Changed opiealarm into a real daemon (fork/detach)

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

1 files changed, 89 insertions, 13 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
@@ -18,28 +18,46 @@
 #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 ))
@@ -53,39 +71,97 @@ void extractevent ( )
                 error_msg_and_die ( 0, "/etc/resumeat contains an invalid time description" );
         
         /* subtract 5 sec from event time... */
         t -= 5;
-        tm = gmtime ( &t );
 
-        /* Write alarm time to RTC */
-        fd = open ( "/dev/misc/rtc", O_RDWR );
-        if ( fd < 0 ) 
-                error_msg_and_die ( 1, "/dev/misc/rtc" );
+                if ( log )
+                fprintf ( log, "Setting RTC alarm to %d\n", t );
         
+        tm = gmtime ( &t );
+
+        // 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" );
-                
+                        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;
 }