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authorTimo Teräs <timo.teras@iki.fi>2010-11-03 04:41:38 +0000
committerDavid S. Miller <davem@davemloft.net>2010-11-15 10:44:04 -0800
commitcc9ff19da9bf76a2f70bcb80225a1c587c162e52 (patch)
tree181efcd617a42a48fa94c51cfe9dc0e77b3b5775 /net/ipv4/xfrm4_policy.c
parente1f2d8c2cc61d2b9472efe44e8a2b098336914b4 (diff)
downloadlinux-cc9ff19da9bf76a2f70bcb80225a1c587c162e52.tar.gz
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>
Diffstat (limited to 'net/ipv4/xfrm4_policy.c')
-rw-r--r--net/ipv4/xfrm4_policy.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index dd1fd8c473fc..4a8c5335770c 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -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;