2 This file is part of GNUnet.
3 (C) 2010,2011 Christian Grothoff (and other contributing authors)
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22 * @file transport/gnunet-service-transport_blacklist.c
23 * @brief blacklisting implementation
24 * @author Christian Grothoff
27 #include "gnunet-service-transport.h"
28 #include "gnunet-service-transport_blacklist.h"
29 #include "gnunet-service-transport_neighbours.h"
30 #include "transport.h"
34 * Size of the blacklist hash map.
36 #define TRANSPORT_BLACKLIST_HT_SIZE 64
40 * Context we use when performing a blacklist check.
42 struct GST_BlacklistCheck;
46 * Information kept for each client registered to perform
52 * This is a linked list.
54 struct Blacklisters *next;
57 * This is a linked list.
59 struct Blacklisters *prev;
62 * Client responsible for this entry.
64 struct GNUNET_SERVER_Client *client;
67 * Blacklist check that we're currently performing (or NULL
68 * if we're performing one that has been cancelled).
70 struct GST_BlacklistCheck *bc;
73 * Set to GNUNET_YES if we're currently waiting for a reply.
75 int waiting_for_reply;
82 * Context we use when performing a blacklist check.
84 struct GST_BlacklistCheck
88 * This is a linked list.
90 struct GST_BlacklistCheck *next;
93 * This is a linked list.
95 struct GST_BlacklistCheck *prev;
100 struct GNUNET_PeerIdentity peer;
103 * Continuation to call with the result.
105 GST_BlacklistTestContinuation cont;
113 * Current transmission request handle for this client, or NULL if no
114 * request is pending.
116 struct GNUNET_SERVER_TransmitHandle *th;
119 * Our current position in the blacklisters list.
121 struct Blacklisters *bl_pos;
124 * Current task performing the check.
126 GNUNET_SCHEDULER_TaskIdentifier task;
132 * Head of DLL of active blacklisting queries.
134 static struct GST_BlacklistCheck *bc_head;
137 * Tail of DLL of active blacklisting queries.
139 static struct GST_BlacklistCheck *bc_tail;
142 * Head of DLL of blacklisting clients.
144 static struct Blacklisters *bl_head;
147 * Tail of DLL of blacklisting clients.
149 static struct Blacklisters *bl_tail;
152 * Hashmap of blacklisted peers. Values are of type 'char *' (transport names),
153 * can be NULL if we have no static blacklist.
155 static struct GNUNET_CONTAINER_MultiHashMap *blacklist;
159 * Perform next action in the blacklist check.
161 * @param cls the 'struct BlacklistCheck*'
165 do_blacklist_check (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
169 * Called whenever a client is disconnected. Frees our
170 * resources associated with that client.
172 * @param cls closure (unused)
173 * @param client identification of the client
176 client_disconnect_notification (void *cls, struct GNUNET_SERVER_Client *client)
178 struct Blacklisters *bl;
179 struct GST_BlacklistCheck *bc;
183 for (bl = bl_head; bl != NULL; bl = bl->next)
185 if (bl->client != client)
187 for (bc = bc_head; bc != NULL; bc = bc->next)
189 if (bc->bl_pos != bl)
191 bc->bl_pos = bl->next;
194 GNUNET_SERVER_notify_transmit_ready_cancel (bc->th);
197 if (bc->task == GNUNET_SCHEDULER_NO_TASK)
198 bc->task = GNUNET_SCHEDULER_add_now (&do_blacklist_check, bc);
201 GNUNET_CONTAINER_DLL_remove (bl_head, bl_tail, bl);
202 GNUNET_SERVER_client_drop (bl->client);
210 * Read the blacklist file, containing transport:peer entries.
211 * Provided the transport is loaded, set up hashmap with these
212 * entries to blacklist peers by transport.
216 read_blacklist_file ()
223 struct GNUNET_PeerIdentity pid;
225 struct GNUNET_CRYPTO_HashAsciiEncoded enc;
226 unsigned int entries_found;
227 char *transport_name;
230 GNUNET_CONFIGURATION_get_value_filename (GST_cfg, "TRANSPORT",
231 "BLACKLIST_FILE", &fn))
233 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_DEBUG,
234 "transport", "BLACKLIST_FILE");
237 if (GNUNET_OK != GNUNET_DISK_file_test (fn))
240 return; /* no blacklist */
242 if (GNUNET_OK != GNUNET_DISK_file_size (fn,
243 &fsize, GNUNET_NO, GNUNET_YES))
245 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
246 _("Could not read blacklist file `%s'\n"), fn);
252 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Blacklist file `%s' is empty.\n",
257 /* FIXME: use mmap */
258 data = GNUNET_malloc_large (fsize);
259 GNUNET_assert (data != NULL);
260 if (fsize != GNUNET_DISK_fn_read (fn, data, fsize))
262 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
263 _("Failed to read blacklist from `%s'\n"), fn);
270 while ((pos < fsize) && isspace ((unsigned char) data[pos]))
272 while ((fsize >= sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded)) &&
274 fsize - sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded)))
277 while ((colon_pos < fsize) && (data[colon_pos] != ':') &&
278 (!isspace ((unsigned char) data[colon_pos])))
280 if (colon_pos >= fsize)
282 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
284 ("Syntax error in blacklist file at offset %llu, giving up!\n"),
285 (unsigned long long) colon_pos);
291 if (isspace ((unsigned char) data[colon_pos]))
293 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
295 ("Syntax error in blacklist file at offset %llu, skipping bytes.\n"),
296 (unsigned long long) colon_pos);
298 while ((pos < fsize) && isspace ((unsigned char) data[pos]))
302 tsize = colon_pos - pos;
303 if ((pos >= fsize) || (pos + tsize >= fsize) ||
306 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
308 ("Syntax error in blacklist file at offset %llu, giving up!\n"),
309 (unsigned long long) colon_pos);
318 transport_name = GNUNET_malloc (tsize + 1);
319 memcpy (transport_name, &data[pos], tsize);
321 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
322 "Read transport name `%s' in blacklist file.\n",
324 memcpy (&enc, &data[pos], sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded));
327 enc.encoding[sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1]))
329 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
331 ("Syntax error in blacklist file at offset %llu, skipping bytes.\n"),
332 (unsigned long long) pos);
334 while ((pos < fsize) && (!isspace ((unsigned char) data[pos])))
336 GNUNET_free_non_null (transport_name);
339 enc.encoding[sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1] = '\0';
341 GNUNET_CRYPTO_hash_from_string ((char *) &enc, &pid.hashPubKey))
343 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
345 ("Syntax error in blacklist file at offset %llu, skipping bytes `%s'.\n"),
346 (unsigned long long) pos, &enc);
351 memcmp (&pid, &GST_my_identity, sizeof (struct GNUNET_PeerIdentity)))
354 GST_blacklist_add_peer (&pid, transport_name);
358 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
359 _("Found myself `%s' in blacklist (useless, ignored)\n"),
363 pos = pos + sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded);
364 GNUNET_free_non_null (transport_name);
365 while ((pos < fsize) && isspace ((unsigned char) data[pos]))
368 GNUNET_STATISTICS_update (GST_stats, "# Transport entries blacklisted",
369 entries_found, GNUNET_NO);
375 * Function to iterate over options in the blacklisting section for a peer.
378 * @param section name of the section
379 * @param option name of the option
380 * @param value value of the option
382 void blacklist_cfg_iter (void *cls, const char *section,
386 struct GNUNET_PeerIdentity peer;
391 if (GNUNET_OK != GNUNET_CRYPTO_hash_from_string2(option,
392 strlen (option), &peer.hashPubKey))
395 if ((NULL == value) || (0 == strcmp(value, "")))
397 /* Blacklist whole peer */
398 GST_blacklist_add_peer (&peer, NULL);
399 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
400 _("Adding blacklisting entry for peer `%s'\n"), GNUNET_i2s (&peer));
404 plugs = GNUNET_strdup (value);
405 for (pos = strtok (plugs, " "); pos != NULL; pos = strtok (NULL, " "))
407 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
408 _("Adding blacklisting entry for peer `%s':`%s'\n"),
409 GNUNET_i2s (&peer), pos);
410 GST_blacklist_add_peer (&peer, pos);
421 * Read blacklist configuration
423 * @param cfg the configuration handle
424 * @param my_id my peer identity
427 read_blacklist_configuration (const struct GNUNET_CONFIGURATION_Handle *cfg,
428 const struct GNUNET_PeerIdentity *my_id)
432 GNUNET_asprintf (&cfg_sect, "transport-blacklist-%s", GNUNET_i2s_full (my_id));
433 GNUNET_CONFIGURATION_iterate_section_values (cfg, cfg_sect, &blacklist_cfg_iter, &res);
434 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
435 "Loaded %u blacklisting entries from configuration\n", res);
436 GNUNET_free (cfg_sect);
440 * Start blacklist subsystem.
442 * @param server server used to accept clients from
443 * @param cfg configuration handle
444 * @param my_id my peer id
447 GST_blacklist_start (struct GNUNET_SERVER_Handle *server,
448 const struct GNUNET_CONFIGURATION_Handle *cfg,
449 const struct GNUNET_PeerIdentity *my_id)
451 GNUNET_assert (NULL != cfg);
452 GNUNET_assert (NULL != my_id);
453 //read_blacklist_file ();
454 read_blacklist_configuration (cfg, my_id);
455 GNUNET_SERVER_disconnect_notify (server, &client_disconnect_notification,
461 * Free the given entry in the blacklist.
464 * @param key host identity (unused)
465 * @param value the blacklist entry
466 * @return GNUNET_OK (continue to iterate)
469 free_blacklist_entry (void *cls, const struct GNUNET_HashCode * key, void *value)
473 GNUNET_free_non_null (be);
479 * Stop blacklist subsystem.
482 GST_blacklist_stop ()
484 if (NULL != blacklist)
486 GNUNET_CONTAINER_multihashmap_iterate (blacklist, &free_blacklist_entry,
488 GNUNET_CONTAINER_multihashmap_destroy (blacklist);
495 * Transmit blacklist query to the client.
497 * @param cls the 'struct GST_BlacklistCheck'
498 * @param size number of bytes allowed
499 * @param buf where to copy the message
500 * @return number of bytes copied to buf
503 transmit_blacklist_message (void *cls, size_t size, void *buf)
505 struct GST_BlacklistCheck *bc = cls;
506 struct Blacklisters *bl;
507 struct BlacklistMessage bm;
512 GNUNET_assert (bc->task == GNUNET_SCHEDULER_NO_TASK);
513 bc->task = GNUNET_SCHEDULER_add_now (&do_blacklist_check, bc);
514 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
515 "Failed to send blacklist test for peer `%s' to client\n",
516 GNUNET_i2s (&bc->peer));
519 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
520 "Sending blacklist test for peer `%s' to client\n",
521 GNUNET_i2s (&bc->peer));
523 bm.header.size = htons (sizeof (struct BlacklistMessage));
524 bm.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_BLACKLIST_QUERY);
525 bm.is_allowed = htonl (0);
527 memcpy (buf, &bm, sizeof (bm));
528 GNUNET_SERVER_receive_done (bl->client, GNUNET_OK);
529 bl->waiting_for_reply = GNUNET_YES;
535 * Perform next action in the blacklist check.
537 * @param cls the 'struct GST_BlacklistCheck*'
541 do_blacklist_check (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
543 struct GST_BlacklistCheck *bc = cls;
544 struct Blacklisters *bl;
546 bc->task = GNUNET_SCHEDULER_NO_TASK;
550 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
551 "No other blacklist clients active, will allow neighbour `%s'\n",
552 GNUNET_i2s (&bc->peer));
553 bc->cont (bc->cont_cls, &bc->peer, GNUNET_OK);
554 GNUNET_CONTAINER_DLL_remove(bc_head, bc_tail, bc);
558 if ((bl->bc != NULL) || (bl->waiting_for_reply != GNUNET_NO))
559 return; /* someone else busy with this client */
562 GNUNET_SERVER_notify_transmit_ready (bl->client,
563 sizeof (struct BlacklistMessage),
564 GNUNET_TIME_UNIT_FOREVER_REL,
565 &transmit_blacklist_message, bc);
570 * Got the result about an existing connection from a new blacklister.
571 * Shutdown the neighbour if necessary.
574 * @param peer the neighbour that was investigated
575 * @param allowed GNUNET_OK if we can keep it,
576 * GNUNET_NO if we must shutdown the connection
579 confirm_or_drop_neighbour (void *cls, const struct GNUNET_PeerIdentity *peer,
582 if (GNUNET_OK == allowed)
583 return; /* we're done */
584 GNUNET_STATISTICS_update (GST_stats,
585 gettext_noop ("# disconnects due to blacklist"), 1,
587 GST_neighbours_force_disconnect (peer);
592 * Closure for 'test_connection_ok'.
594 struct TestConnectionContext
597 * Is this the first neighbour we're checking?
602 * Handle to the blacklisting client we need to ask.
604 struct Blacklisters *bl;
609 * Test if an existing connection is still acceptable given a new
610 * blacklisting client.
612 * @param cls the 'struct TestConnectionContest'
613 * @param neighbour neighbour's identity
614 * @param address the address
615 * @param bandwidth_in inbound quota in NBO
616 * @param bandwidth_out outbound quota in NBO
619 test_connection_ok (void *cls, const struct GNUNET_PeerIdentity *neighbour,
620 const struct GNUNET_HELLO_Address *address,
621 struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
622 struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out)
624 struct TestConnectionContext *tcc = cls;
625 struct GST_BlacklistCheck *bc;
627 bc = GNUNET_malloc (sizeof (struct GST_BlacklistCheck));
628 GNUNET_CONTAINER_DLL_insert (bc_head, bc_tail, bc);
629 bc->peer = *neighbour;
630 bc->cont = &confirm_or_drop_neighbour;
632 bc->bl_pos = tcc->bl;
633 if (GNUNET_YES == tcc->first)
635 /* all would wait for the same client, no need to
636 * create more than just the first task right now */
637 bc->task = GNUNET_SCHEDULER_add_now (&do_blacklist_check, bc);
638 tcc->first = GNUNET_NO;
644 * Initialize a blacklisting client. We got a blacklist-init
645 * message from this client, add him to the list of clients
646 * to query for blacklisting.
649 * @param client the client
650 * @param message the blacklist-init message that was sent
653 GST_blacklist_handle_init (void *cls, struct GNUNET_SERVER_Client *client,
654 const struct GNUNET_MessageHeader *message)
656 struct Blacklisters *bl;
657 struct TestConnectionContext tcc;
662 if (bl->client == client)
665 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
670 GNUNET_SERVER_client_mark_monitor (client);
671 bl = GNUNET_malloc (sizeof (struct Blacklisters));
673 GNUNET_SERVER_client_keep (client);
674 GNUNET_CONTAINER_DLL_insert_after (bl_head, bl_tail, bl_tail, bl);
676 /* confirm that all existing connections are OK! */
678 tcc.first = GNUNET_YES;
679 GST_neighbours_iterate (&test_connection_ok, &tcc);
684 * A blacklisting client has sent us reply. Process it.
687 * @param client the client
688 * @param message the blacklist-init message that was sent
691 GST_blacklist_handle_reply (void *cls, struct GNUNET_SERVER_Client *client,
692 const struct GNUNET_MessageHeader *message)
694 const struct BlacklistMessage *msg =
695 (const struct BlacklistMessage *) message;
696 struct Blacklisters *bl;
697 struct GST_BlacklistCheck *bc;
700 while ((bl != NULL) && (bl->client != client))
704 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Blacklist client disconnected\n");
705 /* FIXME: other error handling here!? */
706 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
711 bl->waiting_for_reply = GNUNET_NO;
714 /* only run this if the blacklist check has not been
715 * cancelled in the meantime... */
716 if (ntohl (msg->is_allowed) == GNUNET_SYSERR)
718 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
719 "Blacklist check failed, peer not allowed\n");
720 bc->cont (bc->cont_cls, &bc->peer, GNUNET_NO);
721 GNUNET_CONTAINER_DLL_remove (bc_head, bc_tail, bc);
726 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
727 "Blacklist check succeeded, continuing with checks\n");
728 bc->bl_pos = bc->bl_pos->next;
729 bc->task = GNUNET_SCHEDULER_add_now (&do_blacklist_check, bc);
732 /* check if any other bc's are waiting for this blacklister */
734 for (bc = bc_head; bc != NULL; bc = bc->next)
735 if ((bc->bl_pos == bl) && (GNUNET_SCHEDULER_NO_TASK == bc->task))
737 bc->task = GNUNET_SCHEDULER_add_now (&do_blacklist_check, bc);
744 * Add the given peer to the blacklist (for the given transport).
746 * @param peer peer to blacklist
747 * @param transport_name transport to blacklist for this peer, NULL for all
750 GST_blacklist_add_peer (const struct GNUNET_PeerIdentity *peer,
751 const char *transport_name)
753 char * transport = NULL;
755 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
756 "Adding peer `%s' with plugin `%s' to blacklist\n",
757 GNUNET_i2s (peer), transport_name);
758 if (blacklist == NULL)
760 GNUNET_CONTAINER_multihashmap_create (TRANSPORT_BLACKLIST_HT_SIZE,
762 if (NULL != transport_name)
763 transport = GNUNET_strdup ("");
765 GNUNET_CONTAINER_multihashmap_put (blacklist, &peer->hashPubKey,
767 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
772 * Test if the given blacklist entry matches. If so,
773 * abort the iteration.
775 * @param cls the transport name to match (const char*)
776 * @param key the key (unused)
777 * @param value the 'char *' (name of a blacklisted transport)
778 * @return GNUNET_OK if the entry does not match, GNUNET_NO if it matches
781 test_blacklisted (void *cls, const struct GNUNET_HashCode * key, void *value)
783 const char *transport_name = cls;
786 /* blacklist check for specific no specific transport*/
787 if (transport_name == NULL)
789 /* all plugins for this peer were blacklisted */
793 /* blacklist check for specific transport */
794 if (0 == strcmp (transport_name, be))
795 return GNUNET_NO; /* abort iteration! */
801 * Test if a peer/transport combination is blacklisted.
803 * @param peer the identity of the peer to test
804 * @param transport_name name of the transport to test, never NULL
805 * @param cont function to call with result
806 * @param cont_cls closure for 'cont'
807 * @return handle to the blacklist check, NULL if the decision
808 * was made instantly and 'cont' was already called
810 struct GST_BlacklistCheck *
811 GST_blacklist_test_allowed (const struct GNUNET_PeerIdentity *peer,
812 const char *transport_name,
813 GST_BlacklistTestContinuation cont, void *cont_cls)
815 struct GST_BlacklistCheck *bc;
817 GNUNET_assert (peer != NULL);
819 if ((blacklist != NULL) &&
821 GNUNET_CONTAINER_multihashmap_get_multiple (blacklist, &peer->hashPubKey,
823 (void *) transport_name)))
825 /* disallowed by config, disapprove instantly */
826 GNUNET_STATISTICS_update (GST_stats,
827 gettext_noop ("# disconnects due to blacklist"),
830 cont (cont_cls, peer, GNUNET_NO);
836 /* no blacklist clients, approve instantly */
838 cont (cont_cls, peer, GNUNET_OK);
842 /* need to query blacklist clients */
843 bc = GNUNET_malloc (sizeof (struct GST_BlacklistCheck));
844 GNUNET_CONTAINER_DLL_insert (bc_head, bc_tail, bc);
847 bc->cont_cls = cont_cls;
848 bc->bl_pos = bl_head;
849 bc->task = GNUNET_SCHEDULER_add_now (&do_blacklist_check, bc);
855 * Cancel a blacklist check.
857 * @param bc check to cancel
860 GST_blacklist_test_cancel (struct GST_BlacklistCheck *bc)
862 GNUNET_CONTAINER_DLL_remove (bc_head, bc_tail, bc);
863 if (bc->bl_pos != NULL)
865 if (bc->bl_pos->bc == bc)
867 /* we're at the head of the queue, remove us! */
868 bc->bl_pos->bc = NULL;
871 if (GNUNET_SCHEDULER_NO_TASK != bc->task)
873 GNUNET_SCHEDULER_cancel (bc->task);
874 bc->task = GNUNET_SCHEDULER_NO_TASK;
878 GNUNET_SERVER_notify_transmit_ready_cancel (bc->th);
885 /* end of file gnunet-service-transport_blacklist.c */