+#define VNET_REWRITE_TOTAL_BYTES (VLIB_BUFFER_PRE_DATA_SIZE)
+
+STATIC_ASSERT (STRUCT_SIZE_OF (vnet_buffer_opaque_t, ip.save_rewrite_length)
+ == STRUCT_SIZE_OF (vnet_buffer_opaque_t,
+ ip.reass.save_rewrite_length)
+ && STRUCT_SIZE_OF (vnet_buffer_opaque_t,
+ ip.reass.save_rewrite_length) ==
+ STRUCT_SIZE_OF (vnet_buffer_opaque_t, mpls.save_rewrite_length)
+ && STRUCT_SIZE_OF (vnet_buffer_opaque_t,
+ mpls.save_rewrite_length) == 1
+ && VNET_REWRITE_TOTAL_BYTES < UINT8_MAX,
+ "save_rewrite_length member must be able to hold the max value of rewrite length");
+
+STATIC_ASSERT (STRUCT_OFFSET_OF (vnet_buffer_opaque_t, ip.save_rewrite_length)
+ == STRUCT_OFFSET_OF (vnet_buffer_opaque_t,
+ ip.reass.save_rewrite_length)
+ && STRUCT_OFFSET_OF (vnet_buffer_opaque_t,
+ mpls.save_rewrite_length) ==
+ STRUCT_OFFSET_OF (vnet_buffer_opaque_t,
+ ip.reass.save_rewrite_length),
+ "save_rewrite_length must be aligned so that reass doesn't overwrite it");
+