dev: always advertise rx_flags changes via netlink

When flags IFF_PROMISC and IFF_ALLMULTI are changed, netlink messages are not
consistent. For example, if a multicast daemon is running (flag IFF_ALLMULTI
set in dev->flags but not dev->gflags, ie not exported to userspace) and then a
user sets it via netlink (flag IFF_ALLMULTI set in dev->flags and dev->gflags, ie
exported to userspace), no netlink message is sent.
Same for IFF_PROMISC and because dev->promiscuity is exported via
IFLA_PROMISCUITY, we may send a netlink message after each change of this
counter.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index 594a6b0ab3dab7bbeac47489479518f52a3434e1..81340ed7f0f42f3dfe3ff17041841ba2125b3d95 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4988,7 +4988,7 @@ static void dev_change_rx_flags(struct net_device *dev, int flags)
                ops->ndo_change_rx_flags(dev, flags);
 }
 
-static int __dev_set_promiscuity(struct net_device *dev, int inc)
+static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
 {
        unsigned int old_flags = dev->flags;
        kuid_t uid;
@@ -5031,6 +5031,8 @@ static int __dev_set_promiscuity(struct net_device *dev, int inc)
 
                dev_change_rx_flags(dev, IFF_PROMISC);
        }
+       if (notify)
+               __dev_notify_flags(dev, old_flags, IFF_PROMISC);
        return 0;
 }
 
@@ -5050,7 +5052,7 @@ int dev_set_promiscuity(struct net_device *dev, int inc)
        unsigned int old_flags = dev->flags;
        int err;
 
-       err = __dev_set_promiscuity(dev, inc);
+       err = __dev_set_promiscuity(dev, inc, true);
        if (err < 0)
                return err;
        if (dev->flags != old_flags)
@@ -5059,22 +5061,9 @@ int dev_set_promiscuity(struct net_device *dev, int inc)
 }
 EXPORT_SYMBOL(dev_set_promiscuity);
 
-/**
- *     dev_set_allmulti        - update allmulti count on a device
- *     @dev: device
- *     @inc: modifier
- *
- *     Add or remove reception of all multicast frames to a device. While the
- *     count in the device remains above zero the interface remains listening
- *     to all interfaces. Once it hits zero the device reverts back to normal
- *     filtering operation. A negative @inc value is used to drop the counter
- *     when releasing a resource needing all multicasts.
- *     Return 0 if successful or a negative errno code on error.
- */
-
-int dev_set_allmulti(struct net_device *dev, int inc)
+static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
 {
-       unsigned int old_flags = dev->flags;
+       unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
 
        ASSERT_RTNL();
 
@@ -5097,9 +5086,30 @@ int dev_set_allmulti(struct net_device *dev, int inc)
        if (dev->flags ^ old_flags) {
                dev_change_rx_flags(dev, IFF_ALLMULTI);
                dev_set_rx_mode(dev);
+               if (notify)
+                       __dev_notify_flags(dev, old_flags,
+                                          dev->gflags ^ old_gflags);
        }
        return 0;
 }
+
+/**
+ *     dev_set_allmulti        - update allmulti count on a device
+ *     @dev: device
+ *     @inc: modifier
+ *
+ *     Add or remove reception of all multicast frames to a device. While the
+ *     count in the device remains above zero the interface remains listening
+ *     to all interfaces. Once it hits zero the device reverts back to normal
+ *     filtering operation. A negative @inc value is used to drop the counter
+ *     when releasing a resource needing all multicasts.
+ *     Return 0 if successful or a negative errno code on error.
+ */
+
+int dev_set_allmulti(struct net_device *dev, int inc)
+{
+       return __dev_set_allmulti(dev, inc, true);
+}
 EXPORT_SYMBOL(dev_set_allmulti);
 
 /*
@@ -5124,10 +5134,10 @@ void __dev_set_rx_mode(struct net_device *dev)
                 * therefore calling __dev_set_promiscuity here is safe.
                 */
                if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
-                       __dev_set_promiscuity(dev, 1);
+                       __dev_set_promiscuity(dev, 1, false);
                        dev->uc_promisc = true;
                } else if (netdev_uc_empty(dev) && dev->uc_promisc) {
-                       __dev_set_promiscuity(dev, -1);
+                       __dev_set_promiscuity(dev, -1, false);
                        dev->uc_promisc = false;
                }
        }
@@ -5216,9 +5226,13 @@ int __dev_change_flags(struct net_device *dev, unsigned int flags)
 
        if ((flags ^ dev->gflags) & IFF_PROMISC) {
                int inc = (flags & IFF_PROMISC) ? 1 : -1;
+               unsigned int old_flags = dev->flags;
 
                dev->gflags ^= IFF_PROMISC;
-               dev_set_promiscuity(dev, inc);
+
+               if (__dev_set_promiscuity(dev, inc, false) >= 0)
+                       if (dev->flags != old_flags)
+                               dev_set_rx_mode(dev);
        }
 
        /* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
@@ -5229,7 +5243,7 @@ int __dev_change_flags(struct net_device *dev, unsigned int flags)
                int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
 
                dev->gflags ^= IFF_ALLMULTI;
-               dev_set_allmulti(dev, inc);
+               __dev_set_allmulti(dev, inc, false);
        }
 
        return ret;
@@ -5271,13 +5285,13 @@ void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
 int dev_change_flags(struct net_device *dev, unsigned int flags)
 {
        int ret;
-       unsigned int changes, old_flags = dev->flags;
+       unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
 
        ret = __dev_change_flags(dev, flags);
        if (ret < 0)
                return ret;
 
-       changes = old_flags ^ dev->flags;
+       changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
        __dev_notify_flags(dev, old_flags, changes);
        return ret;
 }