src/odhcp6c.c

   1 /**
   2  * Copyright (C) 2012-2014 Steven Barth <steven@midlink.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License v2 as published by
   6  * the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  */
  14
  15 #include <time.h>
  16 #include <errno.h>
  17 #include <fcntl.h>
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <stddef.h>
  21 #include <unistd.h>
  22 #include <syslog.h>
  23 #include <signal.h>
  24 #include <string.h>
  25 #include <stdbool.h>
  26
  27 #include <net/if.h>
  28 #include <sys/wait.h>
  29 #include <sys/syscall.h>
  30 #include <arpa/inet.h>
  31
  32 #include "odhcp6c.h"
  33 #include "ra.h"
  34
  35 #ifdef EXT_BFD_PING
  36 #include "bfd.h"
  37 #endif
  38
  39
  40 static void sighandler(int signal);
  41 static int usage(void);
  42
  43 static uint8_t *state_data[_STATE_MAX] = {NULL};
  44 static size_t state_len[_STATE_MAX] = {0};
  45
  46 static volatile bool signal_io = false;
  47 static volatile bool signal_usr1 = false;
  48 static volatile bool signal_usr2 = false;
  49 static volatile bool signal_term = false;
  50
  51 static int urandom_fd = -1, allow_slaac_only = 0;
  52 static bool bound = false, release = true;
  53 static time_t last_update = 0;
  54
  55 static unsigned int min_update_interval = DEFAULT_MIN_UPDATE_INTERVAL;
  56
  57 int main(_unused int argc, char* const argv[])
  58 {
  59         // Allocate ressources
  60         const char *pidfile = NULL;
  61         const char *script = "/usr/sbin/odhcp6c-update";
  62         ssize_t l;
  63         uint8_t buf[134];
  64         char *optpos;
  65         uint16_t opttype;
  66         uint16_t optlen;
  67         enum odhcp6c_ia_mode ia_na_mode = IA_MODE_TRY;
  68         enum odhcp6c_ia_mode ia_pd_mode = IA_MODE_NONE;
  69         int ia_pd_iaid_index = 0;
  70         static struct in6_addr ifid = IN6ADDR_ANY_INIT;
  71         int sol_timeout = DHCPV6_SOL_MAX_RT;
  72
  73 #ifdef EXT_BFD_PING
  74         int bfd_interval = 0, bfd_loss = 3;
  75 #endif
  76
  77         bool help = false, daemonize = false;
  78         int logopt = LOG_PID;
  79         int c;
  80         unsigned int client_options = DHCPV6_CLIENT_FQDN | DHCPV6_ACCEPT_RECONFIGURE;
  81
  82         while ((c = getopt(argc, argv, "S::N:V:P:FB:c:i:r:Ru:s:kt:m:hedp:fa")) != -1) {
  83                 switch (c) {
  84                 case 'S':
  85                         allow_slaac_only = (optarg) ? atoi(optarg) : -1;
  86                         break;
  87
  88                 case 'N':
  89                         if (!strcmp(optarg, "force")) {
  90                                 ia_na_mode = IA_MODE_FORCE;
  91                                 allow_slaac_only = -1;
  92                         } else if (!strcmp(optarg, "none")) {
  93                                 ia_na_mode = IA_MODE_NONE;
  94                         } else if (!strcmp(optarg, "try")) {
  95                                 ia_na_mode = IA_MODE_TRY;
  96                         } else{
  97                                 help = true;
  98                         }
  99                         break;
 100
 101                 case 'V':
 102                         l = script_unhexlify(buf, sizeof(buf), optarg);
 103                         if (!l)
 104                                 help=true;
 105
 106                         odhcp6c_add_state(STATE_VENDORCLASS, buf, l);
 107
 108                         break;
 109                 case 'P':
 110                         if (ia_pd_mode == IA_MODE_NONE)
 111                                 ia_pd_mode = IA_MODE_TRY;
 112
 113                         if (allow_slaac_only >= 0 && allow_slaac_only < 10)
 114                                 allow_slaac_only = 10;
 115
 116                         char *iaid_begin;
 117                         int iaid_len = 0;
 118
 119                         int prefix_length = strtoul(optarg, &iaid_begin, 10);
 120
 121                         if (*iaid_begin != '\0' && *iaid_begin != ',' && *iaid_begin != ':') {
 122                                 syslog(LOG_ERR, "invalid argument: '%s'", optarg);
 123                                 return 1;
 124                         }
 125
 126                         struct odhcp6c_request_prefix prefix = { 0, prefix_length };
 127
 128                         if (*iaid_begin == ',' && (iaid_len = strlen(iaid_begin)) > 1)
 129                                 memcpy(&prefix.iaid, iaid_begin + 1, iaid_len > 4 ? 4 : iaid_len);
 130                         else if (*iaid_begin == ':')
 131                                 prefix.iaid = htonl((uint32_t)strtoul(&iaid_begin[1], NULL, 16));
 132                         else
 133                                 prefix.iaid = htonl(++ia_pd_iaid_index);
 134
 135                         odhcp6c_add_state(STATE_IA_PD_INIT, &prefix, sizeof(prefix));
 136
 137                         break;
 138
 139                 case 'F':
 140                         allow_slaac_only = -1;
 141                         ia_pd_mode = IA_MODE_FORCE;
 142                         break;
 143
 144 #ifdef EXT_BFD_PING
 145                 case 'B':
 146                         bfd_interval = atoi(optarg);
 147                         break;
 148 #endif
 149
 150                 case 'c':
 151                         l = script_unhexlify(&buf[4], sizeof(buf) - 4, optarg);
 152                         if (l > 0) {
 153                                 buf[0] = 0;
 154                                 buf[1] = DHCPV6_OPT_CLIENTID;
 155                                 buf[2] = 0;
 156                                 buf[3] = l;
 157                                 odhcp6c_add_state(STATE_CLIENT_ID, buf, l + 4);
 158                         } else {
 159                                 help = true;
 160                         }
 161                         break;
 162
 163                 case 'i':
 164                         if (inet_pton(AF_INET6, optarg, &ifid) != 1)
 165                                 help = true;
 166                         break;
 167
 168                 case 'r':
 169                         optpos = optarg;
 170                         while (optpos[0]) {
 171                                 opttype = htons(strtoul(optarg, &optpos, 10));
 172                                 if (optpos == optarg)
 173                                         break;
 174                                 else if (optpos[0])
 175                                         optarg = &optpos[1];
 176                                 odhcp6c_add_state(STATE_ORO, &opttype, 2);
 177                         }
 178                         break;
 179
 180                 case 'R':
 181                         client_options |= DHCPV6_STRICT_OPTIONS;
 182                         break;
 183
 184                 case 'u':
 185                         optlen = htons(strlen(optarg));
 186                         odhcp6c_add_state(STATE_USERCLASS, &optlen, 2);
 187                         odhcp6c_add_state(STATE_USERCLASS, optarg, strlen(optarg));
 188                         break;
 189
 190                 case 's':
 191                         script = optarg;
 192                         break;
 193
 194                 case 'k':
 195                         release = false;
 196                         break;
 197
 198                 case 't':
 199                         sol_timeout = atoi(optarg);
 200                         break;
 201
 202                 case 'm':
 203                         min_update_interval = atoi(optarg);
 204                         break;
 205
 206                 case 'e':
 207                         logopt |= LOG_PERROR;
 208                         break;
 209
 210                 case 'd':
 211                         daemonize = true;
 212                         break;
 213
 214                 case 'p':
 215                         pidfile = optarg;
 216                         break;
 217
 218                 case 'f':
 219                         client_options &= ~DHCPV6_CLIENT_FQDN;
 220                         break;
 221
 222                 case 'a':
 223                         client_options &= ~DHCPV6_ACCEPT_RECONFIGURE;
 224                         break;
 225
 226                 default:
 227                         help = true;
 228                         break;
 229                 }
 230         }
 231
 232         openlog("odhcp6c", logopt, LOG_DAEMON);
 233         const char *ifname = argv[optind];
 234
 235         if (help || !ifname)
 236                 return usage();
 237
 238         signal(SIGIO, sighandler);
 239         signal(SIGHUP, sighandler);
 240         signal(SIGINT, sighandler);
 241         signal(SIGCHLD, sighandler);
 242         signal(SIGTERM, sighandler);
 243         signal(SIGUSR1, sighandler);
 244         signal(SIGUSR2, sighandler);
 245
 246         if ((urandom_fd = open("/dev/urandom", O_CLOEXEC | O_RDONLY)) < 0 ||
 247                         init_dhcpv6(ifname, client_options, sol_timeout) ||
 248                         ra_init(ifname, &ifid) || script_init(script, ifname)) {
 249                 syslog(LOG_ERR, "failed to initialize: %s", strerror(errno));
 250                 return 3;
 251         }
 252
 253         if (daemonize) {
 254                 openlog("odhcp6c", LOG_PID, LOG_DAEMON); // Disable LOG_PERROR
 255                 if (daemon(0, 0)) {
 256                         syslog(LOG_ERR, "Failed to daemonize: %s",
 257                                         strerror(errno));
 258                         return 4;
 259                 }
 260
 261                 char pidbuf[128];
 262                 if (!pidfile) {
 263                         snprintf(pidbuf, sizeof(pidbuf),
 264                                         "/var/run/odhcp6c.%s.pid", ifname);
 265                         pidfile = pidbuf;
 266                 }
 267
 268                 int fd = open(pidfile, O_WRONLY | O_CREAT, 0644);
 269                 if (fd >= 0) {
 270                         char buf[8];
 271                         int len = snprintf(buf, sizeof(buf), "%i\n", getpid());
 272                         write(fd, buf, len);
 273                         close(fd);
 274                 }
 275         }
 276
 277         script_call("started");
 278
 279         while (!signal_term) { // Main logic
 280                 odhcp6c_clear_state(STATE_SERVER_ID);
 281                 odhcp6c_clear_state(STATE_IA_NA);
 282                 odhcp6c_clear_state(STATE_IA_PD);
 283                 odhcp6c_clear_state(STATE_SNTP_IP);
 284                 odhcp6c_clear_state(STATE_NTP_IP);
 285                 odhcp6c_clear_state(STATE_NTP_FQDN);
 286                 odhcp6c_clear_state(STATE_SIP_IP);
 287                 odhcp6c_clear_state(STATE_SIP_FQDN);
 288                 dhcpv6_set_ia_mode(ia_na_mode, ia_pd_mode);
 289                 bound = false;
 290
 291                 syslog(LOG_NOTICE, "(re)starting transaction on %s", ifname);
 292
 293                 signal_usr1 = signal_usr2 = false;
 294                 int mode = dhcpv6_request(DHCPV6_MSG_SOLICIT);
 295                 odhcp6c_signal_process();
 296
 297                 if (mode < 0)
 298                         continue;
 299
 300                 do {
 301                         int res = dhcpv6_request(mode == DHCPV6_STATELESS ?
 302                                         DHCPV6_MSG_INFO_REQ : DHCPV6_MSG_REQUEST);
 303                         bool signalled = odhcp6c_signal_process();
 304
 305                         if (res > 0)
 306                                 break;
 307                         else if (signalled) {
 308                                 mode = -1;
 309                                 break;
 310                         }
 311
 312                         mode = dhcpv6_promote_server_cand();
 313                 } while (mode > DHCPV6_UNKNOWN);
 314
 315                 if (mode < 0)
 316                         continue;
 317
 318                 switch (mode) {
 319                 case DHCPV6_STATELESS:
 320                         bound = true;
 321                         syslog(LOG_NOTICE, "entering stateless-mode on %s", ifname);
 322
 323                         while (!signal_usr2 && !signal_term) {
 324                                 signal_usr1 = false;
 325                                 script_call("informed");
 326
 327                                 int res = dhcpv6_poll_reconfigure();
 328                                 odhcp6c_signal_process();
 329
 330                                 if (res > 0)
 331                                         continue;
 332
 333                                 if (signal_usr1) {
 334                                         signal_usr1 = false; // Acknowledged
 335                                         continue;
 336                                 }
 337                                 if (signal_usr2 || signal_term)
 338                                         break;
 339
 340                                 res = dhcpv6_request(DHCPV6_MSG_INFO_REQ);
 341                                 odhcp6c_signal_process();
 342                                 if (signal_usr1)
 343                                         continue;
 344                                 else if (res < 0)
 345                                         break;
 346                         }
 347                         break;
 348
 349                 case DHCPV6_STATEFUL:
 350                         script_call("bound");
 351                         bound = true;
 352                         syslog(LOG_NOTICE, "entering stateful-mode on %s", ifname);
 353 #ifdef EXT_BFD_PING
 354                         if (bfd_interval > 0)
 355                                 bfd_start(ifname, bfd_loss, bfd_interval);
 356 #endif
 357
 358                         while (!signal_usr2 && !signal_term) {
 359                                 // Renew Cycle
 360                                 // Wait for T1 to expire or until we get a reconfigure
 361                                 int res = dhcpv6_poll_reconfigure();
 362                                 odhcp6c_signal_process();
 363                                 if (res > 0) {
 364                                         script_call("updated");
 365                                         continue;
 366                                 }
 367
 368                                 // Handle signal, if necessary
 369                                 if (signal_usr1)
 370                                         signal_usr1 = false; // Acknowledged
 371                                 if (signal_usr2 || signal_term)
 372                                         break; // Other signal type
 373
 374                                 // Send renew as T1 expired
 375                                 size_t ia_pd_len, ia_na_len;
 376                                 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
 377                                 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
 378
 379                                 // If we have any IAs, send renew, otherwise request
 380                                 if (ia_pd_len == 0 && ia_na_len == 0)
 381                                         res = dhcpv6_request(DHCPV6_MSG_REQUEST);
 382                                 else
 383                                         res = dhcpv6_request(DHCPV6_MSG_RENEW);
 384
 385                                 odhcp6c_signal_process();
 386                                 if (res > 0) { // Renew was succesfull
 387                                         // Publish updates
 388                                         script_call("updated");
 389                                         continue; // Renew was successful
 390                                 }
 391
 392                                 odhcp6c_clear_state(STATE_SERVER_ID); // Remove binding
 393
 394                                 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
 395                                 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
 396
 397                                 if (ia_pd_len == 0 && ia_na_len == 0)
 398                                         break;
 399
 400                                 // If we have IAs, try rebind otherwise restart
 401                                 res = dhcpv6_request(DHCPV6_MSG_REBIND);
 402                                 odhcp6c_signal_process();
 403
 404                                 if (res > 0)
 405                                         script_call("rebound");
 406                                 else {
 407 #ifdef EXT_BFD_PING
 408                                         bfd_stop();
 409 #endif
 410                                         break;
 411                                 }
 412                         }
 413                         break;
 414
 415                 default:
 416                         break;
 417                 }
 418
 419                 size_t ia_pd_len, ia_na_len, server_id_len;
 420                 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
 421                 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
 422                 odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
 423
 424                 // Add all prefixes to lost prefixes
 425                 bound = false;
 426                 script_call("unbound");
 427
 428                 if (server_id_len > 0 && (ia_pd_len > 0 || ia_na_len > 0) && release)
 429                         dhcpv6_request(DHCPV6_MSG_RELEASE);
 430
 431                 odhcp6c_clear_state(STATE_IA_NA);
 432                 odhcp6c_clear_state(STATE_IA_PD);
 433         }
 434
 435         script_call("stopped");
 436         return 0;
 437 }
 438
 439
 440 static int usage(void)
 441 {
 442         const char buf[] =
 443         "Usage: odhcp6c [options] <interface>\n"
 444         "\nFeature options:\n"
 445         "       -S <time>       Wait at least <time> sec for a DHCP-server (0)\n"
 446         "       -N <mode>       Mode for requesting addresses [try|force|none]\n"
 447         "       -P <length>     Request IPv6-Prefix (0 = auto)\n"
 448         "       -F              Force IPv6-Prefix\n"
 449         "       -V <class>      Set vendor-class option (base-16 encoded)\n"
 450 #ifdef EXT_BFD_PING
 451         "       -B <interval>   Enable BFD ping check\n"
 452 #endif
 453         "       -u <user-class> Set user-class option string\n"
 454         "       -c <clientid>   Override client-ID (base-16 encoded)\n"
 455         "       -i <iface-id>   Use a custom interface identifier for RA handling\n"
 456         "       -r <options>    Options to be requested (comma-separated)\n"
 457         "       -R              Do not request any options except those specified with -r\n"
 458         "       -s <script>     Status update script (/usr/sbin/odhcp6c-update)\n"
 459         "       -a              Don't send Accept Reconfigure option\n"
 460         "       -f              Don't send Client FQDN option\n"
 461         "       -k              Don't send a RELEASE when stopping\n"
 462         "       -t <seconds>    Maximum timeout for DHCPv6-SOLICIT (3600)\n"
 463         "       -m <seconds>    Minimum time between accepting updates (30)\n"
 464         "\nInvocation options:\n"
 465         "       -p <pidfile>    Set pidfile (/var/run/odhcp6c.pid)\n"
 466         "       -d              Daemonize\n"
 467         "       -e              Write logmessages to stderr\n"
 468         //"     -v              Increase logging verbosity\n"
 469         "       -h              Show this help\n\n";
 470         write(STDERR_FILENO, buf, sizeof(buf));
 471         return 1;
 472 }
 473
 474
 475 // Don't want to pull-in librt and libpthread just for a monotonic clock...
 476 uint64_t odhcp6c_get_milli_time(void)
 477 {
 478         struct timespec t = {0, 0};
 479         syscall(SYS_clock_gettime, CLOCK_MONOTONIC, &t);
 480         return ((uint64_t)t.tv_sec) * 1000 + ((uint64_t)t.tv_nsec) / 1000000;
 481 }
 482
 483
 484 static uint8_t* odhcp6c_resize_state(enum odhcp6c_state state, ssize_t len)
 485 {
 486         if (len == 0)
 487                 return state_data[state] + state_len[state];
 488         else if (state_len[state] + len > 1024)
 489                 return NULL;
 490
 491         uint8_t *n = realloc(state_data[state], state_len[state] + len);
 492         if (n || state_len[state] + len == 0) {
 493                 state_data[state] = n;
 494                 n += state_len[state];
 495                 state_len[state] += len;
 496         }
 497         return n;
 498 }
 499
 500
 501 bool odhcp6c_signal_process(void)
 502 {
 503         while (signal_io) {
 504                 signal_io = false;
 505
 506                 bool ra_updated = ra_process();
 507
 508                 if (ra_link_up())
 509                         signal_usr2 = true;
 510
 511                 if (ra_updated && (bound || allow_slaac_only == 0))
 512                         script_call("ra-updated"); // Immediate process urgent events
 513                 else if (ra_updated && !bound && allow_slaac_only > 0)
 514                         script_delay_call("ra-updated", allow_slaac_only);
 515
 516 #ifdef EXT_BFD_PING
 517                 bfd_receive();
 518 #endif
 519         }
 520
 521         return signal_usr1 || signal_usr2 || signal_term;
 522 }
 523
 524
 525 void odhcp6c_clear_state(enum odhcp6c_state state)
 526 {
 527         state_len[state] = 0;
 528 }
 529
 530
 531 void odhcp6c_add_state(enum odhcp6c_state state, const void *data, size_t len)
 532 {
 533         uint8_t *n = odhcp6c_resize_state(state, len);
 534         if (n)
 535                 memcpy(n, data, len);
 536 }
 537
 538 void odhcp6c_insert_state(enum odhcp6c_state state, size_t offset, const void *data, size_t len)
 539 {
 540         ssize_t len_after = state_len[state] - offset;
 541         if (len_after < 0)
 542                 return;
 543
 544         uint8_t *n = odhcp6c_resize_state(state, len);
 545         if (n) {
 546                 uint8_t *sdata = state_data[state];
 547
 548                 memmove(sdata + offset + len, sdata + offset, len_after);
 549                 memcpy(sdata + offset, data, len);
 550         }
 551 }
 552
 553 size_t odhcp6c_remove_state(enum odhcp6c_state state, size_t offset, size_t len)
 554 {
 555         uint8_t *data = state_data[state];
 556         ssize_t len_after = state_len[state] - (offset + len);
 557         if (len_after < 0)
 558                 return state_len[state];
 559
 560         memmove(data + offset, data + offset + len, len_after);
 561         return state_len[state] -= len;
 562 }
 563
 564
 565 void* odhcp6c_move_state(enum odhcp6c_state state, size_t *len)
 566 {
 567         *len = state_len[state];
 568         void *data = state_data[state];
 569
 570         state_len[state] = 0;
 571         state_data[state] = NULL;
 572
 573         return data;
 574 }
 575
 576
 577 void* odhcp6c_get_state(enum odhcp6c_state state, size_t *len)
 578 {
 579         *len = state_len[state];
 580         return state_data[state];
 581 }
 582
 583
 584 struct odhcp6c_entry* odhcp6c_find_entry(enum odhcp6c_state state, const struct odhcp6c_entry *new)
 585 {
 586         size_t len, cmplen = offsetof(struct odhcp6c_entry, target) + new->length / 8;
 587         struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
 588         struct odhcp6c_entry *x = NULL;
 589
 590         for (struct odhcp6c_entry *c = start; !x && c < &start[len/sizeof(*c)]; ++c)
 591                 if (!memcmp(c, new, cmplen))
 592                         return c;
 593
 594         return NULL;
 595 }
 596
 597
 598 bool odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *new, uint32_t safe)
 599 {
 600         size_t len;
 601         struct odhcp6c_entry *x = odhcp6c_find_entry(state, new);
 602         struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
 603
 604         if (x && x->valid > new->valid && new->valid < safe)
 605                 new->valid = safe;
 606
 607         if (new->valid > 0) {
 608                 if (x) {
 609                         if (new->valid >= x->valid && new->valid != UINT32_MAX &&
 610                                         new->valid - x->valid < min_update_interval &&
 611                                         new->preferred >= x->preferred &&
 612                                         new->preferred != UINT32_MAX &&
 613                                         new->preferred - x->preferred < min_update_interval &&
 614                                         x->class == new->class)
 615                                 return false;
 616                         x->valid = new->valid;
 617                         x->preferred = new->preferred;
 618                         x->t1 = new->t1;
 619                         x->t2 = new->t2;
 620                         x->class = new->class;
 621                         x->iaid = new->iaid;
 622                 } else {
 623                         odhcp6c_add_state(state, new, sizeof(*new));
 624                 }
 625         } else if (x) {
 626                 odhcp6c_remove_state(state, (x - start) * sizeof(*x), sizeof(*x));
 627         }
 628         return true;
 629 }
 630
 631
 632 bool odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new)
 633 {
 634         return odhcp6c_update_entry_safe(state, new, 0);
 635 }
 636
 637
 638 static void odhcp6c_expire_list(enum odhcp6c_state state, uint32_t elapsed)
 639 {
 640         size_t len;
 641         struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
 642         for (struct odhcp6c_entry *c = start; c < &start[len / sizeof(*c)]; ++c) {
 643                 if (c->t1 < elapsed)
 644                         c->t1 = 0;
 645                 else if (c->t1 != UINT32_MAX)
 646                         c->t1 -= elapsed;
 647
 648                 if (c->t2 < elapsed)
 649                         c->t2 = 0;
 650                 else if (c->t2 != UINT32_MAX)
 651                         c->t2 -= elapsed;
 652
 653                 if (c->preferred < elapsed)
 654                         c->preferred = 0;
 655                 else if (c->preferred != UINT32_MAX)
 656                         c->preferred -= elapsed;
 657
 658                 if (c->valid < elapsed)
 659                         c->valid = 0;
 660                 else if (c->valid != UINT32_MAX)
 661                         c->valid -= elapsed;
 662
 663                 if (!c->valid)
 664                         odhcp6c_remove_state(state, (c - start) * sizeof(*c), sizeof(*c));
 665         }
 666 }
 667
 668
 669 void odhcp6c_expire(void)
 670 {
 671         time_t now = odhcp6c_get_milli_time() / 1000;
 672         uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
 673         last_update = now;
 674
 675         odhcp6c_expire_list(STATE_RA_PREFIX, elapsed);
 676         odhcp6c_expire_list(STATE_RA_ROUTE, elapsed);
 677         odhcp6c_expire_list(STATE_RA_DNS, elapsed);
 678         odhcp6c_expire_list(STATE_IA_NA, elapsed);
 679         odhcp6c_expire_list(STATE_IA_PD, elapsed);
 680 }
 681
 682
 683 uint32_t odhcp6c_elapsed(void)
 684 {
 685         return odhcp6c_get_milli_time() / 1000 - last_update;
 686 }
 687
 688
 689 void odhcp6c_random(void *buf, size_t len)
 690 {
 691         read(urandom_fd, buf, len);
 692 }
 693
 694 bool odhcp6c_is_bound(void)
 695 {
 696         return bound;
 697 }
 698
 699 static void sighandler(int signal)
 700 {
 701         if (signal == SIGCHLD)
 702                 while (waitpid(-1, NULL, WNOHANG) > 0);
 703         else if (signal == SIGUSR1)
 704                 signal_usr1 = true;
 705         else if (signal == SIGUSR2)
 706                 signal_usr2 = true;
 707         else if (signal == SIGIO)
 708                 signal_io = true;
 709         else
 710                 signal_term = true;
 711 }