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 apply_lease(struct dhcp_assignment *a, bool add);
  44 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b);
  45 static void handle_addrlist_change(struct netevent_handler_info *info);
  46 static void start_reconf(struct dhcp_assignment *a);
  47 static void stop_reconf(struct dhcp_assignment *a);
  48 static void valid_until_cb(struct uloop_timeout *event);
  49
  50 static struct netevent_handler dhcpv6_netevent_handler = { .cb = dhcpv6_netevent_cb, };
  51 static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb};
  52 static uint32_t serial = 0;
  53 static uint8_t statemd5[16];
  54
  55 int dhcpv6_ia_init(void)
  56 {
  57         uloop_timeout_set(&valid_until_timeout, 1000);
  58
  59         netlink_add_netevent_handler(&dhcpv6_netevent_handler);
  60
  61         return 0;
  62 }
  63
  64 int dhcpv6_ia_setup_interface(struct interface *iface, bool enable)
  65 {
  66         enable = enable && (iface->dhcpv6 == MODE_SERVER);
  67
  68         if (enable) {
  69                 struct dhcp_assignment *border;
  70
  71                 if (list_empty(&iface->ia_assignments)) {
  72                         border = alloc_assignment(0);
  73
  74                         if (!border) {
  75                                 syslog(LOG_WARNING, "Failed to alloc border on %s", iface->name);
  76                                 return -1;
  77                         }
  78
  79                         border->length = 64;
  80                         list_add(&border->head, &iface->ia_assignments);
  81                 } else
  82                         border = list_last_entry(&iface->ia_assignments, struct dhcp_assignment, head);
  83
  84                 set_border_assignment_size(iface, border);
  85         } else {
  86                 struct dhcp_assignment *c;
  87
  88                 while (!list_empty(&iface->ia_assignments)) {
  89                         c = list_first_entry(&iface->ia_assignments, struct dhcp_assignment, head);
  90                         free_assignment(c);
  91                 }
  92         }
  93
  94         return 0;
  95 }
  96
  97
  98 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info)
  99 {
 100         struct interface *iface = info->iface;
 101
 102         if (!iface || iface->dhcpv6 != MODE_SERVER)
 103                 return;
 104
 105         switch (event) {
 106         case NETEV_ADDR6LIST_CHANGE:
 107                 handle_addrlist_change(info);
 108                 break;
 109         default:
 110                 break;
 111         }
 112 }
 113
 114
 115 static inline bool valid_prefix_length(const struct dhcp_assignment *a, const uint8_t prefix_length)
 116 {
 117         return (a->managed_size || a->length > prefix_length);
 118 }
 119
 120 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 121 {
 122         return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
 123 }
 124
 125 static size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
 126 {
 127         size_t i, m;
 128
 129         for (i = 0, m = 0; i < addrlen; ++i) {
 130                 if (addrs[i].preferred > addrs[m].preferred ||
 131                                 (addrs[i].preferred == addrs[m].preferred &&
 132                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 133                         m = i;
 134         }
 135
 136         return m;
 137 }
 138
 139 static int send_reconf(struct dhcp_assignment *assign)
 140 {
 141         struct {
 142                 struct dhcpv6_client_header hdr;
 143                 uint16_t srvid_type;
 144                 uint16_t srvid_len;
 145                 uint16_t duid_type;
 146                 uint16_t hardware_type;
 147                 uint8_t mac[6];
 148                 uint16_t msg_type;
 149                 uint16_t msg_len;
 150                 uint8_t msg_id;
 151                 struct dhcpv6_auth_reconfigure auth;
 152                 uint16_t clid_type;
 153                 uint16_t clid_len;
 154                 uint8_t clid_data[128];
 155         } __attribute__((packed)) reconf_msg = {
 156                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 157                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 158                 .srvid_len = htons(10),
 159                 .duid_type = htons(3),
 160                 .hardware_type = htons(1),
 161                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 162                 .msg_len = htons(1),
 163                 .msg_id = DHCPV6_MSG_RENEW,
 164                 .auth = {htons(DHCPV6_OPT_AUTH),
 165                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 166                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 167                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 168                 .clid_len = htons(assign->clid_len),
 169                 .clid_data = {0},
 170         };
 171         struct interface *iface = assign->iface;
 172
 173         odhcpd_get_mac(iface, reconf_msg.mac);
 174         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 175         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 176
 177         md5_ctx_t md5;
 178         uint8_t secretbytes[64];
 179         memset(secretbytes, 0, sizeof(secretbytes));
 180         memcpy(secretbytes, assign->key, sizeof(assign->key));
 181
 182         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 183                 secretbytes[i] ^= 0x36;
 184
 185         md5_begin(&md5);
 186         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 187         md5_hash(iov.iov_base, iov.iov_len, &md5);
 188         md5_end(reconf_msg.auth.key, &md5);
 189
 190         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 191                 secretbytes[i] ^= 0x36;
 192                 secretbytes[i] ^= 0x5c;
 193         }
 194
 195         md5_begin(&md5);
 196         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 197         md5_hash(reconf_msg.auth.key, 16, &md5);
 198         md5_end(reconf_msg.auth.key, &md5);
 199
 200         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 201 }
 202
 203 static void dhcpv6_ia_free_assignment(struct dhcp_assignment *a)
 204 {
 205         if (a->managed_sock.fd.registered) {
 206                 ustream_free(&a->managed_sock.stream);
 207                 close(a->managed_sock.fd.fd);
 208         }
 209
 210         if ((a->flags & OAF_BOUND) && (a->flags & OAF_DHCPV6_PD))
 211                 apply_lease(a, false);
 212
 213         if (a->reconf_cnt)
 214                 stop_reconf(a);
 215
 216         free(a->managed);
 217 }
 218
 219 void dhcpv6_ia_enum_addrs(struct interface *iface, struct dhcp_assignment *c,
 220                           time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
 221 {
 222         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->addr6;
 223         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->addr6_len;
 224         size_t m = get_preferred_addr(addrs, addrlen);
 225
 226         for (size_t i = 0; i < addrlen; ++i) {
 227                 struct in6_addr addr;
 228                 uint32_t pref, valid;
 229                 int prefix = c->managed ? addrs[i].prefix : c->length;
 230
 231                 if (!valid_addr(&addrs[i], now))
 232                         continue;
 233
 234                 addr = addrs[i].addr.in6;
 235                 pref = addrs[i].preferred;
 236                 valid = addrs[i].valid;
 237                 if (prefix == 128) {
 238                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 239                                 continue;
 240
 241                         addr.s6_addr32[3] = htonl(c->assigned);
 242                 } else {
 243                         if (!valid_prefix_length(c, addrs[i].prefix))
 244                                 continue;
 245
 246                         addr.s6_addr32[1] |= htonl(c->assigned);
 247                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 248                 }
 249
 250                 if (pref != UINT32_MAX)
 251                         pref -= now;
 252
 253                 if (valid != UINT32_MAX)
 254                         valid -= now;
 255
 256                 func(&addr, prefix, pref, valid, arg);
 257         }
 258 }
 259
 260 struct write_ctxt {
 261         FILE *fp;
 262         md5_ctx_t md5;
 263         struct dhcp_assignment *c;
 264         struct interface *iface;
 265         char *buf;
 266         int buf_len;
 267         int buf_idx;
 268 };
 269
 270 static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 271                                 _unused uint32_t valid, void *arg)
 272 {
 273         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
 274         char ipbuf[INET6_ADDRSTRLEN];
 275
 276         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 277
 278         if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
 279             !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
 280                 fputs(ipbuf, ctxt->fp);
 281
 282                 char b[256];
 283                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
 284                                 ctxt->iface->search, b, sizeof(b)) > 0)
 285                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
 286
 287                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
 288                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
 289                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
 290         }
 291
 292         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
 293                                         "%s/%d ", ipbuf, prefix);
 294 }
 295
 296 void dhcpv6_ia_write_statefile(void)
 297 {
 298         struct write_ctxt ctxt;
 299
 300         md5_begin(&ctxt.md5);
 301
 302         if (config.dhcp_statefile) {
 303                 time_t now = odhcpd_time(), wall_time = time(NULL);
 304                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 305                 char leasebuf[512];
 306
 307                 if (fd < 0)
 308                         return;
 309                 int ret;
 310                 ret = lockf(fd, F_LOCK, 0);
 311                 if (ret < 0) {
 312                         close(fd);
 313                         return;
 314                 }
 315                 if (ftruncate(fd, 0) < 0) {}
 316
 317                 ctxt.fp = fdopen(fd, "w");
 318                 if (!ctxt.fp) {
 319                         close(fd);
 320                         return;
 321                 }
 322
 323                 ctxt.buf = leasebuf;
 324                 ctxt.buf_len = sizeof(leasebuf);
 325
 326                 avl_for_each_element(&interfaces, ctxt.iface, avl) {
 327                         if (ctxt.iface->dhcpv6 != MODE_SERVER &&
 328                                         ctxt.iface->dhcpv4 != MODE_SERVER)
 329                                 continue;
 330
 331                         if (ctxt.iface->dhcpv6 == MODE_SERVER) {
 332                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 333                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 334                                                 continue;
 335
 336                                         char duidbuf[264];
 337
 338                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
 339
 340                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 341                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s%s %ld %x %u ",
 342                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
 343                                                                 (ctxt.c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 344                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
 345                                                                 (ctxt.c->valid_until > now ?
 346                                                                         (ctxt.c->valid_until - now + wall_time) :
 347                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)),
 348                                                                 ctxt.c->assigned, (unsigned)ctxt.c->length);
 349
 350                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
 351                                                 dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
 352                                                                         dhcpv6_write_ia_addr, &ctxt);
 353
 354                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 355                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 356                                 }
 357                         }
 358
 359                         if (ctxt.iface->dhcpv4 == MODE_SERVER) {
 360                                 struct dhcp_assignment *c;
 361
 362                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 363                                         if (!(c->flags & OAF_BOUND))
 364                                                 continue;
 365
 366                                         char ipbuf[INET6_ADDRSTRLEN];
 367                                         char duidbuf[16];
 368                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 369
 370                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 371                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s%s %ld %x 32 ",
 372                                                                 ctxt.iface->ifname, duidbuf,
 373                                                                 (c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 374                                                                 (c->hostname ? c->hostname : "-"),
 375                                                                 (c->valid_until > now ?
 376                                                                         (c->valid_until - now + wall_time) :
 377                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 378                                                                 ntohl(c->addr));
 379
 380                                         struct in_addr addr = {.s_addr = c->addr};
 381                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 382
 383                                         if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
 384                                                 fputs(ipbuf, ctxt.fp);
 385
 386                                                 char b[256];
 387                                                 if (dn_expand(ctxt.iface->search,
 388                                                                 ctxt.iface->search + ctxt.iface->search_len,
 389                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
 390                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
 391
 392                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
 393                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
 394                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
 395                                         }
 396
 397                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
 398                                                                         ctxt.buf_len - ctxt.buf_idx,
 399                                                                         "%s/32 ", ipbuf);
 400                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 401                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 402                                 }
 403                         }
 404                 }
 405
 406                 fclose(ctxt.fp);
 407         }
 408
 409         uint8_t newmd5[16];
 410         md5_end(newmd5, &ctxt.md5);
 411
 412         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 413                 memcpy(statemd5, newmd5, sizeof(statemd5));
 414                 char *argv[2] = {config.dhcp_cb, NULL};
 415                 if (!vfork()) {
 416                         execv(argv[0], argv);
 417                         _exit(128);
 418                 }
 419         }
 420 }
 421
 422 static void __apply_lease(struct dhcp_assignment *a,
 423                 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
 424 {
 425         if (a->flags & OAF_DHCPV6_NA)
 426                 return;
 427
 428         for (ssize_t i = 0; i < addr_len; ++i) {
 429                 struct in6_addr prefix = addrs[i].addr.in6;
 430                 prefix.s6_addr32[1] |= htonl(a->assigned);
 431                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
 432                 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 433                                 a->iface->ifindex, &a->peer.sin6_addr, 1024, add);
 434         }
 435 }
 436
 437 static void apply_lease(struct dhcp_assignment *a, bool add)
 438 {
 439         struct interface *iface = a->iface;
 440         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 441         ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
 442
 443         __apply_lease(a, addrs, addrlen, add);
 444 }
 445
 446 /* Set border assignment size based on the IPv6 address prefixes */
 447 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b)
 448 {
 449         time_t now = odhcpd_time();
 450         int minprefix = -1;
 451
 452         for (size_t i = 0; i < iface->addr6_len; ++i) {
 453                 if (iface->addr6[i].preferred > (uint32_t)now &&
 454                                 iface->addr6[i].prefix < 64 &&
 455                                 iface->addr6[i].prefix > minprefix)
 456                         minprefix = iface->addr6[i].prefix;
 457         }
 458
 459         if (minprefix > 32 && minprefix <= 64)
 460                 b->assigned = 1U << (64 - minprefix);
 461         else
 462                 b->assigned = 0;
 463 }
 464
 465 /* More data was received from TCP connection */
 466 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 467 {
 468         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 469         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
 470         time_t now = odhcpd_time();
 471         bool first = c->managed_size < 0;
 472
 473         for (;;) {
 474                 int pending;
 475                 char *data = ustream_get_read_buf(s, &pending);
 476                 char *end = memmem(data, pending, "\n\n", 2);
 477
 478                 if (!end)
 479                         break;
 480
 481                 end += 2;
 482                 end[-1] = 0;
 483
 484                 c->managed_size = 0;
 485                 if (c->accept_reconf)
 486                         c->reconf_cnt = 1;
 487
 488                 char *saveptr;
 489                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 490                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 491                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 492
 493                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 494                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 495                                 continue;
 496
 497                         x = strtok_r(NULL, ",", &saveptr2);
 498                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 499                                 continue;
 500
 501                         x = strtok_r(NULL, ",", &saveptr2);
 502                         if (sscanf(x, "%u", &n->preferred) < 1)
 503                                 continue;
 504
 505                         x = strtok_r(NULL, ",", &saveptr2);
 506                         if (sscanf(x, "%u", &n->valid) < 1)
 507                                 continue;
 508
 509                         if (n->preferred > n->valid)
 510                                 continue;
 511
 512                         if (UINT32_MAX - now < n->preferred)
 513                                 n->preferred = UINT32_MAX;
 514                         else
 515                                 n->preferred += now;
 516
 517                         if (UINT32_MAX - now < n->valid)
 518                                 n->valid = UINT32_MAX;
 519                         else
 520                                 n->valid += now;
 521
 522                         n->dprefix = 0;
 523
 524                         ++c->managed_size;
 525                 }
 526
 527                 ustream_consume(s, end - data);
 528         }
 529
 530         if (first && c->managed_size == 0)
 531                 free_assignment(c);
 532         else if (first && !(c->flags & OAF_STATIC))
 533                 c->valid_until = now + 150;
 534 }
 535
 536
 537 /* TCP transmission has ended, either because of success or timeout or other error */
 538 static void managed_handle_pd_done(struct ustream *s)
 539 {
 540         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 541         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
 542
 543         if (!(c->flags & OAF_STATIC))
 544                 c->valid_until = odhcpd_time() + 15;
 545
 546         c->managed_size = 0;
 547
 548         if (c->accept_reconf)
 549                 c->reconf_cnt = 1;
 550 }
 551
 552 static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
 553 {
 554         struct dhcp_assignment *c;
 555
 556         if (iface->dhcpv6_pd_manager[0]) {
 557                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 558                 if (fd >= 0) {
 559                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 560                         char iaidbuf[298];
 561
 562                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 563
 564                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 565                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 566                         ustream_fd_init(&assign->managed_sock, fd);
 567                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 568                                         iaidbuf, assign->iaid, assign->length);
 569                         ustream_write_pending(&assign->managed_sock.stream);
 570                         assign->managed_size = -1;
 571
 572                         if (!(assign->flags & OAF_STATIC))
 573                                 assign->valid_until = odhcpd_time() + 15;
 574
 575                         list_add(&assign->head, &iface->ia_assignments);
 576
 577                         /* Wait initial period of up to 250ms for immediate assignment */
 578                         if (poll(&pfd, 1, 250) < 0) {
 579                                 syslog(LOG_ERR, "poll(): %m");
 580                                 return false;
 581                         }
 582
 583                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 584
 585                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 586                                 return true;
 587                 }
 588
 589                 return false;
 590         } else if (iface->addr6_len < 1)
 591                 return false;
 592
 593         /* Try honoring the hint first */
 594         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 595         if (assign->assigned) {
 596                 list_for_each_entry(c, &iface->ia_assignments, head) {
 597                         if (c->flags & OAF_DHCPV6_NA)
 598                                 continue;
 599
 600                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 601                                 list_add_tail(&assign->head, &c->head);
 602
 603                                 if (assign->flags & OAF_BOUND)
 604                                         apply_lease(assign, true);
 605
 606                                 return true;
 607                         }
 608
 609                         if (c->assigned != 0)
 610                                 current = (c->assigned + (1 << (64 - c->length)));
 611                 }
 612         }
 613
 614         /* Fallback to a variable assignment */
 615         current = 1;
 616         list_for_each_entry(c, &iface->ia_assignments, head) {
 617                 if (c->flags & OAF_DHCPV6_NA)
 618                         continue;
 619
 620                 current = (current + asize) & (~asize);
 621                 if (current + asize < c->assigned) {
 622                         assign->assigned = current;
 623                         list_add_tail(&assign->head, &c->head);
 624
 625                         if (assign->flags & OAF_BOUND)
 626                                 apply_lease(assign, true);
 627
 628                         return true;
 629                 }
 630
 631                 if (c->assigned != 0)
 632                         current = (c->assigned + (1 << (64 - c->length)));
 633         }
 634
 635         return false;
 636 }
 637
 638 static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
 639 {
 640         struct dhcp_assignment *c;
 641         uint32_t seed = 0;
 642
 643         /* Preconfigured assignment by static lease */
 644         if (a->assigned) {
 645                 list_for_each_entry(c, &iface->ia_assignments, head) {
 646                         if (c->assigned > a->assigned || !(c->flags & OAF_DHCPV6_NA)) {
 647                                 list_add_tail(&a->head, &c->head);
 648                                 return true;
 649                         } else if (c->assigned == a->assigned)
 650                                 return false;
 651                 }
 652         }
 653
 654         /* Seed RNG with checksum of DUID */
 655         for (size_t i = 0; i < a->clid_len; ++i)
 656                 seed += a->clid_data[i];
 657         srand(seed);
 658
 659         /* Try to assign up to 100x */
 660         for (size_t i = 0; i < 100; ++i) {
 661                 uint32_t try;
 662                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 663
 664                 if (config_find_lease_by_hostid(try))
 665                         continue;
 666
 667                 list_for_each_entry(c, &iface->ia_assignments, head) {
 668                         if (c->assigned > try || !(c->flags & OAF_DHCPV6_NA)) {
 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->flags & OAF_DHCPV6_PD) && !(iface->ra_flags & ND_RA_FLAG_MANAGED)
 690                                 && (c->flags & OAF_BOUND))
 691                         __apply_lease(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 ||
 699                     !(c->flags & OAF_DHCPV6_PD) ||
 700                     (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 701                     c->managed_size)
 702                         continue;
 703
 704                 if (c->assigned == 0 || c->assigned >= border->assigned)
 705                         list_move(&c->head, &reassign);
 706                 else if (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->dhcp_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_pref > leasetime)
 846                                 prefix_pref = leasetime;
 847
 848                         if (prefix_valid != UINT32_MAX)
 849                                 prefix_valid -= now;
 850
 851                         if (prefix_valid > leasetime)
 852                                 prefix_valid = leasetime;
 853
 854                         if (a->flags & OAF_DHCPV6_PD) {
 855                                 struct dhcpv6_ia_prefix o_ia_p = {
 856                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 857                                         .len = htons(sizeof(o_ia_p) - 4),
 858                                         .preferred = htonl(prefix_pref),
 859                                         .valid = htonl(prefix_valid),
 860                                         .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 861                                         .addr = addrs[i].addr.in6,
 862                                 };
 863
 864                                 o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned);
 865                                 o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0;
 866
 867                                 if ((a->assigned == 0 && a->managed_size == 0) ||
 868                                                 !valid_prefix_length(a, addrs[i].prefix))
 869                                         continue;
 870
 871                                 if (buflen < ia_len + sizeof(o_ia_p))
 872                                         return 0;
 873
 874                                 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
 875                                 ia_len += sizeof(o_ia_p);
 876                         }
 877
 878                         if (a->flags & OAF_DHCPV6_NA) {
 879                                 struct dhcpv6_ia_addr o_ia_a = {
 880                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 881                                         .len = htons(sizeof(o_ia_a) - 4),
 882                                         .addr = addrs[i].addr.in6,
 883                                         .preferred = htonl(prefix_pref),
 884                                         .valid = htonl(prefix_valid)
 885                                 };
 886
 887                                 o_ia_a.addr.s6_addr32[3] = htonl(a->assigned);
 888
 889                                 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
 890                                                 a->assigned == 0)
 891                                         continue;
 892
 893                                 if (buflen < ia_len + sizeof(o_ia_a))
 894                                         return 0;
 895
 896                                 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
 897                                 ia_len += sizeof(o_ia_a);
 898                         }
 899
 900                         /* Calculate T1 / T2 based on non-deprecated addresses */
 901                         if (prefix_pref > 0) {
 902                                 if (prefix_pref < pref)
 903                                         pref = prefix_pref;
 904
 905                                 if (prefix_valid < valid)
 906                                         valid = prefix_valid;
 907                         }
 908                 }
 909
 910                 if (!INFINITE_VALID(a->valid_until))
 911                         /* UINT32_MAX is considered as infinite leasetime */
 912                         a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 913
 914                 o_ia.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 915                 o_ia.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 916
 917                 if (!o_ia.t1)
 918                         o_ia.t1 = htonl(1);
 919
 920                 if (!o_ia.t2)
 921                         o_ia.t2 = htonl(1);
 922         }
 923
 924         if (!request) {
 925                 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 926                 uint16_t otype, olen;
 927
 928                 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 929                         struct dhcpv6_ia_prefix *ia_p = (struct dhcpv6_ia_prefix *)&odata[-4];
 930                         struct dhcpv6_ia_addr *ia_a = (struct dhcpv6_ia_addr *)&odata[-4];
 931                         bool found = false;
 932
 933                         if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*ia_p) - 4) &&
 934                                         (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*ia_a) - 4))
 935                                 continue;
 936
 937                         if (a) {
 938                                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 939                                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
 940
 941                                 for (size_t i = 0; i < addrlen; ++i) {
 942                                         if (!valid_addr(&addrs[i], now))
 943                                                 continue;
 944
 945                                         struct in6_addr addr = addrs[i].addr.in6;
 946                                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 947                                                 addr.s6_addr32[1] |= htonl(a->assigned);
 948                                                 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 949
 950                                                 if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) &&
 951                                                                 ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 952                                                         found = true;
 953                                         } else {
 954                                                 addr.s6_addr32[3] = htonl(a->assigned);
 955
 956                                                 if (!memcmp(&ia_a->addr, &addr, sizeof(addr)))
 957                                                         found = true;
 958                                         }
 959                                 }
 960                         }
 961
 962                         if (!found) {
 963                                 if (otype == DHCPV6_OPT_IA_PREFIX) {
 964                                         struct dhcpv6_ia_prefix o_ia_p = {
 965                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 966                                                 .len = htons(sizeof(o_ia_p) - 4),
 967                                                 .preferred = 0,
 968                                                 .valid = 0,
 969                                                 .prefix = ia_p->prefix,
 970                                                 .addr = ia_p->addr,
 971                                         };
 972
 973                                         if (buflen < ia_len + sizeof(o_ia_p))
 974                                                 return 0;
 975
 976                                         memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
 977                                         ia_len += sizeof(o_ia_p);
 978                                 } else {
 979                                         struct dhcpv6_ia_addr o_ia_a = {
 980                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 981                                                 .len = htons(sizeof(o_ia_a) - 4),
 982                                                 .addr = ia_a->addr,
 983                                                 .preferred = 0,
 984                                                 .valid = 0,
 985                                         };
 986
 987                                         if (buflen < ia_len + sizeof(o_ia_a))
 988                                                 continue;
 989
 990                                         memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
 991                                         ia_len += sizeof(o_ia_a);
 992                                 }
 993                         }
 994                 }
 995         }
 996
 997         o_ia.len = htons(ia_len - 4);
 998         memcpy(buf, &o_ia, sizeof(o_ia));
 999         return ia_len;
1000 }
1001
1002 struct log_ctxt {
1003         char *buf;
1004         int buf_len;
1005         int buf_idx;
1006 };
1007
1008 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
1009                                 _unused uint32_t valid, void *arg)
1010 {
1011         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1012         char addrbuf[INET6_ADDRSTRLEN];
1013
1014         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1015         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1016                                         "%s/%d ", addrbuf, prefix);
1017 }
1018
1019 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1020                 const char *duidbuf, bool is_pd, struct dhcp_assignment *a, int code)
1021 {
1022         const char *type = "UNKNOWN";
1023         const char *status = "UNKNOWN";
1024
1025         switch (msgtype) {
1026         case DHCPV6_MSG_SOLICIT:
1027                 type = "SOLICIT";
1028                 break;
1029         case DHCPV6_MSG_REQUEST:
1030                 type = "REQUEST";
1031                 break;
1032         case DHCPV6_MSG_CONFIRM:
1033                 type = "CONFIRM";
1034                 break;
1035         case DHCPV6_MSG_RENEW:
1036                 type = "RENEW";
1037                 break;
1038         case DHCPV6_MSG_REBIND:
1039                 type = "REBIND";
1040                 break;
1041         case DHCPV6_MSG_RELEASE:
1042                 type = "RELEASE";
1043                 break;
1044         case DHCPV6_MSG_DECLINE:
1045                 type = "DECLINE";
1046                 break;
1047         }
1048
1049         switch (code) {
1050         case DHCPV6_STATUS_OK:
1051                 status = "ok";
1052                 break;
1053         case DHCPV6_STATUS_NOADDRSAVAIL:
1054                 status = "no addresses available";
1055                 break;
1056         case DHCPV6_STATUS_NOBINDING:
1057                 status = "no binding";
1058                 break;
1059         case DHCPV6_STATUS_NOTONLINK:
1060                 status = "not on-link";
1061                 break;
1062         case DHCPV6_STATUS_NOPREFIXAVAIL:
1063                 status = "no prefix available";
1064                 break;
1065         }
1066
1067         char leasebuf[256] = "";
1068
1069         if (a) {
1070                 struct log_ctxt ctxt = {.buf = leasebuf,
1071                                         .buf_len = sizeof(leasebuf),
1072                                         .buf_idx = 0 };
1073
1074                 dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1075         }
1076
1077         syslog(LOG_INFO, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1078                          duidbuf, iface->name, status, leasebuf);
1079 }
1080
1081 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1082                 struct interface *iface)
1083 {
1084         struct odhcpd_ipaddr *addrs = (a && a->managed) ? a->managed : iface->addr6;
1085         size_t addrlen = (a && a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1086         time_t now = odhcpd_time();
1087         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1088         uint16_t otype, olen;
1089         bool onlink = true;
1090
1091         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1092                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix *)&odata[-4];
1093                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr *)&odata[-4];
1094
1095                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
1096                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
1097                         continue;
1098
1099                 onlink = false;
1100                 for (size_t i = 0; i < addrlen; ++i) {
1101                         if (!valid_addr(&addrs[i], now))
1102                                 continue;
1103
1104                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1105                                 if (p->prefix < addrs[i].prefix ||
1106                                     odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
1107                                         continue;
1108
1109                         } else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
1110                                 continue;
1111
1112                         onlink = true;
1113                 }
1114
1115                 if (!onlink)
1116                         break;
1117         }
1118
1119         return onlink;
1120 }
1121
1122 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
1123                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1124 {
1125         struct lease *l;
1126         struct dhcp_assignment *first = NULL;
1127         const struct dhcpv6_client_header *hdr = data;
1128         time_t now = odhcpd_time();
1129         uint16_t otype, olen, clid_len = 0;
1130         uint8_t *start = (uint8_t *)&hdr[1], *odata;
1131         uint8_t *clid_data = NULL, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1132         size_t hostname_len = 0, response_len = 0;
1133         bool notonlink = false, rapid_commit = false, accept_reconf = false;
1134         char duidbuf[261], hostname[256];
1135
1136         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1137                 if (otype == DHCPV6_OPT_CLIENTID) {
1138                         clid_data = odata;
1139                         clid_len = olen;
1140
1141                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1142                                 memcpy(mac, &odata[8], sizeof(mac));
1143                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1144                                 memcpy(mac, &odata[4], sizeof(mac));
1145
1146                         if (olen <= 130)
1147                                 odhcpd_hexlify(duidbuf, odata, olen);
1148                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1149                         uint8_t fqdn_buf[256];
1150                         memcpy(fqdn_buf, odata, olen);
1151                         fqdn_buf[olen++] = 0;
1152
1153                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1154                                 hostname_len = strcspn(hostname, ".");
1155                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1156                         accept_reconf = true;
1157                 else if (otype == DHCPV6_OPT_RAPID_COMMIT && hdr->msg_type == DHCPV6_MSG_SOLICIT)
1158                         rapid_commit = true;
1159         }
1160
1161         if (!clid_data || !clid_len || clid_len > 130)
1162                 goto out;
1163
1164         l = config_find_lease_by_duid(clid_data, clid_len);
1165         if (!l)
1166                 l = config_find_lease_by_mac(mac);
1167
1168         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1169                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1170                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1171                 bool ia_addr_present = false;
1172                 if (!is_pd && !is_na)
1173                         continue;
1174
1175                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1176                 size_t ia_response_len = 0;
1177                 uint8_t reqlen = (is_pd) ? 62 : 128;
1178                 uint32_t reqhint = 0;
1179
1180                 /* Parse request hint for IA-PD */
1181                 if (is_pd) {
1182                         uint8_t *sdata;
1183                         uint16_t stype, slen;
1184                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1185                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1186                                         continue;
1187
1188                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1189                                 if (p->prefix) {
1190                                         reqlen = p->prefix;
1191                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1192                                         if (reqlen > 32 && reqlen <= 64)
1193                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1194                                 }
1195                         }
1196
1197                         if (reqlen > 64)
1198                                 reqlen = 64;
1199                 } else if (is_na) {
1200                         uint8_t *sdata;
1201                         uint16_t stype, slen;
1202                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1203                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1204                                         continue;
1205
1206                                 ia_addr_present = true;
1207                         }
1208                 }
1209
1210                 /* Find assignment */
1211                 struct dhcp_assignment *c, *a = NULL;
1212                 list_for_each_entry(c, &iface->ia_assignments, head) {
1213                         if ((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) &&
1214                             c->iaid == ia->iaid && (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1215                             ((is_pd && (c->flags & OAF_DHCPV6_PD)) || (is_na && (c->flags & OAF_DHCPV6_NA)))) {
1216                                 a = c;
1217
1218                                 /* Reset state */
1219                                 if (a->flags & OAF_BOUND)
1220                                         apply_lease(a, false);
1221
1222                                 stop_reconf(a);
1223                                 break;
1224                         }
1225                 }
1226
1227                 if (l && a && a->lease != l) {
1228                         free_assignment(a);
1229                         a = NULL;
1230                 }
1231
1232                 /* Generic message handling */
1233                 uint16_t status = DHCPV6_STATUS_OK;
1234                 if (a && a->managed_size < 0)
1235                         return -1;
1236
1237                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1238                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1239                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1240                         bool assigned = !!a;
1241
1242                         if (!a) {
1243                                 if ((!iface->no_dynamic_dhcp || (l && is_na)) &&
1244                                     (iface->dhcpv6_pd || iface->dhcpv6_na)) {
1245                                         /* Create new binding */
1246                                         a = alloc_assignment(clid_len);
1247
1248                                         if (a) {
1249                                                 a->clid_len = clid_len;
1250                                                 memcpy(a->clid_data, clid_data, clid_len);
1251                                                 a->iaid = ia->iaid;
1252                                                 a->length = reqlen;
1253                                                 a->peer = *addr;
1254                                                 a->assigned = is_na && l ? l->hostid : reqhint;
1255                                                 /* Set valid time to 0 for static lease indicating */
1256                                                 /* infinite lifetime otherwise current time        */
1257                                                 a->valid_until = l ? 0 : now;
1258                                                 a->dhcp_free_cb = dhcpv6_ia_free_assignment;
1259                                                 a->iface = iface;
1260                                                 a->flags = (is_pd ? OAF_DHCPV6_PD : OAF_DHCPV6_NA);
1261
1262                                                 if (first)
1263                                                         memcpy(a->key, first->key, sizeof(a->key));
1264                                                 else
1265                                                         odhcpd_urandom(a->key, sizeof(a->key));
1266
1267                                                 if (is_pd && iface->dhcpv6_pd)
1268                                                         while (!(assigned = assign_pd(iface, a)) &&
1269                                                                !a->managed_size && ++a->length <= 64);
1270                                                 else if (is_na && iface->dhcpv6_na)
1271                                                         assigned = assign_na(iface, a);
1272
1273                                                 if (l && assigned) {
1274                                                         a->flags |= OAF_STATIC;
1275
1276                                                         if (l->hostname)
1277                                                                 a->hostname = strdup(l->hostname);
1278
1279                                                         if (l->leasetime)
1280                                                                 a->leasetime = l->leasetime;
1281
1282                                                         list_add(&a->lease_list, &l->assignments);
1283                                                         a->lease = l;
1284                                                 }
1285
1286                                                 if (a->managed_size && !assigned)
1287                                                         return -1;
1288                                         }
1289                                 }
1290                         }
1291
1292                         if (!assigned || iface->addr6_len == 0)
1293                                 /* Set error status */
1294                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1295                         else if (hdr->msg_type == DHCPV6_MSG_REQUEST && !dhcpv6_ia_on_link(ia, a, iface)) {
1296                                 /* Send NOTONLINK staus for the IA */
1297                                 status = DHCPV6_STATUS_NOTONLINK;
1298                                 assigned = false;
1299                         } else if (accept_reconf && assigned && !first &&
1300                                         hdr->msg_type != DHCPV6_MSG_REBIND) {
1301                                 size_t handshake_len = 4;
1302                                 buf[0] = 0;
1303                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1304                                 buf[2] = 0;
1305                                 buf[3] = 0;
1306
1307                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1308                                         struct dhcpv6_auth_reconfigure auth = {
1309                                                 htons(DHCPV6_OPT_AUTH),
1310                                                 htons(sizeof(auth) - 4),
1311                                                 3, 1, 0,
1312                                                 {htonl(time(NULL)), htonl(++serial)},
1313                                                 1,
1314                                                 {0}
1315                                         };
1316                                         memcpy(auth.key, a->key, sizeof(a->key));
1317                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1318                                         handshake_len += sizeof(auth);
1319                                 }
1320
1321
1322                                 buf += handshake_len;
1323                                 buflen -= handshake_len;
1324                                 response_len += handshake_len;
1325
1326                                 first = a;
1327                         }
1328
1329                         ia_response_len = build_ia(buf, buflen, status, ia, a, iface,
1330                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1331
1332                         /* Was only a solicitation: mark binding for removal */
1333                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT && !rapid_commit) {
1334                                 a->flags &= ~OAF_BOUND;
1335                                 a->flags |= OAF_TENTATIVE;
1336
1337                                 if (!(a->flags & OAF_STATIC))
1338                                         /* Keep tentative assignment around for 60 seconds */
1339                                         a->valid_until = now + 60;
1340
1341                         } else if (assigned &&
1342                                    ((hdr->msg_type == DHCPV6_MSG_SOLICIT && rapid_commit) ||
1343                                     hdr->msg_type == DHCPV6_MSG_REQUEST ||
1344                                     hdr->msg_type == DHCPV6_MSG_REBIND)) {
1345                                 if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
1346                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1347                                         if (a->hostname) {
1348                                                 memcpy(a->hostname, hostname, hostname_len);
1349                                                 a->hostname[hostname_len] = 0;
1350
1351                                                 if (odhcpd_valid_hostname(a->hostname))
1352                                                         a->flags &= ~OAF_BROKEN_HOSTNAME;
1353                                                 else
1354                                                         a->flags |= OAF_BROKEN_HOSTNAME;
1355                                         }
1356                                 }
1357                                 a->accept_reconf = accept_reconf;
1358                                 a->flags &= ~OAF_TENTATIVE;
1359                                 a->flags |= OAF_BOUND;
1360                                 apply_lease(a, true);
1361                         } else if (!assigned && a && a->managed_size == 0) {
1362                                 /* Cleanup failed assignment */
1363                                 free_assignment(a);
1364                                 a = NULL;
1365                         }
1366                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1367                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1368                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1369                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1370                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1371                                 status = DHCPV6_STATUS_NOBINDING;
1372                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1373                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1374                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1375                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1376                                 if (a) {
1377                                         a->flags |= OAF_BOUND;
1378                                         apply_lease(a, true);
1379                                 }
1380                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1381                                 if (a->flags & OAF_STATIC) {
1382                                         apply_lease(a, false);
1383                                         a->flags &= ~OAF_BOUND;
1384                                 }
1385                                 else
1386                                         a->valid_until = now - 1;
1387
1388                         } else if ((a->flags & OAF_DHCPV6_NA) && hdr->msg_type == DHCPV6_MSG_DECLINE) {
1389                                 a->flags &= ~OAF_BOUND;
1390
1391                                 if (!(a->flags & OAF_STATIC)) {
1392                                         memset(a->clid_data, 0, a->clid_len);
1393                                         a->valid_until = now + 3600; /* Block address for 1h */
1394                                 }
1395                         }
1396                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1397                         if (ia_addr_present && !dhcpv6_ia_on_link(ia, a, iface)) {
1398                                 notonlink = true;
1399                                 break;
1400                         }
1401
1402                         if (!ia_addr_present || !a || !(a->flags & OAF_BOUND)) {
1403                                 response_len = 0;
1404                                 goto out;
1405                         }
1406                 }
1407
1408                 buf += ia_response_len;
1409                 buflen -= ia_response_len;
1410                 response_len += ia_response_len;
1411                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1412         }
1413
1414         switch (hdr->msg_type) {
1415         case DHCPV6_MSG_RELEASE:
1416         case DHCPV6_MSG_DECLINE:
1417         case DHCPV6_MSG_CONFIRM:
1418                 if (response_len + 6 < buflen) {
1419                         buf[0] = 0;
1420                         buf[1] = DHCPV6_OPT_STATUS;
1421                         buf[2] = 0;
1422                         buf[3] = 2;
1423                         buf[4] = 0;
1424                         buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1425                         response_len += 6;
1426                 }
1427                 break;
1428
1429         default:
1430                 break;
1431         }
1432
1433         dhcpv6_ia_write_statefile();
1434
1435 out:
1436         return response_len;
1437 }