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_SHIFT         11
  69 #define FNHE_HASH_SIZE          (1 << FNHE_HASH_SHIFT)
  70 #define FNHE_RECLAIM_DEPTH      5
  71
  72 struct fib_nh {
  73         struct net_device       *nh_dev;
  74         struct hlist_node       nh_hash;
  75         struct fib_info         *nh_parent;
  76         unsigned int            nh_flags;
  77         unsigned char           nh_scope;
  78 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  79         int                     nh_weight;
  80         int                     nh_power;
  81 #endif
  82 #ifdef CONFIG_IP_ROUTE_CLASSID
  83         __u32                   nh_tclassid;
  84 #endif
  85         int                     nh_oif;
  86         __be32                  nh_gw;
  87         __be32                  nh_saddr;
  88         int                     nh_saddr_genid;
  89         struct rtable __rcu * __percpu *nh_pcpu_rth_output;
  90         struct rtable __rcu     *nh_rth_input;
  91         struct fnhe_hash_bucket __rcu *nh_exceptions;
  92 };
  93
  94 /*
  95  * This structure contains data shared by many of routes.
  96  */
  97
  98 struct fib_info {
  99         struct hlist_node       fib_hash;
 100         struct hlist_node       fib_lhash;
 101         struct net              *fib_net;
 102         int                     fib_treeref;
 103         atomic_t                fib_clntref;
 104         unsigned int            fib_flags;
 105         unsigned char           fib_dead;
 106         unsigned char           fib_protocol;
 107         unsigned char           fib_scope;
 108         unsigned char           fib_type;
 109         __be32                  fib_prefsrc;
 110         u32                     fib_priority;
 111         u32                     *fib_metrics;
 112 #define fib_mtu fib_metrics[RTAX_MTU-1]
 113 #define fib_window fib_metrics[RTAX_WINDOW-1]
 114 #define fib_rtt fib_metrics[RTAX_RTT-1]
 115 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
 116         int                     fib_nhs;
 117 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 118         int                     fib_power;
 119 #endif
 120         struct rcu_head         rcu;
 121         struct fib_nh           fib_nh[0];
 122 #define fib_dev         fib_nh[0].nh_dev
 123 };
 124
 125
 126 #ifdef CONFIG_IP_MULTIPLE_TABLES
 127 struct fib_rule;
 128 #endif
 129
 130 struct fib_table;
 131 struct fib_result {
 132         unsigned char   prefixlen;
 133         unsigned char   nh_sel;
 134         unsigned char   type;
 135         unsigned char   scope;
 136         u32             tclassid;
 137         struct fib_info *fi;
 138         struct fib_table *table;
 139         struct hlist_head *fa_head;
 140 };
 141
 142 struct fib_result_nl {
 143         __be32          fl_addr;   /* To be looked up*/
 144         u32             fl_mark;
 145         unsigned char   fl_tos;
 146         unsigned char   fl_scope;
 147         unsigned char   tb_id_in;
 148
 149         unsigned char   tb_id;      /* Results */
 150         unsigned char   prefixlen;
 151         unsigned char   nh_sel;
 152         unsigned char   type;
 153         unsigned char   scope;
 154         int             err;
 155 };
 156
 157 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 158 #define FIB_RES_NH(res)         ((res).fi->fib_nh[(res).nh_sel])
 159 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 160 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 161 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 162
 163 #ifdef CONFIG_IP_MULTIPLE_TABLES
 164 #define FIB_TABLE_HASHSZ 256
 165 #else
 166 #define FIB_TABLE_HASHSZ 2
 167 #endif
 168
 169 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
 170
 171 #define FIB_RES_SADDR(net, res)                         \
 172         ((FIB_RES_NH(res).nh_saddr_genid ==             \
 173           atomic_read(&(net)->ipv4.dev_addr_genid)) ?   \
 174          FIB_RES_NH(res).nh_saddr :                     \
 175          fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
 176 #define FIB_RES_GW(res)                 (FIB_RES_NH(res).nh_gw)
 177 #define FIB_RES_DEV(res)                (FIB_RES_NH(res).nh_dev)
 178 #define FIB_RES_OIF(res)                (FIB_RES_NH(res).nh_oif)
 179
 180 #define FIB_RES_PREFSRC(net, res)       ((res).fi->fib_prefsrc ? : \
 181                                          FIB_RES_SADDR(net, res))
 182
 183 struct fib_table {
 184         struct hlist_node       tb_hlist;
 185         u32                     tb_id;
 186         int                     tb_num_default;
 187         struct rcu_head         rcu;
 188         unsigned long           *tb_data;
 189         unsigned long           __data[0];
 190 };
 191
 192 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 193                      struct fib_result *res, int fib_flags);
 194 int fib_table_insert(struct fib_table *, struct fib_config *);
 195 int fib_table_delete(struct fib_table *, struct fib_config *);
 196 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
 197                    struct netlink_callback *cb);
 198 int fib_table_flush(struct fib_table *table);
 199 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
 200 void fib_table_flush_external(struct fib_table *table);
 201 void fib_free_table(struct fib_table *tb);
 202
 203 #ifndef CONFIG_IP_MULTIPLE_TABLES
 204
 205 #define TABLE_LOCAL_INDEX       (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
 206 #define TABLE_MAIN_INDEX        (RT_TABLE_MAIN  & (FIB_TABLE_HASHSZ - 1))
 207
 208 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
 209 {
 210         struct hlist_node *tb_hlist;
 211         struct hlist_head *ptr;
 212
 213         ptr = id == RT_TABLE_LOCAL ?
 214                 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
 215                 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
 216
 217         tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
 218
 219         return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
 220 }
 221
 222 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
 223 {
 224         return fib_get_table(net, id);
 225 }
 226
 227 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
 228                              struct fib_result *res, unsigned int flags)
 229 {
 230         struct fib_table *tb;
 231         int err = -ENETUNREACH;
 232
 233         rcu_read_lock();
 234
 235         tb = fib_get_table(net, RT_TABLE_MAIN);
 236         if (tb && !fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF))
 237                 err = 0;
 238
 239         rcu_read_unlock();
 240
 241         return err;
 242 }
 243
 244 #else /* CONFIG_IP_MULTIPLE_TABLES */
 245 int __net_init fib4_rules_init(struct net *net);
 246 void __net_exit fib4_rules_exit(struct net *net);
 247
 248 struct fib_table *fib_new_table(struct net *net, u32 id);
 249 struct fib_table *fib_get_table(struct net *net, u32 id);
 250
 251 int __fib_lookup(struct net *net, struct flowi4 *flp,
 252                  struct fib_result *res, unsigned int flags);
 253
 254 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
 255                              struct fib_result *res, unsigned int flags)
 256 {
 257         struct fib_table *tb;
 258         int err;
 259
 260         flags |= FIB_LOOKUP_NOREF;
 261         if (net->ipv4.fib_has_custom_rules)
 262                 return __fib_lookup(net, flp, res, flags);
 263
 264         rcu_read_lock();
 265
 266         res->tclassid = 0;
 267
 268         for (err = 0; !err; err = -ENETUNREACH) {
 269                 tb = rcu_dereference_rtnl(net->ipv4.fib_main);
 270                 if (tb && !fib_table_lookup(tb, flp, res, flags))
 271                         break;
 272
 273                 tb = rcu_dereference_rtnl(net->ipv4.fib_default);
 274                 if (tb && !fib_table_lookup(tb, flp, res, flags))
 275                         break;
 276         }
 277
 278         rcu_read_unlock();
 279
 280         return err;
 281 }
 282
 283 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 284
 285 /* Exported by fib_frontend.c */
 286 extern const struct nla_policy rtm_ipv4_policy[];
 287 void ip_fib_init(void);
 288 __be32 fib_compute_spec_dst(struct sk_buff *skb);
 289 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 290                         u8 tos, int oif, struct net_device *dev,
 291                         struct in_device *idev, u32 *itag);
 292 void fib_select_default(const struct flowi4 *flp, struct fib_result *res);
 293 #ifdef CONFIG_IP_ROUTE_CLASSID
 294 static inline int fib_num_tclassid_users(struct net *net)
 295 {
 296         return net->ipv4.fib_num_tclassid_users;
 297 }
 298 #else
 299 static inline int fib_num_tclassid_users(struct net *net)
 300 {
 301         return 0;
 302 }
 303 #endif
 304 int fib_unmerge(struct net *net);
 305 void fib_flush_external(struct net *net);
 306
 307 /* Exported by fib_semantics.c */
 308 int ip_fib_check_default(__be32 gw, struct net_device *dev);
 309 int fib_sync_down_dev(struct net_device *dev, unsigned long event);
 310 int fib_sync_down_addr(struct net *net, __be32 local);
 311 int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
 312 void fib_select_multipath(struct fib_result *res);
 313
 314 /* Exported by fib_trie.c */
 315 void fib_trie_init(void);
 316 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
 317
 318 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
 319 {
 320 #ifdef CONFIG_IP_ROUTE_CLASSID
 321 #ifdef CONFIG_IP_MULTIPLE_TABLES
 322         u32 rtag;
 323 #endif
 324         *itag = FIB_RES_NH(*res).nh_tclassid<<16;
 325 #ifdef CONFIG_IP_MULTIPLE_TABLES
 326         rtag = res->tclassid;
 327         if (*itag == 0)
 328                 *itag = (rtag<<16);
 329         *itag |= (rtag>>16);
 330 #endif
 331 #endif
 332 }
 333
 334 void free_fib_info(struct fib_info *fi);
 335
 336 static inline void fib_info_put(struct fib_info *fi)
 337 {
 338         if (atomic_dec_and_test(&fi->fib_clntref))
 339                 free_fib_info(fi);
 340 }
 341
 342 #ifdef CONFIG_PROC_FS
 343 int __net_init fib_proc_init(struct net *net);
 344 void __net_exit fib_proc_exit(struct net *net);
 345 #else
 346 static inline int fib_proc_init(struct net *net)
 347 {
 348         return 0;
 349 }
 350 static inline void fib_proc_exit(struct net *net)
 351 {
 352 }
 353 #endif
 354
 355 #endif  /* _NET_FIB_H */