nuttx/net/socket/net_monitor.c

339 lines
10 KiB
C

/****************************************************************************
* net/socket/net_monitor.c
*
* Copyright (C) 2007-2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#if defined(CONFIG_NET) && defined(CONFIG_NET_TCP)
#include <stdint.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/net/tcp.h>
#include "devif/devif.h"
#include "tcp/tcp.h"
#include "socket/socket.h"
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void connection_closed(FAR struct socket *psock, uint16_t flags);
static uint16_t connection_event(FAR struct net_driver_s *dev,
FAR void *pvconn, FAR void *pvpriv,
uint16_t flags);
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: connection_closed
*
* Description:
* Called when a loss-of-connection event has occurred.
*
* Parameters:
* psock The TCP socket structure associated.
* flags Set of connection events events
*
* Returned Value:
* None
*
* Assumptions:
* The caller holds the network lock.
*
****************************************************************************/
static void connection_closed(FAR struct socket *psock, uint16_t flags)
{
/* These loss-of-connection events may be reported:
*
* TCP_CLOSE: The remote host has closed the connection
* TCP_ABORT: The remote host has aborted the connection
* TCP_TIMEDOUT: Connection aborted due to too many retransmissions.
* NETDEV_DOWN: The network device went down
*
* And we need to set these two socket status bits appropriately:
*
* _SF_CONNECTED==1 && _SF_CLOSED==0 - the socket is connected
* _SF_CONNECTED==0 && _SF_CLOSED==1 - the socket was gracefully disconnected
* _SF_CONNECTED==0 && _SF_CLOSED==0 - the socket was rudely disconnected
*/
if ((flags & TCP_CLOSE) != 0)
{
/* The peer gracefully closed the connection. Marking the
* connection as disconnected will suppress some subsequent
* ENOTCONN errors from receive. A graceful disconnection is
* not handle as an error but as an "end-of-file"
*/
psock->s_flags &= ~_SF_CONNECTED;
psock->s_flags |= _SF_CLOSED;
}
else if ((flags & (TCP_ABORT | TCP_TIMEDOUT | NETDEV_DOWN)) != 0)
{
/* The loss of connection was less than graceful. This will (eventually)
* be reported as an ENOTCONN error.
*/
psock->s_flags &= ~(_SF_CONNECTED |_SF_CLOSED);
}
}
/****************************************************************************
* Name: connection_event
*
* Description:
* Some connection related event has occurred
*
* Parameters:
* dev The device which as active when the event was detected.
* conn The connection structure associated with the socket
* flags Set of events describing why the callback was invoked
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
static uint16_t connection_event(FAR struct net_driver_s *dev,
FAR void *pvconn, FAR void *pvpriv,
uint16_t flags)
{
FAR struct socket *psock = (FAR struct socket *)pvpriv;
if (psock)
{
nllvdbg("flags: %04x s_flags: %02x\n", flags, psock->s_flags);
/* TCP_DISCONN_EVENTS: TCP_CLOSE, TCP_ABORT, TCP_TIMEDOUT, or
* NETDEV_DOWN. All loss-of-connection events.
*/
if ((flags & TCP_DISCONN_EVENTS) != 0)
{
connection_closed(psock, flags);
}
/* TCP_CONNECTED: The socket is successfully connected */
else if ((flags & TCP_CONNECTED) != 0)
{
/* Indicate that the socket is now connected */
psock->s_flags |= _SF_CONNECTED;
psock->s_flags &= ~_SF_CLOSED;
}
}
return flags;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: net_startmonitor
*
* Description:
* Set up to receive TCP connection state changes for a given socket
*
* Input Parameters:
* psock - The socket of interest
*
* Returned Value:
* On success, net_startmonitor returns OK; On any failure,
* net_startmonitor will return a negated errno value. The only failure
* that can occur is if the socket has already been closed and, in this
* case, -ENOTCONN is returned.
*
* Assumptions:
* The caller holds the network lock (if not, it will be locked momentarily
* by this function).
*
****************************************************************************/
int net_startmonitor(FAR struct socket *psock)
{
FAR struct tcp_conn_s *conn;
FAR struct devif_callback_s *cb;
net_lock_t save;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL);
conn = (FAR struct tcp_conn_s *)psock->s_conn;
/* Check if the connection has already been closed before any callbacks
* have been registered. (Maybe the connection is lost before accept has
* registered the monitoring callback.)
*/
save = net_lock();
if (!(conn->tcpstateflags == TCP_ESTABLISHED ||
conn->tcpstateflags == TCP_SYN_RCVD))
{
/* Invoke the TCP_CLOSE connection event now */
(void)connection_event(NULL, conn, psock, TCP_CLOSE);
/* Make sure that the monitor is stopped */
conn->connection_private = NULL;
conn->connection_devcb = NULL;
conn->connection_event = NULL;
/* And return -ENOTCONN to indicate the the monitor was not started
* because the socket was already disconnected.
*/
net_unlock(save);
return -ENOTCONN;
}
DEBUGASSERT(conn->connection_event == NULL &&
conn->connection_devcb == NULL);
/* Allocate a callback structure that we will use to get callbacks if
* the network goes down.
*/
cb = tcp_monitor_callback_alloc(conn);
if (cb != NULL)
{
cb->event = connection_event;
cb->priv = (void*)psock;
cb->flags = NETDEV_DOWN;
}
conn->connection_devcb = cb;
/* Set up to receive callbacks on connection-related events */
conn->connection_private = (void*)psock;
conn->connection_event = connection_event;
net_unlock(save);
return OK;
}
/****************************************************************************
* Name: net_stopmonitor
*
* Description:
* Stop monitoring TCP connection changes for a given socket
*
* Input Parameters:
* conn - The TCP connection of interest
*
* Returned Value:
* None
*
* Assumptions:
* The caller holds the network lock (if not, it will be locked momentarily
* by this function).
*
****************************************************************************/
void net_stopmonitor(FAR struct tcp_conn_s *conn)
{
net_lock_t save;
DEBUGASSERT(conn);
/* Free any allocated device event callback structure */
save = net_lock();
if (conn->connection_devcb)
{
tcp_monitor_callback_free(conn, conn->connection_devcb);
}
/* Nullify all connection event data */
conn->connection_private = NULL;
conn->connection_devcb = NULL;
conn->connection_event = NULL;
net_unlock(save);
}
/****************************************************************************
* Name: net_lostconnection
*
* Description:
* Called when a loss-of-connection event has occurred.
*
* Parameters:
* psock The TCP socket structure associated.
* flags Set of connection events events
*
* Returned Value:
* None
*
* Assumptions:
* The caller holds the network lock (if not, it will be locked momentarily
* by this function).
*
****************************************************************************/
void net_lostconnection(FAR struct socket *psock, uint16_t flags)
{
net_lock_t save;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL);
/* Close the connection */
save = net_lock();
connection_closed(psock, flags);
/* Stop the network monitor */
net_stopmonitor((FAR struct tcp_conn_s *)psock->s_conn);
net_unlock(save);
}
#endif /* CONFIG_NET && CONFIG_NET_TCP */