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 #include <linux/refcount.h>
  27
  28 struct fib_config {
  29         u8                      fc_dst_len;
  30         u8                      fc_tos;
  31         u8                      fc_protocol;
  32         u8                      fc_scope;
  33         u8                      fc_type;
  34         /* 3 bytes unused */
  35         u32                     fc_table;
  36         __be32                  fc_dst;
  37         __be32                  fc_gw;
  38         int                     fc_oif;
  39         u32                     fc_flags;
  40         u32                     fc_priority;
  41         __be32                  fc_prefsrc;
  42         struct nlattr           *fc_mx;
  43         struct rtnexthop        *fc_mp;
  44         int                     fc_mx_len;
  45         int                     fc_mp_len;
  46         u32                     fc_flow;
  47         u32                     fc_nlflags;
  48         struct nl_info          fc_nlinfo;
  49         struct nlattr           *fc_encap;
  50         u16                     fc_encap_type;
  51 };
  52
  53 struct fib_info;
  54 struct rtable;
  55
  56 struct fib_nh_exception {
  57         struct fib_nh_exception __rcu   *fnhe_next;
  58         int                             fnhe_genid;
  59         __be32                          fnhe_daddr;
  60         u32                             fnhe_pmtu;
  61         __be32                          fnhe_gw;
  62         unsigned long                   fnhe_expires;
  63         struct rtable __rcu             *fnhe_rth_input;
  64         struct rtable __rcu             *fnhe_rth_output;
  65         unsigned long                   fnhe_stamp;
  66         struct rcu_head                 rcu;
  67 };
  68
  69 struct fnhe_hash_bucket {
  70         struct fib_nh_exception __rcu   *chain;
  71 };
  72
  73 #define FNHE_HASH_SHIFT         11
  74 #define FNHE_HASH_SIZE          (1 << FNHE_HASH_SHIFT)
  75 #define FNHE_RECLAIM_DEPTH      5
  76
  77 struct fib_nh {
  78         struct net_device       *nh_dev;
  79         struct hlist_node       nh_hash;
  80         struct fib_info         *nh_parent;
  81         unsigned int            nh_flags;
  82         unsigned char           nh_scope;
  83 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  84         int                     nh_weight;
  85         atomic_t                nh_upper_bound;
  86 #endif
  87 #ifdef CONFIG_IP_ROUTE_CLASSID
  88         __u32                   nh_tclassid;
  89 #endif
  90         int                     nh_oif;
  91         __be32                  nh_gw;
  92         __be32                  nh_saddr;
  93         int                     nh_saddr_genid;
  94         struct rtable __rcu * __percpu *nh_pcpu_rth_output;
  95         struct rtable __rcu     *nh_rth_input;
  96         struct fnhe_hash_bucket __rcu *nh_exceptions;
  97         struct lwtunnel_state   *nh_lwtstate;
  98 };
  99
 100 /*
 101  * This structure contains data shared by many of routes.
 102  */
 103
 104 struct fib_info {
 105         struct hlist_node       fib_hash;
 106         struct hlist_node       fib_lhash;
 107         struct net              *fib_net;
 108         int                     fib_treeref;
 109         refcount_t              fib_clntref;
 110         unsigned int            fib_flags;
 111         unsigned char           fib_dead;
 112         unsigned char           fib_protocol;
 113         unsigned char           fib_scope;
 114         unsigned char           fib_type;
 115         __be32                  fib_prefsrc;
 116         u32                     fib_tb_id;
 117         u32                     fib_priority;
 118         struct dst_metrics      *fib_metrics;
 119 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1]
 120 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1]
 121 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1]
 122 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1]
 123         int                     fib_nhs;
 124 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 125         int                     fib_weight;
 126 #endif
 127         unsigned int            fib_offload_cnt;
 128         struct rcu_head         rcu;
 129         struct fib_nh           fib_nh[0];
 130 #define fib_dev         fib_nh[0].nh_dev
 131 };
 132
 133
 134 #ifdef CONFIG_IP_MULTIPLE_TABLES
 135 struct fib_rule;
 136 #endif
 137
 138 struct fib_table;
 139 struct fib_result {
 140         __be32          prefix;
 141         unsigned char   prefixlen;
 142         unsigned char   nh_sel;
 143         unsigned char   type;
 144         unsigned char   scope;
 145         u32             tclassid;
 146         struct fib_info *fi;
 147         struct fib_table *table;
 148         struct hlist_head *fa_head;
 149 };
 150
 151 struct fib_result_nl {
 152         __be32          fl_addr;   /* To be looked up*/
 153         u32             fl_mark;
 154         unsigned char   fl_tos;
 155         unsigned char   fl_scope;
 156         unsigned char   tb_id_in;
 157
 158         unsigned char   tb_id;      /* Results */
 159         unsigned char   prefixlen;
 160         unsigned char   nh_sel;
 161         unsigned char   type;
 162         unsigned char   scope;
 163         int             err;
 164 };
 165
 166 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 167 #define FIB_RES_NH(res)         ((res).fi->fib_nh[(res).nh_sel])
 168 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 169 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 170 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 171
 172 #ifdef CONFIG_IP_MULTIPLE_TABLES
 173 #define FIB_TABLE_HASHSZ 256
 174 #else
 175 #define FIB_TABLE_HASHSZ 2
 176 #endif
 177
 178 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
 179
 180 static inline void fib_info_offload_inc(struct fib_info *fi)
 181 {
 182         fi->fib_offload_cnt++;
 183         fi->fib_flags |= RTNH_F_OFFLOAD;
 184 }
 185
 186 static inline void fib_info_offload_dec(struct fib_info *fi)
 187 {
 188         if (--fi->fib_offload_cnt == 0)
 189                 fi->fib_flags &= ~RTNH_F_OFFLOAD;
 190 }
 191
 192 #define FIB_RES_SADDR(net, res)                         \
 193         ((FIB_RES_NH(res).nh_saddr_genid ==             \
 194           atomic_read(&(net)->ipv4.dev_addr_genid)) ?   \
 195          FIB_RES_NH(res).nh_saddr :                     \
 196          fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
 197 #define FIB_RES_GW(res)                 (FIB_RES_NH(res).nh_gw)
 198 #define FIB_RES_DEV(res)                (FIB_RES_NH(res).nh_dev)
 199 #define FIB_RES_OIF(res)                (FIB_RES_NH(res).nh_oif)
 200
 201 #define FIB_RES_PREFSRC(net, res)       ((res).fi->fib_prefsrc ? : \
 202                                          FIB_RES_SADDR(net, res))
 203
 204 struct fib_notifier_info {
 205         struct net *net;
 206 };
 207
 208 struct fib_entry_notifier_info {
 209         struct fib_notifier_info info; /* must be first */
 210         u32 dst;
 211         int dst_len;
 212         struct fib_info *fi;
 213         u8 tos;
 214         u8 type;
 215         u32 tb_id;
 216 };
 217
 218 struct fib_rule_notifier_info {
 219         struct fib_notifier_info info; /* must be first */
 220         struct fib_rule *rule;
 221 };
 222
 223 struct fib_nh_notifier_info {
 224         struct fib_notifier_info info; /* must be first */
 225         struct fib_nh *fib_nh;
 226 };
 227
 228 enum fib_event_type {
 229         FIB_EVENT_ENTRY_REPLACE,
 230         FIB_EVENT_ENTRY_APPEND,
 231         FIB_EVENT_ENTRY_ADD,
 232         FIB_EVENT_ENTRY_DEL,
 233         FIB_EVENT_RULE_ADD,
 234         FIB_EVENT_RULE_DEL,
 235         FIB_EVENT_NH_ADD,
 236         FIB_EVENT_NH_DEL,
 237 };
 238
 239 int register_fib_notifier(struct notifier_block *nb,
 240                           void (*cb)(struct notifier_block *nb));
 241 int unregister_fib_notifier(struct notifier_block *nb);
 242 int call_fib_notifier(struct notifier_block *nb, struct net *net,
 243                       enum fib_event_type event_type,
 244                       struct fib_notifier_info *info);
 245 int call_fib_notifiers(struct net *net, enum fib_event_type event_type,
 246                        struct fib_notifier_info *info);
 247
 248 void fib_notify(struct net *net, struct notifier_block *nb);
 249 #ifdef CONFIG_IP_MULTIPLE_TABLES
 250 void fib_rules_notify(struct net *net, struct notifier_block *nb);
 251 #else
 252 static inline void fib_rules_notify(struct net *net, struct notifier_block *nb)
 253 {
 254 }
 255 #endif
 256
 257 struct fib_table {
 258         struct hlist_node       tb_hlist;
 259         u32                     tb_id;
 260         int                     tb_num_default;
 261         struct rcu_head         rcu;
 262         unsigned long           *tb_data;
 263         unsigned long           __data[0];
 264 };
 265
 266 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 267                      struct fib_result *res, int fib_flags);
 268 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
 269                      struct netlink_ext_ack *extack);
 270 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
 271                      struct netlink_ext_ack *extack);
 272 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
 273                    struct netlink_callback *cb);
 274 int fib_table_flush(struct net *net, struct fib_table *table);
 275 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
 276 void fib_table_flush_external(struct fib_table *table);
 277 void fib_free_table(struct fib_table *tb);
 278
 279 #ifndef CONFIG_IP_MULTIPLE_TABLES
 280
 281 #define TABLE_LOCAL_INDEX       (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
 282 #define TABLE_MAIN_INDEX        (RT_TABLE_MAIN  & (FIB_TABLE_HASHSZ - 1))
 283
 284 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
 285 {
 286         struct hlist_node *tb_hlist;
 287         struct hlist_head *ptr;
 288
 289         ptr = id == RT_TABLE_LOCAL ?
 290                 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
 291                 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
 292
 293         tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
 294
 295         return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
 296 }
 297
 298 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
 299 {
 300         return fib_get_table(net, id);
 301 }
 302
 303 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
 304                              struct fib_result *res, unsigned int flags)
 305 {
 306         struct fib_table *tb;
 307         int err = -ENETUNREACH;
 308
 309         rcu_read_lock();
 310
 311         tb = fib_get_table(net, RT_TABLE_MAIN);
 312         if (tb)
 313                 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
 314
 315         if (err == -EAGAIN)
 316                 err = -ENETUNREACH;
 317
 318         rcu_read_unlock();
 319
 320         return err;
 321 }
 322
 323 static inline bool fib4_rule_default(const struct fib_rule *rule)
 324 {
 325         return true;
 326 }
 327
 328 #else /* CONFIG_IP_MULTIPLE_TABLES */
 329 int __net_init fib4_rules_init(struct net *net);
 330 void __net_exit fib4_rules_exit(struct net *net);
 331
 332 struct fib_table *fib_new_table(struct net *net, u32 id);
 333 struct fib_table *fib_get_table(struct net *net, u32 id);
 334
 335 int __fib_lookup(struct net *net, struct flowi4 *flp,
 336                  struct fib_result *res, unsigned int flags);
 337
 338 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
 339                              struct fib_result *res, unsigned int flags)
 340 {
 341         struct fib_table *tb;
 342         int err = -ENETUNREACH;
 343
 344         flags |= FIB_LOOKUP_NOREF;
 345         if (net->ipv4.fib_has_custom_rules)
 346                 return __fib_lookup(net, flp, res, flags);
 347
 348         rcu_read_lock();
 349
 350         res->tclassid = 0;
 351
 352         tb = rcu_dereference_rtnl(net->ipv4.fib_main);
 353         if (tb)
 354                 err = fib_table_lookup(tb, flp, res, flags);
 355
 356         if (!err)
 357                 goto out;
 358
 359         tb = rcu_dereference_rtnl(net->ipv4.fib_default);
 360         if (tb)
 361                 err = fib_table_lookup(tb, flp, res, flags);
 362
 363 out:
 364         if (err == -EAGAIN)
 365                 err = -ENETUNREACH;
 366
 367         rcu_read_unlock();
 368
 369         return err;
 370 }
 371
 372 bool fib4_rule_default(const struct fib_rule *rule);
 373
 374 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 375
 376 /* Exported by fib_frontend.c */
 377 extern const struct nla_policy rtm_ipv4_policy[];
 378 void ip_fib_init(void);
 379 __be32 fib_compute_spec_dst(struct sk_buff *skb);
 380 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 381                         u8 tos, int oif, struct net_device *dev,
 382                         struct in_device *idev, u32 *itag);
 383 #ifdef CONFIG_IP_ROUTE_CLASSID
 384 static inline int fib_num_tclassid_users(struct net *net)
 385 {
 386         return net->ipv4.fib_num_tclassid_users;
 387 }
 388 #else
 389 static inline int fib_num_tclassid_users(struct net *net)
 390 {
 391         return 0;
 392 }
 393 #endif
 394 int fib_unmerge(struct net *net);
 395
 396 /* Exported by fib_semantics.c */
 397 int ip_fib_check_default(__be32 gw, struct net_device *dev);
 398 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
 399 int fib_sync_down_addr(struct net_device *dev, __be32 local);
 400 int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
 401
 402 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 403 int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4,
 404                        const struct sk_buff *skb);
 405 #endif
 406 void fib_select_multipath(struct fib_result *res, int hash);
 407 void fib_select_path(struct net *net, struct fib_result *res,
 408                      struct flowi4 *fl4, const struct sk_buff *skb);
 409
 410 /* Exported by fib_trie.c */
 411 void fib_trie_init(void);
 412 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
 413
 414 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
 415 {
 416 #ifdef CONFIG_IP_ROUTE_CLASSID
 417 #ifdef CONFIG_IP_MULTIPLE_TABLES
 418         u32 rtag;
 419 #endif
 420         *itag = FIB_RES_NH(*res).nh_tclassid<<16;
 421 #ifdef CONFIG_IP_MULTIPLE_TABLES
 422         rtag = res->tclassid;
 423         if (*itag == 0)
 424                 *itag = (rtag<<16);
 425         *itag |= (rtag>>16);
 426 #endif
 427 #endif
 428 }
 429
 430 void free_fib_info(struct fib_info *fi);
 431
 432 static inline void fib_info_hold(struct fib_info *fi)
 433 {
 434         refcount_inc(&fi->fib_clntref);
 435 }
 436
 437 static inline void fib_info_put(struct fib_info *fi)
 438 {
 439         if (refcount_dec_and_test(&fi->fib_clntref))
 440                 free_fib_info(fi);
 441 }
 442
 443 #ifdef CONFIG_PROC_FS
 444 int __net_init fib_proc_init(struct net *net);
 445 void __net_exit fib_proc_exit(struct net *net);
 446 #else
 447 static inline int fib_proc_init(struct net *net)
 448 {
 449         return 0;
 450 }
 451 static inline void fib_proc_exit(struct net *net)
 452 {
 453 }
 454 #endif
 455
 456 #endif  /* _NET_FIB_H */