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 (c->flags & OAF_DHCPV6_NA) {
 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_t)c->valid_until)
 251                         pref = c->valid_until;
 252
 253                 if (pref != UINT32_MAX)
 254                         pref -= now;
 255
 256                 if (valid > (uint32_t)c->valid_until)
 257                         valid = c->valid_until;
 258
 259                 if (valid != UINT32_MAX)
 260                         valid -= now;
 261
 262                 func(&addr, prefix, pref, valid, arg);
 263         }
 264 }
 265
 266 struct write_ctxt {
 267         FILE *fp;
 268         md5_ctx_t md5;
 269         struct dhcp_assignment *c;
 270         struct interface *iface;
 271         char *buf;
 272         int buf_len;
 273         int buf_idx;
 274 };
 275
 276 static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 277                                 _unused uint32_t valid, void *arg)
 278 {
 279         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
 280         char ipbuf[INET6_ADDRSTRLEN];
 281
 282         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 283
 284         if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
 285             !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
 286                 fputs(ipbuf, ctxt->fp);
 287
 288                 char b[256];
 289                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
 290                                 ctxt->iface->search, b, sizeof(b)) > 0)
 291                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
 292
 293                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
 294                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
 295                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
 296         }
 297
 298         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
 299                                         "%s/%d ", ipbuf, prefix);
 300 }
 301
 302 void dhcpv6_ia_write_statefile(void)
 303 {
 304         struct write_ctxt ctxt;
 305
 306         md5_begin(&ctxt.md5);
 307
 308         if (config.dhcp_statefile) {
 309                 time_t now = odhcpd_time(), wall_time = time(NULL);
 310                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 311                 char leasebuf[512];
 312
 313                 if (fd < 0)
 314                         return;
 315                 int ret;
 316                 ret = lockf(fd, F_LOCK, 0);
 317                 if (ret < 0) {
 318                         close(fd);
 319                         return;
 320                 }
 321                 if (ftruncate(fd, 0) < 0) {}
 322
 323                 ctxt.fp = fdopen(fd, "w");
 324                 if (!ctxt.fp) {
 325                         close(fd);
 326                         return;
 327                 }
 328
 329                 ctxt.buf = leasebuf;
 330                 ctxt.buf_len = sizeof(leasebuf);
 331
 332                 avl_for_each_element(&interfaces, ctxt.iface, avl) {
 333                         if (ctxt.iface->dhcpv6 != MODE_SERVER &&
 334                                         ctxt.iface->dhcpv4 != MODE_SERVER)
 335                                 continue;
 336
 337                         if (ctxt.iface->dhcpv6 == MODE_SERVER) {
 338                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 339                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 340                                                 continue;
 341
 342                                         char duidbuf[264];
 343
 344                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
 345
 346                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 347                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s%s %"PRId64" %x %u ",
 348                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
 349                                                                 (ctxt.c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 350                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
 351                                                                 (ctxt.c->valid_until > now ?
 352                                                                         (int64_t)(ctxt.c->valid_until - now + wall_time) :
 353                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)),
 354                                                                 ctxt.c->assigned, (unsigned)ctxt.c->length);
 355
 356                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
 357                                                 dhcpv6_ia_enum_addrs(ctxt.iface, ctxt.c, now,
 358                                                                         dhcpv6_write_ia_addr, &ctxt);
 359
 360                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 361                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 362                                 }
 363                         }
 364
 365                         if (ctxt.iface->dhcpv4 == MODE_SERVER) {
 366                                 struct dhcp_assignment *c;
 367
 368                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 369                                         if (!(c->flags & OAF_BOUND))
 370                                                 continue;
 371
 372                                         char ipbuf[INET6_ADDRSTRLEN];
 373                                         char duidbuf[16];
 374                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 375
 376                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 377                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s%s %"PRId64" %x 32 ",
 378                                                                 ctxt.iface->ifname, duidbuf,
 379                                                                 (c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 380                                                                 (c->hostname ? c->hostname : "-"),
 381                                                                 (c->valid_until > now ?
 382                                                                         (int64_t)(c->valid_until - now + wall_time) :
 383                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 384                                                                 ntohl(c->addr));
 385
 386                                         struct in_addr addr = {.s_addr = c->addr};
 387                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 388
 389                                         if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
 390                                                 fputs(ipbuf, ctxt.fp);
 391
 392                                                 char b[256];
 393                                                 if (dn_expand(ctxt.iface->search,
 394                                                                 ctxt.iface->search + ctxt.iface->search_len,
 395                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
 396                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
 397
 398                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
 399                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
 400                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
 401                                         }
 402
 403                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
 404                                                                         ctxt.buf_len - ctxt.buf_idx,
 405                                                                         "%s/32 ", ipbuf);
 406                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 407                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 408                                 }
 409                         }
 410                 }
 411
 412                 fclose(ctxt.fp);
 413         }
 414
 415         uint8_t newmd5[16];
 416         md5_end(newmd5, &ctxt.md5);
 417
 418         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 419                 memcpy(statemd5, newmd5, sizeof(statemd5));
 420                 char *argv[2] = {config.dhcp_cb, NULL};
 421                 if (!vfork()) {
 422                         execv(argv[0], argv);
 423                         _exit(128);
 424                 }
 425         }
 426 }
 427
 428 static void __apply_lease(struct dhcp_assignment *a,
 429                 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
 430 {
 431         if (a->flags & OAF_DHCPV6_NA)
 432                 return;
 433
 434         for (ssize_t i = 0; i < addr_len; ++i) {
 435                 struct in6_addr prefix = addrs[i].addr.in6;
 436                 prefix.s6_addr32[1] |= htonl(a->assigned);
 437                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
 438                 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 439                                 a->iface->ifindex, &a->peer.sin6_addr, 1024, add);
 440         }
 441 }
 442
 443 static void apply_lease(struct dhcp_assignment *a, bool add)
 444 {
 445         struct interface *iface = a->iface;
 446         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 447         ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
 448
 449         __apply_lease(a, addrs, addrlen, add);
 450 }
 451
 452 /* Set border assignment size based on the IPv6 address prefixes */
 453 static void set_border_assignment_size(struct interface *iface, struct dhcp_assignment *b)
 454 {
 455         time_t now = odhcpd_time();
 456         int minprefix = -1;
 457
 458         for (size_t i = 0; i < iface->addr6_len; ++i) {
 459                 if (iface->addr6[i].preferred > (uint32_t)now &&
 460                                 iface->addr6[i].prefix < 64 &&
 461                                 iface->addr6[i].prefix > minprefix)
 462                         minprefix = iface->addr6[i].prefix;
 463         }
 464
 465         if (minprefix > 32 && minprefix <= 64)
 466                 b->assigned = 1U << (64 - minprefix);
 467         else
 468                 b->assigned = 0;
 469 }
 470
 471 /* More data was received from TCP connection */
 472 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 473 {
 474         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 475         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
 476         time_t now = odhcpd_time();
 477         bool first = c->managed_size < 0;
 478
 479         for (;;) {
 480                 int pending;
 481                 char *data = ustream_get_read_buf(s, &pending);
 482                 char *end = memmem(data, pending, "\n\n", 2);
 483
 484                 if (!end)
 485                         break;
 486
 487                 end += 2;
 488                 end[-1] = 0;
 489
 490                 c->managed_size = 0;
 491                 if (c->accept_reconf)
 492                         c->reconf_cnt = 1;
 493
 494                 char *saveptr;
 495                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 496                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 497                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 498
 499                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 500                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 501                                 continue;
 502
 503                         x = strtok_r(NULL, ",", &saveptr2);
 504                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 505                                 continue;
 506
 507                         x = strtok_r(NULL, ",", &saveptr2);
 508                         if (sscanf(x, "%u", &n->preferred) < 1)
 509                                 continue;
 510
 511                         x = strtok_r(NULL, ",", &saveptr2);
 512                         if (sscanf(x, "%u", &n->valid) < 1)
 513                                 continue;
 514
 515                         if (n->preferred > n->valid)
 516                                 continue;
 517
 518                         if (UINT32_MAX - now < n->preferred)
 519                                 n->preferred = UINT32_MAX;
 520                         else
 521                                 n->preferred += now;
 522
 523                         if (UINT32_MAX - now < n->valid)
 524                                 n->valid = UINT32_MAX;
 525                         else
 526                                 n->valid += now;
 527
 528                         n->dprefix = 0;
 529
 530                         ++c->managed_size;
 531                 }
 532
 533                 ustream_consume(s, end - data);
 534         }
 535
 536         if (first && c->managed_size == 0)
 537                 free_assignment(c);
 538         else if (first)
 539                 c->valid_until = now + 150;
 540 }
 541
 542
 543 /* TCP transmission has ended, either because of success or timeout or other error */
 544 static void managed_handle_pd_done(struct ustream *s)
 545 {
 546         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 547         struct dhcp_assignment *c = container_of(fd, struct dhcp_assignment, managed_sock);
 548
 549         c->valid_until = odhcpd_time() + 15;
 550
 551         c->managed_size = 0;
 552
 553         if (c->accept_reconf)
 554                 c->reconf_cnt = 1;
 555 }
 556
 557 static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
 558 {
 559         struct dhcp_assignment *c;
 560
 561         if (iface->dhcpv6_pd_manager[0]) {
 562                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 563                 if (fd >= 0) {
 564                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 565                         char iaidbuf[298];
 566
 567                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 568
 569                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 570                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 571                         ustream_fd_init(&assign->managed_sock, fd);
 572                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 573                                         iaidbuf, assign->iaid, assign->length);
 574                         ustream_write_pending(&assign->managed_sock.stream);
 575                         assign->managed_size = -1;
 576
 577                         assign->valid_until = odhcpd_time() + 15;
 578
 579                         list_add(&assign->head, &iface->ia_assignments);
 580
 581                         /* Wait initial period of up to 250ms for immediate assignment */
 582                         if (poll(&pfd, 1, 250) < 0) {
 583                                 syslog(LOG_ERR, "poll(): %m");
 584                                 return false;
 585                         }
 586
 587                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 588
 589                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 590                                 return true;
 591                 }
 592
 593                 return false;
 594         } else if (iface->addr6_len < 1)
 595                 return false;
 596
 597         /* Try honoring the hint first */
 598         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 599         if (assign->assigned) {
 600                 list_for_each_entry(c, &iface->ia_assignments, head) {
 601                         if (c->flags & OAF_DHCPV6_NA)
 602                                 continue;
 603
 604                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 605                                 list_add_tail(&assign->head, &c->head);
 606
 607                                 if (assign->flags & OAF_BOUND)
 608                                         apply_lease(assign, true);
 609
 610                                 return true;
 611                         }
 612
 613                         if (c->assigned != 0)
 614                                 current = (c->assigned + (1 << (64 - c->length)));
 615                 }
 616         }
 617
 618         /* Fallback to a variable assignment */
 619         current = 1;
 620         list_for_each_entry(c, &iface->ia_assignments, head) {
 621                 if (c->flags & OAF_DHCPV6_NA)
 622                         continue;
 623
 624                 current = (current + asize) & (~asize);
 625                 if (current + asize < c->assigned) {
 626                         assign->assigned = current;
 627                         list_add_tail(&assign->head, &c->head);
 628
 629                         if (assign->flags & OAF_BOUND)
 630                                 apply_lease(assign, true);
 631
 632                         return true;
 633                 }
 634
 635                 if (c->assigned != 0)
 636                         current = (c->assigned + (1 << (64 - c->length)));
 637         }
 638
 639         return false;
 640 }
 641
 642 static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
 643 {
 644         struct dhcp_assignment *c;
 645         uint32_t seed = 0;
 646
 647         /* Preconfigured assignment by static lease */
 648         if (a->assigned) {
 649                 list_for_each_entry(c, &iface->ia_assignments, head) {
 650                         if (c->assigned > a->assigned || !(c->flags & OAF_DHCPV6_NA)) {
 651                                 list_add_tail(&a->head, &c->head);
 652                                 return true;
 653                         } else if (c->assigned == a->assigned)
 654                                 return false;
 655                 }
 656         }
 657
 658         /* Seed RNG with checksum of DUID */
 659         for (size_t i = 0; i < a->clid_len; ++i)
 660                 seed += a->clid_data[i];
 661         srand(seed);
 662
 663         /* Try to assign up to 100x */
 664         for (size_t i = 0; i < 100; ++i) {
 665                 uint32_t try;
 666                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 667
 668                 if (config_find_lease_by_hostid(try))
 669                         continue;
 670
 671                 list_for_each_entry(c, &iface->ia_assignments, head) {
 672                         if (c->assigned > try || !(c->flags & OAF_DHCPV6_NA)) {
 673                                 a->assigned = try;
 674                                 list_add_tail(&a->head, &c->head);
 675                                 return true;
 676                         } else if (c->assigned == try)
 677                                 break;
 678                 }
 679         }
 680
 681         return false;
 682 }
 683
 684 static void handle_addrlist_change(struct netevent_handler_info *info)
 685 {
 686         struct interface *iface = info->iface;
 687         struct dhcp_assignment *c, *d, *border = list_last_entry(
 688                         &iface->ia_assignments, struct dhcp_assignment, head);
 689         struct list_head reassign = LIST_HEAD_INIT(reassign);
 690         time_t now = odhcpd_time();
 691
 692         list_for_each_entry(c, &iface->ia_assignments, head) {
 693                 if ((c->flags & OAF_DHCPV6_PD) && !(iface->ra_flags & ND_RA_FLAG_MANAGED)
 694                                 && (c->flags & OAF_BOUND))
 695                         __apply_lease(c, info->addrs_old.addrs,
 696                                         info->addrs_old.len, false);
 697         }
 698
 699         set_border_assignment_size(iface, border);
 700
 701         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 702                 if (c->clid_len == 0 ||
 703                     !(c->flags & OAF_DHCPV6_PD) ||
 704                     (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 705                     c->managed_size)
 706                         continue;
 707
 708                 if (c->assigned == 0 || c->assigned >= border->assigned)
 709                         list_move(&c->head, &reassign);
 710                 else if (c->flags & OAF_BOUND)
 711                         apply_lease(c, true);
 712
 713                 if (c->accept_reconf && c->reconf_cnt == 0) {
 714                         struct dhcp_assignment *a;
 715
 716                         start_reconf(c);
 717
 718                         /* Leave all other assignments of that client alone */
 719                         list_for_each_entry(a, &iface->ia_assignments, head)
 720                                 if (a != c && a->clid_len == c->clid_len &&
 721                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 722                                         a->reconf_cnt = INT_MAX;
 723                 }
 724         }
 725
 726         while (!list_empty(&reassign)) {
 727                 c = list_first_entry(&reassign, struct dhcp_assignment, head);
 728                 list_del_init(&c->head);
 729                 if (!assign_pd(iface, c)) {
 730                         c->assigned = 0;
 731                         list_add(&c->head, &iface->ia_assignments);
 732                 }
 733         }
 734
 735         dhcpv6_ia_write_statefile();
 736 }
 737
 738 static void reconf_timeout_cb(struct uloop_timeout *event)
 739 {
 740         struct dhcp_assignment *a = container_of(event, struct dhcp_assignment, reconf_timer);
 741
 742         if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
 743                 send_reconf(a);
 744                 uloop_timeout_set(&a->reconf_timer,
 745                                         DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 746                 a->reconf_cnt++;
 747         } else
 748                 stop_reconf(a);
 749 }
 750
 751 static void start_reconf(struct dhcp_assignment *a)
 752 {
 753         uloop_timeout_set(&a->reconf_timer,
 754                                 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 755         a->reconf_timer.cb = reconf_timeout_cb;
 756         a->reconf_cnt++;
 757
 758         send_reconf(a);
 759 }
 760
 761 static void stop_reconf(struct dhcp_assignment *a)
 762 {
 763         uloop_timeout_cancel(&a->reconf_timer);
 764         a->reconf_cnt = 0;
 765         a->reconf_timer.cb = NULL;
 766 }
 767
 768 static void valid_until_cb(struct uloop_timeout *event)
 769 {
 770         struct interface *iface;
 771         time_t now = odhcpd_time();
 772
 773         avl_for_each_element(&interfaces, iface, avl) {
 774                 struct dhcp_assignment *a, *n;
 775
 776                 if (iface->dhcpv6 != MODE_SERVER)
 777                         continue;
 778
 779                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 780                         if (a->clid_len > 0 && !INFINITE_VALID(a->valid_until) && a->valid_until < now)
 781                                 free_assignment(a);
 782                 }
 783         }
 784         uloop_timeout_set(event, 1000);
 785 }
 786
 787 static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 788                 const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
 789                 struct interface *iface, bool request)
 790 {
 791         struct dhcpv6_ia_hdr o_ia = {
 792                 .type = ia->type,
 793                 .len = 0,
 794                 .iaid = ia->iaid,
 795                 .t1 = 0,
 796                 .t2 = 0,
 797         };
 798         size_t ia_len = sizeof(o_ia);
 799         time_t now = odhcpd_time();
 800
 801         if (buflen < ia_len)
 802                 return 0;
 803
 804         if (status) {
 805                 struct __attribute__((packed)) {
 806                         uint16_t type;
 807                         uint16_t len;
 808                         uint16_t val;
 809                 } o_status = {
 810                         .type = htons(DHCPV6_OPT_STATUS),
 811                         .len = htons(sizeof(o_status) - 4),
 812                         .val = htons(status),
 813                 };
 814
 815                 memcpy(buf + ia_len, &o_status, sizeof(o_status));
 816                 ia_len += sizeof(o_status);
 817
 818                 o_ia.len = htons(ia_len - 4);
 819                 memcpy(buf, &o_ia, sizeof(o_ia));
 820
 821                 return ia_len;
 822         }
 823
 824         if (a) {
 825                 uint32_t leasetime;
 826
 827                 if (a->leasetime)
 828                         leasetime = a->leasetime;
 829                 else
 830                         leasetime = iface->dhcp_leasetime;
 831
 832                 uint32_t pref = leasetime;
 833                 uint32_t valid = leasetime;
 834
 835                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 836                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
 837                 size_t m = get_preferred_addr(addrs, addrlen);
 838
 839                 for (size_t i = 0; i < addrlen; ++i) {
 840                         uint32_t prefix_pref = addrs[i].preferred;
 841                         uint32_t prefix_valid = addrs[i].valid;
 842
 843                         if (!valid_addr(&addrs[i], now))
 844                                 continue;
 845
 846                         if (prefix_pref != UINT32_MAX)
 847                                 prefix_pref -= now;
 848
 849                         if (prefix_pref > leasetime)
 850                                 prefix_pref = leasetime;
 851
 852                         if (prefix_valid != UINT32_MAX)
 853                                 prefix_valid -= now;
 854
 855                         if (prefix_valid > leasetime)
 856                                 prefix_valid = leasetime;
 857
 858                         if (a->flags & OAF_DHCPV6_PD) {
 859                                 struct dhcpv6_ia_prefix o_ia_p = {
 860                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 861                                         .len = htons(sizeof(o_ia_p) - 4),
 862                                         .preferred = htonl(prefix_pref),
 863                                         .valid = htonl(prefix_valid),
 864                                         .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 865                                         .addr = addrs[i].addr.in6,
 866                                 };
 867
 868                                 o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned);
 869                                 o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0;
 870
 871                                 if ((a->assigned == 0 && a->managed_size == 0) ||
 872                                                 !valid_prefix_length(a, addrs[i].prefix))
 873                                         continue;
 874
 875                                 if (buflen < ia_len + sizeof(o_ia_p))
 876                                         return 0;
 877
 878                                 memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
 879                                 ia_len += sizeof(o_ia_p);
 880                         }
 881
 882                         if (a->flags & OAF_DHCPV6_NA) {
 883                                 struct dhcpv6_ia_addr o_ia_a = {
 884                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 885                                         .len = htons(sizeof(o_ia_a) - 4),
 886                                         .addr = addrs[i].addr.in6,
 887                                         .preferred = htonl(prefix_pref),
 888                                         .valid = htonl(prefix_valid)
 889                                 };
 890
 891                                 o_ia_a.addr.s6_addr32[3] = htonl(a->assigned);
 892
 893                                 if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
 894                                                 a->assigned == 0)
 895                                         continue;
 896
 897                                 if (buflen < ia_len + sizeof(o_ia_a))
 898                                         return 0;
 899
 900                                 memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
 901                                 ia_len += sizeof(o_ia_a);
 902                         }
 903
 904                         /* Calculate T1 / T2 based on non-deprecated addresses */
 905                         if (prefix_pref > 0) {
 906                                 if (prefix_pref < pref)
 907                                         pref = prefix_pref;
 908
 909                                 if (prefix_valid < valid)
 910                                         valid = prefix_valid;
 911                         }
 912                 }
 913
 914                 if (!INFINITE_VALID(a->valid_until))
 915                         /* UINT32_MAX is considered as infinite leasetime */
 916                         a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 917
 918                 o_ia.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 919                 o_ia.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 920
 921                 if (!o_ia.t1)
 922                         o_ia.t1 = htonl(1);
 923
 924                 if (!o_ia.t2)
 925                         o_ia.t2 = htonl(1);
 926         }
 927
 928         if (!request) {
 929                 uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 930                 uint16_t otype, olen;
 931
 932                 dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 933                         struct dhcpv6_ia_prefix *ia_p = (struct dhcpv6_ia_prefix *)&odata[-4];
 934                         struct dhcpv6_ia_addr *ia_a = (struct dhcpv6_ia_addr *)&odata[-4];
 935                         bool found = false;
 936
 937                         if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*ia_p) - 4) &&
 938                                         (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*ia_a) - 4))
 939                                 continue;
 940
 941                         if (a) {
 942                                 struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 943                                 size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
 944
 945                                 for (size_t i = 0; i < addrlen; ++i) {
 946                                         if (!valid_addr(&addrs[i], now))
 947                                                 continue;
 948
 949                                         struct in6_addr addr = addrs[i].addr.in6;
 950                                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 951                                                 addr.s6_addr32[1] |= htonl(a->assigned);
 952                                                 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 953
 954                                                 if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) &&
 955                                                                 ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 956                                                         found = true;
 957                                         } else {
 958                                                 addr.s6_addr32[3] = htonl(a->assigned);
 959
 960                                                 if (!memcmp(&ia_a->addr, &addr, sizeof(addr)))
 961                                                         found = true;
 962                                         }
 963                                 }
 964                         }
 965
 966                         if (!found) {
 967                                 if (otype == DHCPV6_OPT_IA_PREFIX) {
 968                                         struct dhcpv6_ia_prefix o_ia_p = {
 969                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 970                                                 .len = htons(sizeof(o_ia_p) - 4),
 971                                                 .preferred = 0,
 972                                                 .valid = 0,
 973                                                 .prefix = ia_p->prefix,
 974                                                 .addr = ia_p->addr,
 975                                         };
 976
 977                                         if (buflen < ia_len + sizeof(o_ia_p))
 978                                                 return 0;
 979
 980                                         memcpy(buf + ia_len, &o_ia_p, sizeof(o_ia_p));
 981                                         ia_len += sizeof(o_ia_p);
 982                                 } else {
 983                                         struct dhcpv6_ia_addr o_ia_a = {
 984                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 985                                                 .len = htons(sizeof(o_ia_a) - 4),
 986                                                 .addr = ia_a->addr,
 987                                                 .preferred = 0,
 988                                                 .valid = 0,
 989                                         };
 990
 991                                         if (buflen < ia_len + sizeof(o_ia_a))
 992                                                 continue;
 993
 994                                         memcpy(buf + ia_len, &o_ia_a, sizeof(o_ia_a));
 995                                         ia_len += sizeof(o_ia_a);
 996                                 }
 997                         }
 998                 }
 999         }
1000
1001         o_ia.len = htons(ia_len - 4);
1002         memcpy(buf, &o_ia, sizeof(o_ia));
1003         return ia_len;
1004 }
1005
1006 struct log_ctxt {
1007         char *buf;
1008         int buf_len;
1009         int buf_idx;
1010 };
1011
1012 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
1013                                 _unused uint32_t valid, void *arg)
1014 {
1015         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1016         char addrbuf[INET6_ADDRSTRLEN];
1017
1018         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1019         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1020                                         "%s/%d ", addrbuf, prefix);
1021 }
1022
1023 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1024                 const char *duidbuf, bool is_pd, struct dhcp_assignment *a, int code)
1025 {
1026         const char *type = "UNKNOWN";
1027         const char *status = "UNKNOWN";
1028
1029         switch (msgtype) {
1030         case DHCPV6_MSG_SOLICIT:
1031                 type = "SOLICIT";
1032                 break;
1033         case DHCPV6_MSG_REQUEST:
1034                 type = "REQUEST";
1035                 break;
1036         case DHCPV6_MSG_CONFIRM:
1037                 type = "CONFIRM";
1038                 break;
1039         case DHCPV6_MSG_RENEW:
1040                 type = "RENEW";
1041                 break;
1042         case DHCPV6_MSG_REBIND:
1043                 type = "REBIND";
1044                 break;
1045         case DHCPV6_MSG_RELEASE:
1046                 type = "RELEASE";
1047                 break;
1048         case DHCPV6_MSG_DECLINE:
1049                 type = "DECLINE";
1050                 break;
1051         }
1052
1053         switch (code) {
1054         case DHCPV6_STATUS_OK:
1055                 status = "ok";
1056                 break;
1057         case DHCPV6_STATUS_NOADDRSAVAIL:
1058                 status = "no addresses available";
1059                 break;
1060         case DHCPV6_STATUS_NOBINDING:
1061                 status = "no binding";
1062                 break;
1063         case DHCPV6_STATUS_NOTONLINK:
1064                 status = "not on-link";
1065                 break;
1066         case DHCPV6_STATUS_NOPREFIXAVAIL:
1067                 status = "no prefix available";
1068                 break;
1069         }
1070
1071         char leasebuf[256] = "";
1072
1073         if (a) {
1074                 struct log_ctxt ctxt = {.buf = leasebuf,
1075                                         .buf_len = sizeof(leasebuf),
1076                                         .buf_idx = 0 };
1077
1078                 dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1079         }
1080
1081         syslog(LOG_INFO, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1082                          duidbuf, iface->name, status, leasebuf);
1083 }
1084
1085 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
1086                 struct interface *iface)
1087 {
1088         struct odhcpd_ipaddr *addrs = (a && a->managed) ? a->managed : iface->addr6;
1089         size_t addrlen = (a && a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1090         time_t now = odhcpd_time();
1091         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1092         uint16_t otype, olen;
1093         bool onlink = true;
1094
1095         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1096                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix *)&odata[-4];
1097                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr *)&odata[-4];
1098
1099                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
1100                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
1101                         continue;
1102
1103                 onlink = false;
1104                 for (size_t i = 0; i < addrlen; ++i) {
1105                         if (!valid_addr(&addrs[i], now))
1106                                 continue;
1107
1108                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1109                                 if (p->prefix < addrs[i].prefix ||
1110                                     odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
1111                                         continue;
1112
1113                         } else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
1114                                 continue;
1115
1116                         onlink = true;
1117                 }
1118
1119                 if (!onlink)
1120                         break;
1121         }
1122
1123         return onlink;
1124 }
1125
1126 ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *iface,
1127                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1128 {
1129         struct lease *l;
1130         struct dhcp_assignment *first = NULL;
1131         const struct dhcpv6_client_header *hdr = data;
1132         time_t now = odhcpd_time();
1133         uint16_t otype, olen, clid_len = 0;
1134         uint8_t *start = (uint8_t *)&hdr[1], *odata;
1135         uint8_t *clid_data = NULL, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1136         size_t hostname_len = 0, response_len = 0;
1137         bool notonlink = false, rapid_commit = false, accept_reconf = false;
1138         char duidbuf[261], hostname[256];
1139
1140         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1141                 if (otype == DHCPV6_OPT_CLIENTID) {
1142                         clid_data = odata;
1143                         clid_len = olen;
1144
1145                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1146                                 memcpy(mac, &odata[8], sizeof(mac));
1147                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1148                                 memcpy(mac, &odata[4], sizeof(mac));
1149
1150                         if (olen <= 130)
1151                                 odhcpd_hexlify(duidbuf, odata, olen);
1152                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1153                         uint8_t fqdn_buf[256];
1154                         memcpy(fqdn_buf, odata, olen);
1155                         fqdn_buf[olen++] = 0;
1156
1157                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1158                                 hostname_len = strcspn(hostname, ".");
1159                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1160                         accept_reconf = true;
1161                 else if (otype == DHCPV6_OPT_RAPID_COMMIT && hdr->msg_type == DHCPV6_MSG_SOLICIT)
1162                         rapid_commit = true;
1163         }
1164
1165         if (!clid_data || !clid_len || clid_len > 130)
1166                 goto out;
1167
1168         l = config_find_lease_by_duid(clid_data, clid_len);
1169         if (!l)
1170                 l = config_find_lease_by_mac(mac);
1171
1172         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1173                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1174                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1175                 bool ia_addr_present = false;
1176                 if (!is_pd && !is_na)
1177                         continue;
1178
1179                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1180                 size_t ia_response_len = 0;
1181                 uint8_t reqlen = (is_pd) ? 62 : 128;
1182                 uint32_t reqhint = 0;
1183
1184                 /* Parse request hint for IA-PD */
1185                 if (is_pd) {
1186                         uint8_t *sdata;
1187                         uint16_t stype, slen;
1188                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1189                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1190                                         continue;
1191
1192                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1193                                 if (p->prefix) {
1194                                         reqlen = p->prefix;
1195                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1196                                         if (reqlen > 32 && reqlen <= 64)
1197                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1198                                 }
1199                         }
1200
1201                         if (reqlen > 64)
1202                                 reqlen = 64;
1203                 } else if (is_na) {
1204                         uint8_t *sdata;
1205                         uint16_t stype, slen;
1206                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1207                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1208                                         continue;
1209
1210                                 ia_addr_present = true;
1211                         }
1212                 }
1213
1214                 /* Find assignment */
1215                 struct dhcp_assignment *c, *a = NULL;
1216                 list_for_each_entry(c, &iface->ia_assignments, head) {
1217                         if ((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) &&
1218                             c->iaid == ia->iaid && (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1219                             ((is_pd && (c->flags & OAF_DHCPV6_PD)) || (is_na && (c->flags & OAF_DHCPV6_NA)))) {
1220                                 a = c;
1221
1222                                 /* Reset state */
1223                                 if (a->flags & OAF_BOUND)
1224                                         apply_lease(a, false);
1225
1226                                 stop_reconf(a);
1227                                 break;
1228                         }
1229                 }
1230
1231                 if (l && a && a->lease != l) {
1232                         free_assignment(a);
1233                         a = NULL;
1234                 }
1235
1236                 /* Generic message handling */
1237                 uint16_t status = DHCPV6_STATUS_OK;
1238                 if (a && a->managed_size < 0)
1239                         return -1;
1240
1241                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1242                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1243                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1244                         bool assigned = !!a;
1245
1246                         if (!a) {
1247                                 if ((!iface->no_dynamic_dhcp || (l && is_na)) &&
1248                                     (iface->dhcpv6_pd || iface->dhcpv6_na)) {
1249                                         /* Create new binding */
1250                                         a = alloc_assignment(clid_len);
1251
1252                                         if (a) {
1253                                                 a->clid_len = clid_len;
1254                                                 memcpy(a->clid_data, clid_data, clid_len);
1255                                                 a->iaid = ia->iaid;
1256                                                 a->length = reqlen;
1257                                                 a->peer = *addr;
1258                                                 a->assigned = is_na && l ? l->hostid : reqhint;
1259                                                 a->valid_until =  now;
1260                                                 a->dhcp_free_cb = dhcpv6_ia_free_assignment;
1261                                                 a->iface = iface;
1262                                                 a->flags = (is_pd ? OAF_DHCPV6_PD : OAF_DHCPV6_NA);
1263
1264                                                 if (first)
1265                                                         memcpy(a->key, first->key, sizeof(a->key));
1266                                                 else
1267                                                         odhcpd_urandom(a->key, sizeof(a->key));
1268
1269                                                 if (is_pd && iface->dhcpv6_pd)
1270                                                         while (!(assigned = assign_pd(iface, a)) &&
1271                                                                !a->managed_size && ++a->length <= 64);
1272                                                 else if (is_na && iface->dhcpv6_na)
1273                                                         assigned = assign_na(iface, a);
1274
1275                                                 if (l && assigned) {
1276                                                         a->flags |= OAF_STATIC;
1277
1278                                                         if (l->hostname)
1279                                                                 a->hostname = strdup(l->hostname);
1280
1281                                                         if (l->leasetime)
1282                                                                 a->leasetime = l->leasetime;
1283
1284                                                         list_add(&a->lease_list, &l->assignments);
1285                                                         a->lease = l;
1286                                                 }
1287
1288                                                 if (a->managed_size && !assigned)
1289                                                         return -1;
1290                                         }
1291                                 }
1292                         }
1293
1294                         if (!assigned || iface->addr6_len == 0)
1295                                 /* Set error status */
1296                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1297                         else if (hdr->msg_type == DHCPV6_MSG_REQUEST && !dhcpv6_ia_on_link(ia, a, iface)) {
1298                                 /* Send NOTONLINK staus for the IA */
1299                                 status = DHCPV6_STATUS_NOTONLINK;
1300                                 assigned = false;
1301                         } else if (accept_reconf && assigned && !first &&
1302                                         hdr->msg_type != DHCPV6_MSG_REBIND) {
1303                                 size_t handshake_len = 4;
1304                                 buf[0] = 0;
1305                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1306                                 buf[2] = 0;
1307                                 buf[3] = 0;
1308
1309                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1310                                         struct dhcpv6_auth_reconfigure auth = {
1311                                                 htons(DHCPV6_OPT_AUTH),
1312                                                 htons(sizeof(auth) - 4),
1313                                                 3, 1, 0,
1314                                                 {htonl(time(NULL)), htonl(++serial)},
1315                                                 1,
1316                                                 {0}
1317                                         };
1318                                         memcpy(auth.key, a->key, sizeof(a->key));
1319                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1320                                         handshake_len += sizeof(auth);
1321                                 }
1322
1323
1324                                 buf += handshake_len;
1325                                 buflen -= handshake_len;
1326                                 response_len += handshake_len;
1327
1328                                 first = a;
1329                         }
1330
1331                         ia_response_len = build_ia(buf, buflen, status, ia, a, iface,
1332                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1333
1334                         /* Was only a solicitation: mark binding for removal */
1335                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT && !rapid_commit) {
1336                                 a->flags &= ~OAF_BOUND;
1337                                 a->flags |= OAF_TENTATIVE;
1338
1339                                 /* Keep tentative assignment around for 60 seconds */
1340                                 a->valid_until = now + 60;
1341
1342                         } else if (assigned &&
1343                                    ((hdr->msg_type == DHCPV6_MSG_SOLICIT && rapid_commit) ||
1344                                     hdr->msg_type == DHCPV6_MSG_REQUEST ||
1345                                     hdr->msg_type == DHCPV6_MSG_REBIND)) {
1346                                 if ((!(a->flags & OAF_STATIC) || !a->hostname) && hostname_len > 0) {
1347                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1348                                         if (a->hostname) {
1349                                                 memcpy(a->hostname, hostname, hostname_len);
1350                                                 a->hostname[hostname_len] = 0;
1351
1352                                                 if (odhcpd_valid_hostname(a->hostname))
1353                                                         a->flags &= ~OAF_BROKEN_HOSTNAME;
1354                                                 else
1355                                                         a->flags |= OAF_BROKEN_HOSTNAME;
1356                                         }
1357                                 }
1358                                 a->accept_reconf = accept_reconf;
1359                                 a->flags &= ~OAF_TENTATIVE;
1360                                 a->flags |= OAF_BOUND;
1361                                 apply_lease(a, true);
1362                         } else if (!assigned && a && a->managed_size == 0) {
1363                                 /* Cleanup failed assignment */
1364                                 free_assignment(a);
1365                                 a = NULL;
1366                         }
1367                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1368                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1369                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1370                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1371                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1372                                 status = DHCPV6_STATUS_NOBINDING;
1373                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1374                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1375                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1376                                 ia_response_len = build_ia(buf, buflen, status, ia, a, iface, false);
1377                                 if (a) {
1378                                         a->flags |= OAF_BOUND;
1379                                         apply_lease(a, true);
1380                                 }
1381                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1382                                 a->valid_until = now - 1;
1383                         } else if ((a->flags & OAF_DHCPV6_NA) && hdr->msg_type == DHCPV6_MSG_DECLINE) {
1384                                 a->flags &= ~OAF_BOUND;
1385
1386                                 if (!(a->flags & OAF_STATIC) || a->lease->hostid != a->assigned) {
1387                                         memset(a->clid_data, 0, a->clid_len);
1388                                         a->valid_until = now + 3600; /* Block address for 1h */
1389                                 } else
1390                                         a->valid_until = now - 1;
1391                         }
1392                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
1393                         if (ia_addr_present && !dhcpv6_ia_on_link(ia, a, iface)) {
1394                                 notonlink = true;
1395                                 break;
1396                         }
1397
1398                         if (!ia_addr_present || !a || !(a->flags & OAF_BOUND)) {
1399                                 response_len = 0;
1400                                 goto out;
1401                         }
1402                 }
1403
1404                 buf += ia_response_len;
1405                 buflen -= ia_response_len;
1406                 response_len += ia_response_len;
1407                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1408         }
1409
1410         switch (hdr->msg_type) {
1411         case DHCPV6_MSG_RELEASE:
1412         case DHCPV6_MSG_DECLINE:
1413         case DHCPV6_MSG_CONFIRM:
1414                 if (response_len + 6 < buflen) {
1415                         buf[0] = 0;
1416                         buf[1] = DHCPV6_OPT_STATUS;
1417                         buf[2] = 0;
1418                         buf[3] = 2;
1419                         buf[4] = 0;
1420                         buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1421                         response_len += 6;
1422                 }
1423                 break;
1424
1425         default:
1426                 break;
1427         }
1428
1429         dhcpv6_ia_write_statefile();
1430
1431 out:
1432         return response_len;
1433 }