root/include/net/netfilter/nf_conntrack_extend.h

INCLUDED FROM

DEFINITIONS

1. __nf_ct_ext_exist
2. nf_ct_ext_exist
3. __nf_ct_ext_find
4. nf_ct_ext_free

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _NF_CONNTRACK_EXTEND_H
   3 #define _NF_CONNTRACK_EXTEND_H
   4 
   5 #include <linux/slab.h>
   6 
   7 #include <net/netfilter/nf_conntrack.h>
   8 
   9 enum nf_ct_ext_id {
  10         NF_CT_EXT_HELPER,
  11 #if IS_ENABLED(CONFIG_NF_NAT)
  12         NF_CT_EXT_NAT,
  13 #endif
  14         NF_CT_EXT_SEQADJ,
  15         NF_CT_EXT_ACCT,
  16 #ifdef CONFIG_NF_CONNTRACK_EVENTS
  17         NF_CT_EXT_ECACHE,
  18 #endif
  19 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
  20         NF_CT_EXT_TSTAMP,
  21 #endif
  22 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
  23         NF_CT_EXT_TIMEOUT,
  24 #endif
  25 #ifdef CONFIG_NF_CONNTRACK_LABELS
  26         NF_CT_EXT_LABELS,
  27 #endif
  28 #if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
  29         NF_CT_EXT_SYNPROXY,
  30 #endif
  31         NF_CT_EXT_NUM,
  32 };
  33 
  34 #define NF_CT_EXT_HELPER_TYPE struct nf_conn_help
  35 #define NF_CT_EXT_NAT_TYPE struct nf_conn_nat
  36 #define NF_CT_EXT_SEQADJ_TYPE struct nf_conn_seqadj
  37 #define NF_CT_EXT_ACCT_TYPE struct nf_conn_acct
  38 #define NF_CT_EXT_ECACHE_TYPE struct nf_conntrack_ecache
  39 #define NF_CT_EXT_TSTAMP_TYPE struct nf_conn_tstamp
  40 #define NF_CT_EXT_TIMEOUT_TYPE struct nf_conn_timeout
  41 #define NF_CT_EXT_LABELS_TYPE struct nf_conn_labels
  42 #define NF_CT_EXT_SYNPROXY_TYPE struct nf_conn_synproxy
  43 
  44 /* Extensions: optional stuff which isn't permanently in struct. */
  45 struct nf_ct_ext {
  46         struct rcu_head rcu;
  47         u8 offset[NF_CT_EXT_NUM];
  48         u8 len;
  49         char data[0];
  50 };
  51 
  52 static inline bool __nf_ct_ext_exist(const struct nf_ct_ext *ext, u8 id)
  53 {
  54         return !!ext->offset[id];
  55 }
  56 
  57 static inline bool nf_ct_ext_exist(const struct nf_conn *ct, u8 id)
  58 {
  59         return (ct->ext && __nf_ct_ext_exist(ct->ext, id));
  60 }
  61 
  62 static inline void *__nf_ct_ext_find(const struct nf_conn *ct, u8 id)
  63 {
  64         if (!nf_ct_ext_exist(ct, id))
  65                 return NULL;
  66 
  67         return (void *)ct->ext + ct->ext->offset[id];
  68 }
  69 #define nf_ct_ext_find(ext, id) \
  70         ((id##_TYPE *)__nf_ct_ext_find((ext), (id)))
  71 
  72 /* Destroy all relationships */
  73 void nf_ct_ext_destroy(struct nf_conn *ct);
  74 
  75 /* Free operation. If you want to free a object referred from private area,
  76  * please implement __nf_ct_ext_free() and call it.
  77  */
  78 static inline void nf_ct_ext_free(struct nf_conn *ct)
  79 {
  80         if (ct->ext)
  81                 kfree_rcu(ct->ext, rcu);
  82 }
  83 
  84 /* Add this type, returns pointer to data or NULL. */
  85 void *nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp);
  86 
  87 struct nf_ct_ext_type {
  88         /* Destroys relationships (can be NULL). */
  89         void (*destroy)(struct nf_conn *ct);
  90 
  91         enum nf_ct_ext_id id;
  92 
  93         /* Length and min alignment. */
  94         u8 len;
  95         u8 align;
  96 };
  97 
  98 int nf_ct_extend_register(const struct nf_ct_ext_type *type);
  99 void nf_ct_extend_unregister(const struct nf_ct_ext_type *type);
 100 #endif /* _NF_CONNTRACK_EXTEND_H */