xref: /linux/include/net/netfilter/nf_conntrack_timeout.h (revision 7d6a9cdb8d3a51d9cfe546a09a518ab3d2671549)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _NF_CONNTRACK_TIMEOUT_H
3 #define _NF_CONNTRACK_TIMEOUT_H
4 
5 #include <net/net_namespace.h>
6 #include <linux/netfilter/nf_conntrack_common.h>
7 #include <linux/netfilter/nf_conntrack_tuple_common.h>
8 #include <linux/refcount.h>
9 #include <net/netfilter/nf_conntrack.h>
10 #include <net/netfilter/nf_conntrack_extend.h>
11 
12 #define CTNL_TIMEOUT_NAME_MAX	32
13 
14 struct nf_ct_timeout {
15 	refcount_t		refcnt;
16 	__u16			l3num;
17 	const struct nf_conntrack_l4proto *l4proto;
18 	struct rcu_head		rcu;
19 	char			data[];
20 };
21 
22 struct nf_conn_timeout {
23 	struct nf_ct_timeout __rcu *timeout;
24 };
25 
26 static inline void nf_ct_timeout_put(const struct nf_conn *ct)
27 {
28 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
29 	struct nf_conn_timeout *timeout_ext;
30 	struct nf_ct_timeout *timeout;
31 
32 	timeout_ext = nf_ct_ext_find(ct, NF_CT_EXT_TIMEOUT);
33 	if (!timeout_ext)
34 		return;
35 
36 	timeout = rcu_dereference(timeout_ext->timeout);
37 	if (timeout && refcount_dec_and_test(&timeout->refcnt))
38 		kfree_rcu(timeout, rcu);
39 #endif
40 }
41 
42 static inline unsigned int *
43 nf_ct_timeout_data(const struct nf_conn_timeout *t)
44 {
45 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
46 	struct nf_ct_timeout *timeout;
47 
48 	timeout = rcu_dereference(t->timeout);
49 	if (timeout == NULL)
50 		return NULL;
51 
52 	return (unsigned int *)timeout->data;
53 #else
54 	return NULL;
55 #endif
56 }
57 
58 static inline
59 struct nf_conn_timeout *nf_ct_timeout_find(const struct nf_conn *ct)
60 {
61 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
62 	return nf_ct_ext_find(ct, NF_CT_EXT_TIMEOUT);
63 #else
64 	return NULL;
65 #endif
66 }
67 
68 static inline
69 struct nf_conn_timeout *nf_ct_timeout_ext_add(struct nf_conn *ct,
70 					      struct nf_ct_timeout *timeout,
71 					      gfp_t gfp)
72 {
73 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
74 	struct nf_conn_timeout *timeout_ext;
75 
76 	if (!timeout)
77 		return NULL;
78 
79 	timeout_ext = nf_ct_ext_add(ct, NF_CT_EXT_TIMEOUT, gfp);
80 	if (!timeout_ext || timeout_ext->timeout)
81 		return NULL;
82 
83 	if (!refcount_inc_not_zero(&timeout->refcnt))
84 		return NULL;
85 
86 	rcu_assign_pointer(timeout_ext->timeout, timeout);
87 
88 	return timeout_ext;
89 #else
90 	return NULL;
91 #endif
92 };
93 
94 static inline unsigned int *nf_ct_timeout_lookup(const struct nf_conn *ct)
95 {
96 	unsigned int *timeouts = NULL;
97 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
98 	struct nf_conn_timeout *timeout_ext;
99 
100 	timeout_ext = nf_ct_timeout_find(ct);
101 	if (timeout_ext && rcu_access_pointer(timeout_ext->timeout))
102 		timeouts = nf_ct_timeout_data(timeout_ext);
103 #endif
104 	return timeouts;
105 }
106 
107 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
108 void nf_ct_untimeout(struct net *net, struct nf_ct_timeout *timeout);
109 int nf_ct_set_timeout(struct net *net, struct nf_conn *ct, u8 l3num, u8 l4num,
110 		      const char *timeout_name);
111 void nf_ct_destroy_timeout(struct nf_conn *ct);
112 #else
113 static inline int nf_ct_set_timeout(struct net *net, struct nf_conn *ct,
114 				    u8 l3num, u8 l4num,
115 				    const char *timeout_name)
116 {
117 	return -EOPNOTSUPP;
118 }
119 
120 static inline void nf_ct_destroy_timeout(struct nf_conn *ct)
121 {
122 	return;
123 }
124 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
125 
126 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
127 struct nf_ct_timeout_hooks {
128 	struct nf_ct_timeout *(*timeout_find_get)(struct net *net, const char *name);
129 	void (*timeout_put)(struct nf_ct_timeout *timeout);
130 };
131 
132 extern const struct nf_ct_timeout_hooks __rcu *nf_ct_timeout_hook;
133 #endif
134 
135 #endif /* _NF_CONNTRACK_TIMEOUT_H */
136