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