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>
This commit is contained in:
Haishuang Yan 2018-09-14 12:26:48 +08:00 committed by David S. Miller
parent b0350d51f0
commit a82738adff

View File

@ -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))
if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IPV6),
offset) < 0)
return;
greh = (const struct gre_base_hdr *)(skb->data + offset);
flags = greh->flags;
if (flags & (GRE_VERSION | GRE_ROUTING))
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;