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         if (!enable) {
  66                 struct dhcp_assignment *c;
  67
  68                 while (!list_empty(&iface->ia_assignments)) {
  69                         c = list_first_entry(&iface->ia_assignments, struct dhcp_assignment, head);
  70                         free_assignment(c);
  71                 }
  72         }
  73
  74         if (enable && iface->dhcpv6 == MODE_SERVER) {
  75                 struct dhcp_assignment *border;
  76
  77                 if (list_empty(&iface->ia_assignments)) {
  78                         border = alloc_assignment(0);
  79
  80                         if (!border) {
  81                                 syslog(LOG_ERR, "Failed to alloc border on %s", iface->name);
  82                                 return -1;
  83                         }
  84
  85                         border->length = 64;
  86                         list_add(&border->head, &iface->ia_assignments);
  87                 } else
  88                         border = list_last_entry(&iface->ia_assignments, struct dhcp_assignment, head);
  89
  90                 set_border_assignment_size(iface, border);
  91         }
  92         return 0;
  93 }
  94
  95
  96 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info)
  97 {
  98         struct interface *iface = info->iface;
  99
 100         if (!iface || iface->dhcpv6 != MODE_SERVER)
 101                 return;
 102
 103         switch (event) {
 104         case NETEV_ADDR6LIST_CHANGE:
 105                 handle_addrlist_change(info);
 106                 break;
 107         default:
 108                 break;
 109         }
 110 }
 111
 112
 113 static inline bool valid_prefix_length(const struct dhcp_assignment *a, const uint8_t prefix_length)
 114 {
 115         return (a->managed_size || a->length > prefix_length);
 116 }
 117
 118 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 119 {
 120         return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
 121 }
 122
 123 static size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
 124 {
 125         size_t i, m;
 126
 127         for (i = 0, m = 0; i < addrlen; ++i) {
 128                 if (addrs[i].preferred > addrs[m].preferred ||
 129                                 (addrs[i].preferred == addrs[m].preferred &&
 130                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 131                         m = i;
 132         }
 133
 134         return m;
 135 }
 136
 137 static int send_reconf(struct dhcp_assignment *assign)
 138 {
 139         struct {
 140                 struct dhcpv6_client_header hdr;
 141                 uint16_t srvid_type;
 142                 uint16_t srvid_len;
 143                 uint16_t duid_type;
 144                 uint16_t hardware_type;
 145                 uint8_t mac[6];
 146                 uint16_t msg_type;
 147                 uint16_t msg_len;
 148                 uint8_t msg_id;
 149                 struct dhcpv6_auth_reconfigure auth;
 150                 uint16_t clid_type;
 151                 uint16_t clid_len;
 152                 uint8_t clid_data[128];
 153         } __attribute__((packed)) reconf_msg = {
 154                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 155                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 156                 .srvid_len = htons(10),
 157                 .duid_type = htons(3),
 158                 .hardware_type = htons(1),
 159                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 160                 .msg_len = htons(1),
 161                 .msg_id = DHCPV6_MSG_RENEW,
 162                 .auth = {htons(DHCPV6_OPT_AUTH),
 163                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 164                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 165                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 166                 .clid_len = htons(assign->clid_len),
 167                 .clid_data = {0},
 168         };
 169         struct interface *iface = assign->iface;
 170
 171         odhcpd_get_mac(iface, reconf_msg.mac);
 172         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 173         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 174
 175         md5_ctx_t md5;
 176         uint8_t secretbytes[64];
 177         memset(secretbytes, 0, sizeof(secretbytes));
 178         memcpy(secretbytes, assign->key, sizeof(assign->key));
 179
 180         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 181                 secretbytes[i] ^= 0x36;
 182
 183         md5_begin(&md5);
 184         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 185         md5_hash(iov.iov_base, iov.iov_len, &md5);
 186         md5_end(reconf_msg.auth.key, &md5);
 187
 188         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 189                 secretbytes[i] ^= 0x36;
 190                 secretbytes[i] ^= 0x5c;
 191         }
 192
 193         md5_begin(&md5);
 194         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 195         md5_hash(reconf_msg.auth.key, 16, &md5);
 196         md5_end(reconf_msg.auth.key, &md5);
 197
 198         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 199 }
 200
 201 static void dhcpv6_ia_free_assignment(struct dhcp_assignment *a)
 202 {
 203         if (a->managed_sock.fd.registered) {
 204                 ustream_free(&a->managed_sock.stream);
 205                 close(a->managed_sock.fd.fd);
 206         }
 207
 208         if (a->reconf_cnt)
 209                 stop_reconf(a);
 210
 211         free(a->managed);
 212 }
 213
 214 void dhcpv6_ia_enum_addrs(struct interface *iface, struct dhcp_assignment *c,
 215                           time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
 216 {
 217         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->addr6;
 218         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->addr6_len;
 219         size_t m = get_preferred_addr(addrs, addrlen);
 220
 221         for (size_t i = 0; i < addrlen; ++i) {
 222                 struct in6_addr addr;
 223                 uint32_t pref, valid;
 224                 int prefix = c->managed ? addrs[i].prefix : c->length;
 225
 226                 if (!valid_addr(&addrs[i], now))
 227                         continue;
 228
 229                 addr = addrs[i].addr.in6;
 230                 pref = addrs[i].preferred;
 231                 valid = addrs[i].valid;
 232                 if (prefix == 128) {
 233                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 234                                 continue;
 235
 236                         addr.s6_addr32[3] = htonl(c->assigned);
 237                 } else {
 238                         if (!valid_prefix_length(c, addrs[i].prefix))
 239                                 continue;
 240
 241                         addr.s6_addr32[1] |= htonl(c->assigned);
 242                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 243                 }
 244
 245                 if (pref != UINT32_MAX)
 246                         pref -= now;
 247
 248                 if (valid != UINT32_MAX)
 249                         valid -= now;
 250
 251                 func(&addr, prefix, pref, valid, arg);
 252         }
 253 }
 254
 255 struct write_ctxt {
 256         FILE *fp;
 257         md5_ctx_t md5;
 258         struct dhcp_assignment *c;
 259         struct interface *iface;
 260         char *buf;
 261         int buf_len;
 262         int buf_idx;
 263 };
 264
 265 static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 266                                 _unused uint32_t valid, void *arg)
 267 {
 268         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
 269         char ipbuf[INET6_ADDRSTRLEN];
 270
 271         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 272
 273         if (ctxt->c->length == 128 && ctxt->c->hostname &&
 274             !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
 275                 fputs(ipbuf, ctxt->fp);
 276
 277                 char b[256];
 278                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
 279                                 ctxt->iface->search, b, sizeof(b)) > 0)
 280                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
 281
 282                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
 283                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
 284                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
 285         }
 286
 287         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
 288                                         "%s/%d ", ipbuf, prefix);
 289 }
 290
 291 void dhcpv6_ia_write_statefile(void)
 292 {
 293         struct write_ctxt ctxt;
 294
 295         md5_begin(&ctxt.md5);
 296
 297         if (config.dhcp_statefile) {
 298                 time_t now = odhcpd_time(), wall_time = time(NULL);
 299                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 300                 char leasebuf[512];
 301
 302                 if (fd < 0)
 303                         return;
 304                 int ret;
 305                 ret = lockf(fd, F_LOCK, 0);
 306                 if (ret < 0) {
 307                         close(fd);
 308                         return;
 309                 }
 310                 if (ftruncate(fd, 0) < 0) {}
 311
 312                 ctxt.fp = fdopen(fd, "w");
 313                 if (!ctxt.fp) {
 314                         close(fd);
 315                         return;
 316                 }
 317
 318                 ctxt.buf = leasebuf;
 319                 ctxt.buf_len = sizeof(leasebuf);
 320
 321                 avl_for_each_element(&interfaces, ctxt.iface, avl) {
 322                         if (ctxt.iface->dhcpv6 != MODE_SERVER &&
 323                                         ctxt.iface->dhcpv4 != MODE_SERVER)
 324                                 continue;
 325
 326                         if (ctxt.iface->dhcpv6 == MODE_SERVER) {
 327                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 328                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 329                                                 continue;
 330
 331                                         char duidbuf[264];
 332
 333                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
 334
 335                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 336                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s%s %ld %x %u ",
 337                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
 338                                                                 (ctxt.c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 339                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
 340                                                                 (ctxt.c->valid_until > now ?
 341                                                                         (ctxt.c->valid_until - now + wall_time) :
 342                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)),
 343                                                                 ctxt.c->assigned, (unsigned)ctxt.c->length);
 344
 345                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
 346                                                 dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
 347                                                                         dhcpv6_write_ia_addr, &ctxt);
 348
 349                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 350                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 351                                 }
 352                         }
 353
 354                         if (ctxt.iface->dhcpv4 == MODE_SERVER) {
 355                                 struct dhcp_assignment *c;
 356
 357                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 358                                         if (!(c->flags & OAF_BOUND))
 359                                                 continue;
 360
 361                                         char ipbuf[INET6_ADDRSTRLEN];
 362                                         char duidbuf[16];
 363                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 364
 365                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 366                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s%s %ld %x 32 ",
 367                                                                 ctxt.iface->ifname, duidbuf,
 368                                                                 (c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 369                                                                 (c->hostname ? c->hostname : "-"),
 370                                                                 (c->valid_until > now ?
 371                                                                         (c->valid_until - now + wall_time) :
 372                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 373                                                                 ntohl(c->addr));
 374
 375                                         struct in_addr addr = {.s_addr = c->addr};
 376                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 377
 378                                         if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
 379                                                 fputs(ipbuf, ctxt.fp);
 380
 381                                                 char b[256];
 382                                                 if (dn_expand(ctxt.iface->search,
 383                                                                 ctxt.iface->search + ctxt.iface->search_len,
 384                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
 385                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
 386
 387                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
 388                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
 389                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
 390                                         }
 391
 392                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
 393                                                                         ctxt.buf_len - ctxt.buf_idx,
 394                                                                         "%s/32 ", ipbuf);
 395                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 396                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 397                                 }
 398                         }
 399                 }
 400
 401                 fclose(ctxt.fp);
 402         }
 403
 404         uint8_t newmd5[16];
 405         md5_end(newmd5, &ctxt.md5);
 406
 407         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 408                 memcpy(statemd5, newmd5, sizeof(statemd5));
 409                 char *argv[2] = {config.dhcp_cb, NULL};
 410                 if (!vfork()) {
 411                         execv(argv[0], argv);
 412                         _exit(128);
 413                 }
 414         }
 415 }
 416
 417 static void __apply_lease(struct interface *iface, struct dhcp_assignment *a,
 418                 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
 419 {
 420         if (a->length > 64)
 421                 return;
 422
 423         for (ssize_t i = 0; i < addr_len; ++i) {
 424                 struct in6_addr prefix = addrs[i].addr.in6;
 425                 prefix.s6_addr32[1] |= htonl(a->assigned);
 426                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
 427                 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 428                                 iface->ifindex, &a->peer.sin6_addr, 1024, add);
 429         }
 430 }
 431
 432 static void apply_lease(struct interface *iface, struct dhcp_assignment *a, bool add)
 433 {
 434         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 435         ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
 436
 437         __apply_lease(iface, a, addrs, addrlen, add);
 438 }
 439
 440 /* Set border assignment size based on the IPv6 address prefixes */
 441 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b)
 442 {
 443         time_t now = odhcpd_time();
 444         int minprefix = -1;
 445
 446         for (size_t i = 0; i < iface->addr6_len; ++i) {
 447                 if (iface->addr6[i].preferred > (uint32_t)now &&
 448                                 iface->addr6[i].prefix < 64 &&
 449                                 iface->addr6[i].prefix > minprefix)
 450                         minprefix = iface->addr6[i].prefix;
 451         }
 452
 453         if (minprefix > 32 && minprefix <= 64)
 454                 b->assigned = 1U << (64 - minprefix);
 455         else
 456                 b->assigned = 0;
 457 }
 458
 459 /* More data was received from TCP connection */
 460 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 461 {
 462         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 463         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
 464         time_t now = odhcpd_time();
 465         bool first = c->managed_size < 0;
 466
 467         for (;;) {
 468                 int pending;
 469                 char *data = ustream_get_read_buf(s, &pending);
 470                 char *end = memmem(data, pending, "\n\n", 2);
 471
 472                 if (!end)
 473                         break;
 474
 475                 end += 2;
 476                 end[-1] = 0;
 477
 478                 c->managed_size = 0;
 479                 if (c->accept_reconf)
 480                         c->reconf_cnt = 1;
 481
 482                 char *saveptr;
 483                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 484                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 485                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 486
 487                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 488                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 489                                 continue;
 490
 491                         x = strtok_r(NULL, ",", &saveptr2);
 492                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 493                                 continue;
 494
 495                         x = strtok_r(NULL, ",", &saveptr2);
 496                         if (sscanf(x, "%u", &n->preferred) < 1)
 497                                 continue;
 498
 499                         x = strtok_r(NULL, ",", &saveptr2);
 500                         if (sscanf(x, "%u", &n->valid) < 1)
 501                                 continue;
 502
 503                         if (n->preferred > n->valid)
 504                                 continue;
 505
 506                         if (UINT32_MAX - now < n->preferred)
 507                                 n->preferred = UINT32_MAX;
 508                         else
 509                                 n->preferred += now;
 510
 511                         if (UINT32_MAX - now < n->valid)
 512                                 n->valid = UINT32_MAX;
 513                         else
 514                                 n->valid += now;
 515
 516                         n->dprefix = 0;
 517
 518                         ++c->managed_size;
 519                 }
 520
 521                 ustream_consume(s, end - data);
 522         }
 523
 524         if (first && c->managed_size == 0)
 525                 free_assignment(c);
 526         else if (first && !(c->flags & OAF_STATIC))
 527                 c->valid_until = now + 150;
 528 }
 529
 530
 531 /* TCP transmission has ended, either because of success or timeout or other error */
 532 static void managed_handle_pd_done(struct ustream *s)
 533 {
 534         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 535         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
 536
 537         if (!(c->flags & OAF_STATIC))
 538                 c->valid_until = odhcpd_time() + 15;
 539
 540         c->managed_size = 0;
 541
 542         if (c->accept_reconf)
 543                 c->reconf_cnt = 1;
 544 }
 545
 546 static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
 547 {
 548         struct dhcp_assignment *c;
 549
 550         if (iface->dhcpv6_pd_manager[0]) {
 551                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 552                 if (fd >= 0) {
 553                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 554                         char iaidbuf[298];
 555
 556                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 557
 558                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 559                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 560                         ustream_fd_init(&assign->managed_sock, fd);
 561                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 562                                         iaidbuf, assign->iaid, assign->length);
 563                         ustream_write_pending(&assign->managed_sock.stream);
 564                         assign->managed_size = -1;
 565
 566                         if (!(assign->flags & OAF_STATIC))
 567                                 assign->valid_until = odhcpd_time() + 15;
 568
 569                         list_add(&assign->head, &iface->ia_assignments);
 570
 571                         /* Wait initial period of up to 250ms for immediate assignment */
 572                         if (poll(&pfd, 1, 250) < 0) {
 573                                 syslog(LOG_ERR, "poll(): %m");
 574                                 return false;
 575                         }
 576
 577                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 578
 579                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 580                                 return true;
 581                 }
 582
 583                 return false;
 584         } else if (iface->addr6_len < 1)
 585                 return false;
 586
 587         /* Try honoring the hint first */
 588         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 589         if (assign->assigned) {
 590                 list_for_each_entry(c, &iface->ia_assignments, head) {
 591                         if (c->length == 128 || c->length == 0)
 592                                 continue;
 593
 594                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 595                                 list_add_tail(&assign->head, &c->head);
 596
 597                                 if (assign->flags & OAF_BOUND)
 598                                         apply_lease(iface, assign, true);
 599
 600                                 return true;
 601                         }
 602
 603                         if (c->assigned != 0)
 604                                 current = (c->assigned + (1 << (64 - c->length)));
 605                 }
 606         }
 607
 608         /* Fallback to a variable assignment */
 609         current = 1;
 610         list_for_each_entry(c, &iface->ia_assignments, head) {
 611                 if (c->length == 128 || c->length == 0)
 612                         continue;
 613
 614                 current = (current + asize) & (~asize);
 615                 if (current + asize < c->assigned) {
 616                         assign->assigned = current;
 617                         list_add_tail(&assign->head, &c->head);
 618
 619                         if (assign->flags & OAF_BOUND)
 620                                 apply_lease(iface, assign, true);
 621
 622                         return true;
 623                 }
 624
 625                 if (c->assigned != 0)
 626                         current = (c->assigned + (1 << (64 - c->length)));
 627         }
 628
 629         return false;
 630 }
 631
 632 static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
 633 {
 634         struct dhcp_assignment *c;
 635         uint32_t seed = 0;
 636
 637         /* Preconfigured assignment by static lease */
 638         if (a->assigned) {
 639                 list_for_each_entry(c, &iface->ia_assignments, head) {
 640                         if (c->length == 0)
 641                                 continue;
 642
 643                         if (c->assigned > a->assigned || c->length != 128) {
 644                                 list_add_tail(&a->head, &c->head);
 645                                 return true;
 646                         } else if (c->assigned == a->assigned)
 647                                 return false;
 648                 }
 649         }
 650
 651         /* Seed RNG with checksum of DUID */
 652         for (size_t i = 0; i < a->clid_len; ++i)
 653                 seed += a->clid_data[i];
 654         srand(seed);
 655
 656         /* Try to assign up to 100x */
 657         for (size_t i = 0; i < 100; ++i) {
 658                 uint32_t try;
 659                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 660
 661                 if (config_find_lease_by_hostid(try))
 662                         continue;
 663
 664                 list_for_each_entry(c, &iface->ia_assignments, head) {
 665                         if (c->length == 0)
 666                                 continue;
 667
 668                         if (c->assigned > try || c->length != 128) {
 669                                 a->assigned = try;
 670                                 list_add_tail(&a->head, &c->head);
 671                                 return true;
 672                         } else if (c->assigned == try)
 673                                 break;
 674                 }
 675         }
 676
 677         return false;
 678 }
 679
 680 static void handle_addrlist_change(struct netevent_handler_info *info)
 681 {
 682         struct interface *iface = info->iface;
 683         struct dhcp_assignment *c, *d, *border = list_last_entry(
 684                         &iface->ia_assignments, struct dhcp_assignment, head);
 685         struct list_head reassign = LIST_HEAD_INIT(reassign);
 686         time_t now = odhcpd_time();
 687
 688         list_for_each_entry(c, &iface->ia_assignments, head) {
 689                 if (c != border && iface->ra_managed == RA_MANAGED_NO_MFLAG
 690                                 && (c->flags & OAF_BOUND))
 691                         __apply_lease(iface, c, info->addrs_old.addrs,
 692                                         info->addrs_old.len, false);
 693         }
 694
 695         set_border_assignment_size(iface, border);
 696
 697         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 698                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 699                                 c->managed_size)
 700                         continue;
 701
 702                 if (c->length < 128 && c->assigned >= border->assigned && c != border)
 703                         list_move(&c->head, &reassign);
 704                 else if (c != border && (c->flags & OAF_BOUND))
 705                         apply_lease(iface, c, true);
 706
 707                 if (c->accept_reconf && c->reconf_cnt == 0) {
 708                         struct dhcp_assignment *a;
 709
 710                         start_reconf(c);
 711
 712                         /* Leave all other assignments of that client alone */
 713                         list_for_each_entry(a, &iface->ia_assignments, head)
 714                                 if (a != c && a->clid_len == c->clid_len &&
 715                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 716                                         a->reconf_cnt = INT_MAX;
 717                 }
 718         }
 719
 720         while (!list_empty(&reassign)) {
 721                 c = list_first_entry(&reassign, struct dhcp_assignment, head);
 722                 list_del_init(&c->head);
 723                 if (!assign_pd(iface, c)) {
 724                         c->assigned = 0;
 725                         list_add(&c->head, &iface->ia_assignments);
 726                 }
 727         }
 728
 729         dhcpv6_ia_write_statefile();
 730 }
 731
 732 static void reconf_timeout_cb(struct uloop_timeout *event)
 733 {
 734         struct dhcp_assignment *a = container_of(event, struct dhcp_assignment, reconf_timer);
 735
 736         if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
 737                 send_reconf(a);
 738                 uloop_timeout_set(&a->reconf_timer,
 739                                         DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 740                 a->reconf_cnt++;
 741         } else
 742                 stop_reconf(a);
 743 }
 744
 745 static void start_reconf(struct dhcp_assignment *a)
 746 {
 747         uloop_timeout_set(&a->reconf_timer,
 748                                 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 749         a->reconf_timer.cb = reconf_timeout_cb;
 750         a->reconf_cnt++;
 751
 752         send_reconf(a);
 753 }
 754
 755 static void stop_reconf(struct dhcp_assignment *a)
 756 {
 757         uloop_timeout_cancel(&a->reconf_timer);
 758         a->reconf_cnt = 0;
 759         a->reconf_timer.cb = NULL;
 760 }
 761
 762 static void valid_until_cb(struct uloop_timeout *event)
 763 {
 764         struct interface *iface;
 765         time_t now = odhcpd_time();
 766
 767         avl_for_each_element(&interfaces, iface, avl) {
 768                 struct dhcp_assignment *a, *n;
 769
 770                 if (iface->dhcpv6 != MODE_SERVER)
 771                         continue;
 772
 773                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 774                         if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
 775                                 if ((a->length < 128 && a->clid_len > 0) ||
 776                                                 (a->length == 128 && a->clid_len == 0))
 777                                         free_assignment(a);
 778
 779                         }
 780                 }
 781         }
 782         uloop_timeout_set(event, 1000);
 783 }
 784
 785 static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 786                 const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
 787                 struct interface *iface, bool request)
 788 {
 789         struct dhcpv6_ia_hdr o_ia = {
 790                 .type = ia->type,
 791                 .len = 0,
 792                 .iaid = ia->iaid,
 793                 .t1 = 0,
 794                 .t2 = 0,
 795         };
 796         size_t ia_len = sizeof(o_ia);
 797         time_t now = odhcpd_time();
 798
 799         if (buflen < ia_len)
 800                 return 0;
 801
 802         if (status) {
 803                 struct __attribute__((packed)) {
 804                         uint16_t type;
 805                         uint16_t len;
 806                         uint16_t val;
 807                 } o_status = {
 808                         .type = htons(DHCPV6_OPT_STATUS),
 809                         .len = htons(sizeof(o_status) - 4),
 810                         .val = htons(status),
 811                 };
 812
 813                 memcpy(buf + ia_len, &o_status, sizeof(o_status));
 814                 ia_len += sizeof(o_status);
 815
 816                 o_ia.len = htons(ia_len - 4);
 817                 memcpy(buf, &o_ia, sizeof(o_ia));
 818
 819                 return ia_len;
 820         }
 821
 822         if (a) {
 823                 uint32_t leasetime;
 824
 825                 if (a->leasetime)
 826                         leasetime = a->leasetime;
 827                 else
 828                         leasetime = iface->dhcpv4_leasetime;
 829
 830                 uint32_t pref = leasetime;
 831                 uint32_t valid = leasetime;
 832
 833                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 834                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
 835                 size_t m = get_preferred_addr(addrs, addrlen);
 836
 837                 for (size_t i = 0; i < addrlen; ++i) {
 838                         uint32_t prefix_pref = addrs[i].preferred;
 839                         uint32_t prefix_valid = addrs[i].valid;
 840
 841                         if (!valid_addr(&addrs[i], now))
 842                                 continue;
 843
 844                         if (prefix_pref != UINT32_MAX)
 845                                 prefix_pref -= now;
 846
 847                         if (prefix_valid != UINT32_MAX)
 848                                 prefix_valid -= now;
 849
 850                         if (a->length < 128) {
 851                                 struct dhcpv6_ia_prefix o_ia_p = {
 852                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 853                                         .len = htons(sizeof(o_ia_p) - 4),
 854                                         .preferred = htonl(prefix_pref),
 855                                         .valid = htonl(prefix_valid),
 856                                         .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 857                                         .addr = addrs[i].addr.in6,
 858                                 };
 859
 860                                 o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned);
 861                                 o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0;
 862
 863                                 if ((a->assigned == 0 && a->managed_size == 0) ||
 864                                                 !valid_prefix_length(a, addrs[i].prefix))
 865                                         continue;
 866
 867                                 if (buflen < ia_len + sizeof(o_ia_p))
 868                                         return 0;
 869
 870                                 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
 871                                 ia_len += sizeof(o_ia_p);
 872                         } else {
 873                                 struct dhcpv6_ia_addr o_ia_a = {
 874                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 875                                         .len = htons(sizeof(o_ia_a) - 4),
 876                                         .addr = addrs[i].addr.in6,
 877                                         .preferred = htonl(prefix_pref),
 878                                         .valid = htonl(prefix_valid)
 879                                 };
 880
 881                                 o_ia_a.addr.s6_addr32[3] = htonl(a->assigned);
 882
 883                                 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
 884                                                 a->assigned == 0)
 885                                         continue;
 886
 887                                 if (buflen < ia_len + sizeof(o_ia_a))
 888                                         return 0;
 889
 890                                 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
 891                                 ia_len += sizeof(o_ia_a);
 892                         }
 893
 894                         /* Calculate T1 / T2 based on non-deprecated addresses */
 895                         if (prefix_pref > 0) {
 896                                 if (prefix_pref < pref)
 897                                         pref = prefix_pref;
 898
 899                                 if (prefix_valid < valid)
 900                                         valid = prefix_valid;
 901                         }
 902                 }
 903
 904                 if (!INFINITE_VALID(a->valid_until))
 905                         /* UINT32_MAX is considered as infinite leasetime */
 906                         a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 907
 908                 o_ia.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 909                 o_ia.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 910
 911                 if (!o_ia.t1)
 912                         o_ia.t1 = htonl(1);
 913
 914                 if (!o_ia.t2)
 915                         o_ia.t2 = htonl(1);
 916         }
 917
 918         if (!request) {
 919                 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 920                 uint16_t otype, olen;
 921
 922                 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 923                         struct dhcpv6_ia_prefix *ia_p = (struct dhcpv6_ia_prefix *)&odata[-4];
 924                         struct dhcpv6_ia_addr *ia_a = (struct dhcpv6_ia_addr *)&odata[-4];
 925                         bool found = false;
 926
 927                         if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*ia_p) - 4) &&
 928                                         (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*ia_a) - 4))
 929                                 continue;
 930
 931                         if (a) {
 932                                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 933                                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
 934
 935                                 for (size_t i = 0; i < addrlen; ++i) {
 936                                         if (!valid_addr(&addrs[i], now))
 937                                                 continue;
 938
 939                                         struct in6_addr addr = addrs[i].addr.in6;
 940                                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 941                                                 addr.s6_addr32[1] |= htonl(a->assigned);
 942                                                 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 943
 944                                                 if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) &&
 945                                                                 ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 946                                                         found = true;
 947                                         } else {
 948                                                 addr.s6_addr32[3] = htonl(a->assigned);
 949
 950                                                 if (!memcmp(&ia_a->addr, &addr, sizeof(addr)))
 951                                                         found = true;
 952                                         }
 953                                 }
 954                         }
 955
 956                         if (!found) {
 957                                 if (otype == DHCPV6_OPT_IA_PREFIX) {
 958                                         struct dhcpv6_ia_prefix o_ia_p = {
 959                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 960                                                 .len = htons(sizeof(o_ia_p) - 4),
 961                                                 .preferred = 0,
 962                                                 .valid = 0,
 963                                                 .prefix = ia_p->prefix,
 964                                                 .addr = ia_p->addr,
 965                                         };
 966
 967                                         if (buflen < ia_len + sizeof(o_ia_p))
 968                                                 return 0;
 969
 970                                         memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
 971                                         ia_len += sizeof(o_ia_p);
 972                                 } else {
 973                                         struct dhcpv6_ia_addr o_ia_a = {
 974                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 975                                                 .len = htons(sizeof(o_ia_a) - 4),
 976                                                 .addr = ia_a->addr,
 977                                                 .preferred = 0,
 978                                                 .valid = 0,
 979                                         };
 980
 981                                         if (buflen < ia_len + sizeof(o_ia_a))
 982                                                 continue;
 983
 984                                         memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
 985                                         ia_len += sizeof(o_ia_a);
 986                                 }
 987                         }
 988                 }
 989         }
 990
 991         o_ia.len = htons(ia_len - 4);
 992         memcpy(buf, &o_ia, sizeof(o_ia));
 993         return ia_len;
 994 }
 995
 996 struct log_ctxt {
 997         char *buf;
 998         int buf_len;
 999         int buf_idx;
1000 };
1001
1002 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
1003                                 _unused uint32_t valid, void *arg)
1004 {
1005         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1006         char addrbuf[INET6_ADDRSTRLEN];
1007
1008         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1009         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1010                                         "%s/%d ", addrbuf, prefix);
1011 }
1012
1013 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1014                 const char *duidbuf, bool is_pd, struct dhcp_assignment *a, int code)
1015 {
1016         const char *type = "UNKNOWN";
1017         const char *status = "UNKNOWN";
1018
1019         switch (msgtype) {
1020         case DHCPV6_MSG_SOLICIT:
1021                 type = "SOLICIT";
1022                 break;
1023         case DHCPV6_MSG_REQUEST:
1024                 type = "REQUEST";
1025                 break;
1026         case DHCPV6_MSG_CONFIRM:
1027                 type = "CONFIRM";
1028                 break;
1029         case DHCPV6_MSG_RENEW:
1030                 type = "RENEW";
1031                 break;
1032         case DHCPV6_MSG_REBIND:
1033                 type = "REBIND";
1034                 break;
1035         case DHCPV6_MSG_RELEASE:
1036                 type = "RELEASE";
1037                 break;
1038         case DHCPV6_MSG_DECLINE:
1039                 type = "DECLINE";
1040                 break;
1041         }
1042
1043         switch (code) {
1044         case DHCPV6_STATUS_OK:
1045                 status = "ok";
1046                 break;
1047         case DHCPV6_STATUS_NOADDRSAVAIL:
1048                 status = "no addresses available";
1049                 break;
1050         case DHCPV6_STATUS_NOBINDING:
1051                 status = "no binding";
1052                 break;
1053         case DHCPV6_STATUS_NOTONLINK:
1054                 status = "not on-link";
1055                 break;
1056         case DHCPV6_STATUS_NOPREFIXAVAIL:
1057                 status = "no prefix available";
1058                 break;
1059         }
1060
1061         char leasebuf[256] = "";
1062
1063         if (a) {
1064                 struct log_ctxt ctxt = {.buf = leasebuf,
1065                                         .buf_len = sizeof(leasebuf),
1066                                         .buf_idx = 0 };
1067
1068                 dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1069         }
1070
1071         syslog(LOG_NOTICE, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1072                         duidbuf, iface->name, status, leasebuf);
1073 }
1074
1075 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1076                 struct interface *iface)
1077 {
1078         struct odhcpd_ipaddr *addrs = (a && a->managed) ? a->managed : iface->addr6;
1079         size_t addrlen = (a && a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1080         time_t now = odhcpd_time();
1081         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1082         uint16_t otype, olen;
1083         bool onlink = true;
1084
1085         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1086                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix *)&odata[-4];
1087                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr *)&odata[-4];
1088
1089                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
1090                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
1091                         continue;
1092
1093                 onlink = false;
1094                 for (size_t i = 0; i < addrlen; ++i) {
1095                         if (!valid_addr(&addrs[i], now))
1096                                 continue;
1097
1098                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1099                                 if (p->prefix < addrs[i].prefix ||
1100                                     odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
1101                                         continue;
1102
1103                         } else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
1104                                 continue;
1105
1106                         onlink = true;
1107                 }
1108
1109                 if (!onlink)
1110                         break;
1111         }
1112
1113         return onlink;
1114 }
1115
1116 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
1117                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1118 {
1119         struct lease *l;
1120         struct dhcp_assignment *first = NULL;
1121         const struct dhcpv6_client_header *hdr = data;
1122         time_t now = odhcpd_time();
1123         uint16_t otype, olen, clid_len = 0;
1124         uint8_t *start = (uint8_t *)&hdr[1], *odata;
1125         uint8_t *clid_data = NULL, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1126         size_t hostname_len = 0, response_len = 0;
1127         bool notonlink = false, rapid_commit = false, accept_reconf = false;
1128         char duidbuf[261], hostname[256];
1129
1130         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1131                 if (otype == DHCPV6_OPT_CLIENTID) {
1132                         clid_data = odata;
1133                         clid_len = olen;
1134
1135                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1136                                 memcpy(mac, &odata[8], sizeof(mac));
1137                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1138                                 memcpy(mac, &odata[4], sizeof(mac));
1139
1140                         if (olen <= 130)
1141                                 odhcpd_hexlify(duidbuf, odata, olen);
1142                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1143                         uint8_t fqdn_buf[256];
1144                         memcpy(fqdn_buf, odata, olen);
1145                         fqdn_buf[olen++] = 0;
1146
1147                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1148                                 hostname_len = strcspn(hostname, ".");
1149                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1150                         accept_reconf = true;
1151                 else if (otype == DHCPV6_OPT_RAPID_COMMIT && hdr->msg_type == DHCPV6_MSG_SOLICIT)
1152                         rapid_commit = true;
1153         }
1154
1155         if (!clid_data || !clid_len || clid_len > 130)
1156                 goto out;
1157
1158         l = config_find_lease_by_duid(clid_data, clid_len);
1159         if (!l)
1160                 l = config_find_lease_by_mac(mac);
1161
1162         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1163                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1164                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1165                 bool ia_addr_present = false;
1166                 if (!is_pd && !is_na)
1167                         continue;
1168
1169                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1170                 size_t ia_response_len = 0;
1171                 uint8_t reqlen = (is_pd) ? 62 : 128;
1172                 uint32_t reqhint = 0;
1173
1174                 /* Parse request hint for IA-PD */
1175                 if (is_pd) {
1176                         uint8_t *sdata;
1177                         uint16_t stype, slen;
1178                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1179                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1180                                         continue;
1181
1182                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1183                                 if (p->prefix) {
1184                                         reqlen = p->prefix;
1185                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1186                                         if (reqlen > 32 && reqlen <= 64)
1187                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1188                                 }
1189                         }
1190
1191                         if (reqlen > 64)
1192                                 reqlen = 64;
1193                 } else if (is_na) {
1194                         uint8_t *sdata;
1195                         uint16_t stype, slen;
1196                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1197                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1198                                         continue;
1199
1200                                 ia_addr_present = true;
1201                         }
1202                 }
1203
1204                 /* Find assignment */
1205                 struct dhcp_assignment *c, *a = NULL;
1206                 list_for_each_entry(c, &iface->ia_assignments, head) {
1207                         if ((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) &&
1208                             c->iaid == ia->iaid && (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1209                             ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1210                                 a = c;
1211
1212                                 /* Reset state */
1213                                 if (a->flags & OAF_BOUND)
1214                                         apply_lease(iface, a, false);
1215
1216                                 stop_reconf(a);
1217                                 break;
1218                         }
1219                 }
1220
1221                 if (l && a && a->lease != l) {
1222                         free_assignment(a);
1223                         a = NULL;
1224                 }
1225
1226                 /* Generic message handling */
1227                 uint16_t status = DHCPV6_STATUS_OK;
1228                 if (a && a->managed_size < 0)
1229                         return -1;
1230
1231                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1232                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1233                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1234                         bool assigned = !!a;
1235
1236                         if (!a) {
1237                                 if ((!iface->no_dynamic_dhcp || (l && is_na)) &&
1238                                     (iface->dhcpv6_pd || iface->dhcpv6_na)) {
1239                                         /* Create new binding */
1240                                         a = alloc_assignment(clid_len);
1241
1242                                         if (a) {
1243                                                 a->clid_len = clid_len;
1244                                                 memcpy(a->clid_data, clid_data, clid_len);
1245                                                 a->iaid = ia->iaid;
1246                                                 a->length = reqlen;
1247                                                 a->peer = *addr;
1248                                                 a->assigned = is_na && l ? l->hostid : reqhint;
1249                                                 /* Set valid time to 0 for static lease indicating */
1250                                                 /* infinite lifetime otherwise current time        */
1251                                                 a->valid_until = l ? 0 : now;
1252                                                 a->dhcp_free_cb = dhcpv6_ia_free_assignment;
1253                                                 a->iface = iface;
1254                                                 a->flags = OAF_DHCPV6;
1255
1256                                                 if (first)
1257                                                         memcpy(a->key, first->key, sizeof(a->key));
1258                                                 else
1259                                                         odhcpd_urandom(a->key, sizeof(a->key));
1260
1261                                                 if (is_pd && iface->dhcpv6_pd)
1262                                                         while (!(assigned = assign_pd(iface, a)) &&
1263                                                                !a->managed_size && ++a->length <= 64);
1264                                                 else if (is_na && iface->dhcpv6_na)
1265                                                         assigned = assign_na(iface, a);
1266
1267                                                 if (l && assigned) {
1268                                                         a->flags |= OAF_STATIC;
1269
1270                                                         if (l->hostname)
1271                                                                 a->hostname = strdup(l->hostname);
1272
1273                                                         if (l->leasetime)
1274                                                                 a->leasetime = l->leasetime;
1275
1276                                                         list_add(&a->lease_list, &l->assignments);
1277                                                         a->lease = l;
1278                                                 }
1279
1280                                                 if (a->managed_size && !assigned)
1281                                                         return -1;
1282                                         }
1283                                 }
1284                         }
1285
1286                         if (!assigned || iface->addr6_len == 0)
1287                                 /* Set error status */
1288                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1289                         else if (hdr->msg_type == DHCPV6_MSG_REQUEST && !dhcpv6_ia_on_link(ia, a, iface)) {
1290                                 /* Send NOTONLINK staus for the IA */
1291                                 status = DHCPV6_STATUS_NOTONLINK;
1292                                 assigned = false;
1293                         } else if (accept_reconf && assigned && !first &&
1294                                         hdr->msg_type != DHCPV6_MSG_REBIND) {
1295                                 size_t handshake_len = 4;
1296                                 buf[0] = 0;
1297                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1298                                 buf[2] = 0;
1299                                 buf[3] = 0;
1300
1301                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1302                                         struct dhcpv6_auth_reconfigure auth = {
1303                                                 htons(DHCPV6_OPT_AUTH),
1304                                                 htons(sizeof(auth) - 4),
1305                                                 3, 1, 0,
1306                                                 {htonl(time(NULL)), htonl(++serial)},
1307                                                 1,
1308                                                 {0}
1309                                         };
1310                                         memcpy(auth.key, a->key, sizeof(a->key));
1311                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1312                                         handshake_len += sizeof(auth);
1313                                 }
1314
1315
1316                                 buf += handshake_len;
1317                                 buflen -= handshake_len;
1318                                 response_len += handshake_len;
1319
1320                                 first = a;
1321                         }
1322
1323                         ia_response_len = build_ia(buf, buflen, status, ia, a, iface,
1324                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1325
1326                         /* Was only a solicitation: mark binding for removal */
1327                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT && !rapid_commit) {
1328                                 a->flags &= ~OAF_BOUND;
1329                                 a->flags |= OAF_TENTATIVE;
1330
1331                                 if (!(a->flags & OAF_STATIC))
1332                                         /* Keep tentative assignment around for 60 seconds */
1333                                         a->valid_until = now + 60;
1334
1335                         } else if (assigned &&
1336                                    ((hdr->msg_type == DHCPV6_MSG_SOLICIT && rapid_commit) ||
1337                                     hdr->msg_type == DHCPV6_MSG_REQUEST ||
1338                                     hdr->msg_type == DHCPV6_MSG_REBIND)) {
1339                                 if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
1340                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1341                                         if (a->hostname) {
1342                                                 memcpy(a->hostname, hostname, hostname_len);
1343                                                 a->hostname[hostname_len] = 0;
1344
1345                                                 if (odhcpd_valid_hostname(a->hostname))
1346                                                         a->flags &= ~OAF_BROKEN_HOSTNAME;
1347                                                 else
1348                                                         a->flags |= OAF_BROKEN_HOSTNAME;
1349                                         }
1350                                 }
1351                                 a->accept_reconf = accept_reconf;
1352                                 a->flags &= ~OAF_TENTATIVE;
1353                                 a->flags |= OAF_BOUND;
1354                                 apply_lease(iface, a, true);
1355                         } else if (!assigned && a && a->managed_size == 0) {
1356                                 /* Cleanup failed assignment */
1357                                 free_assignment(a);
1358                                 a = NULL;
1359                         }
1360                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1361                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1362                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1363                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1364                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1365                                 status = DHCPV6_STATUS_NOBINDING;
1366                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1367                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1368                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1369                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1370                                 if (a) {
1371                                         a->flags |= OAF_BOUND;
1372                                         apply_lease(iface, a, true);
1373                                 }
1374                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1375                                 if (!(a->flags & OAF_STATIC))
1376                                         a->valid_until = now - 1;
1377
1378                                 if (a->flags & OAF_BOUND) {
1379                                         apply_lease(iface, a, false);
1380                                         a->flags &= ~OAF_BOUND;
1381                                 }
1382                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1383                                 a->flags &= ~OAF_BOUND;
1384
1385                                 if (!(a->flags & OAF_STATIC)) {
1386                                         a->clid_len = 0;
1387                                         a->valid_until = now + 3600; /* Block address for 1h */
1388                                 }
1389                         }
1390                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1391                         if (ia_addr_present && !dhcpv6_ia_on_link(ia, a, iface)) {
1392                                 notonlink = true;
1393                                 break;
1394                         }
1395
1396                         if (!ia_addr_present || !a || !(a->flags & OAF_BOUND)) {
1397                                 response_len = 0;
1398                                 goto out;
1399                         }
1400                 }
1401
1402                 buf += ia_response_len;
1403                 buflen -= ia_response_len;
1404                 response_len += ia_response_len;
1405                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1406         }
1407
1408         switch (hdr->msg_type) {
1409         case DHCPV6_MSG_RELEASE:
1410         case DHCPV6_MSG_DECLINE:
1411         case DHCPV6_MSG_CONFIRM:
1412                 if (response_len + 6 < buflen) {
1413                         buf[0] = 0;
1414                         buf[1] = DHCPV6_OPT_STATUS;
1415                         buf[2] = 0;
1416                         buf[3] = 2;
1417                         buf[4] = 0;
1418                         buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1419                         response_len += 6;
1420                 }
1421                 break;
1422
1423         default:
1424                 break;
1425         }
1426
1427         dhcpv6_ia_write_statefile();
1428
1429 out:
1430         return response_len;
1431 }