WinSock网络编程经络----读书笔记(1)

一、echo客户/服务器程序

1、网络结构模型

a、集中式系统----有一个大型的中央处理系统，有点是数据容易备份，不易感染病毒，日常生活中的ATM、POS等使用的都是集中式系统

b、分布式系统----具有高度的可靠性、均衡负载、满足不同的需要

c、对等网络模型----P2P网络，每一台主机处于同等地位，既作为客户端，又充当其他主机的服务器，有可非为无结构网络、有结构网络、混合式网络、集中式网络

2、echo客户程序

mySocketClient.cpp：

 #include "stdafx.h"
 #include "winsock2.h"
 #include "iostream"
 #pragma comment(lib, "ws2_32")

 #define ECHO_DEF_PORT   7   //连接的默认端口
 #define ECHO_BUF_SIZE   256 //缓冲区的大小

 #define InitSockets()   {               \
     WORD    version;                    \
     WSADATA wsaData;                    \
     version = MAKEWORD( 2,0 );          \
     WSAStartup(version, &wsaData);  }

 #define CleanupSockets()    WSACleanup()

 void DoSoming()
 {
     SOCKET echoSoc = 0;
     struct sockaddr_in servAddr;
     unsigned short port = ECHO_DEF_PORT;
     int result  = 0;
     int sendLen = 0;
     char *testSendData = "hello world";
     char recv_buf[ECHO_BUF_SIZE];

     sendLen = strlen(testSendData);

     servAddr.sin_family = AF_INET;
     servAddr.sin_port = htons(port);
     servAddr.sin_addr.s_addr = inet_addr("127.0.0.1");

     if (servAddr.sin_addr.s_addr == INADDR_NONE)
     {
         std::cout << "[ECHO] invalid address" << WSAGetLastError() << std::endl;
         exit(-1);
     }

     echoSoc = socket(AF_INET, SOCK_STREAM, 0);
     result = connect(echoSoc, (struct sockaddr *)&servAddr, sizeof(servAddr));

     if (result == 0)
     {
         result = send(echoSoc, testSendData, sendLen, 0);
         result = recv(echoSoc, recv_buf, ECHO_BUF_SIZE, 0);
     }

     if (result > 0)
     {
         recv_buf[result] = 0;
         std::cout << "[Echo Client] receives : " << recv_buf << std::endl;
     }
     else
     {
         std::cout << "[Echo Client] error : " << WSAGetLastError() << std::endl;
     }

     closesocket(echoSoc);
     CleanupSockets();
 }

 int _tmain(int argc, _TCHAR* argv[])
 {
     DoSoming();

     return 0;
 }

3、echo服务器程序

mySokcetSer.cpp：

 #include "stdafx.h"
 #include "winsock2.h"
 #include "iostream"
 #pragma comment(lib, "ws2_32")

 #define ECHO_DEF_PORT   7   //连接的默认端口
 #define ECHO_BUF_SIZE   256 //缓冲区的大小

 #define InitSockets()   {               \
     WORD    version;                    \
     WSADATA wsaData;                    \
     version = MAKEWORD( 2,0 );          \
     WSAStartup(version, &wsaData);  }

 #define CleanupSockets()    WSACleanup()

 void DoSoming()
 {
     SOCKET  echoSoc = 0;
     SOCKET  acptSoc = 0;

     struct sockaddr_in servAddr;
     struct sockaddr_in clntAddr;

     unsigned short port = ECHO_DEF_PORT;
     int result = 0;
     int addrLen = sizeof(struct sockaddr_in);
     char recvBuf[ECHO_BUF_SIZE];

     echoSoc = socket(AF_INET, SOCK_STREAM, 0);

     servAddr.sin_family = AF_INET;
     servAddr.sin_port = htons(port);
     servAddr.sin_addr.s_addr = INADDR_ANY;

     result = bind(echoSoc, (struct sockaddr *)&servAddr, sizeof(servAddr));
     if (result == SOCKET_ERROR)
     {
         std::cout << "[Echo Server] bind error : " << WSAGetLastError() << std::endl;
         closesocket(echoSoc);
         exit(-1);
     }

     listen(echoSoc, SOMAXCONN);

     std::cout << "[Echo Server] is running ... ..." << std::endl;
     while (true)
     {
         acptSoc = accept(echoSoc, (struct sockaddr *)&clntAddr, &addrLen);
         if (acptSoc == INVALID_SOCKET)
         {
             std::cout << "[Echo Server] bind error : " << WSAGetLastError() << std::endl;
             break;
         }

         result = recv(acptSoc, recvBuf, ECHO_BUF_SIZE, 0);
         if (result > 0)
         {
             recvBuf[result] = 0;
             std::cout << "[Echo Server] receives : " << recvBuf << "from : "
                       << inet_ntoa(clntAddr.sin_addr) << std::endl;

             result = send(acptSoc, recvBuf, result, 0);
         }

         closesocket(acptSoc);
     }

     closesocket(acptSoc);
     CleanupSockets();
 }

 int _tmain(int argc, _TCHAR* argv[])
 {
     DoSoming();

     return 0;
 }