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, lifetime_preferred;
 386         _cleanup_set_free_ Set *addresses = NULL;
 387         struct in6_addr prefix, *a;
 388         unsigned prefixlen;
 389         usec_t time_now;
 390         int r;
 391
 392         assert(link);
 393         assert(rt);
 394
 395         /* Do not use clock_boottime_or_monotonic() here, as the kernel internally manages cstamp and
 396          * tstamp with jiffies, and it is not increased while the system is suspended. */
 397         r = sd_ndisc_router_get_timestamp(rt, CLOCK_MONOTONIC, &time_now);
 398         if (r < 0)
 399                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 400
 401         r = sd_ndisc_router_prefix_get_address(rt, &prefix);
 402         if (r < 0)
 403                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
 404
 405         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
 406         if (r < 0)
 407                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
 408
 409         /* ndisc_generate_addresses() below requires the prefix length <= 64. */
 410         if (prefixlen > 64) {
 411                 _cleanup_free_ char *buf = NULL;
 412
 413                 (void) in6_addr_prefix_to_string(&prefix, prefixlen, &buf);
 414                 log_link_debug(link, "Prefix is longer than 64, ignoring autonomous prefix %s.", strna(buf));
 415                 return 0;
 416         }
 417
 418         r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_valid);
 419         if (r < 0)
 420                 return log_link_error_errno(link, r, "Failed to get prefix valid lifetime: %m");
 421
 422         if (lifetime_valid == 0) {
 423                 log_link_debug(link, "Ignoring prefix as its valid lifetime is zero.");
 424                 return 0;
 425         }
 426
 427         r = sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred);
 428         if (r < 0)
 429                 return log_link_error_errno(link, r, "Failed to get prefix preferred lifetime: %m");
 430
 431         /* The preferred lifetime is never greater than the valid lifetime */
 432         if (lifetime_preferred > lifetime_valid)
 433                 return 0;
 434
 435         r = ndisc_generate_addresses(link, &prefix, prefixlen, &addresses);
 436         if (r < 0)
 437                 return log_link_error_errno(link, r, "Failed to generate SLAAC addresses: %m");
 438
 439         SET_FOREACH(a, addresses) {
 440                 _cleanup_(address_freep) Address *address = NULL;
 441                 Address *e;
 442
 443                 r = address_new(&address);
 444                 if (r < 0)
 445                         return log_oom();
 446
 447                 address->family = AF_INET6;
 448                 address->in_addr.in6 = *a;
 449                 address->prefixlen = prefixlen;
 450                 address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR;
 451                 address->cinfo.ifa_valid = lifetime_valid;
 452                 address->cinfo.ifa_prefered = lifetime_preferred;
 453
 454                 /* See RFC4862, section 5.5.3.e. But the following logic is deviated from RFC4862 by
 455                  * honoring all valid lifetimes to improve the reaction of SLAAC to renumbering events.
 456                  * See draft-ietf-6man-slaac-renum-02, section 4.2. */
 457                 r = address_get(link, address, &e);
 458                 if (r > 0) {
 459                         /* If the address is already assigned, but not valid anymore, then refuse to
 460                          * update the address, and it will be removed. */
 461                         if (e->cinfo.ifa_valid != CACHE_INFO_INFINITY_LIFE_TIME &&
 462                             usec_add(e->cinfo.tstamp / 100 * USEC_PER_SEC,
 463                                      e->cinfo.ifa_valid * USEC_PER_SEC) < time_now)
 464                                 continue;
 465                 }
 466
 467                 r = ndisc_request_address(TAKE_PTR(address), link, rt);
 468                 if (r < 0)
 469                         return log_link_error_errno(link, r, "Could not request SLAAC address: %m");
 470         }
 471
 472         return 0;
 473 }
 474
 475 static int ndisc_router_process_onlink_prefix(Link *link, sd_ndisc_router *rt) {
 476         _cleanup_(route_freep) Route *route = NULL;
 477         usec_t timestamp_usec;
 478         uint32_t lifetime_sec;
 479         unsigned prefixlen;
 480         int r;
 481
 482         assert(link);
 483         assert(rt);
 484
 485         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &timestamp_usec);
 486         if (r < 0)
 487                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 488
 489         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
 490         if (r < 0)
 491                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
 492
 493         r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_sec);
 494         if (r < 0)
 495                 return log_link_error_errno(link, r, "Failed to get prefix lifetime: %m");
 496
 497         r = route_new(&route);
 498         if (r < 0)
 499                 return log_oom();
 500
 501         route->family = AF_INET6;
 502         route->flags = RTM_F_PREFIX;
 503         route->dst_prefixlen = prefixlen;
 504         route->lifetime_usec = usec_add(timestamp_usec, lifetime_sec * USEC_PER_SEC);
 505
 506         r = sd_ndisc_router_prefix_get_address(rt, &route->dst.in6);
 507         if (r < 0)
 508                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
 509
 510         r = ndisc_request_route(TAKE_PTR(route), link, rt);
 511         if (r < 0)
 512                 return log_link_error_errno(link, r, "Could not request prefix route: %m");;
 513
 514         return 0;
 515 }
 516
 517 static int ndisc_router_process_route(Link *link, sd_ndisc_router *rt) {
 518         _cleanup_(route_freep) Route *route = NULL;
 519         unsigned preference, prefixlen;
 520         struct in6_addr gateway, dst;
 521         uint32_t lifetime_sec;
 522         usec_t timestamp_usec;
 523         int r;
 524
 525         assert(link);
 526
 527         r = sd_ndisc_router_route_get_lifetime(rt, &lifetime_sec);
 528         if (r < 0)
 529                 return log_link_error_errno(link, r, "Failed to get route lifetime from RA: %m");
 530
 531         if (lifetime_sec == 0)
 532                 return 0;
 533
 534         r = sd_ndisc_router_route_get_address(rt, &dst);
 535         if (r < 0)
 536                 return log_link_error_errno(link, r, "Failed to get route destination address: %m");
 537
 538         r = sd_ndisc_router_route_get_prefixlen(rt, &prefixlen);
 539         if (r < 0)
 540                 return log_link_error_errno(link, r, "Failed to get route prefix length: %m");
 541
 542         if (in6_prefix_is_filtered(&dst, prefixlen, link->network->ndisc_allow_listed_route_prefix, link->network->ndisc_deny_listed_route_prefix)) {
 543                 if (DEBUG_LOGGING) {
 544                         _cleanup_free_ char *buf = NULL;
 545
 546                         (void) in6_addr_prefix_to_string(&dst, prefixlen, &buf);
 547                         if (!set_isempty(link->network->ndisc_allow_listed_route_prefix))
 548                                 log_link_debug(link, "Route prefix '%s' is not in allow list, ignoring", strna(buf));
 549                         else
 550                                 log_link_debug(link, "Route prefix '%s' is in deny list, ignoring", strna(buf));
 551                 }
 552                 return 0;
 553         }
 554
 555         r = sd_ndisc_router_get_address(rt, &gateway);
 556         if (r < 0)
 557                 return log_link_error_errno(link, r, "Failed to get gateway address from RA: %m");
 558
 559         if (link_get_ipv6_address(link, &gateway, NULL) >= 0) {
 560                 if (DEBUG_LOGGING) {
 561                         _cleanup_free_ char *buf = NULL;
 562
 563                         (void) in6_addr_to_string(&gateway, &buf);
 564                         log_link_debug(link, "Advertised route gateway %s is local to the link, ignoring route", strna(buf));
 565                 }
 566                 return 0;
 567         }
 568
 569         r = sd_ndisc_router_route_get_preference(rt, &preference);
 570         if (r < 0)
 571                 return log_link_error_errno(link, r, "Failed to get default router preference from RA: %m");
 572
 573         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &timestamp_usec);
 574         if (r < 0)
 575                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 576
 577         r = route_new(&route);
 578         if (r < 0)
 579                 return log_oom();
 580
 581         route->family = AF_INET6;
 582         route->pref = preference;
 583         route->gw.in6 = gateway;
 584         route->gw_family = AF_INET6;
 585         route->dst.in6 = dst;
 586         route->dst_prefixlen = prefixlen;
 587         route->lifetime_usec = usec_add(timestamp_usec, lifetime_sec * USEC_PER_SEC);
 588
 589         r = ndisc_request_route(TAKE_PTR(route), link, rt);
 590         if (r < 0)
 591                 return log_link_error_errno(link, r, "Could not request additional route: %m");
 592
 593         return 0;
 594 }
 595
 596 static void ndisc_rdnss_hash_func(const NDiscRDNSS *x, struct siphash *state) {
 597         siphash24_compress(&x->address, sizeof(x->address), state);
 598 }
 599
 600 static int ndisc_rdnss_compare_func(const NDiscRDNSS *a, const NDiscRDNSS *b) {
 601         return memcmp(&a->address, &b->address, sizeof(a->address));
 602 }
 603
 604 DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
 605                 ndisc_rdnss_hash_ops,
 606                 NDiscRDNSS,
 607                 ndisc_rdnss_hash_func,
 608                 ndisc_rdnss_compare_func,
 609                 free);
 610
 611 static int ndisc_router_process_rdnss(Link *link, sd_ndisc_router *rt) {
 612         uint32_t lifetime;
 613         const struct in6_addr *a;
 614         struct in6_addr router;
 615         usec_t time_now;
 616         bool updated = false;
 617         int n, r;
 618
 619         assert(link);
 620         assert(rt);
 621
 622         r = sd_ndisc_router_get_address(rt, &router);
 623         if (r < 0)
 624                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
 625
 626         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
 627         if (r < 0)
 628                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 629
 630         r = sd_ndisc_router_rdnss_get_lifetime(rt, &lifetime);
 631         if (r < 0)
 632                 return log_link_error_errno(link, r, "Failed to get RDNSS lifetime: %m");
 633
 634         n = sd_ndisc_router_rdnss_get_addresses(rt, &a);
 635         if (n < 0)
 636                 return log_link_error_errno(link, n, "Failed to get RDNSS addresses: %m");
 637
 638         if (lifetime == 0)
 639                 return 0;
 640
 641         if (n >= (int) NDISC_RDNSS_MAX) {
 642                 log_link_warning(link, "Too many RDNSS records per link. Only first %i records will be used.", NDISC_RDNSS_MAX);
 643                 n = NDISC_RDNSS_MAX;
 644         }
 645
 646         for (int j = 0; j < n; j++) {
 647                 _cleanup_free_ NDiscRDNSS *x = NULL;
 648                 NDiscRDNSS *rdnss, d = {
 649                         .address = a[j],
 650                 };
 651
 652                 rdnss = set_get(link->ndisc_rdnss, &d);
 653                 if (rdnss) {
 654                         rdnss->marked = false;
 655                         rdnss->router = router;
 656                         rdnss->valid_until = usec_add(time_now, lifetime * USEC_PER_SEC);
 657                         continue;
 658                 }
 659
 660                 x = new(NDiscRDNSS, 1);
 661                 if (!x)
 662                         return log_oom();
 663
 664                 *x = (NDiscRDNSS) {
 665                         .address = a[j],
 666                         .router = router,
 667                         .valid_until = usec_add(time_now, lifetime * USEC_PER_SEC),
 668                 };
 669
 670                 r = set_ensure_consume(&link->ndisc_rdnss, &ndisc_rdnss_hash_ops, TAKE_PTR(x));
 671                 if (r < 0)
 672                         return log_oom();
 673                 assert(r > 0);
 674
 675                 updated = true;
 676         }
 677
 678         if (updated)
 679                 link_dirty(link);
 680
 681         return 0;
 682 }
 683
 684 static void ndisc_dnssl_hash_func(const NDiscDNSSL *x, struct siphash *state) {
 685         siphash24_compress_string(NDISC_DNSSL_DOMAIN(x), state);
 686 }
 687
 688 static int ndisc_dnssl_compare_func(const NDiscDNSSL *a, const NDiscDNSSL *b) {
 689         return strcmp(NDISC_DNSSL_DOMAIN(a), NDISC_DNSSL_DOMAIN(b));
 690 }
 691
 692 DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
 693                 ndisc_dnssl_hash_ops,
 694                 NDiscDNSSL,
 695                 ndisc_dnssl_hash_func,
 696                 ndisc_dnssl_compare_func,
 697                 free);
 698
 699 static int ndisc_router_process_dnssl(Link *link, sd_ndisc_router *rt) {
 700         _cleanup_strv_free_ char **l = NULL;
 701         struct in6_addr router;
 702         uint32_t lifetime;
 703         usec_t time_now;
 704         bool updated = false;
 705         char **j;
 706         int r;
 707
 708         assert(link);
 709         assert(rt);
 710
 711         r = sd_ndisc_router_get_address(rt, &router);
 712         if (r < 0)
 713                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
 714
 715         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
 716         if (r < 0)
 717                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 718
 719         r = sd_ndisc_router_dnssl_get_lifetime(rt, &lifetime);
 720         if (r < 0)
 721                 return log_link_error_errno(link, r, "Failed to get DNSSL lifetime: %m");
 722
 723         r = sd_ndisc_router_dnssl_get_domains(rt, &l);
 724         if (r < 0)
 725                 return log_link_error_errno(link, r, "Failed to get DNSSL addresses: %m");
 726
 727         if (lifetime == 0)
 728                 return 0;
 729
 730         if (strv_length(l) >= NDISC_DNSSL_MAX) {
 731                 log_link_warning(link, "Too many DNSSL records per link. Only first %i records will be used.", NDISC_DNSSL_MAX);
 732                 STRV_FOREACH(j, l + NDISC_DNSSL_MAX)
 733                         *j = mfree(*j);
 734         }
 735
 736         STRV_FOREACH(j, l) {
 737                 _cleanup_free_ NDiscDNSSL *s = NULL;
 738                 NDiscDNSSL *dnssl;
 739
 740                 s = malloc0(ALIGN(sizeof(NDiscDNSSL)) + strlen(*j) + 1);
 741                 if (!s)
 742                         return log_oom();
 743
 744                 strcpy(NDISC_DNSSL_DOMAIN(s), *j);
 745
 746                 dnssl = set_get(link->ndisc_dnssl, s);
 747                 if (dnssl) {
 748                         dnssl->marked = false;
 749                         dnssl->router = router;
 750                         dnssl->valid_until = usec_add(time_now, lifetime * USEC_PER_SEC);
 751                         continue;
 752                 }
 753
 754                 s->router = router;
 755                 s->valid_until = usec_add(time_now, lifetime * USEC_PER_SEC);
 756
 757                 r = set_ensure_consume(&link->ndisc_dnssl, &ndisc_dnssl_hash_ops, TAKE_PTR(s));
 758                 if (r < 0)
 759                         return log_oom();
 760                 assert(r > 0);
 761
 762                 updated = true;
 763         }
 764
 765         if (updated)
 766                 link_dirty(link);
 767
 768         return 0;
 769 }
 770
 771 static int ndisc_router_process_options(Link *link, sd_ndisc_router *rt) {
 772         assert(link);
 773         assert(link->network);
 774         assert(rt);
 775
 776         for (int r = sd_ndisc_router_option_rewind(rt); ; r = sd_ndisc_router_option_next(rt)) {
 777                 uint8_t type;
 778
 779                 if (r < 0)
 780                         return log_link_error_errno(link, r, "Failed to iterate through options: %m");
 781                 if (r == 0) /* EOF */
 782                         return 0;
 783
 784                 r = sd_ndisc_router_option_get_type(rt, &type);
 785                 if (r < 0)
 786                         return log_link_error_errno(link, r, "Failed to get RA option type: %m");
 787
 788                 switch (type) {
 789
 790                 case SD_NDISC_OPTION_PREFIX_INFORMATION: {
 791                         unsigned prefixlen;
 792                         struct in6_addr a;
 793                         uint8_t flags;
 794
 795                         r = sd_ndisc_router_prefix_get_address(rt, &a);
 796                         if (r < 0)
 797                                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
 798
 799                         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
 800                         if (r < 0)
 801                                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
 802
 803                         if (in6_prefix_is_filtered(&a, prefixlen, link->network->ndisc_allow_listed_prefix, link->network->ndisc_deny_listed_prefix)) {
 804                                 if (DEBUG_LOGGING) {
 805                                         _cleanup_free_ char *b = NULL;
 806
 807                                         (void) in6_addr_prefix_to_string(&a, prefixlen, &b);
 808                                         if (!set_isempty(link->network->ndisc_allow_listed_prefix))
 809                                                 log_link_debug(link, "Prefix '%s' is not in allow list, ignoring", strna(b));
 810                                         else
 811                                                 log_link_debug(link, "Prefix '%s' is in deny list, ignoring", strna(b));
 812                                 }
 813                                 break;
 814                         }
 815
 816                         r = sd_ndisc_router_prefix_get_flags(rt, &flags);
 817                         if (r < 0)
 818                                 return log_link_error_errno(link, r, "Failed to get RA prefix flags: %m");
 819
 820                         if (link->network->ipv6_accept_ra_use_onlink_prefix &&
 821                             FLAGS_SET(flags, ND_OPT_PI_FLAG_ONLINK)) {
 822                                 r = ndisc_router_process_onlink_prefix(link, rt);
 823                                 if (r < 0)
 824                                         return r;
 825                         }
 826
 827                         if (link->network->ipv6_accept_ra_use_autonomous_prefix &&
 828                             FLAGS_SET(flags, ND_OPT_PI_FLAG_AUTO)) {
 829                                 r = ndisc_router_process_autonomous_prefix(link, rt);
 830                                 if (r < 0)
 831                                         return r;
 832                         }
 833                         break;
 834                 }
 835
 836                 case SD_NDISC_OPTION_ROUTE_INFORMATION:
 837                         r = ndisc_router_process_route(link, rt);
 838                         if (r < 0)
 839                                 return r;
 840                         break;
 841
 842                 case SD_NDISC_OPTION_RDNSS:
 843                         if (link->network->ipv6_accept_ra_use_dns) {
 844                                 r = ndisc_router_process_rdnss(link, rt);
 845                                 if (r < 0)
 846                                         return r;
 847                         }
 848                         break;
 849
 850                 case SD_NDISC_OPTION_DNSSL:
 851                         if (link->network->ipv6_accept_ra_use_dns) {
 852                                 r = ndisc_router_process_dnssl(link, rt);
 853                                 if (r < 0)
 854                                         return r;
 855                         }
 856                         break;
 857                 }
 858         }
 859 }
 860
 861 static void ndisc_mark(Link *link, const struct in6_addr *router) {
 862         NDiscRDNSS *rdnss;
 863         NDiscDNSSL *dnssl;
 864
 865         assert(link);
 866         assert(router);
 867
 868         link_mark_addresses(link, NETWORK_CONFIG_SOURCE_NDISC, router);
 869         link_mark_routes(link, NETWORK_CONFIG_SOURCE_NDISC, router);
 870
 871         SET_FOREACH(rdnss, link->ndisc_rdnss)
 872                 if (in6_addr_equal(&rdnss->router, router))
 873                         rdnss->marked = true;
 874
 875         SET_FOREACH(dnssl, link->ndisc_dnssl)
 876                 if (in6_addr_equal(&dnssl->router, router))
 877                         dnssl->marked = true;
 878 }
 879
 880 static int ndisc_router_handler(Link *link, sd_ndisc_router *rt) {
 881         struct in6_addr router;
 882         uint64_t flags;
 883         int r;
 884
 885         assert(link);
 886         assert(link->network);
 887         assert(link->manager);
 888         assert(rt);
 889
 890         r = sd_ndisc_router_get_address(rt, &router);
 891         if (r < 0)
 892                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
 893
 894         if (in6_prefix_is_filtered(&router, 128, link->network->ndisc_allow_listed_router, link->network->ndisc_deny_listed_router)) {
 895                 if (DEBUG_LOGGING) {
 896                         _cleanup_free_ char *buf = NULL;
 897
 898                         (void) in6_addr_to_string(&router, &buf);
 899                         if (!set_isempty(link->network->ndisc_allow_listed_router))
 900                                 log_link_debug(link, "Router '%s' is not in allow list, ignoring", strna(buf));
 901                         else
 902                                 log_link_debug(link, "Router '%s' is in deny list, ignoring", strna(buf));
 903                 }
 904                 return 0;
 905         }
 906
 907         ndisc_mark(link, &router);
 908
 909         r = sd_ndisc_router_get_flags(rt, &flags);
 910         if (r < 0)
 911                 return log_link_error_errno(link, r, "Failed to get RA flags: %m");
 912
 913         if ((flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER) &&
 914              link->network->ipv6_accept_ra_start_dhcp6_client != IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO) ||
 915             link->network->ipv6_accept_ra_start_dhcp6_client == IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS) {
 916
 917                 if (flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER))
 918                         /* (re)start DHCPv6 client in stateful or stateless mode according to RA flags */
 919                         r = dhcp6_request_information(link, !(flags & ND_RA_FLAG_MANAGED));
 920                 else
 921                         /* When IPv6AcceptRA.DHCPv6Client=always, start dhcp6 client in managed mode
 922                          * even if router does not have M or O flag. */
 923                         r = dhcp6_request_information(link, false);
 924                 if (r < 0 && r != -EBUSY)
 925                         return log_link_error_errno(link, r, "Could not acquire DHCPv6 lease on NDisc request: %m");
 926                 else
 927                         log_link_debug(link, "Acquiring DHCPv6 lease on NDisc request");
 928         }
 929
 930         r = ndisc_router_process_default(link, rt);
 931         if (r < 0)
 932                 return r;
 933         r = ndisc_router_process_options(link, rt);
 934         if (r < 0)
 935                 return r;
 936
 937         if (link->ndisc_messages == 0) {
 938                 link->ndisc_configured = true;
 939
 940                 r = ndisc_remove(link, &router);
 941                 if (r < 0)
 942                         return r;
 943         } else
 944                 log_link_debug(link, "Setting SLAAC addresses and router.");
 945
 946         if (!link->ndisc_configured)
 947                 link_set_state(link, LINK_STATE_CONFIGURING);
 948
 949         link_check_ready(link);
 950         return 0;
 951 }
 952
 953 static void ndisc_handler(sd_ndisc *nd, sd_ndisc_event_t event, sd_ndisc_router *rt, void *userdata) {
 954         Link *link = userdata;
 955         int r;
 956
 957         assert(link);
 958
 959         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
 960                 return;
 961
 962         switch (event) {
 963
 964         case SD_NDISC_EVENT_ROUTER:
 965                 r = ndisc_router_handler(link, rt);
 966                 if (r < 0) {
 967                         link_enter_failed(link);
 968                         return;
 969                 }
 970                 break;
 971
 972         case SD_NDISC_EVENT_TIMEOUT:
 973                 log_link_debug(link, "NDisc handler get timeout event");
 974                 if (link->ndisc_messages == 0) {
 975                         link->ndisc_configured = true;
 976                         link_check_ready(link);
 977                 }
 978                 break;
 979         default:
 980                 assert_not_reached();
 981         }
 982 }
 983
 984 int ndisc_configure(Link *link) {
 985         int r;
 986
 987         assert(link);
 988
 989         if (!link_ipv6_accept_ra_enabled(link))
 990                 return 0;
 991
 992         if (link->ndisc)
 993                 return -EBUSY; /* Already configured. */
 994
 995         r = sd_ndisc_new(&link->ndisc);
 996         if (r < 0)
 997                 return r;
 998
 999         r = sd_ndisc_attach_event(link->ndisc, link->manager->event, 0);
1000         if (r < 0)
1001                 return r;
1002
1003         r = sd_ndisc_set_mac(link->ndisc, &link->hw_addr.ether);
1004         if (r < 0)
1005                 return r;
1006
1007         r = sd_ndisc_set_ifindex(link->ndisc, link->ifindex);
1008         if (r < 0)
1009                 return r;
1010
1011         r = sd_ndisc_set_callback(link->ndisc, ndisc_handler, link);
1012         if (r < 0)
1013                 return r;
1014
1015         return 0;
1016 }
1017
1018 int ndisc_start(Link *link) {
1019         assert(link);
1020
1021         if (!link->ndisc || !link->dhcp6_client)
1022                 return 0;
1023
1024         if (!link_has_carrier(link))
1025                 return 0;
1026
1027         if (in6_addr_is_null(&link->ipv6ll_address))
1028                 return 0;
1029
1030         log_link_debug(link, "Discovering IPv6 routers");
1031
1032         return sd_ndisc_start(link->ndisc);
1033 }
1034
1035 void ndisc_vacuum(Link *link) {
1036         NDiscRDNSS *r;
1037         NDiscDNSSL *d;
1038         usec_t time_now;
1039
1040         assert(link);
1041
1042         /* Removes all RDNSS and DNSSL entries whose validity time has passed */
1043
1044         time_now = now(clock_boottime_or_monotonic());
1045
1046         SET_FOREACH(r, link->ndisc_rdnss)
1047                 if (r->valid_until < time_now)
1048                         free(set_remove(link->ndisc_rdnss, r));
1049
1050         SET_FOREACH(d, link->ndisc_dnssl)
1051                 if (d->valid_until < time_now)
1052                         free(set_remove(link->ndisc_dnssl, d));
1053 }
1054
1055 void ndisc_flush(Link *link) {
1056         assert(link);
1057
1058         /* Removes all RDNSS and DNSSL entries, without exception */
1059
1060         link->ndisc_rdnss = set_free(link->ndisc_rdnss);
1061         link->ndisc_dnssl = set_free(link->ndisc_dnssl);
1062 }
1063
1064 static const char* const ipv6_accept_ra_start_dhcp6_client_table[_IPV6_ACCEPT_RA_START_DHCP6_CLIENT_MAX] = {
1065         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO]     = "no",
1066         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS] = "always",
1067         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES]    = "yes",
1068 };
1069
1070 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING_WITH_BOOLEAN(ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client, IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES);
1071
1072 DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_use_domains, dhcp_use_domains, DHCPUseDomains,
1073                          "Failed to parse UseDomains= setting");
1074 DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_start_dhcp6_client, ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client,
1075                          "Failed to parse DHCPv6Client= setting");