include/net/ip6_fib.h

   1 /*
   2  *      Linux INET6 implementation
   3  *
   4  *      Authors:
   5  *      Pedro Roque             <roque@di.fc.ul.pt>
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  */
  12
  13 #ifndef _IP6_FIB_H
  14 #define _IP6_FIB_H
  15
  16 #include <linux/ipv6_route.h>
  17 #include <linux/rtnetlink.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/notifier.h>
  20 #include <net/dst.h>
  21 #include <net/flow.h>
  22 #include <net/netlink.h>
  23 #include <net/inetpeer.h>
  24 #include <net/fib_notifier.h>
  25
  26 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
  27 #define FIB6_TABLE_HASHSZ 256
  28 #else
  29 #define FIB6_TABLE_HASHSZ 1
  30 #endif
  31
  32 struct rt6_info;
  33
  34 struct fib6_config {
  35         u32             fc_table;
  36         u32             fc_metric;
  37         int             fc_dst_len;
  38         int             fc_src_len;
  39         int             fc_ifindex;
  40         u32             fc_flags;
  41         u32             fc_protocol;
  42         u16             fc_type;        /* only 8 bits are used */
  43         u16             fc_delete_all_nh : 1,
  44                         __unused : 15;
  45
  46         struct in6_addr fc_dst;
  47         struct in6_addr fc_src;
  48         struct in6_addr fc_prefsrc;
  49         struct in6_addr fc_gateway;
  50
  51         unsigned long   fc_expires;
  52         struct nlattr   *fc_mx;
  53         int             fc_mx_len;
  54         int             fc_mp_len;
  55         struct nlattr   *fc_mp;
  56
  57         struct nl_info  fc_nlinfo;
  58         struct nlattr   *fc_encap;
  59         u16             fc_encap_type;
  60 };
  61
  62 struct fib6_node {
  63         struct fib6_node        *parent;
  64         struct fib6_node        *left;
  65         struct fib6_node        *right;
  66 #ifdef CONFIG_IPV6_SUBTREES
  67         struct fib6_node        *subtree;
  68 #endif
  69         struct rt6_info         *leaf;
  70
  71         __u16                   fn_bit;         /* bit key */
  72         __u16                   fn_flags;
  73         int                     fn_sernum;
  74         struct rt6_info         *rr_ptr;
  75         struct rcu_head         rcu;
  76 };
  77
  78 #ifndef CONFIG_IPV6_SUBTREES
  79 #define FIB6_SUBTREE(fn)        NULL
  80 #else
  81 #define FIB6_SUBTREE(fn)        ((fn)->subtree)
  82 #endif
  83
  84 struct mx6_config {
  85         const u32 *mx;
  86         DECLARE_BITMAP(mx_valid, RTAX_MAX);
  87 };
  88
  89 /*
  90  *      routing information
  91  *
  92  */
  93
  94 struct rt6key {
  95         struct in6_addr addr;
  96         int             plen;
  97 };
  98
  99 struct fib6_table;
 100
 101 struct rt6_info {
 102         struct dst_entry                dst;
 103
 104         /*
 105          * Tail elements of dst_entry (__refcnt etc.)
 106          * and these elements (rarely used in hot path) are in
 107          * the same cache line.
 108          */
 109         struct fib6_table               *rt6i_table;
 110         struct fib6_node __rcu          *rt6i_node;
 111
 112         struct in6_addr                 rt6i_gateway;
 113
 114         /* Multipath routes:
 115          * siblings is a list of rt6_info that have the the same metric/weight,
 116          * destination, but not the same gateway. nsiblings is just a cache
 117          * to speed up lookup.
 118          */
 119         struct list_head                rt6i_siblings;
 120         unsigned int                    rt6i_nsiblings;
 121
 122         atomic_t                        rt6i_ref;
 123
 124         unsigned int                    rt6i_nh_flags;
 125
 126         /* These are in a separate cache line. */
 127         struct rt6key                   rt6i_dst ____cacheline_aligned_in_smp;
 128         u32                             rt6i_flags;
 129         struct rt6key                   rt6i_src;
 130         struct rt6key                   rt6i_prefsrc;
 131
 132         struct list_head                rt6i_uncached;
 133         struct uncached_list            *rt6i_uncached_list;
 134
 135         struct inet6_dev                *rt6i_idev;
 136         struct rt6_info * __percpu      *rt6i_pcpu;
 137
 138         u32                             rt6i_metric;
 139         u32                             rt6i_pmtu;
 140         /* more non-fragment space at head required */
 141         unsigned short                  rt6i_nfheader_len;
 142         u8                              rt6i_protocol;
 143 };
 144
 145 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
 146 {
 147         return ((struct rt6_info *)dst)->rt6i_idev;
 148 }
 149
 150 static inline void rt6_clean_expires(struct rt6_info *rt)
 151 {
 152         rt->rt6i_flags &= ~RTF_EXPIRES;
 153         rt->dst.expires = 0;
 154 }
 155
 156 static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)
 157 {
 158         rt->dst.expires = expires;
 159         rt->rt6i_flags |= RTF_EXPIRES;
 160 }
 161
 162 static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)
 163 {
 164         struct rt6_info *rt;
 165
 166         for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES);
 167              rt = (struct rt6_info *)rt->dst.from);
 168         if (rt && rt != rt0)
 169                 rt0->dst.expires = rt->dst.expires;
 170
 171         dst_set_expires(&rt0->dst, timeout);
 172         rt0->rt6i_flags |= RTF_EXPIRES;
 173 }
 174
 175 /* Function to safely get fn->sernum for passed in rt
 176  * and store result in passed in cookie.
 177  * Return true if we can get cookie safely
 178  * Return false if not
 179  */
 180 static inline bool rt6_get_cookie_safe(const struct rt6_info *rt,
 181                                        u32 *cookie)
 182 {
 183         struct fib6_node *fn;
 184         bool status = false;
 185
 186         rcu_read_lock();
 187         fn = rcu_dereference(rt->rt6i_node);
 188
 189         if (fn) {
 190                 *cookie = fn->fn_sernum;
 191                 status = true;
 192         }
 193
 194         rcu_read_unlock();
 195         return status;
 196 }
 197
 198 static inline u32 rt6_get_cookie(const struct rt6_info *rt)
 199 {
 200         u32 cookie = 0;
 201
 202         if (rt->rt6i_flags & RTF_PCPU ||
 203             (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->dst.from))
 204                 rt = (struct rt6_info *)(rt->dst.from);
 205
 206         rt6_get_cookie_safe(rt, &cookie);
 207
 208         return cookie;
 209 }
 210
 211 static inline void ip6_rt_put(struct rt6_info *rt)
 212 {
 213         /* dst_release() accepts a NULL parameter.
 214          * We rely on dst being first structure in struct rt6_info
 215          */
 216         BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
 217         dst_release(&rt->dst);
 218 }
 219
 220 void rt6_free_pcpu(struct rt6_info *non_pcpu_rt);
 221
 222 static inline void rt6_hold(struct rt6_info *rt)
 223 {
 224         atomic_inc(&rt->rt6i_ref);
 225 }
 226
 227 static inline void rt6_release(struct rt6_info *rt)
 228 {
 229         if (atomic_dec_and_test(&rt->rt6i_ref)) {
 230                 rt6_free_pcpu(rt);
 231                 dst_dev_put(&rt->dst);
 232                 dst_release(&rt->dst);
 233         }
 234 }
 235
 236 enum fib6_walk_state {
 237 #ifdef CONFIG_IPV6_SUBTREES
 238         FWS_S,
 239 #endif
 240         FWS_L,
 241         FWS_R,
 242         FWS_C,
 243         FWS_U
 244 };
 245
 246 struct fib6_walker {
 247         struct list_head lh;
 248         struct fib6_node *root, *node;
 249         struct rt6_info *leaf;
 250         enum fib6_walk_state state;
 251         bool prune;
 252         unsigned int skip;
 253         unsigned int count;
 254         int (*func)(struct fib6_walker *);
 255         void *args;
 256 };
 257
 258 struct rt6_statistics {
 259         __u32           fib_nodes;
 260         __u32           fib_route_nodes;
 261         __u32           fib_rt_alloc;           /* permanent routes     */
 262         __u32           fib_rt_entries;         /* rt entries in table  */
 263         __u32           fib_rt_cache;           /* cache routes         */
 264         __u32           fib_discarded_routes;
 265 };
 266
 267 #define RTN_TL_ROOT     0x0001
 268 #define RTN_ROOT        0x0002          /* tree root node               */
 269 #define RTN_RTINFO      0x0004          /* node with valid routing info */
 270
 271 /*
 272  *      priority levels (or metrics)
 273  *
 274  */
 275
 276
 277 struct fib6_table {
 278         struct hlist_node       tb6_hlist;
 279         u32                     tb6_id;
 280         rwlock_t                tb6_lock;
 281         struct fib6_node        tb6_root;
 282         struct inet_peer_base   tb6_peers;
 283         unsigned int            flags;
 284         unsigned int            fib_seq;
 285 #define RT6_TABLE_HAS_DFLT_ROUTER       BIT(0)
 286 };
 287
 288 #define RT6_TABLE_UNSPEC        RT_TABLE_UNSPEC
 289 #define RT6_TABLE_MAIN          RT_TABLE_MAIN
 290 #define RT6_TABLE_DFLT          RT6_TABLE_MAIN
 291 #define RT6_TABLE_INFO          RT6_TABLE_MAIN
 292 #define RT6_TABLE_PREFIX        RT6_TABLE_MAIN
 293
 294 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 295 #define FIB6_TABLE_MIN          1
 296 #define FIB6_TABLE_MAX          RT_TABLE_MAX
 297 #define RT6_TABLE_LOCAL         RT_TABLE_LOCAL
 298 #else
 299 #define FIB6_TABLE_MIN          RT_TABLE_MAIN
 300 #define FIB6_TABLE_MAX          FIB6_TABLE_MIN
 301 #define RT6_TABLE_LOCAL         RT6_TABLE_MAIN
 302 #endif
 303
 304 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
 305                                          struct fib6_table *,
 306                                          struct flowi6 *, int);
 307
 308 struct fib6_entry_notifier_info {
 309         struct fib_notifier_info info; /* must be first */
 310         struct rt6_info *rt;
 311 };
 312
 313 /*
 314  *      exported functions
 315  */
 316
 317 struct fib6_table *fib6_get_table(struct net *net, u32 id);
 318 struct fib6_table *fib6_new_table(struct net *net, u32 id);
 319 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
 320                                    int flags, pol_lookup_t lookup);
 321
 322 struct fib6_node *fib6_lookup(struct fib6_node *root,
 323                               const struct in6_addr *daddr,
 324                               const struct in6_addr *saddr);
 325
 326 struct fib6_node *fib6_locate(struct fib6_node *root,
 327                               const struct in6_addr *daddr, int dst_len,
 328                               const struct in6_addr *saddr, int src_len);
 329
 330 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
 331                     void *arg);
 332
 333 int fib6_add(struct fib6_node *root, struct rt6_info *rt,
 334              struct nl_info *info, struct mx6_config *mxc,
 335              struct netlink_ext_ack *extack);
 336 int fib6_del(struct rt6_info *rt, struct nl_info *info);
 337
 338 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info,
 339                      unsigned int flags);
 340
 341 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
 342
 343 void fib6_gc_cleanup(void);
 344
 345 int fib6_init(void);
 346
 347 int ipv6_route_open(struct inode *inode, struct file *file);
 348
 349 int call_fib6_notifier(struct notifier_block *nb, struct net *net,
 350                        enum fib_event_type event_type,
 351                        struct fib_notifier_info *info);
 352 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
 353                         struct fib_notifier_info *info);
 354
 355 int __net_init fib6_notifier_init(struct net *net);
 356 void __net_exit fib6_notifier_exit(struct net *net);
 357
 358 unsigned int fib6_tables_seq_read(struct net *net);
 359 int fib6_tables_dump(struct net *net, struct notifier_block *nb);
 360
 361 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 362 int fib6_rules_init(void);
 363 void fib6_rules_cleanup(void);
 364 bool fib6_rule_default(const struct fib_rule *rule);
 365 int fib6_rules_dump(struct net *net, struct notifier_block *nb);
 366 unsigned int fib6_rules_seq_read(struct net *net);
 367 #else
 368 static inline int               fib6_rules_init(void)
 369 {
 370         return 0;
 371 }
 372 static inline void              fib6_rules_cleanup(void)
 373 {
 374         return ;
 375 }
 376 static inline bool fib6_rule_default(const struct fib_rule *rule)
 377 {
 378         return true;
 379 }
 380 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb)
 381 {
 382         return 0;
 383 }
 384 static inline unsigned int fib6_rules_seq_read(struct net *net)
 385 {
 386         return 0;
 387 }
 388 #endif
 389 #endif