ng_device(4)

NAME

ng_device - device netgraph node type

SYNOPSIS

#include <netgraph/ng_device.h>

DESCRIPTION

A device node is both a netgraph node and a system device

interface.
When a device node is created, a new device entry appears

which is accessible via the regular file operators such as open(2),

close(2), read(2),
write(2), etc.

The first node is created as /dev/ngd0, all subsequent nodes

/dev/ngd1,
/dev/ngd2, etc.

HOOKS

A device node has a single hook with an arbitrary name. All

data coming
in over the hook will be presented to the device for

read(2). All data
coming in from the device entry by write(2) will be forward

ed to the
hook.

CONTROL MESSAGES

The device node supports one non-generic control message:

NGM_DEVICE_GET_DEVNAME

Returns device name corresponding to a node.

SHUTDOWN

This node shuts down upon receipt of a NGM_SHUTDOWN control

message, or
upon hook disconnection. The associated device entry is re

moved and
becomes available for use by future device nodes.

SEE ALSO

netgraph(4), ngctl(8)

HISTORY

The device node type was first implemented in FreeBSD 5.0.

AUTHORS

Mark Santcroos <marks@ripe.net>
Gleb Smirnoff <glebius@FreeBSD.org>

BSD October 19, 2004

BSD