include/net/netfilter/nf_conntrack_extend.h

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