1 files changed, 17 insertions, 0 deletions

diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c
index a4bf22ee3aed..7c4a41dc04bb 100644
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c
@@ -25,6 +25,7 @@
 #include <linux/spinlock.h>
 #include <net/protocol.h>
 #include <net/gre.h>
+#include <net/erspan.h>
 
 #include <net/icmp.h>
 #include <net/route.h>
@@ -119,6 +120,22 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
                         hdr_len += 4;
         }
         tpi->hdr_len = hdr_len;
+
+        /* ERSPAN ver 1 and 2 protocol sets GRE key field
+         * to 0 and sets the configured key in the
+         * inner erspan header field
+         */
+        if (greh->protocol == htons(ETH_P_ERSPAN) ||
+            greh->protocol == htons(ETH_P_ERSPAN2)) {
+                struct erspan_base_hdr *ershdr;
+
+                if (!pskb_may_pull(skb, nhs + hdr_len + sizeof(*ershdr)))
+                        return -EINVAL;
+
+                ershdr = (struct erspan_base_hdr *)options;
+                tpi->key = cpu_to_be32(get_session_id(ershdr));
+        }
+
         return hdr_len;
 }
 EXPORT_SYMBOL(gre_parse_header);