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