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/*
This file is part of GNUnet.
(C) 2009, 2010, 2012 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 core/core_api_is_connected.c
* @brief implementation of the 'GNUNET_CORE_is_peer_connected function
* @author Christian Grothoff
* @author Nathan Evans
*
* TODO:
* - define nice structs for the IPC messages in core.h
* - consider NOT always sending the 'END' message -- it is redundant!
*/
#include "platform.h"
#include "gnunet_core_service.h"
#include "core.h"
/**
* Closure for 'transmit_is_connected_request"
*/
struct GNUNET_CORE_ConnectTestHandle
{
/**
* Our connection to the service.
*/
struct GNUNET_CLIENT_Connection *client;
/**
* Handle for transmitting a request.
*/
struct GNUNET_CLIENT_TransmitHandle *th;
/**
* Function called with the peer.
*/
GNUNET_CORE_ConnectEventHandler peer_cb;
/**
* Peer to check for.
*/
struct GNUNET_PeerIdentity peer;
/**
* Closure for peer_cb.
*/
void *cb_cls;
};
/**
* Receive reply from core service with information about a peer.
*
* @param cls our 'struct GNUNET_CORE_RequestContext *'
* @param msg NULL on error or last entry
*/
static void
receive_connect_info (void *cls, const struct GNUNET_MessageHeader *msg)
{
struct GNUNET_CORE_ConnectTestHandle *cth = cls;
const struct ConnectNotifyMessage *connect_message;
uint16_t msize;
if (NULL == msg)
{
/* core died, failure */
cth->peer_cb (cth->cb_cls, NULL);
GNUNET_CORE_is_peer_connected_cancel (cth);
return;
}
if ((ntohs (msg->type) == GNUNET_MESSAGE_TYPE_CORE_ITERATE_PEERS_END) &&
(ntohs (msg->size) == sizeof (struct GNUNET_MessageHeader)))
{
/* end of transmissions */
cth->peer_cb (cth->cb_cls, NULL);
GNUNET_CORE_is_peer_connected_cancel (cth);
return;
}
msize = ntohs (msg->size);
/* Handle incorrect message type or size, disconnect and clean up */
if ((ntohs (msg->type) != GNUNET_MESSAGE_TYPE_CORE_NOTIFY_CONNECT) ||
(msize < sizeof (struct ConnectNotifyMessage)))
{
GNUNET_break (0);
cth->peer_cb (cth->cb_cls, NULL);
GNUNET_CORE_is_peer_connected_cancel (cth);
return;
}
connect_message = (const struct ConnectNotifyMessage *) msg;
if (msize != sizeof (struct ConnectNotifyMessage))
{
GNUNET_break (0);
cth->peer_cb (cth->cb_cls, NULL);
GNUNET_CORE_is_peer_connected_cancel (cth);
return;
}
/* Normal case */
cth->peer_cb (cth->cb_cls, &connect_message->peer);
GNUNET_CLIENT_receive (cth->client, &receive_connect_info,
cth, GNUNET_TIME_UNIT_FOREVER_REL);
}
/**
* Function called to notify a client about the socket
* begin ready to queue more data. "buf" will be
* NULL and "size" zero if the socket was closed for
* writing in the meantime.
*
* @param cls closure
* @param size number of bytes available in buf
* @param buf where the callee should write the message
* @return number of bytes written to buf
*/
static size_t
transmit_is_connected_request (void *cls, size_t size, void *buf)
{
struct GNUNET_CORE_ConnectTestHandle *cth = cls;
struct GNUNET_MessageHeader *msg;
unsigned int msize;
cth->th = NULL;
msize =
sizeof (struct GNUNET_MessageHeader) +
sizeof (struct GNUNET_PeerIdentity);
if ( (NULL == buf) || (0 == size) )
{
cth->peer_cb (cth->cb_cls, NULL);
GNUNET_CLIENT_disconnect (cth->client);
GNUNET_free (cth);
return 0;
}
GNUNET_assert (size >= msize);
msg = (struct GNUNET_MessageHeader *) buf;
msg->size = htons (msize);
msg->type = htons (GNUNET_MESSAGE_TYPE_CORE_PEER_CONNECTED);
memcpy (&msg[1], &cth->peer, sizeof (struct GNUNET_PeerIdentity));
GNUNET_CLIENT_receive (cth->client, &receive_connect_info, cth,
GNUNET_TIME_UNIT_FOREVER_REL);
return msize;
}
/**
* Iterate over all currently connected peers.
* Calls peer_cb with each connected peer, and then
* once with NULL to indicate that all peers have
* been handled.
*
* @param cfg configuration to use
* @param peer the specific peer to check for
* @param peer_cb function to call with the peer information
* @param cb_cls closure for peer_cb
*
* @return GNUNET_OK if iterating, GNUNET_SYSERR on error
*/
struct GNUNET_CORE_ConnectTestHandle *
GNUNET_CORE_is_peer_connected (const struct GNUNET_CONFIGURATION_Handle *cfg,
const struct GNUNET_PeerIdentity *peer,
GNUNET_CORE_ConnectEventHandler peer_cb,
void *cb_cls)
{
struct GNUNET_CORE_ConnectTestHandle *cth;
struct GNUNET_CLIENT_Connection *client;
GNUNET_assert (NULL != peer);
GNUNET_assert (NULL != peer_cb);
client = GNUNET_CLIENT_connect ("core", cfg);
if (NULL == client)
return NULL;
cth = GNUNET_malloc (sizeof (struct GNUNET_CORE_ConnectTestHandle));
cth->peer = *peer;
cth->client = client;
cth->peer_cb = peer_cb;
cth->cb_cls = cb_cls;
cth->th =
GNUNET_CLIENT_notify_transmit_ready (client,
sizeof (struct GNUNET_MessageHeader) +
sizeof (struct GNUNET_PeerIdentity),
GNUNET_TIME_UNIT_FOREVER_REL,
GNUNET_YES, &transmit_is_connected_request, cth);
GNUNET_assert (NULL != cth->th);
return cth;
}
/**
* Abort 'is_connected' test operation.
*
* @param cth handle for operation to cancel
*/
void
GNUNET_CORE_is_peer_connected_cancel (struct GNUNET_CORE_ConnectTestHandle *cth)
{
if (NULL != cth->th)
{
GNUNET_CLIENT_notify_transmit_ready_cancel (cth->th);
cth->th = NULL;
}
GNUNET_CLIENT_disconnect (cth->client);
GNUNET_free (cth);
}
/* end of core_api_is_connected.c */
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