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