parse ethernet header in ct6_in2out

fix a debug CLI scripting bug: cp_ip6_address_add_del_command_function
ate any subsequent commands, yielding indigestion.

Change-Id: Iaca7bed5687759da36ae91dc658e758549b71796
Signed-off-by: Dave Barach <dave@barachs.net>
diff --git a/src/plugins/ct6/ct6_in2out.c b/src/plugins/ct6/ct6_in2out.c
index b28d349..4f2ebae 100644
--- a/src/plugins/ct6/ct6_in2out.c
+++ b/src/plugins/ct6/ct6_in2out.c
@@ -235,7 +235,10 @@
 
       /*
        * 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 @@
       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);
 
       /*
diff --git a/src/vnet/dhcp/dhcp6_pd_client_cp.c b/src/vnet/dhcp/dhcp6_pd_client_cp.c
index eb18ed2..a157b16 100644
--- a/src/vnet/dhcp/dhcp6_pd_client_cp.c
+++ b/src/vnet/dhcp/dhcp6_pd_client_cp.c
@@ -966,26 +966,33 @@
   u32 prefix_length;
   u8 address_set = 0;
   u8 add = 1;
+  unformat_input_t _line_input, *line_input = &_line_input;
 
-  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
     {
       if (unformat
-	  (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index));
-      else if (unformat (input, "prefix group %s", &prefix_group));
+	  (line_input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index));
+      else if (unformat (line_input, "prefix group %s", &prefix_group));
       else
-	if (unformat
-	    (input, "%U/%d", unformat_ip6_address, &address, &prefix_length))
+	if (unformat (line_input, "%U/%d", unformat_ip6_address,
+		      &address, &prefix_length))
 	address_set = 1;
-      else if (unformat (input, "del"))
+      else if (unformat (line_input, "del"))
 	add = 0;
       else
 	{
 	  error = clib_error_return (0, "unexpected input `%U'",
-				     format_unformat_error, input);
+				     format_unformat_error, line_input);
+	  unformat_free (line_input);
 	  goto done;
 	}
     }
 
+  unformat_free (line_input);
+
   if (sw_if_index == ~0)
     error = clib_error_return (0, "Missing sw_if_index");
   else if (address_set == 0)