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 free_dhcpv6_assignment(struct dhcpv6_assignment *c);
  44 static void set_border_assignment_size(struct interface *iface, struct dhcpv6_assignment *b);
  45 static void handle_addrlist_change(struct netevent_handler_info *info);
  46 static void start_reconf(struct dhcpv6_assignment *a);
  47 static void stop_reconf(struct dhcpv6_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_setup_ia_interface(struct interface *iface, bool enable)
  65 {
  66         if (!enable && iface->ia_assignments.next) {
  67                 struct dhcpv6_assignment *c;
  68
  69                 while (!list_empty(&iface->ia_assignments)) {
  70                         c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
  71                         free_dhcpv6_assignment(c);
  72                 }
  73         }
  74
  75         if (enable && iface->dhcpv6 == MODE_SERVER) {
  76                 struct dhcpv6_assignment *border;
  77                 struct lease *lease;
  78
  79                 if (!iface->ia_assignments.next)
  80                         INIT_LIST_HEAD(&iface->ia_assignments);
  81
  82                 if (list_empty(&iface->ia_assignments)) {
  83                         border = calloc(1, sizeof(*border));
  84
  85                         if (!border) {
  86                                 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
  87                                 return -1;
  88                         }
  89
  90                         border->length = 64;
  91                         list_add(&border->head, &iface->ia_assignments);
  92                 } else
  93                         border = list_last_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
  94
  95                 set_border_assignment_size(iface, border);
  96
  97                 /* Parse static entries */
  98                 list_for_each_entry(lease, &leases, head) {
  99                         /* Construct entry */
 100                         size_t duid_len = lease->duid_len ? lease->duid_len : 14;
 101                         struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
 102                         if (!a) {
 103                                 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
 104                                         iface->ifname);
 105                                 return -1;
 106                         }
 107
 108                         a->leasetime = lease->dhcpv4_leasetime;
 109
 110                         a->clid_len = duid_len;
 111                         a->length = 128;
 112                         if (lease->hostid) {
 113                                 a->assigned = lease->hostid;
 114                         } else {
 115                                 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
 116                                 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
 117                         }
 118
 119                         odhcpd_urandom(a->key, sizeof(a->key));
 120                         memcpy(a->clid_data, lease->duid, lease->duid_len);
 121                         memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
 122                         /* Static assignment */
 123                         a->flags |= OAF_STATIC;
 124                         /* Infinite valid */
 125                         a->valid_until = 0;
 126
 127                         /* Assign to all interfaces */
 128                         struct dhcpv6_assignment *c;
 129                         list_for_each_entry(c, &iface->ia_assignments, head) {
 130                                 if (c->length != 128 || c->assigned > a->assigned) {
 131                                         list_add_tail(&a->head, &c->head);
 132                                         break;
 133                                 } else if (c->assigned == a->assigned)
 134                                         /* Already an assignment with that number */
 135                                         break;
 136                         }
 137
 138                         if (a->head.next) {
 139                                 a->iface = iface;
 140                                 if (lease->hostname[0]) {
 141                                         free(a->hostname);
 142                                         a->hostname = strdup(lease->hostname);
 143                                 }
 144                         } else
 145                                 free_dhcpv6_assignment(a);
 146                 }
 147         }
 148         return 0;
 149 }
 150
 151
 152 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info)
 153 {
 154         struct interface *iface = info->iface;
 155
 156         if (!iface || iface->dhcpv6 != MODE_SERVER)
 157                 return;
 158
 159         switch (event) {
 160         case NETEV_ADDR6LIST_CHANGE:
 161                 handle_addrlist_change(info);
 162                 break;
 163         default:
 164                 break;
 165         }
 166 }
 167
 168
 169 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
 170 {
 171         if (c->managed_sock.fd.registered) {
 172                 ustream_free(&c->managed_sock.stream);
 173                 close(c->managed_sock.fd.fd);
 174         }
 175
 176         if (c->head.next)
 177                 list_del(&c->head);
 178
 179         if (c->reconf_cnt)
 180                 stop_reconf(c);
 181
 182         free(c->managed);
 183         free(c->hostname);
 184         free(c);
 185 }
 186
 187 static inline bool valid_prefix_length(const struct dhcpv6_assignment *a, const uint8_t prefix_length)
 188 {
 189         return (a->managed_size || a->length > prefix_length);
 190 }
 191
 192 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 193 {
 194         return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
 195 }
 196
 197 static size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
 198 {
 199         size_t i, m;
 200
 201         for (i = 0, m = 0; i < addrlen; ++i) {
 202                 if (addrs[i].preferred > addrs[m].preferred ||
 203                                 (addrs[i].preferred == addrs[m].preferred &&
 204                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 205                         m = i;
 206         }
 207
 208         return m;
 209 }
 210
 211 static int send_reconf(struct dhcpv6_assignment *assign)
 212 {
 213         struct {
 214                 struct dhcpv6_client_header hdr;
 215                 uint16_t srvid_type;
 216                 uint16_t srvid_len;
 217                 uint16_t duid_type;
 218                 uint16_t hardware_type;
 219                 uint8_t mac[6];
 220                 uint16_t msg_type;
 221                 uint16_t msg_len;
 222                 uint8_t msg_id;
 223                 struct dhcpv6_auth_reconfigure auth;
 224                 uint16_t clid_type;
 225                 uint16_t clid_len;
 226                 uint8_t clid_data[128];
 227         } __attribute__((packed)) reconf_msg = {
 228                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 229                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 230                 .srvid_len = htons(10),
 231                 .duid_type = htons(3),
 232                 .hardware_type = htons(1),
 233                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 234                 .msg_len = htons(1),
 235                 .msg_id = DHCPV6_MSG_RENEW,
 236                 .auth = {htons(DHCPV6_OPT_AUTH),
 237                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 238                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 239                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 240                 .clid_len = htons(assign->clid_len),
 241                 .clid_data = {0},
 242         };
 243         struct interface *iface = assign->iface;
 244
 245         odhcpd_get_mac(iface, reconf_msg.mac);
 246         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 247         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 248
 249         md5_ctx_t md5;
 250         uint8_t secretbytes[64];
 251         memset(secretbytes, 0, sizeof(secretbytes));
 252         memcpy(secretbytes, assign->key, sizeof(assign->key));
 253
 254         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 255                 secretbytes[i] ^= 0x36;
 256
 257         md5_begin(&md5);
 258         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 259         md5_hash(iov.iov_base, iov.iov_len, &md5);
 260         md5_end(reconf_msg.auth.key, &md5);
 261
 262         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 263                 secretbytes[i] ^= 0x36;
 264                 secretbytes[i] ^= 0x5c;
 265         }
 266
 267         md5_begin(&md5);
 268         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 269         md5_hash(reconf_msg.auth.key, 16, &md5);
 270         md5_end(reconf_msg.auth.key, &md5);
 271
 272         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 273 }
 274
 275 void dhcpv6_enum_ia_addrs(struct interface *iface, struct dhcpv6_assignment *c,
 276                                 time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
 277 {
 278         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->addr6;
 279         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->addr6_len;
 280         size_t m = get_preferred_addr(addrs, addrlen);
 281
 282         for (size_t i = 0; i < addrlen; ++i) {
 283                 struct in6_addr addr;
 284                 uint32_t pref, valid;
 285                 int prefix = c->managed ? addrs[i].prefix : c->length;
 286
 287                 if (!valid_addr(&addrs[i], now))
 288                         continue;
 289
 290                 addr = addrs[i].addr.in6;
 291                 pref = addrs[i].preferred;
 292                 valid = addrs[i].valid;
 293                 if (prefix == 128) {
 294                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 295                                 continue;
 296
 297                         addr.s6_addr32[3] = htonl(c->assigned);
 298                 } else {
 299                         if (!valid_prefix_length(c, addrs[i].prefix))
 300                                 continue;
 301
 302                         addr.s6_addr32[1] |= htonl(c->assigned);
 303                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 304                 }
 305
 306                 if (pref != UINT32_MAX)
 307                         pref -= now;
 308
 309                 if (valid != UINT32_MAX)
 310                         valid -= now;
 311
 312                 func(&addr, prefix, pref, valid, arg);
 313         }
 314 }
 315
 316 struct write_ctxt {
 317         FILE *fp;
 318         md5_ctx_t md5;
 319         struct dhcpv6_assignment *c;
 320         struct interface *iface;
 321         char *buf;
 322         int buf_len;
 323         int buf_idx;
 324 };
 325
 326 void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 327                                 _unused uint32_t valid, void *arg)
 328 {
 329         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
 330         char ipbuf[INET6_ADDRSTRLEN];
 331
 332         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 333
 334         if (ctxt->c->length == 128 && ctxt->c->hostname &&
 335             !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
 336                 fputs(ipbuf, ctxt->fp);
 337
 338                 char b[256];
 339                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
 340                                 ctxt->iface->search, b, sizeof(b)) > 0)
 341                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
 342
 343                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
 344                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
 345                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
 346         }
 347
 348         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
 349                                         "%s/%d ", ipbuf, prefix);
 350 }
 351
 352 void dhcpv6_write_statefile(void)
 353 {
 354         struct write_ctxt ctxt;
 355
 356         md5_begin(&ctxt.md5);
 357
 358         if (config.dhcp_statefile) {
 359                 time_t now = odhcpd_time(), wall_time = time(NULL);
 360                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 361                 char leasebuf[512];
 362
 363                 if (fd < 0)
 364                         return;
 365                 int ret;
 366                 ret = lockf(fd, F_LOCK, 0);
 367                 if (ret < 0) {
 368                         close(fd);
 369                         return;
 370                 }
 371                 if (ftruncate(fd, 0) < 0) {}
 372
 373                 ctxt.fp = fdopen(fd, "w");
 374                 if (!ctxt.fp) {
 375                         close(fd);
 376                         return;
 377                 }
 378
 379                 ctxt.buf = leasebuf;
 380                 ctxt.buf_len = sizeof(leasebuf);
 381
 382                 list_for_each_entry(ctxt.iface, &interfaces, head) {
 383                         if (ctxt.iface->dhcpv6 != MODE_SERVER &&
 384                                         ctxt.iface->dhcpv4 != MODE_SERVER)
 385                                 continue;
 386
 387                         if (ctxt.iface->dhcpv6 == MODE_SERVER &&
 388                                         ctxt.iface->ia_assignments.next) {
 389                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 390                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 391                                                 continue;
 392
 393                                         char duidbuf[264];
 394
 395                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
 396
 397                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 398                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s%s %ld %x %u ",
 399                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
 400                                                                 (ctxt.c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 401                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
 402                                                                 (ctxt.c->valid_until > now ?
 403                                                                         (ctxt.c->valid_until - now + wall_time) :
 404                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)),
 405                                                                 ctxt.c->assigned, (unsigned)ctxt.c->length);
 406
 407                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
 408                                                 dhcpv6_enum_ia_addrs(ctxt.iface, ctxt.c, now,
 409                                                                         dhcpv6_write_ia_addr, &ctxt);
 410
 411                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 412                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 413                                 }
 414                         }
 415
 416                         if (ctxt.iface->dhcpv4 == MODE_SERVER &&
 417                                         ctxt.iface->dhcpv4_assignments.next) {
 418                                 struct dhcpv4_assignment *c;
 419                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 420                                         if (!(c->flags & OAF_BOUND))
 421                                                 continue;
 422
 423                                         char ipbuf[INET6_ADDRSTRLEN];
 424                                         char duidbuf[16];
 425                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 426
 427                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 428                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s%s %ld %x 32 ",
 429                                                                 ctxt.iface->ifname, duidbuf,
 430                                                                 (c->flags & OAF_BROKEN_HOSTNAME) ? "broken\\x20" : "",
 431                                                                 (c->hostname ? c->hostname : "-"),
 432                                                                 (c->valid_until > now ?
 433                                                                         (c->valid_until - now + wall_time) :
 434                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 435                                                                 ntohl(c->addr));
 436
 437                                         struct in_addr addr = {.s_addr = c->addr};
 438                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 439
 440                                         if (c->hostname && !(c->flags & OAF_BROKEN_HOSTNAME)) {
 441                                                 fputs(ipbuf, ctxt.fp);
 442
 443                                                 char b[256];
 444                                                 if (dn_expand(ctxt.iface->search,
 445                                                                 ctxt.iface->search + ctxt.iface->search_len,
 446                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
 447                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
 448
 449                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
 450                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
 451                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
 452                                         }
 453
 454                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
 455                                                                         ctxt.buf_len - ctxt.buf_idx,
 456                                                                         "%s/32 ", ipbuf);
 457                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 458                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 459                                 }
 460                         }
 461                 }
 462
 463                 fclose(ctxt.fp);
 464         }
 465
 466         uint8_t newmd5[16];
 467         md5_end(newmd5, &ctxt.md5);
 468
 469         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 470                 memcpy(statemd5, newmd5, sizeof(statemd5));
 471                 char *argv[2] = {config.dhcp_cb, NULL};
 472                 if (!vfork()) {
 473                         execv(argv[0], argv);
 474                         _exit(128);
 475                 }
 476         }
 477 }
 478
 479 static void __apply_lease(struct interface *iface, struct dhcpv6_assignment *a,
 480                 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
 481 {
 482         if (a->length > 64)
 483                 return;
 484
 485         for (ssize_t i = 0; i < addr_len; ++i) {
 486                 struct in6_addr prefix = addrs[i].addr.in6;
 487                 prefix.s6_addr32[1] |= htonl(a->assigned);
 488                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
 489                 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 490                                 iface->ifindex, &a->peer.sin6_addr, 1024, add);
 491         }
 492 }
 493
 494 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
 495 {
 496         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 497         ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
 498
 499         __apply_lease(iface, a, addrs, addrlen, add);
 500 }
 501
 502 /* Set border assignment size based on the IPv6 address prefixes */
 503 static void set_border_assignment_size(struct interface *iface, struct dhcpv6_assignment *b)
 504 {
 505         time_t now = odhcpd_time();
 506         int minprefix = -1;
 507
 508         for (size_t i = 0; i < iface->addr6_len; ++i) {
 509                 if (iface->addr6[i].preferred > (uint32_t)now &&
 510                                 iface->addr6[i].prefix < 64 &&
 511                                 iface->addr6[i].prefix > minprefix)
 512                         minprefix = iface->addr6[i].prefix;
 513         }
 514
 515         if (minprefix > 32 && minprefix <= 64)
 516                 b->assigned = 1U << (64 - minprefix);
 517         else
 518                 b->assigned = 0;
 519 }
 520
 521 /* More data was received from TCP connection */
 522 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 523 {
 524         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 525         struct dhcpv6_assignment *c = container_of(fd, struct dhcpv6_assignment, managed_sock);
 526         time_t now = odhcpd_time();
 527         bool first = c->managed_size < 0;
 528
 529         for (;;) {
 530                 int pending;
 531                 char *data = ustream_get_read_buf(s, &pending);
 532                 char *end = memmem(data, pending, "\n\n", 2);
 533
 534                 if (!end)
 535                         break;
 536
 537                 end += 2;
 538                 end[-1] = 0;
 539
 540                 c->managed_size = 0;
 541                 if (c->accept_reconf)
 542                         c->reconf_cnt = 1;
 543
 544                 char *saveptr;
 545                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 546                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 547                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 548
 549                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 550                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 551                                 continue;
 552
 553                         x = strtok_r(NULL, ",", &saveptr2);
 554                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 555                                 continue;
 556
 557                         x = strtok_r(NULL, ",", &saveptr2);
 558                         if (sscanf(x, "%u", &n->preferred) < 1)
 559                                 continue;
 560
 561                         x = strtok_r(NULL, ",", &saveptr2);
 562                         if (sscanf(x, "%u", &n->valid) < 1)
 563                                 continue;
 564
 565                         if (n->preferred > n->valid)
 566                                 continue;
 567
 568                         if (UINT32_MAX - now < n->preferred)
 569                                 n->preferred = UINT32_MAX;
 570                         else
 571                                 n->preferred += now;
 572
 573                         if (UINT32_MAX - now < n->valid)
 574                                 n->valid = UINT32_MAX;
 575                         else
 576                                 n->valid += now;
 577
 578                         n->dprefix = 0;
 579
 580                         ++c->managed_size;
 581                 }
 582
 583                 ustream_consume(s, end - data);
 584         }
 585
 586         if (first && c->managed_size == 0)
 587                 free_dhcpv6_assignment(c);
 588         else if (first && !(c->flags & OAF_STATIC))
 589                 c->valid_until = now + 150;
 590 }
 591
 592
 593 /* TCP transmission has ended, either because of success or timeout or other error */
 594 static void managed_handle_pd_done(struct ustream *s)
 595 {
 596         struct ustream_fd *fd = container_of(s, struct ustream_fd, stream);
 597         struct dhcpv6_assignment *c = container_of(fd, struct dhcpv6_assignment, managed_sock);
 598
 599         if (!(c->flags & OAF_STATIC))
 600                 c->valid_until = odhcpd_time() + 15;
 601
 602         c->managed_size = 0;
 603
 604         if (c->accept_reconf)
 605                 c->reconf_cnt = 1;
 606 }
 607
 608 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
 609 {
 610         struct dhcpv6_assignment *c;
 611
 612         if (iface->dhcpv6_pd_manager[0]) {
 613                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 614                 if (fd >= 0) {
 615                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 616                         char iaidbuf[298];
 617
 618                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 619
 620                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 621                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 622                         ustream_fd_init(&assign->managed_sock, fd);
 623                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 624                                         iaidbuf, assign->iaid, assign->length);
 625                         ustream_write_pending(&assign->managed_sock.stream);
 626                         assign->managed_size = -1;
 627
 628                         if (!(assign->flags & OAF_STATIC))
 629                                 assign->valid_until = odhcpd_time() + 15;
 630
 631                         list_add(&assign->head, &iface->ia_assignments);
 632
 633                         /* Wait initial period of up to 250ms for immediate assignment */
 634                         if (poll(&pfd, 1, 250) < 0) {
 635                                 syslog(LOG_ERR, "poll(): %m");
 636                                 return false;
 637                         }
 638
 639                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 640
 641                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 642                                 return true;
 643                 }
 644
 645                 return false;
 646         } else if (iface->addr6_len < 1)
 647                 return false;
 648
 649         /* Try honoring the hint first */
 650         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 651         if (assign->assigned) {
 652                 list_for_each_entry(c, &iface->ia_assignments, head) {
 653                         if (c->length == 128 || c->length == 0)
 654                                 continue;
 655
 656                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 657                                 list_add_tail(&assign->head, &c->head);
 658
 659                                 if (assign->flags & OAF_BOUND)
 660                                         apply_lease(iface, assign, true);
 661
 662                                 return true;
 663                         }
 664
 665                         if (c->assigned != 0)
 666                                 current = (c->assigned + (1 << (64 - c->length)));
 667                 }
 668         }
 669
 670         /* Fallback to a variable assignment */
 671         current = 1;
 672         list_for_each_entry(c, &iface->ia_assignments, head) {
 673                 if (c->length == 128 || c->length == 0)
 674                         continue;
 675
 676                 current = (current + asize) & (~asize);
 677                 if (current + asize < c->assigned) {
 678                         assign->assigned = current;
 679                         list_add_tail(&assign->head, &c->head);
 680
 681                         if (assign->flags & OAF_BOUND)
 682                                 apply_lease(iface, assign, true);
 683
 684                         return true;
 685                 }
 686
 687                 if (c->assigned != 0)
 688                         current = (c->assigned + (1 << (64 - c->length)));
 689         }
 690
 691         return false;
 692 }
 693
 694 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 695 {
 696         /* Seed RNG with checksum of DUID */
 697         uint32_t seed = 0;
 698         for (size_t i = 0; i < assign->clid_len; ++i)
 699                 seed += assign->clid_data[i];
 700         srand(seed);
 701
 702         /* Try to assign up to 100x */
 703         for (size_t i = 0; i < 100; ++i) {
 704                 uint32_t try;
 705                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 706
 707                 struct dhcpv6_assignment *c;
 708                 list_for_each_entry(c, &iface->ia_assignments, head) {
 709                         if (c->length == 0)
 710                                 continue;
 711
 712                         if (c->assigned > try || c->length != 128) {
 713                                 assign->assigned = try;
 714                                 list_add_tail(&assign->head, &c->head);
 715                                 return true;
 716                         } else if (c->assigned == try)
 717                                 break;
 718                 }
 719         }
 720
 721         return false;
 722 }
 723
 724 static void handle_addrlist_change(struct netevent_handler_info *info)
 725 {
 726         struct interface *iface = info->iface;
 727         struct dhcpv6_assignment *c, *d, *border = list_last_entry(
 728                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 729         struct list_head reassign = LIST_HEAD_INIT(reassign);
 730         time_t now = odhcpd_time();
 731
 732         list_for_each_entry(c, &iface->ia_assignments, head) {
 733                 if (c != border && iface->ra_managed == RA_MANAGED_NO_MFLAG
 734                                 && (c->flags & OAF_BOUND))
 735                         __apply_lease(iface, c, info->addrs_old.addrs,
 736                                         info->addrs_old.len, false);
 737         }
 738
 739         set_border_assignment_size(iface, border);
 740
 741         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 742                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 743                                 c->managed_size)
 744                         continue;
 745
 746                 if (c->length < 128 && c->assigned >= border->assigned && c != border)
 747                         list_move(&c->head, &reassign);
 748                 else if (c != border && (c->flags & OAF_BOUND))
 749                         apply_lease(iface, c, true);
 750
 751                 if (c->accept_reconf && c->reconf_cnt == 0) {
 752                         struct dhcpv6_assignment *a;
 753
 754                         start_reconf(c);
 755
 756                         /* Leave all other assignments of that client alone */
 757                         list_for_each_entry(a, &iface->ia_assignments, head)
 758                                 if (a != c && a->clid_len == c->clid_len &&
 759                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 760                                         a->reconf_cnt = INT_MAX;
 761                 }
 762         }
 763
 764         while (!list_empty(&reassign)) {
 765                 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
 766                 list_del(&c->head);
 767                 if (!assign_pd(iface, c)) {
 768                         c->assigned = 0;
 769                         list_add(&c->head, &iface->ia_assignments);
 770                 }
 771         }
 772
 773         dhcpv6_write_statefile();
 774 }
 775
 776 static void reconf_timeout_cb(struct uloop_timeout *event)
 777 {
 778         struct dhcpv6_assignment *a = container_of(event, struct dhcpv6_assignment, reconf_timer);
 779
 780         if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
 781                 send_reconf(a);
 782                 uloop_timeout_set(&a->reconf_timer,
 783                                         DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 784                 a->reconf_cnt++;
 785         } else
 786                 stop_reconf(a);
 787 }
 788
 789 static void start_reconf(struct dhcpv6_assignment *a)
 790 {
 791         uloop_timeout_set(&a->reconf_timer,
 792                                 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 793         a->reconf_timer.cb = reconf_timeout_cb;
 794         a->reconf_cnt++;
 795
 796         send_reconf(a);
 797 }
 798
 799 static void stop_reconf(struct dhcpv6_assignment *a)
 800 {
 801         uloop_timeout_cancel(&a->reconf_timer);
 802         a->reconf_cnt = 0;
 803         a->reconf_timer.cb = NULL;
 804 }
 805
 806 static void valid_until_cb(struct uloop_timeout *event)
 807 {
 808         time_t now = odhcpd_time();
 809         struct interface *iface;
 810         list_for_each_entry(iface, &interfaces, head) {
 811                 if (iface->dhcpv6 != MODE_SERVER || iface->ia_assignments.next == NULL)
 812                         continue;
 813
 814                 struct dhcpv6_assignment *a, *n;
 815                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 816                         if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
 817                                 if ((a->length < 128 && a->clid_len > 0) ||
 818                                                 (a->length == 128 && a->clid_len == 0))
 819                                         free_dhcpv6_assignment(a);
 820
 821                         }
 822                 }
 823         }
 824         uloop_timeout_set(event, 1000);
 825 }
 826
 827 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
 828                 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
 829                 struct interface *iface, bool request)
 830 {
 831         if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
 832                 return 0;
 833
 834         struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
 835         size_t datalen = sizeof(out);
 836         time_t now = odhcpd_time();
 837
 838         if (status) {
 839                 struct __attribute__((packed)) {
 840                         uint16_t type;
 841                         uint16_t len;
 842                         uint16_t value;
 843                 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
 844                                 htons(status)};
 845
 846                 memcpy(buf + datalen, &stat, sizeof(stat));
 847                 datalen += sizeof(stat);
 848         } else {
 849                 if (a) {
 850                         uint32_t leasetime;
 851                         if (a->leasetime)
 852                                 leasetime = a->leasetime;
 853                         else
 854                                 leasetime = iface->dhcpv4_leasetime;
 855
 856                         uint32_t pref = leasetime;
 857                         uint32_t valid = leasetime;
 858
 859                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 860                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
 861                         size_t m = get_preferred_addr(addrs, addrlen);
 862
 863                         for (size_t i = 0; i < addrlen; ++i) {
 864                                 uint32_t prefix_pref = addrs[i].preferred;
 865                                 uint32_t prefix_valid = addrs[i].valid;
 866
 867                                 if (!valid_addr(&addrs[i], now))
 868                                         continue;
 869
 870                                 if (prefix_pref != UINT32_MAX)
 871                                         prefix_pref -= now;
 872
 873                                 if (prefix_valid != UINT32_MAX)
 874                                         prefix_valid -= now;
 875
 876                                 if (a->length < 128) {
 877                                         struct dhcpv6_ia_prefix p = {
 878                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 879                                                 .len = htons(sizeof(p) - 4),
 880                                                 .preferred = htonl(prefix_pref),
 881                                                 .valid = htonl(prefix_valid),
 882                                                 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 883                                                 .addr = addrs[i].addr.in6,
 884                                         };
 885                                         p.addr.s6_addr32[1] |= htonl(a->assigned);
 886                                         p.addr.s6_addr32[2] = p.addr.s6_addr32[3] = 0;
 887
 888                                         size_t entrlen = sizeof(p) - 4;
 889
 890                                         if (datalen + entrlen + 4 > buflen ||
 891                                                         (a->assigned == 0 && a->managed_size == 0) ||
 892                                                         !valid_prefix_length(a, addrs[i].prefix))
 893                                                 continue;
 894
 895                                         memcpy(buf + datalen, &p, sizeof(p));
 896                                         datalen += entrlen + 4;
 897                                 } else {
 898                                         struct dhcpv6_ia_addr n = {
 899                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 900                                                 .len = htons(sizeof(n) - 4),
 901                                                 .addr = addrs[i].addr.in6,
 902                                                 .preferred = htonl(prefix_pref),
 903                                                 .valid = htonl(prefix_valid)
 904                                         };
 905                                         n.addr.s6_addr32[3] = htonl(a->assigned);
 906                                         size_t entrlen = sizeof(n) - 4;
 907
 908                                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
 909                                                         a->assigned == 0 ||
 910                                                         datalen + entrlen + 4 > buflen)
 911                                                 continue;
 912
 913                                         memcpy(buf + datalen, &n, sizeof(n));
 914                                         datalen += entrlen + 4;
 915                                 }
 916
 917                                 /* Calculate T1 / T2 based on non-deprecated addresses */
 918                                 if (prefix_pref > 0) {
 919                                         if (prefix_pref < pref)
 920                                                 pref = prefix_pref;
 921
 922                                         if (prefix_valid < valid)
 923                                                 valid = prefix_valid;
 924                                 }
 925                         }
 926
 927                         if (!INFINITE_VALID(a->valid_until))
 928                                 /* UINT32_MAX is considered as infinite leasetime */
 929                                 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 930
 931                         out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 932                         out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 933
 934                         if (!out.t1)
 935                                 out.t1 = htonl(1);
 936
 937                         if (!out.t2)
 938                                 out.t2 = htonl(1);
 939                 }
 940
 941                 if (!request) {
 942                         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 943                         uint16_t otype, olen;
 944
 945                         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 946                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
 947                                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
 948                                 bool found = false;
 949
 950                                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
 951                                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
 952                                         continue;
 953
 954                                 if (a) {
 955                                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 956                                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
 957
 958                                         for (size_t i = 0; i < addrlen; ++i) {
 959                                                 if (!valid_addr(&addrs[i], now))
 960                                                         continue;
 961
 962                                                 struct in6_addr addr = addrs[i].addr.in6;
 963                                                 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 964                                                         addr.s6_addr32[1] |= htonl(a->assigned);
 965                                                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 966
 967                                                         if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
 968                                                                         p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 969                                                                 found = true;
 970                                                 } else {
 971                                                         addr.s6_addr32[3] = htonl(a->assigned);
 972
 973                                                         if (!memcmp(&n->addr, &addr, sizeof(addr)))
 974                                                                 found = true;
 975                                                 }
 976                                         }
 977                                 }
 978
 979                                 if (!found) {
 980                                         if (otype == DHCPV6_OPT_IA_PREFIX) {
 981                                                 struct dhcpv6_ia_prefix inv = {
 982                                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 983                                                         .len = htons(sizeof(inv) - 4),
 984                                                         .preferred = 0,
 985                                                         .valid = 0,
 986                                                         .prefix = p->prefix,
 987                                                         .addr = p->addr
 988                                                 };
 989
 990                                                 if (datalen + sizeof(inv) > buflen)
 991                                                         continue;
 992
 993                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 994                                                 datalen += sizeof(inv);
 995                                         } else {
 996                                                 struct dhcpv6_ia_addr inv = {
 997                                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 998                                                         .len = htons(sizeof(inv) - 4),
 999                                                         .addr = n->addr,
1000                                                         .preferred = 0,
1001                                                         .valid = 0
1002                                                 };
1003
1004                                                 if (datalen + sizeof(inv) > buflen)
1005                                                         continue;
1006
1007                                                 memcpy(buf + datalen, &inv, sizeof(inv));
1008                                                 datalen += sizeof(inv);
1009                                         }
1010                                 }
1011                         }
1012                 }
1013         }
1014
1015         out.len = htons(datalen - 4);
1016         memcpy(buf, &out, sizeof(out));
1017         return datalen;
1018 }
1019
1020 struct log_ctxt {
1021         char *buf;
1022         int buf_len;
1023         int buf_idx;
1024 };
1025
1026 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
1027                                 _unused uint32_t valid, void *arg)
1028 {
1029         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1030         char addrbuf[INET6_ADDRSTRLEN];
1031
1032         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1033         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1034                                         "%s/%d ", addrbuf, prefix);
1035 }
1036
1037 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1038                 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
1039 {
1040         const char *type = "UNKNOWN";
1041         const char *status = "UNKNOWN";
1042
1043         switch (msgtype) {
1044         case DHCPV6_MSG_SOLICIT:
1045                 type = "SOLICIT";
1046                 break;
1047         case DHCPV6_MSG_REQUEST:
1048                 type = "REQUEST";
1049                 break;
1050         case DHCPV6_MSG_CONFIRM:
1051                 type = "CONFIRM";
1052                 break;
1053         case DHCPV6_MSG_RENEW:
1054                 type = "RENEW";
1055                 break;
1056         case DHCPV6_MSG_REBIND:
1057                 type = "REBIND";
1058                 break;
1059         case DHCPV6_MSG_RELEASE:
1060                 type = "RELEASE";
1061                 break;
1062         case DHCPV6_MSG_DECLINE:
1063                 type = "DECLINE";
1064                 break;
1065         }
1066
1067         switch (code) {
1068         case DHCPV6_STATUS_OK:
1069                 status = "ok";
1070                 break;
1071         case DHCPV6_STATUS_NOADDRSAVAIL:
1072                 status = "no addresses available";
1073                 break;
1074         case DHCPV6_STATUS_NOBINDING:
1075                 status = "no binding";
1076                 break;
1077         case DHCPV6_STATUS_NOTONLINK:
1078                 status = "not on-link";
1079                 break;
1080         case DHCPV6_STATUS_NOPREFIXAVAIL:
1081                 status = "no prefix available";
1082                 break;
1083         }
1084
1085         char leasebuf[256] = "";
1086
1087         if (a) {
1088                 struct log_ctxt ctxt = {.buf = leasebuf,
1089                                         .buf_len = sizeof(leasebuf),
1090                                         .buf_idx = 0 };
1091
1092                 dhcpv6_enum_ia_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1093         }
1094
1095         syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1096                         duidbuf, iface->ifname, status, leasebuf);
1097 }
1098
1099 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
1100                 struct interface *iface)
1101 {
1102         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
1103         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
1104         time_t now = odhcpd_time();
1105         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
1106         uint16_t otype, olen;
1107         bool onlink = false;
1108
1109         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
1110                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
1111                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
1112
1113                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
1114                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
1115                         continue;
1116
1117                 for (size_t i = 0; i < addrlen; ++i) {
1118                         struct in6_addr addr = addrs[i].addr.in6;
1119
1120                         if (!valid_addr(&addrs[i], now))
1121                                 continue;
1122
1123                         if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
1124                                 addr.s6_addr32[1] |= htonl(a->assigned);
1125                                 addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
1126
1127                                 if (memcmp(&p->addr, &addr, sizeof(addr)) ||
1128                                                 p->prefix != ((a->managed) ? addrs[i].prefix : a->length))
1129                                         continue;
1130                         } else {
1131                                 addr.s6_addr32[3] = htonl(a->assigned);
1132
1133                                 if (memcmp(&n->addr, &addr, sizeof(addr)))
1134                                         continue;
1135                         }
1136                         onlink = true;
1137                 }
1138
1139                 if (!onlink)
1140                         break;
1141         }
1142
1143         return onlink;
1144 }
1145
1146 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
1147                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1148 {
1149         time_t now = odhcpd_time();
1150         size_t response_len = 0;
1151         const struct dhcpv6_client_header *hdr = data;
1152         uint8_t *start = (uint8_t*)&hdr[1], *odata;
1153         uint16_t otype, olen;
1154         /* Find and parse client-id and hostname */
1155         bool accept_reconf = false;
1156         uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1157         char hostname[256];
1158         size_t hostname_len = 0;
1159         bool notonlink = false;
1160         char duidbuf[261];
1161
1162         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1163                 if (otype == DHCPV6_OPT_CLIENTID) {
1164                         clid_data = odata;
1165                         clid_len = olen;
1166
1167                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1168                                 memcpy(mac, &odata[8], sizeof(mac));
1169                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1170                                 memcpy(mac, &odata[4], sizeof(mac));
1171
1172                         if (olen <= 130)
1173                                 odhcpd_hexlify(duidbuf, odata, olen);
1174                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1175                         uint8_t fqdn_buf[256];
1176                         memcpy(fqdn_buf, odata, olen);
1177                         fqdn_buf[olen++] = 0;
1178
1179                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1180                                 hostname_len = strcspn(hostname, ".");
1181                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1182                         accept_reconf = true;
1183         }
1184
1185         if (!clid_data || !clid_len || clid_len > 130)
1186                 goto out;
1187
1188         struct dhcpv6_assignment *first = NULL;
1189         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1190                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1191                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1192                 bool ia_addr_present = false;
1193                 if (!is_pd && !is_na)
1194                         continue;
1195
1196                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1197                 size_t ia_response_len = 0;
1198                 uint8_t reqlen = (is_pd) ? 62 : 128;
1199                 uint32_t reqhint = 0;
1200
1201                 /* Parse request hint for IA-PD */
1202                 if (is_pd) {
1203                         uint8_t *sdata;
1204                         uint16_t stype, slen;
1205                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1206                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1207                                         continue;
1208
1209                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1210                                 if (p->prefix) {
1211                                         reqlen = p->prefix;
1212                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1213                                         if (reqlen > 32 && reqlen <= 64)
1214                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1215                                 }
1216                         }
1217
1218                         if (reqlen > 64)
1219                                 reqlen = 64;
1220                 } else if (is_na) {
1221                         uint8_t *sdata;
1222                         uint16_t stype, slen;
1223                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1224                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1225                                         continue;
1226
1227                                 ia_addr_present = true;
1228                         }
1229                 }
1230
1231                 /* Find assignment */
1232                 struct dhcpv6_assignment *c, *a = NULL;
1233                 list_for_each_entry(c, &iface->ia_assignments, head) {
1234                         if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1235                                         (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1236                                                 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1237                                         (!(c->flags & (OAF_BOUND|OAF_TENTATIVE)) || c->iaid == ia->iaid) &&
1238                                         (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1239                                         ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1240                                 a = c;
1241
1242                                 /* Reset state */
1243                                 if (a->flags & OAF_BOUND)
1244                                         apply_lease(iface, a, false);
1245
1246                                 memcpy(a->clid_data, clid_data, clid_len);
1247                                 a->clid_len = clid_len;
1248                                 a->iaid = ia->iaid;
1249                                 a->peer = *addr;
1250                                 stop_reconf(a);
1251                                 break;
1252                         }
1253                 }
1254
1255                 /* Generic message handling */
1256                 uint16_t status = DHCPV6_STATUS_OK;
1257                 if (a && a->managed_size < 0)
1258                         return -1;
1259
1260                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1261                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1262                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1263                         bool assigned = !!a;
1264
1265                         if (!a && !iface->no_dynamic_dhcp && (iface->dhcpv6_pd || iface->dhcpv6_na)) {
1266                                 /* Create new binding */
1267                                 a = calloc(1, sizeof(*a) + clid_len);
1268                                 if (a) {
1269                                         a->clid_len = clid_len;
1270                                         a->iaid = ia->iaid;
1271                                         a->length = reqlen;
1272                                         a->peer = *addr;
1273                                         a->assigned = reqhint;
1274                                         /* Set valid time to current time indicating  */
1275                                         /* assignment is not having infinite lifetime */
1276                                         a->valid_until = now;
1277                                         a->iface = iface;
1278
1279                                         if (first)
1280                                                 memcpy(a->key, first->key, sizeof(a->key));
1281                                         else
1282                                                 odhcpd_urandom(a->key, sizeof(a->key));
1283                                         memcpy(a->clid_data, clid_data, clid_len);
1284
1285                                         if (is_pd && iface->dhcpv6_pd)
1286                                                 while (!(assigned = assign_pd(iface, a)) &&
1287                                                                 !a->managed_size && ++a->length <= 64);
1288                                         else if (is_na && iface->dhcpv6_na)
1289                                                 assigned = assign_na(iface, a);
1290
1291                                         if (a->managed_size && !assigned)
1292                                                 return -1;
1293                                 }
1294                         }
1295
1296                         if (!assigned || iface->addr6_len == 0)
1297                                 /* Set error status */
1298                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1299                         else if (hdr->msg_type == DHCPV6_MSG_REQUEST && !dhcpv6_ia_on_link(ia, a, iface)) {
1300                                 /* Send NOTONLINK staus for the IA */
1301                                 status = DHCPV6_STATUS_NOTONLINK;
1302                                 assigned = false;
1303                         } else if (accept_reconf && assigned && !first &&
1304                                         hdr->msg_type != DHCPV6_MSG_REBIND) {
1305                                 size_t handshake_len = 4;
1306                                 buf[0] = 0;
1307                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1308                                 buf[2] = 0;
1309                                 buf[3] = 0;
1310
1311                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1312                                         struct dhcpv6_auth_reconfigure auth = {
1313                                                 htons(DHCPV6_OPT_AUTH),
1314                                                 htons(sizeof(auth) - 4),
1315                                                 3, 1, 0,
1316                                                 {htonl(time(NULL)), htonl(++serial)},
1317                                                 1,
1318                                                 {0}
1319                                         };
1320                                         memcpy(auth.key, a->key, sizeof(a->key));
1321                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1322                                         handshake_len += sizeof(auth);
1323                                 }
1324
1325                                 buf += handshake_len;
1326                                 buflen -= handshake_len;
1327                                 response_len += handshake_len;
1328
1329                                 first = a;
1330                         }
1331
1332                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface,
1333                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1334
1335                         /* Was only a solicitation: mark binding for removal */
1336                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1337                                 a->flags &= ~OAF_BOUND;
1338                                 a->flags |= OAF_TENTATIVE;
1339
1340                                 if (!(a->flags & OAF_STATIC))
1341                                         /* Keep tentative assignment around for 60 seconds */
1342                                         a->valid_until = now + 60;
1343                         } else if (assigned &&
1344                                         (hdr->msg_type == DHCPV6_MSG_REQUEST ||
1345                                          hdr->msg_type == DHCPV6_MSG_REBIND)) {
1346                                 if (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(iface, a, true);
1362                         } else if (!assigned && a && a->managed_size == 0) {
1363                                 /* Cleanup failed assignment */
1364                                 free_dhcpv6_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 = append_reply(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 = append_reply(buf, buflen, status, ia, a, iface, false);
1377                                 if (a) {
1378                                         a->flags |= OAF_BOUND;
1379                                         apply_lease(iface, a, true);
1380                                 }
1381                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1382                                 if (!(a->flags & OAF_STATIC))
1383                                         a->valid_until = now - 1;
1384
1385                                 if (a->flags & OAF_BOUND) {
1386                                         apply_lease(iface, a, false);
1387                                         a->flags &= ~OAF_BOUND;
1388                                 }
1389                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1390                                 a->flags &= ~OAF_BOUND;
1391
1392                                 if (!(a->flags & OAF_STATIC)) {
1393                                         a->clid_len = 0;
1394                                         a->valid_until = now + 3600; /* Block address for 1h */
1395                                 }
1396                         }
1397                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1398                         /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1399                         status = DHCPV6_STATUS_NOTONLINK;
1400                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1401                         notonlink = true;
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         if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1411                         response_len + 6 < buflen) {
1412                 buf[0] = 0;
1413                 buf[1] = DHCPV6_OPT_STATUS;
1414                 buf[2] = 0;
1415                 buf[3] = 2;
1416                 buf[4] = 0;
1417                 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1418                 response_len += 6;
1419         }
1420
1421         dhcpv6_write_statefile();
1422
1423 out:
1424         return response_len;
1425 }