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
  54                 while (!list_empty(&iface->ia_assignments)) {
  55                         c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
  56                         free_dhcpv6_assignment(c);
  57                 }
  58         }
  59
  60         if (enable && iface->dhcpv6 == RELAYD_SERVER) {
  61                 if (!iface->ia_assignments.next)
  62                         INIT_LIST_HEAD(&iface->ia_assignments);
  63
  64                 if (list_empty(&iface->ia_assignments)) {
  65                         struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
  66                         if (!border) {
  67                                 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
  68                                 return -1;
  69                         }
  70
  71                         border->length = 64;
  72                         list_add(&border->head, &iface->ia_assignments);
  73                 }
  74
  75                 /* Parse static entries */
  76                 struct lease *lease;
  77                 list_for_each_entry(lease, &leases, head) {
  78                         /* Construct entry */
  79                         size_t duid_len = lease->duid_len ? lease->duid_len : 14;
  80                         struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
  81                         if (!a) {
  82                                 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
  83                                         iface->ifname);
  84                                 return -1;
  85                         }
  86
  87                         if (lease->dhcpv4_leasetime > 0)
  88                                 a->leasetime = lease->dhcpv4_leasetime;
  89
  90                         a->clid_len = duid_len;
  91                         a->length = 128;
  92                         if (lease->hostid) {
  93                                 a->assigned = lease->hostid;
  94                         } else {
  95                                 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
  96                                 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
  97                         }
  98
  99                         odhcpd_urandom(a->key, sizeof(a->key));
 100                         memcpy(a->clid_data, lease->duid, lease->duid_len);
 101                         memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
 102                         /* Static assignment */
 103                         a->flags |= OAF_STATIC;
 104                         /* Infinite valid */
 105                         a->valid_until = 0;
 106
 107                         /* Assign to all interfaces */
 108                         struct dhcpv6_assignment *c;
 109                         list_for_each_entry(c, &iface->ia_assignments, head) {
 110                                 if (c->length != 128 || c->assigned > a->assigned) {
 111                                         list_add_tail(&a->head, &c->head);
 112                                         break;
 113                                 } else if (c->assigned == a->assigned)
 114                                         /* Already an assignment with that number */
 115                                         break;
 116                         }
 117
 118                         if (a->head.next) {
 119                                 if (lease->hostname[0]) {
 120                                         free(a->hostname);
 121                                         a->hostname = strdup(lease->hostname);
 122                                 }
 123                         } else
 124                                 free_dhcpv6_assignment(a);
 125                 }
 126         }
 127         return 0;
 128 }
 129
 130 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
 131 {
 132         if (c->managed_sock.fd.registered) {
 133                 ustream_free(&c->managed_sock.stream);
 134                 close(c->managed_sock.fd.fd);
 135         }
 136
 137         if (c->head.next)
 138                 list_del(&c->head);
 139
 140         free(c->managed);
 141         free(c->hostname);
 142         free(c);
 143 }
 144
 145 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 146 {
 147         return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
 148 }
 149
 150 static size_t elect_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
 151 {
 152         size_t i, m;
 153
 154         for (i = 0, m = 0; i < addrlen; ++i) {
 155                 if (addrs[i].preferred > addrs[m].preferred ||
 156                         (addrs[i].preferred == addrs[m].preferred &&
 157                          memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 158                         m = i;
 159         }
 160
 161         return m;
 162 }
 163
 164 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
 165 {
 166         struct {
 167                 struct dhcpv6_client_header hdr;
 168                 uint16_t srvid_type;
 169                 uint16_t srvid_len;
 170                 uint16_t duid_type;
 171                 uint16_t hardware_type;
 172                 uint8_t mac[6];
 173                 uint16_t msg_type;
 174                 uint16_t msg_len;
 175                 uint8_t msg_id;
 176                 struct dhcpv6_auth_reconfigure auth;
 177                 uint16_t clid_type;
 178                 uint16_t clid_len;
 179                 uint8_t clid_data[128];
 180         } __attribute__((packed)) reconf_msg = {
 181                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 182                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 183                 .srvid_len = htons(10),
 184                 .duid_type = htons(3),
 185                 .hardware_type = htons(1),
 186                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 187                 .msg_len = htons(1),
 188                 .msg_id = DHCPV6_MSG_RENEW,
 189                 .auth = {htons(DHCPV6_OPT_AUTH),
 190                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 191                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 192                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 193                 .clid_len = htons(assign->clid_len),
 194                 .clid_data = {0},
 195         };
 196
 197         odhcpd_get_mac(iface, reconf_msg.mac);
 198         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 199         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 200
 201         md5_ctx_t md5;
 202         uint8_t secretbytes[64];
 203         memset(secretbytes, 0, sizeof(secretbytes));
 204         memcpy(secretbytes, assign->key, sizeof(assign->key));
 205
 206         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 207                 secretbytes[i] ^= 0x36;
 208
 209         md5_begin(&md5);
 210         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 211         md5_hash(iov.iov_base, iov.iov_len, &md5);
 212         md5_end(reconf_msg.auth.key, &md5);
 213
 214         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 215                 secretbytes[i] ^= 0x36;
 216                 secretbytes[i] ^= 0x5c;
 217         }
 218
 219         md5_begin(&md5);
 220         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 221         md5_hash(reconf_msg.auth.key, 16, &md5);
 222         md5_end(reconf_msg.auth.key, &md5);
 223
 224         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 225 }
 226
 227 void dhcpv6_write_statefile(void)
 228 {
 229         md5_ctx_t md5;
 230         md5_begin(&md5);
 231
 232         if (config.dhcp_statefile) {
 233                 time_t now = odhcpd_time(), wall_time = time(NULL);
 234                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 235                 if (fd < 0)
 236                         return;
 237
 238                 lockf(fd, F_LOCK, 0);
 239                 if (ftruncate(fd, 0) < 0) {}
 240
 241                 FILE *fp = fdopen(fd, "w");
 242                 if (!fp) {
 243                         close(fd);
 244                         return;
 245                 }
 246
 247                 struct interface *iface;
 248                 list_for_each_entry(iface, &interfaces, head) {
 249                         if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
 250                                 continue;
 251
 252                         if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
 253                                 struct dhcpv6_assignment *c;
 254                                 list_for_each_entry(c, &iface->ia_assignments, head) {
 255                                         if (!(c->flags & OAF_BOUND) || c->managed_size < 0)
 256                                                 continue;
 257
 258                                         char ipbuf[INET6_ADDRSTRLEN];
 259                                         char leasebuf[512];
 260                                         char duidbuf[264];
 261                                         odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
 262
 263                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 264                                         int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %ld %x %u ",
 265                                                         iface->ifname, duidbuf, ntohl(c->iaid),
 266                                                         (c->hostname ? c->hostname : "-"),
 267                                                         (c->valid_until > now ?
 268                                                                 (c->valid_until - now + wall_time) :
 269                                                                 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 270                                                         c->assigned, (unsigned)c->length);
 271
 272                                         struct in6_addr addr;
 273                                         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
 274                                         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
 275                                         size_t m = elect_addr(addrs, addrlen);
 276
 277                                         for (size_t i = 0; i < addrlen; ++i) {
 278                                                 if (!valid_addr(&addrs[i], now) || (!INFINITE_VALID(c->valid_until) && c->valid_until <= now) ||
 279                                                                 (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
 280                                                                                 addrs[i].prefix <= 64))
 281                                                         continue;
 282
 283                                                 addr = addrs[i].addr;
 284                                                 if (c->length == 128)
 285                                                         addr.s6_addr32[3] = htonl(c->assigned);
 286                                                 else
 287                                                         addr.s6_addr32[1] |= htonl(c->assigned);
 288
 289                                                 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
 290
 291                                                 if (c->length == 128 && c->hostname) {
 292                                                         fputs(ipbuf, fp);
 293
 294                                                         char b[256];
 295                                                         if (dn_expand(iface->search, iface->search + iface->search_len,
 296                                                                         iface->search, b, sizeof(b)) > 0)
 297                                                                 fprintf(fp, "\t%s.%s", c->hostname, b);
 298
 299                                                         fprintf(fp, "\t%s\n", c->hostname);
 300                                                         md5_hash(ipbuf, strlen(ipbuf), &md5);
 301                                                         md5_hash(c->hostname, strlen(c->hostname), &md5);
 302                                                 }
 303
 304                                                 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
 305                                                                 (c->managed_size) ? addrs[i].prefix : c->length);
 306                                         }
 307                                         leasebuf[l - 1] = '\n';
 308                                         fwrite(leasebuf, 1, l, fp);
 309                                 }
 310                         }
 311
 312                         if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
 313                                 struct dhcpv4_assignment *c;
 314                                 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
 315                                         if (!(c->flags & OAF_BOUND))
 316                                                 continue;
 317
 318                                         char ipbuf[INET6_ADDRSTRLEN];
 319                                         char leasebuf[512];
 320                                         char duidbuf[16];
 321                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 322
 323                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 324                                         int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %ld %x 32 ",
 325                                                         iface->ifname, duidbuf,
 326                                                         (c->hostname ? c->hostname : "-"),
 327                                                         (c->valid_until > now ?
 328                                                                 (c->valid_until - now + wall_time) :
 329                                                                 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 330                                                         c->addr);
 331
 332                                         struct in_addr addr = {htonl(c->addr)};
 333                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 334
 335                                         if (c->hostname) {
 336                                                 fputs(ipbuf, fp);
 337
 338                                                 char b[256];
 339                                                 if (dn_expand(iface->search, iface->search + iface->search_len,
 340                                                                 iface->search, b, sizeof(b)) > 0)
 341                                                         fprintf(fp, "\t%s.%s", c->hostname, b);
 342
 343                                                 fprintf(fp, "\t%s\n", c->hostname);
 344                                                 md5_hash(ipbuf, strlen(ipbuf), &md5);
 345                                                 md5_hash(c->hostname, strlen(c->hostname), &md5);
 346                                         }
 347
 348                                         l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
 349                                         leasebuf[l - 1] = '\n';
 350                                         fwrite(leasebuf, 1, l, fp);
 351                                 }
 352                         }
 353                 }
 354
 355                 fclose(fp);
 356         }
 357
 358         uint8_t newmd5[16];
 359         md5_end(newmd5, &md5);
 360
 361         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 362                 memcpy(statemd5, newmd5, sizeof(statemd5));
 363                 char *argv[2] = {config.dhcp_cb, NULL};
 364                 if (!vfork()) {
 365                         execv(argv[0], argv);
 366                         _exit(128);
 367                 }
 368         }
 369 }
 370
 371
 372 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
 373 {
 374         if (a->length > 64 || a->managed_size < 0)
 375                 return;
 376
 377         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 378         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 379
 380         for (size_t i = 0; i < addrlen; ++i) {
 381                 struct in6_addr prefix = addrs[i].addr;
 382                 prefix.s6_addr32[1] |= htonl(a->assigned);
 383                 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 384                                 iface, &a->peer.sin6_addr, 1024, add);
 385         }
 386 }
 387
 388 /* More data was received from TCP connection */
 389 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 390 {
 391         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 392         time_t now = odhcpd_time();
 393         bool first = c->managed_size < 0;
 394
 395         for (;;) {
 396                 int pending;
 397                 char *data = ustream_get_read_buf(s, &pending);
 398                 char *end = memmem(data, pending, "\n\n", 2);
 399
 400                 if (!end)
 401                         break;
 402
 403                 end += 2;
 404                 end[-1] = 0;
 405
 406                 c->managed_size = 0;
 407                 if (c->accept_reconf)
 408                         c->reconf_cnt = 1;
 409
 410                 char *saveptr;
 411                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 412                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 413                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 414
 415                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 416                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 417                                 continue;
 418
 419                         x = strtok_r(NULL, ",", &saveptr2);
 420                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 421                                 continue;
 422
 423                         x = strtok_r(NULL, ",", &saveptr2);
 424                         if (sscanf(x, "%u", &n->preferred) < 1)
 425                                 continue;
 426
 427                         x = strtok_r(NULL, ",", &saveptr2);
 428                         if (sscanf(x, "%u", &n->valid) < 1)
 429                                 continue;
 430
 431                         if (n->preferred > n->valid)
 432                                 continue;
 433
 434                         if (UINT32_MAX - now < n->preferred)
 435                                 n->preferred = UINT32_MAX;
 436                         else
 437                                 n->preferred += now;
 438
 439                         if (UINT32_MAX - now < n->valid)
 440                                 n->valid = UINT32_MAX;
 441                         else
 442                                 n->valid += now;
 443
 444                         n->dprefix = 0;
 445
 446                         ++c->managed_size;
 447                 }
 448
 449                 ustream_consume(s, end - data);
 450         }
 451
 452         if (first && c->managed_size == 0)
 453                 free_dhcpv6_assignment(c);
 454         else if (first && !(c->flags & OAF_STATIC))
 455                 c->valid_until = now + 150;
 456 }
 457
 458
 459 /* TCP transmission has ended, either because of success or timeout or other error */
 460 static void managed_handle_pd_done(struct ustream *s)
 461 {
 462         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 463
 464         if (!(c->flags & OAF_STATIC))
 465                 c->valid_until = odhcpd_time() + 15;
 466
 467         c->managed_size = 0;
 468
 469         if (c->accept_reconf)
 470                 c->reconf_cnt = 1;
 471 }
 472
 473 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
 474 {
 475         struct dhcpv6_assignment *c;
 476
 477         if (iface->dhcpv6_pd_manager[0]) {
 478                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 479                 if (fd >= 0) {
 480                         char iaidbuf[298];
 481                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 482
 483                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 484                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 485                         ustream_fd_init(&assign->managed_sock, fd);
 486                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 487                                         iaidbuf, assign->iaid, assign->length);
 488                         ustream_write_pending(&assign->managed_sock.stream);
 489                         assign->managed_size = -1;
 490
 491                         if (!(assign->flags & OAF_STATIC))
 492                                 assign->valid_until = odhcpd_time() + 15;
 493
 494                         list_add(&assign->head, &iface->ia_assignments);
 495
 496                         /* Wait initial period of up to 250ms for immediate assignment */
 497                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 498                         poll(&pfd, 1, 250);
 499                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 500
 501                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 502                                 return true;
 503                 }
 504
 505                 return false;
 506         } else if (iface->ia_addr_len < 1)
 507                 return false;
 508
 509         /* Try honoring the hint first */
 510         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 511         if (assign->assigned) {
 512                 list_for_each_entry(c, &iface->ia_assignments, head) {
 513                         if (c->length == 128 || c->length == 0)
 514                                 continue;
 515
 516                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 517                                 list_add_tail(&assign->head, &c->head);
 518                                 apply_lease(iface, assign, true);
 519                                 return true;
 520                         }
 521
 522                         if (c->assigned != 0)
 523                                 current = (c->assigned + (1 << (64 - c->length)));
 524                 }
 525         }
 526
 527         /* Fallback to a variable assignment */
 528         current = 1;
 529         list_for_each_entry(c, &iface->ia_assignments, head) {
 530                 if (c->length == 128 || c->length == 0)
 531                         continue;
 532
 533                 current = (current + asize) & (~asize);
 534                 if (current + asize < c->assigned) {
 535                         assign->assigned = current;
 536                         list_add_tail(&assign->head, &c->head);
 537                         apply_lease(iface, assign, true);
 538                         return true;
 539                 }
 540
 541                 if (c->assigned != 0)
 542                         current = (c->assigned + (1 << (64 - c->length)));
 543         }
 544
 545         return false;
 546 }
 547
 548 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 549 {
 550         /* Seed RNG with checksum of DUID */
 551         uint32_t seed = 0;
 552         for (size_t i = 0; i < assign->clid_len; ++i)
 553                 seed += assign->clid_data[i];
 554         srand(seed);
 555
 556         /* Try to assign up to 100x */
 557         for (size_t i = 0; i < 100; ++i) {
 558                 uint32_t try;
 559                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 560
 561                 struct dhcpv6_assignment *c;
 562                 list_for_each_entry(c, &iface->ia_assignments, head) {
 563                         if (c->length == 0)
 564                                 continue;
 565
 566                         if (c->assigned > try || c->length != 128) {
 567                                 assign->assigned = try;
 568                                 list_add_tail(&assign->head, &c->head);
 569                                 return true;
 570                         } else if (c->assigned == try)
 571                                 break;
 572                 }
 573         }
 574
 575         return false;
 576 }
 577
 578 void dhcpv6_ia_preupdate(struct interface *iface)
 579 {
 580         if (iface->dhcpv6 != RELAYD_SERVER)
 581                 return;
 582
 583         struct dhcpv6_assignment *c, *border = list_last_entry(
 584                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 585
 586         list_for_each_entry(c, &iface->ia_assignments, head)
 587                 if (c != border && !iface->managed)
 588                         apply_lease(iface, c, false);
 589 }
 590
 591 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
 592 {
 593         if (iface->dhcpv6 != RELAYD_SERVER)
 594                 return;
 595
 596         int minprefix = -1;
 597         for (size_t i = 0; i < iface->ia_addr_len; ++i) {
 598                 if (iface->ia_addr[i].preferred > (uint32_t)now &&
 599                                 iface->ia_addr[i].prefix < 64 &&
 600                                 iface->ia_addr[i].prefix > minprefix)
 601                         minprefix = iface->ia_addr[i].prefix;
 602         }
 603
 604         struct dhcpv6_assignment *border = list_last_entry(
 605                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 606
 607         if (minprefix > 32 && minprefix <= 64)
 608                 border->assigned = 1U << (64 - minprefix);
 609         else
 610                 border->assigned = 0;
 611
 612         struct list_head reassign = LIST_HEAD_INIT(reassign);
 613         struct dhcpv6_assignment *c, *d;
 614         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 615                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 616                                 c->managed_size)
 617                         continue;
 618
 619                 if (c->length < 128 && c->assigned >= border->assigned && c != border)
 620                         list_move(&c->head, &reassign);
 621                 else if (c != border)
 622                         apply_lease(iface, c, true);
 623
 624                 if (c->accept_reconf && c->reconf_cnt == 0) {
 625                         c->reconf_cnt = 1;
 626                         c->reconf_sent = now;
 627                         send_reconf(iface, c);
 628
 629                         /* Leave all other assignments of that client alone */
 630                         struct dhcpv6_assignment *a;
 631                         list_for_each_entry(a, &iface->ia_assignments, head)
 632                                 if (a != c && a->clid_len == c->clid_len &&
 633                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 634                                         c->reconf_cnt = INT_MAX;
 635                 }
 636         }
 637
 638         while (!list_empty(&reassign)) {
 639                 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
 640                 list_del(&c->head);
 641                 if (!assign_pd(iface, c)) {
 642                         c->assigned = 0;
 643                         list_add(&c->head, &iface->ia_assignments);
 644                 }
 645         }
 646
 647         dhcpv6_write_statefile();
 648 }
 649
 650 static void reconf_timer(struct uloop_timeout *event)
 651 {
 652         time_t now = odhcpd_time();
 653         struct interface *iface;
 654         list_for_each_entry(iface, &interfaces, head) {
 655                 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
 656                         continue;
 657
 658                 struct dhcpv6_assignment *a, *n;
 659                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 660                         if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
 661                                 if ((a->length < 128 && a->clid_len > 0) ||
 662                                                 (a->length == 128 && a->clid_len == 0))
 663                                         free_dhcpv6_assignment(a);
 664
 665                         } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
 666                                         now > a->reconf_sent + (1 << a->reconf_cnt)) {
 667                                 ++a->reconf_cnt;
 668                                 a->reconf_sent = now;
 669                                 send_reconf(iface, a);
 670                         }
 671                 }
 672         }
 673         uloop_timeout_set(event, 2000);
 674 }
 675
 676 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
 677                 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
 678                 struct interface *iface, bool request)
 679 {
 680         if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
 681                 return 0;
 682
 683         struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
 684         size_t datalen = sizeof(out);
 685         time_t now = odhcpd_time();
 686
 687         if (status) {
 688                 struct __attribute__((packed)) {
 689                         uint16_t type;
 690                         uint16_t len;
 691                         uint16_t value;
 692                 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
 693                                 htons(status)};
 694
 695                 memcpy(buf + datalen, &stat, sizeof(stat));
 696                 datalen += sizeof(stat);
 697         } else {
 698                 if (a) {
 699                         uint32_t leasetime;
 700                         if (a->leasetime > 0)
 701                                 leasetime = a->leasetime;
 702                         else
 703                                 leasetime = iface->dhcpv4_leasetime;
 704
 705                         if (leasetime == 0)
 706                                 leasetime = 3600;
 707                         else if (leasetime < 60)
 708                                 leasetime = 60;
 709
 710                         uint32_t pref = leasetime;
 711                         uint32_t valid = leasetime;
 712
 713                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 714                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 715                         size_t m = elect_addr(addrs, addrlen);
 716
 717                         for (size_t i = 0; i < addrlen; ++i) {
 718                                 uint32_t prefix_pref = addrs[i].preferred;
 719                                 uint32_t prefix_valid = addrs[i].valid;
 720
 721                                 if (!valid_addr(&addrs[i], now))
 722                                         continue;
 723
 724                                 if (prefix_pref != UINT32_MAX)
 725                                         prefix_pref -= now;
 726
 727                                 if (prefix_valid != UINT32_MAX)
 728                                         prefix_valid -= now;
 729
 730                                 if (a->length < 128) {
 731                                         struct dhcpv6_ia_prefix p = {
 732                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 733                                                 .len = htons(sizeof(p) - 4),
 734                                                 .preferred = htonl(prefix_pref),
 735                                                 .valid = htonl(prefix_valid),
 736                                                 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 737                                                 .addr = addrs[i].addr
 738                                         };
 739                                         p.addr.s6_addr32[1] |= htonl(a->assigned);
 740
 741                                         size_t entrlen = sizeof(p) - 4;
 742
 743                                         if (datalen + entrlen + 4 > buflen ||
 744                                                         (a->assigned == 0 && a->managed_size == 0) ||
 745                                                         (!a->managed_size && a->length <= addrs[i].prefix))
 746                                                 continue;
 747
 748                                         memcpy(buf + datalen, &p, sizeof(p));
 749                                         datalen += entrlen + 4;
 750                                 } else {
 751                                         struct dhcpv6_ia_addr n = {
 752                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 753                                                 .len = htons(sizeof(n) - 4),
 754                                                 .addr = addrs[i].addr,
 755                                                 .preferred = htonl(prefix_pref),
 756                                                 .valid = htonl(prefix_valid)
 757                                         };
 758                                         n.addr.s6_addr32[3] = htonl(a->assigned);
 759                                         size_t entrlen = sizeof(n) - 4;
 760
 761                                         if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
 762                                                         addrs[i].prefix <= 64)
 763                                                 continue;
 764
 765                                         if (datalen + entrlen + 4 > buflen || a->assigned == 0)
 766                                                 continue;
 767
 768                                         memcpy(buf + datalen, &n, sizeof(n));
 769                                         datalen += entrlen + 4;
 770                                 }
 771
 772                                 /* Calculate T1 / T2 based on non-deprecated addresses */
 773                                 if (prefix_pref > 0) {
 774                                         if (prefix_pref < pref)
 775                                                 pref = prefix_pref;
 776
 777                                         if (prefix_valid < valid)
 778                                                 valid = prefix_valid;
 779                                 }
 780                         }
 781
 782                         if (!INFINITE_VALID(a->valid_until))
 783                                 /* UINT32_MAX is considered as infinite leasetime */
 784                                 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 785
 786                         out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 787                         out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 788
 789                         if (!out.t1)
 790                                 out.t1 = htonl(1);
 791
 792                         if (!out.t2)
 793                                 out.t2 = htonl(1);
 794                 }
 795
 796                 if (!request) {
 797                         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 798                         uint16_t otype, olen;
 799                         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 800                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
 801                                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
 802                                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
 803                                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
 804                                         continue;
 805
 806                                 bool found = false;
 807                                 if (a) {
 808                                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 809                                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 810
 811                                         for (size_t i = 0; i < addrlen; ++i) {
 812                                                 if (!valid_addr(&addrs[i], now))
 813                                                         continue;
 814
 815                                                 struct in6_addr addr = addrs[i].addr;
 816                                                 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 817                                                         addr.s6_addr32[1] |= htonl(a->assigned);
 818
 819                                                         if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
 820                                                                         p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 821                                                                 found = true;
 822                                                 } else {
 823                                                         addr.s6_addr32[3] = htonl(a->assigned);
 824
 825                                                         if (!memcmp(&n->addr, &addr, sizeof(addr)))
 826                                                                 found = true;
 827                                                 }
 828                                         }
 829                                 }
 830
 831                                 if (!found) {
 832                                         if (otype == DHCPV6_OPT_IA_PREFIX) {
 833                                                 struct dhcpv6_ia_prefix inv = {
 834                                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 835                                                         .len = htons(sizeof(inv) - 4),
 836                                                         .preferred = 0,
 837                                                         .valid = 0,
 838                                                         .prefix = p->prefix,
 839                                                         .addr = p->addr
 840                                                 };
 841
 842                                                 if (datalen + sizeof(inv) > buflen)
 843                                                         continue;
 844
 845                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 846                                                 datalen += sizeof(inv);
 847                                         } else {
 848                                                 struct dhcpv6_ia_addr inv = {
 849                                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 850                                                         .len = htons(sizeof(inv) - 4),
 851                                                         .addr = n->addr,
 852                                                         .preferred = 0,
 853                                                         .valid = 0
 854                                                 };
 855
 856                                                 if (datalen + sizeof(inv) > buflen)
 857                                                         continue;
 858
 859                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 860                                                 datalen += sizeof(inv);
 861                                         }
 862                                 }
 863                         }
 864                 }
 865         }
 866
 867         out.len = htons(datalen - 4);
 868         memcpy(buf, &out, sizeof(out));
 869         return datalen;
 870 }
 871
 872 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
 873                 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
 874 {
 875         const char *type = "UNKNOWN";
 876         const char *status = "UNKNOWN";
 877
 878         if (msgtype == DHCPV6_MSG_RENEW)
 879                 return;
 880
 881         switch (msgtype) {
 882         case DHCPV6_MSG_SOLICIT:
 883                 type = "SOLICIT";
 884                 break;
 885         case DHCPV6_MSG_REQUEST:
 886                 type = "REQUEST";
 887                 break;
 888         case DHCPV6_MSG_CONFIRM:
 889                 type = "CONFIRM";
 890                 break;
 891         case DHCPV6_MSG_RENEW:
 892                 type = "RENEW";
 893                 break;
 894         case DHCPV6_MSG_REBIND:
 895                 type = "REBIND";
 896                 break;
 897         case DHCPV6_MSG_RELEASE:
 898                 type = "RELEASE";
 899                 break;
 900         case DHCPV6_MSG_DECLINE:
 901                 type = "DECLINE";
 902                 break;
 903         }
 904
 905         switch (code) {
 906         case DHCPV6_STATUS_OK:
 907                 status = "ok";
 908                 break;
 909         case DHCPV6_STATUS_NOADDRSAVAIL:
 910                 status = "no addresses available";
 911                 break;
 912         case DHCPV6_STATUS_NOBINDING:
 913                 status = "no binding";
 914                 break;
 915         case DHCPV6_STATUS_NOTONLINK:
 916                 status = "not on-link";
 917                 break;
 918         case DHCPV6_STATUS_NOPREFIXAVAIL:
 919                 status = "no prefix available";
 920                 break;
 921         }
 922
 923         char leasebuf[256] = "";
 924
 925         if (a) {
 926                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 927                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 928                 size_t lbsize = 0;
 929                 char addrbuf[INET6_ADDRSTRLEN];
 930
 931                 for (size_t i = 0; i < addrlen; ++i) {
 932                         if (!valid_addr(&addrs[i], now))
 933                                 continue;
 934
 935                         struct in6_addr addr = addrs[i].addr;
 936                         int prefix = a->managed ? addrs[i].prefix : a->length;
 937                         if (prefix == 128)
 938                                 addr.s6_addr32[3] = htonl(a->assigned);
 939                         else
 940                                 addr.s6_addr32[1] |= htonl(a->assigned);
 941
 942                         inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
 943                         lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
 944                 }
 945         }
 946
 947         syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
 948                         duidbuf, iface->ifname, status, leasebuf);
 949 }
 950
 951 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
 952                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
 953 {
 954         time_t now = odhcpd_time();
 955         size_t response_len = 0;
 956         const struct dhcpv6_client_header *hdr = data;
 957         uint8_t *start = (uint8_t*)&hdr[1], *odata;
 958         uint16_t otype, olen;
 959         /* Find and parse client-id and hostname */
 960         bool accept_reconf = false;
 961         uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 962         char hostname[256];
 963         size_t hostname_len = 0;
 964         bool notonlink = false;
 965         char duidbuf[261];
 966
 967         dhcpv6_for_each_option(start, end, otype, olen, odata) {
 968                 if (otype == DHCPV6_OPT_CLIENTID) {
 969                         clid_data = odata;
 970                         clid_len = olen;
 971
 972                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
 973                                 memcpy(mac, &odata[8], sizeof(mac));
 974                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
 975                                 memcpy(mac, &odata[4], sizeof(mac));
 976
 977                         if (olen <= 130)
 978                                 odhcpd_hexlify(duidbuf, odata, olen);
 979                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
 980                         uint8_t fqdn_buf[256];
 981                         memcpy(fqdn_buf, odata, olen);
 982                         fqdn_buf[olen++] = 0;
 983
 984                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
 985                                 hostname_len = strcspn(hostname, ".");
 986                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
 987                         accept_reconf = true;
 988         }
 989
 990         if (!clid_data || !clid_len || clid_len > 130)
 991                 goto out;
 992
 993         struct dhcpv6_assignment *first = NULL;
 994         dhcpv6_for_each_option(start, end, otype, olen, odata) {
 995                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
 996                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
 997                 bool ia_addr_present = false;
 998                 if (!is_pd && !is_na)
 999                         continue;
1000
1001                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1002                 size_t ia_response_len = 0;
1003                 uint8_t reqlen = (is_pd) ? 62 : 128;
1004                 uint32_t reqhint = 0;
1005
1006                 /* Parse request hint for IA-PD */
1007                 if (is_pd) {
1008                         uint8_t *sdata;
1009                         uint16_t stype, slen;
1010                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1011                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1012                                         continue;
1013
1014                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1015                                 if (p->prefix) {
1016                                         reqlen = p->prefix;
1017                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1018                                         if (reqlen > 32 && reqlen <= 64)
1019                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1020                                 }
1021                         }
1022
1023                         if (reqlen > 64)
1024                                 reqlen = 64;
1025                 } else if (is_na) {
1026                         uint8_t *sdata;
1027                         uint16_t stype, slen;
1028                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1029                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1030                                         continue;
1031
1032                                 ia_addr_present = true;
1033                         }
1034                 }
1035
1036                 /* Find assignment */
1037                 struct dhcpv6_assignment *c, *a = NULL;
1038                 list_for_each_entry(c, &iface->ia_assignments, head) {
1039                         if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1040                                         (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1041                                                 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1042                                         (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1043                                         ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1044                                 a = c;
1045
1046                                 // Reset state
1047                                 apply_lease(iface, a, false);
1048                                 memcpy(a->clid_data, clid_data, clid_len);
1049                                 a->clid_len = clid_len;
1050                                 a->iaid = ia->iaid;
1051                                 a->peer = *addr;
1052                                 a->reconf_cnt = 0;
1053                                 a->reconf_sent = 0;
1054                                 break;
1055                         }
1056                 }
1057
1058                 /* Generic message handling */
1059                 uint16_t status = DHCPV6_STATUS_OK;
1060                 if (a && a->managed_size < 0)
1061                         return -1;
1062
1063                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1064                         bool assigned = !!a;
1065
1066                         if (!a && !iface->no_dynamic_dhcp) {
1067                                 /* Create new binding */
1068                                 a = calloc(1, sizeof(*a) + clid_len);
1069                                 if (a) {
1070                                         a->clid_len = clid_len;
1071                                         a->iaid = ia->iaid;
1072                                         a->length = reqlen;
1073                                         a->peer = *addr;
1074                                         a->assigned = reqhint;
1075                                         /* Set valid time to current time indicating  */
1076                                         /* assignment is not having infinite lifetime */
1077                                         a->valid_until = now;
1078
1079                                         if (first)
1080                                                 memcpy(a->key, first->key, sizeof(a->key));
1081                                         else
1082                                                 odhcpd_urandom(a->key, sizeof(a->key));
1083                                         memcpy(a->clid_data, clid_data, clid_len);
1084
1085                                         if (is_pd)
1086                                                 while (!(assigned = assign_pd(iface, a)) &&
1087                                                                 !a->managed_size && ++a->length <= 64);
1088                                         else
1089                                                 assigned = assign_na(iface, a);
1090
1091                                         if (a->managed_size && !assigned)
1092                                                 return -1;
1093                                 }
1094                         }
1095
1096                         if (!assigned || iface->ia_addr_len == 0)
1097                                 /* Set error status */
1098                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1099                         else if (assigned && !first) {
1100                                 size_t handshake_len = 4;
1101                                 buf[0] = 0;
1102                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1103                                 buf[2] = 0;
1104                                 buf[3] = 0;
1105
1106                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1107                                         struct dhcpv6_auth_reconfigure auth = {
1108                                                 htons(DHCPV6_OPT_AUTH),
1109                                                 htons(sizeof(auth) - 4),
1110                                                 3, 1, 0,
1111                                                 {htonl(time(NULL)), htonl(++serial)},
1112                                                 1,
1113                                                 {0}
1114                                         };
1115                                         memcpy(auth.key, a->key, sizeof(a->key));
1116                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1117                                         handshake_len += sizeof(auth);
1118                                 }
1119
1120                                 buf += handshake_len;
1121                                 buflen -= handshake_len;
1122                                 response_len += handshake_len;
1123
1124                                 first = a;
1125                         }
1126
1127                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1128
1129                         /* Was only a solicitation: mark binding for removal */
1130                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1131                                 a->flags &= ~OAF_BOUND;
1132
1133                                 if (!(a->flags & OAF_STATIC))
1134                                         a->valid_until = now;
1135                         } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1136                                 if (hostname_len > 0) {
1137                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1138                                         if (a->hostname) {
1139                                                 memcpy(a->hostname, hostname, hostname_len);
1140                                                 a->hostname[hostname_len] = 0;
1141                                         }
1142                                 }
1143                                 a->accept_reconf = accept_reconf;
1144                                 a->flags |= OAF_BOUND;
1145                                 apply_lease(iface, a, true);
1146                         } else if (!assigned && a && a->managed_size == 0)
1147                                 /* Cleanup failed assignment */
1148                                 free_dhcpv6_assignment(a);
1149
1150                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1151                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1152                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1153                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1154                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1155                                 status = DHCPV6_STATUS_NOBINDING;
1156                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1157                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1158                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1159                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1160                                 if (a) {
1161                                         a->flags |= OAF_BOUND;
1162                                         apply_lease(iface, a, true);
1163                                 }
1164                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1165                                 if (!(a->flags & OAF_STATIC))
1166                                         a->valid_until = now - 1;
1167
1168                                 a->flags &= ~OAF_BOUND;
1169                                 apply_lease(iface, a, false);
1170                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1171                                 a->flags &= ~OAF_BOUND;
1172
1173                                 if (!(a->flags & OAF_STATIC)) {
1174                                         a->clid_len = 0;
1175                                         a->valid_until = now + 3600; /* Block address for 1h */
1176                                 }
1177                         }
1178                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1179                         /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1180                         status = DHCPV6_STATUS_NOTONLINK;
1181                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1182                         notonlink = true;
1183                 }
1184
1185                 buf += ia_response_len;
1186                 buflen -= ia_response_len;
1187                 response_len += ia_response_len;
1188                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1189         }
1190
1191         if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1192                         response_len + 6 < buflen) {
1193                 buf[0] = 0;
1194                 buf[1] = DHCPV6_OPT_STATUS;
1195                 buf[2] = 0;
1196                 buf[3] = 2;
1197                 buf[4] = 0;
1198                 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1199                 response_len += 6;
1200         }
1201
1202         dhcpv6_write_statefile();
1203
1204 out:
1205         return response_len;
1206 }