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 #include <linux/notifier.h>
  26
  27 struct fib_config {
  28         u8                      fc_dst_len;
  29         u8                      fc_tos;
  30         u8                      fc_protocol;
  31         u8                      fc_scope;
  32         u8                      fc_type;
  33         /* 3 bytes unused */
  34         u32                     fc_table;
  35         __be32                  fc_dst;
  36         __be32                  fc_gw;
  37         int                     fc_oif;
  38         u32                     fc_flags;
  39         u32                     fc_priority;
  40         __be32                  fc_prefsrc;
  41         struct nlattr           *fc_mx;
  42         struct rtnexthop        *fc_mp;
  43         int                     fc_mx_len;
  44         int                     fc_mp_len;
  45         u32                     fc_flow;
  46         u32                     fc_nlflags;
  47         struct nl_info          fc_nlinfo;
  48         struct nlattr           *fc_encap;
  49         u16                     fc_encap_type;
  50 };
  51
  52 struct fib_info;
  53 struct rtable;
  54
  55 struct fib_nh_exception {
  56         struct fib_nh_exception __rcu   *fnhe_next;
  57         int                             fnhe_genid;
  58         __be32                          fnhe_daddr;
  59         u32                             fnhe_pmtu;
  60         __be32                          fnhe_gw;
  61         unsigned long                   fnhe_expires;
  62         struct rtable __rcu             *fnhe_rth_input;
  63         struct rtable __rcu             *fnhe_rth_output;
  64         unsigned long                   fnhe_stamp;
  65         struct rcu_head                 rcu;
  66 };
  67
  68 struct fnhe_hash_bucket {
  69         struct fib_nh_exception __rcu   *chain;
  70 };
  71
  72 #define FNHE_HASH_SHIFT         11
  73 #define FNHE_HASH_SIZE          (1 << FNHE_HASH_SHIFT)
  74 #define FNHE_RECLAIM_DEPTH      5
  75
  76 struct fib_nh {
  77         struct net_device       *nh_dev;
  78         struct hlist_node       nh_hash;
  79         struct fib_info         *nh_parent;
  80         unsigned int            nh_flags;
  81         unsigned char           nh_scope;
  82 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  83         int                     nh_weight;
  84         atomic_t                nh_upper_bound;
  85 #endif
  86 #ifdef CONFIG_IP_ROUTE_CLASSID
  87         __u32                   nh_tclassid;
  88 #endif
  89         int                     nh_oif;
  90         __be32                  nh_gw;
  91         __be32                  nh_saddr;
  92         int                     nh_saddr_genid;
  93         struct rtable __rcu * __percpu *nh_pcpu_rth_output;
  94         struct rtable __rcu     *nh_rth_input;
  95         struct fnhe_hash_bucket __rcu *nh_exceptions;
  96         struct lwtunnel_state   *nh_lwtstate;
  97 };
  98
  99 /*
 100  * This structure contains data shared by many of routes.
 101  */
 102
 103 struct fib_info {
 104         struct hlist_node       fib_hash;
 105         struct hlist_node       fib_lhash;
 106         struct net              *fib_net;
 107         int                     fib_treeref;
 108         atomic_t                fib_clntref;
 109         unsigned int            fib_flags;
 110         unsigned char           fib_dead;
 111         unsigned char           fib_protocol;
 112         unsigned char           fib_scope;
 113         unsigned char           fib_type;
 114         __be32                  fib_prefsrc;
 115         u32                     fib_tb_id;
 116         u32                     fib_priority;
 117         struct dst_metrics      *fib_metrics;
 118 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1]
 119 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1]
 120 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1]
 121 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1]
 122         int                     fib_nhs;
 123 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 124         int                     fib_weight;
 125 #endif
 126         unsigned int            fib_offload_cnt;
 127         struct rcu_head         rcu;
 128         struct fib_nh           fib_nh[0];
 129 #define fib_dev         fib_nh[0].nh_dev
 130 };
 131
 132
 133 #ifdef CONFIG_IP_MULTIPLE_TABLES
 134 struct fib_rule;
 135 #endif
 136
 137 struct fib_table;
 138 struct fib_result {
 139         unsigned char   prefixlen;
 140         unsigned char   nh_sel;
 141         unsigned char   type;
 142         unsigned char   scope;
 143         u32             tclassid;
 144         struct fib_info *fi;
 145         struct fib_table *table;
 146         struct hlist_head *fa_head;
 147 };
 148
 149 struct fib_result_nl {
 150         __be32          fl_addr;   /* To be looked up*/
 151         u32             fl_mark;
 152         unsigned char   fl_tos;
 153         unsigned char   fl_scope;
 154         unsigned char   tb_id_in;
 155
 156         unsigned char   tb_id;      /* Results */
 157         unsigned char   prefixlen;
 158         unsigned char   nh_sel;
 159         unsigned char   type;
 160         unsigned char   scope;
 161         int             err;
 162 };
 163
 164 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 165 #define FIB_RES_NH(res)         ((res).fi->fib_nh[(res).nh_sel])
 166 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 167 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 168 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 169
 170 #ifdef CONFIG_IP_MULTIPLE_TABLES
 171 #define FIB_TABLE_HASHSZ 256
 172 #else
 173 #define FIB_TABLE_HASHSZ 2
 174 #endif
 175
 176 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
 177
 178 static inline void fib_info_offload_inc(struct fib_info *fi)
 179 {
 180         fi->fib_offload_cnt++;
 181         fi->fib_flags |= RTNH_F_OFFLOAD;
 182 }
 183
 184 static inline void fib_info_offload_dec(struct fib_info *fi)
 185 {
 186         if (--fi->fib_offload_cnt == 0)
 187                 fi->fib_flags &= ~RTNH_F_OFFLOAD;
 188 }
 189
 190 #define FIB_RES_SADDR(net, res)                         \
 191         ((FIB_RES_NH(res).nh_saddr_genid ==             \
 192           atomic_read(&(net)->ipv4.dev_addr_genid)) ?   \
 193          FIB_RES_NH(res).nh_saddr :                     \
 194          fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
 195 #define FIB_RES_GW(res)                 (FIB_RES_NH(res).nh_gw)
 196 #define FIB_RES_DEV(res)                (FIB_RES_NH(res).nh_dev)
 197 #define FIB_RES_OIF(res)                (FIB_RES_NH(res).nh_oif)
 198
 199 #define FIB_RES_PREFSRC(net, res)       ((res).fi->fib_prefsrc ? : \
 200                                          FIB_RES_SADDR(net, res))
 201
 202 struct fib_notifier_info {
 203         struct net *net;
 204 };
 205
 206 struct fib_entry_notifier_info {
 207         struct fib_notifier_info info; /* must be first */
 208         u32 dst;
 209         int dst_len;
 210         struct fib_info *fi;
 211         u8 tos;
 212         u8 type;
 213         u32 tb_id;
 214 };
 215
 216 struct fib_nh_notifier_info {
 217         struct fib_notifier_info info; /* must be first */
 218         struct fib_nh *fib_nh;
 219 };
 220
 221 enum fib_event_type {
 222         FIB_EVENT_ENTRY_REPLACE,
 223         FIB_EVENT_ENTRY_APPEND,
 224         FIB_EVENT_ENTRY_ADD,
 225         FIB_EVENT_ENTRY_DEL,
 226         FIB_EVENT_RULE_ADD,
 227         FIB_EVENT_RULE_DEL,
 228         FIB_EVENT_NH_ADD,
 229         FIB_EVENT_NH_DEL,
 230 };
 231
 232 int register_fib_notifier(struct notifier_block *nb,
 233                           void (*cb)(struct notifier_block *nb));
 234 int unregister_fib_notifier(struct notifier_block *nb);
 235 int call_fib_notifiers(struct net *net, enum fib_event_type event_type,
 236                        struct fib_notifier_info *info);
 237
 238 struct fib_table {
 239         struct hlist_node       tb_hlist;
 240         u32                     tb_id;
 241         int                     tb_num_default;
 242         struct rcu_head         rcu;
 243         unsigned long           *tb_data;
 244         unsigned long           __data[0];
 245 };
 246
 247 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 248                      struct fib_result *res, int fib_flags);
 249 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *);
 250 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *);
 251 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
 252                    struct netlink_callback *cb);
 253 int fib_table_flush(struct net *net, struct fib_table *table);
 254 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
 255 void fib_table_flush_external(struct fib_table *table);
 256 void fib_free_table(struct fib_table *tb);
 257
 258 #ifndef CONFIG_IP_MULTIPLE_TABLES
 259
 260 #define TABLE_LOCAL_INDEX       (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
 261 #define TABLE_MAIN_INDEX        (RT_TABLE_MAIN  & (FIB_TABLE_HASHSZ - 1))
 262
 263 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
 264 {
 265         struct hlist_node *tb_hlist;
 266         struct hlist_head *ptr;
 267
 268         ptr = id == RT_TABLE_LOCAL ?
 269                 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
 270                 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
 271
 272         tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
 273
 274         return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
 275 }
 276
 277 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
 278 {
 279         return fib_get_table(net, id);
 280 }
 281
 282 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
 283                              struct fib_result *res, unsigned int flags)
 284 {
 285         struct fib_table *tb;
 286         int err = -ENETUNREACH;
 287
 288         rcu_read_lock();
 289
 290         tb = fib_get_table(net, RT_TABLE_MAIN);
 291         if (tb)
 292                 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
 293
 294         if (err == -EAGAIN)
 295                 err = -ENETUNREACH;
 296
 297         rcu_read_unlock();
 298
 299         return err;
 300 }
 301
 302 #else /* CONFIG_IP_MULTIPLE_TABLES */
 303 int __net_init fib4_rules_init(struct net *net);
 304 void __net_exit fib4_rules_exit(struct net *net);
 305
 306 struct fib_table *fib_new_table(struct net *net, u32 id);
 307 struct fib_table *fib_get_table(struct net *net, u32 id);
 308
 309 int __fib_lookup(struct net *net, struct flowi4 *flp,
 310                  struct fib_result *res, unsigned int flags);
 311
 312 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
 313                              struct fib_result *res, unsigned int flags)
 314 {
 315         struct fib_table *tb;
 316         int err = -ENETUNREACH;
 317
 318         flags |= FIB_LOOKUP_NOREF;
 319         if (net->ipv4.fib_has_custom_rules)
 320                 return __fib_lookup(net, flp, res, flags);
 321
 322         rcu_read_lock();
 323
 324         res->tclassid = 0;
 325
 326         tb = rcu_dereference_rtnl(net->ipv4.fib_main);
 327         if (tb)
 328                 err = fib_table_lookup(tb, flp, res, flags);
 329
 330         if (!err)
 331                 goto out;
 332
 333         tb = rcu_dereference_rtnl(net->ipv4.fib_default);
 334         if (tb)
 335                 err = fib_table_lookup(tb, flp, res, flags);
 336
 337 out:
 338         if (err == -EAGAIN)
 339                 err = -ENETUNREACH;
 340
 341         rcu_read_unlock();
 342
 343         return err;
 344 }
 345
 346 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 347
 348 /* Exported by fib_frontend.c */
 349 extern const struct nla_policy rtm_ipv4_policy[];
 350 void ip_fib_init(void);
 351 __be32 fib_compute_spec_dst(struct sk_buff *skb);
 352 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 353                         u8 tos, int oif, struct net_device *dev,
 354                         struct in_device *idev, u32 *itag);
 355 #ifdef CONFIG_IP_ROUTE_CLASSID
 356 static inline int fib_num_tclassid_users(struct net *net)
 357 {
 358         return net->ipv4.fib_num_tclassid_users;
 359 }
 360 #else
 361 static inline int fib_num_tclassid_users(struct net *net)
 362 {
 363         return 0;
 364 }
 365 #endif
 366 int fib_unmerge(struct net *net);
 367
 368 /* Exported by fib_semantics.c */
 369 int ip_fib_check_default(__be32 gw, struct net_device *dev);
 370 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
 371 int fib_sync_down_addr(struct net_device *dev, __be32 local);
 372 int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
 373
 374 extern u32 fib_multipath_secret __read_mostly;
 375
 376 static inline int fib_multipath_hash(__be32 saddr, __be32 daddr)
 377 {
 378         return jhash_2words((__force u32)saddr, (__force u32)daddr,
 379                             fib_multipath_secret) >> 1;
 380 }
 381
 382 void fib_select_multipath(struct fib_result *res, int hash);
 383 void fib_select_path(struct net *net, struct fib_result *res,
 384                      struct flowi4 *fl4, int mp_hash);
 385
 386 /* Exported by fib_trie.c */
 387 void fib_trie_init(void);
 388 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
 389
 390 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
 391 {
 392 #ifdef CONFIG_IP_ROUTE_CLASSID
 393 #ifdef CONFIG_IP_MULTIPLE_TABLES
 394         u32 rtag;
 395 #endif
 396         *itag = FIB_RES_NH(*res).nh_tclassid<<16;
 397 #ifdef CONFIG_IP_MULTIPLE_TABLES
 398         rtag = res->tclassid;
 399         if (*itag == 0)
 400                 *itag = (rtag<<16);
 401         *itag |= (rtag>>16);
 402 #endif
 403 #endif
 404 }
 405
 406 void free_fib_info(struct fib_info *fi);
 407
 408 static inline void fib_info_hold(struct fib_info *fi)
 409 {
 410         atomic_inc(&fi->fib_clntref);
 411 }
 412
 413 static inline void fib_info_put(struct fib_info *fi)
 414 {
 415         if (atomic_dec_and_test(&fi->fib_clntref))
 416                 free_fib_info(fi);
 417 }
 418
 419 #ifdef CONFIG_PROC_FS
 420 int __net_init fib_proc_init(struct net *net);
 421 void __net_exit fib_proc_exit(struct net *net);
 422 #else
 423 static inline int fib_proc_init(struct net *net)
 424 {
 425         return 0;
 426 }
 427 static inline void fib_proc_exit(struct net *net)
 428 {
 429 }
 430 #endif
 431
 432 #endif  /* _NET_FIB_H */