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 & !(c->flags & OAF_STATIC))
 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         if (!(c->flags & OAF_STATIC))
 464                 c->valid_until = odhcpd_time() + 15;
 465
 466         c->managed_size = 0;
 467
 468         if (c->accept_reconf)
 469                 c->reconf_cnt = 1;
 470 }
 471
 472 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
 473 {
 474         struct dhcpv6_assignment *c;
 475
 476         if (iface->dhcpv6_pd_manager[0]) {
 477                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 478                 if (fd >= 0) {
 479                         char iaidbuf[298];
 480                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 481
 482                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 483                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 484                         ustream_fd_init(&assign->managed_sock, fd);
 485                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 486                                         iaidbuf, assign->iaid, assign->length);
 487                         ustream_write_pending(&assign->managed_sock.stream);
 488                         assign->managed_size = -1;
 489
 490                         if (!(assign->flags & OAF_STATIC))
 491                                 assign->valid_until = odhcpd_time() + 15;
 492
 493                         list_add(&assign->head, &iface->ia_assignments);
 494
 495                         /* Wait initial period of up to 250ms for immediate assignment */
 496                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 497                         poll(&pfd, 1, 250);
 498                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 499
 500                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 501                                 return true;
 502                 }
 503
 504                 return false;
 505         } else if (iface->ia_addr_len < 1)
 506                 return false;
 507
 508         /* Try honoring the hint first */
 509         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 510         if (assign->assigned) {
 511                 list_for_each_entry(c, &iface->ia_assignments, head) {
 512                         if (c->length == 128 || c->length == 0)
 513                                 continue;
 514
 515                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 516                                 list_add_tail(&assign->head, &c->head);
 517                                 apply_lease(iface, assign, true);
 518                                 return true;
 519                         }
 520
 521                         if (c->assigned != 0)
 522                                 current = (c->assigned + (1 << (64 - c->length)));
 523                 }
 524         }
 525
 526         /* Fallback to a variable assignment */
 527         current = 1;
 528         list_for_each_entry(c, &iface->ia_assignments, head) {
 529                 if (c->length == 128 || c->length == 0)
 530                         continue;
 531
 532                 current = (current + asize) & (~asize);
 533                 if (current + asize < c->assigned) {
 534                         assign->assigned = current;
 535                         list_add_tail(&assign->head, &c->head);
 536                         apply_lease(iface, assign, true);
 537                         return true;
 538                 }
 539
 540                 if (c->assigned != 0)
 541                         current = (c->assigned + (1 << (64 - c->length)));
 542         }
 543
 544         return false;
 545 }
 546
 547 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 548 {
 549         /* Seed RNG with checksum of DUID */
 550         uint32_t seed = 0;
 551         for (size_t i = 0; i < assign->clid_len; ++i)
 552                 seed += assign->clid_data[i];
 553         srand(seed);
 554
 555         /* Try to assign up to 100x */
 556         for (size_t i = 0; i < 100; ++i) {
 557                 uint32_t try;
 558                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 559
 560                 struct dhcpv6_assignment *c;
 561                 list_for_each_entry(c, &iface->ia_assignments, head) {
 562                         if (c->length == 0)
 563                                 continue;
 564
 565                         if (c->assigned > try || c->length != 128) {
 566                                 assign->assigned = try;
 567                                 list_add_tail(&assign->head, &c->head);
 568                                 return true;
 569                         } else if (c->assigned == try)
 570                                 break;
 571                 }
 572         }
 573
 574         return false;
 575 }
 576
 577 void dhcpv6_ia_preupdate(struct interface *iface)
 578 {
 579         if (iface->dhcpv6 != RELAYD_SERVER)
 580                 return;
 581
 582         struct dhcpv6_assignment *c, *border = list_last_entry(
 583                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 584
 585         list_for_each_entry(c, &iface->ia_assignments, head)
 586                 if (c != border && !iface->managed)
 587                         apply_lease(iface, c, false);
 588 }
 589
 590 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
 591 {
 592         if (iface->dhcpv6 != RELAYD_SERVER)
 593                 return;
 594
 595         int minprefix = -1;
 596         for (size_t i = 0; i < iface->ia_addr_len; ++i) {
 597                 if (iface->ia_addr[i].preferred > (uint32_t)now &&
 598                                 iface->ia_addr[i].prefix < 64 &&
 599                                 iface->ia_addr[i].prefix > minprefix)
 600                         minprefix = iface->ia_addr[i].prefix;
 601         }
 602
 603         struct dhcpv6_assignment *border = list_last_entry(
 604                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 605
 606         if (minprefix > 32 && minprefix <= 64)
 607                 border->assigned = 1U << (64 - minprefix);
 608         else
 609                 border->assigned = 0;
 610
 611         struct list_head reassign = LIST_HEAD_INIT(reassign);
 612         struct dhcpv6_assignment *c, *d;
 613         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 614                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 615                                 c->managed_size)
 616                         continue;
 617
 618                 if (c->length < 128 && c->assigned >= border->assigned && c != border)
 619                         list_move(&c->head, &reassign);
 620                 else if (c != border)
 621                         apply_lease(iface, c, true);
 622
 623                 if (c->accept_reconf && c->reconf_cnt == 0) {
 624                         c->reconf_cnt = 1;
 625                         c->reconf_sent = now;
 626                         send_reconf(iface, c);
 627
 628                         /* Leave all other assignments of that client alone */
 629                         struct dhcpv6_assignment *a;
 630                         list_for_each_entry(a, &iface->ia_assignments, head)
 631                                 if (a != c && a->clid_len == c->clid_len &&
 632                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 633                                         c->reconf_cnt = INT_MAX;
 634                 }
 635         }
 636
 637         while (!list_empty(&reassign)) {
 638                 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
 639                 list_del(&c->head);
 640                 if (!assign_pd(iface, c)) {
 641                         c->assigned = 0;
 642                         list_add(&c->head, &iface->ia_assignments);
 643                 }
 644         }
 645
 646         dhcpv6_write_statefile();
 647 }
 648
 649 static void reconf_timer(struct uloop_timeout *event)
 650 {
 651         time_t now = odhcpd_time();
 652         struct interface *iface;
 653         list_for_each_entry(iface, &interfaces, head) {
 654                 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
 655                         continue;
 656
 657                 struct dhcpv6_assignment *a, *n;
 658                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 659                         if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
 660                                 if ((a->length < 128 && a->clid_len > 0) ||
 661                                                 (a->length == 128 && a->clid_len == 0))
 662                                         free_dhcpv6_assignment(a);
 663
 664                         } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
 665                                         now > a->reconf_sent + (1 << a->reconf_cnt)) {
 666                                 ++a->reconf_cnt;
 667                                 a->reconf_sent = now;
 668                                 send_reconf(iface, a);
 669                         }
 670                 }
 671         }
 672         uloop_timeout_set(event, 2000);
 673 }
 674
 675 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
 676                 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
 677                 struct interface *iface, bool request)
 678 {
 679         if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
 680                 return 0;
 681
 682         struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
 683         size_t datalen = sizeof(out);
 684         time_t now = odhcpd_time();
 685
 686         if (status) {
 687                 struct __attribute__((packed)) {
 688                         uint16_t type;
 689                         uint16_t len;
 690                         uint16_t value;
 691                 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
 692                                 htons(status)};
 693
 694                 memcpy(buf + datalen, &stat, sizeof(stat));
 695                 datalen += sizeof(stat);
 696         } else {
 697                 if (a) {
 698                         uint32_t leasetime;
 699                         if (a->leasetime > 0)
 700                                 leasetime = a->leasetime;
 701                         else
 702                                 leasetime = iface->dhcpv4_leasetime;
 703
 704                         if (leasetime == 0)
 705                                 leasetime = 3600;
 706                         else if (leasetime < 60)
 707                                 leasetime = 60;
 708
 709                         uint32_t pref = leasetime;
 710                         uint32_t valid = leasetime;
 711
 712                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 713                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 714                         size_t m = elect_addr(addrs, addrlen);
 715
 716                         for (size_t i = 0; i < addrlen; ++i) {
 717                                 uint32_t prefix_pref = addrs[i].preferred;
 718                                 uint32_t prefix_valid = addrs[i].valid;
 719
 720                                 if (!valid_addr(&addrs[i], now))
 721                                         continue;
 722
 723                                 if (prefix_pref != UINT32_MAX)
 724                                         prefix_pref -= now;
 725
 726                                 if (prefix_valid != UINT32_MAX)
 727                                         prefix_valid -= now;
 728
 729                                 if (a->length < 128) {
 730                                         struct dhcpv6_ia_prefix p = {
 731                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 732                                                 .len = htons(sizeof(p) - 4),
 733                                                 .preferred = htonl(prefix_pref),
 734                                                 .valid = htonl(prefix_valid),
 735                                                 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 736                                                 .addr = addrs[i].addr
 737                                         };
 738                                         p.addr.s6_addr32[1] |= htonl(a->assigned);
 739
 740                                         size_t entrlen = sizeof(p) - 4;
 741
 742                                         if (datalen + entrlen + 4 > buflen ||
 743                                                         (a->assigned == 0 && a->managed_size == 0) ||
 744                                                         (!a->managed_size && a->length <= addrs[i].prefix))
 745                                                 continue;
 746
 747                                         memcpy(buf + datalen, &p, sizeof(p));
 748                                         datalen += entrlen + 4;
 749                                 } else {
 750                                         struct dhcpv6_ia_addr n = {
 751                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 752                                                 .len = htons(sizeof(n) - 4),
 753                                                 .addr = addrs[i].addr,
 754                                                 .preferred = htonl(prefix_pref),
 755                                                 .valid = htonl(prefix_valid)
 756                                         };
 757                                         n.addr.s6_addr32[3] = htonl(a->assigned);
 758                                         size_t entrlen = sizeof(n) - 4;
 759
 760                                         if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
 761                                                         addrs[i].prefix <= 64)
 762                                                 continue;
 763
 764                                         if (datalen + entrlen + 4 > buflen || a->assigned == 0)
 765                                                 continue;
 766
 767                                         memcpy(buf + datalen, &n, sizeof(n));
 768                                         datalen += entrlen + 4;
 769                                 }
 770
 771                                 /* Calculate T1 / T2 based on non-deprecated addresses */
 772                                 if (prefix_pref > 0) {
 773                                         if (prefix_pref < pref)
 774                                                 pref = prefix_pref;
 775
 776                                         if (prefix_valid < valid)
 777                                                 valid = prefix_valid;
 778                                 }
 779                         }
 780
 781                         if (!INFINITE_VALID(a->valid_until))
 782                                 /* UINT32_MAX is considered as infinite leasetime */
 783                                 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 784
 785                         out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 786                         out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 787
 788                         if (!out.t1)
 789                                 out.t1 = htonl(1);
 790
 791                         if (!out.t2)
 792                                 out.t2 = htonl(1);
 793                 }
 794
 795                 if (!request) {
 796                         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 797                         uint16_t otype, olen;
 798                         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 799                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
 800                                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
 801                                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
 802                                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
 803                                         continue;
 804
 805                                 bool found = false;
 806                                 if (a) {
 807                                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 808                                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 809
 810                                         for (size_t i = 0; i < addrlen; ++i) {
 811                                                 if (!valid_addr(&addrs[i], now))
 812                                                         continue;
 813
 814                                                 struct in6_addr addr = addrs[i].addr;
 815                                                 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 816                                                         addr.s6_addr32[1] |= htonl(a->assigned);
 817
 818                                                         if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
 819                                                                         p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 820                                                                 found = true;
 821                                                 } else {
 822                                                         addr.s6_addr32[3] = htonl(a->assigned);
 823
 824                                                         if (!memcmp(&n->addr, &addr, sizeof(addr)))
 825                                                                 found = true;
 826                                                 }
 827                                         }
 828                                 }
 829
 830                                 if (!found) {
 831                                         if (otype == DHCPV6_OPT_IA_PREFIX) {
 832                                                 struct dhcpv6_ia_prefix inv = {
 833                                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 834                                                         .len = htons(sizeof(inv) - 4),
 835                                                         .preferred = 0,
 836                                                         .valid = 0,
 837                                                         .prefix = p->prefix,
 838                                                         .addr = p->addr
 839                                                 };
 840
 841                                                 if (datalen + sizeof(inv) > buflen)
 842                                                         continue;
 843
 844                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 845                                                 datalen += sizeof(inv);
 846                                         } else {
 847                                                 struct dhcpv6_ia_addr inv = {
 848                                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 849                                                         .len = htons(sizeof(inv) - 4),
 850                                                         .addr = n->addr,
 851                                                         .preferred = 0,
 852                                                         .valid = 0
 853                                                 };
 854
 855                                                 if (datalen + sizeof(inv) > buflen)
 856                                                         continue;
 857
 858                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 859                                                 datalen += sizeof(inv);
 860                                         }
 861                                 }
 862                         }
 863                 }
 864         }
 865
 866         out.len = htons(datalen - 4);
 867         memcpy(buf, &out, sizeof(out));
 868         return datalen;
 869 }
 870
 871 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
 872                 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
 873 {
 874         const char *type = "UNKNOWN";
 875         const char *status = "UNKNOWN";
 876
 877         if (msgtype == DHCPV6_MSG_RENEW)
 878                 return;
 879
 880         switch (msgtype) {
 881         case DHCPV6_MSG_SOLICIT:
 882                 type = "SOLICIT";
 883                 break;
 884         case DHCPV6_MSG_REQUEST:
 885                 type = "REQUEST";
 886                 break;
 887         case DHCPV6_MSG_CONFIRM:
 888                 type = "CONFIRM";
 889                 break;
 890         case DHCPV6_MSG_RENEW:
 891                 type = "RENEW";
 892                 break;
 893         case DHCPV6_MSG_REBIND:
 894                 type = "REBIND";
 895                 break;
 896         case DHCPV6_MSG_RELEASE:
 897                 type = "RELEASE";
 898                 break;
 899         case DHCPV6_MSG_DECLINE:
 900                 type = "DECLINE";
 901                 break;
 902         }
 903
 904         switch (code) {
 905         case DHCPV6_STATUS_OK:
 906                 status = "ok";
 907                 break;
 908         case DHCPV6_STATUS_NOADDRSAVAIL:
 909                 status = "no addresses available";
 910                 break;
 911         case DHCPV6_STATUS_NOBINDING:
 912                 status = "no binding";
 913                 break;
 914         case DHCPV6_STATUS_NOTONLINK:
 915                 status = "not on-link";
 916                 break;
 917         case DHCPV6_STATUS_NOPREFIXAVAIL:
 918                 status = "no prefix available";
 919                 break;
 920         }
 921
 922         char leasebuf[256] = "";
 923
 924         if (a) {
 925                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 926                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 927                 size_t lbsize = 0;
 928                 char addrbuf[INET6_ADDRSTRLEN];
 929
 930                 for (size_t i = 0; i < addrlen; ++i) {
 931                         if (!valid_addr(&addrs[i], now))
 932                                 continue;
 933
 934                         struct in6_addr addr = addrs[i].addr;
 935                         int prefix = a->managed ? addrs[i].prefix : a->length;
 936                         if (prefix == 128)
 937                                 addr.s6_addr32[3] = htonl(a->assigned);
 938                         else
 939                                 addr.s6_addr32[1] |= htonl(a->assigned);
 940
 941                         inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
 942                         lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
 943                 }
 944         }
 945
 946         syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
 947                         duidbuf, iface->ifname, status, leasebuf);
 948 }
 949
 950 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
 951                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
 952 {
 953         time_t now = odhcpd_time();
 954         size_t response_len = 0;
 955         const struct dhcpv6_client_header *hdr = data;
 956         uint8_t *start = (uint8_t*)&hdr[1], *odata;
 957         uint16_t otype, olen;
 958         /* Find and parse client-id and hostname */
 959         bool accept_reconf = false;
 960         uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 961         char hostname[256];
 962         size_t hostname_len = 0;
 963         bool notonlink = false;
 964         char duidbuf[261];
 965
 966         dhcpv6_for_each_option(start, end, otype, olen, odata) {
 967                 if (otype == DHCPV6_OPT_CLIENTID) {
 968                         clid_data = odata;
 969                         clid_len = olen;
 970
 971                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
 972                                 memcpy(mac, &odata[8], sizeof(mac));
 973                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
 974                                 memcpy(mac, &odata[4], sizeof(mac));
 975
 976                         if (olen <= 130)
 977                                 odhcpd_hexlify(duidbuf, odata, olen);
 978                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
 979                         uint8_t fqdn_buf[256];
 980                         memcpy(fqdn_buf, odata, olen);
 981                         fqdn_buf[olen++] = 0;
 982
 983                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
 984                                 hostname_len = strcspn(hostname, ".");
 985                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
 986                         accept_reconf = true;
 987         }
 988
 989         if (!clid_data || !clid_len || clid_len > 130)
 990                 goto out;
 991
 992         struct dhcpv6_assignment *first = NULL;
 993         dhcpv6_for_each_option(start, end, otype, olen, odata) {
 994                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
 995                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
 996                 bool ia_addr_present = false;
 997                 if (!is_pd && !is_na)
 998                         continue;
 999
1000                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1001                 size_t ia_response_len = 0;
1002                 uint8_t reqlen = (is_pd) ? 62 : 128;
1003                 uint32_t reqhint = 0;
1004
1005                 /* Parse request hint for IA-PD */
1006                 if (is_pd) {
1007                         uint8_t *sdata;
1008                         uint16_t stype, slen;
1009                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1010                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1011                                         continue;
1012
1013                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1014                                 if (p->prefix) {
1015                                         reqlen = p->prefix;
1016                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1017                                         if (reqlen > 32 && reqlen <= 64)
1018                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1019                                 }
1020                         }
1021
1022                         if (reqlen > 64)
1023                                 reqlen = 64;
1024                 } else if (is_na) {
1025                         uint8_t *sdata;
1026                         uint16_t stype, slen;
1027                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1028                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1029                                         continue;
1030
1031                                 ia_addr_present = true;
1032                         }
1033                 }
1034
1035                 /* Find assignment */
1036                 struct dhcpv6_assignment *c, *a = NULL;
1037                 list_for_each_entry(c, &iface->ia_assignments, head) {
1038                         if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1039                                         (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1040                                                 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1041                                         (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1042                                         ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1043                                 a = c;
1044
1045                                 // Reset state
1046                                 apply_lease(iface, a, false);
1047                                 memcpy(a->clid_data, clid_data, clid_len);
1048                                 a->clid_len = clid_len;
1049                                 a->iaid = ia->iaid;
1050                                 a->peer = *addr;
1051                                 a->reconf_cnt = 0;
1052                                 a->reconf_sent = 0;
1053                                 break;
1054                         }
1055                 }
1056
1057                 /* Generic message handling */
1058                 uint16_t status = DHCPV6_STATUS_OK;
1059                 if (a && a->managed_size < 0)
1060                         return -1;
1061
1062                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1063                         bool assigned = !!a;
1064
1065                         if (!a && !iface->no_dynamic_dhcp) {
1066                                 /* Create new binding */
1067                                 a = calloc(1, sizeof(*a) + clid_len);
1068                                 if (a) {
1069                                         a->clid_len = clid_len;
1070                                         a->iaid = ia->iaid;
1071                                         a->length = reqlen;
1072                                         a->peer = *addr;
1073                                         a->assigned = reqhint;
1074                                         /* Set valid time to current time indicating  */
1075                                         /* assignment is not having infinite lifetime */
1076                                         a->valid_until = now;
1077
1078                                         if (first)
1079                                                 memcpy(a->key, first->key, sizeof(a->key));
1080                                         else
1081                                                 odhcpd_urandom(a->key, sizeof(a->key));
1082                                         memcpy(a->clid_data, clid_data, clid_len);
1083
1084                                         if (is_pd)
1085                                                 while (!(assigned = assign_pd(iface, a)) &&
1086                                                                 !a->managed_size && ++a->length <= 64);
1087                                         else
1088                                                 assigned = assign_na(iface, a);
1089
1090                                         if (a->managed_size && !assigned)
1091                                                 return -1;
1092                                 }
1093                         }
1094
1095                         if (!assigned || iface->ia_addr_len == 0)
1096                                 /* Set error status */
1097                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1098                         else if (assigned && !first) {
1099                                 size_t handshake_len = 4;
1100                                 buf[0] = 0;
1101                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1102                                 buf[2] = 0;
1103                                 buf[3] = 0;
1104
1105                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1106                                         struct dhcpv6_auth_reconfigure auth = {
1107                                                 htons(DHCPV6_OPT_AUTH),
1108                                                 htons(sizeof(auth) - 4),
1109                                                 3, 1, 0,
1110                                                 {htonl(time(NULL)), htonl(++serial)},
1111                                                 1,
1112                                                 {0}
1113                                         };
1114                                         memcpy(auth.key, a->key, sizeof(a->key));
1115                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1116                                         handshake_len += sizeof(auth);
1117                                 }
1118
1119                                 buf += handshake_len;
1120                                 buflen -= handshake_len;
1121                                 response_len += handshake_len;
1122
1123                                 first = a;
1124                         }
1125
1126                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1127
1128                         /* Was only a solicitation: mark binding for removal */
1129                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1130                                 a->flags &= ~OAF_BOUND;
1131
1132                                 if (!(a->flags & OAF_STATIC))
1133                                         a->valid_until = now;
1134                         } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1135                                 if (hostname_len > 0) {
1136                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1137                                         if (a->hostname) {
1138                                                 memcpy(a->hostname, hostname, hostname_len);
1139                                                 a->hostname[hostname_len] = 0;
1140                                         }
1141                                 }
1142                                 a->accept_reconf = accept_reconf;
1143                                 a->flags |= OAF_BOUND;
1144                                 apply_lease(iface, a, true);
1145                         } else if (!assigned && a && a->managed_size == 0)
1146                                 /* Cleanup failed assignment */
1147                                 free_dhcpv6_assignment(a);
1148
1149                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1150                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1151                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1152                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1153                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1154                                 status = DHCPV6_STATUS_NOBINDING;
1155                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1156                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1157                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1158                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1159                                 if (a) {
1160                                         a->flags |= OAF_BOUND;
1161                                         apply_lease(iface, a, true);
1162                                 }
1163                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1164                                 if (!(a->flags & OAF_STATIC))
1165                                         a->valid_until = now - 1;
1166
1167                                 a->flags &= ~OAF_BOUND;
1168                                 apply_lease(iface, a, false);
1169                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1170                                 a->flags &= ~OAF_BOUND;
1171
1172                                 if (!(a->flags & OAF_STATIC)) {
1173                                         a->clid_len = 0;
1174                                         a->valid_until = now + 3600; /* Block address for 1h */
1175                                 }
1176                         }
1177                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1178                         /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1179                         status = DHCPV6_STATUS_NOTONLINK;
1180                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1181                         notonlink = true;
1182                 }
1183
1184                 buf += ia_response_len;
1185                 buflen -= ia_response_len;
1186                 response_len += ia_response_len;
1187                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1188         }
1189
1190         if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1191                         response_len + 6 < buflen) {
1192                 buf[0] = 0;
1193                 buf[1] = DHCPV6_OPT_STATUS;
1194                 buf[2] = 0;
1195                 buf[3] = 2;
1196                 buf[4] = 0;
1197                 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1198                 response_len += 6;
1199         }
1200
1201         dhcpv6_write_statefile();
1202
1203 out:
1204         return response_len;
1205 }