p2pclient.cpp

一个UDP穿透NAT的实例程序

// 解析命令，暂时只有exit和send命令
// 新增getu命令，获取当前服务器的所有用户
void ParseCommand(char * CommandLine)
{
	if(strlen(CommandLine)<4)
		return;
	char Command[10];
	strncpy(Command, CommandLine, 4);
	Command[4]='\0';

	if(strcmp(Command,"exit")==0)
	{
		stMessage sendbuf;
		sendbuf.iMessageType = LOGOUT;
		strncpy(sendbuf.message.logoutmember.userName, UserName, 10);
		sockaddr_in server;
		server.sin_addr.S_un.S_addr = inet_addr(ServerIP);
		server.sin_family = AF_INET;
		server.sin_port = htons(g_nServerPort);

		sendto(PrimaryUDP,(const char*)&sendbuf, sizeof(sendbuf), 0, (const sockaddr *)&server, sizeof(server));
		shutdown(PrimaryUDP, 2);
		closesocket(PrimaryUDP);
		exit(0);
	}
	else if(strcmp(Command,"send")==0)
	{
		char sendname[20];
		char message[COMMANDMAXC];
		int i;
		for(i=5;;i++)
		{
			if(CommandLine[i]!=' ')
				sendname[i-5]=CommandLine[i];
			else
			{
				sendname[i-5]='\0';
				break;
			}
		}
		strcpy(message, &(CommandLine[i+1]));
		if(SendMessageTo(sendname, message))
			printf("Send OK!\n");
		else 
			printf("Send Failure!\n");
	}
	else if(strcmp(Command,"tell")==0)
	{
		char sendname[20];
		char sendto[ 64 ] = {0};
		char message[COMMANDMAXC];
		int i;
		for(i=5;;i++)
		{
			if(CommandLine[i]!=' ')
				sendname[i-5]=CommandLine[i];
			else
			{
				sendname[i-5]='\0';
				break;
			}
		}

		i++;
		int nStart = i;
		for(;;i++)
		{
			if(CommandLine[i]!=' ')
				sendto[i-nStart]=CommandLine[i];
			else
			{
				sendto[i-nStart]='\0';
				break;
			}
		}

		strcpy(message, &(CommandLine[i+1]));

		char szIP[32] = {0};
		char *p1 = sendto;
		char *p2 = szIP;
		while ( *p1 != ':' )
		{
			*p2++ = *p1++;	
		}

		p1++;
		USHORT nPort = atoi( p1 );

		if(SendMessageTo2(sendname, message, strcmp( szIP, "255.255.255.255" ) ? szIP : NULL, nPort ))
			printf("Send OK!\n");
		else 
			printf("Send Failure!\n");
	}
	else if(strcmp(Command,"getu")==0)
	{
		int command = GETALLUSER;
		sockaddr_in server;
		server.sin_addr.S_un.S_addr = inet_addr(ServerIP);
		server.sin_family = AF_INET;
		server.sin_port = htons(g_nServerPort);

		sendto(PrimaryUDP,(const char*)&command, sizeof(command), 0, (const sockaddr *)&server, sizeof(server));
	}
}

// 接受消息线程
DWORD WINAPI RecvThreadProc(LPVOID lpParameter)
{
	sockaddr_in remote;
	int sinlen = sizeof(remote);
	stP2PMessage recvbuf;
	for(;;)
	{
		int iread = recvfrom(PrimaryUDP, (char *)&recvbuf, sizeof(recvbuf), 0, (sockaddr *)&remote, &sinlen);
		if(iread<=0)
		{
			printf("recv error\n");
			continue;
		}
		switch(recvbuf.iMessageType)
		{
		case P2PMESSAGE:
			{
				// 接收到P2P的消息
				char *comemessage= new char[recvbuf.iStringLen];
				int iread1 = recvfrom(PrimaryUDP, comemessage, 256, 0, (sockaddr *)&remote, &sinlen);
				comemessage[iread1-1] = '\0';
				if(iread1<=0)
					throw Exception("Recv Message Error\n");
				else
				{
					printf("Recv a Message, %s:%ld -> %s\n", inet_ntoa( remote.sin_addr), htons(remote.sin_port), comemessage);
					
					stP2PMessage sendbuf;
					sendbuf.iMessageType = P2PMESSAGEACK;
					sendto(PrimaryUDP, (const char*)&sendbuf, sizeof(sendbuf), 0, (const sockaddr*)&remote, sizeof(remote));
					printf("Send a Message Ack to %s:%ld\n", inet_ntoa( remote.sin_addr), htons(remote.sin_port) );
				}

				delete []comemessage;
				break;

			}
		case P2PSOMEONEWANTTOCALLYOU:
			{
				// 接收到打洞命令，向指定的IP地址打洞
				printf("Recv p2someonewanttocallyou from %s:%ld\n", inet_ntoa( remote.sin_addr), htons(remote.sin_port) );

				sockaddr_in remote;
				remote.sin_addr.S_un.S_addr = htonl(recvbuf.iStringLen);
				remote.sin_family = AF_INET;
				remote.sin_port = htons(recvbuf.Port);

				// UDP hole punching
				stP2PMessage message;
				message.iMessageType = P2PTRASH;
				sendto(PrimaryUDP, (const char *)&message, sizeof(message), 0, (const sockaddr*)&remote, sizeof(remote));
	
				printf("Send p2ptrash to %s:%ld\n", inet_ntoa( remote.sin_addr), htons(remote.sin_port) );
                
				break;
			}
		case P2PMESSAGEACK:
			{
				// 发送消息的应答
				RecvedACK = true;
				printf("Recv message ack from %s:%ld\n", inet_ntoa( remote.sin_addr), htons(remote.sin_port) );

				break;
			}
		case P2PTRASH:
			{
				// 对方发送的打洞消息，忽略掉。
				//do nothing ...
				printf("Recv p2ptrash data from %s:%ld\n", inet_ntoa( remote.sin_addr), htons(remote.sin_port) );

				break;
			}
		case GETALLUSER:
			{
				int usercount;
				int fromlen = sizeof(remote);
				int iread = recvfrom(PrimaryUDP, (char *)&usercount, sizeof(int), 0, (sockaddr *)&remote, &fromlen);
				if(iread<=0)
				{
					throw Exception("Login error\n");
				}
				
				ClientList.clear();

				cout<<"Have "<<usercount<<" users logined server:"<<endl;
				for(int i = 0;i<usercount;i++)
				{
					stUserListNode *node = new stUserListNode;
					recvfrom(PrimaryUDP, (char*)node, sizeof(stUserListNode), 0, (sockaddr *)&remote, &fromlen);
					ClientList.push_back(node);
					cout<<"Username:"<<node->userName<<endl;
					in_addr tmp;
					tmp.S_un.S_addr = htonl(node->ip);
					cout<<"UserIP:"<<inet_ntoa(tmp)<<endl;
					cout<<"UserPort:"<<node->port<<endl;
					cout<<""<<endl;
				}
				break;
			}
		}
	}
}

int testNATProp()
{
	try
	{
		InitWinSock();
		
		PrimaryUDP = mksock(SOCK_DGRAM);
		BindSock(PrimaryUDP);

		char szServerIP1[ 32 ] = {0};
		char szServerIP2[ 32 ] = {0};

		cout<<"Please input server1 ip:";
		cin>>szServerIP1;

		cout<<"Please input server2 ip:";
		cin>>szServerIP2;

		sockaddr_in remote1;
		remote1.sin_addr.S_un.S_addr = inet_addr(szServerIP1);
		remote1.sin_family = AF_INET;
		remote1.sin_port = htons(g_nServerPort);
		
		sockaddr_in remote2;
		remote2.sin_addr.S_un.S_addr = inet_addr(szServerIP2);
		remote2.sin_family = AF_INET;
		remote2.sin_port = htons(g_nServerPort);

		char chData = 'A';
		int nCount = 0;

		for(;;)
		{
			nCount++;
			printf( "send message to: %s:%ld, %ld\n", szServerIP1, g_nServerPort, nCount );

			sendto(PrimaryUDP, (const char*)&chData, sizeof(char), 0, (const sockaddr*)&remote1,sizeof(remote1));

			if ( szServerIP2[ 0 ] != 'x' )
			{
				printf( "send message to: %s:%ld, %ld\n", szServerIP2, g_nServerPort, nCount );
				sendto(PrimaryUDP, (const char*)&chData, sizeof(char), 0, (const sockaddr*)&remote2,sizeof(remote2));
			}

			Sleep( 5000 );
		}
	}
	catch(Exception &e)
	{
		printf(e.GetMessage());
		return 1;
	}
	return 0;
}


int main(int argc, char* argv[])
{
//	testNATProp();
// 	return 0;

	if ( argc > 1 )
	{
		g_nClientPort = atoi( argv[ 1 ] );
	}

	if ( argc > 2 )
	{
		g_nServerPort = atoi( argv[ 2 ] );
	}

	try
	{
		InitWinSock();
		
		PrimaryUDP = mksock(SOCK_DGRAM);
		BindSock(PrimaryUDP);

		cout<<"Please input server ip:";
		cin>>ServerIP;

		cout<<"Please input your name:";
		cin>>UserName;

		ConnectToServer(PrimaryUDP, UserName, ServerIP);

		HANDLE threadhandle = CreateThread(NULL, 0, RecvThreadProc, NULL, NULL, NULL);
		CloseHandle(threadhandle);
		OutputUsage();

		for(;;)
		{
			char Command[COMMANDMAXC];
			gets(Command);
			ParseCommand(Command);
		}
	}
	catch(Exception &e)
	{
		printf(e.GetMessage());
		return 1;
	}
	return 0;
}