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- /****************************************************************************
- * net/tcp/tcp_monitor.c
- *
- * Copyright (C) 2007-2013, 2017-2018 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>
- #include <stdint.h>
- #include <assert.h>
- #include <debug.h>
- #include <nuttx/net/tcp.h>
- #include "devif/devif.h"
- #include "socket/socket.h"
- #include "tcp/tcp.h"
- #ifdef NET_TCP_HAVE_STACK
- /****************************************************************************
- * Private Function Prototypes
- ****************************************************************************/
- static void tcp_close_connection(FAR struct socket *psock, uint16_t flags);
- static uint16_t tcp_disconnect_event(FAR struct net_driver_s *dev,
- FAR void *pvconn, FAR void *pvpriv,
- uint16_t flags);
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: tcp_close_connection
- *
- * Description:
- * Called when a loss-of-connection event has occurred.
- *
- * Input 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 tcp_close_connection(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: tcp_disconnect_event
- *
- * Description:
- * Some connection related event has occurred
- *
- * Input 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 tcp_disconnect_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 != NULL)
- {
- ninfo("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)
- {
- tcp_close_connection(psock, flags);
- }
- /* TCP_CONNECTED: The socket is successfully connected */
- else if ((flags & TCP_CONNECTED) != 0)
- {
- #if 0 /* REVISIT: Assertion fires. Why? */
- FAR struct tcp_conn_s *conn =
- (FAR struct tcp_conn_s *)psock->s_conn;
- /* Make sure that this is the device bound to the connection */
- DEBUGASSERT(conn->dev == NULL || conn->dev == dev);
- conn->dev = dev;
- #endif
- /* If there is no local address assigned to the socket (perhaps
- * because it was INADDR_ANY), then assign it the address of the
- * connecting device.
- *
- * TODO: Implement this.
- */
- /* Indicate that the socket is now connected */
- psock->s_flags |= _SF_CONNECTED;
- psock->s_flags &= ~_SF_CLOSED;
- }
- }
- return flags;
- }
- /****************************************************************************
- * Name: tcp_shutdown_monitor
- *
- * Description:
- * Stop monitoring TCP connection changes for a given socket.
- *
- * Input Parameters:
- * conn - The TCP connection of interest
- * flags - Indicates the type of shutdown. TCP_CLOSE or TCP_ABORT
- *
- * Returned Value:
- * None
- *
- * Assumptions:
- * The caller holds the network lock (if not, it will be locked momentarily
- * by this function).
- *
- ****************************************************************************/
- static void tcp_shutdown_monitor(FAR struct tcp_conn_s *conn, uint16_t flags)
- {
- DEBUGASSERT(conn);
- /* Perform callbacks to assure that all sockets, including dup'ed copies,
- * are informed of the loss of connection event.
- */
- net_lock();
- (void)tcp_callback(conn->dev, conn, flags);
- /* Free all allocated connection event callback structures */
- while (conn->connevents != NULL)
- {
- devif_conn_callback_free(conn->dev, conn->connevents,
- &conn->connevents);
- }
- net_unlock();
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: tcp_start_monitor
- *
- * Description:
- * Set up to receive TCP connection state changes for a given socket
- *
- * Input Parameters:
- * psock - The socket of interest
- *
- * Returned Value:
- * On success, tcp_start_monitor returns OK; On any failure,
- * tcp_start_monitor 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 tcp_start_monitor(FAR struct socket *psock)
- {
- FAR struct tcp_conn_s *conn;
- FAR struct devif_callback_s *cb;
- 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.)
- */
- net_lock();
- if (!(conn->tcpstateflags == TCP_ESTABLISHED ||
- conn->tcpstateflags == TCP_SYN_RCVD))
- {
- /* Invoke the TCP_CLOSE connection event now */
- tcp_shutdown_monitor(conn, TCP_CLOSE);
- /* And return -ENOTCONN to indicate the monitor was not started
- * because the socket was already disconnected.
- */
- net_unlock();
- return -ENOTCONN;
- }
- /* Allocate a callback structure that we will use to get callbacks if
- * the network goes down.
- */
- cb = devif_callback_alloc(conn->dev, &conn->connevents);
- if (cb != NULL)
- {
- cb->event = tcp_disconnect_event;
- cb->priv = (FAR void *)psock;
- cb->flags = TCP_DISCONN_EVENTS;
- }
- net_unlock();
- return OK;
- }
- /****************************************************************************
- * Name: tcp_stop_monitor
- *
- * Description:
- * Stop monitoring TCP connection changes for a sockets associated with
- * a given TCP connection stucture.
- *
- * Input Parameters:
- * conn - The TCP connection of interest
- * flags Set of disconnection events
- *
- * Returned Value:
- * None
- *
- * Assumptions:
- * The caller holds the network lock (if not, it will be locked momentarily
- * by this function).
- *
- ****************************************************************************/
- void tcp_stop_monitor(FAR struct tcp_conn_s *conn, uint16_t flags)
- {
- DEBUGASSERT(conn != NULL);
- /* Stop the network monitor */
- tcp_shutdown_monitor(conn, flags);
- }
- /****************************************************************************
- * Name: tcp_close_monitor
- *
- * Description:
- * One socket in a group of dup'ed sockets has been closed. We need to
- * selectively terminate just those things that are waiting of events
- * from this specific socket. And also recover any resources that are
- * committed to monitoring this socket.
- *
- * Input Parameters:
- * psock - The TCP socket structure that is closed
- *
- * Returned Value:
- * None
- *
- * Assumptions:
- * The caller holds the network lock (if not, it will be locked momentarily
- * by this function).
- *
- ****************************************************************************/
- void tcp_close_monitor(FAR struct socket *psock)
- {
- FAR struct tcp_conn_s *conn;
- FAR struct devif_callback_s *cb;
- DEBUGASSERT(psock != NULL && psock->s_conn != NULL);
- conn = (FAR struct tcp_conn_s *)psock->s_conn;
- /* Find and free the the connection event callback */
- net_lock();
- for (cb = conn->connevents;
- cb != NULL && cb->priv != (FAR void *)psock;
- cb = cb->nxtconn)
- {
- }
- if (cb != NULL)
- {
- devif_conn_callback_free(conn->dev, cb, &conn->connevents);
- }
- /* Make sure that this socket is explicitly marked as closed */
- tcp_close_connection(psock, TCP_CLOSE);
- /* Now notify any sockets waiting for events from this particular sockets.
- * Other dup'ed sockets sharing the same connection must not be effected.
- */
- /* REVISIT: The following logic won't work: There is no way to compare
- * psocks to check for a match. This missing logic could only be an issue
- * if the same socket were being used on one thread, but then closed on
- * another. Some redesign would be required to find only those event
- * handlers that are waiting specifically for this socket (vs. a dup of
- * this socket)
- */
- #if 0
- for (cb = conn->list; cb != NULL; cb = cb->nxtconn)
- {
- if (cb->event != NULL && (cb->flags & TCP_CLOSE) != 0)
- {
- (void)cb->event(conn->dev, conn, cb->priv, TCP_CLOSE);
- }
- }
- #endif
- net_unlock();
- }
- /****************************************************************************
- * Name: tcp_lost_connection
- *
- * Description:
- * Called when a loss-of-connection event has been detected by network
- * event handling logic. Perform operations like tcp_stop_monitor but (1)
- * explicitly mark this socket and (2) disable further callbacks the to the
- * event handler.
- *
- * Input Parameters:
- * psock - The TCP socket structure whose connection was lost.
- * cb - devif callback structure
- * 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 tcp_lost_connection(FAR struct socket *psock,
- FAR struct devif_callback_s *cb, uint16_t flags)
- {
- DEBUGASSERT(psock != NULL && psock->s_conn != NULL);
- /* Nullify the callback structure so that recursive callbacks are not
- * received by the event handler due to disconnection processing.
- *
- * NOTE: In a configuration with CONFIG_NET_TCP_WRITE_BUFFERS=y,
- * the "semi-permanent" callback structure may have already been
- * nullified.
- */
- if (cb != NULL)
- {
- cb->flags = 0;
- cb->priv = NULL;
- cb->event = NULL;
- }
- /* Make sure that this socket is explicitly marked. It may not get a
- * callback due to the above nullification.
- */
- tcp_close_connection(psock, flags);
- /* Then stop the network monitor for all sockets. */
- tcp_shutdown_monitor((FAR struct tcp_conn_s *)psock->s_conn, flags);
- }
- #endif /* NET_TCP_HAVE_STACK */
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