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                                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
 149                                                 ETHER_ADDR_LEN);
 150                         }
 151                 }
 152
 153                 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
 154         }
 155
 156         // Create ORO
 157         uint16_t oro[] = {
 158                         htons(DHCPV6_OPT_SIP_SERVER_D),
 159                         htons(DHCPV6_OPT_SIP_SERVER_A),
 160                         htons(DHCPV6_OPT_DNS_SERVERS),
 161                         htons(DHCPV6_OPT_DNS_DOMAIN),
 162                         htons(DHCPV6_OPT_UNICAST),
 163                         htons(DHCPV6_OPT_NTP_SERVER),
 164                         htons(DHCPV6_OPT_AFTR_NAME),
 165                         htons(DHCPV6_OPT_PD_EXCLUDE),
 166 #ifdef EXT_PREFIX_CLASS
 167                         htons(DHCPV6_OPT_PREFIX_CLASS),
 168 #endif
 169         };
 170         odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
 171
 172         do {
 173                 // Configure IPv6-options
 174                 int val = 1;
 175                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val)) < 0)
 176                         break;
 177                 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0)
 178                         break;
 179                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val)) < 0)
 180                         break;
 181
 182                 val = 0;
 183                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val)) < 0)
 184                         break;
 185                 if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)) < 0)
 186                         break;
 187
 188                 struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
 189                         .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
 190                 if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
 191                         break;
 192
 193                 return 0;
 194         } while (0);
 195
 196         return -1;
 197 }
 198
 199
 200 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
 201 {
 202         na_mode = na;
 203         pd_mode = pd;
 204 }
 205
 206
 207 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
 208 {
 209         // Build FQDN
 210         char fqdn_buf[256];
 211         gethostname(fqdn_buf, sizeof(fqdn_buf));
 212         struct {
 213                 uint16_t type;
 214                 uint16_t len;
 215                 uint8_t flags;
 216                 uint8_t data[256];
 217         } fqdn;
 218         size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
 219                         sizeof(fqdn.data), NULL, NULL);
 220         fqdn.type = htons(DHCPV6_OPT_FQDN);
 221         fqdn.len = htons(fqdn_len - 4);
 222         fqdn.flags = 0;
 223
 224
 225         // Build Client ID
 226         size_t cl_id_len;
 227         void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
 228
 229         // Get Server ID
 230         size_t srv_id_len;
 231         void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
 232
 233         // Build IA_PDs
 234         size_t ia_pd_entries, ia_pd_len = 0;
 235         struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
 236         ia_pd_entries /= sizeof(*e);
 237         struct dhcpv6_ia_hdr hdr_ia_pd = {
 238                 htons(DHCPV6_OPT_IA_PD),
 239                 htons(sizeof(hdr_ia_pd) - 4),
 240                 1, 0, 0
 241         };
 242
 243
 244         uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
 245         for (size_t i = 0; i < ia_pd_entries; ++i) {
 246                 uint8_t ex_len = 0;
 247                 if (e[i].priority > 0)
 248                         ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
 249
 250                 struct dhcpv6_ia_prefix p = {
 251                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 252                         .len = htons(sizeof(p) - 4U + ex_len),
 253                         .prefix = e[i].length,
 254                         .addr = e[i].target
 255                 };
 256
 257                 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
 258                 ia_pd_len += sizeof(p);
 259
 260                 if (ex_len) {
 261                         ia_pd[ia_pd_len++] = 0;
 262                         ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
 263                         ia_pd[ia_pd_len++] = 0;
 264                         ia_pd[ia_pd_len++] = ex_len - 4;
 265                         ia_pd[ia_pd_len++] = e[i].priority;
 266
 267                         uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
 268                         excl >>= (64 - e[i].priority);
 269                         excl <<= 8 - ((e[i].priority - e[i].length) % 8);
 270
 271                         for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
 272                                 ia_pd[ia_pd_len + i] = excl & 0xff;
 273                         ia_pd_len += ex_len - 5;
 274                 }
 275         }
 276
 277         struct dhcpv6_ia_prefix pref = {
 278                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 279                 .len = htons(25), .prefix = request_prefix
 280         };
 281         if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
 282                 ia_pd = (uint8_t*)&pref;
 283                 ia_pd_len = sizeof(pref);
 284         }
 285         hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
 286
 287         // Build IA_NAs
 288         size_t ia_na_entries, ia_na_len = 0;
 289         void *ia_na = NULL;
 290         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
 291         ia_na_entries /= sizeof(*e);
 292
 293         struct dhcpv6_ia_hdr hdr_ia_na = {
 294                 htons(DHCPV6_OPT_IA_NA),
 295                 htons(sizeof(hdr_ia_na) - 4),
 296                 1, 0, 0
 297         };
 298
 299         struct dhcpv6_ia_addr pa[ia_na_entries];
 300         for (size_t i = 0; i < ia_na_entries; ++i) {
 301                 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
 302                 pa[i].len = htons(sizeof(pa[i]) - 4U);
 303                 pa[i].addr = e[i].target;
 304                 pa[i].preferred = 0;
 305                 pa[i].valid = 0;
 306         }
 307
 308         ia_na = pa;
 309         ia_na_len = sizeof(pa);
 310         hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
 311
 312         // Reconfigure Accept
 313         struct {
 314                 uint16_t type;
 315                 uint16_t length;
 316         } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
 317
 318         // Request Information Refresh
 319         uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
 320
 321         // Prepare Header
 322         size_t oro_len;
 323         void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
 324         struct {
 325                 uint8_t type;
 326                 uint8_t trid[3];
 327                 uint16_t elapsed_type;
 328                 uint16_t elapsed_len;
 329                 uint16_t elapsed_value;
 330                 uint16_t oro_type;
 331                 uint16_t oro_len;
 332         } hdr = {
 333                 type, {trid[0], trid[1], trid[2]},
 334                 htons(DHCPV6_OPT_ELAPSED), htons(2),
 335                         htons((ecs > 0xffff) ? 0xffff : ecs),
 336                 htons(DHCPV6_OPT_ORO), htons(oro_len),
 337         };
 338
 339         struct iovec iov[] = {
 340                 {&hdr, sizeof(hdr)},
 341                 {oro, oro_len},
 342                 {&oro_refresh, 0},
 343                 {cl_id, cl_id_len},
 344                 {srv_id, srv_id_len},
 345                 {&reconf_accept, sizeof(reconf_accept)},
 346                 {&fqdn, fqdn_len},
 347                 {&hdr_ia_na, sizeof(hdr_ia_na)},
 348                 {ia_na, ia_na_len},
 349                 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
 350                 {ia_pd, ia_pd_len},
 351         };
 352
 353         size_t cnt = ARRAY_SIZE(iov);
 354         if (type == DHCPV6_MSG_INFO_REQ) {
 355                 cnt = 5;
 356                 iov[2].iov_len = sizeof(oro_refresh);
 357                 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
 358         } else if (!request_prefix) {
 359                 cnt = 9;
 360         }
 361
 362         // Disable IAs if not used
 363         if (type != DHCPV6_MSG_SOLICIT) {
 364                 iov[5].iov_len = 0;
 365                 if (ia_na_len == 0)
 366                         iov[7].iov_len = 0;
 367                 if (ia_pd_len == 0)
 368                         iov[9].iov_len = 0;
 369         }
 370
 371         if (na_mode == IA_MODE_NONE)
 372                 iov[7].iov_len = 0;
 373
 374         struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
 375                 0, ALL_DHCPV6_RELAYS, ifindex};
 376         struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
 377
 378         switch (type) {
 379         case DHCPV6_MSG_REQUEST:
 380         case DHCPV6_MSG_RENEW:
 381         case DHCPV6_MSG_RELEASE:
 382         case DHCPV6_MSG_DECLINE:
 383                 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
 384                         odhcp6c_addr_in_scope(&server_addr)) {
 385                         srv.sin6_addr = server_addr;
 386                         if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
 387                                 srv.sin6_scope_id = 0;
 388                 }
 389                 break;
 390         default:
 391                 break;
 392         }
 393
 394         if (sendmsg(sock, &msg, 0) < 0) {
 395                 char in6_str[INET6_ADDRSTRLEN];
 396
 397                 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
 398                         inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
 399                                 in6_str, sizeof(in6_str)), strerror(errno));
 400         }
 401 }
 402
 403
 404 static int64_t dhcpv6_rand_delay(int64_t time)
 405 {
 406         int random;
 407         odhcp6c_random(&random, sizeof(random));
 408         return (time * ((int64_t)random % 1000LL)) / 10000LL;
 409 }
 410
 411
 412 int dhcpv6_request(enum dhcpv6_msg type)
 413 {
 414         uint8_t rc = 0;
 415         uint64_t timeout = UINT32_MAX;
 416         struct dhcpv6_retx *retx = &dhcpv6_retx[type];
 417
 418         if (retx->delay) {
 419                 struct timespec ts = {0, 0};
 420                 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
 421                 nanosleep(&ts, NULL);
 422         }
 423
 424         if (type == DHCPV6_MSG_UNKNOWN)
 425                 timeout = t1;
 426         else if (type == DHCPV6_MSG_RENEW)
 427                 timeout = (t2 > t1) ? t2 - t1 : 0;
 428         else if (type == DHCPV6_MSG_REBIND)
 429                 timeout = (t3 > t2) ? t3 - t2 : 0;
 430
 431         if (timeout == 0)
 432                 return -1;
 433
 434         syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
 435                         retx->name, (unsigned long long)timeout, retx->max_rc);
 436
 437         uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
 438
 439         // Generate transaction ID
 440         uint8_t trid[3] = {0, 0, 0};
 441         if (type != DHCPV6_MSG_UNKNOWN)
 442                 odhcp6c_random(trid, sizeof(trid));
 443         ssize_t len = -1;
 444         int64_t rto = 0;
 445
 446         do {
 447                 if (rto == 0) {
 448                         int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 449
 450                         // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
 451                         while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
 452                                 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 453
 454                         rto = (retx->init_timeo * 1000 + delay);
 455                 }
 456                 else
 457                         rto = (2 * rto + dhcpv6_rand_delay(rto));
 458
 459                 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
 460                         rto = retx->max_timeo * 1000 +
 461                                 dhcpv6_rand_delay(retx->max_timeo * 1000);
 462
 463                 // Calculate end for this round and elapsed time
 464                 uint64_t round_end = round_start + rto;
 465                 elapsed = round_start - start;
 466
 467                 // Don't wait too long
 468                 if (round_end - start > timeout * 1000)
 469                         round_end = timeout * 1000 + start;
 470
 471                 // Built and send package
 472                 if (type != DHCPV6_MSG_UNKNOWN) {
 473                         if (type != DHCPV6_MSG_SOLICIT)
 474                                 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
 475                                                 retx->name, (unsigned long long)elapsed, rc);
 476                         dhcpv6_send(type, trid, elapsed / 10);
 477                         rc++;
 478                 }
 479
 480                 // Receive rounds
 481                 for (; len < 0 && round_start < round_end;
 482                                 round_start = odhcp6c_get_milli_time()) {
 483                         uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 484                         struct iovec iov = {buf, sizeof(buf)};
 485                         struct msghdr msg = {NULL, 0, &iov, 1,
 486                                         cmsg_buf, sizeof(cmsg_buf), 0};
 487                         struct in6_pktinfo *pktinfo = NULL;
 488
 489                         // Check for pending signal
 490                         if (odhcp6c_signal_process())
 491                                 return -1;
 492
 493                         // Set timeout for receiving
 494                         uint64_t t = round_end - round_start;
 495                         struct timeval timeout = {t / 1000, (t % 1000) * 1000};
 496                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
 497                                         &timeout, sizeof(timeout));
 498
 499                         // Receive cycle
 500                         len = recvmsg(sock, &msg, 0);
 501                         if (len < 0)
 502                                 continue;
 503
 504                         for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
 505                                 ch = CMSG_NXTHDR(&msg, ch)) {
 506                                 if (ch->cmsg_level == SOL_IPV6 &&
 507                                         ch->cmsg_type == IPV6_PKTINFO) {
 508                                         pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
 509                                         break;
 510                                 }
 511                         }
 512
 513                         if (pktinfo == NULL) {
 514                                 len = -1;
 515                                 continue;
 516                         }
 517
 518                         if (!dhcpv6_response_is_valid(buf, len, trid,
 519                                                         type, &pktinfo->ipi6_addr)) {
 520                                 len = -1;
 521                                 continue;
 522                         }
 523
 524                         uint8_t *opt = &buf[4];
 525                         uint8_t *opt_end = opt + len - 4;
 526
 527                         round_start = odhcp6c_get_milli_time();
 528                         elapsed = round_start - start;
 529                         syslog(LOG_NOTICE, "Got a valid reply after "
 530                                         "%llums", (unsigned long long)elapsed);
 531
 532                         if (retx->handler_reply)
 533                                 len = retx->handler_reply(type, rc, opt, opt_end);
 534
 535                         if (len > 0 && round_end - round_start > 1000)
 536                                 round_end = 1000 + round_start;
 537                 }
 538
 539                 // Allow
 540                 if (retx->handler_finish)
 541                         len = retx->handler_finish();
 542         } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
 543
 544         return len;
 545 }
 546
 547 // Message validation checks according to RFC3315 chapter 15
 548 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
 549                 const uint8_t transaction[3], enum dhcpv6_msg type,
 550                 const struct in6_addr *daddr)
 551 {
 552         const struct dhcpv6_header *rep = buf;
 553         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
 554                         transaction, sizeof(rep->tr_id)))
 555                 return false; // Invalid reply
 556
 557         if (type == DHCPV6_MSG_SOLICIT) {
 558                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
 559                                 rep->msg_type != DHCPV6_MSG_REPLY)
 560                         return false;
 561         } else if (type == DHCPV6_MSG_UNKNOWN) {
 562                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
 563                         return false;
 564         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
 565                 return false;
 566         }
 567
 568         uint8_t *end = ((uint8_t*)buf) + len, *odata,
 569                 rcmsg = DHCPV6_MSG_UNKNOWN;
 570         uint16_t otype, olen;
 571         bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
 572                 ia_present = false, options_valid = true;
 573
 574         size_t client_id_len, server_id_len;
 575         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 576         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
 577
 578         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
 579                 if (otype == DHCPV6_OPT_CLIENTID) {
 580                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
 581                                         &odata[-4], client_id, client_id_len);
 582                 } else if (otype == DHCPV6_OPT_SERVERID) {
 583                         if (server_id_len)
 584                                 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
 585                                                 &odata[-4], server_id, server_id_len);
 586                         else
 587                                 serverid_ok = true;
 588                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 589                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 590                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 591                         if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
 592                                 continue;
 593
 594                         md5_state_t md5;
 595                         uint8_t serverhash[16], secretbytes[16], hash[16];
 596                         memcpy(serverhash, r->key, sizeof(serverhash));
 597                         memset(r->key, 0, sizeof(r->key));
 598                         memcpy(secretbytes, reconf_key, sizeof(secretbytes));
 599
 600                         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 601                                 secretbytes[i] ^= 0x36;
 602
 603                         md5_init(&md5);
 604                         md5_append(&md5, secretbytes, sizeof(secretbytes));
 605                         md5_append(&md5, buf, len);
 606                         md5_finish(&md5, hash);
 607
 608                         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 609                                 secretbytes[i] ^= 0x36;
 610                                 secretbytes[i] ^= 0x5c;
 611                         }
 612
 613                         md5_init(&md5);
 614                         md5_append(&md5, secretbytes, sizeof(secretbytes));
 615                         md5_append(&md5, hash, 16);
 616                         md5_finish(&md5, hash);
 617
 618                         rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
 619                 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
 620                         rcmsg = odata[0];
 621                 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
 622                         ia_present = true;
 623                         if (olen < sizeof(struct dhcpv6_ia_hdr))
 624                                 options_valid = false;
 625                 }
 626                 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
 627                                 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
 628                         // Options are not allowed on global level
 629                         options_valid = false;
 630                 }
 631         }
 632
 633         if (!options_valid)
 634                 return false;
 635
 636         if (type == DHCPV6_MSG_INFO_REQ && ia_present)
 637                 return false;
 638
 639         if (rep->msg_type == DHCPV6_MSG_RECONF) {
 640                 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
 641                         (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
 642                         !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
 643                         return false;
 644         }
 645
 646         return clientid_ok && serverid_ok;
 647 }
 648
 649
 650 int dhcpv6_poll_reconfigure(void)
 651 {
 652         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
 653         if (ret != -1)
 654                 ret = dhcpv6_request(ret);
 655
 656         return ret;
 657 }
 658
 659
 660 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
 661                 const void *opt, const void *end)
 662 {
 663         uint16_t otype, olen;
 664         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
 665         dhcpv6_for_each_option(opt, end, otype, olen, odata)
 666                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
 667                                 odata[0] == DHCPV6_MSG_RENEW ||
 668                                 odata[0] == DHCPV6_MSG_INFO_REQ))
 669                         msg = odata[0];
 670
 671         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
 672         return msg;
 673 }
 674
 675
 676 // Collect all advertised servers
 677 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
 678                 const void *opt, const void *end)
 679 {
 680         uint16_t olen, otype;
 681         uint8_t *odata, pref = 0;
 682         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
 683                                         IN6ADDR_ANY_INIT, NULL, NULL, 0, 0};
 684         bool have_na = false;
 685         int have_pd = 0;
 686
 687         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 688                 if (orig == DHCPV6_MSG_SOLICIT &&
 689                                 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
 690                                 olen > sizeof(struct dhcpv6_ia_hdr)) {
 691                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 692                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 693                 }
 694
 695                 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
 696                         memcpy(cand.duid, odata, olen);
 697                         cand.duid_len = olen;
 698                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 699                         int error = ((int)odata[0] << 8 | (int)odata[1]);
 700
 701                         switch (error) {
 702                         case DHCPV6_NoPrefixAvail:
 703                                 // Status code on global level
 704                                 if (pd_mode == IA_MODE_FORCE)
 705                                         return -1;
 706                                 cand.preference -= 2000;
 707                                 break;
 708
 709                         case DHCPV6_NoAddrsAvail:
 710                                 // Status code on global level
 711                                 if (na_mode == IA_MODE_FORCE)
 712                                         return -1;
 713                                 break;
 714
 715                         default :
 716                                 break;
 717                         }
 718                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
 719                                 cand.preference >= 0) {
 720                         cand.preference = pref = odata[0];
 721                 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
 722                         cand.server_addr = *(struct in6_addr *)odata;
 723                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
 724                         cand.wants_reconfigure = true;
 725                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
 726                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 727                         uint8_t *oend = odata + olen, *d;
 728                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
 729                                 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
 730                                                 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
 731                                         struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
 732                                         have_pd = p->prefix;
 733                                 }
 734                         }
 735                 } else if (otype == DHCPV6_OPT_IA_NA) {
 736                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 737                         uint8_t *oend = odata + olen, *d;
 738                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
 739                                 if (otype == DHCPV6_OPT_IA_ADDR)
 740                                         have_na = true;
 741                 }
 742         }
 743
 744         if ((!have_na && na_mode == IA_MODE_FORCE) ||
 745                         (!have_pd && pd_mode == IA_MODE_FORCE))
 746                 return -1;
 747
 748         if (na_mode != IA_MODE_NONE && !have_na) {
 749                 cand.has_noaddravail = true;
 750                 cand.preference -= 1000;
 751         }
 752
 753         if (pd_mode != IA_MODE_NONE) {
 754                 if (have_pd)
 755                         cand.preference += 2000 + (128 - have_pd);
 756                 else
 757                         cand.preference -= 2000;
 758         }
 759
 760         if (cand.duid_len > 0) {
 761                 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
 762                 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
 763                 odhcp6c_add_state(STATE_SERVER_CAND, &cand, sizeof(cand));
 764         }
 765
 766         return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
 767 }
 768
 769
 770 static int dhcpv6_commit_advert(void)
 771 {
 772         size_t cand_len;
 773         struct dhcpv6_server_cand *c = NULL, *cand =
 774                         odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
 775
 776         bool retry = false;
 777         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
 778                 if (cand[i].has_noaddravail)
 779                         retry = true; // We want to try again
 780
 781                 if (!c || c->preference < cand[i].preference)
 782                         c = &cand[i];
 783         }
 784
 785         if (retry && na_mode == IA_MODE_TRY) {
 786                 // We give it a second try without the IA_NA
 787                 na_mode = IA_MODE_NONE;
 788                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
 789         }
 790
 791         if (c) {
 792                 uint16_t hdr[2] = {htons(DHCPV6_OPT_SERVERID),
 793                                 htons(c->duid_len)};
 794                 odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
 795                 odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len);
 796                 accept_reconfig = c->wants_reconfigure;
 797                 server_addr = c->server_addr;
 798                 if (c->ia_na_len)
 799                         odhcp6c_add_state(STATE_IA_NA, c->ia_na, c->ia_na_len);
 800                 if (c->ia_pd_len)
 801                         odhcp6c_add_state(STATE_IA_PD, c->ia_pd, c->ia_pd_len);
 802         }
 803
 804         for (size_t i = 0; i < cand_len / sizeof(*c); ++i) {
 805                 free(cand[i].ia_na);
 806                 free(cand[i].ia_pd);
 807         }
 808         odhcp6c_clear_state(STATE_SERVER_CAND);
 809
 810         if (!c)
 811                 return -1;
 812         else if ((request_prefix && c->ia_pd_len) || (na_mode != IA_MODE_NONE && c->ia_na_len))
 813                 return DHCPV6_STATEFUL;
 814         else
 815                 return DHCPV6_STATELESS;
 816 }
 817
 818
 819 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
 820                 const void *opt, const void *end)
 821 {
 822         dhcpv6_handle_advert(orig, rc, opt, end);
 823         if (dhcpv6_commit_advert() < 0)
 824                 return -1;
 825
 826         return dhcpv6_handle_reply(orig, rc, opt, end);
 827 }
 828
 829
 830 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
 831                 const void *opt, const void *end)
 832 {
 833         uint8_t *odata;
 834         uint16_t otype, olen;
 835         uint32_t refresh = UINT32_MAX;
 836         int ret = 1;
 837         bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
 838
 839         odhcp6c_expire();
 840
 841         if (orig == DHCPV6_MSG_UNKNOWN) {
 842                 static time_t last_update = 0;
 843                 time_t now = odhcp6c_get_milli_time() / 1000;
 844
 845                 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
 846                 last_update = now;
 847
 848                 t1 -= elapsed;
 849                 t2 -= elapsed;
 850                 t3 -= elapsed;
 851
 852                 if (t1 < 0)
 853                         t1 = 0;
 854
 855                 if (t2 < 0)
 856                         t2 = 0;
 857
 858                 if (t3 < 0)
 859                         t3 = 0;
 860         }
 861
 862         if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
 863                 // Delete NA and PD we have in the state from the Advert
 864                 odhcp6c_clear_state(STATE_IA_NA);
 865                 odhcp6c_clear_state(STATE_IA_PD);
 866         }
 867
 868         if (opt) {
 869                 odhcp6c_clear_state(STATE_DNS);
 870                 odhcp6c_clear_state(STATE_SEARCH);
 871                 odhcp6c_clear_state(STATE_SNTP_IP);
 872                 odhcp6c_clear_state(STATE_SNTP_FQDN);
 873                 odhcp6c_clear_state(STATE_SIP_IP);
 874                 odhcp6c_clear_state(STATE_SIP_FQDN);
 875                 odhcp6c_clear_state(STATE_AFTR_NAME);
 876         }
 877
 878         // Parse and find all matching IAs
 879         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 880                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
 881                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
 882                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 883
 884                         // Test ID
 885                         if (ia_hdr->iaid != 1)
 886                                 continue;
 887
 888                         uint16_t code = DHCPV6_Success;
 889                         uint16_t stype, slen;
 890                         uint8_t *sdata;
 891                         // Get and handle status code
 892                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
 893                                         stype, slen, sdata) {
 894                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
 895                                         uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
 896                                         uint16_t mlen = (slen > 2) ? slen - 2 : 0;
 897
 898                                         code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
 899
 900                                         if (code == DHCPV6_Success)
 901                                                 continue;
 902
 903                                         dhcpv6_handle_ia_status_code(orig, ia_hdr,
 904                                                 code, mdata, mlen, handled_status_codes, &ret);
 905
 906
 907                                         if (ret > 0)
 908                                                 return ret;
 909                                         break;
 910                                 }
 911                         }
 912
 913                         if (code != DHCPV6_Success)
 914                                 continue;
 915
 916                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 917                 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
 918                         server_addr = *(struct in6_addr *)odata;
 919                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 920                         uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
 921                         uint16_t mlen = (olen > 2) ? olen - 2 : 0;
 922                         uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
 923
 924                         dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
 925                 }
 926                 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
 927                         if (olen % 16 == 0)
 928                                 odhcp6c_add_state(STATE_DNS, odata, olen);
 929                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
 930                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
 931                 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
 932                         uint16_t stype, slen;
 933                         uint8_t *sdata;
 934                         // Test status and bail if error
 935                         dhcpv6_for_each_option(odata, odata + olen,
 936                                         stype, slen, sdata) {
 937                                 if (slen == 16 && (stype == NTP_MC_ADDR ||
 938                                                 stype == NTP_SRV_ADDR))
 939                                         odhcp6c_add_state(STATE_SNTP_IP,
 940                                                         sdata, slen);
 941                                 else if (slen > 0 && stype == NTP_SRV_FQDN)
 942                                         odhcp6c_add_state(STATE_SNTP_FQDN,
 943                                                         sdata, slen);
 944                         }
 945                 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
 946                         if (olen == 16)
 947                                 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
 948                 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
 949                         odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
 950                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
 951                         refresh = ntohl(*((uint32_t*)odata));
 952                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 953                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 954                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 955                         if (r->protocol == 3 && r->algorithm == 1 &&
 956                                         r->reconf_type == 1)
 957                                 memcpy(reconf_key, r->key, sizeof(r->key));
 958                 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
 959                         size_t cur_len;
 960                         odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
 961                         if (cur_len == 0)
 962                                 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
 963                 } else if (otype != DHCPV6_OPT_CLIENTID &&
 964                                 otype != DHCPV6_OPT_SERVERID) {
 965                         odhcp6c_add_state(STATE_CUSTOM_OPTS,
 966                                         &odata[-4], olen + 4);
 967                 }
 968         }
 969
 970         if (orig != DHCPV6_MSG_INFO_REQ) {
 971                 // Update refresh timers if no fatal status code was received
 972                 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
 973                         switch (orig) {
 974                         case DHCPV6_MSG_RENEW:
 975                                 // Send further renews if T1 is not set
 976                                 if (!t1)
 977                                         ret = -1;
 978                                 break;
 979                         case DHCPV6_MSG_REBIND:
 980                                 // Send further rebinds if T1 and T2 is not set
 981                                 if (!t1 && !t2)
 982                                         ret = -1;
 983                                 break;
 984
 985                         default :
 986                                 break;
 987                         }
 988                 }
 989         }
 990         else if (ret > 0)
 991                 t1 = refresh;
 992
 993         return ret;
 994 }
 995
 996
 997 static int dhcpv6_parse_ia(void *opt, void *end)
 998 {
 999         struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
1000         int parsed_ia = 0;
1001         uint32_t t1, t2;
1002         uint16_t otype, olen;
1003         uint8_t *odata;
1004
1005         t1 = ntohl(ia_hdr->t1);
1006         t2 = ntohl(ia_hdr->t2);
1007
1008         if (t1 > t2)
1009                 return 0;
1010
1011         // Update address IA
1012         dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
1013                 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
1014                                 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
1015
1016                 if (otype == DHCPV6_OPT_IA_PREFIX) {
1017                         struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
1018                         if (olen + 4U < sizeof(*prefix))
1019                                 continue;
1020
1021                         entry.valid = ntohl(prefix->valid);
1022                         entry.preferred = ntohl(prefix->preferred);
1023
1024                         if (entry.preferred > entry.valid)
1025                                 continue;
1026
1027                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1028                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1029                         if (entry.t1 > entry.t2)
1030                                 entry.t1 = entry.t2;
1031
1032                         entry.length = prefix->prefix;
1033                         entry.target = prefix->addr;
1034                         uint16_t stype, slen;
1035                         uint8_t *sdata;
1036
1037 #ifdef EXT_PREFIX_CLASS
1038                         // Find prefix class, if any
1039                         dhcpv6_for_each_option(&prefix[1], odata + olen,
1040                                         stype, slen, sdata)
1041                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1042                                         entry.class = sdata[0] << 8 | sdata[1];
1043 #endif
1044
1045                         // Parse PD-exclude
1046                         bool ok = true;
1047                         dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1048                                         odata + olen, stype, slen, sdata) {
1049                                 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1050                                         continue;
1051
1052                                 uint8_t elen = sdata[0];
1053                                 if (elen > 64)
1054                                         elen = 64;
1055
1056                                 if (elen <= 32 || elen <= entry.length) {
1057                                         ok = false;
1058                                         continue;
1059                                 }
1060
1061
1062                                 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1063                                 if (slen <= bytes) {
1064                                         ok = false;
1065                                         continue;
1066                                 }
1067
1068                                 uint32_t exclude = 0;
1069                                 do {
1070                                         exclude = exclude << 8 | sdata[bytes];
1071                                 } while (--bytes);
1072
1073                                 exclude >>= 8 - ((elen - entry.length) % 8);
1074                                 exclude <<= 64 - elen;
1075
1076                                 // Abusing router & priority fields for exclusion
1077                                 entry.router = entry.target;
1078                                 entry.router.s6_addr32[1] |= htonl(exclude);
1079                                 entry.priority = elen;
1080                         }
1081
1082                         if (ok) {
1083                                 odhcp6c_update_entry(STATE_IA_PD, &entry);
1084                                 parsed_ia++;
1085                         }
1086
1087                         entry.priority = 0;
1088                         memset(&entry.router, 0, sizeof(entry.router));
1089                 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1090                         struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1091                         if (olen + 4U < sizeof(*addr))
1092                                 continue;
1093
1094                         entry.preferred = ntohl(addr->preferred);
1095                         entry.valid = ntohl(addr->valid);
1096
1097                         if (entry.preferred > entry.valid)
1098                                 continue;
1099
1100                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1101                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1102                         if (entry.t1 > entry.t2)
1103                                 entry.t1 = entry.t2;
1104
1105                         entry.length = 128;
1106                         entry.target = addr->addr;
1107
1108 #ifdef EXT_PREFIX_CLASS
1109                         uint16_t stype, slen;
1110                         uint8_t *sdata;
1111                         // Find prefix class, if any
1112                         dhcpv6_for_each_option(&addr[1], odata + olen,
1113                                         stype, slen, sdata)
1114                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1115                                         entry.class = sdata[0] << 8 | sdata[1];
1116 #endif
1117
1118                         odhcp6c_update_entry(STATE_IA_NA, &entry);
1119                         parsed_ia++;
1120                 }
1121         }
1122         return parsed_ia;
1123 }
1124
1125
1126 static int dhcpv6_calc_refresh_timers(void)
1127 {
1128         struct odhcp6c_entry *e;
1129         size_t ia_na_entries, ia_pd_entries, i;
1130         int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1131
1132         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1133         ia_na_entries /= sizeof(*e);
1134         for (i = 0; i < ia_na_entries; i++) {
1135                 if (e[i].t1 < l_t1)
1136                         l_t1 = e[i].t1;
1137
1138                 if (e[i].t2 < l_t2)
1139                         l_t2 = e[i].t2;
1140
1141                 if (e[i].valid > l_t3)
1142                         l_t3 = e[i].valid;
1143         }
1144
1145         e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1146         ia_pd_entries /= sizeof(*e);
1147         for (i = 0; i < ia_pd_entries; i++) {
1148                 if (e[i].t1 < l_t1)
1149                         l_t1 = e[i].t1;
1150
1151                 if (e[i].t2 < l_t2)
1152                         l_t2 = e[i].t2;
1153
1154                 if (e[i].valid > l_t3)
1155                         l_t3 = e[i].valid;
1156         }
1157
1158         if (ia_pd_entries || ia_na_entries) {
1159                 t1 = l_t1;
1160                 t2 = l_t2;
1161                 t3 = l_t3;
1162         }
1163
1164         return (int)(ia_pd_entries + ia_na_entries);
1165 }
1166
1167
1168 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1169                 const void *status_msg, const int len)
1170 {
1171         uint8_t buf[len + 3];
1172
1173         memset(buf, 0, sizeof(buf));
1174         if (len) {
1175                 buf[0] = '(';
1176                 memcpy(&buf[1], status_msg, len);
1177                 buf[len + 1] = ')';
1178         }
1179
1180         syslog(LOG_WARNING, "Server returned %s status %i %s",
1181                 scope, code, buf);
1182 }
1183
1184
1185 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1186                 const uint16_t code, const void *status_msg, const int len,
1187                 int *ret)
1188 {
1189         dhcpv6_log_status_code(code, "message", status_msg, len);
1190
1191         switch (code) {
1192         case DHCPV6_UnspecFail:
1193                 // Generic failure
1194                 *ret = 0;
1195                 break;
1196
1197         case DHCPV6_UseMulticast:
1198                 switch(orig) {
1199                 case DHCPV6_MSG_REQUEST:
1200                 case DHCPV6_MSG_RENEW:
1201                 case DHCPV6_MSG_RELEASE:
1202                 case DHCPV6_MSG_DECLINE:
1203                         // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1204                         server_addr = in6addr_any;
1205                         *ret = 0;
1206                         break;
1207                 default:
1208                         break;
1209                 }
1210                 break;
1211
1212         case DHCPV6_NoAddrsAvail:
1213         case DHCPV6_NoPrefixAvail:
1214                 if (orig == DHCPV6_MSG_REQUEST)
1215                         *ret = 0; // Failure
1216                 break;
1217
1218         default:
1219                 break;
1220         }
1221 }
1222
1223
1224 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1225                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1226                 const void *status_msg, const int len,
1227                 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1228 {
1229         dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1230                 "IA_NA" : "IA_PD", status_msg, len);
1231
1232         switch (code) {
1233         case DHCPV6_NoBinding:
1234                 switch (orig) {
1235                 case DHCPV6_MSG_RENEW:
1236                 case DHCPV6_MSG_REBIND:
1237                         if ((*ret > 0) && !handled_status_codes[code])
1238                                 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1239                         break;
1240
1241                 default:
1242                         break;
1243                 }
1244                 break;
1245
1246         case DHCPV6_NoAddrsAvail:
1247         case DHCPV6_NoPrefixAvail:
1248                 switch (orig) {
1249                 case DHCPV6_MSG_REQUEST:
1250                         if (*ret != 0)
1251                                 *ret = 0;
1252                         break;
1253                 default:
1254                         break;
1255                 }
1256                 break;
1257
1258         case DHCPV6_NotOnLink:
1259                 // TODO handle not onlink in case of confirm
1260                 break;
1261
1262         default:
1263                 break;
1264         }
1265 }