xref: /freebsd/share/man/man4/ng_hole.4 (revision b2d48be1bc7df45ddd13b143a160d0acb5a383c5)
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33.\" Author: Archie Cobbs <archie@FreeBSD.org>
34.\"
35.\" $FreeBSD$
36.\" $Whistle: ng_hole.8,v 1.4 1999/01/25 23:46:26 archie Exp $
37.\"
38.Dd May 19, 2004
39.Dt NG_HOLE 4
40.Os
41.Sh NAME
42.Nm ng_hole
43.Nd netgraph discard node type
44.Sh SYNOPSIS
45.In sys/types.h
46.In netgraph/ng_hole.h
47.Sh DESCRIPTION
48The
49.Nm hole
50node type silently discards all data and control messages it receives.
51This type is used for testing and debugging.
52.Sh HOOKS
53A
54.Nm
55node accepts any request to connect, regardless of the hook name,
56as long as the name is unique.
57.Sh CONTROL MESSAGES
58This node type supports the generic control messages, plus the
59following:
60.Bl -tag -width foo
61.It Dv NGM_HOLE_GET_STATS Pq Ic getstats
62This command takes an
63.Tn ASCII
64string argument, the hook name, and returns the statistics
65associated with the hook as a
66.Vt "struct ng_hole_hookstat" .
67.It Dv NGM_HOLE_CLR_STATS Pq Ic clrstats
68This command takes an
69.Tn ASCII
70string argument, the hook name, and clears the statistics
71associated with the hook.
72.It Dv NGM_HOLE_GETCLR_STATS Pq Ic getclrstats
73This command is identical to
74.Dv NGM_HOLE_GET_STATS ,
75except that the statistics are also atomically cleared.
76.El
77.Sh SHUTDOWN
78This node shuts down upon receipt of a
79.Dv NGM_SHUTDOWN
80control message, or when all hooks have been disconnected.
81.Sh SEE ALSO
82.Xr netgraph 4 ,
83.Xr ng_echo 4 ,
84.Xr ngctl 8
85.Sh HISTORY
86The
87.Nm
88node type was implemented in
89.Fx 4.0 .
90.Sh AUTHORS
91.An Julian Elischer Aq Mt julian@FreeBSD.org
92