/**************************************************************************** * net/socket/net_monitor.c * * Copyright (C) 2007-2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #if defined(CONFIG_NET) && defined(CONFIG_NET_TCP) #include #include #include #include #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 */