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 int fnhe_genid; 55 __be32 fnhe_daddr; 56 u32 fnhe_pmtu; 57 __be32 fnhe_gw; 58 unsigned long fnhe_expires; 59 struct rtable __rcu *fnhe_rth_input; 60 struct rtable __rcu *fnhe_rth_output; 61 unsigned long fnhe_stamp; 62 }; 63 64 struct fnhe_hash_bucket { 65 struct fib_nh_exception __rcu *chain; 66 }; 67 68 #define FNHE_HASH_SIZE 2048 69 #define FNHE_RECLAIM_DEPTH 5 70 71 struct fib_nh { 72 struct net_device *nh_dev; 73 struct hlist_node nh_hash; 74 struct fib_info *nh_parent; 75 unsigned int nh_flags; 76 unsigned char nh_scope; 77 #ifdef CONFIG_IP_ROUTE_MULTIPATH 78 int nh_weight; 79 int nh_power; 80 #endif 81 #ifdef CONFIG_IP_ROUTE_CLASSID 82 __u32 nh_tclassid; 83 #endif 84 int nh_oif; 85 __be32 nh_gw; 86 __be32 nh_saddr; 87 int nh_saddr_genid; 88 struct rtable __rcu * __percpu *nh_pcpu_rth_output; 89 struct rtable __rcu *nh_rth_input; 90 struct fnhe_hash_bucket *nh_exceptions; 91 }; 92 93 /* 94 * This structure contains data shared by many of routes. 95 */ 96 97 struct fib_info { 98 struct hlist_node fib_hash; 99 struct hlist_node fib_lhash; 100 struct net *fib_net; 101 int fib_treeref; 102 atomic_t fib_clntref; 103 unsigned int fib_flags; 104 unsigned char fib_dead; 105 unsigned char fib_protocol; 106 unsigned char fib_scope; 107 unsigned char fib_type; 108 __be32 fib_prefsrc; 109 u32 fib_priority; 110 u32 *fib_metrics; 111 #define fib_mtu fib_metrics[RTAX_MTU-1] 112 #define fib_window fib_metrics[RTAX_WINDOW-1] 113 #define fib_rtt fib_metrics[RTAX_RTT-1] 114 #define fib_advmss fib_metrics[RTAX_ADVMSS-1] 115 int fib_nhs; 116 #ifdef CONFIG_IP_ROUTE_MULTIPATH 117 int fib_power; 118 #endif 119 struct rcu_head rcu; 120 struct fib_nh fib_nh[0]; 121 #define fib_dev fib_nh[0].nh_dev 122 }; 123 124 125 #ifdef CONFIG_IP_MULTIPLE_TABLES 126 struct fib_rule; 127 #endif 128 129 struct fib_table; 130 struct fib_result { 131 unsigned char prefixlen; 132 unsigned char nh_sel; 133 unsigned char type; 134 unsigned char scope; 135 u32 tclassid; 136 struct fib_info *fi; 137 struct fib_table *table; 138 struct list_head *fa_head; 139 }; 140 141 struct fib_result_nl { 142 __be32 fl_addr; /* To be looked up*/ 143 u32 fl_mark; 144 unsigned char fl_tos; 145 unsigned char fl_scope; 146 unsigned char tb_id_in; 147 148 unsigned char tb_id; /* Results */ 149 unsigned char prefixlen; 150 unsigned char nh_sel; 151 unsigned char type; 152 unsigned char scope; 153 int err; 154 }; 155 156 #ifdef CONFIG_IP_ROUTE_MULTIPATH 157 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel]) 158 #else /* CONFIG_IP_ROUTE_MULTIPATH */ 159 #define FIB_RES_NH(res) ((res).fi->fib_nh[0]) 160 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 161 162 #ifdef CONFIG_IP_MULTIPLE_TABLES 163 #define FIB_TABLE_HASHSZ 256 164 #else 165 #define FIB_TABLE_HASHSZ 2 166 #endif 167 168 __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 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 191 struct fib_result *res, int fib_flags); 192 int fib_table_insert(struct fib_table *, struct fib_config *); 193 int fib_table_delete(struct fib_table *, struct fib_config *); 194 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 195 struct netlink_callback *cb); 196 int fib_table_flush(struct fib_table *table); 197 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 int __net_init fib4_rules_init(struct net *net); 238 void __net_exit fib4_rules_exit(struct net *net); 239 240 struct fib_table *fib_new_table(struct net *net, u32 id); 241 struct fib_table *fib_get_table(struct net *net, u32 id); 242 243 int __fib_lookup(struct net *net, struct flowi4 *flp, 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 void ip_fib_init(void); 272 __be32 fib_compute_spec_dst(struct sk_buff *skb); 273 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 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 int ip_fib_check_default(__be32 gw, struct net_device *dev); 291 int fib_sync_down_dev(struct net_device *dev, int force); 292 int fib_sync_down_addr(struct net *net, __be32 local); 293 int fib_sync_up(struct net_device *dev); 294 void fib_select_multipath(struct fib_result *res); 295 296 /* Exported by fib_trie.c */ 297 void fib_trie_init(void); 298 struct fib_table *fib_trie_table(u32 id); 299 300 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 301 { 302 #ifdef CONFIG_IP_ROUTE_CLASSID 303 #ifdef CONFIG_IP_MULTIPLE_TABLES 304 u32 rtag; 305 #endif 306 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 307 #ifdef CONFIG_IP_MULTIPLE_TABLES 308 rtag = res->tclassid; 309 if (*itag == 0) 310 *itag = (rtag<<16); 311 *itag |= (rtag>>16); 312 #endif 313 #endif 314 } 315 316 void free_fib_info(struct fib_info *fi); 317 318 static inline void fib_info_put(struct fib_info *fi) 319 { 320 if (atomic_dec_and_test(&fi->fib_clntref)) 321 free_fib_info(fi); 322 } 323 324 #ifdef CONFIG_PROC_FS 325 int __net_init fib_proc_init(struct net *net); 326 void __net_exit fib_proc_exit(struct net *net); 327 #else 328 static inline int fib_proc_init(struct net *net) 329 { 330 return 0; 331 } 332 static inline void fib_proc_exit(struct net *net) 333 { 334 } 335 #endif 336 337 #endif /* _NET_FIB_H */ 338