NG_UI(4)               FreeBSD Kernel Interfaces Manual               NG_UI(4)

NAME
     ng_UI - UI netgraph node type

SYNOPSIS
     #include <netgraph/ng_UI.h>

DESCRIPTION
     The UI node type has two hooks, upstream and downstream.  Packets
     received on downstream must have 0x03 (indicating unnumbered information)
     as their first byte; if not the packet is dropped.  This byte is then
     stripped and the remainder of the packet sent out on upstream.

     Conversely, packets received on upstream will have a 0x03 byte prepended
     to them before being forwarded out on the downstream hook.

HOOKS
     This node type supports the following hooks:

     downstream      Downstream connection.  Packets on this side of the node
                     have a 0x03 as their first byte.

     upstream        Upstream connection.  Packets on this side of the node
                     have the initial 0x03 byte stripped off.

CONTROL MESSAGES
     This node type supports only the generic control messages.

SHUTDOWN
     This node shuts down upon receipt of a NGM_SHUTDOWN control message, or
     when both hooks have been disconnected.

SEE ALSO
     netgraph(4), ngctl(8)

HISTORY
     The ng_UI node type was implemented in FreeBSD 4.0.

AUTHORS
     Julian Elischer <julian@FreeBSD.org>

FreeBSD 13.1-RELEASE-p6        January 19, 1999        FreeBSD 13.1-RELEASE-p6