xref: /freebsd/share/man/man4/ng_hole.4 (revision 02e9120893770924227138ba49df1edb3896112a)
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_hole.8,v 1.4 1999/01/25 23:46:26 archie Exp $
35.\"
36.Dd May 19, 2004
37.Dt NG_HOLE 4
38.Os
39.Sh NAME
40.Nm ng_hole
41.Nd netgraph discard node type
42.Sh SYNOPSIS
43.In sys/types.h
44.In netgraph/ng_hole.h
45.Sh DESCRIPTION
46The
47.Nm hole
48node type silently discards all data and control messages it receives.
49This type is used for testing and debugging.
50.Sh HOOKS
51A
52.Nm
53node accepts any request to connect, regardless of the hook name,
54as long as the name is unique.
55.Sh CONTROL MESSAGES
56This node type supports the generic control messages, plus the
57following:
58.Bl -tag -width foo
59.It Dv NGM_HOLE_GET_STATS Pq Ic getstats
60This command takes an
61.Tn ASCII
62string argument, the hook name, and returns the statistics
63associated with the hook as a
64.Vt "struct ng_hole_hookstat" .
65.It Dv NGM_HOLE_CLR_STATS Pq Ic clrstats
66This command takes an
67.Tn ASCII
68string argument, the hook name, and clears the statistics
69associated with the hook.
70.It Dv NGM_HOLE_GETCLR_STATS Pq Ic getclrstats
71This command is identical to
72.Dv NGM_HOLE_GET_STATS ,
73except that the statistics are also atomically cleared.
74.El
75.Sh SHUTDOWN
76This node shuts down upon receipt of a
77.Dv NGM_SHUTDOWN
78control message, or when all hooks have been disconnected.
79.Sh SEE ALSO
80.Xr netgraph 4 ,
81.Xr ng_echo 4 ,
82.Xr ngctl 8
83.Sh HISTORY
84The
85.Nm
86node type was implemented in
87.Fx 4.0 .
88.Sh AUTHORS
89.An Julian Elischer Aq Mt julian@FreeBSD.org
90