1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * net/l3mdev/l3mdev.c - L3 master device implementation 4 * Copyright (c) 2015 Cumulus Networks 5 * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com> 6 */ 7 8 #include <linux/netdevice.h> 9 #include <net/fib_rules.h> 10 #include <net/l3mdev.h> 11 12 static DEFINE_SPINLOCK(l3mdev_lock); 13 14 struct l3mdev_handler { 15 lookup_by_table_id_t dev_lookup; 16 }; 17 18 static struct l3mdev_handler l3mdev_handlers[L3MDEV_TYPE_MAX + 1]; 19 20 static int l3mdev_check_type(enum l3mdev_type l3type) 21 { 22 if (l3type <= L3MDEV_TYPE_UNSPEC || l3type > L3MDEV_TYPE_MAX) 23 return -EINVAL; 24 25 return 0; 26 } 27 28 int l3mdev_table_lookup_register(enum l3mdev_type l3type, 29 lookup_by_table_id_t fn) 30 { 31 struct l3mdev_handler *hdlr; 32 int res; 33 34 res = l3mdev_check_type(l3type); 35 if (res) 36 return res; 37 38 hdlr = &l3mdev_handlers[l3type]; 39 40 spin_lock(&l3mdev_lock); 41 42 if (hdlr->dev_lookup) { 43 res = -EBUSY; 44 goto unlock; 45 } 46 47 hdlr->dev_lookup = fn; 48 res = 0; 49 50 unlock: 51 spin_unlock(&l3mdev_lock); 52 53 return res; 54 } 55 EXPORT_SYMBOL_GPL(l3mdev_table_lookup_register); 56 57 void l3mdev_table_lookup_unregister(enum l3mdev_type l3type, 58 lookup_by_table_id_t fn) 59 { 60 struct l3mdev_handler *hdlr; 61 62 if (l3mdev_check_type(l3type)) 63 return; 64 65 hdlr = &l3mdev_handlers[l3type]; 66 67 spin_lock(&l3mdev_lock); 68 69 if (hdlr->dev_lookup == fn) 70 hdlr->dev_lookup = NULL; 71 72 spin_unlock(&l3mdev_lock); 73 } 74 EXPORT_SYMBOL_GPL(l3mdev_table_lookup_unregister); 75 76 int l3mdev_ifindex_lookup_by_table_id(enum l3mdev_type l3type, 77 struct net *net, u32 table_id) 78 { 79 lookup_by_table_id_t lookup; 80 struct l3mdev_handler *hdlr; 81 int ifindex = -EINVAL; 82 int res; 83 84 res = l3mdev_check_type(l3type); 85 if (res) 86 return res; 87 88 hdlr = &l3mdev_handlers[l3type]; 89 90 spin_lock(&l3mdev_lock); 91 92 lookup = hdlr->dev_lookup; 93 if (!lookup) 94 goto unlock; 95 96 ifindex = lookup(net, table_id); 97 98 unlock: 99 spin_unlock(&l3mdev_lock); 100 101 return ifindex; 102 } 103 EXPORT_SYMBOL_GPL(l3mdev_ifindex_lookup_by_table_id); 104 105 /** 106 * l3mdev_master_ifindex_rcu - get index of L3 master device 107 * @dev: targeted interface 108 */ 109 110 int l3mdev_master_ifindex_rcu(const struct net_device *dev) 111 { 112 int ifindex = 0; 113 114 if (!dev) 115 return 0; 116 117 if (netif_is_l3_master(dev)) { 118 ifindex = dev->ifindex; 119 } else if (netif_is_l3_slave(dev)) { 120 struct net_device *master; 121 struct net_device *_dev = (struct net_device *)dev; 122 123 /* netdev_master_upper_dev_get_rcu calls 124 * list_first_or_null_rcu to walk the upper dev list. 125 * list_first_or_null_rcu does not handle a const arg. We aren't 126 * making changes, just want the master device from that list so 127 * typecast to remove the const 128 */ 129 master = netdev_master_upper_dev_get_rcu(_dev); 130 if (master) 131 ifindex = master->ifindex; 132 } 133 134 return ifindex; 135 } 136 EXPORT_SYMBOL_GPL(l3mdev_master_ifindex_rcu); 137 138 /** 139 * l3mdev_master_upper_ifindex_by_index_rcu - get index of upper l3 master 140 * device 141 * @net: network namespace for device index lookup 142 * @ifindex: targeted interface 143 */ 144 int l3mdev_master_upper_ifindex_by_index_rcu(struct net *net, int ifindex) 145 { 146 struct net_device *dev; 147 148 dev = dev_get_by_index_rcu(net, ifindex); 149 while (dev && !netif_is_l3_master(dev)) 150 dev = netdev_master_upper_dev_get(dev); 151 152 return dev ? dev->ifindex : 0; 153 } 154 EXPORT_SYMBOL_GPL(l3mdev_master_upper_ifindex_by_index_rcu); 155 156 /** 157 * l3mdev_fib_table_rcu - get FIB table id associated with an L3 158 * master interface 159 * @dev: targeted interface 160 */ 161 162 u32 l3mdev_fib_table_rcu(const struct net_device *dev) 163 { 164 u32 tb_id = 0; 165 166 if (!dev) 167 return 0; 168 169 if (netif_is_l3_master(dev)) { 170 if (dev->l3mdev_ops->l3mdev_fib_table) 171 tb_id = dev->l3mdev_ops->l3mdev_fib_table(dev); 172 } else if (netif_is_l3_slave(dev)) { 173 /* Users of netdev_master_upper_dev_get_rcu need non-const, 174 * but current inet_*type functions take a const 175 */ 176 struct net_device *_dev = (struct net_device *) dev; 177 const struct net_device *master; 178 179 master = netdev_master_upper_dev_get_rcu(_dev); 180 if (master && 181 master->l3mdev_ops->l3mdev_fib_table) 182 tb_id = master->l3mdev_ops->l3mdev_fib_table(master); 183 } 184 185 return tb_id; 186 } 187 EXPORT_SYMBOL_GPL(l3mdev_fib_table_rcu); 188 189 u32 l3mdev_fib_table_by_index(struct net *net, int ifindex) 190 { 191 struct net_device *dev; 192 u32 tb_id = 0; 193 194 if (!ifindex) 195 return 0; 196 197 rcu_read_lock(); 198 199 dev = dev_get_by_index_rcu(net, ifindex); 200 if (dev) 201 tb_id = l3mdev_fib_table_rcu(dev); 202 203 rcu_read_unlock(); 204 205 return tb_id; 206 } 207 EXPORT_SYMBOL_GPL(l3mdev_fib_table_by_index); 208 209 /** 210 * l3mdev_link_scope_lookup - IPv6 route lookup based on flow for link 211 * local and multicast addresses 212 * @net: network namespace for device index lookup 213 * @fl6: IPv6 flow struct for lookup 214 * This function does not hold refcnt on the returned dst. 215 * Caller must hold rcu_read_lock(). 216 */ 217 218 struct dst_entry *l3mdev_link_scope_lookup(struct net *net, 219 struct flowi6 *fl6) 220 { 221 struct dst_entry *dst = NULL; 222 struct net_device *dev; 223 224 WARN_ON_ONCE(!rcu_read_lock_held()); 225 if (fl6->flowi6_oif) { 226 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif); 227 if (dev && netif_is_l3_slave(dev)) 228 dev = netdev_master_upper_dev_get_rcu(dev); 229 230 if (dev && netif_is_l3_master(dev) && 231 dev->l3mdev_ops->l3mdev_link_scope_lookup) 232 dst = dev->l3mdev_ops->l3mdev_link_scope_lookup(dev, fl6); 233 } 234 235 return dst; 236 } 237 EXPORT_SYMBOL_GPL(l3mdev_link_scope_lookup); 238 239 /** 240 * l3mdev_fib_rule_match - Determine if flowi references an 241 * L3 master device 242 * @net: network namespace for device index lookup 243 * @fl: flow struct 244 * @arg: store the table the rule matched with here 245 */ 246 247 int l3mdev_fib_rule_match(struct net *net, struct flowi *fl, 248 struct fib_lookup_arg *arg) 249 { 250 struct net_device *dev; 251 int rc = 0; 252 253 /* update flow ensures flowi_l3mdev is set when relevant */ 254 if (!fl->flowi_l3mdev) 255 return 0; 256 257 rcu_read_lock(); 258 259 dev = dev_get_by_index_rcu(net, fl->flowi_l3mdev); 260 if (dev && netif_is_l3_master(dev) && 261 dev->l3mdev_ops->l3mdev_fib_table) { 262 arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev); 263 rc = 1; 264 } 265 266 rcu_read_unlock(); 267 268 return rc; 269 } 270 271 void l3mdev_update_flow(struct net *net, struct flowi *fl) 272 { 273 struct net_device *dev; 274 275 rcu_read_lock(); 276 277 if (fl->flowi_oif) { 278 dev = dev_get_by_index_rcu(net, fl->flowi_oif); 279 if (dev) { 280 if (!fl->flowi_l3mdev) 281 fl->flowi_l3mdev = l3mdev_master_ifindex_rcu(dev); 282 283 /* oif set to L3mdev directs lookup to its table; 284 * reset to avoid oif match in fib_lookup 285 */ 286 if (netif_is_l3_master(dev)) 287 fl->flowi_oif = 0; 288 goto out; 289 } 290 } 291 292 if (fl->flowi_iif > LOOPBACK_IFINDEX && !fl->flowi_l3mdev) { 293 dev = dev_get_by_index_rcu(net, fl->flowi_iif); 294 if (dev) 295 fl->flowi_l3mdev = l3mdev_master_ifindex_rcu(dev); 296 } 297 298 out: 299 rcu_read_unlock(); 300 } 301 EXPORT_SYMBOL_GPL(l3mdev_update_flow); 302