gre: change gre_parse_header to return the header length
It's easier for gre_parse_header to return the header length instead of
filing it into a parameter. That way, the callers that don't care about the
header length can just check whether the returned value is lower than zero.
In gre_err, the tunnel header must not be pulled. See commit b7f8fe251e46
("gre: do not pull header in ICMP error processing") for details.
This patch reduces the conflict between the mentioned commit and commit
95f5c64c3c13 ("gre: Move utility functions to common headers").
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Tom Herbert <tom@herbertland.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 1012774..47b671a 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -468,7 +468,8 @@
bool csum_err = false;
int hdr_len;
- if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len) < 0)
+ hdr_len = gre_parse_header(skb, &tpi, &csum_err);
+ if (hdr_len < 0)
goto drop;
if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))