incubator-nuttx/net/socket/net_dup2.c

145 lines
5.0 KiB
C

/****************************************************************************
* net/socket/net_dup2.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/socket.h>
#include <string.h>
#include <sched.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/net/net.h>
#include <nuttx/net/tcp.h>
#include "inet/inet.h"
#include "tcp/tcp.h"
#include "socket/socket.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: psock_dup2
*
* Description:
* Performs the low level, common portion of dup
*
* Input Parameters:
* psock1 - The existing socket that is being cloned.
* psock2 - A reference to an uninitialized socket structure allocated by
* the caller.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned on
* any failure.
*
****************************************************************************/
int psock_dup2(FAR struct socket *psock1, FAR struct socket *psock2)
{
#ifdef NET_TCP_HAVE_STACK
FAR struct tcp_conn_s *conn;
#endif
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 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.
*/
conn = (FAR struct tcp_conn_s *)psock2->s_conn;
if ((psock2->s_domain == PF_INET ||
psock2->s_domain == PF_INET6) &&
psock2->s_type == SOCK_STREAM && conn &&
(conn->tcpstateflags == TCP_ESTABLISHED ||
conn->tcpstateflags == TCP_SYN_RCVD))
{
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);
/* The socket will not persist... reset it */
memset(psock2, 0, sizeof(*psock2));
}
}
#endif
net_unlock();
return ret;
}