/****************************************************************************
* net/udp/udp_finddev.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>
#if defined(CONFIG_NET) && defined(CONFIG_NET_UDP)
#include <string.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include "netdev/netdev.h"
#include "inet/inet.h"
#include "udp/udp.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: upd_bound_device
*
* Description:
* If the UDP socket is bound to a device, return the reference to the
* bound device.
*
* Input Parameters:
* conn - UDP connection structure (not currently used).
*
* Returned Value:
* A reference to the bound device. If the retained interface index no
* longer refers to a valid device, this function will unbind the device
* and return an arbitrary network device at the head of the list of
* registered devices. This supports legacy IPv4 DHCPD behavior when
* there is only a single registered network device.
*
****************************************************************************/
#ifdef CONFIG_NET_UDP_BINDTODEVICE
static FAR struct net_driver_s *upd_bound_device(FAR struct udp_conn_s *conn)
{
FAR struct net_driver_s *dev = NULL;
/* Is the UDP socket bound to a device? */
if (conn->boundto != 0)
{
/* Yes..This socket has been bound to an interface. Convert the
* interface index into a device structure reference.
*/
dev = netdev_findbyindex(conn->boundto);
if (dev == NULL)
{
/* No device? It must have been unregistered. Un-bind the UDP
* socket.
*/
conn->boundto = 0;
}
}
/* If no device was bound or the bound device is no longer valid,
* then let's try the default network device.
*/
return dev == NULL ? netdev_default() : dev;
}
#else
# define upd_bound_device(c) netdev_default();
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: udp_find_laddr_device
*
* Description:
* Select the network driver to use with the UDP transaction using the
* locally bound IP address.
*
* This is currently used in the UDP network poll setup to determine
* which device is being polled.
*
* Input Parameters:
* conn - UDP connection structure (not currently used).
*
* Returned Value:
* A pointer to the network driver to use. NULL is returned if driver is
* not bound to any local device.
*
****************************************************************************/
FAR struct net_driver_s *udp_find_laddr_device(FAR struct udp_conn_s *conn)
{
/* There are multiple network devices. We need to select the device that
* is going to route the UDP packet based on the provided IP address.
*/
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
/* Make sure that the socket is bound to some non-zero, local
* address. Zero is used as an indication that the laddr is
* uninitialized and that the socket is, hence, not bound.
*/
if (conn->u.ipv4.laddr == 0)
{
return NULL;
}
else
{
return netdev_findby_ripv4addr(conn->u.ipv4.laddr,
conn->u.ipv4.laddr);
}
}
#endif
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
/* Make sure that the socket is bound to some non-zero, local
* address. The IPv6 unspecified address is used as an indication
* that the laddr is uninitialized and that the socket is, hence,
* not bound.
*/
if (net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr))
{
return NULL;
}
else
{
return netdev_findby_ripv6addr(conn->u.ipv6.laddr,
conn->u.ipv6.laddr);
}
}
#endif
}
/****************************************************************************
* Name: udp_find_raddr_device
*
* Description:
* Select the network driver to use with the UDP transaction using the
* remote IP address.
*
* This function is called for UDP sendto() in order to determine which
* network device that the UDP pack should be sent on.
*
* Input Parameters:
* conn - UDP connection structure.
*
* Returned Value:
* A pointer to the network driver to use.
*
****************************************************************************/
FAR struct net_driver_s *udp_find_raddr_device(FAR struct udp_conn_s *conn)
{
/* We need to select the device that is going to route the UDP packet
* based on the provided IP address.
*/
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
if (conn->domain == PF_INET)
#endif
{
/* Check if the remote, destination address is the broadcast
* or multicast address. If this is the case, select the device
* using the locally bound address (assuming that there is one).
*/
if (conn->u.ipv4.raddr == INADDR_BROADCAST ||
IN_MULTICAST(NTOHL(conn->u.ipv4.raddr)))
{
/* Make sure that the socket is bound to some non-zero, local
* address. Zero is used as an indication that the laddr is
* uninitialized and that the socket is, hence, not bound.
*/
if (conn->u.ipv4.laddr == 0) /* INADDR_ANY */
{
/* Return the device bound to this UDP socket, if any */
return upd_bound_device(conn);
}
else
{
return netdev_findby_ripv4addr(conn->u.ipv4.laddr,
conn->u.ipv4.laddr);
}
}
/* There is no unique device associated with the unspecified
* address.
*/
else if (conn->u.ipv4.raddr != INADDR_ANY)
{
/* Normal lookup using the verified remote address */
return netdev_findby_ripv4addr(conn->u.ipv4.laddr,
conn->u.ipv4.raddr);
}
else
{
/* Not a suitable IPv4 unicast address for device lookup.
* Return the device bound to this UDP socket, if any.
*/
return upd_bound_device(conn);
}
}
#endif
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
else
#endif
{
/* Check if the remote, destination address is a multicast
* address. If this is the case, select the device
* using the locally bound address (assuming that there is one).
*/
if (net_is_addr_mcast(conn->u.ipv6.raddr))
{
/* Make sure that the socket is bound to some non-zero, local
* address. The IPv6 unspecified address is used as an
* indication that the laddr is uninitialized and that the
* socket is, hence, not bound.
*/
if (net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr))
{
/* Return the device bound to this UDP socket, if any */
return upd_bound_device(conn);
}
else
{
return netdev_findby_ripv6addr(conn->u.ipv6.laddr,
conn->u.ipv6.laddr);
}
}
/* There is no unique device associated with the unspecified
* address.
*/
else if (!net_ipv6addr_cmp(conn->u.ipv6.raddr, g_ipv6_unspecaddr))
{
/* Normal lookup using the verified remote address */
return netdev_findby_ripv6addr(conn->u.ipv6.laddr,
conn->u.ipv6.raddr);
}
else
{
/* Not a suitable IPv6 unicast address for device lookup.
* Return the device bound to this UDP socket, if any.
*/
return upd_bound_device(conn);
}
}
#endif
}
#endif /* CONFIG_NET && CONFIG_NET_UDP */