incubator-nuttx/net/tcp/tcp_shutdown.c

169 lines
4.6 KiB
C

/****************************************************************************
* net/tcp/tcp_shutdown.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>
#ifdef CONFIG_NET_TCP
#include <errno.h>
#include <debug.h>
#include <assert.h>
#include <nuttx/net/net.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/tcp.h>
#include "netdev/netdev.h"
#include "devif/devif.h"
#include "tcp/tcp.h"
#include "socket/socket.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: tcp_shutdown_eventhandler
****************************************************************************/
static uint16_t tcp_shutdown_eventhandler(FAR struct net_driver_s *dev,
FAR void *pvpriv, uint16_t flags)
{
FAR struct tcp_conn_s *conn = pvpriv;
ninfo("flags: %04x\n", flags);
#ifdef CONFIG_NET_TCP_WRITE_BUFFERS
/* We don't need the send callback anymore. */
if (conn->sndcb != NULL)
{
conn->sndcb->flags = 0;
conn->sndcb->event = NULL;
/* The callback will be freed by tcp_free. */
conn->sndcb = NULL;
}
#endif
dev->d_len = 0;
flags = (flags & ~TCP_NEWDATA) | TCP_CLOSE;
if (conn->shdcb != NULL)
{
tcp_callback_free(conn, conn->shdcb);
conn->shdcb = NULL;
}
return flags;
}
/****************************************************************************
* Name: tcp_send_fin
*
* Description:
* Send a FIN for TCP connection
*
* Input Parameters:
* conn - TCP connection structure
*
* Returned Value:
* None
*
* Assumptions:
* Called from normal user-level logic
*
****************************************************************************/
static inline int tcp_send_fin(FAR struct socket *psock)
{
FAR struct tcp_conn_s *conn;
int ret = OK;
/* Interrupts are disabled here to avoid race conditions */
net_lock();
conn = psock->s_conn;
DEBUGASSERT(conn != NULL);
if ((conn->tcpstateflags == TCP_ESTABLISHED ||
conn->tcpstateflags == TCP_SYN_SENT ||
conn->tcpstateflags == TCP_SYN_RCVD))
{
if ((conn->shdcb = tcp_callback_alloc(conn)) == NULL)
{
ret = -EBUSY;
goto out;
}
/* Set up to receive TCP data event callbacks */
conn->shdcb->flags = TCP_POLL;
conn->shdcb->event = tcp_shutdown_eventhandler;
conn->shdcb->priv = conn; /* reference for event handler to free cb */
/* Notify the device driver of the availability of TX data */
tcp_send_txnotify(psock, conn);
}
out:
net_unlock();
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: tcp_shutdown
*
* Description:
* Gracefully shutdown a TCP connection by sending a FIN
*
* Input Parameters:
* psock - An instance of the internal socket structure.
* how - Specifies the type of shutdown.
*
* Assumptions:
* Called from normal user-level logic
*
****************************************************************************/
int tcp_shutdown(FAR struct socket *psock, int how)
{
if (!(how & SHUT_WR))
{
return -EOPNOTSUPP;
}
tcp_unlisten(psock->s_conn); /* No longer accepting connections */
return tcp_send_fin(psock);
}
#endif /* CONFIG_NET_TCP */