NG_HOLE(4)             FreeBSD Kernel Interfaces Manual             NG_HOLE(4)

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>

FreeBSD 13.1-RELEASE-p6          May 19, 2004          FreeBSD 13.1-RELEASE-p6