Subject: Can ndo_select_queue save data in skb->cb?

From: James Yonan <[email-masked]>
Date: Wed, 05 Nov 2014 10:57:00 -0700

Is it permissible for a net driver's ndo_select_queue method to save 
data in skb->cb for later use in ndo_start_xmit?

Also, is it necessary for users of skb->cb to zero out their private 
data after use to prevent it from being misinterpreted by other layers? 
  I noticed some commits in the log (such as 462fb2) are zeroing out the 
skb->cb area for this reason.

Thanks,
James