From 24edeaaacf0648b3df0032ef5d1deb3a9e11b388 Mon Sep 17 00:00:00 2001
From: Oyvind Albrigtsen <oalbrigt@redhat.com>
Date: Wed, 11 Jan 2017 14:11:21 +0100
Subject: [PATCH] IPaddr2 detect duplicate IP

---
 heartbeat/IPaddr2 | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/heartbeat/IPaddr2 b/heartbeat/IPaddr2
index b416e31..2d5e1ea 100755
--- a/heartbeat/IPaddr2
+++ b/heartbeat/IPaddr2
@@ -79,6 +79,7 @@ OCF_RESKEY_arp_count_default=5
 OCF_RESKEY_arp_count_refresh_default=0
 OCF_RESKEY_arp_bg_default=true
 OCF_RESKEY_arp_mac_default="ffffffffffff"
+OCF_RESKEY_run_arping_default=false
 
 : ${OCF_RESKEY_lvs_support=${OCF_RESKEY_lvs_support_default}}
 : ${OCF_RESKEY_lvs_ipv6_addrlabel=${OCF_RESKEY_lvs_ipv6_addrlabel_default}}
@@ -90,6 +91,7 @@ OCF_RESKEY_arp_mac_default="ffffffffffff"
 : ${OCF_RESKEY_arp_count_refresh=${OCF_RESKEY_arp_count_refresh_default}}
 : ${OCF_RESKEY_arp_bg=${OCF_RESKEY_arp_bg_default}}
 : ${OCF_RESKEY_arp_mac=${OCF_RESKEY_arp_mac_default}}
+: ${OCF_RESKEY_run_arping=${OCF_RESKEY_run_arping_default}}
 #######################################################################
 
 SENDARP=$HA_BIN/send_arp
@@ -340,6 +342,14 @@ IP address goes away.
 <content type="boolean" default="false"/>
 </parameter>
 
+<parameter name="run_arping">
+<longdesc lang="en">
+Whether or not to run arping for IPv4 collision detection check.
+</longdesc>
+<shortdesc lang="en">Run arping for IPv4 collision detection check</shortdesc>
+<content type="string" default="${OCF_RESKEY_run_arping_default}"/>
+</parameter>
+
 </parameters>
 <actions>
 <action name="start"   timeout="20s" />
@@ -556,6 +566,15 @@ add_interface () {
 	iface="$4"
 	label="$5"
 
+	if [ "$FAMILY" = "inet" ] && ocf_is_true $OCF_RESKEY_run_arping &&
+	   check_binary arping; then
+		arping -q -c 2 -w 3 -D -I $iface $ipaddr
+		if [ $? = 1 ]; then
+			ocf_log err "IPv4 address collision $ipaddr [DAD]"
+			return $OCF_ERR_CONFIGURED
+		fi
+	fi
+
 	if [ "$FAMILY" = "inet6" ] && ocf_is_true $OCF_RESKEY_lvs_ipv6_addrlabel ;then
 	    add_ipv6_addrlabel $ipaddr
 	fi
@@ -877,10 +896,11 @@ ip_start() {
 		fi
 		
 		add_interface $OCF_RESKEY_ip $NETMASK ${BRDCAST:-none} $NIC $IFLABEL
-		
-		if [ $? -ne 0 ]; then
-			ocf_exit_reason "$CMD failed."
-			exit $OCF_ERR_GENERIC
+		rc=$?
+
+		if [ $rc -ne $OCF_SUCCESS ]; then
+			ocf_exit_reason "Failed to add $OCF_RESKEY_ip"
+			exit $rc
 		fi
 	fi