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 #define ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) \
  38     ((iface)->managed == RELAYD_MANAGED_NO_AFLAG || (i) == (m) || \
  39      (addrs)[(i)].prefix > 64)
  40
  41 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c);
  42 static void reconf_timer(struct uloop_timeout *event);
  43 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
  44 static uint32_t serial = 0;
  45 static uint8_t statemd5[16];
  46
  47 int dhcpv6_ia_init(void)
  48 {
  49         uloop_timeout_set(&reconf_event, 2000);
  50         return 0;
  51 }
  52
  53 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
  54 {
  55         if (!enable && iface->ia_assignments.next) {
  56                 struct dhcpv6_assignment *c;
  57
  58                 while (!list_empty(&iface->ia_assignments)) {
  59                         c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
  60                         free_dhcpv6_assignment(c);
  61                 }
  62         }
  63
  64         if (enable && iface->dhcpv6 == RELAYD_SERVER) {
  65                 if (!iface->ia_assignments.next)
  66                         INIT_LIST_HEAD(&iface->ia_assignments);
  67
  68                 if (list_empty(&iface->ia_assignments)) {
  69                         struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
  70                         if (!border) {
  71                                 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
  72                                 return -1;
  73                         }
  74
  75                         border->length = 64;
  76                         list_add(&border->head, &iface->ia_assignments);
  77                 }
  78
  79                 /* Parse static entries */
  80                 struct lease *lease;
  81                 list_for_each_entry(lease, &leases, head) {
  82                         /* Construct entry */
  83                         size_t duid_len = lease->duid_len ? lease->duid_len : 14;
  84                         struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
  85                         if (!a) {
  86                                 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
  87                                         iface->ifname);
  88                                 return -1;
  89                         }
  90
  91                         if (lease->dhcpv4_leasetime > 0)
  92                                 a->leasetime = lease->dhcpv4_leasetime;
  93
  94                         a->clid_len = duid_len;
  95                         a->length = 128;
  96                         if (lease->hostid) {
  97                                 a->assigned = lease->hostid;
  98                         } else {
  99                                 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
 100                                 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
 101                         }
 102
 103                         odhcpd_urandom(a->key, sizeof(a->key));
 104                         memcpy(a->clid_data, lease->duid, lease->duid_len);
 105                         memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
 106                         /* Static assignment */
 107                         a->flags |= OAF_STATIC;
 108                         /* Infinite valid */
 109                         a->valid_until = 0;
 110
 111                         /* Assign to all interfaces */
 112                         struct dhcpv6_assignment *c;
 113                         list_for_each_entry(c, &iface->ia_assignments, head) {
 114                                 if (c->length != 128 || c->assigned > a->assigned) {
 115                                         list_add_tail(&a->head, &c->head);
 116                                         break;
 117                                 } else if (c->assigned == a->assigned)
 118                                         /* Already an assignment with that number */
 119                                         break;
 120                         }
 121
 122                         if (a->head.next) {
 123                                 if (lease->hostname[0]) {
 124                                         free(a->hostname);
 125                                         a->hostname = strdup(lease->hostname);
 126                                 }
 127                         } else
 128                                 free_dhcpv6_assignment(a);
 129                 }
 130         }
 131         return 0;
 132 }
 133
 134 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
 135 {
 136         if (c->managed_sock.fd.registered) {
 137                 ustream_free(&c->managed_sock.stream);
 138                 close(c->managed_sock.fd.fd);
 139         }
 140
 141         if (c->head.next)
 142                 list_del(&c->head);
 143
 144         free(c->managed);
 145         free(c->hostname);
 146         free(c);
 147 }
 148
 149 static inline bool valid_prefix_length(const struct dhcpv6_assignment *a, const uint8_t prefix_length)
 150 {
 151         return (a->managed_size || a->length > prefix_length);
 152 }
 153
 154 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 155 {
 156         return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
 157 }
 158
 159 static size_t elect_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
 160 {
 161         size_t i, m;
 162
 163         for (i = 0, m = 0; i < addrlen; ++i) {
 164                 if (addrs[i].preferred > addrs[m].preferred ||
 165                         (addrs[i].preferred == addrs[m].preferred &&
 166                          memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 167                         m = i;
 168         }
 169
 170         return m;
 171 }
 172
 173 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
 174 {
 175         struct {
 176                 struct dhcpv6_client_header hdr;
 177                 uint16_t srvid_type;
 178                 uint16_t srvid_len;
 179                 uint16_t duid_type;
 180                 uint16_t hardware_type;
 181                 uint8_t mac[6];
 182                 uint16_t msg_type;
 183                 uint16_t msg_len;
 184                 uint8_t msg_id;
 185                 struct dhcpv6_auth_reconfigure auth;
 186                 uint16_t clid_type;
 187                 uint16_t clid_len;
 188                 uint8_t clid_data[128];
 189         } __attribute__((packed)) reconf_msg = {
 190                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 191                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 192                 .srvid_len = htons(10),
 193                 .duid_type = htons(3),
 194                 .hardware_type = htons(1),
 195                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 196                 .msg_len = htons(1),
 197                 .msg_id = DHCPV6_MSG_RENEW,
 198                 .auth = {htons(DHCPV6_OPT_AUTH),
 199                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 200                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 201                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 202                 .clid_len = htons(assign->clid_len),
 203                 .clid_data = {0},
 204         };
 205
 206         odhcpd_get_mac(iface, reconf_msg.mac);
 207         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 208         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 209
 210         md5_ctx_t md5;
 211         uint8_t secretbytes[64];
 212         memset(secretbytes, 0, sizeof(secretbytes));
 213         memcpy(secretbytes, assign->key, sizeof(assign->key));
 214
 215         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 216                 secretbytes[i] ^= 0x36;
 217
 218         md5_begin(&md5);
 219         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 220         md5_hash(iov.iov_base, iov.iov_len, &md5);
 221         md5_end(reconf_msg.auth.key, &md5);
 222
 223         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 224                 secretbytes[i] ^= 0x36;
 225                 secretbytes[i] ^= 0x5c;
 226         }
 227
 228         md5_begin(&md5);
 229         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 230         md5_hash(reconf_msg.auth.key, 16, &md5);
 231         md5_end(reconf_msg.auth.key, &md5);
 232
 233         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 234 }
 235
 236 void dhcpv6_write_statefile(void)
 237 {
 238         md5_ctx_t md5;
 239         md5_begin(&md5);
 240
 241         if (config.dhcp_statefile) {
 242                 time_t now = odhcpd_time(), wall_time = time(NULL);
 243                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 244                 if (fd < 0)
 245                         return;
 246
 247                 lockf(fd, F_LOCK, 0);
 248                 if (ftruncate(fd, 0) < 0) {}
 249
 250                 FILE *fp = fdopen(fd, "w");
 251                 if (!fp) {
 252                         close(fd);
 253                         return;
 254                 }
 255
 256                 struct interface *iface;
 257                 list_for_each_entry(iface, &interfaces, head) {
 258                         if (iface->dhcpv6 != RELAYD_SERVER && iface->dhcpv4 != RELAYD_SERVER)
 259                                 continue;
 260
 261                         if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
 262                                 struct dhcpv6_assignment *c;
 263                                 list_for_each_entry(c, &iface->ia_assignments, head) {
 264                                         if (!(c->flags & OAF_BOUND) || c->managed_size < 0)
 265                                                 continue;
 266
 267                                         char ipbuf[INET6_ADDRSTRLEN];
 268                                         char leasebuf[512];
 269                                         char duidbuf[264];
 270                                         odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
 271
 272                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 273                                         int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %ld %x %u ",
 274                                                         iface->ifname, duidbuf, ntohl(c->iaid),
 275                                                         (c->hostname ? c->hostname : "-"),
 276                                                         (c->valid_until > now ?
 277                                                                 (c->valid_until - now + wall_time) :
 278                                                                 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 279                                                         c->assigned, (unsigned)c->length);
 280
 281                                         struct in6_addr addr;
 282                                         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
 283                                         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
 284                                         size_t m = elect_addr(addrs, addrlen);
 285
 286                                         for (size_t i = 0; i < addrlen; ++i) {
 287                                                 if (!valid_addr(&addrs[i], now) ||
 288                                                             (!INFINITE_VALID(c->valid_until) && c->valid_until <= now))
 289                                                         continue;
 290
 291                                                 addr = addrs[i].addr;
 292                                                 if (c->length == 128) {
 293                                                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 294                                                                 continue;
 295
 296                                                         addr.s6_addr32[3] = htonl(c->assigned);
 297                                                 }
 298                                                 else {
 299                                                         if (!valid_prefix_length(c, addrs[i].prefix))
 300                                                                 continue;
 301
 302                                                         addr.s6_addr32[1] |= htonl(c->assigned);
 303                                                 }
 304
 305                                                 inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1);
 306
 307                                                 if (c->length == 128 && c->hostname) {
 308                                                         fputs(ipbuf, fp);
 309
 310                                                         char b[256];
 311                                                         if (dn_expand(iface->search, iface->search + iface->search_len,
 312                                                                         iface->search, b, sizeof(b)) > 0)
 313                                                                 fprintf(fp, "\t%s.%s", c->hostname, b);
 314
 315                                                         fprintf(fp, "\t%s\n", c->hostname);
 316                                                         md5_hash(ipbuf, strlen(ipbuf), &md5);
 317                                                         md5_hash(c->hostname, strlen(c->hostname), &md5);
 318                                                 }
 319
 320                                                 l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/%d ", ipbuf,
 321                                                                 (c->managed_size) ? addrs[i].prefix : c->length);
 322                                         }
 323                                         leasebuf[l - 1] = '\n';
 324                                         fwrite(leasebuf, 1, l, fp);
 325                                 }
 326                         }
 327
 328                         if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
 329                                 struct dhcpv4_assignment *c;
 330                                 list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
 331                                         if (!(c->flags & OAF_BOUND))
 332                                                 continue;
 333
 334                                         char ipbuf[INET6_ADDRSTRLEN];
 335                                         char leasebuf[512];
 336                                         char duidbuf[16];
 337                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 338
 339                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 340                                         int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %ld %x 32 ",
 341                                                         iface->ifname, duidbuf,
 342                                                         (c->hostname ? c->hostname : "-"),
 343                                                         (c->valid_until > now ?
 344                                                                 (c->valid_until - now + wall_time) :
 345                                                                 (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 346                                                         c->addr);
 347
 348                                         struct in_addr addr = {htonl(c->addr)};
 349                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 350
 351                                         if (c->hostname) {
 352                                                 fputs(ipbuf, fp);
 353
 354                                                 char b[256];
 355                                                 if (dn_expand(iface->search, iface->search + iface->search_len,
 356                                                                 iface->search, b, sizeof(b)) > 0)
 357                                                         fprintf(fp, "\t%s.%s", c->hostname, b);
 358
 359                                                 fprintf(fp, "\t%s\n", c->hostname);
 360                                                 md5_hash(ipbuf, strlen(ipbuf), &md5);
 361                                                 md5_hash(c->hostname, strlen(c->hostname), &md5);
 362                                         }
 363
 364                                         l += snprintf(leasebuf + l, sizeof(leasebuf) - l, "%s/32 ", ipbuf);
 365                                         leasebuf[l - 1] = '\n';
 366                                         fwrite(leasebuf, 1, l, fp);
 367                                 }
 368                         }
 369                 }
 370
 371                 fclose(fp);
 372         }
 373
 374         uint8_t newmd5[16];
 375         md5_end(newmd5, &md5);
 376
 377         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 378                 memcpy(statemd5, newmd5, sizeof(statemd5));
 379                 char *argv[2] = {config.dhcp_cb, NULL};
 380                 if (!vfork()) {
 381                         execv(argv[0], argv);
 382                         _exit(128);
 383                 }
 384         }
 385 }
 386
 387
 388 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
 389 {
 390         if (a->length > 64 || a->managed_size < 0)
 391                 return;
 392
 393         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 394         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 395
 396         for (size_t i = 0; i < addrlen; ++i) {
 397                 struct in6_addr prefix = addrs[i].addr;
 398                 prefix.s6_addr32[1] |= htonl(a->assigned);
 399                 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 400                                 iface, &a->peer.sin6_addr, 1024, add);
 401         }
 402 }
 403
 404 /* More data was received from TCP connection */
 405 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 406 {
 407         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 408         time_t now = odhcpd_time();
 409         bool first = c->managed_size < 0;
 410
 411         for (;;) {
 412                 int pending;
 413                 char *data = ustream_get_read_buf(s, &pending);
 414                 char *end = memmem(data, pending, "\n\n", 2);
 415
 416                 if (!end)
 417                         break;
 418
 419                 end += 2;
 420                 end[-1] = 0;
 421
 422                 c->managed_size = 0;
 423                 if (c->accept_reconf)
 424                         c->reconf_cnt = 1;
 425
 426                 char *saveptr;
 427                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 428                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 429                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 430
 431                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 432                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 433                                 continue;
 434
 435                         x = strtok_r(NULL, ",", &saveptr2);
 436                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 437                                 continue;
 438
 439                         x = strtok_r(NULL, ",", &saveptr2);
 440                         if (sscanf(x, "%u", &n->preferred) < 1)
 441                                 continue;
 442
 443                         x = strtok_r(NULL, ",", &saveptr2);
 444                         if (sscanf(x, "%u", &n->valid) < 1)
 445                                 continue;
 446
 447                         if (n->preferred > n->valid)
 448                                 continue;
 449
 450                         if (UINT32_MAX - now < n->preferred)
 451                                 n->preferred = UINT32_MAX;
 452                         else
 453                                 n->preferred += now;
 454
 455                         if (UINT32_MAX - now < n->valid)
 456                                 n->valid = UINT32_MAX;
 457                         else
 458                                 n->valid += now;
 459
 460                         n->dprefix = 0;
 461
 462                         ++c->managed_size;
 463                 }
 464
 465                 ustream_consume(s, end - data);
 466         }
 467
 468         if (first && c->managed_size == 0)
 469                 free_dhcpv6_assignment(c);
 470         else if (first && !(c->flags & OAF_STATIC))
 471                 c->valid_until = now + 150;
 472 }
 473
 474
 475 /* TCP transmission has ended, either because of success or timeout or other error */
 476 static void managed_handle_pd_done(struct ustream *s)
 477 {
 478         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 479
 480         if (!(c->flags & OAF_STATIC))
 481                 c->valid_until = odhcpd_time() + 15;
 482
 483         c->managed_size = 0;
 484
 485         if (c->accept_reconf)
 486                 c->reconf_cnt = 1;
 487 }
 488
 489 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
 490 {
 491         struct dhcpv6_assignment *c;
 492
 493         if (iface->dhcpv6_pd_manager[0]) {
 494                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 495                 if (fd >= 0) {
 496                         char iaidbuf[298];
 497                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 498
 499                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 500                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 501                         ustream_fd_init(&assign->managed_sock, fd);
 502                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 503                                         iaidbuf, assign->iaid, assign->length);
 504                         ustream_write_pending(&assign->managed_sock.stream);
 505                         assign->managed_size = -1;
 506
 507                         if (!(assign->flags & OAF_STATIC))
 508                                 assign->valid_until = odhcpd_time() + 15;
 509
 510                         list_add(&assign->head, &iface->ia_assignments);
 511
 512                         /* Wait initial period of up to 250ms for immediate assignment */
 513                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 514                         poll(&pfd, 1, 250);
 515                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 516
 517                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 518                                 return true;
 519                 }
 520
 521                 return false;
 522         } else if (iface->ia_addr_len < 1)
 523                 return false;
 524
 525         /* Try honoring the hint first */
 526         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 527         if (assign->assigned) {
 528                 list_for_each_entry(c, &iface->ia_assignments, head) {
 529                         if (c->length == 128 || c->length == 0)
 530                                 continue;
 531
 532                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 533                                 list_add_tail(&assign->head, &c->head);
 534                                 apply_lease(iface, assign, true);
 535                                 return true;
 536                         }
 537
 538                         if (c->assigned != 0)
 539                                 current = (c->assigned + (1 << (64 - c->length)));
 540                 }
 541         }
 542
 543         /* Fallback to a variable assignment */
 544         current = 1;
 545         list_for_each_entry(c, &iface->ia_assignments, head) {
 546                 if (c->length == 128 || c->length == 0)
 547                         continue;
 548
 549                 current = (current + asize) & (~asize);
 550                 if (current + asize < c->assigned) {
 551                         assign->assigned = current;
 552                         list_add_tail(&assign->head, &c->head);
 553                         apply_lease(iface, assign, true);
 554                         return true;
 555                 }
 556
 557                 if (c->assigned != 0)
 558                         current = (c->assigned + (1 << (64 - c->length)));
 559         }
 560
 561         return false;
 562 }
 563
 564 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 565 {
 566         /* Seed RNG with checksum of DUID */
 567         uint32_t seed = 0;
 568         for (size_t i = 0; i < assign->clid_len; ++i)
 569                 seed += assign->clid_data[i];
 570         srand(seed);
 571
 572         /* Try to assign up to 100x */
 573         for (size_t i = 0; i < 100; ++i) {
 574                 uint32_t try;
 575                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 576
 577                 struct dhcpv6_assignment *c;
 578                 list_for_each_entry(c, &iface->ia_assignments, head) {
 579                         if (c->length == 0)
 580                                 continue;
 581
 582                         if (c->assigned > try || c->length != 128) {
 583                                 assign->assigned = try;
 584                                 list_add_tail(&assign->head, &c->head);
 585                                 return true;
 586                         } else if (c->assigned == try)
 587                                 break;
 588                 }
 589         }
 590
 591         return false;
 592 }
 593
 594 void dhcpv6_ia_preupdate(struct interface *iface)
 595 {
 596         if (iface->dhcpv6 != RELAYD_SERVER)
 597                 return;
 598
 599         struct dhcpv6_assignment *c, *border = list_last_entry(
 600                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 601
 602         list_for_each_entry(c, &iface->ia_assignments, head)
 603                 if (c != border && !iface->managed)
 604                         apply_lease(iface, c, false);
 605 }
 606
 607 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
 608 {
 609         if (iface->dhcpv6 != RELAYD_SERVER)
 610                 return;
 611
 612         int minprefix = -1;
 613         for (size_t i = 0; i < iface->ia_addr_len; ++i) {
 614                 if (iface->ia_addr[i].preferred > (uint32_t)now &&
 615                                 iface->ia_addr[i].prefix < 64 &&
 616                                 iface->ia_addr[i].prefix > minprefix)
 617                         minprefix = iface->ia_addr[i].prefix;
 618         }
 619
 620         struct dhcpv6_assignment *border = list_last_entry(
 621                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 622
 623         if (minprefix > 32 && minprefix <= 64)
 624                 border->assigned = 1U << (64 - minprefix);
 625         else
 626                 border->assigned = 0;
 627
 628         struct list_head reassign = LIST_HEAD_INIT(reassign);
 629         struct dhcpv6_assignment *c, *d;
 630         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 631                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 632                                 c->managed_size)
 633                         continue;
 634
 635                 if (c->length < 128 && c->assigned >= border->assigned && c != border)
 636                         list_move(&c->head, &reassign);
 637                 else if (c != border)
 638                         apply_lease(iface, c, true);
 639
 640                 if (c->accept_reconf && c->reconf_cnt == 0) {
 641                         c->reconf_cnt = 1;
 642                         c->reconf_sent = now;
 643                         send_reconf(iface, c);
 644
 645                         /* Leave all other assignments of that client alone */
 646                         struct dhcpv6_assignment *a;
 647                         list_for_each_entry(a, &iface->ia_assignments, head)
 648                                 if (a != c && a->clid_len == c->clid_len &&
 649                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 650                                         c->reconf_cnt = INT_MAX;
 651                 }
 652         }
 653
 654         while (!list_empty(&reassign)) {
 655                 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
 656                 list_del(&c->head);
 657                 if (!assign_pd(iface, c)) {
 658                         c->assigned = 0;
 659                         list_add(&c->head, &iface->ia_assignments);
 660                 }
 661         }
 662
 663         dhcpv6_write_statefile();
 664 }
 665
 666 static void reconf_timer(struct uloop_timeout *event)
 667 {
 668         time_t now = odhcpd_time();
 669         struct interface *iface;
 670         list_for_each_entry(iface, &interfaces, head) {
 671                 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
 672                         continue;
 673
 674                 struct dhcpv6_assignment *a, *n;
 675                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 676                         if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
 677                                 if ((a->length < 128 && a->clid_len > 0) ||
 678                                                 (a->length == 128 && a->clid_len == 0))
 679                                         free_dhcpv6_assignment(a);
 680
 681                         } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
 682                                         now > a->reconf_sent + (1 << a->reconf_cnt)) {
 683                                 ++a->reconf_cnt;
 684                                 a->reconf_sent = now;
 685                                 send_reconf(iface, a);
 686                         }
 687                 }
 688         }
 689         uloop_timeout_set(event, 2000);
 690 }
 691
 692 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
 693                 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
 694                 struct interface *iface, bool request)
 695 {
 696         if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
 697                 return 0;
 698
 699         struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
 700         size_t datalen = sizeof(out);
 701         time_t now = odhcpd_time();
 702
 703         if (status) {
 704                 struct __attribute__((packed)) {
 705                         uint16_t type;
 706                         uint16_t len;
 707                         uint16_t value;
 708                 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
 709                                 htons(status)};
 710
 711                 memcpy(buf + datalen, &stat, sizeof(stat));
 712                 datalen += sizeof(stat);
 713         } else {
 714                 if (a) {
 715                         uint32_t leasetime;
 716                         if (a->leasetime > 0)
 717                                 leasetime = a->leasetime;
 718                         else
 719                                 leasetime = iface->dhcpv4_leasetime;
 720
 721                         if (leasetime == 0)
 722                                 leasetime = 3600;
 723                         else if (leasetime < 60)
 724                                 leasetime = 60;
 725
 726                         uint32_t pref = leasetime;
 727                         uint32_t valid = leasetime;
 728
 729                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 730                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 731                         size_t m = elect_addr(addrs, addrlen);
 732
 733                         for (size_t i = 0; i < addrlen; ++i) {
 734                                 uint32_t prefix_pref = addrs[i].preferred;
 735                                 uint32_t prefix_valid = addrs[i].valid;
 736
 737                                 if (!valid_addr(&addrs[i], now))
 738                                         continue;
 739
 740                                 if (prefix_pref != UINT32_MAX)
 741                                         prefix_pref -= now;
 742
 743                                 if (prefix_valid != UINT32_MAX)
 744                                         prefix_valid -= now;
 745
 746                                 if (a->length < 128) {
 747                                         struct dhcpv6_ia_prefix p = {
 748                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 749                                                 .len = htons(sizeof(p) - 4),
 750                                                 .preferred = htonl(prefix_pref),
 751                                                 .valid = htonl(prefix_valid),
 752                                                 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 753                                                 .addr = addrs[i].addr
 754                                         };
 755                                         p.addr.s6_addr32[1] |= htonl(a->assigned);
 756
 757                                         size_t entrlen = sizeof(p) - 4;
 758
 759                                         if (datalen + entrlen + 4 > buflen ||
 760                                                         (a->assigned == 0 && a->managed_size == 0) ||
 761                                                         !valid_prefix_length(a, addrs[i].prefix))
 762                                                 continue;
 763
 764                                         memcpy(buf + datalen, &p, sizeof(p));
 765                                         datalen += entrlen + 4;
 766                                 } else {
 767                                         struct dhcpv6_ia_addr n = {
 768                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 769                                                 .len = htons(sizeof(n) - 4),
 770                                                 .addr = addrs[i].addr,
 771                                                 .preferred = htonl(prefix_pref),
 772                                                 .valid = htonl(prefix_valid)
 773                                         };
 774                                         n.addr.s6_addr32[3] = htonl(a->assigned);
 775                                         size_t entrlen = sizeof(n) - 4;
 776
 777                                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
 778                                                         a->assigned == 0 ||
 779                                                         datalen + entrlen + 4 > buflen)
 780                                                 continue;
 781
 782                                         memcpy(buf + datalen, &n, sizeof(n));
 783                                         datalen += entrlen + 4;
 784                                 }
 785
 786                                 /* Calculate T1 / T2 based on non-deprecated addresses */
 787                                 if (prefix_pref > 0) {
 788                                         if (prefix_pref < pref)
 789                                                 pref = prefix_pref;
 790
 791                                         if (prefix_valid < valid)
 792                                                 valid = prefix_valid;
 793                                 }
 794                         }
 795
 796                         if (!INFINITE_VALID(a->valid_until))
 797                                 /* UINT32_MAX is considered as infinite leasetime */
 798                                 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 799
 800                         out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 801                         out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 802
 803                         if (!out.t1)
 804                                 out.t1 = htonl(1);
 805
 806                         if (!out.t2)
 807                                 out.t2 = htonl(1);
 808                 }
 809
 810                 if (!request) {
 811                         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 812                         uint16_t otype, olen;
 813                         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 814                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
 815                                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
 816                                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
 817                                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
 818                                         continue;
 819
 820                                 bool found = false;
 821                                 if (a) {
 822                                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 823                                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 824
 825                                         for (size_t i = 0; i < addrlen; ++i) {
 826                                                 if (!valid_addr(&addrs[i], now))
 827                                                         continue;
 828
 829                                                 struct in6_addr addr = addrs[i].addr;
 830                                                 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 831                                                         addr.s6_addr32[1] |= htonl(a->assigned);
 832
 833                                                         if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
 834                                                                         p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 835                                                                 found = true;
 836                                                 } else {
 837                                                         addr.s6_addr32[3] = htonl(a->assigned);
 838
 839                                                         if (!memcmp(&n->addr, &addr, sizeof(addr)))
 840                                                                 found = true;
 841                                                 }
 842                                         }
 843                                 }
 844
 845                                 if (!found) {
 846                                         if (otype == DHCPV6_OPT_IA_PREFIX) {
 847                                                 struct dhcpv6_ia_prefix inv = {
 848                                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 849                                                         .len = htons(sizeof(inv) - 4),
 850                                                         .preferred = 0,
 851                                                         .valid = 0,
 852                                                         .prefix = p->prefix,
 853                                                         .addr = p->addr
 854                                                 };
 855
 856                                                 if (datalen + sizeof(inv) > buflen)
 857                                                         continue;
 858
 859                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 860                                                 datalen += sizeof(inv);
 861                                         } else {
 862                                                 struct dhcpv6_ia_addr inv = {
 863                                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 864                                                         .len = htons(sizeof(inv) - 4),
 865                                                         .addr = n->addr,
 866                                                         .preferred = 0,
 867                                                         .valid = 0
 868                                                 };
 869
 870                                                 if (datalen + sizeof(inv) > buflen)
 871                                                         continue;
 872
 873                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 874                                                 datalen += sizeof(inv);
 875                                         }
 876                                 }
 877                         }
 878                 }
 879         }
 880
 881         out.len = htons(datalen - 4);
 882         memcpy(buf, &out, sizeof(out));
 883         return datalen;
 884 }
 885
 886 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
 887                 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
 888 {
 889         const char *type = "UNKNOWN";
 890         const char *status = "UNKNOWN";
 891
 892         if (msgtype == DHCPV6_MSG_RENEW)
 893                 return;
 894
 895         switch (msgtype) {
 896         case DHCPV6_MSG_SOLICIT:
 897                 type = "SOLICIT";
 898                 break;
 899         case DHCPV6_MSG_REQUEST:
 900                 type = "REQUEST";
 901                 break;
 902         case DHCPV6_MSG_CONFIRM:
 903                 type = "CONFIRM";
 904                 break;
 905         case DHCPV6_MSG_RENEW:
 906                 type = "RENEW";
 907                 break;
 908         case DHCPV6_MSG_REBIND:
 909                 type = "REBIND";
 910                 break;
 911         case DHCPV6_MSG_RELEASE:
 912                 type = "RELEASE";
 913                 break;
 914         case DHCPV6_MSG_DECLINE:
 915                 type = "DECLINE";
 916                 break;
 917         }
 918
 919         switch (code) {
 920         case DHCPV6_STATUS_OK:
 921                 status = "ok";
 922                 break;
 923         case DHCPV6_STATUS_NOADDRSAVAIL:
 924                 status = "no addresses available";
 925                 break;
 926         case DHCPV6_STATUS_NOBINDING:
 927                 status = "no binding";
 928                 break;
 929         case DHCPV6_STATUS_NOTONLINK:
 930                 status = "not on-link";
 931                 break;
 932         case DHCPV6_STATUS_NOPREFIXAVAIL:
 933                 status = "no prefix available";
 934                 break;
 935         }
 936
 937         char leasebuf[256] = "";
 938
 939         if (a) {
 940                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 941                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 942                 size_t lbsize = 0;
 943                 size_t m = elect_addr(addrs, addrlen);
 944                 char addrbuf[INET6_ADDRSTRLEN];
 945
 946                 for (size_t i = 0; i < addrlen; ++i) {
 947                         if (!valid_addr(&addrs[i], now))
 948                                 continue;
 949
 950                         struct in6_addr addr = addrs[i].addr;
 951                         int prefix = a->managed ? addrs[i].prefix : a->length;
 952                         if (prefix == 128) {
 953                                 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
 954                                                 a->assigned == 0)
 955                                         continue;
 956
 957                                 addr.s6_addr32[3] = htonl(a->assigned);
 958                         }
 959                         else {
 960                                 if (!valid_prefix_length(a, addrs[i].prefix))
 961                                         continue;
 962
 963                                 addr.s6_addr32[1] |= htonl(a->assigned);
 964                         }
 965
 966                         inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf));
 967                         lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix);
 968                 }
 969         }
 970
 971         syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
 972                         duidbuf, iface->ifname, status, leasebuf);
 973 }
 974
 975 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
 976                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
 977 {
 978         time_t now = odhcpd_time();
 979         size_t response_len = 0;
 980         const struct dhcpv6_client_header *hdr = data;
 981         uint8_t *start = (uint8_t*)&hdr[1], *odata;
 982         uint16_t otype, olen;
 983         /* Find and parse client-id and hostname */
 984         bool accept_reconf = false;
 985         uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 986         char hostname[256];
 987         size_t hostname_len = 0;
 988         bool notonlink = false;
 989         char duidbuf[261];
 990
 991         dhcpv6_for_each_option(start, end, otype, olen, odata) {
 992                 if (otype == DHCPV6_OPT_CLIENTID) {
 993                         clid_data = odata;
 994                         clid_len = olen;
 995
 996                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
 997                                 memcpy(mac, &odata[8], sizeof(mac));
 998                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
 999                                 memcpy(mac, &odata[4], sizeof(mac));
1000
1001                         if (olen <= 130)
1002                                 odhcpd_hexlify(duidbuf, odata, olen);
1003                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1004                         uint8_t fqdn_buf[256];
1005                         memcpy(fqdn_buf, odata, olen);
1006                         fqdn_buf[olen++] = 0;
1007
1008                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1009                                 hostname_len = strcspn(hostname, ".");
1010                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1011                         accept_reconf = true;
1012         }
1013
1014         if (!clid_data || !clid_len || clid_len > 130)
1015                 goto out;
1016
1017         struct dhcpv6_assignment *first = NULL;
1018         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1019                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1020                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1021                 bool ia_addr_present = false;
1022                 if (!is_pd && !is_na)
1023                         continue;
1024
1025                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1026                 size_t ia_response_len = 0;
1027                 uint8_t reqlen = (is_pd) ? 62 : 128;
1028                 uint32_t reqhint = 0;
1029
1030                 /* Parse request hint for IA-PD */
1031                 if (is_pd) {
1032                         uint8_t *sdata;
1033                         uint16_t stype, slen;
1034                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1035                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1036                                         continue;
1037
1038                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1039                                 if (p->prefix) {
1040                                         reqlen = p->prefix;
1041                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1042                                         if (reqlen > 32 && reqlen <= 64)
1043                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1044                                 }
1045                         }
1046
1047                         if (reqlen > 64)
1048                                 reqlen = 64;
1049                 } else if (is_na) {
1050                         uint8_t *sdata;
1051                         uint16_t stype, slen;
1052                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1053                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1054                                         continue;
1055
1056                                 ia_addr_present = true;
1057                         }
1058                 }
1059
1060                 /* Find assignment */
1061                 struct dhcpv6_assignment *c, *a = NULL;
1062                 list_for_each_entry(c, &iface->ia_assignments, head) {
1063                         if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1064                                         (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1065                                                 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1066                                         (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1067                                         ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1068                                 a = c;
1069
1070                                 /* Reset state */
1071                                 apply_lease(iface, a, false);
1072                                 memcpy(a->clid_data, clid_data, clid_len);
1073                                 a->clid_len = clid_len;
1074                                 a->iaid = ia->iaid;
1075                                 a->peer = *addr;
1076                                 a->reconf_cnt = 0;
1077                                 a->reconf_sent = 0;
1078                                 break;
1079                         }
1080                 }
1081
1082                 /* Generic message handling */
1083                 uint16_t status = DHCPV6_STATUS_OK;
1084                 if (a && a->managed_size < 0)
1085                         return -1;
1086
1087                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_REQUEST) {
1088                         bool assigned = !!a;
1089
1090                         if (!a && !iface->no_dynamic_dhcp) {
1091                                 /* Create new binding */
1092                                 a = calloc(1, sizeof(*a) + clid_len);
1093                                 if (a) {
1094                                         a->clid_len = clid_len;
1095                                         a->iaid = ia->iaid;
1096                                         a->length = reqlen;
1097                                         a->peer = *addr;
1098                                         a->assigned = reqhint;
1099                                         /* Set valid time to current time indicating  */
1100                                         /* assignment is not having infinite lifetime */
1101                                         a->valid_until = now;
1102
1103                                         if (first)
1104                                                 memcpy(a->key, first->key, sizeof(a->key));
1105                                         else
1106                                                 odhcpd_urandom(a->key, sizeof(a->key));
1107                                         memcpy(a->clid_data, clid_data, clid_len);
1108
1109                                         if (is_pd)
1110                                                 while (!(assigned = assign_pd(iface, a)) &&
1111                                                                 !a->managed_size && ++a->length <= 64);
1112                                         else
1113                                                 assigned = assign_na(iface, a);
1114
1115                                         if (a->managed_size && !assigned)
1116                                                 return -1;
1117                                 }
1118                         }
1119
1120                         if (!assigned || iface->ia_addr_len == 0)
1121                                 /* Set error status */
1122                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1123                         else if (assigned && !first) {
1124                                 size_t handshake_len = 4;
1125                                 buf[0] = 0;
1126                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1127                                 buf[2] = 0;
1128                                 buf[3] = 0;
1129
1130                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1131                                         struct dhcpv6_auth_reconfigure auth = {
1132                                                 htons(DHCPV6_OPT_AUTH),
1133                                                 htons(sizeof(auth) - 4),
1134                                                 3, 1, 0,
1135                                                 {htonl(time(NULL)), htonl(++serial)},
1136                                                 1,
1137                                                 {0}
1138                                         };
1139                                         memcpy(auth.key, a->key, sizeof(a->key));
1140                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1141                                         handshake_len += sizeof(auth);
1142                                 }
1143
1144                                 buf += handshake_len;
1145                                 buflen -= handshake_len;
1146                                 response_len += handshake_len;
1147
1148                                 first = a;
1149                         }
1150
1151                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1152
1153                         /* Was only a solicitation: mark binding for removal */
1154                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1155                                 a->flags &= ~OAF_BOUND;
1156
1157                                 if (!(a->flags & OAF_STATIC))
1158                                         a->valid_until = now;
1159                         } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
1160                                 if (hostname_len > 0) {
1161                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1162                                         if (a->hostname) {
1163                                                 memcpy(a->hostname, hostname, hostname_len);
1164                                                 a->hostname[hostname_len] = 0;
1165                                         }
1166                                 }
1167                                 a->accept_reconf = accept_reconf;
1168                                 a->flags |= OAF_BOUND;
1169                                 apply_lease(iface, a, true);
1170                         } else if (!assigned && a && a->managed_size == 0) {
1171                                 /* Cleanup failed assignment */
1172                                 free_dhcpv6_assignment(a);
1173                                 a = NULL;
1174                         }
1175                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1176                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1177                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1178                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1179                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1180                                 status = DHCPV6_STATUS_NOBINDING;
1181                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1182                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1183                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1184                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1185                                 if (a) {
1186                                         a->flags |= OAF_BOUND;
1187                                         apply_lease(iface, a, true);
1188                                 }
1189                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1190                                 if (!(a->flags & OAF_STATIC))
1191                                         a->valid_until = now - 1;
1192
1193                                 a->flags &= ~OAF_BOUND;
1194                                 apply_lease(iface, a, false);
1195                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1196                                 a->flags &= ~OAF_BOUND;
1197
1198                                 if (!(a->flags & OAF_STATIC)) {
1199                                         a->clid_len = 0;
1200                                         a->valid_until = now + 3600; /* Block address for 1h */
1201                                 }
1202                         }
1203                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1204                         /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1205                         status = DHCPV6_STATUS_NOTONLINK;
1206                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1207                         notonlink = true;
1208                 }
1209
1210                 buf += ia_response_len;
1211                 buflen -= ia_response_len;
1212                 response_len += ia_response_len;
1213                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1214         }
1215
1216         if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1217                         response_len + 6 < buflen) {
1218                 buf[0] = 0;
1219                 buf[1] = DHCPV6_OPT_STATUS;
1220                 buf[2] = 0;
1221                 buf[3] = 2;
1222                 buf[4] = 0;
1223                 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1224                 response_len += 6;
1225         }
1226
1227         dhcpv6_write_statefile();
1228
1229 out:
1230         return response_len;
1231 }