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_link_scope_lookup - IPv6 route lookup based on flow for link 104 * local and multicast addresses 105 * @net: network namespace for device index lookup 106 * @fl6: IPv6 flow struct for lookup 107 */ 108 109 struct dst_entry *l3mdev_link_scope_lookup(struct net *net, 110 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_link_scope_lookup) 124 dst = dev->l3mdev_ops->l3mdev_link_scope_lookup(dev, fl6); 125 126 rcu_read_unlock(); 127 } 128 129 return dst; 130 } 131 EXPORT_SYMBOL_GPL(l3mdev_link_scope_lookup); 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); 163 164 int l3mdev_get_saddr6(struct net *net, const struct sock *sk, 165 struct flowi6 *fl6) 166 { 167 struct net_device *dev; 168 int rc = 0; 169 170 if (fl6->flowi6_oif) { 171 rcu_read_lock(); 172 173 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif); 174 if (dev && netif_is_l3_slave(dev)) 175 dev = netdev_master_upper_dev_get_rcu(dev); 176 177 if (dev && netif_is_l3_master(dev) && 178 dev->l3mdev_ops->l3mdev_get_saddr6) 179 rc = dev->l3mdev_ops->l3mdev_get_saddr6(dev, sk, fl6); 180 181 rcu_read_unlock(); 182 } 183 184 return rc; 185 } 186 EXPORT_SYMBOL_GPL(l3mdev_get_saddr6); 187 188 /** 189 * l3mdev_fib_rule_match - Determine if flowi references an 190 * L3 master device 191 * @net: network namespace for device index lookup 192 * @fl: flow struct 193 */ 194 195 int l3mdev_fib_rule_match(struct net *net, struct flowi *fl, 196 struct fib_lookup_arg *arg) 197 { 198 struct net_device *dev; 199 int rc = 0; 200 201 rcu_read_lock(); 202 203 dev = dev_get_by_index_rcu(net, fl->flowi_oif); 204 if (dev && netif_is_l3_master(dev) && 205 dev->l3mdev_ops->l3mdev_fib_table) { 206 arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev); 207 rc = 1; 208 goto out; 209 } 210 211 dev = dev_get_by_index_rcu(net, fl->flowi_iif); 212 if (dev && netif_is_l3_master(dev) && 213 dev->l3mdev_ops->l3mdev_fib_table) { 214 arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev); 215 rc = 1; 216 goto out; 217 } 218 219 out: 220 rcu_read_unlock(); 221 222 return rc; 223 } 224 225 void l3mdev_update_flow(struct net *net, struct flowi *fl) 226 { 227 struct net_device *dev; 228 int ifindex; 229 230 rcu_read_lock(); 231 232 if (fl->flowi_oif) { 233 dev = dev_get_by_index_rcu(net, fl->flowi_oif); 234 if (dev) { 235 ifindex = l3mdev_master_ifindex_rcu(dev); 236 if (ifindex) { 237 fl->flowi_oif = ifindex; 238 fl->flowi_flags |= FLOWI_FLAG_SKIP_NH_OIF; 239 goto out; 240 } 241 } 242 } 243 244 if (fl->flowi_iif) { 245 dev = dev_get_by_index_rcu(net, fl->flowi_iif); 246 if (dev) { 247 ifindex = l3mdev_master_ifindex_rcu(dev); 248 if (ifindex) { 249 fl->flowi_iif = ifindex; 250 fl->flowi_flags |= FLOWI_FLAG_SKIP_NH_OIF; 251 } 252 } 253 } 254 255 out: 256 rcu_read_unlock(); 257 } 258 EXPORT_SYMBOL_GPL(l3mdev_update_flow); 259