ftpcmd.y

伯克利大学的一个ftp协议的实现源代码,包括客户端和服务器端.

/*
 * Copyright (c) 1985, 1988, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)ftpcmd.y	8.3 (Berkeley) 4/6/94
 *	NetBSD: ftpcmd.y,v 1.7 1996/04/08 19:03:11 jtc Exp
 *      OpenBSD: ?
 */

/*
 * Grammar for FTP commands.
 * See RFC 959.
 */

%{

char ftpcmd_rcsid[] = 
  "$Id: ftpcmd.y,v 1.6 1997/05/19 13:21:19 dholland Exp $";

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/stat.h>

#include <netinet/in.h>
#include <arpa/ftp.h>

#include <ctype.h>
#include <errno.h>
#include <glob.h>
#include <pwd.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>
#include <unistd.h>
#ifdef __linux__
typedef int64_t quad_t;
#endif

#include "extern.h"

extern	struct sockaddr_in data_dest;
extern	int logged_in;
extern	struct passwd *pw;
extern	int guest;
extern	int logging;
extern	int type;
extern	int form;
extern	int debug;
extern	int timeout;
extern	int maxtimeout;
extern  int pdata;
extern	char hostname[], remotehost[];
extern	char proctitle[];
extern	int usedefault;
extern  int transflag;
extern  char tmpline[];

off_t	restart_point;

static	int cmd_type;
static	int cmd_form;
static	int cmd_bytesz;
char	cbuf[512];
char	*fromname;

struct tab;
static int	 yylex __P((void));
static void	 sizecmd __P((char *));
static void	 help __P((struct tab *, char *));

extern struct tab cmdtab[];
extern struct tab sitetab[];

%}

%union {
	int	i;
	char   *s;
}

%token
	A	B	C	E	F	I
	L	N	P	R	S	T

	SP	CRLF	COMMA

	USER	PASS	ACCT	REIN	QUIT	PORT
	PASV	TYPE	STRU	MODE	RETR	STOR
	APPE	MLFL	MAIL	MSND	MSOM	MSAM
	MRSQ	MRCP	ALLO	REST	RNFR	RNTO
	ABOR	DELE	CWD	LIST	NLST	SITE
	STAT	HELP	NOOP	MKD	RMD	PWD
	CDUP	STOU	SMNT	SYST	SIZE	MDTM

	UMASK	IDLE	CHMOD

	LEXERR

%token	<s> STRING
%token	<i> NUMBER

%type	<i> check_login octal_number byte_size
%type	<i> struct_code mode_code type_code form_code
%type	<s> pathstring pathname password username

%start	cmd_list

%%

cmd_list
	: /* empty */
	| cmd_list cmd
		{
			fromname = (char *) 0;
			restart_point = (off_t) 0;
		}
	| cmd_list rcmd
	;

cmd
	: USER SP username CRLF
		{
			user($3);
			free($3);
		}
	| PASS SP password CRLF
		{
			pass($3);
			memset($3, 0, strlen($3));
			free($3);
		}
	| PORT check_login SP host_port CRLF
		{
			if ($2) {
				usedefault = 0;
				if (pdata >= 0) {
					(void) close(pdata);
					pdata = -1;
				}
				reply(200, "PORT command successful.");
			}
		}
	| PASV check_login CRLF
		{
			if ($2) {
				passive();
			}
		}
	| TYPE check_login SP type_code CRLF
		{
			if ($2) {
				switch (cmd_type) {

				case TYPE_A:
					if (cmd_form == FORM_N) {
						reply(200, "Type set to A.");
						type = cmd_type;
						form = cmd_form;
					} else
						reply(504, "Form must be N.");
					break;

				case TYPE_E:
					reply(504, "Type E not implemented.");
					break;
	
				case TYPE_I:
					reply(200, "Type set to I.");
					type = cmd_type;
					break;

				case TYPE_L:
					if (cmd_bytesz == 8) {
					       reply(200,
					       "Type set to L (byte size 8).");
					       type = cmd_type;
					} else
					    reply(504, "Byte size must be 8.");

				}
			}
		}
	| STRU check_login SP struct_code CRLF
		{
			if ($2) {
				switch ($4) {

				case STRU_F:
					reply(200, "STRU F ok.");
					break;

				default:
					reply(504, "Unimplemented STRU type.");
				}
			}
		}
	| MODE check_login SP mode_code CRLF
		{
			if ($2) {
				switch ($4) {

				case MODE_S:
					reply(200, "MODE S ok.");
					break;

				default:
					reply(502, "Unimplemented MODE type.");
				}
			}
		}
	| ALLO check_login SP NUMBER CRLF
		{
			if ($2) {
				reply(202, "ALLO command ignored.");
			}
		}
	| ALLO check_login SP NUMBER SP R SP NUMBER CRLF
		{
			if ($2) {
				reply(202, "ALLO command ignored.");
			}
		}
	| RETR check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL)
				retrieve((char *) 0, $4);
			if ($4 != NULL)
				free($4);
		}
	| STOR check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL)
				store($4, "w", 0);
			if ($4 != NULL)
				free($4);
		}
	| APPE check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL)
				store($4, "a", 0);
			if ($4 != NULL)
				free($4);
		}
	| NLST check_login CRLF
		{
			if ($2)
				send_file_list(".");
		}
	| NLST check_login SP STRING CRLF
		{
			if ($2 && $4 != NULL)
				send_file_list($4);
			if ($4 != NULL)
				free($4);
		}
	| LIST check_login CRLF
		{
			if ($2)
				retrieve("/bin/ls -lgA", "");
		}
	| LIST check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL)
				retrieve("/bin/ls -lgA %s", $4);
			if ($4 != NULL)
				free($4);
		}
	| STAT check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL)
				statfilecmd($4);
			if ($4 != NULL)
				free($4);
		}
	| STAT check_login CRLF
		{
			if ($2)
				statcmd();
		}
	| DELE check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL)
				delete($4);
			if ($4 != NULL)
				free($4);
		}
	| RNTO check_login SP pathname CRLF
		{
			if ($2) {
				if (fromname) {
					renamecmd(fromname, $4);
					free(fromname);
					fromname = (char *) 0;
				} else {
					reply(503, 
                                          "Bad sequence of commands.");
				}
			}
			free($4);
		}
	| ABOR check_login CRLF
		{
			if ($2) 
				reply(225, "ABOR command successful.");
		}
	| CWD check_login CRLF
		{
			if ($2)
				cwd(pw->pw_dir);
		}
	| CWD check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL)
				cwd($4);
			if ($4 != NULL)
				free($4);
		}
	| HELP CRLF
		{
			help(cmdtab, (char *) 0);
		}
	| HELP SP STRING CRLF
		{
			char *cp = $3;

			if (strncasecmp(cp, "SITE", 4) == 0) {
				cp = $3 + 4;
				if (*cp == ' ')
					cp++;
				if (*cp)
					help(sitetab, cp);
				else
					help(sitetab, (char *) 0);
			} else
				help(cmdtab, $3);

		        if ($3 != NULL)
		        	free ($3);
		}
	| NOOP CRLF
		{
			reply(200, "NOOP command successful.");
		}
	| MKD check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL)
				makedir($4);
			if ($4 != NULL)
				free($4);
		}
	| RMD check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL)
				removedir($4);
			if ($4 != NULL)
				free($4);
		}
	| PWD check_login CRLF
		{
			if ($2)
				pwd();
		}
	| CDUP check_login CRLF
		{
			if ($2)
				cwd("..");
		}
	| SITE SP HELP CRLF
		{
			help(sitetab, (char *) 0);
		}
	| SITE SP HELP SP STRING CRLF
		{
			help(sitetab, $5);

			if ($5 != NULL)
				free ($5);
		}
	| SITE SP UMASK check_login CRLF
		{
			int oldmask;

			if ($4) {
				oldmask = umask(0);
				(void) umask(oldmask);
				reply(200, "Current UMASK is %03o", oldmask);
			}
		}
	| SITE SP UMASK check_login SP octal_number CRLF
		{
			int oldmask;

			if ($4) {
				if (($6 == -1) || ($6 > 0777)) {
					reply(501, "Bad UMASK value");
				} else {
					oldmask = umask($6);
					reply(200,
					    "UMASK set to %03o (was %03o)",
					    $6, oldmask);
				}
			}
		}
	| SITE SP CHMOD check_login SP octal_number SP pathname CRLF
		{
			if ($4 && ($8 != NULL)) {
				if ($6 > 0777)
					reply(501,
				"CHMOD: Mode value must be between 0 and 0777");
				else if (chmod($8, $6) < 0)
					perror_reply(550, $8);
				else
					reply(200, "CHMOD command successful.");
			}
			if ($8 != NULL)
				free($8);
		}
	| SITE SP check_login IDLE CRLF
		{
			if ($3)
			  reply(200,
	       		    "Current IDLE time limit is %d seconds; max %d",
				timeout, maxtimeout);
		}
	| SITE SP check_login IDLE SP NUMBER CRLF
		{
			if ($3) {
				if ($6 < 30 || $6 > maxtimeout) {
				reply(501,
	       		 "Maximum IDLE time must be between 30 and %d seconds",
				    maxtimeout);
				} else {
					timeout = $6;
					(void) alarm((unsigned) timeout);
					reply(200,
				         "Maximum IDLE time set to %d seconds",
					    timeout);
				}
			}
		}
	| STOU check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL)
				store($4, "w", 1);
			if ($4 != NULL)
				free($4);
		}
	| SYST check_login CRLF
		{
			if ($2)
#ifdef __linux__
			reply(215, "UNIX Type: L%d (Linux)", CHAR_BIT);
#else
#ifdef unix
#ifdef BSD
			reply(215, "UNIX Type: L%d Version: BSD-%d",
				CHAR_BIT, BSD);
#else /* BSD */
			reply(215, "UNIX Type: L%d", CHAR_BIT);
#endif /* BSD */
#else /* unix */
			reply(215, "UNKNOWN Type: L%d", CHAR_BIT);
#endif /* unix */
#endif /* __linux__ */
		}

		/*
		 * SIZE is not in RFC959, but Postel has blessed it and
		 * it will be in the updated RFC.
		 *
		 * Return size of file in a format suitable for
		 * using with RESTART (we just count bytes).
		 */
	| SIZE check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL)
				sizecmd($4);
			if ($4 != NULL)
				free($4);
		}

		/*
		 * MDTM is not in RFC959, but Postel has blessed it and
		 * it will be in the updated RFC.
		 *
		 * Return modification time of file as an ISO 3307
		 * style time. E.g. YYYYMMDDHHMMSS or YYYYMMDDHHMMSS.xxx
		 * where xxx is the fractional second (of any precision,
		 * not necessarily 3 digits)
		 */
	| MDTM check_login SP pathname CRLF
		{
			if ($2 && $4 != NULL) {
				struct stat stbuf;
				if (stat($4, &stbuf) < 0)
					reply(550, "%s: %s",
					    $4, strerror(errno));
				else if (!S_ISREG(stbuf.st_mode)) {
					reply(550, "%s: not a plain file.", $4);
				} else {
					struct tm *t;
					t = gmtime(&stbuf.st_mtime);
					reply(213,
					    "%04d%02d%02d%02d%02d%02d",
					    1900 + t->tm_year,
					    t->tm_mon+1, t->tm_mday,
					    t->tm_hour, t->tm_min, t->tm_sec);
				}
			}
			if ($4 != NULL)
				free($4);
		}
	| QUIT CRLF
		{
			reply(221, "Goodbye.");
			dologout(0);
		}
	| error CRLF
		{
			yyerrok;
		}
	;
rcmd
	: RNFR check_login SP pathname CRLF
		{
			restart_point = (off_t) 0;
			if ($2 && $4) {
				fromname = renamefrom($4);
				if (fromname == (char *) 0 && $4) {
					free($4);
				}
			} else {
                        	if ($4)
					free ($4);
			}
		}

	| REST check_login SP byte_size CRLF
		{
			if ($2) {
			    fromname = (char *) 0;
			    restart_point = $4;	/* XXX $4 is only "int" */
			    reply(350, "Restarting at %qd. %s", 
			       (quad_t) restart_point,
			       "Send STORE or RETRIEVE to initiate transfer.");
			}
		}
	;

username
	: STRING
	;

password
	: /* empty */
		{
			$$ = (char *)calloc(1, sizeof(char));
		}
	| STRING
	;

byte_size
	: NUMBER
	;

host_port
	: NUMBER COMMA NUMBER COMMA NUMBER COMMA NUMBER COMMA
		NUMBER COMMA NUMBER
		{
			char *a, *p;

#ifndef __linux__
			data_dest.sin_len = sizeof(struct sockaddr_in);
#endif
			data_dest.sin_family = AF_INET;
			p = (char *)&data_dest.sin_port;
			p[0] = $9; p[1] = $11;
			a = (char *)&data_dest.sin_addr;
			a[0] = $1; a[1] = $3; a[2] = $5; a[3] = $7;
		}
	;

form_code
	: N
		{
			$$ = FORM_N;
		}
	| T
		{
			$$ = FORM_T;
		}
	| C
		{
			$$ = FORM_C;
		}
	;

type_code
	: A
		{
			cmd_type = TYPE_A;
			cmd_form = FORM_N;
		}
	| A SP form_code
		{
			cmd_type = TYPE_A;
			cmd_form = $3;
		}
	| E
		{
			cmd_type = TYPE_E;
			cmd_form = FORM_N;
		}
	| E SP form_code
		{
			cmd_type = TYPE_E;
			cmd_form = $3;
		}
	| I
		{
			cmd_type = TYPE_I;
		}
	| L
		{
			cmd_type = TYPE_L;
			cmd_bytesz = CHAR_BIT;