/**************************************************************************** * 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 #if defined(CONFIG_NET) && defined(CONFIG_NET_UDP) #include #include #include #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 */