incubator-nuttx/net/socket/net_clone.c

159 lines
5.7 KiB
C

/****************************************************************************
* net/socket/net_clone.c
*
* Copyright (C) 2009, 2011-2015, 2017 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 <sys/socket.h>
#include <string.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/net/net.h>
#include <nuttx/net/udp.h>
#include "inet/inet.h"
#include "tcp/tcp.h"
#include "socket/socket.h"
#ifdef CONFIG_NET
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: net_clone
*
* Description:
* Performs the low level, common portion of net_dupsd() and net_dupsd2()
*
* Input Parameters:
* psock1 - The existing socket that is being cloned.
* psock2 - A reference to an uninitialized socket structure alloated by
* the caller.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned on
* any failure.
*
****************************************************************************/
int net_clone(FAR struct socket *psock1, FAR struct socket *psock2)
{
int ret = OK;
/* Parts of this operation need to be atomic */
net_lock();
/* Duplicate the relevant socket state (zeroing everything else) */
memset(psock2, 0, sizeof(struct socket));
psock2->s_domain = psock1->s_domain; /* IP domain: PF_INET, PF_INET6, or PF_PACKET */
psock2->s_type = psock1->s_type; /* Protocol type: Only SOCK_STREAM or SOCK_DGRAM */
psock2->s_sockif = psock1->s_sockif; /* Socket interface */
psock2->s_flags = psock1->s_flags; /* See _SF_* definitions */
#ifdef CONFIG_NET_SOCKOPTS
psock2->s_options = psock1->s_options; /* Selected socket options */
psock2->s_rcvtimeo = psock1->s_rcvtimeo; /* Receive timeout value (in deciseconds) */
psock2->s_sndtimeo = psock1->s_sndtimeo; /* Send timeout value (in deciseconds) */
#ifdef CONFIG_NET_SOLINGER
psock2->s_linger = psock1->s_linger; /* Linger timeout value (in deciseconds) */
#endif
#endif
psock2->s_conn = psock1->s_conn; /* UDP or TCP connection structure */
/* Increment the reference count on the socket */
psock2->s_crefs = 1; /* One reference on the new socket itself */
/* Increment the reference count on the underlying connection structure
* for this address family type.
*/
DEBUGASSERT(psock2->s_sockif != NULL && psock2->s_sockif->si_addref != NULL);
psock2->s_sockif->si_addref(psock2);
#ifdef NET_TCP_HAVE_STACK
/* For connected socket types, it is necessary to also start the network
* monitor so that the newly cloned socket can receive a notification if
* the network connection is lost.
*/
if (psock2->s_type == SOCK_STREAM)
{
ret = tcp_start_monitor(psock2);
/* On failure, back out the reference count on the TCP connection
* structure. tcp_start_monitor() will fail only in the race condition
* where the TCP connection has been lost.
*/
if (ret < 0)
{
/* There should be at least two reference counts on the connection
* structure: At least one from the original socket and the one
* from above where we incremented the reference count.
* inet_close() will handle all cases.
*
* NOTE: As a side-effect, inet_close()will also call
* tcp_stop_monitor() which could inform the loss of connection to
* all open sockets on the connection structure if the reference
* count decrements to zero.
*/
inet_close(psock2);
/* Then release our reference on the socket structure containing
* the connection.
*/
psock_release(psock2);
}
}
#endif
net_unlock();
return ret;
}
#endif /* CONFIG_NET */