src/dhcpv6-ia.c

   1 /**
   2  * Copyright (C) 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 "odhcpd.h"
  16 #include "dhcpv6.h"
  17 #include "dhcpv4.h"
  18 #include "libubox/md5.h"
  19 #include "libubox/usock.h"
  20
  21 #include <time.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <stdio.h>
  25 #include <poll.h>
  26 #include <alloca.h>
  27 #include <resolv.h>
  28 #include <limits.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32 #include <stdbool.h>
  33 #include <arpa/inet.h>
  34 #include <sys/timerfd.h>
  35
  36
  37 static void reconf_timer(struct uloop_timeout *event);
  38 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
  39 static uint32_t serial = 0;
  40 static uint8_t statemd5[16];
  41
  42
  43 int dhcpv6_ia_init(void)
  44 {
  45         uloop_timeout_set(&reconf_event, 2000);
  46         return 0;
  47 }
  48
  49
  50 void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
  51 {
  52         if (c->managed_sock.fd.registered) {
  53                 ustream_free(&c->managed_sock.stream);
  54                 close(c->managed_sock.fd.fd);
  55         }
  56
  57         if (c->head.next)
  58                 list_del(&c->head);
  59
  60         free(c->managed);
  61         free(c->hostname);
  62         free(c);
  63 }
  64
  65
  66 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
  67 {
  68         if (!enable && iface->ia_assignments.next) {
  69                 struct dhcpv6_assignment *c;
  70                 while (!list_empty(&iface->ia_assignments)) {
  71                         c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
  72                         free_dhcpv6_assignment(c);
  73                 }
  74         }
  75
  76         if (enable && iface->dhcpv6 == RELAYD_SERVER) {
  77                 if (!iface->ia_assignments.next)
  78                         INIT_LIST_HEAD(&iface->ia_assignments);
  79
  80                 if (list_empty(&iface->ia_assignments)) {
  81                         struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
  82                         if (!border) {
  83                                 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
  84                                 return -1;
  85                         }
  86
  87                         border->length = 64;
  88                         list_add(&border->head, &iface->ia_assignments);
  89                 }
  90
  91                 // Parse static entries
  92                 struct lease *lease;
  93                 list_for_each_entry(lease, &leases, head) {
  94                         // Construct entry
  95                         struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + lease->duid_len);
  96                         if (!a) {
  97                                 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
  98                                         iface->ifname);
  99                                 return -1;
 100                         }
 101
 102                         a->clid_len = lease->duid_len;
 103                         a->length = 128;
 104                         if (lease->hostid) {
 105                                 a->assigned = lease->hostid;
 106                         } else {
 107                                 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
 108                                 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
 109                         }
 110                         odhcpd_urandom(a->key, sizeof(a->key));
 111                         memcpy(a->clid_data, lease->duid, a->clid_len);
 112                         memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
 113
 114                         // Assign to all interfaces
 115                         struct dhcpv6_assignment *c;
 116                         list_for_each_entry(c, &iface->ia_assignments, head) {
 117                                 if (c->length != 128 || c->assigned > a->assigned) {
 118                                         list_add_tail(&a->head, &c->head);
 119                                         break;
 120                                 } else if (c->assigned == a->assigned) {
 121                                         // Already an assignment with that number
 122                                         break;
 123                                 }
 124                         }
 125
 126                         if (a->head.next) {
 127                                 if (lease->hostname[0]) {
 128                                         free(a->hostname);
 129                                         a->hostname = strdup(lease->hostname);
 130                                 }
 131                         } else {
 132                                 free(a->hostname);
 133                                 free(a);
 134                         }
 135                 }
 136         }
 137         return 0;
 138 }
 139
 140
 141 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
 142 {
 143         struct {
 144                 struct dhcpv6_client_header hdr;
 145                 uint16_t srvid_type;
 146                 uint16_t srvid_len;
 147                 uint16_t duid_type;
 148                 uint16_t hardware_type;
 149                 uint8_t mac[6];
 150                 uint16_t msg_type;
 151                 uint16_t msg_len;
 152                 uint8_t msg_id;
 153                 struct dhcpv6_auth_reconfigure auth;
 154                 uint16_t clid_type;
 155                 uint16_t clid_len;
 156                 uint8_t clid_data[128];
 157         } __attribute__((packed)) reconf_msg = {
 158                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 159                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 160                 .srvid_len = htons(10),
 161                 .duid_type = htons(3),
 162                 .hardware_type = htons(1),
 163                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 164                 .msg_len = htons(1),
 165                 .msg_id = DHCPV6_MSG_RENEW,
 166                 .auth = {htons(DHCPV6_OPT_AUTH),
 167                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 168                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 169                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 170                 .clid_len = htons(assign->clid_len),
 171                 .clid_data = {0},
 172         };
 173
 174         odhcpd_get_mac(iface, reconf_msg.mac);
 175         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 176         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 177
 178         md5_ctx_t md5;
 179         uint8_t secretbytes[64];
 180         memset(secretbytes, 0, sizeof(secretbytes));
 181         memcpy(secretbytes, assign->key, sizeof(assign->key));
 182
 183         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 184                 secretbytes[i] ^= 0x36;
 185
 186         md5_begin(&md5);
 187         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 188         md5_hash(iov.iov_base, iov.iov_len, &md5);
 189         md5_end(reconf_msg.auth.key, &md5);
 190
 191         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 192                 secretbytes[i] ^= 0x36;
 193                 secretbytes[i] ^= 0x5c;
 194         }
 195
 196         md5_begin(&md5);
 197         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 198         md5_hash(reconf_msg.auth.key, 16, &md5);
 199         md5_end(reconf_msg.auth.key, &md5);
 200
 201         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 202 }
 203
 204
 205 void dhcpv6_write_statefile(void)
 206 {
 207         md5_ctx_t md5;
 208         md5_begin(&md5);
 209
 210         if (config.dhcp_statefile) {
 211                 time_t now = odhcpd_time(), wall_time = time(NULL);
 212                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 213                 if (fd < 0)
 214                         return;
 215
 216                 lockf(fd, F_LOCK, 0);
 217                 if (ftruncate(fd, 0) < 0) {}
 218
 219                 FILE *fp = fdopen(fd, "w");
 220                 if (!fp) {
 221                         close(fd);
 222                         return;
 223                 }
 224
 225                 struct interface *iface;
 226                 list_for_each_entry(iface, &interfaces, head) {
 227                         if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
 228                                 continue;
 229
 230                         if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
 231                                 struct dhcpv6_assignment *c;
 232                                 list_for_each_entry(c, &iface->ia_assignments, head) {
 233                                         if (c->clid_len == 0 || c->managed_size < 0)
 234                                                 continue;
 235
 236                                         char ipbuf[INET6_ADDRSTRLEN];
 237                                         char leasebuf[512];
 238                                         char duidbuf[264];
 239                                         odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
 240
 241                                         // iface DUID iaid hostname lifetime assigned length [addrs...]
 242                                         int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %u %x %u ",
 243                                                         iface->ifname, duidbuf, ntohl(c->iaid),
 244                                                         (c->hostname ? c->hostname : "-"),
 245                                                         (unsigned)(c->valid_until > now ?
 246                                                                         (c->valid_until - now + wall_time) : 0),
 247                                                         c->assigned, (unsigned)c->length);
 248
 249                                         struct in6_addr addr;
 250                                         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
 251                                         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
 252                                         size_t m = 0;
 253
 254                                         for (size_t i = 0; i < addrlen; ++i)
 255                                                 if (addrs[i].preferred > addrs[m].preferred ||
 256                                                                 (addrs[i].preferred == addrs[m].preferred &&
 257                                                                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 258                                                         m = i;
 259
 260                                         for (size_t i = 0; i < addrlen; ++i) {
 261                                                 if (addrs[i].prefix > 96 || c->valid_until <= now ||
 262                                                                 (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
 263                                                                                 addrs[i].prefix == 64))
 264                                                         continue;
 265
 266                                                 addr = addrs[i].addr;
 267                                                 if (c->length == 128)
 268                                                         addr.s6_addr32[3] = htonl(c->assigned);
 269                                                 else
 270                                                         addr.s6_addr32[1] |= htonl(c->assigned);
 271
 272                                                 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
 273
 274                                                 if (c->length == 128 && c->hostname) {
 275                                                         fputs(ipbuf, fp);
 276
 277                                                         char b[256];
 278                                                         if (dn_expand(iface->search, iface->search + iface->search_len,
 279                                                                         iface->search, b, sizeof(b)) > 0)
 280                                                                 fprintf(fp, "\t%s.%s", c->hostname, b);
 281
 282                                                         fprintf(fp, "\t%s\n", c->hostname);
 283                                                         md5_hash(ipbuf, strlen(ipbuf), &md5);
 284                                                         md5_hash(c->hostname, strlen(c->hostname), &md5);
 285                                                 }
 286
 287                                                 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
 288                                                                 (c->managed_size) ? addrs[i].prefix : c->length);
 289                                         }
 290                                         leasebuf[l - 1] = '\n';
 291                                         fwrite(leasebuf, 1, l, fp);
 292                                 }
 293                         }
 294
 295                         if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
 296                                 struct dhcpv4_assignment *c;
 297                                 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
 298                                         char ipbuf[INET6_ADDRSTRLEN];
 299                                         char leasebuf[512];
 300                                         char duidbuf[16];
 301                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 302
 303                                         // iface DUID iaid hostname lifetime assigned length [addrs...]
 304                                         int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %u %x 32 ",
 305                                                         iface->ifname, duidbuf,
 306                                                         (c->hostname ? c->hostname : "-"),
 307                                                         (unsigned)(c->valid_until > now ?
 308                                                                         (c->valid_until - now + wall_time) : 0),
 309                                                         c->addr);
 310
 311                                         struct in_addr addr = {htonl(c->addr)};
 312                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 313
 314                                         if (c->hostname[0]) {
 315                                                 fputs(ipbuf, fp);
 316
 317                                                 char b[256];
 318                                                 if (dn_expand(iface->search, iface->search + iface->search_len,
 319                                                                 iface->search, b, sizeof(b)) > 0)
 320                                                         fprintf(fp, "\t%s.%s", c->hostname, b);
 321
 322                                                 fprintf(fp, "\t%s\n", c->hostname);
 323                                                 md5_hash(ipbuf, strlen(ipbuf), &md5);
 324                                                 md5_hash(c->hostname, strlen(c->hostname), &md5);
 325                                         }
 326
 327                                         l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
 328                                         leasebuf[l - 1] = '\n';
 329                                         fwrite(leasebuf, 1, l, fp);
 330                                 }
 331                         }
 332                 }
 333
 334                 fclose(fp);
 335         }
 336
 337         uint8_t newmd5[16];
 338         md5_end(newmd5, &md5);
 339
 340         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 341                 memcpy(statemd5, newmd5, sizeof(statemd5));
 342                 char *argv[2] = {config.dhcp_cb, NULL};
 343                 if (!vfork()) {
 344                         execv(argv[0], argv);
 345                         _exit(128);
 346                 }
 347         }
 348 }
 349
 350
 351 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
 352 {
 353         if (a->length > 64 || a->managed_size < 0)
 354                 return;
 355
 356         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 357         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 358
 359         for (size_t i = 0; i < addrlen; ++i) {
 360                 struct in6_addr prefix = addrs[i].addr;
 361                 prefix.s6_addr32[1] |= htonl(a->assigned);
 362                 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 363                                 iface, &a->peer.sin6_addr, 1024, add);
 364         }
 365 }
 366
 367
 368 // More data was received from TCP connection
 369 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 370 {
 371         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 372         time_t now = odhcpd_time();
 373         bool first = c->managed_size < 0;
 374
 375         for (;;) {
 376                 int pending;
 377                 char *data = ustream_get_read_buf(s, &pending);
 378                 char *end = memmem(data, pending, "\n\n", 2);
 379
 380                 if (!end)
 381                         break;
 382
 383                 end += 2;
 384                 end[-1] = 0;
 385
 386                 c->managed_size = 0;
 387                 if (c->accept_reconf)
 388                         c->reconf_cnt = 1;
 389
 390                 char *saveptr;
 391                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 392                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 393                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 394
 395                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 396                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 397                                 continue;
 398
 399                         x = strtok_r(NULL, ",", &saveptr2);
 400                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 401                                 continue;
 402
 403                         x = strtok_r(NULL, ",", &saveptr2);
 404                         if (sscanf(x, "%u", &n->preferred) < 1)
 405                                 continue;
 406
 407                         x = strtok_r(NULL, ",", &saveptr2);
 408                         if (sscanf(x, "%u", &n->valid) < 1)
 409                                 continue;
 410
 411                         if (n->preferred > n->valid)
 412                                 continue;
 413
 414                         if (UINT32_MAX - now < n->preferred)
 415                                 n->preferred = UINT32_MAX;
 416                         else
 417                                 n->preferred += now;
 418
 419                         if (UINT32_MAX - now < n->valid)
 420                                 n->valid = UINT32_MAX;
 421                         else
 422                                 n->valid += now;
 423
 424                         n->dprefix = 0;
 425
 426                         ++c->managed_size;
 427                 }
 428
 429                 ustream_consume(s, end - data);
 430         }
 431
 432         if (first && c->managed_size == 0)
 433                 free_dhcpv6_assignment(c);
 434         else if (first)
 435                 c->valid_until = now + 150;
 436 }
 437
 438
 439 // TCP transmission has ended, either because of success or timeout or other error
 440 static void managed_handle_pd_done(struct ustream *s)
 441 {
 442         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 443         c->valid_until = odhcpd_time() + 15;
 444         c->managed_size = 0;
 445         if (c->accept_reconf)
 446                 c->reconf_cnt = 1;
 447 }
 448
 449
 450
 451 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
 452 {
 453         struct dhcpv6_assignment *c;
 454
 455         if (iface->dhcpv6_pd_manager[0]) {
 456                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 457                 if (fd >= 0) {
 458                         char iaidbuf[298];
 459                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 460
 461                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 462                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 463                         ustream_fd_init(&assign->managed_sock, fd);
 464                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 465                                         iaidbuf, assign->iaid, assign->length);
 466                         ustream_write_pending(&assign->managed_sock.stream);
 467                         assign->managed_size = -1;
 468                         assign->valid_until = odhcpd_time() + 15;
 469                         list_add(&assign->head, &iface->ia_assignments);
 470
 471                         // Wait initial period of up to 250ms for immediate assignment
 472                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 473                         poll(&pfd, 1, 250);
 474                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 475
 476                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 477                                 return true;
 478                 }
 479
 480                 return false;
 481         } else if (iface->ia_addr_len < 1) {
 482                 return false;
 483         }
 484
 485         // Try honoring the hint first
 486         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 487         if (assign->assigned) {
 488                 list_for_each_entry(c, &iface->ia_assignments, head) {
 489                         if (c->length == 128 || c->length == 0)
 490                                 continue;
 491
 492                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 493                                 list_add_tail(&assign->head, &c->head);
 494                                 apply_lease(iface, assign, true);
 495                                 return true;
 496                         }
 497
 498                         if (c->assigned != 0)
 499                                 current = (c->assigned + (1 << (64 - c->length)));
 500                 }
 501         }
 502
 503         // Fallback to a variable assignment
 504         current = 1;
 505         list_for_each_entry(c, &iface->ia_assignments, head) {
 506                 if (c->length == 128 || c->length == 0)
 507                         continue;
 508
 509                 current = (current + asize) & (~asize);
 510                 if (current + asize < c->assigned) {
 511                         assign->assigned = current;
 512                         list_add_tail(&assign->head, &c->head);
 513                         apply_lease(iface, assign, true);
 514                         return true;
 515                 }
 516
 517                 if (c->assigned != 0)
 518                         current = (c->assigned + (1 << (64 - c->length)));
 519         }
 520
 521         return false;
 522 }
 523
 524
 525 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 526 {
 527         // Seed RNG with checksum of DUID
 528         uint32_t seed = 0;
 529         for (size_t i = 0; i < assign->clid_len; ++i)
 530                 seed += assign->clid_data[i];
 531         srand(seed);
 532
 533         // Try to assign up to 100x
 534         for (size_t i = 0; i < 100; ++i) {
 535                 uint32_t try;
 536                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 537
 538                 struct dhcpv6_assignment *c;
 539                 list_for_each_entry(c, &iface->ia_assignments, head) {
 540                         if (c->length == 0)
 541                                 continue;
 542
 543                         if (c->assigned > try || c->length != 128) {
 544                                 assign->assigned = try;
 545                                 list_add_tail(&assign->head, &c->head);
 546                                 return true;
 547                         } else if (c->assigned == try) {
 548                                 break;
 549                         }
 550                 }
 551         }
 552
 553         return false;
 554 }
 555
 556 void dhcpv6_ia_preupdate(struct interface *iface)
 557 {
 558         if (iface->dhcpv6 != RELAYD_SERVER)
 559                 return;
 560
 561         struct dhcpv6_assignment *c, *border = list_last_entry(
 562                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 563         list_for_each_entry(c, &iface->ia_assignments, head)
 564                 if (c != border && !iface->managed)
 565                         apply_lease(iface, c, false);
 566 }
 567
 568 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
 569 {
 570         if (iface->dhcpv6 != RELAYD_SERVER)
 571                 return;
 572
 573         int minprefix = -1;
 574         for (size_t i = 0; i < iface->ia_addr_len; ++i) {
 575                 if (iface->ia_addr[i].preferred > (uint32_t)now &&
 576                                 iface->ia_addr[i].prefix < 64 &&
 577                                 iface->ia_addr[i].prefix > minprefix)
 578                         minprefix = iface->ia_addr[i].prefix;
 579         }
 580
 581         struct dhcpv6_assignment *border = list_last_entry(
 582                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 583         if (minprefix > 32 && minprefix <= 64)
 584                 border->assigned = 1U << (64 - minprefix);
 585         else
 586                 border->assigned = 0;
 587
 588         struct list_head reassign = LIST_HEAD_INIT(reassign);
 589         struct dhcpv6_assignment *c, *d;
 590         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 591                 if (c->clid_len == 0 || c->valid_until < now || c->managed_size)
 592                         continue;
 593
 594                 if (c->length < 128 && c->assigned >= border->assigned && c != border)
 595                         list_move(&c->head, &reassign);
 596                 else if (c != border)
 597                         apply_lease(iface, c, true);
 598
 599                 if (c->accept_reconf && c->reconf_cnt == 0) {
 600                         c->reconf_cnt = 1;
 601                         c->reconf_sent = now;
 602                         send_reconf(iface, c);
 603
 604                         // Leave all other assignments of that client alone
 605                         struct dhcpv6_assignment *a;
 606                         list_for_each_entry(a, &iface->ia_assignments, head)
 607                                 if (a != c && a->clid_len == c->clid_len &&
 608                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 609                                         c->reconf_cnt = INT_MAX;
 610                 }
 611         }
 612
 613         while (!list_empty(&reassign)) {
 614                 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
 615                 list_del(&c->head);
 616                 if (!assign_pd(iface, c)) {
 617                         c->assigned = 0;
 618                         list_add(&c->head, &iface->ia_assignments);
 619                 }
 620         }
 621
 622         dhcpv6_write_statefile();
 623 }
 624
 625
 626 static void reconf_timer(struct uloop_timeout *event)
 627 {
 628         time_t now = odhcpd_time();
 629         struct interface *iface;
 630         list_for_each_entry(iface, &interfaces, head) {
 631                 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
 632                         continue;
 633
 634                 struct dhcpv6_assignment *a, *n;
 635                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 636                         if (a->valid_until < now) {
 637                                 if ((a->length < 128 && a->clid_len > 0) ||
 638                                                 (a->length == 128 && a->clid_len == 0)) {
 639                                         list_del(&a->head);
 640                                         free_dhcpv6_assignment(a);
 641                                 }
 642                         } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
 643                                         now > a->reconf_sent + (1 << a->reconf_cnt)) {
 644                                 ++a->reconf_cnt;
 645                                 a->reconf_sent = now;
 646                                 send_reconf(iface, a);
 647                         }
 648                 }
 649         }
 650         uloop_timeout_set(event, 2000);
 651 }
 652
 653
 654 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
 655                 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
 656                 struct interface *iface, bool request)
 657 {
 658         if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
 659                 return 0;
 660
 661         struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
 662         size_t datalen = sizeof(out);
 663         time_t now = odhcpd_time();
 664
 665         if (status) {
 666                 struct __attribute__((packed)) {
 667                         uint16_t type;
 668                         uint16_t len;
 669                         uint16_t value;
 670                 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
 671                                 htons(status)};
 672
 673                 memcpy(buf + datalen, &stat, sizeof(stat));
 674                 datalen += sizeof(stat);
 675         } else {
 676                 if (a) {
 677                         uint32_t leasetime = iface->dhcpv4_leasetime;
 678                         if (leasetime == 0)
 679                                 leasetime = 3600;
 680                         else if (leasetime < 60)
 681                                 leasetime = 60;
 682
 683                         uint32_t pref = leasetime;
 684                         uint32_t valid = leasetime;
 685
 686                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 687                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 688                         size_t m = 0;
 689
 690                         for (size_t i = 0; i < addrlen; ++i)
 691                                 if (addrs[i].preferred > addrs[m].preferred ||
 692                                                 (addrs[i].preferred == addrs[m].preferred &&
 693                                                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 694                                         m = i;
 695
 696                         for (size_t i = 0; i < addrlen; ++i) {
 697                                 uint32_t prefix_pref = addrs[i].preferred;
 698                                 uint32_t prefix_valid = addrs[i].valid;
 699
 700                                 if (addrs[i].prefix > 96 ||
 701                                                 addrs[i].preferred <= (uint32_t)now)
 702                                         continue;
 703
 704                                 if (prefix_pref != UINT32_MAX)
 705                                         prefix_pref -= now;
 706
 707                                 if (prefix_valid != UINT32_MAX)
 708                                         prefix_valid -= now;
 709
 710                                 if (a->length < 128) {
 711                                         struct dhcpv6_ia_prefix p = {
 712                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 713                                                 .len = htons(sizeof(p) - 4),
 714                                                 .preferred = htonl(prefix_pref),
 715                                                 .valid = htonl(prefix_valid),
 716                                                 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 717                                                 .addr = addrs[i].addr
 718                                         };
 719                                         p.addr.s6_addr32[1] |= htonl(a->assigned);
 720
 721                                         size_t entrlen = sizeof(p) - 4;
 722
 723                                         if (datalen + entrlen + 4 > buflen ||
 724                                                         (a->assigned == 0 && a->managed_size == 0) ||
 725                                                         (!a->managed_size && a->length <= addrs[i].prefix))
 726                                                 continue;
 727
 728                                         memcpy(buf + datalen, &p, sizeof(p));
 729                                         datalen += entrlen + 4;
 730                                 } else {
 731                                         struct dhcpv6_ia_addr n = {
 732                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 733                                                 .len = htons(sizeof(n) - 4),
 734                                                 .addr = addrs[i].addr,
 735                                                 .preferred = htonl(prefix_pref),
 736                                                 .valid = htonl(prefix_valid)
 737                                         };
 738                                         n.addr.s6_addr32[3] = htonl(a->assigned);
 739                                         size_t entrlen = sizeof(n) - 4;
 740
 741                                         if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
 742                                                         addrs[i].prefix <= 64)
 743                                                 continue;
 744
 745                                         if (datalen + entrlen + 4 > buflen || a->assigned == 0)
 746                                                 continue;
 747
 748                                         memcpy(buf + datalen, &n, sizeof(n));
 749                                         datalen += entrlen + 4;
 750                                 }
 751
 752                                 // Calculate T1 / T2 based on non-deprecated addresses
 753                                 if (prefix_pref > 0) {
 754                                         if (prefix_pref < pref)
 755                                                 pref = prefix_pref;
 756
 757                                         if (prefix_valid < valid)
 758                                                 valid = prefix_valid;
 759                                 }
 760                         }
 761
 762                         a->valid_until = valid + now;
 763                         out.t1 = htonl(pref * 5 / 10);
 764                         out.t2 = htonl(pref * 8 / 10);
 765
 766                         if (!out.t1)
 767                                 out.t1 = htonl(1);
 768
 769                         if (!out.t2)
 770                                 out.t2 = htonl(1);
 771                 }
 772
 773                 if (!request) {
 774                         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 775                         uint16_t otype, olen;
 776                         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 777                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
 778                                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
 779                                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
 780                                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
 781                                         continue;
 782
 783                                 bool found = false;
 784                                 if (a) {
 785                                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 786                                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 787
 788                                         for (size_t i = 0; i < addrlen; ++i) {
 789                                                 if (addrs[i].prefix > 96 ||
 790                                                                 addrs[i].preferred <= (uint32_t)now)
 791                                                         continue;
 792
 793                                                 struct in6_addr addr = addrs[i].addr;
 794                                                 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 795                                                         addr.s6_addr32[1] |= htonl(a->assigned);
 796
 797                                                         if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
 798                                                                         p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 799                                                                 found = true;
 800                                                 } else {
 801                                                         addr.s6_addr32[3] = htonl(a->assigned);
 802
 803                                                         if (!memcmp(&n->addr, &addr, sizeof(addr)))
 804                                                                 found = true;
 805                                                 }
 806                                         }
 807                                 }
 808
 809                                 if (!found) {
 810                                         if (otype == DHCPV6_OPT_IA_PREFIX) {
 811                                                 struct dhcpv6_ia_prefix inv = {
 812                                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 813                                                         .len = htons(sizeof(inv) - 4),
 814                                                         .preferred = 0,
 815                                                         .valid = 0,
 816                                                         .prefix = p->prefix,
 817                                                         .addr = p->addr
 818                                                 };
 819
 820                                                 if (datalen + sizeof(inv) > buflen)
 821                                                         continue;
 822
 823                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 824                                                 datalen += sizeof(inv);
 825                                         } else {
 826                                                 struct dhcpv6_ia_addr inv = {
 827                                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 828                                                         .len = htons(sizeof(inv) - 4),
 829                                                         .addr = n->addr,
 830                                                         .preferred = 0,
 831                                                         .valid = 0
 832                                                 };
 833
 834                                                 if (datalen + sizeof(inv) > buflen)
 835                                                         continue;
 836
 837                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 838                                                 datalen += sizeof(inv);
 839                                         }
 840                                 }
 841                         }
 842                 }
 843         }
 844
 845         out.len = htons(datalen - 4);
 846         memcpy(buf, &out, sizeof(out));
 847         return datalen;
 848 }
 849
 850
 851 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
 852                 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
 853 {
 854         const char *type = "UNKNOWN";
 855         const char *status = "UNKNOWN";
 856
 857         if (msgtype == DHCPV6_MSG_RENEW)
 858                 return;
 859
 860         switch (msgtype) {
 861         case DHCPV6_MSG_SOLICIT:
 862                 type = "SOLICIT";
 863                 break;
 864         case DHCPV6_MSG_REQUEST:
 865                 type = "REQUEST";
 866                 break;
 867         case DHCPV6_MSG_CONFIRM:
 868                 type = "CONFIRM";
 869                 break;
 870         case DHCPV6_MSG_RENEW:
 871                 type = "RENEW";
 872                 break;
 873         case DHCPV6_MSG_REBIND:
 874                 type = "REBIND";
 875                 break;
 876         case DHCPV6_MSG_RELEASE:
 877                 type = "RELEASE";
 878                 break;
 879         case DHCPV6_MSG_DECLINE:
 880                 type = "DECLINE";
 881                 break;
 882         }
 883
 884         switch (code) {
 885         case DHCPV6_STATUS_OK:
 886                 status = "ok";
 887                 break;
 888         case DHCPV6_STATUS_NOADDRSAVAIL:
 889                 status = "no addresses available";
 890                 break;
 891         case DHCPV6_STATUS_NOBINDING:
 892                 status = "no binding";
 893                 break;
 894         case DHCPV6_STATUS_NOTONLINK:
 895                 status = "not on-link";
 896                 break;
 897         case DHCPV6_STATUS_NOPREFIXAVAIL:
 898                 status = "no prefix available";
 899                 break;
 900         }
 901
 902         char leasebuf[256] = "";
 903
 904         if (a) {
 905                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 906                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 907                 size_t lbsize = 0;
 908                 char addrbuf[INET6_ADDRSTRLEN];
 909
 910                 for (size_t i = 0; i < addrlen; ++i) {
 911                         if (addrs[i].prefix > 96 || addrs[i].preferred <= (uint32_t)now)
 912                                 continue;
 913
 914                         struct in6_addr addr = addrs[i].addr;
 915                         int prefix = a->managed ? addrs[i].prefix : a->length;
 916                         if (prefix == 128)
 917                                 addr.s6_addr32[3] = htonl(a->assigned);
 918                         else
 919                                 addr.s6_addr32[1] |= htonl(a->assigned);
 920
 921                         inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
 922                         lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
 923                 }
 924         }
 925
 926         syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
 927                         duidbuf, iface->ifname, status, leasebuf);
 928 }
 929
 930
 931
 932 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
 933                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
 934 {
 935         time_t now = odhcpd_time();
 936         size_t response_len = 0;
 937         const struct dhcpv6_client_header *hdr = data;
 938         uint8_t *start = (uint8_t*)&hdr[1], *odata;
 939         uint16_t otype, olen;
 940
 941         // Find and parse client-id and hostname
 942         bool accept_reconf = false;
 943         uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 944         char hostname[256];
 945         size_t hostname_len = 0;
 946         bool notonlink = false;
 947         char duidbuf[261];
 948
 949         dhcpv6_for_each_option(start, end, otype, olen, odata) {
 950                 if (otype == DHCPV6_OPT_CLIENTID) {
 951                         clid_data = odata;
 952                         clid_len = olen;
 953
 954                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
 955                                 memcpy(mac, &odata[8], sizeof(mac));
 956                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
 957                                 memcpy(mac, &odata[4], sizeof(mac));
 958
 959                         if (olen <= 130)
 960                                 odhcpd_hexlify(duidbuf, odata, olen);
 961                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
 962                         uint8_t fqdn_buf[256];
 963                         memcpy(fqdn_buf, odata, olen);
 964                         fqdn_buf[olen++] = 0;
 965
 966                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
 967                                 hostname_len = strcspn(hostname, ".");
 968                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) {
 969                         accept_reconf = true;
 970                 }
 971         }
 972
 973         if (!clid_data || !clid_len || clid_len > 130)
 974                 goto out;
 975
 976         struct dhcpv6_assignment *first = NULL;
 977         dhcpv6_for_each_option(start, end, otype, olen, odata) {
 978                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
 979                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
 980                 bool ia_addr_present = false;
 981                 if (!is_pd && !is_na)
 982                         continue;
 983
 984                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
 985                 size_t ia_response_len = 0;
 986                 uint8_t reqlen = (is_pd) ? 62 : 128;
 987                 uint32_t reqhint = 0;
 988
 989                 // Parse request hint for IA-PD
 990                 if (is_pd) {
 991                         uint8_t *sdata;
 992                         uint16_t stype, slen;
 993                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
 994                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
 995                                         continue;
 996
 997                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
 998                                 if (p->prefix) {
 999                                         reqlen = p->prefix;
1000                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1001                                         if (reqlen > 32 && reqlen <= 64)
1002                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1003                                 }
1004                         }
1005
1006                         if (reqlen > 64)
1007                                 reqlen = 64;
1008                 } else if (is_na) {
1009                         uint8_t *sdata;
1010                         uint16_t stype, slen;
1011                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1012                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1013                                         continue;
1014
1015                                 ia_addr_present = true;
1016                         }
1017                 }
1018
1019                 // Find assignment
1020                 struct dhcpv6_assignment *c, *a = NULL;
1021                 list_for_each_entry(c, &iface->ia_assignments, head) {
1022                         if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1023                                         (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1024                                                 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1025                                         (c->iaid == ia->iaid || c->valid_until < now) &&
1026                                         ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1027                                 a = c;
1028
1029                                 // Reset state
1030                                 apply_lease(iface, a, false);
1031                                 memcpy(a->clid_data, clid_data, clid_len);
1032                                 a->clid_len = clid_len;
1033                                 a->iaid = ia->iaid;
1034                                 a->peer = *addr;
1035                                 a->reconf_cnt = 0;
1036                                 a->reconf_sent = 0;
1037                                 break;
1038                         }
1039                 }
1040
1041                 // Generic message handling
1042                 uint16_t status = DHCPV6_STATUS_OK;
1043                 if (a && a->managed_size < 0) {
1044                         return -1;
1045                 } else if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1046                         bool assigned = !!a;
1047
1048                         if (!a && !iface->no_dynamic_dhcp) { // Create new binding
1049                                 a = calloc(1, sizeof(*a) + clid_len);
1050                                 if (a) {
1051                                         a->clid_len = clid_len;
1052                                         a->iaid = ia->iaid;
1053                                         a->length = reqlen;
1054                                         a->peer = *addr;
1055                                         a->assigned = reqhint;
1056
1057                                         if (first)
1058                                                 memcpy(a->key, first->key, sizeof(a->key));
1059                                         else
1060                                                 odhcpd_urandom(a->key, sizeof(a->key));
1061                                         memcpy(a->clid_data, clid_data, clid_len);
1062
1063                                         if (is_pd)
1064                                                 while (!(assigned = assign_pd(iface, a)) &&
1065                                                                 !a->managed_size && ++a->length <= 64);
1066                                         else
1067                                                 assigned = assign_na(iface, a);
1068
1069                                         if (a->managed_size && !assigned)
1070                                                 return -1;
1071                                 }
1072                         }
1073
1074                         if (!assigned || iface->ia_addr_len == 0) { // Set error status
1075                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1076                         } else if (assigned && !first) { //
1077                                 size_t handshake_len = 4;
1078                                 buf[0] = 0;
1079                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1080                                 buf[2] = 0;
1081                                 buf[3] = 0;
1082
1083                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1084                                         struct dhcpv6_auth_reconfigure auth = {
1085                                                 htons(DHCPV6_OPT_AUTH),
1086                                                 htons(sizeof(auth) - 4),
1087                                                 3, 1, 0,
1088                                                 {htonl(time(NULL)), htonl(++serial)},
1089                                                 1,
1090                                                 {0}
1091                                         };
1092                                         memcpy(auth.key, a->key, sizeof(a->key));
1093                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1094                                         handshake_len += sizeof(auth);
1095                                 }
1096
1097                                 buf += handshake_len;
1098                                 buflen -= handshake_len;
1099                                 response_len += handshake_len;
1100
1101                                 first = a;
1102                         }
1103
1104                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1105
1106                         // Was only a solicitation: mark binding for removal
1107                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1108                                 a->valid_until = 0;
1109                         } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1110                                 if (hostname_len > 0) {
1111                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1112                                         if (a->hostname) {
1113                                                 memcpy(a->hostname, hostname, hostname_len);
1114                                                 a->hostname[hostname_len] = 0;
1115                                         }
1116                                 }
1117                                 a->accept_reconf = accept_reconf;
1118                                 apply_lease(iface, a, true);
1119                         } else if (!assigned && a && a->managed_size == 0) { // Cleanup failed assignment
1120                                 free_dhcpv6_assignment(a);
1121                         }
1122                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1123                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1124                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1125                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1126                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1127                                 status = DHCPV6_STATUS_NOBINDING;
1128                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1129                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1130                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1131                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1132                                 if (a)
1133                                         apply_lease(iface, a, true);
1134                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1135                                 a->valid_until = 0;
1136                                 apply_lease(iface, a, false);
1137                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1138                                 a->clid_len = 0;
1139                                 a->valid_until = now + 3600; // Block address for 1h
1140                         }
1141                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1142                         // Send NOTONLINK for CONFIRM with addr present so that clients restart connection
1143                         status = DHCPV6_STATUS_NOTONLINK;
1144                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1145                         notonlink = true;
1146                 }
1147
1148                 buf += ia_response_len;
1149                 buflen -= ia_response_len;
1150                 response_len += ia_response_len;
1151                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1152         }
1153
1154         if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1155                         response_len + 6 < buflen) {
1156                 buf[0] = 0;
1157                 buf[1] = DHCPV6_OPT_STATUS;
1158                 buf[2] = 0;
1159                 buf[3] = 2;
1160                 buf[4] = 0;
1161                 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1162                 response_len += 6;
1163         }
1164
1165         dhcpv6_write_statefile();
1166
1167 out:
1168         return response_len;
1169 }