Misra fix or suppress remaining violations (#529)

* Fix Remaning misra issues

* Suppress rule 8.6

* Fix/Suppress more misra violations

* Style: for formatting

* Style: fix formatting

* Style: fix spelling

* Fix Rule 11.1

* Fix undeteced suppressions

* Enable 32 bits

* Fix more misra leftover violations

* Add justification for a missed violation

* Fix comment for rule 8.13

* Fix comment

* fix misra comments

* Update MISRA.md

Co-authored-by: Aniruddha Kanhere <[email protected]>

* Update source/FreeRTOS_Sockets.c

Co-authored-by: Aniruddha Kanhere <[email protected]>

* Update source/portable/BufferManagement/BufferAllocation_2.c

Co-authored-by: Aniruddha Kanhere <[email protected]>

* Update MISRA.md

Co-authored-by: Aniruddha Kanhere <[email protected]>

* Update MISRA.md

Co-authored-by: Aniruddha Kanhere <[email protected]>

* Suppress Rule 8.9

* Fix build error

* fix build error

* Fix coverity supression bugs

Co-authored-by: Aniruddha Kanhere <[email protected]>

Author: alfred2g

MISRA.md

@@ -31,6 +31,35 @@ _Ref 8.9.1_
        order of execution, some variables have file scope definitions rather
        than function scope.
 
+#### Rule 8.13
+_Ref 8.13.1_
+
+- MISRA C-2012 Rule 8.13 Parameter passed is never used, should be declared as
+    const.  The argument passed to the `prvIPTask` function is left unused which is
+    considered as the variable not being used and thus warranting the use of `const`.
+    However, the FreeRTOS-kernel function `xTaskCreate` expects a function signature
+    of type `void vSomeFunction( void * pvArgs )`. To satisfy that requirement, the
+    function signature of `prvIPTask` does not have a `const` qualifier in the
+    parameter signature.
+
+#### Rule 10.5
+_Ref 10.5.1_
+
+- MISRA C-2012 Rule 10.5 Converting from an unsigned to an enum type. The
+    operation is safe to perform in that case, as we are using a generic API
+    to send and receive data, in that case the exact data sent it is received
+
+#### Rule 11.1
+_Ref 11.1.1_
+
+- MISRA C-2012 Rule 11.1 Converting from a void pointer to a function pointer.
+   The `FreeRTOS_setsockopt` API allows users to configure sockets by setting
+   various options. In order to do so, the function must accept one parameter
+   which, based on the option value, can be casted to the corresponding socket
+   field. To that end, that parameter is of `void *` type to accommodate all values.
+   The caller of the API is responsible for providing correct function pointer to the
+   API. Thus, this violation can be safely suppressed.
+
 #### Rule 11.3
 _Ref 11.3.1_
 
@@ -107,16 +136,6 @@ _Ref 14.3.1_
 - MISRA C-2012 Rule 14.3 False positive as the value might be changed
         depending on the conditionally compiled code
 
-#### Rule 21.6
-_Ref 21.6.1_
-
-- MISRA C-2012 Rule 21.6 warns about the use of standard library input/output
-        functions as they might have implementation defined or undefined
-        behaviour. The function `snprintf` is used to insert information in a
-        logging string. This is only used in a utility function which aids in
-        debugging and is not part of the 'core' code governing the
-        functionality of the TCP/IP stack.
-
 #### Rule 17.2
 _Ref 17.2.1_
 
@@ -128,10 +147,32 @@ _Ref 17.2.1_
         have a secondary child socket thereby limiting the number of recursive
         calls to one.
 
+#### Rule 20.5
+_Ref 20.5.1_
+
+- MISRA C-2012 Rule 20.5 warns against the use of #undef.
+   FreeRTOS-Plus-TCP allows its users to set some configuration macros
+   to modify the behavior/performance of the library according to their
+   needs. However, the macros values must be within certain bounds.
+   To achieve that, if the macro values lie outside of the bounds, they
+   are undefined using `#undef` before being redefined to a proper
+   value.
+
 #### Rule 20.10
 _Ref 20.10.1_
 
 - MISRA C-2012 Rule 20.10 warns against the use of ## concatination operator.
         However, in this case, it must be used to support compile time
         assertions in case the preprocessor does not suppport sizeof. This
         operation (assert) has no runtime execution.
+
+#### Rule 21.6
+_Ref 21.6.1_
+
+- MISRA C-2012 Rule 21.6 warns about the use of standard library input/output
+        functions as they might have implementation defined or undefined
+        behaviour. The function `snprintf` is used to insert information in a
+        logging string. This is only used in a utility function which aids in
+        debugging and is not part of the 'core' code governing the
+        functionality of the TCP/IP stack.
+

source/FreeRTOS_IP.c

@@ -122,7 +122,7 @@ static void prvProcessIPEventsAndTimers( void );
  * from the network hardware drivers and tasks that are using sockets.  It also
  * maintains a set of protocol timers.
  */
-static void prvIPTask( const void * pvParameters );
+static void prvIPTask( void * pvParameters );
 
 /*
  * Called when new data is available from the network interface.
@@ -229,7 +229,11 @@ static BaseType_t xIPTaskInitialised = pdFALSE;
  *
  * @param[in] pvParameters: Not used.
  */
-static void prvIPTask( const void * pvParameters )
+
+/* MISRA Ref 8.13.1 [Not decorating a pointer to const parameter with const] */
+/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-813 */
+/* coverity[misra_c_2012_rule_8_13_violation] */
+static void prvIPTask( void * pvParameters )
 {
     /* Just to prevent compiler warnings about unused parameters. */
     ( void ) pvParameters;
@@ -390,9 +394,11 @@ static void prvProcessIPEventsAndTimers( void )
                     eDHCPState_t eState;
 
                     /* MISRA Ref 11.6.1 [DHCP events and conversion to void] */
-/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-116 */
+                    /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-116 */
                     /* coverity[misra_c_2012_rule_11_6_violation] */
                     uxState = ( uintptr_t ) xReceivedEvent.pvData;
+                    /* MISRA Ref 10.5.1 [DHCP events Enum] */
+                    /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-105 */
                     /* coverity[misra_c_2012_rule_10_5_violation] */
                     eState = ( eDHCPState_t ) uxState;
 
@@ -708,6 +714,7 @@ void * FreeRTOS_GetUDPPayloadBuffer( size_t uxRequestedSizeBytes,
  * @return pdPASS if the task was successfully created and added to a ready
  * list, otherwise an error code defined in the file projdefs.h
  */
+/* coverity[single_use] */
 BaseType_t FreeRTOS_IPInit( const uint8_t ucIPAddress[ ipIP_ADDRESS_LENGTH_BYTES ],
                             const uint8_t ucNetMask[ ipIP_ADDRESS_LENGTH_BYTES ],
                             const uint8_t ucGatewayAddress[ ipIP_ADDRESS_LENGTH_BYTES ],
@@ -1171,7 +1178,7 @@ eFrameProcessingResult_t eConsiderFrameForProcessing( const uint8_t * const pucE
     /* Map the buffer onto Ethernet Header struct for easy access to fields. */
 
     /* MISRA Ref 11.3.1 [Misaligned access] */
-/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
+    /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
     /* coverity[misra_c_2012_rule_11_3_violation] */
     pxEthernetHeader = ( ( const EthernetHeader_t * ) pucEthernetBuffer );
 
@@ -1245,7 +1252,7 @@ static void prvProcessEthernetPacket( NetworkBufferDescriptor_t * const pxNetwor
         /* Map the buffer onto the Ethernet Header struct for easy access to the fields. */
 
         /* MISRA Ref 11.3.1 [Misaligned access] */
-/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
+        /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
         /* coverity[misra_c_2012_rule_11_3_violation] */
         pxEthernetHeader = ( ( const EthernetHeader_t * ) pxNetworkBuffer->pucEthernetBuffer );
 
@@ -1263,7 +1270,7 @@ static void prvProcessEthernetPacket( NetworkBufferDescriptor_t * const pxNetwor
                     if( pxNetworkBuffer->xDataLength >= sizeof( ARPPacket_t ) )
                     {
                         /* MISRA Ref 11.3.1 [Misaligned access] */
-/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
+                        /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
                         /* coverity[misra_c_2012_rule_11_3_violation] */
                         eReturned = eARPProcessPacket( ( ( ARPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer ) );
                     }
@@ -1280,7 +1287,7 @@ static void prvProcessEthernetPacket( NetworkBufferDescriptor_t * const pxNetwor
                     if( pxNetworkBuffer->xDataLength >= sizeof( IPPacket_t ) )
                     {
                         /* MISRA Ref 11.3.1 [Misaligned access] */
-/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
+                        /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
                         /* coverity[misra_c_2012_rule_11_3_violation] */
                         eReturned = prvProcessIPPacket( ( ( IPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer ), pxNetworkBuffer );
                     }
@@ -1542,7 +1549,7 @@ static eFrameProcessingResult_t prvAllowIPPacket( const IPPacket_t * const pxIPP
                             /* pxProtPack will point to the offset were the protocols begin. */
 
                             /* MISRA Ref 11.3.1 [Misaligned access] */
-/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
+                            /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
                             /* coverity[misra_c_2012_rule_11_3_violation] */
                             pxProtPack = ( ( ProtocolPacket_t * ) &( pxNetworkBuffer->pucEthernetBuffer[ uxHeaderLength - ipSIZE_OF_IPv4_HEADER ] ) );
 
@@ -1610,6 +1617,10 @@ static eFrameProcessingResult_t prvProcessIPPacket( IPPacket_t * pxIPPacket,
         /* Check if the IP headers are acceptable and if it has our destination. */
         eReturn = prvAllowIPPacket( pxIPPacket, pxNetworkBuffer, uxHeaderLength );
 
+        /* MISRA Ref 14.3.1 [Configuration dependent invariant] */
+        /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-143 */
+        /* coverity[misra_c_2012_rule_14_3_violation] */
+        /* coverity[cond_const] */
         if( eReturn == eProcessBuffer )
         {
             /* Are there IP-options. */
@@ -1647,8 +1658,9 @@ static eFrameProcessingResult_t prvProcessIPPacket( IPPacket_t * pxIPPacket,
             }
 
             /* MISRA Ref 14.3.1 [Configuration dependent invariant] */
-/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-143 */
+            /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-143 */
             /* coverity[misra_c_2012_rule_14_3_violation] */
+            /* coverity[const] */
             if( eReturn != eReleaseBuffer )
             {
                 /* Add the IP and MAC addresses to the ARP table if they are not
@@ -1838,7 +1850,7 @@ static eFrameProcessingResult_t prvProcessIPPacket( IPPacket_t * pxIPPacket,
              * fields of the IP packet. */
 
             /* MISRA Ref 11.3.1 [Misaligned access] */
-/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
+            /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
             /* coverity[misra_c_2012_rule_11_3_violation] */
             pxIPPacket = ( ( const IPPacket_t * ) pucEthernetBuffer );
 
@@ -1991,7 +2003,7 @@ void vReturnEthernetFrame( NetworkBufferDescriptor_t * pxNetworkBuffer,
         /* Map the Buffer to Ethernet Header struct for easy access to fields. */
 
         /* MISRA Ref 11.3.1 [Misaligned access] */
-/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
+        /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
         /* coverity[misra_c_2012_rule_11_3_violation] */
         pxEthernetHeader = ( ( EthernetHeader_t * ) pxNetworkBuffer->pucEthernetBuffer );
 

source/FreeRTOS_IP_Utils.c

@@ -78,6 +78,7 @@
 /* MISRA Ref 8.9.1 [File scoped variables] */
 /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-89 */
 /* coverity[misra_c_2012_rule_8_9_violation] */
+/* coverity[single_use] */
     static BaseType_t xCallEventHook = pdFALSE;
 #endif
 
@@ -974,10 +975,10 @@ uint16_t usGenerateChecksum( uint16_t usSum,
     /* coverity[value_overwrite] */
     xSum.u32 = ( uint32_t ) xSum.u16[ 0 ] + xSum.u16[ 1 ];
 
-    /* coverity[value_overwrite] */
     /* MISRA Ref 2.2.1 [Unions and dead code] */
     /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-22 */
     /* coverity[misra_c_2012_rule_2_2_violation] */
+    /* coverity[value_overwrite] */
     xSum.u32 = ( uint32_t ) xSum.u16[ 0 ] + xSum.u16[ 1 ];
 
     if( ( uxAlignBits & 1U ) != 0U )