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

NAME
     ng_ipfw - interface between netgraph and IP firewall

SYNOPSIS
     #include <netinet/ip_var.h>
     #include <netgraph/ng_ipfw.h>

DESCRIPTION
     The ipfw node implements interface between ipfw(4) and netgraph(4)
     subsystems.

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
     discarded.  Packets injected via the netgraph command are tagged with
     struct ipfw_rule_ref.  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).

     Packets received by a node from netgraph(4) subsystem must be tagged with
     struct ipfw_rule_ref 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 13.1-RELEASE-p6          March 2, 2010         FreeBSD 13.1-RELEASE-p6