From d371c4769dac5d84fa2089299efd77b5341c5079 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppisar@redhat.com>

Date: Thu, 3 Feb 2011 17:57:09 +0100

Subject: [PATCH] Store PID of quota_nld

If quota_nld is run as daemon, daemon's PID will be stored into

/var/run/${PROGNAME}.pid file and it will be deleted on receiving SIGTERM

just before program termination.

PID file is used by init scripts to find and kill forked daemon.

---

 quota_nld.c |   79 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

 1 files changed, 79 insertions(+), 0 deletions(-)

diff --git a/quota_nld.c b/quota_nld.c

index 538702d..600bdf1 100644

--- a/quota_nld.c

+++ b/quota_nld.c

@@ -25,6 +25,7 @@

 #include <string.h>

 #include <fcntl.h>

 #include <limits.h>

+#include <signal.h>

 #include <netlink/genl/genl.h>

 #include <netlink/genl/ctrl.h>

@@ -369,6 +370,83 @@ static void run(struct nl_handle *nhandle)

 	}

 }

+/* Build file name (absolute path) to PID file of this daemon.

+ * The returned name is allocated on heap. */

+static char *build_pid_file_name(void)

+{

+	char *pid_name = NULL;

+	if (!progname) {

+		errstr(_("Undefined program name.\n"));

+		return NULL;

+	}

+	pid_name = malloc(9 + strlen(progname) + 4 + 1);

+	if (!pid_name) {

+		errstr(_("Not enough memory to build PID file name.\n"));

+		return NULL;

+	}

+	sprintf(pid_name, "/var/run/%s.pid", progname);

+	return pid_name;

+}

+

+/* Store daemon's PID to file */

+static int store_pid(void)

+{

+	FILE *pid_file;

+	char *pid_name;

+

+	pid_name = build_pid_file_name();

+	if (!pid_name) return -1;

+

+	pid_file = fopen(pid_name, "w");

+	if (!pid_file) {

+		errstr(_("Could not open PID file '%s': %s\n"),

+			pid_name, strerror(errno));

+		free(pid_name);

+		return -1;

+	}

+	if (0 > fprintf(pid_file, "%jd\n", (intmax_t)getpid())) {

+		errstr(_("Could not write daemon's PID into '%s'.\n"),

+		       	pid_name);

+		fclose(pid_file);

+		free(pid_name);

+		return -1;

+	}

+	if (fclose(pid_file)) {

+		errstr(_("Could not close PID file '%s'.\n"), pid_name);

+		free(pid_name);

+		return -1;

+	}

+

+	free(pid_name);

+	return 0;

+}

+

+/* Handler for SIGTERM to remove PID file */

+static void remove_pid(int signal)

+{

+	char *pid_name;

+

+	pid_name = build_pid_file_name();

+	if (pid_name) {

+		unlink(pid_name);

+		free(pid_name);

+	}

+	exit(EXIT_SUCCESS);

+}

+

+/* Store daemon's PID into file and register its removal on SIGTERM */

+static int use_pid_file(void)

+{

+	struct sigaction term_action;

+

+	term_action.sa_handler = remove_pid;

+	term_action.sa_flags = 0;

+	if (sigaction(SIGTERM, &term_action, NULL))

+		errstr(_("Could not register PID file removal on SIGTERM.\n"));

+	if (store_pid())

+		errstr(_("Could not store my PID %jd.\n"), (intmax_t )getpid());

+}

+

 int main(int argc, char **argv)

 {

 	struct nl_handle *nhandle;

@@ -383,6 +461,7 @@ int main(int argc, char **argv)

 	if (!(flags & FL_NODAEMON)) {

 		use_syslog();

 		daemon(0, 0);

+		use_pid_file();

 	}

 	run(nhandle);

 	return 0;

-- 

1.7.4