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.\" $Whistle: ng_tee.8,v 1.4 1999/01/25 23:46:27 archie Exp $ 35.\" 36.Dd May 28, 2004 37.Dt NG_TEE 4 38.Os 39.Sh NAME 40.Nm ng_tee 41.Nd netgraph ``tee'' node type 42.Sh SYNOPSIS 43.In sys/types.h 44.In netgraph/ng_tee.h 45.Sh DESCRIPTION 46The 47.Nm tee 48node type has a purpose similar to the 49.Xr tee 1 50command. 51.Nm Tee 52nodes are useful for debugging or 53.Dq snooping 54on a connection 55between two netgraph nodes. 56.Nm Tee 57nodes have four hooks, 58.Dv right , 59.Dv left , 60.Dv right2left , 61and 62.Dv left2right . 63All data received on 64.Dv right 65is sent unmodified to 66.Em both 67hooks 68.Dv left 69and 70.Dv right2left . 71Similarly, all data received on 72.Dv left 73is sent unmodified to both 74.Dv right 75and 76.Dv left2right . 77.Pp 78Packets may also be received on 79.Dv right2left 80and 81.Dv left2right ; 82if so, they are forwarded unchanged out hooks 83.Dv right 84and 85.Dv left , 86respectively. 87.Sh HOOKS 88This node type supports the following hooks: 89.Bl -tag -width ".Va left2right" 90.It Va right 91The connection to the node on the right. 92.It Va left 93The connection to the node on the left. 94.It Va right2left 95Tap for right to left traffic. 96.It Va left2right 97Tap for left to right traffic. 98.El 99.Sh CONTROL MESSAGES 100This node type supports the generic control messages, plus the following. 101.Bl -tag -width foo 102.It Dv NGM_TEE_GET_STATS Pq Ic getstats 103Get statistics, returned as a 104.Dv "struct ng_tee_stats" . 105.It Dv NGM_TEE_CLR_STATS Pq Ic clrstats 106Clear statistics. 107.El 108.Sh SHUTDOWN 109This node shuts down upon receipt of an 110.Dv NGM_SHUTDOWN 111control message, or when all hooks have been disconnected. 112If both 113.Dv right 114and 115.Dv left 116hooks are present, node removes itself from the chain gently, 117connecting 118.Dv right 119and 120.Dv left 121together. 122.Sh SEE ALSO 123.Xr tee 1 , 124.Xr netgraph 4 , 125.Xr ngctl 8 126.Sh HISTORY 127The 128.Nm 129node type was implemented in 130.Fx 4.0 . 131.Sh AUTHORS 132.An Julian Elischer Aq Mt julian@FreeBSD.org 133