src/libsystemd-network/sd-radv.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 /***
   3   Copyright © 2017 Intel Corporation. All rights reserved.
   4 ***/
   5
   6 #include <netinet/icmp6.h>
   7 #include <netinet/in.h>
   8 #include <arpa/inet.h>
   9
  10 #include "sd-radv.h"
  11
  12 #include "alloc-util.h"
  13 #include "dns-domain.h"
  14 #include "ether-addr-util.h"
  15 #include "event-util.h"
  16 #include "fd-util.h"
  17 #include "icmp6-util.h"
  18 #include "in-addr-util.h"
  19 #include "iovec-util.h"
  20 #include "macro.h"
  21 #include "memory-util.h"
  22 #include "ndisc-router-solicit-internal.h"
  23 #include "network-common.h"
  24 #include "radv-internal.h"
  25 #include "random-util.h"
  26 #include "socket-util.h"
  27 #include "string-util.h"
  28 #include "strv.h"
  29 #include "unaligned.h"
  30
  31 int sd_radv_new(sd_radv **ret) {
  32         _cleanup_(sd_radv_unrefp) sd_radv *ra = NULL;
  33
  34         assert_return(ret, -EINVAL);
  35
  36         ra = new(sd_radv, 1);
  37         if (!ra)
  38                 return -ENOMEM;
  39
  40         *ra = (sd_radv) {
  41                 .n_ref = 1,
  42                 .fd = -EBADF,
  43                 .lifetime_usec = RADV_DEFAULT_ROUTER_LIFETIME_USEC,
  44         };
  45
  46         *ret = TAKE_PTR(ra);
  47
  48         return 0;
  49 }
  50
  51 int sd_radv_attach_event(sd_radv *ra, sd_event *event, int64_t priority) {
  52         int r;
  53
  54         assert_return(ra, -EINVAL);
  55         assert_return(!ra->event, -EBUSY);
  56
  57         if (event)
  58                 ra->event = sd_event_ref(event);
  59         else {
  60                 r = sd_event_default(&ra->event);
  61                 if (r < 0)
  62                         return 0;
  63         }
  64
  65         ra->event_priority = priority;
  66
  67         return 0;
  68 }
  69
  70 int sd_radv_detach_event(sd_radv *ra) {
  71
  72         assert_return(ra, -EINVAL);
  73
  74         ra->event = sd_event_unref(ra->event);
  75         return 0;
  76 }
  77
  78 sd_event *sd_radv_get_event(sd_radv *ra) {
  79         assert_return(ra, NULL);
  80
  81         return ra->event;
  82 }
  83
  84 int sd_radv_is_running(sd_radv *ra) {
  85         if (!ra)
  86                 return false;
  87
  88         return ra->state != RADV_STATE_IDLE;
  89 }
  90
  91 static void radv_reset(sd_radv *ra) {
  92         assert(ra);
  93
  94         (void) event_source_disable(ra->timeout_event_source);
  95
  96         ra->recv_event_source = sd_event_source_disable_unref(ra->recv_event_source);
  97
  98         ra->ra_sent = 0;
  99 }
 100
 101 static sd_radv *radv_free(sd_radv *ra) {
 102         if (!ra)
 103                 return NULL;
 104
 105         LIST_CLEAR(prefix, ra->prefixes, sd_radv_prefix_unref);
 106         LIST_CLEAR(prefix, ra->route_prefixes, sd_radv_route_prefix_unref);
 107         LIST_CLEAR(prefix, ra->pref64_prefixes, sd_radv_pref64_prefix_unref);
 108
 109         free(ra->rdnss);
 110         free(ra->dnssl);
 111
 112         radv_reset(ra);
 113
 114         sd_event_source_unref(ra->timeout_event_source);
 115         sd_radv_detach_event(ra);
 116
 117         ra->fd = safe_close(ra->fd);
 118         free(ra->ifname);
 119
 120         return mfree(ra);
 121 }
 122
 123 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv, sd_radv, radv_free);
 124
 125 static bool router_lifetime_is_valid(usec_t lifetime_usec) {
 126         assert_cc(RADV_MAX_ROUTER_LIFETIME_USEC <= UINT16_MAX * USEC_PER_SEC);
 127         return lifetime_usec == 0 ||
 128                 (lifetime_usec >= RADV_MIN_ROUTER_LIFETIME_USEC &&
 129                  lifetime_usec <= RADV_MAX_ROUTER_LIFETIME_USEC);
 130 }
 131
 132 static int radv_send_router_on_stop(sd_radv *ra) {
 133         static const struct nd_router_advert adv = {
 134                 .nd_ra_type = ND_ROUTER_ADVERT,
 135         };
 136
 137         _cleanup_set_free_ Set *options = NULL;
 138         usec_t time_now;
 139         int r;
 140
 141         assert(ra);
 142
 143         r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
 144         if (r < 0)
 145                 return r;
 146
 147         if (!ether_addr_is_null(&ra->mac_addr)) {
 148                 r = ndisc_option_set_link_layer_address(&options, SD_NDISC_OPTION_SOURCE_LL_ADDRESS, &ra->mac_addr);
 149                 if (r < 0)
 150                         return r;
 151         }
 152
 153         return ndisc_send(ra->fd, &IN6_ADDR_ALL_NODES_MULTICAST, &adv.nd_ra_hdr, options, time_now);
 154 }
 155
 156 static int radv_send_router(sd_radv *ra, const struct in6_addr *dst) {
 157         assert(ra);
 158
 159         struct sockaddr_in6 dst_addr = {
 160                 .sin6_family = AF_INET6,
 161                 .sin6_addr = IN6_ADDR_ALL_NODES_MULTICAST,
 162         };
 163         struct nd_router_advert adv = {
 164                 .nd_ra_type = ND_ROUTER_ADVERT,
 165                 .nd_ra_router_lifetime = usec_to_be16_sec(ra->lifetime_usec),
 166                 .nd_ra_reachable = usec_to_be32_msec(ra->reachable_usec),
 167                 .nd_ra_retransmit = usec_to_be32_msec(ra->retransmit_usec),
 168         };
 169         struct {
 170                 struct nd_opt_hdr opthdr;
 171                 struct ether_addr slladdr;
 172         } _packed_ opt_mac = {
 173                 .opthdr = {
 174                         .nd_opt_type = ND_OPT_SOURCE_LINKADDR,
 175                         .nd_opt_len = DIV_ROUND_UP(sizeof(struct nd_opt_hdr) + sizeof(struct ether_addr), 8),
 176                 },
 177                 .slladdr = ra->mac_addr,
 178         };
 179         struct nd_opt_mtu opt_mtu =  {
 180                 .nd_opt_mtu_type = ND_OPT_MTU,
 181                 .nd_opt_mtu_len = 1,
 182                 .nd_opt_mtu_mtu = htobe32(ra->mtu),
 183         };
 184         /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, N routes, N pref64 prefixes, RDNSS,
 185          * DNSSL, and home agent. */
 186         struct iovec iov[6 + ra->n_prefixes + ra->n_route_prefixes + ra->n_pref64_prefixes];
 187         struct msghdr msg = {
 188                 .msg_name = &dst_addr,
 189                 .msg_namelen = sizeof(dst_addr),
 190                 .msg_iov = iov,
 191         };
 192         usec_t time_now;
 193         int r;
 194
 195         r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
 196         if (r < 0)
 197                 return r;
 198
 199         if (dst && in6_addr_is_set(dst))
 200                 dst_addr.sin6_addr = *dst;
 201
 202         /* The nd_ra_curhoplimit and nd_ra_flags_reserved fields cannot specified with nd_ra_router_lifetime
 203          * simultaneously in the structured initializer in the above. */
 204         adv.nd_ra_curhoplimit = ra->hop_limit;
 205         /* RFC 4191, Section 2.2,
 206          * "...If the Router Lifetime is zero, the preference value MUST be set to (00) by the sender..." */
 207         adv.nd_ra_flags_reserved = ra->flags | (ra->lifetime_usec > 0 ? (ra->preference << 3) : 0);
 208         iov[msg.msg_iovlen++] = IOVEC_MAKE(&adv, sizeof(adv));
 209
 210         /* MAC address is optional, either because the link does not use L2 addresses or load sharing is
 211          * desired. See RFC 4861, Section 4.2. */
 212         if (!ether_addr_is_null(&ra->mac_addr))
 213                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mac, sizeof(opt_mac));
 214
 215         if (ra->mtu > 0)
 216                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mtu, sizeof(opt_mtu));
 217
 218         LIST_FOREACH(prefix, p, ra->prefixes) {
 219                 usec_t lifetime_valid_usec, lifetime_preferred_usec;
 220
 221                 lifetime_valid_usec = MIN(usec_sub_unsigned(p->valid_until, time_now),
 222                                           p->lifetime_valid_usec);
 223
 224                 lifetime_preferred_usec = MIN3(usec_sub_unsigned(p->preferred_until, time_now),
 225                                                p->lifetime_preferred_usec,
 226                                                lifetime_valid_usec);
 227
 228                 p->opt.lifetime_valid = usec_to_be32_sec(lifetime_valid_usec);
 229                 p->opt.lifetime_preferred = usec_to_be32_sec(lifetime_preferred_usec);
 230
 231                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&p->opt, sizeof(p->opt));
 232         }
 233
 234         LIST_FOREACH(prefix, rt, ra->route_prefixes) {
 235                 rt->opt.lifetime = usec_to_be32_sec(MIN(usec_sub_unsigned(rt->valid_until, time_now),
 236                                                         rt->lifetime_usec));
 237
 238                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&rt->opt, sizeof(rt->opt));
 239         }
 240
 241         LIST_FOREACH(prefix, p, ra->pref64_prefixes)
 242                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&p->opt, sizeof(p->opt));
 243
 244         if (ra->rdnss)
 245                 iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->rdnss, ra->rdnss->length * 8);
 246
 247         if (ra->dnssl)
 248                 iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->dnssl, ra->dnssl->length * 8);
 249
 250         if (FLAGS_SET(ra->flags, ND_RA_FLAG_HOME_AGENT)) {
 251                 ra->home_agent.nd_opt_home_agent_info_type = ND_OPT_HOME_AGENT_INFO;
 252                 ra->home_agent.nd_opt_home_agent_info_len = 1;
 253
 254                 /* 0 means to place the current Router Lifetime value */
 255                 if (ra->home_agent.nd_opt_home_agent_info_lifetime == 0)
 256                         ra->home_agent.nd_opt_home_agent_info_lifetime = adv.nd_ra_router_lifetime;
 257
 258                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&ra->home_agent, sizeof(ra->home_agent));
 259         }
 260
 261         if (sendmsg(ra->fd, &msg, 0) < 0)
 262                 return -errno;
 263
 264         return 0;
 265 }
 266
 267 static int radv_process_packet(sd_radv *ra, ICMP6Packet *packet) {
 268         int r;
 269
 270         assert(ra);
 271         assert(packet);
 272
 273         if (icmp6_packet_get_type(packet) != ND_ROUTER_SOLICIT)
 274                 return log_radv_errno(ra, SYNTHETIC_ERRNO(EBADMSG), "Received ICMP6 packet with unexpected type, ignoring.");
 275
 276         _cleanup_(sd_ndisc_router_solicit_unrefp) sd_ndisc_router_solicit *rs = NULL;
 277         rs = ndisc_router_solicit_new(packet);
 278         if (!rs)
 279                 return log_oom_debug();
 280
 281         r = ndisc_router_solicit_parse(ra, rs);
 282         if (r < 0)
 283                 return r;
 284
 285         struct in6_addr src;
 286         r = sd_ndisc_router_solicit_get_sender_address(rs, &src);
 287         if (r == -ENODATA) /* null address is allowed */
 288                 return sd_radv_send(ra); /* When an unsolicited RA, we need to also update timer. */
 289         if (r < 0)
 290                 return log_radv_errno(ra, r, "Failed to get sender address of RS, ignoring: %m");
 291         if (in6_addr_equal(&src, &ra->ipv6ll))
 292                 /* This should be definitely caused by a misconfiguration. If we send RA to ourself, the
 293                  * kernel complains about that. Let's ignore the packet. */
 294                 return log_radv_errno(ra, SYNTHETIC_ERRNO(EADDRINUSE), "Received RS from the same interface, ignoring.");
 295
 296         r = radv_send_router(ra, &src);
 297         if (r < 0)
 298                 return log_radv_errno(ra, r, "Unable to send solicited Router Advertisement to %s, ignoring: %m", IN6_ADDR_TO_STRING(&src));
 299
 300         log_radv(ra, "Sent solicited Router Advertisement to %s.", IN6_ADDR_TO_STRING(&src));
 301         return 0;
 302 }
 303
 304 static int radv_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 305         _cleanup_(icmp6_packet_unrefp) ICMP6Packet *packet = NULL;
 306         sd_radv *ra = ASSERT_PTR(userdata);
 307         int r;
 308
 309         assert(fd >= 0);
 310
 311         r = icmp6_packet_receive(fd, &packet);
 312         if (r < 0) {
 313                 log_radv_errno(ra, r, "Failed to receive ICMPv6 packet, ignoring: %m");
 314                 return 0;
 315         }
 316
 317         (void) radv_process_packet(ra, packet);
 318         return 0;
 319 }
 320
 321 static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
 322         sd_radv *ra = ASSERT_PTR(userdata);
 323
 324         if (sd_radv_send(ra) < 0)
 325                 (void) sd_radv_stop(ra);
 326
 327         return 0;
 328 }
 329
 330 int sd_radv_send(sd_radv *ra) {
 331         usec_t min_timeout, max_timeout, time_now, timeout;
 332         int r;
 333
 334         assert_return(ra, -EINVAL);
 335         assert_return(ra->event, -EINVAL);
 336         assert_return(sd_radv_is_running(ra), -EINVAL);
 337         assert(router_lifetime_is_valid(ra->lifetime_usec));
 338
 339         r = sd_event_now(ra->event, CLOCK_BOOTTIME, &time_now);
 340         if (r < 0)
 341                 return r;
 342
 343         r = radv_send_router(ra, NULL);
 344         if (r < 0)
 345                 return log_radv_errno(ra, r, "Unable to send Router Advertisement: %m");
 346
 347         ra->ra_sent++;
 348
 349         /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
 350         if (ra->ra_sent <= RADV_MAX_INITIAL_RTR_ADVERTISEMENTS)
 351                 max_timeout = RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
 352         else
 353                 max_timeout = RADV_DEFAULT_MAX_TIMEOUT_USEC;
 354
 355         /* RFC 4861, Section 6.2.1, lifetime must be at least MaxRtrAdvInterval,
 356          * so lower the interval here */
 357         if (ra->lifetime_usec > 0)
 358                 max_timeout = MIN(max_timeout, ra->lifetime_usec);
 359
 360         if (max_timeout >= 9 * USEC_PER_SEC)
 361                 min_timeout = max_timeout / 3;
 362         else
 363                 min_timeout = max_timeout * 3 / 4;
 364
 365         /* RFC 4861, Section 6.2.1.
 366          * MaxRtrAdvInterval MUST be no less than 4 seconds and no greater than 1800 seconds.
 367          * MinRtrAdvInterval MUST be no less than 3 seconds and no greater than .75 * MaxRtrAdvInterval. */
 368         assert(max_timeout >= RADV_MIN_MAX_TIMEOUT_USEC);
 369         assert(max_timeout <= RADV_MAX_MAX_TIMEOUT_USEC);
 370         assert(min_timeout >= RADV_MIN_MIN_TIMEOUT_USEC);
 371         assert(min_timeout <= max_timeout * 3 / 4);
 372
 373         timeout = min_timeout + random_u64_range(max_timeout - min_timeout);
 374         log_radv(ra, "Sent unsolicited Router Advertisement. Next advertisement will be in %s.",
 375                  FORMAT_TIMESPAN(timeout, USEC_PER_SEC));
 376
 377         return event_reset_time(
 378                         ra->event, &ra->timeout_event_source,
 379                         CLOCK_BOOTTIME,
 380                         usec_add(time_now, timeout), MSEC_PER_SEC,
 381                         radv_timeout, ra,
 382                         ra->event_priority, "radv-timeout", true);
 383 }
 384
 385 int sd_radv_stop(sd_radv *ra) {
 386         int r;
 387
 388         if (!sd_radv_is_running(ra))
 389                 return 0; /* Already stopped. */
 390
 391         log_radv(ra, "Stopping IPv6 Router Advertisement daemon");
 392
 393         /* RFC 4861, Section 6.2.5:
 394          * the router SHOULD transmit one or more (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
 395          * multicast Router Advertisements on the interface with a Router Lifetime field of zero. */
 396         r = radv_send_router_on_stop(ra);
 397         if (r < 0)
 398                 log_radv_errno(ra, r, "Unable to send last Router Advertisement with router lifetime set to zero, ignoring: %m");
 399
 400         radv_reset(ra);
 401         ra->fd = safe_close(ra->fd);
 402         ra->state = RADV_STATE_IDLE;
 403
 404         return 0;
 405 }
 406
 407 static int radv_setup_recv_event(sd_radv *ra) {
 408         int r;
 409
 410         assert(ra);
 411         assert(ra->event);
 412         assert(ra->ifindex > 0);
 413
 414         _cleanup_close_ int fd = -EBADF;
 415         fd = icmp6_bind(ra->ifindex, /* is_router = */ true);
 416         if (fd < 0)
 417                 return fd;
 418
 419         _cleanup_(sd_event_source_unrefp) sd_event_source *s = NULL;
 420         r = sd_event_add_io(ra->event, &s, fd, EPOLLIN, radv_recv, ra);
 421         if (r < 0)
 422                 return r;
 423
 424         r = sd_event_source_set_priority(s, ra->event_priority);
 425         if (r < 0)
 426                 return r;
 427
 428         (void) sd_event_source_set_description(s, "radv-receive-message");
 429
 430         ra->fd = TAKE_FD(fd);
 431         ra->recv_event_source = TAKE_PTR(s);
 432         return 0;
 433 }
 434
 435 int sd_radv_start(sd_radv *ra) {
 436         int r;
 437
 438         assert_return(ra, -EINVAL);
 439         assert_return(ra->event, -EINVAL);
 440         assert_return(ra->ifindex > 0, -EINVAL);
 441
 442         if (sd_radv_is_running(ra))
 443                 return 0; /* Already started. */
 444
 445         r = radv_setup_recv_event(ra);
 446         if (r < 0)
 447                 goto fail;
 448
 449         r = event_reset_time(ra->event, &ra->timeout_event_source,
 450                              CLOCK_BOOTTIME,
 451                              0, 0,
 452                              radv_timeout, ra,
 453                              ra->event_priority, "radv-timeout", true);
 454         if (r < 0)
 455                 goto fail;
 456
 457         ra->state = RADV_STATE_ADVERTISING;
 458
 459         log_radv(ra, "Started IPv6 Router Advertisement daemon");
 460
 461         return 0;
 462
 463  fail:
 464         radv_reset(ra);
 465
 466         return r;
 467 }
 468
 469 int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
 470         assert_return(ra, -EINVAL);
 471         assert_return(!sd_radv_is_running(ra), -EBUSY);
 472         assert_return(ifindex > 0, -EINVAL);
 473
 474         ra->ifindex = ifindex;
 475         return 0;
 476 }
 477
 478 int sd_radv_set_ifname(sd_radv *ra, const char *ifname) {
 479         assert_return(ra, -EINVAL);
 480         assert_return(ifname, -EINVAL);
 481
 482         if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE))
 483                 return -EINVAL;
 484
 485         return free_and_strdup(&ra->ifname, ifname);
 486 }
 487
 488 int sd_radv_get_ifname(sd_radv *ra, const char **ret) {
 489         int r;
 490
 491         assert_return(ra, -EINVAL);
 492
 493         r = get_ifname(ra->ifindex, &ra->ifname);
 494         if (r < 0)
 495                 return r;
 496
 497         if (ret)
 498                 *ret = ra->ifname;
 499
 500         return 0;
 501 }
 502
 503 int sd_radv_set_link_local_address(sd_radv *ra, const struct in6_addr *addr) {
 504         assert_return(ra, -EINVAL);
 505         assert_return(!addr || in6_addr_is_link_local(addr), -EINVAL);
 506
 507         if (addr)
 508                 ra->ipv6ll = *addr;
 509         else
 510                 zero(ra->ipv6ll);
 511
 512         return 0;
 513 }
 514
 515 int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
 516         assert_return(ra, -EINVAL);
 517
 518         if (mac_addr)
 519                 ra->mac_addr = *mac_addr;
 520         else
 521                 zero(ra->mac_addr);
 522
 523         return 0;
 524 }
 525
 526 int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
 527         assert_return(ra, -EINVAL);
 528         assert_return(mtu >= 1280, -EINVAL);
 529
 530         ra->mtu = mtu;
 531
 532         return 0;
 533 }
 534
 535 int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
 536         assert_return(ra, -EINVAL);
 537
 538         ra->hop_limit = hop_limit;
 539         return 0;
 540 }
 541
 542 int sd_radv_set_reachable_time(sd_radv *ra, uint64_t usec) {
 543         assert_return(ra, -EINVAL);
 544
 545         ra->reachable_usec = usec;
 546         return 0;
 547 }
 548
 549 int sd_radv_set_retransmit(sd_radv *ra, uint64_t usec) {
 550         assert_return(ra, -EINVAL);
 551
 552         ra->retransmit_usec = usec;
 553         return 0;
 554 }
 555
 556 int sd_radv_set_router_lifetime(sd_radv *ra, uint64_t usec) {
 557         assert_return(ra, -EINVAL);
 558
 559         if (!router_lifetime_is_valid(usec))
 560                 return -EINVAL;
 561
 562         ra->lifetime_usec = usec;
 563         return 0;
 564 }
 565
 566 int sd_radv_set_managed_information(sd_radv *ra, int b) {
 567         assert_return(ra, -EINVAL);
 568
 569         SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, b);
 570         return 0;
 571 }
 572
 573 int sd_radv_set_other_information(sd_radv *ra, int b) {
 574         assert_return(ra, -EINVAL);
 575
 576         SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, b);
 577         return 0;
 578 }
 579
 580 int sd_radv_set_preference(sd_radv *ra, uint8_t preference) {
 581         assert_return(ra, -EINVAL);
 582         assert_return(IN_SET(preference,
 583                              SD_NDISC_PREFERENCE_LOW,
 584                              SD_NDISC_PREFERENCE_MEDIUM,
 585                              SD_NDISC_PREFERENCE_HIGH), -EINVAL);
 586
 587         ra->preference = preference;
 588         return 0;
 589 }
 590
 591 int sd_radv_set_home_agent_information(sd_radv *ra, int home_agent) {
 592         assert_return(ra, -EINVAL);
 593
 594         SET_FLAG(ra->flags, ND_RA_FLAG_HOME_AGENT, home_agent);
 595         return 0;
 596 }
 597
 598 int sd_radv_set_home_agent_preference(sd_radv *ra, uint16_t preference) {
 599         assert_return(ra, -EINVAL);
 600
 601         ra->home_agent.nd_opt_home_agent_info_preference = htobe16(preference);
 602         return 0;
 603 }
 604
 605 int sd_radv_set_home_agent_lifetime(sd_radv *ra, uint64_t lifetime_usec) {
 606         assert_return(ra, -EINVAL);
 607
 608         if (lifetime_usec > RADV_HOME_AGENT_MAX_LIFETIME_USEC)
 609                 return -EINVAL;
 610
 611         ra->home_agent.nd_opt_home_agent_info_lifetime = usec_to_be16_sec(lifetime_usec);
 612         return 0;
 613 }
 614
 615 int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p) {
 616         sd_radv_prefix *found = NULL;
 617         int r;
 618
 619         assert_return(ra, -EINVAL);
 620         assert_return(p, -EINVAL);
 621
 622         /* Refuse prefixes that don't have a prefix set */
 623         if (in6_addr_is_null(&p->opt.in6_addr))
 624                 return -ENOEXEC;
 625
 626         const char *addr_p = IN6_ADDR_PREFIX_TO_STRING(&p->opt.in6_addr, p->opt.prefixlen);
 627
 628         LIST_FOREACH(prefix, cur, ra->prefixes) {
 629                 r = in_addr_prefix_intersect(AF_INET6,
 630                                              (const union in_addr_union*) &cur->opt.in6_addr,
 631                                              cur->opt.prefixlen,
 632                                              (const union in_addr_union*) &p->opt.in6_addr,
 633                                              p->opt.prefixlen);
 634                 if (r < 0)
 635                         return r;
 636                 if (r == 0)
 637                         continue;
 638
 639                 if (cur->opt.prefixlen == p->opt.prefixlen) {
 640                         found = cur;
 641                         break;
 642                 }
 643
 644                 return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
 645                                       "IPv6 prefix %s conflicts with %s, ignoring.",
 646                                       addr_p,
 647                                       IN6_ADDR_PREFIX_TO_STRING(&cur->opt.in6_addr, cur->opt.prefixlen));
 648         }
 649
 650         if (found) {
 651                 /* p and cur may be equivalent. First increment the reference counter. */
 652                 sd_radv_prefix_ref(p);
 653
 654                 /* Then, remove the old entry. */
 655                 LIST_REMOVE(prefix, ra->prefixes, found);
 656                 sd_radv_prefix_unref(found);
 657
 658                 /* Finally, add the new entry. */
 659                 LIST_APPEND(prefix, ra->prefixes, p);
 660
 661                 log_radv(ra, "Updated/replaced IPv6 prefix %s (preferred: %s, valid: %s)",
 662                          addr_p,
 663                          FORMAT_TIMESPAN(p->lifetime_preferred_usec, USEC_PER_SEC),
 664                          FORMAT_TIMESPAN(p->lifetime_valid_usec, USEC_PER_SEC));
 665         } else {
 666                 /* The prefix is new. Let's simply add it. */
 667
 668                 sd_radv_prefix_ref(p);
 669                 LIST_APPEND(prefix, ra->prefixes, p);
 670                 ra->n_prefixes++;
 671
 672                 log_radv(ra, "Added prefix %s", addr_p);
 673         }
 674
 675         return 0;
 676 }
 677
 678 void sd_radv_remove_prefix(
 679                 sd_radv *ra,
 680                 const struct in6_addr *prefix,
 681                 unsigned char prefixlen) {
 682
 683         if (!ra)
 684                 return;
 685
 686         if (!prefix)
 687                 return;
 688
 689         LIST_FOREACH(prefix, cur, ra->prefixes) {
 690                 if (prefixlen != cur->opt.prefixlen)
 691                         continue;
 692
 693                 if (!in6_addr_equal(prefix, &cur->opt.in6_addr))
 694                         continue;
 695
 696                 LIST_REMOVE(prefix, ra->prefixes, cur);
 697                 ra->n_prefixes--;
 698                 sd_radv_prefix_unref(cur);
 699                 return;
 700         }
 701 }
 702
 703 int sd_radv_add_route_prefix(sd_radv *ra, sd_radv_route_prefix *p) {
 704         sd_radv_route_prefix *found = NULL;
 705
 706         assert_return(ra, -EINVAL);
 707         assert_return(p, -EINVAL);
 708
 709         LIST_FOREACH(prefix, cur, ra->route_prefixes)
 710                 if (cur->opt.prefixlen == p->opt.prefixlen &&
 711                     in6_addr_equal(&cur->opt.in6_addr, &p->opt.in6_addr)) {
 712                         found = cur;
 713                         break;
 714                 }
 715
 716         if (found) {
 717                 /* p and cur may be equivalent. First increment the reference counter. */
 718                 sd_radv_route_prefix_ref(p);
 719
 720                 /* Then, remove the old entry. */
 721                 LIST_REMOVE(prefix, ra->route_prefixes, found);
 722                 sd_radv_route_prefix_unref(found);
 723
 724                 /* Finally, add the new entry. */
 725                 LIST_APPEND(prefix, ra->route_prefixes, p);
 726
 727                 log_radv(ra, "Updated/replaced IPv6 route prefix %s (lifetime: %s)",
 728                          IN6_ADDR_PREFIX_TO_STRING(&p->opt.in6_addr, p->opt.prefixlen),
 729                          FORMAT_TIMESPAN(p->lifetime_usec, USEC_PER_SEC));
 730         } else {
 731                 /* The route prefix is new. Let's simply add it. */
 732
 733                 sd_radv_route_prefix_ref(p);
 734                 LIST_APPEND(prefix, ra->route_prefixes, p);
 735                 ra->n_route_prefixes++;
 736
 737                 log_radv(ra, "Added route prefix %s",
 738                          IN6_ADDR_PREFIX_TO_STRING(&p->opt.in6_addr, p->opt.prefixlen));
 739         }
 740
 741         return 0;
 742 }
 743
 744 int sd_radv_add_pref64_prefix(sd_radv *ra, sd_radv_pref64_prefix *p) {
 745         sd_radv_pref64_prefix *found = NULL;
 746
 747         assert_return(ra, -EINVAL);
 748         assert_return(p, -EINVAL);
 749
 750         LIST_FOREACH(prefix, cur, ra->pref64_prefixes)
 751                 if (cur->prefixlen == p->prefixlen &&
 752                     in6_addr_equal(&cur->in6_addr, &p->in6_addr)) {
 753                         found = cur;
 754                         break;
 755                 }
 756
 757         if (found) {
 758                 /* p and cur may be equivalent. First increment the reference counter. */
 759                 sd_radv_pref64_prefix_ref(p);
 760
 761                 /* Then, remove the old entry. */
 762                 LIST_REMOVE(prefix, ra->pref64_prefixes, found);
 763                 sd_radv_pref64_prefix_unref(found);
 764
 765                 /* Finally, add the new entry. */
 766                 LIST_APPEND(prefix, ra->pref64_prefixes, p);
 767
 768                 log_radv(ra, "Updated/replaced IPv6 PREF64 prefix %s (lifetime: %s)",
 769                          IN6_ADDR_PREFIX_TO_STRING(&p->in6_addr, p->prefixlen),
 770                          FORMAT_TIMESPAN(p->lifetime_usec, USEC_PER_SEC));
 771         } else {
 772                 /* The route prefix is new. Let's simply add it. */
 773
 774                 sd_radv_pref64_prefix_ref(p);
 775                 LIST_APPEND(prefix, ra->pref64_prefixes, p);
 776                 ra->n_pref64_prefixes++;
 777
 778                 log_radv(ra, "Added PREF64 prefix %s",
 779                          IN6_ADDR_PREFIX_TO_STRING(&p->in6_addr, p->prefixlen));
 780         }
 781
 782         return 0;
 783 }
 784
 785 int sd_radv_set_rdnss(
 786                 sd_radv *ra,
 787                 uint64_t lifetime_usec,
 788                 const struct in6_addr *dns,
 789                 size_t n_dns) {
 790
 791         _cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
 792         size_t len;
 793
 794         assert_return(ra, -EINVAL);
 795         assert_return(n_dns < 128, -EINVAL);
 796
 797         if (lifetime_usec > RADV_RDNSS_MAX_LIFETIME_USEC)
 798                 return -EINVAL;
 799
 800         if (!dns || n_dns == 0) {
 801                 ra->rdnss = mfree(ra->rdnss);
 802                 ra->n_rdnss = 0;
 803
 804                 return 0;
 805         }
 806
 807         len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
 808
 809         opt_rdnss = malloc0(len);
 810         if (!opt_rdnss)
 811                 return -ENOMEM;
 812
 813         opt_rdnss->type = RADV_OPT_RDNSS;
 814         opt_rdnss->length = len / 8;
 815         opt_rdnss->lifetime = usec_to_be32_sec(lifetime_usec);
 816
 817         memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
 818
 819         free_and_replace(ra->rdnss, opt_rdnss);
 820
 821         ra->n_rdnss = n_dns;
 822
 823         return 0;
 824 }
 825
 826 int sd_radv_set_dnssl(
 827                 sd_radv *ra,
 828                 uint64_t lifetime_usec,
 829                 char **search_list) {
 830
 831         _cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
 832         size_t len = 0;
 833         uint8_t *p;
 834
 835         assert_return(ra, -EINVAL);
 836
 837         if (lifetime_usec > RADV_DNSSL_MAX_LIFETIME_USEC)
 838                 return -EINVAL;
 839
 840         if (strv_isempty(search_list)) {
 841                 ra->dnssl = mfree(ra->dnssl);
 842                 return 0;
 843         }
 844
 845         STRV_FOREACH(s, search_list)
 846                 len += strlen(*s) + 2;
 847
 848         len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
 849
 850         opt_dnssl = malloc0(len);
 851         if (!opt_dnssl)
 852                 return -ENOMEM;
 853
 854         opt_dnssl->type = RADV_OPT_DNSSL;
 855         opt_dnssl->length = len / 8;
 856         opt_dnssl->lifetime = usec_to_be32_sec(lifetime_usec);
 857
 858         p = (uint8_t *)(opt_dnssl + 1);
 859         len -= sizeof(struct sd_radv_opt_dns);
 860
 861         STRV_FOREACH(s, search_list) {
 862                 int r;
 863
 864                 r = dns_name_to_wire_format(*s, p, len, false);
 865                 if (r < 0)
 866                         return r;
 867
 868                 if (len < (size_t)r)
 869                         return -ENOBUFS;
 870
 871                 p += r;
 872                 len -= r;
 873         }
 874
 875         free_and_replace(ra->dnssl, opt_dnssl);
 876
 877         return 0;
 878 }
 879
 880 int sd_radv_prefix_new(sd_radv_prefix **ret) {
 881         sd_radv_prefix *p;
 882
 883         assert_return(ret, -EINVAL);
 884
 885         p = new(sd_radv_prefix, 1);
 886         if (!p)
 887                 return -ENOMEM;
 888
 889         *p = (sd_radv_prefix) {
 890                 .n_ref = 1,
 891
 892                 .opt.type = ND_OPT_PREFIX_INFORMATION,
 893                 .opt.length = (sizeof(p->opt) - 1)/8 + 1,
 894                 .opt.prefixlen = 64,
 895
 896                 /* RFC 4861, Section 6.2.1 */
 897                 .opt.flags = ND_OPT_PI_FLAG_ONLINK|ND_OPT_PI_FLAG_AUTO,
 898
 899                 .lifetime_valid_usec = RADV_DEFAULT_VALID_LIFETIME_USEC,
 900                 .lifetime_preferred_usec = RADV_DEFAULT_PREFERRED_LIFETIME_USEC,
 901                 .valid_until = USEC_INFINITY,
 902                 .preferred_until = USEC_INFINITY,
 903         };
 904
 905         *ret = p;
 906         return 0;
 907 }
 908
 909 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_prefix, sd_radv_prefix, mfree);
 910
 911 int sd_radv_prefix_set_prefix(
 912                 sd_radv_prefix *p,
 913                 const struct in6_addr *in6_addr,
 914                 unsigned char prefixlen) {
 915
 916         assert_return(p, -EINVAL);
 917         assert_return(in6_addr, -EINVAL);
 918
 919         if (prefixlen < 3 || prefixlen > 128)
 920                 return -EINVAL;
 921
 922         if (prefixlen > 64)
 923                 /* unusual but allowed, log it */
 924                 log_radv(NULL, "Unusual prefix length %d greater than 64", prefixlen);
 925
 926         p->opt.in6_addr = *in6_addr;
 927         p->opt.prefixlen = prefixlen;
 928
 929         return 0;
 930 }
 931
 932 int sd_radv_prefix_get_prefix(
 933                 sd_radv_prefix *p,
 934                 struct in6_addr *ret_in6_addr,
 935                 unsigned char *ret_prefixlen) {
 936
 937         assert_return(p, -EINVAL);
 938         assert_return(ret_in6_addr, -EINVAL);
 939         assert_return(ret_prefixlen, -EINVAL);
 940
 941         *ret_in6_addr = p->opt.in6_addr;
 942         *ret_prefixlen = p->opt.prefixlen;
 943
 944         return 0;
 945 }
 946
 947 int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
 948         assert_return(p, -EINVAL);
 949
 950         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
 951
 952         return 0;
 953 }
 954
 955 int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p, int address_autoconfiguration) {
 956         assert_return(p, -EINVAL);
 957
 958         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
 959
 960         return 0;
 961 }
 962
 963 int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
 964         assert_return(p, -EINVAL);
 965
 966         p->lifetime_valid_usec = lifetime_usec;
 967         p->valid_until = valid_until;
 968
 969         return 0;
 970 }
 971
 972 int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
 973         assert_return(p, -EINVAL);
 974
 975         p->lifetime_preferred_usec = lifetime_usec;
 976         p->preferred_until = valid_until;
 977
 978         return 0;
 979 }
 980
 981 int sd_radv_route_prefix_new(sd_radv_route_prefix **ret) {
 982         sd_radv_route_prefix *p;
 983
 984         assert_return(ret, -EINVAL);
 985
 986         p = new(sd_radv_route_prefix, 1);
 987         if (!p)
 988                 return -ENOMEM;
 989
 990         *p = (sd_radv_route_prefix) {
 991                 .n_ref = 1,
 992
 993                 .opt.type = RADV_OPT_ROUTE_INFORMATION,
 994                 .opt.length = DIV_ROUND_UP(sizeof(p->opt), 8),
 995                 .opt.prefixlen = 64,
 996
 997                 .lifetime_usec = RADV_DEFAULT_VALID_LIFETIME_USEC,
 998                 .valid_until = USEC_INFINITY,
 999         };
1000
1001         *ret = p;
1002         return 0;
1003 }
1004
1005 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_route_prefix, sd_radv_route_prefix, mfree);
1006
1007 int sd_radv_route_prefix_set_prefix(
1008                 sd_radv_route_prefix *p,
1009                 const struct in6_addr *in6_addr,
1010                 unsigned char prefixlen) {
1011
1012         assert_return(p, -EINVAL);
1013         assert_return(in6_addr, -EINVAL);
1014
1015         if (prefixlen > 128)
1016                 return -EINVAL;
1017
1018         if (prefixlen > 64)
1019                 /* unusual but allowed, log it */
1020                 log_radv(NULL, "Unusual prefix length %u greater than 64", prefixlen);
1021
1022         p->opt.in6_addr = *in6_addr;
1023         p->opt.prefixlen = prefixlen;
1024
1025         return 0;
1026 }
1027
1028 int sd_radv_route_prefix_set_lifetime(sd_radv_route_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
1029         assert_return(p, -EINVAL);
1030
1031         p->lifetime_usec = lifetime_usec;
1032         p->valid_until = valid_until;
1033
1034         return 0;
1035 }
1036
1037 int sd_radv_pref64_prefix_new(sd_radv_pref64_prefix **ret) {
1038         sd_radv_pref64_prefix *p;
1039
1040         assert_return(ret, -EINVAL);
1041
1042         p = new(sd_radv_pref64_prefix, 1);
1043         if (!p)
1044                 return -ENOMEM;
1045
1046         *p = (sd_radv_pref64_prefix) {
1047                 .n_ref = 1,
1048
1049                 .opt.type = RADV_OPT_PREF64,
1050                 .opt.length = 2,
1051         };
1052
1053         *ret = p;
1054         return 0;
1055 }
1056
1057 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_pref64_prefix, sd_radv_pref64_prefix, mfree);
1058
1059 int sd_radv_pref64_prefix_set_prefix(
1060                 sd_radv_pref64_prefix *p,
1061                 const struct in6_addr *prefix,
1062                 uint8_t prefixlen,
1063                 uint64_t lifetime_usec) {
1064
1065         uint16_t pref64_lifetime;
1066         uint8_t prefixlen_code;
1067         int r;
1068
1069         assert_return(p, -EINVAL);
1070         assert_return(prefix, -EINVAL);
1071
1072         r = pref64_prefix_length_to_plc(prefixlen, &prefixlen_code);
1073         if (r < 0)
1074                 return log_radv_errno(NULL, r,
1075                                       "Unsupported PREF64 prefix length %u. Valid lengths are 32, 40, 48, 56, 64 and 96", prefixlen);
1076
1077         if (lifetime_usec > PREF64_MAX_LIFETIME_USEC)
1078                 return -EINVAL;
1079
1080         /* RFC 8781 - 4.1 rounding up lifetime to multiply of 8 */
1081         pref64_lifetime = DIV_ROUND_UP(lifetime_usec, 8 * USEC_PER_SEC) << 3;
1082         pref64_lifetime |= prefixlen_code;
1083
1084         unaligned_write_be16(&p->opt.lifetime_and_plc, pref64_lifetime);
1085         memcpy(&p->opt.prefix, prefix, sizeof(p->opt.prefix));
1086
1087         p->in6_addr = *prefix;
1088         p->prefixlen = prefixlen;
1089
1090         return 0;
1091 }