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 #if IS_ENABLED(CONFIG_NF_NAT)
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 
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 /* Allow to reuse expectations with the same tuples from different master
80  * conntracks.
81  */
82 #define NF_CT_EXP_F_SKIP_MASTER	0x1
83 
84 int nf_conntrack_expect_pernet_init(struct net *net);
85 void nf_conntrack_expect_pernet_fini(struct net *net);
86 
87 int nf_conntrack_expect_init(void);
88 void nf_conntrack_expect_fini(void);
89 
90 struct nf_conntrack_expect *
91 __nf_ct_expect_find(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_expect_find_get(struct net *net,
97 		      const struct nf_conntrack_zone *zone,
98 		      const struct nf_conntrack_tuple *tuple);
99 
100 struct nf_conntrack_expect *
101 nf_ct_find_expectation(struct net *net,
102 		       const struct nf_conntrack_zone *zone,
103 		       const struct nf_conntrack_tuple *tuple);
104 
105 void nf_ct_unlink_expect_report(struct nf_conntrack_expect *exp,
106 				u32 portid, int report);
107 static inline void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
108 {
109 	nf_ct_unlink_expect_report(exp, 0, 0);
110 }
111 
112 void nf_ct_remove_expectations(struct nf_conn *ct);
113 void nf_ct_unexpect_related(struct nf_conntrack_expect *exp);
114 bool nf_ct_remove_expect(struct nf_conntrack_expect *exp);
115 
116 void nf_ct_expect_iterate_destroy(bool (*iter)(struct nf_conntrack_expect *e, void *data), void *data);
117 void nf_ct_expect_iterate_net(struct net *net,
118 			      bool (*iter)(struct nf_conntrack_expect *e, void *data),
119                               void *data, u32 portid, int report);
120 
121 /* Allocate space for an expectation: this is mandatory before calling
122    nf_ct_expect_related.  You will have to call put afterwards. */
123 struct nf_conntrack_expect *nf_ct_expect_alloc(struct nf_conn *me);
124 void nf_ct_expect_init(struct nf_conntrack_expect *, unsigned int, u_int8_t,
125 		       const union nf_inet_addr *,
126 		       const union nf_inet_addr *,
127 		       u_int8_t, const __be16 *, const __be16 *);
128 void nf_ct_expect_put(struct nf_conntrack_expect *exp);
129 int nf_ct_expect_related_report(struct nf_conntrack_expect *expect,
130 				u32 portid, int report, unsigned int flags);
131 static inline int nf_ct_expect_related(struct nf_conntrack_expect *expect,
132 				       unsigned int flags)
133 {
134 	return nf_ct_expect_related_report(expect, 0, 0, flags);
135 }
136 
137 #endif /*_NF_CONNTRACK_EXPECT_H*/
138 
139