1 files changed, 109 insertions, 0 deletions
diff --git a/source4/lib/pidfile.c b/source4/lib/pidfile.c
new file mode 100644
index 0000000000..3471f27b8e
--- /dev/null
+++ b/source4/lib/pidfile.c
@@ -0,0 +1,109 @@
+/* this code is broken - there is a race condition with the unlink (tridge) */
+
+/* 
+   Unix SMB/CIFS implementation.
+   pidfile handling
+   Copyright (C) Andrew Tridgell 1998
+   
+   This program 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 program 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 this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+#ifndef O_NONBLOCK
+#define O_NONBLOCK
+#endif
+
+/* return the pid in a pidfile. return 0 if the process (or pidfile)
+   does not exist */
+pid_t pidfile_pid(const char *name)
+{
+	int fd;
+	char pidstr[20];
+	unsigned ret;
+	pstring pidFile;
+
+	slprintf(pidFile, sizeof(pidFile)-1, "%s/%s.pid", lp_piddir(), name);
+
+	fd = sys_open(pidFile, O_NONBLOCK | O_RDONLY, 0644);
+	if (fd == -1) {
+		return 0;
+	}
+
+	ZERO_ARRAY(pidstr);
+
+	if (read(fd, pidstr, sizeof(pidstr)-1) <= 0) {
+		goto noproc;
+	}
+
+	ret = atoi(pidstr);
+	
+	if (!process_exists((pid_t)ret)) {
+		goto noproc;
+	}
+
+	if (fcntl_lock(fd,SMB_F_SETLK,0,1,F_RDLCK)) {
+		/* we could get the lock - it can't be a Samba process */
+		goto noproc;
+	}
+
+	close(fd);
+	return (pid_t)ret;
+
+ noproc:
+	close(fd);
+	unlink(pidFile);
+	return 0;
+}
+
+/* create a pid file in the pid directory. open it and leave it locked */
+void pidfile_create(const char *name)
+{
+	int     fd;
+	char    buf[20];
+	pstring pidFile;
+	pid_t pid;
+
+	slprintf(pidFile, sizeof(pidFile)-1, "%s/%s.pid", lp_piddir(), name);
+
+	pid = pidfile_pid(name);
+	if (pid != 0) {
+		DEBUG(0,("ERROR: %s is already running. File %s exists and process id %d is running.\n", 
+			 name, pidFile, (int)pid));
+		exit(1);
+	}
+
+	fd = sys_open(pidFile, O_NONBLOCK | O_CREAT | O_WRONLY | O_EXCL, 0644);
+	if (fd == -1) {
+		DEBUG(0,("ERROR: can't open %s: Error was %s\n", pidFile, 
+			 strerror(errno)));
+		exit(1);
+	}
+
+	if (fcntl_lock(fd,SMB_F_SETLK,0,1,F_WRLCK)==False) {
+		DEBUG(0,("ERROR: %s : fcntl lock of file %s failed. Error was %s\n",  
+              name, pidFile, strerror(errno)));
+		exit(1);
+	}
+
+	memset(buf, 0, sizeof(buf));
+	slprintf(buf, sizeof(buf) - 1, "%u\n", (unsigned int) getpid());
+	if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)) {
+		DEBUG(0,("ERROR: can't write to file %s: %s\n", 
+			 pidFile, strerror(errno)));
+		exit(1);
+	}
+	/* Leave pid file open & locked for the duration... */
+}