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
 133         radv_reset(ra);
 134
 135         sd_radv_detach_event(ra);
 136         return mfree(ra);
 137 }
 138
 139 static int radv_send(sd_radv *ra, const struct in6_addr *dst,
 140                      const uint32_t router_lifetime) {
 141         static const struct ether_addr mac_zero = {};
 142         sd_radv_prefix *p;
 143         struct sockaddr_in6 dst_addr = {
 144                 .sin6_family = AF_INET6,
 145                 .sin6_addr = IN6ADDR_ALL_NODES_MULTICAST_INIT,
 146         };
 147         struct nd_router_advert adv = {};
 148         struct {
 149                 struct nd_opt_hdr opthdr;
 150                 struct ether_addr slladdr;
 151         } _packed_ opt_mac = {
 152                 .opthdr = {
 153                         .nd_opt_type = ND_OPT_SOURCE_LINKADDR,
 154                         .nd_opt_len = (sizeof(struct nd_opt_hdr) +
 155                                        sizeof(struct ether_addr) - 1) /8 + 1,
 156                 },
 157         };
 158         struct nd_opt_mtu opt_mtu =  {
 159                 .nd_opt_mtu_type = ND_OPT_MTU,
 160                 .nd_opt_mtu_len = 1,
 161         };
 162         /* Reserve iov space for RA header, linkaddr, MTU, N prefixes, RDNSS */
 163         struct iovec iov[4 + ra->n_prefixes];
 164         struct msghdr msg = {
 165                 .msg_name = &dst_addr,
 166                 .msg_namelen = sizeof(dst_addr),
 167                 .msg_iov = iov,
 168         };
 169
 170         if (dst && !in_addr_is_null(AF_INET6, (union in_addr_union*) 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].iov_base = &adv;
 178         iov[msg.msg_iovlen].iov_len = sizeof(adv);
 179         msg.msg_iovlen++;
 180
 181         /* MAC address is optional, either because the link does not use L2
 182            addresses or load sharing is desired. See RFC 4861, Section 4.2 */
 183         if (memcmp(&mac_zero, &ra->mac_addr, sizeof(mac_zero))) {
 184                 opt_mac.slladdr = ra->mac_addr;
 185                 iov[msg.msg_iovlen].iov_base = &opt_mac;
 186                 iov[msg.msg_iovlen].iov_len = sizeof(opt_mac);
 187                 msg.msg_iovlen++;
 188         }
 189
 190         if (ra->mtu) {
 191                 opt_mtu.nd_opt_mtu_mtu = htobe32(ra->mtu);
 192                 iov[msg.msg_iovlen].iov_base = &opt_mtu;
 193                 iov[msg.msg_iovlen].iov_len = sizeof(opt_mtu);
 194                 msg.msg_iovlen++;
 195         }
 196
 197         LIST_FOREACH(prefix, p, ra->prefixes) {
 198                 iov[msg.msg_iovlen].iov_base = &p->opt;
 199                 iov[msg.msg_iovlen].iov_len = sizeof(p->opt);
 200                 msg.msg_iovlen++;
 201         }
 202
 203         if (ra->rdnss) {
 204                 iov[msg.msg_iovlen].iov_base = ra->rdnss;
 205                 iov[msg.msg_iovlen].iov_len = ra->rdnss->length * 8;
 206                 msg.msg_iovlen++;
 207         }
 208
 209         if (ra->dnssl) {
 210                 iov[msg.msg_iovlen].iov_base = ra->dnssl;
 211                 iov[msg.msg_iovlen].iov_len = ra->dnssl->length * 8;
 212                 msg.msg_iovlen++;
 213         }
 214
 215         if (sendmsg(ra->fd, &msg, 0) < 0)
 216                 return -errno;
 217
 218         return 0;
 219 }
 220
 221 static int radv_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 222         sd_radv *ra = userdata;
 223         _cleanup_free_ char *addr = NULL;
 224         struct in6_addr src;
 225         triple_timestamp timestamp;
 226         int r;
 227         ssize_t buflen;
 228         _cleanup_free_ char *buf = NULL;
 229
 230         assert(s);
 231         assert(ra);
 232         assert(ra->event);
 233
 234         buflen = next_datagram_size_fd(fd);
 235
 236         if ((unsigned) buflen < sizeof(struct nd_router_solicit))
 237                 return log_radv("Too short packet received");
 238
 239         buf = new0(char, buflen);
 240         if (!buf)
 241                 return 0;
 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                 default:
 260                         log_radv_warning_errno(r, "Error receiving from ICMPv6 socket: %m");
 261                         break;
 262                 }
 263
 264                 return 0;
 265         }
 266
 267         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &src, &addr);
 268
 269         r = radv_send(ra, &src, ra->lifetime);
 270         if (r < 0)
 271                 log_radv_warning_errno(r, "Unable to send solicited Router Advertisment to %s: %m", addr);
 272         else
 273                 log_radv("Sent solicited Router Advertisement to %s", addr);
 274
 275         return 0;
 276 }
 277
 278 static usec_t radv_compute_timeout(usec_t min, usec_t max) {
 279         assert_return(min <= max, SD_RADV_DEFAULT_MIN_TIMEOUT_USEC);
 280
 281         return min + (random_u32() % (max - min));
 282 }
 283
 284 static int radv_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
 285         int r;
 286         sd_radv *ra = userdata;
 287         usec_t min_timeout = SD_RADV_DEFAULT_MIN_TIMEOUT_USEC;
 288         usec_t max_timeout = SD_RADV_DEFAULT_MAX_TIMEOUT_USEC;
 289         usec_t time_now, timeout;
 290         char time_string[FORMAT_TIMESPAN_MAX];
 291
 292         assert(s);
 293         assert(ra);
 294         assert(ra->event);
 295
 296         ra->timeout_event_source = sd_event_source_unref(ra->timeout_event_source);
 297
 298         r = sd_event_now(ra->event, clock_boottime_or_monotonic(), &time_now);
 299         if (r < 0)
 300                 goto fail;
 301
 302         r = radv_send(ra, NULL, ra->lifetime);
 303         if (r < 0)
 304                 log_radv_warning_errno(r, "Unable to send Router Advertisement: %m");
 305
 306         /* RFC 4861, Section 6.2.4, sending initial Router Advertisements */
 307         if (ra->ra_sent < SD_RADV_MAX_INITIAL_RTR_ADVERTISEMENTS) {
 308                 max_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC;
 309                 min_timeout = SD_RADV_MAX_INITIAL_RTR_ADVERT_INTERVAL_USEC / 3;
 310         }
 311
 312         timeout = radv_compute_timeout(min_timeout, max_timeout);
 313
 314         log_radv("Next Router Advertisement in %s",
 315                  format_timespan(time_string, FORMAT_TIMESPAN_MAX,
 316                                  timeout, USEC_PER_SEC));
 317
 318         r = sd_event_add_time(ra->event, &ra->timeout_event_source,
 319                               clock_boottime_or_monotonic(),
 320                               time_now + timeout, MSEC_PER_SEC,
 321                               radv_timeout, ra);
 322         if (r < 0)
 323                 goto fail;
 324
 325         r = sd_event_source_set_priority(ra->timeout_event_source,
 326                                          ra->event_priority);
 327         if (r < 0)
 328                 goto fail;
 329
 330         r = sd_event_source_set_description(ra->timeout_event_source,
 331                                             "radv-timeout");
 332         if (r < 0)
 333                 goto fail;
 334
 335         ra->ra_sent++;
 336
 337 fail:
 338         if (r < 0)
 339                 sd_radv_stop(ra);
 340
 341         return 0;
 342 }
 343
 344 _public_ int sd_radv_stop(sd_radv *ra) {
 345         int r;
 346
 347         assert_return(ra, -EINVAL);
 348
 349         log_radv("Stopping IPv6 Router Advertisement daemon");
 350
 351         /* RFC 4861, Section 6.2.5, send at least one Router Advertisement
 352            with zero lifetime  */
 353         r = radv_send(ra, NULL, 0);
 354         if (r < 0)
 355                 log_radv_warning_errno(r, "Unable to send last Router Advertisement with router lifetime set to zero: %m");
 356
 357         radv_reset(ra);
 358         ra->fd = safe_close(ra->fd);
 359         ra->state = SD_RADV_STATE_IDLE;
 360
 361         return 0;
 362 }
 363
 364 _public_ int sd_radv_start(sd_radv *ra) {
 365         int r = 0;
 366
 367         assert_return(ra, -EINVAL);
 368         assert_return(ra->event, -EINVAL);
 369         assert_return(ra->ifindex > 0, -EINVAL);
 370
 371         if (ra->state != SD_RADV_STATE_IDLE)
 372                 return 0;
 373
 374         r = sd_event_add_time(ra->event, &ra->timeout_event_source,
 375                               clock_boottime_or_monotonic(), 0, 0,
 376                               radv_timeout, ra);
 377         if (r < 0)
 378                 goto fail;
 379
 380         r = sd_event_source_set_priority(ra->timeout_event_source,
 381                                          ra->event_priority);
 382         if (r < 0)
 383                 goto fail;
 384
 385         (void) sd_event_source_set_description(ra->timeout_event_source,
 386                                                "radv-timeout");
 387
 388         r = icmp6_bind_router_advertisement(ra->ifindex);
 389         if (r < 0)
 390                 goto fail;
 391
 392         ra->fd = r;
 393
 394         r = sd_event_add_io(ra->event, &ra->recv_event_source, ra->fd, EPOLLIN, radv_recv, ra);
 395         if (r < 0)
 396                 goto fail;
 397
 398         r = sd_event_source_set_priority(ra->recv_event_source, ra->event_priority);
 399         if (r < 0)
 400                 goto fail;
 401
 402         (void) sd_event_source_set_description(ra->recv_event_source, "radv-receive-message");
 403
 404         ra->state = SD_RADV_STATE_ADVERTISING;
 405
 406         log_radv("Started IPv6 Router Advertisement daemon");
 407
 408         return 0;
 409
 410  fail:
 411         radv_reset(ra);
 412
 413         return r;
 414 }
 415
 416 _public_ int sd_radv_set_ifindex(sd_radv *ra, int ifindex) {
 417         assert_return(ra, -EINVAL);
 418         assert_return(ifindex >= -1, -EINVAL);
 419
 420         if (ra->state != SD_RADV_STATE_IDLE)
 421                 return -EBUSY;
 422
 423         ra->ifindex = ifindex;
 424
 425         return 0;
 426 }
 427
 428 _public_ int sd_radv_set_mac(sd_radv *ra, const struct ether_addr *mac_addr) {
 429         assert_return(ra, -EINVAL);
 430
 431         if (ra->state != SD_RADV_STATE_IDLE)
 432                 return -EBUSY;
 433
 434         if (mac_addr)
 435                 ra->mac_addr = *mac_addr;
 436         else
 437                 zero(ra->mac_addr);
 438
 439         return 0;
 440 }
 441
 442 _public_ int sd_radv_set_mtu(sd_radv *ra, uint32_t mtu) {
 443         assert_return(ra, -EINVAL);
 444         assert_return(mtu >= 1280, -EINVAL);
 445
 446         if (ra->state != SD_RADV_STATE_IDLE)
 447                 return -EBUSY;
 448
 449         ra->mtu = mtu;
 450
 451         return 0;
 452 }
 453
 454 _public_ int sd_radv_set_hop_limit(sd_radv *ra, uint8_t hop_limit) {
 455         assert_return(ra, -EINVAL);
 456
 457         if (ra->state != SD_RADV_STATE_IDLE)
 458                 return -EBUSY;
 459
 460         ra->hop_limit = hop_limit;
 461
 462         return 0;
 463 }
 464
 465 _public_ int sd_radv_set_router_lifetime(sd_radv *ra, uint32_t router_lifetime) {
 466         assert_return(ra, -EINVAL);
 467
 468         if (ra->state != SD_RADV_STATE_IDLE)
 469                 return -EBUSY;
 470
 471         /* RFC 4191, Section 2.2, "...If the Router Lifetime is zero, the
 472            preference value MUST be set to (00) by the sender..." */
 473         if (router_lifetime == 0 &&
 474             (ra->flags & (0x3 << 3)) != (SD_NDISC_PREFERENCE_MEDIUM << 3))
 475                 return -ETIME;
 476
 477         ra->lifetime = router_lifetime;
 478
 479         return 0;
 480 }
 481
 482 _public_ int sd_radv_set_managed_information(sd_radv *ra, int managed) {
 483         assert_return(ra, -EINVAL);
 484
 485         if (ra->state != SD_RADV_STATE_IDLE)
 486                 return -EBUSY;
 487
 488         SET_FLAG(ra->flags, ND_RA_FLAG_MANAGED, managed);
 489
 490         return 0;
 491 }
 492
 493 _public_ int sd_radv_set_other_information(sd_radv *ra, int other) {
 494         assert_return(ra, -EINVAL);
 495
 496         if (ra->state != SD_RADV_STATE_IDLE)
 497                 return -EBUSY;
 498
 499         SET_FLAG(ra->flags, ND_RA_FLAG_OTHER, other);
 500
 501         return 0;
 502 }
 503
 504 _public_ int sd_radv_set_preference(sd_radv *ra, unsigned preference) {
 505         int r = 0;
 506
 507         assert_return(ra, -EINVAL);
 508         assert_return(IN_SET(preference,
 509                              SD_NDISC_PREFERENCE_LOW,
 510                              SD_NDISC_PREFERENCE_MEDIUM,
 511                              SD_NDISC_PREFERENCE_HIGH), -EINVAL);
 512
 513         ra->flags = (ra->flags & ~(0x3 << 3)) | (preference << 3);
 514
 515         return r;
 516 }
 517
 518 _public_ int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p) {
 519         sd_radv_prefix *cur;
 520         _cleanup_free_ char *addr_p = NULL;
 521
 522         assert_return(ra, -EINVAL);
 523
 524         if (!p)
 525                 return -EINVAL;
 526
 527         LIST_FOREACH(prefix, cur, ra->prefixes) {
 528                 int r;
 529
 530                 r = in_addr_prefix_intersect(AF_INET6,
 531                                              (union in_addr_union*) &cur->opt.in6_addr,
 532                                              cur->opt.prefixlen,
 533                                              (union in_addr_union*) &p->opt.in6_addr,
 534                                              p->opt.prefixlen);
 535                 if (r > 0) {
 536                         _cleanup_free_ char *addr_cur = NULL;
 537
 538                         (void) in_addr_to_string(AF_INET6,
 539                                                  (union in_addr_union*) &cur->opt.in6_addr,
 540                                                  &addr_cur);
 541                         (void) in_addr_to_string(AF_INET6,
 542                                                  (union in_addr_union*) &p->opt.in6_addr,
 543                                                  &addr_p);
 544
 545                         log_radv("IPv6 prefix %s/%u already configured, ignoring %s/%u",
 546                                  addr_cur, cur->opt.prefixlen,
 547                                  addr_p, p->opt.prefixlen);
 548
 549                         return -EEXIST;
 550                 }
 551         }
 552
 553         p = sd_radv_prefix_ref(p);
 554
 555         LIST_APPEND(prefix, ra->prefixes, p);
 556
 557         ra->n_prefixes++;
 558
 559         (void) in_addr_to_string(AF_INET6, (union in_addr_union*) &p->opt.in6_addr, &addr_p);
 560         log_radv("Added prefix %s/%d", addr_p, p->opt.prefixlen);
 561
 562         return 0;
 563 }
 564
 565 _public_ int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
 566                                const struct in6_addr *dns, size_t n_dns) {
 567         _cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
 568         size_t len;
 569
 570         assert_return(ra, -EINVAL);
 571         assert_return(n_dns < 128, -EINVAL);
 572
 573         if (!dns || n_dns == 0) {
 574                 ra->rdnss = mfree(ra->rdnss);
 575                 ra->n_rdnss = 0;
 576
 577                 return 0;
 578         }
 579
 580         len = sizeof(struct sd_radv_opt_dns) + sizeof(struct in6_addr) * n_dns;
 581
 582         opt_rdnss = malloc0(len);
 583         if (!opt_rdnss)
 584                 return -ENOMEM;
 585
 586         opt_rdnss->type = SD_RADV_OPT_RDNSS;
 587         opt_rdnss->length = len / 8;
 588         opt_rdnss->lifetime = htobe32(lifetime);
 589
 590         memcpy(opt_rdnss + 1, dns, n_dns * sizeof(struct in6_addr));
 591
 592         free(ra->rdnss);
 593         ra->rdnss = opt_rdnss;
 594         opt_rdnss = NULL;
 595
 596         ra->n_rdnss = n_dns;
 597
 598         return 0;
 599 }
 600
 601 _public_ int sd_radv_set_dnssl(sd_radv *ra, uint32_t lifetime,
 602                                char **search_list) {
 603         _cleanup_free_ struct sd_radv_opt_dns *opt_dnssl = NULL;
 604         size_t len = 0;
 605         char **s;
 606         uint8_t *p;
 607
 608         assert_return(ra, -EINVAL);
 609
 610         if (!search_list || *search_list == NULL) {
 611                 ra->dnssl = mfree(ra->dnssl);
 612
 613                 return 0;
 614         }
 615
 616         STRV_FOREACH(s, search_list)
 617                 len += strlen(*s) + 2;
 618
 619         len = (sizeof(struct sd_radv_opt_dns) + len + 7) & ~0x7;
 620
 621         opt_dnssl = malloc0(len);
 622         if (!opt_dnssl)
 623                 return -ENOMEM;
 624
 625         opt_dnssl->type = SD_RADV_OPT_DNSSL;
 626         opt_dnssl->length = len / 8;
 627         opt_dnssl->lifetime = htobe32(lifetime);
 628
 629         p = (uint8_t *)(opt_dnssl + 1);
 630         len -= sizeof(struct sd_radv_opt_dns);
 631
 632         STRV_FOREACH(s, search_list) {
 633                 int r;
 634
 635                 r = dns_name_to_wire_format(*s, p, len, false);
 636                 if (r < 0)
 637                         return r;
 638
 639                 if (len < (size_t)r)
 640                         return -ENOBUFS;
 641
 642                 p += r;
 643                 len -= r;
 644         }
 645
 646         free(ra->dnssl);
 647         ra->dnssl = opt_dnssl;
 648         opt_dnssl = NULL;
 649
 650         return 0;
 651 }
 652
 653 _public_ int sd_radv_prefix_new(sd_radv_prefix **ret) {
 654         _cleanup_(sd_radv_prefix_unrefp) sd_radv_prefix *p = NULL;
 655
 656         assert_return(ret, -EINVAL);
 657
 658         p = new0(sd_radv_prefix, 1);
 659         if (!p)
 660                 return -ENOMEM;
 661
 662         p->n_ref = 1;
 663
 664         p->opt.type = ND_OPT_PREFIX_INFORMATION;
 665         p->opt.length = (sizeof(p->opt) - 1) /8 + 1;
 666
 667         p->opt.prefixlen = 64;
 668
 669         /* RFC 4861, Section 6.2.1 */
 670         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, true);
 671         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, true);
 672         p->opt.preferred_lifetime = htobe32(604800);
 673         p->opt.valid_lifetime = htobe32(2592000);
 674
 675         LIST_INIT(prefix, p);
 676
 677         *ret = p;
 678         p = NULL;
 679
 680         return 0;
 681 }
 682
 683 _public_ sd_radv_prefix *sd_radv_prefix_ref(sd_radv_prefix *p) {
 684         if (!p)
 685                 return NULL;
 686
 687         assert(p->n_ref > 0);
 688         p->n_ref++;
 689
 690         return p;
 691 }
 692
 693 _public_ sd_radv_prefix *sd_radv_prefix_unref(sd_radv_prefix *p) {
 694         if (!p)
 695                 return NULL;
 696
 697         assert(p->n_ref > 0);
 698         p->n_ref--;
 699
 700         if (p->n_ref > 0)
 701                 return NULL;
 702
 703         return mfree(p);
 704 }
 705
 706 _public_ int sd_radv_prefix_set_prefix(sd_radv_prefix *p, struct in6_addr *in6_addr,
 707                                        unsigned char prefixlen) {
 708         assert_return(p, -EINVAL);
 709         assert_return(in6_addr, -EINVAL);
 710
 711         if (prefixlen < 3 || prefixlen > 128)
 712                 return -EINVAL;
 713
 714         if (prefixlen > 64)
 715                 /* unusual but allowed, log it */
 716                 log_radv("Unusual prefix length %d greater than 64", prefixlen);
 717
 718         p->opt.in6_addr = *in6_addr;
 719         p->opt.prefixlen = prefixlen;
 720
 721         return 0;
 722 }
 723
 724 _public_ int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
 725         assert_return(p, -EINVAL);
 726
 727         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
 728
 729         return 0;
 730 }
 731
 732 _public_ int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
 733                                                           int address_autoconfiguration) {
 734         assert_return(p, -EINVAL);
 735
 736         SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
 737
 738         return 0;
 739 }
 740
 741 _public_ int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p,
 742                                                uint32_t valid_lifetime) {
 743         assert_return(p, -EINVAL);
 744
 745         p->opt.valid_lifetime = htobe32(valid_lifetime);
 746
 747         return 0;
 748 }
 749
 750 _public_ int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p,
 751                                                    uint32_t preferred_lifetime) {
 752         assert_return(p, -EINVAL);
 753
 754         p->opt.preferred_lifetime = htobe32(preferred_lifetime);
 755
 756         return 0;
 757 }