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
  20 #include <time.h>
  21 #include <errno.h>
  22 #include <fcntl.h>
  23 #include <stdio.h>
  24 #include <poll.h>
  25 #include <alloca.h>
  26 #include <resolv.h>
  27 #include <limits.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31 #include <stdbool.h>
  32 #include <arpa/inet.h>
  33 #include <sys/timerfd.h>
  34
  35 #include <libubox/md5.h>
  36 #include <libubox/usock.h>
  37
  38 #define ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) \
  39     ((iface)->managed == RELAYD_MANAGED_NO_AFLAG || (i) == (m) || \
  40      (addrs)[(i)].prefix > 64)
  41
  42 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c);
  43 static void reconf_timer(struct uloop_timeout *event);
  44 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
  45 static uint32_t serial = 0;
  46 static uint8_t statemd5[16];
  47
  48 int dhcpv6_ia_init(void)
  49 {
  50         uloop_timeout_set(&reconf_event, 2000);
  51         return 0;
  52 }
  53
  54 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
  55 {
  56         if (!enable && iface->ia_assignments.next) {
  57                 struct dhcpv6_assignment *c;
  58
  59                 while (!list_empty(&iface->ia_assignments)) {
  60                         c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
  61                         free_dhcpv6_assignment(c);
  62                 }
  63         }
  64
  65         if (enable && iface->dhcpv6 == RELAYD_SERVER) {
  66                 if (!iface->ia_assignments.next)
  67                         INIT_LIST_HEAD(&iface->ia_assignments);
  68
  69                 if (list_empty(&iface->ia_assignments)) {
  70                         struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
  71                         if (!border) {
  72                                 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
  73                                 return -1;
  74                         }
  75
  76                         border->length = 64;
  77                         list_add(&border->head, &iface->ia_assignments);
  78                 }
  79
  80                 /* Parse static entries */
  81                 struct lease *lease;
  82                 list_for_each_entry(lease, &leases, head) {
  83                         /* Construct entry */
  84                         size_t duid_len = lease->duid_len ? lease->duid_len : 14;
  85                         struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
  86                         if (!a) {
  87                                 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
  88                                         iface->ifname);
  89                                 return -1;
  90                         }
  91
  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 get_preferred_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_enum_ia_addrs(struct interface *iface, struct dhcpv6_assignment *c,
 237                                 time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
 238 {
 239         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
 240         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
 241         size_t m = get_preferred_addr(addrs, addrlen);
 242
 243         for (size_t i = 0; i < addrlen; ++i) {
 244                 struct in6_addr addr;
 245                 uint32_t pref, valid;
 246                 int prefix = c->managed ? addrs[i].prefix : c->length;
 247
 248                 if (!valid_addr(&addrs[i], now))
 249                         continue;
 250
 251                 addr = addrs[i].addr.in6;
 252                 pref = addrs[i].preferred;
 253                 valid = addrs[i].valid;
 254                 if (prefix == 128) {
 255                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 256                                 continue;
 257
 258                         addr.s6_addr32[3] = htonl(c->assigned);
 259                 } else {
 260                         if (!valid_prefix_length(c, addrs[i].prefix))
 261                                 continue;
 262
 263                         addr.s6_addr32[1] |= htonl(c->assigned);
 264                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 265                 }
 266
 267                 if (pref != UINT32_MAX)
 268                         pref -= now;
 269
 270                 if (valid != UINT32_MAX)
 271                         valid -= now;
 272
 273                 func(&addr, prefix, pref, valid, arg);
 274         }
 275 }
 276
 277 struct write_ctxt {
 278         FILE *fp;
 279         md5_ctx_t md5;
 280         struct dhcpv6_assignment *c;
 281         struct interface *iface;
 282         char *buf;
 283         int buf_len;
 284         int buf_idx;
 285 };
 286
 287 void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 288                                 _unused uint32_t valid, void *arg)
 289 {
 290         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
 291         char ipbuf[INET6_ADDRSTRLEN];
 292
 293         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 294
 295         if (ctxt->c->length == 128 && ctxt->c->hostname) {
 296                 fputs(ipbuf, ctxt->fp);
 297
 298                 char b[256];
 299                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
 300                                 ctxt->iface->search, b, sizeof(b)) > 0)
 301                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
 302
 303                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
 304                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
 305                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
 306         }
 307
 308         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
 309                                         "%s/%d ", ipbuf, prefix);
 310 }
 311
 312 void dhcpv6_write_statefile(void)
 313 {
 314         struct write_ctxt ctxt;
 315
 316         md5_begin(&ctxt.md5);
 317
 318         if (config.dhcp_statefile) {
 319                 time_t now = odhcpd_time(), wall_time = time(NULL);
 320                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 321                 char leasebuf[512];
 322
 323                 if (fd < 0)
 324                         return;
 325                 int ret;
 326                 ret = lockf(fd, F_LOCK, 0);
 327                 if (ret < 0) {
 328                         close(fd);
 329                         return;
 330                 }
 331                 if (ftruncate(fd, 0) < 0) {}
 332
 333                 ctxt.fp = fdopen(fd, "w");
 334                 if (!ctxt.fp) {
 335                         close(fd);
 336                         return;
 337                 }
 338
 339                 ctxt.buf = leasebuf;
 340                 ctxt.buf_len = sizeof(leasebuf);
 341
 342                 list_for_each_entry(ctxt.iface, &interfaces, head) {
 343                         if (ctxt.iface->dhcpv6 != RELAYD_SERVER &&
 344                                         ctxt.iface->dhcpv4 != RELAYD_SERVER)
 345                                 continue;
 346
 347                         if (ctxt.iface->dhcpv6 == RELAYD_SERVER &&
 348                                         ctxt.iface->ia_assignments.next) {
 349                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 350                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 351                                                 continue;
 352
 353                                         char duidbuf[264];
 354
 355                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
 356
 357                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 358                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s %ld %x %u ",
 359                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
 360                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
 361                                                                 (ctxt.c->valid_until > now ?
 362                                                                         (ctxt.c->valid_until - now + wall_time) :
 363                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)),
 364                                                                 ctxt.c->assigned, (unsigned)ctxt.c->length);
 365
 366                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
 367                                                 dhcpv6_enum_ia_addrs(ctxt.iface, ctxt.c, now,
 368                                                                         dhcpv6_write_ia_addr, &ctxt);
 369
 370                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 371                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 372                                 }
 373                         }
 374
 375                         if (ctxt.iface->dhcpv4 == RELAYD_SERVER &&
 376                                         ctxt.iface->dhcpv4_assignments.next) {
 377                                 struct dhcpv4_assignment *c;
 378                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 379                                         if (!(c->flags & OAF_BOUND))
 380                                                 continue;
 381
 382                                         char ipbuf[INET6_ADDRSTRLEN];
 383                                         char duidbuf[16];
 384                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 385
 386                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 387                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s %ld %x 32 ",
 388                                                                 ctxt.iface->ifname, duidbuf,
 389                                                                 (c->hostname ? c->hostname : "-"),
 390                                                                 (c->valid_until > now ?
 391                                                                         (c->valid_until - now + wall_time) :
 392                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 393                                                                 c->addr);
 394
 395                                         struct in_addr addr = {htonl(c->addr)};
 396                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 397
 398                                         if (c->hostname) {
 399                                                 fputs(ipbuf, ctxt.fp);
 400
 401                                                 char b[256];
 402                                                 if (dn_expand(ctxt.iface->search,
 403                                                                 ctxt.iface->search + ctxt.iface->search_len,
 404                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
 405                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
 406
 407                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
 408                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
 409                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
 410                                         }
 411
 412                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
 413                                                                         ctxt.buf_len - ctxt.buf_idx,
 414                                                                         "%s/32 ", ipbuf);
 415                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 416                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 417                                 }
 418                         }
 419                 }
 420
 421                 fclose(ctxt.fp);
 422         }
 423
 424         uint8_t newmd5[16];
 425         md5_end(newmd5, &ctxt.md5);
 426
 427         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 428                 memcpy(statemd5, newmd5, sizeof(statemd5));
 429                 char *argv[2] = {config.dhcp_cb, NULL};
 430                 if (!vfork()) {
 431                         execv(argv[0], argv);
 432                         _exit(128);
 433                 }
 434         }
 435 }
 436
 437
 438 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
 439 {
 440         if (a->length > 64 || a->managed_size < 0)
 441                 return;
 442
 443         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 444         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 445
 446         for (size_t i = 0; i < addrlen; ++i) {
 447                 struct in6_addr prefix = addrs[i].addr.in6;
 448                 prefix.s6_addr32[1] |= htonl(a->assigned);
 449                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
 450                 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 451                                 iface, &a->peer.sin6_addr, 1024, add);
 452         }
 453 }
 454
 455 /* More data was received from TCP connection */
 456 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 457 {
 458         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 459         time_t now = odhcpd_time();
 460         bool first = c->managed_size < 0;
 461
 462         for (;;) {
 463                 int pending;
 464                 char *data = ustream_get_read_buf(s, &pending);
 465                 char *end = memmem(data, pending, "\n\n", 2);
 466
 467                 if (!end)
 468                         break;
 469
 470                 end += 2;
 471                 end[-1] = 0;
 472
 473                 c->managed_size = 0;
 474                 if (c->accept_reconf)
 475                         c->reconf_cnt = 1;
 476
 477                 char *saveptr;
 478                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 479                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 480                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 481
 482                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 483                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 484                                 continue;
 485
 486                         x = strtok_r(NULL, ",", &saveptr2);
 487                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 488                                 continue;
 489
 490                         x = strtok_r(NULL, ",", &saveptr2);
 491                         if (sscanf(x, "%u", &n->preferred) < 1)
 492                                 continue;
 493
 494                         x = strtok_r(NULL, ",", &saveptr2);
 495                         if (sscanf(x, "%u", &n->valid) < 1)
 496                                 continue;
 497
 498                         if (n->preferred > n->valid)
 499                                 continue;
 500
 501                         if (UINT32_MAX - now < n->preferred)
 502                                 n->preferred = UINT32_MAX;
 503                         else
 504                                 n->preferred += now;
 505
 506                         if (UINT32_MAX - now < n->valid)
 507                                 n->valid = UINT32_MAX;
 508                         else
 509                                 n->valid += now;
 510
 511                         n->dprefix = 0;
 512
 513                         ++c->managed_size;
 514                 }
 515
 516                 ustream_consume(s, end - data);
 517         }
 518
 519         if (first && c->managed_size == 0)
 520                 free_dhcpv6_assignment(c);
 521         else if (first && !(c->flags & OAF_STATIC))
 522                 c->valid_until = now + 150;
 523 }
 524
 525
 526 /* TCP transmission has ended, either because of success or timeout or other error */
 527 static void managed_handle_pd_done(struct ustream *s)
 528 {
 529         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 530
 531         if (!(c->flags & OAF_STATIC))
 532                 c->valid_until = odhcpd_time() + 15;
 533
 534         c->managed_size = 0;
 535
 536         if (c->accept_reconf)
 537                 c->reconf_cnt = 1;
 538 }
 539
 540 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
 541 {
 542         struct dhcpv6_assignment *c;
 543
 544         if (iface->dhcpv6_pd_manager[0]) {
 545                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 546                 if (fd >= 0) {
 547                         char iaidbuf[298];
 548                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 549
 550                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 551                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 552                         ustream_fd_init(&assign->managed_sock, fd);
 553                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 554                                         iaidbuf, assign->iaid, assign->length);
 555                         ustream_write_pending(&assign->managed_sock.stream);
 556                         assign->managed_size = -1;
 557
 558                         if (!(assign->flags & OAF_STATIC))
 559                                 assign->valid_until = odhcpd_time() + 15;
 560
 561                         list_add(&assign->head, &iface->ia_assignments);
 562
 563                         /* Wait initial period of up to 250ms for immediate assignment */
 564                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 565                         poll(&pfd, 1, 250);
 566                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 567
 568                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 569                                 return true;
 570                 }
 571
 572                 return false;
 573         } else if (iface->ia_addr_len < 1)
 574                 return false;
 575
 576         /* Try honoring the hint first */
 577         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 578         if (assign->assigned) {
 579                 list_for_each_entry(c, &iface->ia_assignments, head) {
 580                         if (c->length == 128 || c->length == 0)
 581                                 continue;
 582
 583                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 584                                 list_add_tail(&assign->head, &c->head);
 585
 586                                 if (assign->flags & OAF_BOUND)
 587                                         apply_lease(iface, assign, true);
 588
 589                                 return true;
 590                         }
 591
 592                         if (c->assigned != 0)
 593                                 current = (c->assigned + (1 << (64 - c->length)));
 594                 }
 595         }
 596
 597         /* Fallback to a variable assignment */
 598         current = 1;
 599         list_for_each_entry(c, &iface->ia_assignments, head) {
 600                 if (c->length == 128 || c->length == 0)
 601                         continue;
 602
 603                 current = (current + asize) & (~asize);
 604                 if (current + asize < c->assigned) {
 605                         assign->assigned = current;
 606                         list_add_tail(&assign->head, &c->head);
 607
 608                         if (assign->flags & OAF_BOUND)
 609                                 apply_lease(iface, assign, true);
 610
 611                         return true;
 612                 }
 613
 614                 if (c->assigned != 0)
 615                         current = (c->assigned + (1 << (64 - c->length)));
 616         }
 617
 618         return false;
 619 }
 620
 621 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 622 {
 623         /* Seed RNG with checksum of DUID */
 624         uint32_t seed = 0;
 625         for (size_t i = 0; i < assign->clid_len; ++i)
 626                 seed += assign->clid_data[i];
 627         srand(seed);
 628
 629         /* Try to assign up to 100x */
 630         for (size_t i = 0; i < 100; ++i) {
 631                 uint32_t try;
 632                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 633
 634                 struct dhcpv6_assignment *c;
 635                 list_for_each_entry(c, &iface->ia_assignments, head) {
 636                         if (c->length == 0)
 637                                 continue;
 638
 639                         if (c->assigned > try || c->length != 128) {
 640                                 assign->assigned = try;
 641                                 list_add_tail(&assign->head, &c->head);
 642                                 return true;
 643                         } else if (c->assigned == try)
 644                                 break;
 645                 }
 646         }
 647
 648         return false;
 649 }
 650
 651 void dhcpv6_ia_preupdate(struct interface *iface)
 652 {
 653         if (iface->dhcpv6 != RELAYD_SERVER)
 654                 return;
 655
 656         struct dhcpv6_assignment *c, *border = list_last_entry(
 657                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 658
 659         list_for_each_entry(c, &iface->ia_assignments, head)
 660                 if (c != border && !iface->managed && (c->flags & OAF_BOUND))
 661                         apply_lease(iface, c, false);
 662 }
 663
 664 void dhcpv6_ia_postupdate(struct interface *iface)
 665 {
 666         if (iface->dhcpv6 != RELAYD_SERVER)
 667                 return;
 668
 669         time_t now = odhcpd_time();
 670         int minprefix = -1;
 671         for (size_t i = 0; i < iface->ia_addr_len; ++i) {
 672                 if (iface->ia_addr[i].preferred > (uint32_t)now &&
 673                                 iface->ia_addr[i].prefix < 64 &&
 674                                 iface->ia_addr[i].prefix > minprefix)
 675                         minprefix = iface->ia_addr[i].prefix;
 676         }
 677
 678         struct dhcpv6_assignment *border = list_last_entry(
 679                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 680
 681         if (minprefix > 32 && minprefix <= 64)
 682                 border->assigned = 1U << (64 - minprefix);
 683         else
 684                 border->assigned = 0;
 685
 686         struct list_head reassign = LIST_HEAD_INIT(reassign);
 687         struct dhcpv6_assignment *c, *d;
 688         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 689                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 690                                 c->managed_size)
 691                         continue;
 692
 693                 if (c->length < 128 && c->assigned >= border->assigned && c != border)
 694                         list_move(&c->head, &reassign);
 695                 else if (c != border && (c->flags & OAF_BOUND))
 696                         apply_lease(iface, c, true);
 697
 698                 if (c->accept_reconf && c->reconf_cnt == 0) {
 699                         c->reconf_cnt = 1;
 700                         c->reconf_sent = now;
 701                         send_reconf(iface, c);
 702
 703                         /* Leave all other assignments of that client alone */
 704                         struct dhcpv6_assignment *a;
 705                         list_for_each_entry(a, &iface->ia_assignments, head)
 706                                 if (a != c && a->clid_len == c->clid_len &&
 707                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 708                                         c->reconf_cnt = INT_MAX;
 709                 }
 710         }
 711
 712         while (!list_empty(&reassign)) {
 713                 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
 714                 list_del(&c->head);
 715                 if (!assign_pd(iface, c)) {
 716                         c->assigned = 0;
 717                         list_add(&c->head, &iface->ia_assignments);
 718                 }
 719         }
 720
 721         dhcpv6_write_statefile();
 722 }
 723
 724 static void reconf_timer(struct uloop_timeout *event)
 725 {
 726         time_t now = odhcpd_time();
 727         struct interface *iface;
 728         list_for_each_entry(iface, &interfaces, head) {
 729                 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
 730                         continue;
 731
 732                 struct dhcpv6_assignment *a, *n;
 733                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 734                         if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
 735                                 if ((a->length < 128 && a->clid_len > 0) ||
 736                                                 (a->length == 128 && a->clid_len == 0))
 737                                         free_dhcpv6_assignment(a);
 738
 739                         } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
 740                                         now > a->reconf_sent + (1 << a->reconf_cnt)) {
 741                                 ++a->reconf_cnt;
 742                                 a->reconf_sent = now;
 743                                 send_reconf(iface, a);
 744                         }
 745                 }
 746         }
 747         uloop_timeout_set(event, 2000);
 748 }
 749
 750 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
 751                 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
 752                 struct interface *iface, bool request)
 753 {
 754         if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
 755                 return 0;
 756
 757         struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
 758         size_t datalen = sizeof(out);
 759         time_t now = odhcpd_time();
 760
 761         if (status) {
 762                 struct __attribute__((packed)) {
 763                         uint16_t type;
 764                         uint16_t len;
 765                         uint16_t value;
 766                 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
 767                                 htons(status)};
 768
 769                 memcpy(buf + datalen, &stat, sizeof(stat));
 770                 datalen += sizeof(stat);
 771         } else {
 772                 if (a) {
 773                         uint32_t leasetime;
 774                         if (a->leasetime)
 775                                 leasetime = a->leasetime;
 776                         else
 777                                 leasetime = iface->dhcpv4_leasetime;
 778
 779                         uint32_t pref = leasetime;
 780                         uint32_t valid = leasetime;
 781
 782                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 783                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 784                         size_t m = get_preferred_addr(addrs, addrlen);
 785
 786                         for (size_t i = 0; i < addrlen; ++i) {
 787                                 uint32_t prefix_pref = addrs[i].preferred;
 788                                 uint32_t prefix_valid = addrs[i].valid;
 789
 790                                 if (!valid_addr(&addrs[i], now))
 791                                         continue;
 792
 793                                 if (prefix_pref != UINT32_MAX)
 794                                         prefix_pref -= now;
 795
 796                                 if (prefix_valid != UINT32_MAX)
 797                                         prefix_valid -= now;
 798
 799                                 if (a->length < 128) {
 800                                         struct dhcpv6_ia_prefix p = {
 801                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 802                                                 .len = htons(sizeof(p) - 4),
 803                                                 .preferred = htonl(prefix_pref),
 804                                                 .valid = htonl(prefix_valid),
 805                                                 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 806                                                 .addr = addrs[i].addr.in6,
 807                                         };
 808                                         p.addr.s6_addr32[1] |= htonl(a->assigned);
 809                                         p.addr.s6_addr32[2] = p.addr.s6_addr32[3] = 0;
 810
 811                                         size_t entrlen = sizeof(p) - 4;
 812
 813                                         if (datalen + entrlen + 4 > buflen ||
 814                                                         (a->assigned == 0 && a->managed_size == 0) ||
 815                                                         !valid_prefix_length(a, addrs[i].prefix))
 816                                                 continue;
 817
 818                                         memcpy(buf + datalen, &p, sizeof(p));
 819                                         datalen += entrlen + 4;
 820                                 } else {
 821                                         struct dhcpv6_ia_addr n = {
 822                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 823                                                 .len = htons(sizeof(n) - 4),
 824                                                 .addr = addrs[i].addr.in6,
 825                                                 .preferred = htonl(prefix_pref),
 826                                                 .valid = htonl(prefix_valid)
 827                                         };
 828                                         n.addr.s6_addr32[3] = htonl(a->assigned);
 829                                         size_t entrlen = sizeof(n) - 4;
 830
 831                                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
 832                                                         a->assigned == 0 ||
 833                                                         datalen + entrlen + 4 > buflen)
 834                                                 continue;
 835
 836                                         memcpy(buf + datalen, &n, sizeof(n));
 837                                         datalen += entrlen + 4;
 838                                 }
 839
 840                                 /* Calculate T1 / T2 based on non-deprecated addresses */
 841                                 if (prefix_pref > 0) {
 842                                         if (prefix_pref < pref)
 843                                                 pref = prefix_pref;
 844
 845                                         if (prefix_valid < valid)
 846                                                 valid = prefix_valid;
 847                                 }
 848                         }
 849
 850                         if (!INFINITE_VALID(a->valid_until))
 851                                 /* UINT32_MAX is considered as infinite leasetime */
 852                                 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 853
 854                         out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 855                         out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 856
 857                         if (!out.t1)
 858                                 out.t1 = htonl(1);
 859
 860                         if (!out.t2)
 861                                 out.t2 = htonl(1);
 862                 }
 863
 864                 if (!request) {
 865                         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 866                         uint16_t otype, olen;
 867                         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 868                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
 869                                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
 870                                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
 871                                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
 872                                         continue;
 873
 874                                 bool found = false;
 875                                 if (a) {
 876                                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 877                                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 878
 879                                         for (size_t i = 0; i < addrlen; ++i) {
 880                                                 if (!valid_addr(&addrs[i], now))
 881                                                         continue;
 882
 883                                                 struct in6_addr addr = addrs[i].addr.in6;
 884                                                 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 885                                                         addr.s6_addr32[1] |= htonl(a->assigned);
 886                                                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 887
 888                                                         if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
 889                                                                         p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 890                                                                 found = true;
 891                                                 } else {
 892                                                         addr.s6_addr32[3] = htonl(a->assigned);
 893
 894                                                         if (!memcmp(&n->addr, &addr, sizeof(addr)))
 895                                                                 found = true;
 896                                                 }
 897                                         }
 898                                 }
 899
 900                                 if (!found) {
 901                                         if (otype == DHCPV6_OPT_IA_PREFIX) {
 902                                                 struct dhcpv6_ia_prefix inv = {
 903                                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 904                                                         .len = htons(sizeof(inv) - 4),
 905                                                         .preferred = 0,
 906                                                         .valid = 0,
 907                                                         .prefix = p->prefix,
 908                                                         .addr = p->addr
 909                                                 };
 910
 911                                                 if (datalen + sizeof(inv) > buflen)
 912                                                         continue;
 913
 914                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 915                                                 datalen += sizeof(inv);
 916                                         } else {
 917                                                 struct dhcpv6_ia_addr inv = {
 918                                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 919                                                         .len = htons(sizeof(inv) - 4),
 920                                                         .addr = n->addr,
 921                                                         .preferred = 0,
 922                                                         .valid = 0
 923                                                 };
 924
 925                                                 if (datalen + sizeof(inv) > buflen)
 926                                                         continue;
 927
 928                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 929                                                 datalen += sizeof(inv);
 930                                         }
 931                                 }
 932                         }
 933                 }
 934         }
 935
 936         out.len = htons(datalen - 4);
 937         memcpy(buf, &out, sizeof(out));
 938         return datalen;
 939 }
 940
 941 struct log_ctxt {
 942         char *buf;
 943         int buf_len;
 944         int buf_idx;
 945 };
 946
 947 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 948                                 _unused uint32_t valid, void *arg)
 949 {
 950         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
 951         char addrbuf[INET6_ADDRSTRLEN];
 952
 953         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
 954         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
 955                                         "%s/%d ", addrbuf, prefix);
 956 }
 957
 958 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
 959                 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
 960 {
 961         const char *type = "UNKNOWN";
 962         const char *status = "UNKNOWN";
 963
 964         if (msgtype == DHCPV6_MSG_RENEW)
 965                 return;
 966
 967         switch (msgtype) {
 968         case DHCPV6_MSG_SOLICIT:
 969                 type = "SOLICIT";
 970                 break;
 971         case DHCPV6_MSG_REQUEST:
 972                 type = "REQUEST";
 973                 break;
 974         case DHCPV6_MSG_CONFIRM:
 975                 type = "CONFIRM";
 976                 break;
 977         case DHCPV6_MSG_RENEW:
 978                 type = "RENEW";
 979                 break;
 980         case DHCPV6_MSG_REBIND:
 981                 type = "REBIND";
 982                 break;
 983         case DHCPV6_MSG_RELEASE:
 984                 type = "RELEASE";
 985                 break;
 986         case DHCPV6_MSG_DECLINE:
 987                 type = "DECLINE";
 988                 break;
 989         }
 990
 991         switch (code) {
 992         case DHCPV6_STATUS_OK:
 993                 status = "ok";
 994                 break;
 995         case DHCPV6_STATUS_NOADDRSAVAIL:
 996                 status = "no addresses available";
 997                 break;
 998         case DHCPV6_STATUS_NOBINDING:
 999                 status = "no binding";
1000                 break;
1001         case DHCPV6_STATUS_NOTONLINK:
1002                 status = "not on-link";
1003                 break;
1004         case DHCPV6_STATUS_NOPREFIXAVAIL:
1005                 status = "no prefix available";
1006                 break;
1007         }
1008
1009         char leasebuf[256] = "";
1010
1011         if (a) {
1012                 struct log_ctxt ctxt = {.buf = leasebuf,
1013                                         .buf_len = sizeof(leasebuf),
1014                                         .buf_idx = 0 };
1015
1016                 dhcpv6_enum_ia_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1017         }
1018
1019         syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1020                         duidbuf, iface->ifname, status, leasebuf);
1021 }
1022
1023 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
1024                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1025 {
1026         time_t now = odhcpd_time();
1027         size_t response_len = 0;
1028         const struct dhcpv6_client_header *hdr = data;
1029         uint8_t *start = (uint8_t*)&hdr[1], *odata;
1030         uint16_t otype, olen;
1031         /* Find and parse client-id and hostname */
1032         bool accept_reconf = false;
1033         uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1034         char hostname[256];
1035         size_t hostname_len = 0;
1036         bool notonlink = false;
1037         char duidbuf[261];
1038
1039         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1040                 if (otype == DHCPV6_OPT_CLIENTID) {
1041                         clid_data = odata;
1042                         clid_len = olen;
1043
1044                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1045                                 memcpy(mac, &odata[8], sizeof(mac));
1046                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1047                                 memcpy(mac, &odata[4], sizeof(mac));
1048
1049                         if (olen <= 130)
1050                                 odhcpd_hexlify(duidbuf, odata, olen);
1051                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1052                         uint8_t fqdn_buf[256];
1053                         memcpy(fqdn_buf, odata, olen);
1054                         fqdn_buf[olen++] = 0;
1055
1056                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1057                                 hostname_len = strcspn(hostname, ".");
1058                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1059                         accept_reconf = true;
1060         }
1061
1062         if (!clid_data || !clid_len || clid_len > 130)
1063                 goto out;
1064
1065         struct dhcpv6_assignment *first = NULL;
1066         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1067                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1068                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1069                 bool ia_addr_present = false;
1070                 if (!is_pd && !is_na)
1071                         continue;
1072
1073                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1074                 size_t ia_response_len = 0;
1075                 uint8_t reqlen = (is_pd) ? 62 : 128;
1076                 uint32_t reqhint = 0;
1077
1078                 /* Parse request hint for IA-PD */
1079                 if (is_pd) {
1080                         uint8_t *sdata;
1081                         uint16_t stype, slen;
1082                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1083                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1084                                         continue;
1085
1086                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1087                                 if (p->prefix) {
1088                                         reqlen = p->prefix;
1089                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1090                                         if (reqlen > 32 && reqlen <= 64)
1091                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1092                                 }
1093                         }
1094
1095                         if (reqlen > 64)
1096                                 reqlen = 64;
1097                 } else if (is_na) {
1098                         uint8_t *sdata;
1099                         uint16_t stype, slen;
1100                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1101                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1102                                         continue;
1103
1104                                 ia_addr_present = true;
1105                         }
1106                 }
1107
1108                 /* Find assignment */
1109                 struct dhcpv6_assignment *c, *a = NULL;
1110                 list_for_each_entry(c, &iface->ia_assignments, head) {
1111                         if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1112                                         (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1113                                                 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1114                                         (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1115                                         ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1116                                 a = c;
1117
1118                                 /* Reset state */
1119                                 if (a->flags & OAF_BOUND)
1120                                         apply_lease(iface, a, false);
1121
1122                                 memcpy(a->clid_data, clid_data, clid_len);
1123                                 a->clid_len = clid_len;
1124                                 a->iaid = ia->iaid;
1125                                 a->peer = *addr;
1126                                 a->reconf_cnt = 0;
1127                                 a->reconf_sent = 0;
1128                                 break;
1129                         }
1130                 }
1131
1132                 /* Generic message handling */
1133                 uint16_t status = DHCPV6_STATUS_OK;
1134                 if (a && a->managed_size < 0)
1135                         return -1;
1136
1137                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1138                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1139                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1140                         bool assigned = !!a;
1141
1142                         if (!a && !iface->no_dynamic_dhcp) {
1143                                 /* Create new binding */
1144                                 a = calloc(1, sizeof(*a) + clid_len);
1145                                 if (a) {
1146                                         a->clid_len = clid_len;
1147                                         a->iaid = ia->iaid;
1148                                         a->length = reqlen;
1149                                         a->peer = *addr;
1150                                         a->assigned = reqhint;
1151                                         /* Set valid time to current time indicating  */
1152                                         /* assignment is not having infinite lifetime */
1153                                         a->valid_until = now;
1154
1155                                         if (first)
1156                                                 memcpy(a->key, first->key, sizeof(a->key));
1157                                         else
1158                                                 odhcpd_urandom(a->key, sizeof(a->key));
1159                                         memcpy(a->clid_data, clid_data, clid_len);
1160
1161                                         if (is_pd)
1162                                                 while (!(assigned = assign_pd(iface, a)) &&
1163                                                                 !a->managed_size && ++a->length <= 64);
1164                                         else
1165                                                 assigned = assign_na(iface, a);
1166
1167                                         if (a->managed_size && !assigned)
1168                                                 return -1;
1169                                 }
1170                         }
1171
1172                         if (!assigned || iface->ia_addr_len == 0)
1173                                 /* Set error status */
1174                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1175                         else if (assigned && !first && hdr->msg_type != DHCPV6_MSG_REBIND) {
1176                                 size_t handshake_len = 4;
1177                                 buf[0] = 0;
1178                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1179                                 buf[2] = 0;
1180                                 buf[3] = 0;
1181
1182                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1183                                         struct dhcpv6_auth_reconfigure auth = {
1184                                                 htons(DHCPV6_OPT_AUTH),
1185                                                 htons(sizeof(auth) - 4),
1186                                                 3, 1, 0,
1187                                                 {htonl(time(NULL)), htonl(++serial)},
1188                                                 1,
1189                                                 {0}
1190                                         };
1191                                         memcpy(auth.key, a->key, sizeof(a->key));
1192                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1193                                         handshake_len += sizeof(auth);
1194                                 }
1195
1196                                 buf += handshake_len;
1197                                 buflen -= handshake_len;
1198                                 response_len += handshake_len;
1199
1200                                 first = a;
1201                         }
1202
1203                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface,
1204                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1205
1206                         /* Was only a solicitation: mark binding for removal */
1207                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1208                                 a->flags &= ~OAF_BOUND;
1209
1210                                 if (!(a->flags & OAF_STATIC))
1211                                         a->valid_until = now;
1212                         } else if (assigned &&
1213                                         (hdr->msg_type == DHCPV6_MSG_REQUEST ||
1214                                          hdr->msg_type == DHCPV6_MSG_REBIND)) {
1215                                 if (hostname_len > 0) {
1216                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1217                                         if (a->hostname) {
1218                                                 memcpy(a->hostname, hostname, hostname_len);
1219                                                 a->hostname[hostname_len] = 0;
1220                                         }
1221                                 }
1222                                 a->accept_reconf = accept_reconf;
1223                                 a->flags |= OAF_BOUND;
1224                                 apply_lease(iface, a, true);
1225                         } else if (!assigned && a && a->managed_size == 0) {
1226                                 /* Cleanup failed assignment */
1227                                 free_dhcpv6_assignment(a);
1228                                 a = NULL;
1229                         }
1230                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1231                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1232                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1233                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1234                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1235                                 status = DHCPV6_STATUS_NOBINDING;
1236                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1237                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1238                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1239                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1240                                 if (a) {
1241                                         a->flags |= OAF_BOUND;
1242                                         apply_lease(iface, a, true);
1243                                 }
1244                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1245                                 if (!(a->flags & OAF_STATIC))
1246                                         a->valid_until = now - 1;
1247
1248                                 if (a->flags & OAF_BOUND) {
1249                                         apply_lease(iface, a, false);
1250                                         a->flags &= ~OAF_BOUND;
1251                                 }
1252                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1253                                 a->flags &= ~OAF_BOUND;
1254
1255                                 if (!(a->flags & OAF_STATIC)) {
1256                                         a->clid_len = 0;
1257                                         a->valid_until = now + 3600; /* Block address for 1h */
1258                                 }
1259                         }
1260                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1261                         /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1262                         status = DHCPV6_STATUS_NOTONLINK;
1263                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1264                         notonlink = true;
1265                 }
1266
1267                 buf += ia_response_len;
1268                 buflen -= ia_response_len;
1269                 response_len += ia_response_len;
1270                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1271         }
1272
1273         if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1274                         response_len + 6 < buflen) {
1275                 buf[0] = 0;
1276                 buf[1] = DHCPV6_OPT_STATUS;
1277                 buf[2] = 0;
1278                 buf[3] = 2;
1279                 buf[4] = 0;
1280                 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1281                 response_len += 6;
1282         }
1283
1284         dhcpv6_write_statefile();
1285
1286 out:
1287         return response_len;
1288 }