使用socket编程模拟滑动窗口协议

#pragma comment(lib, "ws2_32.lib") #include <winsock.h> #include <stdio.h> ////////////////////////////////////////////////////////////////////////// //发送帧 ////////////////////////////////////////////////////////////////////////// void SendFrame(int * frameNumCurrent,int winSizeCurrent,SOCKET * socketConn) { char sendBuffer[128]; //发送数据 if (_snprintf(sendBuffer,sizeof(sendBuffer)-1,"%d",*frameNumCurrent) < 0) { printf("写数据出错！\n"); return; } else { sendBuffer[sizeof(sendBuffer)-1] = '\0'; } //发送数据 第几帧 if(send(*socketConn,sendBuffer,sizeof(sendBuffer),0) == SOCKET_ERROR) { printf("发送数据失败！\n"); return; } else { printf("现在在传送帧%s\n",sendBuffer); } } ////////////////////////////////////////////////////////////////////////// //接收ACK ////////////////////////////////////////////////////////////////////////// void ReceiveACK(int * frameNumCurrent,SOCKET * socketConn) { char recvBuffer[128];//接收数据 int length = sizeof(struct sockaddr); int frameNum = 0;//接收到的ACK号 //接收ACK，判断是否有超时或者是否错误ACK if(recv(*socketConn,recvBuffer,sizeof(recvBuffer),0) == SOCKET_ERROR)//出现超时 { printf("接收数据超时！需要重新传送帧%d\n\n",*frameNumCurrent); return; } else { frameNum = atoi(recvBuffer); //正确ACK if (frameNum == *frameNumCurrent) { //正确ACK 准备传送下一帧 *frameNumCurrent ^= 1; printf("接收到正确的ACK，已经成功传送帧%d，将要传送帧%d\n\n",(*frameNumCurrent)^1,*frameNumCurrent); } //错误ACK else if (frameNum == ((*frameNumCurrent) ^ 1)) { //得到错误ACK 不进行操作，主函数中进行重传操作 printf("接收到错误ACK，帧%d传送错误，需要重新传送帧%d\n\n",*frameNumCurrent,*frameNumCurrent); } } } ////////////////////////////////////////////////////////////////////////// //初始化发送端监听socket ////////////////////////////////////////////////////////////////////////// BOOL InitSocketSender(SOCKET * socketSender) { SOCKADDR_IN addrSender; WORD wVersionRequested; WSADATA wsaData; //版本 wVersionRequested = MAKEWORD(1,1); //启动 if (WSAStartup( wVersionRequested, &wsaData) != 0) { printf("启动不成功！\n"); return FALSE; } if ( LOBYTE( wsaData.wVersion ) != 1 || HIBYTE( wsaData.wVersion ) != 1 ) { printf("版本错误！\n"); WSACleanup(); return FALSE; } //创建socket *socketSender = socket(AF_INET,SOCK_STREAM,0); if(*socketSender == INVALID_SOCKET) { printf("创建套接字失败！\n"); return FALSE; } //创建地址信息 addrSender.sin_addr.S_un.S_addr=htonl(INADDR_ANY);//所有地址 addrSender.sin_family=AF_INET; addrSender.sin_port=htons(8000);//端口号 //绑定端口 if(bind(*socketSender,(SOCKADDR*)&addrSender,sizeof(struct sockaddr)) == SOCKET_ERROR) { printf("绑定失败！\n"); return FALSE; } //监听 if (listen(*socketSender,SOMAXCONN) == SOCKET_ERROR) { printf("监听失败！\n"); return FALSE; } return TRUE; } ////////////////////////////////////////////////////////////////////////// //线程函数 用于处理一个客户端请求 ////////////////////////////////////////////////////////////////////////// DWORD WINAPI ConnectClient(LPVOID socketConn) { int count = 0;//循环次数计数器 int winSizeCurrent = 0;//当前发送窗口大小 int frameNumCurrent = 0;//当前发送的帧号 printf("初始状态发送窗口是：%d，准备向接收端发送数据\n\n",winSizeCurrent); ++winSizeCurrent; while(count < 20) { SendFrame(&frameNumCurrent,winSizeCurrent,(SOCKET*)socketConn); ReceiveACK(&frameNumCurrent,(SOCKET*)socketConn); ++count; } printf("模拟结束！\n"); //关闭Socket closesocket(*((SOCKET*)socketConn)); free(socketConn); return 0; } void main() { HANDLE hThread;//线程句柄 DWORD threadId; SOCKET socketSender;//监听socket SOCKADDR_IN addrReceiver;//服务器地址 int length = sizeof(struct sockaddr); int timeOut = 3000;//超时3秒 //初始化发送端监听socket if (!InitSocketSender(&socketSender)) { printf("初始化失败，退出！\n"); WSACleanup(); return; } printf("等待建立连接\n\n"); //循环等待请求 while (TRUE) { SOCKET *socketConn = (SOCKET *)malloc(sizeof(SOCKET)); *socketConn = accept(socketSender,(struct sockaddr*)&addrReceiver,&length); printf("连接建立成功！接收端的地址是：%s\n\n",inet_ntoa(addrReceiver.sin_addr)); if (setsockopt(*socketConn,SOL_SOCKET,SO_RCVTIMEO,(char*)&timeOut,sizeof(timeOut)) == SOCKET_ERROR) { printf("设置接收时限错误！"); closesocket(*socketConn); continue; } //开辟线程处理一个客户端请求 hThread = CreateThread(NULL,0,ConnectClient,(LPVOID)socketConn,0,&threadId); } //清理操作 closesocket(socketSender); WSACleanup(); system("pause"); }