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NG_IPFW(4)	       FreeBSD Kernel Interfaces Manual		    NG_IPFW(4)

NAME
     ng_ipfw --	interface between netgraph and IP firewall

SYNOPSIS
     #include <netgraph/ng_ipfw.h>

DESCRIPTION
     The ipfw node implements interface	between	ipfw(4)	and netgraph(4)	sub-
     systems.

HOOKS
     The ipfw node supports an arbitrary number	of hooks, which	must be	named
     using only	numeric	characters.

OPERATION
     Once the ng_ipfw module is	loaded into the	kernel,	a single node named
     ipfw is automatically created.  No	more ipfw nodes	can be created.	 Once
     destroyed,	the only way to	recreate the node is to	reload the ng_ipfw
     module.

     Packets can be injected into netgraph(4) using either the netgraph	or
     ngtee commands of the ipfw(8) utility.  These commands require a numeric
     cookie to be supplied as an argument.  Packets are	sent out of the	hook
     whose name	equals the cookie value.  If no	hook matches, packets are dis-
     carded.  Packets injected via the netgraph	command	are tagged with	struct
     ng_ipfw_tag.  This	tag contains information that helps the	packet to re-
     enter ipfw(4) processing, should the packet come back from	netgraph(4) to
     ipfw(4).

	 struct	ng_ipfw_tag {
		 struct	m_tag	 mt;		 /* tag	header */
		 struct	ip_fw	 *rule;		 /* matching rule */
		 uint32_t	 rule_id;	 /* matching rule id */
		 uint32_t	 chain_id;	 /* ruleset id */
		 struct	ifnet	 *ifp;		 /* interface, for ip_output */
		 int		 dir;		 /* packet direction */
	 #define NG_IPFW_OUT	 0
	 #define NG_IPFW_IN	 1
	 };

     Packets received by a node	from netgraph(4) must be tagged	with struct
     ng_ipfw_tag tag.  Packets re-enter	IP firewall processing at the next
     rule.  If no tag is supplied, packets are discarded.

CONTROL	MESSAGES
     This node type supports only the generic control messages.

SHUTDOWN
     This node shuts down upon receipt of a NGM_SHUTDOWN control message.  Do
     not do this, since	the new	ipfw node can only be created by reloading the
     ng_ipfw module.

SEE ALSO
     ipfw(4), netgraph(4), ipfw(8), mbuf_tags(9)

HISTORY
     The ipfw node type	was implemented	in FreeBSD 6.0.

AUTHORS
     The ipfw node was written by Gleb Smirnoff	<glebius@FreeBSD.org>.

FreeBSD	9.2			 June 10, 2009			   FreeBSD 9.2

NAME | SYNOPSIS | DESCRIPTION | HOOKS | OPERATION | CONTROL MESSAGES | SHUTDOWN | SEE ALSO | HISTORY | AUTHORS

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