ip6_gre: simplify gre header parsing in ip6gre_err

Same as ip_gre, use gre_parse_header to parse gre header in gre error
handler code.

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.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 e493b041d4ac9900d44972a22ebdc898def323fe..515adbdba1d278bf7773b78d42957679418ec0d7 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -427,35 +427,17 @@ static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
                       u8 type, u8 code, int offset, __be32 info)
 {
        struct net *net = dev_net(skb->dev);
-       const struct gre_base_hdr *greh;
        const struct ipv6hdr *ipv6h;
-       int grehlen = sizeof(*greh);
+       struct tnl_ptk_info tpi;
        struct ip6_tnl *t;
-       int key_off = 0;
-       __be16 flags;
-       __be32 key;
 
-       if (!pskb_may_pull(skb, offset + grehlen))
-               return;
-       greh = (const struct gre_base_hdr *)(skb->data + offset);
-       flags = greh->flags;
-       if (flags & (GRE_VERSION | GRE_ROUTING))
+       if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IPV6),
+                            offset) < 0)
                return;
-       if (flags & GRE_CSUM)
-               grehlen += 4;
-       if (flags & GRE_KEY) {
-               key_off = grehlen + offset;
-               grehlen += 4;
-       }
 
-       if (!pskb_may_pull(skb, offset + grehlen))
-               return;
        ipv6h = (const struct ipv6hdr *)skb->data;
-       greh = (const struct gre_base_hdr *)(skb->data + offset);
-       key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
-
        t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
-                                key, greh->protocol);
+                                tpi.key, tpi.proto);
        if (!t)
                return;