bonding: make arp_ip_target parameter checks consistent with sysfs

The module can be loaded with arp_ip_target="255.255.255.255" which makes
 it impossible to remove as the function in sysfs checks for that value,
 so we make the parameter checks consistent with sysfs.

 v2: Fix formatting
 v3: Make description text < 75 columns

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 1445c7d..a7d4735 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -4670,12 +4670,13 @@
 	     arp_ip_count++) {
 		/* not complete check, but should be good enough to
 		   catch mistakes */
-		if (!isdigit(arp_ip_target[arp_ip_count][0])) {
+		__be32 ip = in_aton(arp_ip_target[arp_ip_count]);
+		if (!isdigit(arp_ip_target[arp_ip_count][0]) ||
+		    ip == 0 || ip == htonl(INADDR_BROADCAST)) {
 			pr_warning("Warning: bad arp_ip_target module parameter (%s), ARP monitoring will not be performed\n",
 				   arp_ip_target[arp_ip_count]);
 			arp_interval = 0;
 		} else {
-			__be32 ip = in_aton(arp_ip_target[arp_ip_count]);
 			arp_target[arp_ip_count] = ip;
 		}
 	}