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最新推荐文章于 2021-08-19 09:05:07 发布

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最新推荐文章于 2021-08-19 09:05:07 发布

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分类专栏： IT技术文章标签： socket buffer server struct null initialization

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#include "stdafx.h"
//#include "Proxy.h"
#include < winsock2.h > //WINSOCKET API 2。0
#include < stdlib.h >
#include < stdio.h >
#include < string.h >
#include <iostream> 
using namespace std;

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////


#define HTTP "http://"
#define FTP "ftp://"
#define PROXYPORT 5001 //Proxy 端口
#define BUFSIZE 10240 //缓冲区大小


/*CWinApp theApp;*/

using namespace std;

UINT ProxyToServer(LPVOID pParam);
UINT UserToProxyThread(void *pParam);

struct SocketPair{
    SOCKET user_proxy; //socket : 本地机器到PROXY 服务机
    SOCKET proxy_server; //socket : PROXY 服务机到远程主机
    BOOL IsUser_ProxyClosed; // 本地机器到PROXY 服务机状态
    BOOL IsProxy_ServerClosed; // PROXY 服务机到远程主机状态
};


struct ProxyParam{
    char Address[256]; // 远程主机地址
    HANDLE User_SvrOK; // PROXY 服务机到远程主机的联结状态
    SocketPair *pPair; // 维护一组SOCKET的指针
    int Port; // 用来联结远程主机的端口
}; //这个结构用来PROXY SERVER与远程主机的信息交换.

SOCKET gListen_Socket; //用来侦听的SOCKET。

int StartServer() //启动服务
{
    WSADATA wsaData;
    sockaddr_in local;
    SOCKET listen_socket;

    if(::WSAStartup(0x202,&wsaData)!=0)
    {printf("\nError in Startup session.\n");WSACleanup();return -1;};

    local.sin_family=AF_INET;
    local.sin_addr.s_addr=INADDR_ANY;
    local.sin_port=htons(PROXYPORT);

    listen_socket=socket(AF_INET,SOCK_STREAM,0);
    if(listen_socket==INVALID_SOCKET)
    {printf("\nError in New a Socket.");WSACleanup();return -2;}

    if(::bind(listen_socket,(sockaddr *)&local,sizeof(local))!=0)
    {printf("\n Error in Binding socket."); WSACleanup();return -3; };

    if(::listen(listen_socket,5)!=0)
    {printf("\n Error in Listen."); WSACleanup(); return -4;}
    gListen_Socket=listen_socket; 
    AfxBeginThread(UserToProxyThread,NULL); //启动侦听
    return 1;
}

int CloseServer() //关闭服务
{
    closesocket(gListen_Socket);
    WSACleanup();
    return 1;
}

//分析接收到的字符，得到远程主机地址
int GetAddressAndPort( char * str, char *address, int * port)
{
    char buf[BUFSIZE], command[512], proto[128], *p;
    int i,j;
    sscanf(str,"%s,%s,%s",command,buf,proto);
    p=strstr(buf,HTTP);
    //HTTP
    if(p)
    {
        p+=strlen(HTTP);
        for(int i=0;i< strlen(p);i++)
            if( *(p+i)=='/') break;
        *(p+i)=0;
        strcpy(address,p);
        p=strstr(str,HTTP);
        for(int j=0;j< i+strlen(HTTP);j++)
            *(p+j)=' '; //去掉远程主机名: GET http://www.njust.edu.cn/ HTTP1.1 == > GET / HTTP1.1
        *port=80; //缺省的 http 端口 
    }
    else
    {//FTP, 不支持, 下面的代码可以省略.
        p=strstr(buf,FTP);
        if(!p) return 0;
        p+=strlen(FTP);
        for(int i=0;i< strlen(p);i++)
            if( *(p+i)=='/') break; //Get The Remote Host
        *(p+i)=0;
        for(j=0;j< strlen(p);j++)
            if(*(p+j)==':') 
            {*port=atoi(p+j+1); //Get The Port
        *(p+j)=0;
        }
            else *port=21; 

            strcpy(address,p);
            p=strstr(str,FTP);
            for(j=0;j< i+strlen(FTP);j++)
                *(p+j)=' '; 
    }
    return 1; 
}


UINT UserToProxyThread(void *pParam)
{// 取到本地的数据，发往远程主机
    char Buffer[BUFSIZE];
    int Len;
    sockaddr_in from;
    SOCKET msg_socket;
    int fromlen,retval;
    SocketPair SPair;
    ProxyParam ProxyP;
    CWinThread *pChildThread;
    fromlen=sizeof(from);
    msg_socket=accept(gListen_Socket,(struct sockaddr*)&from,&fromlen);
    AfxBeginThread(UserToProxyThread,pParam); //启动另一侦听.
    if( msg_socket==INVALID_SOCKET)
    { printf( "\nError in accept "); return -5;}

    //读客户的第一行数据
    SPair.IsUser_ProxyClosed=FALSE;
    SPair.IsProxy_ServerClosed=TRUE;
    SPair.user_proxy=msg_socket;

    retval=recv(SPair.user_proxy,Buffer,sizeof(Buffer),0);

    if(retval==SOCKET_ERROR)
    { 
        printf("\nError Recv"); 
        if(SPair.IsUser_ProxyClosed==FALSE)
        {
            closesocket(SPair.user_proxy);
            SPair.IsUser_ProxyClosed=TRUE;
        }
    }
    if(retval==0)
    {
        printf("Client Close connection\n");
        if(SPair.IsUser_ProxyClosed==FALSE)
        {
            closesocket(SPair.user_proxy);
            SPair.IsUser_ProxyClosed=TRUE;
        }
    }
    Len=retval;
#ifdef _DEBUG
    Buffer[Len]=0;
    printf("\n Received %d bytes,data[%s]from client\n",retval,Buffer);
#endif
    //
    SPair.IsUser_ProxyClosed=FALSE;
    SPair.IsProxy_ServerClosed=TRUE;
    SPair.user_proxy=msg_socket;

    ProxyP.pPair=&SPair;
    ProxyP.User_SvrOK=CreateEvent(NULL,TRUE,FALSE,NULL);

    GetAddressAndPort( Buffer,ProxyP.Address,&ProxyP.Port);

    pChildThread=AfxBeginThread(ProxyToServer,(LPVOID)&ProxyP);
    ::WaitForSingleObject(ProxyP.User_SvrOK,60000); //等待连接
    ::CloseHandle(ProxyP.User_SvrOK);

    while(SPair.IsProxy_ServerClosed ==FALSE && SPair.IsUser_ProxyClosed==FALSE)
    { 
        retval=send(SPair.proxy_server,Buffer,Len,0);
        if(retval==SOCKET_ERROR)
        { 
            printf("\n send() failed:error%d\n",WSAGetLastError());
            if(SPair.IsProxy_ServerClosed==FALSE)
            {
                closesocket(SPair.proxy_server);
                SPair.IsProxy_ServerClosed=TRUE;
            }
            continue;
        }
        retval=recv(SPair.user_proxy,Buffer,sizeof(Buffer),0);

        if(retval==SOCKET_ERROR)
        { 
            printf("\nError Recv"); 
            if(SPair.IsUser_ProxyClosed==FALSE)
            {
                closesocket(SPair.user_proxy);
                SPair.IsUser_ProxyClosed=TRUE;
            }
            continue;
        }
        if(retval==0)
        {
            printf("Client Close connection\n");
            if(SPair.IsUser_ProxyClosed==FALSE)
            {
                closesocket(SPair.user_proxy);
                SPair.IsUser_ProxyClosed=TRUE;
            }
            break;
        }
        Len=retval;
#ifdef _DEBUG
        Buffer[Len]=0;
        printf("\n Received %d bytes,data[%s]from client\n",retval,Buffer);
#endif

    } //End While

    if(SPair.IsProxy_ServerClosed==FALSE)
    {
        closesocket(SPair.proxy_server);
        SPair.IsProxy_ServerClosed=TRUE;
    }
    if(SPair.IsUser_ProxyClosed==FALSE)
    {
        closesocket(SPair.user_proxy);
        SPair.IsUser_ProxyClosed=TRUE;
    }
    ::WaitForSingleObject(pChildThread->m_hThread,20000); //Should check the return value
    return 0;
}

// 读取远程主机数据，并发往本地客户机
UINT ProxyToServer(LPVOID pParam)
{
    ProxyParam * pPar=(ProxyParam*)pParam;
    char Buffer[BUFSIZE];
    char *server_name= "localhost";
    unsigned short port ;
    int retval,Len;
    unsigned int addr;
    int socket_type ;
    struct sockaddr_in server;
    struct hostent *hp;
    SOCKET conn_socket;

    socket_type = SOCK_STREAM;
    server_name = pPar->Address;
    port = pPar->Port;

    if (isalpha(server_name[0])) { /* server address is a name */
        hp = gethostbyname(server_name);
    }
    else { /* Convert nnn.nnn address to a usable one */
        addr = inet_addr(server_name);
        hp = gethostbyaddr((char *)&addr,4,AF_INET);
    }
    if (hp == NULL ) {
        fprintf(stderr,"Client: Cannot resolve address [%s]: Error %d\n",
            server_name,WSAGetLastError());
        ::SetEvent(pPar->User_SvrOK); 
        return 0;
    }

    //
    // Copy the resolved information into the sockaddr_in structure
    //
    memset(&server,0,sizeof(server));
    memcpy(&(server.sin_addr),hp->h_addr,hp->h_length);
    server.sin_family = hp->h_addrtype;
    server.sin_port = htons(port);

    conn_socket = socket(AF_INET,socket_type,0); /* 打开一个 socket */
    if (conn_socket < 0 ) {
        fprintf(stderr,"Client: Error Opening socket: Error %d\n",
            WSAGetLastError());
        pPar->pPair->IsProxy_ServerClosed=TRUE;
        ::SetEvent(pPar->User_SvrOK); 
        return -1;
    }

#ifdef _DEBUG
    printf("Client connecting to: %s\n",hp->h_name);
#endif
    if (connect(conn_socket,(struct sockaddr*)&server,sizeof(server))
        == SOCKET_ERROR) {
            fprintf(stderr,"connect() failed: %d\n",WSAGetLastError());
            pPar->pPair->IsProxy_ServerClosed=TRUE; 
            ::SetEvent(pPar->User_SvrOK); 
            return -1;
    }
    pPar->pPair->proxy_server=conn_socket;
    pPar->pPair->IsProxy_ServerClosed=FALSE;
    ::SetEvent(pPar->User_SvrOK);
    // cook up a string to send
    while(!pPar->pPair->IsProxy_ServerClosed &&!pPar->pPair->IsUser_ProxyClosed)
    {
        retval = recv(conn_socket,Buffer,sizeof (Buffer),0 );
        if (retval == SOCKET_ERROR ) {
            fprintf(stderr,"recv() failed: error %d\n",WSAGetLastError());
            closesocket(conn_socket);
            pPar->pPair->IsProxy_ServerClosed=TRUE;
            break;
        }
        Len=retval;
        if (retval == 0) {
            printf("Server closed connection\n");
            closesocket(conn_socket);
            pPar->pPair->IsProxy_ServerClosed=TRUE;
            break;
        }

        retval = send(pPar->pPair->user_proxy,Buffer,Len,0);
        if (retval == SOCKET_ERROR) {
            fprintf(stderr,"send() failed: error %d\n",WSAGetLastError());
            closesocket(pPar->pPair->user_proxy);
            pPar->pPair->IsUser_ProxyClosed=TRUE;
            break; 
        }
#ifdef _DEBUG 
        Buffer[Len]=0; 
        printf("Received %d bytes, data [%s] from server\n",retval,Buffer);
#endif
    }
    if(pPar->pPair->IsProxy_ServerClosed==FALSE)
    {
        closesocket(pPar->pPair->proxy_server);
        pPar->pPair->IsProxy_ServerClosed=TRUE;
    }
    if(pPar->pPair->IsUser_ProxyClosed==FALSE)
    {
        closesocket(pPar->pPair->user_proxy);
        pPar->pPair->IsUser_ProxyClosed=TRUE;
    }
    return 1;
}



int _tmain(int argc, TCHAR* argv[], TCHAR* envp[])
{
    int nRetCode = 0;

    // 初始化SOCKET
    if (!AfxWinInit(::GetModuleHandle(NULL), NULL, ::GetCommandLine(), 0))
    {
        // 错误处理
        cerr << _T("Fatal Error: MFC initialization failed") << endl;
        nRetCode = 1;
    }
    else
    {
        // 主程序开始.
        StartServer(); 
        while(1) 
            if(getchar()=='q') break;
        CloseServer();
    }

    return nRetCode;
}

--------

//stdafx.h


#pragma once

#ifndef _WIN32_WINNT		// 允许使用特定于 Windows XP 或更高版本的功能。
#define _WIN32_WINNT 0x0501	// 将此值更改为相应的值，以适用于 Windows 的其他版本。
#endif

#include <afxwin.h>
#include <winsock2.h> //WINSOCKET API 2。0   
#pragma comment( lib, "ws2_32.lib" )