problem with RPC code

[beginner123]

i got the source code from this website:
http://www.aspfree.com/c/a/net/introduction-to-rpc-on-windows-part-i/

and when i tried running the server and client i get Runtime exception occured:5
in the client console which means access denied

i don't know how to fix it
heres the client code:

#include <stdio.h>
#include "..\RPC1_IDL\DoRPC.h"

int main()
{
   RPC_STATUS status;
   unsigned char* szStringBinding = NULL;

   // Creates a string binding handle.
   // This function formats the passed values in a 
   // predefined format for use by RPC. Just like printf
   // Connection is not done here.
   status = RpcStringBindingCompose(
      NULL, // UUID to bind to.
      (unsigned char*)("ncacn_ip_tcp"), // Use TCP/IP protocol.
      (unsigned char*)("localhost"), // TCP/IP network
      (unsigned char*)("1234"), // TCP/IP port to use.
      NULL, 				// Protocol dependent network options to use.
      &szStringBinding); 		// String binding output.

   if (status)
      exit(status);

   // Validates the format of the string binding handle and converts
   // it to a binding handle.
   // Connection is not done here either.
   status = RpcBindingFromStringBinding(
      szStringBinding, // The string binding to validate.
      &hDoRPCBinding); // Put the result in the implicit binding
                          // handle defined in the IDL file.

	if(status)
	{
		exit(status);
	}

	RpcTryExcept
	{
		// Calls the RPC function. The hDoRPCBinding binding handle
		// is used implicitly.
		// Connection is done here.
		const unsigned char szMsg[] = "Client: I Can RPC Now!";
		Show(szMsg);
	}
	RpcExcept(1)
	{
		printf("Runtime exception occured: %d\n",RpcExceptionCode());
	}
	RpcEndExcept

	// Free the memory allocated by a string.
	status = RpcStringFree(&szStringBinding); // String to be freed.

	if(status)
	{
		exit(status);
	}

	// Releases binding handle resources and disconnects from the server.
	status = RpcBindingFree(
	&hDoRPCBinding);	// Frees the implicit binding handle defined in
						// the IDL file.

	if (status)
	{
		exit(status);
	}

	system ("PAUSE");

	return 0;
}

// Memory allocation function for RPC.
// The runtime uses these two functions for allocating/deallocating
// enough memory to pass the string to the server.
void* __RPC_USER midl_user_allocate(size_t size)
{
	return malloc(size);
}

// Memory deallocation function for RPC.
void __RPC_USER midl_user_free(void* p)
{
	free(p);
}

[beginner123]

i debugged the program and found that the problem was with the line in the show function
NdrSendReceive( (PMIDL_STUB_MESSAGE) &_StubMsg, (unsigned char __RPC_FAR *) _StubMsg.Buffer );

here is the show function:

  void Show( 
    /* [string][in] */ const unsigned char __RPC_FAR *szMsg)
{

    RPC_BINDING_HANDLE _Handle  =   0;

    RPC_MESSAGE _RpcMessage;

    MIDL_STUB_MESSAGE _StubMsg;

    if(!szMsg)
        {
        RpcRaiseException(RPC_X_NULL_REF_POINTER);
        }
    RpcTryFinally
        {
        NdrClientInitializeNew(
                          ( PRPC_MESSAGE  )&_RpcMessage,
                          ( PMIDL_STUB_MESSAGE  )&_StubMsg,
                          ( PMIDL_STUB_DESC  )&DoRPC_StubDesc,
                          0);


        _Handle = hDoRPCBinding;


        _StubMsg.BufferLength = 12U;
        NdrConformantStringBufferSize( (PMIDL_STUB_MESSAGE) &_StubMsg,
                                       (unsigned char __RPC_FAR *)szMsg,
                                       (PFORMAT_STRING) &__MIDL_TypeFormatString.Format[4] );

        NdrGetBuffer( (PMIDL_STUB_MESSAGE) &_StubMsg, _StubMsg.BufferLength, _Handle );

        NdrConformantStringMarshall( (PMIDL_STUB_MESSAGE)& _StubMsg,
                                     (unsigned char __RPC_FAR *)szMsg,
                                     (PFORMAT_STRING) &__MIDL_TypeFormatString.Format[4] );

        NdrSendReceive( (PMIDL_STUB_MESSAGE) &_StubMsg, (unsigned char __RPC_FAR *) _StubMsg.Buffer );

        }
    RpcFinally
        {
        NdrFreeBuffer( (PMIDL_STUB_MESSAGE) &_StubMsg );

        }
    RpcEndFinally

}

so when debugging it jumped to the RpcExcept line when it reached NdrSendReceive

[coder777]

Not that i understand a bit of that code, but, well, did you allocate enough memory for _StubMsg.Buffer before you call NdrSendReceive()?

[beginner123]

the file that the show function is from was automatically generated when i complied a idl file. i haven't changed any of the code from the website i linked in the first post. can you download the code and test it yourself?

[coder777]

well, I can't even compile it. The compiler complains about a switch where I can't find information about.

Honestly, even if it works I wouldn't recommend it. It's way overcomplicated and error prone.

You can easily do it yourself: Just send the name of the function and parameter and on the other side the server will call that function.

[writetonsharma]

This cannot be done by hand. RPC is done this way only. We create stubs and compile them into a C code, which generates server and client code. Then add your own code and lots of things I don't remember now..

I think this is more suitable to post in windows forum.

[beginner123]

@coder777 i don't know to make my own RPC program so that's why i tried the tutorial. i also tried this website: http://www.codeproject.com/Articles/4878/Introduction-to-RPC-Part-2
but again i just got errors