src/libsystemd-network/sd-radv.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright (C) 2017 Intel Corporation. All rights reserved.
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <netinet/icmp6.h>
  21 #include <netinet/in.h>
  22 #include <arpa/inet.h>
  23 #include <linux/in6.h>
  24
  25 #include "sd-radv.h"
  26
  27 #include "macro.h"
  28 #include "alloc-util.h"
  29 #include "dns-domain.h"
  30 #include "fd-util.h"
  31 #include "icmp6-util.h"
  32 #include "in-addr-util.h"
  33 #include "radv-internal.h"
  34 #include "socket-util.h"
  35 #include "string-util.h"
  36 #include "strv.h"
  37 #include "util.h"
  38 #include "random-util.h"
  39
  40 _public_ int sd_radv_new(sd_radv **ret) {
  41         _cleanup_(sd_radv_unrefp) sd_radv *ra = NULL;
  42
  43         assert_return(ret, -EINVAL);
  44
  45         ra = new0(sd_radv, 1);
  46         if (!ra)
  47                 return -ENOMEM;
  48
  49         ra->n_ref = 1;
  50         ra->fd = -1;
  51
  52         LIST_HEAD_INIT(ra->prefixes);
  53
  54         *ret = ra;
  55         ra = NULL;
  56
  57         return 0;
  58 }
  59
  60 _public_ int sd_radv_attach_event(sd_radv *ra, sd_event *event, int64_t priority) {
  61         int r;
  62
  63         assert_return(ra, -EINVAL);
  64         assert_return(!ra->event, -EBUSY);
  65
  66         if (event)
  67                 ra->event = sd_event_ref(event);
  68         else {
  69                 r = sd_event_default(&ra->event);
  70                 if (r < 0)
  71                         return 0;
  72         }
  73
  74         ra->event_priority = priority;
  75
  76         return 0;
  77 }
  78
  79 _public_ int sd_radv_detach_event(sd_radv *ra) {
  80
  81         assert_return(ra, -EINVAL);
  82
  83         ra->event = sd_event_unref(ra->event);
  84         return 0;
  85 }
  86
  87 _public_ sd_event *sd_radv_get_event(sd_radv *ra) {
  88         assert_return(ra, NULL);
  89
  90         return ra->event;
  91 }
  92
  93 static void radv_reset(sd_radv *ra) {
  94
  95         ra->timeout_event_source =
  96                 sd_event_source_unref(ra->timeout_event_source);
  97
  98         ra->recv_event_source =
  99                 sd_event_source_unref(ra->recv_event_source);
 100
 101         ra->ra_sent = 0;
 102 }
 103
 104 _public_ sd_radv *sd_radv_ref(sd_radv *ra) {
 105         if (!ra)
 106                 return NULL;
 107
 108         assert(ra->n_ref > 0);
 109         ra->n_ref++;
 110
 111         return ra;
 112 }
 113
 114 _public_ sd_radv *sd_radv_unref(sd_radv *ra) {
 115         if (!ra)
 116                 return NULL;
 117
 118         assert(ra->n_ref > 0);
 119         ra->n_ref--;
 120
 121         if (ra->n_ref > 0)
 122                 return NULL;
 123
 124         while (ra->prefixes) {
 125                 sd_radv_prefix *p = ra->prefixes;
 126
 127                 LIST_REMOVE(prefix, ra->prefixes, p);
 128                 sd_radv_prefix_unref(p);
 129         }
 130
 131         free(ra->rdnss);
 132         free(ra->dnssl);
 133
 134         radv_reset(ra);
 135
 136         sd_radv_detach_event(ra);
 137         return mfree(ra);
 138 }
 139
 140 static int radv_send(sd_radv *ra, const struct in6_addr *dst,
 141                      const uint32_t router_lifetime) {
 142         static const struct ether_addr mac_zero = {};
 143         sd_radv_prefix *p;
 144         struct sockaddr_in6 dst_addr = {
 145                 .sin6_family = AF_INET6,
 146                 .sin6_addr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
 147         };
 148         struct nd_router_advert adv = {};
 149         struct {
 150                 struct nd_opt_hdr opthdr;
 151                 struct ether_addr slladdr;
 152         } _packed_ opt_mac = {
 153                 .opthdr = {
 154                         .nd_opt_type = ND_OPT_SOURCE_LINKADDR,
 155                         .nd_opt_len = (sizeof(struct nd_opt_hdr) +
 156                                        sizeof(struct ether_addr) - 1) /8 + 1,
 157                 },
 158         };
 159         struct nd_opt_mtu opt_mtu =  {
 160                 .nd_opt_mtu_type = ND_OPT_MTU,
 161                 .nd_opt_mtu_len = 1,
 162         };
 163         /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, RDNSS
 164            and DNSSL */
 165         struct iovec iov[5 + ra->n_prefixes];
 166         struct msghdr msg = {
 167                 .msg_name = &dst_addr,
 168                 .msg_namelen = sizeof(dst_addr),
 169                 .msg_iov = iov,
 170         };
 171
 172         if (dst && !in_addr_is_null(AF_INET6, (union in_addr_union*) dst))
 173                 dst_addr.sin6_addr = *dst;
 174
 175         adv.nd_ra_type = ND_ROUTER_ADVERT;
 176         adv.nd_ra_curhoplimit = ra->hop_limit;
 177         adv.nd_ra_flags_reserved = ra->flags;
 178         adv.nd_ra_router_lifetime = htobe16(router_lifetime);
 179         iov[msg.msg_iovlen].iov_base = &adv;
 180         iov[msg.msg_iovlen].iov_len = sizeof(adv);
 181         msg.msg_iovlen++;
 182
 183         /* MAC address is optional, either because the link does not use L2
 184            addresses or load sharing is desired. See RFC 4861, Section 4.2 */
 185         if (memcmp(&mac_zero, &ra->mac_addr, sizeof(mac_zero))) {
 186                 opt_mac.slladdr = ra->mac_addr;
 187                 iov[msg.msg_iovlen].iov_base = &opt_mac;
 188                 iov[msg.msg_iovlen].iov_len = sizeof(opt_mac);
 189                 msg.msg_iovlen++;
 190         }
 191
 192         if (ra->mtu) {
 193                 opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
 194                 iov[msg.msg_iovlen].iov_base = &opt_mtu;
 195                 iov[msg.msg_iovlen].iov_len = sizeof(opt_mtu);
 196                 msg.msg_iovlen++;
 197         }
 198
 199         LIST_FOREACH(prefix, p, ra->prefixes) {
 200                 iov[msg.msg_iovlen].iov_base = &p->opt;
 201                 iov[msg.msg_iovlen].iov_len = sizeof(p->opt);
 202                 msg.msg_iovlen++;
 203         }
 204
 205         if (ra->rdnss) {
 206                 iov[msg.msg_iovlen].iov_base = ra->rdnss;
 207                 iov[msg.msg_iovlen].iov_len = ra->rdnss->length * 8;
 208                 msg.msg_iovlen++;
 209         }
 210
 211         if (ra->dnssl) {
 212                 iov[msg.msg_iovlen].iov_base = ra->dnssl;
 213                 iov[msg.msg_iovlen].iov_len = ra->dnssl->length * 8;
 214                 msg.msg_iovlen++;
 215         }
 216
 217         if (sendmsg(ra->fd, &msg, 0) < 0)
 218                 return -errno;
 219
 220         return 0;
 221 }
 222
 223 static int radv_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 224         sd_radv *ra = userdata;
 225         _cleanup_free_ char *addr = NULL;
 226         struct in6_addr src;
 227         triple_timestamp timestamp;
 228         int r;
 229         ssize_t buflen;
 230         _cleanup_free_ char *buf = NULL;
 231
 232         assert(s);
 233         assert(ra);
 234         assert(ra->event);
 235
 236         buflen = next_datagram_size_fd(fd);
 237
 238         if ((unsigned) buflen < sizeof(struct nd_router_solicit))
 239                 return log_radv("Too short packet received");
 240
 241         buf = new0(char, buflen);
 242         if (!buf)
 243                 return 0;
 244
 245         r = icmp6_receive(fd, buf, buflen, &src, &timestamp);
 246         if (r < 0) {
 247                 switch (r) {
 248                 case -EADDRNOTAVAIL:
 249                         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
 250                         log_radv("Received RS from non-link-local address %s. Ignoring", addr);
 251                         break;
 252
 253                 case -EMULTIHOP:
 254                         log_radv("Received RS with invalid hop limit. Ignoring.");
 255                         break;
 256
 257                 case -EPFNOSUPPORT:
 258                         log_radv("Received invalid source address from ICMPv6 socket. Ignoring.");
 259                         break;
 260
 261                 default:
 262                         log_radv_warning_errno(r, "Error receiving from ICMPv6 socket: %m");
 263                         break;
 264                 }
 265
 266                 return 0;
 267         }
 268
 269         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
 270
 271         r = radv_send(ra, &src, ra->lifetime);
 272         if (r < 0)
 273                 log_radv_warning_errno(r, "Unable to send solicited Router Advertisment to %s: %m", addr);
 274         else
 275                 log_radv("Sent solicited Router Advertisement to %s", addr);
 276
 277         return 0;
 278 }
 279
 280 static usec_t radv_compute_timeout(usec_t min, usec_t max) {
 281         assert_return(min <= max, SD_RADV_DEFAULT_MIN_TIMEOUT_USEC);
 282
 283         return min + (random_u32() % (max - min));
 284 }
 285
 286 static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
 287         int r;
 288         sd_radv *ra = userdata;
 289         usec_t min_timeout = SD_RADV_DEFAULT_MIN_TIMEOUT_USEC;
 290         usec_t max_timeout = SD_RADV_DEFAULT_MAX_TIMEOUT_USEC;
 291         usec_t time_now, timeout;
 292         char time_string[FORMAT_TIMESPAN_MAX];
 293
 294         assert(s);
 295         assert(ra);
 296         assert(ra->event);
 297
 298         ra->timeout_event_source = sd_event_source_unref(ra->timeout_event_source);
 299
 300         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 301         if (r < 0)
 302                 goto fail;
 303
 304         r = radv_send(ra, NULL, ra->lifetime);
 305         if (r < 0)
 306                 log_radv_warning_errno(r, "Unable to send Router Advertisement: %m");
 307
 308         /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
 309         if (ra->ra_sent < SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS) {
 310                 max_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
 311                 min_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC / 3;
 312         }
 313
 314         timeout = radv_compute_timeout(min_timeout, max_timeout);
 315
 316         log_radv("Next Router Advertisement in %s",
 317                  format_timespan(time_string, FORMAT_TIMESPAN_MAX,
 318                                  timeout, USEC_PER_SEC));
 319
 320         r = sd_event_add_time(ra->event, &ra->timeout_event_source,
 321                               clock_boottime_or_monotonic(),
 322                               time_now + timeout, MSEC_PER_SEC,
 323                               radv_timeout, ra);
 324         if (r < 0)
 325                 goto fail;
 326
 327         r = sd_event_source_set_priority(ra->timeout_event_source,
 328                                          ra->event_priority);
 329         if (r < 0)
 330                 goto fail;
 331
 332         r = sd_event_source_set_description(ra->timeout_event_source,
 333                                             "radv-timeout");
 334         if (r < 0)
 335                 goto fail;
 336
 337         ra->ra_sent++;
 338
 339 fail:
 340         if (r < 0)
 341                 sd_radv_stop(ra);
 342
 343         return 0;
 344 }
 345
 346 _public_ int sd_radv_stop(sd_radv *ra) {
 347         int r;
 348
 349         assert_return(ra, -EINVAL);
 350
 351         log_radv("Stopping IPv6 Router Advertisement daemon");
 352
 353         /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
 354            with zero lifetime  */
 355         r = radv_send(ra, NULL, 0);
 356         if (r < 0)
 357                 log_radv_warning_errno(r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
 358
 359         radv_reset(ra);
 360         ra->fd = safe_close(ra->fd);
 361         ra->state = SD_RADV_STATE_IDLE;
 362
 363         return 0;
 364 }
 365
 366 _public_ int sd_radv_start(sd_radv *ra) {
 367         int r = 0;
 368
 369         assert_return(ra, -EINVAL);
 370         assert_return(ra->event, -EINVAL);
 371         assert_return(ra->ifindex > 0, -EINVAL);
 372
 373         if (ra->state != SD_RADV_STATE_IDLE)
 374                 return 0;
 375
 376         r = sd_event_add_time(ra->event, &ra->timeout_event_source,
 377                               clock_boottime_or_monotonic(), 0, 0,
 378                               radv_timeout, ra);
 379         if (r < 0)
 380                 goto fail;
 381
 382         r = sd_event_source_set_priority(ra->timeout_event_source,
 383                                          ra->event_priority);
 384         if (r < 0)
 385                 goto fail;
 386
 387         (void) sd_event_source_set_description(ra->timeout_event_source,
 388                                                "radv-timeout");
 389
 390         r = icmp6_bind_router_advertisement(ra->ifindex);
 391         if (r < 0)
 392                 goto fail;
 393
 394         ra->fd = r;
 395
 396         r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
 397         if (r < 0)
 398                 goto fail;
 399
 400         r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
 401         if (r < 0)
 402                 goto fail;
 403
 404         (void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
 405
 406         ra->state = SD_RADV_STATE_ADVERTISING;
 407
 408         log_radv("Started IPv6 Router Advertisement daemon");
 409
 410         return 0;
 411
 412  fail:
 413         radv_reset(ra);
 414
 415         return r;
 416 }
 417
 418 _public_ int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
 419         assert_return(ra, -EINVAL);
 420         assert_return(ifindex >= -1, -EINVAL);
 421
 422         if (ra->state != SD_RADV_STATE_IDLE)
 423                 return -EBUSY;
 424
 425         ra->ifindex = ifindex;
 426
 427         return 0;
 428 }
 429
 430 _public_ int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
 431         assert_return(ra, -EINVAL);
 432
 433         if (ra->state != SD_RADV_STATE_IDLE)
 434                 return -EBUSY;
 435
 436         if (mac_addr)
 437                 ra->mac_addr = *mac_addr;
 438         else
 439                 zero(ra->mac_addr);
 440
 441         return 0;
 442 }
 443
 444 _public_ int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
 445         assert_return(ra, -EINVAL);
 446         assert_return(mtu >= 1280, -EINVAL);
 447
 448         if (ra->state != SD_RADV_STATE_IDLE)
 449                 return -EBUSY;
 450
 451         ra->mtu = mtu;
 452
 453         return 0;
 454 }
 455
 456 _public_ int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
 457         assert_return(ra, -EINVAL);
 458
 459         if (ra->state != SD_RADV_STATE_IDLE)
 460                 return -EBUSY;
 461
 462         ra->hop_limit = hop_limit;
 463
 464         return 0;
 465 }
 466
 467 _public_ int sd_radv_set_router_lifetime(sd_radv *ra, uint32_t router_lifetime) {
 468         assert_return(ra, -EINVAL);
 469
 470         if (ra->state != SD_RADV_STATE_IDLE)
 471                 return -EBUSY;
 472
 473         /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the
 474            preference value MUST be set to (00) by the sender..." */
 475         if (router_lifetime == 0 &&
 476             (ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
 477                 return -ETIME;
 478
 479         ra->lifetime = router_lifetime;
 480
 481         return 0;
 482 }
 483
 484 _public_ int sd_radv_set_managed_information(sd_radv *ra, int managed) {
 485         assert_return(ra, -EINVAL);
 486
 487         if (ra->state != SD_RADV_STATE_IDLE)
 488                 return -EBUSY;
 489
 490         SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
 491
 492         return 0;
 493 }
 494
 495 _public_ int sd_radv_set_other_information(sd_radv *ra, int other) {
 496         assert_return(ra, -EINVAL);
 497
 498         if (ra->state != SD_RADV_STATE_IDLE)
 499                 return -EBUSY;
 500
 501         SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
 502
 503         return 0;
 504 }
 505
 506 _public_ int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
 507         int r = 0;
 508
 509         assert_return(ra, -EINVAL);
 510         assert_return(IN_SET(preference,
 511                              SD_NDISC_PREFERENCE_LOW,
 512                              SD_NDISC_PREFERENCE_MEDIUM,
 513                              SD_NDISC_PREFERENCE_HIGH), -EINVAL);
 514
 515         ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);
 516
 517         return r;
 518 }
 519
 520 _public_ int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p) {
 521         sd_radv_prefix *cur;
 522         _cleanup_free_ char *addr_p = NULL;
 523
 524         assert_return(ra, -EINVAL);
 525
 526         if (!p)
 527                 return -EINVAL;
 528
 529         LIST_FOREACH(prefix, cur, ra->prefixes) {
 530                 int r;
 531
 532                 r = in_addr_prefix_intersect(AF_INET6,
 533                                              (union in_addr_union*) &cur->opt.in6_addr,
 534                                              cur->opt.prefixlen,
 535                                              (union in_addr_union*) &p->opt.in6_addr,
 536                                              p->opt.prefixlen);
 537                 if (r > 0) {
 538                         _cleanup_free_ char *addr_cur = NULL;
 539
 540                         (void) in_addr_to_string(AF_INET6,
 541                                                  (union in_addr_union*) &cur->opt.in6_addr,
 542                                                  &addr_cur);
 543                         (void) in_addr_to_string(AF_INET6,
 544                                                  (union in_addr_union*) &p->opt.in6_addr,
 545                                                  &addr_p);
 546
 547                         log_radv("IPv6 prefix %s/%u already configured, ignoring %s/%u",
 548                                  addr_cur, cur->opt.prefixlen,
 549                                  addr_p, p->opt.prefixlen);
 550
 551                         return -EEXIST;
 552                 }
 553         }
 554
 555         p = sd_radv_prefix_ref(p);
 556
 557         LIST_APPEND(prefix, ra->prefixes, p);
 558
 559         ra->n_prefixes++;
 560
 561         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &p->opt.in6_addr, &addr_p);
 562         log_radv("Added prefix %s/%d", addr_p, p->opt.prefixlen);
 563
 564         return 0;
 565 }
 566
 567 _public_ int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
 568                                const struct in6_addr *dns, size_t n_dns) {
 569         _cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
 570         size_t len;
 571
 572         assert_return(ra, -EINVAL);
 573         assert_return(n_dns < 128, -EINVAL);
 574
 575         if (!dns || n_dns == 0) {
 576                 ra->rdnss = mfree(ra->rdnss);
 577                 ra->n_rdnss = 0;
 578
 579                 return 0;
 580         }
 581
 582         len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
 583
 584         opt_rdnss = malloc0(len);
 585         if (!opt_rdnss)
 586                 return -ENOMEM;
 587
 588         opt_rdnss->type = SD_RADV_OPT_RDNSS;
 589         opt_rdnss->length = len / 8;
 590         opt_rdnss->lifetime = htobe32(lifetime);
 591
 592         memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
 593
 594         free(ra->rdnss);
 595         ra->rdnss = opt_rdnss;
 596         opt_rdnss = NULL;
 597
 598         ra->n_rdnss = n_dns;
 599
 600         return 0;
 601 }
 602
 603 _public_ int sd_radv_set_dnssl(sd_radv *ra, uint32_t lifetime,
 604                                char **search_list) {
 605         _cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
 606         size_t len = 0;
 607         char **s;
 608         uint8_t *p;
 609
 610         assert_return(ra, -EINVAL);
 611
 612         if (!search_list || *search_list == NULL) {
 613                 ra->dnssl = mfree(ra->dnssl);
 614
 615                 return 0;
 616         }
 617
 618         STRV_FOREACH(s, search_list)
 619                 len += strlen(*s) + 2;
 620
 621         len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
 622
 623         opt_dnssl = malloc0(len);
 624         if (!opt_dnssl)
 625                 return -ENOMEM;
 626
 627         opt_dnssl->type = SD_RADV_OPT_DNSSL;
 628         opt_dnssl->length = len / 8;
 629         opt_dnssl->lifetime = htobe32(lifetime);
 630
 631         p = (uint8_t *)(opt_dnssl + 1);
 632         len -= sizeof(struct sd_radv_opt_dns);
 633
 634         STRV_FOREACH(s, search_list) {
 635                 int r;
 636
 637                 r = dns_name_to_wire_format(*s, p, len, false);
 638                 if (r < 0)
 639                         return r;
 640
 641                 if (len < (size_t)r)
 642                         return -ENOBUFS;
 643
 644                 p += r;
 645                 len -= r;
 646         }
 647
 648         free(ra->dnssl);
 649         ra->dnssl = opt_dnssl;
 650         opt_dnssl = NULL;
 651
 652         return 0;
 653 }
 654
 655 _public_ int sd_radv_prefix_new(sd_radv_prefix **ret) {
 656         _cleanup_(sd_radv_prefix_unrefp) sd_radv_prefix *p = NULL;
 657
 658         assert_return(ret, -EINVAL);
 659
 660         p = new0(sd_radv_prefix, 1);
 661         if (!p)
 662                 return -ENOMEM;
 663
 664         p->n_ref = 1;
 665
 666         p->opt.type = ND_OPT_PREFIX_INFORMATION;
 667         p->opt.length = (sizeof(p->opt) - 1) /8 + 1;
 668
 669         p->opt.prefixlen = 64;
 670
 671         /* RFC 4861, Section 6.2.1 */
 672         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, true);
 673         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, true);
 674         p->opt.preferred_lifetime = htobe32(604800);
 675         p->opt.valid_lifetime = htobe32(2592000);
 676
 677         LIST_INIT(prefix, p);
 678
 679         *ret = p;
 680         p = NULL;
 681
 682         return 0;
 683 }
 684
 685 _public_ sd_radv_prefix *sd_radv_prefix_ref(sd_radv_prefix *p) {
 686         if (!p)
 687                 return NULL;
 688
 689         assert(p->n_ref > 0);
 690         p->n_ref++;
 691
 692         return p;
 693 }
 694
 695 _public_ sd_radv_prefix *sd_radv_prefix_unref(sd_radv_prefix *p) {
 696         if (!p)
 697                 return NULL;
 698
 699         assert(p->n_ref > 0);
 700         p->n_ref--;
 701
 702         if (p->n_ref > 0)
 703                 return NULL;
 704
 705         return mfree(p);
 706 }
 707
 708 _public_ int sd_radv_prefix_set_prefix(sd_radv_prefix *p, struct in6_addr *in6_addr,
 709                                        unsigned char prefixlen) {
 710         assert_return(p, -EINVAL);
 711         assert_return(in6_addr, -EINVAL);
 712
 713         if (prefixlen < 3 || prefixlen > 128)
 714                 return -EINVAL;
 715
 716         if (prefixlen > 64)
 717                 /* unusual but allowed, log it */
 718                 log_radv("Unusual prefix length %d greater than 64", prefixlen);
 719
 720         p->opt.in6_addr = *in6_addr;
 721         p->opt.prefixlen = prefixlen;
 722
 723         return 0;
 724 }
 725
 726 _public_ int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
 727         assert_return(p, -EINVAL);
 728
 729         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
 730
 731         return 0;
 732 }
 733
 734 _public_ int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
 735                                                           int address_autoconfiguration) {
 736         assert_return(p, -EINVAL);
 737
 738         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
 739
 740         return 0;
 741 }
 742
 743 _public_ int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p,
 744                                                uint32_t valid_lifetime) {
 745         assert_return(p, -EINVAL);
 746
 747         p->opt.valid_lifetime = htobe32(valid_lifetime);
 748
 749         return 0;
 750 }
 751
 752 _public_ int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p,
 753                                                    uint32_t preferred_lifetime) {
 754         assert_return(p, -EINVAL);
 755
 756         p->opt.preferred_lifetime = htobe32(preferred_lifetime);
 757
 758         return 0;
 759 }