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