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>

2 files changed, 8 insertions, 0 deletions

diff --git a/include/net/flow.h b/include/net/flow.h
index 0ac3fb5e0973..7196e6864b8d 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -67,6 +67,7 @@ struct flowi {
                 } dnports;
 
                 __be32          spi;
+                __be32          gre_key;
 
                 struct {
                         __u8    type;
@@ -78,6 +79,7 @@ struct flowi {
 #define fl_icmp_code    uli_u.icmpt.code
 #define fl_ipsec_spi    uli_u.spi
 #define fl_mh_type      uli_u.mht.type
+#define fl_gre_key      uli_u.gre_key
         __u32           secid;  /* used by xfrm; see secid.txt */
 } __attribute__((__aligned__(BITS_PER_LONG/8)));
 
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index bcfb6b24b019..54b283229488 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -805,6 +805,9 @@ __be16 xfrm_flowi_sport(struct flowi *fl)
         case IPPROTO_MH:
                 port = htons(fl->fl_mh_type);
                 break;
+        case IPPROTO_GRE:
+                port = htonl(fl->fl_gre_key) >> 16;
+                break;
         default:
                 port = 0;       /*XXX*/
         }
@@ -826,6 +829,9 @@ __be16 xfrm_flowi_dport(struct flowi *fl)
         case IPPROTO_ICMPV6:
                 port = htons(fl->fl_icmp_code);
                 break;
+        case IPPROTO_GRE:
+                port = htonl(fl->fl_gre_key) & 0xffff;
+                break;
         default:
                 port = 0;       /*XXX*/
         }