src/dhcpv6-ia.c

   1 /**
   2  * Copyright (C) 2013 Steven Barth <steven@midlink.org>
   3  * Copyright (C) 2016 Hans Dedecker <dedeckeh@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License v2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  */
  15
  16 #include "odhcpd.h"
  17 #include "dhcpv6.h"
  18 #include "dhcpv4.h"
  19 #include "libubox/md5.h"
  20 #include "libubox/usock.h"
  21
  22 #include <time.h>
  23 #include <errno.h>
  24 #include <fcntl.h>
  25 #include <stdio.h>
  26 #include <poll.h>
  27 #include <alloca.h>
  28 #include <resolv.h>
  29 #include <limits.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <unistd.h>
  33 #include <stdbool.h>
  34 #include <arpa/inet.h>
  35 #include <sys/timerfd.h>
  36
  37 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c);
  38 static void reconf_timer(struct uloop_timeout *event);
  39 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
  40 static uint32_t serial = 0;
  41 static uint8_t statemd5[16];
  42
  43 int dhcpv6_ia_init(void)
  44 {
  45         uloop_timeout_set(&reconf_event, 2000);
  46         return 0;
  47 }
  48
  49 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
  50 {
  51         if (!enable && iface->ia_assignments.next) {
  52                 struct dhcpv6_assignment *c;
  53                 while (!list_empty(&iface->ia_assignments)) {
  54                         c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
  55                         free_dhcpv6_assignment(c);
  56                 }
  57         }
  58
  59         if (enable && iface->dhcpv6 == RELAYD_SERVER) {
  60                 if (!iface->ia_assignments.next)
  61                         INIT_LIST_HEAD(&iface->ia_assignments);
  62
  63                 if (list_empty(&iface->ia_assignments)) {
  64                         struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
  65                         if (!border) {
  66                                 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
  67                                 return -1;
  68                         }
  69
  70                         border->length = 64;
  71                         list_add(&border->head, &iface->ia_assignments);
  72                 }
  73
  74                 /* Parse static entries */
  75                 struct lease *lease;
  76                 list_for_each_entry(lease, &leases, head) {
  77                         /* Construct entry */
  78                         size_t duid_len = lease->duid_len ? lease->duid_len : 14;
  79                         struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
  80                         if (!a) {
  81                                 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
  82                                         iface->ifname);
  83                                 return -1;
  84                         }
  85
  86                         if (lease->dhcpv4_leasetime > 0)
  87                                 a->leasetime = lease->dhcpv4_leasetime;
  88
  89                         a->clid_len = duid_len;
  90                         a->length = 128;
  91                         if (lease->hostid) {
  92                                 a->assigned = lease->hostid;
  93                         } else {
  94                                 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
  95                                 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
  96                         }
  97
  98                         odhcpd_urandom(a->key, sizeof(a->key));
  99                         memcpy(a->clid_data, lease->duid, lease->duid_len);
 100                         memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
 101                         /* Static assignment */
 102                         a->flags |= OAF_STATIC;
 103                         /* Infinite valid */
 104                         a->valid_until = 0;
 105
 106                         // Assign to all interfaces
 107                         struct dhcpv6_assignment *c;
 108                         list_for_each_entry(c, &iface->ia_assignments, head) {
 109                                 if (c->length != 128 || c->assigned > a->assigned) {
 110                                         list_add_tail(&a->head, &c->head);
 111                                         break;
 112                                 } else if (c->assigned == a->assigned)
 113                                         /* Already an assignment with that number */
 114                                         break;
 115                         }
 116
 117                         if (a->head.next) {
 118                                 if (lease->hostname[0]) {
 119                                         free(a->hostname);
 120                                         a->hostname = strdup(lease->hostname);
 121                                 }
 122                         } else
 123                                 free_dhcpv6_assignment(a);
 124                 }
 125         }
 126         return 0;
 127 }
 128
 129 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
 130 {
 131         if (c->managed_sock.fd.registered) {
 132                 ustream_free(&c->managed_sock.stream);
 133                 close(c->managed_sock.fd.fd);
 134         }
 135
 136         if (c->head.next)
 137                 list_del(&c->head);
 138
 139         free(c->managed);
 140         free(c->hostname);
 141         free(c);
 142 }
 143
 144 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 145 {
 146         return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
 147 }
 148
 149 static size_t elect_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
 150 {
 151         size_t i, m;
 152
 153         for (i = 0, m = 0; i < addrlen; ++i) {
 154                 if (addrs[i].preferred > addrs[m].preferred ||
 155                         (addrs[i].preferred == addrs[m].preferred &&
 156                          memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 157                         m = i;
 158         }
 159
 160         return m;
 161 }
 162
 163 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
 164 {
 165         struct {
 166                 struct dhcpv6_client_header hdr;
 167                 uint16_t srvid_type;
 168                 uint16_t srvid_len;
 169                 uint16_t duid_type;
 170                 uint16_t hardware_type;
 171                 uint8_t mac[6];
 172                 uint16_t msg_type;
 173                 uint16_t msg_len;
 174                 uint8_t msg_id;
 175                 struct dhcpv6_auth_reconfigure auth;
 176                 uint16_t clid_type;
 177                 uint16_t clid_len;
 178                 uint8_t clid_data[128];
 179         } __attribute__((packed)) reconf_msg = {
 180                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 181                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 182                 .srvid_len = htons(10),
 183                 .duid_type = htons(3),
 184                 .hardware_type = htons(1),
 185                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 186                 .msg_len = htons(1),
 187                 .msg_id = DHCPV6_MSG_RENEW,
 188                 .auth = {htons(DHCPV6_OPT_AUTH),
 189                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 190                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 191                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 192                 .clid_len = htons(assign->clid_len),
 193                 .clid_data = {0},
 194         };
 195
 196         odhcpd_get_mac(iface, reconf_msg.mac);
 197         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 198         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 199
 200         md5_ctx_t md5;
 201         uint8_t secretbytes[64];
 202         memset(secretbytes, 0, sizeof(secretbytes));
 203         memcpy(secretbytes, assign->key, sizeof(assign->key));
 204
 205         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 206                 secretbytes[i] ^= 0x36;
 207
 208         md5_begin(&md5);
 209         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 210         md5_hash(iov.iov_base, iov.iov_len, &md5);
 211         md5_end(reconf_msg.auth.key, &md5);
 212
 213         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 214                 secretbytes[i] ^= 0x36;
 215                 secretbytes[i] ^= 0x5c;
 216         }
 217
 218         md5_begin(&md5);
 219         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 220         md5_hash(reconf_msg.auth.key, 16, &md5);
 221         md5_end(reconf_msg.auth.key, &md5);
 222
 223         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 224 }
 225
 226 void dhcpv6_write_statefile(void)
 227 {
 228         md5_ctx_t md5;
 229         md5_begin(&md5);
 230
 231         if (config.dhcp_statefile) {
 232                 time_t now = odhcpd_time(), wall_time = time(NULL);
 233                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 234                 if (fd < 0)
 235                         return;
 236
 237                 lockf(fd, F_LOCK, 0);
 238                 if (ftruncate(fd, 0) < 0) {}
 239
 240                 FILE *fp = fdopen(fd, "w");
 241                 if (!fp) {
 242                         close(fd);
 243                         return;
 244                 }
 245
 246                 struct interface *iface;
 247                 list_for_each_entry(iface, &interfaces, head) {
 248                         if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
 249                                 continue;
 250
 251                         if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
 252                                 struct dhcpv6_assignment *c;
 253                                 list_for_each_entry(c, &iface->ia_assignments, head) {
 254                                         if (!(c->flags & OAF_BOUND) || c->managed_size < 0)
 255                                                 continue;
 256
 257                                         char ipbuf[INET6_ADDRSTRLEN];
 258                                         char leasebuf[512];
 259                                         char duidbuf[264];
 260                                         odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
 261
 262                                         // iface DUID iaid hostname lifetime assigned length [addrs...]
 263                                         int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %ld %x %u ",
 264                                                         iface->ifname, duidbuf, ntohl(c->iaid),
 265                                                         (c->hostname ? c->hostname : "-"),
 266                                                         (c->valid_until > now ?
 267                                                                 (c->valid_until - now + wall_time) :
 268                                                                 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 269                                                         c->assigned, (unsigned)c->length);
 270
 271                                         struct in6_addr addr;
 272                                         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
 273                                         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
 274                                         size_t m = elect_addr(addrs, addrlen);
 275
 276                                         for (size_t i = 0; i < addrlen; ++i) {
 277                                                 if (!valid_addr(&addrs[i], now) || (!INFINITE_VALID(c->valid_until) && c->valid_until <= now) ||
 278                                                                 (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
 279                                                                                 addrs[i].prefix <= 64))
 280                                                         continue;
 281
 282                                                 addr = addrs[i].addr;
 283                                                 if (c->length == 128)
 284                                                         addr.s6_addr32[3] = htonl(c->assigned);
 285                                                 else
 286                                                         addr.s6_addr32[1] |= htonl(c->assigned);
 287
 288                                                 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
 289
 290                                                 if (c->length == 128 && c->hostname) {
 291                                                         fputs(ipbuf, fp);
 292
 293                                                         char b[256];
 294                                                         if (dn_expand(iface->search, iface->search + iface->search_len,
 295                                                                         iface->search, b, sizeof(b)) > 0)
 296                                                                 fprintf(fp, "\t%s.%s", c->hostname, b);
 297
 298                                                         fprintf(fp, "\t%s\n", c->hostname);
 299                                                         md5_hash(ipbuf, strlen(ipbuf), &md5);
 300                                                         md5_hash(c->hostname, strlen(c->hostname), &md5);
 301                                                 }
 302
 303                                                 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
 304                                                                 (c->managed_size) ? addrs[i].prefix : c->length);
 305                                         }
 306                                         leasebuf[l - 1] = '\n';
 307                                         fwrite(leasebuf, 1, l, fp);
 308                                 }
 309                         }
 310
 311                         if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
 312                                 struct dhcpv4_assignment *c;
 313                                 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
 314                                         if (!(c->flags & OAF_BOUND))
 315                                                 continue;
 316
 317                                         char ipbuf[INET6_ADDRSTRLEN];
 318                                         char leasebuf[512];
 319                                         char duidbuf[16];
 320                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 321
 322                                         // iface DUID iaid hostname lifetime assigned length [addrs...]
 323                                         int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %ld %x 32 ",
 324                                                         iface->ifname, duidbuf,
 325                                                         (c->hostname ? c->hostname : "-"),
 326                                                         (c->valid_until > now ?
 327                                                                 (c->valid_until - now + wall_time) :
 328                                                                 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 329                                                         c->addr);
 330
 331                                         struct in_addr addr = {htonl(c->addr)};
 332                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 333
 334                                         if (c->hostname) {
 335                                                 fputs(ipbuf, fp);
 336
 337                                                 char b[256];
 338                                                 if (dn_expand(iface->search, iface->search + iface->search_len,
 339                                                                 iface->search, b, sizeof(b)) > 0)
 340                                                         fprintf(fp, "\t%s.%s", c->hostname, b);
 341
 342                                                 fprintf(fp, "\t%s\n", c->hostname);
 343                                                 md5_hash(ipbuf, strlen(ipbuf), &md5);
 344                                                 md5_hash(c->hostname, strlen(c->hostname), &md5);
 345                                         }
 346
 347                                         l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
 348                                         leasebuf[l - 1] = '\n';
 349                                         fwrite(leasebuf, 1, l, fp);
 350                                 }
 351                         }
 352                 }
 353
 354                 fclose(fp);
 355         }
 356
 357         uint8_t newmd5[16];
 358         md5_end(newmd5, &md5);
 359
 360         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 361                 memcpy(statemd5, newmd5, sizeof(statemd5));
 362                 char *argv[2] = {config.dhcp_cb, NULL};
 363                 if (!vfork()) {
 364                         execv(argv[0], argv);
 365                         _exit(128);
 366                 }
 367         }
 368 }
 369
 370
 371 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
 372 {
 373         if (a->length > 64 || a->managed_size < 0)
 374                 return;
 375
 376         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 377         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 378
 379         for (size_t i = 0; i < addrlen; ++i) {
 380                 struct in6_addr prefix = addrs[i].addr;
 381                 prefix.s6_addr32[1] |= htonl(a->assigned);
 382                 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 383                                 iface, &a->peer.sin6_addr, 1024, add);
 384         }
 385 }
 386
 387 // More data was received from TCP connection
 388 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 389 {
 390         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 391         time_t now = odhcpd_time();
 392         bool first = c->managed_size < 0;
 393
 394         for (;;) {
 395                 int pending;
 396                 char *data = ustream_get_read_buf(s, &pending);
 397                 char *end = memmem(data, pending, "\n\n", 2);
 398
 399                 if (!end)
 400                         break;
 401
 402                 end += 2;
 403                 end[-1] = 0;
 404
 405                 c->managed_size = 0;
 406                 if (c->accept_reconf)
 407                         c->reconf_cnt = 1;
 408
 409                 char *saveptr;
 410                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 411                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 412                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 413
 414                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 415                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 416                                 continue;
 417
 418                         x = strtok_r(NULL, ",", &saveptr2);
 419                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 420                                 continue;
 421
 422                         x = strtok_r(NULL, ",", &saveptr2);
 423                         if (sscanf(x, "%u", &n->preferred) < 1)
 424                                 continue;
 425
 426                         x = strtok_r(NULL, ",", &saveptr2);
 427                         if (sscanf(x, "%u", &n->valid) < 1)
 428                                 continue;
 429
 430                         if (n->preferred > n->valid)
 431                                 continue;
 432
 433                         if (UINT32_MAX - now < n->preferred)
 434                                 n->preferred = UINT32_MAX;
 435                         else
 436                                 n->preferred += now;
 437
 438                         if (UINT32_MAX - now < n->valid)
 439                                 n->valid = UINT32_MAX;
 440                         else
 441                                 n->valid += now;
 442
 443                         n->dprefix = 0;
 444
 445                         ++c->managed_size;
 446                 }
 447
 448                 ustream_consume(s, end - data);
 449         }
 450
 451         if (first && c->managed_size == 0)
 452                 free_dhcpv6_assignment(c);
 453         else if (first)
 454                 c->valid_until = now + 150;
 455 }
 456
 457
 458 /* TCP transmission has ended, either because of success or timeout or other error */
 459 static void managed_handle_pd_done(struct ustream *s)
 460 {
 461         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 462
 463         c->valid_until = odhcpd_time() + 15;
 464         c->managed_size = 0;
 465
 466         if (c->accept_reconf)
 467                 c->reconf_cnt = 1;
 468 }
 469
 470 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
 471 {
 472         struct dhcpv6_assignment *c;
 473
 474         if (iface->dhcpv6_pd_manager[0]) {
 475                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 476                 if (fd >= 0) {
 477                         char iaidbuf[298];
 478                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 479
 480                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 481                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 482                         ustream_fd_init(&assign->managed_sock, fd);
 483                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 484                                         iaidbuf, assign->iaid, assign->length);
 485                         ustream_write_pending(&assign->managed_sock.stream);
 486                         assign->managed_size = -1;
 487                         assign->valid_until = odhcpd_time() + 15;
 488                         list_add(&assign->head, &iface->ia_assignments);
 489
 490                         /* Wait initial period of up to 250ms for immediate assignment */
 491                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 492                         poll(&pfd, 1, 250);
 493                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 494
 495                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 496                                 return true;
 497                 }
 498
 499                 return false;
 500         } else if (iface->ia_addr_len < 1)
 501                 return false;
 502
 503         /* Try honoring the hint first */
 504         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 505         if (assign->assigned) {
 506                 list_for_each_entry(c, &iface->ia_assignments, head) {
 507                         if (c->length == 128 || c->length == 0)
 508                                 continue;
 509
 510                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 511                                 list_add_tail(&assign->head, &c->head);
 512                                 apply_lease(iface, assign, true);
 513                                 return true;
 514                         }
 515
 516                         if (c->assigned != 0)
 517                                 current = (c->assigned + (1 << (64 - c->length)));
 518                 }
 519         }
 520
 521         /* Fallback to a variable assignment */
 522         current = 1;
 523         list_for_each_entry(c, &iface->ia_assignments, head) {
 524                 if (c->length == 128 || c->length == 0)
 525                         continue;
 526
 527                 current = (current + asize) & (~asize);
 528                 if (current + asize < c->assigned) {
 529                         assign->assigned = current;
 530                         list_add_tail(&assign->head, &c->head);
 531                         apply_lease(iface, assign, true);
 532                         return true;
 533                 }
 534
 535                 if (c->assigned != 0)
 536                         current = (c->assigned + (1 << (64 - c->length)));
 537         }
 538
 539         return false;
 540 }
 541
 542 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 543 {
 544         /* Seed RNG with checksum of DUID */
 545         uint32_t seed = 0;
 546         for (size_t i = 0; i < assign->clid_len; ++i)
 547                 seed += assign->clid_data[i];
 548         srand(seed);
 549
 550         /* Try to assign up to 100x */
 551         for (size_t i = 0; i < 100; ++i) {
 552                 uint32_t try;
 553                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 554
 555                 struct dhcpv6_assignment *c;
 556                 list_for_each_entry(c, &iface->ia_assignments, head) {
 557                         if (c->length == 0)
 558                                 continue;
 559
 560                         if (c->assigned > try || c->length != 128) {
 561                                 assign->assigned = try;
 562                                 list_add_tail(&assign->head, &c->head);
 563                                 return true;
 564                         } else if (c->assigned == try)
 565                                 break;
 566                 }
 567         }
 568
 569         return false;
 570 }
 571
 572 void dhcpv6_ia_preupdate(struct interface *iface)
 573 {
 574         if (iface->dhcpv6 != RELAYD_SERVER)
 575                 return;
 576
 577         struct dhcpv6_assignment *c, *border = list_last_entry(
 578                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 579
 580         list_for_each_entry(c, &iface->ia_assignments, head)
 581                 if (c != border && !iface->managed)
 582                         apply_lease(iface, c, false);
 583 }
 584
 585 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
 586 {
 587         if (iface->dhcpv6 != RELAYD_SERVER)
 588                 return;
 589
 590         int minprefix = -1;
 591         for (size_t i = 0; i < iface->ia_addr_len; ++i) {
 592                 if (iface->ia_addr[i].preferred > (uint32_t)now &&
 593                                 iface->ia_addr[i].prefix < 64 &&
 594                                 iface->ia_addr[i].prefix > minprefix)
 595                         minprefix = iface->ia_addr[i].prefix;
 596         }
 597
 598         struct dhcpv6_assignment *border = list_last_entry(
 599                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 600
 601         if (minprefix > 32 && minprefix <= 64)
 602                 border->assigned = 1U << (64 - minprefix);
 603         else
 604                 border->assigned = 0;
 605
 606         struct list_head reassign = LIST_HEAD_INIT(reassign);
 607         struct dhcpv6_assignment *c, *d;
 608         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 609                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 610                                 c->managed_size)
 611                         continue;
 612
 613                 if (c->length < 128 && c->assigned >= border->assigned && c != border)
 614                         list_move(&c->head, &reassign);
 615                 else if (c != border)
 616                         apply_lease(iface, c, true);
 617
 618                 if (c->accept_reconf && c->reconf_cnt == 0) {
 619                         c->reconf_cnt = 1;
 620                         c->reconf_sent = now;
 621                         send_reconf(iface, c);
 622
 623                         /* Leave all other assignments of that client alone */
 624                         struct dhcpv6_assignment *a;
 625                         list_for_each_entry(a, &iface->ia_assignments, head)
 626                                 if (a != c && a->clid_len == c->clid_len &&
 627                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 628                                         c->reconf_cnt = INT_MAX;
 629                 }
 630         }
 631
 632         while (!list_empty(&reassign)) {
 633                 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
 634                 list_del(&c->head);
 635                 if (!assign_pd(iface, c)) {
 636                         c->assigned = 0;
 637                         list_add(&c->head, &iface->ia_assignments);
 638                 }
 639         }
 640
 641         dhcpv6_write_statefile();
 642 }
 643
 644 static void reconf_timer(struct uloop_timeout *event)
 645 {
 646         time_t now = odhcpd_time();
 647         struct interface *iface;
 648         list_for_each_entry(iface, &interfaces, head) {
 649                 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
 650                         continue;
 651
 652                 struct dhcpv6_assignment *a, *n;
 653                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 654                         if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
 655                                 if ((a->length < 128 && a->clid_len > 0) ||
 656                                                 (a->length == 128 && a->clid_len == 0))
 657                                         free_dhcpv6_assignment(a);
 658
 659                         } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
 660                                         now > a->reconf_sent + (1 << a->reconf_cnt)) {
 661                                 ++a->reconf_cnt;
 662                                 a->reconf_sent = now;
 663                                 send_reconf(iface, a);
 664                         }
 665                 }
 666         }
 667         uloop_timeout_set(event, 2000);
 668 }
 669
 670 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
 671                 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
 672                 struct interface *iface, bool request)
 673 {
 674         if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
 675                 return 0;
 676
 677         struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
 678         size_t datalen = sizeof(out);
 679         time_t now = odhcpd_time();
 680
 681         if (status) {
 682                 struct __attribute__((packed)) {
 683                         uint16_t type;
 684                         uint16_t len;
 685                         uint16_t value;
 686                 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
 687                                 htons(status)};
 688
 689                 memcpy(buf + datalen, &stat, sizeof(stat));
 690                 datalen += sizeof(stat);
 691         } else {
 692                 if (a) {
 693                         uint32_t leasetime;
 694                         if (a->leasetime > 0)
 695                                 leasetime = a->leasetime;
 696                         else
 697                                 leasetime = iface->dhcpv4_leasetime;
 698
 699                         if (leasetime == 0)
 700                                 leasetime = 3600;
 701                         else if (leasetime < 60)
 702                                 leasetime = 60;
 703
 704                         uint32_t pref = leasetime;
 705                         uint32_t valid = leasetime;
 706
 707                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 708                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 709                         size_t m = elect_addr(addrs, addrlen);
 710
 711                         for (size_t i = 0; i < addrlen; ++i) {
 712                                 uint32_t prefix_pref = addrs[i].preferred;
 713                                 uint32_t prefix_valid = addrs[i].valid;
 714
 715                                 if (!valid_addr(&addrs[i], now))
 716                                         continue;
 717
 718                                 if (prefix_pref != UINT32_MAX)
 719                                         prefix_pref -= now;
 720
 721                                 if (prefix_valid != UINT32_MAX)
 722                                         prefix_valid -= now;
 723
 724                                 if (a->length < 128) {
 725                                         struct dhcpv6_ia_prefix p = {
 726                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 727                                                 .len = htons(sizeof(p) - 4),
 728                                                 .preferred = htonl(prefix_pref),
 729                                                 .valid = htonl(prefix_valid),
 730                                                 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 731                                                 .addr = addrs[i].addr
 732                                         };
 733                                         p.addr.s6_addr32[1] |= htonl(a->assigned);
 734
 735                                         size_t entrlen = sizeof(p) - 4;
 736
 737                                         if (datalen + entrlen + 4 > buflen ||
 738                                                         (a->assigned == 0 && a->managed_size == 0) ||
 739                                                         (!a->managed_size && a->length <= addrs[i].prefix))
 740                                                 continue;
 741
 742                                         memcpy(buf + datalen, &p, sizeof(p));
 743                                         datalen += entrlen + 4;
 744                                 } else {
 745                                         struct dhcpv6_ia_addr n = {
 746                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 747                                                 .len = htons(sizeof(n) - 4),
 748                                                 .addr = addrs[i].addr,
 749                                                 .preferred = htonl(prefix_pref),
 750                                                 .valid = htonl(prefix_valid)
 751                                         };
 752                                         n.addr.s6_addr32[3] = htonl(a->assigned);
 753                                         size_t entrlen = sizeof(n) - 4;
 754
 755                                         if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
 756                                                         addrs[i].prefix <= 64)
 757                                                 continue;
 758
 759                                         if (datalen + entrlen + 4 > buflen || a->assigned == 0)
 760                                                 continue;
 761
 762                                         memcpy(buf + datalen, &n, sizeof(n));
 763                                         datalen += entrlen + 4;
 764                                 }
 765
 766                                 /* Calculate T1 / T2 based on non-deprecated addresses */
 767                                 if (prefix_pref > 0) {
 768                                         if (prefix_pref < pref)
 769                                                 pref = prefix_pref;
 770
 771                                         if (prefix_valid < valid)
 772                                                 valid = prefix_valid;
 773                                 }
 774                         }
 775
 776                         if (!INFINITE_VALID(a->valid_until))
 777                                 /* UINT32_MAX is considered as infinite leasetime */
 778                                 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 779
 780                         out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 781                         out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 782
 783                         if (!out.t1)
 784                                 out.t1 = htonl(1);
 785
 786                         if (!out.t2)
 787                                 out.t2 = htonl(1);
 788                 }
 789
 790                 if (!request) {
 791                         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 792                         uint16_t otype, olen;
 793                         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 794                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
 795                                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
 796                                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
 797                                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
 798                                         continue;
 799
 800                                 bool found = false;
 801                                 if (a) {
 802                                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 803                                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 804
 805                                         for (size_t i = 0; i < addrlen; ++i) {
 806                                                 if (!valid_addr(&addrs[i], now))
 807                                                         continue;
 808
 809                                                 struct in6_addr addr = addrs[i].addr;
 810                                                 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 811                                                         addr.s6_addr32[1] |= htonl(a->assigned);
 812
 813                                                         if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
 814                                                                         p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 815                                                                 found = true;
 816                                                 } else {
 817                                                         addr.s6_addr32[3] = htonl(a->assigned);
 818
 819                                                         if (!memcmp(&n->addr, &addr, sizeof(addr)))
 820                                                                 found = true;
 821                                                 }
 822                                         }
 823                                 }
 824
 825                                 if (!found) {
 826                                         if (otype == DHCPV6_OPT_IA_PREFIX) {
 827                                                 struct dhcpv6_ia_prefix inv = {
 828                                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 829                                                         .len = htons(sizeof(inv) - 4),
 830                                                         .preferred = 0,
 831                                                         .valid = 0,
 832                                                         .prefix = p->prefix,
 833                                                         .addr = p->addr
 834                                                 };
 835
 836                                                 if (datalen + sizeof(inv) > buflen)
 837                                                         continue;
 838
 839                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 840                                                 datalen += sizeof(inv);
 841                                         } else {
 842                                                 struct dhcpv6_ia_addr inv = {
 843                                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 844                                                         .len = htons(sizeof(inv) - 4),
 845                                                         .addr = n->addr,
 846                                                         .preferred = 0,
 847                                                         .valid = 0
 848                                                 };
 849
 850                                                 if (datalen + sizeof(inv) > buflen)
 851                                                         continue;
 852
 853                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 854                                                 datalen += sizeof(inv);
 855                                         }
 856                                 }
 857                         }
 858                 }
 859         }
 860
 861         out.len = htons(datalen - 4);
 862         memcpy(buf, &out, sizeof(out));
 863         return datalen;
 864 }
 865
 866 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
 867                 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
 868 {
 869         const char *type = "UNKNOWN";
 870         const char *status = "UNKNOWN";
 871
 872         if (msgtype == DHCPV6_MSG_RENEW)
 873                 return;
 874
 875         switch (msgtype) {
 876         case DHCPV6_MSG_SOLICIT:
 877                 type = "SOLICIT";
 878                 break;
 879         case DHCPV6_MSG_REQUEST:
 880                 type = "REQUEST";
 881                 break;
 882         case DHCPV6_MSG_CONFIRM:
 883                 type = "CONFIRM";
 884                 break;
 885         case DHCPV6_MSG_RENEW:
 886                 type = "RENEW";
 887                 break;
 888         case DHCPV6_MSG_REBIND:
 889                 type = "REBIND";
 890                 break;
 891         case DHCPV6_MSG_RELEASE:
 892                 type = "RELEASE";
 893                 break;
 894         case DHCPV6_MSG_DECLINE:
 895                 type = "DECLINE";
 896                 break;
 897         }
 898
 899         switch (code) {
 900         case DHCPV6_STATUS_OK:
 901                 status = "ok";
 902                 break;
 903         case DHCPV6_STATUS_NOADDRSAVAIL:
 904                 status = "no addresses available";
 905                 break;
 906         case DHCPV6_STATUS_NOBINDING:
 907                 status = "no binding";
 908                 break;
 909         case DHCPV6_STATUS_NOTONLINK:
 910                 status = "not on-link";
 911                 break;
 912         case DHCPV6_STATUS_NOPREFIXAVAIL:
 913                 status = "no prefix available";
 914                 break;
 915         }
 916
 917         char leasebuf[256] = "";
 918
 919         if (a) {
 920                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 921                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 922                 size_t lbsize = 0;
 923                 char addrbuf[INET6_ADDRSTRLEN];
 924
 925                 for (size_t i = 0; i < addrlen; ++i) {
 926                         if (!valid_addr(&addrs[i], now))
 927                                 continue;
 928
 929                         struct in6_addr addr = addrs[i].addr;
 930                         int prefix = a->managed ? addrs[i].prefix : a->length;
 931                         if (prefix == 128)
 932                                 addr.s6_addr32[3] = htonl(a->assigned);
 933                         else
 934                                 addr.s6_addr32[1] |= htonl(a->assigned);
 935
 936                         inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
 937                         lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
 938                 }
 939         }
 940
 941         syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
 942                         duidbuf, iface->ifname, status, leasebuf);
 943 }
 944
 945 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
 946                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
 947 {
 948         time_t now = odhcpd_time();
 949         size_t response_len = 0;
 950         const struct dhcpv6_client_header *hdr = data;
 951         uint8_t *start = (uint8_t*)&hdr[1], *odata;
 952         uint16_t otype, olen;
 953         /* Find and parse client-id and hostname */
 954         bool accept_reconf = false;
 955         uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 956         char hostname[256];
 957         size_t hostname_len = 0;
 958         bool notonlink = false;
 959         char duidbuf[261];
 960
 961         dhcpv6_for_each_option(start, end, otype, olen, odata) {
 962                 if (otype == DHCPV6_OPT_CLIENTID) {
 963                         clid_data = odata;
 964                         clid_len = olen;
 965
 966                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
 967                                 memcpy(mac, &odata[8], sizeof(mac));
 968                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
 969                                 memcpy(mac, &odata[4], sizeof(mac));
 970
 971                         if (olen <= 130)
 972                                 odhcpd_hexlify(duidbuf, odata, olen);
 973                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
 974                         uint8_t fqdn_buf[256];
 975                         memcpy(fqdn_buf, odata, olen);
 976                         fqdn_buf[olen++] = 0;
 977
 978                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
 979                                 hostname_len = strcspn(hostname, ".");
 980                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
 981                         accept_reconf = true;
 982         }
 983
 984         if (!clid_data || !clid_len || clid_len > 130)
 985                 goto out;
 986
 987         struct dhcpv6_assignment *first = NULL;
 988         dhcpv6_for_each_option(start, end, otype, olen, odata) {
 989                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
 990                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
 991                 bool ia_addr_present = false;
 992                 if (!is_pd && !is_na)
 993                         continue;
 994
 995                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
 996                 size_t ia_response_len = 0;
 997                 uint8_t reqlen = (is_pd) ? 62 : 128;
 998                 uint32_t reqhint = 0;
 999
1000                 /* Parse request hint for IA-PD */
1001                 if (is_pd) {
1002                         uint8_t *sdata;
1003                         uint16_t stype, slen;
1004                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1005                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1006                                         continue;
1007
1008                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1009                                 if (p->prefix) {
1010                                         reqlen = p->prefix;
1011                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1012                                         if (reqlen > 32 && reqlen <= 64)
1013                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1014                                 }
1015                         }
1016
1017                         if (reqlen > 64)
1018                                 reqlen = 64;
1019                 } else if (is_na) {
1020                         uint8_t *sdata;
1021                         uint16_t stype, slen;
1022                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1023                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1024                                         continue;
1025
1026                                 ia_addr_present = true;
1027                         }
1028                 }
1029
1030                 /* Find assignment */
1031                 struct dhcpv6_assignment *c, *a = NULL;
1032                 list_for_each_entry(c, &iface->ia_assignments, head) {
1033                         if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1034                                         (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1035                                                 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1036                                         (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1037                                         ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1038                                 a = c;
1039
1040                                 // Reset state
1041                                 apply_lease(iface, a, false);
1042                                 memcpy(a->clid_data, clid_data, clid_len);
1043                                 a->clid_len = clid_len;
1044                                 a->iaid = ia->iaid;
1045                                 a->peer = *addr;
1046                                 a->reconf_cnt = 0;
1047                                 a->reconf_sent = 0;
1048                                 break;
1049                         }
1050                 }
1051
1052                 /* Generic message handling */
1053                 uint16_t status = DHCPV6_STATUS_OK;
1054                 if (a && a->managed_size < 0)
1055                         return -1;
1056
1057                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1058                         bool assigned = !!a;
1059
1060                         if (!a && !iface->no_dynamic_dhcp) {
1061                                 /* Create new binding */
1062                                 a = calloc(1, sizeof(*a) + clid_len);
1063                                 if (a) {
1064                                         a->clid_len = clid_len;
1065                                         a->iaid = ia->iaid;
1066                                         a->length = reqlen;
1067                                         a->peer = *addr;
1068                                         a->assigned = reqhint;
1069                                         /* Set valid time to current time indicating  */
1070                                         /* assignment is not having infinite lifetime */
1071                                         a->valid_until = now;
1072
1073                                         if (first)
1074                                                 memcpy(a->key, first->key, sizeof(a->key));
1075                                         else
1076                                                 odhcpd_urandom(a->key, sizeof(a->key));
1077                                         memcpy(a->clid_data, clid_data, clid_len);
1078
1079                                         if (is_pd)
1080                                                 while (!(assigned = assign_pd(iface, a)) &&
1081                                                                 !a->managed_size && ++a->length <= 64);
1082                                         else
1083                                                 assigned = assign_na(iface, a);
1084
1085                                         if (a->managed_size && !assigned)
1086                                                 return -1;
1087                                 }
1088                         }
1089
1090                         if (!assigned || iface->ia_addr_len == 0)
1091                                 /* Set error status */
1092                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1093                         else if (assigned && !first) {
1094                                 size_t handshake_len = 4;
1095                                 buf[0] = 0;
1096                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1097                                 buf[2] = 0;
1098                                 buf[3] = 0;
1099
1100                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1101                                         struct dhcpv6_auth_reconfigure auth = {
1102                                                 htons(DHCPV6_OPT_AUTH),
1103                                                 htons(sizeof(auth) - 4),
1104                                                 3, 1, 0,
1105                                                 {htonl(time(NULL)), htonl(++serial)},
1106                                                 1,
1107                                                 {0}
1108                                         };
1109                                         memcpy(auth.key, a->key, sizeof(a->key));
1110                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1111                                         handshake_len += sizeof(auth);
1112                                 }
1113
1114                                 buf += handshake_len;
1115                                 buflen -= handshake_len;
1116                                 response_len += handshake_len;
1117
1118                                 first = a;
1119                         }
1120
1121                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1122
1123                         /* Was only a solicitation: mark binding for removal */
1124                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1125                                 a->flags &= ~OAF_BOUND;
1126
1127                                 if (!(a->flags & OAF_STATIC))
1128                                         a->valid_until = now;
1129                         } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1130                                 if (hostname_len > 0) {
1131                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1132                                         if (a->hostname) {
1133                                                 memcpy(a->hostname, hostname, hostname_len);
1134                                                 a->hostname[hostname_len] = 0;
1135                                         }
1136                                 }
1137                                 a->accept_reconf = accept_reconf;
1138                                 a->flags |= OAF_BOUND;
1139                                 apply_lease(iface, a, true);
1140                         } else if (!assigned && a && a->managed_size == 0)
1141                                 /* Cleanup failed assignment */
1142                                 free_dhcpv6_assignment(a);
1143
1144                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1145                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1146                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1147                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1148                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1149                                 status = DHCPV6_STATUS_NOBINDING;
1150                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1151                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1152                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1153                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1154                                 if (a) {
1155                                         a->flags |= OAF_BOUND;
1156                                         apply_lease(iface, a, true);
1157                                 }
1158                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1159                                 if (!(a->flags & OAF_STATIC))
1160                                         a->valid_until = now - 1;
1161
1162                                 a->flags &= ~OAF_BOUND;
1163                                 apply_lease(iface, a, false);
1164                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1165                                 a->flags &= ~OAF_BOUND;
1166
1167                                 if (!(a->flags & OAF_STATIC)) {
1168                                         a->clid_len = 0;
1169                                         a->valid_until = now + 3600; /* Block address for 1h */
1170                                 }
1171                         }
1172                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1173                         /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1174                         status = DHCPV6_STATUS_NOTONLINK;
1175                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1176                         notonlink = true;
1177                 }
1178
1179                 buf += ia_response_len;
1180                 buflen -= ia_response_len;
1181                 response_len += ia_response_len;
1182                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1183         }
1184
1185         if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1186                         response_len + 6 < buflen) {
1187                 buf[0] = 0;
1188                 buf[1] = DHCPV6_OPT_STATUS;
1189                 buf[2] = 0;
1190                 buf[3] = 2;
1191                 buf[4] = 0;
1192                 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1193                 response_len += 6;
1194         }
1195
1196         dhcpv6_write_statefile();
1197
1198 out:
1199         return response_len;
1200 }