网络报文的数据格式定义和使用
服务器端：
#include<WinSock2.h> #include<Windows.h> #include<stdio.h> #include<iostream> #pragma comment(lib,"ws2_32.lib") enum CMD { CMD_Login,CMD_Logout,CMD_ERROR }; //包头 struct DataHeader { short dataLength; short cmd; }; //包体 struct Login { char username[32]; char password[32]; }; struct LoginResult { int result; }; struct Logout { char username[32]; }; struct LogoutResult { int result; }; int main() { WORD ver = MAKEWORD(2, 2); WSADATA dat; //WinSocket启动 WSAStartup(ver, &dat); //1、建立一个socket SOCKET _sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); //AF_INET创建一个IPV4的套接字,SOCK_STREAM面向数据流的,IPPROTO_TCP TCP if (INVALID_SOCKET == _sock) { printf("ERROR:建立失败！\n"); } //2.绑定 sockaddr_in _sin = {}; //创建网络地址 _sin.sin_family = AF_INET; _sin.sin_port = htons(4567); //Host to Network Short _sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1"); // IP地址 if (bind(_sock, (sockaddr *)&_sin, sizeof(_sin)) == SOCKET_ERROR) { printf("ERROR:绑定失败！\n"); } else { printf("服务器端绑定成功......\n"); } //3.监听网络端口 if (listen(_sock, 5) == SOCKET_ERROR)//第二个参数为最大等待多少人可以同时连接 { printf("ERROR:监听失败！\n"); } else { printf("服务器端监听成功......\n"); } //4.等待接收客户端连接 sockaddr_in clientAddr = {}; int nAddrLen = sizeof(sockaddr_in); SOCKET _cSOCK = INVALID_SOCKET; _cSOCK = accept(_sock, (sockaddr *)&clientAddr, &nAddrLen); if (_cSOCK == INVALID_SOCKET) { printf("ERROR:无效客户端SOCKET！\n"); } printf("新客户端加入：Socket=%d,IP = %s\n",(int)_cSOCK, inet_ntoa(clientAddr.sin_addr));//inet_ntoa(clientAddr.sin_addr)将接收到的IP地址转化为字符串 while (1) { DataHeader header = {}; //5.接收客户端新数据 int nLen = recv(_cSOCK, (char *)&header, sizeof(DataHeader), 0); if (nLen <= 0) { printf("客户端已退出！任务结束！"); break; } printf("收到命令：%s,数据长度：%d\n",header.cmd,header.dataLength); switch (header.cmd){ case CMD_Login: { Login login = {}; recv(_cSOCK, (char *)&login, sizeof(Login), 0); //忽略判断用户密码是否正确的过程 LoginResult ret = { 1 }; send(_cSOCK, (char *)&header, sizeof(DataHeader), 0); //先发消息头 send(_cSOCK, (char *)&ret, sizeof(LoginResult), 0); //再发消息体 } case CMD_Logout: { Logout logout = {}; recv(_cSOCK, (char *)&logout, sizeof(Logout), 0); //忽略判断用户密码是否正确的过程 LogoutResult let = { 1 }; send(_cSOCK, (char *)&header, sizeof(DataHeader), 0); //先发消息头 send(_cSOCK, (char *)&let, sizeof(LogoutResult), 0); //再发消息体 } break; default: header.cmd = CMD_ERROR; header.dataLength = 0; send(_cSOCK, (char *)&header.cmd, sizeof(header), 0); break; } } //8.关闭自身的socket closesocket(_sock); //WinSocket关闭 WSACleanup(); system("pause"); return 0; }
客户端：
#include<WinSock2.h> #include<Windows.h> #include<stdio.h> #pragma comment(lib,"ws2_32.lib") enum CMD { CMD_Login, CMD_Logout, CMD_ERROR }; //包头 struct DataHeader { short dataLength; short cmd; }; //包体 struct Login { char username[32]; char password[32]; }; struct LoginResult { int result; }; struct Logout { char username[32]; }; struct LogoutResult { int result; }; int main() { WORD ver = MAKEWORD(2, 2); WSADATA dat; WSAStartup(ver, &dat); //1.建立一个socket SOCKET _sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (INVALID_SOCKET == _sock) { printf("ERROR:建立失败！\n"); } else{ printf("客户端绑定成功......\n"); } //2.连接服务器 sockaddr_in _sin = {}; //创建网络地址 _sin.sin_family = AF_INET; _sin.sin_port = htons(4567); //Host to Network Short _sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");//inet_addr("127.0.0.1"); // IP地址 int ret = connect(_sock, (sockaddr *)&_sin, sizeof(sockaddr_in)); if (SOCKET_ERROR == ret) { printf("ERROR:连接失败！\n"); } else { printf("客户端连接成功......\n"); } while (true) { //3.输入请求命令 char cmdBuff[128] = {}; scanf("%s", cmdBuff); //4.处理请求命令 if (0 == strcmp(cmdBuff, "exit")) { printf("收到exit命令，已退出1"); break; } else if (0 == strcmp(cmdBuff, "login")){ Login login = { "sutaoyu01", "sutaoyu01" }; DataHeader dh = { sizeof(login), CMD_Login }; //5.向服务器发送请求命令 //先发数据头 send(_sock, (const char*)&dh, sizeof(dh), 0); //再发数据尾 send(_sock, (const char*)&login, sizeof(login), 0); //接收服务器返回的数据 DataHeader retHeader = {}; LoginResult resulrtRet = {}; //接收服务器发送的数据头 recv(_sock, (char*)&retHeader, sizeof(retHeader), 0); //接收服务器发送的数据体 recv(_sock, (char*)&resulrtRet, sizeof(resulrtRet), 0); printf("LoginResult:%d\n", resulrtRet.result); } else if (0 == strcmp(cmdBuff, "logout")){ Logout logout = { "sutaoyu01"}; DataHeader dh = { sizeof(logout),CMD_Logout }; //5.向服务器发送请求命令 //先发数据头 send(_sock, (const char*)&dh, sizeof(dh), 0); //再发数据尾 send(_sock, (const char*)&logout, sizeof(logout), 0); //接收服务器返回的数据 DataHeader retHeader = {}; LogoutResult resultRet = {}; //接收服务器发送的数据头 recv(_sock, (char*)&retHeader, sizeof(retHeader), 0); //接收服务器发送的数据体 recv(_sock, (char*)&resultRet, sizeof(resultRet), 0); printf("LogoutResult:%d\n", resultRet.result); } else{ printf("不支持的命令，请重新输入！"); } } //7.关闭套接字 closesocket(_sock); //WinSocket启动 WSAStartup(ver, &dat); //WinSocket关闭 WSACleanup(); printf("已退出!"); getchar(); return 0; }
