/**************************************************************************** * net/netdev/netdev_findbyaddr.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 #include #include #include #include #include #include #include #include #include "arp/arp.h" #include "neighbor/neighbor.h" #include "utils/utils.h" #include "devif/devif.h" #include "inet/inet.h" #include "route/route.h" #include "netdev/netdev.h" /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: netdev_prefixlen_findby_lipv4addr * * Description: * Find a previously registered network device by matching a local address * with the subnet served by the device. Only "up" devices are considered * (since a "down" device has no meaningful address). * * Input Parameters: * lipaddr - Local, IPv4 address assigned to the network device. Or any * IPv4 address on the sub-net served by the network device. * prefixlen - The length of matching prefix. Range: -1(no match) ~ 32 * * Returned Value: * Pointer to driver on success; null on failure * ****************************************************************************/ #ifdef CONFIG_NET_IPv4 static FAR struct net_driver_s * netdev_prefixlen_findby_lipv4addr(in_addr_t lipaddr, FAR int8_t *prefixlen) { FAR struct net_driver_s *dev; FAR struct net_driver_s *bestdev = NULL; int8_t bestpref = -1; #ifdef CONFIG_ROUTE_LONGEST_MATCH int8_t len; #endif /* Examine each registered network device */ net_lock(); for (dev = g_netdevices; dev; dev = dev->flink) { /* Is the interface in the "up" state? */ if ((dev->d_flags & IFF_UP) != 0 && !net_ipv4addr_cmp(dev->d_ipaddr, INADDR_ANY)) { #ifndef CONFIG_ROUTE_LONGEST_MATCH /* Yes.. check for an address match (under the netmask) */ if (net_ipv4addr_maskcmp(dev->d_ipaddr, lipaddr, dev->d_netmask)) { /* Its a match */ bestdev = dev; bestpref = 32; /* Regard as best (exact) match */ break; } #else /* Longest prefix flow: First, check for an exact address match */ if (net_ipv4addr_cmp(dev->d_ipaddr, lipaddr)) { /* It's an exact match */ bestdev = dev; bestpref = 32; break; } /* Then, check for an address match (under the netmask) */ if (net_ipv4addr_maskcmp(dev->d_ipaddr, lipaddr, dev->d_netmask)) { len = (int8_t)net_ipv4_mask2pref(dev->d_netmask); /* Regard current device as better if: * 1. It has longer prefix length * 2. It has the same prefix length but it has target address * in the ARP cache (We don't have other information * for the precedence of networks) */ if (len > bestpref #ifdef CONFIG_NET_ARP || (len == bestpref && arp_find(lipaddr, NULL, dev) == OK) #endif ) { bestdev = dev; bestpref = len; } } #endif /* CONFIG_ROUTE_LONGEST_MATCH */ } } net_unlock(); *prefixlen = bestpref; return bestdev; } #endif /* CONFIG_NET_IPv4 */ /**************************************************************************** * Name: netdev_prefixlen_findby_lipv6addr * * Description: * Find a previously registered network device by matching a local address * with the subnet served by the device. Only "up" devices are considered * (since a "down" device has no meaningful address). * * Input Parameters: * lipaddr - Local, IPv6 address assigned to the network device. Or any * IPv6 address on the sub-net served by the network device. * prefixlen - The length of matching prefix. Range: -1(no match) ~ 128 * * Returned Value: * Pointer to driver on success; null on failure * ****************************************************************************/ #ifdef CONFIG_NET_IPv6 static FAR struct net_driver_s * netdev_prefixlen_findby_lipv6addr(const net_ipv6addr_t lipaddr, FAR int16_t *prefixlen) { FAR struct net_driver_s *dev; FAR struct net_driver_s *bestdev = NULL; int16_t bestpref = -1; #ifdef CONFIG_ROUTE_LONGEST_MATCH FAR struct netdev_ifaddr6_s *ifaddr6; FAR struct neighbor_entry_s *ne; FAR struct net_driver_s *hint; int16_t len; #endif net_lock(); #ifdef CONFIG_ROUTE_LONGEST_MATCH /* Find a hint from neighbor table in case same prefix length exists on * multiple devices. */ ne = neighbor_findentry(lipaddr); hint = ne ? ne->ne_dev : NULL; #endif /* Examine each registered network device */ for (dev = g_netdevices; dev; dev = dev->flink) { /* Is the interface in the "up" state? */ if ((dev->d_flags & IFF_UP) != 0 && NETDEV_HAS_V6ADDR(dev)) { #ifndef CONFIG_ROUTE_LONGEST_MATCH /* Yes.. check for an address match (under the netmask) */ if (NETDEV_V6ADDR_ONLINK(dev, lipaddr)) { /* Its a match */ bestdev = dev; bestpref = 128; /* Regard as best (exact) match */ break; } #else /* Longest prefix flow: First, check for an exact address match */ if (NETDEV_IS_MY_V6ADDR(dev, lipaddr)) { /* It's an exact match */ bestdev = dev; bestpref = 128; break; } /* Then, check for an address match (under the netmask) */ if ((ifaddr6 = netdev_ipv6_lookup(dev, lipaddr, true)) != NULL) { len = (int16_t)net_ipv6_mask2pref(ifaddr6->mask); /* Regard current device as better if: * 1. It has longer prefix length * 2. It has the same prefix length but it has target address * in the neighbor cache (We don't have other information * for the precedence of networks) */ if (len > bestpref || (len == bestpref && hint == dev)) { bestdev = dev; bestpref = len; } } #endif /* CONFIG_ROUTE_LONGEST_MATCH */ } } net_unlock(); *prefixlen = bestpref; return bestdev; } #endif /* CONFIG_NET_IPv6 */ /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: netdev_findby_lipv4addr * * Description: * Find a previously registered network device by matching a local address * with the subnet served by the device. Only "up" devices are considered * (since a "down" device has no meaningful address). * * Input Parameters: * lipaddr - Local, IPv4 address assigned to the network device. Or any * IPv4 address on the sub-net served by the network device. * * Returned Value: * Pointer to driver on success; null on failure * ****************************************************************************/ #ifdef CONFIG_NET_IPv4 FAR struct net_driver_s *netdev_findby_lipv4addr(in_addr_t lipaddr) { int8_t prefixlen; return netdev_prefixlen_findby_lipv4addr(lipaddr, &prefixlen); } #endif /* CONFIG_NET_IPv4 */ /**************************************************************************** * Name: netdev_findby_lipv6addr * * Description: * Find a previously registered network device by matching a local address * with the subnet served by the device. Only "up" devices are considered * (since a "down" device has no meaningful address). * * Input Parameters: * lipaddr - Local, IPv6 address assigned to the network device. Or any * IPv6 address on the sub-net served by the network device. * * Returned Value: * Pointer to driver on success; null on failure * ****************************************************************************/ #ifdef CONFIG_NET_IPv6 FAR struct net_driver_s *netdev_findby_lipv6addr( const net_ipv6addr_t lipaddr) { int16_t prefixlen; return netdev_prefixlen_findby_lipv6addr(lipaddr, &prefixlen); } #endif /* CONFIG_NET_IPv6 */ /**************************************************************************** * Name: netdev_findby_ripv4addr * * Description: * Find a previously registered network device by matching the remote * IPv4 address that can be reached by the device. * * Input Parameters: * lipaddr - Local, bound address of a connection (used only if ripaddr is * the broadcast address). * ripaddr - Remote address of a connection to use in the lookup * * Returned Value: * Pointer to driver on success; null on failure * ****************************************************************************/ #ifdef CONFIG_NET_IPv4 FAR struct net_driver_s *netdev_findby_ripv4addr(in_addr_t lipaddr, in_addr_t ripaddr) { FAR struct net_driver_s *dev; int8_t prefixlen; #ifdef CONFIG_NET_ROUTE in_addr_t router; int ret; #endif /* First, check if this is the broadcast IP address */ if (net_ipv4addr_cmp(ripaddr, INADDR_BROADCAST)) { /* Yes.. Check the local, bound address. Is it INADDR_ANY? */ if (net_ipv4addr_cmp(lipaddr, INADDR_ANY)) { /* Yes.. In this case, I think we are supposed to send the * broadcast packet out ALL locally available networks. I am not * sure of that and, in any event, there is nothing we can do * about that here. */ return netdev_default(); } else { /* Return the device associated with the local address */ return netdev_findby_lipv4addr(lipaddr); } } /* Check if the address maps to a locally available network * Note: If longest prefix match is not enabled, prefixlen will be 32 if * matched and it will disable further routing lookup. */ dev = netdev_prefixlen_findby_lipv4addr(ripaddr, &prefixlen); #ifdef CONFIG_NET_ROUTE /* If we have a routing table, then perhaps we can find the local * address of a router that can forward packets to the external network * with longer prefix. */ ret = net_ipv4_router(ripaddr, &router, prefixlen); if (ret >= 0) { /* Success... try to find the network device associated with the local * router address */ dev = netdev_findby_lipv4addr(router); } #endif /* CONFIG_NET_ROUTE */ /* Return the device we found. */ if (dev) { return dev; } /* The above lookup will fail if the packet is being sent out of our * out subnet to a router and there is no routing information. Let's * try the default network device. */ return netdev_default(); } #endif /* CONFIG_NET_IPv4 */ /**************************************************************************** * Name: netdev_findby_ripv6addr * * Description: * Find a previously registered network device by matching the remote * IPv6 address that can be reached by the device. * * Input Parameters: * lipaddr - Local, bound address of a connection (used only if ripaddr is * a multicast address). * ripaddr - Remote address of a connection to use in the lookup * * Returned Value: * Pointer to driver on success; null on failure * ****************************************************************************/ #ifdef CONFIG_NET_IPv6 FAR struct net_driver_s *netdev_findby_ripv6addr( const net_ipv6addr_t lipaddr, const net_ipv6addr_t ripaddr) { FAR struct net_driver_s *dev; int16_t prefixlen; #ifdef CONFIG_NET_ROUTE net_ipv6addr_t router; int ret; #endif /* First, check if this is the multicast IP address */ if (net_is_addr_mcast(ripaddr)) { /* Yes.. Check the local, bound address. Is it the IPv6 unspecified * address? */ if (net_ipv6addr_cmp(lipaddr, g_ipv6_unspecaddr)) { /* Yes.. In this case, I think we are supposed to send the * broadcast packet out ALL locally available networks. I am not * sure of that and, in any event, there is nothing we can do * about that here. */ return netdev_default(); } else { /* Return the device associated with the local address */ return netdev_findby_lipv6addr(lipaddr); } } /* Check if the address maps to a locally available network * Note: If longest prefix match is not enabled, prefixlen will be 128 if * matched and it will disable further routing lookup. */ dev = netdev_prefixlen_findby_lipv6addr(ripaddr, &prefixlen); #ifdef CONFIG_NET_ROUTE /* If we have a routing table, then perhaps we can find the local * address of a router that can forward packets to the external network * with longer prefix. */ ret = net_ipv6_router(ripaddr, router, prefixlen); if (ret >= 0) { /* Success... try to find the network device associated with the local * router address */ dev = netdev_findby_lipv6addr(router); } #endif /* CONFIG_NET_ROUTE */ /* Return the device we found. */ if (dev) { return dev; } /* The above lookup will fail if the packet is being sent out of our * out subnet to a router and there is no routing information. Let's * try the default network device. */ return netdev_default(); } #endif /* CONFIG_NET_IPv6 */