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