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 #include <linux/percpu.h>
  25
  26 struct fib_config {
  27         u8                      fc_dst_len;
  28         u8                      fc_tos;
  29         u8                      fc_protocol;
  30         u8                      fc_scope;
  31         u8                      fc_type;
  32         /* 3 bytes unused */
  33         u32                     fc_table;
  34         __be32                  fc_dst;
  35         __be32                  fc_gw;
  36         int                     fc_oif;
  37         u32                     fc_flags;
  38         u32                     fc_priority;
  39         __be32                  fc_prefsrc;
  40         struct nlattr           *fc_mx;
  41         struct rtnexthop        *fc_mp;
  42         int                     fc_mx_len;
  43         int                     fc_mp_len;
  44         u32                     fc_flow;
  45         u32                     fc_nlflags;
  46         struct nl_info          fc_nlinfo;
  47  };
  48
  49 struct fib_info;
  50 struct rtable;
  51
  52 struct fib_nh_exception {
  53         struct fib_nh_exception __rcu   *fnhe_next;
  54         __be32                          fnhe_daddr;
  55         u32                             fnhe_pmtu;
  56         __be32                          fnhe_gw;
  57         unsigned long                   fnhe_expires;
  58         struct rtable __rcu             *fnhe_rth;
  59         unsigned long                   fnhe_stamp;
  60 };
  61
  62 struct fnhe_hash_bucket {
  63         struct fib_nh_exception __rcu   *chain;
  64 };
  65
  66 #define FNHE_HASH_SIZE          2048
  67 #define FNHE_RECLAIM_DEPTH      5
  68
  69 struct fib_nh {
  70         struct net_device       *nh_dev;
  71         struct hlist_node       nh_hash;
  72         struct fib_info         *nh_parent;
  73         unsigned int            nh_flags;
  74         unsigned char           nh_scope;
  75 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  76         int                     nh_weight;
  77         int                     nh_power;
  78 #endif
  79 #ifdef CONFIG_IP_ROUTE_CLASSID
  80         __u32                   nh_tclassid;
  81 #endif
  82         int                     nh_oif;
  83         __be32                  nh_gw;
  84         __be32                  nh_saddr;
  85         int                     nh_saddr_genid;
  86         struct rtable __rcu * __percpu *nh_pcpu_rth_output;
  87         struct rtable __rcu     *nh_rth_input;
  88         struct fnhe_hash_bucket *nh_exceptions;
  89 };
  90
  91 /*
  92  * This structure contains data shared by many of routes.
  93  */
  94
  95 struct fib_info {
  96         struct hlist_node       fib_hash;
  97         struct hlist_node       fib_lhash;
  98         struct net              *fib_net;
  99         int                     fib_treeref;
 100         atomic_t                fib_clntref;
 101         unsigned int            fib_flags;
 102         unsigned char           fib_dead;
 103         unsigned char           fib_protocol;
 104         unsigned char           fib_scope;
 105         unsigned char           fib_type;
 106         __be32                  fib_prefsrc;
 107         u32                     fib_priority;
 108         u32                     *fib_metrics;
 109 #define fib_mtu fib_metrics[RTAX_MTU-1]
 110 #define fib_window fib_metrics[RTAX_WINDOW-1]
 111 #define fib_rtt fib_metrics[RTAX_RTT-1]
 112 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
 113         int                     fib_nhs;
 114 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 115         int                     fib_power;
 116 #endif
 117         struct rcu_head         rcu;
 118         struct fib_nh           fib_nh[0];
 119 #define fib_dev         fib_nh[0].nh_dev
 120 };
 121
 122
 123 #ifdef CONFIG_IP_MULTIPLE_TABLES
 124 struct fib_rule;
 125 #endif
 126
 127 struct fib_table;
 128 struct fib_result {
 129         unsigned char   prefixlen;
 130         unsigned char   nh_sel;
 131         unsigned char   type;
 132         unsigned char   scope;
 133         u32             tclassid;
 134         struct fib_info *fi;
 135         struct fib_table *table;
 136         struct list_head *fa_head;
 137 };
 138
 139 struct fib_result_nl {
 140         __be32          fl_addr;   /* To be looked up*/
 141         u32             fl_mark;
 142         unsigned char   fl_tos;
 143         unsigned char   fl_scope;
 144         unsigned char   tb_id_in;
 145
 146         unsigned char   tb_id;      /* Results */
 147         unsigned char   prefixlen;
 148         unsigned char   nh_sel;
 149         unsigned char   type;
 150         unsigned char   scope;
 151         int             err;
 152 };
 153
 154 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 155 #define FIB_RES_NH(res)         ((res).fi->fib_nh[(res).nh_sel])
 156 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 157 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 158 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 159
 160 #ifdef CONFIG_IP_MULTIPLE_TABLES
 161 #define FIB_TABLE_HASHSZ 256
 162 #else
 163 #define FIB_TABLE_HASHSZ 2
 164 #endif
 165
 166 extern __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
 167
 168 #define FIB_RES_SADDR(net, res)                         \
 169         ((FIB_RES_NH(res).nh_saddr_genid ==             \
 170           atomic_read(&(net)->ipv4.dev_addr_genid)) ?   \
 171          FIB_RES_NH(res).nh_saddr :                     \
 172          fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
 173 #define FIB_RES_GW(res)                 (FIB_RES_NH(res).nh_gw)
 174 #define FIB_RES_DEV(res)                (FIB_RES_NH(res).nh_dev)
 175 #define FIB_RES_OIF(res)                (FIB_RES_NH(res).nh_oif)
 176
 177 #define FIB_RES_PREFSRC(net, res)       ((res).fi->fib_prefsrc ? : \
 178                                          FIB_RES_SADDR(net, res))
 179
 180 struct fib_table {
 181         struct hlist_node       tb_hlist;
 182         u32                     tb_id;
 183         int                     tb_default;
 184         int                     tb_num_default;
 185         unsigned long           tb_data[0];
 186 };
 187
 188 extern int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 189                             struct fib_result *res, int fib_flags);
 190 extern int fib_table_insert(struct fib_table *, struct fib_config *);
 191 extern int fib_table_delete(struct fib_table *, struct fib_config *);
 192 extern int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
 193                           struct netlink_callback *cb);
 194 extern int fib_table_flush(struct fib_table *table);
 195 extern void fib_free_table(struct fib_table *tb);
 196
 197
 198
 199 #ifndef CONFIG_IP_MULTIPLE_TABLES
 200
 201 #define TABLE_LOCAL_INDEX       0
 202 #define TABLE_MAIN_INDEX        1
 203
 204 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
 205 {
 206         struct hlist_head *ptr;
 207
 208         ptr = id == RT_TABLE_LOCAL ?
 209                 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
 210                 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
 211         return hlist_entry(ptr->first, struct fib_table, tb_hlist);
 212 }
 213
 214 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
 215 {
 216         return fib_get_table(net, id);
 217 }
 218
 219 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
 220                              struct fib_result *res)
 221 {
 222         struct fib_table *table;
 223
 224         table = fib_get_table(net, RT_TABLE_LOCAL);
 225         if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
 226                 return 0;
 227
 228         table = fib_get_table(net, RT_TABLE_MAIN);
 229         if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
 230                 return 0;
 231         return -ENETUNREACH;
 232 }
 233
 234 #else /* CONFIG_IP_MULTIPLE_TABLES */
 235 extern int __net_init fib4_rules_init(struct net *net);
 236 extern void __net_exit fib4_rules_exit(struct net *net);
 237
 238 extern struct fib_table *fib_new_table(struct net *net, u32 id);
 239 extern struct fib_table *fib_get_table(struct net *net, u32 id);
 240
 241 extern int __fib_lookup(struct net *net, struct flowi4 *flp,
 242                         struct fib_result *res);
 243
 244 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
 245                              struct fib_result *res)
 246 {
 247         if (!net->ipv4.fib_has_custom_rules) {
 248                 res->tclassid = 0;
 249                 if (net->ipv4.fib_local &&
 250                     !fib_table_lookup(net->ipv4.fib_local, flp, res,
 251                                       FIB_LOOKUP_NOREF))
 252                         return 0;
 253                 if (net->ipv4.fib_main &&
 254                     !fib_table_lookup(net->ipv4.fib_main, flp, res,
 255                                       FIB_LOOKUP_NOREF))
 256                         return 0;
 257                 if (net->ipv4.fib_default &&
 258                     !fib_table_lookup(net->ipv4.fib_default, flp, res,
 259                                       FIB_LOOKUP_NOREF))
 260                         return 0;
 261                 return -ENETUNREACH;
 262         }
 263         return __fib_lookup(net, flp, res);
 264 }
 265
 266 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 267
 268 /* Exported by fib_frontend.c */
 269 extern const struct nla_policy rtm_ipv4_policy[];
 270 extern void             ip_fib_init(void);
 271 extern __be32 fib_compute_spec_dst(struct sk_buff *skb);
 272 extern int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 273                                u8 tos, int oif, struct net_device *dev,
 274                                struct in_device *idev, u32 *itag);
 275 extern void fib_select_default(struct fib_result *res);
 276 #ifdef CONFIG_IP_ROUTE_CLASSID
 277 static inline int fib_num_tclassid_users(struct net *net)
 278 {
 279         return net->ipv4.fib_num_tclassid_users;
 280 }
 281 #else
 282 static inline int fib_num_tclassid_users(struct net *net)
 283 {
 284         return 0;
 285 }
 286 #endif
 287
 288 /* Exported by fib_semantics.c */
 289 extern int ip_fib_check_default(__be32 gw, struct net_device *dev);
 290 extern int fib_sync_down_dev(struct net_device *dev, int force);
 291 extern int fib_sync_down_addr(struct net *net, __be32 local);
 292 extern void fib_update_nh_saddrs(struct net_device *dev);
 293 extern int fib_sync_up(struct net_device *dev);
 294 extern void fib_select_multipath(struct fib_result *res);
 295
 296 /* Exported by fib_trie.c */
 297 extern void fib_trie_init(void);
 298 extern struct fib_table *fib_trie_table(u32 id);
 299
 300 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
 301 {
 302 #ifdef CONFIG_IP_ROUTE_CLASSID
 303 #ifdef CONFIG_IP_MULTIPLE_TABLES
 304         u32 rtag;
 305 #endif
 306         *itag = FIB_RES_NH(*res).nh_tclassid<<16;
 307 #ifdef CONFIG_IP_MULTIPLE_TABLES
 308         rtag = res->tclassid;
 309         if (*itag == 0)
 310                 *itag = (rtag<<16);
 311         *itag |= (rtag>>16);
 312 #endif
 313 #endif
 314 }
 315
 316 extern void free_fib_info(struct fib_info *fi);
 317
 318 static inline void fib_info_put(struct fib_info *fi)
 319 {
 320         if (atomic_dec_and_test(&fi->fib_clntref))
 321                 free_fib_info(fi);
 322 }
 323
 324 #ifdef CONFIG_PROC_FS
 325 extern int __net_init  fib_proc_init(struct net *net);
 326 extern void __net_exit fib_proc_exit(struct net *net);
 327 #else
 328 static inline int fib_proc_init(struct net *net)
 329 {
 330         return 0;
 331 }
 332 static inline void fib_proc_exit(struct net *net)
 333 {
 334 }
 335 #endif
 336
 337 #endif  /* _NET_FIB_H */