src/libcharon/sa/trap_manager.c

   1 /*
   2  * Copyright (C) 2011-2017 Tobias Brunner
   3  * Copyright (C) 2009 Martin Willi
   4  * HSR Hochschule fuer Technik Rapperswil
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2 of the License, or (at your
   9  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * for more details.
  15  */
  16
  17 #include "trap_manager.h"
  18
  19 #include <daemon.h>
  20 #include <threading/mutex.h>
  21 #include <threading/rwlock.h>
  22 #include <threading/rwlock_condvar.h>
  23 #include <collections/linked_list.h>
  24
  25 #define INSTALL_DISABLED ((u_int)~0)
  26
  27 typedef struct private_trap_manager_t private_trap_manager_t;
  28 typedef struct trap_listener_t trap_listener_t;
  29
  30 /**
  31  * listener to track acquires
  32  */
  33 struct trap_listener_t {
  34
  35         /**
  36          * Implements listener interface
  37          */
  38         listener_t listener;
  39
  40         /**
  41          * points to trap_manager
  42          */
  43         private_trap_manager_t *traps;
  44 };
  45
  46 /**
  47  * Private data of an trap_manager_t object.
  48  */
  49 struct private_trap_manager_t {
  50
  51         /**
  52          * Public trap_manager_t interface.
  53          */
  54         trap_manager_t public;
  55
  56         /**
  57          * Installed traps, as entry_t
  58          */
  59         linked_list_t *traps;
  60
  61         /**
  62          * read write lock for traps list
  63          */
  64         rwlock_t *lock;
  65
  66         /**
  67          * listener to track acquiring IKE_SAs
  68          */
  69         trap_listener_t listener;
  70
  71         /**
  72          * list of acquires we currently handle
  73          */
  74         linked_list_t *acquires;
  75
  76         /**
  77          * mutex for list of acquires
  78          */
  79         mutex_t *mutex;
  80
  81         /**
  82          * number of threads currently installing trap policies, or INSTALL_DISABLED
  83          */
  84         u_int installing;
  85
  86         /**
  87          * condvar to signal trap policy installation
  88          */
  89         rwlock_condvar_t *condvar;
  90
  91         /**
  92          * Whether to ignore traffic selectors from acquires
  93          */
  94         bool ignore_acquire_ts;
  95 };
  96
  97 /**
  98  * A installed trap entry
  99  */
 100 typedef struct {
 101         /** name of the trapped CHILD_SA */
 102         char *name;
 103         /** ref to peer_cfg to initiate */
 104         peer_cfg_t *peer_cfg;
 105         /** ref to instantiated CHILD_SA (i.e the trap policy) */
 106         child_sa_t *child_sa;
 107         /** TRUE in case of wildcard Transport Mode SA */
 108         bool wildcard;
 109 } entry_t;
 110
 111 /**
 112  * A handled acquire
 113  */
 114 typedef struct {
 115         /** pending IKE_SA connecting upon acquire */
 116         ike_sa_t *ike_sa;
 117         /** reqid of pending trap policy */
 118         uint32_t reqid;
 119         /** destination address (wildcard case) */
 120         host_t *dst;
 121 } acquire_t;
 122
 123 /**
 124  * actually uninstall and destroy an installed entry
 125  */
 126 static void destroy_entry(entry_t *this)
 127 {
 128         this->child_sa->destroy(this->child_sa);
 129         this->peer_cfg->destroy(this->peer_cfg);
 130         free(this->name);
 131         free(this);
 132 }
 133
 134 /**
 135  * destroy a cached acquire entry
 136  */
 137 static void destroy_acquire(acquire_t *this)
 138 {
 139         DESTROY_IF(this->dst);
 140         free(this);
 141 }
 142
 143 CALLBACK(acquire_by_reqid, bool,
 144         acquire_t *this, va_list args)
 145 {
 146         uint32_t reqid;
 147
 148         VA_ARGS_VGET(args, reqid);
 149         return this->reqid == reqid;
 150 }
 151
 152 CALLBACK(acquire_by_dst, bool,
 153         acquire_t *this, va_list args)
 154 {
 155         host_t *dst;
 156
 157         VA_ARGS_VGET(args, dst);
 158         return this->dst && this->dst->ip_equals(this->dst, dst);
 159 }
 160
 161 /**
 162  * Check if any remote TS are dynamic
 163  */
 164 static bool dynamic_remote_ts(child_cfg_t *child)
 165 {
 166         enumerator_t *enumerator;
 167         linked_list_t *other_ts;
 168         traffic_selector_t *ts;
 169         bool found = FALSE;
 170
 171         other_ts = child->get_traffic_selectors(child, FALSE, NULL, NULL, FALSE);
 172         enumerator = other_ts->create_enumerator(other_ts);
 173         while (enumerator->enumerate(enumerator, &ts))
 174         {
 175                 if (ts->is_dynamic(ts))
 176                 {
 177                         found = TRUE;
 178                         break;
 179                 }
 180         }
 181         enumerator->destroy(enumerator);
 182         other_ts->destroy_offset(other_ts, offsetof(traffic_selector_t, destroy));
 183         return found;
 184 }
 185
 186 METHOD(trap_manager_t, install, bool,
 187         private_trap_manager_t *this, peer_cfg_t *peer, child_cfg_t *child)
 188 {
 189         entry_t *entry, *found = NULL;
 190         ike_cfg_t *ike_cfg;
 191         child_sa_t *child_sa;
 192         host_t *me, *other;
 193         linked_list_t *my_ts, *other_ts, *list;
 194         enumerator_t *enumerator;
 195         status_t status;
 196         linked_list_t *proposals;
 197         proposal_t *proposal;
 198         protocol_id_t proto = PROTO_ESP;
 199         bool result = FALSE, wildcard = FALSE;
 200
 201         /* try to resolve addresses */
 202         ike_cfg = peer->get_ike_cfg(peer);
 203         other = ike_cfg->resolve_other(ike_cfg, AF_UNSPEC);
 204         if (other && other->is_anyaddr(other) &&
 205                 child->get_mode(child) == MODE_TRANSPORT)
 206         {
 207                 /* allow wildcard for Transport Mode SAs */
 208                 me = host_create_any(other->get_family(other));
 209                 wildcard = TRUE;
 210         }
 211         else if (other && other->is_anyaddr(other))
 212         {
 213                 other->destroy(other);
 214                 DBG1(DBG_CFG, "installing trap failed, remote address unknown");
 215                 return FALSE;
 216         }
 217         else
 218         {       /* depending on the traffic selectors we don't really need a remote
 219                  * host yet, but we might fail later if no IP can be resolved */
 220                 if (!other && dynamic_remote_ts(child))
 221                 {       /* with dynamic TS we do need a host, otherwise 0.0.0.0/0 is used,
 222                          * which is probably not what users expect*/
 223                         DBG1(DBG_CFG, "installing trap failed, remote address unknown with "
 224                                  "dynamic traffic selector");
 225                         return FALSE;
 226                 }
 227                 me = ike_cfg->resolve_me(ike_cfg, other ? other->get_family(other)
 228                                                                                                 : AF_UNSPEC);
 229                 if (!other)
 230                 {
 231                         other = host_create_any(me ? me->get_family(me) : AF_INET);
 232                 }
 233                 other->set_port(other, ike_cfg->get_other_port(ike_cfg));
 234                 if ((!me || me->is_anyaddr(me)) && !other->is_anyaddr(other))
 235                 {
 236                         DESTROY_IF(me);
 237                         me = charon->kernel->get_source_addr(charon->kernel, other, NULL);
 238                 }
 239                 if (!me)
 240                 {
 241                         me = host_create_any(other->get_family(other));
 242                 }
 243                 me->set_port(me, ike_cfg->get_my_port(ike_cfg));
 244         }
 245
 246         this->lock->write_lock(this->lock);
 247         if (this->installing == INSTALL_DISABLED)
 248         {       /* flush() has been called */
 249                 this->lock->unlock(this->lock);
 250                 other->destroy(other);
 251                 me->destroy(me);
 252                 return FALSE;
 253         }
 254         enumerator = this->traps->create_enumerator(this->traps);
 255         while (enumerator->enumerate(enumerator, &entry))
 256         {
 257                 if (streq(entry->name, child->get_name(child)) &&
 258                         streq(entry->peer_cfg->get_name(entry->peer_cfg),
 259                                   peer->get_name(peer)))
 260                 {
 261                         found = entry;
 262                         if (entry->child_sa)
 263                         {       /* replace it with an updated version, if already installed */
 264                                 this->traps->remove_at(this->traps, enumerator);
 265                         }
 266                         break;
 267                 }
 268         }
 269         enumerator->destroy(enumerator);
 270
 271         if (found)
 272         {
 273                 if (!found->child_sa)
 274                 {
 275                         DBG1(DBG_CFG, "CHILD_SA '%s' is already being routed", found->name);
 276                         this->lock->unlock(this->lock);
 277                         other->destroy(other);
 278                         me->destroy(me);
 279                         return FALSE;
 280                 }
 281                 /* config might have changed so update everything */
 282                 DBG1(DBG_CFG, "updating already routed CHILD_SA '%s'", found->name);
 283         }
 284
 285         INIT(entry,
 286                 .name = strdup(child->get_name(child)),
 287                 .peer_cfg = peer->get_ref(peer),
 288                 .wildcard = wildcard,
 289         );
 290         this->traps->insert_first(this->traps, entry);
 291         this->installing++;
 292         /* don't hold lock while creating CHILD_SA and installing policies */
 293         this->lock->unlock(this->lock);
 294
 295         /* create and route CHILD_SA */
 296         child_sa = child_sa_create(me, other, child, 0, FALSE, 0, 0, 0, 0);
 297
 298         list = linked_list_create_with_items(me, NULL);
 299         my_ts = child->get_traffic_selectors(child, TRUE, NULL, list, FALSE);
 300         list->destroy_offset(list, offsetof(host_t, destroy));
 301
 302         list = linked_list_create_with_items(other, NULL);
 303         other_ts = child->get_traffic_selectors(child, FALSE, NULL, list, FALSE);
 304         list->destroy_offset(list, offsetof(host_t, destroy));
 305
 306         /* We don't know the finally negotiated protocol (ESP|AH), we install
 307          * the SA with the protocol of the first proposal */
 308         proposals = child->get_proposals(child, TRUE);
 309         if (proposals->get_first(proposals, (void**)&proposal) == SUCCESS)
 310         {
 311                 proto = proposal->get_protocol(proposal);
 312         }
 313         proposals->destroy_offset(proposals, offsetof(proposal_t, destroy));
 314         child_sa->set_protocol(child_sa, proto);
 315         child_sa->set_mode(child_sa, child->get_mode(child));
 316         child_sa->set_policies(child_sa, my_ts, other_ts);
 317         status = child_sa->install_policies(child_sa);
 318         my_ts->destroy_offset(my_ts, offsetof(traffic_selector_t, destroy));
 319         other_ts->destroy_offset(other_ts, offsetof(traffic_selector_t, destroy));
 320         if (status != SUCCESS)
 321         {
 322                 DBG1(DBG_CFG, "installing trap failed");
 323                 this->lock->write_lock(this->lock);
 324                 this->traps->remove(this->traps, entry, NULL);
 325                 this->lock->unlock(this->lock);
 326                 entry->child_sa = child_sa;
 327                 destroy_entry(entry);
 328         }
 329         else
 330         {
 331                 this->lock->write_lock(this->lock);
 332                 entry->child_sa = child_sa;
 333                 this->lock->unlock(this->lock);
 334                 result = TRUE;
 335         }
 336         if (found)
 337         {
 338                 destroy_entry(found);
 339         }
 340         this->lock->write_lock(this->lock);
 341         /* do this at the end, so entries created temporarily are also destroyed */
 342         this->installing--;
 343         this->condvar->signal(this->condvar);
 344         this->lock->unlock(this->lock);
 345         return result;
 346 }
 347
 348 METHOD(trap_manager_t, uninstall, bool,
 349         private_trap_manager_t *this, char *peer, char *child)
 350 {
 351         enumerator_t *enumerator;
 352         entry_t *entry, *found = NULL;
 353
 354         this->lock->write_lock(this->lock);
 355         while (this->installing)
 356         {
 357                 this->condvar->wait(this->condvar, this->lock);
 358         }
 359         enumerator = this->traps->create_enumerator(this->traps);
 360         while (enumerator->enumerate(enumerator, &entry))
 361         {
 362                 if (streq(entry->name, child) &&
 363                    (!peer || streq(peer, entry->peer_cfg->get_name(entry->peer_cfg))))
 364                 {
 365                         this->traps->remove_at(this->traps, enumerator);
 366                         found = entry;
 367                         break;
 368                 }
 369         }
 370         enumerator->destroy(enumerator);
 371         this->lock->unlock(this->lock);
 372
 373         if (!found)
 374         {
 375                 return FALSE;
 376         }
 377         destroy_entry(found);
 378         return TRUE;
 379 }
 380
 381 CALLBACK(trap_filter, bool,
 382         rwlock_t *lock, enumerator_t *orig, va_list args)
 383 {
 384         entry_t *entry;
 385         peer_cfg_t **peer_cfg;
 386         child_sa_t **child_sa;
 387
 388         VA_ARGS_VGET(args, peer_cfg, child_sa);
 389
 390         while (orig->enumerate(orig, &entry))
 391         {
 392                 if (!entry->child_sa)
 393                 {       /* skip entries that are currently being installed */
 394                         continue;
 395                 }
 396                 if (peer_cfg)
 397                 {
 398                         *peer_cfg = entry->peer_cfg;
 399                 }
 400                 if (child_sa)
 401                 {
 402                         *child_sa = entry->child_sa;
 403                 }
 404                 return TRUE;
 405         }
 406         return FALSE;
 407 }
 408
 409 METHOD(trap_manager_t, create_enumerator, enumerator_t*,
 410         private_trap_manager_t *this)
 411 {
 412         this->lock->read_lock(this->lock);
 413         return enumerator_create_filter(this->traps->create_enumerator(this->traps),
 414                                                                         trap_filter, this->lock,
 415                                                                         (void*)this->lock->unlock);
 416 }
 417
 418 METHOD(trap_manager_t, acquire, void,
 419         private_trap_manager_t *this, uint32_t reqid,
 420         traffic_selector_t *src, traffic_selector_t *dst)
 421 {
 422         enumerator_t *enumerator;
 423         entry_t *entry, *found = NULL;
 424         acquire_t *acquire;
 425         peer_cfg_t *peer;
 426         child_cfg_t *child;
 427         ike_sa_t *ike_sa;
 428         host_t *host;
 429         bool wildcard, ignore = FALSE;
 430
 431         this->lock->read_lock(this->lock);
 432         enumerator = this->traps->create_enumerator(this->traps);
 433         while (enumerator->enumerate(enumerator, &entry))
 434         {
 435                 if (entry->child_sa &&
 436                         entry->child_sa->get_reqid(entry->child_sa) == reqid)
 437                 {
 438                         found = entry;
 439                         break;
 440                 }
 441         }
 442         enumerator->destroy(enumerator);
 443
 444         if (!found)
 445         {
 446                 DBG1(DBG_CFG, "trap not found, unable to acquire reqid %d", reqid);
 447                 this->lock->unlock(this->lock);
 448                 return;
 449         }
 450         reqid = found->child_sa->get_reqid(found->child_sa);
 451         wildcard = found->wildcard;
 452
 453         this->mutex->lock(this->mutex);
 454         if (wildcard)
 455         {       /* for wildcard acquires we check that we don't have a pending acquire
 456                  * with the same peer */
 457                 uint8_t mask;
 458
 459                 dst->to_subnet(dst, &host, &mask);
 460                 if (this->acquires->find_first(this->acquires, acquire_by_dst,
 461                                                                           (void**)&acquire, host))
 462                 {
 463                         host->destroy(host);
 464                         ignore = TRUE;
 465                 }
 466                 else
 467                 {
 468                         INIT(acquire,
 469                                 .dst = host,
 470                                 .reqid = reqid,
 471                         );
 472                         this->acquires->insert_last(this->acquires, acquire);
 473                 }
 474         }
 475         else
 476         {
 477                 if (this->acquires->find_first(this->acquires, acquire_by_reqid,
 478                                                                           (void**)&acquire, reqid))
 479                 {
 480                         ignore = TRUE;
 481                 }
 482                 else
 483                 {
 484                         INIT(acquire,
 485                                 .reqid = reqid,
 486                         );
 487                         this->acquires->insert_last(this->acquires, acquire);
 488                 }
 489         }
 490         this->mutex->unlock(this->mutex);
 491         if (ignore)
 492         {
 493                 DBG1(DBG_CFG, "ignoring acquire, connection attempt pending");
 494                 this->lock->unlock(this->lock);
 495                 return;
 496         }
 497         peer = found->peer_cfg->get_ref(found->peer_cfg);
 498         child = found->child_sa->get_config(found->child_sa);
 499         child = child->get_ref(child);
 500         /* don't hold the lock while checking out the IKE_SA */
 501         this->lock->unlock(this->lock);
 502
 503         if (wildcard)
 504         {       /* the peer config would match IKE_SAs with other peers */
 505                 ike_sa = charon->ike_sa_manager->checkout_new(charon->ike_sa_manager,
 506                                                                                         peer->get_ike_version(peer), TRUE);
 507                 if (ike_sa)
 508                 {
 509                         ike_cfg_t *ike_cfg;
 510                         uint16_t port;
 511                         uint8_t mask;
 512
 513                         ike_sa->set_peer_cfg(ike_sa, peer);
 514                         ike_cfg = ike_sa->get_ike_cfg(ike_sa);
 515
 516                         port = ike_cfg->get_other_port(ike_cfg);
 517                         dst->to_subnet(dst, &host, &mask);
 518                         host->set_port(host, port);
 519                         ike_sa->set_other_host(ike_sa, host);
 520
 521                         port = ike_cfg->get_my_port(ike_cfg);
 522                         src->to_subnet(src, &host, &mask);
 523                         host->set_port(host, port);
 524                         ike_sa->set_my_host(ike_sa, host);
 525
 526                         charon->bus->set_sa(charon->bus, ike_sa);
 527                 }
 528         }
 529         else
 530         {
 531                 ike_sa = charon->ike_sa_manager->checkout_by_config(
 532                                                                                         charon->ike_sa_manager, peer);
 533         }
 534         if (ike_sa)
 535         {
 536                 if (ike_sa->get_peer_cfg(ike_sa) == NULL)
 537                 {
 538                         ike_sa->set_peer_cfg(ike_sa, peer);
 539                 }
 540                 if (this->ignore_acquire_ts || ike_sa->get_version(ike_sa) == IKEV1)
 541                 {       /* in IKEv1, don't prepend the acquiring packet TS, as we only
 542                          * have a single TS that we can establish in a Quick Mode. */
 543                         src = dst = NULL;
 544                 }
 545
 546                 this->mutex->lock(this->mutex);
 547                 acquire->ike_sa = ike_sa;
 548                 this->mutex->unlock(this->mutex);
 549
 550                 if (ike_sa->initiate(ike_sa, child, reqid, src, dst) != DESTROY_ME)
 551                 {
 552                         charon->ike_sa_manager->checkin(charon->ike_sa_manager, ike_sa);
 553                 }
 554                 else
 555                 {
 556                         charon->ike_sa_manager->checkin_and_destroy(charon->ike_sa_manager,
 557                                                                                                                 ike_sa);
 558                 }
 559         }
 560         else
 561         {
 562                 this->mutex->lock(this->mutex);
 563                 this->acquires->remove(this->acquires, acquire, NULL);
 564                 this->mutex->unlock(this->mutex);
 565                 destroy_acquire(acquire);
 566                 child->destroy(child);
 567         }
 568         peer->destroy(peer);
 569 }
 570
 571 /**
 572  * Complete the acquire, if successful or failed
 573  */
 574 static void complete(private_trap_manager_t *this, ike_sa_t *ike_sa,
 575                                          child_sa_t *child_sa)
 576 {
 577         enumerator_t *enumerator;
 578         acquire_t *acquire;
 579
 580         this->mutex->lock(this->mutex);
 581         enumerator = this->acquires->create_enumerator(this->acquires);
 582         while (enumerator->enumerate(enumerator, &acquire))
 583         {
 584                 if (!acquire->ike_sa || acquire->ike_sa != ike_sa)
 585                 {
 586                         continue;
 587                 }
 588                 if (child_sa)
 589                 {
 590                         if (acquire->dst)
 591                         {
 592                                 /* since every wildcard acquire results in a separate IKE_SA
 593                                  * there is no need to compare the destination address */
 594                         }
 595                         else if (child_sa->get_reqid(child_sa) != acquire->reqid)
 596                         {
 597                                 continue;
 598                         }
 599                 }
 600                 this->acquires->remove_at(this->acquires, enumerator);
 601                 destroy_acquire(acquire);
 602         }
 603         enumerator->destroy(enumerator);
 604         this->mutex->unlock(this->mutex);
 605 }
 606
 607 METHOD(listener_t, ike_state_change, bool,
 608         trap_listener_t *listener, ike_sa_t *ike_sa, ike_sa_state_t state)
 609 {
 610         switch (state)
 611         {
 612                 case IKE_DESTROYING:
 613                         complete(listener->traps, ike_sa, NULL);
 614                         return TRUE;
 615                 default:
 616                         return TRUE;
 617         }
 618 }
 619
 620 METHOD(listener_t, child_state_change, bool,
 621         trap_listener_t *listener, ike_sa_t *ike_sa, child_sa_t *child_sa,
 622         child_sa_state_t state)
 623 {
 624         switch (state)
 625         {
 626                 case CHILD_INSTALLED:
 627                 case CHILD_DESTROYING:
 628                         complete(listener->traps, ike_sa, child_sa);
 629                         return TRUE;
 630                 default:
 631                         return TRUE;
 632         }
 633 }
 634
 635 METHOD(trap_manager_t, flush, void,
 636         private_trap_manager_t *this)
 637 {
 638         this->lock->write_lock(this->lock);
 639         while (this->installing)
 640         {
 641                 this->condvar->wait(this->condvar, this->lock);
 642         }
 643         this->traps->destroy_function(this->traps, (void*)destroy_entry);
 644         this->traps = linked_list_create();
 645         this->installing = INSTALL_DISABLED;
 646         this->lock->unlock(this->lock);
 647 }
 648
 649 METHOD(trap_manager_t, destroy, void,
 650         private_trap_manager_t *this)
 651 {
 652         charon->bus->remove_listener(charon->bus, &this->listener.listener);
 653         this->traps->destroy_function(this->traps, (void*)destroy_entry);
 654         this->acquires->destroy_function(this->acquires, (void*)destroy_acquire);
 655         this->condvar->destroy(this->condvar);
 656         this->mutex->destroy(this->mutex);
 657         this->lock->destroy(this->lock);
 658         free(this);
 659 }
 660
 661 /**
 662  * See header
 663  */
 664 trap_manager_t *trap_manager_create(void)
 665 {
 666         private_trap_manager_t *this;
 667
 668         INIT(this,
 669                 .public = {
 670                         .install = _install,
 671                         .uninstall = _uninstall,
 672                         .create_enumerator = _create_enumerator,
 673                         .acquire = _acquire,
 674                         .flush = _flush,
 675                         .destroy = _destroy,
 676                 },
 677                 .listener = {
 678                         .traps = this,
 679                         .listener = {
 680                                 .ike_state_change = _ike_state_change,
 681                                 .child_state_change = _child_state_change,
 682                         },
 683                 },
 684                 .traps = linked_list_create(),
 685                 .acquires = linked_list_create(),
 686                 .mutex = mutex_create(MUTEX_TYPE_DEFAULT),
 687                 .lock = rwlock_create(RWLOCK_TYPE_DEFAULT),
 688                 .condvar = rwlock_condvar_create(),
 689                 .ignore_acquire_ts = lib->settings->get_bool(lib->settings,
 690                                                                                 "%s.ignore_acquire_ts", FALSE, lib->ns),
 691         );
 692         charon->bus->add_listener(charon->bus, &this->listener.listener);
 693
 694         return &this->public;
 695 }