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