1 /* 2 * net/l3mdev/l3mdev.c - L3 master device implementation 3 * Copyright (c) 2015 Cumulus Networks 4 * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 */ 11 12 #include <linux/netdevice.h> 13 #include <net/l3mdev.h> 14 15 /** 16 * l3mdev_master_ifindex - get index of L3 master device 17 * @dev: targeted interface 18 */ 19 20 int l3mdev_master_ifindex_rcu(const struct net_device *dev) 21 { 22 int ifindex = 0; 23 24 if (!dev) 25 return 0; 26 27 if (netif_is_l3_master(dev)) { 28 ifindex = dev->ifindex; 29 } else if (netif_is_l3_slave(dev)) { 30 struct net_device *master; 31 struct net_device *_dev = (struct net_device *)dev; 32 33 /* netdev_master_upper_dev_get_rcu calls 34 * list_first_or_null_rcu to walk the upper dev list. 35 * list_first_or_null_rcu does not handle a const arg. We aren't 36 * making changes, just want the master device from that list so 37 * typecast to remove the const 38 */ 39 master = netdev_master_upper_dev_get_rcu(_dev); 40 if (master) 41 ifindex = master->ifindex; 42 } 43 44 return ifindex; 45 } 46 EXPORT_SYMBOL_GPL(l3mdev_master_ifindex_rcu); 47 48 /** 49 * l3mdev_fib_table - get FIB table id associated with an L3 50 * master interface 51 * @dev: targeted interface 52 */ 53 54 u32 l3mdev_fib_table_rcu(const struct net_device *dev) 55 { 56 u32 tb_id = 0; 57 58 if (!dev) 59 return 0; 60 61 if (netif_is_l3_master(dev)) { 62 if (dev->l3mdev_ops->l3mdev_fib_table) 63 tb_id = dev->l3mdev_ops->l3mdev_fib_table(dev); 64 } else if (netif_is_l3_slave(dev)) { 65 /* Users of netdev_master_upper_dev_get_rcu need non-const, 66 * but current inet_*type functions take a const 67 */ 68 struct net_device *_dev = (struct net_device *) dev; 69 const struct net_device *master; 70 71 master = netdev_master_upper_dev_get_rcu(_dev); 72 if (master && 73 master->l3mdev_ops->l3mdev_fib_table) 74 tb_id = master->l3mdev_ops->l3mdev_fib_table(master); 75 } 76 77 return tb_id; 78 } 79 EXPORT_SYMBOL_GPL(l3mdev_fib_table_rcu); 80 81 u32 l3mdev_fib_table_by_index(struct net *net, int ifindex) 82 { 83 struct net_device *dev; 84 u32 tb_id = 0; 85 86 if (!ifindex) 87 return 0; 88 89 rcu_read_lock(); 90 91 dev = dev_get_by_index_rcu(net, ifindex); 92 if (dev) 93 tb_id = l3mdev_fib_table_rcu(dev); 94 95 rcu_read_unlock(); 96 97 return tb_id; 98 } 99 EXPORT_SYMBOL_GPL(l3mdev_fib_table_by_index); 100 101 /** 102 * l3mdev_get_rt6_dst - IPv6 route lookup based on flow. Returns 103 * cached route for L3 master device if relevant 104 * to flow 105 * @net: network namespace for device index lookup 106 * @fl6: IPv6 flow struct for lookup 107 */ 108 109 struct dst_entry *l3mdev_get_rt6_dst(struct net *net, 110 const struct flowi6 *fl6) 111 { 112 struct dst_entry *dst = NULL; 113 struct net_device *dev; 114 115 if (fl6->flowi6_oif) { 116 rcu_read_lock(); 117 118 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif); 119 if (dev && netif_is_l3_slave(dev)) 120 dev = netdev_master_upper_dev_get_rcu(dev); 121 122 if (dev && netif_is_l3_master(dev) && 123 dev->l3mdev_ops->l3mdev_get_rt6_dst) 124 dst = dev->l3mdev_ops->l3mdev_get_rt6_dst(dev, fl6); 125 126 rcu_read_unlock(); 127 } 128 129 return dst; 130 } 131 EXPORT_SYMBOL_GPL(l3mdev_get_rt6_dst); 132 133 /** 134 * l3mdev_get_saddr - get source address for a flow based on an interface 135 * enslaved to an L3 master device 136 * @net: network namespace for device index lookup 137 * @ifindex: Interface index 138 * @fl4: IPv4 flow struct 139 */ 140 141 int l3mdev_get_saddr(struct net *net, int ifindex, struct flowi4 *fl4) 142 { 143 struct net_device *dev; 144 int rc = 0; 145 146 if (ifindex) { 147 rcu_read_lock(); 148 149 dev = dev_get_by_index_rcu(net, ifindex); 150 if (dev && netif_is_l3_slave(dev)) 151 dev = netdev_master_upper_dev_get_rcu(dev); 152 153 if (dev && netif_is_l3_master(dev) && 154 dev->l3mdev_ops->l3mdev_get_saddr) 155 rc = dev->l3mdev_ops->l3mdev_get_saddr(dev, fl4); 156 157 rcu_read_unlock(); 158 } 159 160 return rc; 161 } 162 EXPORT_SYMBOL_GPL(l3mdev_get_saddr); 163