NG_HOLE (4) | Special files and drivers | Unix Manual Pages | :man▋
ng_hole - netgraph discard node type
The hole node type silently discards all data and control messages it receives. This type is used for testing and debugging.
A ng_hole node accepts any request to connect, regardless of the hook name, as long as the name is unique.
This node type supports the generic control messages, plus the following:
| NGM_BPF_GET_STATS |
| || This command takes an ASCII string argument, the hook name, and returns the statistics associated with the hook as a |
.Vt "struct ng_hole_hookstat" .
| NGM_BPF_CLR_STATS |
| || This command takes an ASCII string argument, the hook name, and clears the statistics associated with the hook. |
| NGM_BPF_GETCLR_STATS |
| || This command is identical to NGM_BPF_GET_STATS, except that the statistics are also atomically cleared. |
This node shuts down upon receipt of a NGM_SHUTDOWN control message, or when all hooks have been disconnected.
netgraph(4), ng_echo(4), ngctl(8)