src/libsystemd-network/sd-radv.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   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 "radv-internal.h"
  23 #include "random-util.h"
  24 #include "socket-util.h"
  25 #include "string-util.h"
  26 #include "strv.h"
  27
  28 _public_ int sd_radv_new(sd_radv **ret) {
  29         _cleanup_(sd_radv_unrefp) sd_radv *ra = NULL;
  30
  31         assert_return(ret, -EINVAL);
  32
  33         ra = new(sd_radv, 1);
  34         if (!ra)
  35                 return -ENOMEM;
  36
  37         *ra = (sd_radv) {
  38                 .n_ref = 1,
  39                 .fd = -1,
  40         };
  41
  42         *ret = TAKE_PTR(ra);
  43
  44         return 0;
  45 }
  46
  47 _public_ int sd_radv_attach_event(sd_radv *ra, sd_event *event, int64_t priority) {
  48         int r;
  49
  50         assert_return(ra, -EINVAL);
  51         assert_return(!ra->event, -EBUSY);
  52
  53         if (event)
  54                 ra->event = sd_event_ref(event);
  55         else {
  56                 r = sd_event_default(&ra->event);
  57                 if (r < 0)
  58                         return 0;
  59         }
  60
  61         ra->event_priority = priority;
  62
  63         return 0;
  64 }
  65
  66 _public_ int sd_radv_detach_event(sd_radv *ra) {
  67
  68         assert_return(ra, -EINVAL);
  69
  70         ra->event = sd_event_unref(ra->event);
  71         return 0;
  72 }
  73
  74 _public_ sd_event *sd_radv_get_event(sd_radv *ra) {
  75         assert_return(ra, NULL);
  76
  77         return ra->event;
  78 }
  79
  80 _public_ int sd_radv_is_running(sd_radv *ra) {
  81         assert_return(ra, false);
  82
  83         return ra->state != SD_RADV_STATE_IDLE;
  84 }
  85
  86 static void radv_reset(sd_radv *ra) {
  87         assert(ra);
  88
  89         (void) event_source_disable(ra->timeout_event_source);
  90
  91         ra->recv_event_source =
  92                 sd_event_source_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         ra->timeout_event_source = sd_event_source_unref(ra->timeout_event_source);
 119
 120         radv_reset(ra);
 121
 122         sd_radv_detach_event(ra);
 123
 124         ra->fd = safe_close(ra->fd);
 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_IS_ADDR_UNSPECIFIED(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, (union in_addr_union*) &src, &addr);
 248                         log_radv("Received RS from non-link-local address %s. Ignoring", addr);
 249                         break;
 250
 251                 case -EMULTIHOP:
 252                         log_radv("Received RS with invalid hop limit. Ignoring.");
 253                         break;
 254
 255                 case -EPFNOSUPPORT:
 256                         log_radv("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(r, "Unexpected error receiving from ICMPv6 socket: %m");
 264                         break;
 265                 }
 266
 267                 return 0;
 268         }
 269
 270         if ((size_t) buflen < sizeof(struct nd_router_solicit)) {
 271                 log_radv("Too short packet received");
 272                 return 0;
 273         }
 274
 275         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
 276
 277         r = radv_send(ra, &src, ra->lifetime);
 278         if (r < 0)
 279                 log_radv_errno(r, "Unable to send solicited Router Advertisement to %s: %m", strnull(addr));
 280         else
 281                 log_radv("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         char time_string[FORMAT_TIMESPAN_MAX];
 303
 304         assert(s);
 305         assert(ra);
 306         assert(ra->event);
 307
 308         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 309         if (r < 0)
 310                 goto fail;
 311
 312         r = radv_send(ra, NULL, ra->lifetime);
 313         if (r < 0)
 314                 log_radv_errno(r, "Unable to send Router Advertisement: %m");
 315
 316         /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
 317         if (ra->ra_sent < SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS) {
 318                 max_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
 319                 min_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC / 3;
 320         }
 321
 322         /* RFC 4861, Section 6.2.1, lifetime must be at least MaxRtrAdvInterval,
 323            so lower the interval here */
 324         if (ra->lifetime > 0 && (ra->lifetime * USEC_PER_SEC) < max_timeout) {
 325                 max_timeout = ra->lifetime * USEC_PER_SEC;
 326                 min_timeout = max_timeout / 3;
 327         }
 328
 329         timeout = radv_compute_timeout(min_timeout, max_timeout);
 330
 331         log_radv("Next Router Advertisement in %s",
 332                  format_timespan(time_string, FORMAT_TIMESPAN_MAX,
 333                                  timeout, USEC_PER_SEC));
 334
 335         r = event_reset_time(ra->event, &ra->timeout_event_source,
 336                              clock_boottime_or_monotonic(),
 337                              time_now + timeout, MSEC_PER_SEC,
 338                              radv_timeout, ra,
 339                              ra->event_priority, "radv-timeout", true);
 340         if (r < 0)
 341                 goto fail;
 342
 343         ra->ra_sent++;
 344
 345         return 0;
 346
 347 fail:
 348         sd_radv_stop(ra);
 349
 350         return 0;
 351 }
 352
 353 _public_ int sd_radv_stop(sd_radv *ra) {
 354         int r;
 355
 356         assert_return(ra, -EINVAL);
 357
 358         if (ra->state == SD_RADV_STATE_IDLE)
 359                 return 0;
 360
 361         log_radv("Stopping IPv6 Router Advertisement daemon");
 362
 363         /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
 364            with zero lifetime  */
 365         r = radv_send(ra, NULL, 0);
 366         if (r < 0)
 367                 log_radv_errno(r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
 368
 369         radv_reset(ra);
 370         ra->fd = safe_close(ra->fd);
 371         ra->state = SD_RADV_STATE_IDLE;
 372
 373         return 0;
 374 }
 375
 376 _public_ int sd_radv_start(sd_radv *ra) {
 377         int r;
 378
 379         assert_return(ra, -EINVAL);
 380         assert_return(ra->event, -EINVAL);
 381         assert_return(ra->ifindex > 0, -EINVAL);
 382
 383         if (ra->state != SD_RADV_STATE_IDLE)
 384                 return 0;
 385
 386         r = event_reset_time(ra->event, &ra->timeout_event_source,
 387                              clock_boottime_or_monotonic(),
 388                              0, 0,
 389                              radv_timeout, ra,
 390                              ra->event_priority, "radv-timeout", true);
 391         if (r < 0)
 392                 goto fail;
 393
 394         r = icmp6_bind_router_advertisement(ra->ifindex);
 395         if (r < 0)
 396                 goto fail;
 397
 398         ra->fd = r;
 399
 400         r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
 401         if (r < 0)
 402                 goto fail;
 403
 404         r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
 405         if (r < 0)
 406                 goto fail;
 407
 408         (void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
 409
 410         ra->state = SD_RADV_STATE_ADVERTISING;
 411
 412         log_radv("Started IPv6 Router Advertisement daemon");
 413
 414         return 0;
 415
 416  fail:
 417         radv_reset(ra);
 418
 419         return r;
 420 }
 421
 422 _public_ int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
 423         assert_return(ra, -EINVAL);
 424         assert_return(ifindex > 0, -EINVAL);
 425
 426         if (ra->state != SD_RADV_STATE_IDLE)
 427                 return -EBUSY;
 428
 429         ra->ifindex = ifindex;
 430
 431         return 0;
 432 }
 433
 434 _public_ int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
 435         assert_return(ra, -EINVAL);
 436
 437         if (ra->state != SD_RADV_STATE_IDLE)
 438                 return -EBUSY;
 439
 440         if (mac_addr)
 441                 ra->mac_addr = *mac_addr;
 442         else
 443                 zero(ra->mac_addr);
 444
 445         return 0;
 446 }
 447
 448 _public_ int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
 449         assert_return(ra, -EINVAL);
 450         assert_return(mtu >= 1280, -EINVAL);
 451
 452         ra->mtu = mtu;
 453
 454         return 0;
 455 }
 456
 457 _public_ int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
 458         assert_return(ra, -EINVAL);
 459
 460         if (ra->state != SD_RADV_STATE_IDLE)
 461                 return -EBUSY;
 462
 463         ra->hop_limit = hop_limit;
 464
 465         return 0;
 466 }
 467
 468 _public_ int sd_radv_set_router_lifetime(sd_radv *ra, uint32_t router_lifetime) {
 469         assert_return(ra, -EINVAL);
 470
 471         if (ra->state != SD_RADV_STATE_IDLE)
 472                 return -EBUSY;
 473
 474         /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the
 475            preference value MUST be set to (00) by the sender..." */
 476         if (router_lifetime == 0 &&
 477             (ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
 478                 return -ETIME;
 479
 480         ra->lifetime = router_lifetime;
 481
 482         return 0;
 483 }
 484
 485 _public_ int sd_radv_set_managed_information(sd_radv *ra, int managed) {
 486         assert_return(ra, -EINVAL);
 487
 488         if (ra->state != SD_RADV_STATE_IDLE)
 489                 return -EBUSY;
 490
 491         SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
 492
 493         return 0;
 494 }
 495
 496 _public_ int sd_radv_set_other_information(sd_radv *ra, int other) {
 497         assert_return(ra, -EINVAL);
 498
 499         if (ra->state != SD_RADV_STATE_IDLE)
 500                 return -EBUSY;
 501
 502         SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
 503
 504         return 0;
 505 }
 506
 507 _public_ int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
 508         int r = 0;
 509
 510         assert_return(ra, -EINVAL);
 511         assert_return(IN_SET(preference,
 512                              SD_NDISC_PREFERENCE_LOW,
 513                              SD_NDISC_PREFERENCE_MEDIUM,
 514                              SD_NDISC_PREFERENCE_HIGH), -EINVAL);
 515
 516         ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);
 517
 518         return r;
 519 }
 520
 521 _public_ int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p, int dynamic) {
 522         sd_radv_prefix *cur;
 523         int r;
 524         _cleanup_free_ char *addr_p = NULL;
 525         char time_string_preferred[FORMAT_TIMESPAN_MAX];
 526         char time_string_valid[FORMAT_TIMESPAN_MAX];
 527         usec_t time_now, valid, preferred, valid_until, preferred_until;
 528
 529         assert_return(ra, -EINVAL);
 530
 531         if (!p)
 532                 return -EINVAL;
 533
 534         /* Refuse prefixes that don't have a prefix set */
 535         if (IN6_IS_ADDR_UNSPECIFIED(&p->opt.in6_addr))
 536                 return -ENOEXEC;
 537
 538         LIST_FOREACH(prefix, cur, ra->prefixes) {
 539
 540                 r = in_addr_prefix_intersect(AF_INET6,
 541                                              (union in_addr_union*) &cur->opt.in6_addr,
 542                                              cur->opt.prefixlen,
 543                                              (union in_addr_union*) &p->opt.in6_addr,
 544                                              p->opt.prefixlen);
 545                 if (r > 0) {
 546                         _cleanup_free_ char *addr_cur = NULL;
 547
 548                         (void) in_addr_to_string(AF_INET6,
 549                                                  (union in_addr_union*) &p->opt.in6_addr,
 550                                                  &addr_p);
 551
 552                         if (dynamic && cur->opt.prefixlen == p->opt.prefixlen)
 553                                 goto update;
 554
 555                         (void) in_addr_to_string(AF_INET6,
 556                                                  (union in_addr_union*) &cur->opt.in6_addr,
 557                                                  &addr_cur);
 558                         log_radv("IPv6 prefix %s/%u already configured, ignoring %s/%u",
 559                                  addr_cur, cur->opt.prefixlen,
 560                                  addr_p, p->opt.prefixlen);
 561
 562                         return -EEXIST;
 563                 }
 564         }
 565
 566         p = sd_radv_prefix_ref(p);
 567
 568         LIST_APPEND(prefix, ra->prefixes, p);
 569
 570         ra->n_prefixes++;
 571
 572         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &p->opt.in6_addr, &addr_p);
 573
 574         if (!dynamic) {
 575                 log_radv("Added prefix %s/%d", addr_p, p->opt.prefixlen);
 576                 return 0;
 577         }
 578
 579         cur = p;
 580
 581  update:
 582         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 583         if (r < 0)
 584                 return r;
 585
 586         valid = be32toh(p->opt.valid_lifetime) * USEC_PER_SEC;
 587         valid_until = usec_add(valid, time_now);
 588         if (valid_until == USEC_INFINITY)
 589                 return -EOVERFLOW;
 590
 591         preferred = be32toh(p->opt.preferred_lifetime) * USEC_PER_SEC;
 592         preferred_until = usec_add(preferred, time_now);
 593         if (preferred_until == USEC_INFINITY)
 594                 return -EOVERFLOW;
 595
 596         cur->valid_until = valid_until;
 597         cur->preferred_until = preferred_until;
 598
 599         log_radv("Updated prefix %s/%u preferred %s valid %s",
 600                  addr_p, p->opt.prefixlen,
 601                  format_timespan(time_string_preferred, FORMAT_TIMESPAN_MAX,
 602                                  preferred, USEC_PER_SEC),
 603                  format_timespan(time_string_valid, FORMAT_TIMESPAN_MAX,
 604                                  valid, USEC_PER_SEC));
 605
 606         return 0;
 607 }
 608
 609 _public_ sd_radv_prefix *sd_radv_remove_prefix(sd_radv *ra,
 610                                                const struct in6_addr *prefix,
 611                                                unsigned char prefixlen) {
 612         sd_radv_prefix *cur, *next;
 613
 614         assert_return(ra, NULL);
 615         assert_return(prefix, NULL);
 616
 617         LIST_FOREACH_SAFE(prefix, cur, next, ra->prefixes) {
 618                 if (prefixlen != cur->opt.prefixlen)
 619                         continue;
 620
 621                 if (!in_addr_equal(AF_INET6,
 622                                    (union in_addr_union *)prefix,
 623                                    (union in_addr_union *)&cur->opt.in6_addr))
 624                         continue;
 625
 626                 LIST_REMOVE(prefix, ra->prefixes, cur);
 627                 ra->n_prefixes--;
 628                 sd_radv_prefix_unref(cur);
 629
 630                 break;
 631         }
 632
 633         return cur;
 634 }
 635
 636 _public_ int sd_radv_add_route_prefix(sd_radv *ra, sd_radv_route_prefix *p, int dynamic) {
 637         char time_string_valid[FORMAT_TIMESPAN_MAX];
 638         usec_t time_now, valid, valid_until;
 639         _cleanup_free_ char *pretty = NULL;
 640         sd_radv_route_prefix *cur;
 641         int r;
 642
 643         assert_return(ra, -EINVAL);
 644
 645         if (!p)
 646                 return -EINVAL;
 647
 648         (void) in_addr_to_string(AF_INET6,
 649                                  (union in_addr_union*) &p->opt.in6_addr,
 650                                  &pretty);
 651
 652         LIST_FOREACH(prefix, cur, ra->route_prefixes) {
 653                 _cleanup_free_ char *addr = NULL;
 654
 655                 r = in_addr_prefix_intersect(AF_INET6,
 656                                              (union in_addr_union*) &cur->opt.in6_addr,
 657                                              cur->opt.prefixlen,
 658                                              (union in_addr_union*) &p->opt.in6_addr,
 659                                              p->opt.prefixlen);
 660                 if (r < 0)
 661                         return r;
 662                 if (r == 0)
 663                         continue;
 664
 665                 if (dynamic && cur->opt.prefixlen == p->opt.prefixlen)
 666                         goto update;
 667
 668                 (void) in_addr_to_string(AF_INET6,
 669                                          (union in_addr_union*) &cur->opt.in6_addr,
 670                                          &addr);
 671                 log_radv("IPv6 route prefix %s/%u already configured, ignoring %s/%u",
 672                          strempty(addr), cur->opt.prefixlen,
 673                          strempty(pretty), p->opt.prefixlen);
 674
 675                 return -EEXIST;
 676         }
 677
 678         p = sd_radv_route_prefix_ref(p);
 679
 680         LIST_APPEND(prefix, ra->route_prefixes, p);
 681         ra->n_route_prefixes++;
 682
 683         cur = p;
 684         if (!dynamic) {
 685                 log_radv("Added prefix %s/%u", strempty(pretty), p->opt.prefixlen);
 686                 return 0;
 687         }
 688
 689  update:
 690         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 691         if (r < 0)
 692                 return r;
 693
 694         valid = be32toh(p->opt.lifetime) * USEC_PER_SEC;
 695         valid_until = usec_add(valid, time_now);
 696         if (valid_until == USEC_INFINITY)
 697                 return -EOVERFLOW;
 698
 699         log_radv("Updated route prefix %s/%u valid %s",
 700                  strempty(pretty), p->opt.prefixlen,
 701                  format_timespan(time_string_valid, FORMAT_TIMESPAN_MAX, valid, USEC_PER_SEC));
 702
 703         return 0;
 704 }
 705
 706 _public_ int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
 707                                const struct in6_addr *dns, size_t n_dns) {
 708         _cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
 709         size_t len;
 710
 711         assert_return(ra, -EINVAL);
 712         assert_return(n_dns < 128, -EINVAL);
 713
 714         if (!dns || n_dns == 0) {
 715                 ra->rdnss = mfree(ra->rdnss);
 716                 ra->n_rdnss = 0;
 717
 718                 return 0;
 719         }
 720
 721         len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
 722
 723         opt_rdnss = malloc0(len);
 724         if (!opt_rdnss)
 725                 return -ENOMEM;
 726
 727         opt_rdnss->type = SD_RADV_OPT_RDNSS;
 728         opt_rdnss->length = len / 8;
 729         opt_rdnss->lifetime = htobe32(lifetime);
 730
 731         memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
 732
 733         free_and_replace(ra->rdnss, opt_rdnss);
 734
 735         ra->n_rdnss = n_dns;
 736
 737         return 0;
 738 }
 739
 740 _public_ int sd_radv_set_dnssl(sd_radv *ra, uint32_t lifetime,
 741                                char **search_list) {
 742         _cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
 743         size_t len = 0;
 744         char **s;
 745         uint8_t *p;
 746
 747         assert_return(ra, -EINVAL);
 748
 749         if (strv_isempty(search_list)) {
 750                 ra->dnssl = mfree(ra->dnssl);
 751                 return 0;
 752         }
 753
 754         STRV_FOREACH(s, search_list)
 755                 len += strlen(*s) + 2;
 756
 757         len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
 758
 759         opt_dnssl = malloc0(len);
 760         if (!opt_dnssl)
 761                 return -ENOMEM;
 762
 763         opt_dnssl->type = SD_RADV_OPT_DNSSL;
 764         opt_dnssl->length = len / 8;
 765         opt_dnssl->lifetime = htobe32(lifetime);
 766
 767         p = (uint8_t *)(opt_dnssl + 1);
 768         len -= sizeof(struct sd_radv_opt_dns);
 769
 770         STRV_FOREACH(s, search_list) {
 771                 int r;
 772
 773                 r = dns_name_to_wire_format(*s, p, len, false);
 774                 if (r < 0)
 775                         return r;
 776
 777                 if (len < (size_t)r)
 778                         return -ENOBUFS;
 779
 780                 p += r;
 781                 len -= r;
 782         }
 783
 784         free_and_replace(ra->dnssl, opt_dnssl);
 785
 786         return 0;
 787 }
 788
 789 _public_ int sd_radv_prefix_new(sd_radv_prefix **ret) {
 790         sd_radv_prefix *p;
 791
 792         assert_return(ret, -EINVAL);
 793
 794         p = new(sd_radv_prefix, 1);
 795         if (!p)
 796                 return -ENOMEM;
 797
 798         *p = (sd_radv_prefix) {
 799                 .n_ref = 1,
 800
 801                 .opt.type = ND_OPT_PREFIX_INFORMATION,
 802                 .opt.length = (sizeof(p->opt) - 1)/8 + 1,
 803                 .opt.prefixlen = 64,
 804
 805                 /* RFC 4861, Section 6.2.1 */
 806                 .opt.flags = ND_OPT_PI_FLAG_ONLINK|ND_OPT_PI_FLAG_AUTO,
 807
 808                 .opt.preferred_lifetime = htobe32(604800),
 809                 .opt.valid_lifetime = htobe32(2592000),
 810         };
 811
 812         *ret = p;
 813         return 0;
 814 }
 815
 816 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_prefix, sd_radv_prefix, mfree);
 817
 818 _public_ int sd_radv_prefix_set_prefix(sd_radv_prefix *p, const struct in6_addr *in6_addr,
 819                                        unsigned char prefixlen) {
 820         assert_return(p, -EINVAL);
 821         assert_return(in6_addr, -EINVAL);
 822
 823         if (prefixlen < 3 || prefixlen > 128)
 824                 return -EINVAL;
 825
 826         if (prefixlen > 64)
 827                 /* unusual but allowed, log it */
 828                 log_radv("Unusual prefix length %d greater than 64", prefixlen);
 829
 830         p->opt.in6_addr = *in6_addr;
 831         p->opt.prefixlen = prefixlen;
 832
 833         return 0;
 834 }
 835
 836 _public_ int sd_radv_prefix_get_prefix(sd_radv_prefix *p, struct in6_addr *ret_in6_addr,
 837                                        unsigned char *ret_prefixlen) {
 838         assert_return(p, -EINVAL);
 839         assert_return(ret_in6_addr, -EINVAL);
 840         assert_return(ret_prefixlen, -EINVAL);
 841
 842         *ret_in6_addr = p->opt.in6_addr;
 843         *ret_prefixlen = p->opt.prefixlen;
 844
 845         return 0;
 846 }
 847
 848 _public_ int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
 849         assert_return(p, -EINVAL);
 850
 851         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
 852
 853         return 0;
 854 }
 855
 856 _public_ int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
 857                                                           int address_autoconfiguration) {
 858         assert_return(p, -EINVAL);
 859
 860         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
 861
 862         return 0;
 863 }
 864
 865 _public_ int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p,
 866                                                uint32_t valid_lifetime) {
 867         assert_return(p, -EINVAL);
 868
 869         p->opt.valid_lifetime = htobe32(valid_lifetime);
 870
 871         return 0;
 872 }
 873
 874 _public_ int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p,
 875                                                    uint32_t preferred_lifetime) {
 876         assert_return(p, -EINVAL);
 877
 878         p->opt.preferred_lifetime = htobe32(preferred_lifetime);
 879
 880         return 0;
 881 }
 882
 883 _public_ int sd_radv_route_prefix_new(sd_radv_route_prefix **ret) {
 884         sd_radv_route_prefix *p;
 885
 886         assert_return(ret, -EINVAL);
 887
 888         p = new(sd_radv_route_prefix, 1);
 889         if (!p)
 890                 return -ENOMEM;
 891
 892         *p = (sd_radv_route_prefix) {
 893                 .n_ref = 1,
 894
 895                 .opt.type = SD_RADV_OPT_ROUTE_INFORMATION,
 896                 .opt.length = DIV_ROUND_UP(sizeof(p->opt), 8),
 897                 .opt.prefixlen = 64,
 898
 899                 .opt.lifetime = htobe32(604800),
 900         };
 901
 902         *ret = p;
 903         return 0;
 904 }
 905
 906 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_route_prefix, sd_radv_route_prefix, mfree);
 907
 908 _public_ int sd_radv_prefix_set_route_prefix(sd_radv_route_prefix *p, const struct in6_addr *in6_addr,
 909                                              unsigned char prefixlen) {
 910         assert_return(p, -EINVAL);
 911         assert_return(in6_addr, -EINVAL);
 912
 913         if (prefixlen > 128)
 914                 return -EINVAL;
 915
 916         if (prefixlen > 64)
 917                 /* unusual but allowed, log it */
 918                 log_radv("Unusual prefix length %u greater than 64", prefixlen);
 919
 920         p->opt.in6_addr = *in6_addr;
 921         p->opt.prefixlen = prefixlen;
 922
 923         return 0;
 924 }
 925
 926 _public_ int sd_radv_route_prefix_set_lifetime(sd_radv_route_prefix *p, uint32_t valid_lifetime) {
 927         assert_return(p, -EINVAL);
 928
 929         p->opt.lifetime = htobe32(valid_lifetime);
 930
 931         return 0;
 932 }