LXR linux/include/net/netfilter/nf_conntrack

   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
   9enum nf_ct_ext_id {
  10        NF_CT_EXT_HELPER,
  11#if defined(CONFIG_NF_NAT) || defined(CONFIG_NF_NAT_MODULE)
  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. */
  45struct nf_ct_ext {
  46        struct rcu_head rcu;
  47        u8 offset[NF_CT_EXT_NUM];
  48        u8 len;
  49        char data[0];
  50};
  51
  52static inline bool __nf_ct_ext_exist(const struct nf_ct_ext *ext, u8 id)
  53{
  54        return !!ext->offset[id];
  55}
  56
  57static 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
  62static 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 */
  73void 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 */
  78static 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. */
  85void *nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp);
  86
  87struct 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
  98int nf_ct_extend_register(const struct nf_ct_ext_type *type);
  99void nf_ct_extend_unregister(const struct nf_ct_ext_type *type);
 100#endif /* _NF_CONNTRACK_EXTEND_H */
 101