LXR linux/include/net/netfilter/nf_conntrack

   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
   8enum 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. */
  44struct nf_ct_ext {
  45        struct rcu_head rcu;
  46        u16 offset[NF_CT_EXT_NUM];
  47        u16 len;
  48        char data[0];
  49};
  50
  51static inline bool __nf_ct_ext_exist(const struct nf_ct_ext *ext, u8 id)
  52{
  53        return !!ext->offset[id];
  54}
  55
  56static 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
  61static 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 */
  72void __nf_ct_ext_destroy(struct nf_conn *ct);
  73static 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 */
  82static 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. */
  89void *__nf_ct_ext_add_length(struct nf_conn *ct, enum nf_ct_ext_id id,
  90                             size_t var_alloc_len, gfp_t gfp);
  91
  92#define nf_ct_ext_add(ct, id, gfp) \
  93        ((id##_TYPE *)__nf_ct_ext_add_length((ct), (id), 0, (gfp)))
  94#define nf_ct_ext_add_length(ct, id, len, gfp) \
  95        ((id##_TYPE *)__nf_ct_ext_add_length((ct), (id), (len), (gfp)))
  96
  97#define NF_CT_EXT_F_PREALLOC    0x0001
  98
  99struct nf_ct_ext_type {
 100        /* Destroys relationships (can be NULL). */
 101        void (*destroy)(struct nf_conn *ct);
 102
 103        enum nf_ct_ext_id id;
 104
 105        unsigned int flags;
 106
 107        /* Length and min alignment. */
 108        u8 len;
 109        u8 align;
 110        /* initial size of nf_ct_ext. */
 111        u8 alloc_size;
 112};
 113
 114int nf_ct_extend_register(struct nf_ct_ext_type *type);
 115void nf_ct_extend_unregister(struct nf_ct_ext_type *type);
 116#endif /* _NF_CONNTRACK_EXTEND_H */
 117