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22 * @file include/gnunet_psyc_service.h
23 * @brief PSYC service; high-level access to the PSYC protocol
24 * note that clients of this API are NOT expected to
25 * understand the PSYC message format, only the semantics!
26 * Parsing (and serializing) the PSYC stream format is done
27 * within the implementation of the libgnunetpsyc library,
28 * and this API deliberately exposes as little as possible
29 * of the actual data stream format to the application!
30 * @author Christian Grothoff
31 * @author Gabor X Toth
34 * - this API does not know about psyc's "root" and "places";
35 * there is no 'root' in GNUnet-Psyc as we're decentralized;
36 * 'places' and 'persons' are combined within the same
37 * abstraction, that of a "channel". Channels are identified
38 * and accessed in this API using a public/private key.
39 * Higher-level applications should use NAMES within GNS
40 * to obtain public keys, and the distinction between
41 * 'places' and 'persons' can then be made with the help
42 * of the naming system (and/or conventions).
43 * Channels are (as in PSYC) organized into a hierarchy; each
44 * channel master (the one with the private key) is then
45 * the operator of the multicast group (its Origin in
46 * the terminology of the multicast API).
47 * - The API supports passing large amounts of data using
48 * 'streaming' for the argument passed to a method. State
49 * and variables must fit into memory and cannot be streamed
50 * (thus, no passing of 4 GB of data in a variable;
51 * once we implement this, we might want to create a
52 * @c \#define for the maximum size of a variable).
53 * - PSYC defines standard variables, methods, etc. This
54 * library deliberately abstracts over all of these; a
55 * higher-level API should combine the naming system (GNS)
56 * and standard methods (message, join, part, warn,
57 * fail, error) and variables (action, color, time,
58 * tag, etc.). However, this API does take over the
59 * routing variables, specifically 'context' (channel),
60 * and 'source'. We only kind-of support 'target', as
61 * the target is either everyone in the group or the
62 * origin, and never just a single member of the group;
63 * for such individual messages, an application needs to
64 * construct an 'inbox' channel where the master (only)
65 * receives messages (but never forwards; private responses
66 * would be transmitted by joining the senders 'inbox'
67 * channel -- or a inbox#bob subchannel). The
68 * goal for all of this is to keep the abstractions in this
69 * API minimal: interaction with multicast, try \& slice,
70 * state/variable/channel management. Higher-level
71 * operations belong elsewhere (so maybe this API should
72 * be called 'PSYC-low', whereas a higher-level API
73 * implementing defaults for standard methods and
74 * variables might be called 'PSYC-std' or 'PSYC-high'.
77 #ifndef GNUNET_PSYC_SERVICE_H
78 #define GNUNET_PSYC_SERVICE_H
83 #if 0 /* keep Emacsens' auto-indent happy */
88 #include "gnunet_util_lib.h"
89 #include "gnunet_env_lib.h"
90 #include "gnunet_multicast_service.h"
94 * Version number of GNUnet-PSYC API.
96 #define GNUNET_PSYC_VERSION 0x00000000
100 * Policy flags for a channel.
102 enum GNUNET_PSYC_ChannelFlags
105 * Admission must be confirmed by the master.
107 GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL = 1 << 0,
110 * Past messages are only available to slaves who were admitted at the time
111 * they were sent to the channel.
113 GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY = 1 << 1
118 * PSYC channel policies.
120 enum GNUNET_PSYC_Policy
123 * Anyone can join the channel, without announcing his presence;
124 * all messages are always public and can be distributed freely.
125 * Joins may be announced, but this is not required.
127 GNUNET_PSYC_CHANNEL_ANONYMOUS = 0,
130 * The master must approve membership to the channel, messages must only be
131 * distributed to current channel slaves. This includes the channel
132 * state as well as transient messages.
134 GNUNET_PSYC_CHANNEL_PRIVATE
135 = GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL
136 | GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY
140 * Anyone can freely join the channel (no approval required);
141 * however, messages must only be distributed to current channel
142 * slaves, so the master must still acknowledge that the slave
143 * joined before transient messages are delivered. As approval is
144 * guaranteed, the presistent channel state can be synchronized freely
145 * immediately, prior to master confirmation.
147 GNUNET_PSYC_CHANNEL_OPEN
148 = GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY,
151 * The master must approve joins to the channel, but past messages can be
152 * freely distributed to slaves.
154 GNUNET_PSYC_CHANNEL_CLOSED
155 = GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL,
160 enum GNUNET_PSYC_MessageFlags
163 * Default / no flags.
165 GNUNET_PSYC_MESSAGE_DEFAULT = 0,
168 * Historic message, retrieved from PSYCstore.
170 GNUNET_PSYC_MESSAGE_HISTORIC = 1 << 0,
173 * Request from slave to master.
175 GNUNET_PSYC_MESSAGE_REQUEST = 1 << 1,
178 * Message can be delivered out of order.
180 GNUNET_PSYC_MESSAGE_ORDER_ANY = 1 << 2
185 * Values for the @a state_delta field of GNUNET_PSYC_MessageHeader.
187 enum GNUNET_PSYC_StateDeltaValues
189 GNUNET_PSYC_STATE_RESET = 0,
191 GNUNET_PSYC_STATE_NOT_MODIFIED = UINT64_MAX
195 GNUNET_NETWORK_STRUCT_BEGIN
200 * Used for single-fragment messages e.g. in a join request or response.
202 struct GNUNET_PSYC_Message
205 * Message header with size and type information.
207 struct GNUNET_MessageHeader header;
209 /* Followed by concatenated PSYC message parts:
210 * messages with GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_* types
216 * Header of a PSYC message.
218 * Only present when receiving a message.
220 struct GNUNET_PSYC_MessageHeader
223 * Generic message header with size and type information.
225 struct GNUNET_MessageHeader header;
228 * Flags for this message fragment.
230 * @see enum GNUNET_PSYC_MessageFlags
232 uint32_t flags GNUNET_PACKED;
235 * Number of the message this message part belongs to.
236 * Monotonically increasing from 1.
238 uint64_t message_id GNUNET_PACKED;
241 * Byte offset of this @e fragment of the @e message.
242 * FIXME: use data_offset instead
244 uint64_t fragment_offset GNUNET_PACKED;
247 * Sending slave's public key.
248 * Not set if the message is from the master.
250 struct GNUNET_CRYPTO_EcdsaPublicKey slave_key;
252 /* Followed by concatenated PSYC message parts:
253 * messages with GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_* types
259 * The method of a message.
261 struct GNUNET_PSYC_MessageMethod
264 * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
266 struct GNUNET_MessageHeader header;
269 * OR'ed GNUNET_PSYC_MasterTransmitFlags
271 uint32_t flags GNUNET_PACKED;
274 * Number of message IDs since the last message that contained state
275 * operations. @see enum GNUNET_PSYC_StateDeltaValues
277 uint64_t state_delta GNUNET_PACKED;
279 /* Followed by NUL-terminated method name. */
284 * A modifier of a message.
286 struct GNUNET_PSYC_MessageModifier
289 * Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
291 struct GNUNET_MessageHeader header;
296 uint32_t value_size GNUNET_PACKED;
299 * Size of name, including NUL terminator.
301 uint16_t name_size GNUNET_PACKED;
304 * enum GNUNET_ENV_Operator
308 /* Followed by NUL-terminated name, then the value. */
312 struct GNUNET_PSYC_CountersResultMessage
315 * Type: GNUNET_MESSAGE_TYPE_PSYC_RESULT_COUNTERS
317 struct GNUNET_MessageHeader header;
320 * Status code for the operation.
322 uint32_t result_code GNUNET_PACKED;
325 * Last message ID sent to the channel.
327 uint64_t max_message_id GNUNET_PACKED;
332 * Join request sent to a PSYC master.
334 struct GNUNET_PSYC_JoinRequestMessage
337 * Type: GNUNET_MESSAGE_TYPE_PSYC_MASTER_JOIN_REQUEST
339 struct GNUNET_MessageHeader header;
341 * Public key of the joining slave.
343 struct GNUNET_CRYPTO_EcdsaPublicKey slave_key;
345 /* Followed by struct GNUNET_MessageHeader join_request */
350 * Join decision sent in reply to a join request.
352 struct GNUNET_PSYC_JoinDecisionMessage
355 * Type: GNUNET_MESSAGE_TYPE_PSYC_JOIN_DECISION
357 struct GNUNET_MessageHeader header;
360 * #GNUNET_YES if the slave was admitted.
365 * Public key of the joining slave.
366 * Only set when the master is sending the decision,
367 * not set when a slave is receiving it.
369 struct GNUNET_CRYPTO_EcdsaPublicKey slave_key;
371 /* Followed by struct GNUNET_MessageHeader join_response */
374 GNUNET_NETWORK_STRUCT_END
377 #define GNUNET_PSYC_MODIFIER_MAX_PAYLOAD \
378 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
379 - sizeof (struct GNUNET_PSYC_MessageModifier)
381 #define GNUNET_PSYC_MOD_CONT_MAX_PAYLOAD \
382 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
383 - sizeof (struct GNUNET_MessageHeader)
385 #define GNUNET_PSYC_DATA_MAX_PAYLOAD \
386 GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
387 - sizeof (struct GNUNET_MessageHeader)
391 * PSYC message part processing states.
393 enum GNUNET_PSYC_MessageState
395 GNUNET_PSYC_MESSAGE_STATE_START = 0,
396 GNUNET_PSYC_MESSAGE_STATE_HEADER = 1,
397 GNUNET_PSYC_MESSAGE_STATE_METHOD = 2,
398 GNUNET_PSYC_MESSAGE_STATE_MODIFIER = 3,
399 GNUNET_PSYC_MESSAGE_STATE_MOD_CONT = 4,
400 GNUNET_PSYC_MESSAGE_STATE_DATA = 5,
401 GNUNET_PSYC_MESSAGE_STATE_END = 6,
402 GNUNET_PSYC_MESSAGE_STATE_CANCEL = 7,
403 GNUNET_PSYC_MESSAGE_STATE_ERROR = 8,
408 * Handle that identifies a join request.
410 * Used to match calls to #GNUNET_PSYC_JoinCallback to the
411 * corresponding calls to GNUNET_PSYC_join_decision().
413 struct GNUNET_PSYC_JoinHandle;
417 * Method called from PSYC upon receiving a message.
419 * @param cls Closure.
420 * @param message_id Sequence number of the message.
421 * @param flags OR'ed GNUNET_PSYC_MessageFlags
422 * @param msg Message part, one of the following types:
425 (*GNUNET_PSYC_MessageCallback) (void *cls,
428 const struct GNUNET_PSYC_MessageHeader *msg);
432 * Method called from PSYC upon receiving part of a message.
434 * @param cls Closure.
435 * @param message_id Sequence number of the message.
436 * @param data_offset Byte offset of data, only set if @a msg has a type
437 * #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_DATA
438 * @param flags OR'ed GNUNET_PSYC_MessageFlags
439 * @param msg Message part, one of the following types:
440 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_HEADER
441 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
442 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
443 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MOD_CONT
444 * - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_DATA
445 * or NULL if an error occurred while receiving a message.
448 (*GNUNET_PSYC_MessagePartCallback) (void *cls,
450 uint64_t data_offset,
452 const struct GNUNET_MessageHeader *msg);
456 * Method called from PSYC upon receiving a join request.
458 * @param cls Closure.
459 * @param slave_key Public key of the slave requesting join.
460 * @param join_msg Join message sent along with the request.
461 * @param jh Join handle to use with GNUNET_PSYC_join_decision()
464 (*GNUNET_PSYC_JoinRequestCallback) (void *cls,
465 const struct GNUNET_PSYC_JoinRequestMessage *req,
466 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
467 const struct GNUNET_PSYC_Message *join_msg,
468 struct GNUNET_PSYC_JoinHandle *jh);
472 * Function to call with the decision made for a join request.
474 * Must be called once and only once in response to an invocation of the
475 * #GNUNET_PSYC_JoinCallback.
477 * @param jh Join request handle.
479 * #GNUNET_YES if the join is approved,
480 * #GNUNET_NO if it is disapproved,
481 * #GNUNET_SYSERR if we cannot answer the request.
482 * @param relay_count Number of relays given.
483 * @param relays Array of suggested peers that might be useful relays to use
484 * when joining the multicast group (essentially a list of peers that
485 * are already part of the multicast group and might thus be willing
486 * to help with routing). If empty, only this local peer (which must
487 * be the multicast origin) is a good candidate for building the
488 * multicast tree. Note that it is unnecessary to specify our own
489 * peer identity in this array.
490 * @param join_resp Application-dependent join response message to send along
493 * @return #GNUNET_OK on success,
494 * #GNUNET_SYSERR if @a join_resp is too large.
497 GNUNET_PSYC_join_decision (struct GNUNET_PSYC_JoinHandle *jh,
499 uint32_t relay_count,
500 const struct GNUNET_PeerIdentity *relays,
501 const struct GNUNET_PSYC_Message *join_resp);
505 * Handle for the master of a PSYC channel.
507 struct GNUNET_PSYC_Master;
511 * Function called after connected to the PSYC service
512 * and the channel master started.
514 * Also called when reconnected to the service
515 * after the connection closed unexpectedly.
520 * #GNUNET_YES if there were already messages sent to the channel,
521 * #GNUNET_NO if the message history is empty,
522 * #GNUNET_SYSERR on error.
523 * @param max_message_id
524 * Last message ID sent to the channel.
527 (*GNUNET_PSYC_MasterStartCallback) (void *cls, int result,
528 uint64_t max_message_id);
532 * Start a PSYC master channel.
534 * Will start a multicast group identified by the given ECC key. Messages
535 * received from group members will be given to the respective handler methods.
536 * If a new member wants to join a group, the "join" method handler will be
537 * invoked; the join handler must then generate a "join" message to approve the
538 * joining of the new member. The channel can also change group membership
539 * without explicit requests. Note that PSYC doesn't itself "understand" join
540 * or part messages, the respective methods must call other PSYC functions to
541 * inform PSYC about the meaning of the respective events.
543 * @param cfg Configuration to use (to connect to PSYC service).
544 * @param channel_key ECC key that will be used to sign messages for this
545 * PSYC session. The public key is used to identify the PSYC channel.
546 * Note that end-users will usually not use the private key directly, but
547 * rather look it up in GNS for places managed by other users, or select
548 * a file with the private key(s) when setting up their own channels
549 * FIXME: we'll likely want to use NOT the p521 curve here, but a cheaper
551 * @param policy Channel policy specifying join and history restrictions.
552 * Used to automate join decisions.
553 * @param master_start_cb Function to invoke after the channel master started.
554 * @param join_request_cb Function to invoke when a slave wants to join.
555 * @param message_cb Function to invoke on message parts sent to the channel
556 * and received from slaves
557 * @param cls Closure for @a method and @a join_cb.
559 * @return Handle for the channel master, NULL on error.
561 struct GNUNET_PSYC_Master *
562 GNUNET_PSYC_master_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
563 const struct GNUNET_CRYPTO_EddsaPrivateKey *channel_key,
564 enum GNUNET_PSYC_Policy policy,
565 GNUNET_PSYC_MasterStartCallback master_start_cb,
566 GNUNET_PSYC_JoinRequestCallback join_request_cb,
567 GNUNET_PSYC_MessageCallback message_cb,
568 GNUNET_PSYC_MessagePartCallback message_part_cb,
573 * Function called to provide data for a transmission via PSYC.
575 * Note that returning #GNUNET_YES or #GNUNET_SYSERR (but not #GNUNET_NO)
576 * invalidates the respective transmission handle.
578 * @param cls Closure.
579 * @param[in,out] data_size Initially set to the number of bytes available in
580 * @a data, should be set to the number of bytes written to data.
581 * @param[out] data Where to write the body of the message to give to the
582 * method. The function must copy at most @a data_size bytes to @a data.
583 * @return #GNUNET_SYSERR on error (fatal, aborts transmission)
584 * #GNUNET_NO on success, if more data is to be transmitted later.
585 * Should be used if @a data_size was not big enough to take all the
586 * data. If 0 is returned in @a data_size the transmission is paused,
587 * and can be resumed with GNUNET_PSYC_master_transmit_resume().
588 * #GNUNET_YES if this completes the transmission (all data supplied)
591 (*GNUNET_PSYC_TransmitNotifyData) (void *cls,
596 * Function called to provide a modifier for a transmission via PSYC.
598 * Note that returning #GNUNET_YES or #GNUNET_SYSERR (but not #GNUNET_NO)
599 * invalidates the respective transmission handle.
601 * @param cls Closure.
602 * @param[in,out] data_size Initially set to the number of bytes available in
603 * @a data, should be set to the number of bytes written to data.
604 * @param[out] data Where to write the modifier's name and value.
605 * The function must copy at most @a data_size bytes to @a data.
606 * When this callback is first called for a modifier, @a data should
607 * contain: "name\0value". If the whole value does not fit, subsequent
608 * calls to this function should write continuations of the value to
610 * @param[out] oper Where to write the operator of the modifier.
611 * Only needed during the first call to this callback at the beginning
612 * of the modifier. In case of subsequent calls asking for value
613 * continuations @a oper is set to #NULL.
614 * @param[out] full_value_size Where to write the full size of the value.
615 * Only needed during the first call to this callback at the beginning
616 * of the modifier. In case of subsequent calls asking for value
617 * continuations @a value_size is set to #NULL.
618 * @return #GNUNET_SYSERR on error (fatal, aborts transmission)
619 * #GNUNET_NO on success, if more data is to be transmitted later.
620 * Should be used if @a data_size was not big enough to take all the
621 * data for the modifier's value (the name must be always returned
622 * during the first call to this callback).
623 * If 0 is returned in @a data_size the transmission is paused,
624 * and can be resumed with GNUNET_PSYC_master_transmit_resume().
625 * #GNUNET_YES if this completes the modifier (the whole value is supplied).
628 (*GNUNET_PSYC_TransmitNotifyModifier) (void *cls,
632 uint32_t *full_value_size);
635 * Flags for transmitting messages to a channel by the master.
637 enum GNUNET_PSYC_MasterTransmitFlags
639 GNUNET_PSYC_MASTER_TRANSMIT_NONE = 0,
642 * Whether this message should reset the channel state,
643 * i.e. remove all previously stored state variables.
646 GNUNET_PSYC_MASTER_TRANSMIT_STATE_RESET = 1 << 0,
649 * Whether this message contains any state modifiers.
651 GNUNET_PSYC_MASTER_TRANSMIT_STATE_MODIFY = 1 << 1,
654 * Add PSYC header variable with the hash of the current channel state.
656 GNUNET_PSYC_MASTER_TRANSMIT_STATE_HASH = 1 << 2,
659 * Whether we need to increment the group generation counter after
660 * transmitting this message.
662 GNUNET_PSYC_MASTER_TRANSMIT_INC_GROUP_GEN = 1 << 3
667 * Handle for a pending PSYC transmission operation.
669 struct GNUNET_PSYC_MasterTransmitHandle;
673 * Send a message to call a method to all members in the PSYC channel.
675 * @param master Handle to the PSYC channel.
676 * @param method_name Which method should be invoked.
677 * @param notify_mod Function to call to obtain modifiers.
678 * @param notify_data Function to call to obtain fragments of the data.
679 * @param notify_cls Closure for @a notify_mod and @a notify_data.
680 * @param flags Flags for the message being transmitted.
681 * @return Transmission handle, NULL on error (i.e. more than one request queued).
683 struct GNUNET_PSYC_MasterTransmitHandle *
684 GNUNET_PSYC_master_transmit (struct GNUNET_PSYC_Master *master,
685 const char *method_name,
686 GNUNET_PSYC_TransmitNotifyModifier notify_mod,
687 GNUNET_PSYC_TransmitNotifyData notify_data,
689 enum GNUNET_PSYC_MasterTransmitFlags flags);
693 * Resume transmission to the channel.
695 * @param th Handle of the request that is being resumed.
698 GNUNET_PSYC_master_transmit_resume (struct GNUNET_PSYC_MasterTransmitHandle *th);
702 * Abort transmission request to channel.
704 * @param th Handle of the request that is being aborted.
707 GNUNET_PSYC_master_transmit_cancel (struct GNUNET_PSYC_MasterTransmitHandle *th);
711 * Stop a PSYC master channel.
714 * PSYC channel master to stop.
716 * Keep place active after last application disconnected.
718 * Function called after the master stopped
719 * and disconnected from the psyc service.
721 * Closure for @a part_cb.
724 GNUNET_PSYC_master_stop (struct GNUNET_PSYC_Master *master,
726 GNUNET_ContinuationCallback stop_cb,
731 * Handle for a PSYC channel slave.
733 struct GNUNET_PSYC_Slave;
737 * Function called after the slave connected to the PSYC service.
739 * Also called when reconnected to the service
740 * after the connection closed unexpectedly.
745 * #GNUNET_YES if there were already messages sent to the channel,
746 * #GNUNET_NO if the message history is empty,
747 * #GNUNET_SYSERR on error.
748 * @param max_message_id
749 * Last message ID sent to the channel.
752 (*GNUNET_PSYC_SlaveConnectCallback) (void *cls, int result,
753 uint64_t max_message_id);
757 * Method called to inform about the decision in response to a join request.
759 * If @a is_admitted is not #GNUNET_YES, then sending messages to the channel is
760 * not possible, but earlier history can be still queried.
762 * @param cls Closure.
763 * @param is_admitted #GNUNET_YES or #GNUNET_NO or #GNUNET_SYSERR
764 * @param join_msg Application-dependent join message from the origin.
767 (*GNUNET_PSYC_JoinDecisionCallback) (void *cls,
768 const struct GNUNET_PSYC_JoinDecisionMessage *dcsn,
770 const struct GNUNET_PSYC_Message *join_msg);
774 * Join a PSYC channel.
776 * The entity joining is always the local peer. The user must immediately use
777 * the GNUNET_PSYC_slave_transmit() functions to transmit a @e join_msg to the
778 * channel; if the join request succeeds, the channel state (and @e recent
779 * method calls) will be replayed to the joining member. There is no explicit
780 * notification on failure (as the channel may simply take days to approve,
781 * and disapproval is simply being ignored).
783 * @param cfg Configuration to use.
784 * @param channel_key ECC public key that identifies the channel we wish to join.
785 * @param slave_key ECC private-public key pair that identifies the slave, and
786 * used by multicast to sign the join request and subsequent unicast
787 * requests sent to the master.
788 * @param origin Peer identity of the origin.
789 * @param relay_count Number of peers in the @a relays array.
790 * @param relays Peer identities of members of the multicast group, which serve
791 * as relays and used to join the group at.
792 * @param message_cb Function to invoke on message parts received from the
793 * channel, typically at least contains method handlers for @e join and
795 * @param slave_connect_cb Function invoked once we have connected to the
797 * @param join_decision_cb Function invoked once we have received a join
799 * @param cls Closure for @a message_cb and @a slave_joined_cb.
800 * @param method_name Method name for the join request.
801 * @param env Environment containing transient variables for the request, or NULL.
802 * @param data Payload for the join message.
803 * @param data_size Number of bytes in @a data.
805 * @return Handle for the slave, NULL on error.
807 struct GNUNET_PSYC_Slave *
808 GNUNET_PSYC_slave_join (const struct GNUNET_CONFIGURATION_Handle *cfg,
809 const struct GNUNET_CRYPTO_EddsaPublicKey *channel_key,
810 const struct GNUNET_CRYPTO_EcdsaPrivateKey *slave_key,
811 const struct GNUNET_PeerIdentity *origin,
812 uint32_t relay_count,
813 const struct GNUNET_PeerIdentity *relays,
814 GNUNET_PSYC_MessageCallback message_cb,
815 GNUNET_PSYC_MessagePartCallback message_part_cb,
816 GNUNET_PSYC_SlaveConnectCallback slave_connect_cb,
817 GNUNET_PSYC_JoinDecisionCallback join_decision_cb,
819 const struct GNUNET_PSYC_Message *join_msg);
823 * Part a PSYC channel.
825 * Will terminate the connection to the PSYC service. Polite clients should
826 * first explicitly send a part request (via GNUNET_PSYC_slave_transmit()).
831 * Keep place active after last application disconnected.
833 * Function called after the slave parted the channel
834 * and disconnected from the psyc service.
836 * Closure for @a part_cb.
839 GNUNET_PSYC_slave_part (struct GNUNET_PSYC_Slave *slave,
841 GNUNET_ContinuationCallback part_cb,
846 * Flags for transmitting messages to the channel master by a slave.
848 enum GNUNET_PSYC_SlaveTransmitFlags
850 GNUNET_PSYC_SLAVE_TRANSMIT_NONE = 0
855 * Handle for a pending PSYC transmission operation.
857 struct GNUNET_PSYC_SlaveTransmitHandle;
861 * Request a message to be sent to the channel master.
863 * @param slave Slave handle.
864 * @param method_name Which (PSYC) method should be invoked (on host).
865 * @param notify_mod Function to call to obtain modifiers.
866 * @param notify_data Function to call to obtain fragments of the data.
867 * @param notify_cls Closure for @a notify.
868 * @param flags Flags for the message being transmitted.
869 * @return Transmission handle, NULL on error (i.e. more than one request queued).
871 struct GNUNET_PSYC_SlaveTransmitHandle *
872 GNUNET_PSYC_slave_transmit (struct GNUNET_PSYC_Slave *slave,
873 const char *method_name,
874 GNUNET_PSYC_TransmitNotifyModifier notify_mod,
875 GNUNET_PSYC_TransmitNotifyData notify_data,
877 enum GNUNET_PSYC_SlaveTransmitFlags flags);
881 * Resume transmission to the master.
883 * @param th Handle of the request that is being resumed.
886 GNUNET_PSYC_slave_transmit_resume (struct GNUNET_PSYC_SlaveTransmitHandle *th);
890 * Abort transmission request to master.
892 * @param th Handle of the request that is being aborted.
895 GNUNET_PSYC_slave_transmit_cancel (struct GNUNET_PSYC_SlaveTransmitHandle *th);
899 * Handle to access PSYC channel operations for both the master and slaves.
901 struct GNUNET_PSYC_Channel;
905 * Function called with the result of an asynchronous operation.
910 * Result of the operation.
911 * Usually one of #GNUNET_OK, #GNUNET_YES, #GNUNET_NO, or #GNUNET_SYSERR.
916 (*GNUNET_PSYC_ResultCallback) (void *cls,
918 const char *err_msg);
922 * Convert a channel @a master to a @e channel handle to access the @e channel
925 * @param master Channel master handle.
926 * @return Channel handle, valid for as long as @a master is valid.
928 struct GNUNET_PSYC_Channel *
929 GNUNET_PSYC_master_get_channel (struct GNUNET_PSYC_Master *master);
933 * Convert @a slave to a @e channel handle to access the @e channel APIs.
935 * @param slave Slave handle.
936 * @return Channel handle, valid for as long as @a slave is valid.
938 struct GNUNET_PSYC_Channel *
939 GNUNET_PSYC_slave_get_channel (struct GNUNET_PSYC_Slave *slave);
943 * Add a slave to the channel's membership list.
945 * Note that this will NOT generate any PSYC traffic, it will merely update the
946 * local database to modify how we react to <em>membership test</em> queries.
947 * The channel master still needs to explicitly transmit a @e join message to
948 * notify other channel members and they then also must still call this function
949 * in their respective methods handling the @e join message. This way, how @e
950 * join and @e part operations are exactly implemented is still up to the
951 * application; for example, there might be a @e part_all method to kick out
954 * Note that channel slaves are explicitly trusted to execute such methods
955 * correctly; not doing so correctly will result in either denying other slaves
956 * access or offering access to channel data to non-members.
958 * @param channel Channel handle.
959 * @param slave_key Identity of channel slave to add.
960 * @param announced_at ID of the message that announced the membership change.
961 * @param effective_since Addition of slave is in effect since this message ID.
964 GNUNET_PSYC_channel_slave_add (struct GNUNET_PSYC_Channel *channel,
965 const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_key,
966 uint64_t announced_at,
967 uint64_t effective_since,
968 GNUNET_PSYC_ResultCallback result_cb,
973 * Remove a slave from the channel's membership list.
975 * Note that this will NOT generate any PSYC traffic, it will merely update the
976 * local database to modify how we react to <em>membership test</em> queries.
977 * The channel master still needs to explicitly transmit a @e part message to
978 * notify other channel members and they then also must still call this function
979 * in their respective methods handling the @e part message. This way, how
980 * @e join and @e part operations are exactly implemented is still up to the
981 * application; for example, there might be a @e part_all message to kick out
984 * Note that channel members are explicitly trusted to perform these
985 * operations correctly; not doing so correctly will result in either
986 * denying members access or offering access to channel data to
989 * @param channel Channel handle.
990 * @param slave_key Identity of channel slave to remove.
991 * @param announced_at ID of the message that announced the membership change.
994 GNUNET_PSYC_channel_slave_remove (struct GNUNET_PSYC_Channel *channel,
995 const struct GNUNET_CRYPTO_EcdsaPublicKey
997 uint64_t announced_at,
998 GNUNET_PSYC_ResultCallback result_cb,
1003 * Function called to inform a member about stored state values for a channel.
1005 * @param cls Closure.
1006 * @param name Name of the state variable. A NULL value indicates that there
1007 * are no more state variables to be returned.
1008 * @param value Value of the state variable.
1009 * @param value_size Number of bytes in @a value.
1012 (*GNUNET_PSYC_StateVarCallback) (void *cls,
1019 * Request to replay a part of the message history of the channel.
1021 * Historic messages (but NOT the state at the time) will be replayed (given to
1022 * the normal method handlers) if available and if access is permitted.
1025 * Which channel should be replayed?
1026 * @param start_message_id
1027 * Earliest interesting point in history.
1028 * @param end_message_id
1029 * Last (inclusive) interesting point in history.
1031 * Function to call when the requested history has been fully replayed
1032 * (counting message IDs might not suffice, as some messages might be
1033 * secret and thus the listener would not know the story is finished
1034 * without being told explicitly)o once this function has been called, the
1035 * client must not call GNUNET_PSYC_channel_history_replay_cancel() anymore.
1037 * Closure for the callbacks.
1039 * @return Handle to cancel history replay operation.
1042 GNUNET_PSYC_channel_history_replay (struct GNUNET_PSYC_Channel *channel,
1043 uint64_t start_message_id,
1044 uint64_t end_message_id,
1045 GNUNET_PSYC_ResultCallback finish_cb,
1050 * Request to replay the latest messages from the message history of the channel.
1052 * Historic messages (but NOT the state at the time) will be replayed (given to
1053 * the normal method handlers) if available and if access is permitted.
1056 * Which channel should be replayed?
1057 * @param message_limit
1058 * Maximum number of messages to replay.
1060 * Function to call when the requested history has been fully replayed
1061 * (counting message IDs might not suffice, as some messages might be
1062 * secret and thus the listener would not know the story is finished
1063 * without being told explicitly)o once this function has been called, the
1064 * client must not call GNUNET_PSYC_channel_history_replay_cancel() anymore.
1066 * Closure for the callbacks.
1068 * @return Handle to cancel history replay operation.
1071 GNUNET_PSYC_channel_history_replay_latest (struct GNUNET_PSYC_Channel *channel,
1072 uint64_t message_limit,
1073 GNUNET_PSYC_ResultCallback finish_cb,
1078 * Retrieve the best matching channel state variable.
1080 * If the requested variable name is not present in the state, the nearest
1081 * less-specific name is matched; for example, requesting "_a_b" will match "_a"
1082 * if "_a_b" does not exist.
1087 * Full name of the requested variable.
1088 * The actual variable returned might have a shorter name.
1090 * Function called once when a matching state variable is found.
1091 * Not called if there's no matching state variable.
1093 * Function called after the operation finished.
1094 * (i.e. all state variables have been returned via @a state_cb)
1096 * Closure for the callbacks.
1099 GNUNET_PSYC_channel_state_get (struct GNUNET_PSYC_Channel *channel,
1100 const char *full_name,
1101 GNUNET_PSYC_StateVarCallback var_cb,
1102 GNUNET_PSYC_ResultCallback result_cb,
1107 * Return all channel state variables whose name matches a given prefix.
1109 * A name matches if it starts with the given @a name_prefix, thus requesting
1110 * the empty prefix ("") will match all values; requesting "_a_b" will also
1111 * return values stored under "_a_b_c".
1113 * The @a state_cb is invoked on all matching state variables asynchronously, as
1114 * the state is stored in and retrieved from the PSYCstore,
1118 * @param name_prefix
1119 * Prefix of the state variable name to match.
1121 * Function called once when a matching state variable is found.
1122 * Not called if there's no matching state variable.
1124 * Function called after the operation finished.
1125 * (i.e. all state variables have been returned via @a state_cb)
1127 * Closure for the callbacks.
1130 GNUNET_PSYC_channel_state_get_prefix (struct GNUNET_PSYC_Channel *channel,
1131 const char *name_prefix,
1132 GNUNET_PSYC_StateVarCallback var_cb,
1133 GNUNET_PSYC_ResultCallback result_cb,
1137 #if 0 /* keep Emacsens' auto-indent happy */
1144 /* ifndef GNUNET_PSYC_SERVICE_H */
1146 /* end of gnunet_psyc_service.h */