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 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 129
 130 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 131 #define FIB_RES_RESET(res)
 132
 133 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 134
 135 #define FIB_RES_PREFSRC(res)            ((res).fi->fib_prefsrc ? : __fib_res_prefsrc(&res))
 136 #define FIB_RES_GW(res)                 (FIB_RES_NH(res).nh_gw)
 137 #define FIB_RES_DEV(res)                (FIB_RES_NH(res).nh_dev)
 138 #define FIB_RES_OIF(res)                (FIB_RES_NH(res).nh_oif)
 139
 140 struct fib_table {
 141         struct hlist_node tb_hlist;
 142         u32             tb_id;
 143         unsigned        tb_stamp;
 144         int             tb_default;
 145         int             (*tb_lookup)(struct fib_table *tb, const struct flowi *flp, struct fib_result *res);
 146         int             (*tb_insert)(struct fib_table *, struct fib_config *);
 147         int             (*tb_delete)(struct fib_table *, struct fib_config *);
 148         int             (*tb_dump)(struct fib_table *table, struct sk_buff *skb,
 149                                      struct netlink_callback *cb);
 150         int             (*tb_flush)(struct fib_table *table);
 151         void            (*tb_select_default)(struct fib_table *table,
 152                                              const struct flowi *flp, struct fib_result *res);
 153
 154         unsigned char   tb_data[0];
 155 };
 156
 157 #ifndef CONFIG_IP_MULTIPLE_TABLES
 158
 159 extern struct fib_table *ip_fib_local_table;
 160 extern struct fib_table *ip_fib_main_table;
 161
 162 static inline struct fib_table *fib_get_table(u32 id)
 163 {
 164         if (id != RT_TABLE_LOCAL)
 165                 return ip_fib_main_table;
 166         return ip_fib_local_table;
 167 }
 168
 169 static inline struct fib_table *fib_new_table(u32 id)
 170 {
 171         return fib_get_table(id);
 172 }
 173
 174 static inline int fib_lookup(const struct flowi *flp, struct fib_result *res)
 175 {
 176         if (ip_fib_local_table->tb_lookup(ip_fib_local_table, flp, res) &&
 177             ip_fib_main_table->tb_lookup(ip_fib_main_table, flp, res))
 178                 return -ENETUNREACH;
 179         return 0;
 180 }
 181
 182 static inline void fib_select_default(const struct flowi *flp, struct fib_result *res)
 183 {
 184         if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 185                 ip_fib_main_table->tb_select_default(ip_fib_main_table, flp, res);
 186 }
 187
 188 #else /* CONFIG_IP_MULTIPLE_TABLES */
 189 extern void __init fib4_rules_init(void);
 190
 191 #ifdef CONFIG_NET_CLS_ROUTE
 192 extern u32 fib_rules_tclass(struct fib_result *res);
 193 #endif
 194
 195 extern int fib_lookup(struct flowi *flp, struct fib_result *res);
 196
 197 extern struct fib_table *fib_new_table(u32 id);
 198 extern struct fib_table *fib_get_table(u32 id);
 199 extern void fib_select_default(const struct flowi *flp, struct fib_result *res);
 200
 201 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 202
 203 /* Exported by fib_frontend.c */
 204 extern const struct nla_policy rtm_ipv4_policy[];
 205 extern void             ip_fib_init(void);
 206 extern int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
 207                                struct net_device *dev, __be32 *spec_dst, u32 *itag);
 208 extern void fib_select_multipath(const struct flowi *flp, struct fib_result *res);
 209
 210 struct rtentry;
 211
 212 /* Exported by fib_semantics.c */
 213 extern int ip_fib_check_default(__be32 gw, struct net_device *dev);
 214 extern int fib_sync_down(__be32 local, struct net_device *dev, int force);
 215 extern int fib_sync_up(struct net_device *dev);
 216 extern __be32  __fib_res_prefsrc(struct fib_result *res);
 217
 218 /* Exported by fib_hash.c */
 219 extern struct fib_table *fib_hash_init(u32 id);
 220
 221 static inline void fib_combine_itag(u32 *itag, struct fib_result *res)
 222 {
 223 #ifdef CONFIG_NET_CLS_ROUTE
 224 #ifdef CONFIG_IP_MULTIPLE_TABLES
 225         u32 rtag;
 226 #endif
 227         *itag = FIB_RES_NH(*res).nh_tclassid<<16;
 228 #ifdef CONFIG_IP_MULTIPLE_TABLES
 229         rtag = fib_rules_tclass(res);
 230         if (*itag == 0)
 231                 *itag = (rtag<<16);
 232         *itag |= (rtag>>16);
 233 #endif
 234 #endif
 235 }
 236
 237 extern void free_fib_info(struct fib_info *fi);
 238
 239 static inline void fib_info_put(struct fib_info *fi)
 240 {
 241         if (atomic_dec_and_test(&fi->fib_clntref))
 242                 free_fib_info(fi);
 243 }
 244
 245 static inline void fib_res_put(struct fib_result *res)
 246 {
 247         if (res->fi)
 248                 fib_info_put(res->fi);
 249 #ifdef CONFIG_IP_MULTIPLE_TABLES
 250         if (res->r)
 251                 fib_rule_put(res->r);
 252 #endif
 253 }
 254
 255 #ifdef CONFIG_PROC_FS
 256 extern int __net_init  fib_proc_init(struct net *net);
 257 extern void __net_exit fib_proc_exit(struct net *net);
 258 #endif
 259
 260 #endif  /* _NET_FIB_H */