1.\" Copyright (c) 1996-1999 Whistle Communications, Inc. 2.\" All rights reserved. 3.\" 4.\" Subject to the following obligations and disclaimer of warranty, use and 5.\" redistribution of this software, in source or object code forms, with or 6.\" without modifications are expressly permitted by Whistle Communications; 7.\" provided, however, that: 8.\" 1. Any and all reproductions of the source or object code must include the 9.\" copyright notice above and the following disclaimer of warranties; and 10.\" 2. No rights are granted, in any manner or form, to use Whistle 11.\" Communications, Inc. trademarks, including the mark "WHISTLE 12.\" COMMUNICATIONS" on advertising, endorsements, or otherwise except as 13.\" such appears in the above copyright notice or in the software. 14.\" 15.\" THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 16.\" TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 17.\" REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 18.\" INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 19.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 20.\" WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 21.\" REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 22.\" SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 23.\" IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 24.\" RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 25.\" WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 26.\" PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 27.\" SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 28.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30.\" THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 31.\" OF SUCH DAMAGE. 32.\" 33.\" Author: Archie Cobbs <archie@FreeBSD.org> 34.\" 35.\" $FreeBSD$ 36.\" $Whistle: ng_tee.8,v 1.4 1999/01/25 23:46:27 archie Exp $ 37.\" 38.Dd May 28, 2004 39.Dt NG_TEE 4 40.Os 41.Sh NAME 42.Nm ng_tee 43.Nd netgraph ``tee'' node type 44.Sh SYNOPSIS 45.In sys/types.h 46.In netgraph/ng_tee.h 47.Sh DESCRIPTION 48The 49.Nm tee 50node type has a purpose similar to the 51.Xr tee 1 52command. 53.Nm Tee 54nodes are useful for debugging or 55.Dq snooping 56on a connection 57between two netgraph nodes. 58.Nm Tee 59nodes have four hooks, 60.Dv right , 61.Dv left , 62.Dv right2left , 63and 64.Dv left2right . 65All data received on 66.Dv right 67is sent unmodified to 68.Em both 69hooks 70.Dv left 71and 72.Dv right2left . 73Similarly, all data received on 74.Dv left 75is sent unmodified to both 76.Dv right 77and 78.Dv left2right . 79.Pp 80Packets may also be received on 81.Dv right2left 82and 83.Dv left2right ; 84if so, they are forwarded unchanged out hooks 85.Dv right 86and 87.Dv left , 88respectively. 89.Sh HOOKS 90This node type supports the following hooks: 91.Pp 92.Bl -tag -width foobarbarfoo 93.It Dv right 94The connection to the node on the right. 95.It Dv left 96The connection to the node on the left. 97.It Dv right2left 98Tap for right to left traffic. 99.It Dv left2right 100Tap for left to right traffic. 101.El 102.Sh CONTROL MESSAGES 103This node type supports the generic control messages, plus the following. 104.Bl -tag -width foo 105.It Dv NGM_TEE_GET_STATS 106Get statistics, returned as a 107.Dv "struct ng_tee_stats" . 108.It Dv NGM_TEE_CLR_STATS 109Clear statistics. 110.El 111.Sh SHUTDOWN 112This node shuts down upon receipt of an 113.Dv NGM_SHUTDOWN 114control message, or when all hooks have been disconnected. 115If both 116.Dv right 117and 118.Dv left 119hooks are present, node removes itself from the chain gently, 120connecting 121.Dv right 122and 123.Dv left 124together. 125.Sh SEE ALSO 126.Xr tee 1 , 127.Xr netgraph 4 , 128.Xr ngctl 8 129.Sh HISTORY 130The 131.Nm 132node type was implemented in 133.Fx 4.0 . 134.Sh AUTHORS 135.An Julian Elischer Aq julian@FreeBSD.org 136