12.1  IP_HDRINCL、SIO_RCVALL没有定义

Q:

编写raw socket程序时需要用到IP_HDRINCL，查阅MSDN后我包含了ws2tcpip.h，编译
时仍报错。

A: scz <scz@nsfocus.com>

这是一个老问题了，参看:

http://support.microsoft.com/kb/257460

必须在包含winsock2.h之后再包含ws2tcpip.h。类似的情形发生在使用SIO_RCVALL时，
必须在包含winsock2.h之后再包含mstcpip.h。有些人不仔细查看MSDN，就自己定义
了这两个宏，那是不必要的，不推荐这样的编程风格。

--------------------------------------------------------------------------
/*
 * For x86/EWindows XP SP1 & VC 7
 * cl winsock2_test.c /Fewinsock2_test.exe /nologo /Os /G6 /Gz /Gs65536 /W3 /WX /D "WIN32" /D "NDEBUG" /D "_CONSOLE" /link /RELEASE
 */

#if 0
> winsock2_test.exe
IP_HDRINCL  = 0x00000002
SIO_RCVALL  = 0x98000001
#endif

#include <stdio.h>
/*
 * 必须在包含windows.h之前包含winsock2.h
 */
#include <winsock2.h>
/*
 * http://support.microsoft.com/kb/257460
 *
 * ws2tcpip.h must be explicitly included after winsock2.h
 */
#include <ws2tcpip.h>
/*
 * mstcpip.h must be explicitly included after winsock2.h
 */
#include <mstcpip.h>

#pragma comment( linker, "/INCREMENTAL:NO"      )
#pragma comment( linker, "/merge:.rdata=.text"  )
#pragma comment( linker, "/subsystem:console"   )

int __cdecl main ( int argc, char * argv[] )
{
    printf
    (

        "IP_HDRINCL  = 0x%08X\n"
        "SIO_RCVALL  = 0x%08X\n",
        IP_HDRINCL,
        SIO_RCVALL
    );
    return( 0 );
}  /* end of main */
--------------------------------------------------------------------------