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_CONNECTION_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_CONNECTION_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,
232 "BLACKLIST_FILE", &fn))
235 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
236 "Option `%s' in section `%s' not specified!\n",
237 "BLACKLIST_FILE", "TRANSPORT");
241 if (GNUNET_OK != GNUNET_DISK_file_test (fn))
242 GNUNET_DISK_fn_write (fn, NULL, 0,
243 GNUNET_DISK_PERM_USER_READ |
244 GNUNET_DISK_PERM_USER_WRITE);
245 if (0 != STAT (fn, &frstat))
247 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
248 _("Could not read blacklist file `%s'\n"), fn);
252 if (frstat.st_size == 0)
255 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
256 _("Blacklist file `%s' is empty.\n"), fn);
261 /* FIXME: use mmap */
262 data = GNUNET_malloc_large (frstat.st_size);
263 GNUNET_assert (data != NULL);
264 if (frstat.st_size != GNUNET_DISK_fn_read (fn, data, frstat.st_size))
266 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
267 _("Failed to read blacklist from `%s'\n"), fn);
274 while ((pos < frstat.st_size) && isspace ((unsigned char) data[pos]))
276 while ((frstat.st_size >= sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded)) &&
278 frstat.st_size - sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded)))
281 while ((colon_pos < frstat.st_size) &&
282 (data[colon_pos] != ':') &&
283 (!isspace ((unsigned char) data[colon_pos])))
285 if (colon_pos >= frstat.st_size)
287 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
289 ("Syntax error in blacklist file at offset %llu, giving up!\n"),
290 (unsigned long long) colon_pos);
296 if (isspace ((unsigned char) data[colon_pos]))
298 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
300 ("Syntax error in blacklist file at offset %llu, skipping bytes.\n"),
301 (unsigned long long) colon_pos);
303 while ((pos < frstat.st_size) && isspace ((unsigned char) data[pos]))
307 tsize = colon_pos - pos;
308 if ((pos >= frstat.st_size) || (pos + tsize >= frstat.st_size) ||
311 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
313 ("Syntax error in blacklist file at offset %llu, giving up!\n"),
314 (unsigned long long) colon_pos);
323 transport_name = GNUNET_malloc (tsize + 1);
324 memcpy (transport_name, &data[pos], tsize);
327 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
328 "Read transport name `%s' in blacklist file.\n",
331 memcpy (&enc, &data[pos], sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded));
334 enc.encoding[sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1]))
336 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
338 ("Syntax error in blacklist file at offset %llu, skipping bytes.\n"),
339 (unsigned long long) pos);
341 while ((pos < frstat.st_size) && (!isspace ((unsigned char) data[pos])))
343 GNUNET_free_non_null (transport_name);
346 enc.encoding[sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1] = '\0';
348 GNUNET_CRYPTO_hash_from_string ((char *) &enc, &pid.hashPubKey))
350 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
352 ("Syntax error in blacklist file at offset %llu, skipping bytes `%s'.\n"),
353 (unsigned long long) pos, &enc);
357 if (0 != memcmp (&pid,
358 &GST_my_identity, sizeof (struct GNUNET_PeerIdentity)))
361 GST_blacklist_add_peer (&pid, transport_name);
365 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
366 _("Found myself `%s' in blacklist (useless, ignored)\n"),
370 pos = pos + sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded);
371 GNUNET_free_non_null (transport_name);
372 while ((pos < frstat.st_size) && isspace ((unsigned char) data[pos]))
375 GNUNET_STATISTICS_update (GST_stats,
376 "# Transport entries blacklisted",
377 entries_found, GNUNET_NO);
384 * Start blacklist subsystem.
386 * @param server server used to accept clients from
389 GST_blacklist_start (struct GNUNET_SERVER_Handle *server)
391 read_blacklist_file ();
392 GNUNET_SERVER_disconnect_notify (server,
393 &client_disconnect_notification, NULL);
398 * Free the given entry in the blacklist.
401 * @param key host identity (unused)
402 * @param value the blacklist entry
403 * @return GNUNET_OK (continue to iterate)
406 free_blacklist_entry (void *cls, const GNUNET_HashCode * key, void *value)
416 * Stop blacklist subsystem.
419 GST_blacklist_stop ()
421 if (NULL != blacklist)
423 GNUNET_CONTAINER_multihashmap_iterate (blacklist,
424 &free_blacklist_entry, NULL);
425 GNUNET_CONTAINER_multihashmap_destroy (blacklist);
432 * Transmit blacklist query to the client.
434 * @param cls the 'struct GST_BlacklistCheck'
435 * @param size number of bytes allowed
436 * @param buf where to copy the message
437 * @return number of bytes copied to buf
440 transmit_blacklist_message (void *cls, size_t size, void *buf)
442 struct GST_BlacklistCheck *bc = cls;
443 struct Blacklisters *bl;
444 struct BlacklistMessage bm;
449 GNUNET_assert (bc->task == GNUNET_SCHEDULER_NO_TASK);
450 bc->task = GNUNET_SCHEDULER_add_now (&do_blacklist_check, bc);
451 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
452 "Failed to send blacklist test for peer `%s' to client\n",
453 GNUNET_i2s (&bc->peer));
457 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
458 "Sending blacklist test for peer `%s' to client\n",
459 GNUNET_i2s (&bc->peer));
462 bm.header.size = htons (sizeof (struct BlacklistMessage));
463 bm.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_BLACKLIST_QUERY);
464 bm.is_allowed = htonl (0);
466 memcpy (buf, &bm, sizeof (bm));
467 GNUNET_SERVER_receive_done (bl->client, GNUNET_OK);
468 bl->waiting_for_reply = GNUNET_YES;
474 * Perform next action in the blacklist check.
476 * @param cls the 'struct GST_BlacklistCheck*'
480 do_blacklist_check (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
482 struct GST_BlacklistCheck *bc = cls;
483 struct Blacklisters *bl;
485 bc->task = GNUNET_SCHEDULER_NO_TASK;
490 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
491 "No other blacklist clients active, will allow neighbour `%s'\n",
492 GNUNET_i2s (&bc->peer));
494 bc->cont (bc->cont_cls, &bc->peer, GNUNET_OK);
498 if ((bl->bc != NULL) || (bl->waiting_for_reply != GNUNET_NO))
499 return; /* someone else busy with this client */
501 bc->th = GNUNET_SERVER_notify_transmit_ready (bl->client,
504 GNUNET_TIME_UNIT_FOREVER_REL,
505 &transmit_blacklist_message,
511 * Got the result about an existing connection from a new blacklister.
512 * Shutdown the neighbour if necessary.
515 * @param peer the neighbour that was investigated
516 * @param allowed GNUNET_OK if we can keep it,
517 * GNUNET_NO if we must shutdown the connection
520 confirm_or_drop_neighbour (void *cls,
521 const struct GNUNET_PeerIdentity *peer, int allowed)
523 if (GNUNET_OK == allowed)
524 return; /* we're done */
525 GNUNET_STATISTICS_update (GST_stats,
526 gettext_noop ("# disconnects due to blacklist"),
528 GST_neighbours_force_disconnect (peer);
533 * Closure for 'test_connection_ok'.
535 struct TestConnectionContext
538 * Is this the first neighbour we're checking?
543 * Handle to the blacklisting client we need to ask.
545 struct Blacklisters *bl;
550 * Test if an existing connection is still acceptable given a new
551 * blacklisting client.
553 * @param cls the 'struct TestConnectionContest'
554 * @param pid neighbour's identity
555 * @param ats performance data
556 * @param ats_count number of entries in ats (excluding 0-termination)
559 test_connection_ok (void *cls,
560 const struct GNUNET_PeerIdentity *neighbour,
561 const struct GNUNET_TRANSPORT_ATS_Information *ats,
564 struct TestConnectionContext *tcc = cls;
565 struct GST_BlacklistCheck *bc;
567 bc = GNUNET_malloc (sizeof (struct GST_BlacklistCheck));
568 GNUNET_CONTAINER_DLL_insert (bc_head, bc_tail, bc);
569 bc->peer = *neighbour;
570 bc->cont = &confirm_or_drop_neighbour;
572 bc->bl_pos = tcc->bl;
573 if (GNUNET_YES == tcc->first)
575 /* all would wait for the same client, no need to
576 * create more than just the first task right now */
577 bc->task = GNUNET_SCHEDULER_add_now (&do_blacklist_check, bc);
578 tcc->first = GNUNET_NO;
585 * Initialize a blacklisting client. We got a blacklist-init
586 * message from this client, add him to the list of clients
587 * to query for blacklisting.
590 * @param client the client
591 * @param message the blacklist-init message that was sent
594 GST_blacklist_handle_init (void *cls,
595 struct GNUNET_SERVER_Client *client,
596 const struct GNUNET_MessageHeader *message)
598 struct Blacklisters *bl;
599 struct TestConnectionContext tcc;
604 if (bl->client == client)
607 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
612 bl = GNUNET_malloc (sizeof (struct Blacklisters));
614 GNUNET_SERVER_client_keep (client);
615 GNUNET_CONTAINER_DLL_insert_after (bl_head, bl_tail, bl_tail, bl);
617 /* confirm that all existing connections are OK! */
619 tcc.first = GNUNET_YES;
620 GST_neighbours_iterate (&test_connection_ok, &tcc);
625 * A blacklisting client has sent us reply. Process it.
628 * @param client the client
629 * @param message the blacklist-init message that was sent
632 GST_blacklist_handle_reply (void *cls,
633 struct GNUNET_SERVER_Client *client,
634 const struct GNUNET_MessageHeader *message)
636 const struct BlacklistMessage *msg =
637 (const struct BlacklistMessage *) message;
638 struct Blacklisters *bl;
639 struct GST_BlacklistCheck *bc;
642 while ((bl != NULL) && (bl->client != client))
647 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Blacklist client disconnected\n");
649 /* FIXME: other error handling here!? */
650 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
655 bl->waiting_for_reply = GNUNET_NO;
658 /* only run this if the blacklist check has not been
659 * cancelled in the meantime... */
660 if (ntohl (msg->is_allowed) == GNUNET_SYSERR)
663 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
664 "Blacklist check failed, peer not allowed\n");
666 bc->cont (bc->cont_cls, &bc->peer, GNUNET_NO);
667 GNUNET_CONTAINER_DLL_remove (bc_head, bc_tail, bc);
673 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
674 "Blacklist check succeeded, continuing with checks\n");
676 bc->bl_pos = bc->bl_pos->next;
677 bc->task = GNUNET_SCHEDULER_add_now (&do_blacklist_check, bc);
680 /* check if any other bc's are waiting for this blacklister */
682 for (bc = bc_head; bc != NULL; bc = bc->next)
683 if ((bc->bl_pos == bl) && (GNUNET_SCHEDULER_NO_TASK == bc->task))
685 bc->task = GNUNET_SCHEDULER_add_now (&do_blacklist_check, bc);
692 * Add the given peer to the blacklist (for the given transport).
694 * @param peer peer to blacklist
695 * @param transport_name transport to blacklist for this peer, NULL for all
698 GST_blacklist_add_peer (const struct GNUNET_PeerIdentity *peer,
699 const char *transport_name)
702 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
703 "Adding peer `%s' with plugin `%s' to blacklist\n",
704 GNUNET_i2s (peer), transport_name);
706 if (blacklist == NULL)
708 GNUNET_CONTAINER_multihashmap_create (TRANSPORT_BLACKLIST_HT_SIZE);
709 GNUNET_CONTAINER_multihashmap_put (blacklist, &peer->hashPubKey,
710 GNUNET_strdup (transport_name),
711 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
716 * Test if the given blacklist entry matches. If so,
717 * abort the iteration.
719 * @param cls the transport name to match (const char*)
720 * @param key the key (unused)
721 * @param value the 'char *' (name of a blacklisted transport)
722 * @return GNUNET_OK if the entry does not match, GNUNET_NO if it matches
725 test_blacklisted (void *cls, const GNUNET_HashCode * key, void *value)
727 const char *transport_name = cls;
730 if (0 == strcmp (transport_name, be))
731 return GNUNET_NO; /* abort iteration! */
737 * Test if a peer/transport combination is blacklisted.
739 * @param peer the identity of the peer to test
740 * @param transport_name name of the transport to test, never NULL
741 * @param cont function to call with result
742 * @param cont_cls closure for 'cont'
743 * @return handle to the blacklist check, NULL if the decision
744 * was made instantly and 'cont' was already called
746 struct GST_BlacklistCheck *
747 GST_blacklist_test_allowed (const struct GNUNET_PeerIdentity *peer,
748 const char *transport_name,
749 GST_BlacklistTestContinuation cont, void *cont_cls)
751 struct GST_BlacklistCheck *bc;
753 if ((blacklist != NULL) &&
755 GNUNET_CONTAINER_multihashmap_get_multiple (blacklist,
758 (void *) transport_name)))
760 /* disallowed by config, disapprove instantly */
761 GNUNET_STATISTICS_update (GST_stats,
762 gettext_noop ("# disconnects due to blacklist"),
765 cont (cont_cls, peer, GNUNET_NO);
771 /* no blacklist clients, approve instantly */
773 cont (cont_cls, peer, GNUNET_OK);
777 /* need to query blacklist clients */
778 bc = GNUNET_malloc (sizeof (struct GST_BlacklistCheck));
779 GNUNET_CONTAINER_DLL_insert (bc_head, bc_tail, bc);
782 bc->cont_cls = cont_cls;
783 bc->bl_pos = bl_head;
784 bc->task = GNUNET_SCHEDULER_add_now (&do_blacklist_check, bc);
790 * Cancel a blacklist check.
792 * @param bc check to cancel
795 GST_blacklist_test_cancel (struct GST_BlacklistCheck *bc)
797 GNUNET_CONTAINER_DLL_remove (bc_head, bc_tail, bc);
798 if (bc->bl_pos != NULL)
800 if (bc->bl_pos->bc == bc)
802 /* we're at the head of the queue, remove us! */
803 bc->bl_pos->bc = NULL;
806 if (GNUNET_SCHEDULER_NO_TASK != bc->task)
808 GNUNET_SCHEDULER_cancel (bc->task);
809 bc->task = GNUNET_SCHEDULER_NO_TASK;
813 GNUNET_CONNECTION_notify_transmit_ready_cancel (bc->th);
820 /* end of file gnunet-service-transport_blacklist.c */