Add configuration option to prevent configASSERT checks on ipBUFFER_PADDING (#1271)

* Added ipconfigSUPPRESS_BUFFER_PADDING_CHECK to eliminate configASSERT checks on ipBUFFER_PADDING in FreeRTOS_IP_Utils.c/vPreCheckConfigs( void )

* Defaults to ipconfigDISABLE to build with configASSERT checks in place.
* User settable to ipconfigENABLE to eliminate configASSERT checks.

* Fix formatting

---------

Co-authored-by: Dave Skok <[email protected]>
Co-authored-by: Tony Josi <[email protected]>

Author: blanco-ether

source/FreeRTOS_IP_Utils.c

@@ -1004,26 +1004,29 @@ void vPreCheckConfigs( void )
     {
         size_t uxSize;
 
-        /* Check if ipBUFFER_PADDING has a minimum size, depending on the platform.
-         * See FreeRTOS_IP.h for more details. */
-        #if ( UINTPTR_MAX > 0xFFFFFFFFU )
+        #if ( ipconfigSUPPRESS_BUFFER_PADDING_CHECK == 0 )
+
+            /* Check if ipBUFFER_PADDING has a minimum size, depending on the platform.
+             * See FreeRTOS_IP.h for more details. */
+            #if ( UINTPTR_MAX > 0xFFFFFFFFU )
+
+                /*
+                 * This is a 64-bit platform, make sure there is enough space in
+                 * pucEthernetBuffer to store a pointer.
+                 */
+                configASSERT( ipBUFFER_PADDING >= 14U );
+            #else
+                /* This is a 32-bit platform. */
+                configASSERT( ipBUFFER_PADDING >= 10U );
+            #endif /* UINTPTR_MAX > 0xFFFFFFFFU */
 
             /*
-             * This is a 64-bit platform, make sure there is enough space in
-             * pucEthernetBuffer to store a pointer.
+             * The size of the Ethernet header (14) plus ipBUFFER_PADDING should be a
+             * multiple of 32 bits, in order to get aligned access to all uint32_t
+             * fields in the protocol headers.
              */
-            configASSERT( ipBUFFER_PADDING >= 14U );
-        #else
-            /* This is a 32-bit platform. */
-            configASSERT( ipBUFFER_PADDING >= 10U );
-        #endif /* UINTPTR_MAX > 0xFFFFFFFFU */
-
-        /*
-         * The size of the Ethernet header (14) plus ipBUFFER_PADDING should be a
-         * multiple of 32 bits, in order to get aligned access to all uint32_t
-         * fields in the protocol headers.
-         */
-        configASSERT( ( ( ( ipSIZE_OF_ETH_HEADER ) + ( ipBUFFER_PADDING ) ) % 4U ) == 0U );
+            configASSERT( ( ( ( ipSIZE_OF_ETH_HEADER ) + ( ipBUFFER_PADDING ) ) % 4U ) == 0U );
+        #endif /* if ( ipconfigSUPPRESS_BUFFER_PADDING_CHECK == 0 ) */
 
         /* LCOV_EXCL_BR_START */
         uxSize = ipconfigNETWORK_MTU;

source/include/FreeRTOSIPConfigDefaults.h

@@ -3403,6 +3403,24 @@ STATIC_ASSERT( ipconfigDNS_SEND_BLOCK_TIME_TICKS <= portMAX_DELAY );
 
 /*---------------------------------------------------------------------------*/
 
+/*
+ * ipconfigSUPPRESS_BUFFER_PADDING_CHECK
+ *
+ * Type: BaseType_t ( ipconfigENABLE | ipconfigDISABLE )
+ *
+ * Suppress configuration check when user configuration
+ * for ipconfigPACKET_FILLER_SIZE or ipconfigBUFFER_PADDING is
+ * sub optimal.  Useful when porting to a MAC that does not include
+ * the option to pad received packets ipconfigPACKET_FILLER_SIZE
+ * within a word boundary.
+ */
+
+#ifndef ipconfigSUPPRESS_BUFFER_PADDING_CHECK
+    #define ipconfigSUPPRESS_BUFFER_PADDING_CHECK    ipconfigDISABLE
+#endif
+
+/*---------------------------------------------------------------------------*/
+
 /*
  * ipconfigINCLUDE_EXAMPLE_FREERTOS_PLUS_TRACE_CALLS
  *