[修改] 增加freeRTOS

1. 版本FreeRTOSv202212.01，命名为kernel；

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSHandlePacket/DNShandlePacket_harness.c

@@ -0,0 +1,24 @@
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "queue.h"
+
+/* FreeRTOS+TCP includes. */
+#include "FreeRTOS_IP.h"
+#include "FreeRTOS_DNS.h"
+#include "FreeRTOS_IP_Private.h"
+
+/* Function prvParseDNSReply is proven to be correct separately.
+ * The proof can be found here: https://github.com/aws/amazon-freertos/tree/master/tools/cbmc/proofs/ParseDNSReply */
+uint32_t prvParseDNSReply( uint8_t * pucUDPPayloadBuffer,
+                           size_t xBufferLength,
+                           BaseType_t xExpected )
+{
+}
+
+void harness()
+{
+    NetworkBufferDescriptor_t xNetworkBuffer;
+
+    xNetworkBuffer.pucEthernetBuffer = malloc( sizeof( UDPPacket_t ) + sizeof( DNSMessage_t ) );
+    ulDNSHandlePacket( &xNetworkBuffer );
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSHandlePacket/Makefile.json

@@ -0,0 +1,12 @@
+{
+  "ENTRY": "DNShandlePacket",
+  "CBMCFLAGS": "--unwind 1",
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS_PLUS_TCP)/source/FreeRTOS_DNS.goto"
+  ],
+  "DEF":
+  [
+  ]
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSclear/DNSclear_harness.c

@@ -0,0 +1,17 @@
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "queue.h"
+
+/* FreeRTOS+TCP includes. */
+#include "FreeRTOS_IP.h"
+#include "FreeRTOS_DNS.h"
+#include "FreeRTOS_IP_Private.h"
+
+
+void harness()
+{
+    if( ipconfigUSE_DNS_CACHE != 0 )
+    {
+        FreeRTOS_dnsclear();
+    }
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSclear/Makefile.json

@@ -0,0 +1,20 @@
+{
+  "ENTRY": "DNSclear",
+  ################################################################
+  # This configuration flag uses DNS cache
+  "USE_CACHE":1,
+  "CBMCFLAGS":
+  [
+  	"--unwind 1",
+	"--nondet-static"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS_PLUS_TCP)/source/FreeRTOS_DNS.goto"
+  ],
+  "DEF":
+  [
+    "ipconfigUSE_DNS_CACHE={USE_CACHE}"
+  ]
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSgetHostByName/DNSgetHostByName_harness.c

@@ -0,0 +1,171 @@
+/* Standard includes. */
+#include <stdint.h>
+#include <stdio.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+#include "semphr.h"
+
+/* FreeRTOS+TCP includes. */
+#include "FreeRTOS_IP.h"
+#include "FreeRTOS_Sockets.h"
+#include "FreeRTOS_IP_Private.h"
+#include "FreeRTOS_UDP_IP.h"
+#include "FreeRTOS_DNS.h"
+#include "FreeRTOS_DHCP.h"
+#include "NetworkBufferManagement.h"
+#include "NetworkInterface.h"
+
+#include "cbmc.h"
+
+uint32_t FreeRTOS_dnslookup( const char * pcHostName );
+Socket_t DNS_CreateSocket( TickType_t uxReadTimeout_ticks );
+void DNS_CloseSocket( Socket_t xDNSSocket );
+void DNS_ReadReply( Socket_t xDNSSocket,
+                    struct freertos_sockaddr * xAddress,
+                    struct xDNSBuffer * pxDNSBuf );
+uint32_t DNS_SendRequest( Socket_t xDNSSocket,
+                          struct freertos_sockaddr * xAddress,
+                          struct xDNSBuffer * pxDNSBuf );
+uint32_t DNS_ParseDNSReply( uint8_t * pucUDPPayloadBuffer,
+                            size_t xBufferLength,
+                            BaseType_t xExpected );
+
+/****************************************************************
+* We abstract:
+*
+*   All kernel task scheduling functions since we are doing
+*   sequential verification and the sequential verification of these
+*   sequential primitives is done elsewhere.
+*
+*   Many methods in the FreeRTOS TCP API in stubs/freertos_api.c
+*
+*   DNS_ParseDNSReply proved memory safe elsewhere
+*
+*   prvCreateDNSMessage
+*
+* This proof assumes the length of pcHostName is bounded by
+* MAX_HOSTNAME_LEN.  We have to bound this length because we have to
+* bound the iterations of strcmp.
+****************************************************************/
+
+/****************************************************************
+* Abstract DNS_ParseDNSReply proved memory safe in ParseDNSReply.
+*
+* We stub out his function to fill the payload buffer with
+* unconstrained data and return an unconstrained size.
+*
+* The function under test uses only the return value of this
+* function.
+****************************************************************/
+
+uint32_t DNS_ParseDNSReply( uint8_t * pucUDPPayloadBuffer,
+                            size_t xBufferLength,
+                            BaseType_t xExpected )
+{
+    uint32_t size;
+
+    __CPROVER_havoc_object( pucUDPPayloadBuffer );
+    return size;
+}
+
+/****************************************************************
+* Abstract  DNS_SendRequest
+*
+* We stub out this function with return constraint of true or false
+*
+****************************************************************/
+uint32_t DNS_SendRequest( Socket_t xDNSSocket,
+                          struct freertos_sockaddr * xAddress,
+                          struct xDNSBuffer * pxDNSBuf )
+{
+    uint32_t ret;
+
+    __CPROVER_assume( ret >= 0 );
+    __CPROVER_assume( ret <= 1 );
+
+    return ret;
+}
+
+/****************************************************************
+* Abstract DNS_ReadReply
+*
+* We stub out this function which returned a dns_buffer filled with random data
+*
+****************************************************************/
+void DNS_ReadReply( Socket_t xDNSSocket,
+                    struct freertos_sockaddr * xAddress,
+                    struct xDNSBuffer * pxDNSBuf )
+{
+    int len;
+
+    pxDNSBuf->pucPayloadBuffer = safeMalloc( len );
+
+    pxDNSBuf->uxPayloadLength = len;
+
+    __CPROVER_assume( len < CBMC_MAX_OBJECT_SIZE );
+    __CPROVER_assume( pxDNSBuf->pucPayloadBuffer != NULL );
+
+    __CPROVER_havoc_slice( pxDNSBuf->pucPayloadBuffer, pxDNSBuf->uxPayloadSize );
+}
+
+
+void DNS_CloseSocket( Socket_t xDNSSocket )
+{
+}
+
+Socket_t DNS_CreateSocket( TickType_t uxReadTimeout_ticks )
+{
+    Socket_t sock;
+
+    return sock;
+}
+
+uint32_t FreeRTOS_dnslookup( const char * pcHostName )
+{
+    int ret;
+
+    __CPROVER_assume( ret < 0xFFFF );
+    __CPROVER_assume( ret > 0 );
+
+    return ret;
+}
+
+
+/****************************************************************
+* Abstract prvCreateDNSMessage
+*
+* This function writes a header, a hostname, and a constant amount of
+* data into the payload buffer, and returns the amount of data
+* written.  This abstraction just fills the entire buffer with
+* unconstrained data and returns and unconstrained length.
+****************************************************************/
+
+size_t prvCreateDNSMessage( uint8_t * pucUDPPayloadBuffer,
+                            const char * pcHostName,
+                            TickType_t uxIdentifier )
+{
+    __CPROVER_havoc_object( pucUDPPayloadBuffer );
+    size_t size;
+
+    return size;
+}
+
+/****************************************************************
+* The proof for FreeRTOS_gethostbyname.
+****************************************************************/
+
+void harness()
+{
+    size_t len;
+
+    __CPROVER_assume( len <= MAX_HOSTNAME_LEN );
+    char * pcHostName = safeMalloc( len );
+
+    __CPROVER_assume( len > 0 ); /* prvProcessDNSCache strcmp */
+    __CPROVER_assume( pcHostName != NULL );
+    pcHostName[ len - 1 ] = NULL;
+
+    FreeRTOS_gethostbyname( pcHostName );
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSgetHostByName/Makefile.json

@@ -0,0 +1,35 @@
+{
+  "ENTRY": "DNSgetHostByName",
+
+  ################################################################
+  # This configuration sets callback to 0.
+  # It also sets MAX_HOSTNAME_LEN to 10 to bound strcmp.
+  # According to the specification MAX_HOST_NAME is upto 255.
+
+  "callback": 0,
+  "MAX_HOSTNAME_LEN": 10,
+  "HOSTNAME_UNWIND": "__eval {MAX_HOSTNAME_LEN} + 1",
+
+  "CBMCFLAGS":
+  [
+    "--unwind 1",
+    "--unwindset prvCreateDNSMessage.0:{HOSTNAME_UNWIND},prvCreateDNSMessage.1:{HOSTNAME_UNWIND},strlen.0:{HOSTNAME_UNWIND},__builtin___strcpy_chk.0:{HOSTNAME_UNWIND},strcmp.0:{HOSTNAME_UNWIND},strcpy.0:{HOSTNAME_UNWIND}",
+    "--unwindset prvGetHostByNameOp_WithRetry.0:{HOSTNAME_UNWIND}",
+    "--nondet-static"
+  ],
+
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS_PLUS_TCP)/test/cbmc/stubs/cbmc.goto",
+    "$(FREERTOS_PLUS_TCP)/test/cbmc/stubs/freertos_api.goto",
+    "$(FREERTOS_PLUS_TCP)/source/FreeRTOS_DNS.goto",
+    "$(FREERTOS_PLUS_TCP)/source/FreeRTOS_DNS_Parser.goto"
+  ],
+
+  "DEF":
+  [
+    "ipconfigDNS_USE_CALLBACKS={callback}",
+    "MAX_HOSTNAME_LEN={MAX_HOSTNAME_LEN}"
+  ]
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSgetHostByName/cbmc-viewer.json

@@ -0,0 +1,9 @@
+{ "expected-missing-functions":
+  [
+    "vLoggingPrintf",
+    "xApplicationGetRandomNumber",
+    "xTaskGetTickCount"
+  ],
+  "proof-name": "DNSgetHostByName",
+  "proof-root": "tools/cbmc/proofs"
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSgetHostByName_a/DNSgetHostByName_a_harness.c

@@ -0,0 +1,113 @@
+/* Standard includes. */
+#include <stdint.h>
+#include <stdio.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+#include "semphr.h"
+
+/* FreeRTOS+TCP includes. */
+#include "FreeRTOS_IP.h"
+#include "FreeRTOS_Sockets.h"
+#include "FreeRTOS_IP_Private.h"
+#include "FreeRTOS_UDP_IP.h"
+#include "FreeRTOS_DNS.h"
+#include "FreeRTOS_DHCP.h"
+#include "NetworkBufferManagement.h"
+#include "NetworkInterface.h"
+
+#include "cbmc.h"
+
+/****************************************************************
+* We abstract:
+*
+*   All kernel task scheduling functions since we are doing
+*   sequential verification and the sequential verification of these
+*   sequential primitives is done elsewhere.
+*
+*   Many methods in the FreeRTOS TCP API in stubs/freertos_api.c
+*
+*   DNS_ParseDNSReply proved memory safe elsewhere
+*
+*   prvCreateDNSMessage
+*
+* This proof assumes the length of pcHostName is bounded by
+* MAX_HOSTNAME_LEN.  We have to bound this length because we have to
+* bound the iterations of strcmp.
+****************************************************************/
+
+/****************************************************************
+* Abstract DNS_ParseDNSReply proved memory safe in ParseDNSReply.
+*
+* We stub out his function to fill the payload buffer with
+* unconstrained data and return an unconstrained size.
+*
+* The function under test uses only the return value of this
+* function.
+****************************************************************/
+
+uint32_t DNS_ParseDNSReply( uint8_t * pucUDPPayloadBuffer,
+                            size_t xBufferLength,
+                            BaseType_t xExpected )
+{
+    __CPROVER_assert( pucUDPPayloadBuffer != NULL,
+                      "Precondition: pucUDPPayloadBuffer != NULL" );
+
+    __CPROVER_havoc_object( pucUDPPayloadBuffer );
+    return nondet_uint32();
+}
+
+/****************************************************************
+* Abstract prvCreateDNSMessage
+*
+* This function writes a header, a hostname, and a constant amount of
+* data into the payload buffer, and returns the amount of data
+* written.  This abstraction just fills the entire buffer with
+* unconstrained data and returns and unconstrained length.
+****************************************************************/
+
+size_t prvCreateDNSMessage( uint8_t * pucUDPPayloadBuffer,
+                            const char * pcHostName,
+                            TickType_t uxIdentifier )
+{
+    __CPROVER_assert( pucUDPPayloadBuffer != NULL,
+                      "Precondition: pucUDPPayloadBuffer != NULL" );
+    __CPROVER_assert( pcHostName != NULL,
+                      "Precondition: pcHostName != NULL" );
+
+    __CPROVER_havoc_object( pucUDPPayloadBuffer );
+    return nondet_sizet();
+}
+
+/****************************************************************
+* A stub for a function callback.
+****************************************************************/
+
+void func( const char * pcHostName,
+           void * pvSearchID,
+           uint32_t ulIPAddress )
+{
+}
+
+/****************************************************************
+* The proof for FreeRTOS_gethostbyname_a.
+****************************************************************/
+
+void harness()
+{
+    size_t len;
+
+    __CPROVER_assume( len <= MAX_HOSTNAME_LEN );
+    char * pcHostName = safeMalloc( len );
+
+    __CPROVER_assume( len > 0 ); /* prvProcessDNSCache strcmp */
+    __CPROVER_assume( pcHostName != NULL );
+    pcHostName[ len - 1 ] = NULL;
+
+    FOnDNSEvent pCallback = func;
+    TickType_t xTimeout;
+    void * pvSearchID;
+
+    FreeRTOS_gethostbyname_a( pcHostName, pCallback, pvSearchID, xTimeout );
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSgetHostByName_a/Makefile.json

@@ -0,0 +1,31 @@
+{
+  "ENTRY": "DNSgetHostByName_a",
+  ################################################################
+  # This configuration flag sets callback to 1. It also sets MAX_HOSTNAME_LEN to 10 and MAX_REQ_SIZE to 50 for performance issues.
+  # According to the specification MAX_HOST_NAME is upto 255.
+  "callback": 1,
+  "MAX_HOSTNAME_LEN": 10,
+  "HOSTNAME_UNWIND": "__eval {MAX_HOSTNAME_LEN} + 1",
+  "CBMCFLAGS":
+  [
+    "--unwind 1",
+    "--unwindset prvCreateDNSMessage.0:{HOSTNAME_UNWIND},prvCreateDNSMessage.1:{HOSTNAME_UNWIND},prvGetHostByName.0:{HOSTNAME_UNWIND},prvProcessDNSCache.0:5,strlen.0:{HOSTNAME_UNWIND},__builtin___strcpy_chk.0:{HOSTNAME_UNWIND},strcmp.0:{HOSTNAME_UNWIND},xTaskResumeAll.0:{HOSTNAME_UNWIND},xTaskResumeAll.1:{HOSTNAME_UNWIND},strcpy.0:{HOSTNAME_UNWIND}",
+    "--nondet-static"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS_PLUS_TCP)/test/cbmc/stubs/cbmc.goto",
+    "$(FREERTOS_PLUS_TCP)/test/cbmc/stubs/freertos_api.goto",
+    "$(FREERTOS_PLUS_TCP)/source/FreeRTOS_DNS.goto",
+    "$(FREERTOS_PLUS_TCP)/source/FreeRTOS_DNS_Parser.goto",
+    "$(FREERTOS_PLUS_TCP)/source/FreeRTOS_IP.goto"
+  ],
+  "DEF":
+  [
+    "ipconfigDNS_USE_CALLBACKS={callback}",
+    "MAX_HOSTNAME_LEN={MAX_HOSTNAME_LEN}",
+    # This value is defined only when ipconfigUSE_DNS_CACHE==1
+    "ipconfigDNS_CACHE_NAME_LENGTH=254"
+  ]
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSgetHostByName_a/cbmc-viewer.json

@@ -0,0 +1,13 @@
+{ "expected-missing-functions":
+  [
+    "vLoggingPrintf",
+    "xApplicationGetRandomNumber",
+    "vListInsertEnd",
+    "vTaskSetTimeOutState",
+    "vTaskSuspendAll",
+    "xTaskGetTickCount",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "DNSgetHostByName_a",
+  "proof-root": "tools/cbmc/proofs"
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSgetHostByName_cancel/DNSgetHostByName_cancel_harness.c

@@ -0,0 +1,71 @@
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "queue.h"
+#include "list.h"
+
+/* FreeRTOS+TCP includes. */
+#include "FreeRTOS_IP.h"
+#include "FreeRTOS_DNS.h"
+#include "FreeRTOS_IP_Private.h"
+
+
+/* This proof assumes the length of pcHostName is bounded by MAX_HOSTNAME_LEN. This also abstracts the concurrency. */
+
+void vDNSInitialise( void );
+
+void vDNSSetCallBack( const char * pcHostName,
+                      void * pvSearchID,
+                      FOnDNSEvent pCallbackFunction,
+                      TickType_t xTimeout,
+                      TickType_t xIdentifier );
+
+void * safeMalloc( size_t xWantedSize ) /* Returns a NULL pointer if the wanted size is 0. */
+{
+    if( xWantedSize == 0 )
+    {
+        return NULL;
+    }
+
+    uint8_t byte;
+
+    return byte ? malloc( xWantedSize ) : NULL;
+}
+
+/* Abstraction of xTaskCheckForTimeOut from task pool. This also abstracts the concurrency. */
+BaseType_t xTaskCheckForTimeOut( TimeOut_t * const pxTimeOut,
+                                 TickType_t * const pxTicksToWait )
+{
+}
+
+/* Abstraction of xTaskResumeAll from task pool. This also abstracts the concurrency. */
+BaseType_t xTaskResumeAll( void )
+{
+}
+
+/* The function func mimics the callback function.*/
+void func( const char * pcHostName,
+           void * pvSearchID,
+           uint32_t ulIPAddress )
+{
+}
+
+void harness()
+{
+    vDNSInitialise(); /* We initialize the callbacklist in order to be able to check for functions that timed out. */
+    size_t pvSearchID;
+    FOnDNSEvent pCallback = func;
+    TickType_t xTimeout;
+    TickType_t xIdentifier;
+    size_t len;
+
+    __CPROVER_assume( len >= 0 && len <= MAX_HOSTNAME_LEN );
+    char * pcHostName = safeMalloc( len );
+
+    if( len && pcHostName )
+    {
+        pcHostName[ len - 1 ] = NULL;
+    }
+
+    vDNSSetCallBack( pcHostName, &pvSearchID, pCallback, xTimeout, xIdentifier ); /* Add an item to be able to check the cancel function if the list is non-empty. */
+    FreeRTOS_gethostbyname_cancel( &pvSearchID );
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSgetHostByName_cancel/Makefile.json

@@ -0,0 +1,29 @@
+{
+  "ENTRY": "DNSgetHostByName_cancel",
+  ################################################################
+	# This configuration flag sets callback to 1. It also sets MAX_HOSTNAME_LEN to 10 for performance issues.
+  # According to the specification MAX_HOST_NAME is upto 255.
+  "callback": 1,
+  "MAX_HOSTNAME_LEN": 10,
+  "HOSTNAME_UNWIND": "__eval {MAX_HOSTNAME_LEN} + 1",
+  "CBMCFLAGS":
+  [
+    "--unwind 1",
+    "--unwindset prvProcessDNSCache.0:5,strlen.0:{HOSTNAME_UNWIND},__builtin___strcpy_chk.0:{HOSTNAME_UNWIND},vDNSCheckCallBack.0:2,strcpy.0:{HOSTNAME_UNWIND}",
+    "--nondet-static"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS_PLUS_TCP)/source/FreeRTOS_DNS.goto",
+    "$(FREERTOS_PLUS_TCP)/test/FreeRTOS-Kernel/tasks.goto",
+    "$(FREERTOS_PLUS_TCP)/test/FreeRTOS-Kernel/list.goto"
+  ],
+  "DEF":
+  [
+    "ipconfigDNS_USE_CALLBACKS={callback}",
+    "MAX_HOSTNAME_LEN={MAX_HOSTNAME_LEN}",
+    # This value is defined only when ipconfigUSE_DNS_CACHE==1
+    "ipconfigDNS_CACHE_NAME_LENGTH=254"
+  ]
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSlookup/DNSlookup_harness.c

@@ -0,0 +1,42 @@
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "queue.h"
+#include "list.h"
+
+/* FreeRTOS+TCP includes. */
+#include "FreeRTOS_IP.h"
+#include "FreeRTOS_DNS.h"
+#include "FreeRTOS_IP_Private.h"
+
+/* This assumes that the length of the hostname is bounded by MAX_HOSTNAME_LEN. */
+void * safeMalloc( size_t xWantedSize )
+{
+    if( xWantedSize == 0 )
+    {
+        return NULL;
+    }
+
+    uint8_t byte;
+
+    return byte ? malloc( xWantedSize ) : NULL;
+}
+
+void harness()
+{
+    if( ipconfigUSE_DNS_CACHE != 0 )
+    {
+        size_t len;
+        __CPROVER_assume( len >= 0 && len <= MAX_HOSTNAME_LEN );
+        char * pcHostName = safeMalloc( len ); /* malloc is replaced by safeMalloc */
+
+        if( len && pcHostName )
+        {
+            pcHostName[ len - 1 ] = NULL;
+        }
+
+        if( pcHostName ) /* guarding against NULL pointer */
+        {
+            FreeRTOS_dnslookup( pcHostName );
+        }
+    }
+}

kernel/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/test/cbmc/proofs/DNS/DNSlookup/Makefile.json

@@ -0,0 +1,26 @@
+{
+  "ENTRY": "DNSlookup",
+  ################################################################
+  # This configuration uses DNS cache and the MAX_HOSTNAME_LEN is set to 255 according to the specification
+  "MAX_HOSTNAME_LEN": 255,
+  "HOSTNAME_UNWIND": "__eval {MAX_HOSTNAME_LEN} + 1",
+  "USE_CACHE": 1,
+  "CBMCFLAGS":
+  [
+    "--unwind 1",
+    "--unwindset prvProcessDNSCache.0:5,strcmp.0:{HOSTNAME_UNWIND}",
+    "--nondet-static"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS_PLUS_TCP)/source/FreeRTOS_DNS.goto",
+    "$(FREERTOS_PLUS_TCP)/test/FreeRTOS-Kernel/tasks.goto"
+  ],
+  "DEF":
+  [
+    "ipconfigUSE_DNS_CACHE={USE_CACHE}",
+    "MAX_HOSTNAME_LEN={MAX_HOSTNAME_LEN}"
+  ],
+  "OPT" : "-m32"
+}