VC ++ 6 to achieve simple proxy servers

#include "stdafx.h" #include "proxy.h" #include // Winsocket API 2.0 # include #include #include # ifdef _DEBUG # define new DEBUG_NEW # undef THIS_FILEstatic char THIS_FILE [] = __FILE __; # endif / #define HTTP "http: //" #define FTP "ftp: //" #define pROXYPORT 5001 // Proxy port #define BUFSIZE 10240 / / buffer size CWinApp theApp; using namespace std; UINT ProxyToServer (LPVOID pParam); UINT UserToProxyThread (void * pParam); struct socketPair {SOCKET user_proxy; // socket: PROXY service machine to the local machine SOCKET proxy_server; // socket: PROXY Servers to remote host BOOL ISUSER_PROXYCLOSED; // Local machine to Proxy server status bool isproxy_serverclosed; // proxy service to remote host status}; struct proxyparam {char address [256]; // Remote host address Handle User_svrok; // Proxy server to the remote host's link status socketpair * pPAIR; / / Maintain a set of socket pointer int port; // used to connect the port of the remote host}; // This structure is used to exchange information with the remote host. Socket Glisten_Socket; // Socket used to listen.

INT StartServer () // Start service {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_Socket, 5)! = 0) {Printf (" / n error in listen. "); Wsacleanup (); return -4;} Glisten_Socket = listen_socket; AFXBEGINTHREAD (UserToproxythread, Null); // Start listening return 1;} int closeServer () // Close service {clossoSocket; wsacleanup (); return 1;} // analysis To the character, get the remote host address int GetDressandport (CHAR * STR, CHAR * Address, Int * Port) {charf [buffs], command [512], proto [128], * p; int J; SSCANF (STR, "% S% S% S", Command, BUF, Proto; P = strstr (buf, http); // httpif (p) {p = Strlen (http); for (int i = 0; i Get / http1.1 * port = 80; // Default HTTP port} else {// ftp, not supported, the following code can be omitted .p = strstr (BUF, FTP); if (! p) return 0; p = strlen (ftp); for (int i = 0; i

ATOI (P J 1); // Get the port * (p j) = 0;} else * port = 21; strcpy (address, p); p = str, ftp); for (j = 0; j

= 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 _DEBUGBuffer [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 (pCh Ildthread-> m_hthread, 20000); // shop the return valuereturn 0;} // read remote host data, and send it to the local client 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);