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>