include/net/netfilter/nf_conntrack_extend.h

   1 #ifndef _NF_CONNTRACK_EXTEND_H
   2 #define _NF_CONNTRACK_EXTEND_H
   3
   4 #include <net/netfilter/nf_conntrack.h>
   5
   6 enum nf_ct_ext_id
   7 {
   8         NF_CT_EXT_HELPER,
   9         NF_CT_EXT_NAT,
  10         NF_CT_EXT_ACCT,
  11         NF_CT_EXT_ECACHE,
  12         NF_CT_EXT_NUM,
  13 };
  14
  15 #define NF_CT_EXT_HELPER_TYPE struct nf_conn_help
  16 #define NF_CT_EXT_NAT_TYPE struct nf_conn_nat
  17 #define NF_CT_EXT_ACCT_TYPE struct nf_conn_counter
  18 #define NF_CT_EXT_ECACHE_TYPE struct nf_conntrack_ecache
  19
  20 /* Extensions: optional stuff which isn't permanently in struct. */
  21 struct nf_ct_ext {
  22         struct rcu_head rcu;
  23         u8 offset[NF_CT_EXT_NUM];
  24         u8 len;
  25         char data[0];
  26 };
  27
  28 static inline int nf_ct_ext_exist(const struct nf_conn *ct, u8 id)
  29 {
  30         return (ct->ext && ct->ext->offset[id]);
  31 }
  32
  33 static inline void *__nf_ct_ext_find(const struct nf_conn *ct, u8 id)
  34 {
  35         if (!nf_ct_ext_exist(ct, id))
  36                 return NULL;
  37
  38         return (void *)ct->ext + ct->ext->offset[id];
  39 }
  40 #define nf_ct_ext_find(ext, id) \
  41         ((id##_TYPE *)__nf_ct_ext_find((ext), (id)))
  42
  43 /* Destroy all relationships */
  44 extern void __nf_ct_ext_destroy(struct nf_conn *ct);
  45 static inline void nf_ct_ext_destroy(struct nf_conn *ct)
  46 {
  47         if (ct->ext)
  48                 __nf_ct_ext_destroy(ct);
  49 }
  50
  51 /* Free operation. If you want to free a object referred from private area,
  52  * please implement __nf_ct_ext_free() and call it.
  53  */
  54 static inline void nf_ct_ext_free(struct nf_conn *ct)
  55 {
  56         if (ct->ext)
  57                 kfree(ct->ext);
  58 }
  59
  60 /* Add this type, returns pointer to data or NULL. */
  61 void *
  62 __nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp);
  63 #define nf_ct_ext_add(ct, id, gfp) \
  64         ((id##_TYPE *)__nf_ct_ext_add((ct), (id), (gfp)))
  65
  66 #define NF_CT_EXT_F_PREALLOC    0x0001
  67
  68 struct nf_ct_ext_type
  69 {
  70         /* Destroys relationships (can be NULL). */
  71         void (*destroy)(struct nf_conn *ct);
  72         /* Called when realloacted (can be NULL).
  73            Contents has already been moved. */
  74         void (*move)(void *new, void *old);
  75
  76         enum nf_ct_ext_id id;
  77
  78         unsigned int flags;
  79
  80         /* Length and min alignment. */
  81         u8 len;
  82         u8 align;
  83         /* initial size of nf_ct_ext. */
  84         u8 alloc_size;
  85 };
  86
  87 int nf_ct_extend_register(struct nf_ct_ext_type *type);
  88 void nf_ct_extend_unregister(struct nf_ct_ext_type *type);
  89 #endif /* _NF_CONNTRACK_EXTEND_H */