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 struct nlattr *fc_encap; 48 u16 fc_encap_type; 49 }; 50 51 struct fib_info; 52 struct rtable; 53 54 struct fib_nh_exception { 55 struct fib_nh_exception __rcu *fnhe_next; 56 int fnhe_genid; 57 __be32 fnhe_daddr; 58 u32 fnhe_pmtu; 59 __be32 fnhe_gw; 60 unsigned long fnhe_expires; 61 struct rtable __rcu *fnhe_rth_input; 62 struct rtable __rcu *fnhe_rth_output; 63 unsigned long fnhe_stamp; 64 }; 65 66 struct fnhe_hash_bucket { 67 struct fib_nh_exception __rcu *chain; 68 }; 69 70 #define FNHE_HASH_SHIFT 11 71 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT) 72 #define FNHE_RECLAIM_DEPTH 5 73 74 struct fib_nh { 75 struct net_device *nh_dev; 76 struct hlist_node nh_hash; 77 struct fib_info *nh_parent; 78 unsigned int nh_flags; 79 unsigned char nh_scope; 80 #ifdef CONFIG_IP_ROUTE_MULTIPATH 81 int nh_weight; 82 atomic_t nh_upper_bound; 83 #endif 84 #ifdef CONFIG_IP_ROUTE_CLASSID 85 __u32 nh_tclassid; 86 #endif 87 int nh_oif; 88 __be32 nh_gw; 89 __be32 nh_saddr; 90 int nh_saddr_genid; 91 struct rtable __rcu * __percpu *nh_pcpu_rth_output; 92 struct rtable __rcu *nh_rth_input; 93 struct fnhe_hash_bucket __rcu *nh_exceptions; 94 struct lwtunnel_state *nh_lwtstate; 95 }; 96 97 /* 98 * This structure contains data shared by many of routes. 99 */ 100 101 struct fib_info { 102 struct hlist_node fib_hash; 103 struct hlist_node fib_lhash; 104 struct net *fib_net; 105 int fib_treeref; 106 atomic_t fib_clntref; 107 unsigned int fib_flags; 108 unsigned char fib_dead; 109 unsigned char fib_protocol; 110 unsigned char fib_scope; 111 unsigned char fib_type; 112 __be32 fib_prefsrc; 113 u32 fib_priority; 114 u32 *fib_metrics; 115 #define fib_mtu fib_metrics[RTAX_MTU-1] 116 #define fib_window fib_metrics[RTAX_WINDOW-1] 117 #define fib_rtt fib_metrics[RTAX_RTT-1] 118 #define fib_advmss fib_metrics[RTAX_ADVMSS-1] 119 int fib_nhs; 120 #ifdef CONFIG_IP_ROUTE_MULTIPATH 121 int fib_weight; 122 #endif 123 struct rcu_head rcu; 124 struct fib_nh fib_nh[0]; 125 #define fib_dev fib_nh[0].nh_dev 126 }; 127 128 129 #ifdef CONFIG_IP_MULTIPLE_TABLES 130 struct fib_rule; 131 #endif 132 133 struct fib_table; 134 struct fib_result { 135 unsigned char prefixlen; 136 unsigned char nh_sel; 137 unsigned char type; 138 unsigned char scope; 139 u32 tclassid; 140 struct fib_info *fi; 141 struct fib_table *table; 142 struct hlist_head *fa_head; 143 }; 144 145 struct fib_result_nl { 146 __be32 fl_addr; /* To be looked up*/ 147 u32 fl_mark; 148 unsigned char fl_tos; 149 unsigned char fl_scope; 150 unsigned char tb_id_in; 151 152 unsigned char tb_id; /* Results */ 153 unsigned char prefixlen; 154 unsigned char nh_sel; 155 unsigned char type; 156 unsigned char scope; 157 int err; 158 }; 159 160 #ifdef CONFIG_IP_ROUTE_MULTIPATH 161 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel]) 162 #else /* CONFIG_IP_ROUTE_MULTIPATH */ 163 #define FIB_RES_NH(res) ((res).fi->fib_nh[0]) 164 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 165 166 #ifdef CONFIG_IP_MULTIPLE_TABLES 167 #define FIB_TABLE_HASHSZ 256 168 #else 169 #define FIB_TABLE_HASHSZ 2 170 #endif 171 172 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 173 174 #define FIB_RES_SADDR(net, res) \ 175 ((FIB_RES_NH(res).nh_saddr_genid == \ 176 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 177 FIB_RES_NH(res).nh_saddr : \ 178 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 179 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 180 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 181 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 182 183 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 184 FIB_RES_SADDR(net, res)) 185 186 struct fib_table { 187 struct hlist_node tb_hlist; 188 u32 tb_id; 189 int tb_num_default; 190 struct rcu_head rcu; 191 unsigned long *tb_data; 192 unsigned long __data[0]; 193 }; 194 195 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 196 struct fib_result *res, int fib_flags); 197 int fib_table_insert(struct fib_table *, struct fib_config *); 198 int fib_table_delete(struct fib_table *, struct fib_config *); 199 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 200 struct netlink_callback *cb); 201 int fib_table_flush(struct fib_table *table); 202 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 203 void fib_table_flush_external(struct fib_table *table); 204 void fib_free_table(struct fib_table *tb); 205 206 #ifndef CONFIG_IP_MULTIPLE_TABLES 207 208 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 209 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 210 211 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 212 { 213 struct hlist_node *tb_hlist; 214 struct hlist_head *ptr; 215 216 ptr = id == RT_TABLE_LOCAL ? 217 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 218 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 219 220 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 221 222 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 223 } 224 225 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 226 { 227 return fib_get_table(net, id); 228 } 229 230 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 231 struct fib_result *res, unsigned int flags) 232 { 233 struct fib_table *tb; 234 int err = -ENETUNREACH; 235 236 rcu_read_lock(); 237 238 tb = fib_get_table(net, RT_TABLE_MAIN); 239 if (tb) 240 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 241 242 if (err == -EAGAIN) 243 err = -ENETUNREACH; 244 245 rcu_read_unlock(); 246 247 return err; 248 } 249 250 #else /* CONFIG_IP_MULTIPLE_TABLES */ 251 int __net_init fib4_rules_init(struct net *net); 252 void __net_exit fib4_rules_exit(struct net *net); 253 254 struct fib_table *fib_new_table(struct net *net, u32 id); 255 struct fib_table *fib_get_table(struct net *net, u32 id); 256 257 int __fib_lookup(struct net *net, struct flowi4 *flp, 258 struct fib_result *res, unsigned int flags); 259 260 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 261 struct fib_result *res, unsigned int flags) 262 { 263 struct fib_table *tb; 264 int err = -ENETUNREACH; 265 266 flags |= FIB_LOOKUP_NOREF; 267 if (net->ipv4.fib_has_custom_rules) 268 return __fib_lookup(net, flp, res, flags); 269 270 rcu_read_lock(); 271 272 res->tclassid = 0; 273 274 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 275 if (tb) 276 err = fib_table_lookup(tb, flp, res, flags); 277 278 if (!err) 279 goto out; 280 281 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 282 if (tb) 283 err = fib_table_lookup(tb, flp, res, flags); 284 285 out: 286 if (err == -EAGAIN) 287 err = -ENETUNREACH; 288 289 rcu_read_unlock(); 290 291 return err; 292 } 293 294 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 295 296 /* Exported by fib_frontend.c */ 297 extern const struct nla_policy rtm_ipv4_policy[]; 298 void ip_fib_init(void); 299 __be32 fib_compute_spec_dst(struct sk_buff *skb); 300 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 301 u8 tos, int oif, struct net_device *dev, 302 struct in_device *idev, u32 *itag); 303 void fib_select_default(const struct flowi4 *flp, struct fib_result *res); 304 #ifdef CONFIG_IP_ROUTE_CLASSID 305 static inline int fib_num_tclassid_users(struct net *net) 306 { 307 return net->ipv4.fib_num_tclassid_users; 308 } 309 #else 310 static inline int fib_num_tclassid_users(struct net *net) 311 { 312 return 0; 313 } 314 #endif 315 int fib_unmerge(struct net *net); 316 void fib_flush_external(struct net *net); 317 318 /* Exported by fib_semantics.c */ 319 int ip_fib_check_default(__be32 gw, struct net_device *dev); 320 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 321 int fib_sync_down_addr(struct net *net, __be32 local); 322 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 323 324 extern u32 fib_multipath_secret __read_mostly; 325 326 static inline int fib_multipath_hash(__be32 saddr, __be32 daddr) 327 { 328 return jhash_2words(saddr, daddr, fib_multipath_secret) >> 1; 329 } 330 331 void fib_select_multipath(struct fib_result *res, int hash); 332 void fib_select_path(struct net *net, struct fib_result *res, 333 struct flowi4 *fl4, int mp_hash); 334 335 /* Exported by fib_trie.c */ 336 void fib_trie_init(void); 337 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 338 339 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 340 { 341 #ifdef CONFIG_IP_ROUTE_CLASSID 342 #ifdef CONFIG_IP_MULTIPLE_TABLES 343 u32 rtag; 344 #endif 345 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 346 #ifdef CONFIG_IP_MULTIPLE_TABLES 347 rtag = res->tclassid; 348 if (*itag == 0) 349 *itag = (rtag<<16); 350 *itag |= (rtag>>16); 351 #endif 352 #endif 353 } 354 355 void free_fib_info(struct fib_info *fi); 356 357 static inline void fib_info_put(struct fib_info *fi) 358 { 359 if (atomic_dec_and_test(&fi->fib_clntref)) 360 free_fib_info(fi); 361 } 362 363 #ifdef CONFIG_PROC_FS 364 int __net_init fib_proc_init(struct net *net); 365 void __net_exit fib_proc_exit(struct net *net); 366 #else 367 static inline int fib_proc_init(struct net *net) 368 { 369 return 0; 370 } 371 static inline void fib_proc_exit(struct net *net) 372 { 373 } 374 #endif 375 376 #endif /* _NET_FIB_H */ 377