src/dhcpv6.c

   1 /**
   2  * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License v2 as published by
   6  * the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  */
  14
  15 #include <time.h>
  16 #include <fcntl.h>
  17 #include <errno.h>
  18 #include <stdlib.h>
  19 #include <signal.h>
  20 #include <limits.h>
  21 #include <resolv.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <syslog.h>
  25 #include <stdbool.h>
  26 #include <sys/time.h>
  27 #include <sys/ioctl.h>
  28 #include <sys/socket.h>
  29 #include <netinet/in.h>
  30
  31 #include <net/if.h>
  32 #include <net/ethernet.h>
  33
  34 #include "odhcp6c.h"
  35 #include "md5.h"
  36
  37
  38 #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\
  39                 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}}
  40 #define DHCPV6_CLIENT_PORT 546
  41 #define DHCPV6_SERVER_PORT 547
  42 #define DHCPV6_DUID_LLADDR 3
  43 #define DHCPV6_REQ_DELAY 1
  44
  45 #define DHCPV6_SOL_MAX_RT_MIN 60
  46 #define DHCPV6_SOL_MAX_RT_MAX 86400
  47 #define DHCPV6_INF_MAX_RT_MIN 60
  48 #define DHCPV6_INF_MAX_RT_MAX 86400
  49
  50 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
  51                 const uint8_t transaction[3], enum dhcpv6_msg type,
  52                 const struct in6_addr *daddr);
  53
  54 static int dhcpv6_parse_ia(void *opt, void *end);
  55
  56 static int dhcpv6_calc_refresh_timers(void);
  57 static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig,
  58                 const uint16_t code, const void *status_msg, const int len,
  59                 int *ret);
  60 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
  61                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
  62                 const void *status_msg, const int len,
  63                 bool handled_status_codes[_DHCPV6_Status_Max],
  64                 int *ret);
  65 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
  66 static void dhcpv6_clear_all_server_cand(void);
  67
  68 static reply_handler dhcpv6_handle_reply;
  69 static reply_handler dhcpv6_handle_advert;
  70 static reply_handler dhcpv6_handle_rebind_reply;
  71 static reply_handler dhcpv6_handle_reconfigure;
  72 static int dhcpv6_commit_advert(void);
  73
  74
  75
  76 // RFC 3315 - 5.5 Timeout and Delay values
  77 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
  78         [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
  79                         dhcpv6_handle_reconfigure, NULL},
  80         [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT",
  81                         dhcpv6_handle_advert, dhcpv6_commit_advert},
  82         [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST",
  83                         dhcpv6_handle_reply, NULL},
  84         [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW",
  85                         dhcpv6_handle_reply, NULL},
  86         [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND",
  87                         dhcpv6_handle_rebind_reply, NULL},
  88         [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
  89         [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
  90         [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ",
  91                         dhcpv6_handle_reply, NULL},
  92 };
  93
  94
  95 // Sockets
  96 static int sock = -1;
  97 static int ifindex = -1;
  98 static int64_t t1 = 0, t2 = 0, t3 = 0;
  99
 100 // IA states
 101 static int request_prefix = -1;
 102 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
 103 static bool accept_reconfig = false;
 104
 105 // Reconfigure key
 106 static uint8_t reconf_key[16];
 107
 108
 109 int init_dhcpv6(const char *ifname, int request_pd, bool strict_options, int sol_timeout)
 110 {
 111         request_prefix = request_pd;
 112         dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
 113
 114         sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
 115         if (sock < 0)
 116                 return -1;
 117
 118         // Detect interface
 119         struct ifreq ifr;
 120         strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 121         if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
 122                 return -1;
 123         ifindex = ifr.ifr_ifindex;
 124
 125         // Create client DUID
 126         size_t client_id_len;
 127         odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 128         if (client_id_len == 0) {
 129                 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
 130                                 DHCPV6_DUID_LLADDR, 0, 1};
 131
 132                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
 133                         memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
 134
 135                 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
 136                 struct ifreq ifs[100], *ifp, *ifend;
 137                 struct ifconf ifc;
 138                 ifc.ifc_req = ifs;
 139                 ifc.ifc_len = sizeof(ifs);
 140
 141                 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
 142                                 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
 143                         // If our interface doesn't have an address...
 144                         ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
 145                         for (ifp = ifc.ifc_req; ifp < ifend &&
 146                                         !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
 147                                 memcpy(ifr.ifr_name, ifp->ifr_name,
 148                                                 sizeof(ifr.ifr_name));
 149                                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
 150                                         continue;
 151
 152                                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
 153                                                 ETHER_ADDR_LEN);
 154                         }
 155                 }
 156
 157                 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
 158         }
 159
 160         // Create ORO
 161         if (!strict_options) {
 162                 uint16_t oro[] = {
 163                         htons(DHCPV6_OPT_SIP_SERVER_D),
 164                         htons(DHCPV6_OPT_SIP_SERVER_A),
 165                         htons(DHCPV6_OPT_DNS_SERVERS),
 166                         htons(DHCPV6_OPT_DNS_DOMAIN),
 167                         htons(DHCPV6_OPT_SNTP_SERVERS),
 168                         htons(DHCPV6_OPT_NTP_SERVER),
 169                         htons(DHCPV6_OPT_AFTR_NAME),
 170                         htons(DHCPV6_OPT_PD_EXCLUDE),
 171                         htons(DHCPV6_OPT_SOL_MAX_RT),
 172                         htons(DHCPV6_OPT_INF_MAX_RT),
 173 #ifdef EXT_PREFIX_CLASS
 174                         htons(DHCPV6_OPT_PREFIX_CLASS),
 175 #endif
 176                 };
 177                 odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
 178         }
 179
 180         // Configure IPv6-options
 181         int val = 1;
 182         setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
 183         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 184         setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
 185         val = 0;
 186         setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
 187         setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
 188
 189         struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
 190                 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
 191         if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
 192                 return -1;
 193
 194         return 0;
 195 }
 196
 197
 198 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
 199 {
 200         na_mode = na;
 201         pd_mode = pd;
 202 }
 203
 204
 205 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
 206 {
 207         // Build FQDN
 208         char fqdn_buf[256];
 209         gethostname(fqdn_buf, sizeof(fqdn_buf));
 210         struct {
 211                 uint16_t type;
 212                 uint16_t len;
 213                 uint8_t flags;
 214                 uint8_t data[256];
 215         } fqdn;
 216         size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
 217                         sizeof(fqdn.data), NULL, NULL);
 218         fqdn.type = htons(DHCPV6_OPT_FQDN);
 219         fqdn.len = htons(fqdn_len - 4);
 220         fqdn.flags = 0;
 221
 222
 223         // Build Client ID
 224         size_t cl_id_len;
 225         void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
 226
 227         // Get Server ID
 228         size_t srv_id_len;
 229         void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
 230
 231         // Build IA_PDs
 232         size_t ia_pd_entries, ia_pd_len = 0;
 233         struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
 234         ia_pd_entries /= sizeof(*e);
 235         struct dhcpv6_ia_hdr hdr_ia_pd = {
 236                 htons(DHCPV6_OPT_IA_PD),
 237                 htons(sizeof(hdr_ia_pd) - 4),
 238                 1, 0, 0
 239         };
 240
 241
 242         uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
 243         for (size_t i = 0; i < ia_pd_entries; ++i) {
 244                 uint8_t ex_len = 0;
 245                 if (e[i].priority > 0)
 246                         ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
 247
 248                 struct dhcpv6_ia_prefix p = {
 249                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 250                         .len = htons(sizeof(p) - 4U + ex_len),
 251                         .prefix = e[i].length,
 252                         .addr = e[i].target
 253                 };
 254
 255                 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
 256                 ia_pd_len += sizeof(p);
 257
 258                 if (ex_len) {
 259                         ia_pd[ia_pd_len++] = 0;
 260                         ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
 261                         ia_pd[ia_pd_len++] = 0;
 262                         ia_pd[ia_pd_len++] = ex_len - 4;
 263                         ia_pd[ia_pd_len++] = e[i].priority;
 264
 265                         uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
 266                         excl >>= (64 - e[i].priority);
 267                         excl <<= 8 - ((e[i].priority - e[i].length) % 8);
 268
 269                         for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
 270                                 ia_pd[ia_pd_len + i] = excl & 0xff;
 271                         ia_pd_len += ex_len - 5;
 272                 }
 273         }
 274
 275         struct dhcpv6_ia_prefix pref = {
 276                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 277                 .len = htons(25), .prefix = request_prefix
 278         };
 279         if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
 280                 ia_pd = (uint8_t*)&pref;
 281                 ia_pd_len = sizeof(pref);
 282         }
 283         hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
 284
 285         // Build IA_NAs
 286         size_t ia_na_entries, ia_na_len = 0;
 287         void *ia_na = NULL;
 288         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
 289         ia_na_entries /= sizeof(*e);
 290
 291         struct dhcpv6_ia_hdr hdr_ia_na = {
 292                 htons(DHCPV6_OPT_IA_NA),
 293                 htons(sizeof(hdr_ia_na) - 4),
 294                 1, 0, 0
 295         };
 296
 297         struct dhcpv6_ia_addr pa[ia_na_entries];
 298         for (size_t i = 0; i < ia_na_entries; ++i) {
 299                 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
 300                 pa[i].len = htons(sizeof(pa[i]) - 4U);
 301                 pa[i].addr = e[i].target;
 302                 pa[i].preferred = 0;
 303                 pa[i].valid = 0;
 304         }
 305
 306         ia_na = pa;
 307         ia_na_len = sizeof(pa);
 308         hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
 309
 310         // Reconfigure Accept
 311         struct {
 312                 uint16_t type;
 313                 uint16_t length;
 314         } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
 315
 316         // Request Information Refresh
 317         uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
 318
 319         // Prepare Header
 320         size_t oro_len;
 321         void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
 322         struct {
 323                 uint8_t type;
 324                 uint8_t trid[3];
 325                 uint16_t elapsed_type;
 326                 uint16_t elapsed_len;
 327                 uint16_t elapsed_value;
 328                 uint16_t oro_type;
 329                 uint16_t oro_len;
 330         } hdr = {
 331                 type, {trid[0], trid[1], trid[2]},
 332                 htons(DHCPV6_OPT_ELAPSED), htons(2),
 333                         htons((ecs > 0xffff) ? 0xffff : ecs),
 334                 htons(DHCPV6_OPT_ORO), htons(oro_len),
 335         };
 336
 337         struct iovec iov[] = {
 338                 {&hdr, sizeof(hdr)},
 339                 {oro, oro_len},
 340                 {&oro_refresh, 0},
 341                 {cl_id, cl_id_len},
 342                 {srv_id, srv_id_len},
 343                 {&reconf_accept, sizeof(reconf_accept)},
 344                 {&fqdn, fqdn_len},
 345                 {&hdr_ia_na, sizeof(hdr_ia_na)},
 346                 {ia_na, ia_na_len},
 347                 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
 348                 {ia_pd, ia_pd_len},
 349         };
 350
 351         size_t cnt = ARRAY_SIZE(iov);
 352         if (type == DHCPV6_MSG_INFO_REQ) {
 353                 cnt = 5;
 354                 iov[2].iov_len = sizeof(oro_refresh);
 355                 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
 356         } else if (!request_prefix) {
 357                 cnt = 9;
 358         }
 359
 360         // Disable IAs if not used
 361         if (type != DHCPV6_MSG_SOLICIT) {
 362                 iov[5].iov_len = 0;
 363                 if (ia_na_len == 0)
 364                         iov[7].iov_len = 0;
 365                 if (ia_pd_len == 0)
 366                         iov[9].iov_len = 0;
 367         }
 368
 369         if (na_mode == IA_MODE_NONE)
 370                 iov[7].iov_len = 0;
 371
 372         struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
 373                 0, ALL_DHCPV6_RELAYS, ifindex};
 374         struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
 375
 376         sendmsg(sock, &msg, 0);
 377 }
 378
 379
 380 static int64_t dhcpv6_rand_delay(int64_t time)
 381 {
 382         int random;
 383         odhcp6c_random(&random, sizeof(random));
 384         return (time * ((int64_t)random % 1000LL)) / 10000LL;
 385 }
 386
 387
 388 int dhcpv6_request(enum dhcpv6_msg type)
 389 {
 390         uint8_t rc = 0;
 391         uint64_t timeout = UINT32_MAX;
 392         struct dhcpv6_retx *retx = &dhcpv6_retx[type];
 393
 394         if (retx->delay) {
 395                 struct timespec ts = {0, 0};
 396                 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
 397                 nanosleep(&ts, NULL);
 398         }
 399
 400         if (type == DHCPV6_MSG_UNKNOWN)
 401                 timeout = t1;
 402         else if (type == DHCPV6_MSG_RENEW)
 403                 timeout = (t2 > t1) ? t2 - t1 : 0;
 404         else if (type == DHCPV6_MSG_REBIND)
 405                 timeout = (t3 > t2) ? t3 - t2 : 0;
 406
 407         if (timeout == 0)
 408                 return -1;
 409
 410         syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
 411                         retx->name, (unsigned long long)timeout, retx->max_rc);
 412
 413         uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
 414
 415         // Generate transaction ID
 416         uint8_t trid[3] = {0, 0, 0};
 417         if (type != DHCPV6_MSG_UNKNOWN)
 418                 odhcp6c_random(trid, sizeof(trid));
 419         ssize_t len = -1;
 420         int64_t rto = 0;
 421
 422         do {
 423                 if (rto == 0) {
 424                         int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 425
 426                         // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
 427                         while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
 428                                 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 429
 430                         rto = (retx->init_timeo * 1000 + delay);
 431                 }
 432                 else
 433                         rto = (2 * rto + dhcpv6_rand_delay(rto));
 434
 435                 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
 436                         rto = retx->max_timeo * 1000 +
 437                                 dhcpv6_rand_delay(retx->max_timeo * 1000);
 438
 439                 // Calculate end for this round and elapsed time
 440                 uint64_t round_end = round_start + rto;
 441                 elapsed = round_start - start;
 442
 443                 // Don't wait too long
 444                 if (round_end - start > timeout * 1000)
 445                         round_end = timeout * 1000 + start;
 446
 447                 // Built and send package
 448                 if (type != DHCPV6_MSG_UNKNOWN) {
 449                         if (type != DHCPV6_MSG_SOLICIT)
 450                                 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
 451                                                 retx->name, (unsigned long long)elapsed, rc);
 452                         dhcpv6_send(type, trid, elapsed / 10);
 453                         rc++;
 454                 }
 455
 456                 // Receive rounds
 457                 for (; len < 0 && (round_start < round_end);
 458                                 round_start = odhcp6c_get_milli_time()) {
 459                         uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 460                         struct iovec iov = {buf, sizeof(buf)};
 461                         struct msghdr msg = {NULL, 0, &iov, 1,
 462                                         cmsg_buf, sizeof(cmsg_buf), 0};
 463                         struct in6_pktinfo *pktinfo = NULL;
 464
 465                         // Check for pending signal
 466                         if (odhcp6c_signal_process())
 467                                 return -1;
 468
 469                         // Set timeout for receiving
 470                         uint64_t t = round_end - round_start;
 471                         struct timeval timeout = {t / 1000, (t % 1000) * 1000};
 472                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
 473                                         &timeout, sizeof(timeout));
 474
 475                         // Receive cycle
 476                         len = recvmsg(sock, &msg, 0);
 477                         if (len < 0)
 478                                 continue;
 479
 480                         for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
 481                                 ch = CMSG_NXTHDR(&msg, ch)) {
 482                                 if (ch->cmsg_level == SOL_IPV6 &&
 483                                         ch->cmsg_type == IPV6_PKTINFO) {
 484                                         pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
 485                                         break;
 486                                 }
 487                         }
 488
 489                         if (pktinfo == NULL) {
 490                                 len = -1;
 491                                 continue;
 492                         }
 493
 494                         if (!dhcpv6_response_is_valid(buf, len, trid,
 495                                                         type, &pktinfo->ipi6_addr)) {
 496                                 len = -1;
 497                                 continue;
 498                         }
 499
 500                         uint8_t *opt = &buf[4];
 501                         uint8_t *opt_end = opt + len - 4;
 502
 503                         round_start = odhcp6c_get_milli_time();
 504                         elapsed = round_start - start;
 505                         syslog(LOG_NOTICE, "Got a valid reply after "
 506                                         "%llums", (unsigned long long)elapsed);
 507
 508                         if (retx->handler_reply)
 509                                 len = retx->handler_reply(type, rc, opt, opt_end);
 510
 511                         if (len > 0 && round_end - round_start > 1000)
 512                                 round_end = 1000 + round_start;
 513                 }
 514
 515                 // Allow
 516                 if (retx->handler_finish)
 517                         len = retx->handler_finish();
 518         } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
 519
 520         return len;
 521 }
 522
 523 // Message validation checks according to RFC3315 chapter 15
 524 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
 525                 const uint8_t transaction[3], enum dhcpv6_msg type,
 526                 const struct in6_addr *daddr)
 527 {
 528         const struct dhcpv6_header *rep = buf;
 529         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
 530                         transaction, sizeof(rep->tr_id)))
 531                 return false; // Invalid reply
 532
 533         if (type == DHCPV6_MSG_SOLICIT) {
 534                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
 535                                 rep->msg_type != DHCPV6_MSG_REPLY)
 536                         return false;
 537         } else if (type == DHCPV6_MSG_UNKNOWN) {
 538                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
 539                         return false;
 540         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
 541                 return false;
 542         }
 543
 544         uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL,
 545                 rcmsg = DHCPV6_MSG_UNKNOWN;
 546         uint16_t otype, olen = UINT16_MAX;
 547         bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
 548                 ia_present = false, options_valid = true;
 549
 550         size_t client_id_len, server_id_len;
 551         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 552         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
 553
 554         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
 555                 if (otype == DHCPV6_OPT_CLIENTID) {
 556                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
 557                                         &odata[-4], client_id, client_id_len);
 558                 } else if (otype == DHCPV6_OPT_SERVERID) {
 559                         if (server_id_len)
 560                                 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
 561                                                 &odata[-4], server_id, server_id_len);
 562                         else
 563                                 serverid_ok = true;
 564                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 565                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 566                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 567                         if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
 568                                 continue;
 569
 570                         md5_ctx_t md5;
 571                         uint8_t serverhash[16], secretbytes[16], hash[16];
 572                         memcpy(serverhash, r->key, sizeof(serverhash));
 573                         memset(r->key, 0, sizeof(r->key));
 574                         memcpy(secretbytes, reconf_key, sizeof(secretbytes));
 575
 576                         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 577                                 secretbytes[i] ^= 0x36;
 578
 579                         md5_begin(&md5);
 580                         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 581                         md5_hash(buf, len, &md5);
 582                         md5_end(hash, &md5);
 583
 584                         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 585                                 secretbytes[i] ^= 0x36;
 586                                 secretbytes[i] ^= 0x5c;
 587                         }
 588
 589                         md5_begin(&md5);
 590                         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 591                         md5_hash(hash, 16, &md5);
 592                         md5_end(hash, &md5);
 593
 594                         rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
 595                 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
 596                         rcmsg = odata[0];
 597                 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
 598                         ia_present = true;
 599                         if (olen < sizeof(struct dhcpv6_ia_hdr))
 600                                 options_valid = false;
 601                 }
 602                 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
 603                                 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
 604                         // Options are not allowed on global level
 605                         options_valid = false;
 606                 }
 607         }
 608
 609         if (!options_valid || ((odata + olen) > end))
 610                 return false;
 611
 612         if (type == DHCPV6_MSG_INFO_REQ && ia_present)
 613                 return false;
 614
 615         if (rep->msg_type == DHCPV6_MSG_RECONF) {
 616                 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
 617                         (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
 618                         !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
 619                         return false;
 620         }
 621
 622         return clientid_ok && serverid_ok;
 623 }
 624
 625
 626 int dhcpv6_poll_reconfigure(void)
 627 {
 628         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
 629         if (ret != -1)
 630                 ret = dhcpv6_request(ret);
 631
 632         return ret;
 633 }
 634
 635
 636 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
 637                 const void *opt, const void *end)
 638 {
 639         uint16_t otype, olen;
 640         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
 641         dhcpv6_for_each_option(opt, end, otype, olen, odata)
 642                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
 643                                 odata[0] == DHCPV6_MSG_RENEW ||
 644                                 odata[0] == DHCPV6_MSG_INFO_REQ))
 645                         msg = odata[0];
 646
 647         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
 648         return msg;
 649 }
 650
 651
 652 // Collect all advertised servers
 653 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
 654                 const void *opt, const void *end)
 655 {
 656         uint16_t olen, otype;
 657         uint8_t *odata, pref = 0;
 658         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
 659                                         DHCPV6_SOL_MAX_RT,
 660                                         DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0};
 661         bool have_na = false;
 662         int have_pd = 0;
 663
 664         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 665                 if (orig == DHCPV6_MSG_SOLICIT &&
 666                                 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
 667                                 olen > sizeof(struct dhcpv6_ia_hdr)) {
 668                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 669                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 670                 }
 671
 672                 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
 673                         memcpy(cand.duid, odata, olen);
 674                         cand.duid_len = olen;
 675                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 676                         int error = ((int)odata[0] << 8 | (int)odata[1]);
 677
 678                         switch (error) {
 679                         case DHCPV6_NoPrefixAvail:
 680                                 // Status code on global level
 681                                 cand.preference -= 2000;
 682                                 break;
 683
 684                         default :
 685                                 break;
 686                         }
 687                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
 688                                 cand.preference >= 0) {
 689                         cand.preference = pref = odata[0];
 690                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
 691                         cand.wants_reconfigure = true;
 692                 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
 693                         uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
 694                         if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
 695                                         sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
 696                                 cand.sol_max_rt = sol_max_rt;
 697                 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
 698                         uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
 699                         if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
 700                                         inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
 701                                 cand.inf_max_rt = inf_max_rt;
 702                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
 703                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 704                         uint8_t *oend = odata + olen, *d;
 705                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
 706                                 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
 707                                                 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
 708                                         struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
 709                                         have_pd = p->prefix;
 710                                 }
 711                         }
 712                 } else if (otype == DHCPV6_OPT_IA_NA) {
 713                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 714                         uint8_t *oend = odata + olen, *d;
 715                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
 716                                 if (otype == DHCPV6_OPT_IA_ADDR)
 717                                         have_na = true;
 718                 }
 719         }
 720
 721         if ((!have_na && na_mode == IA_MODE_FORCE) ||
 722                         (!have_pd && pd_mode == IA_MODE_FORCE)) {
 723                 /*
 724                  * RFC7083 states to process the SOL_MAX_RT and
 725                  * INF_MAX_RT options even if the DHCPv6 server
 726                  * did not propose any IA_NA and/or IA_PD
 727                  */
 728                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt;
 729                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt;
 730                 return -1;
 731         }
 732
 733         if (na_mode != IA_MODE_NONE && !have_na) {
 734                 cand.has_noaddravail = true;
 735                 cand.preference -= 1000;
 736         }
 737
 738         if (pd_mode != IA_MODE_NONE) {
 739                 if (have_pd)
 740                         cand.preference += 2000 + (128 - have_pd);
 741                 else
 742                         cand.preference -= 2000;
 743         }
 744
 745         if (cand.duid_len > 0) {
 746                 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
 747                 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
 748                 dhcpv6_add_server_cand(&cand);
 749         }
 750
 751         return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
 752 }
 753
 754
 755 static int dhcpv6_commit_advert(void)
 756 {
 757         return dhcpv6_promote_server_cand();
 758 }
 759
 760
 761 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
 762                 const void *opt, const void *end)
 763 {
 764         dhcpv6_handle_advert(orig, rc, opt, end);
 765         if (dhcpv6_commit_advert() < 0)
 766                 return -1;
 767
 768         return dhcpv6_handle_reply(orig, rc, opt, end);
 769 }
 770
 771
 772 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
 773                 const void *opt, const void *end)
 774 {
 775         uint8_t *odata;
 776         uint16_t otype, olen;
 777         uint32_t refresh = UINT32_MAX;
 778         int ret = 1;
 779         bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
 780
 781         odhcp6c_expire();
 782
 783         if (orig == DHCPV6_MSG_UNKNOWN) {
 784                 static time_t last_update = 0;
 785                 time_t now = odhcp6c_get_milli_time() / 1000;
 786
 787                 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
 788                 last_update = now;
 789
 790                 t1 -= elapsed;
 791                 t2 -= elapsed;
 792                 t3 -= elapsed;
 793
 794                 if (t1 < 0)
 795                         t1 = 0;
 796
 797                 if (t2 < 0)
 798                         t2 = 0;
 799
 800                 if (t3 < 0)
 801                         t3 = 0;
 802         }
 803
 804         if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
 805                 // Delete NA and PD we have in the state from the Advert
 806                 odhcp6c_clear_state(STATE_IA_NA);
 807                 odhcp6c_clear_state(STATE_IA_PD);
 808         }
 809
 810         if (opt) {
 811                 odhcp6c_clear_state(STATE_DNS);
 812                 odhcp6c_clear_state(STATE_SEARCH);
 813                 odhcp6c_clear_state(STATE_SNTP_IP);
 814                 odhcp6c_clear_state(STATE_NTP_IP);
 815                 odhcp6c_clear_state(STATE_NTP_FQDN);
 816                 odhcp6c_clear_state(STATE_SIP_IP);
 817                 odhcp6c_clear_state(STATE_SIP_FQDN);
 818                 odhcp6c_clear_state(STATE_AFTR_NAME);
 819         }
 820
 821         // Parse and find all matching IAs
 822         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 823                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
 824                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
 825                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 826
 827                         // Test ID
 828                         if (ia_hdr->iaid != 1)
 829                                 continue;
 830
 831                         uint16_t code = DHCPV6_Success;
 832                         uint16_t stype, slen;
 833                         uint8_t *sdata;
 834                         // Get and handle status code
 835                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
 836                                         stype, slen, sdata) {
 837                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
 838                                         uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
 839                                         uint16_t mlen = (slen > 2) ? slen - 2 : 0;
 840
 841                                         code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
 842
 843                                         if (code == DHCPV6_Success)
 844                                                 continue;
 845
 846                                         dhcpv6_handle_ia_status_code(orig, ia_hdr,
 847                                                 code, mdata, mlen, handled_status_codes, &ret);
 848
 849
 850                                         if (ret > 0)
 851                                                 return ret;
 852                                         break;
 853                                 }
 854                         }
 855
 856                         if (code != DHCPV6_Success)
 857                                 continue;
 858
 859                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 860                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 861                         uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
 862                         uint16_t mlen = (olen > 2) ? olen - 2 : 0;
 863                         uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
 864
 865                         dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
 866                 }
 867                 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
 868                         if (olen % 16 == 0)
 869                                 odhcp6c_add_state(STATE_DNS, odata, olen);
 870                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
 871                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
 872                 } else if (otype == DHCPV6_OPT_SNTP_SERVERS) {
 873                         if (olen % 16 == 0)
 874                                 odhcp6c_add_state(STATE_SNTP_IP, odata, olen);
 875                 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
 876                         uint16_t stype, slen;
 877                         uint8_t *sdata;
 878                         // Test status and bail if error
 879                         dhcpv6_for_each_option(odata, odata + olen,
 880                                         stype, slen, sdata) {
 881                                 if (slen == 16 && (stype == NTP_MC_ADDR ||
 882                                                 stype == NTP_SRV_ADDR))
 883                                         odhcp6c_add_state(STATE_NTP_IP,
 884                                                         sdata, slen);
 885                                 else if (slen > 0 && stype == NTP_SRV_FQDN)
 886                                         odhcp6c_add_state(STATE_NTP_FQDN,
 887                                                         sdata, slen);
 888                         }
 889                 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
 890                         if (olen == 16)
 891                                 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
 892                 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
 893                         odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
 894                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
 895                         refresh = ntohl(*((uint32_t*)odata));
 896                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 897                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 898                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 899                         if (r->protocol == 3 && r->algorithm == 1 &&
 900                                         r->reconf_type == 1)
 901                                 memcpy(reconf_key, r->key, sizeof(r->key));
 902                 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
 903                         size_t cur_len;
 904                         odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
 905                         if (cur_len == 0)
 906                                 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
 907                 } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) {
 908                         uint32_t sol_max_rt = ntohl(*((uint32_t *)odata));
 909                         if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN &&
 910                                         sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX)
 911                                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt;
 912                 } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) {
 913                         uint32_t inf_max_rt = ntohl(*((uint32_t *)odata));
 914                         if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN &&
 915                                         inf_max_rt <= DHCPV6_INF_MAX_RT_MAX)
 916                                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt;
 917                 }else if (otype != DHCPV6_OPT_CLIENTID &&
 918                                 otype != DHCPV6_OPT_SERVERID) {
 919                         odhcp6c_add_state(STATE_CUSTOM_OPTS,
 920                                         &odata[-4], olen + 4);
 921                 }
 922         }
 923
 924         if (orig != DHCPV6_MSG_INFO_REQ) {
 925                 // Update refresh timers if no fatal status code was received
 926                 if ((ret > 0) && dhcpv6_calc_refresh_timers()) {
 927                         switch (orig) {
 928                         case DHCPV6_MSG_RENEW:
 929                                 // Send further renews if T1 is not set
 930                                 if (!t1)
 931                                         ret = -1;
 932                                 break;
 933                         case DHCPV6_MSG_REBIND:
 934                                 // Send further rebinds if T1 and T2 is not set
 935                                 if (!t1 && !t2)
 936                                         ret = -1;
 937                                 break;
 938
 939                         case DHCPV6_MSG_REQUEST:
 940                                 // All server candidates can be cleared if not yet bound
 941                                 if (!odhcp6c_is_bound())
 942                                         dhcpv6_clear_all_server_cand();
 943
 944                         default :
 945                                 break;
 946                         }
 947                 }
 948         }
 949         else if (ret > 0) {
 950                 // All server candidates can be cleared if not yet bound
 951                 if (!odhcp6c_is_bound())
 952                         dhcpv6_clear_all_server_cand();
 953
 954                 t1 = refresh;
 955         }
 956
 957         return ret;
 958 }
 959
 960
 961 static int dhcpv6_parse_ia(void *opt, void *end)
 962 {
 963         struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt;
 964         int parsed_ia = 0;
 965         uint32_t t1, t2;
 966         uint16_t otype, olen;
 967         uint8_t *odata;
 968
 969         t1 = ntohl(ia_hdr->t1);
 970         t2 = ntohl(ia_hdr->t2);
 971
 972         if (t1 > t2)
 973                 return 0;
 974
 975         // Update address IA
 976         dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) {
 977                 struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0,
 978                                 IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0};
 979
 980                 if (otype == DHCPV6_OPT_IA_PREFIX) {
 981                         struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4];
 982                         if (olen + 4U < sizeof(*prefix))
 983                                 continue;
 984
 985                         entry.valid = ntohl(prefix->valid);
 986                         entry.preferred = ntohl(prefix->preferred);
 987
 988                         if (entry.preferred > entry.valid)
 989                                 continue;
 990
 991                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
 992                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
 993                         if (entry.t1 > entry.t2)
 994                                 entry.t1 = entry.t2;
 995
 996                         entry.length = prefix->prefix;
 997                         entry.target = prefix->addr;
 998                         uint16_t stype, slen;
 999                         uint8_t *sdata;
1000
1001 #ifdef EXT_PREFIX_CLASS
1002                         // Find prefix class, if any
1003                         dhcpv6_for_each_option(&prefix[1], odata + olen,
1004                                         stype, slen, sdata)
1005                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1006                                         entry.class = sdata[0] << 8 | sdata[1];
1007 #endif
1008
1009                         // Parse PD-exclude
1010                         bool ok = true;
1011                         dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U,
1012                                         odata + olen, stype, slen, sdata) {
1013                                 if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2)
1014                                         continue;
1015
1016                                 uint8_t elen = sdata[0];
1017                                 if (elen > 64)
1018                                         elen = 64;
1019
1020                                 if (elen <= 32 || elen <= entry.length) {
1021                                         ok = false;
1022                                         continue;
1023                                 }
1024
1025
1026                                 uint8_t bytes = ((elen - entry.length - 1) / 8) + 1;
1027                                 if (slen <= bytes) {
1028                                         ok = false;
1029                                         continue;
1030                                 }
1031
1032                                 uint32_t exclude = 0;
1033                                 do {
1034                                         exclude = exclude << 8 | sdata[bytes];
1035                                 } while (--bytes);
1036
1037                                 exclude >>= 8 - ((elen - entry.length) % 8);
1038                                 exclude <<= 64 - elen;
1039
1040                                 // Abusing router & priority fields for exclusion
1041                                 entry.router = entry.target;
1042                                 entry.router.s6_addr32[1] |= htonl(exclude);
1043                                 entry.priority = elen;
1044                         }
1045
1046                         if (ok) {
1047                                 odhcp6c_update_entry(STATE_IA_PD, &entry);
1048                                 parsed_ia++;
1049                         }
1050
1051                         entry.priority = 0;
1052                         memset(&entry.router, 0, sizeof(entry.router));
1053                 } else if (otype == DHCPV6_OPT_IA_ADDR) {
1054                         struct dhcpv6_ia_addr *addr = (void*)&odata[-4];
1055                         if (olen + 4U < sizeof(*addr))
1056                                 continue;
1057
1058                         entry.preferred = ntohl(addr->preferred);
1059                         entry.valid = ntohl(addr->valid);
1060
1061                         if (entry.preferred > entry.valid)
1062                                 continue;
1063
1064                         entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX));
1065                         entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX));
1066                         if (entry.t1 > entry.t2)
1067                                 entry.t1 = entry.t2;
1068
1069                         entry.length = 128;
1070                         entry.target = addr->addr;
1071
1072 #ifdef EXT_PREFIX_CLASS
1073                         uint16_t stype, slen;
1074                         uint8_t *sdata;
1075                         // Find prefix class, if any
1076                         dhcpv6_for_each_option(&addr[1], odata + olen,
1077                                         stype, slen, sdata)
1078                                 if (stype == DHCPV6_OPT_PREFIX_CLASS && slen == 2)
1079                                         entry.class = sdata[0] << 8 | sdata[1];
1080 #endif
1081
1082                         odhcp6c_update_entry(STATE_IA_NA, &entry);
1083                         parsed_ia++;
1084                 }
1085         }
1086         return parsed_ia;
1087 }
1088
1089
1090 static int dhcpv6_calc_refresh_timers(void)
1091 {
1092         struct odhcp6c_entry *e;
1093         size_t ia_na_entries, ia_pd_entries, i;
1094         int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0;
1095
1096         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
1097         ia_na_entries /= sizeof(*e);
1098         for (i = 0; i < ia_na_entries; i++) {
1099                 if (e[i].t1 < l_t1)
1100                         l_t1 = e[i].t1;
1101
1102                 if (e[i].t2 < l_t2)
1103                         l_t2 = e[i].t2;
1104
1105                 if (e[i].valid > l_t3)
1106                         l_t3 = e[i].valid;
1107         }
1108
1109         e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
1110         ia_pd_entries /= sizeof(*e);
1111         for (i = 0; i < ia_pd_entries; i++) {
1112                 if (e[i].t1 < l_t1)
1113                         l_t1 = e[i].t1;
1114
1115                 if (e[i].t2 < l_t2)
1116                         l_t2 = e[i].t2;
1117
1118                 if (e[i].valid > l_t3)
1119                         l_t3 = e[i].valid;
1120         }
1121
1122         if (ia_pd_entries || ia_na_entries) {
1123                 t1 = l_t1;
1124                 t2 = l_t2;
1125                 t3 = l_t3;
1126         } else {
1127                 t1 = 600;
1128         }
1129
1130         return (int)(ia_pd_entries + ia_na_entries);
1131 }
1132
1133
1134 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1135                 const void *status_msg, const int len)
1136 {
1137         uint8_t buf[len + 3];
1138
1139         memset(buf, 0, sizeof(buf));
1140         if (len) {
1141                 buf[0] = '(';
1142                 memcpy(&buf[1], status_msg, len);
1143                 buf[len + 1] = ')';
1144         }
1145
1146         syslog(LOG_WARNING, "Server returned %s status %i %s",
1147                 scope, code, buf);
1148 }
1149
1150
1151 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1152                 const uint16_t code, const void *status_msg, const int len,
1153                 int *ret)
1154 {
1155         dhcpv6_log_status_code(code, "message", status_msg, len);
1156
1157         switch (code) {
1158         case DHCPV6_UnspecFail:
1159                 // Generic failure
1160                 *ret = 0;
1161                 break;
1162
1163         case DHCPV6_UseMulticast:
1164                 // TODO handle multicast status code
1165                 break;
1166
1167         case DHCPV6_NoAddrsAvail:
1168         case DHCPV6_NoPrefixAvail:
1169                 if (orig == DHCPV6_MSG_REQUEST)
1170                         *ret = 0; // Failure
1171                 break;
1172
1173         default:
1174                 break;
1175         }
1176 }
1177
1178
1179 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1180                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1181                 const void *status_msg, const int len,
1182                 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1183 {
1184         dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1185                 "IA_NA" : "IA_PD", status_msg, len);
1186
1187         switch (code) {
1188         case DHCPV6_NoBinding:
1189                 switch (orig) {
1190                 case DHCPV6_MSG_RENEW:
1191                 case DHCPV6_MSG_REBIND:
1192                         if ((*ret > 0) && !handled_status_codes[code])
1193                                 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1194                         break;
1195
1196                 default:
1197                         break;
1198                 }
1199                 break;
1200
1201         case DHCPV6_NoAddrsAvail:
1202         case DHCPV6_NoPrefixAvail:
1203                 switch (orig) {
1204                 case DHCPV6_MSG_REQUEST:
1205                         if (*ret != 0)
1206                                 *ret = 0;
1207                         break;
1208                 default:
1209                         break;
1210                 }
1211                 break;
1212
1213         case DHCPV6_NotOnLink:
1214                 // TODO handle not onlink in case of confirm
1215                 break;
1216
1217         default:
1218                 break;
1219         }
1220 }
1221
1222 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1223 {
1224         size_t cand_len, i;
1225         struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1226
1227         // Remove identical duid server candidate
1228         for (i = 0; i < cand_len / sizeof(*c); ++i) {
1229                 if (cand->duid_len == c[i].duid_len &&
1230                                 !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1231                         free(c[i].ia_na);
1232                         free(c[i].ia_pd);
1233                         odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1234                         break;
1235                 }
1236         }
1237
1238         for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1239                 i < cand_len / sizeof(*c); ++i) {
1240                 if (c[i].preference < cand->preference)
1241                         break;
1242         }
1243
1244         odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1245 }
1246
1247 static void dhcpv6_clear_all_server_cand(void)
1248 {
1249         size_t cand_len, i;
1250         struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1251
1252         // Server candidates need deep delete for IA_NA/IA_PD
1253         for (i = 0; i < cand_len / sizeof(*c); ++i) {
1254                 free(c[i].ia_na);
1255                 free(c[i].ia_pd);
1256         }
1257         odhcp6c_clear_state(STATE_SERVER_CAND);
1258 }
1259
1260 int dhcpv6_promote_server_cand(void)
1261 {
1262         size_t cand_len;
1263         struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1264         uint16_t hdr[2];
1265         int ret = (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) ?
1266                         DHCPV6_STATELESS : DHCPV6_STATEFUL;
1267
1268         // Clear lingering candidate state info
1269         odhcp6c_clear_state(STATE_SERVER_ID);
1270         odhcp6c_clear_state(STATE_IA_NA);
1271         odhcp6c_clear_state(STATE_IA_PD);
1272
1273         if (!cand_len)
1274                 return -1;
1275
1276         if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1277                 na_mode = IA_MODE_NONE;
1278
1279                 dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1280                 dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1281
1282                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1283         }
1284
1285         hdr[0] = htons(DHCPV6_OPT_SERVERID);
1286         hdr[1] = htons(cand->duid_len);
1287         odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1288         odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1289         accept_reconfig = cand->wants_reconfigure;
1290         if (cand->ia_na_len) {
1291                 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1292                 free(cand->ia_na);
1293                 if (na_mode != IA_MODE_NONE)
1294                         ret = DHCPV6_STATEFUL;
1295         }
1296         if (cand->ia_pd_len) {
1297                 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1298                 free(cand->ia_pd);
1299                 if (request_prefix)
1300                         ret = DHCPV6_STATEFUL;
1301         }
1302
1303         dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt;
1304         dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt;
1305
1306         odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1307
1308         return ret;
1309 }