Library setup

Functions
int	nfct_callback_register (struct nfct_handle *h, enum nf_conntrack_msg_type type, int(*cb)(enum nf_conntrack_msg_type type, struct nf_conntrack *ct, void *data), void *data)
void	nfct_callback_unregister (struct nfct_handle *h)
int	nfct_callback_register2 (struct nfct_handle *h, enum nf_conntrack_msg_type type, int(*cb)(const struct nlmsghdr *nlh, enum nf_conntrack_msg_type type, struct nf_conntrack *ct, void *data), void *data)
void	nfct_callback_unregister2 (struct nfct_handle *h)
int	nfexp_callback_register (struct nfct_handle *h, enum nf_conntrack_msg_type type, int(*cb)(enum nf_conntrack_msg_type type, struct nf_expect *exp, void *data), void *data)
void	nfexp_callback_unregister (struct nfct_handle *h)
int	nfexp_callback_register2 (struct nfct_handle *h, enum nf_conntrack_msg_type type, int(*cb)(const struct nlmsghdr *nlh, enum nf_conntrack_msg_type type, struct nf_expect *exp, void *data), void *data)
void	nfexp_callback_unregister2 (struct nfct_handle *h)
struct nfct_handle *	nfct_open (uint8_t subsys_id, unsigned subscriptions)
int	nfct_close (struct nfct_handle *cth)
int	nfct_fd (struct nfct_handle *cth)
const struct nfnl_handle *	nfct_nfnlh (struct nfct_handle *cth)

Detailed Description

Function Documentation

int nfct_callback_register	(	struct nfct_handle *	h,
		enum nf_conntrack_msg_type	type,
		int(*)(enum nf_conntrack_msg_type type, struct nf_conntrack *ct, void *data)	cb,
		void *	data
	)

nf_callback_register - register a callback

Parameters

h	library handler
type	message type (see enum nf_conntrack_msg_type definition)
cb	callback used to process conntrack received
data	data used by the callback, if any.

This function register a callback to handle the conntrack received, in case of error -1 is returned and errno is set appropiately, otherwise 0 is returned.

Note that the data parameter is optional, if you do not want to pass any data to your callback, then use NULL.

Definition at line 223 of file conntrack/api.c.

int nfct_callback_register2	(	struct nfct_handle *	h,
		enum nf_conntrack_msg_type	type,
		int(*)(const struct nlmsghdr *nlh, enum nf_conntrack_msg_type type, struct nf_conntrack *ct, void *data)	cb,
		void *	data
	)

nf_callback_register2 - register a callback

Parameters

h	library handler
cb	callback used to process conntrack received
data	data used by the callback, if any.

This function register a callback to handle the conntrack received, in case of error -1 is returned and errno is set appropiately, otherwise 0 is returned.

Note that the data parameter is optional, if you do not want to pass any data to your callback, then use NULL.

NOTICE: The difference with nf_callback_register() is that this function uses the new callback interface that includes the Netlink header.

WARNING: Don't mix nf_callback_register() and nf_callback_register2() calls, use only once at a time.

Definition at line 297 of file conntrack/api.c.

void nfct_callback_unregister

(

struct nfct_handle *

h

)

nfct_callback_unregister - unregister a callback

Parameters

h	library handler

Definition at line 263 of file conntrack/api.c.

void nfct_callback_unregister2

(

struct nfct_handle *

h

)

nfct_callback_unregister2 - unregister a callback

Parameters

h	library handler

Definition at line 337 of file conntrack/api.c.

int nfct_close

(

struct nfct_handle *

cth

)

nfct_close - close a ctnetlink handler

Parameters

cth	handler obtained via nfct_open()

This function returns -1 on error and errno is explicitly set.

Definition at line 105 of file main.c.

int nfct_fd

(

struct nfct_handle *

cth

)

nfct_fd - get the Netlink file descriptor of one existing ctnetlink handler

Parameters

cth	handler obtained via nfct_open()

Definition at line 144 of file main.c.

struct nfct_handle* nfct_open	(	uint8_t	subsys_id,
		unsigned	subscriptions
	)

nfct_open - open a ctnetlink handler

Parameters

subsys_id	can be NFNL_SUBSYS_CTNETLINK or NFNL_SUBSYS_CTNETLINK_EXP
subscriptions	ctnetlink groups to subscribe to events

This function returns a handler to send commands to and receive replies from kernel-space. You can pass the following subsystem IDs:

• NFNL_SUBSYS_CTNETLINK: if you are only interested in conntrack operations (excluding expectations).
• NFNL_SUBSYS_CTNETLINK_EXP: if you are only interested in expectation operations (exclude conntracks).
• NFNL_SUBSYS_NONE: if you are interested in both conntrack and expectation operations.

On error, NULL is returned and errno is explicitly set.

Definition at line 84 of file main.c.

int nfexp_callback_register	(	struct nfct_handle *	h,
		enum nf_conntrack_msg_type	type,
		int(*)(enum nf_conntrack_msg_type type, struct nf_expect *exp, void *data)	cb,
		void *	data
	)

nfexp_callback_register - register a callback

Parameters

h	library handler
cb	callback used to process expect received
data	data used by the callback, if any.

This function register a callback to handle the expect received, in case of error -1 is returned and errno is set appropiately, otherwise 0 is returned.

Note that the data parameter is optional, if you do not want to pass any data to your callback, then use NULL.

Definition at line 157 of file expect/api.c.

int nfexp_callback_register2	(	struct nfct_handle *	h,
		enum nf_conntrack_msg_type	type,
		int(*)(const struct nlmsghdr *nlh, enum nf_conntrack_msg_type type, struct nf_expect *exp, void *data)	cb,
		void *	data
	)

nfexp_callback_register2 - register a callback

Parameters

h	library handler
cb	callback used to process expect received
data	data used by the callback, if any.

This function register a callback to handle the expect received, in case of error -1 is returned and errno is set appropiately, otherwise 0 is returned.

Note that the data parameter is optional, if you do not want to pass any data to your callback, then use NULL.

NOTICE: The difference with nfexp_callback_register() is that this function uses the new callback interface that includes the Netlink header.

WARNING: Don't mix nfexp_callback_register() and nfexp_callback_register2() calls, use only once at a time.

Definition at line 231 of file expect/api.c.

void nfexp_callback_unregister

(

struct nfct_handle *

h

)

nfexp_callback_unregister - unregister a callback

Parameters

h	library handler

Definition at line 197 of file expect/api.c.

void nfexp_callback_unregister2

(

struct nfct_handle *

h

)

nfexp_callback_unregister2 - unregister a callback

Parameters

h	library handler

Definition at line 272 of file expect/api.c.