1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Definitions for the Forwarding Information Base. 7 * 8 * Authors: A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 #ifndef _NET_IP_FIB_H 17 #define _NET_IP_FIB_H 18 19 #include <net/flow.h> 20 #include <linux/seq_file.h> 21 #include <linux/rcupdate.h> 22 #include <net/fib_rules.h> 23 #include <net/inetpeer.h> 24 #include <linux/percpu.h> 25 26 struct fib_config { 27 u8 fc_dst_len; 28 u8 fc_tos; 29 u8 fc_protocol; 30 u8 fc_scope; 31 u8 fc_type; 32 /* 3 bytes unused */ 33 u32 fc_table; 34 __be32 fc_dst; 35 __be32 fc_gw; 36 int fc_oif; 37 u32 fc_flags; 38 u32 fc_priority; 39 __be32 fc_prefsrc; 40 struct nlattr *fc_mx; 41 struct rtnexthop *fc_mp; 42 int fc_mx_len; 43 int fc_mp_len; 44 u32 fc_flow; 45 u32 fc_nlflags; 46 struct nl_info fc_nlinfo; 47 }; 48 49 struct fib_info; 50 struct rtable; 51 52 struct fib_nh_exception { 53 struct fib_nh_exception __rcu *fnhe_next; 54 int fnhe_genid; 55 __be32 fnhe_daddr; 56 u32 fnhe_pmtu; 57 __be32 fnhe_gw; 58 unsigned long fnhe_expires; 59 struct rtable __rcu *fnhe_rth_input; 60 struct rtable __rcu *fnhe_rth_output; 61 unsigned long fnhe_stamp; 62 }; 63 64 struct fnhe_hash_bucket { 65 struct fib_nh_exception __rcu *chain; 66 }; 67 68 #define FNHE_HASH_SHIFT 11 69 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT) 70 #define FNHE_RECLAIM_DEPTH 5 71 72 struct fib_nh { 73 struct net_device *nh_dev; 74 struct hlist_node nh_hash; 75 struct fib_info *nh_parent; 76 unsigned int nh_flags; 77 unsigned char nh_scope; 78 #ifdef CONFIG_IP_ROUTE_MULTIPATH 79 int nh_weight; 80 int nh_power; 81 #endif 82 #ifdef CONFIG_IP_ROUTE_CLASSID 83 __u32 nh_tclassid; 84 #endif 85 int nh_oif; 86 __be32 nh_gw; 87 __be32 nh_saddr; 88 int nh_saddr_genid; 89 struct rtable __rcu * __percpu *nh_pcpu_rth_output; 90 struct rtable __rcu *nh_rth_input; 91 struct fnhe_hash_bucket __rcu *nh_exceptions; 92 }; 93 94 /* 95 * This structure contains data shared by many of routes. 96 */ 97 98 struct fib_info { 99 struct hlist_node fib_hash; 100 struct hlist_node fib_lhash; 101 struct net *fib_net; 102 int fib_treeref; 103 atomic_t fib_clntref; 104 unsigned int fib_flags; 105 unsigned char fib_dead; 106 unsigned char fib_protocol; 107 unsigned char fib_scope; 108 unsigned char fib_type; 109 __be32 fib_prefsrc; 110 u32 fib_priority; 111 u32 *fib_metrics; 112 #define fib_mtu fib_metrics[RTAX_MTU-1] 113 #define fib_window fib_metrics[RTAX_WINDOW-1] 114 #define fib_rtt fib_metrics[RTAX_RTT-1] 115 #define fib_advmss fib_metrics[RTAX_ADVMSS-1] 116 int fib_nhs; 117 #ifdef CONFIG_IP_ROUTE_MULTIPATH 118 int fib_power; 119 #endif 120 struct rcu_head rcu; 121 struct fib_nh fib_nh[0]; 122 #define fib_dev fib_nh[0].nh_dev 123 }; 124 125 126 #ifdef CONFIG_IP_MULTIPLE_TABLES 127 struct fib_rule; 128 #endif 129 130 struct fib_table; 131 struct fib_result { 132 unsigned char prefixlen; 133 unsigned char nh_sel; 134 unsigned char type; 135 unsigned char scope; 136 u32 tclassid; 137 struct fib_info *fi; 138 struct fib_table *table; 139 struct hlist_head *fa_head; 140 }; 141 142 struct fib_result_nl { 143 __be32 fl_addr; /* To be looked up*/ 144 u32 fl_mark; 145 unsigned char fl_tos; 146 unsigned char fl_scope; 147 unsigned char tb_id_in; 148 149 unsigned char tb_id; /* Results */ 150 unsigned char prefixlen; 151 unsigned char nh_sel; 152 unsigned char type; 153 unsigned char scope; 154 int err; 155 }; 156 157 #ifdef CONFIG_IP_ROUTE_MULTIPATH 158 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel]) 159 #else /* CONFIG_IP_ROUTE_MULTIPATH */ 160 #define FIB_RES_NH(res) ((res).fi->fib_nh[0]) 161 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 162 163 #ifdef CONFIG_IP_MULTIPLE_TABLES 164 #define FIB_TABLE_HASHSZ 256 165 #else 166 #define FIB_TABLE_HASHSZ 2 167 #endif 168 169 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 170 171 #define FIB_RES_SADDR(net, res) \ 172 ((FIB_RES_NH(res).nh_saddr_genid == \ 173 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 174 FIB_RES_NH(res).nh_saddr : \ 175 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 176 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 177 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 178 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 179 180 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 181 FIB_RES_SADDR(net, res)) 182 183 struct fib_table { 184 struct hlist_node tb_hlist; 185 u32 tb_id; 186 int tb_default; 187 int tb_num_default; 188 struct rcu_head rcu; 189 unsigned long *tb_data; 190 unsigned long __data[0]; 191 }; 192 193 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 194 struct fib_result *res, int fib_flags); 195 int fib_table_insert(struct fib_table *, struct fib_config *); 196 int fib_table_delete(struct fib_table *, struct fib_config *); 197 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 198 struct netlink_callback *cb); 199 int fib_table_flush(struct fib_table *table); 200 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 201 void fib_table_flush_external(struct fib_table *table); 202 void fib_free_table(struct fib_table *tb); 203 204 #ifndef CONFIG_IP_MULTIPLE_TABLES 205 206 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 207 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 208 209 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 210 { 211 struct hlist_node *tb_hlist; 212 struct hlist_head *ptr; 213 214 ptr = id == RT_TABLE_LOCAL ? 215 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 216 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 217 218 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 219 220 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 221 } 222 223 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 224 { 225 return fib_get_table(net, id); 226 } 227 228 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 229 struct fib_result *res, unsigned int flags) 230 { 231 struct fib_table *tb; 232 int err = -ENETUNREACH; 233 234 rcu_read_lock(); 235 236 tb = fib_get_table(net, RT_TABLE_MAIN); 237 if (tb && !fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF)) 238 err = 0; 239 240 rcu_read_unlock(); 241 242 return err; 243 } 244 245 #else /* CONFIG_IP_MULTIPLE_TABLES */ 246 int __net_init fib4_rules_init(struct net *net); 247 void __net_exit fib4_rules_exit(struct net *net); 248 249 struct fib_table *fib_new_table(struct net *net, u32 id); 250 struct fib_table *fib_get_table(struct net *net, u32 id); 251 252 int __fib_lookup(struct net *net, struct flowi4 *flp, 253 struct fib_result *res, unsigned int flags); 254 255 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 256 struct fib_result *res, unsigned int flags) 257 { 258 struct fib_table *tb; 259 int err; 260 261 flags |= FIB_LOOKUP_NOREF; 262 if (net->ipv4.fib_has_custom_rules) 263 return __fib_lookup(net, flp, res, flags); 264 265 rcu_read_lock(); 266 267 res->tclassid = 0; 268 269 for (err = 0; !err; err = -ENETUNREACH) { 270 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 271 if (tb && !fib_table_lookup(tb, flp, res, flags)) 272 break; 273 274 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 275 if (tb && !fib_table_lookup(tb, flp, res, flags)) 276 break; 277 } 278 279 rcu_read_unlock(); 280 281 return err; 282 } 283 284 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 285 286 /* Exported by fib_frontend.c */ 287 extern const struct nla_policy rtm_ipv4_policy[]; 288 void ip_fib_init(void); 289 __be32 fib_compute_spec_dst(struct sk_buff *skb); 290 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 291 u8 tos, int oif, struct net_device *dev, 292 struct in_device *idev, u32 *itag); 293 void fib_select_default(struct fib_result *res); 294 #ifdef CONFIG_IP_ROUTE_CLASSID 295 static inline int fib_num_tclassid_users(struct net *net) 296 { 297 return net->ipv4.fib_num_tclassid_users; 298 } 299 #else 300 static inline int fib_num_tclassid_users(struct net *net) 301 { 302 return 0; 303 } 304 #endif 305 int fib_unmerge(struct net *net); 306 void fib_flush_external(struct net *net); 307 308 /* Exported by fib_semantics.c */ 309 int ip_fib_check_default(__be32 gw, struct net_device *dev); 310 int fib_sync_down_dev(struct net_device *dev, unsigned long event); 311 int fib_sync_down_addr(struct net *net, __be32 local); 312 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 313 void fib_select_multipath(struct fib_result *res); 314 315 /* Exported by fib_trie.c */ 316 void fib_trie_init(void); 317 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 318 319 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 320 { 321 #ifdef CONFIG_IP_ROUTE_CLASSID 322 #ifdef CONFIG_IP_MULTIPLE_TABLES 323 u32 rtag; 324 #endif 325 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 326 #ifdef CONFIG_IP_MULTIPLE_TABLES 327 rtag = res->tclassid; 328 if (*itag == 0) 329 *itag = (rtag<<16); 330 *itag |= (rtag>>16); 331 #endif 332 #endif 333 } 334 335 void free_fib_info(struct fib_info *fi); 336 337 static inline void fib_info_put(struct fib_info *fi) 338 { 339 if (atomic_dec_and_test(&fi->fib_clntref)) 340 free_fib_info(fi); 341 } 342 343 #ifdef CONFIG_PROC_FS 344 int __net_init fib_proc_init(struct net *net); 345 void __net_exit fib_proc_exit(struct net *net); 346 #else 347 static inline int fib_proc_init(struct net *net) 348 { 349 return 0; 350 } 351 static inline void fib_proc_exit(struct net *net) 352 { 353 } 354 #endif 355 356 #endif /* _NET_FIB_H */ 357