1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * connection tracking expectations.
4  */
5 
6 #ifndef _NF_CONNTRACK_EXPECT_H
7 #define _NF_CONNTRACK_EXPECT_H
8 
9 #include <linux/refcount.h>
10 
11 #include <net/netfilter/nf_conntrack.h>
12 #include <net/netfilter/nf_conntrack_zones.h>
13 
14 extern unsigned int nf_ct_expect_hsize;
15 extern unsigned int nf_ct_expect_max;
16 extern struct hlist_head *nf_ct_expect_hash;
17 
18 struct nf_conntrack_expect {
19 	/* Conntrack expectation list member */
20 	struct hlist_node lnode;
21 
22 	/* Hash member */
23 	struct hlist_node hnode;
24 
25 	/* We expect this tuple, with the following mask */
26 	struct nf_conntrack_tuple tuple;
27 	struct nf_conntrack_tuple_mask mask;
28 
29 	/* Function to call after setup and insertion */
30 	void (*expectfn)(struct nf_conn *new,
31 			 struct nf_conntrack_expect *this);
32 
33 	/* Helper to assign to new connection */
34 	struct nf_conntrack_helper *helper;
35 
36 	/* The conntrack of the master connection */
37 	struct nf_conn *master;
38 
39 	/* Timer function; deletes the expectation. */
40 	struct timer_list timeout;
41 
42 	/* Usage count. */
43 	refcount_t use;
44 
45 	/* Flags */
46 	unsigned int flags;
47 
48 	/* Expectation class */
49 	unsigned int class;
50 
51 #ifdef CONFIG_NF_NAT_NEEDED
52 	union nf_inet_addr saved_addr;
53 	/* This is the original per-proto part, used to map the
54 	 * expected connection the way the recipient expects. */
55 	union nf_conntrack_man_proto saved_proto;
56 	/* Direction relative to the master connection. */
57 	enum ip_conntrack_dir dir;
58 #endif
59 
60 	struct rcu_head rcu;
61 };
62 
nf_ct_exp_net(struct nf_conntrack_expect * exp)63 static inline struct net *nf_ct_exp_net(struct nf_conntrack_expect *exp)
64 {
65 	return nf_ct_net(exp->master);
66 }
67 
68 #define NF_CT_EXP_POLICY_NAME_LEN	16
69 
70 struct nf_conntrack_expect_policy {
71 	unsigned int	max_expected;
72 	unsigned int	timeout;
73 	char		name[NF_CT_EXP_POLICY_NAME_LEN];
74 };
75 
76 #define NF_CT_EXPECT_CLASS_DEFAULT	0
77 #define NF_CT_EXPECT_MAX_CNT		255
78 
79 int nf_conntrack_expect_pernet_init(struct net *net);
80 void nf_conntrack_expect_pernet_fini(struct net *net);
81 
82 int nf_conntrack_expect_init(void);
83 void nf_conntrack_expect_fini(void);
84 
85 struct nf_conntrack_expect *
86 __nf_ct_expect_find(struct net *net,
87 		    const struct nf_conntrack_zone *zone,
88 		    const struct nf_conntrack_tuple *tuple);
89 
90 struct nf_conntrack_expect *
91 nf_ct_expect_find_get(struct net *net,
92 		      const struct nf_conntrack_zone *zone,
93 		      const struct nf_conntrack_tuple *tuple);
94 
95 struct nf_conntrack_expect *
96 nf_ct_find_expectation(struct net *net,
97 		       const struct nf_conntrack_zone *zone,
98 		       const struct nf_conntrack_tuple *tuple);
99 
100 void nf_ct_unlink_expect_report(struct nf_conntrack_expect *exp,
101 				u32 portid, int report);
nf_ct_unlink_expect(struct nf_conntrack_expect * exp)102 static inline void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
103 {
104 	nf_ct_unlink_expect_report(exp, 0, 0);
105 }
106 
107 void nf_ct_remove_expectations(struct nf_conn *ct);
108 void nf_ct_unexpect_related(struct nf_conntrack_expect *exp);
109 bool nf_ct_remove_expect(struct nf_conntrack_expect *exp);
110 
111 void nf_ct_expect_iterate_destroy(bool (*iter)(struct nf_conntrack_expect *e, void *data), void *data);
112 void nf_ct_expect_iterate_net(struct net *net,
113 			      bool (*iter)(struct nf_conntrack_expect *e, void *data),
114                               void *data, u32 portid, int report);
115 
116 /* Allocate space for an expectation: this is mandatory before calling
117    nf_ct_expect_related.  You will have to call put afterwards. */
118 struct nf_conntrack_expect *nf_ct_expect_alloc(struct nf_conn *me);
119 void nf_ct_expect_init(struct nf_conntrack_expect *, unsigned int, u_int8_t,
120 		       const union nf_inet_addr *,
121 		       const union nf_inet_addr *,
122 		       u_int8_t, const __be16 *, const __be16 *);
123 void nf_ct_expect_put(struct nf_conntrack_expect *exp);
124 int nf_ct_expect_related_report(struct nf_conntrack_expect *expect,
125 				u32 portid, int report);
nf_ct_expect_related(struct nf_conntrack_expect * expect)126 static inline int nf_ct_expect_related(struct nf_conntrack_expect *expect)
127 {
128 	return nf_ct_expect_related_report(expect, 0, 0);
129 }
130 
131 #endif /*_NF_CONNTRACK_EXPECT_H*/
132 
133