RE: [RFC PATCH] rtnetlink: Fix problem with buffer allocation

-----Original Message-----
From: David Miller [mailto:davem@davemloft.net]
Sent: Friday, February 10, 2012 10:52 AM
To: Rose, Gregory V
Cc: netdev@vger.kernel.org
Subject: Re: [RFC PATCH] rtnetlink: Fix problem with buffer allocation

From: Greg Rose <redacted>
Date: Fri, 10 Feb 2012 07:05:18 -0800

quoted

+/*
+ * Applications that set NLM_F_EXT have allocated
+ * a 16K or larger buffer.
+ * (Or they should have before using this flag)
+ */
+#define NLM_F_EXT	0x800   /* Get extended interface info such as VFs

*/

This is not what I meant.

I meant to add a "netlink attribute" that gets passed in with GETLINK
requests.  Which is a u32 set of flag bits, one bit for each extended
feature.  So VF would get one bit.

Like "IFLA_EXT_MASK" or similar.

Then rtnl_getlink() would inspect the mask (using nla_get_32()), if
present, and make this control what extended parts of the per-link
dump are provided.

OK, sounds good.  How about I also add a field to indicate the application buffer size?

- Greg