Added and changed program locks

mbmon/Makefile

@@ -4,9 +4,9 @@
 
 include ../Makefile.global
 
-SRCS		= mutil.c mbmon.c common.c
-HDRS		= mutil.h mbmon.h common.h 
-OBJS		= mutil.o mbmon.o common.o
+SRCS		= mutil.c mbmon.c common.c proglock.c
+HDRS		= mutil.h mbmon.h common.h proglock.h
+OBJS		= mutil.o mbmon.o common.o proglock.o
 LIBS		+= ../lib/libmemwatch.a
 OTHER		= Makefile
 
@@ -58,6 +58,7 @@ depend:
 # DO NOT DELETE THIS LINE - MAKE DEPEND RELIES ON IT
 # Dependencies generated by make depend
 mutil.o: ../config.h ../lib/libs.h ../lib/memwatch.h ../lib/mberrors.h ../lib/structs.h common.h mutil.h
-mbmon.o: ../config.h ../lib/libs.h ../lib/memwatch.h ../lib/mberrors.h ../lib/structs.h common.h mutil.h
+mbmon.o: ../config.h ../lib/libs.h ../lib/memwatch.h ../lib/mberrors.h ../lib/structs.h common.h proglock.h mutil.h
 common.o: ../config.h ../lib/libs.h ../lib/memwatch.h ../lib/mberrors.h common.h
+proglock.o: ../config.h ../lib/libs.h ../lib/memwatch.h ../lib/mberrors.h ../lib/structs.h common.h proglock.h
 # End of generated dependencies

mbmon/mbmon.c

@@ -5,7 +5,7 @@
  * Todo ..................: Chat with user via server
  *
  *****************************************************************************
- * Copyright (C) 1997-2002
+ * Copyright (C) 1997-2003
  *   
  * Michiel Broek		FIDO:		2:280/2802
  * Beekmansbos 10
@@ -35,6 +35,7 @@
 #include "../lib/mberrors.h"
 #include "../lib/structs.h"
 #include "common.h"
+#include "proglock.h"
 #include "mutil.h"
 
 
@@ -58,15 +59,22 @@ static void die(int onsig)
     char    buf[128];
     
     signal(onsig, SIG_IGN);
-    screen_stop(); 
+
+    /*
+     * Prevent clear screen when the program was locked
+     */
+    if (onsig != MBERR_NO_PROGLOCK)
+	screen_stop(); 
+    
     if (onsig && (onsig <= NSIG))
-	Syslog('?', "Finished on signal %s", SigName[onsig]);
+	Syslog('?', "MBMON Finished on signal %s", SigName[onsig]);
     else
-	Syslog(' ', "Normally finished");
+	Syslog(' ', "MBMON Normally finished");
     
     sprintf(buf, "CSYS:2,%d,0;", mypid);
     if (socket_send(buf) == 0)
 	sprintf(buf, "%s", socket_receive());
+    ulockprogram((char *)"mbmon");
     ExitClient(0);
 }
 
@@ -709,7 +717,7 @@ int main(int argc, char *argv[])
      */
     pw = getpwuid(getuid());
     InitClient(pw->pw_name);
-    Syslog(' ', "Started by %s", pw->pw_name);
+    Syslog(' ', "MBMON Started by %s", pw->pw_name);
     bbs_free = FALSE;
 
     /*
@@ -730,7 +738,6 @@ int main(int argc, char *argv[])
     signal(SIGTERM,(void (*))die);
     signal(SIGKILL,(void (*))die);
 
-
     /*
      * Find out if the environment variables LINES and COLUMNS are present,
      * if so, then use these for screen dimensions.
@@ -747,6 +754,10 @@ int main(int argc, char *argv[])
     }
     Syslog('-', "Screen size set to %dx%d", columns, lines);
 
+    if (lockprogram((char *)"mbmon")) {
+	printf("\n\7Another mbmon is already running, abort.\n\n");
+	die(MBERR_NO_PROGLOCK);
+    }
     
     screen_start((char *)"MBmon");
 

mbmon/proglock.c

@@ -0,0 +1,143 @@
+/*****************************************************************************
+ *
+ * $Id$
+ * Purpose ...............: Program Locking
+ *
+ *****************************************************************************
+ * Copyright (C) 1997-2003
+ *   
+ * Michiel Broek		FIDO:		2:280/2802
+ * Beekmansbos 10
+ * 1971 BV IJmuiden
+ * the Netherlands
+ *
+ * This file is part of MBSE BBS.
+ *
+ * This BBS 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, or (at your option) any
+ * later version.
+ *
+ * MBSE BBS 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
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with MBSE BBS; see the file COPYING.  If not, write to the Free
+ * Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ *****************************************************************************/
+
+#include "../config.h"
+#include "../lib/libs.h"
+#include "../lib/memwatch.h"
+#include "../lib/mberrors.h"
+#include "../lib/structs.h"
+#include "common.h"
+#include "proglock.h"
+
+
+
+
+/*
+ *  Put a lock on a program.
+ */
+int lockprogram(char *progname)
+{
+    char    *tempfile, *lockfile;
+    FILE    *fp;
+    pid_t   oldpid;
+
+    tempfile  = calloc(PATH_MAX, sizeof(char));
+    lockfile = calloc(PATH_MAX, sizeof(char));
+
+    sprintf(tempfile, "%s/var/run/%s.tmp", getenv("MBSE_ROOT"), progname);
+    sprintf(lockfile, "%s/var/run/%s", getenv("MBSE_ROOT"), progname);
+
+    if ((fp = fopen(tempfile, "w")) == NULL) {
+	Syslog('?', "$Can't create lockfile \"%s\"", tempfile);
+	free(tempfile);
+	free(lockfile);
+	return 1;
+    }
+    fprintf(fp, "%10u\n", getpid());
+    fclose(fp);
+
+    while (TRUE) {
+	if (link(tempfile, lockfile) == 0) {
+	    unlink(tempfile);
+	    free(tempfile);
+	    free(lockfile);
+	    return 0;
+	}
+	if ((fp = fopen(lockfile, "r")) == NULL) {
+	    Syslog('?', "$Can't open lockfile \"%s\"", lockfile);
+	    unlink(tempfile);
+	    free(tempfile);
+	    free(lockfile);
+	    return 1;
+	}
+	if (fscanf(fp, "%u", &oldpid) != 1) {
+	    Syslog('?', "$Can't read old pid from \"%s\"", tempfile);
+	    fclose(fp);
+	    unlink(tempfile);
+	    free(tempfile);
+	    free(lockfile);
+	    return 1;
+	}
+	fclose(fp);
+	if (kill(oldpid,0) == -1) {
+	    if (errno == ESRCH) {
+		Syslog('+', "Stale lock found for pid %u", oldpid);
+		unlink(lockfile);
+		/* no return, try lock again */  
+	    } else {
+		Syslog('?', "$Kill for %u failed", oldpid);
+		unlink(tempfile);
+		free(tempfile);
+		free(lockfile);
+		return 1;
+	    }
+	} else {
+	    Syslog('+', "%s already running, pid=%u", progname, oldpid);
+	    unlink(tempfile);
+	    free(tempfile);
+	    free(lockfile);
+	    return 1;
+	}
+    }
+}
+
+
+
+void ulockprogram(char *progname)
+{
+    char    *lockfile;
+    pid_t   oldpid;
+    FILE    *fp;
+
+    lockfile = calloc(PATH_MAX, sizeof(char));
+    sprintf(lockfile, "%s/var/run/%s", getenv("MBSE_ROOT"), progname);
+
+    if ((fp = fopen(lockfile, "r")) == NULL) {
+	Syslog('?', "$Can't open lockfile \"%s\"", lockfile);
+	free(lockfile);
+	return;
+    }
+    if (fscanf(fp, "%u", &oldpid) != 1) {
+	Syslog('?', "$Can't read old pid from \"%s\"", lockfile);
+	fclose(fp);
+	unlink(lockfile);
+	free(lockfile);
+	return;
+    }
+
+    if (oldpid == getpid()) {
+	(void)unlink(lockfile);
+    } else {
+	Syslog('?', "Lockfile owned by pid %d, not removed", oldpid);
+    }
+
+    free(lockfile);
+}
+

mbmon/proglock.h

@@ -0,0 +1,9 @@
+#ifndef	_PROGLOCK_H
+#define	_PROGLOCK_H
+
+/* $Id$ */
+
+int lockprogram(char *);
+void ulockprogram(char*);
+
+#endif