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 #if defined(CONFIG_NF_NAT) || defined(CONFIG_NF_NAT_MODULE)
  11         NF_CT_EXT_NAT,
  12 #endif
  13         NF_CT_EXT_ACCT,
  14 #ifdef CONFIG_NF_CONNTRACK_EVENTS
  15         NF_CT_EXT_ECACHE,
  16 #endif
  17 #ifdef CONFIG_NF_CONNTRACK_ZONES
  18         NF_CT_EXT_ZONE,
  19 #endif
  20 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
  21         NF_CT_EXT_TSTAMP,
  22 #endif
  23         NF_CT_EXT_NUM,
  24 };
  25
  26 #define NF_CT_EXT_HELPER_TYPE struct nf_conn_help
  27 #define NF_CT_EXT_NAT_TYPE struct nf_conn_nat
  28 #define NF_CT_EXT_ACCT_TYPE struct nf_conn_counter
  29 #define NF_CT_EXT_ECACHE_TYPE struct nf_conntrack_ecache
  30 #define NF_CT_EXT_ZONE_TYPE struct nf_conntrack_zone
  31 #define NF_CT_EXT_TSTAMP_TYPE struct nf_conn_tstamp
  32
  33 /* Extensions: optional stuff which isn't permanently in struct. */
  34 struct nf_ct_ext {
  35         struct rcu_head rcu;
  36         u8 offset[NF_CT_EXT_NUM];
  37         u8 len;
  38         char data[0];
  39 };
  40
  41 static inline bool __nf_ct_ext_exist(const struct nf_ct_ext *ext, u8 id)
  42 {
  43         return !!ext->offset[id];
  44 }
  45
  46 static inline bool nf_ct_ext_exist(const struct nf_conn *ct, u8 id)
  47 {
  48         return (ct->ext && __nf_ct_ext_exist(ct->ext, id));
  49 }
  50
  51 static inline void *__nf_ct_ext_find(const struct nf_conn *ct, u8 id)
  52 {
  53         if (!nf_ct_ext_exist(ct, id))
  54                 return NULL;
  55
  56         return (void *)ct->ext + ct->ext->offset[id];
  57 }
  58 #define nf_ct_ext_find(ext, id) \
  59         ((id##_TYPE *)__nf_ct_ext_find((ext), (id)))
  60
  61 /* Destroy all relationships */
  62 extern void __nf_ct_ext_destroy(struct nf_conn *ct);
  63 static inline void nf_ct_ext_destroy(struct nf_conn *ct)
  64 {
  65         if (ct->ext)
  66                 __nf_ct_ext_destroy(ct);
  67 }
  68
  69 /* Free operation. If you want to free a object referred from private area,
  70  * please implement __nf_ct_ext_free() and call it.
  71  */
  72 static inline void nf_ct_ext_free(struct nf_conn *ct)
  73 {
  74         if (ct->ext)
  75                 kfree(ct->ext);
  76 }
  77
  78 /* Add this type, returns pointer to data or NULL. */
  79 void *
  80 __nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp);
  81 #define nf_ct_ext_add(ct, id, gfp) \
  82         ((id##_TYPE *)__nf_ct_ext_add((ct), (id), (gfp)))
  83
  84 #define NF_CT_EXT_F_PREALLOC    0x0001
  85
  86 struct nf_ct_ext_type {
  87         /* Destroys relationships (can be NULL). */
  88         void (*destroy)(struct nf_conn *ct);
  89         /* Called when realloacted (can be NULL).
  90            Contents has already been moved. */
  91         void (*move)(void *new, void *old);
  92
  93         enum nf_ct_ext_id id;
  94
  95         unsigned int flags;
  96
  97         /* Length and min alignment. */
  98         u8 len;
  99         u8 align;
 100         /* initial size of nf_ct_ext. */
 101         u8 alloc_size;
 102 };
 103
 104 int nf_ct_extend_register(struct nf_ct_ext_type *type);
 105 void nf_ct_extend_unregister(struct nf_ct_ext_type *type);
 106 #endif /* _NF_CONNTRACK_EXTEND_H */