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_tb_id; 115 u32 fib_priority; 116 u32 *fib_metrics; 117 #define fib_mtu fib_metrics[RTAX_MTU-1] 118 #define fib_window fib_metrics[RTAX_WINDOW-1] 119 #define fib_rtt fib_metrics[RTAX_RTT-1] 120 #define fib_advmss fib_metrics[RTAX_ADVMSS-1] 121 int fib_nhs; 122 #ifdef CONFIG_IP_ROUTE_MULTIPATH 123 int fib_weight; 124 #endif 125 struct rcu_head rcu; 126 struct fib_nh fib_nh[0]; 127 #define fib_dev fib_nh[0].nh_dev 128 }; 129 130 131 #ifdef CONFIG_IP_MULTIPLE_TABLES 132 struct fib_rule; 133 #endif 134 135 struct fib_table; 136 struct fib_result { 137 unsigned char prefixlen; 138 unsigned char nh_sel; 139 unsigned char type; 140 unsigned char scope; 141 u32 tclassid; 142 struct fib_info *fi; 143 struct fib_table *table; 144 struct hlist_head *fa_head; 145 }; 146 147 struct fib_result_nl { 148 __be32 fl_addr; /* To be looked up*/ 149 u32 fl_mark; 150 unsigned char fl_tos; 151 unsigned char fl_scope; 152 unsigned char tb_id_in; 153 154 unsigned char tb_id; /* Results */ 155 unsigned char prefixlen; 156 unsigned char nh_sel; 157 unsigned char type; 158 unsigned char scope; 159 int err; 160 }; 161 162 #ifdef CONFIG_IP_ROUTE_MULTIPATH 163 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel]) 164 #else /* CONFIG_IP_ROUTE_MULTIPATH */ 165 #define FIB_RES_NH(res) ((res).fi->fib_nh[0]) 166 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 167 168 #ifdef CONFIG_IP_MULTIPLE_TABLES 169 #define FIB_TABLE_HASHSZ 256 170 #else 171 #define FIB_TABLE_HASHSZ 2 172 #endif 173 174 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 175 176 #define FIB_RES_SADDR(net, res) \ 177 ((FIB_RES_NH(res).nh_saddr_genid == \ 178 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 179 FIB_RES_NH(res).nh_saddr : \ 180 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 181 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 182 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 183 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 184 185 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 186 FIB_RES_SADDR(net, res)) 187 188 struct fib_table { 189 struct hlist_node tb_hlist; 190 u32 tb_id; 191 int tb_num_default; 192 struct rcu_head rcu; 193 unsigned long *tb_data; 194 unsigned long __data[0]; 195 }; 196 197 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 198 struct fib_result *res, int fib_flags); 199 int fib_table_insert(struct fib_table *, struct fib_config *); 200 int fib_table_delete(struct fib_table *, struct fib_config *); 201 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 202 struct netlink_callback *cb); 203 int fib_table_flush(struct fib_table *table); 204 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 205 void fib_table_flush_external(struct fib_table *table); 206 void fib_free_table(struct fib_table *tb); 207 208 #ifndef CONFIG_IP_MULTIPLE_TABLES 209 210 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 211 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 212 213 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 214 { 215 struct hlist_node *tb_hlist; 216 struct hlist_head *ptr; 217 218 ptr = id == RT_TABLE_LOCAL ? 219 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 220 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 221 222 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 223 224 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 225 } 226 227 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 228 { 229 return fib_get_table(net, id); 230 } 231 232 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 233 struct fib_result *res, unsigned int flags) 234 { 235 struct fib_table *tb; 236 int err = -ENETUNREACH; 237 238 rcu_read_lock(); 239 240 tb = fib_get_table(net, RT_TABLE_MAIN); 241 if (tb) 242 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 243 244 if (err == -EAGAIN) 245 err = -ENETUNREACH; 246 247 rcu_read_unlock(); 248 249 return err; 250 } 251 252 #else /* CONFIG_IP_MULTIPLE_TABLES */ 253 int __net_init fib4_rules_init(struct net *net); 254 void __net_exit fib4_rules_exit(struct net *net); 255 256 struct fib_table *fib_new_table(struct net *net, u32 id); 257 struct fib_table *fib_get_table(struct net *net, u32 id); 258 259 int __fib_lookup(struct net *net, struct flowi4 *flp, 260 struct fib_result *res, unsigned int flags); 261 262 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 263 struct fib_result *res, unsigned int flags) 264 { 265 struct fib_table *tb; 266 int err = -ENETUNREACH; 267 268 flags |= FIB_LOOKUP_NOREF; 269 if (net->ipv4.fib_has_custom_rules) 270 return __fib_lookup(net, flp, res, flags); 271 272 rcu_read_lock(); 273 274 res->tclassid = 0; 275 276 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 277 if (tb) 278 err = fib_table_lookup(tb, flp, res, flags); 279 280 if (!err) 281 goto out; 282 283 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 284 if (tb) 285 err = fib_table_lookup(tb, flp, res, flags); 286 287 out: 288 if (err == -EAGAIN) 289 err = -ENETUNREACH; 290 291 rcu_read_unlock(); 292 293 return err; 294 } 295 296 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 297 298 /* Exported by fib_frontend.c */ 299 extern const struct nla_policy rtm_ipv4_policy[]; 300 void ip_fib_init(void); 301 __be32 fib_compute_spec_dst(struct sk_buff *skb); 302 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 303 u8 tos, int oif, struct net_device *dev, 304 struct in_device *idev, u32 *itag); 305 void fib_select_default(const struct flowi4 *flp, struct fib_result *res); 306 #ifdef CONFIG_IP_ROUTE_CLASSID 307 static inline int fib_num_tclassid_users(struct net *net) 308 { 309 return net->ipv4.fib_num_tclassid_users; 310 } 311 #else 312 static inline int fib_num_tclassid_users(struct net *net) 313 { 314 return 0; 315 } 316 #endif 317 int fib_unmerge(struct net *net); 318 void fib_flush_external(struct net *net); 319 320 /* Exported by fib_semantics.c */ 321 int ip_fib_check_default(__be32 gw, struct net_device *dev); 322 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 323 int fib_sync_down_addr(struct net_device *dev, __be32 local); 324 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 325 326 extern u32 fib_multipath_secret __read_mostly; 327 328 static inline int fib_multipath_hash(__be32 saddr, __be32 daddr) 329 { 330 return jhash_2words((__force u32)saddr, (__force u32)daddr, 331 fib_multipath_secret) >> 1; 332 } 333 334 void fib_select_multipath(struct fib_result *res, int hash); 335 void fib_select_path(struct net *net, struct fib_result *res, 336 struct flowi4 *fl4, int mp_hash); 337 338 /* Exported by fib_trie.c */ 339 void fib_trie_init(void); 340 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 341 342 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 343 { 344 #ifdef CONFIG_IP_ROUTE_CLASSID 345 #ifdef CONFIG_IP_MULTIPLE_TABLES 346 u32 rtag; 347 #endif 348 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 349 #ifdef CONFIG_IP_MULTIPLE_TABLES 350 rtag = res->tclassid; 351 if (*itag == 0) 352 *itag = (rtag<<16); 353 *itag |= (rtag>>16); 354 #endif 355 #endif 356 } 357 358 void free_fib_info(struct fib_info *fi); 359 360 static inline void fib_info_put(struct fib_info *fi) 361 { 362 if (atomic_dec_and_test(&fi->fib_clntref)) 363 free_fib_info(fi); 364 } 365 366 #ifdef CONFIG_PROC_FS 367 int __net_init fib_proc_init(struct net *net); 368 void __net_exit fib_proc_exit(struct net *net); 369 #else 370 static inline int fib_proc_init(struct net *net) 371 { 372 return 0; 373 } 374 static inline void fib_proc_exit(struct net *net) 375 { 376 } 377 #endif 378 379 #endif /* _NET_FIB_H */ 380