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