bonding: prevent sysfs from allowing arp monitoring with alb/tlb

When using module options arp monitoring and balance-alb/balance-tlb
are mutually exclusive options.  Anytime balance-alb/balance-tlb are
enabled mii monitoring is forced to 100ms if not set.  When configuring
via sysfs no checking is currently done.

Handling these cases with sysfs has to be done a bit differently because
we do not have all configuration information available at once.  This
patch will not allow a mode change to balance-alb/balance-tlb if
arp_interval is already non-zero.  It will also not allow the user to
set a non-zero arp_interval value if the mode is already set to
balance-alb/balance-tlb.  They are still mutually exclusive on a
first-come, first serve basis.

Tested with initscripts on Fedora and manual setting via sysfs.

Signed-off-by: Andy Gospodarek <gospo@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_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 1a99764..c311aed 100644 (file)
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -313,19 +313,26 @@ static ssize_t bonding_store_mode(struct device *d,
                       bond->dev->name, (int)strlen(buf) - 1, buf);
                ret = -EINVAL;
                goto out;
-       } else {
-               if (bond->params.mode == BOND_MODE_8023AD)
-                       bond_unset_master_3ad_flags(bond);
+       }
+       if ((new_value == BOND_MODE_ALB ||
+            new_value == BOND_MODE_TLB) &&
+           bond->params.arp_interval) {
+               pr_err("%s: %s mode is incompatible with arp monitoring.\n",
+                      bond->dev->name, bond_mode_tbl[new_value].modename);
+               ret = -EINVAL;
+               goto out;
+       }
+       if (bond->params.mode == BOND_MODE_8023AD)
+               bond_unset_master_3ad_flags(bond);
 
-               if (bond->params.mode == BOND_MODE_ALB)
-                       bond_unset_master_alb_flags(bond);
+       if (bond->params.mode == BOND_MODE_ALB)
+               bond_unset_master_alb_flags(bond);
 
-               bond->params.mode = new_value;
-               bond_set_mode_ops(bond, bond->params.mode);
-               pr_info("%s: setting mode to %s (%d).\n",
-                       bond->dev->name, bond_mode_tbl[new_value].modename,
-                      new_value);
-       }
+       bond->params.mode = new_value;
+       bond_set_mode_ops(bond, bond->params.mode);
+       pr_info("%s: setting mode to %s (%d).\n",
+               bond->dev->name, bond_mode_tbl[new_value].modename,
+               new_value);
 out:
        return ret;
 }
@@ -510,7 +517,13 @@ static ssize_t bonding_store_arp_interval(struct device *d,
                ret = -EINVAL;
                goto out;
        }
-
+       if (bond->params.mode == BOND_MODE_ALB ||
+           bond->params.mode == BOND_MODE_TLB) {
+               pr_info("%s: ARP monitoring cannot be used with ALB/TLB. Only MII monitoring is supported on %s.\n",
+                       bond->dev->name, bond->dev->name);
+               ret = -EINVAL;
+               goto out;
+       }
        pr_info("%s: Setting ARP monitoring interval to %d.\n",
                bond->dev->name, new_value);
        bond->params.arp_interval = new_value;