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3 (C) 2009, 2010, 2011 Christian Grothoff (and other contributing authors)
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22 * @file include/gnunet_transport_service.h
23 * @brief low-level P2P IO
24 * @author Christian Grothoff
27 #ifndef GNUNET_TRANSPORT_SERVICE_H
28 #define GNUNET_TRANSPORT_SERVICE_H
33 #if 0 /* keep Emacsens' auto-indent happy */
38 #include "gnunet_util_lib.h"
39 #include "gnunet_ats_service.h"
42 * Version number of the transport API.
44 #define GNUNET_TRANSPORT_VERSION 0x00000000
48 * Possible state of a neighbour. Initially, we are #GNUNET_TRANSPORT_PS_NOT_CONNECTED.
50 * Then, there are two main paths. If we receive a CONNECT message, we
51 * first run a check against the blacklist (#GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND).
52 * If this check is successful, we give the inbound address to ATS.
53 * After the check we ask ATS for a suggestion (#GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS).
54 * If ATS makes a suggestion, we ALSO give that suggestion to the blacklist
55 * (#GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST). Once the blacklist approves the
56 * address we got from ATS, we send our CONNECT_ACK and go to
57 * #GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK. If we receive a SESSION_ACK, we go to
58 * #GNUNET_TRANSPORT_PS_CONNECTED (and notify everyone about the new connection).
59 * If the operation times out, we go to #GNUNET_TRANSPORT_PS_DISCONNECT.
61 * The other case is where we transmit a CONNECT message first. We
62 * start with #GNUNET_TRANSPORT_PS_INIT_ATS. If we get an address, we enter
63 * #GNUNET_TRANSPORT_PS_INIT_BLACKLIST and check the blacklist. If the blacklist is OK
64 * with the connection, we actually send the CONNECT message and go to
65 * state #GNUNET_TRANSPORT_PS_CONNECT_SENT. Once we receive a CONNECT_ACK, we go to
66 * #GNUNET_TRANSPORT_PS_CONNECTED (and notify everyone about the new connection and send
67 * back a SESSION_ACK). If the operation times out, we go to
68 * #GNUNET_TRANSPORT_PS_DISCONNECT.
70 * If the session is in trouble (i.e. transport-level disconnect or
71 * timeout), we go to #GNUNET_TRANSPORT_PS_RECONNECT_ATS where we ask ATS for a new
72 * address (we don't notify anyone about the disconnect yet). Once we
73 * have a new address, we go to #GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST to check the new
74 * address against the blacklist. If the blacklist approves, we enter
75 * #GNUNET_TRANSPORT_PS_RECONNECT_SENT and send a CONNECT message. If we receive a
76 * CONNECT_ACK, we go to #GNUNET_TRANSPORT_PS_CONNECTED and nobody noticed that we had
77 * trouble; we also send a SESSION_ACK at this time just in case. If
78 * the operation times out, we go to #GNUNET_TRANSPORT_PS_DISCONNECT (and notify everyone
79 * about the lost connection).
81 * If ATS decides to switch addresses while we have a normal
82 * connection, we go to #GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST to check the
83 * new address against the blacklist. If the blacklist approves, we
84 * go to #GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT and send a
85 * SESSION_CONNECT. If we get a SESSION_ACK back, we switch the
86 * primary connection to the suggested alternative from ATS, go back
87 * to #GNUNET_TRANSPORT_PS_CONNECTED and send a SESSION_ACK to the other peer just to be
88 * sure. If the operation times out (or the blacklist disapproves),
89 * we go to #GNUNET_TRANSPORT_PS_CONNECTED (and notify ATS that the given alternative
90 * address is "invalid").
92 * Once a session is in #GNUNET_TRANSPORT_PS_DISCONNECT, it is cleaned up and then goes
93 * to (#GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED). If we receive an explicit disconnect
94 * request, we can go from any state to #GNUNET_TRANSPORT_PS_DISCONNECT, possibly after
95 * generating disconnect notifications.
97 * Note that it is quite possible that while we are in any of these
98 * states, we could receive a 'CONNECT' request from the other peer.
99 * We then enter a 'weird' state where we pursue our own primary state
100 * machine (as described above), but with the 'send_connect_ack' flag
101 * set to 1. If our state machine allows us to send a 'CONNECT_ACK'
102 * (because we have an acceptable address), we send the 'CONNECT_ACK'
103 * and set the 'send_connect_ack' to 2. If we then receive a
104 * 'SESSION_ACK', we go to #GNUNET_TRANSPORT_PS_CONNECTED (and reset 'send_connect_ack'
108 enum GNUNET_TRANSPORT_PeerState
111 * Fresh peer or completely disconnected
113 GNUNET_TRANSPORT_PS_NOT_CONNECTED = 0,
116 * Asked to initiate connection, trying to get address from ATS
118 GNUNET_TRANSPORT_PS_INIT_ATS,
121 * Asked to initiate connection, trying to get address approved
124 GNUNET_TRANSPORT_PS_INIT_BLACKLIST,
127 * Sent CONNECT message to other peer, waiting for CONNECT_ACK
129 GNUNET_TRANSPORT_PS_CONNECT_SENT,
132 * Received a CONNECT, do a blacklist check for inbound address
134 GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST_INBOUND,
137 * Received a CONNECT, asking ATS about address suggestions.
139 GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS,
142 * Received CONNECT from other peer, got an address, checking with blacklist.
144 GNUNET_TRANSPORT_PS_CONNECT_RECV_BLACKLIST,
147 * CONNECT request from other peer was SESSION_ACK'ed, waiting for
150 GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK,
153 * Got our CONNECT_ACK/SESSION_ACK, connection is up.
155 GNUNET_TRANSPORT_PS_CONNECTED,
158 * Connection got into trouble, rest of the system still believes
159 * it to be up, but we're getting a new address from ATS.
161 GNUNET_TRANSPORT_PS_RECONNECT_ATS,
164 * Connection got into trouble, rest of the system still believes
165 * it to be up; we are checking the new address against the blacklist.
167 GNUNET_TRANSPORT_PS_RECONNECT_BLACKLIST,
170 * Sent CONNECT over new address (either by ATS telling us to switch
171 * addresses or from RECONNECT_ATS); if this fails, we need to tell
172 * the rest of the system about a disconnect.
174 GNUNET_TRANSPORT_PS_RECONNECT_SENT,
177 * We have some primary connection, but ATS suggested we switch
178 * to some alternative; we're now checking the alternative against
181 GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_BLACKLIST,
184 * We have some primary connection, but ATS suggested we switch
185 * to some alternative; we now sent a CONNECT message for the
186 * alternative session to the other peer and waiting for a
187 * CONNECT_ACK to make this our primary connection.
189 GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT,
192 * Disconnect in progress (we're sending the DISCONNECT message to the
193 * other peer; after that is finished, the state will be cleaned up).
195 GNUNET_TRANSPORT_PS_DISCONNECT,
198 * We're finished with the disconnect; and are cleaning up the state
199 * now! We put the struct into this state when we are really in the
200 * task that calls 'free' on it and are about to remove the record
201 * from the map. We should never find a 'struct NeighbourMapEntry'
202 * in this state in the map. Accessing a 'struct NeighbourMapEntry'
203 * in this state virtually always means using memory that has been
204 * freed (the exception being the cleanup code in #free_neighbour()).
206 GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED
210 * Current state of a validation process
212 enum GNUNET_TRANSPORT_ValidationState
217 * Used for final callback indicating operation done
219 GNUNET_TRANSPORT_VS_NONE,
222 * Fresh validation entry
224 * Entry was just created, no validation process was executed
226 GNUNET_TRANSPORT_VS_NEW,
229 * Updated validation entry
231 * This is an update for an existing validation entry
233 GNUNET_TRANSPORT_VS_UPDATE,
236 * Timeout for validation entry
238 * A timeout occured during the validation process
240 GNUNET_TRANSPORT_VS_TIMEOUT,
243 * Validation entry is removed
245 * The validation entry is getting removed due to a failed validation
247 GNUNET_TRANSPORT_VS_REMOVE,
251 * Function called by the transport for each received message.
254 * @param peer (claimed) identity of the other peer
255 * @param message the message
256 * @param ats performance data
257 * @param ats_count number of entries in ats
259 typedef void (*GNUNET_TRANSPORT_ReceiveCallback) (void *cls,
261 GNUNET_PeerIdentity * peer,
263 GNUNET_MessageHeader *
268 * Opaque handle to the service.
270 struct GNUNET_TRANSPORT_Handle;
274 * Function called to notify transport users that another
275 * peer connected to us.
278 * @param peer the peer that connected
279 * @param ats performance data
280 * @param ats_count number of entries in ats (excluding 0-termination)
282 typedef void (*GNUNET_TRANSPORT_NotifyConnect) (void *cls,
283 const struct GNUNET_PeerIdentity
287 * Function called to notify transport users that another
288 * peer disconnected from us.
291 * @param peer the peer that disconnected
293 typedef void (*GNUNET_TRANSPORT_NotifyDisconnect) (void *cls,
295 GNUNET_PeerIdentity * peer);
299 * Function to call with result of the try connect request.
303 * @param result GNUNET_OK if message was transmitted to transport service
304 * GNUNET_SYSERR if message was not transmitted to transport service
306 typedef void (*GNUNET_TRANSPORT_TryConnectCallback) (void *cls,
311 * Function to call with a textual representation of an address.
312 * This function will be called several times with different possible
313 * textual representations, and a last time with NULL to signal the end
317 * @param address NULL on error or end of iteration,
318 * otherwise 0-terminated printable UTF-8 string
320 typedef void (*GNUNET_TRANSPORT_AddressToStringCallback) (void *cls,
321 const char *address);
325 * Function to call with information about a peer
327 * If one_shot was set to GNUNET_YES to iterate over all peers once,
328 * a final call with NULL for peer and address will follow when done.
329 * In this case state and timeout do not contain valid values.
331 * The #GNUNET_TRANSPORT_monitor_peers_cancel call MUST not be called from
332 * within this function!
336 * @param peer peer this update is about,
337 * NULL if this is the final last callback for a iteration operation
338 * @param address address, NULL for disconnect notification in monitor mode
339 * @param state current state this peer is in
340 * @param state_timeout timeout for the current state of the peer
342 typedef void (*GNUNET_TRANSPORT_PeerIterateCallback) (void *cls,
343 const struct GNUNET_PeerIdentity *peer,
344 const struct GNUNET_HELLO_Address *address,
345 enum GNUNET_TRANSPORT_PeerState state,
346 struct GNUNET_TIME_Absolute state_timeout);
350 * Function to call with validation information about a peer
352 * This function is called by the transport validation monitoring api to
353 * indicate a change to a validation entry. The information included represent
354 * the current state of the validation entry,
356 * If the monitoring was called with one_shot=GNUNET_YES, a final callback
357 * with peer==NULL and address==NULL is executed.
360 * @param peer peer this update is about,
361 * NULL if this is the final last callback for a iteration operation
362 * @param address address,
363 * NULL for disconnect notification in monitor mode
364 * @param valid_until when does this address expire
365 * @param next_validation time of the next validation operation
368 typedef void (*GNUNET_TRANSPORT_ValidationIterateCallback) (void *cls,
369 const struct GNUNET_PeerIdentity *peer,
370 const struct GNUNET_HELLO_Address *address,
371 struct GNUNET_TIME_Absolute last_validation,
372 struct GNUNET_TIME_Absolute valid_until,
373 struct GNUNET_TIME_Absolute next_validation,
374 enum GNUNET_TRANSPORT_ValidationState state);
379 * Connect to the transport service. Note that the connection may
380 * complete (or fail) asynchronously.
382 * @param cfg configuration to use
383 * @param self our own identity (API should check that it matches
384 * the identity found by transport), or NULL (no check)
385 * @param cls closure for the callbacks
386 * @param rec receive function to call, or NULL
387 * @param nc function to call on connect events, or NULL
388 * @param nd function to call on disconnect events, or NULL
389 * @return NULL on error
391 struct GNUNET_TRANSPORT_Handle *
392 GNUNET_TRANSPORT_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
393 const struct GNUNET_PeerIdentity *self, void *cls,
394 GNUNET_TRANSPORT_ReceiveCallback rec,
395 GNUNET_TRANSPORT_NotifyConnect nc,
396 GNUNET_TRANSPORT_NotifyDisconnect nd);
400 * Disconnect from the transport service.
402 * @param handle handle returned from connect
405 GNUNET_TRANSPORT_disconnect (struct GNUNET_TRANSPORT_Handle *handle);
409 * Opaque handle for a transmission-ready request.
411 struct GNUNET_TRANSPORT_TryConnectHandle;
415 * Ask the transport service to establish a connection to
418 * @param handle connection to transport service
419 * @param target who we should try to connect to
420 * @param cb callback to be called when request was transmitted to transport
422 * @param cb_cls closure for the callback
423 * @return a GNUNET_TRANSPORT_TryConnectHandle handle or
424 * NULL on failure (cb will not be called)
426 struct GNUNET_TRANSPORT_TryConnectHandle *
427 GNUNET_TRANSPORT_try_connect (struct GNUNET_TRANSPORT_Handle *handle,
428 const struct GNUNET_PeerIdentity *target,
429 GNUNET_TRANSPORT_TryConnectCallback cb,
434 * Cancel the request to transport to try a connect
435 * Callback will not be called
437 * @param tch GNUNET_TRANSPORT_TryConnectHandle handle to cancel
440 GNUNET_TRANSPORT_try_connect_cancel (struct GNUNET_TRANSPORT_TryConnectHandle *tch);
444 * Opaque handle for a transmission-ready request.
446 struct GNUNET_TRANSPORT_TransmitHandle;
450 * Check if we could queue a message of the given size for
451 * transmission. The transport service will take both its internal
452 * buffers and bandwidth limits imposed by the other peer into
453 * consideration when answering this query.
455 * @param handle connection to transport service
456 * @param target who should receive the message
457 * @param size how big is the message we want to transmit?
458 * @param priority how important is the message? @deprecated - remove?
459 * @param timeout after how long should we give up (and call
460 * notify with buf NULL and size 0)?
461 * @param notify function to call when we are ready to
462 * send such a message
463 * @param notify_cls closure for notify
464 * @return NULL if someone else is already waiting to be notified
465 * non-NULL if the notify callback was queued (can be used to cancel
466 * using GNUNET_TRANSPORT_notify_transmit_ready_cancel)
468 struct GNUNET_TRANSPORT_TransmitHandle *
469 GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle *handle,
470 const struct GNUNET_PeerIdentity
471 *target, size_t size, uint32_t priority,
472 struct GNUNET_TIME_Relative timeout,
473 GNUNET_CONNECTION_TransmitReadyNotify
474 notify, void *notify_cls);
478 * Cancel the specified transmission-ready notification.
480 * @param th handle of the transmission notification request to cancel
483 GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct
484 GNUNET_TRANSPORT_TransmitHandle
490 * Function called whenever there is an update to the
491 * HELLO of this peer.
494 * @param hello our updated HELLO
496 typedef void (*GNUNET_TRANSPORT_HelloUpdateCallback) (void *cls,
498 GNUNET_MessageHeader *
503 * Handle to cancel a 'GNUNET_TRANSPORT_get_hello' operation.
505 struct GNUNET_TRANSPORT_GetHelloHandle;
509 * Checks if a given peer is connected to us
511 * @param handle connection to transport service
512 * @param peer the peer to check
513 * @return #GNUNET_YES (connected) or #GNUNET_NO (disconnected)
516 GNUNET_TRANSPORT_check_peer_connected (struct GNUNET_TRANSPORT_Handle *handle,
517 const struct GNUNET_PeerIdentity *peer);
521 * Set transport metrics for a peer and a direction
523 * @param handle transport handle
524 * @param peer the peer to set the metric for
525 * @param inbound set inbound direction (GNUNET_YES or GNUNET_NO)
526 * @param outbound set outbound direction (GNUNET_YES or GNUNET_NO)
527 * @param ats the metric as ATS information
528 * @param ats_count the number of metrics
530 * Supported ATS values:
531 * GNUNET_ATS_QUALITY_NET_DELAY (value in ms)
532 * GNUNET_ATS_QUALITY_NET_DISTANCE (value in count(hops))
535 * To enforce a delay of 10 ms for peer p1 in sending direction use:
537 * struct GNUNET_ATS_Information ats;
538 * ats.type = ntohl (GNUNET_ATS_QUALITY_NET_DELAY);
539 * ats.value = ntohl (10);
540 * GNUNET_TRANSPORT_set_traffic_metric (th, p1, TM_SEND, &ats, 1);
543 * Delay restrictions in receiving direction will be enforced with
547 GNUNET_TRANSPORT_set_traffic_metric (struct GNUNET_TRANSPORT_Handle *handle,
548 const struct GNUNET_PeerIdentity *peer,
551 const struct GNUNET_ATS_Information *ats,
556 * Obtain updates on changes to the HELLO message for this peer. The callback
557 * given in this function is never called synchronously.
559 * @param handle connection to transport service
560 * @param rec function to call with the HELLO
561 * @param rec_cls closure for rec
562 * @return handle to cancel the operation
564 struct GNUNET_TRANSPORT_GetHelloHandle *
565 GNUNET_TRANSPORT_get_hello (struct GNUNET_TRANSPORT_Handle *handle,
566 GNUNET_TRANSPORT_HelloUpdateCallback rec,
571 * Stop receiving updates about changes to our HELLO message.
573 * @param ghh handle to cancel
576 GNUNET_TRANSPORT_get_hello_cancel (struct GNUNET_TRANSPORT_GetHelloHandle *ghh);
580 * Offer the transport service the HELLO of another peer. Note that
581 * the transport service may just ignore this message if the HELLO is
582 * malformed or useless due to our local configuration.
584 * @param handle connection to transport service
585 * @param hello the hello message
586 * @param cont continuation to call when HELLO has been sent,
587 * tc reason GNUNET_SCHEDULER_REASON_TIMEOUT for fail
588 * tc reasong GNUNET_SCHEDULER_REASON_READ_READY for success
589 * @param cls closure for continuation
590 * @return a GNUNET_TRANSPORT_OfferHelloHandle handle or NULL on failure,
591 * in case of failure cont will not be called
594 struct GNUNET_TRANSPORT_OfferHelloHandle *
595 GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle,
596 const struct GNUNET_MessageHeader *hello,
597 GNUNET_SCHEDULER_Task cont, void *cls);
601 * Cancel the request to transport to offer the HELLO message
603 * @param ohh the GNUNET_TRANSPORT_OfferHelloHandle to cancel
606 GNUNET_TRANSPORT_offer_hello_cancel (struct GNUNET_TRANSPORT_OfferHelloHandle *ohh);
610 * Handle to cancel a pending address lookup.
612 struct GNUNET_TRANSPORT_AddressToStringContext;
616 * Convert a binary address into a human readable address.
618 * @param cfg configuration to use
619 * @param address address to convert (binary format)
620 * @param numeric should (IP) addresses be displayed in numeric form
621 * (otherwise do reverse DNS lookup)
622 * @param timeout how long is the lookup allowed to take at most
623 * @param aluc function to call with the results
624 * @param aluc_cls closure for aluc
625 * @return handle to cancel the operation, NULL on error
627 struct GNUNET_TRANSPORT_AddressToStringContext *
628 GNUNET_TRANSPORT_address_to_string (const struct GNUNET_CONFIGURATION_Handle
630 const struct GNUNET_HELLO_Address *address,
632 struct GNUNET_TIME_Relative timeout,
633 GNUNET_TRANSPORT_AddressToStringCallback
634 aluc, void *aluc_cls);
638 * Cancel request for address conversion.
640 * @param pic the context handle
643 GNUNET_TRANSPORT_address_to_string_cancel (struct
644 GNUNET_TRANSPORT_AddressToStringContext
648 * Convert a transport state to a human readable string.
650 * @param state the state
653 GNUNET_TRANSPORT_ps2s (enum GNUNET_TRANSPORT_PeerState state);
657 * Check if a state is defined as connected
659 * @param state the state value
660 * @return GNUNET_YES or GNUNET_NO
663 GNUNET_TRANSPORT_is_connected (enum GNUNET_TRANSPORT_PeerState state);
667 * Convert validation state to human-readable string.
669 * @param state the state value
670 * @return corresponding string
673 GNUNET_TRANSPORT_vs2s (enum GNUNET_TRANSPORT_ValidationState state);
677 * Return information about a specific peer or all peers currently known to
678 * transport service once or in monitoring mode. To obtain information about
679 * a specific peer, a peer identity can be passed. To obtain information about
680 * all peers currently known to transport service, NULL can be passed as peer
683 * For each peer, the callback is called with information about the address used
684 * to communicate with this peer, the state this peer is currently in and the
685 * the current timeout for this state.
687 * Upon completion, the 'GNUNET_TRANSPORT_PeerIterateCallback' is called one
688 * more time with 'NULL'. After this, the operation must no longer be
689 * explicitly canceled.
691 * The #GNUNET_TRANSPORT_monitor_peers_cancel call MUST not be called in the
694 * @param cfg configuration to use
695 * @param peer a specific peer identity to obtain information for,
697 * @param one_shot GNUNET_YES to return the current state and then end (with NULL+NULL),
698 * GNUNET_NO to monitor peers continuously
699 * @param timeout how long is the lookup allowed to take at most
700 * @param peer_callback function to call with the results
701 * @param peer_callback_cls closure for peer_address_callback
703 struct GNUNET_TRANSPORT_PeerMonitoringContext *
704 GNUNET_TRANSPORT_monitor_peers (const struct
705 GNUNET_CONFIGURATION_Handle *cfg,
706 const struct GNUNET_PeerIdentity *peer,
708 struct GNUNET_TIME_Relative timeout,
709 GNUNET_TRANSPORT_PeerIterateCallback peer_callback,
710 void *peer_callback_cls);
714 * Cancel request to monitor peers
716 * @param pic handle for the request to cancel
719 GNUNET_TRANSPORT_monitor_peers_cancel (struct GNUNET_TRANSPORT_PeerMonitoringContext *pic);
724 * Return information about pending address validation operations for a specific
727 * @param cfg configuration to use
728 * @param peer a specific peer identity to obtain validation entries for,
730 * @param one_shot GNUNET_YES to return all entries and then end (with NULL+NULL),
731 * GNUNET_NO to monitor validation entries continuously
732 * @param timeout how long is the lookup allowed to take at most
733 * @param validation_callback function to call with the results
734 * @param validation_callback_cls closure for peer_address_callback
736 struct GNUNET_TRANSPORT_ValidationMonitoringContext *
737 GNUNET_TRANSPORT_monitor_validation_entries (const struct
738 GNUNET_CONFIGURATION_Handle *cfg,
739 const struct GNUNET_PeerIdentity *peer,
741 struct GNUNET_TIME_Relative timeout,
742 GNUNET_TRANSPORT_ValidationIterateCallback validation_callback,
743 void *validation_callback_cls);
747 * Return information about all current pending validation operations
749 * @param vic handle for the request to cancel
752 GNUNET_TRANSPORT_monitor_validation_entries_cancel (struct GNUNET_TRANSPORT_ValidationMonitoringContext *vic);
757 * Handle for blacklisting peers.
759 struct GNUNET_TRANSPORT_Blacklist;
763 * Function that decides if a connection is acceptable or not.
766 * @param pid peer to approve or disapproave
767 * @return GNUNET_OK if the connection is allowed, GNUNET_SYSERR if not
769 typedef int (*GNUNET_TRANSPORT_BlacklistCallback) (void *cls,
771 GNUNET_PeerIdentity * pid);
775 * Install a blacklist callback. The service will be queried for all
776 * existing connections as well as any fresh connections to check if
777 * they are permitted. If the blacklisting callback is unregistered,
778 * all hosts that were denied in the past will automatically be
779 * whitelisted again. Cancelling the blacklist handle is also the
780 * only way to re-enable connections from peers that were previously
783 * @param cfg configuration to use
784 * @param cb callback to invoke to check if connections are allowed
785 * @param cb_cls closure for cb
786 * @return NULL on error, otherwise handle for cancellation
788 struct GNUNET_TRANSPORT_Blacklist *
789 GNUNET_TRANSPORT_blacklist (const struct GNUNET_CONFIGURATION_Handle *cfg,
790 GNUNET_TRANSPORT_BlacklistCallback cb,
795 * Abort the blacklist. Note that this function is the only way for
796 * removing a peer from the blacklist.
798 * @param br handle of the request that is to be cancelled
801 GNUNET_TRANSPORT_blacklist_cancel (struct GNUNET_TRANSPORT_Blacklist *br);
805 #if 0 /* keep Emacsens' auto-indent happy */
812 /* ifndef GNUNET_TRANSPORT_SERVICE_H */
814 /* end of gnunet_transport_service.h */