124 lines
3.4 KiB
Groff
124 lines
3.4 KiB
Groff
.\" Copyright (c) 2005 Gleb Smirnoff
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.Dd February 5, 2005
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.Dt NG_IPFW 4
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.Os
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.Sh NAME
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.Nm ng_ipfw
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.Nd interface between netgraph and IP firewall
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.Sh SYNOPSIS
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.In netgraph/ng_ipfw.h
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.Sh DESCRIPTION
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The
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.Nm ipfw
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node implements an interface between
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.Xr ipfw 4
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and
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.Xr netgraph 4
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subsystems.
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.Sh HOOKS
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The
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.Nm ipfw
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node supports an arbitrary number of hooks,
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which must be named using only numeric characters.
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.Sh OPERATION
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Once
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.Nm
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module is loaded into the kernel, a single node named
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.Qq ipfw
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is automatically created.
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No more
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.Nm ipfw
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nodes can be created.
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Once destroyed, the only way to recreate node is reload
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.Nm
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module.
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.Pp
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Packets can be injected into netgraph using either
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.Cm netgraph
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or
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.Cm ngtee
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commands of
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.Xr ipfw 8
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utility.
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These commands require a numeric cookie to be supplied as argument.
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Packets are sent out of the hook, which name is equal cookie value.
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If no hook matches, packets are discarded.
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Packets injected via
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.Cm netgraph
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command are tagged with
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.Vt "struct ng_ipfw_tag" .
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The tag contains information, which helps node to reenter packet into
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.Xr ipfw 4
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processing, if the packet will come back to node from netgraph.
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.Bd -literal -offset 4n
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struct ng_ipfw_tag {
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struct m_tag mt; /* tag header */
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struct ip_fw *rule; /* matching rule */
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struct ifnet *ifp; /* interface, for ip_output */
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int dir; /* packet direction */
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#define NG_IPFW_OUT 0
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#define NG_IPFW_IN 1
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int flags; /* flags, for ip_output() */
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};
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.Ed
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.Pp
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Packets received by node from netgraph must be tagged with
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.Vt "struct ng_ipfw_tag"
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tag.
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Packets reenter IP firewall processing at the next rule.
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If no tag is supplied, packets are discarded.
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.Sh CONTROL MESSAGES
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The
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.Nm ipfw
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node does not have any type specific control messages.
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.Sh SHUTDOWN
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This node shuts down upon receipt of a
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.Dv NGM_SHUTDOWN
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control message.
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Don't do this, since new
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.Nm ipfw
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node can be created only reloading
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.Nm
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module.
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.Sh SEE ALSO
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.Xr netgraph 4 ,
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.Xr ipfw 4 ,
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.Xr ipfw 8 ,
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.Xr mbuf_tags 8
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.Sh HISTORY
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The
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.Nm ipfw
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node type was implemented in
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.Fx 6.0 .
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.Sh AUTHORS
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.An -nosplit
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The
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.Nm ipfw
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node was written by
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.An "Gleb Smirnoff" Aq glebius@FreeBSD.org .
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