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 <net/fib_rules.h>
  22
  23 struct fib_config {
  24         u8                      fc_dst_len;
  25         u8                      fc_tos;
  26         u8                      fc_protocol;
  27         u8                      fc_scope;
  28         u8                      fc_type;
  29         /* 3 bytes unused */
  30         u32                     fc_table;
  31         __be32                  fc_dst;
  32         __be32                  fc_gw;
  33         int                     fc_oif;
  34         u32                     fc_flags;
  35         u32                     fc_priority;
  36         __be32                  fc_prefsrc;
  37         struct nlattr           *fc_mx;
  38         struct rtnexthop        *fc_mp;
  39         int                     fc_mx_len;
  40         int                     fc_mp_len;
  41         u32                     fc_flow;
  42         u32                     fc_nlflags;
  43         struct nl_info          fc_nlinfo;
  44  };
  45
  46 struct fib_info;
  47
  48 struct fib_nh {
  49         struct net_device       *nh_dev;
  50         struct hlist_node       nh_hash;
  51         struct fib_info         *nh_parent;
  52         unsigned                nh_flags;
  53         unsigned char           nh_scope;
  54 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  55         int                     nh_weight;
  56         int                     nh_power;
  57 #endif
  58 #ifdef CONFIG_NET_CLS_ROUTE
  59         __u32                   nh_tclassid;
  60 #endif
  61         int                     nh_oif;
  62         __be32                  nh_gw;
  63 };
  64
  65 /*
  66  * This structure contains data shared by many of routes.
  67  */
  68
  69 struct fib_info {
  70         struct hlist_node       fib_hash;
  71         struct hlist_node       fib_lhash;
  72         int                     fib_treeref;
  73         atomic_t                fib_clntref;
  74         int                     fib_dead;
  75         unsigned                fib_flags;
  76         int                     fib_protocol;
  77         __be32                  fib_prefsrc;
  78         u32                     fib_priority;
  79         u32                     fib_metrics[RTAX_MAX];
  80 #define fib_mtu fib_metrics[RTAX_MTU-1]
  81 #define fib_window fib_metrics[RTAX_WINDOW-1]
  82 #define fib_rtt fib_metrics[RTAX_RTT-1]
  83 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
  84         int                     fib_nhs;
  85 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  86         int                     fib_power;
  87 #endif
  88         struct fib_nh           fib_nh[0];
  89 #define fib_dev         fib_nh[0].nh_dev
  90 };
  91
  92
  93 #ifdef CONFIG_IP_MULTIPLE_TABLES
  94 struct fib_rule;
  95 #endif
  96
  97 struct fib_result {
  98         unsigned char   prefixlen;
  99         unsigned char   nh_sel;
 100         unsigned char   type;
 101         unsigned char   scope;
 102         struct fib_info *fi;
 103 #ifdef CONFIG_IP_MULTIPLE_TABLES
 104         struct fib_rule *r;
 105 #endif
 106 };
 107
 108 struct fib_result_nl {
 109         __be32          fl_addr;   /* To be looked up*/
 110         u32             fl_mark;
 111         unsigned char   fl_tos;
 112         unsigned char   fl_scope;
 113         unsigned char   tb_id_in;
 114
 115         unsigned char   tb_id;      /* Results */
 116         unsigned char   prefixlen;
 117         unsigned char   nh_sel;
 118         unsigned char   type;
 119         unsigned char   scope;
 120         int             err;
 121 };
 122
 123 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 124
 125 #define FIB_RES_NH(res)         ((res).fi->fib_nh[(res).nh_sel])
 126 #define FIB_RES_RESET(res)      ((res).nh_sel = 0)
 127
 128 #define FIB_TABLE_HASHSZ 2
 129
 130 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 131
 132 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 133 #define FIB_RES_RESET(res)
 134
 135 #define FIB_TABLE_HASHSZ 256
 136
 137 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 138
 139 #define FIB_RES_PREFSRC(res)            ((res).fi->fib_prefsrc ? : __fib_res_prefsrc(&res))
 140 #define FIB_RES_GW(res)                 (FIB_RES_NH(res).nh_gw)
 141 #define FIB_RES_DEV(res)                (FIB_RES_NH(res).nh_dev)
 142 #define FIB_RES_OIF(res)                (FIB_RES_NH(res).nh_oif)
 143
 144 struct fib_table {
 145         struct hlist_node tb_hlist;
 146         u32             tb_id;
 147         unsigned        tb_stamp;
 148         int             tb_default;
 149         int             (*tb_lookup)(struct fib_table *tb, const struct flowi *flp, struct fib_result *res);
 150         int             (*tb_insert)(struct fib_table *, struct fib_config *);
 151         int             (*tb_delete)(struct fib_table *, struct fib_config *);
 152         int             (*tb_dump)(struct fib_table *table, struct sk_buff *skb,
 153                                      struct netlink_callback *cb);
 154         int             (*tb_flush)(struct fib_table *table);
 155         void            (*tb_select_default)(struct fib_table *table,
 156                                              const struct flowi *flp, struct fib_result *res);
 157
 158         unsigned char   tb_data[0];
 159 };
 160
 161 #ifndef CONFIG_IP_MULTIPLE_TABLES
 162
 163 #define TABLE_LOCAL_INDEX       0
 164 #define TABLE_MAIN_INDEX        1
 165
 166 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
 167 {
 168         struct hlist_head *ptr;
 169
 170         ptr = id == RT_TABLE_LOCAL ?
 171                 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
 172                 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
 173         return hlist_entry(ptr->first, struct fib_table, tb_hlist);
 174 }
 175
 176 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
 177 {
 178         return fib_get_table(net, id);
 179 }
 180
 181 static inline int fib_lookup(const struct flowi *flp, struct fib_result *res)
 182 {
 183         struct fib_table *table;
 184
 185         table = fib_get_table(&init_net, RT_TABLE_LOCAL);
 186         if (!table->tb_lookup(table, flp, res))
 187                 return 0;
 188
 189         table = fib_get_table(&init_net, RT_TABLE_MAIN);
 190         if (!table->tb_lookup(table, flp, res))
 191                 return 0;
 192         return -ENETUNREACH;
 193 }
 194
 195 static inline void fib_select_default(const struct flowi *flp,
 196                                       struct fib_result *res)
 197 {
 198         struct fib_table *table = fib_get_table(&init_net, RT_TABLE_MAIN);
 199         if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 200                 table->tb_select_default(table, flp, res);
 201 }
 202
 203 #else /* CONFIG_IP_MULTIPLE_TABLES */
 204 extern int __net_init fib4_rules_init(struct net *net);
 205 extern void __net_exit fib4_rules_exit(struct net *net);
 206
 207 #ifdef CONFIG_NET_CLS_ROUTE
 208 extern u32 fib_rules_tclass(struct fib_result *res);
 209 #endif
 210
 211 extern int fib_lookup(struct flowi *flp, struct fib_result *res);
 212
 213 extern struct fib_table *fib_new_table(struct net *net, u32 id);
 214 extern struct fib_table *fib_get_table(struct net *net, u32 id);
 215 extern void fib_select_default(const struct flowi *flp, struct fib_result *res);
 216
 217 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 218
 219 /* Exported by fib_frontend.c */
 220 extern const struct nla_policy rtm_ipv4_policy[];
 221 extern void             ip_fib_init(void);
 222 extern int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
 223                                struct net_device *dev, __be32 *spec_dst, u32 *itag);
 224 extern void fib_select_multipath(const struct flowi *flp, struct fib_result *res);
 225
 226 struct rtentry;
 227
 228 /* Exported by fib_semantics.c */
 229 extern int ip_fib_check_default(__be32 gw, struct net_device *dev);
 230 extern int fib_sync_down(__be32 local, struct net_device *dev, int force);
 231 extern int fib_sync_up(struct net_device *dev);
 232 extern __be32  __fib_res_prefsrc(struct fib_result *res);
 233
 234 /* Exported by fib_{hash|trie}.c */
 235 extern void fib_hash_init(void);
 236 extern struct fib_table *fib_hash_table(u32 id);
 237
 238 static inline void fib_combine_itag(u32 *itag, struct fib_result *res)
 239 {
 240 #ifdef CONFIG_NET_CLS_ROUTE
 241 #ifdef CONFIG_IP_MULTIPLE_TABLES
 242         u32 rtag;
 243 #endif
 244         *itag = FIB_RES_NH(*res).nh_tclassid<<16;
 245 #ifdef CONFIG_IP_MULTIPLE_TABLES
 246         rtag = fib_rules_tclass(res);
 247         if (*itag == 0)
 248                 *itag = (rtag<<16);
 249         *itag |= (rtag>>16);
 250 #endif
 251 #endif
 252 }
 253
 254 extern void free_fib_info(struct fib_info *fi);
 255
 256 static inline void fib_info_put(struct fib_info *fi)
 257 {
 258         if (atomic_dec_and_test(&fi->fib_clntref))
 259                 free_fib_info(fi);
 260 }
 261
 262 static inline void fib_res_put(struct fib_result *res)
 263 {
 264         if (res->fi)
 265                 fib_info_put(res->fi);
 266 #ifdef CONFIG_IP_MULTIPLE_TABLES
 267         if (res->r)
 268                 fib_rule_put(res->r);
 269 #endif
 270 }
 271
 272 #ifdef CONFIG_PROC_FS
 273 extern int __net_init  fib_proc_init(struct net *net);
 274 extern void __net_exit fib_proc_exit(struct net *net);
 275 #endif
 276
 277 #endif  /* _NET_FIB_H */