在网络程序设计过程中，我们经常要与各种类型的代理服务器打交道，比如在企业内部网 通过代理去访问Internet网上的服务器等等，一般代理服务器支持几种常见的代理协议标 准，如Socks4,Socks5,Http代理，其中Socks5需要用户验证，代理相对复杂。我在查阅RF C文档和相关资料后，特总结一些TCP协议穿透代理服务器的程序片断，希望对大家有所帮 助。 //使用到的结构 struct sock4req1 { char VN; char CD; unsigned short Port; unsigned long IPAddr; char other[1]; }; struct sock4ans1 { char VN; char CD; }; struct sock5req1 { char Ver; char nMethods; char Methods[255]; }; struct sock5ans1 { char Ver; char Method; }; struct sock5req2 { char Ver; char Cmd; char Rsv; char Atyp; char other[1]; }; struct sock5ans2 { char Ver; char Rep; char Rsv; char Atyp; char other[1]; }; struct authreq { char Ver; char Ulen; char Name[255]; char PLen; char Pass[255]; }; struct authans { char Ver; char Status; }; //通过Socks4方式代理 if( ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) ) { m_sError = _T("不能连接到代理服务器 "); ClientSock.Close(); return FALSE; } char buff[100]; memset(buff,0,100); struct sock4req1 *m_proxyreq; m_proxyreq = (struct sock4req1 *)buff; m_proxyreq->VN = 4; m_proxyreq->CD = 1; m_proxyreq->Port = ntohs(GetPort()); m_proxyreq->IPAddr = inet_addr(GetServerHostName()); ClientSock.Send(buff,9); struct sock4ans1 *m_proxyans; m_proxyans = (struct sock4ans1 *)buff; memset(buff,0,100); ClientSock.Receive(buff,100); if(m_proxyans->VN = 0 || m_proxyans->CD = 90) { m_sError = _T("通过代理连接主站不成功 "); ClientSock.Close(); return FALSE; } //通过Socks5方式代理 if( ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) ) { m_sError = _T("不能连接到代理服务器 "); ClientSock.Close(); return FALSE; } char buff[600]; struct sock5req1 *m_proxyreq1; m_proxyreq1 = (struct sock5req1 *)buff; m_proxyreq1->Ver = 5; m_proxyreq1->nMethods = 2; m_proxyreq1->Methods[0] = 0; m_proxyreq1->Methods[1] = 2; ClientSock.Send(buff,4); struct sock5ans1 *m_proxyans1; m_proxyans1 = (struct sock5ans1 *)buff; memset(buff,0,600); ClientSock.Receive(buff,600); if(m_proxyans1->Ver = 5 || (m_proxyans1->Method =0 && m_proxyans1->Method =2) ) { m_sError = _T("通过代理连接主站不成功 "); ClientSock.Close(); return FALSE; } if(m_proxyans1->Method == 2) { int nUserLen = strlen(g_ProxyInfo.m_strProxyUser); int nPassLen = strlen(g_ProxyInfo.m_strProxyPass); struct authreq *m_authreq; m_authreq = (struct authreq *)buff; m_authreq->Ver = 1; m_authreq->Ulen = nUserLen; strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser); m_authreq->PLen = nPassLen; strcpy(m_authreq->Pass,g_ProxyInfo.m_strProxyPass); ClientSock.Send(buff,513); struct authans *m_authans; m_authans = (struct authans *)buff; memset(buff,0,600); ClientSock.Receive(buff,600); if(m_authans->Ver = 1 || m_authans->Status = 0) { m_sError = _T("代理服务器用户验证不成功 "); ClientSock.Close(); return FALSE; } } struct sock5req2 *m_proxyreq2; m_proxyreq2 = (struct sock5req2 *)buff; m_proxyreq2->Ver = 5; m_proxyreq2->Cmd = 1; m_proxyreq2->Rsv = 0; m_proxyreq2->Atyp = 1; unsigned long tmpLong = inet_addr(GetServerHostName()); unsigned short port = ntohs(GetPort()); memcpy(m_proxyreq2->other,&tmpLong,4); memcpy(m_proxyreq2->other+4,&port,2); ClientSock.Send(buff,sizeof(struct sock5req2)+5); struct sock5ans2 *m_proxyans2; memset(buff,0,600); m_proxyans2 = (struct sock5ans2 *)buff; ClientSock.Receive(buff,600); if(m_proxyans2->Ver = 5 || m_proxyans2->Rep = 0) { m_sError = _T("通过代理连接主站不成功 "); ClientSock.Close(); return FALSE; } //通过HTTP方式代理 if( ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) ) { m_sError = _T("不能连接到代理服务器 "); ClientSock.Close(); return FALSE; } char buff[600]; sprintf( buff, "%s%s:%d%s","CONNECT ",GetServerHostName(),GetPort()," HTTP/1.1 \r\nUser-Agent: MyApp/0.1\r\n\r\n"); ClientSock.Send(buff,strlen(buff)); //发送请求 memset(buff,0,600); ClientSock.Receive(buff,600); if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功 { m_sError = _T("通过代理连接主站不成功 "); ClientSock.Close(); return FALSE; } 我们一般先与代理服务器连通，然后向代理服务器发送代理验证的用户名和密码(如果需要 ,如Socks5代理)，验证成功后，再向代理服务器发送需要连接的目的地址和端口。以上代 码仅用于TCP连接，如果在内部网侦听或通过UDP协议发送信息，可查阅RFC1829等文档资料 。
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[【技术文档】]穿透代理服务器编程