Re: [PATCH v4 2/2] ip_tunnel: add mpls over gre encapsulation

On 09/29/2017 06:11 AM, Tom Herbert wrote:

quoted

quoted

@@ -122,6 +125,30 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 }
 EXPORT_SYMBOL(gre_parse_header);

+#if IS_ENABLED(CONFIG_MPLS)
+int mpls_gre_rcv(struct sk_buff *skb, int gre_hdr_len)
+{
+       if (unlikely(!pskb_may_pull(skb, gre_hdr_len)))
+               goto drop;
+
+       /* Pop GRE hdr and reset the skb */
+       skb_pull(skb, gre_hdr_len);
+       skb_reset_network_header(skb);
+

I don't see why MPLS/GRE needs to be a special case in gre_rcv. Can't
we just follow the normal processing patch which calls the proto ops
handler for the protocol in the GRE header? Also, if protocol specific
code is added to rcv function that most likely means that we need to
update the related offloads also (grant it that MPLS doesn't support
GRO but it looks like it supports GSO). Additionally, we'd need to
consider if flow dissector needs a similar special case (I will point
out that my recently posted patches there eliminated TEB as the one
special case in GRE dissection).

Thanks,
Tom

Hi Tom,

Thanks for the feedback, I think this is the best way to do it, I'll do 
a v6 asap.

Regards,
Amine