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/fib_rules.h> 14 #include <net/l3mdev.h> 15 16 /** 17 * l3mdev_master_ifindex - get index of L3 master device 18 * @dev: targeted interface 19 */ 20 21 int l3mdev_master_ifindex_rcu(const struct net_device *dev) 22 { 23 int ifindex = 0; 24 25 if (!dev) 26 return 0; 27 28 if (netif_is_l3_master(dev)) { 29 ifindex = dev->ifindex; 30 } else if (netif_is_l3_slave(dev)) { 31 struct net_device *master; 32 struct net_device *_dev = (struct net_device *)dev; 33 34 /* netdev_master_upper_dev_get_rcu calls 35 * list_first_or_null_rcu to walk the upper dev list. 36 * list_first_or_null_rcu does not handle a const arg. We aren't 37 * making changes, just want the master device from that list so 38 * typecast to remove the const 39 */ 40 master = netdev_master_upper_dev_get_rcu(_dev); 41 if (master) 42 ifindex = master->ifindex; 43 } 44 45 return ifindex; 46 } 47 EXPORT_SYMBOL_GPL(l3mdev_master_ifindex_rcu); 48 49 /** 50 * l3mdev_fib_table - get FIB table id associated with an L3 51 * master interface 52 * @dev: targeted interface 53 */ 54 55 u32 l3mdev_fib_table_rcu(const struct net_device *dev) 56 { 57 u32 tb_id = 0; 58 59 if (!dev) 60 return 0; 61 62 if (netif_is_l3_master(dev)) { 63 if (dev->l3mdev_ops->l3mdev_fib_table) 64 tb_id = dev->l3mdev_ops->l3mdev_fib_table(dev); 65 } else if (netif_is_l3_slave(dev)) { 66 /* Users of netdev_master_upper_dev_get_rcu need non-const, 67 * but current inet_*type functions take a const 68 */ 69 struct net_device *_dev = (struct net_device *) dev; 70 const struct net_device *master; 71 72 master = netdev_master_upper_dev_get_rcu(_dev); 73 if (master && 74 master->l3mdev_ops->l3mdev_fib_table) 75 tb_id = master->l3mdev_ops->l3mdev_fib_table(master); 76 } 77 78 return tb_id; 79 } 80 EXPORT_SYMBOL_GPL(l3mdev_fib_table_rcu); 81 82 u32 l3mdev_fib_table_by_index(struct net *net, int ifindex) 83 { 84 struct net_device *dev; 85 u32 tb_id = 0; 86 87 if (!ifindex) 88 return 0; 89 90 rcu_read_lock(); 91 92 dev = dev_get_by_index_rcu(net, ifindex); 93 if (dev) 94 tb_id = l3mdev_fib_table_rcu(dev); 95 96 rcu_read_unlock(); 97 98 return tb_id; 99 } 100 EXPORT_SYMBOL_GPL(l3mdev_fib_table_by_index); 101 102 /** 103 * l3mdev_get_rt6_dst - IPv6 route lookup based on flow. Returns 104 * cached route for L3 master device if relevant 105 * to flow 106 * @net: network namespace for device index lookup 107 * @fl6: IPv6 flow struct for lookup 108 */ 109 110 struct dst_entry *l3mdev_get_rt6_dst(struct net *net, 111 const struct flowi6 *fl6) 112 { 113 struct dst_entry *dst = NULL; 114 struct net_device *dev; 115 116 if (fl6->flowi6_oif) { 117 rcu_read_lock(); 118 119 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif); 120 if (dev && netif_is_l3_slave(dev)) 121 dev = netdev_master_upper_dev_get_rcu(dev); 122 123 if (dev && netif_is_l3_master(dev) && 124 dev->l3mdev_ops->l3mdev_get_rt6_dst) 125 dst = dev->l3mdev_ops->l3mdev_get_rt6_dst(dev, fl6); 126 127 rcu_read_unlock(); 128 } 129 130 return dst; 131 } 132 EXPORT_SYMBOL_GPL(l3mdev_get_rt6_dst); 133 134 /** 135 * l3mdev_get_saddr - get source address for a flow based on an interface 136 * enslaved to an L3 master device 137 * @net: network namespace for device index lookup 138 * @ifindex: Interface index 139 * @fl4: IPv4 flow struct 140 */ 141 142 int l3mdev_get_saddr(struct net *net, int ifindex, struct flowi4 *fl4) 143 { 144 struct net_device *dev; 145 int rc = 0; 146 147 if (ifindex) { 148 rcu_read_lock(); 149 150 dev = dev_get_by_index_rcu(net, ifindex); 151 if (dev && netif_is_l3_slave(dev)) 152 dev = netdev_master_upper_dev_get_rcu(dev); 153 154 if (dev && netif_is_l3_master(dev) && 155 dev->l3mdev_ops->l3mdev_get_saddr) 156 rc = dev->l3mdev_ops->l3mdev_get_saddr(dev, fl4); 157 158 rcu_read_unlock(); 159 } 160 161 return rc; 162 } 163 EXPORT_SYMBOL_GPL(l3mdev_get_saddr); 164 165 /** 166 * l3mdev_fib_rule_match - Determine if flowi references an 167 * L3 master device 168 * @net: network namespace for device index lookup 169 * @fl: flow struct 170 */ 171 172 int l3mdev_fib_rule_match(struct net *net, struct flowi *fl, 173 struct fib_lookup_arg *arg) 174 { 175 struct net_device *dev; 176 int rc = 0; 177 178 rcu_read_lock(); 179 180 dev = dev_get_by_index_rcu(net, fl->flowi_oif); 181 if (dev && netif_is_l3_master(dev) && 182 dev->l3mdev_ops->l3mdev_fib_table) { 183 arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev); 184 rc = 1; 185 goto out; 186 } 187 188 dev = dev_get_by_index_rcu(net, fl->flowi_iif); 189 if (dev && netif_is_l3_master(dev) && 190 dev->l3mdev_ops->l3mdev_fib_table) { 191 arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev); 192 rc = 1; 193 goto out; 194 } 195 196 out: 197 rcu_read_unlock(); 198 199 return rc; 200 } 201