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 _public_ 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 _public_ 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 _public_ 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 _public_ sd_event *sd_radv_get_event(sd_radv *ra) {
  77         assert_return(ra, NULL);
  78
  79         return ra->event;
  80 }
  81
  82 _public_ 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 int radv_send(sd_radv *ra, const struct in6_addr *dst, usec_t lifetime_usec) {
 139         sd_radv_route_prefix *rt;
 140         sd_radv_prefix *p;
 141         struct sockaddr_in6 dst_addr = {
 142                 .sin6_family = AF_INET6,
 143                 .sin6_addr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
 144         };
 145         struct nd_router_advert adv = {};
 146         struct {
 147                 struct nd_opt_hdr opthdr;
 148                 struct ether_addr slladdr;
 149         } _packed_ opt_mac = {
 150                 .opthdr = {
 151                         .nd_opt_type = ND_OPT_SOURCE_LINKADDR,
 152                         .nd_opt_len = (sizeof(struct nd_opt_hdr) +
 153                                        sizeof(struct ether_addr) - 1) /8 + 1,
 154                 },
 155         };
 156         struct nd_opt_mtu opt_mtu =  {
 157                 .nd_opt_mtu_type = ND_OPT_MTU,
 158                 .nd_opt_mtu_len = 1,
 159         };
 160         /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, N routes, RDNSS
 161            and DNSSL */
 162         struct iovec iov[5 + ra->n_prefixes + ra->n_route_prefixes];
 163         struct msghdr msg = {
 164                 .msg_name = &dst_addr,
 165                 .msg_namelen = sizeof(dst_addr),
 166                 .msg_iov = iov,
 167         };
 168         usec_t time_now;
 169         int r;
 170
 171         assert(ra);
 172         assert(router_lifetime_is_valid(lifetime_usec));
 173
 174         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 175         if (r < 0)
 176                 return r;
 177
 178         if (dst && in6_addr_is_set(dst))
 179                 dst_addr.sin6_addr = *dst;
 180
 181         adv.nd_ra_type = ND_ROUTER_ADVERT;
 182         adv.nd_ra_curhoplimit = ra->hop_limit;
 183         adv.nd_ra_flags_reserved = ra->flags;
 184         assert_cc(RADV_MAX_ROUTER_LIFETIME_USEC <= UINT16_MAX * USEC_PER_SEC);
 185         adv.nd_ra_router_lifetime = htobe16(DIV_ROUND_UP(lifetime_usec, USEC_PER_SEC));
 186         iov[msg.msg_iovlen++] = IOVEC_MAKE(&adv, sizeof(adv));
 187
 188         /* MAC address is optional, either because the link does not use L2
 189            addresses or load sharing is desired. See RFC 4861, Section 4.2 */
 190         if (!ether_addr_is_null(&ra->mac_addr)) {
 191                 opt_mac.slladdr = ra->mac_addr;
 192                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mac, sizeof(opt_mac));
 193         }
 194
 195         if (ra->mtu) {
 196                 opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
 197                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mtu, sizeof(opt_mtu));
 198         }
 199
 200         LIST_FOREACH(prefix, p, ra->prefixes) {
 201                 if (p->valid_until) {
 202
 203                         if (time_now > p->valid_until)
 204                                 p->opt.valid_lifetime = 0;
 205                         else
 206                                 p->opt.valid_lifetime = htobe32((p->valid_until - time_now) / USEC_PER_SEC);
 207
 208                         if (time_now > p->preferred_until)
 209                                 p->opt.preferred_lifetime = 0;
 210                         else
 211                                 p->opt.preferred_lifetime = htobe32((p->preferred_until - time_now) / USEC_PER_SEC);
 212                 }
 213                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&p->opt, sizeof(p->opt));
 214         }
 215
 216         LIST_FOREACH(prefix, rt, ra->route_prefixes)
 217                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&rt->opt, sizeof(rt->opt));
 218
 219         if (ra->rdnss)
 220                 iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->rdnss, ra->rdnss->length * 8);
 221
 222         if (ra->dnssl)
 223                 iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->dnssl, ra->dnssl->length * 8);
 224
 225         if (sendmsg(ra->fd, &msg, 0) < 0)
 226                 return -errno;
 227
 228         return 0;
 229 }
 230
 231 static int radv_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 232         sd_radv *ra = userdata;
 233         _cleanup_free_ char *addr = NULL;
 234         struct in6_addr src;
 235         triple_timestamp timestamp;
 236         int r;
 237         ssize_t buflen;
 238         _cleanup_free_ char *buf = NULL;
 239
 240         assert(s);
 241         assert(ra);
 242         assert(ra->event);
 243
 244         buflen = next_datagram_size_fd(fd);
 245         if (buflen < 0)
 246                 return (int) buflen;
 247
 248         buf = new0(char, buflen);
 249         if (!buf)
 250                 return -ENOMEM;
 251
 252         r = icmp6_receive(fd, buf, buflen, &src, &timestamp);
 253         if (r < 0) {
 254                 switch (r) {
 255                 case -EADDRNOTAVAIL:
 256                         (void) in_addr_to_string(AF_INET6, (const union in_addr_union*) &src, &addr);
 257                         log_radv(ra, "Received RS from non-link-local address %s. Ignoring", addr);
 258                         break;
 259
 260                 case -EMULTIHOP:
 261                         log_radv(ra, "Received RS with invalid hop limit. Ignoring.");
 262                         break;
 263
 264                 case -EPFNOSUPPORT:
 265                         log_radv(ra, "Received invalid source address from ICMPv6 socket. Ignoring.");
 266                         break;
 267
 268                 case -EAGAIN: /* ignore spurious wakeups */
 269                         break;
 270
 271                 default:
 272                         log_radv_errno(ra, r, "Unexpected error receiving from ICMPv6 socket, Ignoring: %m");
 273                         break;
 274                 }
 275
 276                 return 0;
 277         }
 278
 279         if ((size_t) buflen < sizeof(struct nd_router_solicit)) {
 280                 log_radv(ra, "Too short packet received, ignoring");
 281                 return 0;
 282         }
 283
 284         (void) in_addr_to_string(AF_INET6, (const union in_addr_union*) &src, &addr);
 285
 286         r = radv_send(ra, &src, ra->lifetime_usec);
 287         if (r < 0)
 288                 log_radv_errno(ra, r, "Unable to send solicited Router Advertisement to %s, ignoring: %m", strnull(addr));
 289         else
 290                 log_radv(ra, "Sent solicited Router Advertisement to %s", strnull(addr));
 291
 292         return 0;
 293 }
 294
 295 static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
 296         usec_t min_timeout, max_timeout, time_now, timeout;
 297         sd_radv *ra = userdata;
 298         int r;
 299
 300         assert(s);
 301         assert(ra);
 302         assert(ra->event);
 303         assert(router_lifetime_is_valid(ra->lifetime_usec));
 304
 305         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 306         if (r < 0)
 307                 goto fail;
 308
 309         r = radv_send(ra, NULL, ra->lifetime_usec);
 310         if (r < 0)
 311                 log_radv_errno(ra, r, "Unable to send Router Advertisement: %m");
 312
 313         /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
 314         if (ra->ra_sent < RADV_MAX_INITIAL_RTR_ADVERTISEMENTS)
 315                 max_timeout = RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
 316         else
 317                 max_timeout = RADV_DEFAULT_MAX_TIMEOUT_USEC;
 318
 319         /* RFC 4861, Section 6.2.1, lifetime must be at least MaxRtrAdvInterval,
 320          * so lower the interval here */
 321         if (ra->lifetime_usec > 0)
 322                 max_timeout = MIN(max_timeout, ra->lifetime_usec);
 323
 324         if (max_timeout >= 9 * USEC_PER_SEC)
 325                 min_timeout = max_timeout / 3;
 326         else
 327                 min_timeout = max_timeout * 3 / 4;
 328
 329         /* RFC 4861, Section 6.2.1.
 330          * MaxRtrAdvInterval MUST be no less than 4 seconds and no greater than 1800 seconds.
 331          * MinRtrAdvInterval MUST be no less than 3 seconds and no greater than .75 * MaxRtrAdvInterval. */
 332         assert(max_timeout >= RADV_MIN_MAX_TIMEOUT_USEC);
 333         assert(max_timeout <= RADV_MAX_MAX_TIMEOUT_USEC);
 334         assert(min_timeout >= RADV_MIN_MIN_TIMEOUT_USEC);
 335         assert(min_timeout <= max_timeout * 3 / 4);
 336
 337         timeout = min_timeout + random_u64_range(max_timeout - min_timeout);
 338         log_radv(ra, "Next Router Advertisement in %s", FORMAT_TIMESPAN(timeout, USEC_PER_SEC));
 339
 340         r = event_reset_time(ra->event, &ra->timeout_event_source,
 341                              clock_boottime_or_monotonic(),
 342                              usec_add(time_now, timeout), MSEC_PER_SEC,
 343                              radv_timeout, ra,
 344                              ra->event_priority, "radv-timeout", true);
 345         if (r < 0)
 346                 goto fail;
 347
 348         ra->ra_sent++;
 349
 350         return 0;
 351
 352 fail:
 353         sd_radv_stop(ra);
 354
 355         return 0;
 356 }
 357
 358 _public_ int sd_radv_stop(sd_radv *ra) {
 359         int r;
 360
 361         if (!ra)
 362                 return 0;
 363
 364         if (ra->state == RADV_STATE_IDLE)
 365                 return 0;
 366
 367         log_radv(ra, "Stopping IPv6 Router Advertisement daemon");
 368
 369         /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
 370            with zero lifetime  */
 371         r = radv_send(ra, NULL, 0);
 372         if (r < 0)
 373                 log_radv_errno(ra, r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
 374
 375         radv_reset(ra);
 376         ra->fd = safe_close(ra->fd);
 377         ra->state = RADV_STATE_IDLE;
 378
 379         return 0;
 380 }
 381
 382 _public_ int sd_radv_start(sd_radv *ra) {
 383         int r;
 384
 385         assert_return(ra, -EINVAL);
 386         assert_return(ra->event, -EINVAL);
 387         assert_return(ra->ifindex > 0, -EINVAL);
 388
 389         if (ra->state != RADV_STATE_IDLE)
 390                 return 0;
 391
 392         r = event_reset_time(ra->event, &ra->timeout_event_source,
 393                              clock_boottime_or_monotonic(),
 394                              0, 0,
 395                              radv_timeout, ra,
 396                              ra->event_priority, "radv-timeout", true);
 397         if (r < 0)
 398                 goto fail;
 399
 400         r = icmp6_bind_router_advertisement(ra->ifindex);
 401         if (r < 0)
 402                 goto fail;
 403
 404         ra->fd = r;
 405
 406         r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
 407         if (r < 0)
 408                 goto fail;
 409
 410         r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
 411         if (r < 0)
 412                 goto fail;
 413
 414         (void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
 415
 416         ra->state = RADV_STATE_ADVERTISING;
 417
 418         log_radv(ra, "Started IPv6 Router Advertisement daemon");
 419
 420         return 0;
 421
 422  fail:
 423         radv_reset(ra);
 424
 425         return r;
 426 }
 427
 428 _public_ int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
 429         assert_return(ra, -EINVAL);
 430         assert_return(ifindex > 0, -EINVAL);
 431
 432         if (ra->state != RADV_STATE_IDLE)
 433                 return -EBUSY;
 434
 435         ra->ifindex = ifindex;
 436
 437         return 0;
 438 }
 439
 440 int sd_radv_set_ifname(sd_radv *ra, const char *ifname) {
 441         assert_return(ra, -EINVAL);
 442         assert_return(ifname, -EINVAL);
 443
 444         if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE))
 445                 return -EINVAL;
 446
 447         return free_and_strdup(&ra->ifname, ifname);
 448 }
 449
 450 int sd_radv_get_ifname(sd_radv *ra, const char **ret) {
 451         int r;
 452
 453         assert_return(ra, -EINVAL);
 454
 455         r = get_ifname(ra->ifindex, &ra->ifname);
 456         if (r < 0)
 457                 return r;
 458
 459         if (ret)
 460                 *ret = ra->ifname;
 461
 462         return 0;
 463 }
 464
 465 _public_ int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
 466         assert_return(ra, -EINVAL);
 467
 468         if (ra->state != RADV_STATE_IDLE)
 469                 return -EBUSY;
 470
 471         if (mac_addr)
 472                 ra->mac_addr = *mac_addr;
 473         else
 474                 zero(ra->mac_addr);
 475
 476         return 0;
 477 }
 478
 479 _public_ int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
 480         assert_return(ra, -EINVAL);
 481         assert_return(mtu >= 1280, -EINVAL);
 482
 483         ra->mtu = mtu;
 484
 485         return 0;
 486 }
 487
 488 _public_ int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
 489         assert_return(ra, -EINVAL);
 490
 491         if (ra->state != RADV_STATE_IDLE)
 492                 return -EBUSY;
 493
 494         ra->hop_limit = hop_limit;
 495
 496         return 0;
 497 }
 498
 499 _public_ int sd_radv_set_router_lifetime(sd_radv *ra, uint64_t lifetime_usec) {
 500         assert_return(ra, -EINVAL);
 501
 502         if (ra->state != RADV_STATE_IDLE)
 503                 return -EBUSY;
 504
 505         if (!router_lifetime_is_valid(lifetime_usec))
 506                 return -EINVAL;
 507
 508         /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the preference value MUST be set
 509          * to (00) by the sender..." */
 510         if (lifetime_usec == 0 &&
 511             (ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
 512                 return -EINVAL;
 513
 514         ra->lifetime_usec = lifetime_usec;
 515
 516         return 0;
 517 }
 518
 519 _public_ int sd_radv_set_managed_information(sd_radv *ra, int managed) {
 520         assert_return(ra, -EINVAL);
 521
 522         if (ra->state != RADV_STATE_IDLE)
 523                 return -EBUSY;
 524
 525         SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
 526
 527         return 0;
 528 }
 529
 530 _public_ int sd_radv_set_other_information(sd_radv *ra, int other) {
 531         assert_return(ra, -EINVAL);
 532
 533         if (ra->state != RADV_STATE_IDLE)
 534                 return -EBUSY;
 535
 536         SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
 537
 538         return 0;
 539 }
 540
 541 _public_ int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
 542         assert_return(ra, -EINVAL);
 543         assert_return(IN_SET(preference,
 544                              SD_NDISC_PREFERENCE_LOW,
 545                              SD_NDISC_PREFERENCE_MEDIUM,
 546                              SD_NDISC_PREFERENCE_HIGH), -EINVAL);
 547
 548         /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the preference value MUST be set
 549          * to (00) by the sender..." */
 550         if (ra->lifetime_usec == 0 && preference != SD_NDISC_PREFERENCE_MEDIUM)
 551                 return -EINVAL;
 552
 553         ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);
 554
 555         return 0;
 556 }
 557
 558 _public_ int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p, int dynamic) {
 559         sd_radv_prefix *cur;
 560         int r;
 561         _cleanup_free_ char *addr_p = NULL;
 562         usec_t time_now, valid, preferred, valid_until, preferred_until;
 563
 564         assert_return(ra, -EINVAL);
 565         assert_return(p, -EINVAL);
 566
 567         /* Refuse prefixes that don't have a prefix set */
 568         if (in6_addr_is_null(&p->opt.in6_addr))
 569                 return -ENOEXEC;
 570
 571         (void) in6_addr_prefix_to_string(&p->opt.in6_addr, p->opt.prefixlen, &addr_p);
 572
 573         LIST_FOREACH(prefix, cur, ra->prefixes) {
 574
 575                 r = in_addr_prefix_intersect(AF_INET6,
 576                                              (const union in_addr_union*) &cur->opt.in6_addr,
 577                                              cur->opt.prefixlen,
 578                                              (const union in_addr_union*) &p->opt.in6_addr,
 579                                              p->opt.prefixlen);
 580                 if (r < 0)
 581                         return r;
 582                 if (r == 0)
 583                         continue;
 584
 585                 if (dynamic && cur->opt.prefixlen == p->opt.prefixlen)
 586                         goto update;
 587
 588                 _cleanup_free_ char *addr_cur = NULL;
 589                 (void) in6_addr_prefix_to_string(&cur->opt.in6_addr, cur->opt.prefixlen, &addr_cur);
 590                 return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
 591                                       "IPv6 prefix %s already configured, ignoring %s",
 592                                       strna(addr_cur), strna(addr_p));
 593         }
 594
 595         p = sd_radv_prefix_ref(p);
 596
 597         LIST_APPEND(prefix, ra->prefixes, p);
 598
 599         ra->n_prefixes++;
 600
 601         if (!dynamic) {
 602                 log_radv(ra, "Added prefix %s", strna(addr_p));
 603                 return 0;
 604         }
 605
 606         cur = p;
 607
 608         /* If RAs have already been sent, send an RA immediately to announce the newly-added prefix */
 609         if (ra->ra_sent > 0) {
 610                 r = radv_send(ra, NULL, ra->lifetime_usec);
 611                 if (r < 0)
 612                         log_radv_errno(ra, r, "Unable to send Router Advertisement for added prefix: %m");
 613                 else
 614                         log_radv(ra, "Sent Router Advertisement for added prefix");
 615         }
 616
 617  update:
 618         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 619         if (r < 0)
 620                 return r;
 621
 622         valid = be32toh(p->opt.valid_lifetime) * USEC_PER_SEC;
 623         valid_until = usec_add(valid, time_now);
 624         if (valid_until == USEC_INFINITY)
 625                 return -EOVERFLOW;
 626
 627         preferred = be32toh(p->opt.preferred_lifetime) * USEC_PER_SEC;
 628         preferred_until = usec_add(preferred, time_now);
 629         if (preferred_until == USEC_INFINITY)
 630                 return -EOVERFLOW;
 631
 632         cur->valid_until = valid_until;
 633         cur->preferred_until = preferred_until;
 634
 635         log_radv(ra, "Updated prefix %s preferred %s valid %s",
 636                  strna(addr_p),
 637                  FORMAT_TIMESPAN(preferred, USEC_PER_SEC),
 638                  FORMAT_TIMESPAN(valid, USEC_PER_SEC));
 639
 640         return 0;
 641 }
 642
 643 _public_ sd_radv_prefix *sd_radv_remove_prefix(sd_radv *ra,
 644                                                const struct in6_addr *prefix,
 645                                                unsigned char prefixlen) {
 646         sd_radv_prefix *cur, *next;
 647
 648         assert_return(ra, NULL);
 649         assert_return(prefix, NULL);
 650
 651         LIST_FOREACH_SAFE(prefix, cur, next, ra->prefixes) {
 652                 if (prefixlen != cur->opt.prefixlen)
 653                         continue;
 654
 655                 if (!in6_addr_equal(prefix, &cur->opt.in6_addr))
 656                         continue;
 657
 658                 LIST_REMOVE(prefix, ra->prefixes, cur);
 659                 ra->n_prefixes--;
 660                 sd_radv_prefix_unref(cur);
 661
 662                 break;
 663         }
 664
 665         return cur;
 666 }
 667
 668 _public_ int sd_radv_add_route_prefix(sd_radv *ra, sd_radv_route_prefix *p, int dynamic) {
 669         usec_t time_now, valid, valid_until;
 670         _cleanup_free_ char *addr_p = NULL;
 671         sd_radv_route_prefix *cur;
 672         int r;
 673
 674         assert_return(ra, -EINVAL);
 675         assert_return(p, -EINVAL);
 676
 677         (void) in6_addr_prefix_to_string(&p->opt.in6_addr, p->opt.prefixlen, &addr_p);
 678
 679         LIST_FOREACH(prefix, cur, ra->route_prefixes) {
 680
 681                 r = in_addr_prefix_intersect(AF_INET6,
 682                                              (const union in_addr_union*) &cur->opt.in6_addr,
 683                                              cur->opt.prefixlen,
 684                                              (const union in_addr_union*) &p->opt.in6_addr,
 685                                              p->opt.prefixlen);
 686                 if (r < 0)
 687                         return r;
 688                 if (r == 0)
 689                         continue;
 690
 691                 if (dynamic && cur->opt.prefixlen == p->opt.prefixlen)
 692                         goto update;
 693
 694                 _cleanup_free_ char *addr_cur = NULL;
 695                 (void) in6_addr_prefix_to_string(&cur->opt.in6_addr, cur->opt.prefixlen, &addr_cur);
 696                 return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
 697                                       "IPv6 route prefix %s already configured, ignoring %s",
 698                                       strna(addr_cur), strna(addr_p));
 699         }
 700
 701         p = sd_radv_route_prefix_ref(p);
 702
 703         LIST_APPEND(prefix, ra->route_prefixes, p);
 704         ra->n_route_prefixes++;
 705
 706         if (!dynamic) {
 707                 log_radv(ra, "Added prefix %s", strna(addr_p));
 708                 return 0;
 709         }
 710
 711         /* If RAs have already been sent, send an RA immediately to announce the newly-added route prefix */
 712         if (ra->ra_sent > 0) {
 713                 r = radv_send(ra, NULL, ra->lifetime_usec);
 714                 if (r < 0)
 715                         log_radv_errno(ra, r, "Unable to send Router Advertisement for added route prefix: %m");
 716                 else
 717                         log_radv(ra, "Sent Router Advertisement for added route prefix");
 718         }
 719
 720  update:
 721         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 722         if (r < 0)
 723                 return r;
 724
 725         valid = be32toh(p->opt.lifetime) * USEC_PER_SEC;
 726         valid_until = usec_add(valid, time_now);
 727         if (valid_until == USEC_INFINITY)
 728                 return -EOVERFLOW;
 729
 730         log_radv(ra, "Updated route prefix %s valid %s",
 731                  strna(addr_p),
 732                  FORMAT_TIMESPAN(valid, USEC_PER_SEC));
 733
 734         return 0;
 735 }
 736
 737 _public_ int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
 738                                const struct in6_addr *dns, size_t n_dns) {
 739         _cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
 740         size_t len;
 741
 742         assert_return(ra, -EINVAL);
 743         assert_return(n_dns < 128, -EINVAL);
 744
 745         if (!dns || n_dns == 0) {
 746                 ra->rdnss = mfree(ra->rdnss);
 747                 ra->n_rdnss = 0;
 748
 749                 return 0;
 750         }
 751
 752         len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
 753
 754         opt_rdnss = malloc0(len);
 755         if (!opt_rdnss)
 756                 return -ENOMEM;
 757
 758         opt_rdnss->type = RADV_OPT_RDNSS;
 759         opt_rdnss->length = len / 8;
 760         opt_rdnss->lifetime = htobe32(lifetime);
 761
 762         memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
 763
 764         free_and_replace(ra->rdnss, opt_rdnss);
 765
 766         ra->n_rdnss = n_dns;
 767
 768         return 0;
 769 }
 770
 771 _public_ int sd_radv_set_dnssl(sd_radv *ra, uint32_t lifetime,
 772                                char **search_list) {
 773         _cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
 774         size_t len = 0;
 775         char **s;
 776         uint8_t *p;
 777
 778         assert_return(ra, -EINVAL);
 779
 780         if (strv_isempty(search_list)) {
 781                 ra->dnssl = mfree(ra->dnssl);
 782                 return 0;
 783         }
 784
 785         STRV_FOREACH(s, search_list)
 786                 len += strlen(*s) + 2;
 787
 788         len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
 789
 790         opt_dnssl = malloc0(len);
 791         if (!opt_dnssl)
 792                 return -ENOMEM;
 793
 794         opt_dnssl->type = RADV_OPT_DNSSL;
 795         opt_dnssl->length = len / 8;
 796         opt_dnssl->lifetime = htobe32(lifetime);
 797
 798         p = (uint8_t *)(opt_dnssl + 1);
 799         len -= sizeof(struct sd_radv_opt_dns);
 800
 801         STRV_FOREACH(s, search_list) {
 802                 int r;
 803
 804                 r = dns_name_to_wire_format(*s, p, len, false);
 805                 if (r < 0)
 806                         return r;
 807
 808                 if (len < (size_t)r)
 809                         return -ENOBUFS;
 810
 811                 p += r;
 812                 len -= r;
 813         }
 814
 815         free_and_replace(ra->dnssl, opt_dnssl);
 816
 817         return 0;
 818 }
 819
 820 _public_ int sd_radv_prefix_new(sd_radv_prefix **ret) {
 821         sd_radv_prefix *p;
 822
 823         assert_return(ret, -EINVAL);
 824
 825         p = new(sd_radv_prefix, 1);
 826         if (!p)
 827                 return -ENOMEM;
 828
 829         *p = (sd_radv_prefix) {
 830                 .n_ref = 1,
 831
 832                 .opt.type = ND_OPT_PREFIX_INFORMATION,
 833                 .opt.length = (sizeof(p->opt) - 1)/8 + 1,
 834                 .opt.prefixlen = 64,
 835
 836                 /* RFC 4861, Section 6.2.1 */
 837                 .opt.flags = ND_OPT_PI_FLAG_ONLINK|ND_OPT_PI_FLAG_AUTO,
 838
 839                 .opt.preferred_lifetime = htobe32(604800),
 840                 .opt.valid_lifetime = htobe32(2592000),
 841         };
 842
 843         *ret = p;
 844         return 0;
 845 }
 846
 847 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_prefix, sd_radv_prefix, mfree);
 848
 849 _public_ int sd_radv_prefix_set_prefix(sd_radv_prefix *p, const struct in6_addr *in6_addr,
 850                                        unsigned char prefixlen) {
 851         assert_return(p, -EINVAL);
 852         assert_return(in6_addr, -EINVAL);
 853
 854         if (prefixlen < 3 || prefixlen > 128)
 855                 return -EINVAL;
 856
 857         if (prefixlen > 64)
 858                 /* unusual but allowed, log it */
 859                 log_radv(NULL, "Unusual prefix length %d greater than 64", prefixlen);
 860
 861         p->opt.in6_addr = *in6_addr;
 862         p->opt.prefixlen = prefixlen;
 863
 864         return 0;
 865 }
 866
 867 _public_ int sd_radv_prefix_get_prefix(sd_radv_prefix *p, struct in6_addr *ret_in6_addr,
 868                                        unsigned char *ret_prefixlen) {
 869         assert_return(p, -EINVAL);
 870         assert_return(ret_in6_addr, -EINVAL);
 871         assert_return(ret_prefixlen, -EINVAL);
 872
 873         *ret_in6_addr = p->opt.in6_addr;
 874         *ret_prefixlen = p->opt.prefixlen;
 875
 876         return 0;
 877 }
 878
 879 _public_ int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
 880         assert_return(p, -EINVAL);
 881
 882         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
 883
 884         return 0;
 885 }
 886
 887 _public_ int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
 888                                                           int address_autoconfiguration) {
 889         assert_return(p, -EINVAL);
 890
 891         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
 892
 893         return 0;
 894 }
 895
 896 _public_ int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p,
 897                                                uint32_t valid_lifetime) {
 898         assert_return(p, -EINVAL);
 899
 900         p->opt.valid_lifetime = htobe32(valid_lifetime);
 901
 902         return 0;
 903 }
 904
 905 _public_ int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p,
 906                                                    uint32_t preferred_lifetime) {
 907         assert_return(p, -EINVAL);
 908
 909         p->opt.preferred_lifetime = htobe32(preferred_lifetime);
 910
 911         return 0;
 912 }
 913
 914 _public_ int sd_radv_route_prefix_new(sd_radv_route_prefix **ret) {
 915         sd_radv_route_prefix *p;
 916
 917         assert_return(ret, -EINVAL);
 918
 919         p = new(sd_radv_route_prefix, 1);
 920         if (!p)
 921                 return -ENOMEM;
 922
 923         *p = (sd_radv_route_prefix) {
 924                 .n_ref = 1,
 925
 926                 .opt.type = RADV_OPT_ROUTE_INFORMATION,
 927                 .opt.length = DIV_ROUND_UP(sizeof(p->opt), 8),
 928                 .opt.prefixlen = 64,
 929
 930                 .opt.lifetime = htobe32(604800),
 931         };
 932
 933         *ret = p;
 934         return 0;
 935 }
 936
 937 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_route_prefix, sd_radv_route_prefix, mfree);
 938
 939 _public_ int sd_radv_route_prefix_set_prefix(sd_radv_route_prefix *p, const struct in6_addr *in6_addr,
 940                                              unsigned char prefixlen) {
 941         assert_return(p, -EINVAL);
 942         assert_return(in6_addr, -EINVAL);
 943
 944         if (prefixlen > 128)
 945                 return -EINVAL;
 946
 947         if (prefixlen > 64)
 948                 /* unusual but allowed, log it */
 949                 log_radv(NULL, "Unusual prefix length %u greater than 64", prefixlen);
 950
 951         p->opt.in6_addr = *in6_addr;
 952         p->opt.prefixlen = prefixlen;
 953
 954         return 0;
 955 }
 956
 957 _public_ int sd_radv_route_prefix_set_lifetime(sd_radv_route_prefix *p, uint32_t valid_lifetime) {
 958         assert_return(p, -EINVAL);
 959
 960         p->opt.lifetime = htobe32(valid_lifetime);
 961
 962         return 0;
 963 }