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         };
  42
  43         *ret = TAKE_PTR(ra);
  44
  45         return 0;
  46 }
  47
  48 _public_ int sd_radv_attach_event(sd_radv *ra, sd_event *event, int64_t priority) {
  49         int r;
  50
  51         assert_return(ra, -EINVAL);
  52         assert_return(!ra->event, -EBUSY);
  53
  54         if (event)
  55                 ra->event = sd_event_ref(event);
  56         else {
  57                 r = sd_event_default(&ra->event);
  58                 if (r < 0)
  59                         return 0;
  60         }
  61
  62         ra->event_priority = priority;
  63
  64         return 0;
  65 }
  66
  67 _public_ int sd_radv_detach_event(sd_radv *ra) {
  68
  69         assert_return(ra, -EINVAL);
  70
  71         ra->event = sd_event_unref(ra->event);
  72         return 0;
  73 }
  74
  75 _public_ sd_event *sd_radv_get_event(sd_radv *ra) {
  76         assert_return(ra, NULL);
  77
  78         return ra->event;
  79 }
  80
  81 _public_ int sd_radv_is_running(sd_radv *ra) {
  82         assert_return(ra, false);
  83
  84         return ra->state != SD_RADV_STATE_IDLE;
  85 }
  86
  87 static void radv_reset(sd_radv *ra) {
  88         assert(ra);
  89
  90         (void) event_source_disable(ra->timeout_event_source);
  91
  92         ra->recv_event_source = sd_event_source_disable_unref(ra->recv_event_source);
  93
  94         ra->ra_sent = 0;
  95 }
  96
  97 static sd_radv *radv_free(sd_radv *ra) {
  98         if (!ra)
  99                 return NULL;
 100
 101         while (ra->prefixes) {
 102                 sd_radv_prefix *p = ra->prefixes;
 103
 104                 LIST_REMOVE(prefix, ra->prefixes, p);
 105                 sd_radv_prefix_unref(p);
 106         }
 107
 108         while (ra->route_prefixes) {
 109                 sd_radv_route_prefix *p = ra->route_prefixes;
 110
 111                 LIST_REMOVE(prefix, ra->route_prefixes, p);
 112                 sd_radv_route_prefix_unref(p);
 113         }
 114
 115         free(ra->rdnss);
 116         free(ra->dnssl);
 117
 118         radv_reset(ra);
 119
 120         sd_event_source_unref(ra->timeout_event_source);
 121         sd_radv_detach_event(ra);
 122
 123         ra->fd = safe_close(ra->fd);
 124         free(ra->ifname);
 125
 126         return mfree(ra);
 127 }
 128
 129 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv, sd_radv, radv_free);
 130
 131 static int radv_send(sd_radv *ra, const struct in6_addr *dst, uint32_t router_lifetime) {
 132         sd_radv_route_prefix *rt;
 133         sd_radv_prefix *p;
 134         struct sockaddr_in6 dst_addr = {
 135                 .sin6_family = AF_INET6,
 136                 .sin6_addr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
 137         };
 138         struct nd_router_advert adv = {};
 139         struct {
 140                 struct nd_opt_hdr opthdr;
 141                 struct ether_addr slladdr;
 142         } _packed_ opt_mac = {
 143                 .opthdr = {
 144                         .nd_opt_type = ND_OPT_SOURCE_LINKADDR,
 145                         .nd_opt_len = (sizeof(struct nd_opt_hdr) +
 146                                        sizeof(struct ether_addr) - 1) /8 + 1,
 147                 },
 148         };
 149         struct nd_opt_mtu opt_mtu =  {
 150                 .nd_opt_mtu_type = ND_OPT_MTU,
 151                 .nd_opt_mtu_len = 1,
 152         };
 153         /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, N routes, RDNSS
 154            and DNSSL */
 155         struct iovec iov[5 + ra->n_prefixes + ra->n_route_prefixes];
 156         struct msghdr msg = {
 157                 .msg_name = &dst_addr,
 158                 .msg_namelen = sizeof(dst_addr),
 159                 .msg_iov = iov,
 160         };
 161         usec_t time_now;
 162         int r;
 163
 164         assert(ra);
 165
 166         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 167         if (r < 0)
 168                 return r;
 169
 170         if (dst && in6_addr_is_set(dst))
 171                 dst_addr.sin6_addr = *dst;
 172
 173         adv.nd_ra_type = ND_ROUTER_ADVERT;
 174         adv.nd_ra_curhoplimit = ra->hop_limit;
 175         adv.nd_ra_flags_reserved = ra->flags;
 176         adv.nd_ra_router_lifetime = htobe16(router_lifetime);
 177         iov[msg.msg_iovlen++] = IOVEC_MAKE(&adv, sizeof(adv));
 178
 179         /* MAC address is optional, either because the link does not use L2
 180            addresses or load sharing is desired. See RFC 4861, Section 4.2 */
 181         if (!ether_addr_is_null(&ra->mac_addr)) {
 182                 opt_mac.slladdr = ra->mac_addr;
 183                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mac, sizeof(opt_mac));
 184         }
 185
 186         if (ra->mtu) {
 187                 opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
 188                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&opt_mtu, sizeof(opt_mtu));
 189         }
 190
 191         LIST_FOREACH(prefix, p, ra->prefixes) {
 192                 if (p->valid_until) {
 193
 194                         if (time_now > p->valid_until)
 195                                 p->opt.valid_lifetime = 0;
 196                         else
 197                                 p->opt.valid_lifetime = htobe32((p->valid_until - time_now) / USEC_PER_SEC);
 198
 199                         if (time_now > p->preferred_until)
 200                                 p->opt.preferred_lifetime = 0;
 201                         else
 202                                 p->opt.preferred_lifetime = htobe32((p->preferred_until - time_now) / USEC_PER_SEC);
 203                 }
 204                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&p->opt, sizeof(p->opt));
 205         }
 206
 207         LIST_FOREACH(prefix, rt, ra->route_prefixes)
 208                 iov[msg.msg_iovlen++] = IOVEC_MAKE(&rt->opt, sizeof(rt->opt));
 209
 210         if (ra->rdnss)
 211                 iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->rdnss, ra->rdnss->length * 8);
 212
 213         if (ra->dnssl)
 214                 iov[msg.msg_iovlen++] = IOVEC_MAKE(ra->dnssl, ra->dnssl->length * 8);
 215
 216         if (sendmsg(ra->fd, &msg, 0) < 0)
 217                 return -errno;
 218
 219         return 0;
 220 }
 221
 222 static int radv_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 223         sd_radv *ra = userdata;
 224         _cleanup_free_ char *addr = NULL;
 225         struct in6_addr src;
 226         triple_timestamp timestamp;
 227         int r;
 228         ssize_t buflen;
 229         _cleanup_free_ char *buf = NULL;
 230
 231         assert(s);
 232         assert(ra);
 233         assert(ra->event);
 234
 235         buflen = next_datagram_size_fd(fd);
 236         if (buflen < 0)
 237                 return (int) buflen;
 238
 239         buf = new0(char, buflen);
 240         if (!buf)
 241                 return -ENOMEM;
 242
 243         r = icmp6_receive(fd, buf, buflen, &src, &timestamp);
 244         if (r < 0) {
 245                 switch (r) {
 246                 case -EADDRNOTAVAIL:
 247                         (void) in_addr_to_string(AF_INET6, (const union in_addr_union*) &src, &addr);
 248                         log_radv(ra, "Received RS from non-link-local address %s. Ignoring", addr);
 249                         break;
 250
 251                 case -EMULTIHOP:
 252                         log_radv(ra, "Received RS with invalid hop limit. Ignoring.");
 253                         break;
 254
 255                 case -EPFNOSUPPORT:
 256                         log_radv(ra, "Received invalid source address from ICMPv6 socket. Ignoring.");
 257                         break;
 258
 259                 case -EAGAIN: /* ignore spurious wakeups */
 260                         break;
 261
 262                 default:
 263                         log_radv_errno(ra, r, "Unexpected error receiving from ICMPv6 socket, Ignoring: %m");
 264                         break;
 265                 }
 266
 267                 return 0;
 268         }
 269
 270         if ((size_t) buflen < sizeof(struct nd_router_solicit)) {
 271                 log_radv(ra, "Too short packet received, ignoring");
 272                 return 0;
 273         }
 274
 275         (void) in_addr_to_string(AF_INET6, (const union in_addr_union*) &src, &addr);
 276
 277         r = radv_send(ra, &src, ra->lifetime);
 278         if (r < 0)
 279                 log_radv_errno(ra, r, "Unable to send solicited Router Advertisement to %s, ignoring: %m", strnull(addr));
 280         else
 281                 log_radv(ra, "Sent solicited Router Advertisement to %s", strnull(addr));
 282
 283         return 0;
 284 }
 285
 286 static usec_t radv_compute_timeout(usec_t min, usec_t max) {
 287         assert_return(min <= max, SD_RADV_DEFAULT_MIN_TIMEOUT_USEC);
 288
 289         /* RFC 4861: min must be no less than 3s, max must be no less than 4s */
 290         min = MAX(min, 3*USEC_PER_SEC);
 291         max = MAX(max, 4*USEC_PER_SEC);
 292
 293         return min + (random_u32() % (max - min));
 294 }
 295
 296 static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
 297         int r;
 298         sd_radv *ra = userdata;
 299         usec_t min_timeout = SD_RADV_DEFAULT_MIN_TIMEOUT_USEC;
 300         usec_t max_timeout = SD_RADV_DEFAULT_MAX_TIMEOUT_USEC;
 301         usec_t time_now, timeout;
 302
 303         assert(s);
 304         assert(ra);
 305         assert(ra->event);
 306
 307         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 308         if (r < 0)
 309                 goto fail;
 310
 311         r = radv_send(ra, NULL, ra->lifetime);
 312         if (r < 0)
 313                 log_radv_errno(ra, r, "Unable to send Router Advertisement: %m");
 314
 315         /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
 316         if (ra->ra_sent < SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS) {
 317                 max_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
 318                 min_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC / 3;
 319         }
 320
 321         /* RFC 4861, Section 6.2.1, lifetime must be at least MaxRtrAdvInterval,
 322            so lower the interval here */
 323         if (ra->lifetime > 0 && (ra->lifetime * USEC_PER_SEC) < max_timeout) {
 324                 max_timeout = ra->lifetime * USEC_PER_SEC;
 325                 min_timeout = max_timeout / 3;
 326         }
 327
 328         timeout = radv_compute_timeout(min_timeout, max_timeout);
 329         log_radv(ra, "Next Router Advertisement in %s", FORMAT_TIMESPAN(timeout, USEC_PER_SEC));
 330
 331         r = event_reset_time(ra->event, &ra->timeout_event_source,
 332                              clock_boottime_or_monotonic(),
 333                              time_now + timeout, MSEC_PER_SEC,
 334                              radv_timeout, ra,
 335                              ra->event_priority, "radv-timeout", true);
 336         if (r < 0)
 337                 goto fail;
 338
 339         ra->ra_sent++;
 340
 341         return 0;
 342
 343 fail:
 344         sd_radv_stop(ra);
 345
 346         return 0;
 347 }
 348
 349 _public_ int sd_radv_stop(sd_radv *ra) {
 350         int r;
 351
 352         if (!ra)
 353                 return 0;
 354
 355         if (ra->state == SD_RADV_STATE_IDLE)
 356                 return 0;
 357
 358         log_radv(ra, "Stopping IPv6 Router Advertisement daemon");
 359
 360         /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
 361            with zero lifetime  */
 362         r = radv_send(ra, NULL, 0);
 363         if (r < 0)
 364                 log_radv_errno(ra, r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
 365
 366         radv_reset(ra);
 367         ra->fd = safe_close(ra->fd);
 368         ra->state = SD_RADV_STATE_IDLE;
 369
 370         return 0;
 371 }
 372
 373 _public_ int sd_radv_start(sd_radv *ra) {
 374         int r;
 375
 376         assert_return(ra, -EINVAL);
 377         assert_return(ra->event, -EINVAL);
 378         assert_return(ra->ifindex > 0, -EINVAL);
 379
 380         if (ra->state != SD_RADV_STATE_IDLE)
 381                 return 0;
 382
 383         r = event_reset_time(ra->event, &ra->timeout_event_source,
 384                              clock_boottime_or_monotonic(),
 385                              0, 0,
 386                              radv_timeout, ra,
 387                              ra->event_priority, "radv-timeout", true);
 388         if (r < 0)
 389                 goto fail;
 390
 391         r = icmp6_bind_router_advertisement(ra->ifindex);
 392         if (r < 0)
 393                 goto fail;
 394
 395         ra->fd = r;
 396
 397         r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
 398         if (r < 0)
 399                 goto fail;
 400
 401         r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
 402         if (r < 0)
 403                 goto fail;
 404
 405         (void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
 406
 407         ra->state = SD_RADV_STATE_ADVERTISING;
 408
 409         log_radv(ra, "Started IPv6 Router Advertisement daemon");
 410
 411         return 0;
 412
 413  fail:
 414         radv_reset(ra);
 415
 416         return r;
 417 }
 418
 419 _public_ int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
 420         assert_return(ra, -EINVAL);
 421         assert_return(ifindex > 0, -EINVAL);
 422
 423         if (ra->state != SD_RADV_STATE_IDLE)
 424                 return -EBUSY;
 425
 426         ra->ifindex = ifindex;
 427
 428         return 0;
 429 }
 430
 431 int sd_radv_set_ifname(sd_radv *ra, const char *ifname) {
 432         assert_return(ra, -EINVAL);
 433         assert_return(ifname, -EINVAL);
 434
 435         if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE))
 436                 return -EINVAL;
 437
 438         return free_and_strdup(&ra->ifname, ifname);
 439 }
 440
 441 int sd_radv_get_ifname(sd_radv *ra, const char **ret) {
 442         int r;
 443
 444         assert_return(ra, -EINVAL);
 445
 446         r = get_ifname(ra->ifindex, &ra->ifname);
 447         if (r < 0)
 448                 return r;
 449
 450         if (ret)
 451                 *ret = ra->ifname;
 452
 453         return 0;
 454 }
 455
 456 _public_ int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
 457         assert_return(ra, -EINVAL);
 458
 459         if (ra->state != SD_RADV_STATE_IDLE)
 460                 return -EBUSY;
 461
 462         if (mac_addr)
 463                 ra->mac_addr = *mac_addr;
 464         else
 465                 zero(ra->mac_addr);
 466
 467         return 0;
 468 }
 469
 470 _public_ int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
 471         assert_return(ra, -EINVAL);
 472         assert_return(mtu >= 1280, -EINVAL);
 473
 474         ra->mtu = mtu;
 475
 476         return 0;
 477 }
 478
 479 _public_ int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
 480         assert_return(ra, -EINVAL);
 481
 482         if (ra->state != SD_RADV_STATE_IDLE)
 483                 return -EBUSY;
 484
 485         ra->hop_limit = hop_limit;
 486
 487         return 0;
 488 }
 489
 490 _public_ int sd_radv_set_router_lifetime(sd_radv *ra, uint16_t router_lifetime) {
 491         assert_return(ra, -EINVAL);
 492
 493         if (ra->state != SD_RADV_STATE_IDLE)
 494                 return -EBUSY;
 495
 496         /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the preference value MUST be set
 497          * to (00) by the sender..." */
 498         if (router_lifetime == 0 &&
 499             (ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
 500                 return -ETIME;
 501
 502         ra->lifetime = router_lifetime;
 503
 504         return 0;
 505 }
 506
 507 _public_ int sd_radv_set_managed_information(sd_radv *ra, int managed) {
 508         assert_return(ra, -EINVAL);
 509
 510         if (ra->state != SD_RADV_STATE_IDLE)
 511                 return -EBUSY;
 512
 513         SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
 514
 515         return 0;
 516 }
 517
 518 _public_ int sd_radv_set_other_information(sd_radv *ra, int other) {
 519         assert_return(ra, -EINVAL);
 520
 521         if (ra->state != SD_RADV_STATE_IDLE)
 522                 return -EBUSY;
 523
 524         SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
 525
 526         return 0;
 527 }
 528
 529 _public_ int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
 530         assert_return(ra, -EINVAL);
 531         assert_return(IN_SET(preference,
 532                              SD_NDISC_PREFERENCE_LOW,
 533                              SD_NDISC_PREFERENCE_MEDIUM,
 534                              SD_NDISC_PREFERENCE_HIGH), -EINVAL);
 535
 536         /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the preference value MUST be set
 537          * to (00) by the sender..." */
 538         if (ra->lifetime == 0 && preference != SD_NDISC_PREFERENCE_MEDIUM)
 539                 return -EINVAL;
 540
 541         ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);
 542
 543         return 0;
 544 }
 545
 546 _public_ int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p, int dynamic) {
 547         sd_radv_prefix *cur;
 548         int r;
 549         _cleanup_free_ char *addr_p = NULL;
 550         usec_t time_now, valid, preferred, valid_until, preferred_until;
 551
 552         assert_return(ra, -EINVAL);
 553
 554         if (!p)
 555                 return -EINVAL;
 556
 557         /* Refuse prefixes that don't have a prefix set */
 558         if (in6_addr_is_null(&p->opt.in6_addr))
 559                 return -ENOEXEC;
 560
 561         (void) in_addr_prefix_to_string(AF_INET6,
 562                                         (const union in_addr_union*) &p->opt.in6_addr,
 563                                         p->opt.prefixlen, &addr_p);
 564
 565         LIST_FOREACH(prefix, cur, ra->prefixes) {
 566
 567                 r = in_addr_prefix_intersect(AF_INET6,
 568                                              (const union in_addr_union*) &cur->opt.in6_addr,
 569                                              cur->opt.prefixlen,
 570                                              (const union in_addr_union*) &p->opt.in6_addr,
 571                                              p->opt.prefixlen);
 572                 if (r < 0)
 573                         return r;
 574                 if (r == 0)
 575                         continue;
 576
 577                 if (dynamic && cur->opt.prefixlen == p->opt.prefixlen)
 578                         goto update;
 579
 580                 _cleanup_free_ char *addr_cur = NULL;
 581                 (void) in_addr_prefix_to_string(AF_INET6,
 582                                                 (const union in_addr_union*) &cur->opt.in6_addr,
 583                                                 cur->opt.prefixlen, &addr_cur);
 584                 return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
 585                                       "IPv6 prefix %s already configured, ignoring %s",
 586                                       strna(addr_cur), strna(addr_p));
 587         }
 588
 589         p = sd_radv_prefix_ref(p);
 590
 591         LIST_APPEND(prefix, ra->prefixes, p);
 592
 593         ra->n_prefixes++;
 594
 595         if (!dynamic) {
 596                 log_radv(ra, "Added prefix %s", strna(addr_p));
 597                 return 0;
 598         }
 599
 600         cur = p;
 601
 602         /* If RAs have already been sent, send an RA immediately to announce the newly-added prefix */
 603         if (ra->ra_sent > 0) {
 604                 r = radv_send(ra, NULL, ra->lifetime);
 605                 if (r < 0)
 606                         log_radv_errno(ra, r, "Unable to send Router Advertisement for added prefix: %m");
 607                 else
 608                         log_radv(ra, "Sent Router Advertisement for added prefix");
 609         }
 610
 611  update:
 612         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 613         if (r < 0)
 614                 return r;
 615
 616         valid = be32toh(p->opt.valid_lifetime) * USEC_PER_SEC;
 617         valid_until = usec_add(valid, time_now);
 618         if (valid_until == USEC_INFINITY)
 619                 return -EOVERFLOW;
 620
 621         preferred = be32toh(p->opt.preferred_lifetime) * USEC_PER_SEC;
 622         preferred_until = usec_add(preferred, time_now);
 623         if (preferred_until == USEC_INFINITY)
 624                 return -EOVERFLOW;
 625
 626         cur->valid_until = valid_until;
 627         cur->preferred_until = preferred_until;
 628
 629         log_radv(ra, "Updated prefix %s preferred %s valid %s",
 630                  strna(addr_p),
 631                  FORMAT_TIMESPAN(preferred, USEC_PER_SEC),
 632                  FORMAT_TIMESPAN(valid, USEC_PER_SEC));
 633
 634         return 0;
 635 }
 636
 637 _public_ sd_radv_prefix *sd_radv_remove_prefix(sd_radv *ra,
 638                                                const struct in6_addr *prefix,
 639                                                unsigned char prefixlen) {
 640         sd_radv_prefix *cur, *next;
 641
 642         assert_return(ra, NULL);
 643         assert_return(prefix, NULL);
 644
 645         LIST_FOREACH_SAFE(prefix, cur, next, ra->prefixes) {
 646                 if (prefixlen != cur->opt.prefixlen)
 647                         continue;
 648
 649                 if (!in6_addr_equal(prefix, &cur->opt.in6_addr))
 650                         continue;
 651
 652                 LIST_REMOVE(prefix, ra->prefixes, cur);
 653                 ra->n_prefixes--;
 654                 sd_radv_prefix_unref(cur);
 655
 656                 break;
 657         }
 658
 659         return cur;
 660 }
 661
 662 _public_ int sd_radv_add_route_prefix(sd_radv *ra, sd_radv_route_prefix *p, int dynamic) {
 663         usec_t time_now, valid, valid_until;
 664         _cleanup_free_ char *pretty = NULL;
 665         sd_radv_route_prefix *cur;
 666         int r;
 667
 668         assert_return(ra, -EINVAL);
 669
 670         if (!p)
 671                 return -EINVAL;
 672
 673         (void) in_addr_prefix_to_string(AF_INET6,
 674                                         (const union in_addr_union*) &p->opt.in6_addr,
 675                                         p->opt.prefixlen, &pretty);
 676
 677         LIST_FOREACH(prefix, cur, ra->route_prefixes) {
 678
 679                 r = in_addr_prefix_intersect(AF_INET6,
 680                                              (const union in_addr_union*) &cur->opt.in6_addr,
 681                                              cur->opt.prefixlen,
 682                                              (const union in_addr_union*) &p->opt.in6_addr,
 683                                              p->opt.prefixlen);
 684                 if (r < 0)
 685                         return r;
 686                 if (r == 0)
 687                         continue;
 688
 689                 if (dynamic && cur->opt.prefixlen == p->opt.prefixlen)
 690                         goto update;
 691
 692                 _cleanup_free_ char *addr = NULL;
 693                 (void) in_addr_prefix_to_string(AF_INET6,
 694                                                 (const union in_addr_union*) &cur->opt.in6_addr,
 695                                                 cur->opt.prefixlen, &addr);
 696                 return log_radv_errno(ra, SYNTHETIC_ERRNO(EEXIST),
 697                                       "IPv6 route prefix %s already configured, ignoring %s",
 698                                       strna(addr), strna(pretty));
 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(pretty));
 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);
 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(pretty),
 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 = SD_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 = SD_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 = SD_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 }