2 * connection tracking helpers.
4 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
5 * - generalize L3 protocol dependent part.
7 * Derived from include/linux/netfiter_ipv4/ip_conntrack_helper.h
10 #ifndef _NF_CONNTRACK_HELPER_H
11 #define _NF_CONNTRACK_HELPER_H
12 #include <linux/refcount.h>
13 #include <net/netfilter/nf_conntrack.h>
14 #include <net/netfilter/nf_conntrack_extend.h>
15 #include <net/netfilter/nf_conntrack_expect.h>
19 enum nf_ct_helper_flags
{
20 NF_CT_HELPER_F_USERSPACE
= (1 << 0),
21 NF_CT_HELPER_F_CONFIGURED
= (1 << 1),
24 #define NF_CT_HELPER_NAME_LEN 16
26 struct nf_conntrack_helper
{
27 struct hlist_node hnode
; /* Internal use. */
29 char name
[NF_CT_HELPER_NAME_LEN
]; /* name of the module */
31 struct module
*me
; /* pointer to self */
32 const struct nf_conntrack_expect_policy
*expect_policy
;
34 /* Tuple of things we will help (compared against server response) */
35 struct nf_conntrack_tuple tuple
;
37 /* Function to call when data passes; return verdict, or -1 to
39 int (*help
)(struct sk_buff
*skb
,
42 enum ip_conntrack_info conntrackinfo
);
44 void (*destroy
)(struct nf_conn
*ct
);
46 int (*from_nlattr
)(struct nlattr
*attr
, struct nf_conn
*ct
);
47 int (*to_nlattr
)(struct sk_buff
*skb
, const struct nf_conn
*ct
);
48 unsigned int expect_class_max
;
52 /* For user-space helpers: */
53 unsigned int queue_num
;
54 /* length of userspace private data stored in nf_conn_help->data */
58 /* Must be kept in sync with the classes defined by helpers */
59 #define NF_CT_MAX_EXPECT_CLASSES 4
61 /* nf_conn feature for connections that have a helper */
64 struct nf_conntrack_helper __rcu
*helper
;
66 struct hlist_head expectations
;
68 /* Current number of expected connections */
69 u8 expecting
[NF_CT_MAX_EXPECT_CLASSES
];
71 /* private helper information. */
72 char data
[32] __aligned(8);
75 #define NF_CT_HELPER_BUILD_BUG_ON(structsize) \
76 BUILD_BUG_ON((structsize) > FIELD_SIZEOF(struct nf_conn_help, data))
78 struct nf_conntrack_helper
*__nf_conntrack_helper_find(const char *name
,
79 u16 l3num
, u8 protonum
);
81 struct nf_conntrack_helper
*nf_conntrack_helper_try_module_get(const char *name
,
84 void nf_conntrack_helper_put(struct nf_conntrack_helper
*helper
);
86 void nf_ct_helper_init(struct nf_conntrack_helper
*helper
,
87 u16 l3num
, u16 protonum
, const char *name
,
88 u16 default_port
, u16 spec_port
, u32 id
,
89 const struct nf_conntrack_expect_policy
*exp_pol
,
91 int (*help
)(struct sk_buff
*skb
, unsigned int protoff
,
93 enum ip_conntrack_info ctinfo
),
94 int (*from_nlattr
)(struct nlattr
*attr
,
96 struct module
*module
);
98 int nf_conntrack_helper_register(struct nf_conntrack_helper
*);
99 void nf_conntrack_helper_unregister(struct nf_conntrack_helper
*);
101 int nf_conntrack_helpers_register(struct nf_conntrack_helper
*, unsigned int);
102 void nf_conntrack_helpers_unregister(struct nf_conntrack_helper
*,
105 struct nf_conn_help
*nf_ct_helper_ext_add(struct nf_conn
*ct
,
106 struct nf_conntrack_helper
*helper
,
109 int __nf_ct_try_assign_helper(struct nf_conn
*ct
, struct nf_conn
*tmpl
,
112 void nf_ct_helper_destroy(struct nf_conn
*ct
);
114 static inline struct nf_conn_help
*nfct_help(const struct nf_conn
*ct
)
116 return nf_ct_ext_find(ct
, NF_CT_EXT_HELPER
);
119 static inline void *nfct_help_data(const struct nf_conn
*ct
)
121 struct nf_conn_help
*help
;
123 help
= nf_ct_ext_find(ct
, NF_CT_EXT_HELPER
);
125 return (void *)help
->data
;
128 int nf_conntrack_helper_pernet_init(struct net
*net
);
129 void nf_conntrack_helper_pernet_fini(struct net
*net
);
131 int nf_conntrack_helper_init(void);
132 void nf_conntrack_helper_fini(void);
134 int nf_conntrack_broadcast_help(struct sk_buff
*skb
, unsigned int protoff
,
136 enum ip_conntrack_info ctinfo
,
137 unsigned int timeout
);
139 struct nf_ct_helper_expectfn
{
140 struct list_head head
;
142 void (*expectfn
)(struct nf_conn
*ct
, struct nf_conntrack_expect
*exp
);
146 void nf_ct_helper_log(struct sk_buff
*skb
, const struct nf_conn
*ct
,
147 const char *fmt
, ...);
149 void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn
*n
);
150 void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn
*n
);
151 struct nf_ct_helper_expectfn
*
152 nf_ct_helper_expectfn_find_by_name(const char *name
);
153 struct nf_ct_helper_expectfn
*
154 nf_ct_helper_expectfn_find_by_symbol(const void *symbol
);
156 extern struct hlist_head
*nf_ct_helper_hash
;
157 extern unsigned int nf_ct_helper_hsize
;
159 #endif /*_NF_CONNTRACK_HELPER_H*/