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