nuttx/net/socket/connect.c

/****************************************************************************
 * net/socket/connect.c
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * 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/types.h>
#include <sys/socket.h>

#include <stdint.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>

#include <nuttx/cancelpt.h>
#include <nuttx/fs/fs.h>
#include <nuttx/net/net.h>

#include "socket/socket.h"

#ifdef CONFIG_NET

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: psock_connect
 *
 * Description:
 *   connect() connects the socket referred to by the structure 'psock'
 *   to the address specified by 'addr'. The addrlen argument specifies
 *   the size of 'addr'.  The format of the address in 'addr' is
 *   determined by the address space of the socket 'psock'.
 *
 *   If the socket 'psock' is of type SOCK_DGRAM then 'addr' is the address
 *   to which datagrams are sent by default, and the only address from which
 *   datagrams are received. If the socket is of type SOCK_STREAM or
 *   SOCK_SEQPACKET, this call attempts to make a connection to the socket
 *   that is bound to the address specified by 'addr'.
 *
 *   Generally, connection-based protocol sockets may successfully connect()
 *   only once; connectionless protocol sockets may use connect() multiple
 *   times to change their association.  Connectionless sockets may dissolve
 *   the association by connecting to an address with the sa_family member of
 *   sockaddr set to AF_UNSPEC.
 *
 * Input Parameters:
 *   psock     Pointer to a socket structure initialized by psock_socket()
 *   addr      Server address (form depends on type of socket)
 *   addrlen   Length of actual 'addr'
 *
 * Returned Value:
 *  Returns zero (OK) on success.  On failure, it returns a negated errno
 *  value to indicate the nature of the error.
 *
 *     EACCES, EPERM
 *       The user tried to connect to a broadcast address without having the
 *       socket broadcast flag enabled or the connection request failed
 *       because of a local firewall rule.
 *     EADDRINUSE
 *       Local address is already in use.
 *     EAFNOSUPPORT
 *       The passed address didn't have the correct address family in its
 *       sa_family field.
 *     EAGAIN
 *       No more free local ports or insufficient entries in the routing
 *       cache.
 *     EALREADY
 *       The socket is non-blocking and a previous connection attempt has
 *       not yet been completed.
 *     EBADF
 *       The file descriptor is not a valid index in the descriptor table.
 *     ECONNREFUSED
 *       No one listening on the remote address.
 *     EFAULT
 *       The socket structure address is outside the user's address space.
 *     EINPROGRESS
 *       The socket is non-blocking and the connection cannot be completed
 *       immediately.
 *     EINTR
 *       The system call was interrupted by a signal that was caught.
 *     EISCONN
 *       The socket is already connected.
 *     ENETUNREACH
 *       Network is unreachable.
 *     ENOTSOCK
 *       The file descriptor is not associated with a socket.
 *     ETIMEDOUT
 *       Timeout while attempting connection. The server may be too busy
 *       to accept new connections.
 *
 * Assumptions:
 *
 ****************************************************************************/

int psock_connect(FAR struct socket *psock, FAR const struct sockaddr *addr,
                  socklen_t addrlen)
{
  int ret;

  /* Verify that the psock corresponds to valid, allocated socket */

  if (psock == NULL || psock->s_conn == NULL)
    {
      return -EBADF;
    }

  /* Make sure that an address was provided */

  if (addr == NULL)
    {
      return -EFAULT;
    }

  /* Let the address family's connect() method handle the operation */

  DEBUGASSERT(psock->s_sockif != NULL);
  if (psock->s_sockif->si_connect == NULL)
    {
      return -EOPNOTSUPP;
    }

  ret = psock->s_sockif->si_connect(psock, addr, addrlen);
  if (ret >= 0 && addr->sa_family != AF_UNSPEC)
    {
      FAR struct socket_conn_s *conn = psock->s_conn;
      conn->s_flags |= _SF_CONNECTED;
    }

  return ret;
}

/****************************************************************************
 * Name: connect
 *
 * Description:
 *   connect() connects the socket referred to by the file descriptor
 *   'sockfd' to the address specified by 'addr'. The addrlen argument
 *   specifies the size of 'addr'.  The format of the address in 'addr' is
 *   determined by the address space of the socket 'sockfd'.
 *
 *   If the socket 'sockfd' is of type SOCK_DGRAM then 'addr' is the address
 *   to which datagrams are sent by default, and the only address from which
 *   datagrams are received. If the socket is of type SOCK_STREAM or
 *   SOCK_SEQPACKET, this call attempts to make a connection to the socket
 *   that is bound to the address specified by 'addr'.
 *
 *   Generally, connection-based protocol sockets may successfully connect()
 *   only once; connectionless protocol sockets may use connect() multiple
 *   times to change their association.  Connectionless sockets may dissolve
 *   the association by connecting to an address with the sa_family member of
 *   sockaddr set to AF_UNSPEC.
 *
 * Input Parameters:
 *   sockfd    Socket descriptor returned by socket()
 *   addr      Server address (form depends on type of socket)
 *   addrlen   Length of actual 'addr'
 *
 * Returned Value:
 *   0 on success; -1 on error with errno set appropriately
 *
 *     EACCES, EPERM
 *       The user tried to connect to a broadcast address without having the
 *       socket broadcast flag enabled or the connection request failed
 *       because of a local firewall rule.
 *     EADDRINUSE
 *       Local address is already in use.
 *     EAFNOSUPPORT
 *       The passed address didn't have the correct address family in its
 *       sa_family field.
 *     EAGAIN
 *       No more free local ports or insufficient entries in the routing
 *       cache.
 *     EALREADY
 *       The socket is non-blocking and a previous connection attempt has
 *       not yet been completed.
 *     EBADF
 *       The file descriptor is not a valid index in the descriptor table.
 *     ECONNREFUSED
 *       No one listening on the remote address.
 *     EFAULT
 *       The socket structure address is outside the user's address space.
 *     EINPROGRESS
 *       The socket is non-blocking and the connection cannot be completed
 *       immediately.
 *     EINTR
 *       The system call was interrupted by a signal that was caught.
 *     EISCONN
 *       The socket is already connected.
 *     ENETUNREACH
 *       Network is unreachable.
 *     ENOTSOCK
 *       The file descriptor is not associated with a socket.
 *     ETIMEDOUT
 *       Timeout while attempting connection. The server may be too busy
 *       to accept new connections.
 *
 * Assumptions:
 *
 ****************************************************************************/

int connect(int sockfd, FAR const struct sockaddr *addr, socklen_t addrlen)
{
  FAR struct socket *psock;
  FAR struct file *filep;
  int ret;

  /* accept() is a cancellation point */

  enter_cancellation_point();

  /* Get the underlying socket structure */

  ret = sockfd_socket(sockfd, &filep, &psock);

  /* Then let psock_connect() do all of the work */

  if (ret == OK)
    {
      ret = psock_connect(psock, addr, addrlen);
      fs_putfilep(filep);
    }

  if (ret < 0)
    {
      set_errno(-ret);
      ret = ERROR;
    }

  leave_cancellation_point();
  return ret;
}

#endif /* CONFIG_NET */