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