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 "macro.h"
  13 #include "alloc-util.h"
  14 #include "dns-domain.h"
  15 #include "fd-util.h"
  16 #include "icmp6-util.h"
  17 #include "in-addr-util.h"
  18 #include "radv-internal.h"
  19 #include "socket-util.h"
  20 #include "string-util.h"
  21 #include "strv.h"
  22 #include "util.h"
  23 #include "random-util.h"
  24
  25 _public_ int sd_radv_new(sd_radv **ret) {
  26         _cleanup_(sd_radv_unrefp) sd_radv *ra = NULL;
  27
  28         assert_return(ret, -EINVAL);
  29
  30         ra = new0(sd_radv, 1);
  31         if (!ra)
  32                 return -ENOMEM;
  33
  34         ra->n_ref = 1;
  35         ra->fd = -1;
  36
  37         LIST_HEAD_INIT(ra->prefixes);
  38
  39         *ret = TAKE_PTR(ra);
  40
  41         return 0;
  42 }
  43
  44 _public_ int sd_radv_attach_event(sd_radv *ra, sd_event *event, int64_t priority) {
  45         int r;
  46
  47         assert_return(ra, -EINVAL);
  48         assert_return(!ra->event, -EBUSY);
  49
  50         if (event)
  51                 ra->event = sd_event_ref(event);
  52         else {
  53                 r = sd_event_default(&ra->event);
  54                 if (r < 0)
  55                         return 0;
  56         }
  57
  58         ra->event_priority = priority;
  59
  60         return 0;
  61 }
  62
  63 _public_ int sd_radv_detach_event(sd_radv *ra) {
  64
  65         assert_return(ra, -EINVAL);
  66
  67         ra->event = sd_event_unref(ra->event);
  68         return 0;
  69 }
  70
  71 _public_ sd_event *sd_radv_get_event(sd_radv *ra) {
  72         assert_return(ra, NULL);
  73
  74         return ra->event;
  75 }
  76
  77 static void radv_reset(sd_radv *ra) {
  78         assert(ra);
  79
  80         ra->timeout_event_source =
  81                 sd_event_source_unref(ra->timeout_event_source);
  82
  83         ra->recv_event_source =
  84                 sd_event_source_unref(ra->recv_event_source);
  85
  86         ra->ra_sent = 0;
  87 }
  88
  89 static sd_radv *radv_free(sd_radv *ra) {
  90         assert(ra);
  91
  92         while (ra->prefixes) {
  93                 sd_radv_prefix *p = ra->prefixes;
  94
  95                 LIST_REMOVE(prefix, ra->prefixes, p);
  96                 sd_radv_prefix_unref(p);
  97         }
  98
  99         free(ra->rdnss);
 100         free(ra->dnssl);
 101
 102         radv_reset(ra);
 103
 104         sd_radv_detach_event(ra);
 105
 106         ra->fd = safe_close(ra->fd);
 107
 108         return mfree(ra);
 109 }
 110
 111 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv, sd_radv, radv_free);
 112
 113 static int radv_send(sd_radv *ra, const struct in6_addr *dst,
 114                      const uint32_t router_lifetime) {
 115         static const struct ether_addr mac_zero = {};
 116         sd_radv_prefix *p;
 117         struct sockaddr_in6 dst_addr = {
 118                 .sin6_family = AF_INET6,
 119                 .sin6_addr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
 120         };
 121         struct nd_router_advert adv = {};
 122         struct {
 123                 struct nd_opt_hdr opthdr;
 124                 struct ether_addr slladdr;
 125         } _packed_ opt_mac = {
 126                 .opthdr = {
 127                         .nd_opt_type = ND_OPT_SOURCE_LINKADDR,
 128                         .nd_opt_len = (sizeof(struct nd_opt_hdr) +
 129                                        sizeof(struct ether_addr) - 1) /8 + 1,
 130                 },
 131         };
 132         struct nd_opt_mtu opt_mtu =  {
 133                 .nd_opt_mtu_type = ND_OPT_MTU,
 134                 .nd_opt_mtu_len = 1,
 135         };
 136         /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, RDNSS
 137            and DNSSL */
 138         struct iovec iov[5 + ra->n_prefixes];
 139         struct msghdr msg = {
 140                 .msg_name = &dst_addr,
 141                 .msg_namelen = sizeof(dst_addr),
 142                 .msg_iov = iov,
 143         };
 144         usec_t time_now;
 145         int r;
 146
 147         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 148         if (r < 0)
 149                 return r;
 150
 151         if (dst && !in_addr_is_null(AF_INET6, (union in_addr_union*) dst))
 152                 dst_addr.sin6_addr = *dst;
 153
 154         adv.nd_ra_type = ND_ROUTER_ADVERT;
 155         adv.nd_ra_curhoplimit = ra->hop_limit;
 156         adv.nd_ra_flags_reserved = ra->flags;
 157         adv.nd_ra_router_lifetime = htobe16(router_lifetime);
 158         iov[msg.msg_iovlen].iov_base = &adv;
 159         iov[msg.msg_iovlen].iov_len = sizeof(adv);
 160         msg.msg_iovlen++;
 161
 162         /* MAC address is optional, either because the link does not use L2
 163            addresses or load sharing is desired. See RFC 4861, Section 4.2 */
 164         if (memcmp(&mac_zero, &ra->mac_addr, sizeof(mac_zero))) {
 165                 opt_mac.slladdr = ra->mac_addr;
 166                 iov[msg.msg_iovlen].iov_base = &opt_mac;
 167                 iov[msg.msg_iovlen].iov_len = sizeof(opt_mac);
 168                 msg.msg_iovlen++;
 169         }
 170
 171         if (ra->mtu) {
 172                 opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
 173                 iov[msg.msg_iovlen].iov_base = &opt_mtu;
 174                 iov[msg.msg_iovlen].iov_len = sizeof(opt_mtu);
 175                 msg.msg_iovlen++;
 176         }
 177
 178         LIST_FOREACH(prefix, p, ra->prefixes) {
 179                 if (p->valid_until) {
 180
 181                         if (time_now > p->valid_until)
 182                                 p->opt.valid_lifetime = 0;
 183                         else
 184                                 p->opt.valid_lifetime = htobe32((p->valid_until - time_now) / USEC_PER_SEC);
 185
 186                         if (time_now > p->preferred_until)
 187                                 p->opt.preferred_lifetime = 0;
 188                         else
 189                                 p->opt.preferred_lifetime = htobe32((p->preferred_until - time_now) / USEC_PER_SEC);
 190                 }
 191                 iov[msg.msg_iovlen].iov_base = &p->opt;
 192                 iov[msg.msg_iovlen].iov_len = sizeof(p->opt);
 193                 msg.msg_iovlen++;
 194         }
 195
 196         if (ra->rdnss) {
 197                 iov[msg.msg_iovlen].iov_base = ra->rdnss;
 198                 iov[msg.msg_iovlen].iov_len = ra->rdnss->length * 8;
 199                 msg.msg_iovlen++;
 200         }
 201
 202         if (ra->dnssl) {
 203                 iov[msg.msg_iovlen].iov_base = ra->dnssl;
 204                 iov[msg.msg_iovlen].iov_len = ra->dnssl->length * 8;
 205                 msg.msg_iovlen++;
 206         }
 207
 208         if (sendmsg(ra->fd, &msg, 0) < 0)
 209                 return -errno;
 210
 211         return 0;
 212 }
 213
 214 static int radv_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 215         sd_radv *ra = userdata;
 216         _cleanup_free_ char *addr = NULL;
 217         struct in6_addr src;
 218         triple_timestamp timestamp;
 219         int r;
 220         ssize_t buflen;
 221         _cleanup_free_ char *buf = NULL;
 222
 223         assert(s);
 224         assert(ra);
 225         assert(ra->event);
 226
 227         buflen = next_datagram_size_fd(fd);
 228
 229         if ((unsigned) buflen < sizeof(struct nd_router_solicit))
 230                 return log_radv("Too short packet received");
 231
 232         buf = new0(char, buflen);
 233         if (!buf)
 234                 return 0;
 235
 236         r = icmp6_receive(fd, buf, buflen, &src, &timestamp);
 237         if (r < 0) {
 238                 switch (r) {
 239                 case -EADDRNOTAVAIL:
 240                         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
 241                         log_radv("Received RS from non-link-local address %s. Ignoring", addr);
 242                         break;
 243
 244                 case -EMULTIHOP:
 245                         log_radv("Received RS with invalid hop limit. Ignoring.");
 246                         break;
 247
 248                 case -EPFNOSUPPORT:
 249                         log_radv("Received invalid source address from ICMPv6 socket. Ignoring.");
 250                         break;
 251
 252                 default:
 253                         log_radv_warning_errno(r, "Error receiving from ICMPv6 socket: %m");
 254                         break;
 255                 }
 256
 257                 return 0;
 258         }
 259
 260         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
 261
 262         r = radv_send(ra, &src, ra->lifetime);
 263         if (r < 0)
 264                 log_radv_warning_errno(r, "Unable to send solicited Router Advertisement to %s: %m", addr);
 265         else
 266                 log_radv("Sent solicited Router Advertisement to %s", addr);
 267
 268         return 0;
 269 }
 270
 271 static usec_t radv_compute_timeout(usec_t min, usec_t max) {
 272         assert_return(min <= max, SD_RADV_DEFAULT_MIN_TIMEOUT_USEC);
 273
 274         return min + (random_u32() % (max - min));
 275 }
 276
 277 static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
 278         int r;
 279         sd_radv *ra = userdata;
 280         usec_t min_timeout = SD_RADV_DEFAULT_MIN_TIMEOUT_USEC;
 281         usec_t max_timeout = SD_RADV_DEFAULT_MAX_TIMEOUT_USEC;
 282         usec_t time_now, timeout;
 283         char time_string[FORMAT_TIMESPAN_MAX];
 284
 285         assert(s);
 286         assert(ra);
 287         assert(ra->event);
 288
 289         ra->timeout_event_source = sd_event_source_unref(ra->timeout_event_source);
 290
 291         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 292         if (r < 0)
 293                 goto fail;
 294
 295         r = radv_send(ra, NULL, ra->lifetime);
 296         if (r < 0)
 297                 log_radv_warning_errno(r, "Unable to send Router Advertisement: %m");
 298
 299         /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
 300         if (ra->ra_sent < SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS) {
 301                 max_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
 302                 min_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC / 3;
 303         }
 304
 305         timeout = radv_compute_timeout(min_timeout, max_timeout);
 306
 307         log_radv("Next Router Advertisement in %s",
 308                  format_timespan(time_string, FORMAT_TIMESPAN_MAX,
 309                                  timeout, USEC_PER_SEC));
 310
 311         r = sd_event_add_time(ra->event, &ra->timeout_event_source,
 312                               clock_boottime_or_monotonic(),
 313                               time_now + timeout, MSEC_PER_SEC,
 314                               radv_timeout, ra);
 315         if (r < 0)
 316                 goto fail;
 317
 318         r = sd_event_source_set_priority(ra->timeout_event_source,
 319                                          ra->event_priority);
 320         if (r < 0)
 321                 goto fail;
 322
 323         r = sd_event_source_set_description(ra->timeout_event_source,
 324                                             "radv-timeout");
 325         if (r < 0)
 326                 goto fail;
 327
 328         ra->ra_sent++;
 329
 330 fail:
 331         if (r < 0)
 332                 sd_radv_stop(ra);
 333
 334         return 0;
 335 }
 336
 337 _public_ int sd_radv_stop(sd_radv *ra) {
 338         int r;
 339
 340         assert_return(ra, -EINVAL);
 341
 342         if (ra->state == SD_RADV_STATE_IDLE)
 343                 return 0;
 344
 345         log_radv("Stopping IPv6 Router Advertisement daemon");
 346
 347         /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
 348            with zero lifetime  */
 349         r = radv_send(ra, NULL, 0);
 350         if (r < 0)
 351                 log_radv_warning_errno(r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
 352
 353         radv_reset(ra);
 354         ra->fd = safe_close(ra->fd);
 355         ra->state = SD_RADV_STATE_IDLE;
 356
 357         return 0;
 358 }
 359
 360 _public_ int sd_radv_start(sd_radv *ra) {
 361         int r = 0;
 362
 363         assert_return(ra, -EINVAL);
 364         assert_return(ra->event, -EINVAL);
 365         assert_return(ra->ifindex > 0, -EINVAL);
 366
 367         if (ra->state != SD_RADV_STATE_IDLE)
 368                 return 0;
 369
 370         r = sd_event_add_time(ra->event, &ra->timeout_event_source,
 371                               clock_boottime_or_monotonic(), 0, 0,
 372                               radv_timeout, ra);
 373         if (r < 0)
 374                 goto fail;
 375
 376         r = sd_event_source_set_priority(ra->timeout_event_source,
 377                                          ra->event_priority);
 378         if (r < 0)
 379                 goto fail;
 380
 381         (void) sd_event_source_set_description(ra->timeout_event_source,
 382                                                "radv-timeout");
 383
 384         r = icmp6_bind_router_advertisement(ra->ifindex);
 385         if (r < 0)
 386                 goto fail;
 387
 388         ra->fd = r;
 389
 390         r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
 391         if (r < 0)
 392                 goto fail;
 393
 394         r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
 395         if (r < 0)
 396                 goto fail;
 397
 398         (void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
 399
 400         ra->state = SD_RADV_STATE_ADVERTISING;
 401
 402         log_radv("Started IPv6 Router Advertisement daemon");
 403
 404         return 0;
 405
 406  fail:
 407         radv_reset(ra);
 408
 409         return r;
 410 }
 411
 412 _public_ int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
 413         assert_return(ra, -EINVAL);
 414         assert_return(ifindex >= -1, -EINVAL);
 415
 416         if (ra->state != SD_RADV_STATE_IDLE)
 417                 return -EBUSY;
 418
 419         ra->ifindex = ifindex;
 420
 421         return 0;
 422 }
 423
 424 _public_ int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
 425         assert_return(ra, -EINVAL);
 426
 427         if (ra->state != SD_RADV_STATE_IDLE)
 428                 return -EBUSY;
 429
 430         if (mac_addr)
 431                 ra->mac_addr = *mac_addr;
 432         else
 433                 zero(ra->mac_addr);
 434
 435         return 0;
 436 }
 437
 438 _public_ int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
 439         assert_return(ra, -EINVAL);
 440         assert_return(mtu >= 1280, -EINVAL);
 441
 442         ra->mtu = mtu;
 443
 444         return 0;
 445 }
 446
 447 _public_ int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
 448         assert_return(ra, -EINVAL);
 449
 450         if (ra->state != SD_RADV_STATE_IDLE)
 451                 return -EBUSY;
 452
 453         ra->hop_limit = hop_limit;
 454
 455         return 0;
 456 }
 457
 458 _public_ int sd_radv_set_router_lifetime(sd_radv *ra, uint32_t router_lifetime) {
 459         assert_return(ra, -EINVAL);
 460
 461         if (ra->state != SD_RADV_STATE_IDLE)
 462                 return -EBUSY;
 463
 464         /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the
 465            preference value MUST be set to (00) by the sender..." */
 466         if (router_lifetime == 0 &&
 467             (ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
 468                 return -ETIME;
 469
 470         ra->lifetime = router_lifetime;
 471
 472         return 0;
 473 }
 474
 475 _public_ int sd_radv_set_managed_information(sd_radv *ra, int managed) {
 476         assert_return(ra, -EINVAL);
 477
 478         if (ra->state != SD_RADV_STATE_IDLE)
 479                 return -EBUSY;
 480
 481         SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
 482
 483         return 0;
 484 }
 485
 486 _public_ int sd_radv_set_other_information(sd_radv *ra, int other) {
 487         assert_return(ra, -EINVAL);
 488
 489         if (ra->state != SD_RADV_STATE_IDLE)
 490                 return -EBUSY;
 491
 492         SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
 493
 494         return 0;
 495 }
 496
 497 _public_ int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
 498         int r = 0;
 499
 500         assert_return(ra, -EINVAL);
 501         assert_return(IN_SET(preference,
 502                              SD_NDISC_PREFERENCE_LOW,
 503                              SD_NDISC_PREFERENCE_MEDIUM,
 504                              SD_NDISC_PREFERENCE_HIGH), -EINVAL);
 505
 506         ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);
 507
 508         return r;
 509 }
 510
 511 _public_ int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p, bool dynamic) {
 512         sd_radv_prefix *cur;
 513         int r;
 514         _cleanup_free_ char *addr_p = NULL;
 515         char time_string_preferred[FORMAT_TIMESPAN_MAX];
 516         char time_string_valid[FORMAT_TIMESPAN_MAX];
 517         usec_t time_now, valid, preferred, valid_until, preferred_until;
 518
 519         assert_return(ra, -EINVAL);
 520
 521         if (!p)
 522                 return -EINVAL;
 523
 524         LIST_FOREACH(prefix, cur, ra->prefixes) {
 525
 526                 r = in_addr_prefix_intersect(AF_INET6,
 527                                              (union in_addr_union*) &cur->opt.in6_addr,
 528                                              cur->opt.prefixlen,
 529                                              (union in_addr_union*) &p->opt.in6_addr,
 530                                              p->opt.prefixlen);
 531                 if (r > 0) {
 532                         _cleanup_free_ char *addr_cur = NULL;
 533
 534                         (void) in_addr_to_string(AF_INET6,
 535                                                  (union in_addr_union*) &p->opt.in6_addr,
 536                                                  &addr_p);
 537
 538                         if (dynamic && cur->opt.prefixlen == p->opt.prefixlen)
 539                                 goto update;
 540
 541                         (void) in_addr_to_string(AF_INET6,
 542                                                  (union in_addr_union*) &cur->opt.in6_addr,
 543                                                  &addr_cur);
 544                         log_radv("IPv6 prefix %s/%u already configured, ignoring %s/%u",
 545                                  addr_cur, cur->opt.prefixlen,
 546                                  addr_p, p->opt.prefixlen);
 547
 548                         return -EEXIST;
 549                 }
 550         }
 551
 552         p = sd_radv_prefix_ref(p);
 553
 554         LIST_APPEND(prefix, ra->prefixes, p);
 555
 556         ra->n_prefixes++;
 557
 558         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &p->opt.in6_addr, &addr_p);
 559
 560         if (!dynamic) {
 561                 log_radv("Added prefix %s/%d", addr_p, p->opt.prefixlen);
 562                 return 0;
 563         }
 564
 565         cur = p;
 566
 567  update:
 568         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 569         if (r < 0)
 570                 return r;
 571
 572         valid = be32toh(p->opt.valid_lifetime) * USEC_PER_SEC;
 573         valid_until = usec_add(valid, time_now);
 574         if (valid_until == USEC_INFINITY)
 575                 return -EOVERFLOW;
 576
 577         preferred = be32toh(p->opt.preferred_lifetime) * USEC_PER_SEC;
 578         preferred_until = usec_add(preferred, time_now);
 579         if (preferred_until == USEC_INFINITY)
 580                 return -EOVERFLOW;
 581
 582         cur->valid_until = valid_until;
 583         cur->preferred_until = preferred_until;
 584
 585         log_radv("%s prefix %s/%u preferred %s valid %s",
 586                  cur? "Updated": "Added",
 587                  addr_p, p->opt.prefixlen,
 588                  format_timespan(time_string_preferred, FORMAT_TIMESPAN_MAX,
 589                                  preferred, USEC_PER_SEC),
 590                  format_timespan(time_string_valid, FORMAT_TIMESPAN_MAX,
 591                                  valid, USEC_PER_SEC));
 592
 593         return 0;
 594 }
 595
 596 _public_ sd_radv_prefix *sd_radv_remove_prefix(sd_radv *ra,
 597                                                const struct in6_addr *prefix,
 598                                                unsigned char prefixlen) {
 599         sd_radv_prefix *cur, *next;
 600
 601         assert_return(ra, NULL);
 602         assert_return(prefix, NULL);
 603
 604         LIST_FOREACH_SAFE(prefix, cur, next, ra->prefixes) {
 605                 if (prefixlen != cur->opt.prefixlen)
 606                         continue;
 607
 608                 if (!in_addr_equal(AF_INET6,
 609                                    (union in_addr_union *)prefix,
 610                                    (union in_addr_union *)&cur->opt.in6_addr))
 611                         continue;
 612
 613                 LIST_REMOVE(prefix, ra->prefixes, cur);
 614                 ra->n_prefixes--;
 615
 616                 break;
 617         }
 618
 619         return cur;
 620 }
 621
 622 _public_ int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
 623                                const struct in6_addr *dns, size_t n_dns) {
 624         _cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
 625         size_t len;
 626
 627         assert_return(ra, -EINVAL);
 628         assert_return(n_dns < 128, -EINVAL);
 629
 630         if (!dns || n_dns == 0) {
 631                 ra->rdnss = mfree(ra->rdnss);
 632                 ra->n_rdnss = 0;
 633
 634                 return 0;
 635         }
 636
 637         len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
 638
 639         opt_rdnss = malloc0(len);
 640         if (!opt_rdnss)
 641                 return -ENOMEM;
 642
 643         opt_rdnss->type = SD_RADV_OPT_RDNSS;
 644         opt_rdnss->length = len / 8;
 645         opt_rdnss->lifetime = htobe32(lifetime);
 646
 647         memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
 648
 649         free_and_replace(ra->rdnss, opt_rdnss);
 650
 651         ra->n_rdnss = n_dns;
 652
 653         return 0;
 654 }
 655
 656 _public_ int sd_radv_set_dnssl(sd_radv *ra, uint32_t lifetime,
 657                                char **search_list) {
 658         _cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
 659         size_t len = 0;
 660         char **s;
 661         uint8_t *p;
 662
 663         assert_return(ra, -EINVAL);
 664
 665         if (strv_isempty(search_list)) {
 666                 ra->dnssl = mfree(ra->dnssl);
 667                 return 0;
 668         }
 669
 670         STRV_FOREACH(s, search_list)
 671                 len += strlen(*s) + 2;
 672
 673         len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
 674
 675         opt_dnssl = malloc0(len);
 676         if (!opt_dnssl)
 677                 return -ENOMEM;
 678
 679         opt_dnssl->type = SD_RADV_OPT_DNSSL;
 680         opt_dnssl->length = len / 8;
 681         opt_dnssl->lifetime = htobe32(lifetime);
 682
 683         p = (uint8_t *)(opt_dnssl + 1);
 684         len -= sizeof(struct sd_radv_opt_dns);
 685
 686         STRV_FOREACH(s, search_list) {
 687                 int r;
 688
 689                 r = dns_name_to_wire_format(*s, p, len, false);
 690                 if (r < 0)
 691                         return r;
 692
 693                 if (len < (size_t)r)
 694                         return -ENOBUFS;
 695
 696                 p += r;
 697                 len -= r;
 698         }
 699
 700         free_and_replace(ra->dnssl, opt_dnssl);
 701
 702         return 0;
 703 }
 704
 705 _public_ int sd_radv_prefix_new(sd_radv_prefix **ret) {
 706         _cleanup_(sd_radv_prefix_unrefp) sd_radv_prefix *p = NULL;
 707
 708         assert_return(ret, -EINVAL);
 709
 710         p = new0(sd_radv_prefix, 1);
 711         if (!p)
 712                 return -ENOMEM;
 713
 714         p->n_ref = 1;
 715
 716         p->opt.type = ND_OPT_PREFIX_INFORMATION;
 717         p->opt.length = (sizeof(p->opt) - 1) /8 + 1;
 718
 719         p->opt.prefixlen = 64;
 720
 721         /* RFC 4861, Section 6.2.1 */
 722         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, true);
 723         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, true);
 724         p->opt.preferred_lifetime = htobe32(604800);
 725         p->opt.valid_lifetime = htobe32(2592000);
 726
 727         LIST_INIT(prefix, p);
 728
 729         *ret = TAKE_PTR(p);
 730
 731         return 0;
 732 }
 733
 734 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_radv_prefix, sd_radv_prefix, mfree);
 735
 736 _public_ int sd_radv_prefix_set_prefix(sd_radv_prefix *p, const struct in6_addr *in6_addr,
 737                                        unsigned char prefixlen) {
 738         assert_return(p, -EINVAL);
 739         assert_return(in6_addr, -EINVAL);
 740
 741         if (prefixlen < 3 || prefixlen > 128)
 742                 return -EINVAL;
 743
 744         if (prefixlen > 64)
 745                 /* unusual but allowed, log it */
 746                 log_radv("Unusual prefix length %d greater than 64", prefixlen);
 747
 748         p->opt.in6_addr = *in6_addr;
 749         p->opt.prefixlen = prefixlen;
 750
 751         return 0;
 752 }
 753
 754 _public_ int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
 755         assert_return(p, -EINVAL);
 756
 757         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
 758
 759         return 0;
 760 }
 761
 762 _public_ int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
 763                                                           int address_autoconfiguration) {
 764         assert_return(p, -EINVAL);
 765
 766         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
 767
 768         return 0;
 769 }
 770
 771 _public_ int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p,
 772                                                uint32_t valid_lifetime) {
 773         assert_return(p, -EINVAL);
 774
 775         p->opt.valid_lifetime = htobe32(valid_lifetime);
 776
 777         return 0;
 778 }
 779
 780 _public_ int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p,
 781                                                    uint32_t preferred_lifetime) {
 782         assert_return(p, -EINVAL);
 783
 784         p->opt.preferred_lifetime = htobe32(preferred_lifetime);
 785
 786         return 0;
 787 }