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 handle_addrlist_change(struct netevent_handler_info *info);
  45 static void start_reconf(struct dhcpv6_assignment *a);
  46 static void stop_reconf(struct dhcpv6_assignment *a);
  47 static void valid_until_cb(struct uloop_timeout *event);
  48
  49 static struct netevent_handler dhcpv6_netevent_handler = { .cb = dhcpv6_netevent_cb, };
  50 static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb};
  51 static uint32_t serial = 0;
  52 static uint8_t statemd5[16];
  53
  54 int dhcpv6_ia_init(void)
  55 {
  56         uloop_timeout_set(&valid_until_timeout, 1000);
  57
  58         netlink_add_netevent_handler(&dhcpv6_netevent_handler);
  59
  60         return 0;
  61 }
  62
  63 int dhcpv6_setup_ia_interface(struct interface *iface, bool enable)
  64 {
  65         if (!enable && iface->ia_assignments.next) {
  66                 struct dhcpv6_assignment *c;
  67
  68                 while (!list_empty(&iface->ia_assignments)) {
  69                         c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
  70                         free_dhcpv6_assignment(c);
  71                 }
  72         }
  73
  74         if (enable && iface->dhcpv6 == MODE_SERVER) {
  75                 if (!iface->ia_assignments.next)
  76                         INIT_LIST_HEAD(&iface->ia_assignments);
  77
  78                 if (list_empty(&iface->ia_assignments)) {
  79                         struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
  80                         if (!border) {
  81                                 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
  82                                 return -1;
  83                         }
  84
  85                         border->length = 64;
  86                         list_add(&border->head, &iface->ia_assignments);
  87                 }
  88
  89                 /* Parse static entries */
  90                 struct lease *lease;
  91                 list_for_each_entry(lease, &leases, head) {
  92                         /* Construct entry */
  93                         size_t duid_len = lease->duid_len ? lease->duid_len : 14;
  94                         struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
  95                         if (!a) {
  96                                 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
  97                                         iface->ifname);
  98                                 return -1;
  99                         }
 100
 101                         a->leasetime = lease->dhcpv4_leasetime;
 102
 103                         a->clid_len = duid_len;
 104                         a->length = 128;
 105                         if (lease->hostid) {
 106                                 a->assigned = lease->hostid;
 107                         } else {
 108                                 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
 109                                 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
 110                         }
 111
 112                         odhcpd_urandom(a->key, sizeof(a->key));
 113                         memcpy(a->clid_data, lease->duid, lease->duid_len);
 114                         memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
 115                         /* Static assignment */
 116                         a->flags |= OAF_STATIC;
 117                         /* Infinite valid */
 118                         a->valid_until = 0;
 119
 120                         /* Assign to all interfaces */
 121                         struct dhcpv6_assignment *c;
 122                         list_for_each_entry(c, &iface->ia_assignments, head) {
 123                                 if (c->length != 128 || c->assigned > a->assigned) {
 124                                         list_add_tail(&a->head, &c->head);
 125                                         break;
 126                                 } else if (c->assigned == a->assigned)
 127                                         /* Already an assignment with that number */
 128                                         break;
 129                         }
 130
 131                         if (a->head.next) {
 132                                 a->iface = iface;
 133                                 if (lease->hostname[0]) {
 134                                         free(a->hostname);
 135                                         a->hostname = strdup(lease->hostname);
 136                                 }
 137                         } else
 138                                 free_dhcpv6_assignment(a);
 139                 }
 140         }
 141         return 0;
 142 }
 143
 144
 145 static void dhcpv6_netevent_cb(unsigned long event, struct netevent_handler_info *info)
 146 {
 147         struct interface *iface = info->iface;
 148
 149         if (!iface || iface->dhcpv6 != MODE_SERVER)
 150                 return;
 151
 152         switch (event) {
 153         case NETEV_ADDR6LIST_CHANGE:
 154                 handle_addrlist_change(info);
 155                 break;
 156         default:
 157                 break;
 158         }
 159 }
 160
 161
 162 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
 163 {
 164         if (c->managed_sock.fd.registered) {
 165                 ustream_free(&c->managed_sock.stream);
 166                 close(c->managed_sock.fd.fd);
 167         }
 168
 169         if (c->head.next)
 170                 list_del(&c->head);
 171
 172         if (c->reconf_cnt)
 173                 stop_reconf(c);
 174
 175         free(c->managed);
 176         free(c->hostname);
 177         free(c);
 178 }
 179
 180 static inline bool valid_prefix_length(const struct dhcpv6_assignment *a, const uint8_t prefix_length)
 181 {
 182         return (a->managed_size || a->length > prefix_length);
 183 }
 184
 185 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 186 {
 187         return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
 188 }
 189
 190 static size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
 191 {
 192         size_t i, m;
 193
 194         for (i = 0, m = 0; i < addrlen; ++i) {
 195                 if (addrs[i].preferred > addrs[m].preferred ||
 196                                 (addrs[i].preferred == addrs[m].preferred &&
 197                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 198                         m = i;
 199         }
 200
 201         return m;
 202 }
 203
 204 static int send_reconf(struct dhcpv6_assignment *assign)
 205 {
 206         struct {
 207                 struct dhcpv6_client_header hdr;
 208                 uint16_t srvid_type;
 209                 uint16_t srvid_len;
 210                 uint16_t duid_type;
 211                 uint16_t hardware_type;
 212                 uint8_t mac[6];
 213                 uint16_t msg_type;
 214                 uint16_t msg_len;
 215                 uint8_t msg_id;
 216                 struct dhcpv6_auth_reconfigure auth;
 217                 uint16_t clid_type;
 218                 uint16_t clid_len;
 219                 uint8_t clid_data[128];
 220         } __attribute__((packed)) reconf_msg = {
 221                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 222                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 223                 .srvid_len = htons(10),
 224                 .duid_type = htons(3),
 225                 .hardware_type = htons(1),
 226                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 227                 .msg_len = htons(1),
 228                 .msg_id = DHCPV6_MSG_RENEW,
 229                 .auth = {htons(DHCPV6_OPT_AUTH),
 230                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 231                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 232                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 233                 .clid_len = htons(assign->clid_len),
 234                 .clid_data = {0},
 235         };
 236         struct interface *iface = assign->iface;
 237
 238         odhcpd_get_mac(iface, reconf_msg.mac);
 239         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 240         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 241
 242         md5_ctx_t md5;
 243         uint8_t secretbytes[64];
 244         memset(secretbytes, 0, sizeof(secretbytes));
 245         memcpy(secretbytes, assign->key, sizeof(assign->key));
 246
 247         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 248                 secretbytes[i] ^= 0x36;
 249
 250         md5_begin(&md5);
 251         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 252         md5_hash(iov.iov_base, iov.iov_len, &md5);
 253         md5_end(reconf_msg.auth.key, &md5);
 254
 255         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 256                 secretbytes[i] ^= 0x36;
 257                 secretbytes[i] ^= 0x5c;
 258         }
 259
 260         md5_begin(&md5);
 261         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 262         md5_hash(reconf_msg.auth.key, 16, &md5);
 263         md5_end(reconf_msg.auth.key, &md5);
 264
 265         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 266 }
 267
 268 void dhcpv6_enum_ia_addrs(struct interface *iface, struct dhcpv6_assignment *c,
 269                                 time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
 270 {
 271         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->addr6;
 272         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->addr6_len;
 273         size_t m = get_preferred_addr(addrs, addrlen);
 274
 275         for (size_t i = 0; i < addrlen; ++i) {
 276                 struct in6_addr addr;
 277                 uint32_t pref, valid;
 278                 int prefix = c->managed ? addrs[i].prefix : c->length;
 279
 280                 if (!valid_addr(&addrs[i], now))
 281                         continue;
 282
 283                 addr = addrs[i].addr.in6;
 284                 pref = addrs[i].preferred;
 285                 valid = addrs[i].valid;
 286                 if (prefix == 128) {
 287                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 288                                 continue;
 289
 290                         addr.s6_addr32[3] = htonl(c->assigned);
 291                 } else {
 292                         if (!valid_prefix_length(c, addrs[i].prefix))
 293                                 continue;
 294
 295                         addr.s6_addr32[1] |= htonl(c->assigned);
 296                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 297                 }
 298
 299                 if (pref != UINT32_MAX)
 300                         pref -= now;
 301
 302                 if (valid != UINT32_MAX)
 303                         valid -= now;
 304
 305                 func(&addr, prefix, pref, valid, arg);
 306         }
 307 }
 308
 309 struct write_ctxt {
 310         FILE *fp;
 311         md5_ctx_t md5;
 312         struct dhcpv6_assignment *c;
 313         struct interface *iface;
 314         char *buf;
 315         int buf_len;
 316         int buf_idx;
 317 };
 318
 319 void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 320                                 _unused uint32_t valid, void *arg)
 321 {
 322         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
 323         char ipbuf[INET6_ADDRSTRLEN];
 324
 325         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 326
 327         if (ctxt->c->length == 128 && ctxt->c->hostname) {
 328                 fputs(ipbuf, ctxt->fp);
 329
 330                 char b[256];
 331                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
 332                                 ctxt->iface->search, b, sizeof(b)) > 0)
 333                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
 334
 335                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
 336                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
 337                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
 338         }
 339
 340         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
 341                                         "%s/%d ", ipbuf, prefix);
 342 }
 343
 344 void dhcpv6_write_statefile(void)
 345 {
 346         struct write_ctxt ctxt;
 347
 348         md5_begin(&ctxt.md5);
 349
 350         if (config.dhcp_statefile) {
 351                 time_t now = odhcpd_time(), wall_time = time(NULL);
 352                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 353                 char leasebuf[512];
 354
 355                 if (fd < 0)
 356                         return;
 357                 int ret;
 358                 ret = lockf(fd, F_LOCK, 0);
 359                 if (ret < 0) {
 360                         close(fd);
 361                         return;
 362                 }
 363                 if (ftruncate(fd, 0) < 0) {}
 364
 365                 ctxt.fp = fdopen(fd, "w");
 366                 if (!ctxt.fp) {
 367                         close(fd);
 368                         return;
 369                 }
 370
 371                 ctxt.buf = leasebuf;
 372                 ctxt.buf_len = sizeof(leasebuf);
 373
 374                 list_for_each_entry(ctxt.iface, &interfaces, head) {
 375                         if (ctxt.iface->dhcpv6 != MODE_SERVER &&
 376                                         ctxt.iface->dhcpv4 != MODE_SERVER)
 377                                 continue;
 378
 379                         if (ctxt.iface->dhcpv6 == MODE_SERVER &&
 380                                         ctxt.iface->ia_assignments.next) {
 381                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 382                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 383                                                 continue;
 384
 385                                         char duidbuf[264];
 386
 387                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
 388
 389                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 390                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s %ld %x %u ",
 391                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
 392                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
 393                                                                 (ctxt.c->valid_until > now ?
 394                                                                         (ctxt.c->valid_until - now + wall_time) :
 395                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)),
 396                                                                 ctxt.c->assigned, (unsigned)ctxt.c->length);
 397
 398                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
 399                                                 dhcpv6_enum_ia_addrs(ctxt.iface, ctxt.c, now,
 400                                                                         dhcpv6_write_ia_addr, &ctxt);
 401
 402                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 403                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 404                                 }
 405                         }
 406
 407                         if (ctxt.iface->dhcpv4 == MODE_SERVER &&
 408                                         ctxt.iface->dhcpv4_assignments.next) {
 409                                 struct dhcpv4_assignment *c;
 410                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 411                                         if (!(c->flags & OAF_BOUND))
 412                                                 continue;
 413
 414                                         char ipbuf[INET6_ADDRSTRLEN];
 415                                         char duidbuf[16];
 416                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 417
 418                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 419                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s %ld %x 32 ",
 420                                                                 ctxt.iface->ifname, duidbuf,
 421                                                                 (c->hostname ? c->hostname : "-"),
 422                                                                 (c->valid_until > now ?
 423                                                                         (c->valid_until - now + wall_time) :
 424                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 425                                                                 ntohl(c->addr));
 426
 427                                         struct in_addr addr = {.s_addr = c->addr};
 428                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 429
 430                                         if (c->hostname) {
 431                                                 fputs(ipbuf, ctxt.fp);
 432
 433                                                 char b[256];
 434                                                 if (dn_expand(ctxt.iface->search,
 435                                                                 ctxt.iface->search + ctxt.iface->search_len,
 436                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
 437                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
 438
 439                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
 440                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
 441                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
 442                                         }
 443
 444                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
 445                                                                         ctxt.buf_len - ctxt.buf_idx,
 446                                                                         "%s/32 ", ipbuf);
 447                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 448                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 449                                 }
 450                         }
 451                 }
 452
 453                 fclose(ctxt.fp);
 454         }
 455
 456         uint8_t newmd5[16];
 457         md5_end(newmd5, &ctxt.md5);
 458
 459         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 460                 memcpy(statemd5, newmd5, sizeof(statemd5));
 461                 char *argv[2] = {config.dhcp_cb, NULL};
 462                 if (!vfork()) {
 463                         execv(argv[0], argv);
 464                         _exit(128);
 465                 }
 466         }
 467 }
 468
 469 static void __apply_lease(struct interface *iface, struct dhcpv6_assignment *a,
 470                 struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
 471 {
 472         if (a->length > 64)
 473                 return;
 474
 475         for (ssize_t i = 0; i < addr_len; ++i) {
 476                 struct in6_addr prefix = addrs[i].addr.in6;
 477                 prefix.s6_addr32[1] |= htonl(a->assigned);
 478                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
 479                 netlink_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 480                                 iface->ifindex, &a->peer.sin6_addr, 1024, add);
 481         }
 482 }
 483
 484 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
 485 {
 486         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 487         ssize_t addrlen = (a->managed) ? a->managed_size : (ssize_t)iface->addr6_len;
 488
 489         __apply_lease(iface, a, addrs, addrlen, add);
 490 }
 491
 492 /* More data was received from TCP connection */
 493 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 494 {
 495         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 496         time_t now = odhcpd_time();
 497         bool first = c->managed_size < 0;
 498
 499         for (;;) {
 500                 int pending;
 501                 char *data = ustream_get_read_buf(s, &pending);
 502                 char *end = memmem(data, pending, "\n\n", 2);
 503
 504                 if (!end)
 505                         break;
 506
 507                 end += 2;
 508                 end[-1] = 0;
 509
 510                 c->managed_size = 0;
 511                 if (c->accept_reconf)
 512                         c->reconf_cnt = 1;
 513
 514                 char *saveptr;
 515                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 516                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 517                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 518
 519                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 520                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 521                                 continue;
 522
 523                         x = strtok_r(NULL, ",", &saveptr2);
 524                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 525                                 continue;
 526
 527                         x = strtok_r(NULL, ",", &saveptr2);
 528                         if (sscanf(x, "%u", &n->preferred) < 1)
 529                                 continue;
 530
 531                         x = strtok_r(NULL, ",", &saveptr2);
 532                         if (sscanf(x, "%u", &n->valid) < 1)
 533                                 continue;
 534
 535                         if (n->preferred > n->valid)
 536                                 continue;
 537
 538                         if (UINT32_MAX - now < n->preferred)
 539                                 n->preferred = UINT32_MAX;
 540                         else
 541                                 n->preferred += now;
 542
 543                         if (UINT32_MAX - now < n->valid)
 544                                 n->valid = UINT32_MAX;
 545                         else
 546                                 n->valid += now;
 547
 548                         n->dprefix = 0;
 549
 550                         ++c->managed_size;
 551                 }
 552
 553                 ustream_consume(s, end - data);
 554         }
 555
 556         if (first && c->managed_size == 0)
 557                 free_dhcpv6_assignment(c);
 558         else if (first && !(c->flags & OAF_STATIC))
 559                 c->valid_until = now + 150;
 560 }
 561
 562
 563 /* TCP transmission has ended, either because of success or timeout or other error */
 564 static void managed_handle_pd_done(struct ustream *s)
 565 {
 566         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 567
 568         if (!(c->flags & OAF_STATIC))
 569                 c->valid_until = odhcpd_time() + 15;
 570
 571         c->managed_size = 0;
 572
 573         if (c->accept_reconf)
 574                 c->reconf_cnt = 1;
 575 }
 576
 577 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
 578 {
 579         struct dhcpv6_assignment *c;
 580
 581         if (iface->dhcpv6_pd_manager[0]) {
 582                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 583                 if (fd >= 0) {
 584                         char iaidbuf[298];
 585                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 586
 587                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 588                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 589                         ustream_fd_init(&assign->managed_sock, fd);
 590                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 591                                         iaidbuf, assign->iaid, assign->length);
 592                         ustream_write_pending(&assign->managed_sock.stream);
 593                         assign->managed_size = -1;
 594
 595                         if (!(assign->flags & OAF_STATIC))
 596                                 assign->valid_until = odhcpd_time() + 15;
 597
 598                         list_add(&assign->head, &iface->ia_assignments);
 599
 600                         /* Wait initial period of up to 250ms for immediate assignment */
 601                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 602                         poll(&pfd, 1, 250);
 603                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 604
 605                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 606                                 return true;
 607                 }
 608
 609                 return false;
 610         } else if (iface->addr6_len < 1)
 611                 return false;
 612
 613         /* Try honoring the hint first */
 614         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 615         if (assign->assigned) {
 616                 list_for_each_entry(c, &iface->ia_assignments, head) {
 617                         if (c->length == 128 || c->length == 0)
 618                                 continue;
 619
 620                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 621                                 list_add_tail(&assign->head, &c->head);
 622
 623                                 if (assign->flags & OAF_BOUND)
 624                                         apply_lease(iface, assign, true);
 625
 626                                 return true;
 627                         }
 628
 629                         if (c->assigned != 0)
 630                                 current = (c->assigned + (1 << (64 - c->length)));
 631                 }
 632         }
 633
 634         /* Fallback to a variable assignment */
 635         current = 1;
 636         list_for_each_entry(c, &iface->ia_assignments, head) {
 637                 if (c->length == 128 || c->length == 0)
 638                         continue;
 639
 640                 current = (current + asize) & (~asize);
 641                 if (current + asize < c->assigned) {
 642                         assign->assigned = current;
 643                         list_add_tail(&assign->head, &c->head);
 644
 645                         if (assign->flags & OAF_BOUND)
 646                                 apply_lease(iface, assign, true);
 647
 648                         return true;
 649                 }
 650
 651                 if (c->assigned != 0)
 652                         current = (c->assigned + (1 << (64 - c->length)));
 653         }
 654
 655         return false;
 656 }
 657
 658 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 659 {
 660         /* Seed RNG with checksum of DUID */
 661         uint32_t seed = 0;
 662         for (size_t i = 0; i < assign->clid_len; ++i)
 663                 seed += assign->clid_data[i];
 664         srand(seed);
 665
 666         /* Try to assign up to 100x */
 667         for (size_t i = 0; i < 100; ++i) {
 668                 uint32_t try;
 669                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 670
 671                 struct dhcpv6_assignment *c;
 672                 list_for_each_entry(c, &iface->ia_assignments, head) {
 673                         if (c->length == 0)
 674                                 continue;
 675
 676                         if (c->assigned > try || c->length != 128) {
 677                                 assign->assigned = try;
 678                                 list_add_tail(&assign->head, &c->head);
 679                                 return true;
 680                         } else if (c->assigned == try)
 681                                 break;
 682                 }
 683         }
 684
 685         return false;
 686 }
 687
 688 static void handle_addrlist_change(struct netevent_handler_info *info)
 689 {
 690         struct interface *iface = info->iface;
 691         struct dhcpv6_assignment *c, *d, *border = list_last_entry(
 692                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 693         time_t now = odhcpd_time();
 694         int minprefix = -1;
 695
 696         list_for_each_entry(c, &iface->ia_assignments, head)
 697                 if (c != border && iface->ra_managed == RA_MANAGED_NO_MFLAG
 698                                 && (c->flags & OAF_BOUND))
 699                         __apply_lease(iface, c, info->addrs_old.addrs,
 700                                         info->addrs_old.len, false);
 701
 702         for (size_t i = 0; i < iface->addr6_len; ++i) {
 703                 if (iface->addr6[i].preferred > (uint32_t)now &&
 704                                 iface->addr6[i].prefix < 64 &&
 705                                 iface->addr6[i].prefix > minprefix)
 706                         minprefix = iface->addr6[i].prefix;
 707         }
 708
 709         if (minprefix > 32 && minprefix <= 64)
 710                 border->assigned = 1U << (64 - minprefix);
 711         else
 712                 border->assigned = 0;
 713
 714         struct list_head reassign = LIST_HEAD_INIT(reassign);
 715         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 716                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 717                                 c->managed_size)
 718                         continue;
 719
 720                 if (c->length < 128 && c->assigned >= border->assigned && c != border)
 721                         list_move(&c->head, &reassign);
 722                 else if (c != border && (c->flags & OAF_BOUND))
 723                         apply_lease(iface, c, true);
 724
 725                 if (c->accept_reconf && c->reconf_cnt == 0) {
 726                         start_reconf(c);
 727
 728                         /* Leave all other assignments of that client alone */
 729                         struct dhcpv6_assignment *a;
 730                         list_for_each_entry(a, &iface->ia_assignments, head)
 731                                 if (a != c && a->clid_len == c->clid_len &&
 732                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 733                                         a->reconf_cnt = INT_MAX;
 734                 }
 735         }
 736
 737         while (!list_empty(&reassign)) {
 738                 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
 739                 list_del(&c->head);
 740                 if (!assign_pd(iface, c)) {
 741                         c->assigned = 0;
 742                         list_add(&c->head, &iface->ia_assignments);
 743                 }
 744         }
 745
 746         dhcpv6_write_statefile();
 747 }
 748
 749 static void reconf_timeout_cb(struct uloop_timeout *event)
 750 {
 751         struct dhcpv6_assignment *a = container_of(event, struct dhcpv6_assignment, reconf_timer);
 752
 753         if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
 754                 send_reconf(a);
 755                 uloop_timeout_set(&a->reconf_timer,
 756                                         DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 757                 a->reconf_cnt++;
 758         } else
 759                 stop_reconf(a);
 760 }
 761
 762 static void start_reconf(struct dhcpv6_assignment *a)
 763 {
 764         uloop_timeout_set(&a->reconf_timer,
 765                                 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 766         a->reconf_timer.cb = reconf_timeout_cb;
 767         a->reconf_cnt++;
 768
 769         send_reconf(a);
 770 }
 771
 772 static void stop_reconf(struct dhcpv6_assignment *a)
 773 {
 774         uloop_timeout_cancel(&a->reconf_timer);
 775         a->reconf_cnt = 0;
 776         a->reconf_timer.cb = NULL;
 777 }
 778
 779 static void valid_until_cb(struct uloop_timeout *event)
 780 {
 781         time_t now = odhcpd_time();
 782         struct interface *iface;
 783         list_for_each_entry(iface, &interfaces, head) {
 784                 if (iface->dhcpv6 != MODE_SERVER || iface->ia_assignments.next == NULL)
 785                         continue;
 786
 787                 struct dhcpv6_assignment *a, *n;
 788                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 789                         if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
 790                                 if ((a->length < 128 && a->clid_len > 0) ||
 791                                                 (a->length == 128 && a->clid_len == 0))
 792                                         free_dhcpv6_assignment(a);
 793
 794                         }
 795                 }
 796         }
 797         uloop_timeout_set(event, 1000);
 798 }
 799
 800 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
 801                 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
 802                 struct interface *iface, bool request)
 803 {
 804         if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
 805                 return 0;
 806
 807         struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
 808         size_t datalen = sizeof(out);
 809         time_t now = odhcpd_time();
 810
 811         if (status) {
 812                 struct __attribute__((packed)) {
 813                         uint16_t type;
 814                         uint16_t len;
 815                         uint16_t value;
 816                 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
 817                                 htons(status)};
 818
 819                 memcpy(buf + datalen, &stat, sizeof(stat));
 820                 datalen += sizeof(stat);
 821         } else {
 822                 if (a) {
 823                         uint32_t leasetime;
 824                         if (a->leasetime)
 825                                 leasetime = a->leasetime;
 826                         else
 827                                 leasetime = iface->dhcpv4_leasetime;
 828
 829                         uint32_t pref = leasetime;
 830                         uint32_t valid = leasetime;
 831
 832                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 833                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
 834                         size_t m = get_preferred_addr(addrs, addrlen);
 835
 836                         for (size_t i = 0; i < addrlen; ++i) {
 837                                 uint32_t prefix_pref = addrs[i].preferred;
 838                                 uint32_t prefix_valid = addrs[i].valid;
 839
 840                                 if (!valid_addr(&addrs[i], now))
 841                                         continue;
 842
 843                                 if (prefix_pref != UINT32_MAX)
 844                                         prefix_pref -= now;
 845
 846                                 if (prefix_valid != UINT32_MAX)
 847                                         prefix_valid -= now;
 848
 849                                 if (a->length < 128) {
 850                                         struct dhcpv6_ia_prefix p = {
 851                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 852                                                 .len = htons(sizeof(p) - 4),
 853                                                 .preferred = htonl(prefix_pref),
 854                                                 .valid = htonl(prefix_valid),
 855                                                 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 856                                                 .addr = addrs[i].addr.in6,
 857                                         };
 858                                         p.addr.s6_addr32[1] |= htonl(a->assigned);
 859                                         p.addr.s6_addr32[2] = p.addr.s6_addr32[3] = 0;
 860
 861                                         size_t entrlen = sizeof(p) - 4;
 862
 863                                         if (datalen + entrlen + 4 > buflen ||
 864                                                         (a->assigned == 0 && a->managed_size == 0) ||
 865                                                         !valid_prefix_length(a, addrs[i].prefix))
 866                                                 continue;
 867
 868                                         memcpy(buf + datalen, &p, sizeof(p));
 869                                         datalen += entrlen + 4;
 870                                 } else {
 871                                         struct dhcpv6_ia_addr n = {
 872                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 873                                                 .len = htons(sizeof(n) - 4),
 874                                                 .addr = addrs[i].addr.in6,
 875                                                 .preferred = htonl(prefix_pref),
 876                                                 .valid = htonl(prefix_valid)
 877                                         };
 878                                         n.addr.s6_addr32[3] = htonl(a->assigned);
 879                                         size_t entrlen = sizeof(n) - 4;
 880
 881                                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
 882                                                         a->assigned == 0 ||
 883                                                         datalen + entrlen + 4 > buflen)
 884                                                 continue;
 885
 886                                         memcpy(buf + datalen, &n, sizeof(n));
 887                                         datalen += entrlen + 4;
 888                                 }
 889
 890                                 /* Calculate T1 / T2 based on non-deprecated addresses */
 891                                 if (prefix_pref > 0) {
 892                                         if (prefix_pref < pref)
 893                                                 pref = prefix_pref;
 894
 895                                         if (prefix_valid < valid)
 896                                                 valid = prefix_valid;
 897                                 }
 898                         }
 899
 900                         if (!INFINITE_VALID(a->valid_until))
 901                                 /* UINT32_MAX is considered as infinite leasetime */
 902                                 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 903
 904                         out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 905                         out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 906
 907                         if (!out.t1)
 908                                 out.t1 = htonl(1);
 909
 910                         if (!out.t2)
 911                                 out.t2 = htonl(1);
 912                 }
 913
 914                 if (!request) {
 915                         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 916                         uint16_t otype, olen;
 917                         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 918                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
 919                                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
 920                                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
 921                                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
 922                                         continue;
 923
 924                                 bool found = false;
 925                                 if (a) {
 926                                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
 927                                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
 928
 929                                         for (size_t i = 0; i < addrlen; ++i) {
 930                                                 if (!valid_addr(&addrs[i], now))
 931                                                         continue;
 932
 933                                                 struct in6_addr addr = addrs[i].addr.in6;
 934                                                 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 935                                                         addr.s6_addr32[1] |= htonl(a->assigned);
 936                                                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 937
 938                                                         if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
 939                                                                         p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 940                                                                 found = true;
 941                                                 } else {
 942                                                         addr.s6_addr32[3] = htonl(a->assigned);
 943
 944                                                         if (!memcmp(&n->addr, &addr, sizeof(addr)))
 945                                                                 found = true;
 946                                                 }
 947                                         }
 948                                 }
 949
 950                                 if (!found) {
 951                                         if (otype == DHCPV6_OPT_IA_PREFIX) {
 952                                                 struct dhcpv6_ia_prefix inv = {
 953                                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 954                                                         .len = htons(sizeof(inv) - 4),
 955                                                         .preferred = 0,
 956                                                         .valid = 0,
 957                                                         .prefix = p->prefix,
 958                                                         .addr = p->addr
 959                                                 };
 960
 961                                                 if (datalen + sizeof(inv) > buflen)
 962                                                         continue;
 963
 964                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 965                                                 datalen += sizeof(inv);
 966                                         } else {
 967                                                 struct dhcpv6_ia_addr inv = {
 968                                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 969                                                         .len = htons(sizeof(inv) - 4),
 970                                                         .addr = n->addr,
 971                                                         .preferred = 0,
 972                                                         .valid = 0
 973                                                 };
 974
 975                                                 if (datalen + sizeof(inv) > buflen)
 976                                                         continue;
 977
 978                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 979                                                 datalen += sizeof(inv);
 980                                         }
 981                                 }
 982                         }
 983                 }
 984         }
 985
 986         out.len = htons(datalen - 4);
 987         memcpy(buf, &out, sizeof(out));
 988         return datalen;
 989 }
 990
 991 struct log_ctxt {
 992         char *buf;
 993         int buf_len;
 994         int buf_idx;
 995 };
 996
 997 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 998                                 _unused uint32_t valid, void *arg)
 999 {
1000         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
1001         char addrbuf[INET6_ADDRSTRLEN];
1002
1003         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
1004         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
1005                                         "%s/%d ", addrbuf, prefix);
1006 }
1007
1008 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
1009                 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
1010 {
1011         const char *type = "UNKNOWN";
1012         const char *status = "UNKNOWN";
1013
1014         if (msgtype == DHCPV6_MSG_RENEW)
1015                 return;
1016
1017         switch (msgtype) {
1018         case DHCPV6_MSG_SOLICIT:
1019                 type = "SOLICIT";
1020                 break;
1021         case DHCPV6_MSG_REQUEST:
1022                 type = "REQUEST";
1023                 break;
1024         case DHCPV6_MSG_CONFIRM:
1025                 type = "CONFIRM";
1026                 break;
1027         case DHCPV6_MSG_RENEW:
1028                 type = "RENEW";
1029                 break;
1030         case DHCPV6_MSG_REBIND:
1031                 type = "REBIND";
1032                 break;
1033         case DHCPV6_MSG_RELEASE:
1034                 type = "RELEASE";
1035                 break;
1036         case DHCPV6_MSG_DECLINE:
1037                 type = "DECLINE";
1038                 break;
1039         }
1040
1041         switch (code) {
1042         case DHCPV6_STATUS_OK:
1043                 status = "ok";
1044                 break;
1045         case DHCPV6_STATUS_NOADDRSAVAIL:
1046                 status = "no addresses available";
1047                 break;
1048         case DHCPV6_STATUS_NOBINDING:
1049                 status = "no binding";
1050                 break;
1051         case DHCPV6_STATUS_NOTONLINK:
1052                 status = "not on-link";
1053                 break;
1054         case DHCPV6_STATUS_NOPREFIXAVAIL:
1055                 status = "no prefix available";
1056                 break;
1057         }
1058
1059         char leasebuf[256] = "";
1060
1061         if (a) {
1062                 struct log_ctxt ctxt = {.buf = leasebuf,
1063                                         .buf_len = sizeof(leasebuf),
1064                                         .buf_idx = 0 };
1065
1066                 dhcpv6_enum_ia_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1067         }
1068
1069         syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1070                         duidbuf, iface->ifname, status, leasebuf);
1071 }
1072
1073 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
1074                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1075 {
1076         time_t now = odhcpd_time();
1077         size_t response_len = 0;
1078         const struct dhcpv6_client_header *hdr = data;
1079         uint8_t *start = (uint8_t*)&hdr[1], *odata;
1080         uint16_t otype, olen;
1081         /* Find and parse client-id and hostname */
1082         bool accept_reconf = false;
1083         uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1084         char hostname[256];
1085         size_t hostname_len = 0;
1086         bool notonlink = false;
1087         char duidbuf[261];
1088
1089         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1090                 if (otype == DHCPV6_OPT_CLIENTID) {
1091                         clid_data = odata;
1092                         clid_len = olen;
1093
1094                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1095                                 memcpy(mac, &odata[8], sizeof(mac));
1096                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1097                                 memcpy(mac, &odata[4], sizeof(mac));
1098
1099                         if (olen <= 130)
1100                                 odhcpd_hexlify(duidbuf, odata, olen);
1101                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1102                         uint8_t fqdn_buf[256];
1103                         memcpy(fqdn_buf, odata, olen);
1104                         fqdn_buf[olen++] = 0;
1105
1106                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1107                                 hostname_len = strcspn(hostname, ".");
1108                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1109                         accept_reconf = true;
1110         }
1111
1112         if (!clid_data || !clid_len || clid_len > 130)
1113                 goto out;
1114
1115         struct dhcpv6_assignment *first = NULL;
1116         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1117                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1118                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1119                 bool ia_addr_present = false;
1120                 if (!is_pd && !is_na)
1121                         continue;
1122
1123                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1124                 size_t ia_response_len = 0;
1125                 uint8_t reqlen = (is_pd) ? 62 : 128;
1126                 uint32_t reqhint = 0;
1127
1128                 /* Parse request hint for IA-PD */
1129                 if (is_pd) {
1130                         uint8_t *sdata;
1131                         uint16_t stype, slen;
1132                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1133                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1134                                         continue;
1135
1136                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1137                                 if (p->prefix) {
1138                                         reqlen = p->prefix;
1139                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1140                                         if (reqlen > 32 && reqlen <= 64)
1141                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1142                                 }
1143                         }
1144
1145                         if (reqlen > 64)
1146                                 reqlen = 64;
1147                 } else if (is_na) {
1148                         uint8_t *sdata;
1149                         uint16_t stype, slen;
1150                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1151                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1152                                         continue;
1153
1154                                 ia_addr_present = true;
1155                         }
1156                 }
1157
1158                 /* Find assignment */
1159                 struct dhcpv6_assignment *c, *a = NULL;
1160                 list_for_each_entry(c, &iface->ia_assignments, head) {
1161                         if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1162                                         (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1163                                                 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1164                                         (!(c->flags & (OAF_BOUND|OAF_TENTATIVE)) || c->iaid == ia->iaid) &&
1165                                         (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1166                                         ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1167                                 a = c;
1168
1169                                 /* Reset state */
1170                                 if (a->flags & OAF_BOUND)
1171                                         apply_lease(iface, a, false);
1172
1173                                 memcpy(a->clid_data, clid_data, clid_len);
1174                                 a->clid_len = clid_len;
1175                                 a->iaid = ia->iaid;
1176                                 a->peer = *addr;
1177                                 stop_reconf(a);
1178                                 break;
1179                         }
1180                 }
1181
1182                 /* Generic message handling */
1183                 uint16_t status = DHCPV6_STATUS_OK;
1184                 if (a && a->managed_size < 0)
1185                         return -1;
1186
1187                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1188                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1189                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1190                         bool assigned = !!a;
1191
1192                         if (!a && !iface->no_dynamic_dhcp) {
1193                                 /* Create new binding */
1194                                 a = calloc(1, sizeof(*a) + clid_len);
1195                                 if (a) {
1196                                         a->clid_len = clid_len;
1197                                         a->iaid = ia->iaid;
1198                                         a->length = reqlen;
1199                                         a->peer = *addr;
1200                                         a->assigned = reqhint;
1201                                         /* Set valid time to current time indicating  */
1202                                         /* assignment is not having infinite lifetime */
1203                                         a->valid_until = now;
1204                                         a->iface = iface;
1205
1206                                         if (first)
1207                                                 memcpy(a->key, first->key, sizeof(a->key));
1208                                         else
1209                                                 odhcpd_urandom(a->key, sizeof(a->key));
1210                                         memcpy(a->clid_data, clid_data, clid_len);
1211
1212                                         if (is_pd)
1213                                                 while (!(assigned = assign_pd(iface, a)) &&
1214                                                                 !a->managed_size && ++a->length <= 64);
1215                                         else
1216                                                 assigned = assign_na(iface, a);
1217
1218                                         if (a->managed_size && !assigned)
1219                                                 return -1;
1220                                 }
1221                         }
1222
1223                         if (!assigned || iface->addr6_len == 0)
1224                                 /* Set error status */
1225                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1226                         else if (accept_reconf && assigned && !first &&
1227                                         hdr->msg_type != DHCPV6_MSG_REBIND) {
1228                                 size_t handshake_len = 4;
1229                                 buf[0] = 0;
1230                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1231                                 buf[2] = 0;
1232                                 buf[3] = 0;
1233
1234                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1235                                         struct dhcpv6_auth_reconfigure auth = {
1236                                                 htons(DHCPV6_OPT_AUTH),
1237                                                 htons(sizeof(auth) - 4),
1238                                                 3, 1, 0,
1239                                                 {htonl(time(NULL)), htonl(++serial)},
1240                                                 1,
1241                                                 {0}
1242                                         };
1243                                         memcpy(auth.key, a->key, sizeof(a->key));
1244                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1245                                         handshake_len += sizeof(auth);
1246                                 }
1247
1248                                 buf += handshake_len;
1249                                 buflen -= handshake_len;
1250                                 response_len += handshake_len;
1251
1252                                 first = a;
1253                         }
1254
1255                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface,
1256                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1257
1258                         /* Was only a solicitation: mark binding for removal */
1259                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1260                                 a->flags &= ~OAF_BOUND;
1261                                 a->flags |= OAF_TENTATIVE;
1262
1263                                 if (!(a->flags & OAF_STATIC))
1264                                         /* Keep tentative assignment around for 60 seconds */
1265                                         a->valid_until = now + 60;
1266                         } else if (assigned &&
1267                                         (hdr->msg_type == DHCPV6_MSG_REQUEST ||
1268                                          hdr->msg_type == DHCPV6_MSG_REBIND)) {
1269                                 if (hostname_len > 0) {
1270                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1271                                         if (a->hostname) {
1272                                                 memcpy(a->hostname, hostname, hostname_len);
1273                                                 a->hostname[hostname_len] = 0;
1274                                         }
1275                                 }
1276                                 a->accept_reconf = accept_reconf;
1277                                 a->flags &= ~OAF_TENTATIVE;
1278                                 a->flags |= OAF_BOUND;
1279                                 apply_lease(iface, a, true);
1280                         } else if (!assigned && a && a->managed_size == 0) {
1281                                 /* Cleanup failed assignment */
1282                                 free_dhcpv6_assignment(a);
1283                                 a = NULL;
1284                         }
1285                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1286                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1287                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1288                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1289                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1290                                 status = DHCPV6_STATUS_NOBINDING;
1291                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1292                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1293                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1294                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1295                                 if (a) {
1296                                         a->flags |= OAF_BOUND;
1297                                         apply_lease(iface, a, true);
1298                                 }
1299                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1300                                 if (!(a->flags & OAF_STATIC))
1301                                         a->valid_until = now - 1;
1302
1303                                 if (a->flags & OAF_BOUND) {
1304                                         apply_lease(iface, a, false);
1305                                         a->flags &= ~OAF_BOUND;
1306                                 }
1307                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1308                                 a->flags &= ~OAF_BOUND;
1309
1310                                 if (!(a->flags & OAF_STATIC)) {
1311                                         a->clid_len = 0;
1312                                         a->valid_until = now + 3600; /* Block address for 1h */
1313                                 }
1314                         }
1315                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1316                         /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1317                         status = DHCPV6_STATUS_NOTONLINK;
1318                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1319                         notonlink = true;
1320                 }
1321
1322                 buf += ia_response_len;
1323                 buflen -= ia_response_len;
1324                 response_len += ia_response_len;
1325                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1326         }
1327
1328         if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1329                         response_len + 6 < buflen) {
1330                 buf[0] = 0;
1331                 buf[1] = DHCPV6_OPT_STATUS;
1332                 buf[2] = 0;
1333                 buf[3] = 2;
1334                 buf[4] = 0;
1335                 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1336                 response_len += 6;
1337         }
1338
1339         dhcpv6_write_statefile();
1340
1341 out:
1342         return response_len;
1343 }