简易TCP与UDP编程模型

TCP服务端与客户端分别调用API函数的流程图:

服务端代码:

// TcpServer.cpp : Defines the entry point for the console application.//#include "stdafx.h"#include <windows.h>#include <Winsock2.h>#pragma comment(lib, "Ws2_32.lib")int main(int argc, char* argv[]){   WSADATA wsd;                            //WSADATA变量SOCKET sServer,sClient;                 //服务端套接字,客户端套接字int    nRetVal;                         //返回值printf("*****************************TCP服务端*******************************\n");//初始化套接字动态库if (WSAStartup(MAKEWORD(2,2), &wsd) != 0){printf("WSAStartup failed!\n");return 1;}//创建套接字sServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);if (INVALID_SOCKET == sServer){printf("socket failed!\n");return -1;                         //释放套接字资源}SOCKADDR_IN addrServer;                //服务器地址//服务器套接字地址addrServer.sin_family = AF_INET;addrServer.sin_port = htons(4999);addrServer.sin_addr.s_addr = INADDR_ANY;//绑定套接字nRetVal = bind(sServer, (LPSOCKADDR)&addrServer, sizeof(SOCKADDR_IN));if (SOCKET_ERROR == nRetVal){printf("bind failed!\n");closesocket(sServer);             //关闭套接字WSACleanup();                     //释放套接字资源return -1;                        }//开始监听nRetVal = listen(sServer, 1);if (SOCKET_ERROR == nRetVal){printf("listen failed!\n");closesocket(sServer);             //关闭套接字WSACleanup();                     //释放套接字资源return -1;}//接收客户端请求SOCKADDR_IN addrClient;int addrClientLen = sizeof(addrClient);sClient = accept(sServer, (LPSOCKADDR)&addrClient, &addrClientLen);if (INVALID_SOCKET == sClient){printf("accept failed!\n");closesocket(sServer);             //关闭套接字WSACleanup();                     //释放套接字资源return -1;}char szBuf[MAX_PATH];ZeroMemory(szBuf, MAX_PATH);nRetVal = recv(sClient, szBuf, MAX_PATH, 0);if (SOCKET_ERROR == nRetVal){printf("recv failed!\n");closesocket(sServer);             //关闭套接字closesocket(sClient);             //关闭套接字WSACleanup();                     //释放套接字资源return -1;}printf("%s\n", szBuf);                //输出客户端发送来的信息//退出closesocket(sServer);                 //关闭套接字closesocket(sClient);                 //关闭套接字WSACleanup();                         //释放套接字资源return 0;}

客户端代码:

// TcpClient.cpp : Defines the entry point for the console application.//#include "stdafx.h"#include <windows.h>#include <Winsock2.h>#pragma comment(lib, "Ws2_32.lib")int main(int argc, char* argv[]){WSADATA wsa;                             //WSADATA变量SOCKET  sServer;                         //服务端套接字SOCKADDR_IN addrServer;                  //服务端地址char    szBuf[MAX_PATH];                 //接收数据缓冲区int     nRetVal;                         //返回值printf("*****************************TCP客户端*******************************\n");//初始化套接字动态库if (WSAStartup(MAKEWORD(2,2), &wsa) != 0){printf("WSAStartup failed!\n");return -1;}//创建套接字sServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);if (INVALID_SOCKET == sServer){printf("socket failed!\n");WSACleanup();return -1;}//设置服务端地址addrServer.sin_family = AF_INET;addrServer.sin_addr.s_addr = inet_addr("192.168.1.138");addrServer.sin_port = htons(4999);int nAddrServerLen = sizeof(addrServer);//连接服务器nRetVal = connect(sServer, (LPSOCKADDR)&addrServer, sizeof(addrServer));if (SOCKET_ERROR == nRetVal){printf("connect failed!\n");closesocket(sServer);             //关闭套接字WSACleanup();                     //释放套接字资源return -1;                 }//向服务端发送数据ZeroMemory(szBuf, MAX_PATH);strcpy(szBuf, "SimpleTcpDemo");nRetVal = send(sServer, szBuf, strlen(szBuf), 0);if (SOCKET_ERROR == nRetVal){printf("send failed!\n");closesocket(sServer);             //关闭套接字WSACleanup();                     //释放套接字资源return -1; }//退出closesocket(sServer);                 //关闭套接字WSACleanup();                         //释放套接字资源return 0;}

wireshark抓包效果:

UDP服务端与客户端分别调用API函数的流程图:

服务端代码:

// UdpServer.cpp : Defines the entry point for the console application.//#include "stdafx.h"#include <windows.h>#include <WINSOCK2.H>#pragma comment(lib, "Ws2_32.lib")int main(int argc, char* argv[]){WSADATA  wsa;                        //WSADATA变量SOCKET   s;                          //套接字printf("*****************************UDP服务端*******************************\n");//初始化套接字动态库if (WSAStartup(MAKEWORD(2,2), &wsa) != 0){printf("WSAStartup failed!\n");return 1;}//创建套接字s = socket(AF_INET, SOCK_DGRAM, 0);if (s == INVALID_SOCKET){printf("socket() failed; %d\n", WSAGetLastError());WSACleanup();                                   //释放套接字资源return 1;}SOCKADDR_IN  addrServer;                            //服务器地址//服务器地址addrServer.sin_family = AF_INET;addrServer.sin_port = htons(5000);                  //端口addrServer.sin_addr.s_addr = htonl(INADDR_ANY);     //IP//绑定if (bind(s, (LPSOCKADDR)&addrServer, sizeof(addrServer)) == SOCKET_ERROR){printf("bind() failed: %d\n", WSAGetLastError());closesocket(s);                                     //关闭套接字WSACleanup();                                       //释放套接字资源return 1; }char szBuf[MAX_PATH];                                   //接收数据缓冲区//接收数据SOCKADDR_IN addrClient;int nClientLen = sizeof(addrClient);ZeroMemory(szBuf, MAX_PATH);if (recvfrom(s, szBuf, MAX_PATH, 0, (LPSOCKADDR)&addrClient, &nClientLen) == SOCKET_ERROR){printf("recvfrom() failed: %d\n", WSAGetLastError());closesocket(s);                                     //关闭套接字WSACleanup();                                       //释放套接字资源return 1;}printf("%s\n", szBuf);                                  //输出客户端发送来的数据closesocket(s);                                         //关闭套接字WSACleanup();                                           //释放套接字资源return 0;}

客户端代码:

// udpClient.cpp : Defines the entry point for the console application.//#include "stdafx.h"#include <windows.h>#include <WINSOCK2.H>#pragma comment(lib, "Ws2_32.lib")int main(int argc, char* argv[]){WSADATA wsa;                           //WSADATA变量SOCKET  s;                             //套接字printf("*****************************UDP客户端*******************************\n");//初始化动态库动态库if (WSAStartup(MAKEWORD(2,2), &wsa) != 0){printf("WSAStartup failed!\n");return 1;}//创建套接字s = socket(AF_INET,SOCK_DGRAM, 0);if (INVALID_SOCKET == s){printf("socket() failed; %d\n", WSAGetLastError());WSACleanup();                      //释放套接字资源           return 1;}char szBuf[MAX_PATH];ZeroMemory(szBuf, MAX_PATH);strcpy(szBuf, "SimpleUdpDemo");//服务器地址SOCKADDR_IN addrServer;addrServer.sin_family = AF_INET;addrServer.sin_addr.s_addr = inet_addr("192.168.1.138");addrServer.sin_port = htons(5000);int nAddrServerLen = sizeof(addrServer);if (sendto(s, szBuf, MAX_PATH, 0, (LPSOCKADDR)&addrServer, nAddrServerLen) == SOCKET_ERROR){printf("sendto() failed: %d\n", WSAGetLastError());closesocket(s);                        //关闭套接字WSACleanup();                          //释放套接字资源return 1;}closesocket(s);                            //关闭套接字WSACleanup();                              //释放套接字资源return 0;}

wireshark抓包效果: