From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Howells <dhowells@redhat.com>
Subject: Re: Getting at the UDP headers from ->data_ready()
Date: Mon, 11 Apr 2016 22:23:33 +0100
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Willem de Bruijn <willemdebruijn.kernel@gmail.com> wrote:

> The network and transport header pointers are still valid. Commit e6afc8ace6dd
> only  changes where skb->data points to. It does not discard the data between
> skb->head and skb->data. This rxrpc follow-up patch fixes some offset
> arithmetic to the payload, which is computed relative to skb->data.
> 
> There are other uses of ip_hdr and udp_hdr in udp_recvmsg and similar
> recvmsg handlers for other protocols. For instance, in the source address
> processing for recvfrom ("if (sin) { .. }")

Excellent, thanks!

David