/*
This file is part of GNUnet.
Copyright (C) 2012, 2013 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
*/
/**
* @author Gabor X Toth
* @author Christian Grothoff
*
* @file
* PSYC service
*
* @defgroup psyc PSYC service
* Send/receive messages in PSYC channels and access the PSYC Store.
*
* Note that clients of this API are NOT expected to understand the PSYC message
* format, only the semantics! Parsing (and serializing) the PSYC stream format
* is done within the implementation of the libgnunetpsyc library, and this API
* deliberately exposes as little as possible of the actual data stream format
* to the application!
*
* NOTE:
* - this API does not know about PSYC's "root" and "places";
* there is no 'root' in GNUnet-PSYC as we're decentralized;
* 'places' and 'persons' are combined within the same
* abstraction, that of a "channel". Channels are identified
* and accessed in this API using a public/private key.
* Higher-level applications should use NAMES within GNS
* to obtain public keys, and the distinction between
* 'places' and 'persons' can then be made with the help
* of the naming system (and/or conventions).
* Channels are (as in PSYC) organized into a hierarchy; each
* channel master (the one with the private key) is then
* the operator of the multicast group (its Origin in
* the terminology of the multicast API).
* - The API supports passing large amounts of data using
* 'streaming' for the argument passed to a method. State
* and variables must fit into memory and cannot be streamed
* (thus, no passing of 4 GB of data in a variable;
* once we implement this, we might want to create a
* @c \#define for the maximum size of a variable).
* - PSYC defines standard variables, methods, etc. This
* library deliberately abstracts over all of these; a
* higher-level API should combine the naming system (GNS)
* and standard methods (_converse, _notice, _request,
* _warning, _error etc) and variables (_action, _color,
* _time, etc). However, this API does take over the
* routing variables, specifically '_context' (channel),
* and '_source'. We only kind-of support '_target', as
* the target is either everyone in the group or the
* origin, and never just a single member of the group;
* for such individual messages, an application needs to
* construct an 'inbox' channel where the master (only)
* receives messages (but never forwards; private responses
* would be transmitted by joining the senders 'inbox'
* channel -- or a inbox#bob subchannel). The
* goal for all of this is to keep the abstractions in this
* API minimal: interaction with multicast, try \& slice,
* state/variable/channel management. Higher-level
* operations belong elsewhere (so maybe this API should
* be called 'PSYC-low', whereas a higher-level API
* implementing defaults for standard methods and
* variables might be called 'PSYC-std' or 'PSYC-high'.
*
* In PSYC terminology this is simply called the "PSYC
* routing layer" and the abstractions, for instance in
* psyced, are quite similar. The higher one is called
* "PSYC entity layer." In the text rendering of the
* protocol the two are separated by an empty line. See
* http://about.psyc.eu/Spec:Packet and related. --lynX
*
* @{
*/
#ifndef GNUNET_PSYC_SERVICE_H
#define GNUNET_PSYC_SERVICE_H
#ifdef __cplusplus
extern "C"
{
#if 0 /* keep Emacsens' auto-indent happy */
}
#endif
#endif
#include "gnunet_util_lib.h"
#include "gnunet_multicast_service.h"
//Mingw work around
#ifdef MINGW
# ifndef UINT64_MAX
# define UINT64_MAX 0xffffffffffffffffULL
# endif
#endif
/**
* Version number of GNUnet-PSYC API.
*/
#define GNUNET_PSYC_VERSION 0x00000000
/**
* Policy flags for a channel.
*/
enum GNUNET_PSYC_ChannelFlags
{
/**
* Admission must be confirmed by the master.
*/
GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL = 1 << 0,
/**
* Past messages are only available to slaves who were admitted at the time
* they were sent to the channel.
*/
GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY = 1 << 1
};
/**
* PSYC channel policies.
*/
enum GNUNET_PSYC_Policy
{
/**
* Anyone can join the channel, without announcing their presence;
* all messages are always public and can be distributed freely.
* Joins may be announced, but this is not required.
*/
GNUNET_PSYC_CHANNEL_ANONYMOUS = 0,
/**
* The master must approve membership to the channel, messages must only be
* distributed to current channel slaves. This includes the channel
* state as well as transient messages.
*/
GNUNET_PSYC_CHANNEL_PRIVATE
= GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL
| GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY
#if IDEAS_FOR_FUTURE
/**
* Anyone can freely join the channel (no approval required);
* however, messages must only be distributed to current channel
* slaves, so the master must still acknowledge that the slave
* joined before transient messages are delivered. As approval is
* guaranteed, the presistent channel state can be synchronized freely
* immediately, prior to master confirmation.
*/
GNUNET_PSYC_CHANNEL_OPEN
= GNUNET_PSYC_CHANNEL_RESTRICTED_HISTORY,
/**
* The master must approve joins to the channel, but past messages can be
* freely distributed to slaves.
*/
GNUNET_PSYC_CHANNEL_CLOSED
= GNUNET_PSYC_CHANNEL_ADMISSION_CONTROL,
#endif
};
enum GNUNET_PSYC_MessageFlags
{
/**
* Default / no flags.
*/
GNUNET_PSYC_MESSAGE_DEFAULT = 0,
/**
* Historic message, retrieved from PSYCstore.
*/
GNUNET_PSYC_MESSAGE_HISTORIC = 1 << 0,
/**
* Request from slave to master.
*/
GNUNET_PSYC_MESSAGE_REQUEST = 1 << 1,
/**
* Message can be delivered out of order.
*/
GNUNET_PSYC_MESSAGE_ORDER_ANY = 1 << 2
};
/**
* Values for the @a state_delta field of GNUNET_PSYC_MessageHeader.
*/
enum GNUNET_PSYC_StateDeltaValues
{
GNUNET_PSYC_STATE_RESET = 0,
GNUNET_PSYC_STATE_NOT_MODIFIED = UINT64_MAX
};
GNUNET_NETWORK_STRUCT_BEGIN
/**
* A PSYC message.
*
* Used for single-fragment messages e.g. in a join request or response.
*/
struct GNUNET_PSYC_Message
{
/**
* Message header with size and type information.
*/
struct GNUNET_MessageHeader header;
/* Followed by concatenated PSYC message parts:
* messages with GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_* types
*/
};
/**
* Header of a PSYC message.
*
* The PSYC service adds this when delivering the message to local clients,
* not present on the multicast layer.
*/
struct GNUNET_PSYC_MessageHeader
{
/**
* Generic message header with size and type information.
*/
struct GNUNET_MessageHeader header;
/**
* Flags for this message fragment.
*
* @see enum GNUNET_PSYC_MessageFlags
*/
uint32_t flags GNUNET_PACKED;
/**
* Number of the message this message part belongs to.
* Monotonically increasing from 1.
*/
uint64_t message_id GNUNET_PACKED;
/**
* Byte offset of this @e fragment of the @e message.
*/
uint64_t fragment_offset GNUNET_PACKED;
/**
* Sending slave's public key.
* Not set if the message is from the master.
*/
struct GNUNET_CRYPTO_EcdsaPublicKey slave_pub_key;
/* Followed by concatenated PSYC message parts:
* messages with GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_* types
*/
};
/**
* The method of a message.
*/
struct GNUNET_PSYC_MessageMethod
{
/**
* Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
*/
struct GNUNET_MessageHeader header;
/**
* OR'ed GNUNET_PSYC_MasterTransmitFlags
*/
uint32_t flags GNUNET_PACKED;
/**
* Number of message IDs since the last message that contained state
* operations. @see enum GNUNET_PSYC_StateDeltaValues
*/
uint64_t state_delta GNUNET_PACKED;
/* Followed by NUL-terminated method name. */
};
/**
* A modifier of a message.
*/
struct GNUNET_PSYC_MessageModifier
{
/**
* Type: GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
*/
struct GNUNET_MessageHeader header;
/**
* Size of value.
*/
uint32_t value_size GNUNET_PACKED;
/**
* Size of name, including NUL terminator.
*/
uint16_t name_size GNUNET_PACKED;
/**
* enum GNUNET_PSYC_Operator
*/
uint8_t oper;
/* Followed by NUL-terminated name, then the value. */
};
struct GNUNET_PSYC_CountersResultMessage
{
/**
* Type: GNUNET_MESSAGE_TYPE_PSYC_RESULT_COUNTERS
*/
struct GNUNET_MessageHeader header;
/**
* Status code for the operation.
*/
uint32_t result_code GNUNET_PACKED;
/**
* Last message ID sent to the channel.
*/
uint64_t max_message_id GNUNET_PACKED;
};
/**
* Join request sent to a PSYC master.
*/
struct GNUNET_PSYC_JoinRequestMessage
{
/**
* Type: GNUNET_MESSAGE_TYPE_PSYC_MASTER_JOIN_REQUEST
*/
struct GNUNET_MessageHeader header;
/**
* Public key of the joining slave.
*/
struct GNUNET_CRYPTO_EcdsaPublicKey slave_pub_key;
/* Followed by struct GNUNET_MessageHeader join_request */
};
/**
* Join decision sent in reply to a join request.
*/
struct GNUNET_PSYC_JoinDecisionMessage
{
/**
* Type: GNUNET_MESSAGE_TYPE_PSYC_JOIN_DECISION
*/
struct GNUNET_MessageHeader header;
/**
* #GNUNET_YES if the slave was admitted.
*/
int32_t is_admitted;
/**
* Public key of the joining slave.
* Only set when the master is sending the decision,
* not set when a slave is receiving it.
*/
struct GNUNET_CRYPTO_EcdsaPublicKey slave_pub_key;
/* Followed by struct GNUNET_MessageHeader join_response */
};
enum GNUNET_PSYC_HistoryReplayFlags
{
/**
* Replay locally available messages.
*/
GNUNET_PSYC_HISTORY_REPLAY_LOCAL = 0,
/**
* Replay messages from remote peers if not found locally.
*/
GNUNET_PSYC_HISTORY_REPLAY_REMOTE = 1,
};
struct GNUNET_PSYC_HistoryRequestMessage
{
/**
* Type: GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_HISTORY_REPLAY
*/
struct GNUNET_MessageHeader header;
/**
* @see enum GNUNET_PSYC_HistoryReplayFlags
*/
uint32_t flags GNUNET_PACKED;
/**
* ID for this operation.
*/
uint64_t op_id GNUNET_PACKED;
uint64_t start_message_id GNUNET_PACKED;
uint64_t end_message_id GNUNET_PACKED;
uint64_t message_limit GNUNET_PACKED;
/* Followed by NUL-terminated method name prefix. */
};
struct GNUNET_PSYC_StateRequestMessage
{
/**
* Types:
* - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_GET
* - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_GET_PREFIX
*/
struct GNUNET_MessageHeader header;
uint32_t reserved GNUNET_PACKED;
/**
* ID for this operation.
*/
uint64_t op_id GNUNET_PACKED;
/* Followed by NUL-terminated name. */
};
/**** service -> library ****/
/**
* Answer from service to client about last operation.
*/
struct GNUNET_PSYC_OperationResultMessage
{
/**
* Types:
* - GNUNET_MESSAGE_TYPE_PSYC_RESULT_CODE
* - GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_STATE_RESULT
*/
struct GNUNET_MessageHeader header;
uint32_t reserved GNUNET_PACKED;
/**
* Operation ID.
*/
uint64_t op_id GNUNET_PACKED;
/**
* Status code for the operation.
*/
uint64_t result_code GNUNET_PACKED;
/* Followed by:
* - on error: NUL-terminated error message
* - on success: one of the following message types
*
* For a STATE_RESULT, one of:
* - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
* - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MOD_CONT
* - GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_END
*/
};
GNUNET_NETWORK_STRUCT_END
#define GNUNET_PSYC_MODIFIER_MAX_PAYLOAD \
GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
- sizeof (struct GNUNET_PSYC_MessageModifier)
#define GNUNET_PSYC_MOD_CONT_MAX_PAYLOAD \
GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
- sizeof (struct GNUNET_MessageHeader)
#define GNUNET_PSYC_DATA_MAX_PAYLOAD \
GNUNET_MULTICAST_FRAGMENT_MAX_PAYLOAD \
- sizeof (struct GNUNET_MessageHeader)
/**
* PSYC message part processing states.
*/
enum GNUNET_PSYC_MessageState
{
GNUNET_PSYC_MESSAGE_STATE_START = 0,
GNUNET_PSYC_MESSAGE_STATE_HEADER = 1,
GNUNET_PSYC_MESSAGE_STATE_METHOD = 2,
GNUNET_PSYC_MESSAGE_STATE_MODIFIER = 3,
GNUNET_PSYC_MESSAGE_STATE_MOD_CONT = 4,
GNUNET_PSYC_MESSAGE_STATE_DATA = 5,
GNUNET_PSYC_MESSAGE_STATE_END = 6,
GNUNET_PSYC_MESSAGE_STATE_CANCEL = 7,
GNUNET_PSYC_MESSAGE_STATE_ERROR = 8,
};
/**
* Handle that identifies a join request.
*
* Used to match calls to #GNUNET_PSYC_JoinCallback to the
* corresponding calls to GNUNET_PSYC_join_decision().
*/
struct GNUNET_PSYC_JoinHandle;
/**
* Method called from PSYC upon receiving a message.
*
* @param cls Closure.
* @param message_id Sequence number of the message.
* @param flags OR'ed GNUNET_PSYC_MessageFlags
* @param msg Message part, one of the following types:
*/
typedef void
(*GNUNET_PSYC_MessageCallback) (void *cls,
const struct GNUNET_PSYC_MessageHeader *msg);
/**
* Method called from PSYC upon receiving part of a message.
*
* @param cls
* Closure.
* @param slave_pub_key
* Public key of the slave sending the message.
* Only set for channel master.
* @param message_id
* Sequence number of the message.
* @param flags
* OR'ed GNUNET_PSYC_MessageFlags
* @param fragment_offset
* Multicast message fragment offset.
* @param msg Message part, one of the following types:
* - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_HEADER
* - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD
* - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER
* - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MOD_CONT
* - #GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_DATA
* or NULL if an error occurred while receiving a message.
*/
typedef void
(*GNUNET_PSYC_MessagePartCallback) (void *cls,
const struct GNUNET_PSYC_MessageHeader *msg,
const struct GNUNET_MessageHeader *pmsg);
/**
* Method called from PSYC upon receiving a join request.
*
* @param cls
* Closure.
* @param slave_pub_key
* Public key of the slave requesting join.
* @param join_msg
* Join message sent along with the request.
* @param jh
* Join handle to use with GNUNET_PSYC_join_decision()
*/
typedef void
(*GNUNET_PSYC_JoinRequestCallback) (void *cls,
const struct GNUNET_PSYC_JoinRequestMessage *req,
const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_pub_key,
const struct GNUNET_PSYC_Message *join_msg,
struct GNUNET_PSYC_JoinHandle *jh);
/**
* Function to call with the decision made for a join request.
*
* Must be called once and only once in response to an invocation of the
* #GNUNET_PSYC_JoinCallback.
*
* @param jh Join request handle.
* @param is_admitted
* #GNUNET_YES if the join is approved,
* #GNUNET_NO if it is disapproved,
* #GNUNET_SYSERR if we cannot answer the request.
* @param relay_count Number of relays given.
* @param relays Array of suggested peers that might be useful relays to use
* when joining the multicast group (essentially a list of peers that
* are already part of the multicast group and might thus be willing
* to help with routing). If empty, only this local peer (which must
* be the multicast origin) is a good candidate for building the
* multicast tree. Note that it is unnecessary to specify our own
* peer identity in this array.
* @param join_resp Application-dependent join response message to send along
* with the decision.
*
* @return #GNUNET_OK on success,
* #GNUNET_SYSERR if @a join_resp is too large.
*/
int
GNUNET_PSYC_join_decision (struct GNUNET_PSYC_JoinHandle *jh,
int is_admitted,
uint32_t relay_count,
const struct GNUNET_PeerIdentity *relays,
const struct GNUNET_PSYC_Message *join_resp);
/**
* Handle for the master of a PSYC channel.
*/
struct GNUNET_PSYC_Master;
/**
* Function called once we are connected to the PSYC service
* and the channel master is started.
*
* Also called when we reconnected to the service
* after the connection closed unexpectedly.
*
* @param cls
* Closure.
* @param result
* #GNUNET_YES if there were already messages sent to the channel,
* #GNUNET_NO if the message history is empty,
* #GNUNET_SYSERR on error.
* @param max_message_id
* Last message ID sent to the channel.
*/
typedef void
(*GNUNET_PSYC_MasterStartCallback) (void *cls, int result,
uint64_t max_message_id);
/**
* Start a PSYC master channel.
*
* Will start a multicast group identified by the given ECC key. Messages
* received from group members will be given to the respective handler methods.
* If a new member wants to join a group, the "join" method handler will be
* invoked; the join handler must then generate a "join" message to approve the
* joining of the new member. The channel can also change group membership
* without explicit requests. Note that PSYC doesn't itself "understand" join
* or part messages, the respective methods must call other PSYC functions to
* inform PSYC about the meaning of the respective events.
*
* @param cfg Configuration to use (to connect to PSYC service).
* @param channel_key ECC key that will be used to sign messages for this
* PSYC session. The public key is used to identify the PSYC channel.
* Note that end-users will usually not use the private key directly, but
* rather look it up in GNS for places managed by other users, or select
* a file with the private key(s) when setting up their own channels
* FIXME: we'll likely want to use NOT the p521 curve here, but a cheaper
* one in the future.
* @param policy Channel policy specifying join and history restrictions.
* Used to automate join decisions.
* @param master_start_cb Function to invoke after the channel master started.
* @param join_request_cb Function to invoke when a slave wants to join.
* @param message_cb Function to invoke on message parts sent to the channel
* and received from slaves
* @param cls Closure for @a method and @a join_cb.
*
* @return Handle for the channel master, NULL on error.
*/
struct GNUNET_PSYC_Master *
GNUNET_PSYC_master_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
const struct GNUNET_CRYPTO_EddsaPrivateKey *channel_key,
enum GNUNET_PSYC_Policy policy,
GNUNET_PSYC_MasterStartCallback master_start_cb,
GNUNET_PSYC_JoinRequestCallback join_request_cb,
GNUNET_PSYC_MessageCallback message_cb,
GNUNET_PSYC_MessagePartCallback message_part_cb,
void *cls);
/**
* Function called to provide data for a transmission via PSYC.
*
* Note that returning #GNUNET_YES or #GNUNET_SYSERR (but not #GNUNET_NO)
* invalidates the respective transmission handle.
*
* @param cls Closure.
* @param[in,out] data_size Initially set to the number of bytes available in
* @a data, should be set to the number of bytes written to data.
* @param[out] data Where to write the body of the message to give to the
* method. The function must copy at most @a data_size bytes to @a data.
* @return #GNUNET_SYSERR on error (fatal, aborts transmission)
* #GNUNET_NO on success, if more data is to be transmitted later.
* Should be used if @a data_size was not big enough to take all the
* data. If 0 is returned in @a data_size the transmission is paused,
* and can be resumed with GNUNET_PSYC_master_transmit_resume().
* #GNUNET_YES if this completes the transmission (all data supplied)
*/
typedef int
(*GNUNET_PSYC_TransmitNotifyData) (void *cls,
uint16_t *data_size,
void *data);
/**
* Function called to provide a modifier for a transmission via PSYC.
*
* Note that returning #GNUNET_YES or #GNUNET_SYSERR (but not #GNUNET_NO)
* invalidates the respective transmission handle.
*
* @param cls Closure.
* @param[in,out] data_size Initially set to the number of bytes available in
* @a data, should be set to the number of bytes written to data.
* @param[out] data Where to write the modifier's name and value.
* The function must copy at most @a data_size bytes to @a data.
* When this callback is first called for a modifier, @a data should
* contain: "name\0value". If the whole value does not fit, subsequent
* calls to this function should write continuations of the value to
* @a data.
* @param[out] oper Where to write the operator of the modifier.
* Only needed during the first call to this callback at the beginning
* of the modifier. In case of subsequent calls asking for value
* continuations @a oper is set to #NULL.
* @param[out] full_value_size Where to write the full size of the value.
* Only needed during the first call to this callback at the beginning
* of the modifier. In case of subsequent calls asking for value
* continuations @a value_size is set to #NULL.
* @return #GNUNET_SYSERR on error (fatal, aborts transmission)
* #GNUNET_NO on success, if more data is to be transmitted later.
* Should be used if @a data_size was not big enough to take all the
* data for the modifier's value (the name must be always returned
* during the first call to this callback).
* If 0 is returned in @a data_size the transmission is paused,
* and can be resumed with GNUNET_PSYC_master_transmit_resume().
* #GNUNET_YES if this completes the modifier (the whole value is supplied).
*/
typedef int
(*GNUNET_PSYC_TransmitNotifyModifier) (void *cls,
uint16_t *data_size,
void *data,
uint8_t *oper,
uint32_t *full_value_size);
/**
* Flags for transmitting messages to a channel by the master.
*/
enum GNUNET_PSYC_MasterTransmitFlags
{
GNUNET_PSYC_MASTER_TRANSMIT_NONE = 0,
/**
* Whether this message should reset the channel state,
* i.e. remove all previously stored state variables.
*/
GNUNET_PSYC_MASTER_TRANSMIT_STATE_RESET = 1 << 0,
/**
* Whether this message contains any state modifiers.
*/
GNUNET_PSYC_MASTER_TRANSMIT_STATE_MODIFY = 1 << 1,
/**
* Add PSYC header variable with the hash of the current channel state.
*/
GNUNET_PSYC_MASTER_TRANSMIT_STATE_HASH = 1 << 2,
/**
* Whether we need to increment the group generation counter after
* transmitting this message.
*/
GNUNET_PSYC_MASTER_TRANSMIT_INC_GROUP_GEN = 1 << 3
};
/**
* Handle for a pending PSYC transmission operation.
*/
struct GNUNET_PSYC_MasterTransmitHandle;
/**
* Send a message to call a method to all members in the PSYC channel.
*
* @param master Handle to the PSYC channel.
* @param method_name Which method should be invoked.
* @param notify_mod Function to call to obtain modifiers.
* @param notify_data Function to call to obtain fragments of the data.
* @param notify_cls Closure for @a notify_mod and @a notify_data.
* @param flags Flags for the message being transmitted.
* @return Transmission handle, NULL on error (i.e. more than one request queued).
*/
struct GNUNET_PSYC_MasterTransmitHandle *
GNUNET_PSYC_master_transmit (struct GNUNET_PSYC_Master *master,
const char *method_name,
GNUNET_PSYC_TransmitNotifyModifier notify_mod,
GNUNET_PSYC_TransmitNotifyData notify_data,
void *notify_cls,
enum GNUNET_PSYC_MasterTransmitFlags flags);
/**
* Resume transmission to the channel.
*
* @param th Handle of the request that is being resumed.
*/
void
GNUNET_PSYC_master_transmit_resume (struct GNUNET_PSYC_MasterTransmitHandle *th);
/**
* Abort transmission request to channel.
*
* @param th Handle of the request that is being aborted.
*/
void
GNUNET_PSYC_master_transmit_cancel (struct GNUNET_PSYC_MasterTransmitHandle *th);
/**
* Relay a message
*
* @param master Handle to the PSYC channel.
* @param method_name Which method should be invoked.
* @param notify_mod Function to call to obtain modifiers.
* @param notify_data Function to call to obtain fragments of the data.
* @param notify_cls Closure for @a notify_mod and @a notify_data.
* @param flags Flags for the message being transmitted.
* @return Transmission handle, NULL on error (i.e. more than one request queued).
*/
struct GNUNET_PSYC_MasterTransmitHandle *
GNUNET_PSYC_master_relay (struct GNUNET_PSYC_Master *master,
uint64_t message_id);
/**
* Stop a PSYC master channel.
*
* @param master
* PSYC channel master to stop.
* @param keep_active
* Keep place active after last application disconnected.
* @param stop_cb
* Function called after the master stopped
* and disconnected from the psyc service.
* @param stop_cls
* Closure for @a part_cb.
*/
void
GNUNET_PSYC_master_stop (struct GNUNET_PSYC_Master *master,
int keep_active,
GNUNET_ContinuationCallback stop_cb,
void *stop_cls);
/**
* Handle for a PSYC channel slave.
*/
struct GNUNET_PSYC_Slave;
/**
* Function called after the slave connected to the PSYC service.
*
* Also called when reconnected to the service
* after the connection closed unexpectedly.
*
* @param cls
* Closure.
* @param result
* #GNUNET_YES if there were already messages sent to the channel,
* #GNUNET_NO if the message history is empty,
* #GNUNET_SYSERR on error.
* @param max_message_id
* Last message ID sent to the channel.
*/
typedef void
(*GNUNET_PSYC_SlaveConnectCallback) (void *cls, int result,
uint64_t max_message_id);
/**
* Method called to inform about the decision in response to a join request.
*
* If @a is_admitted is not #GNUNET_YES, then sending messages to the channel is
* not possible, but earlier history can be still queried.
*
* @param cls Closure.
* @param is_admitted #GNUNET_YES or #GNUNET_NO or #GNUNET_SYSERR
* @param join_msg Application-dependent join message from the origin.
*/
typedef void
(*GNUNET_PSYC_JoinDecisionCallback) (void *cls,
const struct GNUNET_PSYC_JoinDecisionMessage *dcsn,
int is_admitted,
const struct GNUNET_PSYC_Message *join_msg);
/**
* Flags for GNUNET_PSYC_slave_join()
*/
enum GNUNET_PSYC_SlaveJoinFlags
{
GNUNET_PSYC_SLAVE_JOIN_NONE = 0,
/**
* Local join for history access, no network connection is established.
*/
GNUNET_PSYC_SLAVE_JOIN_LOCAL = 1,
};
/**
* Join a PSYC channel.
*
* The entity joining is always the local peer. The user must immediately use
* the GNUNET_PSYC_slave_transmit() functions to transmit a @e join_msg to the
* channel; if the join request succeeds, the channel state (and @e recent
* method calls) will be replayed to the joining member. There is no explicit
* notification on failure (as the channel may simply take days to approve,
* and disapproval is simply being ignored).
*
* @param cfg
* Configuration to use.
* @param channel_pub_key
* ECC public key that identifies the channel we wish to join.
* @param slave_pub_key
* ECC private-public key pair that identifies the slave, and
* used by multicast to sign the join request and subsequent unicast
* requests sent to the master.
* @param flags
* Join flags.
* @param origin
* Peer identity of the origin.
* @param relay_count
* Number of peers in the @a relays array.
* @param relays
* Peer identities of members of the multicast group, which serve
* as relays and used to join the group at.
* @param message_cb
* Function to invoke on message fragments received from the channel.
* @param message_part_cb
* Function to invoke on message parts received from the channel.
* @param slave_connect_cb
* Function invoked once we have connected to the PSYC service.
* @param join_decision_cb
* Function invoked once we have received a join decision.
* @param cls
* Closure for @a message_cb and @a slave_joined_cb.
* @param join_msg
* Join message.
*
* @return Handle for the slave, NULL on error.
*/
struct GNUNET_PSYC_Slave *
GNUNET_PSYC_slave_join (const struct GNUNET_CONFIGURATION_Handle *cfg,
const struct GNUNET_CRYPTO_EddsaPublicKey *channel_pub_key,
const struct GNUNET_CRYPTO_EcdsaPrivateKey *slave_pub_key,
enum GNUNET_PSYC_SlaveJoinFlags flags,
const struct GNUNET_PeerIdentity *origin,
uint32_t relay_count,
const struct GNUNET_PeerIdentity *relays,
GNUNET_PSYC_MessageCallback message_cb,
GNUNET_PSYC_MessagePartCallback message_part_cb,
GNUNET_PSYC_SlaveConnectCallback slave_connect_cb,
GNUNET_PSYC_JoinDecisionCallback join_decision_cb,
void *cls,
const struct GNUNET_PSYC_Message *join_msg);
/**
* Part a PSYC channel.
*
* Will terminate the connection to the PSYC service. Polite clients should
* first explicitly send a part request (via GNUNET_PSYC_slave_transmit()).
*
* @param slave
* Slave handle.
* @param keep_active
* Keep place active after last application disconnected.
* @param part_cb
* Function called after the slave parted the channel
* and disconnected from the psyc service.
* @param part_cls
* Closure for @a part_cb.
*/
void
GNUNET_PSYC_slave_part (struct GNUNET_PSYC_Slave *slave,
int keep_active,
GNUNET_ContinuationCallback part_cb,
void *part_cls);
/**
* Flags for transmitting messages to the channel master by a slave.
*/
enum GNUNET_PSYC_SlaveTransmitFlags
{
GNUNET_PSYC_SLAVE_TRANSMIT_NONE = 0
};
/**
* Handle for a pending PSYC transmission operation.
*/
struct GNUNET_PSYC_SlaveTransmitHandle;
/**
* Request a message to be sent to the channel master.
*
* @param slave Slave handle.
* @param method_name Which (PSYC) method should be invoked (on host).
* @param notify_mod Function to call to obtain modifiers.
* @param notify_data Function to call to obtain fragments of the data.
* @param notify_cls Closure for @a notify.
* @param flags Flags for the message being transmitted.
* @return Transmission handle, NULL on error (i.e. more than one request queued).
*/
struct GNUNET_PSYC_SlaveTransmitHandle *
GNUNET_PSYC_slave_transmit (struct GNUNET_PSYC_Slave *slave,
const char *method_name,
GNUNET_PSYC_TransmitNotifyModifier notify_mod,
GNUNET_PSYC_TransmitNotifyData notify_data,
void *notify_cls,
enum GNUNET_PSYC_SlaveTransmitFlags flags);
/**
* Resume transmission to the master.
*
* @param th Handle of the request that is being resumed.
*/
void
GNUNET_PSYC_slave_transmit_resume (struct GNUNET_PSYC_SlaveTransmitHandle *th);
/**
* Abort transmission request to master.
*
* @param th Handle of the request that is being aborted.
*/
void
GNUNET_PSYC_slave_transmit_cancel (struct GNUNET_PSYC_SlaveTransmitHandle *th);
/**
* Handle to access PSYC channel operations for both the master and slaves.
*/
struct GNUNET_PSYC_Channel;
/**
* Convert a channel @a master to a @e channel handle to access the @e channel
* APIs.
*
* @param master Channel master handle.
* @return Channel handle, valid for as long as @a master is valid.
*/
struct GNUNET_PSYC_Channel *
GNUNET_PSYC_master_get_channel (struct GNUNET_PSYC_Master *master);
/**
* Convert @a slave to a @e channel handle to access the @e channel APIs.
*
* @param slave Slave handle.
* @return Channel handle, valid for as long as @a slave is valid.
*/
struct GNUNET_PSYC_Channel *
GNUNET_PSYC_slave_get_channel (struct GNUNET_PSYC_Slave *slave);
/**
* Add a slave to the channel's membership list.
*
* Note that this will NOT generate any PSYC traffic, it will merely update the
* local database to modify how we react to membership test queries.
* The channel master still needs to explicitly transmit a @e join message to
* notify other channel members and they then also must still call this function
* in their respective methods handling the @e join message. This way, how @e
* join and @e part operations are exactly implemented is still up to the
* application; for example, there might be a @e part_all method to kick out
* everyone.
*
* Note that channel slaves are explicitly trusted to execute such methods
* correctly; not doing so correctly will result in either denying other slaves
* access or offering access to channel data to non-members.
*
* @param channel
* Channel handle.
* @param slave_pub_key
* Identity of channel slave to add.
* @param announced_at
* ID of the message that announced the membership change.
* @param effective_since
* Addition of slave is in effect since this message ID.
* @param result_cb
* Function to call with the result of the operation.
* The @e result_code argument is #GNUNET_OK on success, or
* #GNUNET_SYSERR on error. In case of an error, the @e data argument
* can contain an optional error message.
* @param cls
* Closure for @a result_cb.
*/
void
GNUNET_PSYC_channel_slave_add (struct GNUNET_PSYC_Channel *channel,
const struct GNUNET_CRYPTO_EcdsaPublicKey *slave_pub_key,
uint64_t announced_at,
uint64_t effective_since,
GNUNET_ResultCallback result_cb,
void *cls);
/**
* Remove a slave from the channel's membership list.
*
* Note that this will NOT generate any PSYC traffic, it will merely update the
* local database to modify how we react to membership test queries.
* The channel master still needs to explicitly transmit a @e part message to
* notify other channel members and they then also must still call this function
* in their respective methods handling the @e part message. This way, how
* @e join and @e part operations are exactly implemented is still up to the
* application; for example, there might be a @e part_all message to kick out
* everyone.
*
* Note that channel members are explicitly trusted to perform these
* operations correctly; not doing so correctly will result in either
* denying members access or offering access to channel data to
* non-members.
*
* @param channel
* Channel handle.
* @param slave_pub_key
* Identity of channel slave to remove.
* @param announced_at
* ID of the message that announced the membership change.
* @param result_cb
* Function to call with the result of the operation.
* The @e result_code argument is #GNUNET_OK on success, or
* #GNUNET_SYSERR on error. In case of an error, the @e data argument
* can contain an optional error message.
* @param cls
* Closure for @a result_cb.
*/
void
GNUNET_PSYC_channel_slave_remove (struct GNUNET_PSYC_Channel *channel,
const struct GNUNET_CRYPTO_EcdsaPublicKey
*slave_pub_key,
uint64_t announced_at,
GNUNET_ResultCallback result_cb,
void *cls);
/**
* History request handle.
*/
struct GNUNET_PSYC_HistoryRequest;
/**
* Request to replay a part of the message history of the channel.
*
* Historic messages (but NOT the state at the time) will be replayed (given to
* the normal method handlers) if available and if access is permitted.
*
* @param channel
* Which channel should be replayed?
* @param start_message_id
* Earliest interesting point in history.
* @param end_message_id
* Last (inclusive) interesting point in history.
* @param method_prefix
* Retrieve only messages with a matching method prefix.
* @param flags
* OR'ed enum GNUNET_PSYC_HistoryReplayFlags
* @param result_cb
* Function to call when the requested history has been fully replayed.
* Once this function has been called, the client must not call
* GNUNET_PSYC_channel_history_replay_cancel() anymore.
* @param cls
* Closure for the callbacks.
*
* @return Handle to cancel history replay operation.
*/
struct GNUNET_PSYC_HistoryRequest *
GNUNET_PSYC_channel_history_replay (struct GNUNET_PSYC_Channel *channel,
uint64_t start_message_id,
uint64_t end_message_id,
const char *method_prefix,
uint32_t flags,
GNUNET_PSYC_MessageCallback message_cb,
GNUNET_PSYC_MessagePartCallback message_part_cb,
GNUNET_ResultCallback result_cb,
void *cls);
/**
* Request to replay the latest messages from the message history of the channel.
*
* Historic messages (but NOT the state at the time) will be replayed (given to
* the normal method handlers) if available and if access is permitted.
*
* @param channel
* Which channel should be replayed?
* @param message_limit
* Maximum number of messages to replay.
* @param flags
* OR'ed enum GNUNET_PSYC_HistoryReplayFlags
* @param finish_cb
* Function to call when the requested history has been fully replayed
* (counting message IDs might not suffice, as some messages might be
* secret and thus the listener would not know the story is finished
* without being told explicitly)o once this function has been called, the
* client must not call GNUNET_PSYC_channel_history_replay_cancel() anymore.
* @param cls
* Closure for the callbacks.
*
* @return Handle to cancel history replay operation.
*/
struct GNUNET_PSYC_HistoryRequest *
GNUNET_PSYC_channel_history_replay_latest (struct GNUNET_PSYC_Channel *channel,
uint64_t message_limit,
const char *method_prefix,
uint32_t flags,
GNUNET_PSYC_MessageCallback message_cb,
GNUNET_PSYC_MessagePartCallback message_part_cb,
GNUNET_ResultCallback result_cb,
void *cls);
void
GNUNET_PSYC_channel_history_replay_cancel (struct GNUNET_PSYC_Channel *channel,
struct GNUNET_PSYC_HistoryRequest *hr);
/**
* Function called to inform a member about stored state values for a channel.
*
* If @a full_value_size > value_size then this function is called multiple
* times until the whole value arrived.
*
* @param cls
* Closure.
* @param name
* Name of the state variable.
* NULL if there are no more state variables to be returned.
* @param value
* Value of the state variable.
* @param value_size
* Number of bytes in @a value.
* @param full_value_size
* Number of bytes in the full value, including continuations.
* Only set for the first part of a variable,
* in case of a continuation it is 0.
*/
typedef void
(*GNUNET_PSYC_StateVarCallback) (void *cls,
const struct GNUNET_MessageHeader *mod,
const char *name,
const void *value,
uint32_t value_size,
uint32_t full_value_size);
/**
* State request handle.
*/
struct GNUNET_PSYC_StateRequest;
/**
* Retrieve the best matching channel state variable.
*
* If the requested variable name is not present in the state, the nearest
* less-specific name is matched; for example, requesting "_a_b" will match "_a"
* if "_a_b" does not exist.
*
* @param channel
* Channel handle.
* @param full_name
* Full name of the requested variable.
* The actual variable returned might have a shorter name.
* @param var_cb
* Function called once when a matching state variable is found.
* Not called if there's no matching state variable.
* @param result_cb
* Function called after the operation finished.
* (i.e. all state variables have been returned via @a state_cb)
* @param cls
* Closure for the callbacks.
*/
struct GNUNET_PSYC_StateRequest *
GNUNET_PSYC_channel_state_get (struct GNUNET_PSYC_Channel *channel,
const char *full_name,
GNUNET_PSYC_StateVarCallback var_cb,
GNUNET_ResultCallback result_cb,
void *cls);
/**
* Return all channel state variables whose name matches a given prefix.
*
* A name matches if it starts with the given @a name_prefix, thus requesting
* the empty prefix ("") will match all values; requesting "_a_b" will also
* return values stored under "_a_b_c".
*
* The @a state_cb is invoked on all matching state variables asynchronously, as
* the state is stored in and retrieved from the PSYCstore,
*
* @param channel
* Channel handle.
* @param name_prefix
* Prefix of the state variable name to match.
* @param var_cb
* Function called once when a matching state variable is found.
* Not called if there's no matching state variable.
* @param result_cb
* Function called after the operation finished.
* (i.e. all state variables have been returned via @a state_cb)
* @param cls
* Closure for the callbacks.
*/
struct GNUNET_PSYC_StateRequest *
GNUNET_PSYC_channel_state_get_prefix (struct GNUNET_PSYC_Channel *channel,
const char *name_prefix,
GNUNET_PSYC_StateVarCallback var_cb,
GNUNET_ResultCallback result_cb,
void *cls);
/**
* Cancel a state request operation.
*
* @param sr
* Handle for the operation to cancel.
*/
void
GNUNET_PSYC_channel_state_get_cancel (struct GNUNET_PSYC_StateRequest *sr);
#if 0 /* keep Emacsens' auto-indent happy */
{
#endif
#ifdef __cplusplus
}
#endif
/* ifndef GNUNET_PSYC_SERVICE_H */
#endif
/** @} */ /* end of group */