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 "io-util.h"
  20 #include "macro.h"
  21 #include "memory-util.h"
  22 #include "network-common.h"
  23 #include "radv-internal.h"
  24 #include "random-util.h"
  25 #include "socket-util.h"
  26 #include "string-util.h"
  27 #include "strv.h"
  28
  29 int sd_radv_new(sd_radv **ret) {
  30         _cleanup_(sd_radv_unrefp) sd_radv *ra = NULL;
  31
  32         assert_return(ret, -EINVAL);
  33
  34         ra = new(sd_radv, 1);
  35         if (!ra)
  36                 return -ENOMEM;
  37
  38         *ra = (sd_radv) {
  39                 .n_ref = 1,
  40                 .fd = -1,
  41                 .lifetime_usec = RADV_DEFAULT_ROUTER_LIFETIME_USEC,
  42         };
  43
  44         *ret = TAKE_PTR(ra);
  45
  46         return 0;
  47 }
  48
  49 int sd_radv_attach_event(sd_radv *ra, sd_event *event, int64_t priority) {
  50         int r;
  51
  52         assert_return(ra, -EINVAL);
  53         assert_return(!ra->event, -EBUSY);
  54
  55         if (event)
  56                 ra->event = sd_event_ref(event);
  57         else {
  58                 r = sd_event_default(&ra->event);
  59                 if (r < 0)
  60                         return 0;
  61         }
  62
  63         ra->event_priority = priority;
  64
  65         return 0;
  66 }
  67
  68 int sd_radv_detach_event(sd_radv *ra) {
  69
  70         assert_return(ra, -EINVAL);
  71
  72         ra->event = sd_event_unref(ra->event);
  73         return 0;
  74 }
  75
  76 sd_event *sd_radv_get_event(sd_radv *ra) {
  77         assert_return(ra, NULL);
  78
  79         return ra->event;
  80 }
  81
  82 int sd_radv_is_running(sd_radv *ra) {
  83         assert_return(ra, false);
  84
  85         return ra->state != RADV_STATE_IDLE;
  86 }
  87
  88 static void radv_reset(sd_radv *ra) {
  89         assert(ra);
  90
  91         (void) event_source_disable(ra->timeout_event_source);
  92
  93         ra->recv_event_source = sd_event_source_disable_unref(ra->recv_event_source);
  94
  95         ra->ra_sent = 0;
  96 }
  97
  98 static sd_radv *radv_free(sd_radv *ra) {
  99         if (!ra)
 100                 return NULL;
 101
 102         while (ra->prefixes) {
 103                 sd_radv_prefix *p = ra->prefixes;
 104
 105                 LIST_REMOVE(prefix, ra->prefixes, p);
 106                 sd_radv_prefix_unref(p);
 107         }
 108
 109         while (ra->route_prefixes) {
 110                 sd_radv_route_prefix *p = ra->route_prefixes;
 111
 112                 LIST_REMOVE(prefix, ra->route_prefixes, p);
 113                 sd_radv_route_prefix_unref(p);
 114         }
 115
 116         free(ra->rdnss);
 117         free(ra->dnssl);
 118
 119         radv_reset(ra);
 120
 121         sd_event_source_unref(ra->timeout_event_source);
 122         sd_radv_detach_event(ra);
 123
 124         ra->fd = safe_close(ra->fd);
 125         free(ra->ifname);
 126
 127         return mfree(ra);
 128 }
 129
 130 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv, sd_radv, radv_free);
 131
 132 static bool router_lifetime_is_valid(usec_t lifetime_usec) {
 133         return lifetime_usec == 0 ||
 134                 (lifetime_usec >= RADV_MIN_ROUTER_LIFETIME_USEC &&
 135                  lifetime_usec <= RADV_MAX_ROUTER_LIFETIME_USEC);
 136 }
 137
 138 static be32_t usec_to_be32_sec(usec_t usec) {
 139         if (usec == USEC_INFINITY)
 140                 /* UINT32_MAX is handled as infinity. */
 141                 return htobe32(UINT32_MAX);
 142
 143         if (usec >= UINT32_MAX * USEC_PER_SEC)
 144                 /* Finite but too large. Let's use the largest finite value. */
 145                 return htobe32(UINT32_MAX - 1);
 146
 147         return htobe32(usec / USEC_PER_SEC);
 148 }
 149
 150 static int radv_send(sd_radv *ra, const struct in6_addr *dst, usec_t lifetime_usec) {
 151         sd_radv_route_prefix *rt;
 152         sd_radv_prefix *p;
 153         struct sockaddr_in6 dst_addr = {
 154                 .sin6_family = AF_INET6,
 155                 .sin6_addr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
 156         };
 157         struct nd_router_advert adv = {};
 158         struct {
 159                 struct nd_opt_hdr opthdr;
 160                 struct ether_addr slladdr;
 161         } _packed_ opt_mac = {
 162                 .opthdr = {
 163                         .nd_opt_type = ND_OPT_SOURCE_LINKADDR,
 164                         .nd_opt_len = (sizeof(struct nd_opt_hdr) +
 165                                        sizeof(struct ether_addr) - 1) /8 + 1,
 166                 },
 167         };
 168         struct nd_opt_mtu opt_mtu =  {
 169                 .nd_opt_mtu_type = ND_OPT_MTU,
 170                 .nd_opt_mtu_len = 1,
 171         };
 172         /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, N routes, RDNSS
 173            and DNSSL */
 174         struct iovec iov[5 + ra->n_prefixes + ra->n_route_prefixes];
 175         struct msghdr msg = {
 176                 .msg_name = &dst_addr,
 177                 .msg_namelen = sizeof(dst_addr),
 178                 .msg_iov = iov,
 179         };
 180         usec_t time_now;
 181         int r;
 182
 183         assert(ra);
 184         assert(router_lifetime_is_valid(lifetime_usec));
 185
 186         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 187         if (r < 0)
 188                 return r;
 189
 190         if (dst && in6_addr_is_set(dst))
 191                 dst_addr.sin6_addr = *dst;
 192
 193         adv.nd_ra_type = ND_ROUTER_ADVERT;
 194         adv.nd_ra_curhoplimit = ra->hop_limit;
 195         adv.nd_ra_flags_reserved = ra->flags;
 196         assert_cc(RADV_MAX_ROUTER_LIFETIME_USEC <= UINT16_MAX * USEC_PER_SEC);
 197         adv.nd_ra_router_lifetime = htobe16(DIV_ROUND_UP(lifetime_usec, USEC_PER_SEC));
 198         iov[msg.msg_iovlen++] = IOVEC_MAKE(&adv, sizeof(adv));
 199
 200         /* MAC address is optional, either because the link does not use L2
 201            addresses or load sharing is desired. See RFC 4861, Section 4.2 */
 202         if (!ether_addr_is_null(&ra->mac_addr)) {
 203                 opt_mac.slladdr = ra->mac_addr;
 204                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mac, sizeof(opt_mac));
 205         }
 206
 207         if (ra->mtu > 0) {
 208                 opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
 209                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mtu, sizeof(opt_mtu));
 210         }
 211
 212         LIST_FOREACH(prefix, p, ra->prefixes) {
 213                 usec_t lifetime_valid_usec, lifetime_preferred_usec;
 214
 215                 lifetime_valid_usec = MIN(usec_sub_unsigned(p->valid_until, time_now),
 216                                           p->lifetime_valid_usec);
 217
 218                 lifetime_preferred_usec = MIN3(usec_sub_unsigned(p->preferred_until, time_now),
 219                                                p->lifetime_preferred_usec,
 220                                                lifetime_valid_usec);
 221
 222                 p->opt.lifetime_valid = usec_to_be32_sec(lifetime_valid_usec);
 223                 p->opt.lifetime_preferred = usec_to_be32_sec(lifetime_preferred_usec);
 224
 225                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&p->opt, sizeof(p->opt));
 226         }
 227
 228         LIST_FOREACH(prefix, rt, ra->route_prefixes) {
 229                 rt->opt.lifetime = usec_to_be32_sec(MIN(usec_sub_unsigned(rt->valid_until, time_now),
 230                                                         rt->lifetime_usec));
 231
 232                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&rt->opt, sizeof(rt->opt));
 233         }
 234
 235         if (ra->rdnss)
 236                 iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->rdnss, ra->rdnss->length * 8);
 237
 238         if (ra->dnssl)
 239                 iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->dnssl, ra->dnssl->length * 8);
 240
 241         if (sendmsg(ra->fd, &msg, 0) < 0)
 242                 return -errno;
 243
 244         return 0;
 245 }
 246
 247 static int radv_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 248         sd_radv *ra = userdata;
 249         _cleanup_free_ char *addr = NULL;
 250         struct in6_addr src;
 251         triple_timestamp timestamp;
 252         int r;
 253         ssize_t buflen;
 254         _cleanup_free_ char *buf = NULL;
 255
 256         assert(s);
 257         assert(ra);
 258         assert(ra->event);
 259
 260         buflen = next_datagram_size_fd(fd);
 261         if (buflen < 0)
 262                 return (int) buflen;
 263
 264         buf = new0(char, buflen);
 265         if (!buf)
 266                 return -ENOMEM;
 267
 268         r = icmp6_receive(fd, buf, buflen, &src, &timestamp);
 269         if (r < 0) {
 270                 switch (r) {
 271                 case -EADDRNOTAVAIL:
 272                         (void) in_addr_to_string(AF_INET6, (const union in_addr_union*) &src, &addr);
 273                         log_radv(ra, "Received RS from non-link-local address %s. Ignoring", addr);
 274                         break;
 275
 276                 case -EMULTIHOP:
 277                         log_radv(ra, "Received RS with invalid hop limit. Ignoring.");
 278                         break;
 279
 280                 case -EPFNOSUPPORT:
 281                         log_radv(ra, "Received invalid source address from ICMPv6 socket. Ignoring.");
 282                         break;
 283
 284                 case -EAGAIN: /* ignore spurious wakeups */
 285                         break;
 286
 287                 default:
 288                         log_radv_errno(ra, r, "Unexpected error receiving from ICMPv6 socket, Ignoring: %m");
 289                         break;
 290                 }
 291
 292                 return 0;
 293         }
 294
 295         if ((size_t) buflen < sizeof(struct nd_router_solicit)) {
 296                 log_radv(ra, "Too short packet received, ignoring");
 297                 return 0;
 298         }
 299
 300         (void) in_addr_to_string(AF_INET6, (const union in_addr_union*) &src, &addr);
 301
 302         r = radv_send(ra, &src, ra->lifetime_usec);
 303         if (r < 0)
 304                 log_radv_errno(ra, r, "Unable to send solicited Router Advertisement to %s, ignoring: %m", strnull(addr));
 305         else
 306                 log_radv(ra, "Sent solicited Router Advertisement to %s", strnull(addr));
 307
 308         return 0;
 309 }
 310
 311 static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
 312         usec_t min_timeout, max_timeout, time_now, timeout;
 313         sd_radv *ra = userdata;
 314         int r;
 315
 316         assert(s);
 317         assert(ra);
 318         assert(ra->event);
 319         assert(router_lifetime_is_valid(ra->lifetime_usec));
 320
 321         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 322         if (r < 0)
 323                 goto fail;
 324
 325         r = radv_send(ra, NULL, ra->lifetime_usec);
 326         if (r < 0)
 327                 log_radv_errno(ra, r, "Unable to send Router Advertisement: %m");
 328
 329         /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
 330         if (ra->ra_sent < RADV_MAX_INITIAL_RTR_ADVERTISEMENTS)
 331                 max_timeout = RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
 332         else
 333                 max_timeout = RADV_DEFAULT_MAX_TIMEOUT_USEC;
 334
 335         /* RFC 4861, Section 6.2.1, lifetime must be at least MaxRtrAdvInterval,
 336          * so lower the interval here */
 337         if (ra->lifetime_usec > 0)
 338                 max_timeout = MIN(max_timeout, ra->lifetime_usec);
 339
 340         if (max_timeout >= 9 * USEC_PER_SEC)
 341                 min_timeout = max_timeout / 3;
 342         else
 343                 min_timeout = max_timeout * 3 / 4;
 344
 345         /* RFC 4861, Section 6.2.1.
 346          * MaxRtrAdvInterval MUST be no less than 4 seconds and no greater than 1800 seconds.
 347          * MinRtrAdvInterval MUST be no less than 3 seconds and no greater than .75 * MaxRtrAdvInterval. */
 348         assert(max_timeout >= RADV_MIN_MAX_TIMEOUT_USEC);
 349         assert(max_timeout <= RADV_MAX_MAX_TIMEOUT_USEC);
 350         assert(min_timeout >= RADV_MIN_MIN_TIMEOUT_USEC);
 351         assert(min_timeout <= max_timeout * 3 / 4);
 352
 353         timeout = min_timeout + random_u64_range(max_timeout - min_timeout);
 354         log_radv(ra, "Next Router Advertisement in %s", FORMAT_TIMESPAN(timeout, USEC_PER_SEC));
 355
 356         r = event_reset_time(ra->event, &ra->timeout_event_source,
 357                              clock_boottime_or_monotonic(),
 358                              usec_add(time_now, timeout), MSEC_PER_SEC,
 359                              radv_timeout, ra,
 360                              ra->event_priority, "radv-timeout", true);
 361         if (r < 0)
 362                 goto fail;
 363
 364         ra->ra_sent++;
 365
 366         return 0;
 367
 368 fail:
 369         sd_radv_stop(ra);
 370
 371         return 0;
 372 }
 373
 374 int sd_radv_stop(sd_radv *ra) {
 375         int r;
 376
 377         if (!ra)
 378                 return 0;
 379
 380         if (ra->state == RADV_STATE_IDLE)
 381                 return 0;
 382
 383         log_radv(ra, "Stopping IPv6 Router Advertisement daemon");
 384
 385         /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
 386            with zero lifetime  */
 387         r = radv_send(ra, NULL, 0);
 388         if (r < 0)
 389                 log_radv_errno(ra, r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
 390
 391         radv_reset(ra);
 392         ra->fd = safe_close(ra->fd);
 393         ra->state = RADV_STATE_IDLE;
 394
 395         return 0;
 396 }
 397
 398 int sd_radv_start(sd_radv *ra) {
 399         int r;
 400
 401         assert_return(ra, -EINVAL);
 402         assert_return(ra->event, -EINVAL);
 403         assert_return(ra->ifindex > 0, -EINVAL);
 404
 405         if (ra->state != RADV_STATE_IDLE)
 406                 return 0;
 407
 408         r = event_reset_time(ra->event, &ra->timeout_event_source,
 409                              clock_boottime_or_monotonic(),
 410                              0, 0,
 411                              radv_timeout, ra,
 412                              ra->event_priority, "radv-timeout", true);
 413         if (r < 0)
 414                 goto fail;
 415
 416         r = icmp6_bind_router_advertisement(ra->ifindex);
 417         if (r < 0)
 418                 goto fail;
 419
 420         ra->fd = r;
 421
 422         r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
 423         if (r < 0)
 424                 goto fail;
 425
 426         r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
 427         if (r < 0)
 428                 goto fail;
 429
 430         (void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
 431
 432         ra->state = RADV_STATE_ADVERTISING;
 433
 434         log_radv(ra, "Started IPv6 Router Advertisement daemon");
 435
 436         return 0;
 437
 438  fail:
 439         radv_reset(ra);
 440
 441         return r;
 442 }
 443
 444 int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
 445         assert_return(ra, -EINVAL);
 446         assert_return(ifindex > 0, -EINVAL);
 447
 448         if (ra->state != RADV_STATE_IDLE)
 449                 return -EBUSY;
 450
 451         ra->ifindex = ifindex;
 452
 453         return 0;
 454 }
 455
 456 int sd_radv_set_ifname(sd_radv *ra, const char *ifname) {
 457         assert_return(ra, -EINVAL);
 458         assert_return(ifname, -EINVAL);
 459
 460         if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE))
 461                 return -EINVAL;
 462
 463         return free_and_strdup(&ra->ifname, ifname);
 464 }
 465
 466 int sd_radv_get_ifname(sd_radv *ra, const char **ret) {
 467         int r;
 468
 469         assert_return(ra, -EINVAL);
 470
 471         r = get_ifname(ra->ifindex, &ra->ifname);
 472         if (r < 0)
 473                 return r;
 474
 475         if (ret)
 476                 *ret = ra->ifname;
 477
 478         return 0;
 479 }
 480
 481 int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
 482         assert_return(ra, -EINVAL);
 483
 484         if (ra->state != RADV_STATE_IDLE)
 485                 return -EBUSY;
 486
 487         if (mac_addr)
 488                 ra->mac_addr = *mac_addr;
 489         else
 490                 zero(ra->mac_addr);
 491
 492         return 0;
 493 }
 494
 495 int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
 496         assert_return(ra, -EINVAL);
 497         assert_return(mtu >= 1280, -EINVAL);
 498
 499         ra->mtu = mtu;
 500
 501         return 0;
 502 }
 503
 504 int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
 505         assert_return(ra, -EINVAL);
 506
 507         if (ra->state != RADV_STATE_IDLE)
 508                 return -EBUSY;
 509
 510         ra->hop_limit = hop_limit;
 511
 512         return 0;
 513 }
 514
 515 int sd_radv_set_router_lifetime(sd_radv *ra, uint64_t lifetime_usec) {
 516         assert_return(ra, -EINVAL);
 517
 518         if (ra->state != RADV_STATE_IDLE)
 519                 return -EBUSY;
 520
 521         if (!router_lifetime_is_valid(lifetime_usec))
 522                 return -EINVAL;
 523
 524         /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the preference value MUST be set
 525          * to (00) by the sender..." */
 526         if (lifetime_usec == 0 &&
 527             (ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
 528                 return -EINVAL;
 529
 530         ra->lifetime_usec = lifetime_usec;
 531
 532         return 0;
 533 }
 534
 535 int sd_radv_set_managed_information(sd_radv *ra, int managed) {
 536         assert_return(ra, -EINVAL);
 537
 538         if (ra->state != RADV_STATE_IDLE)
 539                 return -EBUSY;
 540
 541         SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
 542
 543         return 0;
 544 }
 545
 546 int sd_radv_set_other_information(sd_radv *ra, int other) {
 547         assert_return(ra, -EINVAL);
 548
 549         if (ra->state != RADV_STATE_IDLE)
 550                 return -EBUSY;
 551
 552         SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
 553
 554         return 0;
 555 }
 556
 557 int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
 558         assert_return(ra, -EINVAL);
 559         assert_return(IN_SET(preference,
 560                              SD_NDISC_PREFERENCE_LOW,
 561                              SD_NDISC_PREFERENCE_MEDIUM,
 562                              SD_NDISC_PREFERENCE_HIGH), -EINVAL);
 563
 564         /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the preference value MUST be set
 565          * to (00) by the sender..." */
 566         if (ra->lifetime_usec == 0 && preference != SD_NDISC_PREFERENCE_MEDIUM)
 567                 return -EINVAL;
 568
 569         ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);
 570
 571         return 0;
 572 }
 573
 574 int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p) {
 575         _cleanup_free_ char *addr_p = NULL;
 576         sd_radv_prefix *cur;
 577         int r;
 578
 579         assert_return(ra, -EINVAL);
 580         assert_return(p, -EINVAL);
 581
 582         /* Refuse prefixes that don't have a prefix set */
 583         if (in6_addr_is_null(&p->opt.in6_addr))
 584                 return -ENOEXEC;
 585
 586         (void) in6_addr_prefix_to_string(&p->opt.in6_addr, p->opt.prefixlen, &addr_p);
 587
 588         LIST_FOREACH(prefix, cur, ra->prefixes) {
 589
 590                 r = in_addr_prefix_intersect(AF_INET6,
 591                                              (const union in_addr_union*) &cur->opt.in6_addr,
 592                                              cur->opt.prefixlen,
 593                                              (const union in_addr_union*) &p->opt.in6_addr,
 594                                              p->opt.prefixlen);
 595                 if (r < 0)
 596                         return r;
 597                 if (r == 0)
 598                         continue;
 599
 600                 if (cur->opt.prefixlen == p->opt.prefixlen) {
 601                         /* p and cur may be equivalent. First increment the counter. */
 602                         sd_radv_prefix_ref(p);
 603
 604                         /* Then, remove the old entry. */
 605                         LIST_REMOVE(prefix, ra->prefixes, cur);
 606                         sd_radv_prefix_unref(cur);
 607
 608                         /* Finally, add the new entry. */
 609                         LIST_APPEND(prefix, ra->prefixes, p);
 610
 611                         log_radv(ra, "Updated/replaced IPv6 prefix %s (preferred: %s, valid: %s)",
 612                                  strna(addr_p),
 613                                  FORMAT_TIMESPAN(p->lifetime_preferred_usec, USEC_PER_SEC),
 614                                  FORMAT_TIMESPAN(p->lifetime_valid_usec, USEC_PER_SEC));
 615                         return 0;
 616                 }
 617
 618                 _cleanup_free_ char *addr_cur = NULL;
 619                 (void) in6_addr_prefix_to_string(&cur->opt.in6_addr, cur->opt.prefixlen, &addr_cur);
 620                 return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
 621                                       "IPv6 prefix %s conflicts with %s, ignoring.",
 622                                       strna(addr_p), strna(addr_cur));
 623         }
 624
 625         sd_radv_prefix_ref(p);
 626         LIST_APPEND(prefix, ra->prefixes, p);
 627         ra->n_prefixes++;
 628
 629         if (ra->state == RADV_STATE_IDLE) {
 630                 log_radv(ra, "Added prefix %s", strna(addr_p));
 631                 return 0;
 632         }
 633
 634         /* If RAs have already been sent, send an RA immediately to announce the newly-added prefix */
 635         if (ra->ra_sent > 0) {
 636                 r = radv_send(ra, NULL, ra->lifetime_usec);
 637                 if (r < 0)
 638                         log_radv_errno(ra, r, "Unable to send Router Advertisement for added prefix: %m");
 639                 else
 640                         log_radv(ra, "Sent Router Advertisement for added prefix");
 641         }
 642
 643         return 0;
 644 }
 645
 646 sd_radv_prefix *sd_radv_remove_prefix(sd_radv *ra,
 647                                                const struct in6_addr *prefix,
 648                                                unsigned char prefixlen) {
 649         sd_radv_prefix *cur, *next;
 650
 651         assert_return(ra, NULL);
 652         assert_return(prefix, NULL);
 653
 654         LIST_FOREACH_SAFE(prefix, cur, next, ra->prefixes) {
 655                 if (prefixlen != cur->opt.prefixlen)
 656                         continue;
 657
 658                 if (!in6_addr_equal(prefix, &cur->opt.in6_addr))
 659                         continue;
 660
 661                 LIST_REMOVE(prefix, ra->prefixes, cur);
 662                 ra->n_prefixes--;
 663                 sd_radv_prefix_unref(cur);
 664
 665                 break;
 666         }
 667
 668         return cur;
 669 }
 670
 671 int sd_radv_add_route_prefix(sd_radv *ra, sd_radv_route_prefix *p) {
 672         _cleanup_free_ char *addr_p = NULL;
 673         sd_radv_route_prefix *cur;
 674         int r;
 675
 676         assert_return(ra, -EINVAL);
 677         assert_return(p, -EINVAL);
 678
 679         (void) in6_addr_prefix_to_string(&p->opt.in6_addr, p->opt.prefixlen, &addr_p);
 680
 681         LIST_FOREACH(prefix, cur, ra->route_prefixes) {
 682
 683                 r = in_addr_prefix_intersect(AF_INET6,
 684                                              (const union in_addr_union*) &cur->opt.in6_addr,
 685                                              cur->opt.prefixlen,
 686                                              (const union in_addr_union*) &p->opt.in6_addr,
 687                                              p->opt.prefixlen);
 688                 if (r < 0)
 689                         return r;
 690                 if (r == 0)
 691                         continue;
 692
 693                 if (cur->opt.prefixlen == p->opt.prefixlen) {
 694                         /* p and cur may be equivalent. First increment the counter. */
 695                         sd_radv_route_prefix_ref(p);
 696
 697                         /* Then, remove the old entry. */
 698                         LIST_REMOVE(prefix, ra->route_prefixes, cur);
 699                         sd_radv_route_prefix_unref(cur);
 700
 701                         /* Finally, add the new entry. */
 702                         LIST_APPEND(prefix, ra->route_prefixes, p);
 703
 704                         log_radv(ra, "Updated/replaced IPv6 route prefix %s (lifetime: %s)",
 705                                  strna(addr_p),
 706                                  FORMAT_TIMESPAN(p->lifetime_usec, USEC_PER_SEC));
 707                         return 0;
 708                 }
 709
 710                 _cleanup_free_ char *addr_cur = NULL;
 711                 (void) in6_addr_prefix_to_string(&cur->opt.in6_addr, cur->opt.prefixlen, &addr_cur);
 712                 return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
 713                                       "IPv6 route prefix %s conflicts with %s, ignoring.",
 714                                       strna(addr_p), strna(addr_cur));
 715         }
 716
 717         sd_radv_route_prefix_ref(p);
 718         LIST_APPEND(prefix, ra->route_prefixes, p);
 719         ra->n_route_prefixes++;
 720
 721         if (ra->state == RADV_STATE_IDLE) {
 722                 log_radv(ra, "Added route prefix %s", strna(addr_p));
 723                 return 0;
 724         }
 725
 726         /* If RAs have already been sent, send an RA immediately to announce the newly-added route prefix */
 727         if (ra->ra_sent > 0) {
 728                 r = radv_send(ra, NULL, ra->lifetime_usec);
 729                 if (r < 0)
 730                         log_radv_errno(ra, r, "Unable to send Router Advertisement for added route prefix: %m");
 731                 else
 732                         log_radv(ra, "Sent Router Advertisement for added route prefix");
 733         }
 734
 735         return 0;
 736 }
 737
 738 int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
 739                                const struct in6_addr *dns, size_t n_dns) {
 740         _cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
 741         size_t len;
 742
 743         assert_return(ra, -EINVAL);
 744         assert_return(n_dns < 128, -EINVAL);
 745
 746         if (!dns || n_dns == 0) {
 747                 ra->rdnss = mfree(ra->rdnss);
 748                 ra->n_rdnss = 0;
 749
 750                 return 0;
 751         }
 752
 753         len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
 754
 755         opt_rdnss = malloc0(len);
 756         if (!opt_rdnss)
 757                 return -ENOMEM;
 758
 759         opt_rdnss->type = RADV_OPT_RDNSS;
 760         opt_rdnss->length = len / 8;
 761         opt_rdnss->lifetime = htobe32(lifetime);
 762
 763         memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
 764
 765         free_and_replace(ra->rdnss, opt_rdnss);
 766
 767         ra->n_rdnss = n_dns;
 768
 769         return 0;
 770 }
 771
 772 int sd_radv_set_dnssl(sd_radv *ra, uint32_t lifetime,
 773                                char **search_list) {
 774         _cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
 775         size_t len = 0;
 776         char **s;
 777         uint8_t *p;
 778
 779         assert_return(ra, -EINVAL);
 780
 781         if (strv_isempty(search_list)) {
 782                 ra->dnssl = mfree(ra->dnssl);
 783                 return 0;
 784         }
 785
 786         STRV_FOREACH(s, search_list)
 787                 len += strlen(*s) + 2;
 788
 789         len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
 790
 791         opt_dnssl = malloc0(len);
 792         if (!opt_dnssl)
 793                 return -ENOMEM;
 794
 795         opt_dnssl->type = RADV_OPT_DNSSL;
 796         opt_dnssl->length = len / 8;
 797         opt_dnssl->lifetime = htobe32(lifetime);
 798
 799         p = (uint8_t *)(opt_dnssl + 1);
 800         len -= sizeof(struct sd_radv_opt_dns);
 801
 802         STRV_FOREACH(s, search_list) {
 803                 int r;
 804
 805                 r = dns_name_to_wire_format(*s, p, len, false);
 806                 if (r < 0)
 807                         return r;
 808
 809                 if (len < (size_t)r)
 810                         return -ENOBUFS;
 811
 812                 p += r;
 813                 len -= r;
 814         }
 815
 816         free_and_replace(ra->dnssl, opt_dnssl);
 817
 818         return 0;
 819 }
 820
 821 int sd_radv_prefix_new(sd_radv_prefix **ret) {
 822         sd_radv_prefix *p;
 823
 824         assert_return(ret, -EINVAL);
 825
 826         p = new(sd_radv_prefix, 1);
 827         if (!p)
 828                 return -ENOMEM;
 829
 830         *p = (sd_radv_prefix) {
 831                 .n_ref = 1,
 832
 833                 .opt.type = ND_OPT_PREFIX_INFORMATION,
 834                 .opt.length = (sizeof(p->opt) - 1)/8 + 1,
 835                 .opt.prefixlen = 64,
 836
 837                 /* RFC 4861, Section 6.2.1 */
 838                 .opt.flags = ND_OPT_PI_FLAG_ONLINK|ND_OPT_PI_FLAG_AUTO,
 839
 840                 .lifetime_valid_usec = RADV_DEFAULT_VALID_LIFETIME_USEC,
 841                 .lifetime_preferred_usec = RADV_DEFAULT_PREFERRED_LIFETIME_USEC,
 842                 .valid_until = USEC_INFINITY,
 843                 .preferred_until = USEC_INFINITY,
 844         };
 845
 846         *ret = p;
 847         return 0;
 848 }
 849
 850 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_prefix, sd_radv_prefix, mfree);
 851
 852 int sd_radv_prefix_set_prefix(sd_radv_prefix *p, const struct in6_addr *in6_addr,
 853                                        unsigned char prefixlen) {
 854         assert_return(p, -EINVAL);
 855         assert_return(in6_addr, -EINVAL);
 856
 857         if (prefixlen < 3 || prefixlen > 128)
 858                 return -EINVAL;
 859
 860         if (prefixlen > 64)
 861                 /* unusual but allowed, log it */
 862                 log_radv(NULL, "Unusual prefix length %d greater than 64", prefixlen);
 863
 864         p->opt.in6_addr = *in6_addr;
 865         p->opt.prefixlen = prefixlen;
 866
 867         return 0;
 868 }
 869
 870 int sd_radv_prefix_get_prefix(sd_radv_prefix *p, struct in6_addr *ret_in6_addr,
 871                                        unsigned char *ret_prefixlen) {
 872         assert_return(p, -EINVAL);
 873         assert_return(ret_in6_addr, -EINVAL);
 874         assert_return(ret_prefixlen, -EINVAL);
 875
 876         *ret_in6_addr = p->opt.in6_addr;
 877         *ret_prefixlen = p->opt.prefixlen;
 878
 879         return 0;
 880 }
 881
 882 int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
 883         assert_return(p, -EINVAL);
 884
 885         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
 886
 887         return 0;
 888 }
 889
 890 int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
 891                                                           int address_autoconfiguration) {
 892         assert_return(p, -EINVAL);
 893
 894         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
 895
 896         return 0;
 897 }
 898
 899 int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
 900         assert_return(p, -EINVAL);
 901
 902         p->lifetime_valid_usec = lifetime_usec;
 903         p->valid_until = valid_until;
 904
 905         return 0;
 906 }
 907
 908 int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
 909         assert_return(p, -EINVAL);
 910
 911         p->lifetime_preferred_usec = lifetime_usec;
 912         p->preferred_until = valid_until;
 913
 914         return 0;
 915 }
 916
 917 int sd_radv_route_prefix_new(sd_radv_route_prefix **ret) {
 918         sd_radv_route_prefix *p;
 919
 920         assert_return(ret, -EINVAL);
 921
 922         p = new(sd_radv_route_prefix, 1);
 923         if (!p)
 924                 return -ENOMEM;
 925
 926         *p = (sd_radv_route_prefix) {
 927                 .n_ref = 1,
 928
 929                 .opt.type = RADV_OPT_ROUTE_INFORMATION,
 930                 .opt.length = DIV_ROUND_UP(sizeof(p->opt), 8),
 931                 .opt.prefixlen = 64,
 932
 933                 .lifetime_usec = RADV_DEFAULT_VALID_LIFETIME_USEC,
 934                 .valid_until = USEC_INFINITY,
 935         };
 936
 937         *ret = p;
 938         return 0;
 939 }
 940
 941 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_route_prefix, sd_radv_route_prefix, mfree);
 942
 943 int sd_radv_route_prefix_set_prefix(sd_radv_route_prefix *p, const struct in6_addr *in6_addr,
 944                                              unsigned char prefixlen) {
 945         assert_return(p, -EINVAL);
 946         assert_return(in6_addr, -EINVAL);
 947
 948         if (prefixlen > 128)
 949                 return -EINVAL;
 950
 951         if (prefixlen > 64)
 952                 /* unusual but allowed, log it */
 953                 log_radv(NULL, "Unusual prefix length %u greater than 64", prefixlen);
 954
 955         p->opt.in6_addr = *in6_addr;
 956         p->opt.prefixlen = prefixlen;
 957
 958         return 0;
 959 }
 960
 961 int sd_radv_route_prefix_set_lifetime(sd_radv_route_prefix *p, uint64_t lifetime_usec, uint64_t valid_until) {
 962         assert_return(p, -EINVAL);
 963
 964         p->lifetime_usec = lifetime_usec;
 965         p->valid_until = valid_until;
 966
 967         return 0;
 968 }