src/dhcpv6.c

   1 /**
   2  * Copyright (C) 2012 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 <fcntl.h>
  17 #include <errno.h>
  18 #include <signal.h>
  19 #include <limits.h>
  20 #include <resolv.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <syslog.h>
  24 #include <stdbool.h>
  25 #include <sys/time.h>
  26 #include <sys/ioctl.h>
  27 #include <sys/socket.h>
  28 #include <netinet/in.h>
  29
  30 #include <net/if.h>
  31 #include <net/ethernet.h>
  32
  33 #include "odhcp6c.h"
  34
  35
  36 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
  37                 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
  38 #define DHCPV6_CLIENT_PORT 546
  39 #define DHCPV6_SERVER_PORT 547
  40 #define DHCPV6_DUID_LLADDR 3
  41 #define DHCPV6_REQ_DELAY 1
  42
  43
  44 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
  45                 const uint8_t transaction[3], enum dhcpv6_msg type);
  46
  47 static time_t dhcpv6_parse_ia(void *opt, void *end);
  48
  49 static reply_handler dhcpv6_handle_reply;
  50 static reply_handler dhcpv6_handle_advert;
  51 static reply_handler dhcpv6_handle_rebind_reply;
  52 static reply_handler dhcpv6_handle_reconfigure;
  53 static int dhcpv6_commit_advert(uint32_t elapsed);
  54
  55
  56
  57 // RFC 3315 - 5.5 Timeout and Delay values
  58 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
  59         [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, "<POLL>",
  60                         dhcpv6_handle_reconfigure, NULL},
  61         [DHCPV6_MSG_SOLICIT] = {true, 1, 120, "SOLICIT",
  62                         dhcpv6_handle_advert, dhcpv6_commit_advert},
  63         [DHCPV6_MSG_REQUEST] = {true, 30, 10, "REQUEST",
  64                         dhcpv6_handle_reply, NULL},
  65         [DHCPV6_MSG_RENEW] = {false, 10, 600, "RENEW",
  66                         dhcpv6_handle_reply, NULL},
  67         [DHCPV6_MSG_REBIND] = {false, 10, 600, "REBIND",
  68                         dhcpv6_handle_rebind_reply, NULL},
  69         [DHCPV6_MSG_RELEASE] = {false, 1, 600, "RELEASE", NULL, NULL},
  70         [DHCPV6_MSG_DECLINE] = {false, 1, 3, "DECLINE", NULL, NULL},
  71         [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, "INFOREQ",
  72                         dhcpv6_handle_reply, NULL},
  73 };
  74
  75
  76 // Sockets
  77 static int sock = -1;
  78 static int urandom_fd = -1;
  79 static int ifindex = -1;
  80 static time_t t1 = 0, t2 = 0, t3 = 0;
  81
  82 // IA states
  83 static int request_prefix = -1;
  84 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE;
  85 static bool accept_reconfig = false;
  86
  87
  88
  89 int init_dhcpv6(const char *ifname, int request_pd)
  90 {
  91         request_prefix = request_pd;
  92         urandom_fd = open("/dev/urandom", O_CLOEXEC | O_RDONLY);
  93         if (urandom_fd < 0)
  94                 return -1;
  95
  96         sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
  97
  98         // Detect interface
  99         struct ifreq ifr;
 100         strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 101         if (ioctl(sock, SIOCGIFINDEX, &ifr))
 102                 return -1;
 103         ifindex = ifr.ifr_ifindex;
 104
 105         // Create client DUID
 106         size_t client_id_len;
 107         odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 108         if (client_id_len == 0) {
 109                 ioctl(sock, SIOCGIFHWADDR, &ifr);
 110                 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
 111                                 DHCPV6_DUID_LLADDR, 0, 1};
 112                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
 113                 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
 114         }
 115
 116         // Create ORO
 117         uint16_t oro[] = {htons(DHCPV6_OPT_DNS_SERVERS),
 118                         htons(DHCPV6_OPT_DNS_DOMAIN)};
 119         odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
 120
 121
 122         // Configure IPv6-options
 123         int val = 1;
 124         setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
 125         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 126         setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
 127
 128         struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
 129                 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
 130         if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)))
 131                 return -1;
 132
 133         return 0;
 134 }
 135
 136
 137 void dhcpv6_set_ia_na_mode(enum odhcp6c_ia_mode mode)
 138 {
 139         na_mode = mode;
 140 }
 141
 142
 143 void dhcpv6_remove_addrs(void)
 144 {
 145         size_t ia_na_len;
 146         uint8_t *odata, *ia_na = odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
 147         uint16_t otype, olen;
 148         dhcpv6_for_each_option(ia_na, ia_na + ia_na_len, otype, olen, odata) {
 149                 struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
 150                 set_rtnetlink_addr(ifindex, &addr->addr, 0, 0);
 151         }
 152 }
 153
 154
 155 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
 156 {
 157         // Build FQDN
 158         char fqdn_buf[256];
 159         gethostname(fqdn_buf, sizeof(fqdn_buf));
 160         struct {
 161                 uint16_t type;
 162                 uint16_t len;
 163                 uint8_t flags;
 164                 uint8_t data[256];
 165         } fqdn;
 166         size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
 167                         sizeof(fqdn.data), NULL, NULL);
 168         fqdn.type = htons(DHCPV6_OPT_FQDN);
 169         fqdn.len = htons(fqdn_len - 4);
 170         fqdn.flags = 0;
 171
 172
 173         // Build Client ID
 174         size_t cl_id_len;
 175         void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
 176
 177         // Get Server ID
 178         size_t srv_id_len;
 179         void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
 180
 181         // Build IA_PDs
 182         size_t ia_pd_len;
 183         void *ia_pd = odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
 184         struct dhcpv6_ia_hdr hdr_ia_pd = {
 185                 htons(DHCPV6_OPT_IA_PD),
 186                 htons(sizeof(hdr_ia_pd) - 4 + ia_pd_len),
 187                 1, 0, 0
 188         };
 189
 190         struct dhcpv6_ia_prefix pref = {
 191                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 192                 .len = htons(25), .prefix = request_prefix
 193         };
 194
 195         if (ia_pd_len == 0 && request_prefix > 0 &&
 196                         (type == DHCPV6_MSG_SOLICIT ||
 197                         type == DHCPV6_MSG_REQUEST)) {
 198                 ia_pd = &pref;
 199                 ia_pd_len = sizeof(pref);
 200         }
 201
 202         // Build IA_NAs
 203         size_t ia_na_len;
 204         void *ia_na = odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
 205         struct dhcpv6_ia_hdr hdr_ia_na = {
 206                 htons(DHCPV6_OPT_IA_NA),
 207                 htons(sizeof(hdr_ia_na) - 4 + ia_na_len),
 208                 1, 0, 0
 209         };
 210
 211         // Reconfigure Accept
 212         struct {
 213                 uint16_t type;
 214                 uint16_t length;
 215         } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
 216
 217         // Request Information Refresh
 218         uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
 219
 220         // Prepare Header
 221         size_t oro_len;
 222         void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
 223         struct {
 224                 uint8_t type;
 225                 uint8_t trid[3];
 226                 uint16_t elapsed_type;
 227                 uint16_t elapsed_len;
 228                 uint16_t elapsed_value;
 229                 uint16_t oro_type;
 230                 uint16_t oro_len;
 231         } hdr = {
 232                 type, {trid[0], trid[1], trid[2]},
 233                 htons(DHCPV6_OPT_ELAPSED), htons(2),
 234                         htons((ecs > 0xffff) ? 0xffff : ecs),
 235                 htons(DHCPV6_OPT_ORO), htons(oro_len),
 236         };
 237
 238         struct iovec iov[] = {
 239                 {&hdr, sizeof(hdr)},
 240                 {oro, oro_len},
 241                 {&oro_refresh, 0},
 242                 {cl_id, cl_id_len},
 243                 {srv_id, srv_id_len},
 244                 {&reconf_accept, 0},
 245                 {&fqdn, fqdn_len},
 246                 {&hdr_ia_na, sizeof(hdr_ia_na)},
 247                 {ia_na, ia_na_len},
 248                 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
 249                 {ia_pd, ia_pd_len},
 250         };
 251
 252         size_t cnt = ARRAY_SIZE(iov);
 253         if (type == DHCPV6_MSG_INFO_REQ) {
 254                 cnt = 5;
 255                 iov[2].iov_len = sizeof(oro_refresh);
 256                 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
 257         } else if (!request_prefix) {
 258                 cnt = 9;
 259         }
 260
 261         // Disable IAs if not used
 262         if (type == DHCPV6_MSG_SOLICIT) {
 263                 iov[5].iov_len = sizeof(reconf_accept);
 264         } else if (type != DHCPV6_MSG_REQUEST) {
 265                 if (ia_na_len == 0)
 266                         iov[7].iov_len = 0;
 267                 if (ia_pd_len == 0)
 268                         iov[9].iov_len = 0;
 269         }
 270
 271         if (na_mode == IA_MODE_NONE)
 272                 iov[7].iov_len = 0;
 273
 274         struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
 275                 0, ALL_DHCPV6_RELAYS, ifindex};
 276         struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
 277
 278         sendmsg(sock, &msg, 0);
 279 }
 280
 281
 282 static int64_t dhcpv6_rand_delay(int64_t time)
 283 {
 284         int random;
 285         read(urandom_fd, &random, sizeof(random));
 286         return (time * (random % 1000)) / 10000;
 287 }
 288
 289
 290 int dhcpv6_request(enum dhcpv6_msg type)
 291 {
 292         uint8_t buf[1536];
 293         uint32_t timeout = UINT32_MAX;
 294         struct dhcpv6_retx *retx = &dhcpv6_retx[type];
 295
 296         if (retx->delay) {
 297                 struct timespec ts = {0, 0};
 298                 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
 299                 nanosleep(&ts, NULL);
 300         }
 301
 302         if (type == DHCPV6_MSG_RELEASE || type == DHCPV6_MSG_DECLINE)
 303                 timeout = 3;
 304         else if (type == DHCPV6_MSG_UNKNOWN)
 305                 timeout = t1;
 306         else if (type == DHCPV6_MSG_RENEW)
 307                 timeout = t2 - t1;
 308         else if (type == DHCPV6_MSG_REBIND)
 309                 timeout = t3 - t2;
 310
 311         if (timeout == 0)
 312                 return -1;
 313
 314         syslog(LOG_NOTICE, "Sending %s (timeout %us)", retx->name, timeout);
 315
 316         uint64_t start = adhc6c_get_milli_time(), round_start = start, elapsed;
 317
 318         // Generate transaction ID
 319         uint8_t trid[3];
 320         read(urandom_fd, trid, sizeof(trid));
 321         ssize_t len = -1;
 322         int64_t rto = 0;
 323
 324         do {
 325                 rto = (rto == 0) ? (retx->init_timeo * 1000 +
 326                                 dhcpv6_rand_delay(retx->init_timeo * 1000)) :
 327                                 (2 * rto + dhcpv6_rand_delay(rto));
 328
 329                 if (rto >= retx->max_timeo * 1000)
 330                         rto = retx->max_timeo * 1000 +
 331                                 dhcpv6_rand_delay(retx->max_timeo * 1000);
 332
 333                 // Calculate end for this round and elapsed time
 334                 uint64_t round_end = round_start + rto;
 335                 elapsed = round_start - start;
 336
 337                 // Don't wait too long
 338                 if (round_end - start > timeout * 1000)
 339                         round_end = timeout * 1000 + start;
 340
 341                 // Built and send package
 342                 if (type != DHCPV6_MSG_UNKNOWN)
 343                         dhcpv6_send(type, trid, elapsed / 10);
 344
 345                 // Receive rounds
 346                 for (; len < 0 && round_start < round_end;
 347                                 round_start = adhc6c_get_milli_time()) {
 348                         // Check for pending signal
 349                         if (odhcp6c_signal_is_pending())
 350                                 return -1;
 351
 352                         // Set timeout for receiving
 353                         uint64_t t = round_end - round_start;
 354                         struct timeval timeout = {t / 1000, (t % 1000) * 1000};
 355                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
 356                                         &timeout, sizeof(timeout));
 357
 358                         // Receive cycle
 359                         len = recv(sock, buf, sizeof(buf), 0);
 360
 361                         if (!dhcpv6_response_is_valid(buf, len, trid, type))
 362                                 len = -1;
 363
 364                         if (len > 0) {
 365                                 uint8_t *opt = &buf[4];
 366                                 uint8_t *opt_end = opt + len - 4;
 367
 368                                 round_start = adhc6c_get_milli_time();
 369                                 elapsed = round_start - start;
 370                                 syslog(LOG_NOTICE, "Got a valid reply after "
 371                                                 "%ums", (unsigned)elapsed);
 372
 373                                 if (retx->handler_reply)
 374                                         len = retx->handler_reply(type,
 375                                                 opt, opt_end, elapsed / 1000);
 376                         }
 377                 }
 378
 379                 // Allow
 380                 if (retx->handler_finish)
 381                         len = retx->handler_finish(elapsed / 1000);
 382         } while (len < 0 && elapsed / 1000 < timeout);
 383
 384         return len;
 385 }
 386
 387
 388 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
 389                 const uint8_t transaction[3], enum dhcpv6_msg type)
 390 {
 391         const struct dhcpv6_header *rep = buf;
 392         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
 393                         transaction, sizeof(rep->tr_id)))
 394                 return false; // Invalid reply
 395
 396         if (type == DHCPV6_MSG_SOLICIT) {
 397                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
 398                                 rep->msg_type != DHCPV6_MSG_REPLY)
 399                         return false;
 400         } else if (type == DHCPV6_MSG_UNKNOWN) {
 401                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
 402                         return false;
 403         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
 404                 return false;
 405         }
 406
 407         uint8_t *end = ((uint8_t*)buf) + len, *odata;
 408         uint16_t otype, olen;
 409         bool clientid_ok = false, serverid_ok = false;
 410
 411         size_t client_id_len, server_id_len;
 412         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 413         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
 414
 415         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata)
 416                 if (otype == DHCPV6_OPT_CLIENTID)
 417                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
 418                                         &odata[-4], client_id, client_id_len);
 419                 else if (otype == DHCPV6_OPT_SERVERID)
 420                         serverid_ok = (olen + 4U == server_id_len) && !memcmp(
 421                                         &odata[-4], server_id, server_id_len);
 422
 423         return clientid_ok && (serverid_ok || server_id_len == 0);
 424 }
 425
 426
 427 int dhcpv6_poll_reconfigure(void)
 428 {
 429         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
 430         if (ret != -1)
 431                 ret = dhcpv6_request(ret);
 432
 433         return ret;
 434 }
 435
 436
 437 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig,
 438                 const void *opt, const void *end, uint32_t elapsed)
 439 {
 440         // TODO: should verify the reconfigure message
 441         uint16_t otype, olen;
 442         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
 443         dhcpv6_for_each_option(opt, end, otype, olen, odata)
 444                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
 445                                 odata[0] == DHCPV6_MSG_RENEW ||
 446                                 odata[0] == DHCPV6_MSG_INFO_REQ))
 447                         msg = odata[0];
 448
 449         t1 -= elapsed;
 450         t2 -= elapsed;
 451         t3 -= elapsed;
 452
 453         if (t1 < 0)
 454                 t1 = 0;
 455
 456         if (t2 < 0)
 457                 t2 = 0;
 458
 459         if (t3 < 0)
 460                 t3 = 0;
 461
 462         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, NULL, NULL, elapsed);
 463         return msg;
 464 }
 465
 466
 467 // Collect all advertised servers
 468 static int dhcpv6_handle_advert(_unused enum dhcpv6_msg orig,
 469                 const void *opt, const void *end, _unused uint32_t elapsed)
 470 {
 471         uint16_t olen, otype;
 472         uint8_t *odata;
 473         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}};
 474
 475         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 476                 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
 477                         memcpy(cand.duid, odata, olen);
 478                         cand.duid_len = olen;
 479                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2 && !odata[0]
 480                                 && odata[1] == DHCPV6_NoAddrsAvail) {
 481                         if (na_mode == IA_MODE_FORCE) {
 482                                 return -1;
 483                         } else {
 484                                 cand.has_noaddravail = true;
 485                                 cand.preference -= 1000;
 486                         }
 487                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2 && !odata[0]
 488                                 && odata[1] == DHCPV6_NoPrefixAvail) {
 489                         cand.preference -= 2000;
 490                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
 491                                 cand.preference >= 0) {
 492                         cand.preference = odata[1];
 493                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
 494                         cand.wants_reconfigure = true;
 495                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
 496                         struct dhcpv6_ia_hdr *h = (void*)odata;
 497                         uint8_t *oend = odata + olen, *d;
 498                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
 499                                 if (otype == DHCPV6_OPT_IA_PREFIX)
 500                                         cand.preference += 2000;
 501                                 else if (otype == DHCPV6_OPT_STATUS &&
 502                                                 olen >= 2 && d[0] == 0 &&
 503                                                 d[1] == DHCPV6_NoPrefixAvail)
 504                                         cand.preference -= 2000;
 505                         }
 506                 }
 507         }
 508
 509         if (cand.duid_len > 0)
 510                 odhcp6c_add_state(STATE_SERVER_CAND, &cand, sizeof(cand));
 511
 512         return -1;
 513 }
 514
 515
 516 static int dhcpv6_commit_advert(_unused uint32_t elapsed)
 517 {
 518         size_t cand_len;
 519         struct dhcpv6_server_cand *c = NULL, *cand =
 520                         odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
 521
 522         bool retry = false;
 523         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
 524                 if (cand[i].has_noaddravail)
 525                         retry = true; // We want to try again
 526
 527                 if (!c || c->preference < cand[i].preference)
 528                         c = &cand[i];
 529         }
 530
 531         if (retry && na_mode == IA_MODE_TRY) {
 532                 // We give it a second try without the IA_NA
 533                 na_mode = IA_MODE_NONE;
 534                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
 535         }
 536
 537         if (c) {
 538                 uint16_t hdr[2] = {htons(DHCPV6_OPT_SERVERID),
 539                                 htons(c->duid_len)};
 540                 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
 541                 odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len);
 542                 accept_reconfig = c->wants_reconfigure;
 543         }
 544
 545         odhcp6c_clear_state(STATE_SERVER_CAND);
 546
 547         if (!c)
 548                 return -1;
 549         else if (request_prefix || na_mode != IA_MODE_NONE)
 550                 return DHCPV6_STATEFUL;
 551         else
 552                 return DHCPV6_STATELESS;
 553 }
 554
 555
 556 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig,
 557                 const void *opt, const void *end, uint32_t elapsed)
 558 {
 559         dhcpv6_handle_advert(orig, opt, end, elapsed);
 560         if (dhcpv6_commit_advert(elapsed) < 0)
 561                 return -1;
 562
 563         return dhcpv6_handle_reply(orig, opt, end, elapsed);
 564 }
 565
 566
 567 static int dhcpv6_handle_reply(_unused enum dhcpv6_msg orig,
 568                 const void *opt, const void *end, uint32_t elapsed)
 569 {
 570         uint16_t otype, olen;
 571         uint8_t *odata;
 572         bool have_update = false;
 573
 574         t1 = t2 = t3 = 86400;
 575
 576         size_t ia_na_len, dns_len, search_len;
 577         uint8_t *ia_na = odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
 578         uint8_t *ia_end;
 579         odhcp6c_get_state(STATE_DNS, &dns_len);
 580         odhcp6c_get_state(STATE_SEARCH, &search_len);
 581
 582         // Decrease valid and preferred lifetime of prefixes
 583         size_t ia_pd_len;
 584         uint8_t *ia_pd = odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
 585         dhcpv6_for_each_option(ia_pd, ia_pd + ia_pd_len, otype, olen, odata) {
 586                 struct dhcpv6_ia_prefix *p = (void*)&odata[-4];
 587                 uint32_t valid = ntohl(p->valid);
 588                 p->valid = (valid < elapsed) ? 0 : htonl(valid - elapsed);
 589
 590                 uint32_t pref = ntohl(p->preferred);
 591                 p->preferred = (pref < elapsed) ? 0 : htonl(pref - elapsed);
 592         }
 593
 594         // Decrease valid and preferred lifetime of addresses
 595         dhcpv6_for_each_option(ia_na, ia_na + ia_na_len, otype, olen, odata) {
 596                 struct dhcpv6_ia_addr *p = (void*)&odata[-4];
 597                 uint32_t valid = ntohl(p->valid);
 598                 p->valid = (valid < elapsed) ? 0 : htonl(valid - elapsed);
 599
 600                 uint32_t pref = ntohl(p->preferred);
 601                 p->preferred = (pref < elapsed) ? 0 : htonl(pref - elapsed);
 602         }
 603
 604         // Parse and find all matching IAs
 605         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 606                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
 607                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
 608                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 609                         time_t l_t1 = ntohl(ia_hdr->t1);
 610                         time_t l_t2 = ntohl(ia_hdr->t2);
 611
 612                         // Test ID and T1-T2 validity
 613                         if (ia_hdr->iaid != 1 || l_t2 < l_t1)
 614                                 continue;
 615
 616                         uint16_t stype, slen;
 617                         uint8_t *sdata;
 618                         // Test status and bail if error
 619                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
 620                                         stype, slen, sdata)
 621                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2 &&
 622                                                 (sdata[0] || sdata[1]))
 623                                         continue;
 624
 625                         // Update times
 626                         if (l_t1 > 0 && t1 > l_t1)
 627                                 t1 = l_t1;
 628
 629                         if (l_t2 > 0 && t2 > l_t2)
 630                                 t2 = l_t2;
 631
 632
 633                         time_t n = dhcpv6_parse_ia(&ia_hdr[1], odata + olen);
 634
 635                         if (n < t1)
 636                                 t1 = n;
 637
 638                         if (n < t2)
 639                                 t2 = n;
 640
 641                         if (n < t3)
 642                                 t3 = n;
 643
 644                 } else if (otype == DHCPV6_OPT_DNS_SERVERS) {
 645                         odhcp6c_add_state(STATE_DNS, odata, olen);
 646                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
 647                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
 648                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
 649                         uint32_t refresh = ntohl(*((uint32_t*)odata));
 650                         if (refresh < (uint32_t)t1)
 651                                 t1 = refresh;
 652                 } else if (otype != DHCPV6_OPT_CLIENTID &&
 653                                 otype != DHCPV6_OPT_SERVERID) {
 654                         odhcp6c_add_state(STATE_CUSTOM_OPTS,
 655                                         &odata[-4], olen + 4);
 656                 }
 657         }
 658
 659         if (opt) {
 660                 have_update |= odhcp6c_commit_state(STATE_DNS, dns_len);
 661                 have_update |= odhcp6c_commit_state(STATE_SEARCH, search_len);
 662                 size_t new_ia_pd_len, new_ia_na_len;
 663                 odhcp6c_get_state(STATE_IA_PD, &new_ia_pd_len);
 664                 odhcp6c_get_state(STATE_IA_NA, &new_ia_na_len);
 665                 have_update |= (new_ia_pd_len != ia_pd_len) ||
 666                                 (new_ia_na_len != ia_na_len);
 667         }
 668
 669         // Delete prefixes with 0 valid-time
 670         ia_pd = odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
 671         ia_end = ia_pd + ia_pd_len;
 672         dhcpv6_for_each_option(ia_pd, ia_end, otype, olen, odata) {
 673                 struct dhcpv6_ia_prefix *p = (void*)&odata[-4];
 674                 while (!p->valid) {
 675                         ia_end = ia_pd + odhcp6c_remove_state(STATE_IA_PD,
 676                                         (uint8_t*)p - ia_pd, olen + 4);
 677                         have_update = true;
 678                 }
 679         }
 680
 681
 682         // Delete addresses with 0 valid-time
 683         ia_na = odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
 684         ia_end = ia_na + ia_na_len;
 685         dhcpv6_for_each_option(ia_na, ia_end, otype, olen, odata) {
 686                 struct dhcpv6_ia_addr *p = (void*)&odata[-4];
 687                 while (!p->valid) {
 688                         ia_end = ia_na + odhcp6c_remove_state(STATE_IA_NA,
 689                                         (uint8_t*)p - ia_na, olen + 4);
 690                         have_update = true;
 691                 }
 692         }
 693
 694         return have_update;
 695 }
 696
 697
 698 static time_t dhcpv6_parse_ia(void *opt, void *end)
 699 {
 700         uint32_t timeout = UINT32_MAX; // Minimum timeout
 701         uint16_t otype, olen, stype, slen;
 702         uint8_t *odata, *sdata;
 703
 704         // Update address IA
 705         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 706                 if (otype == DHCPV6_OPT_IA_PREFIX) {
 707                         struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
 708                         if (olen + 4U < sizeof(*prefix))
 709                                 continue;
 710
 711                         olen = sizeof(*prefix); // Normalize length
 712                         uint32_t valid = ntohl(prefix->valid);
 713                         uint32_t pref = ntohl(prefix->preferred);
 714
 715                         if (pref > valid)
 716                                 continue;
 717
 718                         // Search matching IA
 719                         struct dhcpv6_ia_prefix *local = NULL;
 720                         size_t pd_len;
 721                         uint8_t *pd = odhcp6c_get_state(STATE_IA_PD, &pd_len);
 722                         dhcpv6_for_each_option(pd, pd + pd_len,
 723                                         stype, slen, sdata)
 724                                 if (!memcmp(sdata + 8, odata + 8,
 725                                                 sizeof(local->addr) + 1))
 726                                         local = (void*)&sdata[-4];
 727
 728                         if (local) { // Already know that IA
 729                                 local->preferred = prefix->preferred;
 730                                 local->valid = prefix->valid;
 731                         } else { // New IA
 732                                 odhcp6c_add_state(STATE_IA_PD, prefix, olen);
 733                         }
 734
 735                         if (timeout > valid)
 736                                 timeout = valid;
 737
 738                         if (prefix->valid == 0) // We probably lost that prefix
 739                                 odhcp6c_add_state(STATE_IA_PD_LOST,
 740                                                 prefix, olen);
 741                 } else if (otype == DHCPV6_OPT_IA_ADDR) {
 742                         struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
 743                         if (olen + 4U < sizeof(*addr))
 744                                 continue;
 745
 746                         olen = sizeof(*addr); // Normalize length
 747                         uint32_t pref = ntohl(addr->preferred);
 748                         uint32_t valid = ntohl(addr->valid);
 749
 750                         if (pref > valid)
 751                                 continue;
 752
 753                         // Search matching IA
 754                         struct dhcpv6_ia_addr *local = NULL;
 755                         size_t na_len;
 756                         uint8_t *na = odhcp6c_get_state(STATE_IA_NA, &na_len);
 757                         dhcpv6_for_each_option(na, na + na_len,
 758                                         stype, slen, sdata)
 759                                 if (!memcmp(sdata, odata, sizeof(local->addr)))
 760                                         local = (void*)&sdata[-4];
 761
 762
 763                         if (local) { // Already know that IA
 764                                 local->preferred = addr->preferred;
 765                                 local->valid = addr->valid;
 766                         } else { // New IA
 767                                 odhcp6c_add_state(STATE_IA_NA, addr, olen);
 768                         }
 769
 770
 771                         if (timeout > valid)
 772                                 timeout = valid;
 773
 774                         if (set_rtnetlink_addr(ifindex, &addr->addr,
 775                                         pref, valid) == -EADDRNOTAVAIL) {
 776                                 dhcpv6_request(DHCPV6_MSG_DECLINE);
 777                                 raise(SIGUSR2);
 778                         }
 779                 }
 780         }
 781
 782         return timeout;
 783 }