include/net/ip_fib.h

   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;
  60         unsigned long                   fnhe_stamp;
  61 };
  62
  63 struct fnhe_hash_bucket {
  64         struct fib_nh_exception __rcu   *chain;
  65 };
  66
  67 #define FNHE_HASH_SIZE          2048
  68 #define FNHE_RECLAIM_DEPTH      5
  69
  70 struct fib_nh {
  71         struct net_device       *nh_dev;
  72         struct hlist_node       nh_hash;
  73         struct fib_info         *nh_parent;
  74         unsigned int            nh_flags;
  75         unsigned char           nh_scope;
  76 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  77         int                     nh_weight;
  78         int                     nh_power;
  79 #endif
  80 #ifdef CONFIG_IP_ROUTE_CLASSID
  81         __u32                   nh_tclassid;
  82 #endif
  83         int                     nh_oif;
  84         __be32                  nh_gw;
  85         __be32                  nh_saddr;
  86         int                     nh_saddr_genid;
  87         struct rtable __rcu * __percpu *nh_pcpu_rth_output;
  88         struct rtable __rcu     *nh_rth_input;
  89         struct fnhe_hash_bucket *nh_exceptions;
  90 };
  91
  92 /*
  93  * This structure contains data shared by many of routes.
  94  */
  95
  96 struct fib_info {
  97         struct hlist_node       fib_hash;
  98         struct hlist_node       fib_lhash;
  99         struct net              *fib_net;
 100         int                     fib_treeref;
 101         atomic_t                fib_clntref;
 102         unsigned int            fib_flags;
 103         unsigned char           fib_dead;
 104         unsigned char           fib_protocol;
 105         unsigned char           fib_scope;
 106         unsigned char           fib_type;
 107         __be32                  fib_prefsrc;
 108         u32                     fib_priority;
 109         u32                     *fib_metrics;
 110 #define fib_mtu fib_metrics[RTAX_MTU-1]
 111 #define fib_window fib_metrics[RTAX_WINDOW-1]
 112 #define fib_rtt fib_metrics[RTAX_RTT-1]
 113 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
 114         int                     fib_nhs;
 115 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 116         int                     fib_power;
 117 #endif
 118         struct rcu_head         rcu;
 119         struct fib_nh           fib_nh[0];
 120 #define fib_dev         fib_nh[0].nh_dev
 121 };
 122
 123
 124 #ifdef CONFIG_IP_MULTIPLE_TABLES
 125 struct fib_rule;
 126 #endif
 127
 128 struct fib_table;
 129 struct fib_result {
 130         unsigned char   prefixlen;
 131         unsigned char   nh_sel;
 132         unsigned char   type;
 133         unsigned char   scope;
 134         u32             tclassid;
 135         struct fib_info *fi;
 136         struct fib_table *table;
 137         struct list_head *fa_head;
 138 };
 139
 140 struct fib_result_nl {
 141         __be32          fl_addr;   /* To be looked up*/
 142         u32             fl_mark;
 143         unsigned char   fl_tos;
 144         unsigned char   fl_scope;
 145         unsigned char   tb_id_in;
 146
 147         unsigned char   tb_id;      /* Results */
 148         unsigned char   prefixlen;
 149         unsigned char   nh_sel;
 150         unsigned char   type;
 151         unsigned char   scope;
 152         int             err;
 153 };
 154
 155 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 156 #define FIB_RES_NH(res)         ((res).fi->fib_nh[(res).nh_sel])
 157 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 158 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 159 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 160
 161 #ifdef CONFIG_IP_MULTIPLE_TABLES
 162 #define FIB_TABLE_HASHSZ 256
 163 #else
 164 #define FIB_TABLE_HASHSZ 2
 165 #endif
 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 */