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 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.

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>