src/dhcpv6.c

   1 /**
   2  * Copyright (C) 2012-2013 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 <stdlib.h>
  19 #include <signal.h>
  20 #include <limits.h>
  21 #include <resolv.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <syslog.h>
  25 #include <stdbool.h>
  26 #include <sys/time.h>
  27 #include <sys/ioctl.h>
  28 #include <sys/socket.h>
  29 #include <netinet/in.h>
  30
  31 #include <net/if.h>
  32 #include <net/ethernet.h>
  33
  34 #include "odhcp6c.h"
  35 #include "md5.h"
  36
  37
  38 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
  39                 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
  40 #define DHCPV6_CLIENT_PORT 546
  41 #define DHCPV6_SERVER_PORT 547
  42 #define DHCPV6_DUID_LLADDR 3
  43 #define DHCPV6_REQ_DELAY 1
  44
  45 #define DHCPV6_SOL_MAX_RT_MIN 60
  46 #define DHCPV6_SOL_MAX_RT_MAX 86400
  47 #define DHCPV6_INF_MAX_RT_MIN 60
  48 #define DHCPV6_INF_MAX_RT_MAX 86400
  49
  50 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
  51                 const uint8_t transaction[3], enum dhcpv6_msg type,
  52                 const struct in6_addr *daddr);
  53
  54 static int dhcpv6_parse_ia(void *opt, void *end);
  55
  56 static int dhcpv6_calc_refresh_timers(void);
  57 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
  58                 const uint16_t code, const void *status_msg, const int len,
  59                 int *ret);
  60 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
  61                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
  62                 const void *status_msg, const int len,
  63                 bool handled_status_codes[_DHCPV6_Status_Max],
  64                 int *ret);
  65 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
  66 static void dhcpv6_clear_all_server_cand(void);
  67
  68 static reply_handler dhcpv6_handle_reply;
  69 static reply_handler dhcpv6_handle_advert;
  70 static reply_handler dhcpv6_handle_rebind_reply;
  71 static reply_handler dhcpv6_handle_reconfigure;
  72 static int dhcpv6_commit_advert(void);
  73
  74
  75
  76 // RFC 3315 - 5.5 Timeout and Delay values
  77 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
  78         [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
  79                         dhcpv6_handle_reconfigure, NULL},
  80         [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT",
  81                         dhcpv6_handle_advert, dhcpv6_commit_advert},
  82         [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST",
  83                         dhcpv6_handle_reply, NULL},
  84         [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW",
  85                         dhcpv6_handle_reply, NULL},
  86         [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND",
  87                         dhcpv6_handle_rebind_reply, NULL},
  88         [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
  89         [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
  90         [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ",
  91                         dhcpv6_handle_reply, NULL},
  92 };
  93
  94
  95 // Sockets
  96 static int sock = -1;
  97 static int ifindex = -1;
  98 static int64_t t1 = 0, t2 = 0, t3 = 0;
  99
 100 // IA states
 101 static int request_prefix = -1;
 102 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
 103 static bool accept_reconfig = false;
 104
 105 // Reconfigure key
 106 static uint8_t reconf_key[16];
 107
 108
 109 int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout)
 110 {
 111         request_prefix = request_pd;
 112         dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
 113
 114         sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
 115         if (sock < 0)
 116                 return -1;
 117
 118         // Detect interface
 119         struct ifreq ifr;
 120         strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 121         if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
 122                 return -1;
 123         ifindex = ifr.ifr_ifindex;
 124
 125         // Create client DUID
 126         size_t client_id_len;
 127         odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 128         if (client_id_len == 0) {
 129                 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
 130                                 DHCPV6_DUID_LLADDR, 0, 1};
 131
 132                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
 133                         memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
 134
 135                 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
 136                 struct ifreq ifs[100], *ifp, *ifend;
 137                 struct ifconf ifc;
 138                 ifc.ifc_req = ifs;
 139                 ifc.ifc_len = sizeof(ifs);
 140
 141                 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
 142                                 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
 143                         // If our interface doesn't have an address...
 144                         ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
 145                         for (ifp = ifc.ifc_req; ifp < ifend &&
 146                                         !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
 147                                 memcpy(ifr.ifr_name, ifp->ifr_name,
 148                                                 sizeof(ifr.ifr_name));
 149                                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
 150                                         continue;
 151
 152                                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
 153                                                 ETHER_ADDR_LEN);
 154                         }
 155                 }
 156
 157                 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
 158         }
 159
 160         // Create ORO
 161         uint16_t oro[] = {
 162                         htons(DHCPV6_OPT_SIP_SERVER_D),
 163                         htons(DHCPV6_OPT_SIP_SERVER_A),
 164                         htons(DHCPV6_OPT_DNS_SERVERS),
 165                         htons(DHCPV6_OPT_DNS_DOMAIN),
 166                         htons(DHCPV6_OPT_SNTP_SERVERS),
 167                         htons(DHCPV6_OPT_NTP_SERVER),
 168                         htons(DHCPV6_OPT_AFTR_NAME),
 169                         htons(DHCPV6_OPT_PD_EXCLUDE),
 170                         htons(DHCPV6_OPT_SOL_MAX_RT),
 171                         htons(DHCPV6_OPT_INF_MAX_RT),
 172 #ifdef EXT_PREFIX_CLASS
 173                         htons(DHCPV6_OPT_PREFIX_CLASS),
 174 #endif
 175         };
 176         odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
 177
 178         // Configure IPv6-options
 179         int val = 1;
 180         setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
 181         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 182         setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
 183         val = 0;
 184         setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
 185         setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
 186
 187         struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
 188                 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
 189         if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
 190                 return -1;
 191
 192         return 0;
 193 }
 194
 195
 196 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
 197 {
 198         na_mode = na;
 199         pd_mode = pd;
 200 }
 201
 202
 203 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
 204 {
 205         // Build FQDN
 206         char fqdn_buf[256];
 207         gethostname(fqdn_buf, sizeof(fqdn_buf));
 208         struct {
 209                 uint16_t type;
 210                 uint16_t len;
 211                 uint8_t flags;
 212                 uint8_t data[256];
 213         } fqdn;
 214         size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
 215                         sizeof(fqdn.data), NULL, NULL);
 216         fqdn.type = htons(DHCPV6_OPT_FQDN);
 217         fqdn.len = htons(fqdn_len - 4);
 218         fqdn.flags = 0;
 219
 220
 221         // Build Client ID
 222         size_t cl_id_len;
 223         void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
 224
 225         // Get Server ID
 226         size_t srv_id_len;
 227         void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
 228
 229         // Build IA_PDs
 230         size_t ia_pd_entries, ia_pd_len = 0;
 231         struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
 232         ia_pd_entries /= sizeof(*e);
 233         struct dhcpv6_ia_hdr hdr_ia_pd = {
 234                 htons(DHCPV6_OPT_IA_PD),
 235                 htons(sizeof(hdr_ia_pd) - 4),
 236                 1, 0, 0
 237         };
 238
 239
 240         uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
 241         for (size_t i = 0; i < ia_pd_entries; ++i) {
 242                 uint8_t ex_len = 0;
 243                 if (e[i].priority > 0)
 244                         ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
 245
 246                 struct dhcpv6_ia_prefix p = {
 247                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 248                         .len = htons(sizeof(p) - 4U + ex_len),
 249                         .prefix = e[i].length,
 250                         .addr = e[i].target
 251                 };
 252
 253                 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
 254                 ia_pd_len += sizeof(p);
 255
 256                 if (ex_len) {
 257                         ia_pd[ia_pd_len++] = 0;
 258                         ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
 259                         ia_pd[ia_pd_len++] = 0;
 260                         ia_pd[ia_pd_len++] = ex_len - 4;
 261                         ia_pd[ia_pd_len++] = e[i].priority;
 262
 263                         uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
 264                         excl >>= (64 - e[i].priority);
 265                         excl <<= 8 - ((e[i].priority - e[i].length) % 8);
 266
 267                         for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
 268                                 ia_pd[ia_pd_len + i] = excl & 0xff;
 269                         ia_pd_len += ex_len - 5;
 270                 }
 271         }
 272
 273         struct dhcpv6_ia_prefix pref = {
 274                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 275                 .len = htons(25), .prefix = request_prefix
 276         };
 277         if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
 278                 ia_pd = (uint8_t*)&pref;
 279                 ia_pd_len = sizeof(pref);
 280         }
 281         hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
 282
 283         // Build IA_NAs
 284         size_t ia_na_entries, ia_na_len = 0;
 285         void *ia_na = NULL;
 286         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
 287         ia_na_entries /= sizeof(*e);
 288
 289         struct dhcpv6_ia_hdr hdr_ia_na = {
 290                 htons(DHCPV6_OPT_IA_NA),
 291                 htons(sizeof(hdr_ia_na) - 4),
 292                 1, 0, 0
 293         };
 294
 295         struct dhcpv6_ia_addr pa[ia_na_entries];
 296         for (size_t i = 0; i < ia_na_entries; ++i) {
 297                 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
 298                 pa[i].len = htons(sizeof(pa[i]) - 4U);
 299                 pa[i].addr = e[i].target;
 300                 pa[i].preferred = 0;
 301                 pa[i].valid = 0;
 302         }
 303
 304         ia_na = pa;
 305         ia_na_len = sizeof(pa);
 306         hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
 307
 308         // Reconfigure Accept
 309         struct {
 310                 uint16_t type;
 311                 uint16_t length;
 312         } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
 313
 314         // Request Information Refresh
 315         uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
 316
 317         // Prepare Header
 318         size_t oro_len;
 319         void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
 320         struct {
 321                 uint8_t type;
 322                 uint8_t trid[3];
 323                 uint16_t elapsed_type;
 324                 uint16_t elapsed_len;
 325                 uint16_t elapsed_value;
 326                 uint16_t oro_type;
 327                 uint16_t oro_len;
 328         } hdr = {
 329                 type, {trid[0], trid[1], trid[2]},
 330                 htons(DHCPV6_OPT_ELAPSED), htons(2),
 331                         htons((ecs > 0xffff) ? 0xffff : ecs),
 332                 htons(DHCPV6_OPT_ORO), htons(oro_len),
 333         };
 334
 335         struct iovec iov[] = {
 336                 {&hdr, sizeof(hdr)},
 337                 {oro, oro_len},
 338                 {&oro_refresh, 0},
 339                 {cl_id, cl_id_len},
 340                 {srv_id, srv_id_len},
 341                 {&reconf_accept, sizeof(reconf_accept)},
 342                 {&fqdn, fqdn_len},
 343                 {&hdr_ia_na, sizeof(hdr_ia_na)},
 344                 {ia_na, ia_na_len},
 345                 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
 346                 {ia_pd, ia_pd_len},
 347         };
 348
 349         size_t cnt = ARRAY_SIZE(iov);
 350         if (type == DHCPV6_MSG_INFO_REQ) {
 351                 cnt = 5;
 352                 iov[2].iov_len = sizeof(oro_refresh);
 353                 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
 354         } else if (!request_prefix) {
 355                 cnt = 9;
 356         }
 357
 358         // Disable IAs if not used
 359         if (type != DHCPV6_MSG_SOLICIT) {
 360                 iov[5].iov_len = 0;
 361                 if (ia_na_len == 0)
 362                         iov[7].iov_len = 0;
 363                 if (ia_pd_len == 0)
 364                         iov[9].iov_len = 0;
 365         }
 366
 367         if (na_mode == IA_MODE_NONE)
 368                 iov[7].iov_len = 0;
 369
 370         struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
 371                 0, ALL_DHCPV6_RELAYS, ifindex};
 372         struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
 373
 374         sendmsg(sock, &msg, 0);
 375 }
 376
 377
 378 static int64_t dhcpv6_rand_delay(int64_t time)
 379 {
 380         int random;
 381         odhcp6c_random(&random, sizeof(random));
 382         return (time * ((int64_t)random % 1000LL)) / 10000LL;
 383 }
 384
 385
 386 int dhcpv6_request(enum dhcpv6_msg type)
 387 {
 388         uint8_t rc = 0;
 389         uint64_t timeout = UINT32_MAX;
 390         struct dhcpv6_retx *retx = &dhcpv6_retx[type];
 391
 392         if (retx->delay) {
 393                 struct timespec ts = {0, 0};
 394                 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
 395                 nanosleep(&ts, NULL);
 396         }
 397
 398         if (type == DHCPV6_MSG_UNKNOWN)
 399                 timeout = t1;
 400         else if (type == DHCPV6_MSG_RENEW)
 401                 timeout = (t2 > t1) ? t2 - t1 : 0;
 402         else if (type == DHCPV6_MSG_REBIND)
 403                 timeout = (t3 > t2) ? t3 - t2 : 0;
 404
 405         if (timeout == 0)
 406                 return -1;
 407
 408         syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
 409                         retx->name, (unsigned long long)timeout, retx->max_rc);
 410
 411         uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
 412
 413         // Generate transaction ID
 414         uint8_t trid[3] = {0, 0, 0};
 415         if (type != DHCPV6_MSG_UNKNOWN)
 416                 odhcp6c_random(trid, sizeof(trid));
 417         ssize_t len = -1;
 418         int64_t rto = 0;
 419
 420         do {
 421                 if (rto == 0) {
 422                         int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 423
 424                         // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
 425                         while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
 426                                 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 427
 428                         rto = (retx->init_timeo * 1000 + delay);
 429                 }
 430                 else
 431                         rto = (2 * rto + dhcpv6_rand_delay(rto));
 432
 433                 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
 434                         rto = retx->max_timeo * 1000 +
 435                                 dhcpv6_rand_delay(retx->max_timeo * 1000);
 436
 437                 // Calculate end for this round and elapsed time
 438                 uint64_t round_end = round_start + rto;
 439                 elapsed = round_start - start;
 440
 441                 // Don't wait too long
 442                 if (round_end - start > timeout * 1000)
 443                         round_end = timeout * 1000 + start;
 444
 445                 // Built and send package
 446                 if (type != DHCPV6_MSG_UNKNOWN) {
 447                         if (type != DHCPV6_MSG_SOLICIT)
 448                                 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
 449                                                 retx->name, (unsigned long long)elapsed, rc);
 450                         dhcpv6_send(type, trid, elapsed / 10);
 451                         rc++;
 452                 }
 453
 454                 // Receive rounds
 455                 for (; len < 0 && (round_start < round_end);
 456                                 round_start = odhcp6c_get_milli_time()) {
 457                         uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 458                         struct iovec iov = {buf, sizeof(buf)};
 459                         struct msghdr msg = {NULL, 0, &iov, 1,
 460                                         cmsg_buf, sizeof(cmsg_buf), 0};
 461                         struct in6_pktinfo *pktinfo = NULL;
 462
 463                         // Check for pending signal
 464                         if (odhcp6c_signal_process())
 465                                 return -1;
 466
 467                         // Set timeout for receiving
 468                         uint64_t t = round_end - round_start;
 469                         struct timeval timeout = {t / 1000, (t % 1000) * 1000};
 470                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
 471                                         &timeout, sizeof(timeout));
 472
 473                         // Receive cycle
 474                         len = recvmsg(sock, &msg, 0);
 475                         if (len < 0)
 476                                 continue;
 477
 478                         for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
 479                                 ch = CMSG_NXTHDR(&msg, ch)) {
 480                                 if (ch->cmsg_level == SOL_IPV6 &&
 481                                         ch->cmsg_type == IPV6_PKTINFO) {
 482                                         pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
 483                                         break;
 484                                 }
 485                         }
 486
 487                         if (pktinfo == NULL) {
 488                                 len = -1;
 489                                 continue;
 490                         }
 491
 492                         if (!dhcpv6_response_is_valid(buf, len, trid,
 493                                                         type, &pktinfo->ipi6_addr)) {
 494                                 len = -1;
 495                                 continue;
 496                         }
 497
 498                         uint8_t *opt = &buf[4];
 499                         uint8_t *opt_end = opt + len - 4;
 500
 501                         round_start = odhcp6c_get_milli_time();
 502                         elapsed = round_start - start;
 503                         syslog(LOG_NOTICE, "Got a valid reply after "
 504                                         "%llums", (unsigned long long)elapsed);
 505
 506                         if (retx->handler_reply)
 507                                 len = retx->handler_reply(type, rc, opt, opt_end);
 508
 509                         if (len > 0 && round_end - round_start > 1000)
 510                                 round_end = 1000 + round_start;
 511                 }
 512
 513                 // Allow
 514                 if (retx->handler_finish)
 515                         len = retx->handler_finish();
 516         } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
 517
 518         return len;
 519 }
 520
 521 // Message validation checks according to RFC3315 chapter 15
 522 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
 523                 const uint8_t transaction[3], enum dhcpv6_msg type,
 524                 const struct in6_addr *daddr)
 525 {
 526         const struct dhcpv6_header *rep = buf;
 527         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
 528                         transaction, sizeof(rep->tr_id)))
 529                 return false; // Invalid reply
 530
 531         if (type == DHCPV6_MSG_SOLICIT) {
 532                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
 533                                 rep->msg_type != DHCPV6_MSG_REPLY)
 534                         return false;
 535         } else if (type == DHCPV6_MSG_UNKNOWN) {
 536                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
 537                         return false;
 538         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
 539                 return false;
 540         }
 541
 542         uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
 543                 rcmsg = DHCPV6_MSG_UNKNOWN;
 544         uint16_t otype, olen = UINT16_MAX;
 545         bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
 546                 ia_present = false, options_valid = true;
 547
 548         size_t client_id_len, server_id_len;
 549         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 550         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
 551
 552         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
 553                 if (otype == DHCPV6_OPT_CLIENTID) {
 554                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
 555                                         &odata[-4], client_id, client_id_len);
 556                 } else if (otype == DHCPV6_OPT_SERVERID) {
 557                         if (server_id_len)
 558                                 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
 559                                                 &odata[-4], server_id, server_id_len);
 560                         else
 561                                 serverid_ok = true;
 562                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 563                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 564                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 565                         if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
 566                                 continue;
 567
 568                         md5_ctx_t md5;
 569                         uint8_t serverhash[16], secretbytes[16], hash[16];
 570                         memcpy(serverhash, r->key, sizeof(serverhash));
 571                         memset(r->key, 0, sizeof(r->key));
 572                         memcpy(secretbytes, reconf_key, sizeof(secretbytes));
 573
 574                         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 575                                 secretbytes[i] ^= 0x36;
 576
 577                         md5_begin(&md5);
 578                         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 579                         md5_hash(buf, len, &md5);
 580                         md5_end(hash, &md5);
 581
 582                         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 583                                 secretbytes[i] ^= 0x36;
 584                                 secretbytes[i] ^= 0x5c;
 585                         }
 586
 587                         md5_begin(&md5);
 588                         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 589                         md5_hash(hash, 16, &md5);
 590                         md5_end(hash, &md5);
 591
 592                         rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
 593                 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
 594                         rcmsg = odata[0];
 595                 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
 596                         ia_present = true;
 597                         if (olen < sizeof(struct dhcpv6_ia_hdr))
 598                                 options_valid = false;
 599                 }
 600                 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
 601                                 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
 602                         // Options are not allowed on global level
 603                         options_valid = false;
 604                 }
 605         }
 606
 607         if (!options_valid || ((odata + olen) > end))
 608                 return false;
 609
 610         if (type == DHCPV6_MSG_INFO_REQ && ia_present)
 611                 return false;
 612
 613         if (rep->msg_type == DHCPV6_MSG_RECONF) {
 614                 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
 615                         (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
 616                         !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
 617                         return false;
 618         }
 619
 620         return clientid_ok && serverid_ok;
 621 }
 622
 623
 624 int dhcpv6_poll_reconfigure(void)
 625 {
 626         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
 627         if (ret != -1)
 628                 ret = dhcpv6_request(ret);
 629
 630         return ret;
 631 }
 632
 633
 634 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
 635                 const void *opt, const void *end)
 636 {
 637         uint16_t otype, olen;
 638         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
 639         dhcpv6_for_each_option(opt, end, otype, olen, odata)
 640                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
 641                                 odata[0] == DHCPV6_MSG_RENEW ||
 642                                 odata[0] == DHCPV6_MSG_INFO_REQ))
 643                         msg = odata[0];
 644
 645         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
 646         return msg;
 647 }
 648
 649
 650 // Collect all advertised servers
 651 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
 652                 const void *opt, const void *end)
 653 {
 654         uint16_t olen, otype;
 655         uint8_t *odata, pref = 0;
 656         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
 657                                         DHCPV6_SOL_MAX_RT,
 658                                         DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
 659         bool have_na = false;
 660         int have_pd = 0;
 661
 662         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 663                 if (orig == DHCPV6_MSG_SOLICIT &&
 664                                 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
 665                                 olen > sizeof(struct dhcpv6_ia_hdr)) {
 666                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 667                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 668                 }
 669
 670                 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
 671                         memcpy(cand.duid, odata, olen);
 672                         cand.duid_len = olen;
 673                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 674                         int error = ((int)odata[0] << 8 | (int)odata[1]);
 675
 676                         switch (error) {
 677                         case DHCPV6_NoPrefixAvail:
 678                                 // Status code on global level
 679                                 cand.preference -= 2000;
 680                                 break;
 681
 682                         default :
 683                                 break;
 684                         }
 685                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
 686                                 cand.preference >= 0) {
 687                         cand.preference = pref = odata[0];
 688                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
 689                         cand.wants_reconfigure = true;
 690                 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
 691                         uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
 692                         if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
 693                                         sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
 694                                 cand.sol_max_rt = sol_max_rt;
 695                 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
 696                         uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
 697                         if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
 698                                         inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
 699                                 cand.inf_max_rt = inf_max_rt;
 700                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
 701                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 702                         uint8_t *oend = odata + olen, *d;
 703                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
 704                                 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
 705                                                 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
 706                                         struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
 707                                         have_pd = p->prefix;
 708                                 }
 709                         }
 710                 } else if (otype == DHCPV6_OPT_IA_NA) {
 711                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 712                         uint8_t *oend = odata + olen, *d;
 713                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
 714                                 if (otype == DHCPV6_OPT_IA_ADDR)
 715                                         have_na = true;
 716                 }
 717         }
 718
 719         if ((!have_na && na_mode == IA_MODE_FORCE) ||
 720                         (!have_pd && pd_mode == IA_MODE_FORCE)) {
 721                 /*
 722                  * RFC7083 states to process the SOL_MAX_RT and
 723                  * INF_MAX_RT options even if the DHCPv6 server
 724                  * did not propose any IA_NA and/or IA_PD
 725                  */
 726                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
 727                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
 728                 return -1;
 729         }
 730
 731         if (na_mode != IA_MODE_NONE && !have_na) {
 732                 cand.has_noaddravail = true;
 733                 cand.preference -= 1000;
 734         }
 735
 736         if (pd_mode != IA_MODE_NONE) {
 737                 if (have_pd)
 738                         cand.preference += 2000 + (128 - have_pd);
 739                 else
 740                         cand.preference -= 2000;
 741         }
 742
 743         if (cand.duid_len > 0) {
 744                 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
 745                 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
 746                 dhcpv6_add_server_cand(&cand);
 747         }
 748
 749         return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
 750 }
 751
 752
 753 static int dhcpv6_commit_advert(void)
 754 {
 755         return dhcpv6_promote_server_cand();
 756 }
 757
 758
 759 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
 760                 const void *opt, const void *end)
 761 {
 762         dhcpv6_handle_advert(orig, rc, opt, end);
 763         if (dhcpv6_commit_advert() < 0)
 764                 return -1;
 765
 766         return dhcpv6_handle_reply(orig, rc, opt, end);
 767 }
 768
 769
 770 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
 771                 const void *opt, const void *end)
 772 {
 773         uint8_t *odata;
 774         uint16_t otype, olen;
 775         uint32_t refresh = UINT32_MAX;
 776         int ret = 1;
 777         bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
 778
 779         odhcp6c_expire();
 780
 781         if (orig == DHCPV6_MSG_UNKNOWN) {
 782                 static time_t last_update = 0;
 783                 time_t now = odhcp6c_get_milli_time() / 1000;
 784
 785                 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
 786                 last_update = now;
 787
 788                 t1 -= elapsed;
 789                 t2 -= elapsed;
 790                 t3 -= elapsed;
 791
 792                 if (t1 < 0)
 793                         t1 = 0;
 794
 795                 if (t2 < 0)
 796                         t2 = 0;
 797
 798                 if (t3 < 0)
 799                         t3 = 0;
 800         }
 801
 802         if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
 803                 // Delete NA and PD we have in the state from the Advert
 804                 odhcp6c_clear_state(STATE_IA_NA);
 805                 odhcp6c_clear_state(STATE_IA_PD);
 806         }
 807
 808         if (opt) {
 809                 odhcp6c_clear_state(STATE_DNS);
 810                 odhcp6c_clear_state(STATE_SEARCH);
 811                 odhcp6c_clear_state(STATE_SNTP_IP);
 812                 odhcp6c_clear_state(STATE_NTP_IP);
 813                 odhcp6c_clear_state(STATE_NTP_FQDN);
 814                 odhcp6c_clear_state(STATE_SIP_IP);
 815                 odhcp6c_clear_state(STATE_SIP_FQDN);
 816                 odhcp6c_clear_state(STATE_AFTR_NAME);
 817         }
 818
 819         // Parse and find all matching IAs
 820         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 821                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
 822                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
 823                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 824
 825                         // Test ID
 826                         if (ia_hdr->iaid != 1)
 827                                 continue;
 828
 829                         uint16_t code = DHCPV6_Success;
 830                         uint16_t stype, slen;
 831                         uint8_t *sdata;
 832                         // Get and handle status code
 833                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
 834                                         stype, slen, sdata) {
 835                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
 836                                         uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
 837                                         uint16_t mlen = (slen > 2) ? slen - 2 : 0;
 838
 839                                         code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
 840
 841                                         if (code == DHCPV6_Success)
 842                                                 continue;
 843
 844                                         dhcpv6_handle_ia_status_code(orig, ia_hdr,
 845                                                 code, mdata, mlen, handled_status_codes, &ret);
 846
 847
 848                                         if (ret > 0)
 849                                                 return ret;
 850                                         break;
 851                                 }
 852                         }
 853
 854                         if (code != DHCPV6_Success)
 855                                 continue;
 856
 857                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 858                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 859                         uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
 860                         uint16_t mlen = (olen > 2) ? olen - 2 : 0;
 861                         uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
 862
 863                         dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
 864                 }
 865                 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
 866                         if (olen % 16 == 0)
 867                                 odhcp6c_add_state(STATE_DNS, odata, olen);
 868                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
 869                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
 870                 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
 871                         if (olen % 16 == 0)
 872                                 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
 873                 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
 874                         uint16_t stype, slen;
 875                         uint8_t *sdata;
 876                         // Test status and bail if error
 877                         dhcpv6_for_each_option(odata, odata + olen,
 878                                         stype, slen, sdata) {
 879                                 if (slen == 16 && (stype == NTP_MC_ADDR ||
 880                                                 stype == NTP_SRV_ADDR))
 881                                         odhcp6c_add_state(STATE_NTP_IP,
 882                                                         sdata, slen);
 883                                 else if (slen > 0 && stype == NTP_SRV_FQDN)
 884                                         odhcp6c_add_state(STATE_NTP_FQDN,
 885                                                         sdata, slen);
 886                         }
 887                 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
 888                         if (olen == 16)
 889                                 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
 890                 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
 891                         odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
 892                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
 893                         refresh = ntohl(*((uint32_t*)odata));
 894                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 895                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 896                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 897                         if (r->protocol == 3 && r->algorithm == 1 &&
 898                                         r->reconf_type == 1)
 899                                 memcpy(reconf_key, r->key, sizeof(r->key));
 900                 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
 901                         size_t cur_len;
 902                         odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
 903                         if (cur_len == 0)
 904                                 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
 905                 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
 906                         uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
 907                         if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
 908                                         sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
 909                                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
 910                 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
 911                         uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
 912                         if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
 913                                         inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
 914                                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
 915                 }else if (otype != DHCPV6_OPT_CLIENTID &&
 916                                 otype != DHCPV6_OPT_SERVERID) {
 917                         odhcp6c_add_state(STATE_CUSTOM_OPTS,
 918                                         &odata[-4], olen + 4);
 919                 }
 920         }
 921
 922         if (orig != DHCPV6_MSG_INFO_REQ) {
 923                 // Update refresh timers if no fatal status code was received
 924                 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
 925                         switch (orig) {
 926                         case DHCPV6_MSG_RENEW:
 927                                 // Send further renews if T1 is not set
 928                                 if (!t1)
 929                                         ret = -1;
 930                                 break;
 931                         case DHCPV6_MSG_REBIND:
 932                                 // Send further rebinds if T1 and T2 is not set
 933                                 if (!t1 && !t2)
 934                                         ret = -1;
 935                                 break;
 936
 937                         case DHCPV6_MSG_REQUEST:
 938                                 // All server candidates can be cleared if not yet bound
 939                                 if (!odhcp6c_is_bound())
 940                                         dhcpv6_clear_all_server_cand();
 941
 942                         default :
 943                                 break;
 944                         }
 945                 }
 946         }
 947         else if (ret > 0) {
 948                 // All server candidates can be cleared if not yet bound
 949                 if (!odhcp6c_is_bound())
 950                         dhcpv6_clear_all_server_cand();
 951
 952                 t1 = refresh;
 953         }
 954
 955         return ret;
 956 }
 957
 958
 959 static int dhcpv6_parse_ia(void *opt, void *end)
 960 {
 961         struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
 962         int parsed_ia = 0;
 963         uint32_t t1, t2;
 964         uint16_t otype, olen;
 965         uint8_t *odata;
 966
 967         t1 = ntohl(ia_hdr->t1);
 968         t2 = ntohl(ia_hdr->t2);
 969
 970         if (t1 > t2)
 971                 return 0;
 972
 973         // Update address IA
 974         dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
 975                 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
 976                                 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
 977
 978                 if (otype == DHCPV6_OPT_IA_PREFIX) {
 979                         struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
 980                         if (olen + 4U < sizeof(*prefix))
 981                                 continue;
 982
 983                         entry.valid = ntohl(prefix->valid);
 984                         entry.preferred = ntohl(prefix->preferred);
 985
 986                         if (entry.preferred > entry.valid)
 987                                 continue;
 988
 989                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
 990                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
 991                         if (entry.t1 > entry.t2)
 992                                 entry.t1 = entry.t2;
 993
 994                         entry.length = prefix->prefix;
 995                         entry.target = prefix->addr;
 996                         uint16_t stype, slen;
 997                         uint8_t *sdata;
 998
 999 #ifdef EXT_PREFIX_CLASS
1000                         // Find prefix class, if any
1001                         dhcpv6_for_each_option(&prefix[1], odata + olen,
1002                                         stype, slen, sdata)
1003                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1004                                         entry.class = sdata[0] << 8 | sdata[1];
1005 #endif
1006
1007                         // Parse PD-exclude
1008                         bool ok = true;
1009                         dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1010                                         odata + olen, stype, slen, sdata) {
1011                                 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1012                                         continue;
1013
1014                                 uint8_t elen = sdata[0];
1015                                 if (elen > 64)
1016                                         elen = 64;
1017
1018                                 if (elen <= 32 || elen <= entry.length) {
1019                                         ok = false;
1020                                         continue;
1021                                 }
1022
1023
1024                                 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1025                                 if (slen <= bytes) {
1026                                         ok = false;
1027                                         continue;
1028                                 }
1029
1030                                 uint32_t exclude = 0;
1031                                 do {
1032                                         exclude = exclude << 8 | sdata[bytes];
1033                                 } while (--bytes);
1034
1035                                 exclude >>= 8 - ((elen - entry.length) % 8);
1036                                 exclude <<= 64 - elen;
1037
1038                                 // Abusing router & priority fields for exclusion
1039                                 entry.router = entry.target;
1040                                 entry.router.s6_addr32[1] |= htonl(exclude);
1041                                 entry.priority = elen;
1042                         }
1043
1044                         if (ok) {
1045                                 odhcp6c_update_entry(STATE_IA_PD, &entry);
1046                                 parsed_ia++;
1047                         }
1048
1049                         entry.priority = 0;
1050                         memset(&entry.router, 0, sizeof(entry.router));
1051                 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1052                         struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1053                         if (olen + 4U < sizeof(*addr))
1054                                 continue;
1055
1056                         entry.preferred = ntohl(addr->preferred);
1057                         entry.valid = ntohl(addr->valid);
1058
1059                         if (entry.preferred > entry.valid)
1060                                 continue;
1061
1062                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1063                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1064                         if (entry.t1 > entry.t2)
1065                                 entry.t1 = entry.t2;
1066
1067                         entry.length = 128;
1068                         entry.target = addr->addr;
1069
1070 #ifdef EXT_PREFIX_CLASS
1071                         uint16_t stype, slen;
1072                         uint8_t *sdata;
1073                         // Find prefix class, if any
1074                         dhcpv6_for_each_option(&addr[1], odata + olen,
1075                                         stype, slen, sdata)
1076                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1077                                         entry.class = sdata[0] << 8 | sdata[1];
1078 #endif
1079
1080                         odhcp6c_update_entry(STATE_IA_NA, &entry);
1081                         parsed_ia++;
1082                 }
1083         }
1084         return parsed_ia;
1085 }
1086
1087
1088 static int dhcpv6_calc_refresh_timers(void)
1089 {
1090         struct odhcp6c_entry *e;
1091         size_t ia_na_entries, ia_pd_entries, i;
1092         int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1093
1094         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1095         ia_na_entries /= sizeof(*e);
1096         for (i = 0; i < ia_na_entries; i++) {
1097                 if (e[i].t1 < l_t1)
1098                         l_t1 = e[i].t1;
1099
1100                 if (e[i].t2 < l_t2)
1101                         l_t2 = e[i].t2;
1102
1103                 if (e[i].valid > l_t3)
1104                         l_t3 = e[i].valid;
1105         }
1106
1107         e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1108         ia_pd_entries /= sizeof(*e);
1109         for (i = 0; i < ia_pd_entries; i++) {
1110                 if (e[i].t1 < l_t1)
1111                         l_t1 = e[i].t1;
1112
1113                 if (e[i].t2 < l_t2)
1114                         l_t2 = e[i].t2;
1115
1116                 if (e[i].valid > l_t3)
1117                         l_t3 = e[i].valid;
1118         }
1119
1120         if (ia_pd_entries || ia_na_entries) {
1121                 t1 = l_t1;
1122                 t2 = l_t2;
1123                 t3 = l_t3;
1124         } else {
1125                 t1 = 600;
1126         }
1127
1128         return (int)(ia_pd_entries + ia_na_entries);
1129 }
1130
1131
1132 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1133                 const void *status_msg, const int len)
1134 {
1135         uint8_t buf[len + 3];
1136
1137         memset(buf, 0, sizeof(buf));
1138         if (len) {
1139                 buf[0] = '(';
1140                 memcpy(&buf[1], status_msg, len);
1141                 buf[len + 1] = ')';
1142         }
1143
1144         syslog(LOG_WARNING, "Server returned %s status %i %s",
1145                 scope, code, buf);
1146 }
1147
1148
1149 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1150                 const uint16_t code, const void *status_msg, const int len,
1151                 int *ret)
1152 {
1153         dhcpv6_log_status_code(code, "message", status_msg, len);
1154
1155         switch (code) {
1156         case DHCPV6_UnspecFail:
1157                 // Generic failure
1158                 *ret = 0;
1159                 break;
1160
1161         case DHCPV6_UseMulticast:
1162                 // TODO handle multicast status code
1163                 break;
1164
1165         case DHCPV6_NoAddrsAvail:
1166         case DHCPV6_NoPrefixAvail:
1167                 if (orig == DHCPV6_MSG_REQUEST)
1168                         *ret = 0; // Failure
1169                 break;
1170
1171         default:
1172                 break;
1173         }
1174 }
1175
1176
1177 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1178                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1179                 const void *status_msg, const int len,
1180                 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1181 {
1182         dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1183                 "IA_NA" : "IA_PD", status_msg, len);
1184
1185         switch (code) {
1186         case DHCPV6_NoBinding:
1187                 switch (orig) {
1188                 case DHCPV6_MSG_RENEW:
1189                 case DHCPV6_MSG_REBIND:
1190                         if ((*ret > 0) && !handled_status_codes[code])
1191                                 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1192                         break;
1193
1194                 default:
1195                         break;
1196                 }
1197                 break;
1198
1199         case DHCPV6_NoAddrsAvail:
1200         case DHCPV6_NoPrefixAvail:
1201                 switch (orig) {
1202                 case DHCPV6_MSG_REQUEST:
1203                         if (*ret != 0)
1204                                 *ret = 0;
1205                         break;
1206                 default:
1207                         break;
1208                 }
1209                 break;
1210
1211         case DHCPV6_NotOnLink:
1212                 // TODO handle not onlink in case of confirm
1213                 break;
1214
1215         default:
1216                 break;
1217         }
1218 }
1219
1220 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1221 {
1222         size_t cand_len, i;
1223         struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1224
1225         // Remove identical duid server candidate
1226         for (i = 0; i < cand_len / sizeof(*c); ++i) {
1227                 if (cand->duid_len == c[i].duid_len &&
1228                                 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1229                         free(c[i].ia_na);
1230                         free(c[i].ia_pd);
1231                         odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1232                         break;
1233                 }
1234         }
1235
1236         for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1237                 i < cand_len / sizeof(*c); ++i) {
1238                 if (c[i].preference < cand->preference)
1239                         break;
1240         }
1241
1242         odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1243 }
1244
1245 static void dhcpv6_clear_all_server_cand(void)
1246 {
1247         size_t cand_len, i;
1248         struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1249
1250         // Server candidates need deep delete for IA_NA/IA_PD
1251         for (i = 0; i < cand_len / sizeof(*c); ++i) {
1252                 free(c[i].ia_na);
1253                 free(c[i].ia_pd);
1254         }
1255         odhcp6c_clear_state(STATE_SERVER_CAND);
1256 }
1257
1258 int dhcpv6_promote_server_cand(void)
1259 {
1260         size_t cand_len;
1261         struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1262         uint16_t hdr[2];
1263         int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1264                         DHCPV6_STATELESS : DHCPV6_STATEFUL;
1265
1266         // Clear lingering candidate state info
1267         odhcp6c_clear_state(STATE_SERVER_ID);
1268         odhcp6c_clear_state(STATE_IA_NA);
1269         odhcp6c_clear_state(STATE_IA_PD);
1270
1271         if (!cand_len)
1272                 return -1;
1273
1274         if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1275                 na_mode = IA_MODE_NONE;
1276
1277                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1278                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1279
1280                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1281         }
1282
1283         hdr[0] = htons(DHCPV6_OPT_SERVERID);
1284         hdr[1] = htons(cand->duid_len);
1285         odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1286         odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1287         accept_reconfig = cand->wants_reconfigure;
1288         if (cand->ia_na_len) {
1289                 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1290                 free(cand->ia_na);
1291                 if (na_mode != IA_MODE_NONE)
1292                         ret = DHCPV6_STATEFUL;
1293         }
1294         if (cand->ia_pd_len) {
1295                 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1296                 free(cand->ia_pd);
1297                 if (request_prefix)
1298                         ret = DHCPV6_STATEFUL;
1299         }
1300
1301         dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1302         dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1303
1304         odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1305
1306         return ret;
1307 }