lockdaemon.c.noinetd

用java控制短信猫发送或接受短信的源代码包以及一些实例程序

/*-------------------------------------------------------------------------
|   lfd is a lock file server.
|   Copyright 2002-2004 by Trent Jarvi [e-mail]
|
|   This software is free software; you can redistribute it and/or
|   modify it under the terms of the GNU General Public
|   License as published by the Free Software Foundation; either
|   version 2 of the License, or (at your option) any later version.
|
|   This library is distributed in the hope that it will be useful,
|   but WITHOUT ANY WARRANTY; without even the implied warranty of
|   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
|   Library General Public License for more details.
|
|   You should have received a copy of the GNU General Public
|   License along with this software; if not, write to the Free
|   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
--------------------------------------------------------------------------*/
#include <sys/types.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <syslog.h>
#include <sys/socket.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <errno.h>
#include <signal.h>
#include <pwd.h>


#define LOCK fhs_lock
#define UNLOCK fhs_unlock
#define LOCKDIR "/var/lock"

char hostname[256];
#define M200 "200 Command okay.\n"
#define M202 "202 Command not implemented\n"
#define M220 "220 %s Lock File Server (Version rxtx-1.5-9) ready\n", hostname
#define M221 "221 Thank you for using the Lock File service on %s\n", hostname
#define M450 "450 : File busy.\n"
#define M500 "500 '%s': command not understood\n", str
#define M550 "550 : Permission denied.\n"

int is_device_locked( const char * );
int check_group_uucp();
int check_lock_status( const char * );
int check_lock_pid( const char *, int  );

#define UNEXPECTED_LOCK_FILE "RXTX Error:  Unexpected lock file: %s\n Please report to the RXTX developers\n"
#define UUCP_ERROR "\n\n\nRXTX WARNING:  This library requires the user running applications to be in\ngroup uucp.  Please consult the INSTALL documentation.  More information is\navaiable under the topic 'How can I use Lock Files with rxtx?'\n" 

extern int errno;

/*----------------------------------------------------------
 fhs_lock

   accept:      The name of the device to try to lock
                termios struct
   perform:     Create a lock file if there is not one already.
   return:      1 on failure 0 on success
   exceptions:  none
   comments:    This is for linux and freebsd only currently.  I see SVR4 does
                this differently and there are other proposed changes to the
		Filesystem Hierachy Standard

		more reading:

----------------------------------------------------------*/
int fhs_lock( const char *filename, int pid )
{
	/*
	 * There is a zoo of lockdir possibilities
	 * Its possible to check for stale processes with most of them.
	 * for now we will just check for the lockfile on most
	 * Problem lockfiles will be dealt with.  Some may not even be in use.
	 *
	 */
	int fd,j;
	char lockinfo[12], message[80];
	char file[80], *p;

	j = strlen( filename );
	p = ( char * ) filename + j;
	/*  FIXME  need to handle subdirectories /dev/cua/... 
	    SCO Unix use lowercase all the time
			taj
	*/
	while( *( p - 1 ) != '/' && j-- != 1 )
	{
#if defined ( __unixware__ )
		*p = tolower( *p );
#endif /* __unixware__ */
		p--;
	}
	sprintf( file, "%s/LCK..%s", LOCKDIR, p );
	if ( check_lock_status( filename ) )
	{
		syslog( LOG_INFO, "fhs_lock() lockstatus fail\n" );
		return 1;
	}
	fd = open( file, O_CREAT | O_WRONLY | O_EXCL, 0444 );
	if( fd < 0 )
	{
		sprintf( message,
			"RXTX fhs_lock() Error: creating lock file: %s: %s\n",
			file, strerror(errno) );
		syslog( LOG_INFO, message );
		return 1;
	}
	sprintf( lockinfo, "%10d\n", pid );
	sprintf( message, "fhs_lock: creating lockfile: %s\n", lockinfo );
	syslog( LOG_INFO, message );
	write( fd, lockinfo, 11 );
	close( fd );
	return 0;
}

/*----------------------------------------------------------
 uucp_lock

   accept:     char * filename.  Device to be locked 
   perform:    Try to get a uucp_lock
   return:     int 0 on success
   exceptions: none 
   comments: 
		The File System Hierarchy Standard
		http://www.pathname.com/fhs/

		UUCP Lock Files
		http://docs.freebsd.org/info/uucp/uucp.info.UUCP_Lock_Files.html

		FSSTND
		ftp://tsx-11.mit.edu/pub/linux/docs/linux-standards/fsstnd/

		Proposed Changes to the File System Hierarchy Standard
		ftp://scicom.alphacdc.com/pub/linux/devlock-0.X.tgz

		"UNIX Network Programming", W. Richard Stevens,
		Prentice-Hall, 1990, pages 96-101.

		There is much to do here.

		1) UUCP style locks (done)
			/var/spool/uucp
		2) SVR4 locks
			/var/spool/locks
		3) FSSTND locks (done)
			/var/lock
		4) handle stale locks  (done except kermit locks)
		5) handle minicom lockfile contents (FSSTND?)
			"     16929 minicom root\n"  (done)
		6) there are other Lock conventions that use Major and Minor
		   numbers...
		7) Stevens recommends LCK..<pid>

		most are caught above.  If they turn out to be problematic
		rather than an exercise, we will handle them.

----------------------------------------------------------*/
int uucp_lock( const char *filename, int pid )
{
	char lockfilename[80], lockinfo[12], message[80];
	char name[80];
	int fd;
	struct stat buf;

	sprintf( message, "uucp_lock( %s );\n", filename ); 
	syslog( LOG_INFO, message );

	if ( check_lock_status( filename ) )
	{
		syslog( LOG_INFO, "RXTX uucp check_lock_status true\n" );
		return 1;
	}
	if ( stat( LOCKDIR, &buf ) != 0 )
	{
		syslog( LOG_INFO, "RXTX uucp_lock() could not find lock directory.\n" );
		return 1;
	}
	if ( stat( filename, &buf ) != 0 )
	{
		syslog( LOG_INFO, "RXTX uucp_lock() could not find device.\n" );
		sprintf( message, "uucp_lock: device was %s\n", name );
		syslog( LOG_INFO, message );
		sprintf( message, "Filename is : %s \n", filename );
		syslog( LOG_INFO, message );
		return 1;
	}
	sprintf( lockfilename, "%s/LK.%03d.%03d.%03d",
		LOCKDIR,
		(int) major( buf.st_dev ),
	 	(int) major( buf.st_rdev ),
		(int) minor( buf.st_rdev )
	);
	sprintf( lockinfo, "%10d\n", pid );
	if ( stat( lockfilename, &buf ) == 0 )
	{
		sprintf( message, "RXTX uucp_lock() %s is there\n",
			lockfilename );
		syslog( LOG_INFO, message );
		syslog( LOG_INFO, message );
		return 1;
	}
	fd = open( lockfilename, O_CREAT | O_WRONLY | O_EXCL, 0444 );
	if( fd < 0 )
	{
		sprintf( message,
			"RXTX uucp_lock() Error: creating lock file: %s\n",
			lockfilename );
		syslog( LOG_INFO, message );
		return 1;
	}
	write( fd, lockinfo,11 );
	close( fd );
/*
	setgid( nobody );
	setuid( nobody );
*/
	return 0;
}

/*----------------------------------------------------------
 check_lock_status

   accept:      the lock name in question
   perform:     Make sure everything is sane
   return:      0 on success
   exceptions:  none
   comments:    
----------------------------------------------------------*/
int check_lock_status( const char *filename )
{
	struct stat buf;
	/*  First, can we find the directory? */

	if ( stat( LOCKDIR, &buf ) != 0 )
	{
		syslog( LOG_INFO, "check_lock_status: could not find lock directory.\n" );
		return 1;
	}

	/*  OK.  Are we able to write to it?  If not lets bail */

	if ( check_group_uucp() )
	{
		syslog( LOG_INFO, "check_lock_status: No permission to create lock file.

		please see: How can I use Lock Files with rxtx? in INSTALL\n" );
		return 1;
	}

	/* is the device alread locked */

	if ( is_device_locked( filename ) )
	{
		syslog( LOG_INFO, "check_lock_status: device is locked by another application\n" );
		return 1;	
	}
	return 0;
	
}

/*----------------------------------------------------------
 fhs_unlock

   accept:      The name of the device to unlock
   perform:     delete the lock file
   return:      none
   exceptions:  none
   comments:    This is for linux only currently.  I see SVR4 does this
                differently and there are other proposed changes to the
		Filesystem Hierachy Standard
----------------------------------------------------------*/
int fhs_unlock( const char *filename, int openpid )
{
	char file[80],*p;
	struct stat buf;
	int i;

	i = strlen( filename );
	p = ( char * ) filename + i;
	/*  FIXME  need to handle subdirectories /dev/cua/... */
	while( *( p - 1 ) != '/' && i-- != 1 ) p--;
	sprintf( file, "%s/LCK..%s", LOCKDIR, p );
	if ( ! check_lock_status( p ) )
	{
		return 0;
	}
	if ( stat( filename, &buf ) != 0 ) 
	{
		/* hmm the file is not there? */
		syslog( LOG_INFO, "uucp_unlock() no such device\n" );
		return(0);
	}

	if( !check_lock_pid( file, openpid ) )
	{
		unlink(file);
		syslog( LOG_INFO,"fhs_unlock: Removing LockFile\n");
		return( 0 );
	}
	else
	{
		syslog( LOG_INFO,"fhs_unlock: Unable to remove LockFile\n");
		return( 1 );
	}
}

/*----------------------------------------------------------
 uucp_unlock

   accept:     char *filename the device that is locked      
   perform:    remove the uucp lockfile if it exists 
   return:     none 
   exceptions: none 
   comments:   http://docs.freebsd.org/info/uucp/uucp.info.UUCP_Lock_Files.html 
----------------------------------------------------------*/
void uucp_unlock( const char *filename, int openpid )
{
	struct stat buf;
	char file[80], message[80];
	/* FIXME */

	sprintf( message, "uucp_unlock( %s );\n", filename );
	syslog( LOG_INFO, message );

	if ( stat( filename, &buf ) != 0 ) 
	{
		/* hmm the file is not there? */
		syslog( LOG_INFO, "uucp_unlock() no such device\n" );
		return;
	}
	sprintf( file, LOCKDIR"/LK.%03d.%03d.%03d",
		(int) major( buf.st_dev ),
	 	(int) major( buf.st_rdev ),
		(int) minor( buf.st_rdev )
	);
	if ( stat( file, &buf ) != 0 ) 
	{
		/* hmm the file is not there? */
		syslog( LOG_INFO, "uucp_unlock no such lockfile\n" );
		return;
	}
	if( !check_lock_pid( file, openpid ) )
	{ 
		sprintf( message, "uucp_unlock: unlinking %s\n", file );
		syslog( LOG_INFO, message );
		unlink(file);
	}
	else
	{
		sprintf( message, "uucp_unlock: unlinking failed %s\n", file );
		syslog( LOG_INFO, message );
	}
}

/*----------------------------------------------------------
 check_lock_pid

   accept:     the name of the lockfile 
   perform:    make sure the lock file is ours.
   return:     0 on success
   exceptions: none
   comments:   
----------------------------------------------------------*/
int check_lock_pid( const char *file, int openpid )
{
	int fd, lockpid;
	char pid_buffer[12];
	char message[80];

	fd=open( file, O_RDONLY );
	if ( fd < 0 )
	{
		return( 1 );
	}
	if ( read( fd, pid_buffer, 11 ) < 0 )
	{
		close( fd );
		return( 1 );
	}
	close( fd );
	pid_buffer[11] = '\0';
	lockpid = atol( pid_buffer );
	if ( lockpid != openpid )
	{
		if( kill( (pid_t) lockpid, 0 ) && errno==ESRCH )
		{
			return( 0 );
		}
		sprintf(message, "check_lock_pid: lock = %s pid = %i gpid=%i openpid=%i\n",
			pid_buffer, (int) getpid(), (int) getppid(), openpid );
		syslog( LOG_INFO, message );
		return( 1 );
	}
	return( 0 );
}

/*----------------------------------------------------------
 check_group_uucp

   accept:     none
   perform:    check if the user is root or in group uucp
   return:     0 on success 
   exceptions: none 
   comments:   
		This checks if the effective user is in group uucp so we can
		create lock files.  If not we give them a warning and bail.
		If its root we just skip the test.

		if someone really wants to override this they can use the			USER_LOCK_DIRECTORY --not recommended.

		In a recent change RedHat 7.2 decided to use group lock.
		In order to get around this we just check the group id
		of the lock directory.
----------------------------------------------------------*/
int check_group_uucp()
{
#ifndef USER_LOCK_DIRECTORY
	int group_count;
	struct passwd *user = getpwuid( geteuid() );
	struct stat buf;
	char msg[80];