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_notifier.h>
  23 #include <net/fib_rules.h>
  24 #include <net/inetpeer.h>
  25 #include <linux/percpu.h>
  26 #include <linux/notifier.h>
  27 #include <linux/refcount.h>
  28
  29 struct fib_config {
  30         u8                      fc_dst_len;
  31         u8                      fc_tos;
  32         u8                      fc_protocol;
  33         u8                      fc_scope;
  34         u8                      fc_type;
  35         /* 3 bytes unused */
  36         u32                     fc_table;
  37         __be32                  fc_dst;
  38         __be32                  fc_gw;
  39         int                     fc_oif;
  40         u32                     fc_flags;
  41         u32                     fc_priority;
  42         __be32                  fc_prefsrc;
  43         struct nlattr           *fc_mx;
  44         struct rtnexthop        *fc_mp;
  45         int                     fc_mx_len;
  46         int                     fc_mp_len;
  47         u32                     fc_flow;
  48         u32                     fc_nlflags;
  49         struct nl_info          fc_nlinfo;
  50         struct nlattr           *fc_encap;
  51         u16                     fc_encap_type;
  52 };
  53
  54 struct fib_info;
  55 struct rtable;
  56
  57 struct fib_nh_exception {
  58         struct fib_nh_exception __rcu   *fnhe_next;
  59         int                             fnhe_genid;
  60         __be32                          fnhe_daddr;
  61         u32                             fnhe_pmtu;
  62         bool                            fnhe_mtu_locked;
  63         __be32                          fnhe_gw;
  64         unsigned long                   fnhe_expires;
  65         struct rtable __rcu             *fnhe_rth_input;
  66         struct rtable __rcu             *fnhe_rth_output;
  67         unsigned long                   fnhe_stamp;
  68         struct rcu_head                 rcu;
  69 };
  70
  71 struct fnhe_hash_bucket {
  72         struct fib_nh_exception __rcu   *chain;
  73 };
  74
  75 #define FNHE_HASH_SHIFT         11
  76 #define FNHE_HASH_SIZE          (1 << FNHE_HASH_SHIFT)
  77 #define FNHE_RECLAIM_DEPTH      5
  78
  79 struct fib_nh {
  80         struct net_device       *nh_dev;
  81         struct hlist_node       nh_hash;
  82         struct fib_info         *nh_parent;
  83         unsigned int            nh_flags;
  84         unsigned char           nh_scope;
  85 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  86         int                     nh_weight;
  87         atomic_t                nh_upper_bound;
  88 #endif
  89 #ifdef CONFIG_IP_ROUTE_CLASSID
  90         __u32                   nh_tclassid;
  91 #endif
  92         int                     nh_oif;
  93         __be32                  nh_gw;
  94         __be32                  nh_saddr;
  95         int                     nh_saddr_genid;
  96         struct rtable __rcu * __percpu *nh_pcpu_rth_output;
  97         struct rtable __rcu     *nh_rth_input;
  98         struct fnhe_hash_bucket __rcu *nh_exceptions;
  99         struct lwtunnel_state   *nh_lwtstate;
 100 };
 101
 102 /*
 103  * This structure contains data shared by many of routes.
 104  */
 105
 106 struct fib_info {
 107         struct hlist_node       fib_hash;
 108         struct hlist_node       fib_lhash;
 109         struct net              *fib_net;
 110         int                     fib_treeref;
 111         refcount_t              fib_clntref;
 112         unsigned int            fib_flags;
 113         unsigned char           fib_dead;
 114         unsigned char           fib_protocol;
 115         unsigned char           fib_scope;
 116         unsigned char           fib_type;
 117         __be32                  fib_prefsrc;
 118         u32                     fib_tb_id;
 119         u32                     fib_priority;
 120         struct dst_metrics      *fib_metrics;
 121 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1]
 122 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1]
 123 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1]
 124 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1]
 125         int                     fib_nhs;
 126 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 127         int                     fib_weight;
 128 #endif
 129         struct rcu_head         rcu;
 130         struct fib_nh           fib_nh[0];
 131 #define fib_dev         fib_nh[0].nh_dev
 132 };
 133
 134
 135 #ifdef CONFIG_IP_MULTIPLE_TABLES
 136 struct fib_rule;
 137 #endif
 138
 139 struct fib_table;
 140 struct fib_result {
 141         __be32          prefix;
 142         unsigned char   prefixlen;
 143         unsigned char   nh_sel;
 144         unsigned char   type;
 145         unsigned char   scope;
 146         u32             tclassid;
 147         struct fib_info *fi;
 148         struct fib_table *table;
 149         struct hlist_head *fa_head;
 150 };
 151
 152 struct fib_result_nl {
 153         __be32          fl_addr;   /* To be looked up*/
 154         u32             fl_mark;
 155         unsigned char   fl_tos;
 156         unsigned char   fl_scope;
 157         unsigned char   tb_id_in;
 158
 159         unsigned char   tb_id;      /* Results */
 160         unsigned char   prefixlen;
 161         unsigned char   nh_sel;
 162         unsigned char   type;
 163         unsigned char   scope;
 164         int             err;
 165 };
 166
 167 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 168 #define FIB_RES_NH(res)         ((res).fi->fib_nh[(res).nh_sel])
 169 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 170 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 171 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 172
 173 #ifdef CONFIG_IP_MULTIPLE_TABLES
 174 #define FIB_TABLE_HASHSZ 256
 175 #else
 176 #define FIB_TABLE_HASHSZ 2
 177 #endif
 178
 179 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
 180
 181 #define FIB_RES_SADDR(net, res)                         \
 182         ((FIB_RES_NH(res).nh_saddr_genid ==             \
 183           atomic_read(&(net)->ipv4.dev_addr_genid)) ?   \
 184          FIB_RES_NH(res).nh_saddr :                     \
 185          fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
 186 #define FIB_RES_GW(res)                 (FIB_RES_NH(res).nh_gw)
 187 #define FIB_RES_DEV(res)                (FIB_RES_NH(res).nh_dev)
 188 #define FIB_RES_OIF(res)                (FIB_RES_NH(res).nh_oif)
 189
 190 #define FIB_RES_PREFSRC(net, res)       ((res).fi->fib_prefsrc ? : \
 191                                          FIB_RES_SADDR(net, res))
 192
 193 struct fib_entry_notifier_info {
 194         struct fib_notifier_info info; /* must be first */
 195         u32 dst;
 196         int dst_len;
 197         struct fib_info *fi;
 198         u8 tos;
 199         u8 type;
 200         u32 tb_id;
 201 };
 202
 203 struct fib_nh_notifier_info {
 204         struct fib_notifier_info info; /* must be first */
 205         struct fib_nh *fib_nh;
 206 };
 207
 208 int call_fib4_notifier(struct notifier_block *nb, struct net *net,
 209                        enum fib_event_type event_type,
 210                        struct fib_notifier_info *info);
 211 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
 212                         struct fib_notifier_info *info);
 213
 214 int __net_init fib4_notifier_init(struct net *net);
 215 void __net_exit fib4_notifier_exit(struct net *net);
 216
 217 void fib_notify(struct net *net, struct notifier_block *nb);
 218
 219 struct fib_table {
 220         struct hlist_node       tb_hlist;
 221         u32                     tb_id;
 222         int                     tb_num_default;
 223         struct rcu_head         rcu;
 224         unsigned long           *tb_data;
 225         unsigned long           __data[0];
 226 };
 227
 228 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 229                      struct fib_result *res, int fib_flags);
 230 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
 231                      struct netlink_ext_ack *extack);
 232 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
 233                      struct netlink_ext_ack *extack);
 234 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
 235                    struct netlink_callback *cb);
 236 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all);
 237 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
 238 void fib_table_flush_external(struct fib_table *table);
 239 void fib_free_table(struct fib_table *tb);
 240
 241 #ifndef CONFIG_IP_MULTIPLE_TABLES
 242
 243 #define TABLE_LOCAL_INDEX       (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
 244 #define TABLE_MAIN_INDEX        (RT_TABLE_MAIN  & (FIB_TABLE_HASHSZ - 1))
 245
 246 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
 247 {
 248         struct hlist_node *tb_hlist;
 249         struct hlist_head *ptr;
 250
 251         ptr = id == RT_TABLE_LOCAL ?
 252                 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
 253                 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
 254
 255         tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
 256
 257         return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
 258 }
 259
 260 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
 261 {
 262         return fib_get_table(net, id);
 263 }
 264
 265 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
 266                              struct fib_result *res, unsigned int flags)
 267 {
 268         struct fib_table *tb;
 269         int err = -ENETUNREACH;
 270
 271         rcu_read_lock();
 272
 273         tb = fib_get_table(net, RT_TABLE_MAIN);
 274         if (tb)
 275                 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
 276
 277         if (err == -EAGAIN)
 278                 err = -ENETUNREACH;
 279
 280         rcu_read_unlock();
 281
 282         return err;
 283 }
 284
 285 static inline bool fib4_rule_default(const struct fib_rule *rule)
 286 {
 287         return true;
 288 }
 289
 290 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb)
 291 {
 292         return 0;
 293 }
 294
 295 static inline unsigned int fib4_rules_seq_read(struct net *net)
 296 {
 297         return 0;
 298 }
 299
 300 #else /* CONFIG_IP_MULTIPLE_TABLES */
 301 int __net_init fib4_rules_init(struct net *net);
 302 void __net_exit fib4_rules_exit(struct net *net);
 303
 304 struct fib_table *fib_new_table(struct net *net, u32 id);
 305 struct fib_table *fib_get_table(struct net *net, u32 id);
 306
 307 int __fib_lookup(struct net *net, struct flowi4 *flp,
 308                  struct fib_result *res, unsigned int flags);
 309
 310 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
 311                              struct fib_result *res, unsigned int flags)
 312 {
 313         struct fib_table *tb;
 314         int err = -ENETUNREACH;
 315
 316         flags |= FIB_LOOKUP_NOREF;
 317         if (net->ipv4.fib_has_custom_rules)
 318                 return __fib_lookup(net, flp, res, flags);
 319
 320         rcu_read_lock();
 321
 322         res->tclassid = 0;
 323
 324         tb = rcu_dereference_rtnl(net->ipv4.fib_main);
 325         if (tb)
 326                 err = fib_table_lookup(tb, flp, res, flags);
 327
 328         if (!err)
 329                 goto out;
 330
 331         tb = rcu_dereference_rtnl(net->ipv4.fib_default);
 332         if (tb)
 333                 err = fib_table_lookup(tb, flp, res, flags);
 334
 335 out:
 336         if (err == -EAGAIN)
 337                 err = -ENETUNREACH;
 338
 339         rcu_read_unlock();
 340
 341         return err;
 342 }
 343
 344 bool fib4_rule_default(const struct fib_rule *rule);
 345 int fib4_rules_dump(struct net *net, struct notifier_block *nb);
 346 unsigned int fib4_rules_seq_read(struct net *net);
 347
 348 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 349
 350 /* Exported by fib_frontend.c */
 351 extern const struct nla_policy rtm_ipv4_policy[];
 352 void ip_fib_init(void);
 353 __be32 fib_compute_spec_dst(struct sk_buff *skb);
 354 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 355                         u8 tos, int oif, struct net_device *dev,
 356                         struct in_device *idev, u32 *itag);
 357 #ifdef CONFIG_IP_ROUTE_CLASSID
 358 static inline int fib_num_tclassid_users(struct net *net)
 359 {
 360         return net->ipv4.fib_num_tclassid_users;
 361 }
 362 #else
 363 static inline int fib_num_tclassid_users(struct net *net)
 364 {
 365         return 0;
 366 }
 367 #endif
 368 int fib_unmerge(struct net *net);
 369
 370 /* Exported by fib_semantics.c */
 371 int ip_fib_check_default(__be32 gw, struct net_device *dev);
 372 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
 373 int fib_sync_down_addr(struct net_device *dev, __be32 local);
 374 int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
 375 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
 376
 377 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 378 int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4,
 379                        const struct sk_buff *skb);
 380 #endif
 381 void fib_select_multipath(struct fib_result *res, int hash);
 382 void fib_select_path(struct net *net, struct fib_result *res,
 383                      struct flowi4 *fl4, const struct sk_buff *skb);
 384
 385 /* Exported by fib_trie.c */
 386 void fib_trie_init(void);
 387 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
 388
 389 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
 390 {
 391 #ifdef CONFIG_IP_ROUTE_CLASSID
 392 #ifdef CONFIG_IP_MULTIPLE_TABLES
 393         u32 rtag;
 394 #endif
 395         *itag = FIB_RES_NH(*res).nh_tclassid<<16;
 396 #ifdef CONFIG_IP_MULTIPLE_TABLES
 397         rtag = res->tclassid;
 398         if (*itag == 0)
 399                 *itag = (rtag<<16);
 400         *itag |= (rtag>>16);
 401 #endif
 402 #endif
 403 }
 404
 405 void free_fib_info(struct fib_info *fi);
 406
 407 static inline void fib_info_hold(struct fib_info *fi)
 408 {
 409         refcount_inc(&fi->fib_clntref);
 410 }
 411
 412 static inline void fib_info_put(struct fib_info *fi)
 413 {
 414         if (refcount_dec_and_test(&fi->fib_clntref))
 415                 free_fib_info(fi);
 416 }
 417
 418 #ifdef CONFIG_PROC_FS
 419 int __net_init fib_proc_init(struct net *net);
 420 void __net_exit fib_proc_exit(struct net *net);
 421 #else
 422 static inline int fib_proc_init(struct net *net)
 423 {
 424         return 0;
 425 }
 426 static inline void fib_proc_exit(struct net *net)
 427 {
 428 }
 429 #endif
 430
 431 #endif  /* _NET_FIB_H */