Fixed a race. Kernel could send iPAQ sleeping while opiealarm had not yet

set the RTC alarm.

1 files changed, 27 insertions, 7 deletions

diff --git a/core/opiealarm/opiealarm.c b/core/opiealarm/opiealarm.c
index ce0103e..d96ffaf 100644
--- a/core/opiealarm/opiealarm.c
+++ b/core/opiealarm/opiealarm.c
@@ -14,111 +14,127 @@
 #include <sys/ioctl.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
 #include <time.h>
 #include <stdlib.h>
 #include <syslog.h>
 #include <signal.h>
 #include <errno.h>
 #include <string.h>
 
 
 #define PIDFILE 	"/var/run/opiealarm.pid"
 #define APMFILE		"/proc/apm"
 
 FILE *log; // debug only
 
 int resume ( int resuspend );
 int suspend ( int fix_rtc );
 int main ( int argc, char **argv );
 int fork_with_pidfile ( void );
 int kill_with_pidfile ( void );
 void remove_pidfile ( void );
 void usage ( void );
 void sig_handler ( int sig );
 void error_msg_and_die ( int perr, const char *msg );
 int onac ( void );
 
 static int opiealarm_was_running;
 
+static pid_t startpid = 0;
+
 
 void log_msg ( const char *msg )
 {
 	if ( log ) {
 		fprintf ( log, msg );
 		fflush ( log );
 	}
 }
 
 void error_msg_and_die ( int perr, const char *msg )
 {
 	if ( perr )
 		log_msg ( strerror ( errno ));
 	log_msg ( msg );
 
+	if ( getpid ( ) != startpid ) 
+		kill ( startpid, SIGUSR1 );
+
 	while ( 1 )		// pretend we are waiting on RTC, so opiealarm -r can kill us
 		sleep ( 1 );
 }
 
 
 void sig_handler ( int sig )
 {
-	log_msg ( "GOT SIGNAL -> EXITING\n" );
-	fclose ( log );
+	if ( log ) {
+		log_msg ( "GOT SIGNAL -> EXITING\n" );
+		fclose ( log );
+	}
 	remove_pidfile ( );
 	exit ( 0 );
 }
 
+void sig_handler_parent ( int sig )
+{
+	exit ( 0 );
+}
+
 void usage ( void )
 {
 	fprintf ( stderr, "Usage: opiealarm -s [-f] | -r [-a]\n\n" );
 	fprintf ( stderr, "\t-s\tSuspend mode: set RTC alarm\n" );
 	fprintf ( stderr, "\t-f    \tFix RTC, if RTC and system have more than 5sec difference (suspend mode)\n" );
 	fprintf ( stderr, "\t-r\tResume mode: kill running opiealarm\n" );
 	fprintf ( stderr, "\t-a <x>\tResuspend in <x> seconds (resume mode)\n\n" );
 	exit ( 1 );
 }
 
 int fork_with_pidfile ( void )
 {
 	FILE *fp;
 	pid_t pid;
 	
 	pid = fork ( );
 	
-	if ( pid > 0 )
+	if ( pid > 0 ) {
+		signal ( SIGUSR1, sig_handler_parent );
+		while ( 1 )
+			sleep ( 1000 );
 		exit ( 0 );
+	}
 	else if ( pid < 0 ) {
 		perror ( "forking failed" );
 		return 0;
 	}
 
 	signal ( SIGTERM, sig_handler );
 	signal ( SIGINT,  sig_handler );
 
 	// save pid
 	if (( fp = fopen ( PIDFILE, "w" ))) {
 		fprintf ( fp, "%d", getpid ( ));
 		fclose ( fp );
 
 		// detach
 		close ( 0 );
 		close ( 1 );
 		close ( 2 );
 
 		setpgid ( 0, 0 );
 
 		return 1;
 	}
 	else {
 		perror ( PIDFILE );
 		return 0;
 	}
 }
 
 int kill_with_pidfile ( void )
 {
 	FILE *fp;
 	pid_t pid;
@@ -151,210 +167,214 @@ int main ( int argc, char **argv )
 		switch ( opt ) {
 			case 's':
 				mode = 's';
 				break;
 			case 'r':
 				mode = 'r';
 				break;
 			case 'a':
 				ac_resusp = atoi ( optarg );
 				if ( ac_resusp < 30 ) {
 					ac_resusp = 120;
 					
 					fprintf ( stderr, "Warning: resuspend timeout must be >= 30 sec. -- now set to 120 sec\n" );
 				}
 				break;
 			case 'f':
 				fix_rtc = 1;
 				break;				
 			default:
 				usage ( );
 		}
 	}	
 	
 	if ( geteuid ( ) != 0 ) {
 		fprintf ( stderr, "You need root priviledges to run opiealarm." );
 		return 2;
 	}
 	
 	if ( !mode )
 		usage ( );
 
 	// kill running opiealarm
+	startpid = getpid ( );
 	opiealarm_was_running = kill_with_pidfile ( );
 	remove_pidfile ( );
 
 	switch ( mode ) {
 		case 'r': return resume ( ac_resusp );
 		case 's':
 		default : return suspend ( fix_rtc );
 	}
 	return 0;
 }		
 		
 
+
 int suspend ( int fix_rtc )
 {
 	FILE *fp;
 	char buf [64];
 	time_t alrt, syst, rtct;
 	struct tm alr, sys, rtc;
 	int fd;
 	int rtc_sys_diff;
 	
 	
 	if ( !fork_with_pidfile ( ))
 		return 3;
 		
 	log = fopen ( "/tmp/opiealarm.log", "w" ); 
 	log_msg ( "STARTING\n" );
 	
 
-
 	if (!( fp = fopen ( "/etc/resumeat", "r" ))) 
 		error_msg_and_die ( 1, "/etc/resumeat" );
 	
 	if ( !fgets ( buf, sizeof( buf ) - 1, fp ))
 		error_msg_and_die ( 1, "/etc/resumeat" );
 
 	fclose ( fp );
 	
 	alrt = atoi ( buf );
 	
 	if ( alrt == 0 )
 		error_msg_and_die ( 0, "/etc/resumeat contains an invalid time description" );
 	
-	/* subtract 5 sec from event time... */
-	alrt -= 5;
+	alrt -= 5; 	// wake up 5 sec before the specified time
+
 
 	if ( log )	
 		fprintf ( log, "Setting RTC alarm to %d\n", alrt );
 
 	tzset ( );
 	
 	alr = *gmtime ( &alrt );
 
 	// get system time
 	time ( &syst );
 	sys = *localtime ( &syst );		
 		
 	// Write alarm time to RTC
 	if (( fd = open ( "/dev/misc/rtc", O_RDWR )) < 0 )
 		error_msg_and_die ( 1, "/dev/misc/rtc" );	
 		
 	// get RTC time
 	memset ( &rtc, 0, sizeof ( struct tm ));
 	if ( ioctl ( fd, RTC_RD_TIME, &rtc ) < 0 )
 		error_msg_and_die ( 1, "ioctl RTC_RD_TIME" );		
 	rtct = mktime ( &rtc );
 
 	fprintf ( log, "System  time: %02d.%02d.%04d %02d:%02d:%02d DST: %d (TZ: %s, offset: %d)\n", sys. tm_mday, sys. tm_mon + 1, sys. tm_year + 1900, sys. tm_hour, sys. tm_min, sys. tm_sec, sys. tm_isdst, sys. tm_zone, sys. tm_gmtoff );
 	fprintf ( log, "RTC     time: %02d.%02d.%04d %02d:%02d:%02d DST: %d (TZ: %s, offset: %d)\n", rtc. tm_mday, rtc. tm_mon + 1, rtc. tm_year + 1900, rtc. tm_hour, rtc. tm_min, rtc. tm_sec, rtc. tm_isdst, rtc. tm_zone, rtc. tm_gmtoff );
 	fprintf ( log, "Wakeup  time: %02d.%02d.%04d %02d:%02d:%02d DST: %d (TZ: %s, offset: %d)\n", alr. tm_mday, alr. tm_mon + 1, alr. tm_year + 1900, alr. tm_hour, alr. tm_min, alr. tm_sec, alr. tm_isdst, alr. tm_zone, alr. tm_gmtoff );
 
 	fprintf ( log, "System/RTC diff: %d seconds\n", (  syst - rtct ) - sys. tm_gmtoff );
 
 
 	rtc_sys_diff = ( syst - rtct ) - sys. tm_gmtoff;
 	
 	if ( fix_rtc && (( rtc_sys_diff < -4 ) || ( rtc_sys_diff > 4 ))) {
 		struct tm set;
 		
 		set = *gmtime ( &syst );
 	
 		fprintf ( log, "Correcting RTC: %d seconds\n", rtc_sys_diff );
 
 	    if ( ioctl ( fd, RTC_SET_TIME, &set ) < 0 )
 	       error_msg_and_die ( 1, "ioctl RTC_SET_TIME" );
 	}
 
 	// set alarm time
 	if ( ioctl ( fd, RTC_ALM_SET, &alr ) < 0 )
 		error_msg_and_die ( 1, "ioctl RTC_ALM_SET" );		
 	// enable alarm irq	
 	if ( ioctl ( fd, RTC_AIE_ON, 0 ) < 0 )
 		error_msg_and_die ( 1, "ioctl RTC_AIE_ON" );
 	
-	log_msg ( "SLEEPING\n" );
+	if ( log )
+		fprintf( log, "SIGUSR: pid %d - SLEEPING: pid %d\n", startpid, getpid ( ));
+	kill ( startpid, SIGUSR1 );
 			
 	// wait for alarm irq
 	if ( read ( fd, buf, sizeof( unsigned long )) < 0 )
 		error_msg_and_die ( 1, "read rtc alarm" );
 	
 	log_msg ( "WAKEUP\n" );
 	
 	// disable alarm irq
 	if ( ioctl ( fd, RTC_AIE_OFF, 0 ) < 0 ) 
 		error_msg_and_die ( 1, "ioctl RTC_AIE_OFF" );
 		
 	close ( fd );
 	
 	log_msg ( "EXITING\n" );
 	
 	fclose ( log );
 	remove_pidfile ( );
 	
 	return 0;
 }
 
 
 int onac ( void )
 {
 	FILE *fp;
 	int on = 0;
 
 	if (( fp = fopen ( APMFILE, "r" ))) { 
 		int ac = 0;
 	
 		if ( fscanf ( fp, "%*[^ ] %*d.%*d 0x%*x 0x%x 0x%*x 0x%*x %*d%% %*i %*c", &ac ) == 1 )
 			on = ( ac == 0x01 ) ? 1 : 0;
 
 		fclose ( fp );
 	}
 	return on;
 }
 
 int resume ( int resuspend )
 {
 	FILE *fp;
 
 	// re-suspend when on AC (optional) when woken up via RTC
 
 	if ( !opiealarm_was_running ) { // opiealarm -s got it's RTC signal -> wake up by RTC
 		if ( resuspend && onac ( )) {	
 			time_t start, now;
 			char *argv [4];
 						
 			if ( !fork_with_pidfile ( ))
 				return 4;
+			kill ( startpid, SIGUSR1 );
 
 			// sleep <resuspend> sec (not less!)
 			time ( &start );
 			do {
 				sleep ( 1 );
 				time ( &now );
 			} while (( now - start ) < resuspend );
 
 			if ( onac ( )) { // still on ac
 				// system() without fork
 				argv[0] = "qcop";
 				argv[1] = "QPE/Desktop";
 				argv[2] = "suspend()";
 				argv[3] = 0;
 	
 				// hard coded for now ...but needed
 				setenv ( "LOGNAME", "root", 1 );
 				setenv ( "HOME", "/root", 1 );
 				setenv ( "LD_LIBRARY_PATH", "/opt/QtPalmtop/lib", 1 );
 				setenv ( "QTDIR", "/opt/QtPalmtop", 1 );
 			
 				remove_pidfile ( );
 			
 				execv ( "/opt/QtPalmtop/bin/qcop", argv );
 				
 				perror ( "exec for qcop failed" );
 				return 5;
 			}
 		}
 	}
 	return 0;
 }