[PATCH] ip neigh: Add ifindex to request when filtering dumps by device

[PATCH] ip neigh: Add ifindex to request when filtering dumps by device

[David Ahern]

Add ifindex to dump request when filtering by device. If the kernel
supports it adding the index to the request limits the amount of data
the kernel pushes to userpsace.

The feature exists in userspace already, so no need to warn the user
if kernel side support does not exist. Using the kernel side filter
makes the request more efficient.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
---
Kernel support was just picked up, 16660f0bd942, so here is the ip
patch. This one depends on the earlier refactoring done for filtering
by master device.

 ip/ipneigh.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/ip/ipneigh.c b/ip/ipneigh.c
index b8973a2d0a08..ded514da642d 100644
--- a/ip/ipneigh.c
+++ b/ip/ipneigh.c
@@ -419,6 +419,7 @@ static int do_show_or_flush(int argc, char **argv, int flush)
 			fprintf(stderr, "Cannot find device \"%s\"\n", filter_dev);
 			return -1;
 		}
+		addattr32(&req.n, sizeof(req), NDA_IFINDEX, filter.index);
 	}
 
 	if (flush) {
-- 
1.9.1

Re: [PATCH] ip neigh: Add ifindex to request when filtering dumps by device

[Stephen Hemminger]

On Wed,  7 Oct 2015 10:23:24 -0700
David Ahern <dsa@cumulusnetworks.com> wrote:

> Add ifindex to dump request when filtering by device. If the kernel
> supports it adding the index to the request limits the amount of data
> the kernel pushes to userpsace.
> 
> The feature exists in userspace already, so no need to warn the user
> if kernel side support does not exist. Using the kernel side filter
> makes the request more efficient.
> 
> Signed-off-by: David Ahern <dsa@cumulusnetworks.com>

Applied to net-next branch