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                         syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
 435                                         retx->name, (unsigned long long)elapsed, rc);
 436                         dhcpv6_send(type, trid, elapsed / 10);
 437                         rc++;
 438                 }
 439
 440                 // Receive rounds
 441                 for (; len < 0 && round_start < round_end;
 442                                 round_start = odhcp6c_get_milli_time()) {
 443                         // Check for pending signal
 444                         if (odhcp6c_signal_process())
 445                                 return -1;
 446
 447                         // Set timeout for receiving
 448                         uint64_t t = round_end - round_start;
 449                         struct timeval timeout = {t / 1000, (t % 1000) * 1000};
 450                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
 451                                         &timeout, sizeof(timeout));
 452
 453                         // Receive cycle
 454                         len = recv(sock, buf, sizeof(buf), 0);
 455
 456                         if (!dhcpv6_response_is_valid(buf, len, trid, type))
 457                                 len = -1;
 458
 459                         if (len > 0) {
 460                                 uint8_t *opt = &buf[4];
 461                                 uint8_t *opt_end = opt + len - 4;
 462
 463                                 round_start = odhcp6c_get_milli_time();
 464                                 elapsed = round_start - start;
 465                                 syslog(LOG_NOTICE, "Got a valid reply after "
 466                                                 "%llums", (unsigned long long)elapsed);
 467
 468                                 if (retx->handler_reply)
 469                                         len = retx->handler_reply(
 470                                                         type, rc, opt, opt_end);
 471
 472                                 if (len > 0 && round_end - round_start > 1000)
 473                                         round_end = 1000 + round_start;
 474                         }
 475                 }
 476
 477                 // Allow
 478                 if (retx->handler_finish)
 479                         len = retx->handler_finish();
 480         } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
 481
 482         return len;
 483 }
 484
 485
 486 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
 487                 const uint8_t transaction[3], enum dhcpv6_msg type)
 488 {
 489         const struct dhcpv6_header *rep = buf;
 490         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
 491                         transaction, sizeof(rep->tr_id)))
 492                 return false; // Invalid reply
 493
 494         if (type == DHCPV6_MSG_SOLICIT) {
 495                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
 496                                 rep->msg_type != DHCPV6_MSG_REPLY)
 497                         return false;
 498         } else if (type == DHCPV6_MSG_UNKNOWN) {
 499                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
 500                         return false;
 501         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
 502                 return false;
 503         }
 504
 505         uint8_t *end = ((uint8_t*)buf) + len, *odata;
 506         uint16_t otype, olen;
 507         bool clientid_ok = false, serverid_ok = false, rcauth_ok = false;
 508
 509         size_t client_id_len, server_id_len;
 510         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 511         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
 512
 513         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
 514                 if (otype == DHCPV6_OPT_CLIENTID) {
 515                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
 516                                         &odata[-4], client_id, client_id_len);
 517                 } else if (otype == DHCPV6_OPT_SERVERID) {
 518                         serverid_ok = (olen + 4U == server_id_len) && !memcmp(
 519                                         &odata[-4], server_id, server_id_len);
 520                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 521                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 522                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 523                         if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
 524                                 continue;
 525
 526                         md5_state_t md5;
 527                         uint8_t serverhash[16], secretbytes[16], hash[16];
 528                         memcpy(serverhash, r->key, sizeof(serverhash));
 529                         memset(r->key, 0, sizeof(r->key));
 530                         memcpy(secretbytes, reconf_key, sizeof(secretbytes));
 531
 532                         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 533                                 secretbytes[i] ^= 0x36;
 534
 535                         md5_init(&md5);
 536                         md5_append(&md5, secretbytes, sizeof(secretbytes));
 537                         md5_append(&md5, buf, len);
 538                         md5_finish(&md5, hash);
 539
 540                         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 541                                 secretbytes[i] ^= 0x36;
 542                                 secretbytes[i] ^= 0x5c;
 543                         }
 544
 545                         md5_init(&md5);
 546                         md5_append(&md5, secretbytes, sizeof(secretbytes));
 547                         md5_append(&md5, hash, 16);
 548                         md5_finish(&md5, hash);
 549
 550                         rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
 551                 }
 552         }
 553
 554         if (rep->msg_type == DHCPV6_MSG_RECONF && !rcauth_ok)
 555                 return false;
 556
 557         return clientid_ok && (serverid_ok || server_id_len == 0);
 558 }
 559
 560
 561 int dhcpv6_poll_reconfigure(void)
 562 {
 563         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
 564         if (ret != -1)
 565                 ret = dhcpv6_request(ret);
 566
 567         return ret;
 568 }
 569
 570
 571 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
 572                 const void *opt, const void *end)
 573 {
 574         // TODO: should verify the reconfigure message
 575         uint16_t otype, olen;
 576         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
 577         dhcpv6_for_each_option(opt, end, otype, olen, odata)
 578                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
 579                                 odata[0] == DHCPV6_MSG_RENEW ||
 580                                 odata[0] == DHCPV6_MSG_INFO_REQ))
 581                         msg = odata[0];
 582
 583         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
 584         return msg;
 585 }
 586
 587
 588 // Collect all advertised servers
 589 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
 590                 const void *opt, const void *end)
 591 {
 592         uint16_t olen, otype;
 593         uint8_t *odata, pref = 0;
 594         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}, NULL, NULL, 0, 0};
 595         bool have_na = false;
 596         int have_pd = 0;
 597
 598         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 599                 if (orig == DHCPV6_MSG_SOLICIT &&
 600                                 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
 601                                 olen > sizeof(struct dhcpv6_ia_hdr)) {
 602                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 603                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 604                 }
 605
 606                 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
 607                         memcpy(cand.duid, odata, olen);
 608                         cand.duid_len = olen;
 609                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 610                         int error = ((int)odata[0] << 8 | (int)odata[1]);
 611
 612                         switch (error) {
 613                         case DHCPV6_NoPrefixAvail:
 614                                 // Status code on global level
 615                                 if (pd_mode == IA_MODE_FORCE)
 616                                         return -1;
 617                                 cand.preference -= 2000;
 618                                 break;
 619
 620                         case DHCPV6_NoAddrsAvail:
 621                                 // Status code on global level
 622                                 if (na_mode == IA_MODE_FORCE)
 623                                         return -1;
 624                                 break;
 625
 626                         default :
 627                                 break;
 628                         }
 629                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
 630                                 cand.preference >= 0) {
 631                         cand.preference = pref = odata[0];
 632                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
 633                         cand.wants_reconfigure = true;
 634                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
 635                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 636                         uint8_t *oend = odata + olen, *d;
 637                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
 638                                 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
 639                                                 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
 640                                         struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
 641                                         have_pd = p->prefix;
 642                                 }
 643                         }
 644                 } else if (otype == DHCPV6_OPT_IA_NA) {
 645                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 646                         uint8_t *oend = odata + olen, *d;
 647                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
 648                                 if (otype == DHCPV6_OPT_IA_ADDR)
 649                                         have_na = true;
 650                 }
 651         }
 652
 653         if ((!have_na && na_mode == IA_MODE_FORCE) ||
 654                         (!have_pd && pd_mode == IA_MODE_FORCE))
 655                 return -1;
 656
 657         if (na_mode != IA_MODE_NONE && !have_na) {
 658                 cand.has_noaddravail = true;
 659                 cand.preference -= 1000;
 660         }
 661
 662         if (pd_mode != IA_MODE_NONE) {
 663                 if (have_pd)
 664                         cand.preference += 2000 + (128 - have_pd);
 665                 else
 666                         cand.preference -= 2000;
 667         }
 668
 669         if (cand.duid_len > 0) {
 670                 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
 671                 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
 672                 odhcp6c_add_state(STATE_SERVER_CAND, &cand, sizeof(cand));
 673         }
 674
 675         if (orig == DHCPV6_MSG_SOLICIT) {
 676                 odhcp6c_clear_state(STATE_IA_NA);
 677                 odhcp6c_clear_state(STATE_IA_PD);
 678         }
 679
 680         return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
 681 }
 682
 683
 684 static int dhcpv6_commit_advert(void)
 685 {
 686         size_t cand_len;
 687         struct dhcpv6_server_cand *c = NULL, *cand =
 688                         odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
 689
 690         bool retry = false;
 691         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
 692                 if (cand[i].has_noaddravail)
 693                         retry = true; // We want to try again
 694
 695                 if (!c || c->preference < cand[i].preference)
 696                         c = &cand[i];
 697         }
 698
 699         if (retry && na_mode == IA_MODE_TRY) {
 700                 // We give it a second try without the IA_NA
 701                 na_mode = IA_MODE_NONE;
 702                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
 703         }
 704
 705         if (c) {
 706                 uint16_t hdr[2] = {htons(DHCPV6_OPT_SERVERID),
 707                                 htons(c->duid_len)};
 708                 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
 709                 odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len);
 710                 accept_reconfig = c->wants_reconfigure;
 711                 if (c->ia_na_len)
 712                         odhcp6c_add_state(STATE_IA_NA, c->ia_na, c->ia_na_len);
 713                 if (c->ia_pd_len)
 714                         odhcp6c_add_state(STATE_IA_PD, c->ia_pd, c->ia_pd_len);
 715         }
 716
 717         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
 718                 free(cand[i].ia_na);
 719                 free(cand[i].ia_pd);
 720         }
 721         odhcp6c_clear_state(STATE_SERVER_CAND);
 722
 723         if (!c)
 724                 return -1;
 725         else if ((request_prefix && c->ia_pd_len) || (na_mode != IA_MODE_NONE && c->ia_na_len))
 726                 return DHCPV6_STATEFUL;
 727         else
 728                 return DHCPV6_STATELESS;
 729 }
 730
 731
 732 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
 733                 const void *opt, const void *end)
 734 {
 735         dhcpv6_handle_advert(orig, rc, opt, end);
 736         if (dhcpv6_commit_advert() < 0) {
 737                 dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
 738                 return -1;
 739         }
 740
 741         return dhcpv6_handle_reply(orig, rc, opt, end);
 742 }
 743
 744
 745 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
 746                 const void *opt, const void *end)
 747 {
 748         uint8_t *odata;
 749         uint16_t otype, olen;
 750         uint32_t refresh = UINT32_MAX;
 751         int ret = 1;
 752         bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
 753
 754         odhcp6c_expire();
 755
 756         if (orig == DHCPV6_MSG_UNKNOWN) {
 757                 static time_t last_update = 0;
 758                 time_t now = odhcp6c_get_milli_time() / 1000;
 759
 760                 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
 761                 last_update = now;
 762
 763                 t1 -= elapsed;
 764                 t2 -= elapsed;
 765                 t3 -= elapsed;
 766
 767                 if (t1 < 0)
 768                         t1 = 0;
 769
 770                 if (t2 < 0)
 771                         t2 = 0;
 772
 773                 if (t3 < 0)
 774                         t3 = 0;
 775         }
 776
 777         if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
 778                 // Delete NA and PD we have in the state from the Advert
 779                 odhcp6c_clear_state(STATE_IA_NA);
 780                 odhcp6c_clear_state(STATE_IA_PD);
 781         }
 782
 783         if (opt) {
 784                 odhcp6c_clear_state(STATE_DNS);
 785                 odhcp6c_clear_state(STATE_SEARCH);
 786                 odhcp6c_clear_state(STATE_SNTP_IP);
 787                 odhcp6c_clear_state(STATE_SNTP_FQDN);
 788                 odhcp6c_clear_state(STATE_SIP_IP);
 789                 odhcp6c_clear_state(STATE_SIP_FQDN);
 790                 odhcp6c_clear_state(STATE_AFTR_NAME);
 791         }
 792
 793         // Parse and find all matching IAs
 794         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 795                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
 796                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
 797                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 798
 799                         // Test ID
 800                         if (ia_hdr->iaid != 1)
 801                                 continue;
 802
 803                         uint16_t code = DHCPV6_Success;
 804                         uint16_t stype, slen;
 805                         uint8_t *sdata;
 806                         // Get and handle status code
 807                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
 808                                         stype, slen, sdata) {
 809                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
 810                                         uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
 811                                         uint16_t mlen = (slen > 2) ? slen - 2 : 0;
 812
 813                                         code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
 814
 815                                         if (code == DHCPV6_Success)
 816                                                 continue;
 817
 818                                         dhcpv6_handle_ia_status_code(orig, ia_hdr,
 819                                                 code, mdata, mlen, handled_status_codes, &ret);
 820
 821
 822                                         if (ret > 0)
 823                                                 return ret;
 824                                         break;
 825                                 }
 826                         }
 827
 828                         if (code != DHCPV6_Success)
 829                                 continue;
 830
 831                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 832                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 833                         uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
 834                         uint16_t mlen = (olen > 2) ? olen - 2 : 0;
 835                         uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
 836
 837                         dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
 838                 }
 839                 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
 840                         if (olen % 16 == 0)
 841                                 odhcp6c_add_state(STATE_DNS, odata, olen);
 842                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
 843                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
 844                 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
 845                         uint16_t stype, slen;
 846                         uint8_t *sdata;
 847                         // Test status and bail if error
 848                         dhcpv6_for_each_option(odata, odata + olen,
 849                                         stype, slen, sdata) {
 850                                 if (slen == 16 && (stype == NTP_MC_ADDR ||
 851                                                 stype == NTP_SRV_ADDR))
 852                                         odhcp6c_add_state(STATE_SNTP_IP,
 853                                                         sdata, slen);
 854                                 else if (slen > 0 && stype == NTP_SRV_FQDN)
 855                                         odhcp6c_add_state(STATE_SNTP_FQDN,
 856                                                         sdata, slen);
 857                         }
 858                 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
 859                         if (olen == 16)
 860                                 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
 861                 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
 862                         odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
 863                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
 864                         refresh = ntohl(*((uint32_t*)odata));
 865                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 866                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 867                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 868                         if (r->protocol == 3 && r->algorithm == 1 &&
 869                                         r->reconf_type == 1)
 870                                 memcpy(reconf_key, r->key, sizeof(r->key));
 871                 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
 872                         size_t cur_len;
 873                         odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
 874                         if (cur_len == 0)
 875                                 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
 876                 } else if (otype != DHCPV6_OPT_CLIENTID &&
 877                                 otype != DHCPV6_OPT_SERVERID) {
 878                         odhcp6c_add_state(STATE_CUSTOM_OPTS,
 879                                         &odata[-4], olen + 4);
 880                 }
 881         }
 882
 883         if (orig != DHCPV6_MSG_INFO_REQ) {
 884                 // Update refresh timers if no fatal status code was received
 885                 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
 886                         switch (orig) {
 887                         case DHCPV6_MSG_RENEW:
 888                                 // Send further renews if T1 is not set
 889                                 if (!t1)
 890                                         ret = -1;
 891                                 break;
 892                         case DHCPV6_MSG_REBIND:
 893                                 // Send further rebinds if T1 and T2 is not set
 894                                 if (!t1 && !t2)
 895                                         ret = -1;
 896                                 break;
 897
 898                         default :
 899                                 break;
 900                         }
 901                 }
 902         }
 903         else if (ret > 0)
 904                 t1 = refresh;
 905
 906         return ret;
 907 }
 908
 909
 910 static int dhcpv6_parse_ia(void *opt, void *end)
 911 {
 912         struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
 913         int parsed_ia = 0;
 914         uint32_t t1, t2;
 915         uint16_t otype, olen;
 916         uint8_t *odata;
 917
 918         t1 = ntohl(ia_hdr->t1);
 919         t2 = ntohl(ia_hdr->t2);
 920
 921         if (t1 > t2)
 922                 return 0;
 923
 924         // Update address IA
 925         dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
 926                 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
 927                                 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
 928
 929                 if (otype == DHCPV6_OPT_IA_PREFIX) {
 930                         struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
 931                         if (olen + 4U < sizeof(*prefix))
 932                                 continue;
 933
 934                         entry.valid = ntohl(prefix->valid);
 935                         entry.preferred = ntohl(prefix->preferred);
 936
 937                         if (entry.preferred > entry.valid)
 938                                 continue;
 939
 940                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
 941                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
 942                         if (entry.t1 > entry.t2)
 943                                 entry.t1 = entry.t2;
 944
 945                         entry.length = prefix->prefix;
 946                         entry.target = prefix->addr;
 947                         uint16_t stype, slen;
 948                         uint8_t *sdata;
 949
 950 #ifdef EXT_PREFIX_CLASS
 951                         // Find prefix class, if any
 952                         dhcpv6_for_each_option(&prefix[1], odata + olen,
 953                                         stype, slen, sdata)
 954                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
 955                                         entry.class = sdata[0] << 8 | sdata[1];
 956 #endif
 957
 958                         // Parse PD-exclude
 959                         bool ok = true;
 960                         dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
 961                                         odata + olen, stype, slen, sdata) {
 962                                 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
 963                                         continue;
 964
 965                                 uint8_t elen = sdata[0];
 966                                 if (elen > 64)
 967                                         elen = 64;
 968
 969                                 if (elen <= 32 || elen <= entry.length) {
 970                                         ok = false;
 971                                         continue;
 972                                 }
 973
 974
 975                                 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
 976                                 if (slen <= bytes) {
 977                                         ok = false;
 978                                         continue;
 979                                 }
 980
 981                                 uint32_t exclude = 0;
 982                                 do {
 983                                         exclude = exclude << 8 | sdata[bytes];
 984                                 } while (--bytes);
 985
 986                                 exclude >>= 8 - ((elen - entry.length) % 8);
 987                                 exclude <<= 64 - elen;
 988
 989                                 // Abusing router & priority fields for exclusion
 990                                 entry.router = entry.target;
 991                                 entry.router.s6_addr32[1] |= htonl(exclude);
 992                                 entry.priority = elen;
 993                         }
 994
 995                         if (ok) {
 996                                 odhcp6c_update_entry(STATE_IA_PD, &entry);
 997                                 parsed_ia++;
 998                         }
 999
1000                         entry.priority = 0;
1001                         memset(&entry.router, 0, sizeof(entry.router));
1002                 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1003                         struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1004                         if (olen + 4U < sizeof(*addr))
1005                                 continue;
1006
1007                         entry.preferred = ntohl(addr->preferred);
1008                         entry.valid = ntohl(addr->valid);
1009
1010                         if (entry.preferred > entry.valid)
1011                                 continue;
1012
1013                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1014                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1015                         if (entry.t1 > entry.t2)
1016                                 entry.t1 = entry.t2;
1017
1018                         entry.length = 128;
1019                         entry.target = addr->addr;
1020
1021 #ifdef EXT_PREFIX_CLASS
1022                         uint16_t stype, slen;
1023                         uint8_t *sdata;
1024                         // Find prefix class, if any
1025                         dhcpv6_for_each_option(&addr[1], odata + olen,
1026                                         stype, slen, sdata)
1027                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1028                                         entry.class = sdata[0] << 8 | sdata[1];
1029 #endif
1030
1031                         odhcp6c_update_entry(STATE_IA_NA, &entry);
1032                         parsed_ia++;
1033                 }
1034         }
1035         return parsed_ia;
1036 }
1037
1038
1039 static int dhcpv6_calc_refresh_timers(void)
1040 {
1041         struct odhcp6c_entry *e;
1042         size_t ia_na_entries, ia_pd_entries, i;
1043         int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1044
1045         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1046         ia_na_entries /= sizeof(*e);
1047         for (i = 0; i < ia_na_entries; i++) {
1048                 if (e[i].t1 < l_t1)
1049                         l_t1 = e[i].t1;
1050
1051                 if (e[i].t2 < l_t2)
1052                         l_t2 = e[i].t2;
1053
1054                 if (e[i].valid > l_t3)
1055                         l_t3 = e[i].valid;
1056         }
1057
1058         e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1059         ia_pd_entries /= sizeof(*e);
1060         for (i = 0; i < ia_pd_entries; i++) {
1061                 if (e[i].t1 < l_t1)
1062                         l_t1 = e[i].t1;
1063
1064                 if (e[i].t2 < l_t2)
1065                         l_t2 = e[i].t2;
1066
1067                 if (e[i].valid > l_t3)
1068                         l_t3 = e[i].valid;
1069         }
1070
1071         if (ia_pd_entries || ia_na_entries) {
1072                 t1 = l_t1;
1073                 t2 = l_t2;
1074                 t3 = l_t3;
1075         }
1076
1077         return (int)(ia_pd_entries + ia_na_entries);
1078 }
1079
1080
1081 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1082                 const void *status_msg, const int len)
1083 {
1084         uint8_t buf[len + 3];
1085
1086         memset(buf, 0, sizeof(buf));
1087         if (len) {
1088                 buf[0] = '(';
1089                 memcpy(&buf[1], status_msg, len);
1090                 buf[len + 1] = ')';
1091         }
1092
1093         syslog(LOG_WARNING, "Server returned %s status %i %s",
1094                 scope, code, buf);
1095 }
1096
1097
1098 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1099                 const uint16_t code, const void *status_msg, const int len,
1100                 int *ret)
1101 {
1102         dhcpv6_log_status_code(code, "message", status_msg, len);
1103
1104         switch (code) {
1105         case DHCPV6_UnspecFail:
1106                 // Generic failure
1107                 *ret = 0;
1108                 break;
1109
1110         case DHCPV6_UseMulticast:
1111                 // TODO handle multicast status code
1112                 break;
1113
1114         case DHCPV6_NoAddrsAvail:
1115         case DHCPV6_NoPrefixAvail:
1116                 if (orig == DHCPV6_MSG_REQUEST)
1117                         *ret = 0; // Failure
1118                 break;
1119
1120         default:
1121                 break;
1122         }
1123 }
1124
1125
1126 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1127                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1128                 const void *status_msg, const int len,
1129                 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1130 {
1131         dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1132                 "IA_NA" : "IA_PD", status_msg, len);
1133
1134         switch (code) {
1135         case DHCPV6_NoBinding:
1136                 switch (orig) {
1137                 case DHCPV6_MSG_RENEW:
1138                 case DHCPV6_MSG_REBIND:
1139                         if ((*ret > 0) && !handled_status_codes[code])
1140                                 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1141                         break;
1142
1143                 default:
1144                         break;
1145                 }
1146                 break;
1147
1148         case DHCPV6_NoAddrsAvail:
1149         case DHCPV6_NoPrefixAvail:
1150                 switch (orig) {
1151                 case DHCPV6_MSG_REQUEST:
1152                         if (*ret != 0)
1153                                 *ret = 0;
1154                         break;
1155                 default:
1156                         break;
1157                 }
1158                 break;
1159
1160         case DHCPV6_NotOnLink:
1161                 // TODO handle not onlink in case of confirm
1162                 break;
1163
1164         default:
1165                 break;
1166         }
1167 }