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 <arpa/inet.h>
  30 #include <netinet/in.h>
  31
  32 #include <net/if.h>
  33 #include <net/ethernet.h>
  34
  35 #include "odhcp6c.h"
  36 #include "md5.h"
  37
  38
  39 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
  40                 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
  41 #define DHCPV6_CLIENT_PORT 546
  42 #define DHCPV6_SERVER_PORT 547
  43 #define DHCPV6_DUID_LLADDR 3
  44 #define DHCPV6_REQ_DELAY 1
  45
  46
  47 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
  48                 const uint8_t transaction[3], enum dhcpv6_msg type,
  49                 const struct in6_addr *daddr);
  50
  51 static int dhcpv6_parse_ia(void *opt, void *end);
  52
  53 static int dhcpv6_calc_refresh_timers(void);
  54 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
  55                 const uint16_t code, const void *status_msg, const int len,
  56                 int *ret);
  57 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
  58                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
  59                 const void *status_msg, const int len,
  60                 bool handled_status_codes[_DHCPV6_Status_Max],
  61                 int *ret);
  62
  63 static reply_handler dhcpv6_handle_reply;
  64 static reply_handler dhcpv6_handle_advert;
  65 static reply_handler dhcpv6_handle_rebind_reply;
  66 static reply_handler dhcpv6_handle_reconfigure;
  67 static int dhcpv6_commit_advert(void);
  68
  69
  70
  71 // RFC 3315 - 5.5 Timeout and Delay values
  72 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
  73         [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
  74                         dhcpv6_handle_reconfigure, NULL},
  75         [DHCPV6_MSG_SOLICIT] = {true, 1, 3600, 0, "SOLICIT",
  76                         dhcpv6_handle_advert, dhcpv6_commit_advert},
  77         [DHCPV6_MSG_REQUEST] = {true, 1, 30, 10, "REQUEST",
  78                         dhcpv6_handle_reply, NULL},
  79         [DHCPV6_MSG_RENEW] = {false, 10, 600, 0, "RENEW",
  80                         dhcpv6_handle_reply, NULL},
  81         [DHCPV6_MSG_REBIND] = {false, 10, 600, 0, "REBIND",
  82                         dhcpv6_handle_rebind_reply, NULL},
  83         [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
  84         [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
  85         [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, 0, "INFOREQ",
  86                         dhcpv6_handle_reply, NULL},
  87 };
  88
  89
  90 // Sockets
  91 static int sock = -1;
  92 static int ifindex = -1;
  93 static int64_t t1 = 0, t2 = 0, t3 = 0;
  94
  95 // IA states
  96 static int request_prefix = -1;
  97 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
  98 static bool accept_reconfig = false;
  99 // Server unicast address
 100 static struct in6_addr server_addr = IN6ADDR_ANY_INIT;
 101
 102 // Reconfigure key
 103 static uint8_t reconf_key[16];
 104
 105
 106 int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout)
 107 {
 108         request_prefix = request_pd;
 109         dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
 110
 111         sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
 112         if (sock < 0)
 113                 return -1;
 114
 115         // Detect interface
 116         struct ifreq ifr;
 117         strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 118         if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
 119                 return -1;
 120         ifindex = ifr.ifr_ifindex;
 121
 122         // Create client DUID
 123         size_t client_id_len;
 124         odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 125         if (client_id_len == 0) {
 126                 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
 127                                 DHCPV6_DUID_LLADDR, 0, 1};
 128
 129                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
 130                         memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
 131
 132                 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
 133                 struct ifreq ifs[100], *ifp, *ifend;
 134                 struct ifconf ifc;
 135                 ifc.ifc_req = ifs;
 136                 ifc.ifc_len = sizeof(ifs);
 137
 138                 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
 139                                 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
 140                         // If our interface doesn't have an address...
 141                         ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
 142                         for (ifp = ifc.ifc_req; ifp < ifend &&
 143                                         !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
 144                                 memcpy(ifr.ifr_name, ifp->ifr_name,
 145                                                 sizeof(ifr.ifr_name));
 146                                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
 147                                         continue;
 148
 149                                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
 150                                                 ETHER_ADDR_LEN);
 151                         }
 152                 }
 153
 154                 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
 155         }
 156
 157         // Create ORO
 158         uint16_t oro[] = {
 159                         htons(DHCPV6_OPT_SIP_SERVER_D),
 160                         htons(DHCPV6_OPT_SIP_SERVER_A),
 161                         htons(DHCPV6_OPT_DNS_SERVERS),
 162                         htons(DHCPV6_OPT_DNS_DOMAIN),
 163                         htons(DHCPV6_OPT_UNICAST),
 164                         htons(DHCPV6_OPT_NTP_SERVER),
 165                         htons(DHCPV6_OPT_AFTR_NAME),
 166                         htons(DHCPV6_OPT_PD_EXCLUDE),
 167 #ifdef EXT_PREFIX_CLASS
 168                         htons(DHCPV6_OPT_PREFIX_CLASS),
 169 #endif
 170         };
 171         odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
 172
 173         // Configure IPv6-options
 174         int val = 1;
 175         setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
 176         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 177         setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
 178         val = 0;
 179         setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
 180         setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
 181
 182         struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
 183                 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
 184         if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
 185                 return -1;
 186
 187         return 0;
 188 }
 189
 190
 191 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
 192 {
 193         na_mode = na;
 194         pd_mode = pd;
 195 }
 196
 197
 198 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
 199 {
 200         // Build FQDN
 201         char fqdn_buf[256];
 202         gethostname(fqdn_buf, sizeof(fqdn_buf));
 203         struct {
 204                 uint16_t type;
 205                 uint16_t len;
 206                 uint8_t flags;
 207                 uint8_t data[256];
 208         } fqdn;
 209         size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
 210                         sizeof(fqdn.data), NULL, NULL);
 211         fqdn.type = htons(DHCPV6_OPT_FQDN);
 212         fqdn.len = htons(fqdn_len - 4);
 213         fqdn.flags = 0;
 214
 215
 216         // Build Client ID
 217         size_t cl_id_len;
 218         void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
 219
 220         // Get Server ID
 221         size_t srv_id_len;
 222         void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
 223
 224         // Build IA_PDs
 225         size_t ia_pd_entries, ia_pd_len = 0;
 226         struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
 227         ia_pd_entries /= sizeof(*e);
 228         struct dhcpv6_ia_hdr hdr_ia_pd = {
 229                 htons(DHCPV6_OPT_IA_PD),
 230                 htons(sizeof(hdr_ia_pd) - 4),
 231                 1, 0, 0
 232         };
 233
 234
 235         uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
 236         for (size_t i = 0; i < ia_pd_entries; ++i) {
 237                 uint8_t ex_len = 0;
 238                 if (e[i].priority > 0)
 239                         ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
 240
 241                 struct dhcpv6_ia_prefix p = {
 242                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 243                         .len = htons(sizeof(p) - 4U + ex_len),
 244                         .prefix = e[i].length,
 245                         .addr = e[i].target
 246                 };
 247
 248                 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
 249                 ia_pd_len += sizeof(p);
 250
 251                 if (ex_len) {
 252                         ia_pd[ia_pd_len++] = 0;
 253                         ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
 254                         ia_pd[ia_pd_len++] = 0;
 255                         ia_pd[ia_pd_len++] = ex_len - 4;
 256                         ia_pd[ia_pd_len++] = e[i].priority;
 257
 258                         uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
 259                         excl >>= (64 - e[i].priority);
 260                         excl <<= 8 - ((e[i].priority - e[i].length) % 8);
 261
 262                         for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
 263                                 ia_pd[ia_pd_len + i] = excl & 0xff;
 264                         ia_pd_len += ex_len - 5;
 265                 }
 266         }
 267
 268         struct dhcpv6_ia_prefix pref = {
 269                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 270                 .len = htons(25), .prefix = request_prefix
 271         };
 272         if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
 273                 ia_pd = (uint8_t*)&pref;
 274                 ia_pd_len = sizeof(pref);
 275         }
 276         hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
 277
 278         // Build IA_NAs
 279         size_t ia_na_entries, ia_na_len = 0;
 280         void *ia_na = NULL;
 281         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
 282         ia_na_entries /= sizeof(*e);
 283
 284         struct dhcpv6_ia_hdr hdr_ia_na = {
 285                 htons(DHCPV6_OPT_IA_NA),
 286                 htons(sizeof(hdr_ia_na) - 4),
 287                 1, 0, 0
 288         };
 289
 290         struct dhcpv6_ia_addr pa[ia_na_entries];
 291         for (size_t i = 0; i < ia_na_entries; ++i) {
 292                 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
 293                 pa[i].len = htons(sizeof(pa[i]) - 4U);
 294                 pa[i].addr = e[i].target;
 295                 pa[i].preferred = 0;
 296                 pa[i].valid = 0;
 297         }
 298
 299         ia_na = pa;
 300         ia_na_len = sizeof(pa);
 301         hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
 302
 303         // Reconfigure Accept
 304         struct {
 305                 uint16_t type;
 306                 uint16_t length;
 307         } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
 308
 309         // Request Information Refresh
 310         uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
 311
 312         // Prepare Header
 313         size_t oro_len;
 314         void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
 315         struct {
 316                 uint8_t type;
 317                 uint8_t trid[3];
 318                 uint16_t elapsed_type;
 319                 uint16_t elapsed_len;
 320                 uint16_t elapsed_value;
 321                 uint16_t oro_type;
 322                 uint16_t oro_len;
 323         } hdr = {
 324                 type, {trid[0], trid[1], trid[2]},
 325                 htons(DHCPV6_OPT_ELAPSED), htons(2),
 326                         htons((ecs > 0xffff) ? 0xffff : ecs),
 327                 htons(DHCPV6_OPT_ORO), htons(oro_len),
 328         };
 329
 330         struct iovec iov[] = {
 331                 {&hdr, sizeof(hdr)},
 332                 {oro, oro_len},
 333                 {&oro_refresh, 0},
 334                 {cl_id, cl_id_len},
 335                 {srv_id, srv_id_len},
 336                 {&reconf_accept, sizeof(reconf_accept)},
 337                 {&fqdn, fqdn_len},
 338                 {&hdr_ia_na, sizeof(hdr_ia_na)},
 339                 {ia_na, ia_na_len},
 340                 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
 341                 {ia_pd, ia_pd_len},
 342         };
 343
 344         size_t cnt = ARRAY_SIZE(iov);
 345         if (type == DHCPV6_MSG_INFO_REQ) {
 346                 cnt = 5;
 347                 iov[2].iov_len = sizeof(oro_refresh);
 348                 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
 349         } else if (!request_prefix) {
 350                 cnt = 9;
 351         }
 352
 353         // Disable IAs if not used
 354         if (type != DHCPV6_MSG_SOLICIT) {
 355                 iov[5].iov_len = 0;
 356                 if (ia_na_len == 0)
 357                         iov[7].iov_len = 0;
 358                 if (ia_pd_len == 0)
 359                         iov[9].iov_len = 0;
 360         }
 361
 362         if (na_mode == IA_MODE_NONE)
 363                 iov[7].iov_len = 0;
 364
 365         struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
 366                 0, ALL_DHCPV6_RELAYS, ifindex};
 367         struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
 368
 369         switch (type) {
 370         case DHCPV6_MSG_REQUEST:
 371         case DHCPV6_MSG_RENEW:
 372         case DHCPV6_MSG_RELEASE:
 373         case DHCPV6_MSG_DECLINE:
 374                 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
 375                         odhcp6c_addr_in_scope(&server_addr)) {
 376                         srv.sin6_addr = server_addr;
 377                         if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
 378                                 srv.sin6_scope_id = 0;
 379                 }
 380                 break;
 381         default:
 382                 break;
 383         }
 384
 385         if (sendmsg(sock, &msg, 0) < 0) {
 386                 char in6_str[INET6_ADDRSTRLEN];
 387
 388                 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
 389                         inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
 390                                 in6_str, sizeof(in6_str)), strerror(errno));
 391         }
 392 }
 393
 394
 395 static int64_t dhcpv6_rand_delay(int64_t time)
 396 {
 397         int random;
 398         odhcp6c_random(&random, sizeof(random));
 399         return (time * ((int64_t)random % 1000LL)) / 10000LL;
 400 }
 401
 402
 403 int dhcpv6_request(enum dhcpv6_msg type)
 404 {
 405         uint8_t rc = 0;
 406         uint64_t timeout = UINT32_MAX;
 407         struct dhcpv6_retx *retx = &dhcpv6_retx[type];
 408
 409         if (retx->delay) {
 410                 struct timespec ts = {0, 0};
 411                 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
 412                 nanosleep(&ts, NULL);
 413         }
 414
 415         if (type == DHCPV6_MSG_UNKNOWN)
 416                 timeout = t1;
 417         else if (type == DHCPV6_MSG_RENEW)
 418                 timeout = (t2 > t1) ? t2 - t1 : 0;
 419         else if (type == DHCPV6_MSG_REBIND)
 420                 timeout = (t3 > t2) ? t3 - t2 : 0;
 421
 422         if (timeout == 0)
 423                 return -1;
 424
 425         syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
 426                         retx->name, (unsigned long long)timeout, retx->max_rc);
 427
 428         uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
 429
 430         // Generate transaction ID
 431         uint8_t trid[3] = {0, 0, 0};
 432         if (type != DHCPV6_MSG_UNKNOWN)
 433                 odhcp6c_random(trid, sizeof(trid));
 434         ssize_t len = -1;
 435         int64_t rto = 0;
 436
 437         do {
 438                 if (rto == 0) {
 439                         int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 440
 441                         // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
 442                         while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
 443                                 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 444
 445                         rto = (retx->init_timeo * 1000 + delay);
 446                 }
 447                 else
 448                         rto = (2 * rto + dhcpv6_rand_delay(rto));
 449
 450                 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
 451                         rto = retx->max_timeo * 1000 +
 452                                 dhcpv6_rand_delay(retx->max_timeo * 1000);
 453
 454                 // Calculate end for this round and elapsed time
 455                 uint64_t round_end = round_start + rto;
 456                 elapsed = round_start - start;
 457
 458                 // Don't wait too long
 459                 if (round_end - start > timeout * 1000)
 460                         round_end = timeout * 1000 + start;
 461
 462                 // Built and send package
 463                 if (type != DHCPV6_MSG_UNKNOWN) {
 464                         if (type != DHCPV6_MSG_SOLICIT)
 465                                 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
 466                                                 retx->name, (unsigned long long)elapsed, rc);
 467                         dhcpv6_send(type, trid, elapsed / 10);
 468                         rc++;
 469                 }
 470
 471                 // Receive rounds
 472                 for (; len < 0 && (round_start < round_end);
 473                                 round_start = odhcp6c_get_milli_time()) {
 474                         uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 475                         struct iovec iov = {buf, sizeof(buf)};
 476                         struct msghdr msg = {NULL, 0, &iov, 1,
 477                                         cmsg_buf, sizeof(cmsg_buf), 0};
 478                         struct in6_pktinfo *pktinfo = NULL;
 479
 480                         // Check for pending signal
 481                         if (odhcp6c_signal_process())
 482                                 return -1;
 483
 484                         // Set timeout for receiving
 485                         uint64_t t = round_end - round_start;
 486                         struct timeval timeout = {t / 1000, (t % 1000) * 1000};
 487                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
 488                                         &timeout, sizeof(timeout));
 489
 490                         // Receive cycle
 491                         len = recvmsg(sock, &msg, 0);
 492                         if (len < 0)
 493                                 continue;
 494
 495                         for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
 496                                 ch = CMSG_NXTHDR(&msg, ch)) {
 497                                 if (ch->cmsg_level == SOL_IPV6 &&
 498                                         ch->cmsg_type == IPV6_PKTINFO) {
 499                                         pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
 500                                         break;
 501                                 }
 502                         }
 503
 504                         if (pktinfo == NULL) {
 505                                 len = -1;
 506                                 continue;
 507                         }
 508
 509                         if (!dhcpv6_response_is_valid(buf, len, trid,
 510                                                         type, &pktinfo->ipi6_addr)) {
 511                                 len = -1;
 512                                 continue;
 513                         }
 514
 515                         uint8_t *opt = &buf[4];
 516                         uint8_t *opt_end = opt + len - 4;
 517
 518                         round_start = odhcp6c_get_milli_time();
 519                         elapsed = round_start - start;
 520                         syslog(LOG_NOTICE, "Got a valid reply after "
 521                                         "%llums", (unsigned long long)elapsed);
 522
 523                         if (retx->handler_reply)
 524                                 len = retx->handler_reply(type, rc, opt, opt_end);
 525
 526                         if (len > 0 && round_end - round_start > 1000)
 527                                 round_end = 1000 + round_start;
 528                 }
 529
 530                 // Allow
 531                 if (retx->handler_finish)
 532                         len = retx->handler_finish();
 533         } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
 534
 535         return len;
 536 }
 537
 538 // Message validation checks according to RFC3315 chapter 15
 539 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
 540                 const uint8_t transaction[3], enum dhcpv6_msg type,
 541                 const struct in6_addr *daddr)
 542 {
 543         const struct dhcpv6_header *rep = buf;
 544         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
 545                         transaction, sizeof(rep->tr_id)))
 546                 return false; // Invalid reply
 547
 548         if (type == DHCPV6_MSG_SOLICIT) {
 549                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
 550                                 rep->msg_type != DHCPV6_MSG_REPLY)
 551                         return false;
 552         } else if (type == DHCPV6_MSG_UNKNOWN) {
 553                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
 554                         return false;
 555         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
 556                 return false;
 557         }
 558
 559         uint8_t *end = ((uint8_t*)buf) + len, *odata,
 560                 rcmsg = DHCPV6_MSG_UNKNOWN;
 561         uint16_t otype, olen;
 562         bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
 563                 ia_present = false, options_valid = true;
 564
 565         size_t client_id_len, server_id_len;
 566         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 567         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
 568
 569         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
 570                 if (otype == DHCPV6_OPT_CLIENTID) {
 571                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
 572                                         &odata[-4], client_id, client_id_len);
 573                 } else if (otype == DHCPV6_OPT_SERVERID) {
 574                         if (server_id_len)
 575                                 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
 576                                                 &odata[-4], server_id, server_id_len);
 577                         else
 578                                 serverid_ok = true;
 579                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 580                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 581                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 582                         if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
 583                                 continue;
 584
 585                         md5_state_t md5;
 586                         uint8_t serverhash[16], secretbytes[16], hash[16];
 587                         memcpy(serverhash, r->key, sizeof(serverhash));
 588                         memset(r->key, 0, sizeof(r->key));
 589                         memcpy(secretbytes, reconf_key, sizeof(secretbytes));
 590
 591                         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 592                                 secretbytes[i] ^= 0x36;
 593
 594                         md5_init(&md5);
 595                         md5_append(&md5, secretbytes, sizeof(secretbytes));
 596                         md5_append(&md5, buf, len);
 597                         md5_finish(&md5, hash);
 598
 599                         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 600                                 secretbytes[i] ^= 0x36;
 601                                 secretbytes[i] ^= 0x5c;
 602                         }
 603
 604                         md5_init(&md5);
 605                         md5_append(&md5, secretbytes, sizeof(secretbytes));
 606                         md5_append(&md5, hash, 16);
 607                         md5_finish(&md5, hash);
 608
 609                         rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
 610                 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
 611                         rcmsg = odata[0];
 612                 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
 613                         ia_present = true;
 614                         if (olen < sizeof(struct dhcpv6_ia_hdr))
 615                                 options_valid = false;
 616                 }
 617                 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
 618                                 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
 619                         // Options are not allowed on global level
 620                         options_valid = false;
 621                 }
 622         }
 623
 624         if (!options_valid)
 625                 return false;
 626
 627         if (type == DHCPV6_MSG_INFO_REQ && ia_present)
 628                 return false;
 629
 630         if (rep->msg_type == DHCPV6_MSG_RECONF) {
 631                 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
 632                         (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
 633                         !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
 634                         return false;
 635         }
 636
 637         return clientid_ok && serverid_ok;
 638 }
 639
 640
 641 int dhcpv6_poll_reconfigure(void)
 642 {
 643         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
 644         if (ret != -1)
 645                 ret = dhcpv6_request(ret);
 646
 647         return ret;
 648 }
 649
 650
 651 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
 652                 const void *opt, const void *end)
 653 {
 654         uint16_t otype, olen;
 655         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
 656         dhcpv6_for_each_option(opt, end, otype, olen, odata)
 657                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
 658                                 odata[0] == DHCPV6_MSG_RENEW ||
 659                                 odata[0] == DHCPV6_MSG_INFO_REQ))
 660                         msg = odata[0];
 661
 662         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
 663         return msg;
 664 }
 665
 666
 667 // Collect all advertised servers
 668 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
 669                 const void *opt, const void *end)
 670 {
 671         uint16_t olen, otype;
 672         uint8_t *odata, pref = 0;
 673         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
 674                                         IN6ADDR_ANY_INIT, NULL, NULL, 0, 0};
 675         bool have_na = false;
 676         int have_pd = 0;
 677
 678         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 679                 if (orig == DHCPV6_MSG_SOLICIT &&
 680                                 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
 681                                 olen > sizeof(struct dhcpv6_ia_hdr)) {
 682                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 683                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 684                 }
 685
 686                 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
 687                         memcpy(cand.duid, odata, olen);
 688                         cand.duid_len = olen;
 689                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 690                         int error = ((int)odata[0] << 8 | (int)odata[1]);
 691
 692                         switch (error) {
 693                         case DHCPV6_NoPrefixAvail:
 694                                 // Status code on global level
 695                                 if (pd_mode == IA_MODE_FORCE)
 696                                         return -1;
 697                                 cand.preference -= 2000;
 698                                 break;
 699
 700                         case DHCPV6_NoAddrsAvail:
 701                                 // Status code on global level
 702                                 if (na_mode == IA_MODE_FORCE)
 703                                         return -1;
 704                                 break;
 705
 706                         default :
 707                                 break;
 708                         }
 709                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
 710                                 cand.preference >= 0) {
 711                         cand.preference = pref = odata[0];
 712                 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
 713                         cand.server_addr = *(struct in6_addr *)odata;
 714                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
 715                         cand.wants_reconfigure = true;
 716                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
 717                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 718                         uint8_t *oend = odata + olen, *d;
 719                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
 720                                 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
 721                                                 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
 722                                         struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
 723                                         have_pd = p->prefix;
 724                                 }
 725                         }
 726                 } else if (otype == DHCPV6_OPT_IA_NA) {
 727                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 728                         uint8_t *oend = odata + olen, *d;
 729                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
 730                                 if (otype == DHCPV6_OPT_IA_ADDR)
 731                                         have_na = true;
 732                 }
 733         }
 734
 735         if ((!have_na && na_mode == IA_MODE_FORCE) ||
 736                         (!have_pd && pd_mode == IA_MODE_FORCE))
 737                 return -1;
 738
 739         if (na_mode != IA_MODE_NONE && !have_na) {
 740                 cand.has_noaddravail = true;
 741                 cand.preference -= 1000;
 742         }
 743
 744         if (pd_mode != IA_MODE_NONE) {
 745                 if (have_pd)
 746                         cand.preference += 2000 + (128 - have_pd);
 747                 else
 748                         cand.preference -= 2000;
 749         }
 750
 751         if (cand.duid_len > 0) {
 752                 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
 753                 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
 754                 odhcp6c_add_state(STATE_SERVER_CAND, &cand, sizeof(cand));
 755         }
 756
 757         return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
 758 }
 759
 760
 761 static int dhcpv6_commit_advert(void)
 762 {
 763         size_t cand_len;
 764         struct dhcpv6_server_cand *c = NULL, *cand =
 765                         odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
 766
 767         bool retry = false;
 768         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
 769                 if (cand[i].has_noaddravail)
 770                         retry = true; // We want to try again
 771
 772                 if (!c || c->preference < cand[i].preference)
 773                         c = &cand[i];
 774         }
 775
 776         if (retry && na_mode == IA_MODE_TRY) {
 777                 // We give it a second try without the IA_NA
 778                 na_mode = IA_MODE_NONE;
 779                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
 780         }
 781
 782         if (c) {
 783                 uint16_t hdr[2] = {htons(DHCPV6_OPT_SERVERID),
 784                                 htons(c->duid_len)};
 785                 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
 786                 odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len);
 787                 accept_reconfig = c->wants_reconfigure;
 788                 server_addr = c->server_addr;
 789                 if (c->ia_na_len)
 790                         odhcp6c_add_state(STATE_IA_NA, c->ia_na, c->ia_na_len);
 791                 if (c->ia_pd_len)
 792                         odhcp6c_add_state(STATE_IA_PD, c->ia_pd, c->ia_pd_len);
 793         }
 794
 795         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
 796                 free(cand[i].ia_na);
 797                 free(cand[i].ia_pd);
 798         }
 799         odhcp6c_clear_state(STATE_SERVER_CAND);
 800
 801         if (!c)
 802                 return -1;
 803         else if ((request_prefix && c->ia_pd_len) || (na_mode != IA_MODE_NONE && c->ia_na_len))
 804                 return DHCPV6_STATEFUL;
 805         else
 806                 return DHCPV6_STATELESS;
 807 }
 808
 809
 810 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
 811                 const void *opt, const void *end)
 812 {
 813         dhcpv6_handle_advert(orig, rc, opt, end);
 814         if (dhcpv6_commit_advert() < 0)
 815                 return -1;
 816
 817         return dhcpv6_handle_reply(orig, rc, opt, end);
 818 }
 819
 820
 821 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
 822                 const void *opt, const void *end)
 823 {
 824         uint8_t *odata;
 825         uint16_t otype, olen;
 826         uint32_t refresh = UINT32_MAX;
 827         int ret = 1;
 828         bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
 829
 830         odhcp6c_expire();
 831
 832         if (orig == DHCPV6_MSG_UNKNOWN) {
 833                 static time_t last_update = 0;
 834                 time_t now = odhcp6c_get_milli_time() / 1000;
 835
 836                 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
 837                 last_update = now;
 838
 839                 t1 -= elapsed;
 840                 t2 -= elapsed;
 841                 t3 -= elapsed;
 842
 843                 if (t1 < 0)
 844                         t1 = 0;
 845
 846                 if (t2 < 0)
 847                         t2 = 0;
 848
 849                 if (t3 < 0)
 850                         t3 = 0;
 851         }
 852
 853         if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
 854                 // Delete NA and PD we have in the state from the Advert
 855                 odhcp6c_clear_state(STATE_IA_NA);
 856                 odhcp6c_clear_state(STATE_IA_PD);
 857         }
 858
 859         if (opt) {
 860                 odhcp6c_clear_state(STATE_DNS);
 861                 odhcp6c_clear_state(STATE_SEARCH);
 862                 odhcp6c_clear_state(STATE_SNTP_IP);
 863                 odhcp6c_clear_state(STATE_SNTP_FQDN);
 864                 odhcp6c_clear_state(STATE_SIP_IP);
 865                 odhcp6c_clear_state(STATE_SIP_FQDN);
 866                 odhcp6c_clear_state(STATE_AFTR_NAME);
 867         }
 868
 869         // Parse and find all matching IAs
 870         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 871                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
 872                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
 873                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 874
 875                         // Test ID
 876                         if (ia_hdr->iaid != 1)
 877                                 continue;
 878
 879                         uint16_t code = DHCPV6_Success;
 880                         uint16_t stype, slen;
 881                         uint8_t *sdata;
 882                         // Get and handle status code
 883                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
 884                                         stype, slen, sdata) {
 885                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
 886                                         uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
 887                                         uint16_t mlen = (slen > 2) ? slen - 2 : 0;
 888
 889                                         code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
 890
 891                                         if (code == DHCPV6_Success)
 892                                                 continue;
 893
 894                                         dhcpv6_handle_ia_status_code(orig, ia_hdr,
 895                                                 code, mdata, mlen, handled_status_codes, &ret);
 896
 897
 898                                         if (ret > 0)
 899                                                 return ret;
 900                                         break;
 901                                 }
 902                         }
 903
 904                         if (code != DHCPV6_Success)
 905                                 continue;
 906
 907                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 908                 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
 909                         server_addr = *(struct in6_addr *)odata;
 910                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 911                         uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
 912                         uint16_t mlen = (olen > 2) ? olen - 2 : 0;
 913                         uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
 914
 915                         dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
 916                 }
 917                 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
 918                         if (olen % 16 == 0)
 919                                 odhcp6c_add_state(STATE_DNS, odata, olen);
 920                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
 921                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
 922                 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
 923                         uint16_t stype, slen;
 924                         uint8_t *sdata;
 925                         // Test status and bail if error
 926                         dhcpv6_for_each_option(odata, odata + olen,
 927                                         stype, slen, sdata) {
 928                                 if (slen == 16 && (stype == NTP_MC_ADDR ||
 929                                                 stype == NTP_SRV_ADDR))
 930                                         odhcp6c_add_state(STATE_SNTP_IP,
 931                                                         sdata, slen);
 932                                 else if (slen > 0 && stype == NTP_SRV_FQDN)
 933                                         odhcp6c_add_state(STATE_SNTP_FQDN,
 934                                                         sdata, slen);
 935                         }
 936                 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
 937                         if (olen == 16)
 938                                 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
 939                 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
 940                         odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
 941                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
 942                         refresh = ntohl(*((uint32_t*)odata));
 943                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 944                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 945                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 946                         if (r->protocol == 3 && r->algorithm == 1 &&
 947                                         r->reconf_type == 1)
 948                                 memcpy(reconf_key, r->key, sizeof(r->key));
 949                 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
 950                         size_t cur_len;
 951                         odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
 952                         if (cur_len == 0)
 953                                 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
 954                 } else if (otype != DHCPV6_OPT_CLIENTID &&
 955                                 otype != DHCPV6_OPT_SERVERID) {
 956                         odhcp6c_add_state(STATE_CUSTOM_OPTS,
 957                                         &odata[-4], olen + 4);
 958                 }
 959         }
 960
 961         if (orig != DHCPV6_MSG_INFO_REQ) {
 962                 // Update refresh timers if no fatal status code was received
 963                 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
 964                         switch (orig) {
 965                         case DHCPV6_MSG_RENEW:
 966                                 // Send further renews if T1 is not set
 967                                 if (!t1)
 968                                         ret = -1;
 969                                 break;
 970                         case DHCPV6_MSG_REBIND:
 971                                 // Send further rebinds if T1 and T2 is not set
 972                                 if (!t1 && !t2)
 973                                         ret = -1;
 974                                 break;
 975
 976                         default :
 977                                 break;
 978                         }
 979                 }
 980         }
 981         else if (ret > 0)
 982                 t1 = refresh;
 983
 984         return ret;
 985 }
 986
 987
 988 static int dhcpv6_parse_ia(void *opt, void *end)
 989 {
 990         struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
 991         int parsed_ia = 0;
 992         uint32_t t1, t2;
 993         uint16_t otype, olen;
 994         uint8_t *odata;
 995
 996         t1 = ntohl(ia_hdr->t1);
 997         t2 = ntohl(ia_hdr->t2);
 998
 999         if (t1 > t2)
1000                 return 0;
1001
1002         // Update address IA
1003         dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1004                 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1005                                 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
1006
1007                 if (otype == DHCPV6_OPT_IA_PREFIX) {
1008                         struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1009                         if (olen + 4U < sizeof(*prefix))
1010                                 continue;
1011
1012                         entry.valid = ntohl(prefix->valid);
1013                         entry.preferred = ntohl(prefix->preferred);
1014
1015                         if (entry.preferred > entry.valid)
1016                                 continue;
1017
1018                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1019                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1020                         if (entry.t1 > entry.t2)
1021                                 entry.t1 = entry.t2;
1022
1023                         entry.length = prefix->prefix;
1024                         entry.target = prefix->addr;
1025                         uint16_t stype, slen;
1026                         uint8_t *sdata;
1027
1028 #ifdef EXT_PREFIX_CLASS
1029                         // Find prefix class, if any
1030                         dhcpv6_for_each_option(&prefix[1], odata + olen,
1031                                         stype, slen, sdata)
1032                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1033                                         entry.class = sdata[0] << 8 | sdata[1];
1034 #endif
1035
1036                         // Parse PD-exclude
1037                         bool ok = true;
1038                         dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1039                                         odata + olen, stype, slen, sdata) {
1040                                 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1041                                         continue;
1042
1043                                 uint8_t elen = sdata[0];
1044                                 if (elen > 64)
1045                                         elen = 64;
1046
1047                                 if (elen <= 32 || elen <= entry.length) {
1048                                         ok = false;
1049                                         continue;
1050                                 }
1051
1052
1053                                 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1054                                 if (slen <= bytes) {
1055                                         ok = false;
1056                                         continue;
1057                                 }
1058
1059                                 uint32_t exclude = 0;
1060                                 do {
1061                                         exclude = exclude << 8 | sdata[bytes];
1062                                 } while (--bytes);
1063
1064                                 exclude >>= 8 - ((elen - entry.length) % 8);
1065                                 exclude <<= 64 - elen;
1066
1067                                 // Abusing router & priority fields for exclusion
1068                                 entry.router = entry.target;
1069                                 entry.router.s6_addr32[1] |= htonl(exclude);
1070                                 entry.priority = elen;
1071                         }
1072
1073                         if (ok) {
1074                                 odhcp6c_update_entry(STATE_IA_PD, &entry);
1075                                 parsed_ia++;
1076                         }
1077
1078                         entry.priority = 0;
1079                         memset(&entry.router, 0, sizeof(entry.router));
1080                 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1081                         struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1082                         if (olen + 4U < sizeof(*addr))
1083                                 continue;
1084
1085                         entry.preferred = ntohl(addr->preferred);
1086                         entry.valid = ntohl(addr->valid);
1087
1088                         if (entry.preferred > entry.valid)
1089                                 continue;
1090
1091                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1092                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1093                         if (entry.t1 > entry.t2)
1094                                 entry.t1 = entry.t2;
1095
1096                         entry.length = 128;
1097                         entry.target = addr->addr;
1098
1099 #ifdef EXT_PREFIX_CLASS
1100                         uint16_t stype, slen;
1101                         uint8_t *sdata;
1102                         // Find prefix class, if any
1103                         dhcpv6_for_each_option(&addr[1], odata + olen,
1104                                         stype, slen, sdata)
1105                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1106                                         entry.class = sdata[0] << 8 | sdata[1];
1107 #endif
1108
1109                         odhcp6c_update_entry(STATE_IA_NA, &entry);
1110                         parsed_ia++;
1111                 }
1112         }
1113         return parsed_ia;
1114 }
1115
1116
1117 static int dhcpv6_calc_refresh_timers(void)
1118 {
1119         struct odhcp6c_entry *e;
1120         size_t ia_na_entries, ia_pd_entries, i;
1121         int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1122
1123         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1124         ia_na_entries /= sizeof(*e);
1125         for (i = 0; i < ia_na_entries; i++) {
1126                 if (e[i].t1 < l_t1)
1127                         l_t1 = e[i].t1;
1128
1129                 if (e[i].t2 < l_t2)
1130                         l_t2 = e[i].t2;
1131
1132                 if (e[i].valid > l_t3)
1133                         l_t3 = e[i].valid;
1134         }
1135
1136         e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1137         ia_pd_entries /= sizeof(*e);
1138         for (i = 0; i < ia_pd_entries; i++) {
1139                 if (e[i].t1 < l_t1)
1140                         l_t1 = e[i].t1;
1141
1142                 if (e[i].t2 < l_t2)
1143                         l_t2 = e[i].t2;
1144
1145                 if (e[i].valid > l_t3)
1146                         l_t3 = e[i].valid;
1147         }
1148
1149         if (ia_pd_entries || ia_na_entries) {
1150                 t1 = l_t1;
1151                 t2 = l_t2;
1152                 t3 = l_t3;
1153         }
1154
1155         return (int)(ia_pd_entries + ia_na_entries);
1156 }
1157
1158
1159 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1160                 const void *status_msg, const int len)
1161 {
1162         uint8_t buf[len + 3];
1163
1164         memset(buf, 0, sizeof(buf));
1165         if (len) {
1166                 buf[0] = '(';
1167                 memcpy(&buf[1], status_msg, len);
1168                 buf[len + 1] = ')';
1169         }
1170
1171         syslog(LOG_WARNING, "Server returned %s status %i %s",
1172                 scope, code, buf);
1173 }
1174
1175
1176 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1177                 const uint16_t code, const void *status_msg, const int len,
1178                 int *ret)
1179 {
1180         dhcpv6_log_status_code(code, "message", status_msg, len);
1181
1182         switch (code) {
1183         case DHCPV6_UnspecFail:
1184                 // Generic failure
1185                 *ret = 0;
1186                 break;
1187
1188         case DHCPV6_UseMulticast:
1189                 switch(orig) {
1190                 case DHCPV6_MSG_REQUEST:
1191                 case DHCPV6_MSG_RENEW:
1192                 case DHCPV6_MSG_RELEASE:
1193                 case DHCPV6_MSG_DECLINE:
1194                         // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1195                         server_addr = in6addr_any;
1196                         *ret = 0;
1197                         break;
1198                 default:
1199                         break;
1200                 }
1201                 break;
1202
1203         case DHCPV6_NoAddrsAvail:
1204         case DHCPV6_NoPrefixAvail:
1205                 if (orig == DHCPV6_MSG_REQUEST)
1206                         *ret = 0; // Failure
1207                 break;
1208
1209         default:
1210                 break;
1211         }
1212 }
1213
1214
1215 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1216                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1217                 const void *status_msg, const int len,
1218                 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1219 {
1220         dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1221                 "IA_NA" : "IA_PD", status_msg, len);
1222
1223         switch (code) {
1224         case DHCPV6_NoBinding:
1225                 switch (orig) {
1226                 case DHCPV6_MSG_RENEW:
1227                 case DHCPV6_MSG_REBIND:
1228                         if ((*ret > 0) && !handled_status_codes[code])
1229                                 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1230                         break;
1231
1232                 default:
1233                         break;
1234                 }
1235                 break;
1236
1237         case DHCPV6_NoAddrsAvail:
1238         case DHCPV6_NoPrefixAvail:
1239                 switch (orig) {
1240                 case DHCPV6_MSG_REQUEST:
1241                         if (*ret != 0)
1242                                 *ret = 0;
1243                         break;
1244                 default:
1245                         break;
1246                 }
1247                 break;
1248
1249         case DHCPV6_NotOnLink:
1250                 // TODO handle not onlink in case of confirm
1251                 break;
1252
1253         default:
1254                 break;
1255         }
1256 }