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         struct iovec iov[4 + ra->n_prefixes];
 165         struct msghdr msg = {
 166                 .msg_name = &dst_addr,
 167                 .msg_namelen = sizeof(dst_addr),
 168                 .msg_iov = iov,
 169         };
 170
 171         if (dst && !in_addr_is_null(AF_INET6, (union in_addr_union*) dst))
 172                 dst_addr.sin6_addr = *dst;
 173
 174         adv.nd_ra_type = ND_ROUTER_ADVERT;
 175         adv.nd_ra_curhoplimit = ra->hop_limit;
 176         adv.nd_ra_flags_reserved = ra->flags;
 177         adv.nd_ra_router_lifetime = htobe16(router_lifetime);
 178         iov[msg.msg_iovlen].iov_base = &adv;
 179         iov[msg.msg_iovlen].iov_len = sizeof(adv);
 180         msg.msg_iovlen++;
 181
 182         /* MAC address is optional, either because the link does not use L2
 183            addresses or load sharing is desired. See RFC 4861, Section 4.2 */
 184         if (memcmp(&mac_zero, &ra->mac_addr, sizeof(mac_zero))) {
 185                 opt_mac.slladdr = ra->mac_addr;
 186                 iov[msg.msg_iovlen].iov_base = &opt_mac;
 187                 iov[msg.msg_iovlen].iov_len = sizeof(opt_mac);
 188                 msg.msg_iovlen++;
 189         }
 190
 191         if (ra->mtu) {
 192                 opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
 193                 iov[msg.msg_iovlen].iov_base = &opt_mtu;
 194                 iov[msg.msg_iovlen].iov_len = sizeof(opt_mtu);
 195                 msg.msg_iovlen++;
 196         }
 197
 198         LIST_FOREACH(prefix, p, ra->prefixes) {
 199                 iov[msg.msg_iovlen].iov_base = &p->opt;
 200                 iov[msg.msg_iovlen].iov_len = sizeof(p->opt);
 201                 msg.msg_iovlen++;
 202         }
 203
 204         if (ra->rdnss) {
 205                 iov[msg.msg_iovlen].iov_base = ra->rdnss;
 206                 iov[msg.msg_iovlen].iov_len = ra->rdnss->length * 8;
 207                 msg.msg_iovlen++;
 208         }
 209
 210         if (ra->dnssl) {
 211                 iov[msg.msg_iovlen].iov_base = ra->dnssl;
 212                 iov[msg.msg_iovlen].iov_len = ra->dnssl->length * 8;
 213                 msg.msg_iovlen++;
 214         }
 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
 237         if ((unsigned) buflen < sizeof(struct nd_router_solicit))
 238                 return log_radv("Too short packet received");
 239
 240         buf = new0(char, buflen);
 241         if (!buf)
 242                 return 0;
 243
 244         r = icmp6_receive(fd, buf, buflen, &src, &timestamp);
 245         if (r < 0) {
 246                 switch (r) {
 247                 case -EADDRNOTAVAIL:
 248                         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
 249                         log_radv("Received RS from non-link-local address %s. Ignoring", addr);
 250                         break;
 251
 252                 case -EMULTIHOP:
 253                         log_radv("Received RS with invalid hop limit. Ignoring.");
 254                         break;
 255
 256                 case -EPFNOSUPPORT:
 257                         log_radv("Received invalid source address from ICMPv6 socket. Ignoring.");
 258                         break;
 259
 260                 default:
 261                         log_radv_warning_errno(r, "Error receiving from ICMPv6 socket: %m");
 262                         break;
 263                 }
 264
 265                 return 0;
 266         }
 267
 268         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
 269
 270         r = radv_send(ra, &src, ra->lifetime);
 271         if (r < 0)
 272                 log_radv_warning_errno(r, "Unable to send solicited Router Advertisment to %s: %m", addr);
 273         else
 274                 log_radv("Sent solicited Router Advertisement to %s", addr);
 275
 276         return 0;
 277 }
 278
 279 static usec_t radv_compute_timeout(usec_t min, usec_t max) {
 280         assert_return(min <= max, SD_RADV_DEFAULT_MIN_TIMEOUT_USEC);
 281
 282         return min + (random_u32() % (max - min));
 283 }
 284
 285 static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
 286         int r;
 287         sd_radv *ra = userdata;
 288         usec_t min_timeout = SD_RADV_DEFAULT_MIN_TIMEOUT_USEC;
 289         usec_t max_timeout = SD_RADV_DEFAULT_MAX_TIMEOUT_USEC;
 290         usec_t time_now, timeout;
 291         char time_string[FORMAT_TIMESPAN_MAX];
 292
 293         assert(s);
 294         assert(ra);
 295         assert(ra->event);
 296
 297         ra->timeout_event_source = sd_event_source_unref(ra->timeout_event_source);
 298
 299         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 300         if (r < 0)
 301                 goto fail;
 302
 303         r = radv_send(ra, NULL, ra->lifetime);
 304         if (r < 0)
 305                 log_radv_warning_errno(r, "Unable to send Router Advertisement: %m");
 306
 307         /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
 308         if (ra->ra_sent < SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS) {
 309                 max_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
 310                 min_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC / 3;
 311         }
 312
 313         timeout = radv_compute_timeout(min_timeout, max_timeout);
 314
 315         log_radv("Next Router Advertisement in %s",
 316                  format_timespan(time_string, FORMAT_TIMESPAN_MAX,
 317                                  timeout, USEC_PER_SEC));
 318
 319         r = sd_event_add_time(ra->event, &ra->timeout_event_source,
 320                               clock_boottime_or_monotonic(),
 321                               time_now + timeout, MSEC_PER_SEC,
 322                               radv_timeout, ra);
 323         if (r < 0)
 324                 goto fail;
 325
 326         r = sd_event_source_set_priority(ra->timeout_event_source,
 327                                          ra->event_priority);
 328         if (r < 0)
 329                 goto fail;
 330
 331         r = sd_event_source_set_description(ra->timeout_event_source,
 332                                             "radv-timeout");
 333         if (r < 0)
 334                 goto fail;
 335
 336         ra->ra_sent++;
 337
 338 fail:
 339         if (r < 0)
 340                 sd_radv_stop(ra);
 341
 342         return 0;
 343 }
 344
 345 _public_ int sd_radv_stop(sd_radv *ra) {
 346         int r;
 347
 348         assert_return(ra, -EINVAL);
 349
 350         log_radv("Stopping IPv6 Router Advertisement daemon");
 351
 352         /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
 353            with zero lifetime  */
 354         r = radv_send(ra, NULL, 0);
 355         if (r < 0)
 356                 log_radv_warning_errno(r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
 357
 358         radv_reset(ra);
 359         ra->fd = safe_close(ra->fd);
 360         ra->state = SD_RADV_STATE_IDLE;
 361
 362         return 0;
 363 }
 364
 365 _public_ int sd_radv_start(sd_radv *ra) {
 366         int r = 0;
 367
 368         assert_return(ra, -EINVAL);
 369         assert_return(ra->event, -EINVAL);
 370         assert_return(ra->ifindex > 0, -EINVAL);
 371
 372         if (ra->state != SD_RADV_STATE_IDLE)
 373                 return 0;
 374
 375         r = sd_event_add_time(ra->event, &ra->timeout_event_source,
 376                               clock_boottime_or_monotonic(), 0, 0,
 377                               radv_timeout, ra);
 378         if (r < 0)
 379                 goto fail;
 380
 381         r = sd_event_source_set_priority(ra->timeout_event_source,
 382                                          ra->event_priority);
 383         if (r < 0)
 384                 goto fail;
 385
 386         (void) sd_event_source_set_description(ra->timeout_event_source,
 387                                                "radv-timeout");
 388
 389         r = icmp6_bind_router_advertisement(ra->ifindex);
 390         if (r < 0)
 391                 goto fail;
 392
 393         ra->fd = r;
 394
 395         r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
 396         if (r < 0)
 397                 goto fail;
 398
 399         r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
 400         if (r < 0)
 401                 goto fail;
 402
 403         (void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
 404
 405         ra->state = SD_RADV_STATE_ADVERTISING;
 406
 407         log_radv("Started IPv6 Router Advertisement daemon");
 408
 409         return 0;
 410
 411  fail:
 412         radv_reset(ra);
 413
 414         return r;
 415 }
 416
 417 _public_ int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
 418         assert_return(ra, -EINVAL);
 419         assert_return(ifindex >= -1, -EINVAL);
 420
 421         if (ra->state != SD_RADV_STATE_IDLE)
 422                 return -EBUSY;
 423
 424         ra->ifindex = ifindex;
 425
 426         return 0;
 427 }
 428
 429 _public_ int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
 430         assert_return(ra, -EINVAL);
 431
 432         if (ra->state != SD_RADV_STATE_IDLE)
 433                 return -EBUSY;
 434
 435         if (mac_addr)
 436                 ra->mac_addr = *mac_addr;
 437         else
 438                 zero(ra->mac_addr);
 439
 440         return 0;
 441 }
 442
 443 _public_ int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
 444         assert_return(ra, -EINVAL);
 445         assert_return(mtu >= 1280, -EINVAL);
 446
 447         if (ra->state != SD_RADV_STATE_IDLE)
 448                 return -EBUSY;
 449
 450         ra->mtu = mtu;
 451
 452         return 0;
 453 }
 454
 455 _public_ int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
 456         assert_return(ra, -EINVAL);
 457
 458         if (ra->state != SD_RADV_STATE_IDLE)
 459                 return -EBUSY;
 460
 461         ra->hop_limit = hop_limit;
 462
 463         return 0;
 464 }
 465
 466 _public_ int sd_radv_set_router_lifetime(sd_radv *ra, uint32_t router_lifetime) {
 467         assert_return(ra, -EINVAL);
 468
 469         if (ra->state != SD_RADV_STATE_IDLE)
 470                 return -EBUSY;
 471
 472         /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the
 473            preference value MUST be set to (00) by the sender..." */
 474         if (router_lifetime == 0 &&
 475             (ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
 476                 return -ETIME;
 477
 478         ra->lifetime = router_lifetime;
 479
 480         return 0;
 481 }
 482
 483 _public_ int sd_radv_set_managed_information(sd_radv *ra, int managed) {
 484         assert_return(ra, -EINVAL);
 485
 486         if (ra->state != SD_RADV_STATE_IDLE)
 487                 return -EBUSY;
 488
 489         SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
 490
 491         return 0;
 492 }
 493
 494 _public_ int sd_radv_set_other_information(sd_radv *ra, int other) {
 495         assert_return(ra, -EINVAL);
 496
 497         if (ra->state != SD_RADV_STATE_IDLE)
 498                 return -EBUSY;
 499
 500         SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
 501
 502         return 0;
 503 }
 504
 505 _public_ int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
 506         int r = 0;
 507
 508         assert_return(ra, -EINVAL);
 509         assert_return(IN_SET(preference,
 510                              SD_NDISC_PREFERENCE_LOW,
 511                              SD_NDISC_PREFERENCE_MEDIUM,
 512                              SD_NDISC_PREFERENCE_HIGH), -EINVAL);
 513
 514         ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);
 515
 516         return r;
 517 }
 518
 519 _public_ int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p) {
 520         sd_radv_prefix *cur;
 521         _cleanup_free_ char *addr_p = NULL;
 522
 523         assert_return(ra, -EINVAL);
 524
 525         if (!p)
 526                 return -EINVAL;
 527
 528         LIST_FOREACH(prefix, cur, ra->prefixes) {
 529                 int r;
 530
 531                 r = in_addr_prefix_intersect(AF_INET6,
 532                                              (union in_addr_union*) &cur->opt.in6_addr,
 533                                              cur->opt.prefixlen,
 534                                              (union in_addr_union*) &p->opt.in6_addr,
 535                                              p->opt.prefixlen);
 536                 if (r > 0) {
 537                         _cleanup_free_ char *addr_cur = NULL;
 538
 539                         (void) in_addr_to_string(AF_INET6,
 540                                                  (union in_addr_union*) &cur->opt.in6_addr,
 541                                                  &addr_cur);
 542                         (void) in_addr_to_string(AF_INET6,
 543                                                  (union in_addr_union*) &p->opt.in6_addr,
 544                                                  &addr_p);
 545
 546                         log_radv("IPv6 prefix %s/%u already configured, ignoring %s/%u",
 547                                  addr_cur, cur->opt.prefixlen,
 548                                  addr_p, p->opt.prefixlen);
 549
 550                         return -EEXIST;
 551                 }
 552         }
 553
 554         p = sd_radv_prefix_ref(p);
 555
 556         LIST_APPEND(prefix, ra->prefixes, p);
 557
 558         ra->n_prefixes++;
 559
 560         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &p->opt.in6_addr, &addr_p);
 561         log_radv("Added prefix %s/%d", addr_p, p->opt.prefixlen);
 562
 563         return 0;
 564 }
 565
 566 _public_ int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
 567                                const struct in6_addr *dns, size_t n_dns) {
 568         _cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
 569         size_t len;
 570
 571         assert_return(ra, -EINVAL);
 572         assert_return(n_dns < 128, -EINVAL);
 573
 574         if (!dns || n_dns == 0) {
 575                 ra->rdnss = mfree(ra->rdnss);
 576                 ra->n_rdnss = 0;
 577
 578                 return 0;
 579         }
 580
 581         len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
 582
 583         opt_rdnss = malloc0(len);
 584         if (!opt_rdnss)
 585                 return -ENOMEM;
 586
 587         opt_rdnss->type = SD_RADV_OPT_RDNSS;
 588         opt_rdnss->length = len / 8;
 589         opt_rdnss->lifetime = htobe32(lifetime);
 590
 591         memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
 592
 593         free(ra->rdnss);
 594         ra->rdnss = opt_rdnss;
 595         opt_rdnss = NULL;
 596
 597         ra->n_rdnss = n_dns;
 598
 599         return 0;
 600 }
 601
 602 _public_ int sd_radv_set_dnssl(sd_radv *ra, uint32_t lifetime,
 603                                char **search_list) {
 604         _cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
 605         size_t len = 0;
 606         char **s;
 607         uint8_t *p;
 608
 609         assert_return(ra, -EINVAL);
 610
 611         if (!search_list || *search_list == NULL) {
 612                 ra->dnssl = mfree(ra->dnssl);
 613
 614                 return 0;
 615         }
 616
 617         STRV_FOREACH(s, search_list)
 618                 len += strlen(*s) + 2;
 619
 620         len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
 621
 622         opt_dnssl = malloc0(len);
 623         if (!opt_dnssl)
 624                 return -ENOMEM;
 625
 626         opt_dnssl->type = SD_RADV_OPT_DNSSL;
 627         opt_dnssl->length = len / 8;
 628         opt_dnssl->lifetime = htobe32(lifetime);
 629
 630         p = (uint8_t *)(opt_dnssl + 1);
 631         len -= sizeof(struct sd_radv_opt_dns);
 632
 633         STRV_FOREACH(s, search_list) {
 634                 int r;
 635
 636                 r = dns_name_to_wire_format(*s, p, len, false);
 637                 if (r < 0)
 638                         return r;
 639
 640                 if (len < (size_t)r)
 641                         return -ENOBUFS;
 642
 643                 p += r;
 644                 len -= r;
 645         }
 646
 647         free(ra->dnssl);
 648         ra->dnssl = opt_dnssl;
 649         opt_dnssl = NULL;
 650
 651         return 0;
 652 }
 653
 654 _public_ int sd_radv_prefix_new(sd_radv_prefix **ret) {
 655         _cleanup_(sd_radv_prefix_unrefp) sd_radv_prefix *p = NULL;
 656
 657         assert_return(ret, -EINVAL);
 658
 659         p = new0(sd_radv_prefix, 1);
 660         if (!p)
 661                 return -ENOMEM;
 662
 663         p->n_ref = 1;
 664
 665         p->opt.type = ND_OPT_PREFIX_INFORMATION;
 666         p->opt.length = (sizeof(p->opt) - 1) /8 + 1;
 667
 668         p->opt.prefixlen = 64;
 669
 670         /* RFC 4861, Section 6.2.1 */
 671         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, true);
 672         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, true);
 673         p->opt.preferred_lifetime = htobe32(604800);
 674         p->opt.valid_lifetime = htobe32(2592000);
 675
 676         LIST_INIT(prefix, p);
 677
 678         *ret = p;
 679         p = NULL;
 680
 681         return 0;
 682 }
 683
 684 _public_ sd_radv_prefix *sd_radv_prefix_ref(sd_radv_prefix *p) {
 685         if (!p)
 686                 return NULL;
 687
 688         assert(p->n_ref > 0);
 689         p->n_ref++;
 690
 691         return p;
 692 }
 693
 694 _public_ sd_radv_prefix *sd_radv_prefix_unref(sd_radv_prefix *p) {
 695         if (!p)
 696                 return NULL;
 697
 698         assert(p->n_ref > 0);
 699         p->n_ref--;
 700
 701         if (p->n_ref > 0)
 702                 return NULL;
 703
 704         return mfree(p);
 705 }
 706
 707 _public_ int sd_radv_prefix_set_prefix(sd_radv_prefix *p, struct in6_addr *in6_addr,
 708                                        unsigned char prefixlen) {
 709         assert_return(p, -EINVAL);
 710         assert_return(in6_addr, -EINVAL);
 711
 712         if (prefixlen < 3 || prefixlen > 128)
 713                 return -EINVAL;
 714
 715         if (prefixlen > 64)
 716                 /* unusual but allowed, log it */
 717                 log_radv("Unusual prefix length %d greater than 64", prefixlen);
 718
 719         p->opt.in6_addr = *in6_addr;
 720         p->opt.prefixlen = prefixlen;
 721
 722         return 0;
 723 }
 724
 725 _public_ int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
 726         assert_return(p, -EINVAL);
 727
 728         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
 729
 730         return 0;
 731 }
 732
 733 _public_ int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
 734                                                           int address_autoconfiguration) {
 735         assert_return(p, -EINVAL);
 736
 737         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
 738
 739         return 0;
 740 }
 741
 742 _public_ int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p,
 743                                                uint32_t valid_lifetime) {
 744         assert_return(p, -EINVAL);
 745
 746         p->opt.valid_lifetime = htobe32(valid_lifetime);
 747
 748         return 0;
 749 }
 750
 751 _public_ int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p,
 752                                                    uint32_t preferred_lifetime) {
 753         assert_return(p, -EINVAL);
 754
 755         p->opt.preferred_lifetime = htobe32(preferred_lifetime);
 756
 757         return 0;
 758 }