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 #include <net/inetpeer.h>
  23
  24 struct fib_config {
  25         u8                      fc_dst_len;
  26         u8                      fc_tos;
  27         u8                      fc_protocol;
  28         u8                      fc_scope;
  29         u8                      fc_type;
  30         /* 3 bytes unused */
  31         u32                     fc_table;
  32         __be32                  fc_dst;
  33         __be32                  fc_gw;
  34         int                     fc_oif;
  35         u32                     fc_flags;
  36         u32                     fc_priority;
  37         __be32                  fc_prefsrc;
  38         struct nlattr           *fc_mx;
  39         struct rtnexthop        *fc_mp;
  40         int                     fc_mx_len;
  41         int                     fc_mp_len;
  42         u32                     fc_flow;
  43         u32                     fc_nlflags;
  44         struct nl_info          fc_nlinfo;
  45  };
  46
  47 struct fib_info;
  48
  49 struct fib_nh {
  50         struct net_device       *nh_dev;
  51         struct hlist_node       nh_hash;
  52         struct fib_info         *nh_parent;
  53         unsigned int            nh_flags;
  54         unsigned char           nh_scope;
  55 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  56         int                     nh_weight;
  57         int                     nh_power;
  58 #endif
  59 #ifdef CONFIG_IP_ROUTE_CLASSID
  60         __u32                   nh_tclassid;
  61 #endif
  62         int                     nh_oif;
  63         __be32                  nh_gw;
  64         __be32                  nh_saddr;
  65         int                     nh_saddr_genid;
  66 };
  67
  68 /*
  69  * This structure contains data shared by many of routes.
  70  */
  71
  72 struct fib_info {
  73         struct hlist_node       fib_hash;
  74         struct hlist_node       fib_lhash;
  75         struct net              *fib_net;
  76         int                     fib_treeref;
  77         atomic_t                fib_clntref;
  78         unsigned int            fib_flags;
  79         unsigned char           fib_dead;
  80         unsigned char           fib_protocol;
  81         unsigned char           fib_scope;
  82         __be32                  fib_prefsrc;
  83         u32                     fib_priority;
  84         u32                     *fib_metrics;
  85 #define fib_mtu fib_metrics[RTAX_MTU-1]
  86 #define fib_window fib_metrics[RTAX_WINDOW-1]
  87 #define fib_rtt fib_metrics[RTAX_RTT-1]
  88 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
  89         int                     fib_nhs;
  90 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  91         int                     fib_power;
  92 #endif
  93         struct rcu_head         rcu;
  94         struct fib_nh           fib_nh[0];
  95 #define fib_dev         fib_nh[0].nh_dev
  96 };
  97
  98
  99 #ifdef CONFIG_IP_MULTIPLE_TABLES
 100 struct fib_rule;
 101 #endif
 102
 103 struct fib_table;
 104 struct fib_result {
 105         unsigned char   prefixlen;
 106         unsigned char   nh_sel;
 107         unsigned char   type;
 108         unsigned char   scope;
 109         struct fib_info *fi;
 110         struct fib_table *table;
 111         struct list_head *fa_head;
 112 #ifdef CONFIG_IP_MULTIPLE_TABLES
 113         struct fib_rule *r;
 114 #endif
 115 };
 116
 117 struct fib_result_nl {
 118         __be32          fl_addr;   /* To be looked up*/
 119         u32             fl_mark;
 120         unsigned char   fl_tos;
 121         unsigned char   fl_scope;
 122         unsigned char   tb_id_in;
 123
 124         unsigned char   tb_id;      /* Results */
 125         unsigned char   prefixlen;
 126         unsigned char   nh_sel;
 127         unsigned char   type;
 128         unsigned char   scope;
 129         int             err;
 130 };
 131
 132 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 133
 134 #define FIB_RES_NH(res)         ((res).fi->fib_nh[(res).nh_sel])
 135
 136 #define FIB_TABLE_HASHSZ 2
 137
 138 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 139
 140 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 141
 142 #define FIB_TABLE_HASHSZ 256
 143
 144 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 145
 146 extern __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
 147
 148 #define FIB_RES_SADDR(net, res)                         \
 149         ((FIB_RES_NH(res).nh_saddr_genid ==             \
 150           atomic_read(&(net)->ipv4.dev_addr_genid)) ?   \
 151          FIB_RES_NH(res).nh_saddr :                     \
 152          fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
 153 #define FIB_RES_GW(res)                 (FIB_RES_NH(res).nh_gw)
 154 #define FIB_RES_DEV(res)                (FIB_RES_NH(res).nh_dev)
 155 #define FIB_RES_OIF(res)                (FIB_RES_NH(res).nh_oif)
 156
 157 #define FIB_RES_PREFSRC(net, res)       ((res).fi->fib_prefsrc ? : \
 158                                          FIB_RES_SADDR(net, res))
 159
 160 struct fib_table {
 161         struct hlist_node       tb_hlist;
 162         u32                     tb_id;
 163         int                     tb_default;
 164         int                     tb_num_default;
 165         unsigned long           tb_data[0];
 166 };
 167
 168 extern int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 169                             struct fib_result *res, int fib_flags);
 170 extern int fib_table_insert(struct fib_table *, struct fib_config *);
 171 extern int fib_table_delete(struct fib_table *, struct fib_config *);
 172 extern int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
 173                           struct netlink_callback *cb);
 174 extern int fib_table_flush(struct fib_table *table);
 175 extern void fib_free_table(struct fib_table *tb);
 176
 177
 178
 179 #ifndef CONFIG_IP_MULTIPLE_TABLES
 180
 181 #define TABLE_LOCAL_INDEX       0
 182 #define TABLE_MAIN_INDEX        1
 183
 184 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
 185 {
 186         struct hlist_head *ptr;
 187
 188         ptr = id == RT_TABLE_LOCAL ?
 189                 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
 190                 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
 191         return hlist_entry(ptr->first, struct fib_table, tb_hlist);
 192 }
 193
 194 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
 195 {
 196         return fib_get_table(net, id);
 197 }
 198
 199 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
 200                              struct fib_result *res)
 201 {
 202         struct fib_table *table;
 203
 204         table = fib_get_table(net, RT_TABLE_LOCAL);
 205         if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
 206                 return 0;
 207
 208         table = fib_get_table(net, RT_TABLE_MAIN);
 209         if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
 210                 return 0;
 211         return -ENETUNREACH;
 212 }
 213
 214 #else /* CONFIG_IP_MULTIPLE_TABLES */
 215 extern int __net_init fib4_rules_init(struct net *net);
 216 extern void __net_exit fib4_rules_exit(struct net *net);
 217
 218 #ifdef CONFIG_IP_ROUTE_CLASSID
 219 extern u32 fib_rules_tclass(const struct fib_result *res);
 220 #endif
 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 extern int __fib_lookup(struct net *net, struct flowi4 *flp,
 226                         struct fib_result *res);
 227
 228 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
 229                              struct fib_result *res)
 230 {
 231         if (!net->ipv4.fib_has_custom_rules) {
 232                 res->r = NULL;
 233                 if (net->ipv4.fib_local &&
 234                     !fib_table_lookup(net->ipv4.fib_local, flp, res,
 235                                       FIB_LOOKUP_NOREF))
 236                         return 0;
 237                 if (net->ipv4.fib_main &&
 238                     !fib_table_lookup(net->ipv4.fib_main, flp, res,
 239                                       FIB_LOOKUP_NOREF))
 240                         return 0;
 241                 if (net->ipv4.fib_default &&
 242                     !fib_table_lookup(net->ipv4.fib_default, flp, res,
 243                                       FIB_LOOKUP_NOREF))
 244                         return 0;
 245                 return -ENETUNREACH;
 246         }
 247         return __fib_lookup(net, flp, res);
 248 }
 249
 250 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 251
 252 /* Exported by fib_frontend.c */
 253 extern const struct nla_policy rtm_ipv4_policy[];
 254 extern void             ip_fib_init(void);
 255 extern __be32 fib_compute_spec_dst(struct sk_buff *skb);
 256 extern int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 257                                u8 tos, int oif, struct net_device *dev,
 258                                struct in_device *idev, u32 *itag);
 259 extern void fib_select_default(struct fib_result *res);
 260 #ifdef CONFIG_IP_ROUTE_CLASSID
 261 static inline int fib_num_tclassid_users(struct net *net)
 262 {
 263         return net->ipv4.fib_num_tclassid_users;
 264 }
 265 #else
 266 static inline int fib_num_tclassid_users(struct net *net)
 267 {
 268         return 0;
 269 }
 270 #endif
 271
 272 /* Exported by fib_semantics.c */
 273 extern int ip_fib_check_default(__be32 gw, struct net_device *dev);
 274 extern int fib_sync_down_dev(struct net_device *dev, int force);
 275 extern int fib_sync_down_addr(struct net *net, __be32 local);
 276 extern void fib_update_nh_saddrs(struct net_device *dev);
 277 extern int fib_sync_up(struct net_device *dev);
 278 extern void fib_select_multipath(struct fib_result *res);
 279
 280 /* Exported by fib_trie.c */
 281 extern void fib_trie_init(void);
 282 extern struct fib_table *fib_trie_table(u32 id);
 283
 284 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
 285 {
 286 #ifdef CONFIG_IP_ROUTE_CLASSID
 287 #ifdef CONFIG_IP_MULTIPLE_TABLES
 288         u32 rtag;
 289 #endif
 290         *itag = FIB_RES_NH(*res).nh_tclassid<<16;
 291 #ifdef CONFIG_IP_MULTIPLE_TABLES
 292         rtag = fib_rules_tclass(res);
 293         if (*itag == 0)
 294                 *itag = (rtag<<16);
 295         *itag |= (rtag>>16);
 296 #endif
 297 #endif
 298 }
 299
 300 extern void free_fib_info(struct fib_info *fi);
 301
 302 static inline void fib_info_put(struct fib_info *fi)
 303 {
 304         if (atomic_dec_and_test(&fi->fib_clntref))
 305                 free_fib_info(fi);
 306 }
 307
 308 #ifdef CONFIG_PROC_FS
 309 extern int __net_init  fib_proc_init(struct net *net);
 310 extern void __net_exit fib_proc_exit(struct net *net);
 311 #else
 312 static inline int fib_proc_init(struct net *net)
 313 {
 314         return 0;
 315 }
 316 static inline void fib_proc_exit(struct net *net)
 317 {
 318 }
 319 #endif
 320
 321 #endif  /* _NET_FIB_H */