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 struct rcu_head rcu; 65 }; 66 67 struct fnhe_hash_bucket { 68 struct fib_nh_exception __rcu *chain; 69 }; 70 71 #define FNHE_HASH_SHIFT 11 72 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT) 73 #define FNHE_RECLAIM_DEPTH 5 74 75 struct fib_nh { 76 struct net_device *nh_dev; 77 struct hlist_node nh_hash; 78 struct fib_info *nh_parent; 79 unsigned int nh_flags; 80 unsigned char nh_scope; 81 #ifdef CONFIG_IP_ROUTE_MULTIPATH 82 int nh_weight; 83 atomic_t nh_upper_bound; 84 #endif 85 #ifdef CONFIG_IP_ROUTE_CLASSID 86 __u32 nh_tclassid; 87 #endif 88 int nh_oif; 89 __be32 nh_gw; 90 __be32 nh_saddr; 91 int nh_saddr_genid; 92 struct rtable __rcu * __percpu *nh_pcpu_rth_output; 93 struct rtable __rcu *nh_rth_input; 94 struct fnhe_hash_bucket __rcu *nh_exceptions; 95 struct lwtunnel_state *nh_lwtstate; 96 }; 97 98 /* 99 * This structure contains data shared by many of routes. 100 */ 101 102 struct fib_info { 103 struct hlist_node fib_hash; 104 struct hlist_node fib_lhash; 105 struct net *fib_net; 106 int fib_treeref; 107 atomic_t fib_clntref; 108 unsigned int fib_flags; 109 unsigned char fib_dead; 110 unsigned char fib_protocol; 111 unsigned char fib_scope; 112 unsigned char fib_type; 113 __be32 fib_prefsrc; 114 u32 fib_priority; 115 u32 *fib_metrics; 116 #define fib_mtu fib_metrics[RTAX_MTU-1] 117 #define fib_window fib_metrics[RTAX_WINDOW-1] 118 #define fib_rtt fib_metrics[RTAX_RTT-1] 119 #define fib_advmss fib_metrics[RTAX_ADVMSS-1] 120 int fib_nhs; 121 #ifdef CONFIG_IP_ROUTE_MULTIPATH 122 int fib_weight; 123 #endif 124 struct rcu_head rcu; 125 struct fib_nh fib_nh[0]; 126 #define fib_dev fib_nh[0].nh_dev 127 }; 128 129 130 #ifdef CONFIG_IP_MULTIPLE_TABLES 131 struct fib_rule; 132 #endif 133 134 struct fib_table; 135 struct fib_result { 136 unsigned char prefixlen; 137 unsigned char nh_sel; 138 unsigned char type; 139 unsigned char scope; 140 u32 tclassid; 141 struct fib_info *fi; 142 struct fib_table *table; 143 struct hlist_head *fa_head; 144 }; 145 146 struct fib_result_nl { 147 __be32 fl_addr; /* To be looked up*/ 148 u32 fl_mark; 149 unsigned char fl_tos; 150 unsigned char fl_scope; 151 unsigned char tb_id_in; 152 153 unsigned char tb_id; /* Results */ 154 unsigned char prefixlen; 155 unsigned char nh_sel; 156 unsigned char type; 157 unsigned char scope; 158 int err; 159 }; 160 161 #ifdef CONFIG_IP_ROUTE_MULTIPATH 162 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel]) 163 #else /* CONFIG_IP_ROUTE_MULTIPATH */ 164 #define FIB_RES_NH(res) ((res).fi->fib_nh[0]) 165 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 166 167 #ifdef CONFIG_IP_MULTIPLE_TABLES 168 #define FIB_TABLE_HASHSZ 256 169 #else 170 #define FIB_TABLE_HASHSZ 2 171 #endif 172 173 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 174 175 #define FIB_RES_SADDR(net, res) \ 176 ((FIB_RES_NH(res).nh_saddr_genid == \ 177 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 178 FIB_RES_NH(res).nh_saddr : \ 179 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 180 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 181 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 182 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 183 184 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 185 FIB_RES_SADDR(net, res)) 186 187 struct fib_table { 188 struct hlist_node tb_hlist; 189 u32 tb_id; 190 int tb_num_default; 191 struct rcu_head rcu; 192 unsigned long *tb_data; 193 unsigned long __data[0]; 194 }; 195 196 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 197 struct fib_result *res, int fib_flags); 198 int fib_table_insert(struct fib_table *, struct fib_config *); 199 int fib_table_delete(struct fib_table *, struct fib_config *); 200 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 201 struct netlink_callback *cb); 202 int fib_table_flush(struct fib_table *table); 203 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 204 void fib_table_flush_external(struct fib_table *table); 205 void fib_free_table(struct fib_table *tb); 206 207 #ifndef CONFIG_IP_MULTIPLE_TABLES 208 209 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 210 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 211 212 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 213 { 214 struct hlist_node *tb_hlist; 215 struct hlist_head *ptr; 216 217 ptr = id == RT_TABLE_LOCAL ? 218 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 219 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 220 221 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 222 223 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 224 } 225 226 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 227 { 228 return fib_get_table(net, id); 229 } 230 231 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 232 struct fib_result *res, unsigned int flags) 233 { 234 struct fib_table *tb; 235 int err = -ENETUNREACH; 236 237 rcu_read_lock(); 238 239 tb = fib_get_table(net, RT_TABLE_MAIN); 240 if (tb) 241 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 242 243 if (err == -EAGAIN) 244 err = -ENETUNREACH; 245 246 rcu_read_unlock(); 247 248 return err; 249 } 250 251 #else /* CONFIG_IP_MULTIPLE_TABLES */ 252 int __net_init fib4_rules_init(struct net *net); 253 void __net_exit fib4_rules_exit(struct net *net); 254 255 struct fib_table *fib_new_table(struct net *net, u32 id); 256 struct fib_table *fib_get_table(struct net *net, u32 id); 257 258 int __fib_lookup(struct net *net, struct flowi4 *flp, 259 struct fib_result *res, unsigned int flags); 260 261 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 262 struct fib_result *res, unsigned int flags) 263 { 264 struct fib_table *tb; 265 int err = -ENETUNREACH; 266 267 flags |= FIB_LOOKUP_NOREF; 268 if (net->ipv4.fib_has_custom_rules) 269 return __fib_lookup(net, flp, res, flags); 270 271 rcu_read_lock(); 272 273 res->tclassid = 0; 274 275 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 276 if (tb) 277 err = fib_table_lookup(tb, flp, res, flags); 278 279 if (!err) 280 goto out; 281 282 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 283 if (tb) 284 err = fib_table_lookup(tb, flp, res, flags); 285 286 out: 287 if (err == -EAGAIN) 288 err = -ENETUNREACH; 289 290 rcu_read_unlock(); 291 292 return err; 293 } 294 295 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 296 297 /* Exported by fib_frontend.c */ 298 extern const struct nla_policy rtm_ipv4_policy[]; 299 void ip_fib_init(void); 300 __be32 fib_compute_spec_dst(struct sk_buff *skb); 301 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 302 u8 tos, int oif, struct net_device *dev, 303 struct in_device *idev, u32 *itag); 304 void fib_select_default(const struct flowi4 *flp, struct fib_result *res); 305 #ifdef CONFIG_IP_ROUTE_CLASSID 306 static inline int fib_num_tclassid_users(struct net *net) 307 { 308 return net->ipv4.fib_num_tclassid_users; 309 } 310 #else 311 static inline int fib_num_tclassid_users(struct net *net) 312 { 313 return 0; 314 } 315 #endif 316 int fib_unmerge(struct net *net); 317 void fib_flush_external(struct net *net); 318 319 /* Exported by fib_semantics.c */ 320 int ip_fib_check_default(__be32 gw, struct net_device *dev); 321 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 322 int fib_sync_down_addr(struct net *net, __be32 local); 323 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 324 325 extern u32 fib_multipath_secret __read_mostly; 326 327 static inline int fib_multipath_hash(__be32 saddr, __be32 daddr) 328 { 329 return jhash_2words((__force u32)saddr, (__force u32)daddr, 330 fib_multipath_secret) >> 1; 331 } 332 333 void fib_select_multipath(struct fib_result *res, int hash); 334 void fib_select_path(struct net *net, struct fib_result *res, 335 struct flowi4 *fl4, int mp_hash); 336 337 /* Exported by fib_trie.c */ 338 void fib_trie_init(void); 339 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 340 341 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 342 { 343 #ifdef CONFIG_IP_ROUTE_CLASSID 344 #ifdef CONFIG_IP_MULTIPLE_TABLES 345 u32 rtag; 346 #endif 347 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 348 #ifdef CONFIG_IP_MULTIPLE_TABLES 349 rtag = res->tclassid; 350 if (*itag == 0) 351 *itag = (rtag<<16); 352 *itag |= (rtag>>16); 353 #endif 354 #endif 355 } 356 357 void free_fib_info(struct fib_info *fi); 358 359 static inline void fib_info_put(struct fib_info *fi) 360 { 361 if (atomic_dec_and_test(&fi->fib_clntref)) 362 free_fib_info(fi); 363 } 364 365 #ifdef CONFIG_PROC_FS 366 int __net_init fib_proc_init(struct net *net); 367 void __net_exit fib_proc_exit(struct net *net); 368 #else 369 static inline int fib_proc_init(struct net *net) 370 { 371 return 0; 372 } 373 static inline void fib_proc_exit(struct net *net) 374 { 375 } 376 #endif 377 378 #endif /* _NET_FIB_H */ 379