Misra rule 11.3, 11.4 suppression and 4.6 fix

source/FreeRTOS_ARP.c

@@ -328,6 +328,9 @@ static void vProcessARPPacketReply( ARPPacket_t * pxARPFrame,
 
     if( pxARPWaitingNetworkBuffer != NULL )
     {
+        /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+         * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+        /* coverity[misra_c_2012_rule_11_3_violation] */
         IPPacket_t * pxARPWaitingIPPacket = ( ( IPPacket_t * ) pxARPWaitingNetworkBuffer->pucEthernetBuffer );
         IPHeader_t * pxARPWaitingIPHeader = &( pxARPWaitingIPPacket->xIPHeader );
 
@@ -401,6 +404,10 @@ BaseType_t xIsIPInARPCache( uint32_t ulAddressToLookup )
 BaseType_t xCheckRequiresARPResolution( NetworkBufferDescriptor_t * pxNetworkBuffer )
 {
     BaseType_t xNeedsARPResolution = pdFALSE;
+
+    /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+     * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+    /* coverity[misra_c_2012_rule_11_3_violation] */
     IPPacket_t * pxIPPacket = ( ( IPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer );
     IPHeader_t * pxIPHeader = &( pxIPPacket->xIPHeader );
 
@@ -1071,6 +1078,9 @@ void vARPGenerateRequestPacket( NetworkBufferDescriptor_t * const pxNetworkBuffe
     configASSERT( pxNetworkBuffer != NULL );
     configASSERT( pxNetworkBuffer->xDataLength >= sizeof( ARPPacket_t ) );
 
+    /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+     * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+    /* coverity[misra_c_2012_rule_11_3_violation] */
     pxARPPacket = ( ( ARPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer );
 
     /* memcpy the const part of the header information into the correct
@@ -1141,6 +1151,10 @@ void FreeRTOS_ClearARP( void )
     {
         BaseType_t xResult = pdFALSE;
         NetworkBufferDescriptor_t * pxUseDescriptor = pxDescriptor;
+
+        /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+         * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+        /* coverity[misra_c_2012_rule_11_3_violation] */
         const IPPacket_t * pxIPPacket = ( ( IPPacket_t * ) pxUseDescriptor->pucEthernetBuffer );
 
         if( pxIPPacket->xEthernetHeader.usFrameType == ipIPv4_FRAME_TYPE )

source/FreeRTOS_DHCP.c

@@ -616,6 +616,11 @@
         {
             xDHCPSocket = FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_DGRAM, FREERTOS_IPPROTO_UDP );
 
+            /* MISRA Rule 11.4 warns about casting pointer to a different type.
+             * The casting here is to use pointer to pass error code.
+             * The pointer will be checked against the error code value
+             * before any further pointer action. */
+            /* coverity[misra_c_2012_rule_11_4_violation] */
             if( xDHCPSocket != FREERTOS_INVALID_SOCKET )
             {
                 /* Ensure the Rx and Tx timeouts are zero as the DHCP executes in the
@@ -732,6 +737,10 @@
         if( lBytes > 0 )
         {
             /* Map a DHCP structure onto the received data. */
+
+            /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+             * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+            /* coverity[misra_c_2012_rule_11_3_violation] */
             pxDHCPMessage = ( ( DHCPMessage_IPv4_t * ) pucUDPPayload );
 
             /* Sanity check. */
@@ -1011,6 +1020,10 @@
         {
             /* Leave space for the UDP header. */
             pucUDPPayloadBuffer = &( pxNetworkBuffer->pucEthernetBuffer[ ipUDP_PAYLOAD_OFFSET_IPv4 ] );
+
+            /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+             * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+            /* coverity[misra_c_2012_rule_11_3_violation] */
             pxDHCPMessage = ( ( DHCPMessage_IPv4_t * ) pucUDPPayloadBuffer );
 
             /* Most fields need to be zero. */

source/FreeRTOS_DNS.c

@@ -421,6 +421,10 @@
     {
         uint32_t ulIPAddress = 0UL;
         BaseType_t xExpected;
+
+        /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+         * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+        /* coverity[misra_c_2012_rule_11_3_violation] */
         const DNSMessage_t * pxDNSMessageHeader =
             ( ( const DNSMessage_t * )
               pxReceiveBuffer->pucPayloadBuffer );
@@ -668,6 +672,10 @@
 
         /* Write in a unique identifier. Cast the Payload Buffer to DNSMessage_t
          * to easily access fields of the DNS Message. */
+
+        /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+         * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+        /* coverity[misra_c_2012_rule_11_3_violation] */
         pxDNSMessageHeader = ( ( DNSMessage_t * ) pucUDPPayloadBuffer );
         pxDNSMessageHeader->usIdentifier = ( uint16_t ) uxIdentifier;
 
@@ -709,6 +717,10 @@
 
         /* Finish off the record. Cast the record onto DNSTail_t structure to easily
          * access the fields of the DNS Message. */
+
+        /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+         * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+        /* coverity[misra_c_2012_rule_11_3_violation] */
         pxTail = ( ( DNSTail_t * ) &( pucUDPPayloadBuffer[ uxStart + 1U ] ) );
 
         #if defined( _lint ) || defined( __COVERITY__ )

source/FreeRTOS_DNS_Cache.c

@@ -230,7 +230,7 @@
         BaseType_t x;
 
         /* For each entry in the DNS cache table. */
-        for( x = 0; x < ( int ) ipconfigDNS_CACHE_ENTRIES; x++ )
+        for( x = 0; x < ipconfigDNS_CACHE_ENTRIES; x++ )
         {
             if( xDNSCache[ x ].pcName[ 0 ] == ( char ) 0 )
             { /* empty slot */

source/FreeRTOS_DNS_Parser.c

@@ -286,6 +286,10 @@
 
             /* Parse the DNS message header. Map the byte stream onto a structure
              * for easier access. */
+
+            /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+             * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+            /* coverity[misra_c_2012_rule_11_3_violation] */
             pxDNSMessageHeader = ( ( DNSMessage_t * )
                                    pucUDPPayloadBuffer );
 
@@ -609,6 +613,10 @@
 
                 /* Mapping pucBuffer to a DNSAnswerRecord allows easy access of the
                  * fields of the structure. */
+
+                /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+                 * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+                /* coverity[misra_c_2012_rule_11_3_violation] */
                 pxDNSAnswerRecord = ( ( DNSAnswerRecord_t * ) pucBuffer );
 
                 /* Sanity check the data length of an IPv4 answer. */
@@ -683,6 +691,10 @@
                 /* It's not an A record, so skip it. Get the header location
                  * and then jump over the header. */
                 /* Cast the response to DNSAnswerRecord for easy access to fields of the DNS response. */
+
+                /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+                 * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+                /* coverity[misra_c_2012_rule_11_3_violation] */
                 pxDNSAnswerRecord = ( ( DNSAnswerRecord_t * ) pucBuffer );
 
                 pucBuffer = &( pucBuffer[ sizeof( DNSAnswerRecord_t ) ] );

source/FreeRTOS_ICMP.c

@@ -91,6 +91,10 @@
         {
             /* Map the buffer onto a ICMP-Packet struct to easily access the
              * fields of ICMP packet. */
+
+            /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+             * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+            /* coverity[misra_c_2012_rule_11_3_violation] */
             ICMPPacket_t * pxICMPPacket = ( ( ICMPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer );
 
             switch( pxICMPPacket->xICMPHeader.ucTypeOfMessage )

source/FreeRTOS_IP.c

@@ -1155,6 +1155,10 @@ eFrameProcessingResult_t eConsiderFrameForProcessing( const uint8_t * const pucE
     const EthernetHeader_t * pxEthernetHeader;
 
     /* Map the buffer onto Ethernet Header struct for easy access to fields. */
+
+    /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+     * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+    /* coverity[misra_c_2012_rule_11_3_violation] */
     pxEthernetHeader = ( ( const EthernetHeader_t * ) pucEthernetBuffer );
 
     if( memcmp( ipLOCAL_MAC_ADDRESS, pxEthernetHeader->xDestinationAddress.ucBytes, sizeof( MACAddress_t ) ) == 0 )
@@ -1225,6 +1229,10 @@ static void prvProcessEthernetPacket( NetworkBufferDescriptor_t * const pxNetwor
         eReturned = ipCONSIDER_FRAME_FOR_PROCESSING( pxNetworkBuffer->pucEthernetBuffer );
 
         /* Map the buffer onto the Ethernet Header struct for easy access to the fields. */
+
+        /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+         * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+        /* coverity[misra_c_2012_rule_11_3_violation] */
         pxEthernetHeader = ( ( const EthernetHeader_t * ) pxNetworkBuffer->pucEthernetBuffer );
 
         /* The condition "eReturned == eProcessBuffer" must be true. */
@@ -1240,6 +1248,9 @@ static void prvProcessEthernetPacket( NetworkBufferDescriptor_t * const pxNetwor
                     /* The Ethernet frame contains an ARP packet. */
                     if( pxNetworkBuffer->xDataLength >= sizeof( ARPPacket_t ) )
                     {
+                        /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+                         * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+                        /* coverity[misra_c_2012_rule_11_3_violation] */
                         eReturned = eARPProcessPacket( ( ( ARPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer ) );
                     }
                     else
@@ -1254,6 +1265,9 @@ static void prvProcessEthernetPacket( NetworkBufferDescriptor_t * const pxNetwor
                     /* The Ethernet frame contains an IP packet. */
                     if( pxNetworkBuffer->xDataLength >= sizeof( IPPacket_t ) )
                     {
+                        /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+                         * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+                        /* coverity[misra_c_2012_rule_11_3_violation] */
                         eReturned = prvProcessIPPacket( ( ( IPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer ), pxNetworkBuffer );
                     }
                     else
@@ -1512,6 +1526,10 @@ static eFrameProcessingResult_t prvAllowIPPacket( const IPPacket_t * const pxIPP
                             ProtocolPacket_t * pxProtPack;
 
                             /* pxProtPack will point to the offset were the protocols begin. */
+
+                            /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+                             * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+                            /* coverity[misra_c_2012_rule_11_3_violation] */
                             pxProtPack = ( ( ProtocolPacket_t * ) &( pxNetworkBuffer->pucEthernetBuffer[ uxHeaderLength - ipSIZE_OF_IPv4_HEADER ] ) );
 
                             if( pxProtPack->xUDPPacket.xUDPHeader.usChecksum == ( uint16_t ) 0U )
@@ -1665,6 +1683,10 @@ static eFrameProcessingResult_t prvProcessIPPacket( IPPacket_t * pxIPPacket,
 
                                /* Map the buffer onto a UDP-Packet struct to easily access the
                                 * fields of UDP packet. */
+
+                               /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+                                * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+                               /* coverity[misra_c_2012_rule_11_3_violation] */
                                const UDPPacket_t * pxUDPPacket = ( ( const UDPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer );
                                uint16_t usLength;
                                BaseType_t xIsWaitingARPResolution = pdFALSE;
@@ -1796,6 +1818,10 @@ static eFrameProcessingResult_t prvProcessIPPacket( IPPacket_t * pxIPPacket,
 
             /* Map the buffer onto a IP-Packet struct to easily access the
              * fields of the IP packet. */
+
+            /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+             * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+            /* coverity[misra_c_2012_rule_11_3_violation] */
             pxIPPacket = ( ( const IPPacket_t * ) pucEthernetBuffer );
 
             ucVersionHeaderLength = pxIPPacket->xIPHeader.ucVersionHeaderLength;
@@ -1945,6 +1971,10 @@ void vReturnEthernetFrame( NetworkBufferDescriptor_t * pxNetworkBuffer,
     #endif /* if ( ipconfigZERO_COPY_TX_DRIVER != 0 ) */
     {
         /* Map the Buffer to Ethernet Header struct for easy access to fields. */
+
+        /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+         * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+        /* coverity[misra_c_2012_rule_11_3_violation] */
         pxEthernetHeader = ( ( EthernetHeader_t * ) pxNetworkBuffer->pucEthernetBuffer );
 
         /*

source/FreeRTOS_IP_Utils.c

@@ -234,6 +234,7 @@ static NetworkBufferDescriptor_t * prvPacketBuffer_to_NetworkBuffer( const void
             /* The following statement may trigger a:
              * warning: cast increases required alignment of target type [-Wcast-align].
              * It has been confirmed though that the alignment is suitable. */
+            /* coverity[misra_c_2012_rule_11_4_violation] */
             pxResult = *( ( NetworkBufferDescriptor_t ** ) uxBuffer );
         }
         else
@@ -461,6 +462,10 @@ uint16_t usGenerateProtocolChecksum( uint8_t * pucEthernetBuffer,
         }
 
         /* Parse the packet length. */
+
+        /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+         * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+        /* coverity[misra_c_2012_rule_11_3_violation] */
         pxIPPacket = ( ( const IPPacket_t * ) pucEthernetBuffer );
 
         /* Per https://tools.ietf.org/html/rfc791, the four-bit Internet Header
@@ -502,6 +507,10 @@ uint16_t usGenerateProtocolChecksum( uint8_t * pucEthernetBuffer,
          * and IP headers incorrectly aligned. However, either way, the "third"
          * protocol (Layer 3 or 4) header will be aligned, which is the convenience
          * of this calculation. */
+
+        /* MISRA C-2012 Rule 11.3 warns about casting pointer type to a different data type.
+         * To be able to access various predefined fields from a data buffer, this mapping is intentional. */
+        /* coverity[misra_c_2012_rule_11_3_violation] */
         pxProtPack = ( ( ProtocolPacket_t * ) &( pucEthernetBuffer[ uxIPHeaderLength - ipSIZE_OF_IPv4_HEADER ] ) );
 
         /* Switch on the Layer 3/4 protocol. */
@@ -825,6 +834,10 @@ uint16_t usGenerateChecksum( uint16_t usSum,
     xTerm.u32 = 0UL;
 
     xSource.u8ptr = ipPOINTER_CAST( uint8_t *, pucNextData );
+
+    /* MISRA Rule 11.4 warns about casting pointer to a different size of pointer.
+    * The casting is used here to help checksum calculation.  It is intentional */
+    /* coverity[misra_c_2012_rule_11_4_violation] */
     uxAlignBits = ( ( ( uintptr_t ) pucNextData ) & 0x03U );
 
     /*
@@ -1109,7 +1122,7 @@ const char * FreeRTOS_strerror_r( BaseType_t xErrnum,
 
         default:
             /* Using function "snprintf". */
-            ( void ) snprintf( pcBuffer, uxLength, "Errno %d", ( int ) xErrnum );
+            ( void ) snprintf( pcBuffer, uxLength, "Errno %d", ( int32_t ) xErrnum );
             pcName = NULL;
             break;
     }