bonding: arp_ip_count and arp_targets can be wrong

When getting arp_ip_targets if we encounter a bad IP, arp_ip_count still
gets increased and all the targets after the wrong one will not be probed
if arp_interval is enabled after that (unless a new IP target is added
through sysfs) because of the zero entry, in this case reading
arp_ip_target through sysfs will show valid targets even if there's a
zero entry.
Example: 1.2.3.4,4.5.6.7,blah,5.6.7.8
When retrieving the list from arp_ip_target the output would be:
1.2.3.4,4.5.6.7,5.6.7.8
but there will be a 0 entry between 4.5.6.7 and 5.6.7.8. If arp_interval
is enabled after that 5.6.7.8 will never be checked because of that.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.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 d463598..29b846c 100644 (file)
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -4471,7 +4471,7 @@ int bond_parse_parm(const char *buf, const struct bond_parm_tbl *tbl)
 
 static int bond_check_params(struct bond_params *params)
 {
-       int arp_validate_value, fail_over_mac_value, primary_reselect_value;
+       int arp_validate_value, fail_over_mac_value, primary_reselect_value, i;
 
        /*
         * Convert string parameters.
@@ -4651,19 +4651,18 @@ static int bond_check_params(struct bond_params *params)
                arp_interval = BOND_LINK_ARP_INTERV;
        }
 
-       for (arp_ip_count = 0;
-            (arp_ip_count < BOND_MAX_ARP_TARGETS) && arp_ip_target[arp_ip_count];
-            arp_ip_count++) {
+       for (arp_ip_count = 0, i = 0;
+            (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[arp_ip_count]);
-               if (!isdigit(arp_ip_target[arp_ip_count][0]) ||
-                   ip == 0 || ip == htonl(INADDR_BROADCAST)) {
+               __be32 ip = in_aton(arp_ip_target[i]);
+               if (!isdigit(arp_ip_target[i][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_ip_target[i]);
                        arp_interval = 0;
                } else {
-                       arp_target[arp_ip_count] = ip;
+                       arp_target[arp_ip_count++] = ip;
                }
        }
 
@@ -4697,8 +4696,6 @@ static int bond_check_params(struct bond_params *params)
        if (miimon) {
                pr_info("MII link monitoring set to %d ms\n", miimon);
        } else if (arp_interval) {
-               int i;
-
                pr_info("ARP monitoring set to %d ms, validate %s, with %d target(s):",
                        arp_interval,
                        arp_validate_tbl[arp_validate_value].modename,