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