抓包工具已经看到数据到本机,但是recvfrom 读不到数据的问题?

[jdzfjfhnui]

#include "stdafx.h"
#include <WinSock2.h>
#include <MSWSock.h>
#pragma comment(lib, "ws2_32.lib")
#include <list>
#include <vector>
#include <string>
#include <iostream>

DWORD WINAPI EchoProc(LPVOID pVoid)
{
	SOCKET ReceivingSocket = (SOCKET)pVoid;
	char szRecvBuf[8193]={0};
	sockaddr_in SenderAddr;
	int nAddrLen   =   sizeof(SenderAddr); 
	int nRecvdBytes = 0;
	int Ret = 0;
	while(true) 
	{ 
		if((nRecvdBytes   =   recvfrom(ReceivingSocket,   szRecvBuf,   8192,   0,   (sockaddr*)&SenderAddr,   &nAddrLen))   ==   SOCKET_ERROR) 
		{ 
			cout<<"ERROR:   recvfrom   failed   with   error:   " <<WSAGetLastError() <<endl; 
			break; 
		} 
		else
		{
			szRecvBuf[nRecvdBytes] = 0;
			cout<<szRecvBuf<<endl;
		}
		
		Ret   =   sendto(ReceivingSocket,   szRecvBuf,   nRecvdBytes,   0,   (SOCKADDR   *)&SenderAddr,   nAddrLen); 
		if(SOCKET_ERROR   ==   Ret) 
		{ 
			cout<<"ERROR:   sendto   failed   with   error:   " <<WSAGetLastError() <<endl; 		
			break; 
		} 
	} 	
	
	closesocket(ReceivingSocket); 
	WSACleanup(); 
	
	return 0;
}


DWORD WINAPI RecvProc(LPVOID pVoid)
{
	SOCKET ReceivingSocket = (SOCKET)pVoid;
	char szRecvBuf[8193]={0};
	sockaddr_in SenderAddr;
	int nAddrLen   =   sizeof(SenderAddr); 
	int nRecvdBytes = 0;
	int Ret = 0;
	while(true) 
	{ 
		if((nRecvdBytes   =   recvfrom(ReceivingSocket,   szRecvBuf,   8192,   0,   (sockaddr*)&SenderAddr,   &nAddrLen))   ==   SOCKET_ERROR) 
		{ 
			cout<<"ERROR:   recvfrom   failed   with   error:   " <<WSAGetLastError() <<endl; 
			break; 
		} 
		else
		{
			szRecvBuf[nRecvdBytes] = 0;
			cout<<szRecvBuf<<endl;
		}		 
	} 	
	
	closesocket(ReceivingSocket); 
	WSACleanup(); 
	
	return 0;
}


SOCKET sock = INVALID_SOCKET;
int main(int argc, TCHAR* argv[], TCHAR* envp[])
{
	int nRetCode = 0;
	
	WSADATA wsaData;
	WSAStartup(MAKEWORD(2,2), &wsaData);
	sockaddr_in sockaddr;
	sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP );
	BOOL   bNewBehavior   =   FALSE;   
	DWORD   dwBytesReturned; 
	WSAIoctl(sock,   SIO_UDP_CONNRESET,   &bNewBehavior,   sizeof   bNewBehavior,   NULL,   0,   &dwBytesReturned,   NULL,   NULL);
	
	int mode = 0;
SELECT_MODE:
	cout << "输入模式:0服务端 1客户端" << endl;
	cin>>mode;
	if (mode == 0)
	{
		int port = 0;
		cout << "输入监听端口" << endl;
		cin>>port;
		
		sockaddr.sin_family = AF_INET;
		sockaddr.sin_port = htons(port);
		sockaddr.sin_addr.S_un.S_addr = htons(INADDR_ANY);
		
		if(bind(sock, (SOCKADDR*)&sockaddr, sizeof(sockaddr)) != SOCKET_ERROR)
		{				
			HANDLE hThread = CreateThread(NULL, 0, EchoProc, (void*)sock, 0, NULL);
			char q = 0;
			while (true)
			{
				cout<<"press q to quit"<<endl;
				cin>>q;
				if (q == 'q')
				{
					closesocket(sock);
					WaitForSingleObject(hThread, INFINITE);
					CloseHandle(hThread);
					break;
				}
			}
		}
		
	}
	else if (mode == 1)
	{
		string ip;
		int port = 0;
		sockaddr_in addr;
		addr.sin_family = AF_INET;
SELECT_IP:
		cout << "输入服务IP" << endl;
		cin>>ip;
		PHOSTENT phost = gethostbyname(ip.c_str());
		if (phost == NULL)
		{
			goto SELECT_IP;
		}
		else
		{
			addr.sin_addr.S_un.S_addr = *(u_long *) phost->h_addr_list[0];; //inet_addr(ip.c_str());
		}
		
		cout<<"输入端口"<<endl;
		cin>>port;
		addr.sin_port = htons(port);
		
		cout<<"输入要发送的数据"<<endl;
		
		
		sockaddr_in bind;
		bind.sin_addr.S_un.S_addr = htons(INADDR_ANY);
		bind.sin_port = htons(port-1);
		bind.sin_family = AF_INET;
		::bind(sock, (SOCKADDR*)&bind, sizeof(bind));
		
		HANDLE hThread = CreateThread(NULL, 0, RecvProc, (void*)sock, 0, NULL);
		
		char q = 0;
		cout<<"press q to quit"<<endl;
		while (true)
		{
			string buffer;
			cin>>buffer;
			int sendResult = sendto(sock, buffer.c_str(), buffer.size(), 0, (SOCKADDR*)&addr, sizeof(addr));
			
			cin>>q;
			if (q == 'q')
			{
				closesocket(sock);
				WaitForSingleObject(hThread, INFINITE);
				CloseHandle(hThread);
				break;
			}				
		}
		
	}
	else
	{
		cout << "输入正确的的模式" << endl;
		goto SELECT_MODE;
	}
	
	
	return nRetCode;
}

这是一个简单的upd 回显程序,运行程序选择0,就是服务端,输入监听端口之后,客户端开始网这个端口发数据,服务端就会把数据打出来,然后在发回客户端.

这个在本机上运行是好的

一台机器是win7 ip:192.168.0.195
一台机器是xp ip:192.168.0.134
都关闭了防火墙,360之类的碉东西
都是用网线连接到路由器的

现在的问题是
如果从win7向xp发包,xp机器能正常收到

如果是xp向win7发包,在win7上打开的抓包程序也都能看到包到本机了,但是就是recvfrom读不到数据.

哪位朋友提供下思路,怎么寻找根源问题.

[Gloveing]

你的机器上的端口和别的程序有冲突嘛？

[向立天]

win7上是不是还有防护措施没有禁用

[Eleven]

如果是xp向win7发包,在win7上打开的抓包程序也都能看到包到本机了,但是就是recvfrom读不到数据.
-------------
你说的读不到数据指的是什么？阻塞在哪里没有返回还是怎么的？

[yby4769250]

我之前好像也遇到过在xp上udp广播少量数据，xp能收到，win7不能收到，很郁闷，后来我设置socket选项禁用Nagle算法后就可以了，按理说，udp是没有tcp_nodelay的，但是反正我用了行，因为时间的关系我也没深入分析，留给楼主探索吧。

[jdzfjfhnui]

[Quote=引用 4 楼 的回复:]
如果是xp向win7发包,在win7上打开的抓包程序也都能看到包到本机了,但是就是recvfrom读不到数据.
-------------
你说的读不到数据指的是什么？阻塞在哪里没有返回还是怎么的？
[/Quote]

对就是recvfrom不返回,一直阻塞在那里,上班, 顶上去啊

[jdzfjfhnui]

已解决,经过了解,该win7系统是ghost方式安装的,最后在我的劝说下,用win7原盘一步一步安装了win7,装好驱动之后,运行程序一切正常.