xfrm: use gre key as flow upper protocol info

The GRE Key field is intended to be used for identifying an individual
traffic flow within a tunnel. It is useful to be able to have XFRM
policy selector matches to have different policies for different
GRE tunnels.

Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Timo Teräs 2010-11-03 04:41:38 +00:00 committed by David S. Miller
parent e1f2d8c2cc
commit cc9ff19da9
4 changed files with 30 additions and 5 deletions

View file

@ -11,6 +11,7 @@
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/inetdevice.h>
#include <linux/if_tunnel.h>
#include <net/dst.h>
#include <net/xfrm.h>
#include <net/ip.h>
@ -154,6 +155,20 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
}
break;
case IPPROTO_GRE:
if (pskb_may_pull(skb, xprth + 12 - skb->data)) {
__be16 *greflags = (__be16 *)xprth;
__be32 *gre_hdr = (__be32 *)xprth;
if (greflags[0] & GRE_KEY) {
if (greflags[0] & GRE_CSUM)
gre_hdr++;
fl->fl_gre_key = gre_hdr[1];
}
}
break;
default:
fl->fl_ipsec_spi = 0;
break;