透析ICMP协议(三): 牛刀初试之一

应用篇ping(ICMP.dll)

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这篇文章出自:http://tangentsoft.net/wskfaq/examples/dllping.html

翻译: bugfree/CSDN, 对原始代码加了些注释

平台: VC6 Windows XP

原理简介:

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这个例子演示了应用微软的ICMP.DLL怎样"ping"另一台机器. 这个DLL是没有文档话的发送ICMP回送包API接口, 也称为"pings," 就像潜水员对声纳信号的术语一样. 这段代码出自一个被一个名叫MarkG的家伙的GUI程序, 他的网页已经消失了.

ICMP.DLL API 现在在Windows平台上与微软的Winsocks工作的很好, 但是微软说更好的产品一出来他们将替换它. 微软说这个自从Windows 95时代就在用, 这些功能在在Windows 2000上仍然存在.

For more information on the ICMP.DLL API, check out sockets.com's ICMP API page.

更详细的ICMP.DLL API的信息到sockets.com的ICMP API网页获取.

具体实现:

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// Borland C++ 5.0: bcc32.cpp ping.cpp

// Visual C++ 5.0: cl ping.cpp wsock32.lib

//

// This sample program is hereby placed in the public domain.

#include <iostream.h>

#include <winsock.h>

#include <windowsx.h>

#include "icmpdefs.h"

==================ping的实现部分==================

int doit(int argc, char* argv[])

{//[bugfree] 建议将这个argc和argv的处理拿到main函数中

  // 检查命令行参数

  if (argc < 2) {

    cerr << "usage: ping <host>" << endl;

    return 1;

  }

  // 装载ICMP.DLL连接库

  HINSTANCE hIcmp = LoadLibrary("ICMP.DLL");

  if (hIcmp == 0) {

    cerr << "Unable to locate ICMP.DLL!" << endl;

    return 2;

  }

  // 查找给定机器的IP地址信息

  struct hostent* phe;

  if ((phe = gethostbyname(argv[1])) == 0) {

    cerr << "Could not find IP address for " << argv[1] << endl;

    return 3;

  }

  // 定义函数三个指针类型

  typedef HANDLE (WINAPI* pfnHV)(VOID);

  typedef BOOL (WINAPI* pfnBH)(HANDLE);

  typedef DWORD (WINAPI* pfnDHDPWPipPDD)(HANDLE, DWORD, LPVOID, WORD,

      PIP_OPTION_INFORMATION, LPVOID, DWORD, DWORD); // evil, no?

  //定义三个指针函数

  pfnHV pIcmpCreateFile;

  pfnBH pIcmpCloseHandle;

  pfnDHDPWPipPDD pIcmpSendEcho;

  //从ICMP.DLL中得到函数入口地址

  pIcmpCreateFile = (pfnHV)GetProcAddress(hIcmp, "IcmpCreateFile");

  pIcmpCloseHandle = (pfnBH)GetProcAddress(hIcmp, "IcmpCloseHandle");

  pIcmpSendEcho = (pfnDHDPWPipPDD)GetProcAddress(hIcmp, "IcmpSendEcho");

  if ((pIcmpCreateFile == 0) || (pIcmpCloseHandle == 0) ||

      (pIcmpSendEcho == 0)) {

    cerr << "Failed to get proc addr for function." << endl;

    return 4;

  }

  // 打开ping服务

  HANDLE hIP = pIcmpCreateFile();

  if (hIP == INVALID_HANDLE_VALUE) {

    cerr << "Unable to open ping service." << endl;

    return 5;

  }

  // 构造ping数据包

  char acPingBuffer[64];

  memset(acPingBuffer, '\xAA', sizeof(acPingBuffer));

  PIP_ECHO_REPLY pIpe = (PIP_ECHO_REPLY)GlobalAlloc( GMEM_FIXED | GMEM_ZEROINIT,

      sizeof(IP_ECHO_REPLY) + sizeof(acPingBuffer));

  if (pIpe == 0) {

    cerr << "Failed to allocate global ping packet buffer." << endl;

    return 6;

  }

  pIpe->Data = acPingBuffer;

  pIpe->DataSize = sizeof(acPingBuffer);   

  // 发送ping数据包

  DWORD dwStatus = pIcmpSendEcho(hIP, *((DWORD*)phe->h_addr_list[0]),

      acPingBuffer, sizeof(acPingBuffer), NULL, pIpe,

      sizeof(IP_ECHO_REPLY) + sizeof(acPingBuffer), 5000);

  if (dwStatus != 0) {

    cout << "Addr: " <<

        int(LOBYTE(LOWORD(pIpe->Address))) << "." <<

        int(HIBYTE(LOWORD(pIpe->Address))) << "." <<

        int(LOBYTE(HIWORD(pIpe->Address))) << "." <<

        int(HIBYTE(HIWORD(pIpe->Address))) << ", " <<

        "RTT: " << int(pIpe->RoundTripTime) << "ms, " <<

        "TTL: " << int(pIpe->Options.Ttl) << endl;

  }

  else {

    cerr << "Error obtaining info from ping packet." << endl;

  }

  // 关闭,回收资源

  GlobalFree(pIpe);

  FreeLibrary(hIcmp);

  return 0;

}

==================主函数==================

int main(int argc, char* argv[])

{

  WSAData wsaData;

  if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0) {

    return 255;

  }

  int retval = doit(argc, argv);

  WSACleanup();

  return retval;

}

==================头文件==================

icmpdefs.h

//ICMP.DLL 函数中需要的结构

typedef struct {

  unsigned char Ttl;             // Time To Live

  unsigned char Tos;             // Type Of Service

  unsigned char Flags;            // IP header flags

  unsigned char OptionsSize;         // Size in bytes of options data

  unsigned char *OptionsData;        // Pointer to options data

} IP_OPTION_INFORMATION, * PIP_OPTION_INFORMATION;

typedef struct {

  DWORD Address;               // Replying address

  unsigned long Status;           // Reply status

  unsigned long RoundTripTime;       // RTT in milliseconds

  unsigned short DataSize;          // Echo data size

  unsigned short Reserved;          // Reserved for system use

  void *Data;                // Pointer to the echo data

  IP_OPTION_INFORMATION Options;       // Reply options

} IP_ECHO_REPLY, * PIP_ECHO_REPLY;