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_SEQADJ,
  14         NF_CT_EXT_ACCT,
  15 #ifdef CONFIG_NF_CONNTRACK_EVENTS
  16         NF_CT_EXT_ECACHE,
  17 #endif
  18 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
  19         NF_CT_EXT_TSTAMP,
  20 #endif
  21 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
  22         NF_CT_EXT_TIMEOUT,
  23 #endif
  24 #ifdef CONFIG_NF_CONNTRACK_LABELS
  25         NF_CT_EXT_LABELS,
  26 #endif
  27 #if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
  28         NF_CT_EXT_SYNPROXY,
  29 #endif
  30         NF_CT_EXT_NUM,
  31 };
  32
  33 #define NF_CT_EXT_HELPER_TYPE struct nf_conn_help
  34 #define NF_CT_EXT_NAT_TYPE struct nf_conn_nat
  35 #define NF_CT_EXT_SEQADJ_TYPE struct nf_conn_seqadj
  36 #define NF_CT_EXT_ACCT_TYPE struct nf_conn_acct
  37 #define NF_CT_EXT_ECACHE_TYPE struct nf_conntrack_ecache
  38 #define NF_CT_EXT_TSTAMP_TYPE struct nf_conn_tstamp
  39 #define NF_CT_EXT_TIMEOUT_TYPE struct nf_conn_timeout
  40 #define NF_CT_EXT_LABELS_TYPE struct nf_conn_labels
  41 #define NF_CT_EXT_SYNPROXY_TYPE struct nf_conn_synproxy
  42
  43 /* Extensions: optional stuff which isn't permanently in struct. */
  44 struct nf_ct_ext {
  45         struct rcu_head rcu;
  46         u8 offset[NF_CT_EXT_NUM];
  47         u8 len;
  48         char data[0];
  49 };
  50
  51 static inline bool __nf_ct_ext_exist(const struct nf_ct_ext *ext, u8 id)
  52 {
  53         return !!ext->offset[id];
  54 }
  55
  56 static inline bool nf_ct_ext_exist(const struct nf_conn *ct, u8 id)
  57 {
  58         return (ct->ext && __nf_ct_ext_exist(ct->ext, id));
  59 }
  60
  61 static inline void *__nf_ct_ext_find(const struct nf_conn *ct, u8 id)
  62 {
  63         if (!nf_ct_ext_exist(ct, id))
  64                 return NULL;
  65
  66         return (void *)ct->ext + ct->ext->offset[id];
  67 }
  68 #define nf_ct_ext_find(ext, id) \
  69         ((id##_TYPE *)__nf_ct_ext_find((ext), (id)))
  70
  71 /* Destroy all relationships */
  72 void __nf_ct_ext_destroy(struct nf_conn *ct);
  73 static inline void nf_ct_ext_destroy(struct nf_conn *ct)
  74 {
  75         if (ct->ext)
  76                 __nf_ct_ext_destroy(ct);
  77 }
  78
  79 /* Free operation. If you want to free a object referred from private area,
  80  * please implement __nf_ct_ext_free() and call it.
  81  */
  82 static inline void nf_ct_ext_free(struct nf_conn *ct)
  83 {
  84         if (ct->ext)
  85                 kfree_rcu(ct->ext, rcu);
  86 }
  87
  88 /* Add this type, returns pointer to data or NULL. */
  89 void *nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t 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
  97         enum nf_ct_ext_id id;
  98
  99         unsigned int flags;
 100
 101         /* Length and min alignment. */
 102         u8 len;
 103         u8 align;
 104         /* initial size of nf_ct_ext. */
 105         u8 alloc_size;
 106 };
 107
 108 int nf_ct_extend_register(struct nf_ct_ext_type *type);
 109 void nf_ct_extend_unregister(struct nf_ct_ext_type *type);
 110 #endif /* _NF_CONNTRACK_EXTEND_H */