/**************************************************************************** * net/tcp/tcp_listen.c * * Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * A direct leverage of logic from uIP which also has b BSD style license * * Author: Adam Dunkels * Copyright (c) 2001-2003, Adam Dunkels. * All rights reserved. * * 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. The name of the author may not be used to endorse or promote * products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 #ifdef CONFIG_NET #include #include #include #include #include #include "devif/devif.h" #include "tcp/tcp.h" /**************************************************************************** * Private Data ****************************************************************************/ /* The tcp_listenports list all currently listening ports. */ static FAR struct tcp_conn_s *tcp_listenports[CONFIG_NET_MAX_LISTENPORTS]; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Function: tcp_findlistener * * Description: * Return the connection listener for connections on this port (if any) * * Assumptions: * Called at interrupt level * ****************************************************************************/ FAR struct tcp_conn_s *tcp_findlistener(uint16_t portno) { int ndx; /* Examine each connection structure in each slot of the listener list */ for (ndx = 0; ndx < CONFIG_NET_MAX_LISTENPORTS; ndx++) { /* Is this slot assigned? If so, does the connection have the same * local port number? */ FAR struct tcp_conn_s *conn = tcp_listenports[ndx]; if (conn && conn->lport == portno) { /* Yes.. we found a listener on this port */ return conn; } } /* No listener for this port */ return NULL; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Function: tcp_listen_initialize * * Description: * Setup the listening data structures * * Assumptions: * Called early in the initialization phase while the system is still * single-threaded. * ****************************************************************************/ void tcp_listen_initialize(void) { int ndx; for (ndx = 0; ndx < CONFIG_NET_MAX_LISTENPORTS; ndx++) { tcp_listenports[ndx] = NULL; } } /**************************************************************************** * Function: tcp_unlisten * * Description: * Stop listening to the port bound to the specified TCP connection * * Assumptions: * Called from normal user code. * ****************************************************************************/ int tcp_unlisten(FAR struct tcp_conn_s *conn) { net_lock_t flags; int ndx; int ret = -EINVAL; flags = net_lock(); for (ndx = 0; ndx < CONFIG_NET_MAX_LISTENPORTS; ndx++) { if (tcp_listenports[ndx] == conn) { tcp_listenports[ndx] = NULL; ret = OK; break; } } net_unlock(flags); return ret; } /**************************************************************************** * Function: tcp_listen * * Description: * Start listening to the port bound to the specified TCP connection * * Assumptions: * Called from normal user code. * ****************************************************************************/ int tcp_listen(FAR struct tcp_conn_s *conn) { net_lock_t flags; int ndx; int ret; /* This must be done with interrupts disabled because the listener table * is accessed from interrupt level as well. */ flags = net_lock(); /* First, check if there is already a socket listening on this port */ if (tcp_islistener(conn->lport)) { /* Yes, then we must refuse this request */ ret = -EADDRINUSE; } else { /* Otherwise, save a reference to the connection structure in the * "listener" list. */ ret = -ENOBUFS; /* Assume failure */ /* Search all slots until an available slot is found */ for (ndx = 0; ndx < CONFIG_NET_MAX_LISTENPORTS; ndx++) { /* Is the next slot available? */ if (!tcp_listenports[ndx]) { /* Yes.. we found it */ tcp_listenports[ndx] = conn; ret = OK; break; } } } net_unlock(flags); return ret; } /**************************************************************************** * Function: tcp_islistener * * Description: * Return true is there is a listener for the specified port * * Assumptions: * Called at interrupt level * ****************************************************************************/ bool tcp_islistener(uint16_t portno) { return tcp_findlistener(portno) != NULL; } /**************************************************************************** * Function: tcp_accept_connection * * Description: * Accept the new connection for the specified listening port. * * Assumptions: * Called at interrupt level * ****************************************************************************/ int tcp_accept_connection(FAR struct net_driver_s *dev, FAR struct tcp_conn_s *conn, uint16_t portno) { FAR struct tcp_conn_s *listener; int ret = ERROR; /* The interrupt logic has already allocated and initialized a TCP * connection -- now check there if is an application in place to accept the * connection. */ listener = tcp_findlistener(portno); if (listener) { /* Yes, there is a listener. Is it accepting connections now? */ if (listener->accept) { /* Yes.. accept the connection */ ret = listener->accept(listener, conn); } #ifdef CONFIG_NET_TCPBACKLOG else { /* Add the connection to the backlog and notify any threads that * may be waiting on poll()/select() that the connection is available. */ ret = tcp_backlogadd(listener, conn); if (ret == OK) { (void)tcp_callback(dev, listener, TCP_BACKLOG); } } #endif } return ret; } #endif /* CONFIG_NET */