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                         a->leasetime = lease->dhcpv4_leasetime;
  92
  93                         a->clid_len = duid_len;
  94                         a->length = 128;
  95                         if (lease->hostid) {
  96                                 a->assigned = lease->hostid;
  97                         } else {
  98                                 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
  99                                 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
 100                         }
 101
 102                         odhcpd_urandom(a->key, sizeof(a->key));
 103                         memcpy(a->clid_data, lease->duid, lease->duid_len);
 104                         memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
 105                         /* Static assignment */
 106                         a->flags |= OAF_STATIC;
 107                         /* Infinite valid */
 108                         a->valid_until = 0;
 109
 110                         /* Assign to all interfaces */
 111                         struct dhcpv6_assignment *c;
 112                         list_for_each_entry(c, &iface->ia_assignments, head) {
 113                                 if (c->length != 128 || c->assigned > a->assigned) {
 114                                         list_add_tail(&a->head, &c->head);
 115                                         break;
 116                                 } else if (c->assigned == a->assigned)
 117                                         /* Already an assignment with that number */
 118                                         break;
 119                         }
 120
 121                         if (a->head.next) {
 122                                 if (lease->hostname[0]) {
 123                                         free(a->hostname);
 124                                         a->hostname = strdup(lease->hostname);
 125                                 }
 126                         } else
 127                                 free_dhcpv6_assignment(a);
 128                 }
 129         }
 130         return 0;
 131 }
 132
 133 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
 134 {
 135         if (c->managed_sock.fd.registered) {
 136                 ustream_free(&c->managed_sock.stream);
 137                 close(c->managed_sock.fd.fd);
 138         }
 139
 140         if (c->head.next)
 141                 list_del(&c->head);
 142
 143         free(c->managed);
 144         free(c->hostname);
 145         free(c);
 146 }
 147
 148 static inline bool valid_prefix_length(const struct dhcpv6_assignment *a, const uint8_t prefix_length)
 149 {
 150         return (a->managed_size || a->length > prefix_length);
 151 }
 152
 153 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 154 {
 155         return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
 156 }
 157
 158 static size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
 159 {
 160         size_t i, m;
 161
 162         for (i = 0, m = 0; i < addrlen; ++i) {
 163                 if (addrs[i].preferred > addrs[m].preferred ||
 164                                 (addrs[i].preferred == addrs[m].preferred &&
 165                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 166                         m = i;
 167         }
 168
 169         return m;
 170 }
 171
 172 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
 173 {
 174         struct {
 175                 struct dhcpv6_client_header hdr;
 176                 uint16_t srvid_type;
 177                 uint16_t srvid_len;
 178                 uint16_t duid_type;
 179                 uint16_t hardware_type;
 180                 uint8_t mac[6];
 181                 uint16_t msg_type;
 182                 uint16_t msg_len;
 183                 uint8_t msg_id;
 184                 struct dhcpv6_auth_reconfigure auth;
 185                 uint16_t clid_type;
 186                 uint16_t clid_len;
 187                 uint8_t clid_data[128];
 188         } __attribute__((packed)) reconf_msg = {
 189                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 190                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 191                 .srvid_len = htons(10),
 192                 .duid_type = htons(3),
 193                 .hardware_type = htons(1),
 194                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 195                 .msg_len = htons(1),
 196                 .msg_id = DHCPV6_MSG_RENEW,
 197                 .auth = {htons(DHCPV6_OPT_AUTH),
 198                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 199                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 200                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 201                 .clid_len = htons(assign->clid_len),
 202                 .clid_data = {0},
 203         };
 204
 205         odhcpd_get_mac(iface, reconf_msg.mac);
 206         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 207         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 208
 209         md5_ctx_t md5;
 210         uint8_t secretbytes[64];
 211         memset(secretbytes, 0, sizeof(secretbytes));
 212         memcpy(secretbytes, assign->key, sizeof(assign->key));
 213
 214         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 215                 secretbytes[i] ^= 0x36;
 216
 217         md5_begin(&md5);
 218         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 219         md5_hash(iov.iov_base, iov.iov_len, &md5);
 220         md5_end(reconf_msg.auth.key, &md5);
 221
 222         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 223                 secretbytes[i] ^= 0x36;
 224                 secretbytes[i] ^= 0x5c;
 225         }
 226
 227         md5_begin(&md5);
 228         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 229         md5_hash(reconf_msg.auth.key, 16, &md5);
 230         md5_end(reconf_msg.auth.key, &md5);
 231
 232         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 233 }
 234
 235 void dhcpv6_enum_ia_addrs(struct interface *iface, struct dhcpv6_assignment *c,
 236                                 time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
 237 {
 238         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
 239         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
 240         size_t m = get_preferred_addr(addrs, addrlen);
 241
 242         for (size_t i = 0; i < addrlen; ++i) {
 243                 struct in6_addr addr;
 244                 uint32_t pref, valid;
 245                 int prefix = c->managed ? addrs[i].prefix : c->length;
 246
 247                 if (!valid_addr(&addrs[i], now))
 248                         continue;
 249
 250                 addr = addrs[i].addr;
 251                 pref = addrs[i].preferred;
 252                 valid = addrs[i].valid;
 253                 if (prefix == 128) {
 254                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 255                                 continue;
 256
 257                         addr.s6_addr32[3] = htonl(c->assigned);
 258                 } else {
 259                         if (!valid_prefix_length(c, addrs[i].prefix))
 260                                 continue;
 261
 262                         addr.s6_addr32[1] |= htonl(c->assigned);
 263                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 264                 }
 265
 266                 if (pref != UINT32_MAX)
 267                         pref -= now;
 268
 269                 if (valid != UINT32_MAX)
 270                         valid -= now;
 271
 272                 func(&addr, prefix, pref, valid, arg);
 273         }
 274 }
 275
 276 struct write_ctxt {
 277         FILE *fp;
 278         md5_ctx_t md5;
 279         struct dhcpv6_assignment *c;
 280         struct interface *iface;
 281         char *buf;
 282         int buf_len;
 283         int buf_idx;
 284 };
 285
 286 void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 287                                 _unused uint32_t valid, void *arg)
 288 {
 289         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
 290         char ipbuf[INET6_ADDRSTRLEN];
 291
 292         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 293
 294         if (ctxt->c->length == 128 && ctxt->c->hostname) {
 295                 fputs(ipbuf, ctxt->fp);
 296
 297                 char b[256];
 298                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
 299                                 ctxt->iface->search, b, sizeof(b)) > 0)
 300                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
 301
 302                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
 303                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
 304                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
 305         }
 306
 307         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
 308                                         "%s/%d ", ipbuf, prefix);
 309 }
 310
 311 void dhcpv6_write_statefile(void)
 312 {
 313         struct write_ctxt ctxt;
 314
 315         md5_begin(&ctxt.md5);
 316
 317         if (config.dhcp_statefile) {
 318                 time_t now = odhcpd_time(), wall_time = time(NULL);
 319                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 320                 char leasebuf[512];
 321
 322                 if (fd < 0)
 323                         return;
 324                 int ret;
 325                 ret = lockf(fd, F_LOCK, 0);
 326                 if (ret < 0) {
 327                         close(fd);
 328                         return;
 329                 }
 330                 if (ftruncate(fd, 0) < 0) {}
 331
 332                 ctxt.fp = fdopen(fd, "w");
 333                 if (!ctxt.fp) {
 334                         close(fd);
 335                         return;
 336                 }
 337
 338                 ctxt.buf = leasebuf;
 339                 ctxt.buf_len = sizeof(leasebuf);
 340
 341                 list_for_each_entry(ctxt.iface, &interfaces, head) {
 342                         if (ctxt.iface->dhcpv6 != RELAYD_SERVER &&
 343                                         ctxt.iface->dhcpv4 != RELAYD_SERVER)
 344                                 continue;
 345
 346                         if (ctxt.iface->dhcpv6 == RELAYD_SERVER &&
 347                                         ctxt.iface->ia_assignments.next) {
 348                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 349                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 350                                                 continue;
 351
 352                                         char duidbuf[264];
 353
 354                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
 355
 356                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 357                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s %ld %x %u ",
 358                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
 359                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
 360                                                                 (ctxt.c->valid_until > now ?
 361                                                                         (ctxt.c->valid_until - now + wall_time) :
 362                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)),
 363                                                                 ctxt.c->assigned, (unsigned)ctxt.c->length);
 364
 365                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
 366                                                 dhcpv6_enum_ia_addrs(ctxt.iface, ctxt.c, now,
 367                                                                         dhcpv6_write_ia_addr, &ctxt);
 368
 369                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 370                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 371                                 }
 372                         }
 373
 374                         if (ctxt.iface->dhcpv4 == RELAYD_SERVER &&
 375                                         ctxt.iface->dhcpv4_assignments.next) {
 376                                 struct dhcpv4_assignment *c;
 377                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 378                                         if (!(c->flags & OAF_BOUND))
 379                                                 continue;
 380
 381                                         char ipbuf[INET6_ADDRSTRLEN];
 382                                         char duidbuf[16];
 383                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 384
 385                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 386                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s %ld %x 32 ",
 387                                                                 ctxt.iface->ifname, duidbuf,
 388                                                                 (c->hostname ? c->hostname : "-"),
 389                                                                 (c->valid_until > now ?
 390                                                                         (c->valid_until - now + wall_time) :
 391                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 392                                                                 c->addr);
 393
 394                                         struct in_addr addr = {htonl(c->addr)};
 395                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 396
 397                                         if (c->hostname) {
 398                                                 fputs(ipbuf, ctxt.fp);
 399
 400                                                 char b[256];
 401                                                 if (dn_expand(ctxt.iface->search,
 402                                                                 ctxt.iface->search + ctxt.iface->search_len,
 403                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
 404                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
 405
 406                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
 407                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
 408                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
 409                                         }
 410
 411                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
 412                                                                         ctxt.buf_len - ctxt.buf_idx,
 413                                                                         "%s/32 ", ipbuf);
 414                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 415                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 416                                 }
 417                         }
 418                 }
 419
 420                 fclose(ctxt.fp);
 421         }
 422
 423         uint8_t newmd5[16];
 424         md5_end(newmd5, &ctxt.md5);
 425
 426         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 427                 memcpy(statemd5, newmd5, sizeof(statemd5));
 428                 char *argv[2] = {config.dhcp_cb, NULL};
 429                 if (!vfork()) {
 430                         execv(argv[0], argv);
 431                         _exit(128);
 432                 }
 433         }
 434 }
 435
 436
 437 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
 438 {
 439         if (a->length > 64 || a->managed_size < 0)
 440                 return;
 441
 442         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 443         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 444
 445         for (size_t i = 0; i < addrlen; ++i) {
 446                 struct in6_addr prefix = addrs[i].addr;
 447                 prefix.s6_addr32[1] |= htonl(a->assigned);
 448                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
 449                 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 450                                 iface, &a->peer.sin6_addr, 1024, add);
 451         }
 452 }
 453
 454 /* More data was received from TCP connection */
 455 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 456 {
 457         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 458         time_t now = odhcpd_time();
 459         bool first = c->managed_size < 0;
 460
 461         for (;;) {
 462                 int pending;
 463                 char *data = ustream_get_read_buf(s, &pending);
 464                 char *end = memmem(data, pending, "\n\n", 2);
 465
 466                 if (!end)
 467                         break;
 468
 469                 end += 2;
 470                 end[-1] = 0;
 471
 472                 c->managed_size = 0;
 473                 if (c->accept_reconf)
 474                         c->reconf_cnt = 1;
 475
 476                 char *saveptr;
 477                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 478                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 479                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 480
 481                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 482                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 483                                 continue;
 484
 485                         x = strtok_r(NULL, ",", &saveptr2);
 486                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 487                                 continue;
 488
 489                         x = strtok_r(NULL, ",", &saveptr2);
 490                         if (sscanf(x, "%u", &n->preferred) < 1)
 491                                 continue;
 492
 493                         x = strtok_r(NULL, ",", &saveptr2);
 494                         if (sscanf(x, "%u", &n->valid) < 1)
 495                                 continue;
 496
 497                         if (n->preferred > n->valid)
 498                                 continue;
 499
 500                         if (UINT32_MAX - now < n->preferred)
 501                                 n->preferred = UINT32_MAX;
 502                         else
 503                                 n->preferred += now;
 504
 505                         if (UINT32_MAX - now < n->valid)
 506                                 n->valid = UINT32_MAX;
 507                         else
 508                                 n->valid += now;
 509
 510                         n->dprefix = 0;
 511
 512                         ++c->managed_size;
 513                 }
 514
 515                 ustream_consume(s, end - data);
 516         }
 517
 518         if (first && c->managed_size == 0)
 519                 free_dhcpv6_assignment(c);
 520         else if (first && !(c->flags & OAF_STATIC))
 521                 c->valid_until = now + 150;
 522 }
 523
 524
 525 /* TCP transmission has ended, either because of success or timeout or other error */
 526 static void managed_handle_pd_done(struct ustream *s)
 527 {
 528         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 529
 530         if (!(c->flags & OAF_STATIC))
 531                 c->valid_until = odhcpd_time() + 15;
 532
 533         c->managed_size = 0;
 534
 535         if (c->accept_reconf)
 536                 c->reconf_cnt = 1;
 537 }
 538
 539 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
 540 {
 541         struct dhcpv6_assignment *c;
 542
 543         if (iface->dhcpv6_pd_manager[0]) {
 544                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 545                 if (fd >= 0) {
 546                         char iaidbuf[298];
 547                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 548
 549                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 550                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 551                         ustream_fd_init(&assign->managed_sock, fd);
 552                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 553                                         iaidbuf, assign->iaid, assign->length);
 554                         ustream_write_pending(&assign->managed_sock.stream);
 555                         assign->managed_size = -1;
 556
 557                         if (!(assign->flags & OAF_STATIC))
 558                                 assign->valid_until = odhcpd_time() + 15;
 559
 560                         list_add(&assign->head, &iface->ia_assignments);
 561
 562                         /* Wait initial period of up to 250ms for immediate assignment */
 563                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 564                         poll(&pfd, 1, 250);
 565                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 566
 567                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 568                                 return true;
 569                 }
 570
 571                 return false;
 572         } else if (iface->ia_addr_len < 1)
 573                 return false;
 574
 575         /* Try honoring the hint first */
 576         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 577         if (assign->assigned) {
 578                 list_for_each_entry(c, &iface->ia_assignments, head) {
 579                         if (c->length == 128 || c->length == 0)
 580                                 continue;
 581
 582                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 583                                 list_add_tail(&assign->head, &c->head);
 584
 585                                 if (assign->flags & OAF_BOUND)
 586                                         apply_lease(iface, assign, true);
 587
 588                                 return true;
 589                         }
 590
 591                         if (c->assigned != 0)
 592                                 current = (c->assigned + (1 << (64 - c->length)));
 593                 }
 594         }
 595
 596         /* Fallback to a variable assignment */
 597         current = 1;
 598         list_for_each_entry(c, &iface->ia_assignments, head) {
 599                 if (c->length == 128 || c->length == 0)
 600                         continue;
 601
 602                 current = (current + asize) & (~asize);
 603                 if (current + asize < c->assigned) {
 604                         assign->assigned = current;
 605                         list_add_tail(&assign->head, &c->head);
 606
 607                         if (assign->flags & OAF_BOUND)
 608                                 apply_lease(iface, assign, true);
 609
 610                         return true;
 611                 }
 612
 613                 if (c->assigned != 0)
 614                         current = (c->assigned + (1 << (64 - c->length)));
 615         }
 616
 617         return false;
 618 }
 619
 620 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 621 {
 622         /* Seed RNG with checksum of DUID */
 623         uint32_t seed = 0;
 624         for (size_t i = 0; i < assign->clid_len; ++i)
 625                 seed += assign->clid_data[i];
 626         srand(seed);
 627
 628         /* Try to assign up to 100x */
 629         for (size_t i = 0; i < 100; ++i) {
 630                 uint32_t try;
 631                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 632
 633                 struct dhcpv6_assignment *c;
 634                 list_for_each_entry(c, &iface->ia_assignments, head) {
 635                         if (c->length == 0)
 636                                 continue;
 637
 638                         if (c->assigned > try || c->length != 128) {
 639                                 assign->assigned = try;
 640                                 list_add_tail(&assign->head, &c->head);
 641                                 return true;
 642                         } else if (c->assigned == try)
 643                                 break;
 644                 }
 645         }
 646
 647         return false;
 648 }
 649
 650 void dhcpv6_ia_preupdate(struct interface *iface)
 651 {
 652         if (iface->dhcpv6 != RELAYD_SERVER)
 653                 return;
 654
 655         struct dhcpv6_assignment *c, *border = list_last_entry(
 656                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 657
 658         list_for_each_entry(c, &iface->ia_assignments, head)
 659                 if (c != border && !iface->managed && (c->flags & OAF_BOUND))
 660                         apply_lease(iface, c, false);
 661 }
 662
 663 void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
 664 {
 665         if (iface->dhcpv6 != RELAYD_SERVER)
 666                 return;
 667
 668         int minprefix = -1;
 669         for (size_t i = 0; i < iface->ia_addr_len; ++i) {
 670                 if (iface->ia_addr[i].preferred > (uint32_t)now &&
 671                                 iface->ia_addr[i].prefix < 64 &&
 672                                 iface->ia_addr[i].prefix > minprefix)
 673                         minprefix = iface->ia_addr[i].prefix;
 674         }
 675
 676         struct dhcpv6_assignment *border = list_last_entry(
 677                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 678
 679         if (minprefix > 32 && minprefix <= 64)
 680                 border->assigned = 1U << (64 - minprefix);
 681         else
 682                 border->assigned = 0;
 683
 684         struct list_head reassign = LIST_HEAD_INIT(reassign);
 685         struct dhcpv6_assignment *c, *d;
 686         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 687                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 688                                 c->managed_size)
 689                         continue;
 690
 691                 if (c->length < 128 && c->assigned >= border->assigned && c != border)
 692                         list_move(&c->head, &reassign);
 693                 else if (c != border && (c->flags & OAF_BOUND))
 694                         apply_lease(iface, c, true);
 695
 696                 if (c->accept_reconf && c->reconf_cnt == 0) {
 697                         c->reconf_cnt = 1;
 698                         c->reconf_sent = now;
 699                         send_reconf(iface, c);
 700
 701                         /* Leave all other assignments of that client alone */
 702                         struct dhcpv6_assignment *a;
 703                         list_for_each_entry(a, &iface->ia_assignments, head)
 704                                 if (a != c && a->clid_len == c->clid_len &&
 705                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 706                                         c->reconf_cnt = INT_MAX;
 707                 }
 708         }
 709
 710         while (!list_empty(&reassign)) {
 711                 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
 712                 list_del(&c->head);
 713                 if (!assign_pd(iface, c)) {
 714                         c->assigned = 0;
 715                         list_add(&c->head, &iface->ia_assignments);
 716                 }
 717         }
 718
 719         dhcpv6_write_statefile();
 720 }
 721
 722 static void reconf_timer(struct uloop_timeout *event)
 723 {
 724         time_t now = odhcpd_time();
 725         struct interface *iface;
 726         list_for_each_entry(iface, &interfaces, head) {
 727                 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
 728                         continue;
 729
 730                 struct dhcpv6_assignment *a, *n;
 731                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 732                         if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
 733                                 if ((a->length < 128 && a->clid_len > 0) ||
 734                                                 (a->length == 128 && a->clid_len == 0))
 735                                         free_dhcpv6_assignment(a);
 736
 737                         } else if (a->reconf_cnt > 0 && a->reconf_cnt < 8 &&
 738                                         now > a->reconf_sent + (1 << a->reconf_cnt)) {
 739                                 ++a->reconf_cnt;
 740                                 a->reconf_sent = now;
 741                                 send_reconf(iface, a);
 742                         }
 743                 }
 744         }
 745         uloop_timeout_set(event, 2000);
 746 }
 747
 748 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
 749                 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
 750                 struct interface *iface, bool request)
 751 {
 752         if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
 753                 return 0;
 754
 755         struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
 756         size_t datalen = sizeof(out);
 757         time_t now = odhcpd_time();
 758
 759         if (status) {
 760                 struct __attribute__((packed)) {
 761                         uint16_t type;
 762                         uint16_t len;
 763                         uint16_t value;
 764                 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
 765                                 htons(status)};
 766
 767                 memcpy(buf + datalen, &stat, sizeof(stat));
 768                 datalen += sizeof(stat);
 769         } else {
 770                 if (a) {
 771                         uint32_t leasetime;
 772                         if (a->leasetime)
 773                                 leasetime = a->leasetime;
 774                         else
 775                                 leasetime = iface->dhcpv4_leasetime;
 776
 777                         uint32_t pref = leasetime;
 778                         uint32_t valid = leasetime;
 779
 780                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 781                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 782                         size_t m = get_preferred_addr(addrs, addrlen);
 783
 784                         for (size_t i = 0; i < addrlen; ++i) {
 785                                 uint32_t prefix_pref = addrs[i].preferred;
 786                                 uint32_t prefix_valid = addrs[i].valid;
 787
 788                                 if (!valid_addr(&addrs[i], now))
 789                                         continue;
 790
 791                                 if (prefix_pref != UINT32_MAX)
 792                                         prefix_pref -= now;
 793
 794                                 if (prefix_valid != UINT32_MAX)
 795                                         prefix_valid -= now;
 796
 797                                 if (a->length < 128) {
 798                                         struct dhcpv6_ia_prefix p = {
 799                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 800                                                 .len = htons(sizeof(p) - 4),
 801                                                 .preferred = htonl(prefix_pref),
 802                                                 .valid = htonl(prefix_valid),
 803                                                 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 804                                                 .addr = addrs[i].addr
 805                                         };
 806                                         p.addr.s6_addr32[1] |= htonl(a->assigned);
 807                                         p.addr.s6_addr32[2] = p.addr.s6_addr32[3] = 0;
 808
 809                                         size_t entrlen = sizeof(p) - 4;
 810
 811                                         if (datalen + entrlen + 4 > buflen ||
 812                                                         (a->assigned == 0 && a->managed_size == 0) ||
 813                                                         !valid_prefix_length(a, addrs[i].prefix))
 814                                                 continue;
 815
 816                                         memcpy(buf + datalen, &p, sizeof(p));
 817                                         datalen += entrlen + 4;
 818                                 } else {
 819                                         struct dhcpv6_ia_addr n = {
 820                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 821                                                 .len = htons(sizeof(n) - 4),
 822                                                 .addr = addrs[i].addr,
 823                                                 .preferred = htonl(prefix_pref),
 824                                                 .valid = htonl(prefix_valid)
 825                                         };
 826                                         n.addr.s6_addr32[3] = htonl(a->assigned);
 827                                         size_t entrlen = sizeof(n) - 4;
 828
 829                                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
 830                                                         a->assigned == 0 ||
 831                                                         datalen + entrlen + 4 > buflen)
 832                                                 continue;
 833
 834                                         memcpy(buf + datalen, &n, sizeof(n));
 835                                         datalen += entrlen + 4;
 836                                 }
 837
 838                                 /* Calculate T1 / T2 based on non-deprecated addresses */
 839                                 if (prefix_pref > 0) {
 840                                         if (prefix_pref < pref)
 841                                                 pref = prefix_pref;
 842
 843                                         if (prefix_valid < valid)
 844                                                 valid = prefix_valid;
 845                                 }
 846                         }
 847
 848                         if (!INFINITE_VALID(a->valid_until))
 849                                 /* UINT32_MAX is considered as infinite leasetime */
 850                                 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 851
 852                         out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 853                         out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 854
 855                         if (!out.t1)
 856                                 out.t1 = htonl(1);
 857
 858                         if (!out.t2)
 859                                 out.t2 = htonl(1);
 860                 }
 861
 862                 if (!request) {
 863                         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 864                         uint16_t otype, olen;
 865                         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 866                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
 867                                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
 868                                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
 869                                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
 870                                         continue;
 871
 872                                 bool found = false;
 873                                 if (a) {
 874                                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 875                                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 876
 877                                         for (size_t i = 0; i < addrlen; ++i) {
 878                                                 if (!valid_addr(&addrs[i], now))
 879                                                         continue;
 880
 881                                                 struct in6_addr addr = addrs[i].addr;
 882                                                 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 883                                                         addr.s6_addr32[1] |= htonl(a->assigned);
 884                                                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 885
 886                                                         if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
 887                                                                         p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 888                                                                 found = true;
 889                                                 } else {
 890                                                         addr.s6_addr32[3] = htonl(a->assigned);
 891
 892                                                         if (!memcmp(&n->addr, &addr, sizeof(addr)))
 893                                                                 found = true;
 894                                                 }
 895                                         }
 896                                 }
 897
 898                                 if (!found) {
 899                                         if (otype == DHCPV6_OPT_IA_PREFIX) {
 900                                                 struct dhcpv6_ia_prefix inv = {
 901                                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 902                                                         .len = htons(sizeof(inv) - 4),
 903                                                         .preferred = 0,
 904                                                         .valid = 0,
 905                                                         .prefix = p->prefix,
 906                                                         .addr = p->addr
 907                                                 };
 908
 909                                                 if (datalen + sizeof(inv) > buflen)
 910                                                         continue;
 911
 912                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 913                                                 datalen += sizeof(inv);
 914                                         } else {
 915                                                 struct dhcpv6_ia_addr inv = {
 916                                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 917                                                         .len = htons(sizeof(inv) - 4),
 918                                                         .addr = n->addr,
 919                                                         .preferred = 0,
 920                                                         .valid = 0
 921                                                 };
 922
 923                                                 if (datalen + sizeof(inv) > buflen)
 924                                                         continue;
 925
 926                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 927                                                 datalen += sizeof(inv);
 928                                         }
 929                                 }
 930                         }
 931                 }
 932         }
 933
 934         out.len = htons(datalen - 4);
 935         memcpy(buf, &out, sizeof(out));
 936         return datalen;
 937 }
 938
 939 struct log_ctxt {
 940         char *buf;
 941         int buf_len;
 942         int buf_idx;
 943 };
 944
 945 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 946                                 _unused uint32_t valid, void *arg)
 947 {
 948         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
 949         char addrbuf[INET6_ADDRSTRLEN];
 950
 951         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
 952         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
 953                                         "%s/%d ", addrbuf, prefix);
 954 }
 955
 956 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
 957                 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
 958 {
 959         const char *type = "UNKNOWN";
 960         const char *status = "UNKNOWN";
 961
 962         if (msgtype == DHCPV6_MSG_RENEW)
 963                 return;
 964
 965         switch (msgtype) {
 966         case DHCPV6_MSG_SOLICIT:
 967                 type = "SOLICIT";
 968                 break;
 969         case DHCPV6_MSG_REQUEST:
 970                 type = "REQUEST";
 971                 break;
 972         case DHCPV6_MSG_CONFIRM:
 973                 type = "CONFIRM";
 974                 break;
 975         case DHCPV6_MSG_RENEW:
 976                 type = "RENEW";
 977                 break;
 978         case DHCPV6_MSG_REBIND:
 979                 type = "REBIND";
 980                 break;
 981         case DHCPV6_MSG_RELEASE:
 982                 type = "RELEASE";
 983                 break;
 984         case DHCPV6_MSG_DECLINE:
 985                 type = "DECLINE";
 986                 break;
 987         }
 988
 989         switch (code) {
 990         case DHCPV6_STATUS_OK:
 991                 status = "ok";
 992                 break;
 993         case DHCPV6_STATUS_NOADDRSAVAIL:
 994                 status = "no addresses available";
 995                 break;
 996         case DHCPV6_STATUS_NOBINDING:
 997                 status = "no binding";
 998                 break;
 999         case DHCPV6_STATUS_NOTONLINK:
1000                 status = "not on-link";
1001                 break;
1002         case DHCPV6_STATUS_NOPREFIXAVAIL:
1003                 status = "no prefix available";
1004                 break;
1005         }
1006
1007         char leasebuf[256] = "";
1008
1009         if (a) {
1010                 struct log_ctxt ctxt = {.buf = leasebuf,
1011                                         .buf_len = sizeof(leasebuf),
1012                                         .buf_idx = 0 };
1013
1014                 dhcpv6_enum_ia_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1015         }
1016
1017         syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1018                         duidbuf, iface->ifname, status, leasebuf);
1019 }
1020
1021 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
1022                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1023 {
1024         time_t now = odhcpd_time();
1025         size_t response_len = 0;
1026         const struct dhcpv6_client_header *hdr = data;
1027         uint8_t *start = (uint8_t*)&hdr[1], *odata;
1028         uint16_t otype, olen;
1029         /* Find and parse client-id and hostname */
1030         bool accept_reconf = false;
1031         uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1032         char hostname[256];
1033         size_t hostname_len = 0;
1034         bool notonlink = false;
1035         char duidbuf[261];
1036
1037         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1038                 if (otype == DHCPV6_OPT_CLIENTID) {
1039                         clid_data = odata;
1040                         clid_len = olen;
1041
1042                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1043                                 memcpy(mac, &odata[8], sizeof(mac));
1044                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1045                                 memcpy(mac, &odata[4], sizeof(mac));
1046
1047                         if (olen <= 130)
1048                                 odhcpd_hexlify(duidbuf, odata, olen);
1049                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1050                         uint8_t fqdn_buf[256];
1051                         memcpy(fqdn_buf, odata, olen);
1052                         fqdn_buf[olen++] = 0;
1053
1054                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1055                                 hostname_len = strcspn(hostname, ".");
1056                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1057                         accept_reconf = true;
1058         }
1059
1060         if (!clid_data || !clid_len || clid_len > 130)
1061                 goto out;
1062
1063         struct dhcpv6_assignment *first = NULL;
1064         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1065                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1066                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1067                 bool ia_addr_present = false;
1068                 if (!is_pd && !is_na)
1069                         continue;
1070
1071                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1072                 size_t ia_response_len = 0;
1073                 uint8_t reqlen = (is_pd) ? 62 : 128;
1074                 uint32_t reqhint = 0;
1075
1076                 /* Parse request hint for IA-PD */
1077                 if (is_pd) {
1078                         uint8_t *sdata;
1079                         uint16_t stype, slen;
1080                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1081                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1082                                         continue;
1083
1084                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1085                                 if (p->prefix) {
1086                                         reqlen = p->prefix;
1087                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1088                                         if (reqlen > 32 && reqlen <= 64)
1089                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1090                                 }
1091                         }
1092
1093                         if (reqlen > 64)
1094                                 reqlen = 64;
1095                 } else if (is_na) {
1096                         uint8_t *sdata;
1097                         uint16_t stype, slen;
1098                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1099                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1100                                         continue;
1101
1102                                 ia_addr_present = true;
1103                         }
1104                 }
1105
1106                 /* Find assignment */
1107                 struct dhcpv6_assignment *c, *a = NULL;
1108                 list_for_each_entry(c, &iface->ia_assignments, head) {
1109                         if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1110                                         (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1111                                                 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1112                                         (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1113                                         ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1114                                 a = c;
1115
1116                                 /* Reset state */
1117                                 if (a->flags & OAF_BOUND)
1118                                         apply_lease(iface, a, false);
1119
1120                                 memcpy(a->clid_data, clid_data, clid_len);
1121                                 a->clid_len = clid_len;
1122                                 a->iaid = ia->iaid;
1123                                 a->peer = *addr;
1124                                 a->reconf_cnt = 0;
1125                                 a->reconf_sent = 0;
1126                                 break;
1127                         }
1128                 }
1129
1130                 /* Generic message handling */
1131                 uint16_t status = DHCPV6_STATUS_OK;
1132                 if (a && a->managed_size < 0)
1133                         return -1;
1134
1135                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1136                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1137                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1138                         bool assigned = !!a;
1139
1140                         if (!a && !iface->no_dynamic_dhcp) {
1141                                 /* Create new binding */
1142                                 a = calloc(1, sizeof(*a) + clid_len);
1143                                 if (a) {
1144                                         a->clid_len = clid_len;
1145                                         a->iaid = ia->iaid;
1146                                         a->length = reqlen;
1147                                         a->peer = *addr;
1148                                         a->assigned = reqhint;
1149                                         /* Set valid time to current time indicating  */
1150                                         /* assignment is not having infinite lifetime */
1151                                         a->valid_until = now;
1152
1153                                         if (first)
1154                                                 memcpy(a->key, first->key, sizeof(a->key));
1155                                         else
1156                                                 odhcpd_urandom(a->key, sizeof(a->key));
1157                                         memcpy(a->clid_data, clid_data, clid_len);
1158
1159                                         if (is_pd)
1160                                                 while (!(assigned = assign_pd(iface, a)) &&
1161                                                                 !a->managed_size && ++a->length <= 64);
1162                                         else
1163                                                 assigned = assign_na(iface, a);
1164
1165                                         if (a->managed_size && !assigned)
1166                                                 return -1;
1167                                 }
1168                         }
1169
1170                         if (!assigned || iface->ia_addr_len == 0)
1171                                 /* Set error status */
1172                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1173                         else if (assigned && !first && hdr->msg_type != DHCPV6_MSG_REBIND) {
1174                                 size_t handshake_len = 4;
1175                                 buf[0] = 0;
1176                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1177                                 buf[2] = 0;
1178                                 buf[3] = 0;
1179
1180                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1181                                         struct dhcpv6_auth_reconfigure auth = {
1182                                                 htons(DHCPV6_OPT_AUTH),
1183                                                 htons(sizeof(auth) - 4),
1184                                                 3, 1, 0,
1185                                                 {htonl(time(NULL)), htonl(++serial)},
1186                                                 1,
1187                                                 {0}
1188                                         };
1189                                         memcpy(auth.key, a->key, sizeof(a->key));
1190                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1191                                         handshake_len += sizeof(auth);
1192                                 }
1193
1194                                 buf += handshake_len;
1195                                 buflen -= handshake_len;
1196                                 response_len += handshake_len;
1197
1198                                 first = a;
1199                         }
1200
1201                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface,
1202                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1203
1204                         /* Was only a solicitation: mark binding for removal */
1205                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1206                                 a->flags &= ~OAF_BOUND;
1207
1208                                 if (!(a->flags & OAF_STATIC))
1209                                         a->valid_until = now;
1210                         } else if (assigned &&
1211                                         (hdr->msg_type == DHCPV6_MSG_REQUEST ||
1212                                          hdr->msg_type == DHCPV6_MSG_REBIND)) {
1213                                 if (hostname_len > 0) {
1214                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1215                                         if (a->hostname) {
1216                                                 memcpy(a->hostname, hostname, hostname_len);
1217                                                 a->hostname[hostname_len] = 0;
1218                                         }
1219                                 }
1220                                 a->accept_reconf = accept_reconf;
1221                                 a->flags |= OAF_BOUND;
1222                                 apply_lease(iface, a, true);
1223                         } else if (!assigned && a && a->managed_size == 0) {
1224                                 /* Cleanup failed assignment */
1225                                 free_dhcpv6_assignment(a);
1226                                 a = NULL;
1227                         }
1228                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1229                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1230                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1231                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1232                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1233                                 status = DHCPV6_STATUS_NOBINDING;
1234                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1235                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1236                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1237                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1238                                 if (a) {
1239                                         a->flags |= OAF_BOUND;
1240                                         apply_lease(iface, a, true);
1241                                 }
1242                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1243                                 if (!(a->flags & OAF_STATIC))
1244                                         a->valid_until = now - 1;
1245
1246                                 if (a->flags & OAF_BOUND) {
1247                                         apply_lease(iface, a, false);
1248                                         a->flags &= ~OAF_BOUND;
1249                                 }
1250                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1251                                 a->flags &= ~OAF_BOUND;
1252
1253                                 if (!(a->flags & OAF_STATIC)) {
1254                                         a->clid_len = 0;
1255                                         a->valid_until = now + 3600; /* Block address for 1h */
1256                                 }
1257                         }
1258                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1259                         /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1260                         status = DHCPV6_STATUS_NOTONLINK;
1261                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1262                         notonlink = true;
1263                 }
1264
1265                 buf += ia_response_len;
1266                 buflen -= ia_response_len;
1267                 response_len += ia_response_len;
1268                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1269         }
1270
1271         if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1272                         response_len + 6 < buflen) {
1273                 buf[0] = 0;
1274                 buf[1] = DHCPV6_OPT_STATUS;
1275                 buf[2] = 0;
1276                 buf[3] = 2;
1277                 buf[4] = 0;
1278                 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1279                 response_len += 6;
1280         }
1281
1282         dhcpv6_write_statefile();
1283
1284 out:
1285         return response_len;
1286 }