[mirror_ubuntu-artful-kernel.git] / include / net / netfilter / nf_conntrack_helper.h

/*
 * connection tracking helpers.
 *
 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
 *	- generalize L3 protocol dependent part.
 *
 * Derived from include/linux/netfiter_ipv4/ip_conntrack_helper.h
 */

#ifndef _NF_CONNTRACK_HELPER_H
#define _NF_CONNTRACK_HELPER_H
#include <linux/refcount.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_extend.h>
#include <net/netfilter/nf_conntrack_expect.h>

struct module;

enum nf_ct_helper_flags {
	NF_CT_HELPER_F_USERSPACE	= (1 << 0),
	NF_CT_HELPER_F_CONFIGURED	= (1 << 1),
};

#define NF_CT_HELPER_NAME_LEN	16

struct nf_conntrack_helper {
	struct hlist_node hnode;	/* Internal use. */

	char name[NF_CT_HELPER_NAME_LEN]; /* name of the module */
	refcount_t refcnt;
	struct module *me;		/* pointer to self */
	const struct nf_conntrack_expect_policy *expect_policy;

	/* Tuple of things we will help (compared against server response) */
	struct nf_conntrack_tuple tuple;

	/* Function to call when data passes; return verdict, or -1 to
           invalidate. */
	int (*help)(struct sk_buff *skb,
		    unsigned int protoff,
		    struct nf_conn *ct,
		    enum ip_conntrack_info conntrackinfo);

	void (*destroy)(struct nf_conn *ct);

	int (*from_nlattr)(struct nlattr *attr, struct nf_conn *ct);
	int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
	unsigned int expect_class_max;

	unsigned int flags;

	/* For user-space helpers: */
	unsigned int queue_num;
	/* length of userspace private data stored in nf_conn_help->data */
	u16 data_len;
};

/* Must be kept in sync with the classes defined by helpers */
#define NF_CT_MAX_EXPECT_CLASSES	4

/* nf_conn feature for connections that have a helper */
struct nf_conn_help {
	/* Helper. if any */
	struct nf_conntrack_helper __rcu *helper;

	struct hlist_head expectations;

	/* Current number of expected connections */
	u8 expecting[NF_CT_MAX_EXPECT_CLASSES];

	/* private helper information. */
	char data[32] __aligned(8);
};

#define NF_CT_HELPER_BUILD_BUG_ON(structsize) \
	BUILD_BUG_ON((structsize) > FIELD_SIZEOF(struct nf_conn_help, data))

struct nf_conntrack_helper *__nf_conntrack_helper_find(const char *name,
						       u16 l3num, u8 protonum);

struct nf_conntrack_helper *nf_conntrack_helper_try_module_get(const char *name,
							       u16 l3num,
							       u8 protonum);
void nf_conntrack_helper_put(struct nf_conntrack_helper *helper);

void nf_ct_helper_init(struct nf_conntrack_helper *helper,
		       u16 l3num, u16 protonum, const char *name,
		       u16 default_port, u16 spec_port, u32 id,
		       const struct nf_conntrack_expect_policy *exp_pol,
		       u32 expect_class_max,
		       int (*help)(struct sk_buff *skb, unsigned int protoff,
				   struct nf_conn *ct,
				   enum ip_conntrack_info ctinfo),
		       int (*from_nlattr)(struct nlattr *attr,
					  struct nf_conn *ct),
		       struct module *module);

int nf_conntrack_helper_register(struct nf_conntrack_helper *);
void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);

int nf_conntrack_helpers_register(struct nf_conntrack_helper *, unsigned int);
void nf_conntrack_helpers_unregister(struct nf_conntrack_helper *,
				     unsigned int);

struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct,
					  struct nf_conntrack_helper *helper,
					  gfp_t gfp);

int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
			      gfp_t flags);

void nf_ct_helper_destroy(struct nf_conn *ct);

static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
{
	return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
}

static inline void *nfct_help_data(const struct nf_conn *ct)
{
	struct nf_conn_help *help;

	help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);

	return (void *)help->data;
}

int nf_conntrack_helper_pernet_init(struct net *net);
void nf_conntrack_helper_pernet_fini(struct net *net);

int nf_conntrack_helper_init(void);
void nf_conntrack_helper_fini(void);

int nf_conntrack_broadcast_help(struct sk_buff *skb, unsigned int protoff,
				struct nf_conn *ct,
				enum ip_conntrack_info ctinfo,
				unsigned int timeout);

struct nf_ct_helper_expectfn {
	struct list_head head;
	const char *name;
	void (*expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
};

__printf(3,4)
void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct,
		      const char *fmt, ...);

void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n);
void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n);
struct nf_ct_helper_expectfn *
nf_ct_helper_expectfn_find_by_name(const char *name);
struct nf_ct_helper_expectfn *
nf_ct_helper_expectfn_find_by_symbol(const void *symbol);

extern struct hlist_head *nf_ct_helper_hash;
extern unsigned int nf_ct_helper_hsize;

#endif /*_NF_CONNTRACK_HELPER_H*/
Commit	Line	Data
9fb9cbb1 YK	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
9338d7b4	12	#include <linux/refcount.h>
9fb9cbb1	13	#include <net/netfilter/nf_conntrack.h>
ceceae1b	14	#include <net/netfilter/nf_conntrack_extend.h>
1afc5679	15	#include <net/netfilter/nf_conntrack_expect.h>
9fb9cbb1 YK	16
	17	struct module;
	18
12f7a505 PNA	19	enum nf_ct_helper_flags {
	20	NF_CT_HELPER_F_USERSPACE = (1 << 0),
	21	NF_CT_HELPER_F_CONFIGURED = (1 << 1),
	22	};
	23
af9d32ad HE	24	#define NF_CT_HELPER_NAME_LEN 16
af9d32ad HE	25
fd2c3ef7	26	struct nf_conntrack_helper {
b8a7fe6c	27	struct hlist_node hnode; /* Internal use. */
9fb9cbb1	28
3a8fc53a	29	char name[NF_CT_HELPER_NAME_LEN]; /* name of the module */
9338d7b4	30	refcount_t refcnt;
9fb9cbb1	31	struct module me; / pointer to self */
6002f266	32	const struct nf_conntrack_expect_policy *expect_policy;
9fb9cbb1	33
d4156e8c	34	/* Tuple of things we will help (compared against server response) */
9fb9cbb1	35	struct nf_conntrack_tuple tuple;
d4156e8c	36
9fb9cbb1 YK	37	/* Function to call when data passes; return verdict, or -1 to
9fb9cbb1 YK	38	invalidate. */
3db05fea	39	int (help)(struct sk_buff skb,
9fb9cbb1 YK	40	unsigned int protoff,
	41	struct nf_conn *ct,
	42	enum ip_conntrack_info conntrackinfo);
c1d10adb	43
f09943fe PM	44	void (destroy)(struct nf_conn ct);
f09943fe PM	45
ae243bee	46	int (from_nlattr)(struct nlattr attr, struct nf_conn *ct);
fdf70832	47	int (to_nlattr)(struct sk_buff skb, const struct nf_conn *ct);
6002f266	48	unsigned int expect_class_max;
12f7a505 PNA	49
12f7a505 PNA	50	unsigned int flags;
9f0f3ebe FW	51
	52	/* For user-space helpers: */
	53	unsigned int queue_num;
	54	/* length of userspace private data stored in nf_conn_help->data */
	55	u16 data_len;
9fb9cbb1 YK	56	};
9fb9cbb1 YK	57
906535b0 FW	58	/* Must be kept in sync with the classes defined by helpers */
	59	#define NF_CT_MAX_EXPECT_CLASSES 4
	60
	61	/* nf_conn feature for connections that have a helper */
	62	struct nf_conn_help {
	63	/* Helper. if any */
	64	struct nf_conntrack_helper __rcu *helper;
	65
	66	struct hlist_head expectations;
	67
	68	/* Current number of expected connections */
	69	u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
	70
	71	/* private helper information. */
dcf67740	72	char data[32] __aligned(8);
906535b0 FW	73	};
906535b0 FW	74
dcf67740 FW	75	#define NF_CT_HELPER_BUILD_BUG_ON(structsize) \
	76	BUILD_BUG_ON((structsize) > FIELD_SIZEOF(struct nf_conn_help, data))
	77
4e77be46 JP	78	struct nf_conntrack_helper __nf_conntrack_helper_find(const char name,
4e77be46 JP	79	u16 l3num, u8 protonum);
7e5d03bb	80
4e77be46 JP	81	struct nf_conntrack_helper nf_conntrack_helper_try_module_get(const char name,
	82	u16 l3num,
	83	u8 protonum);
d91fc59c LZ	84	void nf_conntrack_helper_put(struct nf_conntrack_helper *helper);
d91fc59c LZ	85
82de0be6 GF	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,
9f0f3ebe	90	u32 expect_class_max,
82de0be6 GF	91	int (help)(struct sk_buff skb, unsigned int protoff,
	92	struct nf_conn *ct,
	93	enum ip_conntrack_info ctinfo),
	94	int (from_nlattr)(struct nlattr attr,
	95	struct nf_conn *ct),
	96	struct module *module);
84f3bb9a	97
4e77be46 JP	98	int nf_conntrack_helper_register(struct nf_conntrack_helper *);
4e77be46 JP	99	void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);
9fb9cbb1	100
82de0be6 GF	101	int nf_conntrack_helpers_register(struct nf_conntrack_helper *, unsigned int);
	102	void nf_conntrack_helpers_unregister(struct nf_conntrack_helper *,
	103	unsigned int);
	104
4e77be46 JP	105	struct nf_conn_help nf_ct_helper_ext_add(struct nf_conn ct,
	106	struct nf_conntrack_helper *helper,
	107	gfp_t gfp);
b560580a	108
4e77be46 JP	109	int __nf_ct_try_assign_helper(struct nf_conn ct, struct nf_conn tmpl,
4e77be46 JP	110	gfp_t flags);
226c0c0e	111
4e77be46	112	void nf_ct_helper_destroy(struct nf_conn *ct);
9858a3ae	113
ceceae1b YK	114	static inline struct nf_conn_help nfct_help(const struct nf_conn ct)
	115	{
	116	return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
	117	}
b334aadc	118
1afc5679 PNA	119	static inline void nfct_help_data(const struct nf_conn ct)
	120	{
	121	struct nf_conn_help *help;
	122
	123	help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
	124
	125	return (void *)help->data;
	126	}
	127
4e77be46 JP	128	int nf_conntrack_helper_pernet_init(struct net *net);
4e77be46 JP	129	void nf_conntrack_helper_pernet_fini(struct net *net);
5e615b22	130
4e77be46 JP	131	int nf_conntrack_helper_init(void);
4e77be46 JP	132	void nf_conntrack_helper_fini(void);
b334aadc	133
4e77be46 JP	134	int nf_conntrack_broadcast_help(struct sk_buff *skb, unsigned int protoff,
	135	struct nf_conn *ct,
	136	enum ip_conntrack_info ctinfo,
	137	unsigned int timeout);
93557f53	138
544d5c7d PNA	139	struct nf_ct_helper_expectfn {
	140	struct list_head head;
	141	const char *name;
	142	void (expectfn)(struct nf_conn ct, struct nf_conntrack_expect *exp);
	143	};
	144
b20ab9cc PNA	145	__printf(3,4)
	146	void nf_ct_helper_log(struct sk_buff skb, const struct nf_conn ct,
	147	const char *fmt, ...);
	148
544d5c7d PNA	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);
	155
12f7a505 PNA	156	extern struct hlist_head *nf_ct_helper_hash;
	157	extern unsigned int nf_ct_helper_hsize;
	158
9fb9cbb1	159	#endif /_NF_CONNTRACK_HELPER_H/