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$FreeBSD: releng/10.2/share/man/man4/ng_device.4 140111 2005-01-12 10:14:43Z ru $
.Dd October 19, 2004 .Dt NG_DEVICE 4 .Os .Sh NAME .Nm ng_device .Nd device netgraph node type .Sh SYNOPSIS n netgraph/ng_device.h .Sh DESCRIPTION A .Nm device node is both a netgraph node and a system device interface. When a .Nm device node is created, a new device entry appears which is accessible via the regular file operators such as .Xr open 2 , .Xr close 2 , .Xr read 2 , .Xr write 2 , etc.
p The first node is created as
a /dev/ngd0 , all subsequent nodes
a /dev/ngd1 , /dev/ngd2 ,
etc.
.Sh HOOKS
A
.Nm device
node has a single hook with an arbitrary name.
All data coming in over the hook will be presented to the device
for
.Xr read 2 .
All data coming in from the device entry by
.Xr write 2
will be forwarded to the hook.
.Sh CONTROL MESSAGES
The
.Nm device
node supports one non-generic control message:
l -tag -width 3n t Dv NGM_DEVICE_GET_DEVNAME Returns device name corresponding to a node.
.El
Additionally, the node accepts
.Xr ioctl 2 Ns s
from the device entry.
These will be encapsulated into
.Xr netgraph 4
messages and send out to the hook.
.Sh SHUTDOWN
This node shuts down upon receipt of a
.Dv NGM_SHUTDOWN
control message, or upon hook disconnection.
The associated device entry is removed and becomes available
for use by future
.Nm device
nodes.
.Sh SEE ALSO
.Xr netgraph 4 ,
.Xr ngctl 8
.Sh HISTORY
The
.Nm device
node type was first implemented in
.Fx 5.0 .
.Sh AUTHORS
.An Mark Santcroos Aq marks@ripe.net
.An Gleb Smirnoff Aq glebius@FreeBSD.org