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 <net/if_arp.h>
   9 #include <linux/if.h>
  10
  11 #include "sd-ndisc.h"
  12
  13 #include "missing_network.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-state-file.h"
  20 #include "string-table.h"
  21 #include "string-util.h"
  22 #include "strv.h"
  23
  24 #define NDISC_DNSSL_MAX 64U
  25 #define NDISC_RDNSS_MAX 64U
  26
  27 #define DAD_CONFLICTS_IDGEN_RETRIES_RFC7217 3
  28
  29 /* https://tools.ietf.org/html/rfc5453 */
  30 /* https://www.iana.org/assignments/ipv6-interface-ids/ipv6-interface-ids.xml */
  31
  32 #define SUBNET_ROUTER_ANYCAST_ADDRESS_RFC4291               ((struct in6_addr) { .s6_addr = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 } })
  33 #define SUBNET_ROUTER_ANYCAST_PREFIXLEN                     8
  34 #define RESERVED_IPV6_INTERFACE_IDENTIFIERS_ADDRESS_RFC4291 ((struct in6_addr) { .s6_addr = { 0x02, 0x00, 0x5E, 0xFF, 0xFE } })
  35 #define RESERVED_IPV6_INTERFACE_IDENTIFIERS_PREFIXLEN       5
  36 #define RESERVED_SUBNET_ANYCAST_ADDRESSES_RFC4291           ((struct in6_addr) { .s6_addr = { 0xFD, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF } })
  37 #define RESERVED_SUBNET_ANYCAST_PREFIXLEN                   7
  38
  39 #define NDISC_APP_ID SD_ID128_MAKE(13,ac,81,a7,d5,3f,49,78,92,79,5d,0c,29,3a,bc,7e)
  40
  41 typedef enum IPv6TokenAddressGeneration {
  42         IPV6_TOKEN_ADDRESS_GENERATION_NONE,
  43         IPV6_TOKEN_ADDRESS_GENERATION_STATIC,
  44         IPV6_TOKEN_ADDRESS_GENERATION_PREFIXSTABLE,
  45         _IPV6_TOKEN_ADDRESS_GENERATION_MAX,
  46         _IPV6_TOKEN_ADDRESS_GENERATION_INVALID = -EINVAL,
  47 } IPv6TokenAddressGeneration;
  48
  49 typedef struct IPv6Token {
  50         IPv6TokenAddressGeneration address_generation_type;
  51
  52         uint8_t dad_counter;
  53         struct in6_addr prefix;
  54 } IPv6Token;
  55
  56 bool link_ipv6_accept_ra_enabled(Link *link) {
  57         assert(link);
  58
  59         if (!socket_ipv6_is_supported())
  60                 return false;
  61
  62         if (link->flags & IFF_LOOPBACK)
  63                 return false;
  64
  65         if (!link->network)
  66                 return false;
  67
  68         if (!link_ipv6ll_enabled(link))
  69                 return false;
  70
  71         assert(link->network->ipv6_accept_ra >= 0);
  72         return link->network->ipv6_accept_ra;
  73 }
  74
  75 void network_adjust_ipv6_accept_ra(Network *network) {
  76         assert(network);
  77
  78         if (!FLAGS_SET(network->link_local, ADDRESS_FAMILY_IPV6)) {
  79                 if (network->ipv6_accept_ra > 0)
  80                         log_warning("%s: IPv6AcceptRA= is enabled but IPv6 link local addressing is disabled or not supported. "
  81                                     "Disabling IPv6AcceptRA=.", network->filename);
  82                 network->ipv6_accept_ra = false;
  83         }
  84
  85         if (network->ipv6_accept_ra < 0)
  86                 /* default to accept RA if ip_forward is disabled and ignore RA if ip_forward is enabled */
  87                 network->ipv6_accept_ra = !FLAGS_SET(network->ip_forward, ADDRESS_FAMILY_IPV6);
  88
  89         /* When RouterAllowList=, PrefixAllowList= or RouteAllowList= are specified, then
  90          * RouterDenyList=, PrefixDenyList= or RouteDenyList= are ignored, respectively. */
  91         if (!set_isempty(network->ndisc_allow_listed_router))
  92                 network->ndisc_deny_listed_router = set_free_free(network->ndisc_deny_listed_router);
  93         if (!set_isempty(network->ndisc_allow_listed_prefix))
  94                 network->ndisc_deny_listed_prefix = set_free_free(network->ndisc_deny_listed_prefix);
  95         if (!set_isempty(network->ndisc_allow_listed_route_prefix))
  96                 network->ndisc_deny_listed_route_prefix = set_free_free(network->ndisc_deny_listed_route_prefix);
  97 }
  98
  99 static int ndisc_remove_old_one(Link *link, const struct in6_addr *router, bool force);
 100
 101 static int ndisc_address_callback(Address *address) {
 102         struct in6_addr router = {};
 103         NDiscAddress *n;
 104
 105         assert(address);
 106         assert(address->link);
 107         assert(address->family == AF_INET6);
 108
 109         SET_FOREACH(n, address->link->ndisc_addresses)
 110                 if (n->address == address) {
 111                         router = n->router;
 112                         break;
 113                 }
 114
 115         if (in6_addr_is_null(&router)) {
 116                 _cleanup_free_ char *buf = NULL;
 117
 118                 (void) in6_addr_prefix_to_string(&address->in_addr.in6, address->prefixlen, &buf);
 119                 log_link_debug(address->link, "%s is called for %s, but it is already removed, ignoring.",
 120                                __func__, strna(buf));
 121                 return 0;
 122         }
 123
 124         /* Make this called only once */
 125         SET_FOREACH(n, address->link->ndisc_addresses)
 126                 if (in6_addr_equal(&n->router, &router))
 127                         n->address->callback = NULL;
 128
 129         return ndisc_remove_old_one(address->link, &router, true);
 130 }
 131
 132 static int ndisc_remove_old_one(Link *link, const struct in6_addr *router, bool force) {
 133         NDiscAddress *na;
 134         NDiscRoute *nr;
 135         NDiscDNSSL *dnssl;
 136         NDiscRDNSS *rdnss;
 137         int k, r = 0;
 138         bool updated = false;
 139
 140         assert(link);
 141         assert(router);
 142
 143         if (!force) {
 144                 bool set_callback = false;
 145
 146                 SET_FOREACH(na, link->ndisc_addresses)
 147                         if (!na->marked && in6_addr_equal(&na->router, router)) {
 148                                 set_callback = true;
 149                                 break;
 150                         }
 151
 152                 if (set_callback)
 153                         SET_FOREACH(na, link->ndisc_addresses)
 154                                 if (!na->marked && address_is_ready(na->address)) {
 155                                         set_callback = false;
 156                                         break;
 157                                 }
 158
 159                 if (set_callback) {
 160                         SET_FOREACH(na, link->ndisc_addresses)
 161                                 if (!na->marked && in6_addr_equal(&na->router, router))
 162                                         na->address->callback = ndisc_address_callback;
 163
 164                         if (DEBUG_LOGGING) {
 165                                 _cleanup_free_ char *buf = NULL;
 166
 167                                 (void) in6_addr_to_string(router, &buf);
 168                                 log_link_debug(link, "No SLAAC address obtained from %s is ready. "
 169                                                "The old NDisc information will be removed later.",
 170                                                strna(buf));
 171                         }
 172                         return 0;
 173                 }
 174         }
 175
 176         if (DEBUG_LOGGING) {
 177                 _cleanup_free_ char *buf = NULL;
 178
 179                 (void) in6_addr_to_string(router, &buf);
 180                 log_link_debug(link, "Removing old NDisc information obtained from %s.", strna(buf));
 181         }
 182
 183         SET_FOREACH(na, link->ndisc_addresses)
 184                 if (na->marked && in6_addr_equal(&na->router, router)) {
 185                         k = address_remove(na->address, link);
 186                         if (k < 0)
 187                                 r = k;
 188                 }
 189
 190         SET_FOREACH(nr, link->ndisc_routes)
 191                 if (nr->marked && in6_addr_equal(&nr->router, router)) {
 192                         k = route_remove(nr->route, NULL, link);
 193                         if (k < 0)
 194                                 r = k;
 195                 }
 196
 197         SET_FOREACH(rdnss, link->ndisc_rdnss)
 198                 if (rdnss->marked && in6_addr_equal(&rdnss->router, router)) {
 199                         free(set_remove(link->ndisc_rdnss, rdnss));
 200                         updated = true;
 201                 }
 202
 203         SET_FOREACH(dnssl, link->ndisc_dnssl)
 204                 if (dnssl->marked && in6_addr_equal(&dnssl->router, router)) {
 205                         free(set_remove(link->ndisc_dnssl, dnssl));
 206                         updated = true;
 207                 }
 208
 209         if (updated)
 210                 link_dirty(link);
 211
 212         return r;
 213 }
 214
 215 static int ndisc_remove_old(Link *link) {
 216         _cleanup_set_free_free_ Set *routers = NULL;
 217         _cleanup_free_ struct in6_addr *router = NULL;
 218         struct in6_addr *a;
 219         NDiscAddress *na;
 220         NDiscRoute *nr;
 221         NDiscDNSSL *dnssl;
 222         NDiscRDNSS *rdnss;
 223         int k, r;
 224
 225         assert(link);
 226
 227         if (link->ndisc_addresses_messages > 0 ||
 228             link->ndisc_routes_messages > 0)
 229                 return 0;
 230
 231         routers = set_new(&in6_addr_hash_ops);
 232         if (!routers)
 233                 return -ENOMEM;
 234
 235         SET_FOREACH(na, link->ndisc_addresses)
 236                 if (!set_contains(routers, &na->router)) {
 237                         router = newdup(struct in6_addr, &na->router, 1);
 238                         if (!router)
 239                                 return -ENOMEM;
 240
 241                         r = set_put(routers, router);
 242                         if (r < 0)
 243                                 return r;
 244
 245                         assert(r > 0);
 246                         TAKE_PTR(router);
 247                 }
 248
 249         SET_FOREACH(nr, link->ndisc_routes)
 250                 if (!set_contains(routers, &nr->router)) {
 251                         router = newdup(struct in6_addr, &nr->router, 1);
 252                         if (!router)
 253                                 return -ENOMEM;
 254
 255                         r = set_put(routers, router);
 256                         if (r < 0)
 257                                 return r;
 258
 259                         assert(r > 0);
 260                         TAKE_PTR(router);
 261                 }
 262
 263         SET_FOREACH(rdnss, link->ndisc_rdnss)
 264                 if (!set_contains(routers, &rdnss->router)) {
 265                         router = newdup(struct in6_addr, &rdnss->router, 1);
 266                         if (!router)
 267                                 return -ENOMEM;
 268
 269                         r = set_put(routers, router);
 270                         if (r < 0)
 271                                 return r;
 272
 273                         assert(r > 0);
 274                         TAKE_PTR(router);
 275                 }
 276
 277         SET_FOREACH(dnssl, link->ndisc_dnssl)
 278                 if (!set_contains(routers, &dnssl->router)) {
 279                         router = newdup(struct in6_addr, &dnssl->router, 1);
 280                         if (!router)
 281                                 return -ENOMEM;
 282
 283                         r = set_put(routers, router);
 284                         if (r < 0)
 285                                 return r;
 286
 287                         assert(r > 0);
 288                         TAKE_PTR(router);
 289                 }
 290
 291         r = 0;
 292         SET_FOREACH(a, routers) {
 293                 k = ndisc_remove_old_one(link, a, false);
 294                 if (k < 0)
 295                         r = k;
 296         }
 297
 298         return r;
 299 }
 300
 301 static void ndisc_route_hash_func(const NDiscRoute *x, struct siphash *state) {
 302         route_hash_func(x->route, state);
 303 }
 304
 305 static int ndisc_route_compare_func(const NDiscRoute *a, const NDiscRoute *b) {
 306         return route_compare_func(a->route, b->route);
 307 }
 308
 309 DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
 310                 ndisc_route_hash_ops,
 311                 NDiscRoute,
 312                 ndisc_route_hash_func,
 313                 ndisc_route_compare_func,
 314                 free);
 315
 316 static int ndisc_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
 317         int r;
 318
 319         assert(link);
 320         assert(link->ndisc_routes_messages > 0);
 321
 322         link->ndisc_routes_messages--;
 323
 324         r = route_configure_handler_internal(rtnl, m, link, "Could not set NDisc route");
 325         if (r <= 0)
 326                 return r;
 327
 328         if (link->ndisc_routes_messages == 0) {
 329                 log_link_debug(link, "NDisc routes set.");
 330                 link->ndisc_routes_configured = true;
 331
 332                 r = ndisc_remove_old(link);
 333                 if (r < 0) {
 334                         link_enter_failed(link);
 335                         return 1;
 336                 }
 337
 338                 link_check_ready(link);
 339         }
 340
 341         return 1;
 342 }
 343
 344 static int ndisc_after_route_configure(Request *req, void *object) {
 345         _cleanup_free_ NDiscRoute *nr = NULL;
 346         NDiscRoute *nr_exist;
 347         struct in6_addr router;
 348         Route *route = object;
 349         sd_ndisc_router *rt;
 350         Link *link;
 351         int r;
 352
 353         assert(req);
 354         assert(req->link);
 355         assert(req->type == REQUEST_TYPE_ROUTE);
 356         assert(req->userdata);
 357         assert(route);
 358
 359         link = req->link;
 360         rt = req->userdata;
 361
 362         r = sd_ndisc_router_get_address(rt, &router);
 363         if (r < 0)
 364                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
 365
 366         nr = new(NDiscRoute, 1);
 367         if (!nr)
 368                 return log_oom();
 369
 370         *nr = (NDiscRoute) {
 371                 .router = router,
 372                 .route = route,
 373         };
 374
 375         nr_exist = set_get(link->ndisc_routes, nr);
 376         if (nr_exist) {
 377                 nr_exist->marked = false;
 378                 nr_exist->router = router;
 379                 return 0;
 380         }
 381
 382         r = set_ensure_put(&link->ndisc_routes, &ndisc_route_hash_ops, nr);
 383         if (r < 0)
 384                 return log_link_error_errno(link, r, "Failed to store NDisc SLAAC route: %m");
 385         assert(r > 0);
 386         TAKE_PTR(nr);
 387
 388         return 0;
 389 }
 390
 391 static void ndisc_request_on_free(Request *req) {
 392         assert(req);
 393
 394         sd_ndisc_router_unref(req->userdata);
 395 }
 396
 397 static int ndisc_request_route(Route *in, Link *link, sd_ndisc_router *rt) {
 398         _cleanup_(route_freep) Route *route = in;
 399         Request *req;
 400         int r;
 401
 402         assert(route);
 403         assert(link);
 404         assert(rt);
 405
 406         if (!route->table_set)
 407                 route->table = link_get_ipv6_accept_ra_route_table(link);
 408         if (!route->priority_set)
 409                 route->priority = link->network->ipv6_accept_ra_route_metric;
 410         if (!route->protocol_set)
 411                 route->protocol = RTPROT_RA;
 412
 413         r = link_has_route(link, route);
 414         if (r < 0)
 415                 return r;
 416         if (r == 0)
 417                 link->ndisc_routes_configured = false;
 418
 419         r = link_request_route(link, TAKE_PTR(route), true, &link->ndisc_routes_messages,
 420                                ndisc_route_handler, &req);
 421         if (r <= 0)
 422                 return r;
 423
 424         req->userdata = sd_ndisc_router_ref(rt);
 425         req->after_configure = ndisc_after_route_configure;
 426         req->on_free = ndisc_request_on_free;
 427
 428         return 0;
 429 }
 430
 431 static void ndisc_address_hash_func(const NDiscAddress *x, struct siphash *state) {
 432         address_hash_func(x->address, state);
 433 }
 434
 435 static int ndisc_address_compare_func(const NDiscAddress *a, const NDiscAddress *b) {
 436         return address_compare_func(a->address, b->address);
 437 }
 438
 439 DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
 440                 ndisc_address_hash_ops,
 441                 NDiscAddress,
 442                 ndisc_address_hash_func,
 443                 ndisc_address_compare_func,
 444                 free);
 445
 446 static int ndisc_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
 447         int r;
 448
 449         assert(link);
 450         assert(link->ndisc_addresses_messages > 0);
 451
 452         link->ndisc_addresses_messages--;
 453
 454         r = address_configure_handler_internal(rtnl, m, link, "Could not set NDisc address");
 455         if (r <= 0)
 456                 return r;
 457
 458         if (link->ndisc_addresses_messages == 0) {
 459                 log_link_debug(link, "NDisc SLAAC addresses set.");
 460                 link->ndisc_addresses_configured = true;
 461
 462                 r = ndisc_remove_old(link);
 463                 if (r < 0) {
 464                         link_enter_failed(link);
 465                         return 1;
 466                 }
 467         }
 468
 469         return 1;
 470 }
 471
 472 static int ndisc_after_address_configure(Request *req, void *object) {
 473         _cleanup_free_ NDiscAddress *na = NULL;
 474         NDiscAddress *na_exist;
 475         struct in6_addr router;
 476         sd_ndisc_router *rt;
 477         Address *address = object;
 478         Link *link;
 479         int r;
 480
 481         assert(req);
 482         assert(req->link);
 483         assert(req->type == REQUEST_TYPE_ADDRESS);
 484         assert(req->userdata);
 485         assert(address);
 486
 487         link = req->link;
 488         rt = req->userdata;
 489
 490         r = sd_ndisc_router_get_address(rt, &router);
 491         if (r < 0)
 492                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
 493
 494         na = new(NDiscAddress, 1);
 495         if (!na)
 496                 return log_oom();
 497
 498         *na = (NDiscAddress) {
 499                 .router = router,
 500                 .address = address,
 501         };
 502
 503         na_exist = set_get(link->ndisc_addresses, na);
 504         if (na_exist) {
 505                 na_exist->marked = false;
 506                 na_exist->router = router;
 507                 return 0;
 508         }
 509
 510         r = set_ensure_put(&link->ndisc_addresses, &ndisc_address_hash_ops, na);
 511         if (r < 0)
 512                 return log_link_error_errno(link, r, "Failed to store NDisc SLAAC address: %m");
 513         assert(r > 0);
 514         TAKE_PTR(na);
 515
 516         return 0;
 517 }
 518
 519 static int ndisc_request_address(Address *in, Link *link, sd_ndisc_router *rt) {
 520         _cleanup_(address_freep) Address *address = in;
 521         Request *req;
 522         int r;
 523
 524         assert(address);
 525         assert(link);
 526         assert(rt);
 527
 528         if (address_get(link, address, NULL) < 0)
 529                 link->ndisc_addresses_configured = false;
 530
 531         r = link_request_address(link, TAKE_PTR(address), true, &link->ndisc_addresses_messages,
 532                                  ndisc_address_handler, &req);
 533         if (r <= 0)
 534                 return r;
 535
 536         req->userdata = sd_ndisc_router_ref(rt);
 537         req->after_configure = ndisc_after_address_configure;
 538         req->on_free = ndisc_request_on_free;
 539
 540         return 0;
 541 }
 542
 543 static int ndisc_router_process_default(Link *link, sd_ndisc_router *rt) {
 544         _cleanup_(route_freep) Route *route = NULL;
 545         struct in6_addr gateway;
 546         uint32_t mtu = 0;
 547         unsigned preference;
 548         uint16_t lifetime;
 549         usec_t time_now;
 550         int r;
 551
 552         assert(link);
 553         assert(rt);
 554
 555         r = sd_ndisc_router_get_lifetime(rt, &lifetime);
 556         if (r < 0)
 557                 return log_link_error_errno(link, r, "Failed to get gateway lifetime from RA: %m");
 558
 559         if (lifetime == 0) /* not a default router */
 560                 return 0;
 561
 562         r = sd_ndisc_router_get_address(rt, &gateway);
 563         if (r < 0)
 564                 return log_link_error_errno(link, r, "Failed to get gateway address from RA: %m");
 565
 566         if (link_get_ipv6_address(link, &gateway, NULL) >= 0) {
 567                 if (DEBUG_LOGGING) {
 568                         _cleanup_free_ char *buffer = NULL;
 569
 570                         (void) in6_addr_to_string(&gateway, &buffer);
 571                         log_link_debug(link, "No NDisc route added, gateway %s matches local address",
 572                                        strna(buffer));
 573                 }
 574                 return 0;
 575         }
 576
 577         r = sd_ndisc_router_get_preference(rt, &preference);
 578         if (r < 0)
 579                 return log_link_error_errno(link, r, "Failed to get default router preference from RA: %m");
 580
 581         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
 582         if (r < 0)
 583                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 584
 585         if (link->network->ipv6_accept_ra_use_mtu) {
 586                 r = sd_ndisc_router_get_mtu(rt, &mtu);
 587                 if (r < 0 && r != -ENODATA)
 588                         return log_link_error_errno(link, r, "Failed to get default router MTU from RA: %m");
 589         }
 590
 591         r = route_new(&route);
 592         if (r < 0)
 593                 return log_oom();
 594
 595         route->family = AF_INET6;
 596         route->pref = preference;
 597         route->gw_family = AF_INET6;
 598         route->gw.in6 = gateway;
 599         route->lifetime = usec_add(time_now, lifetime * USEC_PER_SEC);
 600         route->mtu = mtu;
 601
 602         r = ndisc_request_route(TAKE_PTR(route), link, rt);
 603         if (r < 0)
 604                 return log_link_error_errno(link, r, "Could not request default route: %m");
 605
 606         Route *route_gw;
 607         HASHMAP_FOREACH(route_gw, link->network->routes_by_section) {
 608                 if (!route_gw->gateway_from_dhcp_or_ra)
 609                         continue;
 610
 611                 if (route_gw->gw_family != AF_INET6)
 612                         continue;
 613
 614                 r = route_dup(route_gw, &route);
 615                 if (r < 0)
 616                         return r;
 617
 618                 route->gw.in6 = gateway;
 619                 if (!route->pref_set)
 620                         route->pref = preference;
 621                 route->lifetime = usec_add(time_now, lifetime * USEC_PER_SEC);
 622                 if (route->mtu == 0)
 623                         route->mtu = mtu;
 624
 625                 r = ndisc_request_route(TAKE_PTR(route), link, rt);
 626                 if (r < 0)
 627                         return log_link_error_errno(link, r, "Could not request gateway: %m");
 628         }
 629
 630         return 0;
 631 }
 632
 633 static bool stable_private_address_is_valid(const struct in6_addr *addr) {
 634         assert(addr);
 635
 636         /* According to rfc4291, generated address should not be in the following ranges. */
 637
 638         if (memcmp(addr, &SUBNET_ROUTER_ANYCAST_ADDRESS_RFC4291, SUBNET_ROUTER_ANYCAST_PREFIXLEN) == 0)
 639                 return false;
 640
 641         if (memcmp(addr, &RESERVED_IPV6_INTERFACE_IDENTIFIERS_ADDRESS_RFC4291, RESERVED_IPV6_INTERFACE_IDENTIFIERS_PREFIXLEN) == 0)
 642                 return false;
 643
 644         if (memcmp(addr, &RESERVED_SUBNET_ANYCAST_ADDRESSES_RFC4291, RESERVED_SUBNET_ANYCAST_PREFIXLEN) == 0)
 645                 return false;
 646
 647         return true;
 648 }
 649
 650 static int make_stable_private_address(Link *link, const struct in6_addr *prefix, uint8_t prefix_len, uint8_t dad_counter, struct in6_addr **ret) {
 651         _cleanup_free_ struct in6_addr *addr = NULL;
 652         sd_id128_t secret_key;
 653         struct siphash state;
 654         uint64_t rid;
 655         size_t l;
 656         int r;
 657
 658         /* According to rfc7217 section 5.1
 659          * RID = F(Prefix, Net_Iface, Network_ID, DAD_Counter, secret_key) */
 660
 661         r = sd_id128_get_machine_app_specific(NDISC_APP_ID, &secret_key);
 662         if (r < 0)
 663                 return log_link_warning_errno(link, r, "Failed to generate key for IPv6 stable private address: %m");
 664
 665         siphash24_init(&state, secret_key.bytes);
 666
 667         l = MAX(DIV_ROUND_UP(prefix_len, 8), 8);
 668         siphash24_compress(prefix, l, &state);
 669         siphash24_compress_string(link->ifname, &state);
 670         /* Only last 8 bytes of IB MAC are stable */
 671         if (link->iftype == ARPHRD_INFINIBAND)
 672                 siphash24_compress(&link->hw_addr.infiniband[12], 8, &state);
 673         else
 674                 siphash24_compress(link->hw_addr.bytes, link->hw_addr.length, &state);
 675         siphash24_compress(&dad_counter, sizeof(uint8_t), &state);
 676
 677         rid = htole64(siphash24_finalize(&state));
 678
 679         addr = new(struct in6_addr, 1);
 680         if (!addr)
 681                 return log_oom();
 682
 683         memcpy(addr->s6_addr, prefix->s6_addr, l);
 684         memcpy(addr->s6_addr + l, &rid, 16 - l);
 685
 686         if (!stable_private_address_is_valid(addr)) {
 687                 *ret = NULL;
 688                 return 0;
 689         }
 690
 691         *ret = TAKE_PTR(addr);
 692         return 1;
 693 }
 694
 695 static int ndisc_router_generate_addresses(Link *link, struct in6_addr *address, uint8_t prefixlen, Set **ret) {
 696         _cleanup_set_free_free_ Set *addresses = NULL;
 697         IPv6Token *j;
 698         int r;
 699
 700         assert(link);
 701         assert(address);
 702         assert(ret);
 703
 704         addresses = set_new(&in6_addr_hash_ops);
 705         if (!addresses)
 706                 return log_oom();
 707
 708         ORDERED_SET_FOREACH(j, link->network->ipv6_tokens) {
 709                 _cleanup_free_ struct in6_addr *new_address = NULL;
 710
 711                 if (j->address_generation_type == IPV6_TOKEN_ADDRESS_GENERATION_PREFIXSTABLE
 712                     && (in6_addr_is_null(&j->prefix) || in6_addr_equal(&j->prefix, address))) {
 713                         /* While this loop uses dad_counter and a retry limit as specified in RFC 7217, the loop
 714                          * does not actually attempt Duplicate Address Detection; the counter will be incremented
 715                          * only when the address generation algorithm produces an invalid address, and the loop
 716                          * may exit with an address which ends up being unusable due to duplication on the link. */
 717                         for (; j->dad_counter < DAD_CONFLICTS_IDGEN_RETRIES_RFC7217; j->dad_counter++) {
 718                                 r = make_stable_private_address(link, address, prefixlen, j->dad_counter, &new_address);
 719                                 if (r < 0)
 720                                         return r;
 721                                 if (r > 0)
 722                                         break;
 723                         }
 724                 } else if (j->address_generation_type == IPV6_TOKEN_ADDRESS_GENERATION_STATIC) {
 725                         new_address = new(struct in6_addr, 1);
 726                         if (!new_address)
 727                                 return log_oom();
 728
 729                         memcpy(new_address->s6_addr, address->s6_addr, 8);
 730                         memcpy(new_address->s6_addr + 8, j->prefix.s6_addr + 8, 8);
 731                 }
 732
 733                 if (new_address) {
 734                         r = set_put(addresses, new_address);
 735                         if (r < 0)
 736                                 return log_link_error_errno(link, r, "Failed to store SLAAC address: %m");
 737                         else if (r == 0)
 738                                 log_link_debug_errno(link, r, "Generated SLAAC address is duplicated, ignoring.");
 739                         else
 740                                 TAKE_PTR(new_address);
 741                 }
 742         }
 743
 744         /* fall back to EUI-64 if no tokens provided addresses */
 745         if (set_isempty(addresses)) {
 746                 _cleanup_free_ struct in6_addr *new_address = NULL;
 747
 748                 new_address = newdup(struct in6_addr, address, 1);
 749                 if (!new_address)
 750                         return log_oom();
 751
 752                 r = generate_ipv6_eui_64_address(link, new_address);
 753                 if (r < 0)
 754                         return log_link_error_errno(link, r, "Failed to generate EUI64 address: %m");
 755
 756                 r = set_put(addresses, new_address);
 757                 if (r < 0)
 758                         return log_link_error_errno(link, r, "Failed to store SLAAC address: %m");
 759
 760                 TAKE_PTR(new_address);
 761         }
 762
 763         *ret = TAKE_PTR(addresses);
 764
 765         return 0;
 766 }
 767
 768 static int ndisc_router_process_autonomous_prefix(Link *link, sd_ndisc_router *rt) {
 769         uint32_t lifetime_valid, lifetime_preferred;
 770         _cleanup_set_free_free_ Set *addresses = NULL;
 771         struct in6_addr addr, *a;
 772         unsigned prefixlen;
 773         usec_t time_now;
 774         int r;
 775
 776         assert(link);
 777         assert(rt);
 778
 779         /* Do not use clock_boottime_or_monotonic() here, as the kernel internally manages cstamp and
 780          * tstamp with jiffies, and it is not increased while the system is suspended. */
 781         r = sd_ndisc_router_get_timestamp(rt, CLOCK_MONOTONIC, &time_now);
 782         if (r < 0)
 783                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 784
 785         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
 786         if (r < 0)
 787                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
 788
 789         r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_valid);
 790         if (r < 0)
 791                 return log_link_error_errno(link, r, "Failed to get prefix valid lifetime: %m");
 792
 793         if (lifetime_valid == 0) {
 794                 log_link_debug(link, "Ignoring prefix as its valid lifetime is zero.");
 795                 return 0;
 796         }
 797
 798         r = sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred);
 799         if (r < 0)
 800                 return log_link_error_errno(link, r, "Failed to get prefix preferred lifetime: %m");
 801
 802         /* The preferred lifetime is never greater than the valid lifetime */
 803         if (lifetime_preferred > lifetime_valid)
 804                 return 0;
 805
 806         r = sd_ndisc_router_prefix_get_address(rt, &addr);
 807         if (r < 0)
 808                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
 809
 810         r = ndisc_router_generate_addresses(link, &addr, prefixlen, &addresses);
 811         if (r < 0)
 812                 return r;
 813
 814         SET_FOREACH(a, addresses) {
 815                 _cleanup_(address_freep) Address *address = NULL;
 816                 Address *e;
 817
 818                 r = address_new(&address);
 819                 if (r < 0)
 820                         return log_oom();
 821
 822                 address->family = AF_INET6;
 823                 address->in_addr.in6 = *a;
 824                 address->prefixlen = prefixlen;
 825                 address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR;
 826                 address->cinfo.ifa_valid = lifetime_valid;
 827                 address->cinfo.ifa_prefered = lifetime_preferred;
 828
 829                 /* See RFC4862, section 5.5.3.e. But the following logic is deviated from RFC4862 by
 830                  * honoring all valid lifetimes to improve the reaction of SLAAC to renumbering events.
 831                  * See draft-ietf-6man-slaac-renum-02, section 4.2. */
 832                 r = address_get(link, address, &e);
 833                 if (r > 0) {
 834                         /* If the address is already assigned, but not valid anymore, then refuse to
 835                          * update the address, and it will be removed. */
 836                         if (e->cinfo.ifa_valid != CACHE_INFO_INFINITY_LIFE_TIME &&
 837                             usec_add(e->cinfo.tstamp / 100 * USEC_PER_SEC,
 838                                      e->cinfo.ifa_valid * USEC_PER_SEC) < time_now)
 839                                 continue;
 840                 }
 841
 842                 r = ndisc_request_address(TAKE_PTR(address), link, rt);
 843                 if (r < 0)
 844                         return log_link_error_errno(link, r, "Could not request SLAAC address: %m");
 845         }
 846
 847         return 0;
 848 }
 849
 850 static int ndisc_router_process_onlink_prefix(Link *link, sd_ndisc_router *rt) {
 851         _cleanup_(route_freep) Route *route = NULL;
 852         usec_t time_now;
 853         uint32_t lifetime;
 854         unsigned prefixlen;
 855         int r;
 856
 857         assert(link);
 858         assert(rt);
 859
 860         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
 861         if (r < 0)
 862                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 863
 864         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
 865         if (r < 0)
 866                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
 867
 868         r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime);
 869         if (r < 0)
 870                 return log_link_error_errno(link, r, "Failed to get prefix lifetime: %m");
 871
 872         r = route_new(&route);
 873         if (r < 0)
 874                 return log_oom();
 875
 876         route->family = AF_INET6;
 877         route->flags = RTM_F_PREFIX;
 878         route->dst_prefixlen = prefixlen;
 879         route->lifetime = usec_add(time_now, lifetime * USEC_PER_SEC);
 880
 881         r = sd_ndisc_router_prefix_get_address(rt, &route->dst.in6);
 882         if (r < 0)
 883                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
 884
 885         r = ndisc_request_route(TAKE_PTR(route), link, rt);
 886         if (r < 0)
 887                 return log_link_error_errno(link, r, "Could not request prefix route: %m");;
 888
 889         return 0;
 890 }
 891
 892 static int ndisc_router_process_route(Link *link, sd_ndisc_router *rt) {
 893         _cleanup_(route_freep) Route *route = NULL;
 894         struct in6_addr gateway, dst;
 895         uint32_t lifetime;
 896         unsigned preference, prefixlen;
 897         usec_t time_now;
 898         int r;
 899
 900         assert(link);
 901
 902         r = sd_ndisc_router_route_get_lifetime(rt, &lifetime);
 903         if (r < 0)
 904                 return log_link_error_errno(link, r, "Failed to get route lifetime from RA: %m");
 905
 906         if (lifetime == 0)
 907                 return 0;
 908
 909         r = sd_ndisc_router_route_get_address(rt, &dst);
 910         if (r < 0)
 911                 return log_link_error_errno(link, r, "Failed to get route destination address: %m");
 912
 913         r = sd_ndisc_router_route_get_prefixlen(rt, &prefixlen);
 914         if (r < 0)
 915                 return log_link_error_errno(link, r, "Failed to get route prefix length: %m");
 916
 917         if (in6_prefix_is_filtered(&dst, prefixlen, link->network->ndisc_allow_listed_route_prefix, link->network->ndisc_deny_listed_route_prefix)) {
 918                 if (DEBUG_LOGGING) {
 919                         _cleanup_free_ char *buf = NULL;
 920
 921                         (void) in6_addr_prefix_to_string(&dst, prefixlen, &buf);
 922                         if (!set_isempty(link->network->ndisc_allow_listed_route_prefix))
 923                                 log_link_debug(link, "Route prefix '%s' is not in allow list, ignoring", strna(buf));
 924                         else
 925                                 log_link_debug(link, "Route prefix '%s' is in deny list, ignoring", strna(buf));
 926                 }
 927                 return 0;
 928         }
 929
 930         r = sd_ndisc_router_get_address(rt, &gateway);
 931         if (r < 0)
 932                 return log_link_error_errno(link, r, "Failed to get gateway address from RA: %m");
 933
 934         if (link_get_ipv6_address(link, &gateway, NULL) >= 0) {
 935                 if (DEBUG_LOGGING) {
 936                         _cleanup_free_ char *buf = NULL;
 937
 938                         (void) in6_addr_to_string(&gateway, &buf);
 939                         log_link_debug(link, "Advertised route gateway %s is local to the link, ignoring route", strna(buf));
 940                 }
 941                 return 0;
 942         }
 943
 944         r = sd_ndisc_router_route_get_preference(rt, &preference);
 945         if (r < 0)
 946                 return log_link_error_errno(link, r, "Failed to get default router preference from RA: %m");
 947
 948         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
 949         if (r < 0)
 950                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
 951
 952         r = route_new(&route);
 953         if (r < 0)
 954                 return log_oom();
 955
 956         route->family = AF_INET6;
 957         route->pref = preference;
 958         route->gw.in6 = gateway;
 959         route->gw_family = AF_INET6;
 960         route->dst.in6 = dst;
 961         route->dst_prefixlen = prefixlen;
 962         route->lifetime = usec_add(time_now, lifetime * USEC_PER_SEC);
 963
 964         r = ndisc_request_route(TAKE_PTR(route), link, rt);
 965         if (r < 0)
 966                 return log_link_error_errno(link, r, "Could not request additional route: %m");
 967
 968         return 0;
 969 }
 970
 971 static void ndisc_rdnss_hash_func(const NDiscRDNSS *x, struct siphash *state) {
 972         siphash24_compress(&x->address, sizeof(x->address), state);
 973 }
 974
 975 static int ndisc_rdnss_compare_func(const NDiscRDNSS *a, const NDiscRDNSS *b) {
 976         return memcmp(&a->address, &b->address, sizeof(a->address));
 977 }
 978
 979 DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
 980                 ndisc_rdnss_hash_ops,
 981                 NDiscRDNSS,
 982                 ndisc_rdnss_hash_func,
 983                 ndisc_rdnss_compare_func,
 984                 free);
 985
 986 static int ndisc_router_process_rdnss(Link *link, sd_ndisc_router *rt) {
 987         uint32_t lifetime;
 988         const struct in6_addr *a;
 989         struct in6_addr router;
 990         NDiscRDNSS *rdnss;
 991         usec_t time_now;
 992         bool updated = false;
 993         int n, r;
 994
 995         assert(link);
 996         assert(rt);
 997
 998         r = sd_ndisc_router_get_address(rt, &router);
 999         if (r < 0)
1000                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
1001
1002         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
1003         if (r < 0)
1004                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
1005
1006         r = sd_ndisc_router_rdnss_get_lifetime(rt, &lifetime);
1007         if (r < 0)
1008                 return log_link_error_errno(link, r, "Failed to get RDNSS lifetime: %m");
1009
1010         n = sd_ndisc_router_rdnss_get_addresses(rt, &a);
1011         if (n < 0)
1012                 return log_link_error_errno(link, n, "Failed to get RDNSS addresses: %m");
1013
1014         SET_FOREACH(rdnss, link->ndisc_rdnss)
1015                 if (in6_addr_equal(&rdnss->router, &router))
1016                         rdnss->marked = true;
1017
1018         if (lifetime == 0)
1019                 return 0;
1020
1021         if (n >= (int) NDISC_RDNSS_MAX) {
1022                 log_link_warning(link, "Too many RDNSS records per link. Only first %i records will be used.", NDISC_RDNSS_MAX);
1023                 n = NDISC_RDNSS_MAX;
1024         }
1025
1026         for (int j = 0; j < n; j++) {
1027                 _cleanup_free_ NDiscRDNSS *x = NULL;
1028                 NDiscRDNSS d = {
1029                         .address = a[j],
1030                 };
1031
1032                 rdnss = set_get(link->ndisc_rdnss, &d);
1033                 if (rdnss) {
1034                         rdnss->marked = false;
1035                         rdnss->router = router;
1036                         rdnss->valid_until = usec_add(time_now, lifetime * USEC_PER_SEC);
1037                         continue;
1038                 }
1039
1040                 x = new(NDiscRDNSS, 1);
1041                 if (!x)
1042                         return log_oom();
1043
1044                 *x = (NDiscRDNSS) {
1045                         .address = a[j],
1046                         .router = router,
1047                         .valid_until = usec_add(time_now, lifetime * USEC_PER_SEC),
1048                 };
1049
1050                 r = set_ensure_consume(&link->ndisc_rdnss, &ndisc_rdnss_hash_ops, TAKE_PTR(x));
1051                 if (r < 0)
1052                         return log_oom();
1053                 assert(r > 0);
1054
1055                 updated = true;
1056         }
1057
1058         if (updated)
1059                 link_dirty(link);
1060
1061         return 0;
1062 }
1063
1064 static void ndisc_dnssl_hash_func(const NDiscDNSSL *x, struct siphash *state) {
1065         siphash24_compress_string(NDISC_DNSSL_DOMAIN(x), state);
1066 }
1067
1068 static int ndisc_dnssl_compare_func(const NDiscDNSSL *a, const NDiscDNSSL *b) {
1069         return strcmp(NDISC_DNSSL_DOMAIN(a), NDISC_DNSSL_DOMAIN(b));
1070 }
1071
1072 DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
1073                 ndisc_dnssl_hash_ops,
1074                 NDiscDNSSL,
1075                 ndisc_dnssl_hash_func,
1076                 ndisc_dnssl_compare_func,
1077                 free);
1078
1079 static int ndisc_router_process_dnssl(Link *link, sd_ndisc_router *rt) {
1080         _cleanup_strv_free_ char **l = NULL;
1081         struct in6_addr router;
1082         uint32_t lifetime;
1083         usec_t time_now;
1084         NDiscDNSSL *dnssl;
1085         bool updated = false;
1086         char **j;
1087         int r;
1088
1089         assert(link);
1090         assert(rt);
1091
1092         r = sd_ndisc_router_get_address(rt, &router);
1093         if (r < 0)
1094                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
1095
1096         r = sd_ndisc_router_get_timestamp(rt, clock_boottime_or_monotonic(), &time_now);
1097         if (r < 0)
1098                 return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
1099
1100         r = sd_ndisc_router_dnssl_get_lifetime(rt, &lifetime);
1101         if (r < 0)
1102                 return log_link_error_errno(link, r, "Failed to get DNSSL lifetime: %m");
1103
1104         r = sd_ndisc_router_dnssl_get_domains(rt, &l);
1105         if (r < 0)
1106                 return log_link_error_errno(link, r, "Failed to get DNSSL addresses: %m");
1107
1108         SET_FOREACH(dnssl, link->ndisc_dnssl)
1109                 if (in6_addr_equal(&dnssl->router, &router))
1110                         dnssl->marked = true;
1111
1112         if (lifetime == 0)
1113                 return 0;
1114
1115         if (strv_length(l) >= NDISC_DNSSL_MAX) {
1116                 log_link_warning(link, "Too many DNSSL records per link. Only first %i records will be used.", NDISC_DNSSL_MAX);
1117                 STRV_FOREACH(j, l + NDISC_DNSSL_MAX)
1118                         *j = mfree(*j);
1119         }
1120
1121         STRV_FOREACH(j, l) {
1122                 _cleanup_free_ NDiscDNSSL *s = NULL;
1123
1124                 s = malloc0(ALIGN(sizeof(NDiscDNSSL)) + strlen(*j) + 1);
1125                 if (!s)
1126                         return log_oom();
1127
1128                 strcpy(NDISC_DNSSL_DOMAIN(s), *j);
1129
1130                 dnssl = set_get(link->ndisc_dnssl, s);
1131                 if (dnssl) {
1132                         dnssl->marked = false;
1133                         dnssl->router = router;
1134                         dnssl->valid_until = usec_add(time_now, lifetime * USEC_PER_SEC);
1135                         continue;
1136                 }
1137
1138                 s->router = router;
1139                 s->valid_until = usec_add(time_now, lifetime * USEC_PER_SEC);
1140
1141                 r = set_ensure_consume(&link->ndisc_dnssl, &ndisc_dnssl_hash_ops, TAKE_PTR(s));
1142                 if (r < 0)
1143                         return log_oom();
1144                 assert(r > 0);
1145
1146                 updated = true;
1147         }
1148
1149         if (updated)
1150                 link_dirty(link);
1151
1152         return 0;
1153 }
1154
1155 static int ndisc_router_process_options(Link *link, sd_ndisc_router *rt) {
1156         assert(link);
1157         assert(link->network);
1158         assert(rt);
1159
1160         for (int r = sd_ndisc_router_option_rewind(rt); ; r = sd_ndisc_router_option_next(rt)) {
1161                 uint8_t type;
1162
1163                 if (r < 0)
1164                         return log_link_error_errno(link, r, "Failed to iterate through options: %m");
1165                 if (r == 0) /* EOF */
1166                         return 0;
1167
1168                 r = sd_ndisc_router_option_get_type(rt, &type);
1169                 if (r < 0)
1170                         return log_link_error_errno(link, r, "Failed to get RA option type: %m");
1171
1172                 switch (type) {
1173
1174                 case SD_NDISC_OPTION_PREFIX_INFORMATION: {
1175                         unsigned prefixlen;
1176                         struct in6_addr a;
1177                         uint8_t flags;
1178
1179                         r = sd_ndisc_router_prefix_get_address(rt, &a);
1180                         if (r < 0)
1181                                 return log_link_error_errno(link, r, "Failed to get prefix address: %m");
1182
1183                         r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
1184                         if (r < 0)
1185                                 return log_link_error_errno(link, r, "Failed to get prefix length: %m");
1186
1187                         if (in6_prefix_is_filtered(&a, prefixlen, link->network->ndisc_allow_listed_prefix, link->network->ndisc_deny_listed_prefix)) {
1188                                 if (DEBUG_LOGGING) {
1189                                         _cleanup_free_ char *b = NULL;
1190
1191                                         (void) in6_addr_prefix_to_string(&a, prefixlen, &b);
1192                                         if (!set_isempty(link->network->ndisc_allow_listed_prefix))
1193                                                 log_link_debug(link, "Prefix '%s' is not in allow list, ignoring", strna(b));
1194                                         else
1195                                                 log_link_debug(link, "Prefix '%s' is in deny list, ignoring", strna(b));
1196                                 }
1197                                 break;
1198                         }
1199
1200                         r = sd_ndisc_router_prefix_get_flags(rt, &flags);
1201                         if (r < 0)
1202                                 return log_link_error_errno(link, r, "Failed to get RA prefix flags: %m");
1203
1204                         if (link->network->ipv6_accept_ra_use_onlink_prefix &&
1205                             FLAGS_SET(flags, ND_OPT_PI_FLAG_ONLINK)) {
1206                                 r = ndisc_router_process_onlink_prefix(link, rt);
1207                                 if (r < 0)
1208                                         return r;
1209                         }
1210
1211                         if (link->network->ipv6_accept_ra_use_autonomous_prefix &&
1212                             FLAGS_SET(flags, ND_OPT_PI_FLAG_AUTO)) {
1213                                 r = ndisc_router_process_autonomous_prefix(link, rt);
1214                                 if (r < 0)
1215                                         return r;
1216                         }
1217                         break;
1218                 }
1219
1220                 case SD_NDISC_OPTION_ROUTE_INFORMATION:
1221                         r = ndisc_router_process_route(link, rt);
1222                         if (r < 0)
1223                                 return r;
1224                         break;
1225
1226                 case SD_NDISC_OPTION_RDNSS:
1227                         if (link->network->ipv6_accept_ra_use_dns) {
1228                                 r = ndisc_router_process_rdnss(link, rt);
1229                                 if (r < 0)
1230                                         return r;
1231                         }
1232                         break;
1233
1234                 case SD_NDISC_OPTION_DNSSL:
1235                         if (link->network->ipv6_accept_ra_use_dns) {
1236                                 r = ndisc_router_process_dnssl(link, rt);
1237                                 if (r < 0)
1238                                         return r;
1239                         }
1240                         break;
1241                 }
1242         }
1243 }
1244
1245 static int ndisc_router_handler(Link *link, sd_ndisc_router *rt) {
1246         struct in6_addr router;
1247         uint64_t flags;
1248         NDiscAddress *na;
1249         NDiscRoute *nr;
1250         int r;
1251
1252         assert(link);
1253         assert(link->network);
1254         assert(link->manager);
1255         assert(rt);
1256
1257         r = sd_ndisc_router_get_address(rt, &router);
1258         if (r < 0)
1259                 return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
1260
1261         if (in6_prefix_is_filtered(&router, 128, link->network->ndisc_allow_listed_router, link->network->ndisc_deny_listed_router)) {
1262                 if (DEBUG_LOGGING) {
1263                         _cleanup_free_ char *buf = NULL;
1264
1265                         (void) in6_addr_to_string(&router, &buf);
1266                         if (!set_isempty(link->network->ndisc_allow_listed_router))
1267                                 log_link_debug(link, "Router '%s' is not in allow list, ignoring", strna(buf));
1268                         else
1269                                 log_link_debug(link, "Router '%s' is in deny list, ignoring", strna(buf));
1270                 }
1271                 return 0;
1272         }
1273
1274         SET_FOREACH(na, link->ndisc_addresses)
1275                 if (in6_addr_equal(&na->router, &router))
1276                         na->marked = true;
1277
1278         SET_FOREACH(nr, link->ndisc_routes)
1279                 if (in6_addr_equal(&nr->router, &router))
1280                         nr->marked = true;
1281
1282         r = sd_ndisc_router_get_flags(rt, &flags);
1283         if (r < 0)
1284                 return log_link_error_errno(link, r, "Failed to get RA flags: %m");
1285
1286         if ((flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER) &&
1287              link->network->ipv6_accept_ra_start_dhcp6_client != IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO) ||
1288             link->network->ipv6_accept_ra_start_dhcp6_client == IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS) {
1289
1290                 if (flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER))
1291                         /* (re)start DHCPv6 client in stateful or stateless mode according to RA flags */
1292                         r = dhcp6_request_information(link, !(flags & ND_RA_FLAG_MANAGED));
1293                 else
1294                         /* When IPv6AcceptRA.DHCPv6Client=always, start dhcp6 client in managed mode
1295                          * even if router does not have M or O flag. */
1296                         r = dhcp6_request_information(link, false);
1297                 if (r < 0 && r != -EBUSY)
1298                         return log_link_error_errno(link, r, "Could not acquire DHCPv6 lease on NDisc request: %m");
1299                 else
1300                         log_link_debug(link, "Acquiring DHCPv6 lease on NDisc request");
1301         }
1302
1303         r = ndisc_router_process_default(link, rt);
1304         if (r < 0)
1305                 return r;
1306         r = ndisc_router_process_options(link, rt);
1307         if (r < 0)
1308                 return r;
1309
1310         if (link->ndisc_addresses_messages == 0)
1311                 link->ndisc_addresses_configured = true;
1312         else
1313                 log_link_debug(link, "Setting SLAAC addresses.");
1314
1315         if (link->ndisc_routes_messages == 0)
1316                 link->ndisc_routes_configured = true;
1317         else
1318                 log_link_debug(link, "Setting NDisc routes.");
1319
1320         r = ndisc_remove_old(link);
1321         if (r < 0)
1322                 return r;
1323
1324         if (!link->ndisc_addresses_configured || !link->ndisc_routes_configured)
1325                 link_set_state(link, LINK_STATE_CONFIGURING);
1326
1327         link_check_ready(link);
1328         return 0;
1329 }
1330
1331 static void ndisc_handler(sd_ndisc *nd, sd_ndisc_event_t event, sd_ndisc_router *rt, void *userdata) {
1332         Link *link = userdata;
1333         int r;
1334
1335         assert(link);
1336
1337         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
1338                 return;
1339
1340         switch (event) {
1341
1342         case SD_NDISC_EVENT_ROUTER:
1343                 r = ndisc_router_handler(link, rt);
1344                 if (r < 0) {
1345                         link_enter_failed(link);
1346                         return;
1347                 }
1348                 break;
1349
1350         case SD_NDISC_EVENT_TIMEOUT:
1351                 log_link_debug(link, "NDisc handler get timeout event");
1352                 if (link->ndisc_addresses_messages == 0 && link->ndisc_routes_messages == 0) {
1353                         link->ndisc_addresses_configured = true;
1354                         link->ndisc_routes_configured = true;
1355                         link_check_ready(link);
1356                 }
1357                 break;
1358         default:
1359                 assert_not_reached();
1360         }
1361 }
1362
1363 int ndisc_configure(Link *link) {
1364         int r;
1365
1366         assert(link);
1367
1368         if (!link_ipv6_accept_ra_enabled(link))
1369                 return 0;
1370
1371         if (link->ndisc)
1372                 return -EBUSY; /* Already configured. */
1373
1374         r = sd_ndisc_new(&link->ndisc);
1375         if (r < 0)
1376                 return r;
1377
1378         r = sd_ndisc_attach_event(link->ndisc, link->manager->event, 0);
1379         if (r < 0)
1380                 return r;
1381
1382         r = sd_ndisc_set_mac(link->ndisc, &link->hw_addr.ether);
1383         if (r < 0)
1384                 return r;
1385
1386         r = sd_ndisc_set_ifindex(link->ndisc, link->ifindex);
1387         if (r < 0)
1388                 return r;
1389
1390         r = sd_ndisc_set_callback(link->ndisc, ndisc_handler, link);
1391         if (r < 0)
1392                 return r;
1393
1394         return 0;
1395 }
1396
1397 int ndisc_start(Link *link) {
1398         assert(link);
1399
1400         if (!link->ndisc || !link->dhcp6_client)
1401                 return 0;
1402
1403         if (!link_has_carrier(link))
1404                 return 0;
1405
1406         log_link_debug(link, "Discovering IPv6 routers");
1407
1408         return sd_ndisc_start(link->ndisc);
1409 }
1410
1411 void ndisc_vacuum(Link *link) {
1412         NDiscRDNSS *r;
1413         NDiscDNSSL *d;
1414         usec_t time_now;
1415
1416         assert(link);
1417
1418         /* Removes all RDNSS and DNSSL entries whose validity time has passed */
1419
1420         time_now = now(clock_boottime_or_monotonic());
1421
1422         SET_FOREACH(r, link->ndisc_rdnss)
1423                 if (r->valid_until < time_now)
1424                         free(set_remove(link->ndisc_rdnss, r));
1425
1426         SET_FOREACH(d, link->ndisc_dnssl)
1427                 if (d->valid_until < time_now)
1428                         free(set_remove(link->ndisc_dnssl, d));
1429 }
1430
1431 void ndisc_flush(Link *link) {
1432         assert(link);
1433
1434         /* Removes all RDNSS and DNSSL entries, without exception */
1435
1436         link->ndisc_rdnss = set_free(link->ndisc_rdnss);
1437         link->ndisc_dnssl = set_free(link->ndisc_dnssl);
1438 }
1439
1440 static int ipv6token_new(IPv6Token **ret) {
1441         IPv6Token *p;
1442
1443         p = new(IPv6Token, 1);
1444         if (!p)
1445                 return -ENOMEM;
1446
1447         *p = (IPv6Token) {
1448                  .address_generation_type = IPV6_TOKEN_ADDRESS_GENERATION_NONE,
1449         };
1450
1451         *ret = TAKE_PTR(p);
1452
1453         return 0;
1454 }
1455
1456 static void ipv6_token_hash_func(const IPv6Token *p, struct siphash *state) {
1457         siphash24_compress(&p->address_generation_type, sizeof(p->address_generation_type), state);
1458         siphash24_compress(&p->prefix, sizeof(p->prefix), state);
1459 }
1460
1461 static int ipv6_token_compare_func(const IPv6Token *a, const IPv6Token *b) {
1462         int r;
1463
1464         r = CMP(a->address_generation_type, b->address_generation_type);
1465         if (r != 0)
1466                 return r;
1467
1468         return memcmp(&a->prefix, &b->prefix, sizeof(struct in6_addr));
1469 }
1470
1471 DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(
1472                 ipv6_token_hash_ops,
1473                 IPv6Token,
1474                 ipv6_token_hash_func,
1475                 ipv6_token_compare_func,
1476                 free);
1477
1478 int config_parse_address_generation_type(
1479                 const char *unit,
1480                 const char *filename,
1481                 unsigned line,
1482                 const char *section,
1483                 unsigned section_line,
1484                 const char *lvalue,
1485                 int ltype,
1486                 const char *rvalue,
1487                 void *data,
1488                 void *userdata) {
1489
1490         _cleanup_free_ IPv6Token *token = NULL;
1491         union in_addr_union buffer;
1492         Network *network = data;
1493         const char *p;
1494         int r;
1495
1496         assert(filename);
1497         assert(lvalue);
1498         assert(rvalue);
1499         assert(data);
1500
1501         if (isempty(rvalue)) {
1502                 network->ipv6_tokens = ordered_set_free(network->ipv6_tokens);
1503                 return 0;
1504         }
1505
1506         r = ipv6token_new(&token);
1507         if (r < 0)
1508                 return log_oom();
1509
1510         if ((p = startswith(rvalue, "prefixstable"))) {
1511                 token->address_generation_type = IPV6_TOKEN_ADDRESS_GENERATION_PREFIXSTABLE;
1512                 if (*p == ':')
1513                         p++;
1514                 else if (*p == '\0')
1515                         p = NULL;
1516                 else {
1517                         log_syntax(unit, LOG_WARNING, filename, line, 0,
1518                                    "Invalid IPv6 token mode in %s=, ignoring assignment: %s",
1519                                    lvalue, rvalue);
1520                         return 0;
1521                 }
1522         } else {
1523                 token->address_generation_type = IPV6_TOKEN_ADDRESS_GENERATION_STATIC;
1524                 p = startswith(rvalue, "static:");
1525                 if (!p)
1526                         p = rvalue;
1527         }
1528
1529         if (p) {
1530                 r = in_addr_from_string(AF_INET6, p, &buffer);
1531                 if (r < 0) {
1532                         log_syntax(unit, LOG_WARNING, filename, line, r,
1533                                    "Failed to parse IP address in %s=, ignoring assignment: %s",
1534                                    lvalue, rvalue);
1535                         return 0;
1536                 }
1537                 if (token->address_generation_type == IPV6_TOKEN_ADDRESS_GENERATION_STATIC &&
1538                     in_addr_is_null(AF_INET6, &buffer)) {
1539                         log_syntax(unit, LOG_WARNING, filename, line, 0,
1540                                    "IPv6 address in %s= cannot be the ANY address, ignoring assignment: %s",
1541                                    lvalue, rvalue);
1542                         return 0;
1543                 }
1544                 token->prefix = buffer.in6;
1545         }
1546
1547         r = ordered_set_ensure_put(&network->ipv6_tokens, &ipv6_token_hash_ops, token);
1548         if (r == -ENOMEM)
1549                 return log_oom();
1550         if (r == -EEXIST)
1551                 log_syntax(unit, LOG_DEBUG, filename, line, r,
1552                            "IPv6 token '%s' is duplicated, ignoring: %m", rvalue);
1553         else if (r < 0)
1554                 log_syntax(unit, LOG_WARNING, filename, line, r,
1555                            "Failed to store IPv6 token '%s', ignoring: %m", rvalue);
1556         else
1557                 TAKE_PTR(token);
1558
1559         return 0;
1560 }
1561
1562 DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_use_domains, dhcp_use_domains, DHCPUseDomains,
1563                          "Failed to parse UseDomains= setting");
1564 DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_start_dhcp6_client, ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client,
1565                          "Failed to parse DHCPv6Client= setting");
1566 static const char* const ipv6_accept_ra_start_dhcp6_client_table[_IPV6_ACCEPT_RA_START_DHCP6_CLIENT_MAX] = {
1567         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO]     = "no",
1568         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS] = "always",
1569         [IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES]    = "yes",
1570 };
1571
1572 DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client, IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES);