Netlink message helper functions

Functions
struct nlmsghdr *	nfacct_nlmsg_build_hdr (char *buf, uint8_t cmd, uint16_t flags, uint32_t seq)
void	nfacct_nlmsg_build_payload (struct nlmsghdr *nlh, struct nfacct *nfacct)
int	nfacct_nlmsg_parse_payload (const struct nlmsghdr *nlh, struct nfacct *nfacct)

Detailed Description

Function Documentation

struct nlmsghdr* nfacct_nlmsg_build_hdr	(	char *	buf,
		uint8_t	cmd,
		uint16_t	flags,
		uint32_t	seq
	)

nfacct_nlmsg_build_hdr - build netlink message header for nfacct subsystem

Parameters

buf	buffer where this function outputs the netlink message.
cmd	nfacct nfnetlink command.
flags	netlink flags.
seq	sequence number for this message.

Possible commands:

• NFNL_MSG_ACCT_NEW: new accounting object.
• NFNL_MSG_ACCT_GET: get accounting object.
• NFNL_MSG_ACCT_GET_CTRZERO: get accounting object and atomically reset.

Examples:

• Command NFNL_MSG_ACCT_NEW + flags NLM_F_CREATE | NLM_F_ACK, to create one new accounting object (if it does not already exists). You receive one acknoledgment in any case with the result of the operation.
• Command NFNL_MSG_ACCT_GET + flags NLM_F_DUMP, to obtain all the existing accounting objects.
• Command NFNL_MSG_ACCT_GET_CTRZERO + flags NLM_F_DUMP, to atomically obtain all the existing accounting objects and reset them.
• Command NFNL_MSG_ACCT_DEL, to delete all existing unused objects.
• Command NFNL_MSG_ACCT_DEL, to delete one specific nfacct object (if unused, otherwise you hit EBUSY).

Definition at line 488 of file libnetfilter_acct.c.

void nfacct_nlmsg_build_payload	(	struct nlmsghdr *	nlh,
		struct nfacct *	nfacct
	)

nfacct_nlmsg_build_payload - build payload from accounting object

Parameters

nlh	netlink message that you want to use to add the payload.
nfacct	pointer to a accounting object

Definition at line 512 of file libnetfilter_acct.c.

int nfacct_nlmsg_parse_payload	(	const struct nlmsghdr *	nlh,
		struct nfacct *	nfacct
	)

nfacct_nlmsg_parse_payload - set accounting object attributes from message

Parameters

nlh	netlink message that you want to use to add the payload.
nfacct	pointer to a accounting object

This function returns -1 in case that some mandatory attributes are missing. On sucess, it returns 0.

Definition at line 567 of file libnetfilter_acct.c.