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