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 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
  63 static void dhcpv6_clear_all_server_cand(void);
  64
  65 static reply_handler dhcpv6_handle_reply;
  66 static reply_handler dhcpv6_handle_advert;
  67 static reply_handler dhcpv6_handle_rebind_reply;
  68 static reply_handler dhcpv6_handle_reconfigure;
  69 static int dhcpv6_commit_advert(void);
  70
  71
  72
  73 // RFC 3315 - 5.5 Timeout and Delay values
  74 static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
  75         [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
  76                         dhcpv6_handle_reconfigure, NULL},
  77         [DHCPV6_MSG_SOLICIT] = {true, 1, 3600, 0, "SOLICIT",
  78                         dhcpv6_handle_advert, dhcpv6_commit_advert},
  79         [DHCPV6_MSG_REQUEST] = {true, 1, 30, 10, "REQUEST",
  80                         dhcpv6_handle_reply, NULL},
  81         [DHCPV6_MSG_RENEW] = {false, 10, 600, 0, "RENEW",
  82                         dhcpv6_handle_reply, NULL},
  83         [DHCPV6_MSG_REBIND] = {false, 10, 600, 0, "REBIND",
  84                         dhcpv6_handle_rebind_reply, NULL},
  85         [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
  86         [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
  87         [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, 0, "INFOREQ",
  88                         dhcpv6_handle_reply, NULL},
  89 };
  90
  91
  92 // Sockets
  93 static int sock = -1;
  94 static int ifindex = -1;
  95 static int64_t t1 = 0, t2 = 0, t3 = 0;
  96
  97 // IA states
  98 static int request_prefix = -1;
  99 static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE;
 100 static bool accept_reconfig = false;
 101 // Server unicast address
 102 static struct in6_addr server_addr = IN6ADDR_ANY_INIT;
 103
 104 // Reconfigure key
 105 static uint8_t reconf_key[16];
 106
 107
 108 int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout)
 109 {
 110         request_prefix = request_pd;
 111         dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
 112
 113         sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
 114         if (sock < 0)
 115                 return -1;
 116
 117         // Detect interface
 118         struct ifreq ifr;
 119         strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 120         if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
 121                 return -1;
 122         ifindex = ifr.ifr_ifindex;
 123
 124         // Create client DUID
 125         size_t client_id_len;
 126         odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 127         if (client_id_len == 0) {
 128                 uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0,
 129                                 DHCPV6_DUID_LLADDR, 0, 1};
 130
 131                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0)
 132                         memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
 133
 134                 uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0};
 135                 struct ifreq ifs[100], *ifp, *ifend;
 136                 struct ifconf ifc;
 137                 ifc.ifc_req = ifs;
 138                 ifc.ifc_len = sizeof(ifs);
 139
 140                 if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) &&
 141                                 ioctl(sock, SIOCGIFCONF, &ifc) >= 0) {
 142                         // If our interface doesn't have an address...
 143                         ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq));
 144                         for (ifp = ifc.ifc_req; ifp < ifend &&
 145                                         !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) {
 146                                 memcpy(ifr.ifr_name, ifp->ifr_name,
 147                                                 sizeof(ifr.ifr_name));
 148                                 if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
 149                                         continue;
 150
 151                                 memcpy(&duid[8], ifr.ifr_hwaddr.sa_data,
 152                                                 ETHER_ADDR_LEN);
 153                         }
 154                 }
 155
 156                 odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid));
 157         }
 158
 159         // Create ORO
 160         uint16_t oro[] = {
 161                         htons(DHCPV6_OPT_SIP_SERVER_D),
 162                         htons(DHCPV6_OPT_SIP_SERVER_A),
 163                         htons(DHCPV6_OPT_DNS_SERVERS),
 164                         htons(DHCPV6_OPT_DNS_DOMAIN),
 165                         htons(DHCPV6_OPT_UNICAST),
 166                         htons(DHCPV6_OPT_NTP_SERVER),
 167                         htons(DHCPV6_OPT_AFTR_NAME),
 168                         htons(DHCPV6_OPT_PD_EXCLUDE),
 169 #ifdef EXT_PREFIX_CLASS
 170                         htons(DHCPV6_OPT_PREFIX_CLASS),
 171 #endif
 172         };
 173         odhcp6c_add_state(STATE_ORO, oro, sizeof(oro));
 174
 175         // Configure IPv6-options
 176         int val = 1;
 177         setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
 178         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 179         setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
 180         val = 0;
 181         setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
 182         setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
 183
 184         struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
 185                 .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
 186         if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0)
 187                 return -1;
 188
 189         return 0;
 190 }
 191
 192
 193 void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd)
 194 {
 195         na_mode = na;
 196         pd_mode = pd;
 197 }
 198
 199
 200 static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
 201 {
 202         // Build FQDN
 203         char fqdn_buf[256];
 204         gethostname(fqdn_buf, sizeof(fqdn_buf));
 205         struct {
 206                 uint16_t type;
 207                 uint16_t len;
 208                 uint8_t flags;
 209                 uint8_t data[256];
 210         } fqdn;
 211         size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data,
 212                         sizeof(fqdn.data), NULL, NULL);
 213         fqdn.type = htons(DHCPV6_OPT_FQDN);
 214         fqdn.len = htons(fqdn_len - 4);
 215         fqdn.flags = 0;
 216
 217
 218         // Build Client ID
 219         size_t cl_id_len;
 220         void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len);
 221
 222         // Get Server ID
 223         size_t srv_id_len;
 224         void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len);
 225
 226         // Build IA_PDs
 227         size_t ia_pd_entries, ia_pd_len = 0;
 228         struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries);
 229         ia_pd_entries /= sizeof(*e);
 230         struct dhcpv6_ia_hdr hdr_ia_pd = {
 231                 htons(DHCPV6_OPT_IA_PD),
 232                 htons(sizeof(hdr_ia_pd) - 4),
 233                 1, 0, 0
 234         };
 235
 236
 237         uint8_t *ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10));
 238         for (size_t i = 0; i < ia_pd_entries; ++i) {
 239                 uint8_t ex_len = 0;
 240                 if (e[i].priority > 0)
 241                         ex_len = ((e[i].priority - e[i].length - 1) / 8) + 6;
 242
 243                 struct dhcpv6_ia_prefix p = {
 244                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 245                         .len = htons(sizeof(p) - 4U + ex_len),
 246                         .prefix = e[i].length,
 247                         .addr = e[i].target
 248                 };
 249
 250                 memcpy(ia_pd + ia_pd_len, &p, sizeof(p));
 251                 ia_pd_len += sizeof(p);
 252
 253                 if (ex_len) {
 254                         ia_pd[ia_pd_len++] = 0;
 255                         ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE;
 256                         ia_pd[ia_pd_len++] = 0;
 257                         ia_pd[ia_pd_len++] = ex_len - 4;
 258                         ia_pd[ia_pd_len++] = e[i].priority;
 259
 260                         uint32_t excl = ntohl(e[i].router.s6_addr32[1]);
 261                         excl >>= (64 - e[i].priority);
 262                         excl <<= 8 - ((e[i].priority - e[i].length) % 8);
 263
 264                         for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8)
 265                                 ia_pd[ia_pd_len + i] = excl & 0xff;
 266                         ia_pd_len += ex_len - 5;
 267                 }
 268         }
 269
 270         struct dhcpv6_ia_prefix pref = {
 271                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 272                 .len = htons(25), .prefix = request_prefix
 273         };
 274         if (request_prefix > 0 && ia_pd_len == 0 && type == DHCPV6_MSG_SOLICIT) {
 275                 ia_pd = (uint8_t*)&pref;
 276                 ia_pd_len = sizeof(pref);
 277         }
 278         hdr_ia_pd.len = htons(ntohs(hdr_ia_pd.len) + ia_pd_len);
 279
 280         // Build IA_NAs
 281         size_t ia_na_entries, ia_na_len = 0;
 282         void *ia_na = NULL;
 283         e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries);
 284         ia_na_entries /= sizeof(*e);
 285
 286         struct dhcpv6_ia_hdr hdr_ia_na = {
 287                 htons(DHCPV6_OPT_IA_NA),
 288                 htons(sizeof(hdr_ia_na) - 4),
 289                 1, 0, 0
 290         };
 291
 292         struct dhcpv6_ia_addr pa[ia_na_entries];
 293         for (size_t i = 0; i < ia_na_entries; ++i) {
 294                 pa[i].type = htons(DHCPV6_OPT_IA_ADDR);
 295                 pa[i].len = htons(sizeof(pa[i]) - 4U);
 296                 pa[i].addr = e[i].target;
 297                 pa[i].preferred = 0;
 298                 pa[i].valid = 0;
 299         }
 300
 301         ia_na = pa;
 302         ia_na_len = sizeof(pa);
 303         hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len);
 304
 305         // Reconfigure Accept
 306         struct {
 307                 uint16_t type;
 308                 uint16_t length;
 309         } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0};
 310
 311         // Request Information Refresh
 312         uint16_t oro_refresh = htons(DHCPV6_OPT_INFO_REFRESH);
 313
 314         // Prepare Header
 315         size_t oro_len;
 316         void *oro = odhcp6c_get_state(STATE_ORO, &oro_len);
 317         struct {
 318                 uint8_t type;
 319                 uint8_t trid[3];
 320                 uint16_t elapsed_type;
 321                 uint16_t elapsed_len;
 322                 uint16_t elapsed_value;
 323                 uint16_t oro_type;
 324                 uint16_t oro_len;
 325         } hdr = {
 326                 type, {trid[0], trid[1], trid[2]},
 327                 htons(DHCPV6_OPT_ELAPSED), htons(2),
 328                         htons((ecs > 0xffff) ? 0xffff : ecs),
 329                 htons(DHCPV6_OPT_ORO), htons(oro_len),
 330         };
 331
 332         struct iovec iov[] = {
 333                 {&hdr, sizeof(hdr)},
 334                 {oro, oro_len},
 335                 {&oro_refresh, 0},
 336                 {cl_id, cl_id_len},
 337                 {srv_id, srv_id_len},
 338                 {&reconf_accept, sizeof(reconf_accept)},
 339                 {&fqdn, fqdn_len},
 340                 {&hdr_ia_na, sizeof(hdr_ia_na)},
 341                 {ia_na, ia_na_len},
 342                 {&hdr_ia_pd, sizeof(hdr_ia_pd)},
 343                 {ia_pd, ia_pd_len},
 344         };
 345
 346         size_t cnt = ARRAY_SIZE(iov);
 347         if (type == DHCPV6_MSG_INFO_REQ) {
 348                 cnt = 5;
 349                 iov[2].iov_len = sizeof(oro_refresh);
 350                 hdr.oro_len = htons(oro_len + sizeof(oro_refresh));
 351         } else if (!request_prefix) {
 352                 cnt = 9;
 353         }
 354
 355         // Disable IAs if not used
 356         if (type != DHCPV6_MSG_SOLICIT) {
 357                 iov[5].iov_len = 0;
 358                 if (ia_na_len == 0)
 359                         iov[7].iov_len = 0;
 360                 if (ia_pd_len == 0)
 361                         iov[9].iov_len = 0;
 362         }
 363
 364         if (na_mode == IA_MODE_NONE)
 365                 iov[7].iov_len = 0;
 366
 367         struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT),
 368                 0, ALL_DHCPV6_RELAYS, ifindex};
 369         struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0};
 370
 371         switch (type) {
 372         case DHCPV6_MSG_REQUEST:
 373         case DHCPV6_MSG_RENEW:
 374         case DHCPV6_MSG_RELEASE:
 375         case DHCPV6_MSG_DECLINE:
 376                 if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) &&
 377                         odhcp6c_addr_in_scope(&server_addr)) {
 378                         srv.sin6_addr = server_addr;
 379                         if (!IN6_IS_ADDR_LINKLOCAL(&server_addr))
 380                                 srv.sin6_scope_id = 0;
 381                 }
 382                 break;
 383         default:
 384                 break;
 385         }
 386
 387         if (sendmsg(sock, &msg, 0) < 0) {
 388                 char in6_str[INET6_ADDRSTRLEN];
 389
 390                 syslog(LOG_ERR, "Failed to send DHCPV6 message to %s (%s)",
 391                         inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
 392                                 in6_str, sizeof(in6_str)), strerror(errno));
 393         }
 394 }
 395
 396
 397 static int64_t dhcpv6_rand_delay(int64_t time)
 398 {
 399         int random;
 400         odhcp6c_random(&random, sizeof(random));
 401         return (time * ((int64_t)random % 1000LL)) / 10000LL;
 402 }
 403
 404
 405 int dhcpv6_request(enum dhcpv6_msg type)
 406 {
 407         uint8_t rc = 0;
 408         uint64_t timeout = UINT32_MAX;
 409         struct dhcpv6_retx *retx = &dhcpv6_retx[type];
 410
 411         if (retx->delay) {
 412                 struct timespec ts = {0, 0};
 413                 ts.tv_nsec = dhcpv6_rand_delay(10 * DHCPV6_REQ_DELAY);
 414                 nanosleep(&ts, NULL);
 415         }
 416
 417         if (type == DHCPV6_MSG_UNKNOWN)
 418                 timeout = t1;
 419         else if (type == DHCPV6_MSG_RENEW)
 420                 timeout = (t2 > t1) ? t2 - t1 : 0;
 421         else if (type == DHCPV6_MSG_REBIND)
 422                 timeout = (t3 > t2) ? t3 - t2 : 0;
 423
 424         if (timeout == 0)
 425                 return -1;
 426
 427         syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)",
 428                         retx->name, (unsigned long long)timeout, retx->max_rc);
 429
 430         uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
 431
 432         // Generate transaction ID
 433         uint8_t trid[3] = {0, 0, 0};
 434         if (type != DHCPV6_MSG_UNKNOWN)
 435                 odhcp6c_random(trid, sizeof(trid));
 436         ssize_t len = -1;
 437         int64_t rto = 0;
 438
 439         do {
 440                 if (rto == 0) {
 441                         int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 442
 443                         // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
 444                         while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
 445                                 delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
 446
 447                         rto = (retx->init_timeo * 1000 + delay);
 448                 }
 449                 else
 450                         rto = (2 * rto + dhcpv6_rand_delay(rto));
 451
 452                 if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
 453                         rto = retx->max_timeo * 1000 +
 454                                 dhcpv6_rand_delay(retx->max_timeo * 1000);
 455
 456                 // Calculate end for this round and elapsed time
 457                 uint64_t round_end = round_start + rto;
 458                 elapsed = round_start - start;
 459
 460                 // Don't wait too long
 461                 if (round_end - start > timeout * 1000)
 462                         round_end = timeout * 1000 + start;
 463
 464                 // Built and send package
 465                 if (type != DHCPV6_MSG_UNKNOWN) {
 466                         if (type != DHCPV6_MSG_SOLICIT)
 467                                 syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)",
 468                                                 retx->name, (unsigned long long)elapsed, rc);
 469                         dhcpv6_send(type, trid, elapsed / 10);
 470                         rc++;
 471                 }
 472
 473                 // Receive rounds
 474                 for (; len < 0 && (round_start < round_end);
 475                                 round_start = odhcp6c_get_milli_time()) {
 476                         uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 477                         struct iovec iov = {buf, sizeof(buf)};
 478                         struct msghdr msg = {NULL, 0, &iov, 1,
 479                                         cmsg_buf, sizeof(cmsg_buf), 0};
 480                         struct in6_pktinfo *pktinfo = NULL;
 481
 482                         // Check for pending signal
 483                         if (odhcp6c_signal_process())
 484                                 return -1;
 485
 486                         // Set timeout for receiving
 487                         uint64_t t = round_end - round_start;
 488                         struct timeval timeout = {t / 1000, (t % 1000) * 1000};
 489                         setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,
 490                                         &timeout, sizeof(timeout));
 491
 492                         // Receive cycle
 493                         len = recvmsg(sock, &msg, 0);
 494                         if (len < 0)
 495                                 continue;
 496
 497                         for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL;
 498                                 ch = CMSG_NXTHDR(&msg, ch)) {
 499                                 if (ch->cmsg_level == SOL_IPV6 &&
 500                                         ch->cmsg_type == IPV6_PKTINFO) {
 501                                         pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch);
 502                                         break;
 503                                 }
 504                         }
 505
 506                         if (pktinfo == NULL) {
 507                                 len = -1;
 508                                 continue;
 509                         }
 510
 511                         if (!dhcpv6_response_is_valid(buf, len, trid,
 512                                                         type, &pktinfo->ipi6_addr)) {
 513                                 len = -1;
 514                                 continue;
 515                         }
 516
 517                         uint8_t *opt = &buf[4];
 518                         uint8_t *opt_end = opt + len - 4;
 519
 520                         round_start = odhcp6c_get_milli_time();
 521                         elapsed = round_start - start;
 522                         syslog(LOG_NOTICE, "Got a valid reply after "
 523                                         "%llums", (unsigned long long)elapsed);
 524
 525                         if (retx->handler_reply)
 526                                 len = retx->handler_reply(type, rc, opt, opt_end);
 527
 528                         if (len > 0 && round_end - round_start > 1000)
 529                                 round_end = 1000 + round_start;
 530                 }
 531
 532                 // Allow
 533                 if (retx->handler_finish)
 534                         len = retx->handler_finish();
 535         } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
 536
 537         return len;
 538 }
 539
 540 // Message validation checks according to RFC3315 chapter 15
 541 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len,
 542                 const uint8_t transaction[3], enum dhcpv6_msg type,
 543                 const struct in6_addr *daddr)
 544 {
 545         const struct dhcpv6_header *rep = buf;
 546         if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id,
 547                         transaction, sizeof(rep->tr_id)))
 548                 return false; // Invalid reply
 549
 550         if (type == DHCPV6_MSG_SOLICIT) {
 551                 if (rep->msg_type != DHCPV6_MSG_ADVERT &&
 552                                 rep->msg_type != DHCPV6_MSG_REPLY)
 553                         return false;
 554         } else if (type == DHCPV6_MSG_UNKNOWN) {
 555                 if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF)
 556                         return false;
 557         } else if (rep->msg_type != DHCPV6_MSG_REPLY) {
 558                 return false;
 559         }
 560
 561         uint8_t *end = ((uint8_t*)buf) + len, *odata,
 562                 rcmsg = DHCPV6_MSG_UNKNOWN;
 563         uint16_t otype, olen;
 564         bool clientid_ok = false, serverid_ok = false, rcauth_ok = false,
 565                 ia_present = false, options_valid = true;
 566
 567         size_t client_id_len, server_id_len;
 568         void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len);
 569         void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
 570
 571         dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) {
 572                 if ((odata + olen) > end) {
 573                         options_valid = false;
 574                         break;
 575                 }
 576                 else if (otype == DHCPV6_OPT_CLIENTID) {
 577                         clientid_ok = (olen + 4U == client_id_len) && !memcmp(
 578                                         &odata[-4], client_id, client_id_len);
 579                 } else if (otype == DHCPV6_OPT_SERVERID) {
 580                         if (server_id_len)
 581                                 serverid_ok = (olen + 4U == server_id_len) && !memcmp(
 582                                                 &odata[-4], server_id, server_id_len);
 583                         else
 584                                 serverid_ok = true;
 585                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 586                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 587                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 588                         if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2)
 589                                 continue;
 590
 591                         md5_state_t md5;
 592                         uint8_t serverhash[16], secretbytes[16], hash[16];
 593                         memcpy(serverhash, r->key, sizeof(serverhash));
 594                         memset(r->key, 0, sizeof(r->key));
 595                         memcpy(secretbytes, reconf_key, sizeof(secretbytes));
 596
 597                         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 598                                 secretbytes[i] ^= 0x36;
 599
 600                         md5_init(&md5);
 601                         md5_append(&md5, secretbytes, sizeof(secretbytes));
 602                         md5_append(&md5, buf, len);
 603                         md5_finish(&md5, hash);
 604
 605                         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 606                                 secretbytes[i] ^= 0x36;
 607                                 secretbytes[i] ^= 0x5c;
 608                         }
 609
 610                         md5_init(&md5);
 611                         md5_append(&md5, secretbytes, sizeof(secretbytes));
 612                         md5_append(&md5, hash, 16);
 613                         md5_finish(&md5, hash);
 614
 615                         rcauth_ok = !memcmp(hash, serverhash, sizeof(hash));
 616                 } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) {
 617                         rcmsg = odata[0];
 618                 } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) {
 619                         ia_present = true;
 620                         if (olen < sizeof(struct dhcpv6_ia_hdr))
 621                                 options_valid = false;
 622                 }
 623                 else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) ||
 624                                 (otype == DHCPV6_OPT_PD_EXCLUDE)) {
 625                         // Options are not allowed on global level
 626                         options_valid = false;
 627                 }
 628         }
 629
 630         if (!options_valid)
 631                 return false;
 632
 633         if (type == DHCPV6_MSG_INFO_REQ && ia_present)
 634                 return false;
 635
 636         if (rep->msg_type == DHCPV6_MSG_RECONF) {
 637                 if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_INFO_REQ) ||
 638                         (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) ||
 639                         !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr))
 640                         return false;
 641         }
 642
 643         return clientid_ok && serverid_ok;
 644 }
 645
 646
 647 int dhcpv6_poll_reconfigure(void)
 648 {
 649         int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN);
 650         if (ret != -1)
 651                 ret = dhcpv6_request(ret);
 652
 653         return ret;
 654 }
 655
 656
 657 static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
 658                 const void *opt, const void *end)
 659 {
 660         uint16_t otype, olen;
 661         uint8_t *odata, msg = DHCPV6_MSG_RENEW;
 662         dhcpv6_for_each_option(opt, end, otype, olen, odata)
 663                 if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1 && (
 664                                 odata[0] == DHCPV6_MSG_RENEW ||
 665                                 odata[0] == DHCPV6_MSG_INFO_REQ))
 666                         msg = odata[0];
 667
 668         dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
 669         return msg;
 670 }
 671
 672
 673 // Collect all advertised servers
 674 static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc,
 675                 const void *opt, const void *end)
 676 {
 677         uint16_t olen, otype;
 678         uint8_t *odata, pref = 0;
 679         struct dhcpv6_server_cand cand = {false, false, 0, 0, {0},
 680                                         IN6ADDR_ANY_INIT, NULL, NULL, 0, 0};
 681         bool have_na = false;
 682         int have_pd = 0;
 683
 684         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 685                 if (orig == DHCPV6_MSG_SOLICIT &&
 686                                 (otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) &&
 687                                 olen > sizeof(struct dhcpv6_ia_hdr)) {
 688                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 689                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 690                 }
 691
 692                 if (otype == DHCPV6_OPT_SERVERID && olen <= 130) {
 693                         memcpy(cand.duid, odata, olen);
 694                         cand.duid_len = olen;
 695                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 696                         int error = ((int)odata[0] << 8 | (int)odata[1]);
 697
 698                         switch (error) {
 699                         case DHCPV6_NoPrefixAvail:
 700                                 // Status code on global level
 701                                 if (pd_mode == IA_MODE_FORCE)
 702                                         return -1;
 703                                 cand.preference -= 2000;
 704                                 break;
 705
 706                         case DHCPV6_NoAddrsAvail:
 707                                 // Status code on global level
 708                                 if (na_mode == IA_MODE_FORCE)
 709                                         return -1;
 710                                 break;
 711
 712                         default :
 713                                 break;
 714                         }
 715                 } else if (otype == DHCPV6_OPT_PREF && olen >= 1 &&
 716                                 cand.preference >= 0) {
 717                         cand.preference = pref = odata[0];
 718                 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) {
 719                         cand.server_addr = *(struct in6_addr *)odata;
 720                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
 721                         cand.wants_reconfigure = true;
 722                 } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) {
 723                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 724                         uint8_t *oend = odata + olen, *d;
 725                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d) {
 726                                 if (otype == DHCPV6_OPT_IA_PREFIX && (olen + 4) >=
 727                                                 (uint16_t)sizeof(struct dhcpv6_ia_prefix)) {
 728                                         struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4];
 729                                         have_pd = p->prefix;
 730                                 }
 731                         }
 732                 } else if (otype == DHCPV6_OPT_IA_NA) {
 733                         struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4];
 734                         uint8_t *oend = odata + olen, *d;
 735                         dhcpv6_for_each_option(&h[1], oend, otype, olen, d)
 736                                 if (otype == DHCPV6_OPT_IA_ADDR)
 737                                         have_na = true;
 738                 }
 739         }
 740
 741         if ((!have_na && na_mode == IA_MODE_FORCE) ||
 742                         (!have_pd && pd_mode == IA_MODE_FORCE))
 743                 return -1;
 744
 745         if (na_mode != IA_MODE_NONE && !have_na) {
 746                 cand.has_noaddravail = true;
 747                 cand.preference -= 1000;
 748         }
 749
 750         if (pd_mode != IA_MODE_NONE) {
 751                 if (have_pd)
 752                         cand.preference += 2000 + (128 - have_pd);
 753                 else
 754                         cand.preference -= 2000;
 755         }
 756
 757         if (cand.duid_len > 0) {
 758                 cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len);
 759                 cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len);
 760                 dhcpv6_add_server_cand(&cand);
 761         }
 762
 763         return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1;
 764 }
 765
 766
 767 static int dhcpv6_commit_advert(void)
 768 {
 769         return dhcpv6_promote_server_cand();
 770 }
 771
 772
 773 static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
 774                 const void *opt, const void *end)
 775 {
 776         dhcpv6_handle_advert(orig, rc, opt, end);
 777         if (dhcpv6_commit_advert() < 0)
 778                 return -1;
 779
 780         return dhcpv6_handle_reply(orig, rc, opt, end);
 781 }
 782
 783
 784 static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
 785                 const void *opt, const void *end)
 786 {
 787         uint8_t *odata;
 788         uint16_t otype, olen;
 789         uint32_t refresh = UINT32_MAX;
 790         int ret = 1;
 791         bool handled_status_codes[_DHCPV6_Status_Max] = { false, };
 792
 793         odhcp6c_expire();
 794
 795         if (orig == DHCPV6_MSG_UNKNOWN) {
 796                 static time_t last_update = 0;
 797                 time_t now = odhcp6c_get_milli_time() / 1000;
 798
 799                 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
 800                 last_update = now;
 801
 802                 t1 -= elapsed;
 803                 t2 -= elapsed;
 804                 t3 -= elapsed;
 805
 806                 if (t1 < 0)
 807                         t1 = 0;
 808
 809                 if (t2 < 0)
 810                         t2 = 0;
 811
 812                 if (t3 < 0)
 813                         t3 = 0;
 814         }
 815
 816         if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) {
 817                 // Delete NA and PD we have in the state from the Advert
 818                 odhcp6c_clear_state(STATE_IA_NA);
 819                 odhcp6c_clear_state(STATE_IA_PD);
 820         }
 821
 822         if (opt) {
 823                 odhcp6c_clear_state(STATE_DNS);
 824                 odhcp6c_clear_state(STATE_SEARCH);
 825                 odhcp6c_clear_state(STATE_SNTP_IP);
 826                 odhcp6c_clear_state(STATE_SNTP_FQDN);
 827                 odhcp6c_clear_state(STATE_SIP_IP);
 828                 odhcp6c_clear_state(STATE_SIP_FQDN);
 829                 odhcp6c_clear_state(STATE_AFTR_NAME);
 830         }
 831
 832         // Parse and find all matching IAs
 833         dhcpv6_for_each_option(opt, end, otype, olen, odata) {
 834                 if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)
 835                                 && olen > sizeof(struct dhcpv6_ia_hdr)) {
 836                         struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]);
 837
 838                         // Test ID
 839                         if (ia_hdr->iaid != 1)
 840                                 continue;
 841
 842                         uint16_t code = DHCPV6_Success;
 843                         uint16_t stype, slen;
 844                         uint8_t *sdata;
 845                         // Get and handle status code
 846                         dhcpv6_for_each_option(&ia_hdr[1], odata + olen,
 847                                         stype, slen, sdata) {
 848                                 if (stype == DHCPV6_OPT_STATUS && slen >= 2) {
 849                                         uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL;
 850                                         uint16_t mlen = (slen > 2) ? slen - 2 : 0;
 851
 852                                         code = ((int)sdata[0]) << 8 | ((int)sdata[1]);
 853
 854                                         if (code == DHCPV6_Success)
 855                                                 continue;
 856
 857                                         dhcpv6_handle_ia_status_code(orig, ia_hdr,
 858                                                 code, mdata, mlen, handled_status_codes, &ret);
 859
 860
 861                                         if (ret > 0)
 862                                                 return ret;
 863                                         break;
 864                                 }
 865                         }
 866
 867                         if (code != DHCPV6_Success)
 868                                 continue;
 869
 870                         dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr));
 871                 } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) {
 872                         server_addr = *(struct in6_addr *)odata;
 873                 } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) {
 874                         uint8_t *mdata = (olen > 2) ? &odata[2] : NULL;
 875                         uint16_t mlen = (olen > 2) ? olen - 2 : 0;
 876                         uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]);
 877
 878                         dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret);
 879                 }
 880                 else if (otype == DHCPV6_OPT_DNS_SERVERS) {
 881                         if (olen % 16 == 0)
 882                                 odhcp6c_add_state(STATE_DNS, odata, olen);
 883                 } else if (otype == DHCPV6_OPT_DNS_DOMAIN) {
 884                         odhcp6c_add_state(STATE_SEARCH, odata, olen);
 885                 } else if (otype == DHCPV6_OPT_NTP_SERVER) {
 886                         uint16_t stype, slen;
 887                         uint8_t *sdata;
 888                         // Test status and bail if error
 889                         dhcpv6_for_each_option(odata, odata + olen,
 890                                         stype, slen, sdata) {
 891                                 if (slen == 16 && (stype == NTP_MC_ADDR ||
 892                                                 stype == NTP_SRV_ADDR))
 893                                         odhcp6c_add_state(STATE_SNTP_IP,
 894                                                         sdata, slen);
 895                                 else if (slen > 0 && stype == NTP_SRV_FQDN)
 896                                         odhcp6c_add_state(STATE_SNTP_FQDN,
 897                                                         sdata, slen);
 898                         }
 899                 } else if (otype == DHCPV6_OPT_SIP_SERVER_A) {
 900                         if (olen == 16)
 901                                 odhcp6c_add_state(STATE_SIP_IP, odata, olen);
 902                 } else if (otype == DHCPV6_OPT_SIP_SERVER_D) {
 903                         odhcp6c_add_state(STATE_SIP_FQDN, odata, olen);
 904                 } else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) {
 905                         refresh = ntohl(*((uint32_t*)odata));
 906                 } else if (otype == DHCPV6_OPT_AUTH && olen == -4 +
 907                                 sizeof(struct dhcpv6_auth_reconfigure)) {
 908                         struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4];
 909                         if (r->protocol == 3 && r->algorithm == 1 &&
 910                                         r->reconf_type == 1)
 911                                 memcpy(reconf_key, r->key, sizeof(r->key));
 912                 } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) {
 913                         size_t cur_len;
 914                         odhcp6c_get_state(STATE_AFTR_NAME, &cur_len);
 915                         if (cur_len == 0)
 916                                 odhcp6c_add_state(STATE_AFTR_NAME, odata, olen);
 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         }
1127
1128         return (int)(ia_pd_entries + ia_na_entries);
1129 }
1130
1131
1132 static void dhcpv6_log_status_code(const uint16_t code, const char *scope,
1133                 const void *status_msg, const int len)
1134 {
1135         uint8_t buf[len + 3];
1136
1137         memset(buf, 0, sizeof(buf));
1138         if (len) {
1139                 buf[0] = '(';
1140                 memcpy(&buf[1], status_msg, len);
1141                 buf[len + 1] = ')';
1142         }
1143
1144         syslog(LOG_WARNING, "Server returned %s status %i %s",
1145                 scope, code, buf);
1146 }
1147
1148
1149 static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig,
1150                 const uint16_t code, const void *status_msg, const int len,
1151                 int *ret)
1152 {
1153         dhcpv6_log_status_code(code, "message", status_msg, len);
1154
1155         switch (code) {
1156         case DHCPV6_UnspecFail:
1157                 // Generic failure
1158                 *ret = 0;
1159                 break;
1160
1161         case DHCPV6_UseMulticast:
1162                 switch(orig) {
1163                 case DHCPV6_MSG_REQUEST:
1164                 case DHCPV6_MSG_RENEW:
1165                 case DHCPV6_MSG_RELEASE:
1166                 case DHCPV6_MSG_DECLINE:
1167                         // Message needs to be retransmitted according to RFC3315 chapter 18.1.8
1168                         server_addr = in6addr_any;
1169                         *ret = 0;
1170                         break;
1171                 default:
1172                         break;
1173                 }
1174                 break;
1175
1176         case DHCPV6_NoAddrsAvail:
1177         case DHCPV6_NoPrefixAvail:
1178                 if (orig == DHCPV6_MSG_REQUEST)
1179                         *ret = 0; // Failure
1180                 break;
1181
1182         default:
1183                 break;
1184         }
1185 }
1186
1187
1188 static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
1189                 const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code,
1190                 const void *status_msg, const int len,
1191                 bool handled_status_codes[_DHCPV6_Status_Max], int *ret)
1192 {
1193         dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ?
1194                 "IA_NA" : "IA_PD", status_msg, len);
1195
1196         switch (code) {
1197         case DHCPV6_NoBinding:
1198                 switch (orig) {
1199                 case DHCPV6_MSG_RENEW:
1200                 case DHCPV6_MSG_REBIND:
1201                         if ((*ret > 0) && !handled_status_codes[code])
1202                                 *ret = dhcpv6_request(DHCPV6_MSG_REQUEST);
1203                         break;
1204
1205                 default:
1206                         break;
1207                 }
1208                 break;
1209
1210         case DHCPV6_NoAddrsAvail:
1211         case DHCPV6_NoPrefixAvail:
1212                 switch (orig) {
1213                 case DHCPV6_MSG_REQUEST:
1214                         if (*ret != 0)
1215                                 *ret = 0;
1216                         break;
1217                 default:
1218                         break;
1219                 }
1220                 break;
1221
1222         case DHCPV6_NotOnLink:
1223                 // TODO handle not onlink in case of confirm
1224                 break;
1225
1226         default:
1227                 break;
1228         }
1229 }
1230
1231 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
1232 {
1233         size_t cand_len, i;
1234         struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1235
1236         // Remove identical duid server candidate
1237         for (i = 0; i < cand_len / sizeof(*c); ++i) {
1238                 if (cand->duid_len == c[i].duid_len &&
1239                         !memcmp(cand->duid, c[i].duid, cand->duid_len)) {
1240                         free(c[i].ia_na);
1241                         free(c[i].ia_pd);
1242                         odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c));
1243                         break;
1244                 }
1245         }
1246
1247         for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1248                 i < cand_len / sizeof(*c); ++i) {
1249                 if (c[i].preference < cand->preference)
1250                         break;
1251         }
1252
1253         odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
1254 }
1255
1256 static void dhcpv6_clear_all_server_cand(void)
1257 {
1258         size_t cand_len, i;
1259         struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1260
1261         // Server candidates need deep delete for IA_NA/IA_PD
1262         for (i = 0; i < cand_len / sizeof(*c); ++i) {
1263                 if (c[i].ia_na)
1264                         free(c[i].ia_na);
1265                 if (c[i].ia_pd)
1266                         free(c[i].ia_pd);
1267         }
1268         odhcp6c_clear_state(STATE_SERVER_CAND);
1269 }
1270
1271 int dhcpv6_promote_server_cand(void)
1272 {
1273         size_t cand_len;
1274         struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
1275         uint16_t hdr[2];
1276         int ret = DHCPV6_STATELESS;
1277
1278         // Clear lingering candidate state info
1279         odhcp6c_clear_state(STATE_SERVER_ID);
1280         odhcp6c_clear_state(STATE_IA_NA);
1281         odhcp6c_clear_state(STATE_IA_PD);
1282
1283         if (!cand_len)
1284                 return -1;
1285
1286         if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
1287                 na_mode = IA_MODE_NONE;
1288                 return dhcpv6_request(DHCPV6_MSG_SOLICIT);
1289         }
1290
1291         hdr[0] = htons(DHCPV6_OPT_SERVERID);
1292         hdr[1] = htons(cand->duid_len);
1293         odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr));
1294         odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len);
1295         accept_reconfig = cand->wants_reconfigure;
1296         if (cand->ia_na_len) {
1297                 odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len);
1298                 free(cand->ia_na);
1299                 if (na_mode != IA_MODE_NONE)
1300                         ret = DHCPV6_STATEFUL;
1301         }
1302         if (cand->ia_pd_len) {
1303                 odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len);
1304                 free(cand->ia_pd);
1305                 if (request_prefix)
1306                         ret = DHCPV6_STATEFUL;
1307         }
1308
1309         odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand));
1310
1311         return ret;
1312 }