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 25 struct fib_config { 26 u8 fc_dst_len; 27 u8 fc_tos; 28 u8 fc_protocol; 29 u8 fc_scope; 30 u8 fc_type; 31 /* 3 bytes unused */ 32 u32 fc_table; 33 __be32 fc_dst; 34 __be32 fc_gw; 35 int fc_oif; 36 u32 fc_flags; 37 u32 fc_priority; 38 __be32 fc_prefsrc; 39 struct nlattr *fc_mx; 40 struct rtnexthop *fc_mp; 41 int fc_mx_len; 42 int fc_mp_len; 43 u32 fc_flow; 44 u32 fc_nlflags; 45 struct nl_info fc_nlinfo; 46 }; 47 48 struct fib_info; 49 struct rtable; 50 51 struct fib_nh_exception { 52 struct fib_nh_exception __rcu *fnhe_next; 53 __be32 fnhe_daddr; 54 u32 fnhe_pmtu; 55 __be32 fnhe_gw; 56 unsigned long fnhe_expires; 57 unsigned long fnhe_stamp; 58 }; 59 60 struct fnhe_hash_bucket { 61 struct fib_nh_exception __rcu *chain; 62 }; 63 64 #define FNHE_HASH_SIZE 2048 65 #define FNHE_RECLAIM_DEPTH 5 66 67 struct fib_nh { 68 struct net_device *nh_dev; 69 struct hlist_node nh_hash; 70 struct fib_info *nh_parent; 71 unsigned int nh_flags; 72 unsigned char nh_scope; 73 #ifdef CONFIG_IP_ROUTE_MULTIPATH 74 int nh_weight; 75 int nh_power; 76 #endif 77 #ifdef CONFIG_IP_ROUTE_CLASSID 78 __u32 nh_tclassid; 79 #endif 80 int nh_oif; 81 __be32 nh_gw; 82 __be32 nh_saddr; 83 int nh_saddr_genid; 84 struct rtable *nh_rth_output; 85 struct rtable *nh_rth_input; 86 struct fnhe_hash_bucket *nh_exceptions; 87 }; 88 89 /* 90 * This structure contains data shared by many of routes. 91 */ 92 93 struct fib_info { 94 struct hlist_node fib_hash; 95 struct hlist_node fib_lhash; 96 struct net *fib_net; 97 int fib_treeref; 98 atomic_t fib_clntref; 99 unsigned int fib_flags; 100 unsigned char fib_dead; 101 unsigned char fib_protocol; 102 unsigned char fib_scope; 103 __be32 fib_prefsrc; 104 u32 fib_priority; 105 u32 *fib_metrics; 106 #define fib_mtu fib_metrics[RTAX_MTU-1] 107 #define fib_window fib_metrics[RTAX_WINDOW-1] 108 #define fib_rtt fib_metrics[RTAX_RTT-1] 109 #define fib_advmss fib_metrics[RTAX_ADVMSS-1] 110 int fib_nhs; 111 #ifdef CONFIG_IP_ROUTE_MULTIPATH 112 int fib_power; 113 #endif 114 struct rcu_head rcu; 115 struct fib_nh fib_nh[0]; 116 #define fib_dev fib_nh[0].nh_dev 117 }; 118 119 120 #ifdef CONFIG_IP_MULTIPLE_TABLES 121 struct fib_rule; 122 #endif 123 124 struct fib_table; 125 struct fib_result { 126 unsigned char prefixlen; 127 unsigned char nh_sel; 128 unsigned char type; 129 unsigned char scope; 130 u32 tclassid; 131 struct fib_info *fi; 132 struct fib_table *table; 133 struct list_head *fa_head; 134 }; 135 136 struct fib_result_nl { 137 __be32 fl_addr; /* To be looked up*/ 138 u32 fl_mark; 139 unsigned char fl_tos; 140 unsigned char fl_scope; 141 unsigned char tb_id_in; 142 143 unsigned char tb_id; /* Results */ 144 unsigned char prefixlen; 145 unsigned char nh_sel; 146 unsigned char type; 147 unsigned char scope; 148 int err; 149 }; 150 151 #ifdef CONFIG_IP_ROUTE_MULTIPATH 152 153 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel]) 154 155 #define FIB_TABLE_HASHSZ 2 156 157 #else /* CONFIG_IP_ROUTE_MULTIPATH */ 158 159 #define FIB_RES_NH(res) ((res).fi->fib_nh[0]) 160 161 #define FIB_TABLE_HASHSZ 256 162 163 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 164 165 extern __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 166 167 #define FIB_RES_SADDR(net, res) \ 168 ((FIB_RES_NH(res).nh_saddr_genid == \ 169 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 170 FIB_RES_NH(res).nh_saddr : \ 171 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 172 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 173 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 174 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 175 176 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 177 FIB_RES_SADDR(net, res)) 178 179 struct fib_table { 180 struct hlist_node tb_hlist; 181 u32 tb_id; 182 int tb_default; 183 int tb_num_default; 184 unsigned long tb_data[0]; 185 }; 186 187 extern int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 188 struct fib_result *res, int fib_flags); 189 extern int fib_table_insert(struct fib_table *, struct fib_config *); 190 extern int fib_table_delete(struct fib_table *, struct fib_config *); 191 extern int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 192 struct netlink_callback *cb); 193 extern int fib_table_flush(struct fib_table *table); 194 extern void fib_free_table(struct fib_table *tb); 195 196 197 198 #ifndef CONFIG_IP_MULTIPLE_TABLES 199 200 #define TABLE_LOCAL_INDEX 0 201 #define TABLE_MAIN_INDEX 1 202 203 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 204 { 205 struct hlist_head *ptr; 206 207 ptr = id == RT_TABLE_LOCAL ? 208 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 209 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 210 return hlist_entry(ptr->first, struct fib_table, tb_hlist); 211 } 212 213 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 214 { 215 return fib_get_table(net, id); 216 } 217 218 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 219 struct fib_result *res) 220 { 221 struct fib_table *table; 222 223 table = fib_get_table(net, RT_TABLE_LOCAL); 224 if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF)) 225 return 0; 226 227 table = fib_get_table(net, RT_TABLE_MAIN); 228 if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF)) 229 return 0; 230 return -ENETUNREACH; 231 } 232 233 #else /* CONFIG_IP_MULTIPLE_TABLES */ 234 extern int __net_init fib4_rules_init(struct net *net); 235 extern void __net_exit fib4_rules_exit(struct net *net); 236 237 extern struct fib_table *fib_new_table(struct net *net, u32 id); 238 extern struct fib_table *fib_get_table(struct net *net, u32 id); 239 240 extern int __fib_lookup(struct net *net, struct flowi4 *flp, 241 struct fib_result *res); 242 243 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 244 struct fib_result *res) 245 { 246 if (!net->ipv4.fib_has_custom_rules) { 247 res->tclassid = 0; 248 if (net->ipv4.fib_local && 249 !fib_table_lookup(net->ipv4.fib_local, flp, res, 250 FIB_LOOKUP_NOREF)) 251 return 0; 252 if (net->ipv4.fib_main && 253 !fib_table_lookup(net->ipv4.fib_main, flp, res, 254 FIB_LOOKUP_NOREF)) 255 return 0; 256 if (net->ipv4.fib_default && 257 !fib_table_lookup(net->ipv4.fib_default, flp, res, 258 FIB_LOOKUP_NOREF)) 259 return 0; 260 return -ENETUNREACH; 261 } 262 return __fib_lookup(net, flp, res); 263 } 264 265 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 266 267 /* Exported by fib_frontend.c */ 268 extern const struct nla_policy rtm_ipv4_policy[]; 269 extern void ip_fib_init(void); 270 extern __be32 fib_compute_spec_dst(struct sk_buff *skb); 271 extern int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 272 u8 tos, int oif, struct net_device *dev, 273 struct in_device *idev, u32 *itag); 274 extern void fib_select_default(struct fib_result *res); 275 #ifdef CONFIG_IP_ROUTE_CLASSID 276 static inline int fib_num_tclassid_users(struct net *net) 277 { 278 return net->ipv4.fib_num_tclassid_users; 279 } 280 #else 281 static inline int fib_num_tclassid_users(struct net *net) 282 { 283 return 0; 284 } 285 #endif 286 287 /* Exported by fib_semantics.c */ 288 extern int ip_fib_check_default(__be32 gw, struct net_device *dev); 289 extern int fib_sync_down_dev(struct net_device *dev, int force); 290 extern int fib_sync_down_addr(struct net *net, __be32 local); 291 extern void fib_update_nh_saddrs(struct net_device *dev); 292 extern int fib_sync_up(struct net_device *dev); 293 extern void fib_select_multipath(struct fib_result *res); 294 295 /* Exported by fib_trie.c */ 296 extern void fib_trie_init(void); 297 extern struct fib_table *fib_trie_table(u32 id); 298 299 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 300 { 301 #ifdef CONFIG_IP_ROUTE_CLASSID 302 #ifdef CONFIG_IP_MULTIPLE_TABLES 303 u32 rtag; 304 #endif 305 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 306 #ifdef CONFIG_IP_MULTIPLE_TABLES 307 rtag = res->tclassid; 308 if (*itag == 0) 309 *itag = (rtag<<16); 310 *itag |= (rtag>>16); 311 #endif 312 #endif 313 } 314 315 extern void free_fib_info(struct fib_info *fi); 316 317 static inline void fib_info_put(struct fib_info *fi) 318 { 319 if (atomic_dec_and_test(&fi->fib_clntref)) 320 free_fib_info(fi); 321 } 322 323 #ifdef CONFIG_PROC_FS 324 extern int __net_init fib_proc_init(struct net *net); 325 extern void __net_exit fib_proc_exit(struct net *net); 326 #else 327 static inline int fib_proc_init(struct net *net) 328 { 329 return 0; 330 } 331 static inline void fib_proc_exit(struct net *net) 332 { 333 } 334 #endif 335 336 #endif /* _NET_FIB_H */ 337