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 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
  24         NF_CT_EXT_TIMEOUT,
  25 #endif
  26 #ifdef CONFIG_NF_CONNTRACK_LABELS
  27         NF_CT_EXT_LABELS,
  28 #endif
  29         NF_CT_EXT_NUM,
  30 };
  31
  32 #define NF_CT_EXT_HELPER_TYPE struct nf_conn_help
  33 #define NF_CT_EXT_NAT_TYPE struct nf_conn_nat
  34 #define NF_CT_EXT_ACCT_TYPE struct nf_conn_counter
  35 #define NF_CT_EXT_ECACHE_TYPE struct nf_conntrack_ecache
  36 #define NF_CT_EXT_ZONE_TYPE struct nf_conntrack_zone
  37 #define NF_CT_EXT_TSTAMP_TYPE struct nf_conn_tstamp
  38 #define NF_CT_EXT_TIMEOUT_TYPE struct nf_conn_timeout
  39 #define NF_CT_EXT_LABELS_TYPE struct nf_conn_labels
  40
  41 /* Extensions: optional stuff which isn't permanently in struct. */
  42 struct nf_ct_ext {
  43         struct rcu_head rcu;
  44         u8 offset[NF_CT_EXT_NUM];
  45         u8 len;
  46         char data[0];
  47 };
  48
  49 static inline bool __nf_ct_ext_exist(const struct nf_ct_ext *ext, u8 id)
  50 {
  51         return !!ext->offset[id];
  52 }
  53
  54 static inline bool nf_ct_ext_exist(const struct nf_conn *ct, u8 id)
  55 {
  56         return (ct->ext && __nf_ct_ext_exist(ct->ext, id));
  57 }
  58
  59 static inline void *__nf_ct_ext_find(const struct nf_conn *ct, u8 id)
  60 {
  61         if (!nf_ct_ext_exist(ct, id))
  62                 return NULL;
  63
  64         return (void *)ct->ext + ct->ext->offset[id];
  65 }
  66 #define nf_ct_ext_find(ext, id) \
  67         ((id##_TYPE *)__nf_ct_ext_find((ext), (id)))
  68
  69 /* Destroy all relationships */
  70 extern void __nf_ct_ext_destroy(struct nf_conn *ct);
  71 static inline void nf_ct_ext_destroy(struct nf_conn *ct)
  72 {
  73         if (ct->ext)
  74                 __nf_ct_ext_destroy(ct);
  75 }
  76
  77 /* Free operation. If you want to free a object referred from private area,
  78  * please implement __nf_ct_ext_free() and call it.
  79  */
  80 static inline void nf_ct_ext_free(struct nf_conn *ct)
  81 {
  82         if (ct->ext)
  83                 kfree(ct->ext);
  84 }
  85
  86 /* Add this type, returns pointer to data or NULL. */
  87 void *__nf_ct_ext_add_length(struct nf_conn *ct, enum nf_ct_ext_id id,
  88                              size_t var_alloc_len, gfp_t gfp);
  89
  90 #define nf_ct_ext_add(ct, id, gfp) \
  91         ((id##_TYPE *)__nf_ct_ext_add_length((ct), (id), 0, (gfp)))
  92 #define nf_ct_ext_add_length(ct, id, len, gfp) \
  93         ((id##_TYPE *)__nf_ct_ext_add_length((ct), (id), (len), (gfp)))
  94
  95 #define NF_CT_EXT_F_PREALLOC    0x0001
  96
  97 struct nf_ct_ext_type {
  98         /* Destroys relationships (can be NULL). */
  99         void (*destroy)(struct nf_conn *ct);
 100         /* Called when realloacted (can be NULL).
 101            Contents has already been moved. */
 102         void (*move)(void *new, void *old);
 103
 104         enum nf_ct_ext_id id;
 105
 106         unsigned int flags;
 107
 108         /* Length and min alignment. */
 109         u8 len;
 110         u8 align;
 111         /* initial size of nf_ct_ext. */
 112         u8 alloc_size;
 113 };
 114
 115 int nf_ct_extend_register(struct nf_ct_ext_type *type);
 116 void nf_ct_extend_unregister(struct nf_ct_ext_type *type);
 117 #endif /* _NF_CONNTRACK_EXTEND_H */