src/dhcpv6-ia.c

   1 /**
   2  * Copyright (C) 2013 Steven Barth <steven@midlink.org>
   3  * Copyright (C) 2016 Hans Dedecker <dedeckeh@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License v2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  */
  15
  16 #include "odhcpd.h"
  17 #include "dhcpv6.h"
  18 #include "dhcpv4.h"
  19
  20 #include <time.h>
  21 #include <errno.h>
  22 #include <fcntl.h>
  23 #include <stdio.h>
  24 #include <poll.h>
  25 #include <alloca.h>
  26 #include <resolv.h>
  27 #include <limits.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31 #include <stdbool.h>
  32 #include <arpa/inet.h>
  33 #include <sys/timerfd.h>
  34
  35 #include <libubox/md5.h>
  36 #include <libubox/usock.h>
  37
  38 #define ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) \
  39     ((iface)->dhcpv6_assignall || (i) == (m) || \
  40      (addrs)[(i)].prefix > 64)
  41
  42 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info);
  43 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b);
  44 static void handle_addrlist_change(struct netevent_handler_info *info);
  45 static void start_reconf(struct dhcp_assignment *a);
  46 static void stop_reconf(struct dhcp_assignment *a);
  47 static void valid_until_cb(struct uloop_timeout *event);
  48
  49 static struct netevent_handler dhcpv6_netevent_handler = { .cb = dhcpv6_netevent_cb, };
  50 static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb};
  51 static uint32_t serial = 0;
  52 static uint8_t statemd5[16];
  53
  54 int dhcpv6_ia_init(void)
  55 {
  56         uloop_timeout_set(&valid_until_timeout, 1000);
  57
  58         netlink_add_netevent_handler(&dhcpv6_netevent_handler);
  59
  60         return 0;
  61 }
  62
  63 int dhcpv6_ia_setup_interface(struct interface *iface, bool enable)
  64 {
  65         enable = enable && (iface->dhcpv6 == MODE_SERVER);
  66
  67         if (enable) {
  68                 struct dhcp_assignment *border;
  69
  70                 if (list_empty(&iface->ia_assignments)) {
  71                         border = alloc_assignment(0);
  72
  73                         if (!border) {
  74                                 syslog(LOG_WARNING, "Failed to alloc border on %s", iface->name);
  75                                 return -1;
  76                         }
  77
  78                         border->length = 64;
  79                         list_add(&border->head, &iface->ia_assignments);
  80                 } else
  81                         border = list_last_entry(&iface->ia_assignments, struct dhcp_assignment, head);
  82
  83                 set_border_assignment_size(iface, border);
  84         } else {
  85                 struct dhcp_assignment *c;
  86
  87                 while (!list_empty(&iface->ia_assignments)) {
  88                         c = list_first_entry(&iface->ia_assignments, struct dhcp_assignment, head);
  89                         free_assignment(c);
  90                 }
  91         }
  92
  93         return 0;
  94 }
  95
  96
  97 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info)
  98 {
  99         struct interface *iface = info->iface;
 100
 101         if (!iface || iface->dhcpv6 != MODE_SERVER)
 102                 return;
 103
 104         switch (event) {
 105         case NETEV_ADDR6LIST_CHANGE:
 106                 handle_addrlist_change(info);
 107                 break;
 108         default:
 109                 break;
 110         }
 111 }
 112
 113
 114 static inline bool valid_prefix_length(const struct dhcp_assignment *a, const uint8_t prefix_length)
 115 {
 116         return (a->managed_size || a->length > prefix_length);
 117 }
 118
 119 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 120 {
 121         return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
 122 }
 123
 124 static size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
 125 {
 126         size_t i, m;
 127
 128         for (i = 0, m = 0; i < addrlen; ++i) {
 129                 if (addrs[i].preferred > addrs[m].preferred ||
 130                                 (addrs[i].preferred == addrs[m].preferred &&
 131                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 132                         m = i;
 133         }
 134
 135         return m;
 136 }
 137
 138 static int send_reconf(struct dhcp_assignment *assign)
 139 {
 140         struct {
 141                 struct dhcpv6_client_header hdr;
 142                 uint16_t srvid_type;
 143                 uint16_t srvid_len;
 144                 uint16_t duid_type;
 145                 uint16_t hardware_type;
 146                 uint8_t mac[6];
 147                 uint16_t msg_type;
 148                 uint16_t msg_len;
 149                 uint8_t msg_id;
 150                 struct dhcpv6_auth_reconfigure auth;
 151                 uint16_t clid_type;
 152                 uint16_t clid_len;
 153                 uint8_t clid_data[128];
 154         } __attribute__((packed)) reconf_msg = {
 155                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 156                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 157                 .srvid_len = htons(10),
 158                 .duid_type = htons(3),
 159                 .hardware_type = htons(1),
 160                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 161                 .msg_len = htons(1),
 162                 .msg_id = DHCPV6_MSG_RENEW,
 163                 .auth = {htons(DHCPV6_OPT_AUTH),
 164                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 165                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 166                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 167                 .clid_len = htons(assign->clid_len),
 168                 .clid_data = {0},
 169         };
 170         struct interface *iface = assign->iface;
 171
 172         odhcpd_get_mac(iface, reconf_msg.mac);
 173         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 174         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 175
 176         md5_ctx_t md5;
 177         uint8_t secretbytes[64];
 178         memset(secretbytes, 0, sizeof(secretbytes));
 179         memcpy(secretbytes, assign->key, sizeof(assign->key));
 180
 181         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 182                 secretbytes[i] ^= 0x36;
 183
 184         md5_begin(&md5);
 185         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 186         md5_hash(iov.iov_base, iov.iov_len, &md5);
 187         md5_end(reconf_msg.auth.key, &md5);
 188
 189         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 190                 secretbytes[i] ^= 0x36;
 191                 secretbytes[i] ^= 0x5c;
 192         }
 193
 194         md5_begin(&md5);
 195         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 196         md5_hash(reconf_msg.auth.key, 16, &md5);
 197         md5_end(reconf_msg.auth.key, &md5);
 198
 199         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 200 }
 201
 202 static void dhcpv6_ia_free_assignment(struct dhcp_assignment *a)
 203 {
 204         if (a->managed_sock.fd.registered) {
 205                 ustream_free(&a->managed_sock.stream);
 206                 close(a->managed_sock.fd.fd);
 207         }
 208
 209         if (a->reconf_cnt)
 210                 stop_reconf(a);
 211
 212         free(a->managed);
 213 }
 214
 215 void dhcpv6_ia_enum_addrs(struct interface *iface, struct dhcp_assignment *c,
 216                           time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
 217 {
 218         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->addr6;
 219         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->addr6_len;
 220         size_t m = get_preferred_addr(addrs, addrlen);
 221
 222         for (size_t i = 0; i < addrlen; ++i) {
 223                 struct in6_addr addr;
 224                 uint32_t pref, valid;
 225                 int prefix = c->managed ? addrs[i].prefix : c->length;
 226
 227                 if (!valid_addr(&addrs[i], now))
 228                         continue;
 229
 230                 addr = addrs[i].addr.in6;
 231                 pref = addrs[i].preferred;
 232                 valid = addrs[i].valid;
 233                 if (prefix == 128) {
 234                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 235                                 continue;
 236
 237                         addr.s6_addr32[3] = htonl(c->assigned);
 238                 } else {
 239                         if (!valid_prefix_length(c, addrs[i].prefix))
 240                                 continue;
 241
 242                         addr.s6_addr32[1] |= htonl(c->assigned);
 243                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 244                 }
 245
 246                 if (pref != UINT32_MAX)
 247                         pref -= now;
 248
 249                 if (valid != UINT32_MAX)
 250                         valid -= now;
 251
 252                 func(&addr, prefix, pref, valid, arg);
 253         }
 254 }
 255
 256 struct write_ctxt {
 257         FILE *fp;
 258         md5_ctx_t md5;
 259         struct dhcp_assignment *c;
 260         struct interface *iface;
 261         char *buf;
 262         int buf_len;
 263         int buf_idx;
 264 };
 265
 266 static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 267                                 _unused uint32_t valid, void *arg)
 268 {
 269         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
 270         char ipbuf[INET6_ADDRSTRLEN];
 271
 272         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 273
 274         if (ctxt->c->length == 128 && ctxt->c->hostname &&
 275             !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
 276                 fputs(ipbuf, ctxt->fp);
 277
 278                 char b[256];
 279                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
 280                                 ctxt->iface->search, b, sizeof(b)) > 0)
 281                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
 282
 283                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
 284                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
 285                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
 286         }
 287
 288         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
 289                                         "%s/%d ", ipbuf, prefix);
 290 }
 291
 292 void dhcpv6_ia_write_statefile(void)
 293 {
 294         struct write_ctxt ctxt;
 295
 296         md5_begin(&ctxt.md5);
 297
 298         if (config.dhcp_statefile) {
 299                 time_t now = odhcpd_time(), wall_time = time(NULL);
 300                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 301                 char leasebuf[512];
 302
 303                 if (fd < 0)
 304                         return;
 305                 int ret;
 306                 ret = lockf(fd, F_LOCK, 0);
 307                 if (ret < 0) {
 308                         close(fd);
 309                         return;
 310                 }
 311                 if (ftruncate(fd, 0) < 0) {}
 312
 313                 ctxt.fp = fdopen(fd, "w");
 314                 if (!ctxt.fp) {
 315                         close(fd);
 316                         return;
 317                 }
 318
 319                 ctxt.buf = leasebuf;
 320                 ctxt.buf_len = sizeof(leasebuf);
 321
 322                 avl_for_each_element(&interfaces, ctxt.iface, avl) {
 323                         if (ctxt.iface->dhcpv6 != MODE_SERVER &&
 324                                         ctxt.iface->dhcpv4 != MODE_SERVER)
 325                                 continue;
 326
 327                         if (ctxt.iface->dhcpv6 == MODE_SERVER) {
 328                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 329                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 330                                                 continue;
 331
 332                                         char duidbuf[264];
 333
 334                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
 335
 336                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 337                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s%s %ld %x %u ",
 338                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
 339                                                                 (ctxt.c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 340                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
 341                                                                 (ctxt.c->valid_until > now ?
 342                                                                         (ctxt.c->valid_until - now + wall_time) :
 343                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)),
 344                                                                 ctxt.c->assigned, (unsigned)ctxt.c->length);
 345
 346                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
 347                                                 dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
 348                                                                         dhcpv6_write_ia_addr, &ctxt);
 349
 350                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 351                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 352                                 }
 353                         }
 354
 355                         if (ctxt.iface->dhcpv4 == MODE_SERVER) {
 356                                 struct dhcp_assignment *c;
 357
 358                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 359                                         if (!(c->flags & OAF_BOUND))
 360                                                 continue;
 361
 362                                         char ipbuf[INET6_ADDRSTRLEN];
 363                                         char duidbuf[16];
 364                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 365
 366                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 367                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s%s %ld %x 32 ",
 368                                                                 ctxt.iface->ifname, duidbuf,
 369                                                                 (c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 370                                                                 (c->hostname ? c->hostname : "-"),
 371                                                                 (c->valid_until > now ?
 372                                                                         (c->valid_until - now + wall_time) :
 373                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 374                                                                 ntohl(c->addr));
 375
 376                                         struct in_addr addr = {.s_addr = c->addr};
 377                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 378
 379                                         if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
 380                                                 fputs(ipbuf, ctxt.fp);
 381
 382                                                 char b[256];
 383                                                 if (dn_expand(ctxt.iface->search,
 384                                                                 ctxt.iface->search + ctxt.iface->search_len,
 385                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
 386                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
 387
 388                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
 389                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
 390                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
 391                                         }
 392
 393                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
 394                                                                         ctxt.buf_len - ctxt.buf_idx,
 395                                                                         "%s/32 ", ipbuf);
 396                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 397                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 398                                 }
 399                         }
 400                 }
 401
 402                 fclose(ctxt.fp);
 403         }
 404
 405         uint8_t newmd5[16];
 406         md5_end(newmd5, &ctxt.md5);
 407
 408         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 409                 memcpy(statemd5, newmd5, sizeof(statemd5));
 410                 char *argv[2] = {config.dhcp_cb, NULL};
 411                 if (!vfork()) {
 412                         execv(argv[0], argv);
 413                         _exit(128);
 414                 }
 415         }
 416 }
 417
 418 static void __apply_lease(struct dhcp_assignment *a,
 419                 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
 420 {
 421         if (a->length > 64)
 422                 return;
 423
 424         for (ssize_t i = 0; i < addr_len; ++i) {
 425                 struct in6_addr prefix = addrs[i].addr.in6;
 426                 prefix.s6_addr32[1] |= htonl(a->assigned);
 427                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
 428                 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 429                                 a->iface->ifindex, &a->peer.sin6_addr, 1024, add);
 430         }
 431 }
 432
 433 static void apply_lease(struct dhcp_assignment *a, bool add)
 434 {
 435         struct interface *iface = a->iface;
 436         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 437         ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
 438
 439         __apply_lease(a, addrs, addrlen, add);
 440 }
 441
 442 /* Set border assignment size based on the IPv6 address prefixes */
 443 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b)
 444 {
 445         time_t now = odhcpd_time();
 446         int minprefix = -1;
 447
 448         for (size_t i = 0; i < iface->addr6_len; ++i) {
 449                 if (iface->addr6[i].preferred > (uint32_t)now &&
 450                                 iface->addr6[i].prefix < 64 &&
 451                                 iface->addr6[i].prefix > minprefix)
 452                         minprefix = iface->addr6[i].prefix;
 453         }
 454
 455         if (minprefix > 32 && minprefix <= 64)
 456                 b->assigned = 1U << (64 - minprefix);
 457         else
 458                 b->assigned = 0;
 459 }
 460
 461 /* More data was received from TCP connection */
 462 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 463 {
 464         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 465         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
 466         time_t now = odhcpd_time();
 467         bool first = c->managed_size < 0;
 468
 469         for (;;) {
 470                 int pending;
 471                 char *data = ustream_get_read_buf(s, &pending);
 472                 char *end = memmem(data, pending, "\n\n", 2);
 473
 474                 if (!end)
 475                         break;
 476
 477                 end += 2;
 478                 end[-1] = 0;
 479
 480                 c->managed_size = 0;
 481                 if (c->accept_reconf)
 482                         c->reconf_cnt = 1;
 483
 484                 char *saveptr;
 485                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 486                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 487                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 488
 489                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 490                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 491                                 continue;
 492
 493                         x = strtok_r(NULL, ",", &saveptr2);
 494                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 495                                 continue;
 496
 497                         x = strtok_r(NULL, ",", &saveptr2);
 498                         if (sscanf(x, "%u", &n->preferred) < 1)
 499                                 continue;
 500
 501                         x = strtok_r(NULL, ",", &saveptr2);
 502                         if (sscanf(x, "%u", &n->valid) < 1)
 503                                 continue;
 504
 505                         if (n->preferred > n->valid)
 506                                 continue;
 507
 508                         if (UINT32_MAX - now < n->preferred)
 509                                 n->preferred = UINT32_MAX;
 510                         else
 511                                 n->preferred += now;
 512
 513                         if (UINT32_MAX - now < n->valid)
 514                                 n->valid = UINT32_MAX;
 515                         else
 516                                 n->valid += now;
 517
 518                         n->dprefix = 0;
 519
 520                         ++c->managed_size;
 521                 }
 522
 523                 ustream_consume(s, end - data);
 524         }
 525
 526         if (first && c->managed_size == 0)
 527                 free_assignment(c);
 528         else if (first && !(c->flags & OAF_STATIC))
 529                 c->valid_until = now + 150;
 530 }
 531
 532
 533 /* TCP transmission has ended, either because of success or timeout or other error */
 534 static void managed_handle_pd_done(struct ustream *s)
 535 {
 536         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 537         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
 538
 539         if (!(c->flags & OAF_STATIC))
 540                 c->valid_until = odhcpd_time() + 15;
 541
 542         c->managed_size = 0;
 543
 544         if (c->accept_reconf)
 545                 c->reconf_cnt = 1;
 546 }
 547
 548 static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
 549 {
 550         struct dhcp_assignment *c;
 551
 552         if (iface->dhcpv6_pd_manager[0]) {
 553                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 554                 if (fd >= 0) {
 555                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 556                         char iaidbuf[298];
 557
 558                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 559
 560                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 561                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 562                         ustream_fd_init(&assign->managed_sock, fd);
 563                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 564                                         iaidbuf, assign->iaid, assign->length);
 565                         ustream_write_pending(&assign->managed_sock.stream);
 566                         assign->managed_size = -1;
 567
 568                         if (!(assign->flags & OAF_STATIC))
 569                                 assign->valid_until = odhcpd_time() + 15;
 570
 571                         list_add(&assign->head, &iface->ia_assignments);
 572
 573                         /* Wait initial period of up to 250ms for immediate assignment */
 574                         if (poll(&pfd, 1, 250) < 0) {
 575                                 syslog(LOG_ERR, "poll(): %m");
 576                                 return false;
 577                         }
 578
 579                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 580
 581                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 582                                 return true;
 583                 }
 584
 585                 return false;
 586         } else if (iface->addr6_len < 1)
 587                 return false;
 588
 589         /* Try honoring the hint first */
 590         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 591         if (assign->assigned) {
 592                 list_for_each_entry(c, &iface->ia_assignments, head) {
 593                         if (c->length == 128 || c->length == 0)
 594                                 continue;
 595
 596                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 597                                 list_add_tail(&assign->head, &c->head);
 598
 599                                 if (assign->flags & OAF_BOUND)
 600                                         apply_lease(assign, true);
 601
 602                                 return true;
 603                         }
 604
 605                         if (c->assigned != 0)
 606                                 current = (c->assigned + (1 << (64 - c->length)));
 607                 }
 608         }
 609
 610         /* Fallback to a variable assignment */
 611         current = 1;
 612         list_for_each_entry(c, &iface->ia_assignments, head) {
 613                 if (c->length == 128 || c->length == 0)
 614                         continue;
 615
 616                 current = (current + asize) & (~asize);
 617                 if (current + asize < c->assigned) {
 618                         assign->assigned = current;
 619                         list_add_tail(&assign->head, &c->head);
 620
 621                         if (assign->flags & OAF_BOUND)
 622                                 apply_lease(assign, true);
 623
 624                         return true;
 625                 }
 626
 627                 if (c->assigned != 0)
 628                         current = (c->assigned + (1 << (64 - c->length)));
 629         }
 630
 631         return false;
 632 }
 633
 634 static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
 635 {
 636         struct dhcp_assignment *c;
 637         uint32_t seed = 0;
 638
 639         /* Preconfigured assignment by static lease */
 640         if (a->assigned) {
 641                 list_for_each_entry(c, &iface->ia_assignments, head) {
 642                         if (c->length == 0)
 643                                 continue;
 644
 645                         if (c->assigned > a->assigned || c->length != 128) {
 646                                 list_add_tail(&a->head, &c->head);
 647                                 return true;
 648                         } else if (c->assigned == a->assigned)
 649                                 return false;
 650                 }
 651         }
 652
 653         /* Seed RNG with checksum of DUID */
 654         for (size_t i = 0; i < a->clid_len; ++i)
 655                 seed += a->clid_data[i];
 656         srand(seed);
 657
 658         /* Try to assign up to 100x */
 659         for (size_t i = 0; i < 100; ++i) {
 660                 uint32_t try;
 661                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 662
 663                 if (config_find_lease_by_hostid(try))
 664                         continue;
 665
 666                 list_for_each_entry(c, &iface->ia_assignments, head) {
 667                         if (c->length == 0)
 668                                 continue;
 669
 670                         if (c->assigned > try || c->length != 128) {
 671                                 a->assigned = try;
 672                                 list_add_tail(&a->head, &c->head);
 673                                 return true;
 674                         } else if (c->assigned == try)
 675                                 break;
 676                 }
 677         }
 678
 679         return false;
 680 }
 681
 682 static void handle_addrlist_change(struct netevent_handler_info *info)
 683 {
 684         struct interface *iface = info->iface;
 685         struct dhcp_assignment *c, *d, *border = list_last_entry(
 686                         &iface->ia_assignments, struct dhcp_assignment, head);
 687         struct list_head reassign = LIST_HEAD_INIT(reassign);
 688         time_t now = odhcpd_time();
 689
 690         list_for_each_entry(c, &iface->ia_assignments, head) {
 691                 if (c != border && !(iface->ra_flags & ND_RA_FLAG_MANAGED)
 692                                 && (c->flags & OAF_BOUND))
 693                         __apply_lease(c, info->addrs_old.addrs,
 694                                         info->addrs_old.len, false);
 695         }
 696
 697         set_border_assignment_size(iface, border);
 698
 699         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 700                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 701                                 c->managed_size)
 702                         continue;
 703
 704                 if (c->length < 128 && (c->assigned == 0 || c->assigned >= border->assigned) && c != border)
 705                         list_move(&c->head, &reassign);
 706                 else if (c != border && (c->flags & OAF_BOUND))
 707                         apply_lease(c, true);
 708
 709                 if (c->accept_reconf && c->reconf_cnt == 0) {
 710                         struct dhcp_assignment *a;
 711
 712                         start_reconf(c);
 713
 714                         /* Leave all other assignments of that client alone */
 715                         list_for_each_entry(a, &iface->ia_assignments, head)
 716                                 if (a != c && a->clid_len == c->clid_len &&
 717                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 718                                         a->reconf_cnt = INT_MAX;
 719                 }
 720         }
 721
 722         while (!list_empty(&reassign)) {
 723                 c = list_first_entry(&reassign, struct dhcp_assignment, head);
 724                 list_del_init(&c->head);
 725                 if (!assign_pd(iface, c)) {
 726                         c->assigned = 0;
 727                         list_add(&c->head, &iface->ia_assignments);
 728                 }
 729         }
 730
 731         dhcpv6_ia_write_statefile();
 732 }
 733
 734 static void reconf_timeout_cb(struct uloop_timeout *event)
 735 {
 736         struct dhcp_assignment *a = container_of(event, struct dhcp_assignment, reconf_timer);
 737
 738         if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
 739                 send_reconf(a);
 740                 uloop_timeout_set(&a->reconf_timer,
 741                                         DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 742                 a->reconf_cnt++;
 743         } else
 744                 stop_reconf(a);
 745 }
 746
 747 static void start_reconf(struct dhcp_assignment *a)
 748 {
 749         uloop_timeout_set(&a->reconf_timer,
 750                                 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 751         a->reconf_timer.cb = reconf_timeout_cb;
 752         a->reconf_cnt++;
 753
 754         send_reconf(a);
 755 }
 756
 757 static void stop_reconf(struct dhcp_assignment *a)
 758 {
 759         uloop_timeout_cancel(&a->reconf_timer);
 760         a->reconf_cnt = 0;
 761         a->reconf_timer.cb = NULL;
 762 }
 763
 764 static void valid_until_cb(struct uloop_timeout *event)
 765 {
 766         struct interface *iface;
 767         time_t now = odhcpd_time();
 768
 769         avl_for_each_element(&interfaces, iface, avl) {
 770                 struct dhcp_assignment *a, *n;
 771
 772                 if (iface->dhcpv6 != MODE_SERVER)
 773                         continue;
 774
 775                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 776                         if (a->clid_len > 0 && !INFINITE_VALID(a->valid_until) && a->valid_until < now)
 777                                 free_assignment(a);
 778                 }
 779         }
 780         uloop_timeout_set(event, 1000);
 781 }
 782
 783 static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 784                 const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
 785                 struct interface *iface, bool request)
 786 {
 787         struct dhcpv6_ia_hdr o_ia = {
 788                 .type = ia->type,
 789                 .len = 0,
 790                 .iaid = ia->iaid,
 791                 .t1 = 0,
 792                 .t2 = 0,
 793         };
 794         size_t ia_len = sizeof(o_ia);
 795         time_t now = odhcpd_time();
 796
 797         if (buflen < ia_len)
 798                 return 0;
 799
 800         if (status) {
 801                 struct __attribute__((packed)) {
 802                         uint16_t type;
 803                         uint16_t len;
 804                         uint16_t val;
 805                 } o_status = {
 806                         .type = htons(DHCPV6_OPT_STATUS),
 807                         .len = htons(sizeof(o_status) - 4),
 808                         .val = htons(status),
 809                 };
 810
 811                 memcpy(buf + ia_len, &o_status, sizeof(o_status));
 812                 ia_len += sizeof(o_status);
 813
 814                 o_ia.len = htons(ia_len - 4);
 815                 memcpy(buf, &o_ia, sizeof(o_ia));
 816
 817                 return ia_len;
 818         }
 819
 820         if (a) {
 821                 uint32_t leasetime;
 822
 823                 if (a->leasetime)
 824                         leasetime = a->leasetime;
 825                 else
 826                         leasetime = iface->dhcpv4_leasetime;
 827
 828                 uint32_t pref = leasetime;
 829                 uint32_t valid = leasetime;
 830
 831                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 832                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
 833                 size_t m = get_preferred_addr(addrs, addrlen);
 834
 835                 for (size_t i = 0; i < addrlen; ++i) {
 836                         uint32_t prefix_pref = addrs[i].preferred;
 837                         uint32_t prefix_valid = addrs[i].valid;
 838
 839                         if (!valid_addr(&addrs[i], now))
 840                                 continue;
 841
 842                         if (prefix_pref != UINT32_MAX)
 843                                 prefix_pref -= now;
 844
 845                         if (prefix_valid != UINT32_MAX)
 846                                 prefix_valid -= now;
 847
 848                         if (a->length < 128) {
 849                                 struct dhcpv6_ia_prefix o_ia_p = {
 850                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 851                                         .len = htons(sizeof(o_ia_p) - 4),
 852                                         .preferred = htonl(prefix_pref),
 853                                         .valid = htonl(prefix_valid),
 854                                         .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 855                                         .addr = addrs[i].addr.in6,
 856                                 };
 857
 858                                 o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned);
 859                                 o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0;
 860
 861                                 if ((a->assigned == 0 && a->managed_size == 0) ||
 862                                                 !valid_prefix_length(a, addrs[i].prefix))
 863                                         continue;
 864
 865                                 if (buflen < ia_len + sizeof(o_ia_p))
 866                                         return 0;
 867
 868                                 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
 869                                 ia_len += sizeof(o_ia_p);
 870                         } else {
 871                                 struct dhcpv6_ia_addr o_ia_a = {
 872                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 873                                         .len = htons(sizeof(o_ia_a) - 4),
 874                                         .addr = addrs[i].addr.in6,
 875                                         .preferred = htonl(prefix_pref),
 876                                         .valid = htonl(prefix_valid)
 877                                 };
 878
 879                                 o_ia_a.addr.s6_addr32[3] = htonl(a->assigned);
 880
 881                                 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
 882                                                 a->assigned == 0)
 883                                         continue;
 884
 885                                 if (buflen < ia_len + sizeof(o_ia_a))
 886                                         return 0;
 887
 888                                 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
 889                                 ia_len += sizeof(o_ia_a);
 890                         }
 891
 892                         /* Calculate T1 / T2 based on non-deprecated addresses */
 893                         if (prefix_pref > 0) {
 894                                 if (prefix_pref < pref)
 895                                         pref = prefix_pref;
 896
 897                                 if (prefix_valid < valid)
 898                                         valid = prefix_valid;
 899                         }
 900                 }
 901
 902                 if (!INFINITE_VALID(a->valid_until))
 903                         /* UINT32_MAX is considered as infinite leasetime */
 904                         a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 905
 906                 o_ia.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 907                 o_ia.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 908
 909                 if (!o_ia.t1)
 910                         o_ia.t1 = htonl(1);
 911
 912                 if (!o_ia.t2)
 913                         o_ia.t2 = htonl(1);
 914         }
 915
 916         if (!request) {
 917                 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 918                 uint16_t otype, olen;
 919
 920                 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 921                         struct dhcpv6_ia_prefix *ia_p = (struct dhcpv6_ia_prefix *)&odata[-4];
 922                         struct dhcpv6_ia_addr *ia_a = (struct dhcpv6_ia_addr *)&odata[-4];
 923                         bool found = false;
 924
 925                         if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*ia_p) - 4) &&
 926                                         (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*ia_a) - 4))
 927                                 continue;
 928
 929                         if (a) {
 930                                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 931                                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
 932
 933                                 for (size_t i = 0; i < addrlen; ++i) {
 934                                         if (!valid_addr(&addrs[i], now))
 935                                                 continue;
 936
 937                                         struct in6_addr addr = addrs[i].addr.in6;
 938                                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 939                                                 addr.s6_addr32[1] |= htonl(a->assigned);
 940                                                 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 941
 942                                                 if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) &&
 943                                                                 ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 944                                                         found = true;
 945                                         } else {
 946                                                 addr.s6_addr32[3] = htonl(a->assigned);
 947
 948                                                 if (!memcmp(&ia_a->addr, &addr, sizeof(addr)))
 949                                                         found = true;
 950                                         }
 951                                 }
 952                         }
 953
 954                         if (!found) {
 955                                 if (otype == DHCPV6_OPT_IA_PREFIX) {
 956                                         struct dhcpv6_ia_prefix o_ia_p = {
 957                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 958                                                 .len = htons(sizeof(o_ia_p) - 4),
 959                                                 .preferred = 0,
 960                                                 .valid = 0,
 961                                                 .prefix = ia_p->prefix,
 962                                                 .addr = ia_p->addr,
 963                                         };
 964
 965                                         if (buflen < ia_len + sizeof(o_ia_p))
 966                                                 return 0;
 967
 968                                         memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
 969                                         ia_len += sizeof(o_ia_p);
 970                                 } else {
 971                                         struct dhcpv6_ia_addr o_ia_a = {
 972                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 973                                                 .len = htons(sizeof(o_ia_a) - 4),
 974                                                 .addr = ia_a->addr,
 975                                                 .preferred = 0,
 976                                                 .valid = 0,
 977                                         };
 978
 979                                         if (buflen < ia_len + sizeof(o_ia_a))
 980                                                 continue;
 981
 982                                         memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
 983                                         ia_len += sizeof(o_ia_a);
 984                                 }
 985                         }
 986                 }
 987         }
 988
 989         o_ia.len = htons(ia_len - 4);
 990         memcpy(buf, &o_ia, sizeof(o_ia));
 991         return ia_len;
 992 }
 993
 994 struct log_ctxt {
 995         char *buf;
 996         int buf_len;
 997         int buf_idx;
 998 };
 999
1000 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
1001                                 _unused uint32_t valid, void *arg)
1002 {
1003         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1004         char addrbuf[INET6_ADDRSTRLEN];
1005
1006         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1007         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1008                                         "%s/%d ", addrbuf, prefix);
1009 }
1010
1011 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1012                 const char *duidbuf, bool is_pd, struct dhcp_assignment *a, int code)
1013 {
1014         const char *type = "UNKNOWN";
1015         const char *status = "UNKNOWN";
1016
1017         switch (msgtype) {
1018         case DHCPV6_MSG_SOLICIT:
1019                 type = "SOLICIT";
1020                 break;
1021         case DHCPV6_MSG_REQUEST:
1022                 type = "REQUEST";
1023                 break;
1024         case DHCPV6_MSG_CONFIRM:
1025                 type = "CONFIRM";
1026                 break;
1027         case DHCPV6_MSG_RENEW:
1028                 type = "RENEW";
1029                 break;
1030         case DHCPV6_MSG_REBIND:
1031                 type = "REBIND";
1032                 break;
1033         case DHCPV6_MSG_RELEASE:
1034                 type = "RELEASE";
1035                 break;
1036         case DHCPV6_MSG_DECLINE:
1037                 type = "DECLINE";
1038                 break;
1039         }
1040
1041         switch (code) {
1042         case DHCPV6_STATUS_OK:
1043                 status = "ok";
1044                 break;
1045         case DHCPV6_STATUS_NOADDRSAVAIL:
1046                 status = "no addresses available";
1047                 break;
1048         case DHCPV6_STATUS_NOBINDING:
1049                 status = "no binding";
1050                 break;
1051         case DHCPV6_STATUS_NOTONLINK:
1052                 status = "not on-link";
1053                 break;
1054         case DHCPV6_STATUS_NOPREFIXAVAIL:
1055                 status = "no prefix available";
1056                 break;
1057         }
1058
1059         char leasebuf[256] = "";
1060
1061         if (a) {
1062                 struct log_ctxt ctxt = {.buf = leasebuf,
1063                                         .buf_len = sizeof(leasebuf),
1064                                         .buf_idx = 0 };
1065
1066                 dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1067         }
1068
1069         syslog(LOG_INFO, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1070                          duidbuf, iface->name, status, leasebuf);
1071 }
1072
1073 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1074                 struct interface *iface)
1075 {
1076         struct odhcpd_ipaddr *addrs = (a && a->managed) ? a->managed : iface->addr6;
1077         size_t addrlen = (a && a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1078         time_t now = odhcpd_time();
1079         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1080         uint16_t otype, olen;
1081         bool onlink = true;
1082
1083         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1084                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix *)&odata[-4];
1085                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr *)&odata[-4];
1086
1087                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
1088                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
1089                         continue;
1090
1091                 onlink = false;
1092                 for (size_t i = 0; i < addrlen; ++i) {
1093                         if (!valid_addr(&addrs[i], now))
1094                                 continue;
1095
1096                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1097                                 if (p->prefix < addrs[i].prefix ||
1098                                     odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
1099                                         continue;
1100
1101                         } else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
1102                                 continue;
1103
1104                         onlink = true;
1105                 }
1106
1107                 if (!onlink)
1108                         break;
1109         }
1110
1111         return onlink;
1112 }
1113
1114 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
1115                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1116 {
1117         struct lease *l;
1118         struct dhcp_assignment *first = NULL;
1119         const struct dhcpv6_client_header *hdr = data;
1120         time_t now = odhcpd_time();
1121         uint16_t otype, olen, clid_len = 0;
1122         uint8_t *start = (uint8_t *)&hdr[1], *odata;
1123         uint8_t *clid_data = NULL, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1124         size_t hostname_len = 0, response_len = 0;
1125         bool notonlink = false, rapid_commit = false, accept_reconf = false;
1126         char duidbuf[261], hostname[256];
1127
1128         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1129                 if (otype == DHCPV6_OPT_CLIENTID) {
1130                         clid_data = odata;
1131                         clid_len = olen;
1132
1133                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1134                                 memcpy(mac, &odata[8], sizeof(mac));
1135                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1136                                 memcpy(mac, &odata[4], sizeof(mac));
1137
1138                         if (olen <= 130)
1139                                 odhcpd_hexlify(duidbuf, odata, olen);
1140                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1141                         uint8_t fqdn_buf[256];
1142                         memcpy(fqdn_buf, odata, olen);
1143                         fqdn_buf[olen++] = 0;
1144
1145                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1146                                 hostname_len = strcspn(hostname, ".");
1147                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1148                         accept_reconf = true;
1149                 else if (otype == DHCPV6_OPT_RAPID_COMMIT && hdr->msg_type == DHCPV6_MSG_SOLICIT)
1150                         rapid_commit = true;
1151         }
1152
1153         if (!clid_data || !clid_len || clid_len > 130)
1154                 goto out;
1155
1156         l = config_find_lease_by_duid(clid_data, clid_len);
1157         if (!l)
1158                 l = config_find_lease_by_mac(mac);
1159
1160         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1161                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1162                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1163                 bool ia_addr_present = false;
1164                 if (!is_pd && !is_na)
1165                         continue;
1166
1167                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1168                 size_t ia_response_len = 0;
1169                 uint8_t reqlen = (is_pd) ? 62 : 128;
1170                 uint32_t reqhint = 0;
1171
1172                 /* Parse request hint for IA-PD */
1173                 if (is_pd) {
1174                         uint8_t *sdata;
1175                         uint16_t stype, slen;
1176                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1177                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1178                                         continue;
1179
1180                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1181                                 if (p->prefix) {
1182                                         reqlen = p->prefix;
1183                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1184                                         if (reqlen > 32 && reqlen <= 64)
1185                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1186                                 }
1187                         }
1188
1189                         if (reqlen > 64)
1190                                 reqlen = 64;
1191                 } else if (is_na) {
1192                         uint8_t *sdata;
1193                         uint16_t stype, slen;
1194                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1195                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1196                                         continue;
1197
1198                                 ia_addr_present = true;
1199                         }
1200                 }
1201
1202                 /* Find assignment */
1203                 struct dhcp_assignment *c, *a = NULL;
1204                 list_for_each_entry(c, &iface->ia_assignments, head) {
1205                         if ((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) &&
1206                             c->iaid == ia->iaid && (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1207                             ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1208                                 a = c;
1209
1210                                 /* Reset state */
1211                                 if (a->flags & OAF_BOUND)
1212                                         apply_lease(a, false);
1213
1214                                 stop_reconf(a);
1215                                 break;
1216                         }
1217                 }
1218
1219                 if (l && a && a->lease != l) {
1220                         free_assignment(a);
1221                         a = NULL;
1222                 }
1223
1224                 /* Generic message handling */
1225                 uint16_t status = DHCPV6_STATUS_OK;
1226                 if (a && a->managed_size < 0)
1227                         return -1;
1228
1229                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1230                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1231                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1232                         bool assigned = !!a;
1233
1234                         if (!a) {
1235                                 if ((!iface->no_dynamic_dhcp || (l && is_na)) &&
1236                                     (iface->dhcpv6_pd || iface->dhcpv6_na)) {
1237                                         /* Create new binding */
1238                                         a = alloc_assignment(clid_len);
1239
1240                                         if (a) {
1241                                                 a->clid_len = clid_len;
1242                                                 memcpy(a->clid_data, clid_data, clid_len);
1243                                                 a->iaid = ia->iaid;
1244                                                 a->length = reqlen;
1245                                                 a->peer = *addr;
1246                                                 a->assigned = is_na && l ? l->hostid : reqhint;
1247                                                 /* Set valid time to 0 for static lease indicating */
1248                                                 /* infinite lifetime otherwise current time        */
1249                                                 a->valid_until = l ? 0 : now;
1250                                                 a->dhcp_free_cb = dhcpv6_ia_free_assignment;
1251                                                 a->iface = iface;
1252                                                 a->flags = OAF_DHCPV6;
1253
1254                                                 if (first)
1255                                                         memcpy(a->key, first->key, sizeof(a->key));
1256                                                 else
1257                                                         odhcpd_urandom(a->key, sizeof(a->key));
1258
1259                                                 if (is_pd && iface->dhcpv6_pd)
1260                                                         while (!(assigned = assign_pd(iface, a)) &&
1261                                                                !a->managed_size && ++a->length <= 64);
1262                                                 else if (is_na && iface->dhcpv6_na)
1263                                                         assigned = assign_na(iface, a);
1264
1265                                                 if (l && assigned) {
1266                                                         a->flags |= OAF_STATIC;
1267
1268                                                         if (l->hostname)
1269                                                                 a->hostname = strdup(l->hostname);
1270
1271                                                         if (l->leasetime)
1272                                                                 a->leasetime = l->leasetime;
1273
1274                                                         list_add(&a->lease_list, &l->assignments);
1275                                                         a->lease = l;
1276                                                 }
1277
1278                                                 if (a->managed_size && !assigned)
1279                                                         return -1;
1280                                         }
1281                                 }
1282                         }
1283
1284                         if (!assigned || iface->addr6_len == 0)
1285                                 /* Set error status */
1286                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1287                         else if (hdr->msg_type == DHCPV6_MSG_REQUEST && !dhcpv6_ia_on_link(ia, a, iface)) {
1288                                 /* Send NOTONLINK staus for the IA */
1289                                 status = DHCPV6_STATUS_NOTONLINK;
1290                                 assigned = false;
1291                         } else if (accept_reconf && assigned && !first &&
1292                                         hdr->msg_type != DHCPV6_MSG_REBIND) {
1293                                 size_t handshake_len = 4;
1294                                 buf[0] = 0;
1295                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1296                                 buf[2] = 0;
1297                                 buf[3] = 0;
1298
1299                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1300                                         struct dhcpv6_auth_reconfigure auth = {
1301                                                 htons(DHCPV6_OPT_AUTH),
1302                                                 htons(sizeof(auth) - 4),
1303                                                 3, 1, 0,
1304                                                 {htonl(time(NULL)), htonl(++serial)},
1305                                                 1,
1306                                                 {0}
1307                                         };
1308                                         memcpy(auth.key, a->key, sizeof(a->key));
1309                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1310                                         handshake_len += sizeof(auth);
1311                                 }
1312
1313
1314                                 buf += handshake_len;
1315                                 buflen -= handshake_len;
1316                                 response_len += handshake_len;
1317
1318                                 first = a;
1319                         }
1320
1321                         ia_response_len = build_ia(buf, buflen, status, ia, a, iface,
1322                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1323
1324                         /* Was only a solicitation: mark binding for removal */
1325                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT && !rapid_commit) {
1326                                 a->flags &= ~OAF_BOUND;
1327                                 a->flags |= OAF_TENTATIVE;
1328
1329                                 if (!(a->flags & OAF_STATIC))
1330                                         /* Keep tentative assignment around for 60 seconds */
1331                                         a->valid_until = now + 60;
1332
1333                         } else if (assigned &&
1334                                    ((hdr->msg_type == DHCPV6_MSG_SOLICIT && rapid_commit) ||
1335                                     hdr->msg_type == DHCPV6_MSG_REQUEST ||
1336                                     hdr->msg_type == DHCPV6_MSG_REBIND)) {
1337                                 if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
1338                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1339                                         if (a->hostname) {
1340                                                 memcpy(a->hostname, hostname, hostname_len);
1341                                                 a->hostname[hostname_len] = 0;
1342
1343                                                 if (odhcpd_valid_hostname(a->hostname))
1344                                                         a->flags &= ~OAF_BROKEN_HOSTNAME;
1345                                                 else
1346                                                         a->flags |= OAF_BROKEN_HOSTNAME;
1347                                         }
1348                                 }
1349                                 a->accept_reconf = accept_reconf;
1350                                 a->flags &= ~OAF_TENTATIVE;
1351                                 a->flags |= OAF_BOUND;
1352                                 apply_lease(a, true);
1353                         } else if (!assigned && a && a->managed_size == 0) {
1354                                 /* Cleanup failed assignment */
1355                                 free_assignment(a);
1356                                 a = NULL;
1357                         }
1358                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1359                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1360                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1361                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1362                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1363                                 status = DHCPV6_STATUS_NOBINDING;
1364                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1365                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1366                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1367                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1368                                 if (a) {
1369                                         a->flags |= OAF_BOUND;
1370                                         apply_lease(a, true);
1371                                 }
1372                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1373                                 if (!(a->flags & OAF_STATIC))
1374                                         a->valid_until = now - 1;
1375
1376                                 if (a->flags & OAF_BOUND) {
1377                                         apply_lease(a, false);
1378                                         a->flags &= ~OAF_BOUND;
1379                                 }
1380                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1381                                 a->flags &= ~OAF_BOUND;
1382
1383                                 if (!(a->flags & OAF_STATIC)) {
1384                                         memset(a->clid_data, 0, a->clid_len);
1385                                         a->valid_until = now + 3600; /* Block address for 1h */
1386                                 }
1387                         }
1388                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1389                         if (ia_addr_present && !dhcpv6_ia_on_link(ia, a, iface)) {
1390                                 notonlink = true;
1391                                 break;
1392                         }
1393
1394                         if (!ia_addr_present || !a || !(a->flags & OAF_BOUND)) {
1395                                 response_len = 0;
1396                                 goto out;
1397                         }
1398                 }
1399
1400                 buf += ia_response_len;
1401                 buflen -= ia_response_len;
1402                 response_len += ia_response_len;
1403                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1404         }
1405
1406         switch (hdr->msg_type) {
1407         case DHCPV6_MSG_RELEASE:
1408         case DHCPV6_MSG_DECLINE:
1409         case DHCPV6_MSG_CONFIRM:
1410                 if (response_len + 6 < buflen) {
1411                         buf[0] = 0;
1412                         buf[1] = DHCPV6_OPT_STATUS;
1413                         buf[2] = 0;
1414                         buf[3] = 2;
1415                         buf[4] = 0;
1416                         buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1417                         response_len += 6;
1418                 }
1419                 break;
1420
1421         default:
1422                 break;
1423         }
1424
1425         dhcpv6_ia_write_statefile();
1426
1427 out:
1428         return response_len;
1429 }