From: David Ahern <redacted>
Date: Tue, 29 Sep 2015 09:32:03 -0700

Add support for filtering neighbor dumps by master device by adding
the NDA_MASTER attribute to the dump request. A new netlink flag,
NLM_F_DUMP_FILTERED, is added to indicate the kernel supports the
request and output is filtered as requested.

Signed-off-by: David Ahern <redacted>
---
v2
- added NLM_F_DUMP_FILTERED flag for userspace feedback that request is
  supported

This method works for other filters as well and other dump commands.
Works fine for all combinations of new and old kernel and new and old ip:
1. new ip command on old kernel, NDA_MASTER attribute is ignored
2. old ip command on new kernel, NDA_MASTER attribute is not present
3. new ip on new kernel ... goodness ensues by limiting data to
   only what user wants

Applied, thanks.