1.\" Copyright (c) 2005 Gleb Smirnoff <glebius@FreeBSD.org> 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd May 6, 2005 28.Dt NG_NAT 4 29.Os 30.Sh NAME 31.Nm ng_nat 32.Nd "NAT netgraph node type" 33.Sh SYNOPSIS 34.In netgraph/ng_nat.h 35.Sh DESCRIPTION 36An 37.Nm 38node performs network address translation (NAT) of packets 39passing through it. 40A 41.Nm nat 42node uses 43.Xr libalias 3 44engine for packet aliasing. 45At this moment it supports only the basic functionality of the library. 46.Sh HOOKS 47This node type has two hooks: 48.Bl -tag -width indent 49.It Va out 50Packets received on this hook are considered outgoing and will be 51masqueraded to a configured address. 52.It Va in 53Packets coming on this hook are considered incoming and will be 54dealiased. 55.El 56.Sh CONTROL MESSAGES 57This node type supports the generic control messages, plus the following: 58.Bl -tag -width indent 59.It Dv NGM_NAT_SET_IPADDR Pq Li setaliasaddr 60Configure aliasing address for a node. 61After both hooks have been connected and aliasing address was configured, 62a node is ready for aliasing operation. 63.El 64.Sh SHUTDOWN 65This node shuts down upon receipt of a 66.Dv NGM_SHUTDOWN 67control message, or when both hooks are disconnected. 68.Sh EXAMPLES 69In the following example, the packets are injected into a 70.Nm nat 71node using the 72.Xr ng_ipfw 4 73node. 74.Bd -literal -offset indent 75# Create NAT node 76ngctl mkpeer ipfw: nat 60 out 77ngctl name ipfw:60 nat 78ngctl connect ipfw: nat: 61 in 79ngctl msg nat: setaliasaddr x.y.35.8 80 81# Divert traffic into NAT node 82ipfw add 300 netgraph 61 all from any to any in via fxp0 83ipfw add 400 netgraph 60 all from any to any out via fxp0 84 85# Let packets continue with after being (de)aliased 86sysctl net.inet.ip.fw.one_pass=0 87.Ed 88.Pp 89The 90.Nm 91node can be inserted right after the 92.Xr ng_iface 4 93node in the graph. 94In the following example, we perform masquerading on a 95serial line with HDLC encapsulation. 96.Bd -literal -offset indent 97/usr/sbin/ngctl -f- <<-SEQ 98 mkpeer cp0: cisco rawdata downstream 99 name cp0:rawdata hdlc 100 mkpeer hdlc: nat inet in 101 name hdlc:inet nat 102 mkpeer nat: iface out inet 103 msg nat: setaliasaddr x.y.8.35 104SEQ 105ifconfig ng0 x.y.8.35 x.y.8.1 106.Ed 107.Sh SEE ALSO 108.Xr libalias 3 , 109.Xr ng_ipfw 4 , 110.Xr natd 8 , 111.Xr ngctl 8 112.Sh HISTORY 113The 114.Nm 115node type was implemented in 116.Fx 6.0 . 117.Sh AUTHORS 118.An Gleb Smirnoff Aq glebius@FreeBSD.org 119