parse ethernet header in ct6_in2out

[vpp.git] / src / plugins / ct6 / ct6_in2out.c

diff --git a/src/plugins/ct6/ct6_in2out.c b/src/plugins/ct6/ct6_in2out.c
index b28d349..4f2ebae 100644 (file)
--- a/src/plugins/ct6/ct6_in2out.c
+++ b/src/plugins/ct6/ct6_in2out.c
@@ -235,7 +235,10 @@ ct6_in2out_inline (vlib_main_t * vm,
 
       /*
        * This is an output feature which runs at the last possible
-       * moment. Assume an ethernet header.
+       * moment. Assume an ethernet header. Make sure the packet is
+       * actually ipv6 before we do anything else.
+       *
+       * Unfortunately, we have to re-parse the L2 header.
        */
 
       e0 = vlib_buffer_get_current (b[0]);
@@ -245,6 +248,18 @@ ct6_in2out_inline (vlib_main_t * vm,
       delta0 += (e0->type == clib_net_to_host_u16 (ETHERNET_TYPE_DOT1AD))
        ? 8 : 0;
 
+      if (PREDICT_TRUE (delta0 == sizeof (*e0)))
+       {
+         if (e0->type != clib_host_to_net_u16 (ETHERNET_TYPE_IP6))
+           goto trace0;
+       }
+      else
+       {
+         u16 *tagged_etype_ptr = vlib_buffer_get_current (b[0]) + delta0 - 2;
+         if (*tagged_etype_ptr != clib_host_to_net_u16 (ETHERNET_TYPE_IP6))
+           goto trace0;
+       }
+
       ip0 = (ip6_header_t *) (vlib_buffer_get_current (b[0]) + delta0);
 
       /*