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22 * @author Gabor X Toth
23 * @author Christian Grothoff
26 * Multicast service; multicast messaging via CADET
28 * @defgroup multicast Multicast service
29 * Multicast messaging via CADET.
33 #ifndef GNUNET_MULTICAST_SERVICE_H
34 #define GNUNET_MULTICAST_SERVICE_H
39 #if 0 /* keep Emacsens' auto-indent happy */
44 #include "gnunet_util_lib.h"
45 #include "gnunet_transport_service.h"
48 * Version number of GNUnet-multicast API.
50 #define GNUNET_MULTICAST_VERSION 0x00000000
53 * Opaque handle for a multicast group member.
55 struct GNUNET_MULTICAST_Member;
58 * Handle for the origin of a multicast group.
60 struct GNUNET_MULTICAST_Origin;
63 enum GNUNET_MULTICAST_MessageFlags
66 * First fragment of a message.
68 GNUNET_MULTICAST_MESSAGE_FIRST_FRAGMENT = 1 << 0,
71 * Last fragment of a message.
73 GNUNET_MULTICAST_MESSAGE_LAST_FRAGMENT = 1 << 1,
76 * OR'ed flags if message is not fragmented.
78 GNUNET_MULTICAST_MESSAGE_NOT_FRAGMENTED
79 = GNUNET_MULTICAST_MESSAGE_FIRST_FRAGMENT
80 | GNUNET_MULTICAST_MESSAGE_LAST_FRAGMENT,
83 * Historic message, used only locally when replaying messages from local
86 GNUNET_MULTICAST_MESSAGE_HISTORIC = 1 << 30
91 GNUNET_NETWORK_STRUCT_BEGIN
94 * Header of a multicast message fragment.
96 * This format is public as the replay mechanism must replay message fragments using the
97 * same format. This is needed as we want to integrity-check message fragments within
98 * the multicast layer to avoid multicasting mal-formed messages.
100 struct GNUNET_MULTICAST_MessageHeader
104 * Header for all multicast message fragments from the origin.
106 struct GNUNET_MessageHeader header;
109 * Number of hops this message fragment has taken since the origin.
111 * Helpful to determine shortest paths to the origin among honest peers for
112 * unicast requests from members. Updated at each hop and thus not signed and
115 uint32_t hop_counter GNUNET_PACKED;
118 * ECC signature of the message fragment.
120 * Signature must match the public key of the multicast group.
122 struct GNUNET_CRYPTO_EddsaSignature signature;
125 * Purpose for the signature and size of the signed data.
127 struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
130 * Number of the message fragment, monotonically increasing starting from 1.
132 uint64_t fragment_id GNUNET_PACKED;
135 * Byte offset of this @e fragment of the @e message.
137 uint64_t fragment_offset GNUNET_PACKED;
140 * Number of the message this fragment belongs to.
142 * Set in GNUNET_MULTICAST_origin_to_all().
144 uint64_t message_id GNUNET_PACKED;
147 * Counter that monotonically increases whenever a member parts the group.
149 * Set in GNUNET_MULTICAST_origin_to_all().
151 * It has significance in case of replay requests: when a member has missed
152 * messages and gets a replay request: in this case if the @a group_generation
153 * is still the same before and after the missed messages, it means that no
154 * @e join or @e part operations happened during the missed messages.
156 uint64_t group_generation GNUNET_PACKED;
159 * Flags for this message fragment.
161 * @see enum GNUNET_MULTICAST_MessageFlags
163 uint32_t flags GNUNET_PACKED;
165 /* Followed by message body. */
170 * Header of a request from a member to the origin.
172 struct GNUNET_MULTICAST_RequestHeader
175 * Header for all requests from a member to the origin.
177 struct GNUNET_MessageHeader header;
180 * Public key of the sending member.
182 struct GNUNET_CRYPTO_EcdsaPublicKey member_pub_key;
185 * ECC signature of the request fragment.
187 * Signature must match the public key of the multicast group.
189 struct GNUNET_CRYPTO_EcdsaSignature signature;
192 * Purpose for the signature and size of the signed data.
194 struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
197 * Number of the request fragment.
198 * Monotonically increasing from 1.
200 uint64_t fragment_id GNUNET_PACKED;
203 * Byte offset of this @e fragment of the @e request.
205 uint64_t fragment_offset GNUNET_PACKED;
208 * Number of the request this fragment belongs to.
210 * Set in GNUNET_MULTICAST_origin_to_all().
212 uint64_t request_id GNUNET_PACKED;
215 * Flags for this request.
217 enum GNUNET_MULTICAST_MessageFlags flags GNUNET_PACKED;
219 /* Followed by request body. */
222 GNUNET_NETWORK_STRUCT_END
226 * Maximum size of a multicast message fragment.
228 #define GNUNET_MULTICAST_FRAGMENT_MAX_SIZE (63 * 1024)
230 #define GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
231 (GNUNET_MULTICAST_FRAGMENT_MAX_SIZE \
232 - sizeof (struct GNUNET_MULTICAST_MessageHeader))
236 * Handle that identifies a join request.
238 * Used to match calls to #GNUNET_MULTICAST_JoinRequestCallback to the
239 * corresponding calls to #GNUNET_MULTICAST_join_decision().
241 struct GNUNET_MULTICAST_JoinHandle;
245 * Function to call with the decision made for a join request.
247 * Must be called once and only once in response to an invocation of the
248 * #GNUNET_MULTICAST_JoinRequestCallback.
251 * Join request handle.
253 * #GNUNET_YES if the join is approved,
254 * #GNUNET_NO if it is disapproved,
255 * #GNUNET_SYSERR if we cannot answer the request.
257 * Number of relays given.
259 * Array of suggested peers that might be useful relays to use
260 * when joining the multicast group (essentially a list of peers that
261 * are already part of the multicast group and might thus be willing
262 * to help with routing). If empty, only this local peer (which must
263 * be the multicast origin) is a good candidate for building the
264 * multicast tree. Note that it is unnecessary to specify our own
265 * peer identity in this array.
267 * Message to send in response to the joining peer;
268 * can also be used to redirect the peer to a different group at the
269 * application layer; this response is to be transmitted to the
270 * peer that issued the request even if admission is denied.
272 struct GNUNET_MULTICAST_ReplayHandle *
273 GNUNET_MULTICAST_join_decision (struct GNUNET_MULTICAST_JoinHandle *jh,
275 uint16_t relay_count,
276 const struct GNUNET_PeerIdentity *relays,
277 const struct GNUNET_MessageHeader *join_resp);
281 * Method called whenever another peer wants to join the multicast group.
283 * Implementations of this function must call GNUNET_MULTICAST_join_decision()
288 * @param member_pub_key
289 * Public key of the member requesting join.
291 * Application-dependent join message from the new member.
293 * Join handle to pass to GNUNET_MULTICAST_join_decison().
296 (*GNUNET_MULTICAST_JoinRequestCallback) (void *cls,
297 const struct GNUNET_CRYPTO_EcdsaPublicKey *member_pub_key,
298 const struct GNUNET_MessageHeader *join_msg,
299 struct GNUNET_MULTICAST_JoinHandle *jh);
303 * Method called to inform about the decision in response to a join request.
305 * If @a is_admitted is not #GNUNET_YES, then the multicast service disconnects
306 * the client and the multicast member handle returned by
307 * GNUNET_MULTICAST_member_join() is invalidated.
312 * #GNUNET_YES or #GNUNET_NO or #GNUNET_SYSERR
314 * The peer we are connected to and the join decision is from.
316 * Number of peers in the @a relays array.
318 * Peer identities of members of the group, which serve as relays
319 * and can be used to join the group at. If empty, only the origin can
320 * be used to connect to the group.
322 * Application-dependent join message from the origin.
325 (*GNUNET_MULTICAST_JoinDecisionCallback) (void *cls,
327 const struct GNUNET_PeerIdentity *peer,
328 uint16_t relay_count,
329 const struct GNUNET_PeerIdentity *relays,
330 const struct GNUNET_MessageHeader *join_msg);
334 * Function called whenever a group member has transmitted a request
335 * to the origin (other than joining or leaving).
337 * FIXME: need to distinguish between origin cancelling a message (some fragments
338 * were sent, then the rest 'discarded') and the case where we got disconnected;
339 * right now, both would mean 'msg' is NULL, but they could be quite different...
340 * So the semantics from the receiver side of
341 * GNUNET_MULTICAST_member_to_origin_cancel() are not clear here. Maybe we
342 * should do something with the flags in this case?
345 * Closure (set from GNUNET_MULTICAST_origin_start).
347 * Identity of the sender.
349 * Request to the origin.
351 * Flags for the request.
354 (*GNUNET_MULTICAST_RequestCallback) (void *cls,
355 const struct GNUNET_MULTICAST_RequestHeader *req);
359 * Function called whenever a group member is receiving a message fragment from
362 * If admission to the group is denied, this function is called once with the
363 * response of the @e origin (as given to GNUNET_MULTICAST_join_decision()) and
364 * then a second time with NULL to indicate that the connection failed for good.
366 * FIXME: need to distinguish between origin cancelling a message (some fragments
367 * were sent, then the rest 'discarded') and the case where we got disconnected;
368 * right now, both would mean 'msg' is NULL, but they could be quite different...
369 * So the semantics from the receiver side of
370 * GNUNET_MULTICAST_origin_to_all_cancel() are not clear here.
373 * Closure (set from GNUNET_MULTICAST_member_join())
375 * Message from the origin, NULL if the origin shut down
376 * (or we were kicked out, and we should thus call
377 * GNUNET_MULTICAST_member_part() next)
380 (*GNUNET_MULTICAST_MessageCallback) (void *cls,
381 const struct GNUNET_MULTICAST_MessageHeader *msg);
385 * Opaque handle to a replay request from the multicast service.
387 struct GNUNET_MULTICAST_ReplayHandle;
391 * Functions with this signature are called whenever the multicast service needs
392 * a message fragment to be replayed by fragment_id.
394 * Implementations of this function MUST call GNUNET_MULTICAST_replay() ONCE
395 * (with a message or an error); however, if the origin is destroyed or the
396 * group is left, the replay handle must no longer be used.
399 * Closure (set from GNUNET_MULTICAST_origin_start()
400 * or GNUNET_MULTICAST_member_join()).
401 * @param member_pub_key
402 * The member requesting replay.
404 * Which message fragment should be replayed.
406 * Flags for the replay.
408 * Handle to pass to message transmit function.
411 (*GNUNET_MULTICAST_ReplayFragmentCallback) (void *cls,
412 const struct GNUNET_CRYPTO_EcdsaPublicKey *member_pub_key,
413 uint64_t fragment_id,
415 struct GNUNET_MULTICAST_ReplayHandle *rh);
418 * Functions with this signature are called whenever the multicast service needs
419 * a message fragment to be replayed by message_id and fragment_offset.
421 * Implementations of this function MUST call GNUNET_MULTICAST_replay() ONCE
422 * (with a message or an error); however, if the origin is destroyed or the
423 * group is left, the replay handle must no longer be used.
426 * Closure (set from GNUNET_MULTICAST_origin_start()
427 * or GNUNET_MULTICAST_member_join()).
428 * @param member_pub_key
429 * The member requesting replay.
431 * Which message should be replayed.
432 * @param fragment_offset
433 * Offset of the fragment within of @a message_id to be replayed.
435 * Flags for the replay.
437 * Handle to pass to message transmit function.
440 (*GNUNET_MULTICAST_ReplayMessageCallback) (void *cls,
441 const struct GNUNET_CRYPTO_EcdsaPublicKey *member_pub_key,
443 uint64_t fragment_offset,
445 struct GNUNET_MULTICAST_ReplayHandle *rh);
449 * Possible error codes during replay.
451 enum GNUNET_MULTICAST_ReplayErrorCode
455 * Everything is fine.
457 GNUNET_MULTICAST_REC_OK = 0,
460 * Message fragment not found in the message store.
462 * Either discarded if it is too old, or not arrived yet if this member has
463 * missed some messages.
465 GNUNET_MULTICAST_REC_NOT_FOUND = 1,
468 * Fragment ID counter was larger than the highest counter this
469 * replay function has ever encountered; thus it is likely the
470 * origin never sent it and we're at the HEAD of the multicast
471 * stream as far as this node is concerned.
475 GNUNET_MULTICAST_REC_PAST_HEAD = 2,
478 * Access is denied to the requested fragment, membership test did not pass.
480 GNUNET_MULTICAST_REC_ACCESS_DENIED = 3,
483 * Internal error (i.e. database error). Try some other peer.
485 GNUNET_MULTICAST_REC_INTERNAL_ERROR = 4
491 * Replay a message fragment for the multicast group.
494 * Replay handle identifying which replay operation was requested.
496 * Replayed message fragment, NULL if not found / an error occurred.
498 * Error code. See enum GNUNET_MULTICAST_ReplayErrorCode
499 * If not #GNUNET_MULTICAST_REC_OK, the replay handle is invalidated.
502 GNUNET_MULTICAST_replay_response (struct GNUNET_MULTICAST_ReplayHandle *rh,
503 const struct GNUNET_MessageHeader *msg,
504 enum GNUNET_MULTICAST_ReplayErrorCode ec);
508 * Indicate the end of the replay session.
510 * Invalidates the replay handle.
512 * @param rh Replay session to end.
515 GNUNET_MULTICAST_replay_response_end (struct GNUNET_MULTICAST_ReplayHandle *rh);
519 * Function called to provide data for a transmission for a replay.
521 * @see GNUNET_MULTICAST_replay2()
524 (*GNUNET_MULTICAST_ReplayTransmitNotify) (void *cls,
530 * Replay a message for the multicast group.
533 * Replay handle identifying which replay operation was requested.
535 * Function to call to get the message.
537 * Closure for @a notify.
540 GNUNET_MULTICAST_replay_response2 (struct GNUNET_MULTICAST_ReplayHandle *rh,
541 GNUNET_MULTICAST_ReplayTransmitNotify notify,
546 * Start a multicast group.
548 * Peers that issue GNUNET_MULTICAST_member_join() can transmit a join request
549 * to either an existing group member or to the origin. If the joining is
550 * approved, the member is cleared for @e replay and will begin to receive
551 * messages transmitted to the group. If joining is disapproved, the failed
552 * candidate will be given a response. Members in the group can send messages
555 * TODO: This function could optionally offer to advertise the origin in the
556 * P2P overlay network(where?) under the respective public key so that other
557 * peers can find an alternate PeerId to join it. Higher level protocols may
558 * however provide other means of solving the problem of the offline host
559 * (see secushare specs about that) and therefore merely need a way to provide
560 * a list of possible PeerIds.
563 * Configuration to use.
565 * ECC key that will be used to sign messages for this
566 * multicast session; public key is used to identify the multicast group;
567 * @param max_fragment_id
568 * Maximum fragment ID already sent to the group.
570 * @param join_request_cb
571 * Function called to approve / disapprove joining of a peer.
572 * @param replay_frag_cb
573 * Function that can be called to replay a message fragment.
574 * @param replay_msg_cb
575 * Function that can be called to replay a message.
577 * Function called with message fragments from group members.
579 * Function called with the message fragments sent to the
580 * network by GNUNET_MULTICAST_origin_to_all(). These message fragments
581 * should be stored for answering replay requests later.
583 * Closure for the various callbacks that follow.
585 * @return Handle for the origin, NULL on error.
587 struct GNUNET_MULTICAST_Origin *
588 GNUNET_MULTICAST_origin_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
589 const struct GNUNET_CRYPTO_EddsaPrivateKey *priv_key,
590 uint64_t max_fragment_id,
591 GNUNET_MULTICAST_JoinRequestCallback join_request_cb,
592 GNUNET_MULTICAST_ReplayFragmentCallback replay_frag_cb,
593 GNUNET_MULTICAST_ReplayMessageCallback replay_msg_cb,
594 GNUNET_MULTICAST_RequestCallback request_cb,
595 GNUNET_MULTICAST_MessageCallback message_cb,
599 * Function called to provide data for a transmission from the origin to all
602 * Note that returning #GNUNET_OK or #GNUNET_SYSERR (but not #GNUNET_NO)
603 * invalidates the respective transmission handle.
607 * @param[in,out] data_size
608 * Initially set to the number of bytes available in
609 * @a data, should be set to the number of bytes written to data.
611 * Where to write the body of the message to give to the
612 * method. The function must copy at most @a data_size bytes to @a data.
614 * @return #GNUNET_SYSERR on error (fatal, aborts transmission)
615 * #GNUNET_NO on success, if more data is to be transmitted later.
616 * Should be used if @a data_size was not big enough to take all the
617 * data. If 0 is returned in @a data_size the transmission is paused,
618 * and can be resumed with GNUNET_MULTICAST_origin_to_all_resume().
619 * #GNUNET_YES if this completes the transmission (all data supplied)
622 (*GNUNET_MULTICAST_OriginTransmitNotify) (void *cls,
628 * Handle for a request to send a message to all multicast group members
631 struct GNUNET_MULTICAST_OriginTransmitHandle;
635 * Send a message to the multicast group.
638 * Handle to the multicast group.
640 * Application layer ID for the message. Opaque to multicast.
641 * @param group_generation
642 * Group generation of the message. Documented in
643 * struct GNUNET_MULTICAST_MessageHeader.
645 * Function to call to get the message.
647 * Closure for @a notify.
649 * @return NULL on error (i.e. request already pending).
651 struct GNUNET_MULTICAST_OriginTransmitHandle *
652 GNUNET_MULTICAST_origin_to_all (struct GNUNET_MULTICAST_Origin *origin,
654 uint64_t group_generation,
655 GNUNET_MULTICAST_OriginTransmitNotify notify,
661 * Resume message transmission to multicast group.
663 * @param th Transmission to cancel.
666 GNUNET_MULTICAST_origin_to_all_resume (struct GNUNET_MULTICAST_OriginTransmitHandle *th);
670 * Cancel request for message transmission to multicast group.
672 * @param th Transmission to cancel.
675 GNUNET_MULTICAST_origin_to_all_cancel (struct GNUNET_MULTICAST_OriginTransmitHandle *th);
679 * Stop a multicast group.
681 * @param origin Multicast group to stop.
684 GNUNET_MULTICAST_origin_stop (struct GNUNET_MULTICAST_Origin *origin,
685 GNUNET_ContinuationCallback stop_cb,
690 * Join a multicast group.
692 * The entity joining is always the local peer. Further information about the
693 * candidate can be provided in @a join_msg. If the join fails, the
694 * @a message_cb is invoked with a (failure) response and then with NULL. If
695 * the join succeeds, outstanding (state) messages and ongoing multicast
696 * messages will be given to the @a message_cb until the member decides to part
697 * the group. The @a mem_test_cb and @a replay_cb functions may be called at
698 * anytime by the multicast service to support relaying messages to other
699 * members of the group.
702 * Configuration to use.
704 * ECC public key that identifies the group to join.
705 * @param member_pub_key
706 * ECC key that identifies the member
707 * and used to sign requests sent to the origin.
709 * Peer ID of the origin to send unicast requsets to. If NULL,
710 * unicast requests are sent back via multiple hops on the reverse path
711 * of multicast messages.
713 * Number of peers in the @a relays array.
715 * Peer identities of members of the group, which serve as relays
716 * and can be used to join the group at. and send the @a join_request to.
717 * If empty, the @a join_request is sent directly to the @a origin.
719 * Application-dependent join message to be passed to the peer @a origin.
720 * @param join_request_cb
721 * Function called to approve / disapprove joining of a peer.
722 * @param join_decision_cb
723 * Function called to inform about the join decision.
724 * @param replay_frag_cb
725 * Function that can be called to replay message fragments
726 * this peer already knows from this group. NULL if this
727 * client is unable to support replay.
728 * @param replay_msg_cb
729 * Function that can be called to replay message fragments
730 * this peer already knows from this group. NULL if this
731 * client is unable to support replay.
733 * Function to be called for all message fragments we
734 * receive from the group, excluding those our @a replay_cb
737 * Closure for callbacks.
739 * @return Handle for the member, NULL on error.
741 struct GNUNET_MULTICAST_Member *
742 GNUNET_MULTICAST_member_join (const struct GNUNET_CONFIGURATION_Handle *cfg,
743 const struct GNUNET_CRYPTO_EddsaPublicKey *group_key,
744 const struct GNUNET_CRYPTO_EcdsaPrivateKey *member_pub_key,
745 const struct GNUNET_PeerIdentity *origin,
746 uint16_t relay_count,
747 const struct GNUNET_PeerIdentity *relays,
748 const struct GNUNET_MessageHeader *join_request,
749 GNUNET_MULTICAST_JoinRequestCallback join_request_cb,
750 GNUNET_MULTICAST_JoinDecisionCallback join_decision_cb,
751 GNUNET_MULTICAST_ReplayFragmentCallback replay_frag_cb,
752 GNUNET_MULTICAST_ReplayMessageCallback replay_msg_cb,
753 GNUNET_MULTICAST_MessageCallback message_cb,
757 * Handle for a replay request.
759 struct GNUNET_MULTICAST_MemberReplayHandle;
763 * Request a fragment to be replayed by fragment ID.
765 * Useful if messages below the @e max_known_fragment_id given when joining are
766 * needed and not known to the client.
771 * ID of a message fragment that this client would like to see replayed.
773 * Additional flags for the replay request.
774 * It is used and defined by GNUNET_MULTICAST_ReplayFragmentCallback
776 * @return Replay request handle, NULL on error.
778 struct GNUNET_MULTICAST_MemberReplayHandle *
779 GNUNET_MULTICAST_member_replay_fragment (struct GNUNET_MULTICAST_Member *member,
780 uint64_t fragment_id,
785 * Request a message fr to be replayed.
787 * Useful if messages below the @e max_known_fragment_id given when joining are
788 * needed and not known to the client.
793 * ID of the message this client would like to see replayed.
794 * @param fragment_offset
795 * Offset of the fragment within the message to replay.
797 * Additional flags for the replay request.
798 * It is used & defined by GNUNET_MULTICAST_ReplayMessageCallback
800 * @return Replay request handle, NULL on error.
802 struct GNUNET_MULTICAST_MemberReplayHandle *
803 GNUNET_MULTICAST_member_replay_message (struct GNUNET_MULTICAST_Member *member,
805 uint64_t fragment_offset,
810 * Cancel a replay request.
816 GNUNET_MULTICAST_member_replay_cancel (struct GNUNET_MULTICAST_MemberReplayHandle *rh);
820 * Part a multicast group.
822 * Disconnects from all group members and invalidates the @a member handle.
824 * An application-dependent part message can be transmitted beforehand using
825 * #GNUNET_MULTICAST_member_to_origin())
831 GNUNET_MULTICAST_member_part (struct GNUNET_MULTICAST_Member *member,
832 GNUNET_ContinuationCallback part_cb,
837 * Function called to provide data for a transmission from a member to the origin.
839 * Note that returning #GNUNET_OK or #GNUNET_SYSERR (but not #GNUNET_NO)
840 * invalidates the respective transmission handle.
844 * @param[in,out] data_size
845 * Initially set to the number of bytes available in
846 * @a data, should be set to the number of bytes written to data.
848 * Where to write the body of the message to give to the
849 * method. The function must copy at most @a data_size bytes to @a data.
851 * @return #GNUNET_SYSERR on error (fatal, aborts transmission)
852 * #GNUNET_NO on success, if more data is to be transmitted later.
853 * Should be used if @a data_size was not big enough to take all the
854 * data. If 0 is returned in @a data_size the transmission is paused,
855 * and can be resumed with GNUNET_MULTICAST_member_to_origin_resume().
856 * #GNUNET_YES if this completes the transmission (all data supplied)
859 (*GNUNET_MULTICAST_MemberTransmitNotify) (void *cls,
865 * Handle for a message to be delivered from a member to the origin.
867 struct GNUNET_MULTICAST_MemberTransmitHandle;
871 * Send a message to the origin of the multicast group.
876 * Application layer ID for the request. Opaque to multicast.
878 * Callback to call to get the message.
880 * Closure for @a notify.
882 * @return Handle to cancel request, NULL on error (i.e. request already pending).
884 struct GNUNET_MULTICAST_MemberTransmitHandle *
885 GNUNET_MULTICAST_member_to_origin (struct GNUNET_MULTICAST_Member *member,
887 GNUNET_MULTICAST_MemberTransmitNotify notify,
892 * Resume message transmission to origin.
895 * Transmission to cancel.
898 GNUNET_MULTICAST_member_to_origin_resume (struct GNUNET_MULTICAST_MemberTransmitHandle *th);
902 * Cancel request for message transmission to origin.
905 * Transmission to cancel.
908 GNUNET_MULTICAST_member_to_origin_cancel (struct GNUNET_MULTICAST_MemberTransmitHandle *th);
911 #if 0 /* keep Emacsens' auto-indent happy */
918 /* ifndef GNUNET_MULTICAST_SERVICE_H */
921 /** @} */ /* end of group */