Changed opiealarm into a real daemon (fork/detach)

Logging to /tmp/opiealarm.log is intentionally active at the moment.

1 files changed, 87 insertions, 11 deletions

diff --git a/core/opiealarm/opiealarm.c b/core/opiealarm/opiealarm.c
index 071cb24..33d631d 100644
--- a/core/opiealarm/opiealarm.c
+++ b/core/opiealarm/opiealarm.c
@@ -14,78 +14,154 @@
 #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>
 
 
+#define PIDFILE 	"/var/run/opiealarm.pid"
+
+FILE *log;
+
+
+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 )
-		perror ( msg );
-	else
-		fprintf ( stderr, "%s\n", msg );
+		log_msg ( strerror ( errno ));
+	log_msg ( msg );
+
+	unlink ( PIDFILE );
 	exit ( 1 );
 }
 
 
-void extractevent ( ) 
+
+void suspend_on_rtc ( ) 
 {
 	FILE *fp;
 	char buf [64];
 	time_t t;
 	struct tm *tm;
 	int fd;
 	
+
 	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 );
 	
 	t = atoi ( buf );
 	
 	if ( t == 0 )
 		error_msg_and_die ( 0, "/etc/resumeat contains an invalid time description" );
 	
 	/* subtract 5 sec from event time... */
 	t -= 5;
+
+	if ( log )	
+		fprintf ( log, "Setting RTC alarm to %d\n", t );
+	
 	tm = gmtime ( &t );
 
-	/* Write alarm time to RTC */
-	fd = open ( "/dev/misc/rtc", O_RDWR );
-	if ( fd < 0 ) 
+	// Write alarm time to RTC 
+	if (( fd = open ( "/dev/misc/rtc", O_RDWR ) < 0 );
 		error_msg_and_die ( 1, "/dev/misc/rtc" );
-	
 	// set alarm time
 	if ( ioctl ( fd, RTC_ALM_SET, tm ) < 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" );
+			
 	// 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 );
 }
 
 
+void sig_handler ( int sig )
+{
+	log_msg ( "GOT SIGNAL -> EXITING\n" );
+	fclose ( log );
+	unlink ( PIDFILE );
+	exit ( 0 );
+}
+
+
 int main ( ) 
 {
-	if ( geteuid ( ) != 0 )
-		error_msg_and_die ( 0, "You need root priviledges to run opiealarm." );
+	FILE *fp;
+	pid_t pid;
+
+	if ( geteuid ( ) != 0 ) {
+		fprintf ( stderr, "You need root priviledges to run opiealarm." );
+		return 1;
+	}
+	
+	pid = fork ( );
+	
+	if ( pid > 0 )
+		return 0;
+	else if ( pid < 0 ) {
+		perror ( "Could not fork." );
+		return 2;
+	}
+	
+	// save pid
+	if (!( fp = fopen ( PIDFILE, "w" ))) {
+		perror ( PIDFILE );
+		return 3;
+	}
+	
+	fprintf ( fp, "%d", getpid ( ));
+	fclose ( fp );
+
+	// detach
+	close ( 0 );
+	close ( 1 );
+	close ( 2 );
+
+	setpgid ( 0, 0 );
+
+	log = fopen ( "/tmp/opiealarm.log", "w" ); 
+	log_msg ( "STARTING\n" );
+	
+	signal ( SIGTERM, sig_handler );
+	signal ( SIGINT,  sig_handler );
 
 	extractevent ( );
+	
+	signal ( SIGTERM, SIG_DFL );
+	signal ( SIGINT,  SIG_DFL );
+
+	log_msg ( "EXITING\n" );
+	
+	fclose ( log );
+	unlink ( PIDFILE );
 	return 0;
 }