ftp.c

proxy源代码,linux下的ftp 代理的源代码,大家多多支持啊

		copy_string(x->username, p, sizeof(x->username));
		}

	if ((p = strchr(x->password, ':')) != NULL) {
		*p++ = 0;
		copy_string(x->local.password, x->password, sizeof(x->local.password));
		copy_string(x->password, p, sizeof(x->password));
		}

        /*
         * Call the dynamic configuration program.
         */

        if (*x->config->ctp != 0) {
		x->server.port = get_port(x->server.name, 21);

                if (run_ctp(x) != 0)
                        exit (0);       /* Never happens, we exit in run_ctp() */

		if (debug != 0) {
	                fprintf (stderr, "trp debug: server= %s:%u, login= %s, passwd= %s",
					x->server.name, x->server.port,
					x->username, x->password);
			}
                }


	/*
	 * Get port an IP number of server.  Moved code here -- 030404asg
	 */

	x->server.port = get_port(x->server.name, 21);
	if ((hostp = gethostbyname(x->server.name)) == NULL) {
		cfputs(x, "500 service unavailable");
		syslog(LOG_NOTICE, "-ERR: can't resolve hostname: %s", x->server.name);
		exit (1);
		}

	memcpy(&saddr.sin_addr, hostp->h_addr, hostp->h_length);
	copy_string(x->server.ipnum, inet_ntoa(saddr.sin_addr), sizeof(x->server.ipnum));


	/*
	 * Call the access control program to check if the proxy
	 * request is allowed.  Moved code here -- 030404asg
	 */

	if (*x->config->acp != 0) {
		if (run_acp(x) != 0)
			exit (0);
		}


	/*
	 * Verification if the destination server is on the given list
	 * is done now here.
	 *
	 * Notice: Prior to this change you could give a fixed desination
	 * server as command line argument and a list of allowed server
	 * too.  Meaningless because the proxy didn't care when the `server
	 * selection' option wasn't turned on.  Now also the fixed server
	 * is checked against the list.
	 *
	 * I don't expect that this breaks an already running configuration
	 * because as said above this configuration was senseless in earlier
	 * proxy versions -- 030404asg
	 */

	if ((p = x->config->serverlist) != NULL  &&  *p != 0) {
		int	permitted;
		char	pattern[80];

		permitted = 0;
		while ((p = skip_ws(p)), *get_quoted(&p, ',', pattern, sizeof(pattern)) != 0) {
			noctrl(pattern);
			if (strpcmp(x->server.name, pattern) == 0) {
				permitted = 1;
				break;
				}
			}

		if (permitted == 0) {
			cfputs(x, "500 service unavailable");
			syslog(LOG_NOTICE, "-ERR: hostname not permitted: %s", x->server.name);
			exit (1);
			}
		}


	/*
	 * Establish connection to the server
	 */

	if ((x->fd.server = openip(x->server.name, x->server.port, x->config->sourceip, 0)) < 0) {
		cfputs(x, "500 service unavailable");
		syslog(LOG_NOTICE, "-ERR: can't connect to server: %s", x->server.name);
		exit (1);
		}

	syslog(LOG_NOTICE, "connected to server: %s", x->server.name);


	if (sfputc(x, NULL, NULL, line, sizeof(line), NULL) != 220) {
		cfputs(x, "500 service unavailable");
		syslog(LOG_NOTICE, "-ERR: unexpected server greeting: %s", line);
		exit (1);
		}

	/*
	 * Login auf FTP-Server.
	 *
	 * Complete rewrite because of servers wanting no password after
	 * login of anonymous user.
	 */

	rc = sfputc(x, "USER", x->username, line, sizeof(line), NULL);

	if (rc == 230) {
		cfputs(x, "230 login accepted");
		syslog(LOG_NOTICE, "login accepted: %s@%s, no password needed.", x->username, x->server.name);
		return (0);
		}
	else if (rc != 331) {
		cfputs(x, "500 service unavailable");
		syslog(LOG_NOTICE, "-ERR: unexpected reply to USER: %s", line);
		exit (1);
		}
	else if (sfputc(x, "PASS", x->password, line, sizeof(line), NULL) != 230) {
		cfputs(x, "530 bad login");
		syslog(LOG_NOTICE, "-ERR: reply to PASS: %s", line);
		exit (1);
		}

	cfputs(x, "230 login accepted");
	syslog(LOG_NOTICE, "login accepted: %s@%s", x->username, x->server.name);

	return (0);

/*
	if (sfputc(x, "USER", x->username, line, sizeof(line), NULL) != 331) {
		cfputs(x, "500 service unavailable");
		syslog(LOG_NOTICE, "-ERR: unexpected reply to USER: %s", line);
		exit (1);
		}
	else if (sfputc(x, "PASS", x->password, line, sizeof(line), NULL) != 230) {
		cfputs(x, "530 bad login");
		syslog(LOG_NOTICE, "-ERR: reply to PASS: %s", line);
		exit (1);
		}

	cfputs(x, "230 login accepted");
	syslog(LOG_NOTICE, "login accepted: %s@%s", x->username, x->server.name);

	return (0);
*/


}



void signal_handler(int sig)
{
	/*
	 * Changed the way we handle broken pipes (broken control or
	 * data connection).  We ignore it here but write() returns -1
	 * and errno is set to EPIPE which is checked.
	 */

	if (sig == SIGPIPE) {
		signal(SIGPIPE, signal_handler);
		return;
		}

	syslog(LOG_NOTICE, "-ERR: received signal #%d", sig);
	exit (1);
}

int set_signals(void)
{
	signal(SIGHUP, signal_handler);
	signal(SIGINT, signal_handler);
	signal(SIGQUIT, signal_handler);
	signal(SIGSEGV, signal_handler);
	signal(SIGPIPE, signal_handler);
	signal(SIGALRM, signal_handler);
	signal(SIGTERM, signal_handler);
	signal(SIGUSR1, signal_handler);
	signal(SIGUSR2, signal_handler);

	return (0);
}


ftpcmd_t *getcmd(char *name)
{
	int	i;

	for (i=0; cmdtab[i].name[0] != 0; i++) {
		if (strcmp(cmdtab[i].name, name) == 0)
			return (&cmdtab[i]);
		}

	return (NULL);
}


int proxy_request(config_t *config)
{
	int	rc;
	char	*p, command[200], parameter[200], line[300];
	ftpcmd_t *cmd;
	ftp_t	*x;

	set_signals();

	/*
	 * Set socket options to prevent us from the rare case that
	 * we transfer data to/from the client before the client has
	 * seen our "150 ..." message.
	 * Seems so that is doesn't work on all systems.
	 * So temporary only enable it on linux. 
	 */

#if defined(__linux__)

	rc = 1;
	if (setsockopt(1, SOL_TCP, TCP_NODELAY, &rc, sizeof(rc)) != 0)
		syslog(LOG_NOTICE, "can't set TCP_NODELAY, error= %s", strerror(errno));

#endif

	if (config->bsize <= 0)
		config->bsize = 1024;
	else if (config->bsize > FTPMAXBSIZE)
		config->bsize = FTPMAXBSIZE;

	x = allocate(sizeof(ftp_t));
	x->config = config;
	snprintf (x->session, sizeof(x->session) - 2, "%lu-%u", time(NULL), getpid());


	/*
	 * Fix potential problems after immediate initial unseccsesful
	 * up/downloads.  Wasn't a problem since we all do a LIST
	 * at first.
	 */

	x->ch.isock = -1;
	x->ch.osock = -1;


	if (get_client_info(x, 0) < 0) {
		syslog(LOG_NOTICE, "-ERR: can't get client info: %s", strerror(errno));
		exit (1);
		}

	x->port = get_interface_info(0, x->interface, sizeof(x->interface));
	syslog(LOG_NOTICE, "connected to client: %s, interface= %s:%u", x->client,
				x->interface, x->port);

	if (*x->config->configfile != 0) {
		if (readconfig(x->config, x->config->configfile, x->interface) == 0) {
			cfputs(x, "421 not available");
			syslog(LOG_NOTICE, "-ERR: unconfigured interface: %s", x->interface);
			exit (1);
			}
		}

	syslog(LOG_NOTICE, "info: monitor mode: %s, ccp: %s",
			x->config->monitor == 0? "off": "on",
			*x->config->ccp == 0? "<unset>": x->config->ccp);

	cfputs(x, "220 server ready - login please");
	if ((rc = dologin(x)) < 0)
		return (1);
	else if (rc == 2)
		return (0);


	/*
	 * Open the xferlog if we have one.
	 */

	if (*x->config->xferlog != 0) {
		if (*x->server.name == 0)
			copy_string(x->logusername, x->username, sizeof(x->logusername));
		else if (x->server.port != 21)
			snprintf (x->logusername, sizeof(x->logusername), "%s@%s:%u", x->username, x->server.name, x->server.port);
		else
			snprintf (x->logusername, sizeof(x->logusername), "%s@%s", x->username, x->server.name);

		x->xlfp = fopen(x->config->xferlog, "a");
		if (x->xlfp == NULL) {
			syslog(LOG_NOTICE, "-WARN: can't open xferlog: %s, error= %s",
					x->config->xferlog, strerror(errno));
			}
		}

	if (x->config->monitor) {
		get_ftpdir(x);
		copy_string(x->home, x->cwd, sizeof(x->home));
		}

	while ((p = cfgets(x, line, sizeof(line))) != NULL) {
		if (*p == '\001') {
			if (*x->ch.command != 0) {
				syslog(LOG_NOTICE, "%s %s: %ld bytes", x->ch.command, x->ch.filename, x->ch.bytes);

				if (x->xlfp != NULL) {
					unsigned long now;
					char	date[80];

					/*
					 * Write xferlog entry but notice that (1) session are never
					 * flagged as anonymous and (2) the transfer type is always
					 * binary (type flag was added to data channel but is
					 * actually not used. 10MAY04wzk
					 */

					now = time(NULL);
					copy_string(date, ctime(&now), sizeof(date));
					fprintf (x->xlfp, "%s %lu %s %lu %s %c %c %c %c %s %s %d %s %c\n",
							date,
							now - x->ch.started,
							x->client_ip,
							x->ch.bytes,
							x->ch.filename,
							'b',		/* x->ch.type == TYPE_ASC? 'a': 'b', */
							'-',
							strcmp(x->ch.command, "RETR")? 'i': 'o',
							'u',		/* x->isanonymous == 1? 'a': 'u', */
							x->logusername,
							"ftp", 1, x->logusername, 'c');
					fflush(x->xlfp);
					}
				}

			/*
			 * Handle multiline server responses after the
			 * data transfer.
			 */

			sfputc(x, NULL, NULL, line, sizeof(line), NULL);
			cfputs(x, line);

			continue;
			}

		p = noctrl(line);
		get_word(&p, command, sizeof(command));
		strupr(command);

		if ((cmd = getcmd(command)) == NULL  ||  cmd->resp == -1) {
			cfputs(x, "502 command not implemented");
			syslog(LOG_NOTICE, "command not implemented: %s", command);
			continue;
			}

		*x->filepath = 0;
		if (cmd->par == 0)
			*parameter = 0;
		else {
			if (strcmp(command, "CDUP") == 0)
				strcpy(parameter, "..");
			else if (strcmp(command, "SITE") == 0)
				copy_string(parameter, p, sizeof(parameter));
			else {
				if (x->config->allow_blanks != 0)
					copy_string(parameter, p, sizeof(parameter));
				else
					get_word(&p, parameter, sizeof(parameter));
					
				if (*parameter == 0) {
					if (strcmp(command, "LIST") == 0  ||  strcmp(command, "NLST") == 0)
						/* nichts, ist ok */ ;
					else {
						syslog(LOG_NOTICE, "parameter required: %s", command);
						exit (1);
						}
					}
				}

			if (cmd->ispath != 0) {
				if (x->config->monitor) {
					if ((strcmp(command, "LIST") == 0  ||  strcmp(command, "NLST") == 0)
					    &&  *parameter == 0) {

						/*
						 * Sonderfall: wir simulieren `*' als Parameter.
						 */

						get_ftppath(x, "*");
						}
					else
						get_ftppath(x, parameter);
					}
				}
			}


		if (cmd->useccp != 0) {
			if (run_ccp(x, command, parameter) != CCP_OK)
				continue;
			}


		if (strcmp(command, "QUIT") == 0) {
/*		        run_ccp(x, "QUIT", ""); */
			doquit(x);
			break;
			}
		else if (strcmp(command, "PORT") == 0)
			doport(x, command, parameter);
		else if (strcmp(command, "FEAT") == 0)
			dofeat(x);
		else if (strcmp(command, "PASV") == 0)
			dopasv(x, command, parameter);
		else if (strcmp(command, "LIST") == 0  ||  strcmp(command, "NLST") == 0) {
			x->ch.operation = OP_GET;	/* fuer PASV mode */
			rc = sfputc(x, command, parameter, line, sizeof(line), NULL);
			if (rc == 125  ||  rc == 150) {
				x->ch.operation = OP_GET;
				x->ch.seen150   = 1;
				if (debug >= 2)
					fprintf (stderr, "received 150 response\n");
				}
			else
				close_ch(x, &x->ch);

			cfputs(x, line);
			*x->ch.command = 0;
			}
		else if (strcmp(command, "RETR") == 0) {
			x->ch.operation = OP_GET;	/* fuer PASV mode */
			rc = sfputc(x, "RETR", parameter, line, sizeof(line), NULL);
			if (rc == 125  ||  rc == 150) {
				x->ch.operation = OP_GET;
				x->ch.seen150   = 1;
				if (debug >= 2)
					fprintf (stderr, "received 150 response\n");
				}
			else
				close_ch(x, &x->ch);

			cfputs(x, line);
			copy_string(x->ch.command, "RETR", sizeof(x->ch.command));
			copy_string(x->ch.filename, x->config->monitor != 0? x->filepath: parameter, sizeof(x->ch.filename));

			if (extralog != 0)
				syslog(LOG_NOTICE, "%d RETR %s", rc, (x->config->monitor != 0)? parameter: x->filepath);
			}
		else if (strcmp(command, "STOR") == 0  ||  strcmp(command, "APPE") == 0  ||  strcmp(command, "STOU") == 0) {
			x->ch.operation = OP_PUT;	/* fuer PASV mode */
			rc = sfputc(x, command, parameter, line, sizeof(line), NULL);
			if (rc == 125  ||  rc == 150) {
				x->ch.operation = OP_PUT;
				x->ch.seen150   = 1;
				if (debug >= 2)
					fprintf (stderr, "received 150 response\n");

				copy_string(x->ch.command, command, sizeof(x->ch.command));
				}
			else
				close_ch(x, &x->ch);

			cfputs(x, line);
			copy_string(x->ch.filename, x->config->monitor != 0? x->filepath: parameter, sizeof(x->ch.filename));
			if (extralog != 0) {
				if (strcmp(command, "STOU") == 0)
					syslog(LOG_NOTICE, "%d %s %s", rc, command, "-");
				else
					syslog(LOG_NOTICE, "%d %s %s", rc, command, x->ch.filename);
				}
			}
		else {
			if (strcmp(command, "CDUP") == 0)
				*parameter = 0;

			rc = sfputc(x, command, parameter, line, sizeof(line), NULL);
			cfputs(x, line);
			if (extralog != 0  &&  cmd->log != 0) {
				if (x->config->monitor != 0  &&  cmd->ispath != 0)
					syslog(LOG_NOTICE, "%d %s %s", rc, command, x->filepath);
				else
					syslog(LOG_NOTICE, "%d %s%s%s", rc, command, *parameter != 0? " ": "", parameter);
				}

			if (strcmp(command, "CWD") == 0  ||  strcmp(command, "CDUP") == 0) {
				if (x->config->monitor)
					get_ftpdir(x);
				}
			}
		}

	if (*x->config->ccp != 0)
		run_ccp(x, "+EXIT", x->session);

	syslog(LOG_NOTICE, "+OK: proxy terminating");
	return (0);
}