From 0 Mon Sep 17 00:00:00 2001

From: Mikhail Efremov <sem@altlinux.org>

Date: Wed, 24 Oct 2012 19:30:29 +0400

Subject: [PATCH 12] dhclient: Check if dhclient already running.

Based on dhcp-4.2.0-release-by-ifup.patch from Fedora.

diff --git a/dhcp/client/dhclient.c b/dhcp/client/dhclient.c

index defaced..defaced 100644

--- a/dhcp/client/dhclient.c

+++ b/dhcp/client/dhclient.c

@@ -791,8 +791,25 @@ main(int argc, char **argv) {

 			}

 			fclose(pidfd);

 		}

-	}

+	} else {

+		FILE *pidfp = NULL;

+		long pid = 0;

+		int dhc_running = 0;

+		if ((pidfp = fopen(path_dhclient_pid, "r")) != NULL) {

+			if ((fscanf(pidfp, "%ld", &pid) == 1) &&

+					(pid > 0) &&

+					(kill((pid_t) pid, 0) == 0))

+				dhc_running = 1;

+

+			fclose(pidfp);

+		}

+

+		if (dhc_running) {

+			log_fatal("dhclient(%ld) is already running - exiting.", pid);

+			exit(1);

+		}

+	}

 	if (!quiet) {

 		log_info("%s %s", message, PACKAGE_VERSION);

 		log_info("%s", copyright);