/****************************************************************************
* net/socket/accept.c
*
* Copyright (C) 2007-2012, 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/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/cancelpt.h>
#include <arch/irq.h>
#include "socket/socket.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: psock_accept
*
* Description:
* The psock_accept function is used with connection-based socket types
* (SOCK_STREAM, SOCK_SEQPACKET and SOCK_RDM). It extracts the first
* connection request on the queue of pending connections, creates a new
* connected socket with mostly the same properties as 'sockfd', and
* allocates a new socket descriptor for the socket, which is returned. The
* newly created socket is no longer in the listening state. The original
* socket 'sockfd' is unaffected by this call. Per file descriptor flags
* are not inherited across an psock_accept.
*
* The 'sockfd' argument is a socket descriptor that has been created with
* socket(), bound to a local address with bind(), and is listening for
* connections after a call to listen().
*
* On return, the 'addr' structure is filled in with the address of the
* connecting entity. The 'addrlen' argument initially contains the size
* of the structure pointed to by 'addr'; on return it will contain the
* actual length of the address returned.
*
* If no pending connections are present on the queue, and the socket is
* not marked as non-blocking, psock_accept blocks the caller until a
* connection is present. If the socket is marked non-blocking and no
* pending connections are present on the queue, psock_accept returns
* EAGAIN.
*
* Input Parameters:
* psock Reference to the listening socket structure
* addr Receives the address of the connecting client
* addrlen Input: allocated size of 'addr', Return: returned size of 'addr'
* newsock Location to return the accepted socket information.
*
* Returned Value:
* Returns 0 (OK) on success. On failure, it returns a negated errno value
* to indicate the nature of the error.
*
* EAGAIN or EWOULDBLOCK
* The socket is marked non-blocking and no connections are present to
* be accepted.
* EOPNOTSUPP
* The referenced socket is not of type SOCK_STREAM.
* EINTR
* The system call was interrupted by a signal that was caught before
* a valid connection arrived.
* ECONNABORTED
* A connection has been aborted.
* EINVAL
* Socket is not listening for connections.
* EMFILE
* The per-process limit of open file descriptors has been reached.
* ENFILE
* The system maximum for file descriptors has been reached.
* EFAULT
* The addr parameter is not in a writable part of the user address space.
* ENOBUFS or ENOMEM
* Not enough free memory.
* EPROTO
* Protocol error.
* EPERM
* Firewall rules forbid connection.
*
****************************************************************************/
int psock_accept(FAR struct socket *psock, FAR struct sockaddr *addr,
FAR socklen_t *addrlen, FAR struct socket *newsock)
{
int ret;
DEBUGASSERT(psock != NULL && psock->s_conn != NULL && newsock != NULL);
/* May sure that the socket has been opened with socket() */
if (psock == NULL || psock->s_conn == NULL)
{
nerr("ERROR: Socket invalid or not opened\n");
return -EINVAL;
}
/* Is the socket listening for a connection? */
if (!_SS_ISLISTENING(psock->s_flags))
{
nerr("ERROR: Socket is not listening for a connection.\n");
return -EINVAL;
}
/* Let the address family's accept() method handle the operation */
DEBUGASSERT(psock->s_sockif != NULL && psock->s_sockif->si_accept != NULL);
net_lock();
ret = psock->s_sockif->si_accept(psock, addr, addrlen, newsock);
if (ret < 0)
{
nerr("ERROR: si_accept failed: %d\n", ret);
goto errout_with_lock;
}
/* Mark the new socket as connected. */
newsock->s_flags |= _SF_CONNECTED;
newsock->s_flags &= ~_SF_CLOSED;
ret = OK;
errout_with_lock:
net_unlock();
return ret;
}
/****************************************************************************
* Name: accept
*
* Description:
* The accept function is used with connection-based socket types
* (SOCK_STREAM, SOCK_SEQPACKET and SOCK_RDM). It extracts the first
* connection request on the queue of pending connections, creates a new
* connected socket with mostly the same properties as 'sockfd', and
* allocates a new socket descriptor for the socket, which is returned. The
* newly created socket is no longer in the listening state. The original
* socket 'sockfd' is unaffected by this call. Per file descriptor flags
* are not inherited across an accept.
*
* The 'sockfd' argument is a socket descriptor that has been created with
* socket(), bound to a local address with bind(), and is listening for
* connections after a call to listen().
*
* On return, the 'addr' structure is filled in with the address of the
* connecting entity. The 'addrlen' argument initially contains the size
* of the structure pointed to by 'addr'; on return it will contain the
* actual length of the address returned.
*
* If no pending connections are present on the queue, and the socket is
* not marked as non-blocking, accept blocks the caller until a connection
* is present. If the socket is marked non-blocking and no pending
* connections are present on the queue, accept returns EAGAIN.
*
* Input Parameters:
* sockfd The listening socket descriptor
* addr Receives the address of the connecting client
* addrlen Input: allocated size of 'addr', Return: returned size of 'addr'
*
* Returned Value:
* Returns -1 on error. If it succeeds, it returns a non-negative integer
* that is a descriptor for the accepted socket.
*
* EAGAIN or EWOULDBLOCK
* The socket is marked non-blocking and no connections are present to
* be accepted.
* EBADF
* The descriptor is invalid.
* ENOTSOCK
* The descriptor references a file, not a socket.
* EOPNOTSUPP
* The referenced socket is not of type SOCK_STREAM.
* EINTR
* The system call was interrupted by a signal that was caught before
* a valid connection arrived.
* ECONNABORTED
* A connection has been aborted.
* EINVAL
* Socket is not listening for connections.
* EMFILE
* The per-process limit of open file descriptors has been reached.
* ENFILE
* The system maximum for file descriptors has been reached.
* EFAULT
* The addr parameter is not in a writable part of the user address
* space.
* ENOBUFS or ENOMEM
* Not enough free memory.
* EPROTO
* Protocol error.
* EPERM
* Firewall rules forbid connection.
*
****************************************************************************/
int accept(int sockfd, FAR struct sockaddr *addr, FAR socklen_t *addrlen)
{
FAR struct socket *psock = sockfd_socket(sockfd);
FAR struct socket *newsock;
int newfd;
int errcode;
int ret;
/* accept() is a cancellation point */
(void)enter_cancellation_point();
/* Verify that the sockfd corresponds to valid, allocated socket */
if (psock == NULL || psock->s_crefs <= 0)
{
/* It is not a valid socket description. Distinguish between the cases
* where sockfd is a just valid and when it is a valid file descriptor used
* in the wrong context.
*/
if ((unsigned int)sockfd < CONFIG_NFILE_DESCRIPTORS)
{
errcode = ENOTSOCK;
}
else
{
errcode = EBADF;
}
goto errout;
}
/* Allocate a socket descriptor for the new connection now (so that it
* cannot fail later)
*/
newfd = sockfd_allocate(0);
if (newfd < 0)
{
errcode = ENFILE;
goto errout;
}
newsock = sockfd_socket(newfd);
if (newsock == NULL)
{
errcode = ENFILE;
goto errout_with_socket;
}
ret = psock_accept(psock, addr, addrlen, newsock);
if (ret < 0)
{
errcode = -ret;
goto errout_with_socket;
}
leave_cancellation_point();
return newfd;
errout_with_socket:
sockfd_release(newfd);
errout:
leave_cancellation_point();
set_errno(errcode);
return ERROR;
}