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

     NGM_HOLE_GETCLR_STATS
             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>