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authorTom Herbert <therbert@google.com>2014-09-08 19:29:12 +0400
committerDavid S. Miller <davem@davemloft.net>2014-09-09 02:23:05 +0400
commit1e701f16982a9d15488a5aa8c7f5c41444b1de67 (patch)
treeffd2de95a203e68a1f070e80955738f1006dd826 /net/ipv4/gre_demux.c
parentdb91b724b53b1cfd0e258d7cf3a03a062a89fe2d (diff)
downloadlinux-1e701f16982a9d15488a5aa8c7f5c41444b1de67.tar.xz
net: Fix GRE RX to use skb_transport_header for GRE header offset
GRE assumes that the GRE header is at skb_network_header + ip_hrdlen(skb). It is more general to use skb_transport_header and this allows the possbility of inserting additional header between IP and GRE (which is what we will done in Generic UDP Encapsulation for GRE). Signed-off-by: Tom Herbert <therbert@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/gre_demux.c')
-rw-r--r--net/ipv4/gre_demux.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c
index 7e0756da8737..4a7b5b2a1ce3 100644
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c
@@ -98,7 +98,6 @@ EXPORT_SYMBOL_GPL(gre_build_header);
static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
bool *csum_err)
{
- unsigned int ip_hlen = ip_hdrlen(skb);
const struct gre_base_hdr *greh;
__be32 *options;
int hdr_len;
@@ -106,7 +105,7 @@ static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
return -EINVAL;
- greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen);
+ greh = (struct gre_base_hdr *)skb_transport_header(skb);
if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
return -EINVAL;
@@ -116,7 +115,7 @@ static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
if (!pskb_may_pull(skb, hdr_len))
return -EINVAL;
- greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen);
+ greh = (struct gre_base_hdr *)skb_transport_header(skb);
tpi->proto = greh->protocol;
options = (__be32 *)(greh + 1);