[NET]: dev: secondary unicast address support

Add support for configuring secondary unicast addresses on network
devices. To support this devices capable of filtering multiple
unicast addresses need to change their set_multicast_list function
to configure unicast filters as well and assign it to dev->set_rx_mode
instead of dev->set_multicast_list. Other devices are put into promiscous
mode when secondary unicast addresses are present.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 129 insertions, 52 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 18759ccdf219..36e9bf8ec4af 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -942,7 +942,7 @@ int dev_open(struct net_device *dev)
                 /*
                  *      Initialize multicasting status
                  */
-                dev_mc_upload(dev);
+                dev_set_rx_mode(dev);
 
                 /*
                  *      Wakeup transmit queue engine
@@ -2498,17 +2498,7 @@ int netdev_set_master(struct net_device *slave, struct net_device *master)
         return 0;
 }
 
-/**
- *      dev_set_promiscuity     - update promiscuity count on a device
- *      @dev: device
- *      @inc: modifier
- *
- *      Add or remove promiscuity from a device. While the count in the device
- *      remains above zero the interface remains promiscuous. Once it hits zero
- *      the device reverts back to normal filtering operation. A negative inc
- *      value is used to drop promiscuity on the device.
- */
-void dev_set_promiscuity(struct net_device *dev, int inc)
+static void __dev_set_promiscuity(struct net_device *dev, int inc)
 {
         unsigned short old_flags = dev->flags;
 
@@ -2517,7 +2507,6 @@ void dev_set_promiscuity(struct net_device *dev, int inc)
         else
                 dev->flags |= IFF_PROMISC;
         if (dev->flags != old_flags) {
-                dev_mc_upload(dev);
                 printk(KERN_INFO "device %s %s promiscuous mode\n",
                        dev->name, (dev->flags & IFF_PROMISC) ? "entered" :
                                                                "left");
@@ -2531,6 +2520,25 @@ void dev_set_promiscuity(struct net_device *dev, int inc)
 }
 
 /**
+ *      dev_set_promiscuity     - update promiscuity count on a device
+ *      @dev: device
+ *      @inc: modifier
+ *
+ *      Add or remove promiscuity from a device. While the count in the device
+ *      remains above zero the interface remains promiscuous. Once it hits zero
+ *      the device reverts back to normal filtering operation. A negative inc
+ *      value is used to drop promiscuity on the device.
+ */
+void dev_set_promiscuity(struct net_device *dev, int inc)
+{
+        unsigned short old_flags = dev->flags;
+
+        __dev_set_promiscuity(dev, inc);
+        if (dev->flags != old_flags)
+                dev_set_rx_mode(dev);
+}
+
+/**
  *      dev_set_allmulti        - update allmulti count on a device
  *      @dev: device
  *      @inc: modifier
@@ -2550,7 +2558,48 @@ void dev_set_allmulti(struct net_device *dev, int inc)
         if ((dev->allmulti += inc) == 0)
                 dev->flags &= ~IFF_ALLMULTI;
         if (dev->flags ^ old_flags)
-                dev_mc_upload(dev);
+                dev_set_rx_mode(dev);
+}
+
+/*
+ *      Upload unicast and multicast address lists to device and
+ *      configure RX filtering. When the device doesn't support unicast
+ *      filtering it is put in promiscous mode while unicast addresses
+ *      are present.
+ */
+void __dev_set_rx_mode(struct net_device *dev)
+{
+        /* dev_open will call this function so the list will stay sane. */
+        if (!(dev->flags&IFF_UP))
+                return;
+
+        if (!netif_device_present(dev))
+                return;
+
+        if (dev->set_rx_mode)
+                dev->set_rx_mode(dev);
+        else {
+                /* Unicast addresses changes may only happen under the rtnl,
+                 * therefore calling __dev_set_promiscuity here is safe.
+                 */
+                if (dev->uc_count > 0 && !dev->uc_promisc) {
+                        __dev_set_promiscuity(dev, 1);
+                        dev->uc_promisc = 1;
+                } else if (dev->uc_count == 0 && dev->uc_promisc) {
+                        __dev_set_promiscuity(dev, -1);
+                        dev->uc_promisc = 0;
+                }
+
+                if (dev->set_multicast_list)
+                        dev->set_multicast_list(dev);
+        }
+}
+
+void dev_set_rx_mode(struct net_device *dev)
+{
+        netif_tx_lock_bh(dev);
+        __dev_set_rx_mode(dev);
+        netif_tx_unlock_bh(dev);
 }
 
 int __dev_addr_delete(struct dev_addr_list **list, void *addr, int alen,
@@ -2622,6 +2671,66 @@ void __dev_addr_discard(struct dev_addr_list **list)
         }
 }
 
+/**
+ *      dev_unicast_delete      - Release secondary unicast address.
+ *      @dev: device
+ *
+ *      Release reference to a secondary unicast address and remove it
+ *      from the device if the reference count drop to zero.
+ *
+ *      The caller must hold the rtnl_mutex.
+ */
+int dev_unicast_delete(struct net_device *dev, void *addr, int alen)
+{
+        int err;
+
+        ASSERT_RTNL();
+
+        netif_tx_lock_bh(dev);
+        err = __dev_addr_delete(&dev->uc_list, addr, alen, 0);
+        if (!err) {
+                dev->uc_count--;
+                __dev_set_rx_mode(dev);
+        }
+        netif_tx_unlock_bh(dev);
+        return err;
+}
+EXPORT_SYMBOL(dev_unicast_delete);
+
+/**
+ *      dev_unicast_add         - add a secondary unicast address
+ *      @dev: device
+ *
+ *      Add a secondary unicast address to the device or increase
+ *      the reference count if it already exists.
+ *
+ *      The caller must hold the rtnl_mutex.
+ */
+int dev_unicast_add(struct net_device *dev, void *addr, int alen)
+{
+        int err;
+
+        ASSERT_RTNL();
+
+        netif_tx_lock_bh(dev);
+        err = __dev_addr_add(&dev->uc_list, addr, alen, 0);
+        if (!err) {
+                dev->uc_count++;
+                __dev_set_rx_mode(dev);
+        }
+        netif_tx_unlock_bh(dev);
+        return err;
+}
+EXPORT_SYMBOL(dev_unicast_add);
+
+static void dev_unicast_discard(struct net_device *dev)
+{
+        netif_tx_lock_bh(dev);
+        __dev_addr_discard(&dev->uc_list);
+        dev->uc_count = 0;
+        netif_tx_unlock_bh(dev);
+}
+
 unsigned dev_get_flags(const struct net_device *dev)
 {
         unsigned flags;
@@ -2665,7 +2774,7 @@ int dev_change_flags(struct net_device *dev, unsigned flags)
          *      Load in the correct multicast list now the flags have changed.
          */
 
-        dev_mc_upload(dev);
+        dev_set_rx_mode(dev);
 
         /*
          *      Have we downed the interface. We handle IFF_UP ourselves
@@ -2678,7 +2787,7 @@ int dev_change_flags(struct net_device *dev, unsigned flags)
                 ret = ((old_flags & IFF_UP) ? dev_close : dev_open)(dev);
 
                 if (!ret)
-                        dev_mc_upload(dev);
+                        dev_set_rx_mode(dev);
         }
 
         if (dev->flags & IFF_UP &&
@@ -3558,8 +3667,9 @@ void unregister_netdevice(struct net_device *dev)
         raw_notifier_call_chain(&netdev_chain, NETDEV_UNREGISTER, dev);
 
         /*
-         *      Flush the multicast chain
+         *      Flush the unicast and multicast chains
          */
+        dev_unicast_discard(dev);
         dev_mc_discard(dev);
 
         if (dev->uninit)
diff --git a/net/core/dev_mcast.c b/net/core/dev_mcast.c
index 702907434a47..5cc9b448c443 100644
--- a/net/core/dev_mcast.c
+++ b/net/core/dev_mcast.c
@@ -64,39 +64,6 @@
  */
 
 /*
- *      Update the multicast list into the physical NIC controller.
- */
-
-static void __dev_mc_upload(struct net_device *dev)
-{
-        /* Don't do anything till we up the interface
-         * [dev_open will call this function so the list will
-         * stay sane]
-         */
-
-        if (!(dev->flags&IFF_UP))
-                return;
-
-        /*
-         *      Devices with no set multicast or which have been
-         *      detached don't get set.
-         */
-
-        if (dev->set_multicast_list == NULL ||
-            !netif_device_present(dev))
-                return;
-
-        dev->set_multicast_list(dev);
-}
-
-void dev_mc_upload(struct net_device *dev)
-{
-        netif_tx_lock_bh(dev);
-        __dev_mc_upload(dev);
-        netif_tx_unlock_bh(dev);
-}
-
-/*
  *      Delete a device level multicast
  */
 
@@ -114,7 +81,7 @@ int dev_mc_delete(struct net_device *dev, void *addr, int alen, int glbl)
                  *      loaded filter is now wrong. Fix it
                  */
 
-                __dev_mc_upload(dev);
+                __dev_set_rx_mode(dev);
         }
         netif_tx_unlock_bh(dev);
         return err;
@@ -132,7 +99,7 @@ int dev_mc_add(struct net_device *dev, void *addr, int alen, int glbl)
         err = __dev_addr_add(&dev->mc_list, addr, alen, glbl);
         if (!err) {
                 dev->mc_count++;
-                __dev_mc_upload(dev);
+                __dev_set_rx_mode(dev);
         }
         netif_tx_unlock_bh(dev);
         return err;