[PATCH RFC 1/7] net: Fix GRE RX to use skb_transport_header for offset
From: Tom Herbert <hidden>
Date: 2014-01-02 22:12:38
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> --- net/ipv4/gre_demux.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c
index 5893e99..6fe5036 100644
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c@@ -118,7 +118,6 @@ static __sum16 check_checksum(struct sk_buff *skb) 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;
@@ -126,7 +125,7 @@ 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;
@@ -136,7 +135,7 @@ 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);
--
1.8.5.1