xref: /freebsd/share/man/man4/ng_device.4 (revision 7afb8adff33d47f10a11368ff54bb2eec5b30165)
1.\" Copyright (c) 2002 Mark Santcroos <marks@ripe.net>
2.\"
3.\" Redistribution and use in source and binary forms, with or without
4.\" modification, are permitted provided that the following conditions
5.\" are met:
6.\" 1. Redistributions of source code must retain the above copyright
7.\"    notice, this list of conditions and the following disclaimer.
8.\" 2. Redistributions in binary form must reproduce the above copyright
9.\"    notice, this list of conditions and the following disclaimer in the
10.\"    documentation and/or other materials provided with the distribution.
11.\" 3. The name of the author may not be used to endorse or promote products
12.\"    derived from this software without specific prior written permission.
13.\"
14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24.\"
25.\" $FreeBSD$
26.\"
27.Dd October 19, 2004
28.Dt NG_DEVICE 4
29.Os
30.Sh NAME
31.Nm ng_device
32.Nd device netgraph node type
33.Sh SYNOPSIS
34.In netgraph/ng_device.h
35.Sh DESCRIPTION
36A
37.Nm device
38node is both a netgraph node and a system device interface.
39When a
40.Nm device
41node is created, a new device entry appears which is accessible via the
42regular file operators such as
43.Xr open 2 ,
44.Xr close 2 ,
45.Xr read 2 ,
46.Xr write 2 ,
47etc.
48.Pp
49The first node is created as
50.Pa /dev/ngd0 ,
51all subsequent nodes
52.Pa /dev/ngd1 , /dev/ngd2 ,
53etc.
54.Sh HOOKS
55A
56.Nm device
57node has a single hook with an arbitrary name.
58All data coming in over the hook will be presented to the device
59for
60.Xr read 2 .
61All data coming in from the device entry by
62.Xr write 2
63will be forwarded to the hook.
64.Sh CONTROL MESSAGES
65The
66.Nm device
67node supports one non-generic control message:
68.Bl -tag -width 3n
69.It Dv NGM_DEVICE_GET_DEVNAME
70Returns device name corresponding to a node.
71.El
72.\" Additionally, the node accepts
73.\" .Xr ioctl 2 Ns s
74.\" from the device entry.
75.\" These will be encapsulated into
76.\" .Xr netgraph 4
77.\" messages and send out to the hook.
78.Sh SHUTDOWN
79This node shuts down upon receipt of a
80.Dv NGM_SHUTDOWN
81control message, or upon hook disconnection.
82The associated device entry is removed and becomes available
83for use by future
84.Nm device
85nodes.
86.Sh SEE ALSO
87.Xr netgraph 4 ,
88.Xr ngctl 8
89.Sh HISTORY
90The
91.Nm device
92node type was first implemented in
93.Fx 5.0 .
94.Sh AUTHORS
95.An Mark Santcroos Aq Mt marks@ripe.net
96.An Gleb Smirnoff Aq Mt glebius@FreeBSD.org
97