ng_device — device netgraph node type
Contents
Control Messages
The device node supports one non-generic control message:
NGM_DEVICE_GET_DEVNAME
Returns device name corresponding to a node.
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.
History
The device node type was first implemented in FreeBSD 5.0.
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
forwarded to the hook.
Name
ng_device — device netgraph node type
See Also
netgraph(4), ngctl(8)
Shutdown
This node shuts down upon receipt of a NGM_SHUTDOWN control message, or upon hook disconnection. The
associated device entry is removed and becomes available for use by future device nodes.
Synopsis
#include<netgraph/ng_device.h>
