text: /* TEMPLATE GENERATED TESTCASE FILE
  Filename: CWE123_Write_What_Where_Condition__listen_socket_61a.c
  Label Definition File: CWE123_Write_What_Where_Condition.label.xml
  Template File: sources-sink-61a.tmpl.c
  */
  /*
   * @description
   * CWE: 123 Write-What-Where Condition
   * BadSource: listen_socket Overwrite linked list pointers using a listen socket (server side)
   * GoodSource: Don't overwrite linked list pointers
   * Sinks:
   *    BadSink : Remove element from list
   * Flow Variant: 61 Data flow: data returned from one function to another in different source files
   *
   * */
  
  #include "std_testcase.h"
  
  typedef struct _linkedList
  {
      struct _linkedList *next;
      struct _linkedList *prev;
  } linkedList;
  
  typedef struct _badStruct
  {
      linkedList list;
  } badStruct;
  
  static linkedList *linkedListPrev, *linkedListNext;
  
  #ifdef _WIN32
  #include <winsock2.h>
  #include <windows.h>
  #include <direct.h>
  #pragma comment(lib, "ws2_32") /* include ws2_32.lib when linking */
  #define CLOSE_SOCKET closesocket
  #else
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <netinet/in.h>
  #include <arpa/inet.h>
  #include <unistd.h>
  #define INVALID_SOCKET -1
  #define SOCKET_ERROR -1
  #define CLOSE_SOCKET close
  #define SOCKET int
  #endif
  
  #define TCP_PORT 27015
  #define LISTEN_BACKLOG 5
  
  #ifndef OMITBAD
  
  /* bad function declaration */
  badStruct CWE123_Write_What_Where_Condition__listen_socket_61b_badSource(badStruct data);
  
  void CWE123_Write_What_Where_Condition__listen_socket_61_bad()
  {
      badStruct data;
      linkedList head = { &head, &head };
      /* This simulates a Microsoft-style linked list insertion */
      data.list.next = head.next;
      data.list.prev = head.prev;
      head.next = &data.list;
      head.prev = &data.list;
      data = CWE123_Write_What_Where_Condition__listen_socket_61b_badSource(data);
      /* POTENTIAL FLAW: The following removes 'a' from the list.  Because of the possible overflow this
       * causes a "write-what-where" aka "write4".  It does another write as
       * well.  But this is the prototypical "write-what-where" at least from
       * the Windows perspective.
       *
       * linkedListPrev = a->list->prev  WHAT
       * linkedListNext = a->list->next  WHERE
       * linkedListPrev->next = linkedListNext  "at the address that prev/WHERE points, write
       *                    next/WHAT"
       *                    aka "write-what-where"
       * linkedListNext->prev = linkedListPrev  "at the address that next/WHAT points plus 4
       *                    (because prev is the second field in 'list' hence
       *                    4 bytes away on 32b machines), write prev/WHERE"
       */
      linkedListPrev = data.list.prev;
      linkedListNext = data.list.next;
      linkedListPrev->next = linkedListNext;
      linkedListNext->prev = linkedListPrev;
  }
  
  #endif /* OMITBAD */
  
  #ifndef OMITGOOD
  
  /* goodG2B uses the GoodSource with the BadSink */
  badStruct CWE123_Write_What_Where_Condition__listen_socket_61b_goodG2BSource(badStruct data);
  
  static void goodG2B()
  {
      badStruct data;
      linkedList head = { &head, &head };
      /* This simulates a Microsoft-style linked list insertion */
      data.list.next = head.next;
      data.list.prev = head.prev;
      head.next = &data.list;
      head.prev = &data.list;
      data = CWE123_Write_What_Where_Condition__listen_socket_61b_goodG2BSource(data);
      /* POTENTIAL FLAW: The following removes 'a' from the list.  Because of the possible overflow this
       * causes a "write-what-where" aka "write4".  It does another write as
       * well.  But this is the prototypical "write-what-where" at least from
       * the Windows perspective.
       *
       * linkedListPrev = a->list->prev  WHAT
       * linkedListNext = a->list->next  WHERE
       * linkedListPrev->next = linkedListNext  "at the address that prev/WHERE points, write
       *                    next/WHAT"
       *                    aka "write-what-where"
       * linkedListNext->prev = linkedListPrev  "at the address that next/WHAT points plus 4
       *                    (because prev is the second field in 'list' hence
       *                    4 bytes away on 32b machines), write prev/WHERE"
       */
      linkedListPrev = data.list.prev;
      linkedListNext = data.list.next;
      linkedListPrev->next = linkedListNext;
      linkedListNext->prev = linkedListPrev;
  }
  
  void CWE123_Write_What_Where_Condition__listen_socket_61_good()
  {
      goodG2B();
  }
  
  #endif /* OMITGOOD */
  
  /* Below is the main(). It is only used when building this testcase on
   * its own for testing or for building a binary to use in testing binary
   * analysis tools. It is not used when compiling all the testcases as one
   * application, which is how source code analysis tools are tested.
   */
  
  #ifdef INCLUDEMAIN
  
  int main(int argc, char * argv[])
  {
      /* seed randomness */
      srand( (unsigned)time(NULL) );
  #ifndef OMITGOOD
      printLine("Calling good()...");
      CWE123_Write_What_Where_Condition__listen_socket_61_good();
      printLine("Finished good()");
  #endif /* OMITGOOD */
  #ifndef OMITBAD
      printLine("Calling bad()...");
      CWE123_Write_What_Where_Condition__listen_socket_61_bad();
      printLine("Finished bad()");
  #endif /* OMITBAD */
      return 0;
  }
  
  #endif
  