NAME

       ng_hole — netgraph discard node type

SYNOPSIS

       #include <sys/types.h>
       #include <netgraph/ng_hole.h>

DESCRIPTION

       The  hole  node  type silently discards all data and control messages it receives.  This type is used for
       testing and debugging.

HOOKS

       A ng_hole node accepts any request to connect, regardless of the hook  name,  as  long  as  the  name  is
       unique.

CONTROL MESSAGES

       This node type supports the generic control messages, plus the following:

       NGM_HOLE_GET_STATS (getstats)
            This  command  takes  an ASCII string argument, the hook name, and returns the statistics associated
            with the hook as a struct ng_hole_hookstat.

       NGM_HOLE_CLR_STATS (clrstats)
            This command takes an ASCII string argument, the hook name, and  clears  the  statistics  associated
            with the hook.

       NGM_HOLE_GETCLR_STATS (getclrstats)
            This  command  is  identical  to  NGM_HOLE_GET_STATS, except that the statistics are also atomically
            cleared.

SHUTDOWN

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

SEE ALSO

       netgraph(4), ng_echo(4), ngctl(8)

HISTORY

       The ng_hole node type was implemented in FreeBSD 4.0.

AUTHORS

       Julian Elischer <julian@FreeBSD.org>

Debian                                            May 19, 2004                                        NG_HOLE(4)