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 <libgen.h>
  32 #include <stdbool.h>
  33 #include <arpa/inet.h>
  34 #include <sys/timerfd.h>
  35
  36 #include <libubox/md5.h>
  37 #include <libubox/usock.h>
  38
  39 #define ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) \
  40     ((iface)->dhcpv6_assignall || (i) == (m) || \
  41      (addrs)[(i)].prefix > 64)
  42
  43 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info);
  44 static void apply_lease(struct dhcp_assignment *a, bool add);
  45 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b);
  46 static void handle_addrlist_change(struct netevent_handler_info *info);
  47 static void start_reconf(struct dhcp_assignment *a);
  48 static void stop_reconf(struct dhcp_assignment *a);
  49 static void valid_until_cb(struct uloop_timeout *event);
  50
  51 static struct netevent_handler dhcpv6_netevent_handler = { .cb = dhcpv6_netevent_cb, };
  52 static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb};
  53 static uint32_t serial = 0;
  54 static uint8_t statemd5[16];
  55
  56 int dhcpv6_ia_init(void)
  57 {
  58         uloop_timeout_set(&valid_until_timeout, 1000);
  59
  60         netlink_add_netevent_handler(&dhcpv6_netevent_handler);
  61
  62         return 0;
  63 }
  64
  65 int dhcpv6_ia_setup_interface(struct interface *iface, bool enable)
  66 {
  67         enable = enable && (iface->dhcpv6 == MODE_SERVER);
  68
  69         if (enable) {
  70                 struct dhcp_assignment *border;
  71
  72                 if (list_empty(&iface->ia_assignments)) {
  73                         border = alloc_assignment(0);
  74
  75                         if (!border) {
  76                                 syslog(LOG_WARNING, "Failed to alloc border on %s", iface->name);
  77                                 return -1;
  78                         }
  79
  80                         border->length = 64;
  81                         list_add(&border->head, &iface->ia_assignments);
  82                 } else
  83                         border = list_last_entry(&iface->ia_assignments, struct dhcp_assignment, head);
  84
  85                 set_border_assignment_size(iface, border);
  86         } else {
  87                 struct dhcp_assignment *c;
  88
  89                 while (!list_empty(&iface->ia_assignments)) {
  90                         c = list_first_entry(&iface->ia_assignments, struct dhcp_assignment, head);
  91                         free_assignment(c);
  92                 }
  93         }
  94
  95         return 0;
  96 }
  97
  98
  99 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info)
 100 {
 101         struct interface *iface = info->iface;
 102
 103         if (!iface || iface->dhcpv6 != MODE_SERVER)
 104                 return;
 105
 106         switch (event) {
 107         case NETEV_ADDR6LIST_CHANGE:
 108                 handle_addrlist_change(info);
 109                 break;
 110         default:
 111                 break;
 112         }
 113 }
 114
 115
 116 static inline bool valid_prefix_length(const struct dhcp_assignment *a, const uint8_t prefix_length)
 117 {
 118         return (a->managed_size || a->length > prefix_length);
 119 }
 120
 121 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 122 {
 123         return (addr->prefix <= 96 && addr->preferred_lt > (uint32_t)now);
 124 }
 125
 126 static size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
 127 {
 128         size_t i, m;
 129
 130         for (i = 0, m = 0; i < addrlen; ++i) {
 131                 if (addrs[i].preferred_lt > addrs[m].preferred_lt ||
 132                                 (addrs[i].preferred_lt == addrs[m].preferred_lt &&
 133                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 134                         m = i;
 135         }
 136
 137         return m;
 138 }
 139
 140 static int send_reconf(struct dhcp_assignment *assign)
 141 {
 142         struct {
 143                 struct dhcpv6_client_header hdr;
 144                 uint16_t srvid_type;
 145                 uint16_t srvid_len;
 146                 uint16_t duid_type;
 147                 uint16_t hardware_type;
 148                 uint8_t mac[6];
 149                 uint16_t msg_type;
 150                 uint16_t msg_len;
 151                 uint8_t msg_id;
 152                 struct dhcpv6_auth_reconfigure auth;
 153                 uint16_t clid_type;
 154                 uint16_t clid_len;
 155                 uint8_t clid_data[128];
 156         } __attribute__((packed)) reconf_msg = {
 157                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 158                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 159                 .srvid_len = htons(10),
 160                 .duid_type = htons(3),
 161                 .hardware_type = htons(1),
 162                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 163                 .msg_len = htons(1),
 164                 .msg_id = DHCPV6_MSG_RENEW,
 165                 .auth = {htons(DHCPV6_OPT_AUTH),
 166                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 167                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 168                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 169                 .clid_len = htons(assign->clid_len),
 170                 .clid_data = {0},
 171         };
 172         struct interface *iface = assign->iface;
 173
 174         odhcpd_get_mac(iface, reconf_msg.mac);
 175         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 176         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 177
 178         md5_ctx_t md5;
 179         uint8_t secretbytes[64];
 180         memset(secretbytes, 0, sizeof(secretbytes));
 181         memcpy(secretbytes, assign->key, sizeof(assign->key));
 182
 183         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 184                 secretbytes[i] ^= 0x36;
 185
 186         md5_begin(&md5);
 187         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 188         md5_hash(iov.iov_base, iov.iov_len, &md5);
 189         md5_end(reconf_msg.auth.key, &md5);
 190
 191         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 192                 secretbytes[i] ^= 0x36;
 193                 secretbytes[i] ^= 0x5c;
 194         }
 195
 196         md5_begin(&md5);
 197         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 198         md5_hash(reconf_msg.auth.key, 16, &md5);
 199         md5_end(reconf_msg.auth.key, &md5);
 200
 201         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 202 }
 203
 204 static void dhcpv6_ia_free_assignment(struct dhcp_assignment *a)
 205 {
 206         if (a->managed_sock.fd.registered) {
 207                 ustream_free(&a->managed_sock.stream);
 208                 close(a->managed_sock.fd.fd);
 209         }
 210
 211         if ((a->flags & OAF_BOUND) && (a->flags & OAF_DHCPV6_PD))
 212                 apply_lease(a, false);
 213
 214         if (a->reconf_cnt)
 215                 stop_reconf(a);
 216
 217         free(a->managed);
 218 }
 219
 220 void dhcpv6_ia_enum_addrs(struct interface *iface, struct dhcp_assignment *c,
 221                           time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
 222 {
 223         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->addr6;
 224         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->addr6_len;
 225         size_t m = get_preferred_addr(addrs, addrlen);
 226
 227         for (size_t i = 0; i < addrlen; ++i) {
 228                 struct in6_addr addr;
 229                 uint32_t preferred_lt, valid_lt;
 230                 int prefix = c->managed ? addrs[i].prefix : c->length;
 231
 232                 if (!valid_addr(&addrs[i], now))
 233                         continue;
 234
 235                 /* Filter Out Prefixes */
 236                 if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface)) {
 237                         char addrbuf[INET6_ADDRSTRLEN];
 238                         syslog(LOG_INFO, "Address %s filtered out on %s",
 239                                 inet_ntop(AF_INET6, &addrs[i].addr.in6, addrbuf, sizeof(addrbuf)),
 240                                 iface->name);
 241                         continue;
 242                 }
 243
 244                 addr = addrs[i].addr.in6;
 245                 preferred_lt = addrs[i].preferred_lt;
 246                 valid_lt = addrs[i].valid_lt;
 247
 248                 if (c->flags & OAF_DHCPV6_NA) {
 249                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 250                                 continue;
 251
 252                         addr.s6_addr32[2] = htonl(c->assigned_host_id >> 32);
 253                         addr.s6_addr32[3] = htonl(c->assigned_host_id & UINT32_MAX);
 254                 } else {
 255                         if (!valid_prefix_length(c, addrs[i].prefix))
 256                                 continue;
 257
 258                         addr.s6_addr32[1] |= htonl(c->assigned_subnet_id);
 259                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 260                 }
 261
 262                 if (preferred_lt > (uint32_t)c->preferred_until)
 263                         preferred_lt = c->preferred_until;
 264
 265                 if (preferred_lt > (uint32_t)c->valid_until)
 266                         preferred_lt = c->valid_until;
 267
 268                 if (preferred_lt != UINT32_MAX)
 269                         preferred_lt -= now;
 270
 271                 if (valid_lt > (uint32_t)c->valid_until)
 272                         valid_lt = c->valid_until;
 273
 274                 if (valid_lt != UINT32_MAX)
 275                         valid_lt -= now;
 276
 277                 func(&addr, prefix, preferred_lt, valid_lt, arg);
 278         }
 279 }
 280
 281 struct write_ctxt {
 282         FILE *fp;
 283         md5_ctx_t md5;
 284         struct dhcp_assignment *c;
 285         struct interface *iface;
 286         char *buf;
 287         int buf_len;
 288         int buf_idx;
 289 };
 290
 291 static void dhcpv6_write_ia_addrhosts(struct in6_addr *addr, int prefix, _unused uint32_t pref_lt,
 292                                 _unused uint32_t valid_lt, void *arg)
 293 {
 294         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
 295         char ipbuf[INET6_ADDRSTRLEN];
 296
 297         if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
 298             !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
 299                 inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 300                 fputs(ipbuf, ctxt->fp);
 301
 302                 char b[256];
 303                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
 304                                 ctxt->iface->search, b, sizeof(b)) > 0)
 305                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
 306
 307                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
 308         }
 309 }
 310
 311 static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref_lt,
 312                                 _unused uint32_t valid_lt, void *arg)
 313 {
 314         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
 315         char ipbuf[INET6_ADDRSTRLEN];
 316
 317         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 318
 319         if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
 320             !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
 321                 fputs(ipbuf, ctxt->fp);
 322
 323                 char b[256];
 324                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
 325                                 ctxt->iface->search, b, sizeof(b)) > 0)
 326                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
 327
 328                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
 329                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
 330                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
 331         }
 332
 333         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
 334                                         "%s/%d ", ipbuf, prefix);
 335 }
 336
 337 static void dhcpv6_ia_write_hostsfile(time_t now)
 338 {
 339         struct write_ctxt ctxt;
 340
 341         unsigned hostsfile_strlen = strlen(config.dhcp_hostsfile) + 1;
 342         unsigned tmp_hostsfile_strlen = hostsfile_strlen + 1; /* space for . */
 343         char *tmp_hostsfile = alloca(tmp_hostsfile_strlen);
 344
 345         char *dir_hostsfile;
 346         char *base_hostsfile;
 347         char *pdir_hostsfile;
 348         char *pbase_hostsfile;
 349
 350         int fd, ret;
 351
 352         dir_hostsfile = strndup(config.dhcp_hostsfile, hostsfile_strlen);
 353         base_hostsfile = strndup(config.dhcp_hostsfile, hostsfile_strlen);
 354
 355         pdir_hostsfile = dirname(dir_hostsfile);
 356         pbase_hostsfile = basename(base_hostsfile);
 357
 358         snprintf(tmp_hostsfile, tmp_hostsfile_strlen, "%s/.%s", pdir_hostsfile, pbase_hostsfile);
 359
 360         free(dir_hostsfile);
 361         free(base_hostsfile);
 362
 363         fd = open(tmp_hostsfile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 364         if (fd < 0)
 365                 return;
 366
 367         ret = lockf(fd, F_LOCK, 0);
 368         if (ret < 0) {
 369                 close(fd);
 370                 return;
 371         }
 372
 373         if (ftruncate(fd, 0) < 0) {}
 374
 375         ctxt.fp = fdopen(fd, "w");
 376         if (!ctxt.fp) {
 377                 close(fd);
 378                 return;
 379         }
 380
 381         avl_for_each_element(&interfaces, ctxt.iface, avl) {
 382                 if (ctxt.iface->dhcpv6 != MODE_SERVER &&
 383                                 ctxt.iface->dhcpv4 != MODE_SERVER)
 384                         continue;
 385
 386                 if (ctxt.iface->dhcpv6 == MODE_SERVER) {
 387                         list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 388                                 if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 389                                         continue;
 390
 391                                 if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
 392                                         dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
 393                                                                 dhcpv6_write_ia_addrhosts, &ctxt);
 394                         }
 395                 }
 396
 397                 if (ctxt.iface->dhcpv4 == MODE_SERVER) {
 398                         struct dhcp_assignment *c;
 399
 400                         list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 401                                 if (!(c->flags & OAF_BOUND))
 402                                         continue;
 403
 404                                 char ipbuf[INET6_ADDRSTRLEN];
 405                                 struct in_addr addr = {.s_addr = c->addr};
 406                                 inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 407
 408                                 if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
 409                                         fputs(ipbuf, ctxt.fp);
 410
 411                                         char b[256];
 412
 413                                         if (dn_expand(ctxt.iface->search,
 414                                                         ctxt.iface->search + ctxt.iface->search_len,
 415                                                         ctxt.iface->search, b, sizeof(b)) > 0)
 416                                                 fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
 417
 418                                         fprintf(ctxt.fp, "\t%s\n", c->hostname);
 419                                 }
 420                         }
 421                 }
 422         }
 423
 424         fclose(ctxt.fp);
 425
 426         rename(tmp_hostsfile, config.dhcp_hostsfile);
 427 }
 428
 429 void dhcpv6_ia_write_statefile(void)
 430 {
 431         struct write_ctxt ctxt;
 432
 433         md5_begin(&ctxt.md5);
 434
 435         if (config.dhcp_statefile) {
 436                 unsigned statefile_strlen = strlen(config.dhcp_statefile) + 1;
 437                 unsigned tmp_statefile_strlen = statefile_strlen + 1; /* space for . */
 438                 char *tmp_statefile = alloca(tmp_statefile_strlen);
 439
 440                 char *dir_statefile;
 441                 char *base_statefile;
 442                 char *pdir_statefile;
 443                 char *pbase_statefile;
 444
 445                 time_t now = odhcpd_time(), wall_time = time(NULL);
 446                 int fd, ret;
 447                 char leasebuf[512];
 448
 449                 dir_statefile = strndup(config.dhcp_statefile, statefile_strlen);
 450                 base_statefile = strndup(config.dhcp_statefile, statefile_strlen);
 451
 452                 pdir_statefile = dirname(dir_statefile);
 453                 pbase_statefile = basename(base_statefile);
 454
 455                 snprintf(tmp_statefile, tmp_statefile_strlen, "%s/.%s", pdir_statefile, pbase_statefile);
 456
 457                 free(dir_statefile);
 458                 free(base_statefile);
 459
 460                 fd = open(tmp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 461                 if (fd < 0)
 462                         return;
 463
 464                 ret = lockf(fd, F_LOCK, 0);
 465                 if (ret < 0) {
 466                         close(fd);
 467                         return;
 468                 }
 469
 470                 if (ftruncate(fd, 0) < 0) {}
 471
 472                 ctxt.fp = fdopen(fd, "w");
 473                 if (!ctxt.fp) {
 474                         close(fd);
 475                         return;
 476                 }
 477
 478                 ctxt.buf = leasebuf;
 479                 ctxt.buf_len = sizeof(leasebuf);
 480
 481                 avl_for_each_element(&interfaces, ctxt.iface, avl) {
 482                         if (ctxt.iface->dhcpv6 != MODE_SERVER &&
 483                                         ctxt.iface->dhcpv4 != MODE_SERVER)
 484                                 continue;
 485
 486                         if (ctxt.iface->dhcpv6 == MODE_SERVER) {
 487                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 488                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 489                                                 continue;
 490
 491                                         char duidbuf[264];
 492
 493                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
 494
 495                                         /* iface DUID iaid hostname lifetime assigned_host_id length [addrs...] */
 496                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s%s %"PRId64" ",
 497                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
 498                                                                 (ctxt.c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 499                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
 500                                                                 (ctxt.c->valid_until > now ?
 501                                                                         (int64_t)(ctxt.c->valid_until - now + wall_time) :
 502                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)));
 503
 504                                         if (ctxt.c->flags & OAF_DHCPV6_NA)
 505                                                 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx, ctxt.buf_len - ctxt.buf_idx,
 506                                                                          "%" PRIx64" %u ", ctxt.c->assigned_host_id, (unsigned)ctxt.c->length);
 507                                         else
 508                                                 ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx, ctxt.buf_len - ctxt.buf_idx,
 509                                                                          "%" PRIx32" %u ", ctxt.c->assigned_subnet_id, (unsigned)ctxt.c->length);
 510
 511                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
 512                                                 dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
 513                                                                         dhcpv6_write_ia_addr, &ctxt);
 514
 515                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 516                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 517                                 }
 518                         }
 519
 520                         if (ctxt.iface->dhcpv4 == MODE_SERVER) {
 521                                 struct dhcp_assignment *c;
 522
 523                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 524                                         if (!(c->flags & OAF_BOUND))
 525                                                 continue;
 526
 527                                         char ipbuf[INET6_ADDRSTRLEN];
 528                                         char duidbuf[16];
 529                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 530
 531                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 532                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s%s %"PRId64" %x 32 ",
 533                                                                 ctxt.iface->ifname, duidbuf,
 534                                                                 (c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 535                                                                 (c->hostname ? c->hostname : "-"),
 536                                                                 (c->valid_until > now ?
 537                                                                         (int64_t)(c->valid_until - now + wall_time) :
 538                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 539                                                                 ntohl(c->addr));
 540
 541                                         struct in_addr addr = {.s_addr = c->addr};
 542                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 543
 544                                         if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
 545                                                 fputs(ipbuf, ctxt.fp);
 546
 547                                                 char b[256];
 548                                                 if (dn_expand(ctxt.iface->search,
 549                                                                 ctxt.iface->search + ctxt.iface->search_len,
 550                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
 551                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
 552
 553                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
 554                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
 555                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
 556                                         }
 557
 558                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
 559                                                                         ctxt.buf_len - ctxt.buf_idx,
 560                                                                         "%s/32 ", ipbuf);
 561                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 562                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 563                                 }
 564                         }
 565                 }
 566
 567                 fclose(ctxt.fp);
 568
 569                 uint8_t newmd5[16];
 570                 md5_end(newmd5, &ctxt.md5);
 571
 572                 rename(tmp_statefile, config.dhcp_statefile);
 573
 574                 if (memcmp(newmd5, statemd5, sizeof(newmd5))) {
 575                         memcpy(statemd5, newmd5, sizeof(statemd5));
 576
 577                         if (config.dhcp_hostsfile)
 578                                 dhcpv6_ia_write_hostsfile(now);
 579
 580                         if (config.dhcp_cb) {
 581                                 char *argv[2] = {config.dhcp_cb, NULL};
 582                                 if (!vfork()) {
 583                                         execv(argv[0], argv);
 584                                         _exit(128);
 585                                 }
 586                         }
 587                 }
 588         }
 589 }
 590
 591 static void __apply_lease(struct dhcp_assignment *a,
 592                 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
 593 {
 594         if (a->flags & OAF_DHCPV6_NA)
 595                 return;
 596
 597         for (ssize_t i = 0; i < addr_len; ++i) {
 598                 struct in6_addr prefix;
 599
 600                 if (ADDR_MATCH_PIO_FILTER(&addrs[i], a->iface))
 601                         continue;
 602
 603                 prefix = addrs[i].addr.in6;
 604                 prefix.s6_addr32[1] |= htonl(a->assigned_subnet_id);
 605                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
 606                 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 607                                 a->iface->ifindex, &a->peer.sin6_addr, 1024, add);
 608         }
 609 }
 610
 611 static void apply_lease(struct dhcp_assignment *a, bool add)
 612 {
 613         struct interface *iface = a->iface;
 614         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 615         ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
 616
 617         __apply_lease(a, addrs, addrlen, add);
 618 }
 619
 620 /* Set border assignment size based on the IPv6 address prefixes */
 621 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b)
 622 {
 623         time_t now = odhcpd_time();
 624         int minprefix = -1;
 625
 626         for (size_t i = 0; i < iface->addr6_len; ++i) {
 627                 struct odhcpd_ipaddr *addr = &iface->addr6[i];
 628
 629                 if (ADDR_MATCH_PIO_FILTER(addr, iface))
 630                         continue;
 631
 632                 if (addr->preferred_lt > (uint32_t)now &&
 633                     addr->prefix < 64 &&
 634                     addr->prefix > minprefix)
 635                         minprefix = addr->prefix;
 636         }
 637
 638         if (minprefix > 32 && minprefix <= 64)
 639                 b->assigned_subnet_id = 1U << (64 - minprefix);
 640         else
 641                 b->assigned_subnet_id = 0;
 642 }
 643
 644 /* More data was received from TCP connection */
 645 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 646 {
 647         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 648         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
 649         time_t now = odhcpd_time();
 650         bool first = c->managed_size < 0;
 651
 652         for (;;) {
 653                 int pending;
 654                 char *data = ustream_get_read_buf(s, &pending);
 655                 char *end = memmem(data, pending, "\n\n", 2);
 656
 657                 if (!end)
 658                         break;
 659
 660                 end += 2;
 661                 end[-1] = 0;
 662
 663                 c->managed_size = 0;
 664                 if (c->accept_reconf)
 665                         c->reconf_cnt = 1;
 666
 667                 char *saveptr;
 668                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 669                         struct odhcpd_ipaddr *n;
 670                         char *saveptr2, *x;
 671
 672                         n = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 673                         if (!n)
 674                                 continue;
 675                         c->managed = n;
 676                         n = &c->managed[c->managed_size];
 677
 678                         x = strtok_r(line, ",", &saveptr2);
 679                         if (odhcpd_parse_addr6_prefix(x, &n->addr.in6, &n->prefix))
 680                                 continue;
 681
 682                         x = strtok_r(NULL, ",", &saveptr2);
 683                         if (sscanf(x, "%u", &n->preferred_lt) < 1)
 684                                 continue;
 685
 686                         x = strtok_r(NULL, ",", &saveptr2);
 687                         if (sscanf(x, "%u", &n->valid_lt) < 1)
 688                                 continue;
 689
 690                         if (n->preferred_lt > n->valid_lt)
 691                                 continue;
 692
 693                         if (UINT32_MAX - now < n->preferred_lt)
 694                                 n->preferred_lt = UINT32_MAX;
 695                         else
 696                                 n->preferred_lt += now;
 697
 698                         if (UINT32_MAX - now < n->valid_lt)
 699                                 n->valid_lt = UINT32_MAX;
 700                         else
 701                                 n->valid_lt += now;
 702
 703                         n->dprefix = 0;
 704
 705                         ++c->managed_size;
 706                 }
 707
 708                 ustream_consume(s, end - data);
 709         }
 710
 711         if (first && c->managed_size == 0)
 712                 free_assignment(c);
 713         else if (first)
 714                 c->valid_until = now + 150;
 715 }
 716
 717
 718 /* TCP transmission has ended, either because of success or timeout or other error */
 719 static void managed_handle_pd_done(struct ustream *s)
 720 {
 721         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 722         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
 723
 724         c->valid_until = odhcpd_time() + 15;
 725
 726         c->managed_size = 0;
 727
 728         if (c->accept_reconf)
 729                 c->reconf_cnt = 1;
 730 }
 731
 732 static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
 733 {
 734         struct dhcp_assignment *c;
 735
 736         if (iface->dhcpv6_pd_manager[0]) {
 737                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 738                 if (fd >= 0) {
 739                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 740                         char iaidbuf[298];
 741
 742                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 743
 744                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 745                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 746                         ustream_fd_init(&assign->managed_sock, fd);
 747                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 748                                         iaidbuf, assign->iaid, assign->length);
 749                         ustream_write_pending(&assign->managed_sock.stream);
 750                         assign->managed_size = -1;
 751
 752                         assign->valid_until = odhcpd_time() + 15;
 753
 754                         list_add(&assign->head, &iface->ia_assignments);
 755
 756                         /* Wait initial period of up to 250ms for immediate assignment */
 757                         if (poll(&pfd, 1, 250) < 0) {
 758                                 syslog(LOG_ERR, "poll(): %m");
 759                                 return false;
 760                         }
 761
 762                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 763
 764                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 765                                 return true;
 766                 }
 767
 768                 return false;
 769         } else if (iface->addr6_len < 1)
 770                 return false;
 771
 772         /* Try honoring the hint first */
 773         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 774         if (assign->assigned_subnet_id) {
 775                 list_for_each_entry(c, &iface->ia_assignments, head) {
 776                         if (c->flags & OAF_DHCPV6_NA)
 777                                 continue;
 778
 779                         if (assign->assigned_subnet_id >= current && assign->assigned_subnet_id + asize < c->assigned_subnet_id) {
 780                                 list_add_tail(&assign->head, &c->head);
 781
 782                                 if (assign->flags & OAF_BOUND)
 783                                         apply_lease(assign, true);
 784
 785                                 return true;
 786                         }
 787
 788                         current = (c->assigned_subnet_id + (1 << (64 - c->length)));
 789                 }
 790         }
 791
 792         /* Fallback to a variable assignment */
 793         current = 1;
 794         list_for_each_entry(c, &iface->ia_assignments, head) {
 795                 if (c->flags & OAF_DHCPV6_NA)
 796                         continue;
 797
 798                 current = (current + asize) & (~asize);
 799
 800                 if (current + asize < c->assigned_subnet_id) {
 801                         assign->assigned_subnet_id = current;
 802                         list_add_tail(&assign->head, &c->head);
 803
 804                         if (assign->flags & OAF_BOUND)
 805                                 apply_lease(assign, true);
 806
 807                         return true;
 808                 }
 809
 810                 current = (c->assigned_subnet_id + (1 << (64 - c->length)));
 811         }
 812
 813         return false;
 814 }
 815
 816 /* Check iid against reserved IPv6 interface identifiers.
 817    Refer to:
 818      http://www.iana.org/assignments/ipv6-interface-ids */
 819 static bool is_reserved_ipv6_iid(uint64_t iid)
 820 {
 821         if (iid == 0x0000000000000000)
 822                 /* Subnet-Router Anycast [RFC4291] */
 823                 return true;
 824
 825         if ((iid & 0xFFFFFFFFFF000000) == 0x02005EFFFE000000)
 826                 /* Reserved IPv6 Interface Identifiers corresponding
 827                    to the IANA Ethernet Block [RFC4291] */
 828                 return true;
 829
 830         if ((iid & 0xFFFFFFFFFFFFFF80) == 0xFDFFFFFFFFFFFF80)
 831                 /* Reserved Subnet Anycast Addresses [RFC2526] */
 832                 return true;
 833
 834         return false;
 835 }
 836
 837 static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
 838 {
 839         struct dhcp_assignment *c;
 840         uint32_t seed = 0;
 841
 842         /* Preconfigured assignment by static lease */
 843         if (a->assigned_host_id) {
 844                 list_for_each_entry(c, &iface->ia_assignments, head) {
 845                         if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > a->assigned_host_id ) {
 846                                 list_add_tail(&a->head, &c->head);
 847                                 return true;
 848                         } else if (c->assigned_host_id == a->assigned_host_id)
 849                                 return false;
 850                 }
 851         }
 852
 853         /* Seed RNG with checksum of DUID */
 854         for (size_t i = 0; i < a->clid_len; ++i)
 855                 seed += a->clid_data[i];
 856         srandom(seed);
 857
 858         /* Try to assign up to 100x */
 859         for (size_t i = 0; i < 100; ++i) {
 860                 uint64_t try;
 861
 862                 if (iface->dhcpv6_hostid_len > 32) {
 863                         uint32_t mask_high;
 864
 865                         if (iface->dhcpv6_hostid_len >= 64)
 866                                 mask_high = UINT32_MAX;
 867                         else
 868                                 mask_high = (1 << (iface->dhcpv6_hostid_len - 32)) - 1;
 869
 870                         do {
 871                                 try = (uint32_t)random();
 872                                 try |= (uint64_t)((uint32_t)random() & mask_high) << 32;
 873                         } while (try < 0x100);
 874                 } else {
 875                         uint32_t mask_low;
 876
 877                         if (iface->dhcpv6_hostid_len == 32)
 878                                 mask_low = UINT32_MAX;
 879                         else
 880                                 mask_low = (1 << iface->dhcpv6_hostid_len) - 1;
 881                         do try = ((uint32_t)random()) & mask_low; while (try < 0x100);
 882                 }
 883
 884                 if (is_reserved_ipv6_iid(try))
 885                         continue;
 886
 887                 if (config_find_lease_by_hostid(try))
 888                         continue;
 889
 890                 list_for_each_entry(c, &iface->ia_assignments, head) {
 891                         if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > try) {
 892                                 a->assigned_host_id = try;
 893                                 list_add_tail(&a->head, &c->head);
 894                                 return true;
 895                         } else if (c->assigned_host_id == try)
 896                                 break;
 897                 }
 898         }
 899
 900         return false;
 901 }
 902
 903 static void handle_addrlist_change(struct netevent_handler_info *info)
 904 {
 905         struct interface *iface = info->iface;
 906         struct dhcp_assignment *c, *d, *border = list_last_entry(
 907                         &iface->ia_assignments, struct dhcp_assignment, head);
 908         struct list_head reassign = LIST_HEAD_INIT(reassign);
 909         time_t now = odhcpd_time();
 910
 911         list_for_each_entry(c, &iface->ia_assignments, head) {
 912                 if ((c->flags & OAF_DHCPV6_PD) && !(iface->ra_flags & ND_RA_FLAG_MANAGED)
 913                                 && (c->flags & OAF_BOUND))
 914                         __apply_lease(c, info->addrs_old.addrs,
 915                                         info->addrs_old.len, false);
 916         }
 917
 918         set_border_assignment_size(iface, border);
 919
 920         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 921                 if (c->clid_len == 0 ||
 922                     !(c->flags & OAF_DHCPV6_PD) ||
 923                     (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 924                     c->managed_size)
 925                         continue;
 926
 927                 if (c->assigned_subnet_id >= border->assigned_subnet_id)
 928                         list_move(&c->head, &reassign);
 929                 else if (c->flags & OAF_BOUND)
 930                         apply_lease(c, true);
 931
 932                 if (c->accept_reconf && c->reconf_cnt == 0) {
 933                         struct dhcp_assignment *a;
 934
 935                         start_reconf(c);
 936
 937                         /* Leave all other assignments of that client alone */
 938                         list_for_each_entry(a, &iface->ia_assignments, head)
 939                                 if (a != c && a->clid_len == c->clid_len &&
 940                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 941                                         a->reconf_cnt = INT_MAX;
 942                 }
 943         }
 944
 945         while (!list_empty(&reassign)) {
 946                 c = list_first_entry(&reassign, struct dhcp_assignment, head);
 947                 list_del_init(&c->head);
 948                 if (!assign_pd(iface, c))
 949                         free_assignment(c);
 950         }
 951
 952         dhcpv6_ia_write_statefile();
 953 }
 954
 955 static void reconf_timeout_cb(struct uloop_timeout *event)
 956 {
 957         struct dhcp_assignment *a = container_of(event, struct dhcp_assignment, reconf_timer);
 958
 959         if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
 960                 send_reconf(a);
 961                 uloop_timeout_set(&a->reconf_timer,
 962                                         DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 963                 a->reconf_cnt++;
 964         } else
 965                 stop_reconf(a);
 966 }
 967
 968 static void start_reconf(struct dhcp_assignment *a)
 969 {
 970         uloop_timeout_set(&a->reconf_timer,
 971                                 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 972         a->reconf_timer.cb = reconf_timeout_cb;
 973         a->reconf_cnt++;
 974
 975         send_reconf(a);
 976 }
 977
 978 static void stop_reconf(struct dhcp_assignment *a)
 979 {
 980         uloop_timeout_cancel(&a->reconf_timer);
 981         a->reconf_cnt = 0;
 982         a->reconf_timer.cb = NULL;
 983 }
 984
 985 static void valid_until_cb(struct uloop_timeout *event)
 986 {
 987         struct interface *iface;
 988         time_t now = odhcpd_time();
 989
 990         avl_for_each_element(&interfaces, iface, avl) {
 991                 struct dhcp_assignment *a, *n;
 992
 993                 if (iface->dhcpv6 != MODE_SERVER)
 994                         continue;
 995
 996                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 997                         if (a->clid_len > 0 && !INFINITE_VALID(a->valid_until) && a->valid_until < now)
 998                                 free_assignment(a);
 999                 }
1000         }
1001         uloop_timeout_set(event, 1000);
1002 }
1003
1004 static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
1005                 const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1006                 struct interface *iface, bool request)
1007 {
1008         struct dhcpv6_ia_hdr o_ia = {
1009                 .type = ia->type,
1010                 .len = 0,
1011                 .iaid = ia->iaid,
1012                 .t1 = 0,
1013                 .t2 = 0,
1014         };
1015         size_t ia_len = sizeof(o_ia);
1016         time_t now = odhcpd_time();
1017
1018         if (buflen < ia_len)
1019                 return 0;
1020
1021         if (status) {
1022                 struct __attribute__((packed)) {
1023                         uint16_t type;
1024                         uint16_t len;
1025                         uint16_t val;
1026                 } o_status = {
1027                         .type = htons(DHCPV6_OPT_STATUS),
1028                         .len = htons(sizeof(o_status) - 4),
1029                         .val = htons(status),
1030                 };
1031
1032                 memcpy(buf + ia_len, &o_status, sizeof(o_status));
1033                 ia_len += sizeof(o_status);
1034
1035                 o_ia.len = htons(ia_len - 4);
1036                 memcpy(buf, &o_ia, sizeof(o_ia));
1037
1038                 return ia_len;
1039         }
1040
1041         if (a) {
1042                 uint32_t leasetime, preferred_lt;
1043
1044                 if (a->leasetime) {
1045                         leasetime = a->leasetime;
1046                         preferred_lt = a->leasetime;
1047                 } else {
1048                         leasetime = iface->dhcp_leasetime;
1049                         preferred_lt = iface->preferred_lifetime;
1050                 }
1051
1052                 uint32_t valid_lt = leasetime;
1053
1054                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
1055                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1056                 size_t m = get_preferred_addr(addrs, addrlen);
1057
1058                 for (size_t i = 0; i < addrlen; ++i) {
1059                         uint32_t prefix_preferred_lt, prefix_valid_lt;
1060
1061                         if (!valid_addr(&addrs[i], now))
1062                                 continue;
1063
1064                         /* Filter Out Prefixes */
1065                         if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface)) {
1066                                 char addrbuf[INET6_ADDRSTRLEN];
1067                                 syslog(LOG_INFO, "Address %s filtered out on %s",
1068                                         inet_ntop(AF_INET6, &addrs[i].addr.in6, addrbuf, sizeof(addrbuf)),
1069                                         iface->name);
1070                                 continue;
1071                         }
1072
1073                         prefix_preferred_lt = addrs[i].preferred_lt;
1074                         prefix_valid_lt = addrs[i].valid_lt;
1075
1076                         if (prefix_preferred_lt != UINT32_MAX)
1077                                 prefix_preferred_lt -= now;
1078
1079                         if (prefix_preferred_lt > preferred_lt)
1080                                 prefix_preferred_lt = preferred_lt;
1081
1082                         if (prefix_valid_lt != UINT32_MAX)
1083                                 prefix_valid_lt -= now;
1084
1085                         if (prefix_valid_lt > leasetime)
1086                                 prefix_valid_lt = leasetime;
1087
1088                         if (prefix_preferred_lt > prefix_valid_lt)
1089                                 prefix_preferred_lt = prefix_valid_lt;
1090
1091                         if (a->flags & OAF_DHCPV6_PD) {
1092                                 struct dhcpv6_ia_prefix o_ia_p = {
1093                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
1094                                         .len = htons(sizeof(o_ia_p) - 4),
1095                                         .preferred_lt = htonl(prefix_preferred_lt),
1096                                         .valid_lt = htonl(prefix_valid_lt),
1097                                         .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
1098                                         .addr = addrs[i].addr.in6,
1099                                 };
1100
1101                                 o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned_subnet_id);
1102                                 o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0;
1103
1104                                 if (!valid_prefix_length(a, addrs[i].prefix))
1105                                         continue;
1106
1107                                 if (buflen < ia_len + sizeof(o_ia_p))
1108                                         return 0;
1109
1110                                 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
1111                                 ia_len += sizeof(o_ia_p);
1112                         }
1113
1114                         if (a->flags & OAF_DHCPV6_NA) {
1115                                 struct dhcpv6_ia_addr o_ia_a = {
1116                                         .type = htons(DHCPV6_OPT_IA_ADDR),
1117                                         .len = htons(sizeof(o_ia_a) - 4),
1118                                         .addr = addrs[i].addr.in6,
1119                                         .preferred_lt = htonl(prefix_preferred_lt),
1120                                         .valid_lt = htonl(prefix_valid_lt)
1121                                 };
1122
1123                                 o_ia_a.addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
1124                                 o_ia_a.addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
1125
1126                                 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
1127                                         continue;
1128
1129                                 if (buflen < ia_len + sizeof(o_ia_a))
1130                                         return 0;
1131
1132                                 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
1133                                 ia_len += sizeof(o_ia_a);
1134                         }
1135
1136                         /* Calculate T1 / T2 based on non-deprecated addresses */
1137                         if (prefix_preferred_lt > 0) {
1138                                 if (prefix_preferred_lt < preferred_lt)
1139                                         preferred_lt = prefix_preferred_lt;
1140
1141                                 if (prefix_valid_lt < valid_lt)
1142                                         valid_lt = prefix_valid_lt;
1143                         }
1144                 }
1145
1146                 if (!INFINITE_VALID(a->valid_until))
1147                         /* UINT32_MAX is RFC defined as infinite lease-time */
1148                         a->valid_until = (valid_lt == UINT32_MAX) ? 0 : valid_lt + now;
1149
1150                 if (!INFINITE_VALID(a->preferred_until))
1151                         /* UINT32_MAX is RFC defined as infinite lease-time */
1152                         a->preferred_until = (preferred_lt == UINT32_MAX) ? 0 : preferred_lt + now;
1153
1154                 o_ia.t1 = htonl((preferred_lt == UINT32_MAX) ? preferred_lt : preferred_lt * 5 / 10);
1155                 o_ia.t2 = htonl((preferred_lt == UINT32_MAX) ? preferred_lt : preferred_lt * 8 / 10);
1156
1157                 if (!o_ia.t1)
1158                         o_ia.t1 = htonl(1);
1159
1160                 if (!o_ia.t2)
1161                         o_ia.t2 = htonl(1);
1162         }
1163
1164         if (!request) {
1165                 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1166                 uint16_t otype, olen;
1167
1168                 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1169                         struct dhcpv6_ia_prefix *ia_p = (struct dhcpv6_ia_prefix *)&odata[-4];
1170                         struct dhcpv6_ia_addr *ia_a = (struct dhcpv6_ia_addr *)&odata[-4];
1171                         bool found = false;
1172
1173                         if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*ia_p) - 4) &&
1174                                         (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*ia_a) - 4))
1175                                 continue;
1176
1177                         if (a) {
1178                                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
1179                                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1180
1181                                 for (size_t i = 0; i < addrlen; ++i) {
1182                                         struct in6_addr addr;
1183
1184                                         if (!valid_addr(&addrs[i], now))
1185                                                 continue;
1186
1187                                         if (!valid_prefix_length(a, addrs[i].prefix))
1188                                                 continue;
1189
1190                                         if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface))
1191                                                 continue;
1192
1193                                         addr = addrs[i].addr.in6;
1194                                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1195                                                 addr.s6_addr32[1] |= htonl(a->assigned_subnet_id);
1196                                                 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
1197
1198                                                 if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) &&
1199                                                                 ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
1200                                                         found = true;
1201                                         } else {
1202                                                 addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
1203                                                 addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
1204
1205                                                 if (!memcmp(&ia_a->addr, &addr, sizeof(addr)))
1206                                                         found = true;
1207                                         }
1208                                 }
1209                         }
1210
1211                         if (!found) {
1212                                 if (otype == DHCPV6_OPT_IA_PREFIX) {
1213                                         struct dhcpv6_ia_prefix o_ia_p = {
1214                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
1215                                                 .len = htons(sizeof(o_ia_p) - 4),
1216                                                 .preferred_lt = 0,
1217                                                 .valid_lt = 0,
1218                                                 .prefix = ia_p->prefix,
1219                                                 .addr = ia_p->addr,
1220                                         };
1221
1222                                         if (buflen < ia_len + sizeof(o_ia_p))
1223                                                 return 0;
1224
1225                                         memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
1226                                         ia_len += sizeof(o_ia_p);
1227                                 } else {
1228                                         struct dhcpv6_ia_addr o_ia_a = {
1229                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
1230                                                 .len = htons(sizeof(o_ia_a) - 4),
1231                                                 .addr = ia_a->addr,
1232                                                 .preferred_lt = 0,
1233                                                 .valid_lt = 0,
1234                                         };
1235
1236                                         if (buflen < ia_len + sizeof(o_ia_a))
1237                                                 continue;
1238
1239                                         memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
1240                                         ia_len += sizeof(o_ia_a);
1241                                 }
1242                         }
1243                 }
1244         }
1245
1246         o_ia.len = htons(ia_len - 4);
1247         memcpy(buf, &o_ia, sizeof(o_ia));
1248         return ia_len;
1249 }
1250
1251 struct log_ctxt {
1252         char *buf;
1253         int buf_len;
1254         int buf_idx;
1255 };
1256
1257 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref_lt,
1258                                 _unused uint32_t valid_lt, void *arg)
1259 {
1260         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1261         char addrbuf[INET6_ADDRSTRLEN];
1262
1263         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1264         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1265                                         "%s/%d ", addrbuf, prefix);
1266 }
1267
1268 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1269                 const char *duidbuf, bool is_pd, struct dhcp_assignment *a, int code)
1270 {
1271         const char *type = "UNKNOWN";
1272         const char *status = "UNKNOWN";
1273
1274         switch (msgtype) {
1275         case DHCPV6_MSG_SOLICIT:
1276                 type = "SOLICIT";
1277                 break;
1278         case DHCPV6_MSG_REQUEST:
1279                 type = "REQUEST";
1280                 break;
1281         case DHCPV6_MSG_CONFIRM:
1282                 type = "CONFIRM";
1283                 break;
1284         case DHCPV6_MSG_RENEW:
1285                 type = "RENEW";
1286                 break;
1287         case DHCPV6_MSG_REBIND:
1288                 type = "REBIND";
1289                 break;
1290         case DHCPV6_MSG_RELEASE:
1291                 type = "RELEASE";
1292                 break;
1293         case DHCPV6_MSG_DECLINE:
1294                 type = "DECLINE";
1295                 break;
1296         }
1297
1298         switch (code) {
1299         case DHCPV6_STATUS_OK:
1300                 status = "ok";
1301                 break;
1302         case DHCPV6_STATUS_NOADDRSAVAIL:
1303                 status = "no addresses available";
1304                 break;
1305         case DHCPV6_STATUS_NOBINDING:
1306                 status = "no binding";
1307                 break;
1308         case DHCPV6_STATUS_NOTONLINK:
1309                 status = "not on-link";
1310                 break;
1311         case DHCPV6_STATUS_NOPREFIXAVAIL:
1312                 status = "no prefix available";
1313                 break;
1314         }
1315
1316         char leasebuf[256] = "";
1317
1318         if (a) {
1319                 struct log_ctxt ctxt = {.buf = leasebuf,
1320                                         .buf_len = sizeof(leasebuf),
1321                                         .buf_idx = 0 };
1322
1323                 dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1324         }
1325
1326         syslog(LOG_INFO, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1327                          duidbuf, iface->name, status, leasebuf);
1328 }
1329
1330 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1331                 struct interface *iface)
1332 {
1333         struct odhcpd_ipaddr *addrs = (a && a->managed) ? a->managed : iface->addr6;
1334         size_t addrlen = (a && a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1335         time_t now = odhcpd_time();
1336         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1337         uint16_t otype, olen;
1338         bool onlink = true;
1339
1340         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1341                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix *)&odata[-4];
1342                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr *)&odata[-4];
1343
1344                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
1345                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
1346                         continue;
1347
1348                 onlink = false;
1349                 for (size_t i = 0; i < addrlen; ++i) {
1350                         if (!valid_addr(&addrs[i], now))
1351                                 continue;
1352
1353                         if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface))
1354                                 continue;
1355
1356                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1357                                 if (p->prefix < addrs[i].prefix ||
1358                                     odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
1359                                         continue;
1360
1361                         } else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
1362                                 continue;
1363
1364                         onlink = true;
1365                 }
1366
1367                 if (!onlink)
1368                         break;
1369         }
1370
1371         return onlink;
1372 }
1373
1374 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
1375                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1376 {
1377         struct lease *l;
1378         struct dhcp_assignment *first = NULL;
1379         const struct dhcpv6_client_header *hdr = data;
1380         time_t now = odhcpd_time();
1381         uint16_t otype, olen, clid_len = 0;
1382         uint8_t *start = (uint8_t *)&hdr[1], *odata;
1383         uint8_t *clid_data = NULL, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1384         size_t hostname_len = 0, response_len = 0;
1385         bool notonlink = false, rapid_commit = false, accept_reconf = false;
1386         char duidbuf[261], hostname[256];
1387
1388         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1389                 if (otype == DHCPV6_OPT_CLIENTID) {
1390                         clid_data = odata;
1391                         clid_len = olen;
1392
1393                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1394                                 memcpy(mac, &odata[8], sizeof(mac));
1395                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1396                                 memcpy(mac, &odata[4], sizeof(mac));
1397
1398                         if (olen <= 130)
1399                                 odhcpd_hexlify(duidbuf, odata, olen);
1400                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1401                         uint8_t fqdn_buf[256];
1402                         memcpy(fqdn_buf, odata, olen);
1403                         fqdn_buf[olen++] = 0;
1404
1405                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1406                                 hostname_len = strcspn(hostname, ".");
1407                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1408                         accept_reconf = true;
1409                 else if (otype == DHCPV6_OPT_RAPID_COMMIT && hdr->msg_type == DHCPV6_MSG_SOLICIT)
1410                         rapid_commit = true;
1411         }
1412
1413         if (!clid_data || !clid_len || clid_len > 130)
1414                 goto out;
1415
1416         l = config_find_lease_by_duid(clid_data, clid_len);
1417         if (!l)
1418                 l = config_find_lease_by_mac(mac);
1419
1420         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1421                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1422                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1423                 bool ia_addr_present = false;
1424                 if (!is_pd && !is_na)
1425                         continue;
1426
1427                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1428                 size_t ia_response_len = 0;
1429                 uint8_t reqlen = (is_pd) ? 62 : 128;
1430                 uint32_t reqhint = 0;
1431
1432                 /* Parse request hint for IA-PD */
1433                 if (is_pd) {
1434                         uint8_t *sdata;
1435                         uint16_t stype, slen;
1436                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1437                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1438                                         continue;
1439
1440                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1441                                 if (p->prefix) {
1442                                         reqlen = p->prefix;
1443                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1444                                         if (reqlen > 32 && reqlen <= 64)
1445                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1446                                 }
1447                         }
1448
1449                         if (reqlen > 64)
1450                                 reqlen = 64;
1451
1452                         /*
1453                          * A requesting router can include a desired prefix length for its
1454                          * delegation.  The delegating router (us) is not required to honor
1455                          * the hint (RFC3633, section 11.2, we MAY choose to use the
1456                          * information in the option; RFC8168, section 3.2 has several SHOULDs
1457                          * about desired choices for selecting a prefix to delegate).
1458                          *
1459                          * We support a policy setting to conserve prefix space, which purposely
1460                          * assigns prefixes that might not match the requesting router's hint.
1461                          *
1462                          * If the minimum prefix length is set in this interface's
1463                          * configuration, we use it as a floor for the requested (hinted)
1464                          * prefix length.  This allows us to conserve prefix space so that
1465                          * any single router can't grab too much of it.  Consider if we have
1466                          * an interface with a /56 prefix.  A requesting router could ask for
1467                          * a /58 and take 1/4 of our total address space.  But if we set a
1468                          * minimum of /60, we can limit each requesting router to get only
1469                          * 1/16 of our total address space.
1470                          */
1471                         if (iface->dhcpv6_pd_min_len && reqlen < iface->dhcpv6_pd_min_len) {
1472                             syslog(LOG_INFO, "clamping requested PD from %d to %d",
1473                                    reqlen, iface->dhcpv6_pd_min_len);
1474                             reqlen = iface->dhcpv6_pd_min_len;
1475                         }
1476                 } else if (is_na) {
1477                         uint8_t *sdata;
1478                         uint16_t stype, slen;
1479                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1480                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1481                                         continue;
1482
1483                                 ia_addr_present = true;
1484                         }
1485                 }
1486
1487                 /* Find assignment */
1488                 struct dhcp_assignment *c, *a = NULL;
1489                 list_for_each_entry(c, &iface->ia_assignments, head) {
1490                         if ((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) &&
1491                             c->iaid == ia->iaid && (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1492                             ((is_pd && (c->flags & OAF_DHCPV6_PD)) || (is_na && (c->flags & OAF_DHCPV6_NA)))) {
1493                                 a = c;
1494
1495                                 /* Reset state */
1496                                 if (a->flags & OAF_BOUND)
1497                                         apply_lease(a, false);
1498
1499                                 stop_reconf(a);
1500                                 break;
1501                         }
1502                 }
1503
1504                 if (l && a && a->lease != l) {
1505                         free_assignment(a);
1506                         a = NULL;
1507                 }
1508
1509                 /* Generic message handling */
1510                 uint16_t status = DHCPV6_STATUS_OK;
1511                 if (a && a->managed_size < 0)
1512                         return -1;
1513
1514                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1515                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1516                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1517                         bool assigned = !!a;
1518
1519                         if (!a) {
1520                                 if ((!iface->no_dynamic_dhcp || (l && is_na)) &&
1521                                     (iface->dhcpv6_pd || iface->dhcpv6_na)) {
1522                                         /* Create new binding */
1523                                         a = alloc_assignment(clid_len);
1524
1525                                         if (a) {
1526                                                 a->clid_len = clid_len;
1527                                                 memcpy(a->clid_data, clid_data, clid_len);
1528                                                 a->iaid = ia->iaid;
1529                                                 a->length = reqlen;
1530                                                 a->peer = *addr;
1531                                                 if (is_na)
1532                                                         a->assigned_host_id = l ? l->hostid : 0;
1533                                                 else
1534                                                         a->assigned_subnet_id = reqhint;
1535                                                 a->valid_until =  now;
1536                                                 a->preferred_until =  now;
1537                                                 a->dhcp_free_cb = dhcpv6_ia_free_assignment;
1538                                                 a->iface = iface;
1539                                                 a->flags = (is_pd ? OAF_DHCPV6_PD : OAF_DHCPV6_NA);
1540
1541                                                 if (first)
1542                                                         memcpy(a->key, first->key, sizeof(a->key));
1543                                                 else
1544                                                         odhcpd_urandom(a->key, sizeof(a->key));
1545
1546                                                 if (is_pd && iface->dhcpv6_pd)
1547                                                         while (!(assigned = assign_pd(iface, a)) &&
1548                                                                !a->managed_size && ++a->length <= 64);
1549                                                 else if (is_na && iface->dhcpv6_na)
1550                                                         assigned = assign_na(iface, a);
1551
1552                                                 if (l && assigned) {
1553                                                         a->flags |= OAF_STATIC;
1554
1555                                                         if (l->hostname)
1556                                                                 a->hostname = strdup(l->hostname);
1557
1558                                                         if (l->leasetime)
1559                                                                 a->leasetime = l->leasetime;
1560
1561                                                         list_add(&a->lease_list, &l->assignments);
1562                                                         a->lease = l;
1563                                                 }
1564
1565                                                 if (a->managed_size && !assigned)
1566                                                         return -1;
1567                                         }
1568                                 }
1569                         }
1570
1571                         if (!assigned || iface->addr6_len == 0)
1572                                 /* Set error status */
1573                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1574                         else if (hdr->msg_type == DHCPV6_MSG_REQUEST && !dhcpv6_ia_on_link(ia, a, iface)) {
1575                                 /* Send NOTONLINK status for the IA */
1576                                 status = DHCPV6_STATUS_NOTONLINK;
1577                                 assigned = false;
1578                         } else if (accept_reconf && assigned && !first &&
1579                                         hdr->msg_type != DHCPV6_MSG_REBIND) {
1580                                 size_t handshake_len = 4;
1581                                 buf[0] = 0;
1582                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1583                                 buf[2] = 0;
1584                                 buf[3] = 0;
1585
1586                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1587                                         struct dhcpv6_auth_reconfigure auth = {
1588                                                 htons(DHCPV6_OPT_AUTH),
1589                                                 htons(sizeof(auth) - 4),
1590                                                 3, 1, 0,
1591                                                 {htonl(time(NULL)), htonl(++serial)},
1592                                                 1,
1593                                                 {0}
1594                                         };
1595                                         memcpy(auth.key, a->key, sizeof(a->key));
1596                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1597                                         handshake_len += sizeof(auth);
1598                                 }
1599
1600
1601                                 buf += handshake_len;
1602                                 buflen -= handshake_len;
1603                                 response_len += handshake_len;
1604
1605                                 first = a;
1606                         }
1607
1608                         ia_response_len = build_ia(buf, buflen, status, ia, a, iface,
1609                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1610
1611                         /* Was only a solicitation: mark binding for removal */
1612                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT && !rapid_commit) {
1613                                 a->flags &= ~OAF_BOUND;
1614                                 a->flags |= OAF_TENTATIVE;
1615
1616                                 /* Keep tentative assignment around for 60 seconds */
1617                                 a->valid_until = now + 60;
1618
1619                         } else if (assigned &&
1620                                    ((hdr->msg_type == DHCPV6_MSG_SOLICIT && rapid_commit) ||
1621                                     hdr->msg_type == DHCPV6_MSG_REQUEST ||
1622                                     hdr->msg_type == DHCPV6_MSG_REBIND)) {
1623                                 if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
1624                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1625                                         if (a->hostname) {
1626                                                 memcpy(a->hostname, hostname, hostname_len);
1627                                                 a->hostname[hostname_len] = 0;
1628
1629                                                 if (odhcpd_valid_hostname(a->hostname))
1630                                                         a->flags &= ~OAF_BROKEN_HOSTNAME;
1631                                                 else
1632                                                         a->flags |= OAF_BROKEN_HOSTNAME;
1633                                         }
1634                                 }
1635                                 a->accept_reconf = accept_reconf;
1636                                 a->flags &= ~OAF_TENTATIVE;
1637                                 a->flags |= OAF_BOUND;
1638                                 apply_lease(a, true);
1639                         } else if (!assigned && a && a->managed_size == 0) {
1640                                 /* Cleanup failed assignment */
1641                                 free_assignment(a);
1642                                 a = NULL;
1643                         }
1644                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1645                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1646                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1647                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1648                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1649                                 status = DHCPV6_STATUS_NOBINDING;
1650                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1651                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1652                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1653                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1654                                 if (a) {
1655                                         a->flags |= OAF_BOUND;
1656                                         apply_lease(a, true);
1657                                 }
1658                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1659                                 a->valid_until = now - 1;
1660                         } else if ((a->flags & OAF_DHCPV6_NA) && hdr->msg_type == DHCPV6_MSG_DECLINE) {
1661                                 a->flags &= ~OAF_BOUND;
1662
1663                                 if (!(a->flags & OAF_STATIC) || a->lease->hostid != a->assigned_host_id) {
1664                                         memset(a->clid_data, 0, a->clid_len);
1665                                         a->valid_until = now + 3600; /* Block address for 1h */
1666                                 } else
1667                                         a->valid_until = now - 1;
1668                         }
1669                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1670                         if (ia_addr_present && !dhcpv6_ia_on_link(ia, a, iface)) {
1671                                 notonlink = true;
1672                                 break;
1673                         }
1674
1675                         if (!ia_addr_present || !a || !(a->flags & OAF_BOUND)) {
1676                                 response_len = 0;
1677                                 goto out;
1678                         }
1679                 }
1680
1681                 buf += ia_response_len;
1682                 buflen -= ia_response_len;
1683                 response_len += ia_response_len;
1684                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1685         }
1686
1687         switch (hdr->msg_type) {
1688         case DHCPV6_MSG_RELEASE:
1689         case DHCPV6_MSG_DECLINE:
1690         case DHCPV6_MSG_CONFIRM:
1691                 if (response_len + 6 < buflen) {
1692                         buf[0] = 0;
1693                         buf[1] = DHCPV6_OPT_STATUS;
1694                         buf[2] = 0;
1695                         buf[3] = 2;
1696                         buf[4] = 0;
1697                         buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1698                         response_len += 6;
1699                 }
1700                 break;
1701
1702         default:
1703                 break;
1704         }
1705
1706         dhcpv6_ia_write_statefile();
1707
1708 out:
1709         return response_len;
1710 }