/*
* This file is part of GNUnet
* (C) 2013 Christian Grothoff (and other contributing authors)
*
* GNUnet is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 3, 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNUnet; see the file COPYING. If not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* @file psyc/psyc_api.c
* @brief PSYC service; high-level access to the PSYC protocol
* 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!
* @author Gabor X Toth
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_env_lib.h"
#include "gnunet_psyc_service.h"
#include "psyc.h"
#define LOG(kind,...) GNUNET_log_from (kind, "psyc-api",__VA_ARGS__)
struct OperationHandle
{
struct OperationHandle *prev;
struct OperationHandle *next;
const struct GNUNET_MessageHeader *msg;
};
/**
* Handle to access PSYC channel operations for both the master and slaves.
*/
struct GNUNET_PSYC_Channel
{
/**
* Configuration to use.
*/
const struct GNUNET_CONFIGURATION_Handle *cfg;
/**
* Socket (if available).
*/
struct GNUNET_CLIENT_Connection *client;
/**
* Currently pending transmission request, or NULL for none.
*/
struct GNUNET_CLIENT_TransmitHandle *th;
/**
* Head of operations to transmit.
*/
struct OperationHandle *transmit_head;
/**
* Tail of operations to transmit.
*/
struct OperationHandle *transmit_tail;
/**
* Message to send on reconnect.
*/
struct GNUNET_MessageHeader *reconnect_msg;
/**
* Task doing exponential back-off trying to reconnect.
*/
GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
/**
* Time for next connect retry.
*/
struct GNUNET_TIME_Relative reconnect_delay;
GNUNET_PSYC_Method method_cb;
GNUNET_PSYC_JoinCallback join_cb;
void *cb_cls;
/**
* Are we polling for incoming messages right now?
*/
int in_receive;
/**
* Are we currently transmitting a message?
*/
int in_transmit;
};
/**
* Handle for the master of a PSYC channel.
*/
struct GNUNET_PSYC_Master
{
struct GNUNET_PSYC_Channel ch;
GNUNET_PSYC_MasterStartCallback start_cb;
uint64_t max_message_id;
};
/**
* Handle for a PSYC channel slave.
*/
struct GNUNET_PSYC_Slave
{
struct GNUNET_PSYC_Channel ch;
};
/**
* 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
{
};
/**
* Handle for a pending PSYC transmission operation.
*/
struct GNUNET_PSYC_MasterTransmitHandle
{
struct GNUNET_PSYC_Master *master;
const struct GNUNET_ENV_Environment *env;
GNUNET_PSYC_MasterTransmitNotify notify;
void *notify_cls;
enum GNUNET_PSYC_MasterTransmitFlags flags;
};
/**
* Handle for a pending PSYC transmission operation.
*/
struct GNUNET_PSYC_SlaveTransmitHandle
{
};
/**
* Handle to a story telling operation.
*/
struct GNUNET_PSYC_Story
{
};
/**
* Handle for a state query operation.
*/
struct GNUNET_PSYC_StateQuery
{
};
/**
* Try again to connect to the PSYCstore service.
*
* @param cls handle to the PSYCstore service.
* @param tc scheduler context
*/
static void
reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
/**
* Reschedule a connect attempt to the service.
*
* @param h transport service to reconnect
*/
static void
reschedule_connect (struct GNUNET_PSYC_Channel *c)
{
GNUNET_assert (c->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
if (NULL != c->th)
{
GNUNET_CLIENT_notify_transmit_ready_cancel (c->th);
c->th = NULL;
}
if (NULL != c->client)
{
GNUNET_CLIENT_disconnect (c->client);
c->client = NULL;
}
c->in_receive = GNUNET_NO;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Scheduling task to reconnect to PSYCstore service in %s.\n",
GNUNET_STRINGS_relative_time_to_string (c->reconnect_delay, GNUNET_YES));
c->reconnect_task =
GNUNET_SCHEDULER_add_delayed (c->reconnect_delay, &reconnect, c);
c->reconnect_delay = GNUNET_TIME_STD_BACKOFF (c->reconnect_delay);
}
/**
* Schedule transmission of the next message from our queue.
*
* @param h PSYCstore handle
*/
static void
transmit_next (struct GNUNET_PSYC_Channel *c);
/**
* Type of a function to call when we receive a message
* from the service.
*
* @param cls closure
* @param msg message received, NULL on timeout or fatal error
*/
static void
message_handler (void *cls, const struct GNUNET_MessageHeader *msg)
{
struct GNUNET_PSYC_Channel *ch = cls;
struct GNUNET_PSYC_Master *mst = cls;
struct GNUNET_PSYC_Slave *slv = cls;
if (NULL == msg)
{
reschedule_connect (ch);
return;
}
uint16_t size_eq = 0;
uint16_t size_min = 0;
const uint16_t size = ntohs (msg->size);
const uint16_t type = ntohs (msg->type);
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Received message of type %d from PSYC service\n", type);
switch (type)
{
case GNUNET_MESSAGE_TYPE_PSYC_MASTER_START_ACK:
case GNUNET_MESSAGE_TYPE_PSYC_SLAVE_JOIN_ACK:
size_eq = sizeof (struct CountersResult);
break;
}
if (! ((0 < size_eq && size == size_eq)
|| (0 < size_min && size >= size_min)))
{
GNUNET_break (0);
reschedule_connect (ch);
return;
}
struct CountersResult *cres;
switch (type)
{
case GNUNET_MESSAGE_TYPE_PSYC_MASTER_START_ACK:
cres = (struct CountersResult *) msg;
mst->max_message_id = GNUNET_ntohll (cres->max_message_id);
if (NULL != mst->start_cb)
mst->start_cb (ch->cb_cls, mst->max_message_id);
break;
case GNUNET_MESSAGE_TYPE_PSYC_SLAVE_JOIN_ACK:
cres = (struct CountersResult *) msg;
#if TODO
slv->max_message_id = GNUNET_ntohll (cres->max_message_id);
if (NULL != slv->join_ack_cb)
mst->join_ack_cb (ch->cb_cls, mst->max_message_id);
#endif
break;
}
GNUNET_CLIENT_receive (ch->client, &message_handler, ch,
GNUNET_TIME_UNIT_FOREVER_REL);
}
/**
* Transmit next message to service.
*
* @param cls The 'struct GNUNET_PSYCSTORE_Handle'.
* @param size Number of bytes available in buf.
* @param buf Where to copy the message.
* @return Number of bytes copied to buf.
*/
static size_t
send_next_message (void *cls, size_t size, void *buf)
{
struct GNUNET_PSYC_Channel *ch = cls;
struct OperationHandle *op = ch->transmit_head;
size_t ret;
ch->th = NULL;
if (NULL == op->msg)
return 0;
ret = ntohs (op->msg->size);
if (ret > size)
{
reschedule_connect (ch);
return 0;
}
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Sending message of type %d to PSYCstore service\n",
ntohs (op->msg->type));
memcpy (buf, op->msg, ret);
GNUNET_CONTAINER_DLL_remove (ch->transmit_head, ch->transmit_tail, op);
GNUNET_free (op);
if (NULL != ch->transmit_head)
transmit_next (ch);
if (GNUNET_NO == ch->in_receive)
{
ch->in_receive = GNUNET_YES;
GNUNET_CLIENT_receive (ch->client, &message_handler, ch,
GNUNET_TIME_UNIT_FOREVER_REL);
}
return ret;
}
/**
* Schedule transmission of the next message from our queue.
*
* @param h PSYCstore handle.
*/
static void
transmit_next (struct GNUNET_PSYC_Channel *ch)
{
if (NULL != ch->th || NULL == ch->client)
return;
struct OperationHandle *op = ch->transmit_head;
if (NULL == op)
return;
ch->th = GNUNET_CLIENT_notify_transmit_ready (ch->client,
ntohs (op->msg->size),
GNUNET_TIME_UNIT_FOREVER_REL,
GNUNET_NO,
&send_next_message,
ch);
}
/**
* Try again to connect to the PSYC service.
*
* @param cls Channel handle.
* @param tc Scheduler context.
*/
static void
reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
struct GNUNET_PSYC_Channel *ch = cls;
ch->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Connecting to PSYC service.\n");
GNUNET_assert (NULL == ch->client);
ch->client = GNUNET_CLIENT_connect ("psyc", ch->cfg);
GNUNET_assert (NULL != ch->client);
if (NULL == ch->transmit_head ||
ch->transmit_head->msg->type != ch->reconnect_msg->type)
{
struct OperationHandle *op
= GNUNET_malloc (sizeof (struct OperationHandle)
+ ntohs (ch->reconnect_msg->size));
memcpy (&op[1], ch->reconnect_msg, ntohs (ch->reconnect_msg->size));
op->msg = (struct GNUNET_MessageHeader *) &op[1];
GNUNET_CONTAINER_DLL_insert (ch->transmit_head, ch->transmit_tail, op);
}
transmit_next (ch);
}
/**
* Disconnect from the PSYC service.
*
* @param cls Channel handle.
* @param tc Scheduler context.
*/
static void
disconnect (void *c)
{
struct GNUNET_PSYC_Channel *ch = c;
GNUNET_assert (NULL != ch);
GNUNET_assert (ch->transmit_head == ch->transmit_tail);
if (ch->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
{
GNUNET_SCHEDULER_cancel (ch->reconnect_task);
ch->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
}
if (NULL != ch->th)
{
GNUNET_CLIENT_notify_transmit_ready_cancel (ch->th);
ch->th = NULL;
}
if (NULL != ch->client)
{
GNUNET_CLIENT_disconnect (ch->client);
ch->client = NULL;
}
if (NULL != ch->reconnect_msg)
ch->reconnect_msg = NULL;
}
/**
* 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 method Function to invoke on messages received from slaves.
* @param join_cb Function to invoke when a peer wants to join.
* @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_EccPrivateKey *channel_key,
enum GNUNET_PSYC_Policy policy,
GNUNET_PSYC_Method method,
GNUNET_PSYC_JoinCallback join_cb,
GNUNET_PSYC_MasterStartCallback master_started_cb,
void *cls)
{
struct GNUNET_PSYC_Master *mst = GNUNET_malloc (sizeof (*mst));
struct GNUNET_PSYC_Channel *ch = &mst->ch;
struct MasterStartRequest *req = GNUNET_malloc (sizeof (*req));
req->header.size = htons (sizeof (*req) + sizeof (*channel_key));
req->header.type = htons (GNUNET_MESSAGE_TYPE_PSYC_MASTER_START);
req->channel_key = *channel_key;
req->policy = policy;
ch->cfg = cfg;
ch->reconnect_msg = (struct GNUNET_MessageHeader *) req;
ch->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
ch->reconnect_task = GNUNET_SCHEDULER_add_now (&reconnect, mst);
ch->method_cb = method;
ch->join_cb = join_cb;
ch->cb_cls = cls;
mst->start_cb = master_started_cb;
return mst;
}
/**
* Stop a PSYC master channel.
*
* @param master PSYC channel master to stop.
*/
void
GNUNET_PSYC_master_stop (struct GNUNET_PSYC_Master *mst)
{
disconnect (mst);
GNUNET_free (mst);
}
/**
* 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 joining is approved,
* #GNUNET_NO if it is disapproved.
* @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 method_name Method name for the message transmitted with the response.
* @param env Environment containing transient variables for the message, or NULL.
* @param data Data of the message.
* @param data_size Size of @a data.
*/
void
GNUNET_PSYC_join_decision (struct GNUNET_PSYC_JoinHandle *jh,
int is_admitted,
unsigned int relay_count,
const struct GNUNET_PeerIdentity *relays,
const char *method_name,
const struct GNUNET_ENV_Environment *env,
const void *data,
size_t data_size)
{
}
/* FIXME: split up value into <64K chunks and transmit the continuations in
* MOD_CONT msgs */
int
send_modifier (void *cls, struct GNUNET_ENV_Modifier *mod)
{
struct GNUNET_PSYC_Channel *ch = cls;
size_t name_size = strlen (mod->name) + 1;
struct GNUNET_PSYC_MessageModifier *pmod;
struct OperationHandle *op = GNUNET_malloc (sizeof (*op) + sizeof (*pmod)
+ name_size + mod->value_size);
pmod = (struct GNUNET_PSYC_MessageModifier *) &op[1];
op->msg = (struct GNUNET_MessageHeader *) pmod;
pmod->header.type = GNUNET_MESSAGE_TYPE_PSYC_TRANSMIT_MODIFIER;
pmod->header.size = htons (sizeof (*pmod) + name_size + mod->value_size);
pmod->name_size = htons (name_size);
memcpy (&pmod[1], mod->name, name_size);
memcpy ((void *) &pmod[1] + name_size, mod->value, mod->value_size);
GNUNET_CONTAINER_DLL_insert (ch->transmit_head, ch->transmit_tail, op);
return GNUNET_YES;
}
/**
* Send a message to call a method to all members in the PSYC channel.
*
* @param mst Handle to the PSYC channel.
* @param method_name Which method should be invoked.
* @param env Environment containing state operations and transient variables
* for the message, or NULL.
* @param notify Function to call to obtain the arguments.
* @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_MasterTransmitHandle *
GNUNET_PSYC_master_transmit (struct GNUNET_PSYC_Master *mst,
const char *method_name,
const struct GNUNET_ENV_Environment *env,
GNUNET_PSYC_MasterTransmitNotify notify,
void *notify_cls,
enum GNUNET_PSYC_MasterTransmitFlags flags)
{
GNUNET_assert (NULL != mst);
struct GNUNET_PSYC_Channel *ch = &mst->ch;
if (GNUNET_NO != ch->in_transmit)
return NULL;
ch->in_transmit = GNUNET_YES;
struct GNUNET_PSYC_MessageMethod *pmeth;
struct OperationHandle *op = GNUNET_malloc (sizeof (*op) + sizeof (*pmeth));
pmeth = (struct GNUNET_PSYC_MessageMethod *) &op[1];
op->msg = (struct GNUNET_MessageHeader *) pmeth;
pmeth->header.type = GNUNET_MESSAGE_TYPE_PSYC_TRANSMIT_METHOD;
size_t size = strlen (method_name) + 1;
pmeth->header.size = htons (sizeof (*pmeth) + size);
pmeth->flags = htonl (flags);
pmeth->mod_count
= GNUNET_ntohll (GNUNET_ENV_environment_get_mod_count (env));
memcpy (&pmeth[1], method_name, size);
GNUNET_CONTAINER_DLL_insert (ch->transmit_head, ch->transmit_tail, op);
GNUNET_ENV_environment_iterate (env, send_modifier, mst);
struct GNUNET_PSYC_MasterTransmitHandle *th = GNUNET_malloc (sizeof (*th));
th->master = mst;
th->env = env;
th->notify = notify;
th->notify_cls = notify_cls;
return th;
}
/**
* Abort transmission request to the channel.
*
* @param th Handle of the request that is being aborted.
*/
void
GNUNET_PSYC_master_transmit_cancel (struct GNUNET_PSYC_MasterTransmitHandle *th)
{
struct GNUNET_PSYC_Master *mst = th->master;
struct GNUNET_PSYC_Channel *ch = &mst->ch;
if (GNUNET_NO != ch->in_transmit)
return;
}
/**
* 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_key ECC public key that identifies the channel we wish to join.
* @param slave_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 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 method Function to invoke on messages received from the channel,
* typically at least contains functions for @e join and @e part.
* @param join_cb Function to invoke when a peer wants to join.
* @param cls Closure for @a method_cb and @a join_cb.
* @param method_name Method name for the join request.
* @param env Environment containing transient variables for the request, or NULL.
* @param data Payload for the join message.
* @param data_size Number of bytes in @a data.
* @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_EccPublicSignKey *channel_key,
const struct GNUNET_CRYPTO_EccPrivateKey *slave_key,
const struct GNUNET_PeerIdentity *origin,
size_t relay_count,
const struct GNUNET_PeerIdentity *relays,
GNUNET_PSYC_Method method,
GNUNET_PSYC_JoinCallback join_cb,
GNUNET_PSYC_SlaveJoinCallback slave_joined_cb,
void *cls,
const char *method_name,
const struct GNUNET_ENV_Environment *env,
const void *data,
size_t data_size)
{
struct GNUNET_PSYC_Slave *slv = GNUNET_malloc (sizeof (*slv));
struct GNUNET_PSYC_Channel *ch = &slv->ch;
struct SlaveJoinRequest *req = GNUNET_malloc (sizeof (*req));
req->header.size = htons (sizeof (*req)
+ sizeof (*channel_key) + sizeof (*slave_key)
+ relay_count * sizeof (*relays));
req->header.type = htons (GNUNET_MESSAGE_TYPE_PSYC_SLAVE_JOIN);
req->channel_key = *channel_key;
req->slave_key = *slave_key;
req->relay_count = relay_count;
memcpy (&req[1], relays, relay_count * sizeof (*relays));
ch->cfg = cfg;
ch->reconnect_msg = (struct GNUNET_MessageHeader *) req;
ch->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
ch->reconnect_task = GNUNET_SCHEDULER_add_now (&reconnect, slv);
return slv;
}
/**
* Part a PSYC channel.
*
* Will terminate the connection to the PSYC service. Polite clients should
* first explicitly send a @e part request (via GNUNET_PSYC_slave_transmit()).
*
* @param slv Slave handle.
*/
void
GNUNET_PSYC_slave_part (struct GNUNET_PSYC_Slave *slv)
{
disconnect (slv);
GNUNET_free (slv);
}
/**
* 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 env Environment containing transient variables for the message, or
* NULL.
* @param notify Function to call when we are allowed to transmit (to get 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,
const struct GNUNET_ENV_Environment *env,
GNUNET_PSYC_SlaveTransmitNotify notify,
void *notify_cls,
enum GNUNET_PSYC_SlaveTransmitFlags flags)
{
return NULL;
}
/**
* 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)
{
}
/**
* 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)
{
return (struct GNUNET_PSYC_Channel *) 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)
{
return (struct GNUNET_PSYC_Channel *) 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 ch Channel handle.
* @param slave_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.
*/
void
GNUNET_PSYC_channel_slave_add (struct GNUNET_PSYC_Channel *ch,
const struct GNUNET_CRYPTO_EccPublicSignKey
*slave_key,
uint64_t announced_at,
uint64_t effective_since)
{
struct ChannelSlaveAdd *slvadd;
struct OperationHandle *op = GNUNET_malloc (sizeof (*op) + sizeof (*slvadd));
slvadd = (struct ChannelSlaveAdd *) &op[1];
op->msg = (struct GNUNET_MessageHeader *) slvadd;
slvadd->header.type = GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_SLAVE_ADD;
slvadd->header.size = htons (sizeof (*slvadd));
slvadd->announced_at = GNUNET_htonll (announced_at);
slvadd->effective_since = GNUNET_htonll (effective_since);
GNUNET_CONTAINER_DLL_insert (ch->transmit_head, ch->transmit_tail, op);
transmit_next (ch);
}
/**
* 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 ch Channel handle.
* @param slave_key Identity of channel slave to remove.
* @param announced_at ID of the message that announced the membership change.
*/
void
GNUNET_PSYC_channel_slave_remove (struct GNUNET_PSYC_Channel *ch,
const struct GNUNET_CRYPTO_EccPublicSignKey
*slave_key,
uint64_t announced_at)
{
struct ChannelSlaveRemove *slvrm;
struct OperationHandle *op = GNUNET_malloc (sizeof (*op) + sizeof (*slvrm));
slvrm = (struct ChannelSlaveRemove *) &op[1];
op->msg = (struct GNUNET_MessageHeader *) slvrm;
slvrm->header.type = GNUNET_MESSAGE_TYPE_PSYC_CHANNEL_SLAVE_RM;
slvrm->header.size = htons (sizeof (*slvrm));
slvrm->announced_at = GNUNET_htonll (announced_at);
GNUNET_CONTAINER_DLL_insert (ch->transmit_head, ch->transmit_tail, op);
transmit_next (ch);
}
/**
* Request to be told 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.
*
* To get the latest message, use 0 for both the start and end message ID.
*
* @param ch Which channel should be replayed?
* @param start_message_id Earliest interesting point in history.
* @param end_message_id Last (exclusive) interesting point in history.
* @param method Function to invoke on messages received from the story.
* @param finish_cb Function to call when the requested story has been fully
* told (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)
{
return NULL;
} once this function
* has been called, the client must not call
* GNUNET_PSYC_channel_story_tell_cancel() anymore.
* @param cls Closure for the callbacks.
* @return Handle to cancel story telling operation.
*/
struct GNUNET_PSYC_Story *
GNUNET_PSYC_channel_story_tell (struct GNUNET_PSYC_Channel *ch,
uint64_t start_message_id,
uint64_t end_message_id,
GNUNET_PSYC_Method method,
GNUNET_PSYC_FinishCallback *finish_cb,
void *cls)
{
return NULL;
}
/**
* Abort story telling.
*
* This function must not be called from within method handlers (as given to
* GNUNET_PSYC_slave_join()) of the slave.
*
* @param story Story telling operation to stop.
*/
void
GNUNET_PSYC_channel_story_tell_cancel (struct GNUNET_PSYC_Story *story)
{
}
/**
* 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 cb Function called once when a matching state variable is found.
* Not called if there's no matching state variable.
* @param cb_cls Closure for the callbacks.
* @return Handle that can be used to cancel the query operation.
*/
struct GNUNET_PSYC_StateQuery *
GNUNET_PSYC_channel_state_get (struct GNUNET_PSYC_Channel *channel,
const char *full_name,
GNUNET_PSYC_StateCallback cb,
void *cb_cls)
{
return NULL;
}
/**
* 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 cb Function to call with the matching state variables.
* @param cb_cls Closure for the callbacks.
* @return Handle that can be used to cancel the query operation.
*/
struct GNUNET_PSYC_StateQuery *
GNUNET_PSYC_channel_state_get_prefix (struct GNUNET_PSYC_Channel *channel,
const char *name_prefix,
GNUNET_PSYC_StateCallback cb,
void *cb_cls)
{
return NULL;
}
/**
* Cancel a state query operation.
*
* @param query Handle for the operation to cancel.
*/
void
GNUNET_PSYC_channel_state_get_cancel (struct GNUNET_PSYC_StateQuery *query)
{
}
/* end of psyc_api.c */