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 free_dhcpv6_assignment(struct dhcpv6_assignment *c);
  43 static void stop_reconf(struct dhcpv6_assignment *a);
  44 static void valid_until_cb(struct uloop_timeout *event);
  45
  46 static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb};
  47 static uint32_t serial = 0;
  48 static uint8_t statemd5[16];
  49
  50 int dhcpv6_ia_init(void)
  51 {
  52         uloop_timeout_set(&valid_until_timeout, 1000);
  53         return 0;
  54 }
  55
  56 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
  57 {
  58         if (!enable && iface->ia_assignments.next) {
  59                 struct dhcpv6_assignment *c;
  60
  61                 while (!list_empty(&iface->ia_assignments)) {
  62                         c = list_first_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
  63                         free_dhcpv6_assignment(c);
  64                 }
  65         }
  66
  67         if (enable && iface->dhcpv6 == RELAYD_SERVER) {
  68                 if (!iface->ia_assignments.next)
  69                         INIT_LIST_HEAD(&iface->ia_assignments);
  70
  71                 if (list_empty(&iface->ia_assignments)) {
  72                         struct dhcpv6_assignment *border = calloc(1, sizeof(*border));
  73                         if (!border) {
  74                                 syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
  75                                 return -1;
  76                         }
  77
  78                         border->length = 64;
  79                         list_add(&border->head, &iface->ia_assignments);
  80                 }
  81
  82                 /* Parse static entries */
  83                 struct lease *lease;
  84                 list_for_each_entry(lease, &leases, head) {
  85                         /* Construct entry */
  86                         size_t duid_len = lease->duid_len ? lease->duid_len : 14;
  87                         struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
  88                         if (!a) {
  89                                 syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
  90                                         iface->ifname);
  91                                 return -1;
  92                         }
  93
  94                         a->leasetime = lease->dhcpv4_leasetime;
  95
  96                         a->clid_len = duid_len;
  97                         a->length = 128;
  98                         if (lease->hostid) {
  99                                 a->assigned = lease->hostid;
 100                         } else {
 101                                 uint32_t i4a = ntohl(lease->ipaddr.s_addr) & 0xff;
 102                                 a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
 103                         }
 104
 105                         odhcpd_urandom(a->key, sizeof(a->key));
 106                         memcpy(a->clid_data, lease->duid, lease->duid_len);
 107                         memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
 108                         /* Static assignment */
 109                         a->flags |= OAF_STATIC;
 110                         /* Infinite valid */
 111                         a->valid_until = 0;
 112
 113                         /* Assign to all interfaces */
 114                         struct dhcpv6_assignment *c;
 115                         list_for_each_entry(c, &iface->ia_assignments, head) {
 116                                 if (c->length != 128 || c->assigned > a->assigned) {
 117                                         list_add_tail(&a->head, &c->head);
 118                                         break;
 119                                 } else if (c->assigned == a->assigned)
 120                                         /* Already an assignment with that number */
 121                                         break;
 122                         }
 123
 124                         if (a->head.next) {
 125                                 a->iface = iface;
 126                                 if (lease->hostname[0]) {
 127                                         free(a->hostname);
 128                                         a->hostname = strdup(lease->hostname);
 129                                 }
 130                         } else
 131                                 free_dhcpv6_assignment(a);
 132                 }
 133         }
 134         return 0;
 135 }
 136
 137 static void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
 138 {
 139         if (c->managed_sock.fd.registered) {
 140                 ustream_free(&c->managed_sock.stream);
 141                 close(c->managed_sock.fd.fd);
 142         }
 143
 144         if (c->head.next)
 145                 list_del(&c->head);
 146
 147         if (c->reconf_cnt)
 148                 stop_reconf(c);
 149
 150         free(c->managed);
 151         free(c->hostname);
 152         free(c);
 153 }
 154
 155 static inline bool valid_prefix_length(const struct dhcpv6_assignment *a, const uint8_t prefix_length)
 156 {
 157         return (a->managed_size || a->length > prefix_length);
 158 }
 159
 160 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 161 {
 162         return (addr->prefix <= 96 && addr->preferred > (uint32_t)now);
 163 }
 164
 165 static size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen)
 166 {
 167         size_t i, m;
 168
 169         for (i = 0, m = 0; i < addrlen; ++i) {
 170                 if (addrs[i].preferred > addrs[m].preferred ||
 171                                 (addrs[i].preferred == addrs[m].preferred &&
 172                                 memcmp(&addrs[i].addr, &addrs[m].addr, 16) > 0))
 173                         m = i;
 174         }
 175
 176         return m;
 177 }
 178
 179 static int send_reconf(struct dhcpv6_assignment *assign)
 180 {
 181         struct {
 182                 struct dhcpv6_client_header hdr;
 183                 uint16_t srvid_type;
 184                 uint16_t srvid_len;
 185                 uint16_t duid_type;
 186                 uint16_t hardware_type;
 187                 uint8_t mac[6];
 188                 uint16_t msg_type;
 189                 uint16_t msg_len;
 190                 uint8_t msg_id;
 191                 struct dhcpv6_auth_reconfigure auth;
 192                 uint16_t clid_type;
 193                 uint16_t clid_len;
 194                 uint8_t clid_data[128];
 195         } __attribute__((packed)) reconf_msg = {
 196                 .hdr = {DHCPV6_MSG_RECONFIGURE, {0, 0, 0}},
 197                 .srvid_type = htons(DHCPV6_OPT_SERVERID),
 198                 .srvid_len = htons(10),
 199                 .duid_type = htons(3),
 200                 .hardware_type = htons(1),
 201                 .msg_type = htons(DHCPV6_OPT_RECONF_MSG),
 202                 .msg_len = htons(1),
 203                 .msg_id = DHCPV6_MSG_RENEW,
 204                 .auth = {htons(DHCPV6_OPT_AUTH),
 205                                 htons(sizeof(reconf_msg.auth) - 4), 3, 1, 0,
 206                                 {htonl(time(NULL)), htonl(++serial)}, 2, {0}},
 207                 .clid_type = htons(DHCPV6_OPT_CLIENTID),
 208                 .clid_len = htons(assign->clid_len),
 209                 .clid_data = {0},
 210         };
 211         struct interface *iface = assign->iface;
 212
 213         odhcpd_get_mac(iface, reconf_msg.mac);
 214         memcpy(reconf_msg.clid_data, assign->clid_data, assign->clid_len);
 215         struct iovec iov = {&reconf_msg, sizeof(reconf_msg) - 128 + assign->clid_len};
 216
 217         md5_ctx_t md5;
 218         uint8_t secretbytes[64];
 219         memset(secretbytes, 0, sizeof(secretbytes));
 220         memcpy(secretbytes, assign->key, sizeof(assign->key));
 221
 222         for (size_t i = 0; i < sizeof(secretbytes); ++i)
 223                 secretbytes[i] ^= 0x36;
 224
 225         md5_begin(&md5);
 226         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 227         md5_hash(iov.iov_base, iov.iov_len, &md5);
 228         md5_end(reconf_msg.auth.key, &md5);
 229
 230         for (size_t i = 0; i < sizeof(secretbytes); ++i) {
 231                 secretbytes[i] ^= 0x36;
 232                 secretbytes[i] ^= 0x5c;
 233         }
 234
 235         md5_begin(&md5);
 236         md5_hash(secretbytes, sizeof(secretbytes), &md5);
 237         md5_hash(reconf_msg.auth.key, 16, &md5);
 238         md5_end(reconf_msg.auth.key, &md5);
 239
 240         return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 241 }
 242
 243 void dhcpv6_enum_ia_addrs(struct interface *iface, struct dhcpv6_assignment *c,
 244                                 time_t now, dhcpv6_binding_cb_handler_t func, void *arg)
 245 {
 246         struct odhcpd_ipaddr *addrs = (c->managed) ? c->managed : iface->ia_addr;
 247         size_t addrlen = (c->managed) ? (size_t)c->managed_size : iface->ia_addr_len;
 248         size_t m = get_preferred_addr(addrs, addrlen);
 249
 250         for (size_t i = 0; i < addrlen; ++i) {
 251                 struct in6_addr addr;
 252                 uint32_t pref, valid;
 253                 int prefix = c->managed ? addrs[i].prefix : c->length;
 254
 255                 if (!valid_addr(&addrs[i], now))
 256                         continue;
 257
 258                 addr = addrs[i].addr.in6;
 259                 pref = addrs[i].preferred;
 260                 valid = addrs[i].valid;
 261                 if (prefix == 128) {
 262                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 263                                 continue;
 264
 265                         addr.s6_addr32[3] = htonl(c->assigned);
 266                 } else {
 267                         if (!valid_prefix_length(c, addrs[i].prefix))
 268                                 continue;
 269
 270                         addr.s6_addr32[1] |= htonl(c->assigned);
 271                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 272                 }
 273
 274                 if (pref != UINT32_MAX)
 275                         pref -= now;
 276
 277                 if (valid != UINT32_MAX)
 278                         valid -= now;
 279
 280                 func(&addr, prefix, pref, valid, arg);
 281         }
 282 }
 283
 284 struct write_ctxt {
 285         FILE *fp;
 286         md5_ctx_t md5;
 287         struct dhcpv6_assignment *c;
 288         struct interface *iface;
 289         char *buf;
 290         int buf_len;
 291         int buf_idx;
 292 };
 293
 294 void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 295                                 _unused uint32_t valid, void *arg)
 296 {
 297         struct write_ctxt *ctxt = (struct write_ctxt *)arg;
 298         char ipbuf[INET6_ADDRSTRLEN];
 299
 300         inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 301
 302         if (ctxt->c->length == 128 && ctxt->c->hostname) {
 303                 fputs(ipbuf, ctxt->fp);
 304
 305                 char b[256];
 306                 if (dn_expand(ctxt->iface->search, ctxt->iface->search + ctxt->iface->search_len,
 307                                 ctxt->iface->search, b, sizeof(b)) > 0)
 308                         fprintf(ctxt->fp, "\t%s.%s", ctxt->c->hostname, b);
 309
 310                 fprintf(ctxt->fp, "\t%s\n", ctxt->c->hostname);
 311                 md5_hash(ipbuf, strlen(ipbuf), &ctxt->md5);
 312                 md5_hash(ctxt->c->hostname, strlen(ctxt->c->hostname), &ctxt->md5);
 313         }
 314
 315         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx,ctxt->buf_len - ctxt->buf_idx,
 316                                         "%s/%d ", ipbuf, prefix);
 317 }
 318
 319 void dhcpv6_write_statefile(void)
 320 {
 321         struct write_ctxt ctxt;
 322
 323         md5_begin(&ctxt.md5);
 324
 325         if (config.dhcp_statefile) {
 326                 time_t now = odhcpd_time(), wall_time = time(NULL);
 327                 int fd = open(config.dhcp_statefile, O_CREAT | O_WRONLY | O_CLOEXEC, 0644);
 328                 char leasebuf[512];
 329
 330                 if (fd < 0)
 331                         return;
 332                 int ret;
 333                 ret = lockf(fd, F_LOCK, 0);
 334                 if (ret < 0) {
 335                         close(fd);
 336                         return;
 337                 }
 338                 if (ftruncate(fd, 0) < 0) {}
 339
 340                 ctxt.fp = fdopen(fd, "w");
 341                 if (!ctxt.fp) {
 342                         close(fd);
 343                         return;
 344                 }
 345
 346                 ctxt.buf = leasebuf;
 347                 ctxt.buf_len = sizeof(leasebuf);
 348
 349                 list_for_each_entry(ctxt.iface, &interfaces, head) {
 350                         if (ctxt.iface->dhcpv6 != RELAYD_SERVER &&
 351                                         ctxt.iface->dhcpv4 != RELAYD_SERVER)
 352                                 continue;
 353
 354                         if (ctxt.iface->dhcpv6 == RELAYD_SERVER &&
 355                                         ctxt.iface->ia_assignments.next) {
 356                                 list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 357                                         if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 358                                                 continue;
 359
 360                                         char duidbuf[264];
 361
 362                                         odhcpd_hexlify(duidbuf, ctxt.c->clid_data, ctxt.c->clid_len);
 363
 364                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 365                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s %x %s %ld %x %u ",
 366                                                                 ctxt.iface->ifname, duidbuf, ntohl(ctxt.c->iaid),
 367                                                                 (ctxt.c->hostname ? ctxt.c->hostname : "-"),
 368                                                                 (ctxt.c->valid_until > now ?
 369                                                                         (ctxt.c->valid_until - now + wall_time) :
 370                                                                         (INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)),
 371                                                                 ctxt.c->assigned, (unsigned)ctxt.c->length);
 372
 373                                         if (INFINITE_VALID(ctxt.c->valid_until) || ctxt.c->valid_until > now)
 374                                                 dhcpv6_enum_ia_addrs(ctxt.iface, ctxt.c, now,
 375                                                                         dhcpv6_write_ia_addr, &ctxt);
 376
 377                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 378                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 379                                 }
 380                         }
 381
 382                         if (ctxt.iface->dhcpv4 == RELAYD_SERVER &&
 383                                         ctxt.iface->dhcpv4_assignments.next) {
 384                                 struct dhcpv4_assignment *c;
 385                                 list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 386                                         if (!(c->flags & OAF_BOUND))
 387                                                 continue;
 388
 389                                         char ipbuf[INET6_ADDRSTRLEN];
 390                                         char duidbuf[16];
 391                                         odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 392
 393                                         /* iface DUID iaid hostname lifetime assigned length [addrs...] */
 394                                         ctxt.buf_idx = snprintf(ctxt.buf, ctxt.buf_len, "# %s %s ipv4 %s %ld %x 32 ",
 395                                                                 ctxt.iface->ifname, duidbuf,
 396                                                                 (c->hostname ? c->hostname : "-"),
 397                                                                 (c->valid_until > now ?
 398                                                                         (c->valid_until - now + wall_time) :
 399                                                                         (INFINITE_VALID(c->valid_until) ? -1 : 0)),
 400                                                                 c->addr);
 401
 402                                         struct in_addr addr = {htonl(c->addr)};
 403                                         inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 404
 405                                         if (c->hostname) {
 406                                                 fputs(ipbuf, ctxt.fp);
 407
 408                                                 char b[256];
 409                                                 if (dn_expand(ctxt.iface->search,
 410                                                                 ctxt.iface->search + ctxt.iface->search_len,
 411                                                                 ctxt.iface->search, b, sizeof(b)) > 0)
 412                                                         fprintf(ctxt.fp, "\t%s.%s", c->hostname, b);
 413
 414                                                 fprintf(ctxt.fp, "\t%s\n", c->hostname);
 415                                                 md5_hash(ipbuf, strlen(ipbuf), &ctxt.md5);
 416                                                 md5_hash(c->hostname, strlen(c->hostname), &ctxt.md5);
 417                                         }
 418
 419                                         ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx,
 420                                                                         ctxt.buf_len - ctxt.buf_idx,
 421                                                                         "%s/32 ", ipbuf);
 422                                         ctxt.buf[ctxt.buf_idx - 1] = '\n';
 423                                         fwrite(ctxt.buf, 1, ctxt.buf_idx, ctxt.fp);
 424                                 }
 425                         }
 426                 }
 427
 428                 fclose(ctxt.fp);
 429         }
 430
 431         uint8_t newmd5[16];
 432         md5_end(newmd5, &ctxt.md5);
 433
 434         if (config.dhcp_cb && memcmp(newmd5, statemd5, sizeof(newmd5))) {
 435                 memcpy(statemd5, newmd5, sizeof(statemd5));
 436                 char *argv[2] = {config.dhcp_cb, NULL};
 437                 if (!vfork()) {
 438                         execv(argv[0], argv);
 439                         _exit(128);
 440                 }
 441         }
 442 }
 443
 444
 445 static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bool add)
 446 {
 447         if (a->length > 64 || a->managed_size < 0)
 448                 return;
 449
 450         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 451         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 452
 453         for (size_t i = 0; i < addrlen; ++i) {
 454                 struct in6_addr prefix = addrs[i].addr.in6;
 455                 prefix.s6_addr32[1] |= htonl(a->assigned);
 456                 prefix.s6_addr32[2] = prefix.s6_addr32[3] = 0;
 457                 odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
 458                                 iface, &a->peer.sin6_addr, 1024, add);
 459         }
 460 }
 461
 462 /* More data was received from TCP connection */
 463 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 464 {
 465         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 466         time_t now = odhcpd_time();
 467         bool first = c->managed_size < 0;
 468
 469         for (;;) {
 470                 int pending;
 471                 char *data = ustream_get_read_buf(s, &pending);
 472                 char *end = memmem(data, pending, "\n\n", 2);
 473
 474                 if (!end)
 475                         break;
 476
 477                 end += 2;
 478                 end[-1] = 0;
 479
 480                 c->managed_size = 0;
 481                 if (c->accept_reconf)
 482                         c->reconf_cnt = 1;
 483
 484                 char *saveptr;
 485                 for (char *line = strtok_r(data, "\n", &saveptr); line; line = strtok_r(NULL, "\n", &saveptr)) {
 486                         c->managed = realloc(c->managed, (c->managed_size + 1) * sizeof(*c->managed));
 487                         struct odhcpd_ipaddr *n = &c->managed[c->managed_size];
 488
 489                         char *saveptr2, *x = strtok_r(line, "/", &saveptr2);
 490                         if (!x || inet_pton(AF_INET6, x, &n->addr) < 1)
 491                                 continue;
 492
 493                         x = strtok_r(NULL, ",", &saveptr2);
 494                         if (sscanf(x, "%hhu", &n->prefix) < 1)
 495                                 continue;
 496
 497                         x = strtok_r(NULL, ",", &saveptr2);
 498                         if (sscanf(x, "%u", &n->preferred) < 1)
 499                                 continue;
 500
 501                         x = strtok_r(NULL, ",", &saveptr2);
 502                         if (sscanf(x, "%u", &n->valid) < 1)
 503                                 continue;
 504
 505                         if (n->preferred > n->valid)
 506                                 continue;
 507
 508                         if (UINT32_MAX - now < n->preferred)
 509                                 n->preferred = UINT32_MAX;
 510                         else
 511                                 n->preferred += now;
 512
 513                         if (UINT32_MAX - now < n->valid)
 514                                 n->valid = UINT32_MAX;
 515                         else
 516                                 n->valid += now;
 517
 518                         n->dprefix = 0;
 519
 520                         ++c->managed_size;
 521                 }
 522
 523                 ustream_consume(s, end - data);
 524         }
 525
 526         if (first && c->managed_size == 0)
 527                 free_dhcpv6_assignment(c);
 528         else if (first && !(c->flags & OAF_STATIC))
 529                 c->valid_until = now + 150;
 530 }
 531
 532
 533 /* TCP transmission has ended, either because of success or timeout or other error */
 534 static void managed_handle_pd_done(struct ustream *s)
 535 {
 536         struct dhcpv6_assignment *c = container_of(s, struct dhcpv6_assignment, managed_sock);
 537
 538         if (!(c->flags & OAF_STATIC))
 539                 c->valid_until = odhcpd_time() + 15;
 540
 541         c->managed_size = 0;
 542
 543         if (c->accept_reconf)
 544                 c->reconf_cnt = 1;
 545 }
 546
 547 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
 548 {
 549         struct dhcpv6_assignment *c;
 550
 551         if (iface->dhcpv6_pd_manager[0]) {
 552                 int fd = usock(USOCK_UNIX | USOCK_TCP, iface->dhcpv6_pd_manager, NULL);
 553                 if (fd >= 0) {
 554                         char iaidbuf[298];
 555                         odhcpd_hexlify(iaidbuf, assign->clid_data, assign->clid_len);
 556
 557                         assign->managed_sock.stream.notify_read = managed_handle_pd_data;
 558                         assign->managed_sock.stream.notify_state = managed_handle_pd_done;
 559                         ustream_fd_init(&assign->managed_sock, fd);
 560                         ustream_printf(&assign->managed_sock.stream, "%s,%x\n::/%d,0,0\n\n",
 561                                         iaidbuf, assign->iaid, assign->length);
 562                         ustream_write_pending(&assign->managed_sock.stream);
 563                         assign->managed_size = -1;
 564
 565                         if (!(assign->flags & OAF_STATIC))
 566                                 assign->valid_until = odhcpd_time() + 15;
 567
 568                         list_add(&assign->head, &iface->ia_assignments);
 569
 570                         /* Wait initial period of up to 250ms for immediate assignment */
 571                         struct pollfd pfd = { .fd = fd, .events = POLLIN };
 572                         poll(&pfd, 1, 250);
 573                         managed_handle_pd_data(&assign->managed_sock.stream, 0);
 574
 575                         if (fcntl(fd, F_GETFL) >= 0 && assign->managed_size > 0)
 576                                 return true;
 577                 }
 578
 579                 return false;
 580         } else if (iface->ia_addr_len < 1)
 581                 return false;
 582
 583         /* Try honoring the hint first */
 584         uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 585         if (assign->assigned) {
 586                 list_for_each_entry(c, &iface->ia_assignments, head) {
 587                         if (c->length == 128 || c->length == 0)
 588                                 continue;
 589
 590                         if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
 591                                 list_add_tail(&assign->head, &c->head);
 592
 593                                 if (assign->flags & OAF_BOUND)
 594                                         apply_lease(iface, assign, true);
 595
 596                                 return true;
 597                         }
 598
 599                         if (c->assigned != 0)
 600                                 current = (c->assigned + (1 << (64 - c->length)));
 601                 }
 602         }
 603
 604         /* Fallback to a variable assignment */
 605         current = 1;
 606         list_for_each_entry(c, &iface->ia_assignments, head) {
 607                 if (c->length == 128 || c->length == 0)
 608                         continue;
 609
 610                 current = (current + asize) & (~asize);
 611                 if (current + asize < c->assigned) {
 612                         assign->assigned = current;
 613                         list_add_tail(&assign->head, &c->head);
 614
 615                         if (assign->flags & OAF_BOUND)
 616                                 apply_lease(iface, assign, true);
 617
 618                         return true;
 619                 }
 620
 621                 if (c->assigned != 0)
 622                         current = (c->assigned + (1 << (64 - c->length)));
 623         }
 624
 625         return false;
 626 }
 627
 628 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 629 {
 630         /* Seed RNG with checksum of DUID */
 631         uint32_t seed = 0;
 632         for (size_t i = 0; i < assign->clid_len; ++i)
 633                 seed += assign->clid_data[i];
 634         srand(seed);
 635
 636         /* Try to assign up to 100x */
 637         for (size_t i = 0; i < 100; ++i) {
 638                 uint32_t try;
 639                 do try = ((uint32_t)rand()) % 0x0fff; while (try < 0x100);
 640
 641                 struct dhcpv6_assignment *c;
 642                 list_for_each_entry(c, &iface->ia_assignments, head) {
 643                         if (c->length == 0)
 644                                 continue;
 645
 646                         if (c->assigned > try || c->length != 128) {
 647                                 assign->assigned = try;
 648                                 list_add_tail(&assign->head, &c->head);
 649                                 return true;
 650                         } else if (c->assigned == try)
 651                                 break;
 652                 }
 653         }
 654
 655         return false;
 656 }
 657
 658 void dhcpv6_ia_preupdate(struct interface *iface)
 659 {
 660         if (iface->dhcpv6 != RELAYD_SERVER)
 661                 return;
 662
 663         struct dhcpv6_assignment *c, *border = list_last_entry(
 664                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 665
 666         list_for_each_entry(c, &iface->ia_assignments, head)
 667                 if (c != border && iface->ra_managed == RA_MANAGED_NO_MFLAG
 668                                 && (c->flags & OAF_BOUND))
 669                         apply_lease(iface, c, false);
 670 }
 671
 672 static void reconf_timeout_cb(struct uloop_timeout *event)
 673 {
 674         struct dhcpv6_assignment *a = container_of(event, struct dhcpv6_assignment, reconf_timer);
 675
 676         if (a->reconf_cnt > 0 && a->reconf_cnt < DHCPV6_REC_MAX_RC) {
 677                 send_reconf(a);
 678                 uloop_timeout_set(&a->reconf_timer,
 679                                         DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 680                 a->reconf_cnt++;
 681         } else
 682                 stop_reconf(a);
 683 }
 684
 685 static void start_reconf(struct dhcpv6_assignment *a)
 686 {
 687         uloop_timeout_set(&a->reconf_timer,
 688                                 DHCPV6_REC_TIMEOUT << a->reconf_cnt);
 689         a->reconf_timer.cb = reconf_timeout_cb;
 690         a->reconf_cnt++;
 691
 692         send_reconf(a);
 693 }
 694
 695 static void stop_reconf(struct dhcpv6_assignment *a)
 696 {
 697         uloop_timeout_cancel(&a->reconf_timer);
 698         a->reconf_cnt = 0;
 699         a->reconf_timer.cb = NULL;
 700 }
 701
 702 void dhcpv6_ia_postupdate(struct interface *iface)
 703 {
 704         if (iface->dhcpv6 != RELAYD_SERVER)
 705                 return;
 706
 707         time_t now = odhcpd_time();
 708         int minprefix = -1;
 709         for (size_t i = 0; i < iface->ia_addr_len; ++i) {
 710                 if (iface->ia_addr[i].preferred > (uint32_t)now &&
 711                                 iface->ia_addr[i].prefix < 64 &&
 712                                 iface->ia_addr[i].prefix > minprefix)
 713                         minprefix = iface->ia_addr[i].prefix;
 714         }
 715
 716         struct dhcpv6_assignment *border = list_last_entry(
 717                         &iface->ia_assignments, struct dhcpv6_assignment, head);
 718
 719         if (minprefix > 32 && minprefix <= 64)
 720                 border->assigned = 1U << (64 - minprefix);
 721         else
 722                 border->assigned = 0;
 723
 724         struct list_head reassign = LIST_HEAD_INIT(reassign);
 725         struct dhcpv6_assignment *c, *d;
 726         list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
 727                 if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
 728                                 c->managed_size)
 729                         continue;
 730
 731                 if (c->length < 128 && c->assigned >= border->assigned && c != border)
 732                         list_move(&c->head, &reassign);
 733                 else if (c != border && (c->flags & OAF_BOUND))
 734                         apply_lease(iface, c, true);
 735
 736                 if (c->accept_reconf && c->reconf_cnt == 0) {
 737                         start_reconf(c);
 738
 739                         /* Leave all other assignments of that client alone */
 740                         struct dhcpv6_assignment *a;
 741                         list_for_each_entry(a, &iface->ia_assignments, head)
 742                                 if (a != c && a->clid_len == c->clid_len &&
 743                                                 !memcmp(a->clid_data, c->clid_data, a->clid_len))
 744                                         a->reconf_cnt = INT_MAX;
 745                 }
 746         }
 747
 748         while (!list_empty(&reassign)) {
 749                 c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
 750                 list_del(&c->head);
 751                 if (!assign_pd(iface, c)) {
 752                         c->assigned = 0;
 753                         list_add(&c->head, &iface->ia_assignments);
 754                 }
 755         }
 756
 757         dhcpv6_write_statefile();
 758 }
 759
 760 static void valid_until_cb(struct uloop_timeout *event)
 761 {
 762         time_t now = odhcpd_time();
 763         struct interface *iface;
 764         list_for_each_entry(iface, &interfaces, head) {
 765                 if (iface->dhcpv6 != RELAYD_SERVER || iface->ia_assignments.next == NULL)
 766                         continue;
 767
 768                 struct dhcpv6_assignment *a, *n;
 769                 list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
 770                         if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
 771                                 if ((a->length < 128 && a->clid_len > 0) ||
 772                                                 (a->length == 128 && a->clid_len == 0))
 773                                         free_dhcpv6_assignment(a);
 774
 775                         }
 776                 }
 777         }
 778         uloop_timeout_set(event, 1000);
 779 }
 780
 781 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
 782                 const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
 783                 struct interface *iface, bool request)
 784 {
 785         if (buflen < sizeof(*ia) + sizeof(struct dhcpv6_ia_prefix))
 786                 return 0;
 787
 788         struct dhcpv6_ia_hdr out = {ia->type, 0, ia->iaid, 0, 0};
 789         size_t datalen = sizeof(out);
 790         time_t now = odhcpd_time();
 791
 792         if (status) {
 793                 struct __attribute__((packed)) {
 794                         uint16_t type;
 795                         uint16_t len;
 796                         uint16_t value;
 797                 } stat = {htons(DHCPV6_OPT_STATUS), htons(sizeof(stat) - 4),
 798                                 htons(status)};
 799
 800                 memcpy(buf + datalen, &stat, sizeof(stat));
 801                 datalen += sizeof(stat);
 802         } else {
 803                 if (a) {
 804                         uint32_t leasetime;
 805                         if (a->leasetime)
 806                                 leasetime = a->leasetime;
 807                         else
 808                                 leasetime = iface->dhcpv4_leasetime;
 809
 810                         uint32_t pref = leasetime;
 811                         uint32_t valid = leasetime;
 812
 813                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 814                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 815                         size_t m = get_preferred_addr(addrs, addrlen);
 816
 817                         for (size_t i = 0; i < addrlen; ++i) {
 818                                 uint32_t prefix_pref = addrs[i].preferred;
 819                                 uint32_t prefix_valid = addrs[i].valid;
 820
 821                                 if (!valid_addr(&addrs[i], now))
 822                                         continue;
 823
 824                                 if (prefix_pref != UINT32_MAX)
 825                                         prefix_pref -= now;
 826
 827                                 if (prefix_valid != UINT32_MAX)
 828                                         prefix_valid -= now;
 829
 830                                 if (a->length < 128) {
 831                                         struct dhcpv6_ia_prefix p = {
 832                                                 .type = htons(DHCPV6_OPT_IA_PREFIX),
 833                                                 .len = htons(sizeof(p) - 4),
 834                                                 .preferred = htonl(prefix_pref),
 835                                                 .valid = htonl(prefix_valid),
 836                                                 .prefix = (a->managed_size) ? addrs[i].prefix : a->length,
 837                                                 .addr = addrs[i].addr.in6,
 838                                         };
 839                                         p.addr.s6_addr32[1] |= htonl(a->assigned);
 840                                         p.addr.s6_addr32[2] = p.addr.s6_addr32[3] = 0;
 841
 842                                         size_t entrlen = sizeof(p) - 4;
 843
 844                                         if (datalen + entrlen + 4 > buflen ||
 845                                                         (a->assigned == 0 && a->managed_size == 0) ||
 846                                                         !valid_prefix_length(a, addrs[i].prefix))
 847                                                 continue;
 848
 849                                         memcpy(buf + datalen, &p, sizeof(p));
 850                                         datalen += entrlen + 4;
 851                                 } else {
 852                                         struct dhcpv6_ia_addr n = {
 853                                                 .type = htons(DHCPV6_OPT_IA_ADDR),
 854                                                 .len = htons(sizeof(n) - 4),
 855                                                 .addr = addrs[i].addr.in6,
 856                                                 .preferred = htonl(prefix_pref),
 857                                                 .valid = htonl(prefix_valid)
 858                                         };
 859                                         n.addr.s6_addr32[3] = htonl(a->assigned);
 860                                         size_t entrlen = sizeof(n) - 4;
 861
 862                                         if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) ||
 863                                                         a->assigned == 0 ||
 864                                                         datalen + entrlen + 4 > buflen)
 865                                                 continue;
 866
 867                                         memcpy(buf + datalen, &n, sizeof(n));
 868                                         datalen += entrlen + 4;
 869                                 }
 870
 871                                 /* Calculate T1 / T2 based on non-deprecated addresses */
 872                                 if (prefix_pref > 0) {
 873                                         if (prefix_pref < pref)
 874                                                 pref = prefix_pref;
 875
 876                                         if (prefix_valid < valid)
 877                                                 valid = prefix_valid;
 878                                 }
 879                         }
 880
 881                         if (!INFINITE_VALID(a->valid_until))
 882                                 /* UINT32_MAX is considered as infinite leasetime */
 883                                 a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
 884
 885                         out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
 886                         out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 887
 888                         if (!out.t1)
 889                                 out.t1 = htonl(1);
 890
 891                         if (!out.t2)
 892                                 out.t2 = htonl(1);
 893                 }
 894
 895                 if (!request) {
 896                         uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
 897                         uint16_t otype, olen;
 898                         dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
 899                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
 900                                 struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
 901                                 if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
 902                                                 (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
 903                                         continue;
 904
 905                                 bool found = false;
 906                                 if (a) {
 907                                         struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->ia_addr;
 908                                         size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->ia_addr_len;
 909
 910                                         for (size_t i = 0; i < addrlen; ++i) {
 911                                                 if (!valid_addr(&addrs[i], now))
 912                                                         continue;
 913
 914                                                 struct in6_addr addr = addrs[i].addr.in6;
 915                                                 if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
 916                                                         addr.s6_addr32[1] |= htonl(a->assigned);
 917                                                         addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 918
 919                                                         if (!memcmp(&p->addr, &addr, sizeof(addr)) &&
 920                                                                         p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 921                                                                 found = true;
 922                                                 } else {
 923                                                         addr.s6_addr32[3] = htonl(a->assigned);
 924
 925                                                         if (!memcmp(&n->addr, &addr, sizeof(addr)))
 926                                                                 found = true;
 927                                                 }
 928                                         }
 929                                 }
 930
 931                                 if (!found) {
 932                                         if (otype == DHCPV6_OPT_IA_PREFIX) {
 933                                                 struct dhcpv6_ia_prefix inv = {
 934                                                         .type = htons(DHCPV6_OPT_IA_PREFIX),
 935                                                         .len = htons(sizeof(inv) - 4),
 936                                                         .preferred = 0,
 937                                                         .valid = 0,
 938                                                         .prefix = p->prefix,
 939                                                         .addr = p->addr
 940                                                 };
 941
 942                                                 if (datalen + sizeof(inv) > buflen)
 943                                                         continue;
 944
 945                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 946                                                 datalen += sizeof(inv);
 947                                         } else {
 948                                                 struct dhcpv6_ia_addr inv = {
 949                                                         .type = htons(DHCPV6_OPT_IA_ADDR),
 950                                                         .len = htons(sizeof(inv) - 4),
 951                                                         .addr = n->addr,
 952                                                         .preferred = 0,
 953                                                         .valid = 0
 954                                                 };
 955
 956                                                 if (datalen + sizeof(inv) > buflen)
 957                                                         continue;
 958
 959                                                 memcpy(buf + datalen, &inv, sizeof(inv));
 960                                                 datalen += sizeof(inv);
 961                                         }
 962                                 }
 963                         }
 964                 }
 965         }
 966
 967         out.len = htons(datalen - 4);
 968         memcpy(buf, &out, sizeof(out));
 969         return datalen;
 970 }
 971
 972 struct log_ctxt {
 973         char *buf;
 974         int buf_len;
 975         int buf_idx;
 976 };
 977
 978 static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32_t pref,
 979                                 _unused uint32_t valid, void *arg)
 980 {
 981         struct log_ctxt *ctxt = (struct log_ctxt *)arg;
 982         char addrbuf[INET6_ADDRSTRLEN];
 983
 984         inet_ntop(AF_INET6, addr, addrbuf, sizeof(addrbuf));
 985         ctxt->buf_idx += snprintf(ctxt->buf + ctxt->buf_idx, ctxt->buf_len - ctxt->buf_idx,
 986                                         "%s/%d ", addrbuf, prefix);
 987 }
 988
 989 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
 990                 const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
 991 {
 992         const char *type = "UNKNOWN";
 993         const char *status = "UNKNOWN";
 994
 995         if (msgtype == DHCPV6_MSG_RENEW)
 996                 return;
 997
 998         switch (msgtype) {
 999         case DHCPV6_MSG_SOLICIT:
1000                 type = "SOLICIT";
1001                 break;
1002         case DHCPV6_MSG_REQUEST:
1003                 type = "REQUEST";
1004                 break;
1005         case DHCPV6_MSG_CONFIRM:
1006                 type = "CONFIRM";
1007                 break;
1008         case DHCPV6_MSG_RENEW:
1009                 type = "RENEW";
1010                 break;
1011         case DHCPV6_MSG_REBIND:
1012                 type = "REBIND";
1013                 break;
1014         case DHCPV6_MSG_RELEASE:
1015                 type = "RELEASE";
1016                 break;
1017         case DHCPV6_MSG_DECLINE:
1018                 type = "DECLINE";
1019                 break;
1020         }
1021
1022         switch (code) {
1023         case DHCPV6_STATUS_OK:
1024                 status = "ok";
1025                 break;
1026         case DHCPV6_STATUS_NOADDRSAVAIL:
1027                 status = "no addresses available";
1028                 break;
1029         case DHCPV6_STATUS_NOBINDING:
1030                 status = "no binding";
1031                 break;
1032         case DHCPV6_STATUS_NOTONLINK:
1033                 status = "not on-link";
1034                 break;
1035         case DHCPV6_STATUS_NOPREFIXAVAIL:
1036                 status = "no prefix available";
1037                 break;
1038         }
1039
1040         char leasebuf[256] = "";
1041
1042         if (a) {
1043                 struct log_ctxt ctxt = {.buf = leasebuf,
1044                                         .buf_len = sizeof(leasebuf),
1045                                         .buf_idx = 0 };
1046
1047                 dhcpv6_enum_ia_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
1048         }
1049
1050         syslog(LOG_WARNING, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
1051                         duidbuf, iface->ifname, status, leasebuf);
1052 }
1053
1054 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
1055                 const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
1056 {
1057         time_t now = odhcpd_time();
1058         size_t response_len = 0;
1059         const struct dhcpv6_client_header *hdr = data;
1060         uint8_t *start = (uint8_t*)&hdr[1], *odata;
1061         uint16_t otype, olen;
1062         /* Find and parse client-id and hostname */
1063         bool accept_reconf = false;
1064         uint8_t *clid_data = NULL, clid_len = 0, mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1065         char hostname[256];
1066         size_t hostname_len = 0;
1067         bool notonlink = false;
1068         char duidbuf[261];
1069
1070         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1071                 if (otype == DHCPV6_OPT_CLIENTID) {
1072                         clid_data = odata;
1073                         clid_len = olen;
1074
1075                         if (olen == 14 && odata[0] == 0 && odata[1] == 1)
1076                                 memcpy(mac, &odata[8], sizeof(mac));
1077                         else if (olen == 10 && odata[0] == 0 && odata[1] == 3)
1078                                 memcpy(mac, &odata[4], sizeof(mac));
1079
1080                         if (olen <= 130)
1081                                 odhcpd_hexlify(duidbuf, odata, olen);
1082                 } else if (otype == DHCPV6_OPT_FQDN && olen >= 2 && olen <= 255) {
1083                         uint8_t fqdn_buf[256];
1084                         memcpy(fqdn_buf, odata, olen);
1085                         fqdn_buf[olen++] = 0;
1086
1087                         if (dn_expand(&fqdn_buf[1], &fqdn_buf[olen], &fqdn_buf[1], hostname, sizeof(hostname)) > 0)
1088                                 hostname_len = strcspn(hostname, ".");
1089                 } else if (otype == DHCPV6_OPT_RECONF_ACCEPT)
1090                         accept_reconf = true;
1091         }
1092
1093         if (!clid_data || !clid_len || clid_len > 130)
1094                 goto out;
1095
1096         struct dhcpv6_assignment *first = NULL;
1097         dhcpv6_for_each_option(start, end, otype, olen, odata) {
1098                 bool is_pd = (otype == DHCPV6_OPT_IA_PD);
1099                 bool is_na = (otype == DHCPV6_OPT_IA_NA);
1100                 bool ia_addr_present = false;
1101                 if (!is_pd && !is_na)
1102                         continue;
1103
1104                 struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
1105                 size_t ia_response_len = 0;
1106                 uint8_t reqlen = (is_pd) ? 62 : 128;
1107                 uint32_t reqhint = 0;
1108
1109                 /* Parse request hint for IA-PD */
1110                 if (is_pd) {
1111                         uint8_t *sdata;
1112                         uint16_t stype, slen;
1113                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1114                                 if (stype != DHCPV6_OPT_IA_PREFIX || slen < sizeof(struct dhcpv6_ia_prefix) - 4)
1115                                         continue;
1116
1117                                 struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
1118                                 if (p->prefix) {
1119                                         reqlen = p->prefix;
1120                                         reqhint = ntohl(p->addr.s6_addr32[1]);
1121                                         if (reqlen > 32 && reqlen <= 64)
1122                                                 reqhint &= (1U << (64 - reqlen)) - 1;
1123                                 }
1124                         }
1125
1126                         if (reqlen > 64)
1127                                 reqlen = 64;
1128                 } else if (is_na) {
1129                         uint8_t *sdata;
1130                         uint16_t stype, slen;
1131                         dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
1132                                 if (stype != DHCPV6_OPT_IA_ADDR || slen < sizeof(struct dhcpv6_ia_addr) - 4)
1133                                         continue;
1134
1135                                 ia_addr_present = true;
1136                         }
1137                 }
1138
1139                 /* Find assignment */
1140                 struct dhcpv6_assignment *c, *a = NULL;
1141                 list_for_each_entry(c, &iface->ia_assignments, head) {
1142                         if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
1143                                         (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
1144                                                 && !memcmp(c->mac, mac, sizeof(mac)))) &&
1145                                         (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
1146                                         ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
1147                                 a = c;
1148
1149                                 /* Reset state */
1150                                 if (a->flags & OAF_BOUND)
1151                                         apply_lease(iface, a, false);
1152
1153                                 memcpy(a->clid_data, clid_data, clid_len);
1154                                 a->clid_len = clid_len;
1155                                 a->iaid = ia->iaid;
1156                                 a->peer = *addr;
1157                                 stop_reconf(a);
1158                                 break;
1159                         }
1160                 }
1161
1162                 /* Generic message handling */
1163                 uint16_t status = DHCPV6_STATUS_OK;
1164                 if (a && a->managed_size < 0)
1165                         return -1;
1166
1167                 if (hdr->msg_type == DHCPV6_MSG_SOLICIT ||
1168                                 hdr->msg_type == DHCPV6_MSG_REQUEST ||
1169                                 (hdr->msg_type == DHCPV6_MSG_REBIND && !a)) {
1170                         bool assigned = !!a;
1171
1172                         if (!a && !iface->no_dynamic_dhcp) {
1173                                 /* Create new binding */
1174                                 a = calloc(1, sizeof(*a) + clid_len);
1175                                 if (a) {
1176                                         a->clid_len = clid_len;
1177                                         a->iaid = ia->iaid;
1178                                         a->length = reqlen;
1179                                         a->peer = *addr;
1180                                         a->assigned = reqhint;
1181                                         /* Set valid time to current time indicating  */
1182                                         /* assignment is not having infinite lifetime */
1183                                         a->valid_until = now;
1184                                         a->iface = iface;
1185
1186                                         if (first)
1187                                                 memcpy(a->key, first->key, sizeof(a->key));
1188                                         else
1189                                                 odhcpd_urandom(a->key, sizeof(a->key));
1190                                         memcpy(a->clid_data, clid_data, clid_len);
1191
1192                                         if (is_pd)
1193                                                 while (!(assigned = assign_pd(iface, a)) &&
1194                                                                 !a->managed_size && ++a->length <= 64);
1195                                         else
1196                                                 assigned = assign_na(iface, a);
1197
1198                                         if (a->managed_size && !assigned)
1199                                                 return -1;
1200                                 }
1201                         }
1202
1203                         if (!assigned || iface->ia_addr_len == 0)
1204                                 /* Set error status */
1205                                 status = (is_pd) ? DHCPV6_STATUS_NOPREFIXAVAIL : DHCPV6_STATUS_NOADDRSAVAIL;
1206                         else if (assigned && !first && hdr->msg_type != DHCPV6_MSG_REBIND) {
1207                                 size_t handshake_len = 4;
1208                                 buf[0] = 0;
1209                                 buf[1] = DHCPV6_OPT_RECONF_ACCEPT;
1210                                 buf[2] = 0;
1211                                 buf[3] = 0;
1212
1213                                 if (hdr->msg_type == DHCPV6_MSG_REQUEST) {
1214                                         struct dhcpv6_auth_reconfigure auth = {
1215                                                 htons(DHCPV6_OPT_AUTH),
1216                                                 htons(sizeof(auth) - 4),
1217                                                 3, 1, 0,
1218                                                 {htonl(time(NULL)), htonl(++serial)},
1219                                                 1,
1220                                                 {0}
1221                                         };
1222                                         memcpy(auth.key, a->key, sizeof(a->key));
1223                                         memcpy(buf + handshake_len, &auth, sizeof(auth));
1224                                         handshake_len += sizeof(auth);
1225                                 }
1226
1227                                 buf += handshake_len;
1228                                 buflen -= handshake_len;
1229                                 response_len += handshake_len;
1230
1231                                 first = a;
1232                         }
1233
1234                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface,
1235                                                         hdr->msg_type == DHCPV6_MSG_REBIND ? false : true);
1236
1237                         /* Was only a solicitation: mark binding for removal */
1238                         if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
1239                                 a->flags &= ~OAF_BOUND;
1240
1241                                 if (!(a->flags & OAF_STATIC))
1242                                         a->valid_until = now;
1243                         } else if (assigned &&
1244                                         (hdr->msg_type == DHCPV6_MSG_REQUEST ||
1245                                          hdr->msg_type == DHCPV6_MSG_REBIND)) {
1246                                 if (hostname_len > 0) {
1247                                         a->hostname = realloc(a->hostname, hostname_len + 1);
1248                                         if (a->hostname) {
1249                                                 memcpy(a->hostname, hostname, hostname_len);
1250                                                 a->hostname[hostname_len] = 0;
1251                                         }
1252                                 }
1253                                 a->accept_reconf = accept_reconf;
1254                                 a->flags |= OAF_BOUND;
1255                                 apply_lease(iface, a, true);
1256                         } else if (!assigned && a && a->managed_size == 0) {
1257                                 /* Cleanup failed assignment */
1258                                 free_dhcpv6_assignment(a);
1259                                 a = NULL;
1260                         }
1261                 } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1262                                 hdr->msg_type == DHCPV6_MSG_RELEASE ||
1263                                 hdr->msg_type == DHCPV6_MSG_REBIND ||
1264                                 hdr->msg_type == DHCPV6_MSG_DECLINE) {
1265                         if (!a && hdr->msg_type != DHCPV6_MSG_REBIND) {
1266                                 status = DHCPV6_STATUS_NOBINDING;
1267                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1268                         } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
1269                                         hdr->msg_type == DHCPV6_MSG_REBIND) {
1270                                 ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
1271                                 if (a) {
1272                                         a->flags |= OAF_BOUND;
1273                                         apply_lease(iface, a, true);
1274                                 }
1275                         } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
1276                                 if (!(a->flags & OAF_STATIC))
1277                                         a->valid_until = now - 1;
1278
1279                                 if (a->flags & OAF_BOUND) {
1280                                         apply_lease(iface, a, false);
1281                                         a->flags &= ~OAF_BOUND;
1282                                 }
1283                         } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
1284                                 a->flags &= ~OAF_BOUND;
1285
1286                                 if (!(a->flags & OAF_STATIC)) {
1287                                         a->clid_len = 0;
1288                                         a->valid_until = now + 3600; /* Block address for 1h */
1289                                 }
1290                         }
1291                 } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
1292                         /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
1293                         status = DHCPV6_STATUS_NOTONLINK;
1294                         ia_response_len = append_reply(buf, buflen, status, ia, a, iface, true);
1295                         notonlink = true;
1296                 }
1297
1298                 buf += ia_response_len;
1299                 buflen -= ia_response_len;
1300                 response_len += ia_response_len;
1301                 dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
1302         }
1303
1304         if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
1305                         response_len + 6 < buflen) {
1306                 buf[0] = 0;
1307                 buf[1] = DHCPV6_OPT_STATUS;
1308                 buf[2] = 0;
1309                 buf[3] = 2;
1310                 buf[4] = 0;
1311                 buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
1312                 response_len += 6;
1313         }
1314
1315         dhcpv6_write_statefile();
1316
1317 out:
1318         return response_len;
1319 }