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 };
  74
  75 #ifndef CONFIG_IPV6_SUBTREES
  76 #define FIB6_SUBTREE(fn)        NULL
  77 #else
  78 #define FIB6_SUBTREE(fn)        ((fn)->subtree)
  79 #endif
  80
  81 struct mx6_config {
  82         const u32 *mx;
  83         DECLARE_BITMAP(mx_valid, RTAX_MAX);
  84 };
  85
  86 /*
  87  *      routing information
  88  *
  89  */
  90
  91 struct rt6key {
  92         struct in6_addr addr;
  93         int             plen;
  94 };
  95
  96 struct fib6_table;
  97
  98 struct rt6_info {
  99         struct dst_entry                dst;
 100
 101         /*
 102          * Tail elements of dst_entry (__refcnt etc.)
 103          * and these elements (rarely used in hot path) are in
 104          * the same cache line.
 105          */
 106         struct fib6_table               *rt6i_table;
 107         struct fib6_node                *rt6i_node;
 108
 109         struct in6_addr                 rt6i_gateway;
 110
 111         /* Multipath routes:
 112          * siblings is a list of rt6_info that have the the same metric/weight,
 113          * destination, but not the same gateway. nsiblings is just a cache
 114          * to speed up lookup.
 115          */
 116         struct list_head                rt6i_siblings;
 117         unsigned int                    rt6i_nsiblings;
 118
 119         atomic_t                        rt6i_ref;
 120
 121         /* These are in a separate cache line. */
 122         struct rt6key                   rt6i_dst ____cacheline_aligned_in_smp;
 123         u32                             rt6i_flags;
 124         struct rt6key                   rt6i_src;
 125         struct rt6key                   rt6i_prefsrc;
 126
 127         struct list_head                rt6i_uncached;
 128         struct uncached_list            *rt6i_uncached_list;
 129
 130         struct inet6_dev                *rt6i_idev;
 131         struct rt6_info * __percpu      *rt6i_pcpu;
 132
 133         u32                             rt6i_metric;
 134         u32                             rt6i_pmtu;
 135         /* more non-fragment space at head required */
 136         unsigned short                  rt6i_nfheader_len;
 137         u8                              rt6i_protocol;
 138 };
 139
 140 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
 141 {
 142         return ((struct rt6_info *)dst)->rt6i_idev;
 143 }
 144
 145 static inline void rt6_clean_expires(struct rt6_info *rt)
 146 {
 147         rt->rt6i_flags &= ~RTF_EXPIRES;
 148         rt->dst.expires = 0;
 149 }
 150
 151 static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)
 152 {
 153         rt->dst.expires = expires;
 154         rt->rt6i_flags |= RTF_EXPIRES;
 155 }
 156
 157 static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)
 158 {
 159         struct rt6_info *rt;
 160
 161         for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES);
 162              rt = (struct rt6_info *)rt->dst.from);
 163         if (rt && rt != rt0)
 164                 rt0->dst.expires = rt->dst.expires;
 165
 166         dst_set_expires(&rt0->dst, timeout);
 167         rt0->rt6i_flags |= RTF_EXPIRES;
 168 }
 169
 170 static inline u32 rt6_get_cookie(const struct rt6_info *rt)
 171 {
 172         if (rt->rt6i_flags & RTF_PCPU ||
 173             (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->dst.from))
 174                 rt = (struct rt6_info *)(rt->dst.from);
 175
 176         return rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
 177 }
 178
 179 static inline void ip6_rt_put(struct rt6_info *rt)
 180 {
 181         /* dst_release() accepts a NULL parameter.
 182          * We rely on dst being first structure in struct rt6_info
 183          */
 184         BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
 185         dst_release(&rt->dst);
 186 }
 187
 188 enum fib6_walk_state {
 189 #ifdef CONFIG_IPV6_SUBTREES
 190         FWS_S,
 191 #endif
 192         FWS_L,
 193         FWS_R,
 194         FWS_C,
 195         FWS_U
 196 };
 197
 198 struct fib6_walker {
 199         struct list_head lh;
 200         struct fib6_node *root, *node;
 201         struct rt6_info *leaf;
 202         enum fib6_walk_state state;
 203         bool prune;
 204         unsigned int skip;
 205         unsigned int count;
 206         int (*func)(struct fib6_walker *);
 207         void *args;
 208 };
 209
 210 struct rt6_statistics {
 211         __u32           fib_nodes;
 212         __u32           fib_route_nodes;
 213         __u32           fib_rt_alloc;           /* permanent routes     */
 214         __u32           fib_rt_entries;         /* rt entries in table  */
 215         __u32           fib_rt_cache;           /* cache routes         */
 216         __u32           fib_discarded_routes;
 217 };
 218
 219 #define RTN_TL_ROOT     0x0001
 220 #define RTN_ROOT        0x0002          /* tree root node               */
 221 #define RTN_RTINFO      0x0004          /* node with valid routing info */
 222
 223 /*
 224  *      priority levels (or metrics)
 225  *
 226  */
 227
 228
 229 struct fib6_table {
 230         struct hlist_node       tb6_hlist;
 231         u32                     tb6_id;
 232         rwlock_t                tb6_lock;
 233         struct fib6_node        tb6_root;
 234         struct inet_peer_base   tb6_peers;
 235         unsigned int            flags;
 236 #define RT6_TABLE_HAS_DFLT_ROUTER       BIT(0)
 237 };
 238
 239 #define RT6_TABLE_UNSPEC        RT_TABLE_UNSPEC
 240 #define RT6_TABLE_MAIN          RT_TABLE_MAIN
 241 #define RT6_TABLE_DFLT          RT6_TABLE_MAIN
 242 #define RT6_TABLE_INFO          RT6_TABLE_MAIN
 243 #define RT6_TABLE_PREFIX        RT6_TABLE_MAIN
 244
 245 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 246 #define FIB6_TABLE_MIN          1
 247 #define FIB6_TABLE_MAX          RT_TABLE_MAX
 248 #define RT6_TABLE_LOCAL         RT_TABLE_LOCAL
 249 #else
 250 #define FIB6_TABLE_MIN          RT_TABLE_MAIN
 251 #define FIB6_TABLE_MAX          FIB6_TABLE_MIN
 252 #define RT6_TABLE_LOCAL         RT6_TABLE_MAIN
 253 #endif
 254
 255 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
 256                                          struct fib6_table *,
 257                                          struct flowi6 *, int);
 258
 259 /*
 260  *      exported functions
 261  */
 262
 263 struct fib6_table *fib6_get_table(struct net *net, u32 id);
 264 struct fib6_table *fib6_new_table(struct net *net, u32 id);
 265 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
 266                                    int flags, pol_lookup_t lookup);
 267
 268 struct fib6_node *fib6_lookup(struct fib6_node *root,
 269                               const struct in6_addr *daddr,
 270                               const struct in6_addr *saddr);
 271
 272 struct fib6_node *fib6_locate(struct fib6_node *root,
 273                               const struct in6_addr *daddr, int dst_len,
 274                               const struct in6_addr *saddr, int src_len);
 275
 276 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
 277                     void *arg);
 278
 279 int fib6_add(struct fib6_node *root, struct rt6_info *rt,
 280              struct nl_info *info, struct mx6_config *mxc,
 281              struct netlink_ext_ack *extack);
 282 int fib6_del(struct rt6_info *rt, struct nl_info *info);
 283
 284 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info,
 285                      unsigned int flags);
 286
 287 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
 288
 289 void fib6_gc_cleanup(void);
 290
 291 int fib6_init(void);
 292
 293 int ipv6_route_open(struct inode *inode, struct file *file);
 294
 295 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 296 int fib6_rules_init(void);
 297 void fib6_rules_cleanup(void);
 298 #else
 299 static inline int               fib6_rules_init(void)
 300 {
 301         return 0;
 302 }
 303 static inline void              fib6_rules_cleanup(void)
 304 {
 305         return ;
 306 }
 307 #endif
 308 #endif