NG_DEVICE(4) |
FreeBSD Kernel Interfaces Manual |
NG_DEVICE(4) |
NAME
ng_device —
device netgraph node type
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 forwarded 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 removed and becomes available for use by future
device nodes.
HISTORY
The
device node type was first implemented in
FreeBSD 5.0.
AUTHORS
Mark Santcroos <marks@ripe.net>
Gleb Smirnoff <glebius@FreeBSD.org>