From 5e36815867dec8757ad7f1e386061d90874832ad Mon Sep 17 00:00:00 2001
From: Dirk Ziegelmeier <dirk@ziegelmeier.net>
Date: Fri, 19 Aug 2016 13:05:51 +0200
Subject: [PATCH] init.c: Implement check for correct implementation of struct
 packing in lwip port

---
 src/core/init.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/src/core/init.c b/src/core/init.c
index 182aaff7..3e39f9d5 100644
--- a/src/core/init.c
+++ b/src/core/init.c
@@ -61,6 +61,25 @@
 #include "netif/ppp/ppp_opts.h"
 #include "netif/ppp/ppp_impl.h"
 
+#ifndef LWIP_SKIP_PACKING_CHECK
+
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/bpstruct.h"
+#endif
+PACK_STRUCT_BEGIN
+struct packed_struct_test
+{
+  PACK_STRUCT_FLD_8(u8_t  dummy1);
+  PACK_STRUCT_FIELD(u32_t dummy2);
+} PACK_STRUCT_STRUCT;
+PACK_STRUCT_END
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/epstruct.h"
+#endif
+#define PACKED_STRUCT_TEST_EXPECTED_SIZE 5
+
+#endif
+
 /* Compile-time sanity checks for configuration errors.
  * These can be done independently of LWIP_DEBUG, without penalty.
  */
@@ -323,6 +342,10 @@
 void
 lwip_init(void)
 {
+#ifndef LWIP_SKIP_PACKING_CHECK
+  LWIP_ASSERT("Struct packing not implemented correctly. Check your lwIP port.", sizeof(struct packed_struct_test) == PACKED_STRUCT_TEST_EXPECTED_SIZE);
+#endif
+
   /* Modules initialization */
   stats_init();
 #if !NO_SYS