bonding: add arp_ip_target checks when install the module

When I install the bonding with the wrong arp_ip_target,
just like arp_ip_target=500.500.500.500, the arp_ip_target
was transfored to 245.245.245.244 and stored in the ip
target success, it is uncorrect, so I add checks to avoid
adding wrong address.

The in4_pton() will set wrong ip address to 0.0.0.0 and
return 0, also use the micro IS_IP_TARGET_UNUSABLE_ADDRESS
to simplify the code.
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -4199,9 +4199,9 @@ static int bond_check_params(struct bond_params *params)
 	     (arp_ip_count < BOND_MAX_ARP_TARGETS) && arp_ip_target[i]; i++) {
 		/* not complete check, but should be good enough to
 		   catch mistakes */
-		__be32 ip = in_aton(arp_ip_target[i]);
-		if (!isdigit(arp_ip_target[i][0]) || ip == 0 ||
-		    ip == htonl(INADDR_BROADCAST)) {
+		__be32 ip;
+		if (!in4_pton(arp_ip_target[i], -1, (u8 *)&ip, -1, NULL) ||
+		    IS_IP_TARGET_UNUSABLE_ADDRESS(ip)) {
 			pr_warning("Warning: bad arp_ip_target module parameter (%s), ARP monitoring will not be performed\n",
 				   arp_ip_target[i]);
 			arp_interval = 0;