Re: [PATCH v2 net] gre: fix error handler

On Wed, 15 Jun 2016 06:24:00 -0700, Eric Dumazet wrote:

From: Eric Dumazet <edumazet@google.com>

1) gre_parse_header() can be called from gre_err()

   At this point transport header points to ICMP header, not the inner
header.

2) We can not really change transport header as ipgre_err() will later
assume transport header still points to ICMP header (using icmp_hdr())

3) pskb_may_pull() logic in gre_parse_header() really works
  if we are interested at zone pointed by skb->data

4) As Jiri explained in commit b7f8fe251e46 ("gre: do not pull header in
ICMP error processing") we should not pull headers in error handler.

So this fix :

A) changes gre_parse_header() to use skb->data instead of
skb_transport_header()

B) Adds a nhs parameter to gre_parse_header() so that we can skip the
not pulled IP header from error path.
  This offset is 0 for normal receive path.

C) remove obsolete IPV6 includes

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <redacted>
Cc: Maciej Żenczykowski <redacted>
Cc: Jiri Benc <redacted>

Reviewed-by: Jiri Benc <redacted>

I know this has already been applied. Didn't get to it earlier, sorry.
The patch looks good. Thanks!

 Jiri