xref: /freebsd/share/man/man4/ng_device.4 (revision c6ec7d31830ab1c80edae95ad5e4b9dba10c47ac)
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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 marks@ripe.net
96.An Gleb Smirnoff Aq glebius@FreeBSD.org
97