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 __be32 fnhe_daddr; 55 u32 fnhe_pmtu; 56 __be32 fnhe_gw; 57 unsigned long fnhe_expires; 58 struct rtable __rcu *fnhe_rth; 59 unsigned long fnhe_stamp; 60 }; 61 62 struct fnhe_hash_bucket { 63 struct fib_nh_exception __rcu *chain; 64 }; 65 66 #define FNHE_HASH_SIZE 2048 67 #define FNHE_RECLAIM_DEPTH 5 68 69 struct fib_nh { 70 struct net_device *nh_dev; 71 struct hlist_node nh_hash; 72 struct fib_info *nh_parent; 73 unsigned int nh_flags; 74 unsigned char nh_scope; 75 #ifdef CONFIG_IP_ROUTE_MULTIPATH 76 int nh_weight; 77 int nh_power; 78 #endif 79 #ifdef CONFIG_IP_ROUTE_CLASSID 80 __u32 nh_tclassid; 81 #endif 82 int nh_oif; 83 __be32 nh_gw; 84 __be32 nh_saddr; 85 int nh_saddr_genid; 86 struct rtable __rcu * __percpu *nh_pcpu_rth_output; 87 struct rtable __rcu *nh_rth_input; 88 struct fnhe_hash_bucket *nh_exceptions; 89 }; 90 91 /* 92 * This structure contains data shared by many of routes. 93 */ 94 95 struct fib_info { 96 struct hlist_node fib_hash; 97 struct hlist_node fib_lhash; 98 struct net *fib_net; 99 int fib_treeref; 100 atomic_t fib_clntref; 101 unsigned int fib_flags; 102 unsigned char fib_dead; 103 unsigned char fib_protocol; 104 unsigned char fib_scope; 105 unsigned char fib_type; 106 __be32 fib_prefsrc; 107 u32 fib_priority; 108 u32 *fib_metrics; 109 #define fib_mtu fib_metrics[RTAX_MTU-1] 110 #define fib_window fib_metrics[RTAX_WINDOW-1] 111 #define fib_rtt fib_metrics[RTAX_RTT-1] 112 #define fib_advmss fib_metrics[RTAX_ADVMSS-1] 113 int fib_nhs; 114 #ifdef CONFIG_IP_ROUTE_MULTIPATH 115 int fib_power; 116 #endif 117 struct rcu_head rcu; 118 struct fib_nh fib_nh[0]; 119 #define fib_dev fib_nh[0].nh_dev 120 }; 121 122 123 #ifdef CONFIG_IP_MULTIPLE_TABLES 124 struct fib_rule; 125 #endif 126 127 struct fib_table; 128 struct fib_result { 129 unsigned char prefixlen; 130 unsigned char nh_sel; 131 unsigned char type; 132 unsigned char scope; 133 u32 tclassid; 134 struct fib_info *fi; 135 struct fib_table *table; 136 struct list_head *fa_head; 137 }; 138 139 struct fib_result_nl { 140 __be32 fl_addr; /* To be looked up*/ 141 u32 fl_mark; 142 unsigned char fl_tos; 143 unsigned char fl_scope; 144 unsigned char tb_id_in; 145 146 unsigned char tb_id; /* Results */ 147 unsigned char prefixlen; 148 unsigned char nh_sel; 149 unsigned char type; 150 unsigned char scope; 151 int err; 152 }; 153 154 #ifdef CONFIG_IP_ROUTE_MULTIPATH 155 156 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel]) 157 158 #define FIB_TABLE_HASHSZ 2 159 160 #else /* CONFIG_IP_ROUTE_MULTIPATH */ 161 162 #define FIB_RES_NH(res) ((res).fi->fib_nh[0]) 163 164 #define FIB_TABLE_HASHSZ 256 165 166 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 167 168 extern __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 169 170 #define FIB_RES_SADDR(net, res) \ 171 ((FIB_RES_NH(res).nh_saddr_genid == \ 172 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 173 FIB_RES_NH(res).nh_saddr : \ 174 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 175 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 176 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 177 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 178 179 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 180 FIB_RES_SADDR(net, res)) 181 182 struct fib_table { 183 struct hlist_node tb_hlist; 184 u32 tb_id; 185 int tb_default; 186 int tb_num_default; 187 unsigned long tb_data[0]; 188 }; 189 190 extern int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 191 struct fib_result *res, int fib_flags); 192 extern int fib_table_insert(struct fib_table *, struct fib_config *); 193 extern int fib_table_delete(struct fib_table *, struct fib_config *); 194 extern int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 195 struct netlink_callback *cb); 196 extern int fib_table_flush(struct fib_table *table); 197 extern void fib_free_table(struct fib_table *tb); 198 199 200 201 #ifndef CONFIG_IP_MULTIPLE_TABLES 202 203 #define TABLE_LOCAL_INDEX 0 204 #define TABLE_MAIN_INDEX 1 205 206 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 207 { 208 struct hlist_head *ptr; 209 210 ptr = id == RT_TABLE_LOCAL ? 211 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 212 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 213 return hlist_entry(ptr->first, struct fib_table, tb_hlist); 214 } 215 216 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 217 { 218 return fib_get_table(net, id); 219 } 220 221 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 222 struct fib_result *res) 223 { 224 struct fib_table *table; 225 226 table = fib_get_table(net, RT_TABLE_LOCAL); 227 if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF)) 228 return 0; 229 230 table = fib_get_table(net, RT_TABLE_MAIN); 231 if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF)) 232 return 0; 233 return -ENETUNREACH; 234 } 235 236 #else /* CONFIG_IP_MULTIPLE_TABLES */ 237 extern int __net_init fib4_rules_init(struct net *net); 238 extern void __net_exit fib4_rules_exit(struct net *net); 239 240 extern struct fib_table *fib_new_table(struct net *net, u32 id); 241 extern struct fib_table *fib_get_table(struct net *net, u32 id); 242 243 extern int __fib_lookup(struct net *net, struct flowi4 *flp, 244 struct fib_result *res); 245 246 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 247 struct fib_result *res) 248 { 249 if (!net->ipv4.fib_has_custom_rules) { 250 res->tclassid = 0; 251 if (net->ipv4.fib_local && 252 !fib_table_lookup(net->ipv4.fib_local, flp, res, 253 FIB_LOOKUP_NOREF)) 254 return 0; 255 if (net->ipv4.fib_main && 256 !fib_table_lookup(net->ipv4.fib_main, flp, res, 257 FIB_LOOKUP_NOREF)) 258 return 0; 259 if (net->ipv4.fib_default && 260 !fib_table_lookup(net->ipv4.fib_default, flp, res, 261 FIB_LOOKUP_NOREF)) 262 return 0; 263 return -ENETUNREACH; 264 } 265 return __fib_lookup(net, flp, res); 266 } 267 268 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 269 270 /* Exported by fib_frontend.c */ 271 extern const struct nla_policy rtm_ipv4_policy[]; 272 extern void ip_fib_init(void); 273 extern __be32 fib_compute_spec_dst(struct sk_buff *skb); 274 extern int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 275 u8 tos, int oif, struct net_device *dev, 276 struct in_device *idev, u32 *itag); 277 extern void fib_select_default(struct fib_result *res); 278 #ifdef CONFIG_IP_ROUTE_CLASSID 279 static inline int fib_num_tclassid_users(struct net *net) 280 { 281 return net->ipv4.fib_num_tclassid_users; 282 } 283 #else 284 static inline int fib_num_tclassid_users(struct net *net) 285 { 286 return 0; 287 } 288 #endif 289 290 /* Exported by fib_semantics.c */ 291 extern int ip_fib_check_default(__be32 gw, struct net_device *dev); 292 extern int fib_sync_down_dev(struct net_device *dev, int force); 293 extern int fib_sync_down_addr(struct net *net, __be32 local); 294 extern void fib_update_nh_saddrs(struct net_device *dev); 295 extern int fib_sync_up(struct net_device *dev); 296 extern void fib_select_multipath(struct fib_result *res); 297 298 /* Exported by fib_trie.c */ 299 extern void fib_trie_init(void); 300 extern struct fib_table *fib_trie_table(u32 id); 301 302 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 303 { 304 #ifdef CONFIG_IP_ROUTE_CLASSID 305 #ifdef CONFIG_IP_MULTIPLE_TABLES 306 u32 rtag; 307 #endif 308 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 309 #ifdef CONFIG_IP_MULTIPLE_TABLES 310 rtag = res->tclassid; 311 if (*itag == 0) 312 *itag = (rtag<<16); 313 *itag |= (rtag>>16); 314 #endif 315 #endif 316 } 317 318 extern void free_fib_info(struct fib_info *fi); 319 320 static inline void fib_info_put(struct fib_info *fi) 321 { 322 if (atomic_dec_and_test(&fi->fib_clntref)) 323 free_fib_info(fi); 324 } 325 326 #ifdef CONFIG_PROC_FS 327 extern int __net_init fib_proc_init(struct net *net); 328 extern void __net_exit fib_proc_exit(struct net *net); 329 #else 330 static inline int fib_proc_init(struct net *net) 331 { 332 return 0; 333 } 334 static inline void fib_proc_exit(struct net *net) 335 { 336 } 337 #endif 338 339 #endif /* _NET_FIB_H */ 340