1 /*
2 * connection tracking helpers.
3 *
4 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
5 * - generalize L3 protocol dependent part.
6 *
7 * Derived from include/linux/netfiter_ipv4/ip_conntrack_helper.h
8 */
9
10 #ifndef _NF_CONNTRACK_HELPER_H
11 #define _NF_CONNTRACK_HELPER_H
12 #include <net/netfilter/nf_conntrack.h>
13 #include <net/netfilter/nf_conntrack_extend.h>
14
15 struct module;
16
17 #define NF_CT_HELPER_NAME_LEN 16
18
19 struct nf_conntrack_helper {
20 struct hlist_node hnode; /* Internal use. */
21
22 const char *name; /* name of the module */
23 struct module *me; /* pointer to self */
24 const struct nf_conntrack_expect_policy *expect_policy;
25
26 /* Tuple of things we will help (compared against server response) */
27 struct nf_conntrack_tuple tuple;
28
29 /* Function to call when data passes; return verdict, or -1 to
30 invalidate. */
31 int (*help)(struct sk_buff *skb,
32 unsigned int protoff,
33 struct nf_conn *ct,
34 enum ip_conntrack_info conntrackinfo);
35
36 void (*destroy)(struct nf_conn *ct);
37
38 int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
39 unsigned int expect_class_max;
40 };
41
42 extern struct nf_conntrack_helper *
43 __nf_conntrack_helper_find(const char *name, u16 l3num, u8 protonum);
44
45 extern struct nf_conntrack_helper *
46 nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum);
47
48 extern int nf_conntrack_helper_register(struct nf_conntrack_helper *);
49 extern void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);
50
51 extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp);
52
53 extern int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
54 gfp_t flags);
55
56 extern void nf_ct_helper_destroy(struct nf_conn *ct);
57
nfct_help(const struct nf_conn * ct)58 static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
59 {
60 return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
61 }
62
63 extern int nf_conntrack_helper_init(void);
64 extern void nf_conntrack_helper_fini(void);
65
66 extern int nf_conntrack_broadcast_help(struct sk_buff *skb,
67 unsigned int protoff,
68 struct nf_conn *ct,
69 enum ip_conntrack_info ctinfo,
70 unsigned int timeout);
71
72 struct nf_ct_helper_expectfn {
73 struct list_head head;
74 const char *name;
75 void (*expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
76 };
77
78 void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n);
79 void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n);
80 struct nf_ct_helper_expectfn *
81 nf_ct_helper_expectfn_find_by_name(const char *name);
82 struct nf_ct_helper_expectfn *
83 nf_ct_helper_expectfn_find_by_symbol(const void *symbol);
84
85 #endif /*_NF_CONNTRACK_HELPER_H*/
86