对ICMP路由跟踪的研究(1)(2)

五、路由跟踪代码

在完成了对各控件的设置和类的添加以后就是对代码的编写了，这里给出了新建类CICMP和RouteTraceDlg.cpp的代码，详细代码请参看源程序。

ICMP.cpp文件代码：

// ICMP.cpp: implementation of the CICMP class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "RouteTrace.h"
#include "ICMP.h"
#include "ws2tcpip.h"//实现 IP_TTL 设置的关键
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
CICMP::CICMP()
{
winsock = 0;
m_pIp = NULL;
m_pIcmp = NULL;
m_pIp = (IP_HEAD *)new BYTE[MAX_PACKET];
m_pIcmp = (ICMP_HEAD *)new BYTE[MAX_PACKET];
}
CICMP::~CICMP()
{
delete [] m_pIp;
delete [] m_pIcmp;
}
BOOL CICMP::Initialize()
{
WSADATA wsadata;
if( WSAStartup(MAKEWORD(2, 1),&wsadata) )　
{
AfxMessageBox("WSAStartup初始化失败!");
return FALSE;
}

winsock= WSASocket (AF_INET,　//建立socket
　 SOCK_RAW,
　 IPPROTO_ICMP,
　 NULL, 0,0);
if(!winsock){
AfxMessageBox( "Socket创建失败!");
return FALSE;
}
int timeout =5000;
setsockopt(winsock,SOL_SOCKET,SO_RCVTIMEO,(char *)&timeout,　 //　设置接收超时
sizeof(timeout));
timeout = 5000;
setsockopt(winsock,SOL_SOCKET,SO_SNDTIMEO,(char *)&timeout,//设置发送超时
sizeof(timeout));
return TRUE;
}
void CICMP::Uninitialize()//释放Socket
{
if(winsock)
closesocket(winsock);
WSACleanup();
}
USHORT CICMP::CheckSum(USHORT *buffer, int size)　//计算校验和
{
　unsigned long cksum = 0;
　while(size > 1) {
cksum+=*buffer++;
size -=sizeof(USHORT);
　}
　
　if(size ) {
cksum += *(UCHAR*)buffer;
　}
　cksum = (cksum >> 16) + (cksum & 0xffff);
　cksum += (cksum >>16);
　return (USHORT)(~cksum);
}
//--------------------发送ICMP回应请求报文-------------------
BOOL CICMP::SendICMPPack(char *pAddr)
{
sockaddr_in sockAddr;
memset((void *)&sockAddr,0,sizeof(sockAddr));
sockAddr.sin_family = AF_INET;
sockAddr.sin_port = 0;
sockAddr.sin_addr.S_un.S_addr=inet_addr(pAddr);
return SendICMPPack(&sockAddr);
}
BOOL CICMP::SendICMPPack(sockaddr_in *pAddr)
{
//填充ICMP数据各项
int　state;
char *p_data;
m_pIcmp->type = ICMP_ECHO;
m_pIcmp->code = 0;
m_pIcmp->ID = (USHORT)GetCurrentProcessId();
m_pIcmp->number = 0;
m_pIcmp->time = GetTickCount();
m_pIcmp->cksum = 0;
//填充数据
p_data = ((char *)m_pIcmp + sizeof(ICMP_HEAD));
memset((char *)p_data,''0'',DEF_PACKET);
//校验和
m_pIcmp->cksum = CheckSum((USHORT *)m_pIcmp,
DEF_PACKET+sizeof(ICMP_HEAD));

//发送数据
state = sendto(winsock,(char *)m_pIcmp,
DEF_PACKET+sizeof(ICMP_HEAD),
NULL,(struct sockaddr *)pAddr,sizeof(sockaddr));
if(state == SOCKET_ERROR) {
if(GetLastError()==WSAETIMEDOUT)
m_strInfo = "连接超时!(发送)";
else
m_strInfo.Format("出现未知发送错误!");
return FALSE;
}
if(state <DEF_PACKET) {
m_strInfo = "发送数据错误!";
return FALSE;
}

memcpy((void *)&m_sockAddr,(void *)pAddr,
sizeof(sockaddr_in));
return TRUE;
}
//----------------------接收数据----------------------------
BOOL CICMP::RecvICMPPack()
{
int state;
int len = sizeof(sockaddr_in);
char * addr;
struct hostent *lpHostent = NULL;
addr = inet_ntoa(m_sockAddr.sin_addr);
state = recvfrom(winsock,(char *)m_pIp,MAX_PACKET,0,
(struct sockaddr*)&m_sockAddr,&len);
if (state == SOCKET_ERROR) {
if (WSAGetLastError() == WSAETIMEDOUT)
{m_strInfo="接收超时,路由跟踪失败!";
routestate=0;
RouteState="路由跟踪失败!";
}
else
m_strInfo = "未知接收错误!";
return FALSE;
}
//分析数据
int ipheadlen;
ipheadlen = m_pIp->HeadLen * 4 ;
if (state < (ipheadlen+MIN_PACKET)){
m_strInfo = "目的地址的响应数据不正确";
return FALSE;
}
ICMP_HEAD * p_icmprev;
p_icmprev = (ICMP_HEAD*)((char *)m_pIp + ipheadlen);
switch (p_icmprev->type)
{
case ICMP_ECHOREPLY:　//收到正常回显
{
m_strInfo.Format("接收到%s　%d字节响应数据,响应时间:%dms.",
inet_ntoa(m_sockAddr.sin_addr),len,GetTickCount()-p_icmprev->time);
routeaddr=addr;
routestate=0;
RouteState="到达目的主机!";
return TRUE;
break;
}
case ICMP_TTLOUT:　 // TTL超时
{　 routeaddr=inet_ntoa(m_sockAddr.sin_addr);
routestate=1;
RouteState="测试到路由器!";
return TRUE;
break;
}

case ICMP_DESUNREACH:　//目的不可达
{m_strInfo = "目的不可达!";
　 routestate=0;
RouteState="目的不可达!";
return TRUE;
break;
}

default :{　routestate=0;
m_strInfo="未知错误!";
RouteState="不明状态!";
 }
}
return TRUE;
}
//----------------设置TTL--------------------
int CICMP::SetTTL(int TTL)
{
int nRet=setsockopt(winsock, IPPROTO_IP, IP_TTL,(LPSTR)&TTL,sizeof(int));

if(nRet==SOCKET_ERROR)
{　 CString ttlerr;
ttlerr.Format("设置 TTL 错误!");
AfxMessageBox(ttlerr);
return 0;
}
return 1;
}
RouteTraceDlg.cpp文件代码：
// RouteTraceDlg.cpp : implementation file
//
#include "stdafx.h"
#include "RouteTrace.h"
#include "RouteTraceDlg.h"
#include "afxmt.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About
struct SubThreadInfo
{
CDialog* pDialog;
CListCtrl*list;
CStatic* state;
CString IPStr;
int Maxhot;

} Info;
CEvent eventStopRoute;
//-----------------路由跟踪线程---------------
UINT ThreadRoute(LPVOID pParam)　
{
SubThreadInfo* pInfo = (SubThreadInfo*)pParam;
CRouteTraceDlg* pThreadDlg = (CRouteTraceDlg*)pInfo->pDialog;
CICMP m_icmp;
CString IPStr=pInfo->IPStr;
CString sTTL;
int nTtl;
m_icmp.Initialize();
for(nTtl=1;nTtl<=pInfo->Maxhot;nTtl++)
{
if(m_icmp.SetTTL(nTtl)==0)
return 0;
sTTL.Format("%d",nTtl);
if(m_icmp.SendICMPPack((char *)(LPCSTR)IPStr))　
m_icmp.RecvICMPPack();


{
int i=pInfo->list->InsertItem(0,sTTL);
　pInfo->list->SetItemText(i,1,m_icmp.routeaddr);
　pInfo->list->SetItemText(i,2,m_icmp.RouteState);
　 pInfo->state->SetWindowText(m_icmp.m_strInfo);
　 Sleep(100);
}
if(m_icmp.routestate==0)//收到非TTL超时报文则跳出循环
 break;
if(WaitForSingleObject(eventStopRoute.m_hObject, 0) == WAIT_OBJECT_0)
 break;　//收到停止信号则跳出循环
}
pThreadDlg->Routeflag=TRUE;
　return 0;
}
……　 //系统代码
BOOL CRouteTraceDlg::OnInitDialog()
{
CDialog::OnInitDialog();
…… //系统代码

// TODO: Add extra initialization here
m_list.InsertColumn(0,"标号",LVCFMT_CENTER,60,0);
m_list.InsertColumn(1,"路由器地址",HDF_CENTER,200,0);
m_list.InsertColumn(2,"状态",HDF_CENTER,100,0);
ListView_SetExtendedListViewStyleEx(m_list.m_hWnd, LVS_EX_FULLROWSELECT, 0xFFFFFFFF);
return TRUE;　// return TRUE　unless you set the focus to a control
}
…… //系统代码
void CRouteTraceDlg::OnTrace()
{
CString str;
UpdateData(TRUE);
CWnd * pWnd;
pWnd = GetDlgItem(IDC_COMBO);
pWnd->GetWindowText(str);
if(str.IsEmpty()) {
MessageBox("请输入地址！");
pWnd->SetFocus();
return;
}
　 if (m_comb.FindStringExact(-1, str) == CB_ERR)
m_comb.AddString(str);
 m_list.DeleteAllItems();
 if(Routeflag)
 {
　 Routeflag=FALSE;
　 Info.IPStr=str;
　 Info.pDialog=this;
　 Info.Maxhot=m_maxhot;
　 Info.list=(&m_list);
　 Info.state=(&m_statectl);
　 AfxBeginThread(ThreadRoute, &Info);　//在线程中实现路由跟踪
 }
}
void CRouteTraceDlg::OnStop()
{
 if(!Routeflag)
 {
　 eventStopRoute.SetEvent();// 发出停止信号
 }
}
void CRouteTraceDlg::OnDestroy()
{
CDialog::OnDestroy();

// TODO: Add your message handler code here
m_icmp.Uninitialize();
}

代码运行效果图如下:

六、结束语

本文所述程序在 Windows 98 下 Visual C++6.0 中调试通过，并在宽带网中测试成功。读者可根据实际需要修改程序中的参数，以实现更强大的功能，比如可以把超时值设置成更合适的值，或设置成可动态输入的形式。