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