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