/****************************************************************************
 * net/socket/inet_sockif.c
 *
 *   Copyright (C) 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 <assert.h>
#include <errno.h>
#include <debug.h>

#include <nuttx/net/net.h>

#include "tcp/tcp.h"
#include "udp/udp.h"
#include "socket/socket.h"

#if defined(CONFIG_NET_IPv4) || defined(CONFIG_NET_IPv6)

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

static int inet_setup(FAR struct socket *psock, int protocol);
static ssize_t inet_send(FAR struct socket *psock, FAR const void *buf,
          size_t len, int flags);
static ssize_t inet_sendto(FAR struct socket *psock, FAR const void *buf,
          size_t len, int flags, FAR const struct sockaddr *to,
          socklen_t tolen);

/****************************************************************************
 * Public Data
 ****************************************************************************/

const struct sock_intf_s g_inet_sockif =
{
  inet_setup,   /* si_setup */
  inet_send,    /* si_send */
  inet_sendto,  /* si_sendto */
};

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: inet_tcp_alloc
 *
 * Description:
 *   Allocate and attach a TCP connection structure.
 *
 ****************************************************************************/

#ifdef NET_TCP_HAVE_STACK
static int inet_tcp_alloc(FAR struct socket *psock)
{
  /* Allocate the TCP connection structure */

  FAR struct tcp_conn_s *conn = tcp_alloc(psock->s_domain);
  if (conn == NULL)
    {
      /* Failed to reserve a connection structure */

      nerr("ERROR: Failed to reserve TCP connection structure\n");
      return -ENOMEM;
    }

  /* Set the reference count on the connection structure.  This reference
   * count will be incremented only if the socket is dup'ed
   */

  DEBUGASSERT(conn->crefs == 0);
  conn->crefs = 1;

  /* Save the pre-allocated connection in the socket structure */

  psock->s_conn = conn;
  return OK;
}
#endif /* NET_TCP_HAVE_STACK */

/****************************************************************************
 * Name: inet_udp_alloc
 *
 * Description:
 *   Allocate and attach a UDP connection structure.
 *
 ****************************************************************************/

#ifdef NET_UDP_HAVE_STACK
static int inet_udp_alloc(FAR struct socket *psock)
{
  /* Allocate the UDP connection structure */

  FAR struct udp_conn_s *conn = udp_alloc(psock->s_domain);
  if (conn == NULL)
    {
      /* Failed to reserve a connection structure */

      nerr("ERROR: Failed to reserve UDP connection structure\n");
      return -ENOMEM;
    }

  /* Set the reference count on the connection structure.  This reference
   * count will be incremented only if the socket is dup'ed
   */

  DEBUGASSERT(conn->crefs == 0);
  conn->crefs = 1;

  /* Save the pre-allocated connection in the socket structure */

  psock->s_conn = conn;
  return OK;
}
#endif /* NET_UDP_HAVE_STACK */

/****************************************************************************
 * Name: inet_setup
 *
 * Description:
 *   Called for socket() to verify that the provided socket type and
 *   protocol are usable by this address family.  Perform any family-
 *   specific socket fields.
 *
 *   NOTE:  This is common logic for both the AF_INET and AF_INET6 address
 *   families.
 *
 * Parameters:
 *   psock    A pointer to a user allocated socket structure to be initialized.
 *   protocol (see sys/socket.h)
 *
 * Returned Value:
 *   Zero (OK) is returned on success.  Otherwise, a negater errno value is
 *   returned.
 *
 ****************************************************************************/

static int inet_setup(FAR struct socket *psock, int protocol)
{
  /* Allocate the appropriate connection structure.  This reserves the
   * the connection structure is is unallocated at this point.  It will
   * not actually be initialized until the socket is connected.
   *
   * Only SOCK_STREAM and SOCK_DGRAM and possible SOCK_RAW are supported.
   */

  switch (psock->s_type)
    {
#ifdef CONFIG_NET_TCP
      case SOCK_STREAM:
        if (protocol != 0 && protocol != IPPROTO_TCP)
          {
            nerr("ERROR: Unsupported stream protocol: %d\n", protocol);
            return -EPROTONOSUPPORT;
          }

#ifdef NET_TCP_HAVE_STACK
        /* Allocate and attach the TCP connection structure */

        return inet_tcp_alloc(psock);
#else
        return = -ENETDOWN;
#endif
#endif /* CONFIG_NET_TCP */

#ifdef CONFIG_NET_UDP
      case SOCK_DGRAM:
        if (protocol != 0 && protocol != IPPROTO_UDP)
          {
            nerr("ERROR: Unsupported datagram protocol: %d\n", protocol);
            return -EPROTONOSUPPORT;
          }

#ifdef NET_UDP_HAVE_STACK
        /* Allocate and attach the UDP connection structure */

        return inet_udp_alloc(psock);
#else
        return -ENETDOWN;
#endif
#endif /* CONFIG_NET_UDP */

      default:
        nerr("ERROR: Unsupported type: %d\n", psock->s_type);
        return -EPROTONOSUPPORT;
    }
}

/****************************************************************************
 * Name: inet_send
 *
 * Description:
 *   The inet_send() call may be used only when the socket is in a connected
 *   state  (so that the intended recipient is known).
 *
 * Parameters:
 *   psock    An instance of the internal socket structure.
 *   buf      Data to send
 *   len      Length of data to send
 *   flags    Send flags
 *
 * Returned Value:
 *   On success, returns the number of characters sent.  On  error, -1 is
 *   returned, and errno is set appropriately (see send() for the list of
 *   appropriate errors values.
 *
 ****************************************************************************/

static ssize_t inet_send(FAR struct socket *psock, FAR const void *buf,
                         size_t len, int flags)
{
  ssize_t ret;

  switch (psock->s_type)
    {
#ifdef CONFIG_NET_TCP
      case SOCK_STREAM:
        {
#ifdef CONFIG_NET_6LOWPAN
          /* Try 6LoWPAN TCP packet send */

          ret = psock_6lowpan_tcp_send(psock, buf, len);

#if defined(CONFIG_NETDEV_MULTINIC) && defined(NET_TCP_HAVE_STACK)
          if (ret < 0)
            {
              /* TCP/IP packet send */

              ret = psock_tcp_send(psock, buf, len);
            }
#endif /* CONFIG_NETDEV_MULTINIC && NET_TCP_HAVE_STACK */
#elif defined(NET_TCP_HAVE_STACK)
          ret = psock_tcp_send(psock, buf, len);
#else
          ret = -ENOSYS;
#endif /* CONFIG_NET_6LOWPAN */
        }
        break;
#endif /* CONFIG_NET_TCP */

#ifdef CONFIG_NET_UDP
      case SOCK_DGRAM:
        {
#if defined(CONFIG_NET_6LOWPAN)
           /* Try 6LoWPAN UDP packet send */

           ret = psock_6lowpan_udp_send(psock, buf, len);

#if defined(CONFIG_NETDEV_MULTINIC) && defined(NET_UDP_HAVE_STACK)
          if (ret < 0)
            {
              /* UDP/IP packet send */

              ret = psock_udp_send(psock, buf, len);
            }
#endif /* CONFIG_NETDEV_MULTINIC && NET_UDP_HAVE_STACK */
#elif defined(NET_UDP_HAVE_STACK)
          /* Only UDP/IP packet send */

          ret = psock_udp_send(psock, buf, len);
#else
          ret = -ENOSYS;
#endif /* CONFIG_NET_6LOWPAN */
        }
        break;
#endif /* CONFIG_NET_UDP */

      default:
        {
          /* EDESTADDRREQ.  Signifies that the socket is not connection-mode
           * and no peer address is set.
           */

          nerr("ERROR:  Bad socket type: %d\n", psock->s_type);
          ret = -EDESTADDRREQ;
        }
        break;
    }

  return ret;
}

/****************************************************************************
 * Name: inet_sendto
 *
 * Description:
 *   Implements the sendto() operation for the case of the AF_INET and
 *   AF_INET6 sockets.
 *
 * Parameters:
 *   psock    A pointer to a NuttX-specific, internal socket structure
 *   buf      Data to send
 *   len      Length of data to send
 *   flags    Send flags
 *   to       Address of recipient
 *   tolen    The length of the address structure
 *
 * Returned Value:
 *   On success, returns the number of characters sent.  On  error, -1 is
 *   returned, and errno is set appropriately (see send_to() for the list of
 *   appropriate errors values.
 *
 ****************************************************************************/

static ssize_t inet_sendto(FAR struct socket *psock, FAR const void *buf,
                           size_t len, int flags, FAR const struct sockaddr *to,
                           socklen_t tolen)
{
  socklen_t minlen;
  ssize_t nsent;

  /* Verify that a valid address has been provided */

  switch (to->sa_family)
    {
#ifdef CONFIG_NET_IPv4
    case AF_INET:
      minlen = sizeof(struct sockaddr_in);
      break;
#endif

#ifdef CONFIG_NET_IPv6
    case AF_INET6:
      minlen = sizeof(struct sockaddr_in6);
      break;
#endif

#ifdef CONFIG_NET_LOCAL_DGRAM
    case AF_LOCAL:
      minlen = sizeof(sa_family_t);
      break;
#endif

    default:
      nerr("ERROR: Unrecognized address family: %d\n", to->sa_family);
      return -EAFNOSUPPORT;
    }

  if (tolen < minlen)
    {
      nerr("ERROR: Invalid address length: %d < %d\n", tolen, minlen);
      return -EBADF;
    }

#ifdef CONFIG_NET_UDP
  /* If this is a connected socket, then return EISCONN */

  if (psock->s_type != SOCK_DGRAM)
    {
      nerr("ERROR: Connected socket\n");
      return -EBADF;
    }

  /* Now handle the INET sendto() operation */

#if defined(CONFIG_NET_6LOWPAN)
  /* Try 6LoWPAN UDP packet sendto() */

  nsent = psock_6lowpan_udp_sendto(psock, buf, len, flags, to, tolen);

#if defined(CONFIG_NETDEV_MULTINIC) && defined(NET_UDP_HAVE_STACK)
  if (nsent < 0)
    {
      /* UDP/IP packet sendto */

      nsent = psock_udp_sendto(psock, buf, len, flags, to, tolen);
    }
#endif /* CONFIG_NETDEV_MULTINIC && NET_UDP_HAVE_STACK */
#elif defined(NET_UDP_HAVE_STACK)
  nsent = psock_udp_sendto(psock, buf, len, flags, to, tolen);
#else
  nsent = -ENOSYS;
#endif /* CONFIG_NET_6LOWPAN */
#else
  nsent = -EISCONN;
#endif /* CONFIG_NET_UDP */

  return nsent;
}

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

/****************************************************************************
 * Name: 
 *
 * Description:
 *
 * Parameters:
 *
 * Returned Value:
 *
 * Assumptions:
 *
 ****************************************************************************/

#endif /* CONFIG_NET_IPv4 || CONFIG_NET_IPv6 */