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
  46 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
  47                 const uint8_t transaction[3], enum dhcpv6_msg type);
  48
  49 static int dhcpv6_parse_ia(void *opt, void *end);
  50
  51 static int dhcpv6_calc_refresh_timers(void);
  52 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
  53                 const uint16_t code, const void *status_msg, const int len,
  54                 int *ret);
  55 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
  56                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
  57                 const void *status_msg, const int len,
  58                 bool handled_status_codes[_DHCPV6_Status_Max],
  59                 int *ret);
  60
  61 static reply_handler dhcpv6_handle_reply;
  62 static reply_handler dhcpv6_handle_advert;
  63 static reply_handler dhcpv6_handle_rebind_reply;
  64 static reply_handler dhcpv6_handle_reconfigure;
  65 static int dhcpv6_commit_advert(void);
  66
  67
  68
  69 // RFC 3315 - 5.5 Timeout and Delay values
  70 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
  71         [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
  72                         dhcpv6_handle_reconfigure, NULL},
  73         [DHCPV6_MSG_SOLICIT] = {true, 1, 3600, 0, "SOLICIT",
  74                         dhcpv6_handle_advert, dhcpv6_commit_advert},
  75         [DHCPV6_MSG_REQUEST] = {true, 1, 30, 10, "REQUEST",
  76                         dhcpv6_handle_reply, NULL},
  77         [DHCPV6_MSG_RENEW] = {false, 10, 600, 0, "RENEW",
  78                         dhcpv6_handle_reply, NULL},
  79         [DHCPV6_MSG_REBIND] = {false, 10, 600, 0, "REBIND",
  80                         dhcpv6_handle_rebind_reply, NULL},
  81         [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
  82         [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
  83         [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, 0, "INFOREQ",
  84                         dhcpv6_handle_reply, NULL},
  85 };
  86
  87
  88 // Sockets
  89 static int sock = -1;
  90 static int ifindex = -1;
  91 static int64_t t1 = 0, t2 = 0, t3 = 0;
  92
  93 // IA states
  94 static int request_prefix = -1;
  95 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
  96 static bool accept_reconfig = false;
  97
  98 // Reconfigure key
  99 static uint8_t reconf_key[16];
 100
 101
 102
 103 int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout)
 104 {
 105         request_prefix = request_pd;
 106         dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
 107
 108         sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
 109
 110         // Detect interface
 111         struct ifreq ifr;
 112         strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 113         if (ioctl(sock, SIOCGIFINDEX, &ifr))
 114                 return -1;
 115         ifindex = ifr.ifr_ifindex;
 116
 117         // Create client DUID
 118         size_t client_id_len;
 119         odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 120         if (client_id_len == 0) {
 121                 ioctl(sock, SIOCGIFHWADDR, &ifr);
 122                 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
 123                                 DHCPV6_DUID_LLADDR, 0, 1};
 124                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
 125
 126                 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
 127                 struct ifreq ifs[100], *ifp, *ifend;
 128                 struct ifconf ifc;
 129                 ifc.ifc_req = ifs;
 130                 ifc.ifc_len = sizeof(ifs);
 131
 132                 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
 133                                 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
 134                         // If our interface doesn't have an address...
 135                         ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
 136                         for (ifp = ifc.ifc_req; ifp < ifend &&
 137                                         !memcmp(&duid[8], zero, 6); ifp++) {
 138                                 memcpy(ifr.ifr_name, ifp->ifr_name,
 139                                                 sizeof(ifr.ifr_name));
 140                                 ioctl(sock, SIOCGIFHWADDR, &ifr);
 141                                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
 142                                                 ETHER_ADDR_LEN);
 143                         }
 144                 }
 145
 146                 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
 147         }
 148
 149         // Create ORO
 150         uint16_t oro[] = {
 151                         htons(DHCPV6_OPT_SIP_SERVER_D),
 152                         htons(DHCPV6_OPT_SIP_SERVER_A),
 153                         htons(DHCPV6_OPT_DNS_SERVERS),
 154                         htons(DHCPV6_OPT_DNS_DOMAIN),
 155                         htons(DHCPV6_OPT_NTP_SERVER),
 156                         htons(DHCPV6_OPT_SIP_SERVER_A),
 157                         htons(DHCPV6_OPT_AFTR_NAME),
 158                         htons(DHCPV6_OPT_PD_EXCLUDE),
 159 #ifdef EXT_PREFIX_CLASS
 160                         htons(DHCPV6_OPT_PREFIX_CLASS),
 161 #endif
 162         };
 163         odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
 164
 165
 166         // Configure IPv6-options
 167         int val = 1;
 168         setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
 169         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 170         val = 0;
 171         setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
 172         setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
 173
 174         struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
 175                 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
 176         if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)))
 177                 return -1;
 178
 179         return 0;
 180 }
 181
 182
 183 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
 184 {
 185         na_mode = na;
 186         pd_mode = pd;
 187 }
 188
 189
 190 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
 191 {
 192         // Build FQDN
 193         char fqdn_buf[256];
 194         gethostname(fqdn_buf, sizeof(fqdn_buf));
 195         struct {
 196                 uint16_t type;
 197                 uint16_t len;
 198                 uint8_t flags;
 199                 uint8_t data[256];
 200         } fqdn;
 201         size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
 202                         sizeof(fqdn.data), NULL, NULL);
 203         fqdn.type = htons(DHCPV6_OPT_FQDN);
 204         fqdn.len = htons(fqdn_len - 4);
 205         fqdn.flags = 0;
 206
 207
 208         // Build Client ID
 209         size_t cl_id_len;
 210         void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
 211
 212         // Get Server ID
 213         size_t srv_id_len;
 214         void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
 215
 216         // Build IA_PDs
 217         size_t ia_pd_entries, ia_pd_len = 0;
 218         struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
 219         ia_pd_entries /= sizeof(*e);
 220         struct dhcpv6_ia_hdr hdr_ia_pd = {
 221                 htons(DHCPV6_OPT_IA_PD),
 222                 htons(sizeof(hdr_ia_pd) - 4),
 223                 1, 0, 0
 224         };
 225
 226
 227         uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
 228         for (size_t i = 0; i < ia_pd_entries; ++i) {
 229                 uint8_t ex_len = 0;
 230                 if (e[i].priority > 0)
 231                         ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
 232
 233                 struct dhcpv6_ia_prefix p = {
 234                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 235                         .len = htons(sizeof(p) - 4U + ex_len),
 236                         .prefix = e[i].length,
 237                         .addr = e[i].target
 238                 };
 239
 240                 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
 241                 ia_pd_len += sizeof(p);
 242
 243                 if (ex_len) {
 244                         ia_pd[ia_pd_len++] = 0;
 245                         ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
 246                         ia_pd[ia_pd_len++] = 0;
 247                         ia_pd[ia_pd_len++] = ex_len - 4;
 248                         ia_pd[ia_pd_len++] = e[i].priority;
 249
 250                         uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
 251                         excl >>= (64 - e[i].priority);
 252                         excl <<= 8 - ((e[i].priority - e[i].length) % 8);
 253
 254                         for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
 255                                 ia_pd[ia_pd_len + i] = excl & 0xff;
 256                         ia_pd_len += ex_len - 5;
 257                 }
 258         }
 259
 260         struct dhcpv6_ia_prefix pref = {
 261                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 262                 .len = htons(25), .prefix = request_prefix
 263         };
 264         if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
 265                 ia_pd = (uint8_t*)&pref;
 266                 ia_pd_len = sizeof(pref);
 267         }
 268         hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
 269
 270         // Build IA_NAs
 271         size_t ia_na_entries, ia_na_len = 0;
 272         void *ia_na = NULL;
 273         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
 274         ia_na_entries /= sizeof(*e);
 275
 276         struct dhcpv6_ia_hdr hdr_ia_na = {
 277                 htons(DHCPV6_OPT_IA_NA),
 278                 htons(sizeof(hdr_ia_na) - 4),
 279                 1, 0, 0
 280         };
 281
 282         struct dhcpv6_ia_addr pa[ia_na_entries];
 283         for (size_t i = 0; i < ia_na_entries; ++i) {
 284                 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
 285                 pa[i].len = htons(sizeof(pa[i]) - 4U);
 286                 pa[i].addr = e[i].target;
 287                 pa[i].preferred = 0;
 288                 pa[i].valid = 0;
 289         }
 290
 291         ia_na = pa;
 292         ia_na_len = sizeof(pa);
 293         hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
 294
 295         // Reconfigure Accept
 296         struct {
 297                 uint16_t type;
 298                 uint16_t length;
 299         } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
 300
 301         // Request Information Refresh
 302         uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
 303
 304         // Prepare Header
 305         size_t oro_len;
 306         void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
 307         struct {
 308                 uint8_t type;
 309                 uint8_t trid[3];
 310                 uint16_t elapsed_type;
 311                 uint16_t elapsed_len;
 312                 uint16_t elapsed_value;
 313                 uint16_t oro_type;
 314                 uint16_t oro_len;
 315         } hdr = {
 316                 type, {trid[0], trid[1], trid[2]},
 317                 htons(DHCPV6_OPT_ELAPSED), htons(2),
 318                         htons((ecs > 0xffff) ? 0xffff : ecs),
 319                 htons(DHCPV6_OPT_ORO), htons(oro_len),
 320         };
 321
 322         struct iovec iov[] = {
 323                 {&hdr, sizeof(hdr)},
 324                 {oro, oro_len},
 325                 {&oro_refresh, 0},
 326                 {cl_id, cl_id_len},
 327                 {srv_id, srv_id_len},
 328                 {&reconf_accept, sizeof(reconf_accept)},
 329                 {&fqdn, fqdn_len},
 330                 {&hdr_ia_na, sizeof(hdr_ia_na)},
 331                 {ia_na, ia_na_len},
 332                 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
 333                 {ia_pd, ia_pd_len},
 334         };
 335
 336         size_t cnt = ARRAY_SIZE(iov);
 337         if (type == DHCPV6_MSG_INFO_REQ) {
 338                 cnt = 5;
 339                 iov[2].iov_len = sizeof(oro_refresh);
 340                 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
 341         } else if (!request_prefix) {
 342                 cnt = 9;
 343         }
 344
 345         // Disable IAs if not used
 346         if (type != DHCPV6_MSG_SOLICIT) {
 347                 iov[5].iov_len = 0;
 348                 if (ia_na_len == 0)
 349                         iov[7].iov_len = 0;
 350                 if (ia_pd_len == 0)
 351                         iov[9].iov_len = 0;
 352         }
 353
 354         if (na_mode == IA_MODE_NONE)
 355                 iov[7].iov_len = 0;
 356
 357         struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
 358                 0, ALL_DHCPV6_RELAYS, ifindex};
 359         struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
 360
 361         sendmsg(sock, &msg, 0);
 362 }
 363
 364
 365 static int64_t dhcpv6_rand_delay(int64_t time)
 366 {
 367         int random;
 368         odhcp6c_random(&random, sizeof(random));
 369         return (time * ((int64_t)random % 1000LL)) / 10000LL;
 370 }
 371
 372
 373 int dhcpv6_request(enum dhcpv6_msg type)
 374 {
 375         uint8_t buf[1536], rc = 0;
 376         uint64_t timeout = UINT32_MAX;
 377         struct dhcpv6_retx *retx = &dhcpv6_retx[type];
 378
 379         if (retx->delay) {
 380                 struct timespec ts = {0, 0};
 381                 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
 382                 nanosleep(&ts, NULL);
 383         }
 384
 385         if (type == DHCPV6_MSG_UNKNOWN)
 386                 timeout = t1;
 387         else if (type == DHCPV6_MSG_RENEW)
 388                 timeout = (t2 > t1) ? t2 - t1 : 0;
 389         else if (type == DHCPV6_MSG_REBIND)
 390                 timeout = (t3 > t2) ? t3 - t2 : 0;
 391
 392         if (timeout == 0)
 393                 return -1;
 394
 395         syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
 396                         retx->name, (unsigned long long)timeout, retx->max_rc);
 397
 398         uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
 399
 400         // Generate transaction ID
 401         uint8_t trid[3] = {0, 0, 0};
 402         if (type != DHCPV6_MSG_UNKNOWN)
 403                 odhcp6c_random(trid, sizeof(trid));
 404         ssize_t len = -1;
 405         int64_t rto = 0;
 406
 407         do {
 408                 if (rto == 0) {
 409                         int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 410
 411                         // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
 412                         while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
 413                                 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 414
 415                         rto = (retx->init_timeo * 1000 + delay);
 416                 }
 417                 else
 418                         rto = (2 * rto + dhcpv6_rand_delay(rto));
 419
 420                 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
 421                         rto = retx->max_timeo * 1000 +
 422                                 dhcpv6_rand_delay(retx->max_timeo * 1000);
 423
 424                 // Calculate end for this round and elapsed time
 425                 uint64_t round_end = round_start + rto;
 426                 elapsed = round_start - start;
 427
 428                 // Don't wait too long
 429                 if (round_end - start > timeout * 1000)
 430                         round_end = timeout * 1000 + start;
 431
 432                 // Built and send package
 433                 if (type != DHCPV6_MSG_UNKNOWN) {
 434                         if (type != DHCPV6_MSG_SOLICIT)
 435                                 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
 436                                                 retx->name, (unsigned long long)elapsed, rc);
 437                         dhcpv6_send(type, trid, elapsed / 10);
 438                         rc++;
 439                 }
 440
 441                 // Receive rounds
 442                 for (; len < 0 && round_start < round_end;
 443                                 round_start = odhcp6c_get_milli_time()) {
 444                         // Check for pending signal
 445                         if (odhcp6c_signal_process())
 446                                 return -1;
 447
 448                         // Set timeout for receiving
 449                         uint64_t t = round_end - round_start;
 450                         struct timeval timeout = {t / 1000, (t % 1000) * 1000};
 451                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
 452                                         &timeout, sizeof(timeout));
 453
 454                         // Receive cycle
 455                         len = recv(sock, buf, sizeof(buf), 0);
 456
 457                         if (!dhcpv6_response_is_valid(buf, len, trid, type))
 458                                 len = -1;
 459
 460                         if (len > 0) {
 461                                 uint8_t *opt = &buf[4];
 462                                 uint8_t *opt_end = opt + len - 4;
 463
 464                                 round_start = odhcp6c_get_milli_time();
 465                                 elapsed = round_start - start;
 466                                 syslog(LOG_NOTICE, "Got a valid reply after "
 467                                                 "%llums", (unsigned long long)elapsed);
 468
 469                                 if (retx->handler_reply)
 470                                         len = retx->handler_reply(
 471                                                         type, rc, opt, opt_end);
 472
 473                                 if (len > 0 && round_end - round_start > 1000)
 474                                         round_end = 1000 + round_start;
 475                         }
 476                 }
 477
 478                 // Allow
 479                 if (retx->handler_finish)
 480                         len = retx->handler_finish();
 481         } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
 482
 483         return len;
 484 }
 485
 486
 487 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
 488                 const uint8_t transaction[3], enum dhcpv6_msg type)
 489 {
 490         const struct dhcpv6_header *rep = buf;
 491         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
 492                         transaction, sizeof(rep->tr_id)))
 493                 return false; // Invalid reply
 494
 495         if (type == DHCPV6_MSG_SOLICIT) {
 496                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
 497                                 rep->msg_type != DHCPV6_MSG_REPLY)
 498                         return false;
 499         } else if (type == DHCPV6_MSG_UNKNOWN) {
 500                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
 501                         return false;
 502         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
 503                 return false;
 504         }
 505
 506         uint8_t *end = ((uint8_t*)buf) + len, *odata;
 507         uint16_t otype, olen;
 508         bool clientid_ok = false, serverid_ok = false, rcauth_ok = false;
 509
 510         size_t client_id_len, server_id_len;
 511         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 512         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
 513
 514         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
 515                 if (otype == DHCPV6_OPT_CLIENTID) {
 516                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
 517                                         &odata[-4], client_id, client_id_len);
 518                 } else if (otype == DHCPV6_OPT_SERVERID) {
 519                         serverid_ok = (olen + 4U == server_id_len) && !memcmp(
 520                                         &odata[-4], server_id, server_id_len);
 521                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 522                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 523                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 524                         if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
 525                                 continue;
 526
 527                         md5_state_t md5;
 528                         uint8_t serverhash[16], secretbytes[16], hash[16];
 529                         memcpy(serverhash, r->key, sizeof(serverhash));
 530                         memset(r->key, 0, sizeof(r->key));
 531                         memcpy(secretbytes, reconf_key, sizeof(secretbytes));
 532
 533                         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 534                                 secretbytes[i] ^= 0x36;
 535
 536                         md5_init(&md5);
 537                         md5_append(&md5, secretbytes, sizeof(secretbytes));
 538                         md5_append(&md5, buf, len);
 539                         md5_finish(&md5, hash);
 540
 541                         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 542                                 secretbytes[i] ^= 0x36;
 543                                 secretbytes[i] ^= 0x5c;
 544                         }
 545
 546                         md5_init(&md5);
 547                         md5_append(&md5, secretbytes, sizeof(secretbytes));
 548                         md5_append(&md5, hash, 16);
 549                         md5_finish(&md5, hash);
 550
 551                         rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
 552                 }
 553         }
 554
 555         if (rep->msg_type == DHCPV6_MSG_RECONF && !rcauth_ok)
 556                 return false;
 557
 558         return clientid_ok && (serverid_ok || server_id_len == 0);
 559 }
 560
 561
 562 int dhcpv6_poll_reconfigure(void)
 563 {
 564         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
 565         if (ret != -1)
 566                 ret = dhcpv6_request(ret);
 567
 568         return ret;
 569 }
 570
 571
 572 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
 573                 const void *opt, const void *end)
 574 {
 575         // TODO: should verify the reconfigure message
 576         uint16_t otype, olen;
 577         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
 578         dhcpv6_for_each_option(opt, end, otype, olen, odata)
 579                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
 580                                 odata[0] == DHCPV6_MSG_RENEW ||
 581                                 odata[0] == DHCPV6_MSG_INFO_REQ))
 582                         msg = odata[0];
 583
 584         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
 585         return msg;
 586 }
 587
 588
 589 // Collect all advertised servers
 590 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
 591                 const void *opt, const void *end)
 592 {
 593         uint16_t olen, otype;
 594         uint8_t *odata, pref = 0;
 595         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}, NULL, NULL, 0, 0};
 596         bool have_na = false;
 597         int have_pd = 0;
 598
 599         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 600                 if (orig == DHCPV6_MSG_SOLICIT &&
 601                                 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
 602                                 olen > sizeof(struct dhcpv6_ia_hdr)) {
 603                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 604                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 605                 }
 606
 607                 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
 608                         memcpy(cand.duid, odata, olen);
 609                         cand.duid_len = olen;
 610                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 611                         int error = ((int)odata[0] << 8 | (int)odata[1]);
 612
 613                         switch (error) {
 614                         case DHCPV6_NoPrefixAvail:
 615                                 // Status code on global level
 616                                 if (pd_mode == IA_MODE_FORCE)
 617                                         return -1;
 618                                 cand.preference -= 2000;
 619                                 break;
 620
 621                         case DHCPV6_NoAddrsAvail:
 622                                 // Status code on global level
 623                                 if (na_mode == IA_MODE_FORCE)
 624                                         return -1;
 625                                 break;
 626
 627                         default :
 628                                 break;
 629                         }
 630                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
 631                                 cand.preference >= 0) {
 632                         cand.preference = pref = odata[0];
 633                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
 634                         cand.wants_reconfigure = true;
 635                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
 636                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 637                         uint8_t *oend = odata + olen, *d;
 638                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
 639                                 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
 640                                                 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
 641                                         struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
 642                                         have_pd = p->prefix;
 643                                 }
 644                         }
 645                 } else if (otype == DHCPV6_OPT_IA_NA) {
 646                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 647                         uint8_t *oend = odata + olen, *d;
 648                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
 649                                 if (otype == DHCPV6_OPT_IA_ADDR)
 650                                         have_na = true;
 651                 }
 652         }
 653
 654         if ((!have_na && na_mode == IA_MODE_FORCE) ||
 655                         (!have_pd && pd_mode == IA_MODE_FORCE))
 656                 return -1;
 657
 658         if (na_mode != IA_MODE_NONE && !have_na) {
 659                 cand.has_noaddravail = true;
 660                 cand.preference -= 1000;
 661         }
 662
 663         if (pd_mode != IA_MODE_NONE) {
 664                 if (have_pd)
 665                         cand.preference += 2000 + (128 - have_pd);
 666                 else
 667                         cand.preference -= 2000;
 668         }
 669
 670         if (cand.duid_len > 0) {
 671                 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
 672                 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
 673                 odhcp6c_add_state(STATE_SERVER_CAND, &cand, sizeof(cand));
 674         }
 675
 676         if (orig == DHCPV6_MSG_SOLICIT) {
 677                 odhcp6c_clear_state(STATE_IA_NA);
 678                 odhcp6c_clear_state(STATE_IA_PD);
 679         }
 680
 681         return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
 682 }
 683
 684
 685 static int dhcpv6_commit_advert(void)
 686 {
 687         size_t cand_len;
 688         struct dhcpv6_server_cand *c = NULL, *cand =
 689                         odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
 690
 691         bool retry = false;
 692         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
 693                 if (cand[i].has_noaddravail)
 694                         retry = true; // We want to try again
 695
 696                 if (!c || c->preference < cand[i].preference)
 697                         c = &cand[i];
 698         }
 699
 700         if (retry && na_mode == IA_MODE_TRY) {
 701                 // We give it a second try without the IA_NA
 702                 na_mode = IA_MODE_NONE;
 703                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
 704         }
 705
 706         if (c) {
 707                 uint16_t hdr[2] = {htons(DHCPV6_OPT_SERVERID),
 708                                 htons(c->duid_len)};
 709                 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
 710                 odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len);
 711                 accept_reconfig = c->wants_reconfigure;
 712                 if (c->ia_na_len)
 713                         odhcp6c_add_state(STATE_IA_NA, c->ia_na, c->ia_na_len);
 714                 if (c->ia_pd_len)
 715                         odhcp6c_add_state(STATE_IA_PD, c->ia_pd, c->ia_pd_len);
 716         }
 717
 718         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
 719                 free(cand[i].ia_na);
 720                 free(cand[i].ia_pd);
 721         }
 722         odhcp6c_clear_state(STATE_SERVER_CAND);
 723
 724         if (!c)
 725                 return -1;
 726         else if ((request_prefix && c->ia_pd_len) || (na_mode != IA_MODE_NONE && c->ia_na_len))
 727                 return DHCPV6_STATEFUL;
 728         else
 729                 return DHCPV6_STATELESS;
 730 }
 731
 732
 733 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
 734                 const void *opt, const void *end)
 735 {
 736         dhcpv6_handle_advert(orig, rc, opt, end);
 737         if (dhcpv6_commit_advert() < 0) {
 738                 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
 739                 return -1;
 740         }
 741
 742         return dhcpv6_handle_reply(orig, rc, opt, end);
 743 }
 744
 745
 746 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
 747                 const void *opt, const void *end)
 748 {
 749         uint8_t *odata;
 750         uint16_t otype, olen;
 751         uint32_t refresh = UINT32_MAX;
 752         int ret = 1;
 753         bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
 754
 755         odhcp6c_expire();
 756
 757         if (orig == DHCPV6_MSG_UNKNOWN) {
 758                 static time_t last_update = 0;
 759                 time_t now = odhcp6c_get_milli_time() / 1000;
 760
 761                 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
 762                 last_update = now;
 763
 764                 t1 -= elapsed;
 765                 t2 -= elapsed;
 766                 t3 -= elapsed;
 767
 768                 if (t1 < 0)
 769                         t1 = 0;
 770
 771                 if (t2 < 0)
 772                         t2 = 0;
 773
 774                 if (t3 < 0)
 775                         t3 = 0;
 776         }
 777
 778         if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
 779                 // Delete NA and PD we have in the state from the Advert
 780                 odhcp6c_clear_state(STATE_IA_NA);
 781                 odhcp6c_clear_state(STATE_IA_PD);
 782         }
 783
 784         if (opt) {
 785                 odhcp6c_clear_state(STATE_DNS);
 786                 odhcp6c_clear_state(STATE_SEARCH);
 787                 odhcp6c_clear_state(STATE_SNTP_IP);
 788                 odhcp6c_clear_state(STATE_SNTP_FQDN);
 789                 odhcp6c_clear_state(STATE_SIP_IP);
 790                 odhcp6c_clear_state(STATE_SIP_FQDN);
 791                 odhcp6c_clear_state(STATE_AFTR_NAME);
 792         }
 793
 794         // Parse and find all matching IAs
 795         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 796                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
 797                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
 798                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 799
 800                         // Test ID
 801                         if (ia_hdr->iaid != 1)
 802                                 continue;
 803
 804                         uint16_t code = DHCPV6_Success;
 805                         uint16_t stype, slen;
 806                         uint8_t *sdata;
 807                         // Get and handle status code
 808                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
 809                                         stype, slen, sdata) {
 810                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
 811                                         uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
 812                                         uint16_t mlen = (slen > 2) ? slen - 2 : 0;
 813
 814                                         code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
 815
 816                                         if (code == DHCPV6_Success)
 817                                                 continue;
 818
 819                                         dhcpv6_handle_ia_status_code(orig, ia_hdr,
 820                                                 code, mdata, mlen, handled_status_codes, &ret);
 821
 822
 823                                         if (ret > 0)
 824                                                 return ret;
 825                                         break;
 826                                 }
 827                         }
 828
 829                         if (code != DHCPV6_Success)
 830                                 continue;
 831
 832                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 833                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 834                         uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
 835                         uint16_t mlen = (olen > 2) ? olen - 2 : 0;
 836                         uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
 837
 838                         dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
 839                 }
 840                 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
 841                         if (olen % 16 == 0)
 842                                 odhcp6c_add_state(STATE_DNS, odata, olen);
 843                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
 844                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
 845                 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
 846                         uint16_t stype, slen;
 847                         uint8_t *sdata;
 848                         // Test status and bail if error
 849                         dhcpv6_for_each_option(odata, odata + olen,
 850                                         stype, slen, sdata) {
 851                                 if (slen == 16 && (stype == NTP_MC_ADDR ||
 852                                                 stype == NTP_SRV_ADDR))
 853                                         odhcp6c_add_state(STATE_SNTP_IP,
 854                                                         sdata, slen);
 855                                 else if (slen > 0 && stype == NTP_SRV_FQDN)
 856                                         odhcp6c_add_state(STATE_SNTP_FQDN,
 857                                                         sdata, slen);
 858                         }
 859                 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
 860                         if (olen == 16)
 861                                 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
 862                 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
 863                         odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
 864                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
 865                         refresh = ntohl(*((uint32_t*)odata));
 866                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 867                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 868                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 869                         if (r->protocol == 3 && r->algorithm == 1 &&
 870                                         r->reconf_type == 1)
 871                                 memcpy(reconf_key, r->key, sizeof(r->key));
 872                 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
 873                         size_t cur_len;
 874                         odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
 875                         if (cur_len == 0)
 876                                 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
 877                 } else if (otype != DHCPV6_OPT_CLIENTID &&
 878                                 otype != DHCPV6_OPT_SERVERID) {
 879                         odhcp6c_add_state(STATE_CUSTOM_OPTS,
 880                                         &odata[-4], olen + 4);
 881                 }
 882         }
 883
 884         if (orig != DHCPV6_MSG_INFO_REQ) {
 885                 // Update refresh timers if no fatal status code was received
 886                 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
 887                         switch (orig) {
 888                         case DHCPV6_MSG_RENEW:
 889                                 // Send further renews if T1 is not set
 890                                 if (!t1)
 891                                         ret = -1;
 892                                 break;
 893                         case DHCPV6_MSG_REBIND:
 894                                 // Send further rebinds if T1 and T2 is not set
 895                                 if (!t1 && !t2)
 896                                         ret = -1;
 897                                 break;
 898
 899                         default :
 900                                 break;
 901                         }
 902                 }
 903         }
 904         else if (ret > 0)
 905                 t1 = refresh;
 906
 907         return ret;
 908 }
 909
 910
 911 static int dhcpv6_parse_ia(void *opt, void *end)
 912 {
 913         struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
 914         int parsed_ia = 0;
 915         uint32_t t1, t2;
 916         uint16_t otype, olen;
 917         uint8_t *odata;
 918
 919         t1 = ntohl(ia_hdr->t1);
 920         t2 = ntohl(ia_hdr->t2);
 921
 922         if (t1 > t2)
 923                 return 0;
 924
 925         // Update address IA
 926         dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
 927                 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
 928                                 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
 929
 930                 if (otype == DHCPV6_OPT_IA_PREFIX) {
 931                         struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
 932                         if (olen + 4U < sizeof(*prefix))
 933                                 continue;
 934
 935                         entry.valid = ntohl(prefix->valid);
 936                         entry.preferred = ntohl(prefix->preferred);
 937
 938                         if (entry.preferred > entry.valid)
 939                                 continue;
 940
 941                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
 942                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
 943                         if (entry.t1 > entry.t2)
 944                                 entry.t1 = entry.t2;
 945
 946                         entry.length = prefix->prefix;
 947                         entry.target = prefix->addr;
 948                         uint16_t stype, slen;
 949                         uint8_t *sdata;
 950
 951 #ifdef EXT_PREFIX_CLASS
 952                         // Find prefix class, if any
 953                         dhcpv6_for_each_option(&prefix[1], odata + olen,
 954                                         stype, slen, sdata)
 955                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
 956                                         entry.class = sdata[0] << 8 | sdata[1];
 957 #endif
 958
 959                         // Parse PD-exclude
 960                         bool ok = true;
 961                         dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
 962                                         odata + olen, stype, slen, sdata) {
 963                                 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
 964                                         continue;
 965
 966                                 uint8_t elen = sdata[0];
 967                                 if (elen > 64)
 968                                         elen = 64;
 969
 970                                 if (elen <= 32 || elen <= entry.length) {
 971                                         ok = false;
 972                                         continue;
 973                                 }
 974
 975
 976                                 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
 977                                 if (slen <= bytes) {
 978                                         ok = false;
 979                                         continue;
 980                                 }
 981
 982                                 uint32_t exclude = 0;
 983                                 do {
 984                                         exclude = exclude << 8 | sdata[bytes];
 985                                 } while (--bytes);
 986
 987                                 exclude >>= 8 - ((elen - entry.length) % 8);
 988                                 exclude <<= 64 - elen;
 989
 990                                 // Abusing router & priority fields for exclusion
 991                                 entry.router = entry.target;
 992                                 entry.router.s6_addr32[1] |= htonl(exclude);
 993                                 entry.priority = elen;
 994                         }
 995
 996                         if (ok) {
 997                                 odhcp6c_update_entry(STATE_IA_PD, &entry);
 998                                 parsed_ia++;
 999                         }
1000
1001                         entry.priority = 0;
1002                         memset(&entry.router, 0, sizeof(entry.router));
1003                 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1004                         struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1005                         if (olen + 4U < sizeof(*addr))
1006                                 continue;
1007
1008                         entry.preferred = ntohl(addr->preferred);
1009                         entry.valid = ntohl(addr->valid);
1010
1011                         if (entry.preferred > entry.valid)
1012                                 continue;
1013
1014                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1015                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1016                         if (entry.t1 > entry.t2)
1017                                 entry.t1 = entry.t2;
1018
1019                         entry.length = 128;
1020                         entry.target = addr->addr;
1021
1022 #ifdef EXT_PREFIX_CLASS
1023                         uint16_t stype, slen;
1024                         uint8_t *sdata;
1025                         // Find prefix class, if any
1026                         dhcpv6_for_each_option(&addr[1], odata + olen,
1027                                         stype, slen, sdata)
1028                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1029                                         entry.class = sdata[0] << 8 | sdata[1];
1030 #endif
1031
1032                         odhcp6c_update_entry(STATE_IA_NA, &entry);
1033                         parsed_ia++;
1034                 }
1035         }
1036         return parsed_ia;
1037 }
1038
1039
1040 static int dhcpv6_calc_refresh_timers(void)
1041 {
1042         struct odhcp6c_entry *e;
1043         size_t ia_na_entries, ia_pd_entries, i;
1044         int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1045
1046         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1047         ia_na_entries /= sizeof(*e);
1048         for (i = 0; i < ia_na_entries; i++) {
1049                 if (e[i].t1 < l_t1)
1050                         l_t1 = e[i].t1;
1051
1052                 if (e[i].t2 < l_t2)
1053                         l_t2 = e[i].t2;
1054
1055                 if (e[i].valid > l_t3)
1056                         l_t3 = e[i].valid;
1057         }
1058
1059         e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1060         ia_pd_entries /= sizeof(*e);
1061         for (i = 0; i < ia_pd_entries; i++) {
1062                 if (e[i].t1 < l_t1)
1063                         l_t1 = e[i].t1;
1064
1065                 if (e[i].t2 < l_t2)
1066                         l_t2 = e[i].t2;
1067
1068                 if (e[i].valid > l_t3)
1069                         l_t3 = e[i].valid;
1070         }
1071
1072         if (ia_pd_entries || ia_na_entries) {
1073                 t1 = l_t1;
1074                 t2 = l_t2;
1075                 t3 = l_t3;
1076         }
1077
1078         return (int)(ia_pd_entries + ia_na_entries);
1079 }
1080
1081
1082 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1083                 const void *status_msg, const int len)
1084 {
1085         uint8_t buf[len + 3];
1086
1087         memset(buf, 0, sizeof(buf));
1088         if (len) {
1089                 buf[0] = '(';
1090                 memcpy(&buf[1], status_msg, len);
1091                 buf[len + 1] = ')';
1092         }
1093
1094         syslog(LOG_WARNING, "Server returned %s status %i %s",
1095                 scope, code, buf);
1096 }
1097
1098
1099 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1100                 const uint16_t code, const void *status_msg, const int len,
1101                 int *ret)
1102 {
1103         dhcpv6_log_status_code(code, "message", status_msg, len);
1104
1105         switch (code) {
1106         case DHCPV6_UnspecFail:
1107                 // Generic failure
1108                 *ret = 0;
1109                 break;
1110
1111         case DHCPV6_UseMulticast:
1112                 // TODO handle multicast status code
1113                 break;
1114
1115         case DHCPV6_NoAddrsAvail:
1116         case DHCPV6_NoPrefixAvail:
1117                 if (orig == DHCPV6_MSG_REQUEST)
1118                         *ret = 0; // Failure
1119                 break;
1120
1121         default:
1122                 break;
1123         }
1124 }
1125
1126
1127 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1128                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1129                 const void *status_msg, const int len,
1130                 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1131 {
1132         dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1133                 "IA_NA" : "IA_PD", status_msg, len);
1134
1135         switch (code) {
1136         case DHCPV6_NoBinding:
1137                 switch (orig) {
1138                 case DHCPV6_MSG_RENEW:
1139                 case DHCPV6_MSG_REBIND:
1140                         if ((*ret > 0) && !handled_status_codes[code])
1141                                 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1142                         break;
1143
1144                 default:
1145                         break;
1146                 }
1147                 break;
1148
1149         case DHCPV6_NoAddrsAvail:
1150         case DHCPV6_NoPrefixAvail:
1151                 switch (orig) {
1152                 case DHCPV6_MSG_REQUEST:
1153                         if (*ret != 0)
1154                                 *ret = 0;
1155                         break;
1156                 default:
1157                         break;
1158                 }
1159                 break;
1160
1161         case DHCPV6_NotOnLink:
1162                 // TODO handle not onlink in case of confirm
1163                 break;
1164
1165         default:
1166                 break;
1167         }
1168 }