Useful stuff. There are things along these lines that i have been
contemplating myself.

I think it would be valuable to specify a set of flags for filtering
what gets sent to user space instead of unconditionally.

Example, 
filter level 0:
  - what we have before your patch
filter level 1:
  - protocol version
  - header size
  - maximum number of attributes
filter level 2:
  - the rest of the stuff you have
 
What netlink does today to filter at user space is something that can be
avoided with the above (an improvement in my opinion if you have a lot
of genl items in the kernel).

cheers,
jamal

On Thu, 2006-31-08 at 23:21 +0200, Thomas Graf wrote:

Additionaly exports the following information when providing
the list of registered generic netlink families:
  - protocol version
  - header size
  - maximum number of attributes

  - list of available operations including
      - id
      - flags
      - avaiability of policy and doit/dumpit function

libnl HEAD provides a utility to read this new information:

	0x0010 nlctrl version 1
	    hdrsize 0 maxattr 6
	      op GETFAMILY (0x03) [POLICY,DOIT,DUMPIT]
	0x0011 NLBL_MGMT version 1
	    hdrsize 0 maxattr 0
	      op unknown (0x02) [DOIT]
	      op unknown (0x03) [DOIT]
	      ....