src/libsystemd-network/sd-ndisc.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright (C) 2014 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/ip6.h>
  22 #include <string.h>
  23 #include <stdbool.h>
  24 #include <netinet/in.h>
  25 #include <sys/ioctl.h>
  26
  27 #include "async.h"
  28 #include "list.h"
  29 #include "socket-util.h"
  30
  31 #include "icmp6-util.h"
  32 #include "sd-ndisc.h"
  33
  34 #define NDISC_ROUTER_SOLICITATION_INTERVAL      4 * USEC_PER_SEC
  35 #define NDISC_MAX_ROUTER_SOLICITATIONS          3
  36
  37 enum NDiscState {
  38         NDISC_STATE_IDLE,
  39         NDISC_STATE_SOLICITATION_SENT,
  40         NDISC_STATE_ADVERTISMENT_LISTEN,
  41         _NDISC_STATE_MAX,
  42         _NDISC_STATE_INVALID = -1,
  43 };
  44
  45 #define IP6_MIN_MTU (unsigned)1280
  46 #define ICMP6_RECV_SIZE (IP6_MIN_MTU - sizeof(struct ip6_hdr))
  47 #define NDISC_OPT_LEN_UNITS 8
  48
  49 typedef struct NDiscPrefix NDiscPrefix;
  50
  51 struct NDiscPrefix {
  52         unsigned n_ref;
  53
  54         LIST_FIELDS(NDiscPrefix, prefixes);
  55
  56         uint8_t len;
  57         sd_event_source *timeout_valid;
  58         struct in6_addr addr;
  59 };
  60
  61 struct sd_ndisc {
  62         unsigned n_ref;
  63
  64         enum NDiscState state;
  65         sd_event *event;
  66         int event_priority;
  67         int index;
  68         struct ether_addr mac_addr;
  69         uint32_t mtu;
  70         LIST_HEAD(NDiscPrefix, prefixes);
  71         int fd;
  72         sd_event_source *recv;
  73         sd_event_source *timeout;
  74         int nd_sent;
  75         sd_ndisc_callback_t callback;
  76         void *userdata;
  77 };
  78
  79 #define log_ndisc(p, fmt, ...) log_internal(LOG_DEBUG, 0, __FILE__, __LINE__, __func__, "NDisc CLIENT: " fmt, ##__VA_ARGS__)
  80
  81 static NDiscPrefix *ndisc_prefix_unref(NDiscPrefix *prefix) {
  82
  83         if (!prefix)
  84                 return NULL;
  85
  86         assert(prefix->n_ref > 0);
  87         prefix->n_ref--;
  88
  89         if (prefix->n_ref > 0)
  90                 return NULL;
  91
  92         prefix->timeout_valid = sd_event_source_unref(prefix->timeout_valid);
  93         free(prefix);
  94         return NULL;
  95 }
  96
  97 static int ndisc_prefix_new(NDiscPrefix **ret) {
  98         _cleanup_free_ NDiscPrefix *prefix = NULL;
  99
 100         assert(ret);
 101
 102         prefix = new0(NDiscPrefix, 1);
 103         if (!prefix)
 104                 return -ENOMEM;
 105
 106         prefix->n_ref = 1;
 107         LIST_INIT(prefixes, prefix);
 108
 109         *ret = prefix;
 110         prefix = NULL;
 111
 112         return 0;
 113 }
 114
 115 static void ndisc_notify(sd_ndisc *nd, int event) {
 116         if (nd->callback)
 117                 nd->callback(nd, event, nd->userdata);
 118 }
 119
 120 int sd_ndisc_set_callback(sd_ndisc *nd, sd_ndisc_callback_t callback,
 121                              void *userdata) {
 122         assert(nd);
 123
 124         nd->callback = callback;
 125         nd->userdata = userdata;
 126
 127         return 0;
 128 }
 129
 130 int sd_ndisc_set_index(sd_ndisc *nd, int interface_index) {
 131         assert(nd);
 132         assert(interface_index >= -1);
 133
 134         nd->index = interface_index;
 135
 136         return 0;
 137 }
 138
 139 int sd_ndisc_set_mac(sd_ndisc *nd, const struct ether_addr *mac_addr) {
 140         assert(nd);
 141
 142         if (mac_addr)
 143                 memcpy(&nd->mac_addr, mac_addr, sizeof(nd->mac_addr));
 144         else
 145                 zero(nd->mac_addr);
 146
 147         return 0;
 148
 149 }
 150
 151 int sd_ndisc_attach_event(sd_ndisc *nd, sd_event *event, int priority) {
 152         int r;
 153
 154         assert_return(nd, -EINVAL);
 155         assert_return(!nd->event, -EBUSY);
 156
 157         if (event)
 158                 nd->event = sd_event_ref(event);
 159         else {
 160                 r = sd_event_default(&nd->event);
 161                 if (r < 0)
 162                         return 0;
 163         }
 164
 165         nd->event_priority = priority;
 166
 167         return 0;
 168 }
 169
 170 int sd_ndisc_detach_event(sd_ndisc *nd) {
 171         assert_return(nd, -EINVAL);
 172
 173         nd->event = sd_event_unref(nd->event);
 174
 175         return 0;
 176 }
 177
 178 sd_event *sd_ndisc_get_event(sd_ndisc *nd) {
 179         assert(nd);
 180
 181         return nd->event;
 182 }
 183
 184 sd_ndisc *sd_ndisc_ref(sd_ndisc *nd) {
 185
 186         if (!nd)
 187                 return NULL;
 188
 189         assert(nd->n_ref > 0);
 190         nd->n_ref++;
 191
 192         return nd;
 193 }
 194
 195 static int ndisc_init(sd_ndisc *nd) {
 196         assert(nd);
 197
 198         nd->recv = sd_event_source_unref(nd->recv);
 199         nd->fd = asynchronous_close(nd->fd);
 200         nd->timeout = sd_event_source_unref(nd->timeout);
 201
 202         return 0;
 203 }
 204
 205 sd_ndisc *sd_ndisc_unref(sd_ndisc *nd) {
 206         NDiscPrefix *prefix, *p;
 207
 208         if (!nd)
 209                 return NULL;
 210
 211         assert(nd->n_ref > 0);
 212         nd->n_ref--;
 213
 214         if (nd->n_ref > 0)
 215                 return NULL;
 216
 217         ndisc_init(nd);
 218         sd_ndisc_detach_event(nd);
 219
 220         LIST_FOREACH_SAFE(prefixes, prefix, p, nd->prefixes) {
 221                 LIST_REMOVE(prefixes, nd->prefixes, prefix);
 222
 223                 prefix = ndisc_prefix_unref(prefix);
 224         }
 225
 226         free(nd);
 227
 228         return NULL;
 229 }
 230
 231 DEFINE_TRIVIAL_CLEANUP_FUNC(sd_ndisc*, sd_ndisc_unref);
 232 #define _cleanup_sd_ndisc_free_ _cleanup_(sd_ndisc_unrefp)
 233
 234 int sd_ndisc_new(sd_ndisc **ret) {
 235         _cleanup_sd_ndisc_free_ sd_ndisc *nd = NULL;
 236
 237         assert(ret);
 238
 239         nd = new0(sd_ndisc, 1);
 240         if (!nd)
 241                 return -ENOMEM;
 242
 243         nd->n_ref = 1;
 244
 245         nd->index = -1;
 246         nd->fd = -1;
 247
 248         LIST_HEAD_INIT(nd->prefixes);
 249
 250         *ret = nd;
 251         nd = NULL;
 252
 253         return 0;
 254 }
 255
 256 int sd_ndisc_get_mtu(sd_ndisc *nd, uint32_t *mtu) {
 257         assert_return(nd, -EINVAL);
 258         assert_return(mtu, -EINVAL);
 259
 260         if (nd->mtu == 0)
 261                 return -ENOMSG;
 262
 263         *mtu = nd->mtu;
 264
 265         return 0;
 266 }
 267
 268 static int ndisc_prefix_timeout(sd_event_source *s, uint64_t usec,
 269                                    void *userdata) {
 270         sd_ndisc *nd = userdata;
 271         NDiscPrefix *prefix, *p;
 272
 273         assert(nd);
 274
 275         LIST_FOREACH_SAFE(prefixes, prefix, p, nd->prefixes) {
 276                 if (prefix->timeout_valid != s)
 277                         continue;
 278
 279                 log_ndisc(nd, "Prefix expired "SD_NDISC_ADDRESS_FORMAT_STR"/%d",
 280                              SD_NDISC_ADDRESS_FORMAT_VAL(prefix->addr),
 281                              prefix->len);
 282
 283                 LIST_REMOVE(prefixes, nd->prefixes, prefix);
 284
 285                 prefix = ndisc_prefix_unref(prefix);
 286
 287                 break;
 288         }
 289
 290         return 0;
 291 }
 292
 293 static int ndisc_prefix_set_timeout(sd_ndisc *nd,
 294                                        NDiscPrefix *prefix,
 295                                        usec_t valid) {
 296         usec_t time_now;
 297         int r;
 298
 299         assert_return(prefix, -EINVAL);
 300
 301         r = sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now);
 302         if (r < 0)
 303                 return r;
 304
 305         prefix->timeout_valid = sd_event_source_unref(prefix->timeout_valid);
 306
 307         r = sd_event_add_time(nd->event, &prefix->timeout_valid,
 308                         clock_boottime_or_monotonic(), time_now + valid,
 309                         USEC_PER_SEC, ndisc_prefix_timeout, nd);
 310         if (r < 0)
 311                 goto error;
 312
 313         r = sd_event_source_set_priority(prefix->timeout_valid,
 314                                         nd->event_priority);
 315         if (r < 0)
 316                 goto error;
 317
 318         r = sd_event_source_set_description(prefix->timeout_valid,
 319                                         "ndisc-prefix-timeout");
 320
 321 error:
 322         if (r < 0)
 323                 prefix->timeout_valid =
 324                         sd_event_source_unref(prefix->timeout_valid);
 325
 326         return r;
 327 }
 328
 329 static int prefix_match(const struct in6_addr *prefix, uint8_t prefixlen,
 330                         const struct in6_addr *addr,
 331                         uint8_t addr_prefixlen) {
 332         uint8_t bytes, mask, len;
 333
 334         assert_return(prefix, -EINVAL);
 335         assert_return(addr, -EINVAL);
 336
 337         len = MIN(prefixlen, addr_prefixlen);
 338
 339         bytes = len / 8;
 340         mask = 0xff << (8 - len % 8);
 341
 342         if (memcmp(prefix, addr, bytes) != 0 ||
 343             (prefix->s6_addr[bytes] & mask) != (addr->s6_addr[bytes] & mask))
 344                 return -EADDRNOTAVAIL;
 345
 346         return 0;
 347 }
 348
 349 static int ndisc_prefix_match(NDiscPrefix *head, const struct in6_addr *addr,
 350                                  uint8_t addr_len, NDiscPrefix **result) {
 351         NDiscPrefix *prefix;
 352
 353         LIST_FOREACH(prefixes, prefix, head) {
 354                 if (prefix_match(&prefix->addr, prefix->len, addr, addr_len) >= 0) {
 355                         *result = prefix;
 356                         return 0;
 357                 }
 358         }
 359
 360         return -EADDRNOTAVAIL;
 361 }
 362
 363 int sd_ndisc_prefix_match(struct in6_addr *prefix, uint8_t prefixlen,
 364                           struct in6_addr *addr) {
 365         return prefix_match(prefix, prefixlen, addr, sizeof(addr->s6_addr) * 8);
 366 }
 367
 368 int sd_ndisc_get_prefixlen(sd_ndisc *nd, const struct in6_addr *addr,
 369                               uint8_t *prefixlen) {
 370         int r;
 371         NDiscPrefix *prefix;
 372
 373         assert_return(nd, -EINVAL);
 374         assert_return(addr, -EINVAL);
 375         assert_return(prefixlen, -EINVAL);
 376
 377         r = ndisc_prefix_match(nd->prefixes, addr,
 378                                   sizeof(addr->s6_addr) * 8, &prefix);
 379         if (r < 0)
 380                 return r;
 381
 382         *prefixlen = prefix->len;
 383
 384         return 0;
 385 }
 386
 387 static int ndisc_prefix_update(sd_ndisc *nd, ssize_t len,
 388                                   const struct nd_opt_prefix_info *prefix_opt) {
 389         int r;
 390         NDiscPrefix *prefix;
 391         uint32_t lifetime;
 392         char time_string[FORMAT_TIMESPAN_MAX];
 393
 394         assert_return(nd, -EINVAL);
 395         assert_return(prefix_opt, -EINVAL);
 396
 397         if (len < prefix_opt->nd_opt_pi_len)
 398                 return -ENOMSG;
 399
 400         if (!(prefix_opt->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK))
 401                 return 0;
 402
 403         lifetime = be32toh(prefix_opt->nd_opt_pi_valid_time);
 404
 405         r = ndisc_prefix_match(nd->prefixes,
 406                                   &prefix_opt->nd_opt_pi_prefix,
 407                                   prefix_opt->nd_opt_pi_prefix_len, &prefix);
 408
 409         if (r < 0 && r != -EADDRNOTAVAIL)
 410                 return r;
 411
 412         /* if router advertisment prefix valid timeout is zero, the timeout
 413            callback will be called immediately to clean up the prefix */
 414
 415         if (r == -EADDRNOTAVAIL) {
 416                 r = ndisc_prefix_new(&prefix);
 417                 if (r < 0)
 418                         return r;
 419
 420                 prefix->len = prefix_opt->nd_opt_pi_prefix_len;
 421
 422                 memcpy(&prefix->addr, &prefix_opt->nd_opt_pi_prefix,
 423                         sizeof(prefix->addr));
 424
 425                 log_ndisc(nd, "New prefix "SD_NDISC_ADDRESS_FORMAT_STR"/%d lifetime %d expires in %s",
 426                              SD_NDISC_ADDRESS_FORMAT_VAL(prefix->addr),
 427                              prefix->len, lifetime,
 428                              format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime * USEC_PER_SEC, USEC_PER_SEC));
 429
 430                 LIST_PREPEND(prefixes, nd->prefixes, prefix);
 431
 432         } else {
 433                 if (prefix->len != prefix_opt->nd_opt_pi_prefix_len) {
 434                         uint8_t prefixlen;
 435
 436                         prefixlen = MIN(prefix->len, prefix_opt->nd_opt_pi_prefix_len);
 437
 438                         log_ndisc(nd, "Prefix length mismatch %d/%d using %d",
 439                                      prefix->len,
 440                                      prefix_opt->nd_opt_pi_prefix_len,
 441                                      prefixlen);
 442
 443                         prefix->len = prefixlen;
 444                 }
 445
 446                 log_ndisc(nd, "Update prefix "SD_NDISC_ADDRESS_FORMAT_STR"/%d lifetime %d expires in %s",
 447                              SD_NDISC_ADDRESS_FORMAT_VAL(prefix->addr),
 448                              prefix->len, lifetime,
 449                              format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime * USEC_PER_SEC, USEC_PER_SEC));
 450         }
 451
 452         r = ndisc_prefix_set_timeout(nd, prefix, lifetime * USEC_PER_SEC);
 453
 454         return r;
 455 }
 456
 457 static int ndisc_ra_parse(sd_ndisc *nd, struct nd_router_advert *ra,
 458                           ssize_t len) {
 459         void *opt;
 460         struct nd_opt_hdr *opt_hdr;
 461
 462         assert_return(nd, -EINVAL);
 463         assert_return(ra, -EINVAL);
 464
 465         len -= sizeof(*ra);
 466         if (len < NDISC_OPT_LEN_UNITS) {
 467                 log_ndisc(nd, "Router Advertisement below minimum length");
 468
 469                 return -ENOMSG;
 470         }
 471
 472         opt = ra + 1;
 473         opt_hdr = opt;
 474
 475         while (len != 0 && len >= opt_hdr->nd_opt_len * NDISC_OPT_LEN_UNITS) {
 476                 struct nd_opt_mtu *opt_mtu;
 477                 uint32_t mtu;
 478                 struct nd_opt_prefix_info *opt_prefix;
 479
 480                 if (opt_hdr->nd_opt_len == 0)
 481                         return -ENOMSG;
 482
 483                 switch (opt_hdr->nd_opt_type) {
 484                 case ND_OPT_MTU:
 485                         opt_mtu = opt;
 486
 487                         mtu = be32toh(opt_mtu->nd_opt_mtu_mtu);
 488
 489                         if (mtu != nd->mtu) {
 490                                 nd->mtu = MAX(mtu, IP6_MIN_MTU);
 491
 492                                 log_ndisc(nd, "Router Advertisement link MTU %d using %d",
 493                                              mtu, nd->mtu);
 494                         }
 495
 496                         break;
 497
 498                 case ND_OPT_PREFIX_INFORMATION:
 499                         opt_prefix = opt;
 500
 501                         ndisc_prefix_update(nd, len, opt_prefix);
 502
 503                         break;
 504                 }
 505
 506                 len -= opt_hdr->nd_opt_len * NDISC_OPT_LEN_UNITS;
 507                 opt = (void *)((char *)opt +
 508                         opt_hdr->nd_opt_len * NDISC_OPT_LEN_UNITS);
 509                 opt_hdr = opt;
 510         }
 511
 512         if (len > 0)
 513                 log_ndisc(nd, "Router Advertisement contains %zd bytes of trailing garbage", len);
 514
 515         return 0;
 516 }
 517
 518 static int ndisc_router_advertisment_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 519         sd_ndisc *nd = userdata;
 520         int r, buflen = 0;
 521         ssize_t len;
 522         _cleanup_free_ struct nd_router_advert *ra = NULL;
 523         int event = SD_NDISC_EVENT_ROUTER_ADVERTISMENT_NONE;
 524
 525         assert(s);
 526         assert(nd);
 527         assert(nd->event);
 528
 529         r = ioctl(fd, FIONREAD, &buflen);
 530         if (r < 0 || buflen <= 0)
 531                 buflen = ICMP6_RECV_SIZE;
 532
 533         ra = malloc(buflen);
 534         if (!ra)
 535                 return -ENOMEM;
 536
 537         len = read(fd, ra, buflen);
 538         if (len < 0) {
 539                 log_ndisc(nd, "Could not receive message from UDP socket: %m");
 540                 return 0;
 541         }
 542
 543         if (ra->nd_ra_type != ND_ROUTER_ADVERT)
 544                 return 0;
 545
 546         if (ra->nd_ra_code != 0)
 547                 return 0;
 548
 549         nd->timeout = sd_event_source_unref(nd->timeout);
 550
 551         nd->state = NDISC_STATE_ADVERTISMENT_LISTEN;
 552
 553         if (ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER )
 554                 event = SD_NDISC_EVENT_ROUTER_ADVERTISMENT_OTHER;
 555
 556         if (ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED)
 557                 event = SD_NDISC_EVENT_ROUTER_ADVERTISMENT_MANAGED;
 558
 559         log_ndisc(nd, "Received Router Advertisement flags %s/%s",
 560                      ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED? "MANAGED": "none",
 561                      ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER? "OTHER": "none");
 562
 563         if (event != SD_NDISC_EVENT_ROUTER_ADVERTISMENT_NONE) {
 564                 r = ndisc_ra_parse(nd, ra, len);
 565                 if (r < 0) {
 566                         log_ndisc(nd, "Could not parse Router Advertisement: %s",
 567                                      strerror(-r));
 568                         return 0;
 569                 }
 570         }
 571
 572         ndisc_notify(nd, event);
 573
 574         return 0;
 575 }
 576
 577 static int ndisc_router_solicitation_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
 578         sd_ndisc *nd = userdata;
 579         uint64_t time_now, next_timeout;
 580         struct ether_addr unset = { };
 581         struct ether_addr *addr = NULL;
 582         int r;
 583
 584         assert(s);
 585         assert(nd);
 586         assert(nd->event);
 587
 588         nd->timeout = sd_event_source_unref(nd->timeout);
 589
 590         if (nd->nd_sent >= NDISC_MAX_ROUTER_SOLICITATIONS) {
 591                 ndisc_notify(nd, SD_NDISC_EVENT_ROUTER_ADVERTISMENT_TIMEOUT);
 592                 nd->state = NDISC_STATE_ADVERTISMENT_LISTEN;
 593         } else {
 594                 if (memcmp(&nd->mac_addr, &unset, sizeof(struct ether_addr)))
 595                         addr = &nd->mac_addr;
 596
 597                 r = icmp6_send_router_solicitation(nd->fd, addr);
 598                 if (r < 0)
 599                         log_ndisc(nd, "Error sending Router Solicitation");
 600                 else {
 601                         nd->state = NDISC_STATE_SOLICITATION_SENT;
 602                         log_ndisc(nd, "Sent Router Solicitation");
 603                 }
 604
 605                 nd->nd_sent++;
 606
 607                 r = sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now);
 608                 if (r < 0) {
 609                         ndisc_notify(nd, r);
 610                         return 0;
 611                 }
 612
 613                 next_timeout = time_now + NDISC_ROUTER_SOLICITATION_INTERVAL;
 614
 615                 r = sd_event_add_time(nd->event, &nd->timeout, clock_boottime_or_monotonic(),
 616                                       next_timeout, 0,
 617                                       ndisc_router_solicitation_timeout, nd);
 618                 if (r < 0) {
 619                         ndisc_notify(nd, r);
 620                         return 0;
 621                 }
 622
 623                 r = sd_event_source_set_priority(nd->timeout,
 624                                                  nd->event_priority);
 625                 if (r < 0) {
 626                         ndisc_notify(nd, r);
 627                         return 0;
 628                 }
 629
 630                 r = sd_event_source_set_description(nd->timeout, "ndisc-timeout");
 631                 if (r < 0) {
 632                         ndisc_notify(nd, r);
 633                         return 0;
 634                 }
 635         }
 636
 637         return 0;
 638 }
 639
 640 int sd_ndisc_stop(sd_ndisc *nd) {
 641         assert_return(nd, -EINVAL);
 642         assert_return(nd->event, -EINVAL);
 643
 644         log_ndisc(client, "Stop NDisc");
 645
 646         ndisc_init(nd);
 647
 648         nd->state = NDISC_STATE_IDLE;
 649
 650         return 0;
 651 }
 652
 653 int sd_ndisc_router_discovery_start(sd_ndisc *nd) {
 654         int r;
 655
 656         assert(nd);
 657         assert(nd->event);
 658
 659         if (nd->state != NDISC_STATE_IDLE)
 660                 return -EINVAL;
 661
 662         if (nd->index < 1)
 663                 return -EINVAL;
 664
 665         r = icmp6_bind_router_solicitation(nd->index);
 666         if (r < 0)
 667                 return r;
 668
 669         nd->fd = r;
 670
 671         r = sd_event_add_io(nd->event, &nd->recv, nd->fd, EPOLLIN,
 672                             ndisc_router_advertisment_recv, nd);
 673         if (r < 0)
 674                 goto error;
 675
 676         r = sd_event_source_set_priority(nd->recv, nd->event_priority);
 677         if (r < 0)
 678                 goto error;
 679
 680         r = sd_event_source_set_description(nd->recv, "ndisc-receive-message");
 681         if (r < 0)
 682                 goto error;
 683
 684         r = sd_event_add_time(nd->event, &nd->timeout, clock_boottime_or_monotonic(),
 685                               0, 0, ndisc_router_solicitation_timeout, nd);
 686         if (r < 0)
 687                 goto error;
 688
 689         r = sd_event_source_set_priority(nd->timeout, nd->event_priority);
 690         if (r < 0)
 691                 goto error;
 692
 693         r = sd_event_source_set_description(nd->timeout, "ndisc-timeout");
 694 error:
 695         if (r < 0)
 696                 ndisc_init(nd);
 697         else
 698                 log_ndisc(client, "Start Router Solicitation");
 699
 700         return r;
 701 }