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