gre: fix error handler
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 <tom@herbertland.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index fdc9de2..776d145 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -468,7 +468,7 @@
bool csum_err = false;
int hdr_len;
- hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6));
+ hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
if (hdr_len < 0)
goto drop;