130
 131                 free(set_remove(link->ndisc_dnssl, dnssl));
 132                 updated = true;
 133         }
 134
 135         if (updated)
 136                 link_dirty(link);
 137
 138         return r;
 139 }
 140
 141 static int ndisc_check_ready(Link *link);
 142
 143 static int ndisc_address_ready_callback(Address *address) {
 144         Address *a;
 145
 146         assert(address);
 147         assert(address->link);
 148
 149         SET_FOREACH(a, address->link->addresses)
 150                 if (a->source == NETWORK_CONFIG_SOURCE_NDISC)
 151                         a->callback = NULL;
 152
 153         return ndisc_check_ready(address->link);
 154 }
 155
 156 static int ndisc_check_ready(Link *link) {
 157         bool found = false, ready = false;
 158         Address *address;
 159         int r;
 160
 161         assert(link);
 162
 163         if (link->ndisc_messages > 0) {
 164                 log_link_debug(link, "%s(): SLAAC addresses and routes are not set.", __func__);
 165                 return 0;
 166         }
 167
 168         SET_FOREACH(address, link->addresses) {
 169                 if (address->source != NETWORK_CONFIG_SOURCE_NDISC)
 170                         continue;
 171
 172                 found = true;
 173
 174                 if (address_is_ready(address)) {
 175                         ready = true;
 176                         break;
 177                 }
 178         }
 179
 180         if (found && !ready) {
 181                 SET_FOREACH(address, link->addresses)
 182                         if (address->source == NETWORK_CONFIG_SOURCE_NDISC)
 183                                 address->callback = ndisc_address_ready_callback;
 184
 185                 log_link_debug(link, "%s(): no SLAAC address is ready.", __func__);
 186                 return 0;
 187         }
 188
 189         link->ndisc_configured = true;
 190         log_link_debug(link, "SLAAC addresses and routes set.");
 191
 192         r = ndisc_remove(link, NULL);
 193         if (r < 0)
 194                 return r;
 195
 196         link_check_ready(link);
 197         return 0;
 198 }
 199
 200 static int ndisc_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, Route *route) {
 201         int r;
 202
 203         assert(link);
 204
 205         r = route_configure_handler_internal(rtnl, m, link, "Could not set NDisc route");
 206         if (r <= 0)
 207                 return r;
 208
 209         r = ndisc_check_ready(link);
 210         if (r < 0)
 211                 link_enter_failed(link);
 212
 213         return 1;
 214 }
 215
 216 static int ndisc_request_route(Route *in, Link *link, sd_ndisc_router *rt) {
 217         _cleanup_(route_freep) Route *route = in;
 218         struct in6_addr router;
 219         Route *existing;
 220         int r;
 221
 222         assert(route);
 223         assert(link);
 224         assert(rt);
 225
 226         r = sd_ndisc_router_get_address(rt, &router);
 227         if (r < 0)
 228                 return r;
 229
 230         route->source = NETWORK_CONFIG_SOURCE_NDISC;
 231         route->provider.in6 = router;
 232         if (!route->table_set)
 233                 route->table = link_get_ipv6_accept_ra_route_table(link);
 234         if (!route->priority_set)
 235                 route->priority = link->network->ipv6_accept_ra_route_metric;
 236         if (!route->protocol_set)
 237                 route->protocol = RTPROT_RA;
 238
 239         if (route_get(NULL, link, route, &existing) < 0)
 240                 link->ndisc_configured = false;
 241         else
 242                 route_unmark(existing);
 243
 244         return link_request_route(link, TAKE_PTR(route), true, &link->ndisc_messages,
 245                                   ndisc_route_handler, NULL);
 246 }
 247
 248 static int ndisc_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, Address *address) {
 249         int r;
 250
 251         assert(link);
 252
 253         r = address_configure_handler_internal(rtnl, m, link, "Could not set NDisc address");
 254         if (r <= 0)
 255                 return r;
 256
 257         r = ndisc_check_ready(link);
 258         if (r < 0)
 259                 link_enter_failed(link);
 260
 261         return 1;
 262 }
 263
 264 static int ndisc_request_address(Address *in, Link *link, sd_ndisc_router *rt) {
 265         _cleanup_(address_freep) Address *address = in;
 266         struct in6_addr router;
 267         Address *existing;
 268         int r;
 269
 270         assert(address);
 271         assert(link);
 272         assert(rt);
 273
 274         r = sd_ndisc_router_get_address(rt, &router);
 275         if (r < 0)
 276                 return r;
 277
 278         address->source = NETWORK_CONFIG_SOURCE_NDISC;
 279         address->provider.in6 = router;
 280
 281         if (address_get(link, address, &existing) < 0)
 282                 link->ndisc_configured = false;
 283         else
 284                 address_unmark(existing);
 285
 286         return link_request_address(link, TAKE_PTR(address), true, &link->ndisc_messages,
 287                                  ndisc_address_handler, NULL);
 288 }
 289
 290 static int ndisc_router_process_default(Link *link, sd_ndisc_router *rt) {
 291         usec_t lifetime_usec, timestamp_usec;
 292         struct in6_addr gateway;
 293         uint16_t lifetime_sec;
 294         unsigned preference;
 295         uint32_t mtu = 0;
 296         int r;
 297
 298         assert(link);
 299         assert(link->network);
 300         assert(rt);
 301
 302         if (!link->network->ipv6_accept_ra_use_gateway &&
 303             hashmap_isempty(link->network->routes_by_section))
 304                 return 0;
 305
 306         r = sd_ndisc_router_get_lifetime(rt, &lifetime_sec);
 307         if (r < 0)
 308                 return log_link_error_errno(link, r, "Failed to get gateway lifetime from RA: %m");
 309
 310         if (lifetime_sec == 0) /* not a default router */
 311                 return 0;
 312
 313         r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
 314         if (r < 0)
 315                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 316
 317         lifetime_usec = sec16_to_usec(lifetime_sec, timestamp_usec);
 318
 319         r = sd_ndisc_router_get_address(rt, &gateway);
 320         if (r < 0)
 321                 return log_link_error_errno(link, r, "Failed to get gateway address from RA: %m");
 322
 323         if (link_get_ipv6_address(link, &gateway, 0, NULL) >= 0) {
 324                 if (DEBUG_LOGGING)
 325                         log_link_debug(link, "No NDisc route added, gateway %s matches local address",
 326                                        IN6_ADDR_TO_STRING(&gateway));
 327                 return 0;
 328         }
 329
 330         r = sd_ndisc_router_get_preference(rt, &preference);
 331         if (r < 0)
 332                 return log_link_error_errno(link, r, "Failed to get default router preference from RA: %m");
 333
 334         if (link->network->ipv6_accept_ra_use_mtu) {
 335                 r = sd_ndisc_router_get_mtu(rt, &mtu);
 336                 if (r < 0 && r != -ENODATA)
 337                         return log_link_error_errno(link, r, "Failed to get default router MTU from RA: %m");
 338         }
 339
 340         if (link->network->ipv6_accept_ra_use_gateway) {
 341                 _cleanup_(route_freep) Route *route = NULL;
 342
 343                 r = route_new(&route);
 344                 if (r < 0)
 345                         return log_oom();
 346
 347                 route->family = AF_INET6;
 348                 route->pref = preference;
 349                 route->gw_family = AF_INET6;
 350                 route->gw.in6 = gateway;
 351                 route->lifetime_usec = lifetime_usec;
 352                 route->mtu = mtu;
 353
 354                 r = ndisc_request_route(TAKE_PTR(route), link, rt);
 355                 if (r < 0)
 356                         return log_link_error_errno(link, r, "Could not request default route: %m");
 357         }
 358
 359         Route *route_gw;
 360         HASHMAP_FOREACH(route_gw, link->network->routes_by_section) {
 361                 _cleanup_(route_freep) Route *route = NULL;
 362
 363                 if (!route_gw->gateway_from_dhcp_or_ra)
 364                         continue;
 365
 366                 if (route_gw->gw_family != AF_INET6)
 367                         continue;
 368
 369                 r = route_dup(route_gw, &route);
 370                 if (r < 0)
 371                         return r;
 372
 373                 route->gw.in6 = gateway;
 374                 if (!route->pref_set)
 375                         route->pref = preference;
 376                 route->lifetime_usec = lifetime_usec;
 377                 if (route->mtu == 0)
 378                         route->mtu = mtu;
 379
 380                 r = ndisc_request_route(TAKE_PTR(route), link, rt);
 381                 if (r < 0)
 382                         return log_link_error_errno(link, r, "Could not request gateway: %m");
 383         }
 384
 385         return 0;
 386 }
 387
 388 static int ndisc_router_process_autonomous_prefix(Link *link, sd_ndisc_router *rt) {
 389         uint32_t lifetime_valid_sec, lifetime_preferred_sec;
 390         usec_t lifetime_valid_usec, lifetime_preferred_usec, timestamp_usec;
 391         _cleanup_set_free_ Set *addresses = NULL;
 392         struct in6_addr prefix, *a;
 393         unsigned prefixlen;
 394         int r;
 395
 396         assert(link);
 397         assert(link->network);
 398         assert(rt);
 399
 400         if (!link->network->ipv6_accept_ra_use_autonomous_prefix)
 401                 return 0;
 402
 403         r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
 404         if (r < 0)
 405                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 406
 407         r = sd_ndisc_router_prefix_get_address(rt, &prefix);
 408         if (r < 0)
 409                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
 410
 411         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
 412         if (r < 0)
 413                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
 414
 415         /* ndisc_generate_addresses() below requires the prefix length <= 64. */
 416         if (prefixlen > 64) {
 417                 log_link_debug(link, "Prefix is longer than 64, ignoring autonomous prefix %s.",
 418                                IN6_ADDR_PREFIX_TO_STRING(&prefix, prefixlen));
 419                 return 0;
 420         }
 421
 422         r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_valid_sec);
 423         if (r < 0)
 424                 return log_link_error_errno(link, r, "Failed to get prefix valid lifetime: %m");
 425
 426         if (lifetime_valid_sec == 0) {
 427                 log_link_debug(link, "Ignoring prefix as its valid lifetime is zero.");
 428                 return 0;
 429         }
 430
 431         r = sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred_sec);
 432         if (r < 0)
 433                 return log_link_error_errno(link, r, "Failed to get prefix preferred lifetime: %m");
 434
 435         /* The preferred lifetime is never greater than the valid lifetime */
 436         if (lifetime_preferred_sec > lifetime_valid_sec)
 437                 return 0;
 438
 439         lifetime_valid_usec = sec_to_usec(lifetime_valid_sec, timestamp_usec);
 440         lifetime_preferred_usec = sec_to_usec(lifetime_preferred_sec, timestamp_usec);
 441
 442         r = ndisc_generate_addresses(link, &prefix, prefixlen, &addresses);
 443         if (r < 0)
 444                 return log_link_error_errno(link, r, "Failed to generate SLAAC addresses: %m");
 445
 446         SET_FOREACH(a, addresses) {
 447                 _cleanup_(address_freep) Address *address = NULL;
 448                 Address *e;
 449
 450                 r = address_new(&address);
 451                 if (r < 0)
 452                         return log_oom();
 453
 454                 address->family = AF_INET6;
 455                 address->in_addr.in6 = *a;
 456                 address->prefixlen = prefixlen;
 457                 address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR;
 458                 address->lifetime_valid_usec = lifetime_valid_usec;
 459                 address->lifetime_preferred_usec = lifetime_preferred_usec;
 460
 461                 /* See RFC4862, section 5.5.3.e. But the following logic is deviated from RFC4862 by
 462                  * honoring all valid lifetimes to improve the reaction of SLAAC to renumbering events.
 463                  * See draft-ietf-6man-slaac-renum-02, section 4.2. */
 464                 r = address_get(link, address, &e);
 465                 if (r > 0) {
 466                         /* If the address is already assigned, but not valid anymore, then refuse to
 467                          * update the address, and it will be removed. */
 468                         if (e->lifetime_valid_usec < timestamp_usec)
 469                                 continue;
 470                 }
 471
 472                 r = ndisc_request_address(TAKE_PTR(address), link, rt);
 473                 if (r < 0)
 474                         return log_link_error_errno(link, r, "Could not request SLAAC address: %m");
 475         }
 476
 477         return 0;
 478 }
 479
 480 static int ndisc_router_process_onlink_prefix(Link *link, sd_ndisc_router *rt) {
 481         _cleanup_(route_freep) Route *route = NULL;
 482         usec_t timestamp_usec;
 483         uint32_t lifetime_sec;
 484         unsigned prefixlen;
 485         int r;
 486
 487         assert(link);
 488         assert(link->network);
 489         assert(rt);
 490
 491         if (!link->network->ipv6_accept_ra_use_onlink_prefix)
 492                 return 0;
 493
 494         r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_sec);
 495         if (r < 0)
 496                 return log_link_error_errno(link, r, "Failed to get prefix lifetime: %m");
 497
 498         if (lifetime_sec == 0)
 499                 return 0;
 500
 501         r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
 502         if (r < 0)
 503                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 504
 505         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
 506         if (r < 0)
 507                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
 508
 509         r = route_new(&route);
 510         if (r < 0)
 511                 return log_oom();
 512
 513         route->family = AF_INET6;
 514         route->flags = RTM_F_PREFIX;
 515         route->dst_prefixlen = prefixlen;
 516         route->lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec);
 517
 518         r = sd_ndisc_router_prefix_get_address(rt, &route->dst.in6);
 519         if (r < 0)
 520                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
 521
 522         r = ndisc_request_route(TAKE_PTR(route), link, rt);
 523         if (r < 0)
 524                 return log_link_error_errno(link, r, "Could not request prefix route: %m");
 525
 526         return 0;
 527 }
 528
 529 static int ndisc_router_process_prefix(Link *link, sd_ndisc_router *rt) {
 530         unsigned prefixlen;
 531         struct in6_addr a;
 532         uint8_t flags;
 533         int r;
 534
 535         assert(link);
 536         assert(link->network);
 537         assert(rt);
 538
 539         r = sd_ndisc_router_prefix_get_address(rt, &a);
 540         if (r < 0)
 541                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
 542
 543         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
 544         if (r < 0)
 545                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
 546
 547         if (in6_prefix_is_filtered(&a, prefixlen, link->network->ndisc_allow_listed_prefix, link->network->ndisc_deny_listed_prefix)) {
 548                 if (DEBUG_LOGGING)
 549                         log_link_debug(link, "Prefix '%s' is %s, ignoring",
 550                                        !set_isempty(link->network->ndisc_allow_listed_prefix) ? "not in allow list"
 551                                                                                               : "in deny list",
 552                                        IN6_ADDR_PREFIX_TO_STRING(&a, prefixlen));
 553                 return 0;
 554         }
 555
 556         r = sd_ndisc_router_prefix_get_flags(rt, &flags);
 557         if (r < 0)
 558                 return log_link_error_errno(link, r, "Failed to get RA prefix flags: %m");
 559
 560         if (FLAGS_SET(flags, ND_OPT_PI_FLAG_ONLINK)) {
 561                 r = ndisc_router_process_onlink_prefix(link, rt);
 562                 if (r < 0)
 563                         return r;
 564         }
 565
 566         if (FLAGS_SET(flags, ND_OPT_PI_FLAG_AUTO)) {
 567                 r = ndisc_router_process_autonomous_prefix(link, rt);
 568                 if (r < 0)
 569                         return r;
 570         }
 571
 572         return 0;
 573 }
 574
 575 static int ndisc_router_process_route(Link *link, sd_ndisc_router *rt) {
 576         _cleanup_(route_freep) Route *route = NULL;
 577         unsigned preference, prefixlen;
 578         struct in6_addr gateway, dst;
 579         uint32_t lifetime_sec;
 580         usec_t timestamp_usec;
 581         int r;
 582
 583         assert(link);
 584
 585         if (!link->network->ipv6_accept_ra_use_route_prefix)
 586                 return 0;
 587
 588         r = sd_ndisc_router_route_get_lifetime(rt, &lifetime_sec);
 589         if (r < 0)
 590                 return log_link_error_errno(link, r, "Failed to get route lifetime from RA: %m");
 591
 592         if (lifetime_sec == 0)
 593                 return 0;
 594
 595         r = sd_ndisc_router_route_get_address(rt, &dst);
 596         if (r < 0)
 597                 return log_link_error_errno(link, r, "Failed to get route destination address: %m");
 598
 599         r = sd_ndisc_router_route_get_prefixlen(rt, &prefixlen);
 600         if (r < 0)
 601                 return log_link_error_errno(link, r, "Failed to get route prefix length: %m");
 602
 603         if (in6_addr_is_null(&dst) && prefixlen == 0) {
 604                 log_link_debug(link, "Route prefix is ::/0, ignoring");
 605                 return 0;
 606         }
 607
 608         if (in6_prefix_is_filtered(&dst, prefixlen,
 609                                    link->network->ndisc_allow_listed_route_prefix,
 610                                    link->network->ndisc_deny_listed_route_prefix)) {
 611
 612                 if (DEBUG_LOGGING)
 613                         log_link_debug(link, "Route prefix %s is %s, ignoring",
 614                                        !set_isempty(link->network->ndisc_allow_listed_route_prefix) ? "not in allow list"
 615                                                                                                     : "in deny list",
 616                                        IN6_ADDR_PREFIX_TO_STRING(&dst, prefixlen));
 617                 return 0;
 618         }
 619
 620         r = sd_ndisc_router_get_address(rt, &gateway);
 621         if (r < 0)
 622                 return log_link_error_errno(link, r, "Failed to get gateway address from RA: %m");
 623
 624         if (link_get_ipv6_address(link, &gateway, 0, NULL) >= 0) {
 625                 if (DEBUG_LOGGING)
 626                         log_link_debug(link, "Advertised route gateway %s is local to the link, ignoring route",
 627                                        IN6_ADDR_TO_STRING(&gateway));
 628                 return 0;
 629         }
 630
 631         r = sd_ndisc_router_route_get_preference(rt, &preference);
 632         if (r < 0)
 633                 return log_link_error_errno(link, r, "Failed to get default router preference from RA: %m");
 634
 635         r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
 636         if (r < 0)
 637                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 638
 639         r = route_new(&route);
 640         if (r < 0)
 641                 return log_oom();
 642
 643         route->family = AF_INET6;
 644         route->pref = preference;
 645         route->gw.in6 = gateway;
 646         route->gw_family = AF_INET6;
 647         route->dst.in6 = dst;
 648         route->dst_prefixlen = prefixlen;
 649         route->lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec);
 650
 651         r = ndisc_request_route(TAKE_PTR(route), link, rt);
 652         if (r < 0)
 653                 return log_link_error_errno(link, r, "Could not request additional route: %m");
 654
 655         return 0;
 656 }
 657
 658 static void ndisc_rdnss_hash_func(const NDiscRDNSS *x, struct siphash *state) {
 659         siphash24_compress(&x->address, sizeof(x->address), state);
 660 }
 661
 662 static int ndisc_rdnss_compare_func(const NDiscRDNSS *a, const NDiscRDNSS *b) {
 663         return memcmp(&a->address, &b->address, sizeof(a->address));
 664 }
 665
 666 DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
 667                 ndisc_rdnss_hash_ops,
 668                 NDiscRDNSS,
 669                 ndisc_rdnss_hash_func,
 670                 ndisc_rdnss_compare_func,
 671                 free);
 672
 673 static int ndisc_router_process_rdnss(Link *link, sd_ndisc_router *rt) {
 674         usec_t lifetime_usec, timestamp_usec;
 675         uint32_t lifetime_sec;
 676         const struct in6_addr *a;
 677         struct in6_addr router;
 678         bool updated = false;
 679         int n, r;
 680
 681         assert(link);
 682         assert(link->network);
 683         assert(rt);
 684
 685         if (!link->network->ipv6_accept_ra_use_dns)
 686                 return 0;
 687
 688         r = sd_ndisc_router_get_address(rt, &router);
 689         if (r < 0)
 690                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
 691
 692         r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
 693         if (r < 0)
 694                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 695
 696         r = sd_ndisc_router_rdnss_get_lifetime(rt, &lifetime_sec);
 697         if (r < 0)
 698                 return log_link_error_errno(link, r, "Failed to get RDNSS lifetime: %m");
 699
 700         if (lifetime_sec == 0)
 701                 return 0;
 702
 703         lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec);
 704
 705         n = sd_ndisc_router_rdnss_get_addresses(rt, &a);
 706         if (n < 0)
 707                 return log_link_error_errno(link, n, "Failed to get RDNSS addresses: %m");
 708
 709         if (n >= (int) NDISC_RDNSS_MAX) {
 710                 log_link_warning(link, "Too many RDNSS records per link. Only first %i records will be used.", NDISC_RDNSS_MAX);
 711                 n = NDISC_RDNSS_MAX;
 712         }
 713
 714         for (int j = 0; j < n; j++) {
 715                 _cleanup_free_ NDiscRDNSS *x = NULL;
 716                 NDiscRDNSS *rdnss, d = {
 717                         .address = a[j],
 718                 };
 719
 720                 rdnss = set_get(link->ndisc_rdnss, &d);
 721                 if (rdnss) {
 722                         rdnss->marked = false;
 723                         rdnss->router = router;
 724                         rdnss->lifetime_usec = lifetime_usec;
 725                         continue;
 726                 }
 727
 728                 x = new(NDiscRDNSS, 1);
 729                 if (!x)
 730                         return log_oom();
 731
 732                 *x = (NDiscRDNSS) {
 733                         .address = a[j],
 734                         .router = router,
 735                         .lifetime_usec = lifetime_usec,
 736                 };
 737
 738                 r = set_ensure_consume(&link->ndisc_rdnss, &ndisc_rdnss_hash_ops, TAKE_PTR(x));
 739                 if (r < 0)
 740                         return log_oom();
 741                 assert(r > 0);
 742
 743                 updated = true;
 744         }
 745
 746         if (updated)
 747                 link_dirty(link);
 748
 749         return 0;
 750 }
 751
 752 static void ndisc_dnssl_hash_func(const NDiscDNSSL *x, struct siphash *state) {
 753         siphash24_compress_string(NDISC_DNSSL_DOMAIN(x), state);
 754 }
 755
 756 static int ndisc_dnssl_compare_func(const NDiscDNSSL *a, const NDiscDNSSL *b) {
 757         return strcmp(NDISC_DNSSL_DOMAIN(a), NDISC_DNSSL_DOMAIN(b));
 758 }
 759
 760 DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
 761                 ndisc_dnssl_hash_ops,
 762                 NDiscDNSSL,
 763                 ndisc_dnssl_hash_func,
 764                 ndisc_dnssl_compare_func,
 765                 free);
 766
 767 static int ndisc_router_process_dnssl(Link *link, sd_ndisc_router *rt) {
 768         _cleanup_strv_free_ char **l = NULL;
 769         usec_t lifetime_usec, timestamp_usec;
 770         struct in6_addr router;
 771         uint32_t lifetime_sec;
 772         bool updated = false;
 773         int r;
 774
 775         assert(link);
 776         assert(link->network);
 777         assert(rt);
 778
 779         if (link->network->ipv6_accept_ra_use_domains == DHCP_USE_DOMAINS_NO)
 780                 return 0;
 781
 782         r = sd_ndisc_router_get_address(rt, &router);
 783         if (r < 0)
 784                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
 785
 786         r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
 787         if (r < 0)
 788                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 789
 790         r = sd_ndisc_router_dnssl_get_lifetime(rt, &lifetime_sec);
 791         if (r < 0)
 792                 return log_link_error_errno(link, r, "Failed to get DNSSL lifetime: %m");
 793
 794         if (lifetime_sec == 0)
 795                 return 0;
 796
 797         lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec);
 798
 799         r = sd_ndisc_router_dnssl_get_domains(rt, &l);
 800         if (r < 0)
 801                 return log_link_error_errno(link, r, "Failed to get DNSSL addresses: %m");
 802
 803         if (strv_length(l) >= NDISC_DNSSL_MAX) {
 804                 log_link_warning(link, "Too many DNSSL records per link. Only first %i records will be used.", NDISC_DNSSL_MAX);
 805                 STRV_FOREACH(j, l + NDISC_DNSSL_MAX)
 806                         *j = mfree(*j);
 807         }
 808
 809         STRV_FOREACH(j, l) {
 810                 _cleanup_free_ NDiscDNSSL *s = NULL;
 811                 NDiscDNSSL *dnssl;
 812
 813                 s = malloc0(ALIGN(sizeof(NDiscDNSSL)) + strlen(*j) + 1);
 814                 if (!s)
 815                         return log_oom();
 816
 817                 strcpy(NDISC_DNSSL_DOMAIN(s), *j);
 818
 819                 dnssl = set_get(link->ndisc_dnssl, s);
 820                 if (dnssl) {
 821                         dnssl->marked = false;
 822                         dnssl->router = router;
 823                         dnssl->lifetime_usec = lifetime_usec;
 824                         continue;
 825                 }
 826
 827                 s->router = router;
 828                 s->lifetime_usec = lifetime_usec;
 829
 830                 r = set_ensure_consume(&link->ndisc_dnssl, &ndisc_dnssl_hash_ops, TAKE_PTR(s));
 831                 if (r < 0)
 832                         return log_oom();
 833                 assert(r > 0);
 834
 835                 updated = true;
 836         }
 837
 838         if (updated)
 839                 link_dirty(link);
 840
 841         return 0;
 842 }
 843
 844 static int ndisc_router_process_options(Link *link, sd_ndisc_router *rt) {
 845         int r;
 846
 847         assert(link);
 848         assert(link->network);
 849         assert(rt);
 850
 851         for (r = sd_ndisc_router_option_rewind(rt); ; r = sd_ndisc_router_option_next(rt)) {
 852                 uint8_t type;
 853
 854                 if (r < 0)
 855                         return log_link_error_errno(link, r, "Failed to iterate through options: %m");
 856                 if (r == 0) /* EOF */
 857                         return 0;
 858
 859                 r = sd_ndisc_router_option_get_type(rt, &type);
 860                 if (r < 0)
 861                         return log_link_error_errno(link, r, "Failed to get RA option type: %m");
 862
 863                 switch (type) {
 864
 865                 case SD_NDISC_OPTION_PREFIX_INFORMATION:
 866                         r = ndisc_router_process_prefix(link, rt);
 867                         if (r < 0)
 868                                 return r;
 869                         break;
 870
 871                 case SD_NDISC_OPTION_ROUTE_INFORMATION:
 872                         r = ndisc_router_process_route(link, rt);
 873                         if (r < 0)
 874                                 return r;
 875                         break;
 876
 877                 case SD_NDISC_OPTION_RDNSS:
 878                         r = ndisc_router_process_rdnss(link, rt);
 879                         if (r < 0)
 880                                 return r;
 881                         break;
 882
 883                 case SD_NDISC_OPTION_DNSSL:
 884                         r = ndisc_router_process_dnssl(link, rt);
 885                         if (r < 0)
 886                                 return r;
 887                         break;
 888                 }
 889         }
 890 }
 891
 892 static void ndisc_mark(Link *link, const struct in6_addr *router) {
 893         NDiscRDNSS *rdnss;
 894         NDiscDNSSL *dnssl;
 895
 896         assert(link);
 897         assert(router);
 898
 899         link_mark_addresses(link, NETWORK_CONFIG_SOURCE_NDISC, router);
 900         link_mark_routes(link, NETWORK_CONFIG_SOURCE_NDISC, router);
 901
 902         SET_FOREACH(rdnss, link->ndisc_rdnss)
 903                 if (in6_addr_equal(&rdnss->router, router))
 904                         rdnss->marked = true;
 905
 906         SET_FOREACH(dnssl, link->ndisc_dnssl)
 907                 if (in6_addr_equal(&dnssl->router, router))
 908                         dnssl->marked = true;
 909 }
 910
 911 static int ndisc_start_dhcp6_client(Link *link, sd_ndisc_router *rt) {
 912         int r;
 913
 914         assert(link);
 915         assert(link->network);
 916
 917         switch (link->network->ipv6_accept_ra_start_dhcp6_client) {
 918         case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO:
 919                 return 0;
 920
 921         case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES: {
 922                 uint64_t flags;
 923
 924                 r = sd_ndisc_router_get_flags(rt, &flags);
 925                 if (r < 0)
 926                         return log_link_warning_errno(link, r, "Failed to get RA flags: %m");
 927
 928                 if ((flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER)) == 0)
 929                         return 0;
 930
 931                 /* (re)start DHCPv6 client in stateful or stateless mode according to RA flags.
 932                  * Note, if both "managed" and "other configuration" bits are set, then ignore
 933                  * "other configuration" bit. See RFC 4861. */
 934                 r = dhcp6_start_on_ra(link, !(flags & ND_RA_FLAG_MANAGED));
 935                 break;
 936         }
 937         case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS:
 938                 /* When IPv6AcceptRA.DHCPv6Client=always, start dhcp6 client in solicit mode
 939                  * even if the router flags have neither M nor O flags. */
 940                 r = dhcp6_start_on_ra(link, /* information_request = */ false);
 941                 break;
 942
 943         default:
 944                 assert_not_reached();
 945         }
 946
 947         if (r < 0)
 948                 return log_link_error_errno(link, r, "Could not acquire DHCPv6 lease on NDisc request: %m");
 949
 950         log_link_debug(link, "Acquiring DHCPv6 lease on NDisc request");
 951         return 0;
 952 }
 953
 954 static int ndisc_router_handler(Link *link, sd_ndisc_router *rt) {
 955         struct in6_addr router;
 956         int r;
 957
 958         assert(link);
 959         assert(link->network);
 960         assert(link->manager);
 961         assert(rt);
 962
 963         r = sd_ndisc_router_get_address(rt, &router);
 964         if (r < 0)
 965                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
 966
 967         if (in6_prefix_is_filtered(&router, 128, link->network->ndisc_allow_listed_router, link->network->ndisc_deny_listed_router)) {
 968                 if (DEBUG_LOGGING) {
 969                         if (!set_isempty(link->network->ndisc_allow_listed_router))
 970                                 log_link_debug(link, "Router %s is not in allow list, ignoring.", IN6_ADDR_TO_STRING(&router));
 971                         else
 972                                 log_link_debug(link, "Router %s is in deny list, ignoring.", IN6_ADDR_TO_STRING(&router));
 973                 }
 974                 return 0;
 975         }
 976
 977         ndisc_mark(link, &router);
 978
 979         r = ndisc_start_dhcp6_client(link, rt);
 980         if (r < 0)
 981                 return r;
 982
 983         r = ndisc_router_process_default(link, rt);
 984         if (r < 0)
 985                 return r;
 986
 987         r = ndisc_router_process_options(link, rt);
 988         if (r < 0)
 989                 return r;
 990
 991         if (link->ndisc_messages == 0) {
 992                 link->ndisc_configured = true;
 993
 994                 r = ndisc_remove(link, &router);
 995                 if (r < 0)
 996                         return r;
 997         } else
 998                 log_link_debug(link, "Setting SLAAC addresses and router.");
 999
1000         if (!link->ndisc_configured)
1001                 link_set_state(link, LINK_STATE_CONFIGURING);
1002
1003         link_check_ready(link);
1004         return 0;
1005 }
1006
1007 static void ndisc_handler(sd_ndisc *nd, sd_ndisc_event_t event, sd_ndisc_router *rt, void *userdata) {
1008         Link *link = userdata;
1009         int r;
1010
1011         assert(link);
1012
1013         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
1014                 return;
1015
1016         switch (event) {
1017
1018         case SD_NDISC_EVENT_ROUTER:
1019                 r = ndisc_router_handler(link, rt);
1020                 if (r < 0) {
1021                         link_enter_failed(link);
1022                         return;
1023                 }
1024                 break;
1025
1026         case SD_NDISC_EVENT_TIMEOUT:
1027                 log_link_debug(link, "NDisc handler get timeout event");
1028                 if (link->ndisc_messages == 0) {
1029                         link->ndisc_configured = true;
1030                         link_check_ready(link);
1031                 }
1032                 break;
1033         default:
1034                 assert_not_reached();
1035         }
1036 }
1037
1038 static int ndisc_configure(Link *link) {
1039         int r;
1040
1041         assert(link);
1042
1043         if (!link_ipv6_accept_ra_enabled(link))
1044                 return 0;
1045
1046         if (link->ndisc)
1047                 return -EBUSY; /* Already configured. */
1048
1049         r = sd_ndisc_new(&link->ndisc);
1050         if (r < 0)
1051                 return r;
1052
1053         r = sd_ndisc_attach_event(link->ndisc, link->manager->event, 0);
1054         if (r < 0)
1055                 return r;
1056
1057         if (link->hw_addr.length == ETH_ALEN) {
1058                 r = sd_ndisc_set_mac(link->ndisc, &link->hw_addr.ether);
1059                 if (r < 0)
1060                         return r;
1061         }
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         int r;
1076
1077         assert(link);
1078
1079         if (!link->ndisc || !link->dhcp6_client)
1080                 return 0;
1081
1082         if (!link_has_carrier(link))
1083                 return 0;
1084
1085         if (in6_addr_is_null(&link->ipv6ll_address))
1086                 return 0;
1087
1088         log_link_debug(link, "Discovering IPv6 routers");
1089
1090         r = sd_ndisc_start(link->ndisc);
1091         if (r < 0)
1092                 return r;
1093
1094         return 1;
1095 }
1096
1097 static int ndisc_process_request(Request *req, Link *link, void *userdata) {
1098         int r;
1099
1100         assert(link);
1101
1102         if (!IN_SET(link->state, LINK_STATE_CONFIGURING, LINK_STATE_CONFIGURED))
1103                 return 0;
1104
1105         r = ndisc_configure(link);
1106         if (r < 0)
1107                 return log_link_warning_errno(link, r, "Failed to configure IPv6 Router Discovery: %m");
1108
1109         r = ndisc_start(link);
1110         if (r < 0)
1111                 return log_link_warning_errno(link, r, "Failed to start IPv6 Router Discovery: %m");
1112
1113         log_link_debug(link, "IPv6 Router Discovery is configured%s.",
1114                        r > 0 ? " and started" : "");
1115         return 1;
1116 }
1117
1118 int link_request_ndisc(Link *link) {
1119         int r;
1120
1121         assert(link);
1122
1123         if (!link_ipv6_accept_ra_enabled(link))
1124                 return 0;
1125
1126         if (link->ndisc)
1127                 return 0;
1128
1129         r = link_queue_request(link, REQUEST_TYPE_NDISC, ndisc_process_request, NULL);
1130         if (r < 0)
1131                 return log_link_warning_errno(link, r, "Failed to request configuring of the IPv6 Router Discovery: %m");
1132
1133         log_link_debug(link, "Requested configuring of the IPv6 Router Discovery.");
1134         return 0;
1135 }
1136
1137 void ndisc_vacuum(Link *link) {
1138         NDiscRDNSS *r;
1139         NDiscDNSSL *d;
1140         usec_t now_usec;
1141
1142         assert(link);
1143         assert(link->manager);
1144
1145         /* Removes all RDNSS and DNSSL entries whose validity time has passed */
1146
1147         assert_se(sd_event_now(link->manager->event, CLOCK_BOOTTIME, &now_usec) >= 0);
1148
1149         SET_FOREACH(r, link->ndisc_rdnss)
1150                 if (r->lifetime_usec < now_usec)
1151                         free(set_remove(link->ndisc_rdnss, r));
1152
1153         SET_FOREACH(d, link->ndisc_dnssl)
1154                 if (d->lifetime_usec < now_usec)
1155                         free(set_remove(link->ndisc_dnssl, d));
1156 }
1157
1158 void ndisc_flush(Link *link) {
1159         assert(link);
1160
1161         /* Removes all RDNSS and DNSSL entries, without exception */
1162
1163         link->ndisc_rdnss = set_free(link->ndisc_rdnss);
1164         link->ndisc_dnssl = set_free(link->ndisc_dnssl);
1165 }
1166
1167 static const char* const ipv6_accept_ra_start_dhcp6_client_table[_IPV6_ACCEPT_RA_START_DHCP6_CLIENT_MAX] = {
1168         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO]     = "no",
1169         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS] = "always",
1170         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES]    = "yes",
1171 };
1172
1173 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING_WITH_BOOLEAN(ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client, IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES);
1174
1175 DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_use_domains, dhcp_use_domains, DHCPUseDomains,
1176                          "Failed to parse UseDomains= setting");
1177 DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_start_dhcp6_client, ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client,
1178                          "Failed to parse DHCPv6Client= setting");