Merge branch 'macvlan-Fix-some-issues-with-changing-mac-addresses'

Vladislav Yasevich says:

====================
macvlan: Fix some issues with changing mac addresses

There are some issues in macvlan wrt to changing it's mac address.
* An error is returned in the specified address is the same as an already
  assigned address.
* In passthru mode, the mac address of the macvlan device doesn't change.
* After changing the mac address of a passthru macvlan and then removing it,
  the mac address of the physical device remains changed.

This patch series attempts to resolve these issues.

V2: Address a small issue in p4 where we save the address from the lowerdev
    (from girish.moodalbail@oracle.com)
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/macvlan.c

@@ -39,16 +39,20 @@
 #define MACVLAN_HASH_SIZE	(1<<MACVLAN_HASH_BITS)
 #define MACVLAN_BC_QUEUE_LEN	1000
 
+#define MACVLAN_F_PASSTHRU	1
+#define MACVLAN_F_ADDRCHANGE	2
+
 struct macvlan_port {
 	struct net_device	*dev;
 	struct hlist_head	vlan_hash[MACVLAN_HASH_SIZE];
 	struct list_head	vlans;
 	struct sk_buff_head	bc_queue;
 	struct work_struct	bc_work;
-	bool 			passthru;
+	u32			flags;
 	int			count;
 	struct hlist_head	vlan_source_hash[MACVLAN_HASH_SIZE];
 	DECLARE_BITMAP(mc_filter, MACVLAN_MC_FILTER_SZ);
+	unsigned char           perm_addr[ETH_ALEN];
 };
 
 struct macvlan_source_entry {
@@ -66,6 +70,31 @@ struct macvlan_skb_cb {
 
 static void macvlan_port_destroy(struct net_device *dev);
 
+static inline bool macvlan_passthru(const struct macvlan_port *port)
+{
+	return port->flags & MACVLAN_F_PASSTHRU;
+}
+
+static inline void macvlan_set_passthru(struct macvlan_port *port)
+{
+	port->flags |= MACVLAN_F_PASSTHRU;
+}
+
+static inline bool macvlan_addr_change(const struct macvlan_port *port)
+{
+	return port->flags & MACVLAN_F_ADDRCHANGE;
+}
+
+static inline void macvlan_set_addr_change(struct macvlan_port *port)
+{
+	port->flags |= MACVLAN_F_ADDRCHANGE;
+}
+
+static inline void macvlan_clear_addr_change(struct macvlan_port *port)
+{
+	port->flags &= ~MACVLAN_F_ADDRCHANGE;
+}
+
 /* Hash Ethernet address */
 static u32 macvlan_eth_hash(const unsigned char *addr)
 {
@@ -181,11 +210,12 @@ static void macvlan_hash_change_addr(struct macvlan_dev *vlan,
 static bool macvlan_addr_busy(const struct macvlan_port *port,
 			      const unsigned char *addr)
 {
-	/* Test to see if the specified multicast address is
+	/* Test to see if the specified address is
 	 * currently in use by the underlying device or
 	 * another macvlan.
 	 */
-	if (ether_addr_equal_64bits(port->dev->dev_addr, addr))
+	if (!macvlan_passthru(port) && !macvlan_addr_change(port) &&
+	    ether_addr_equal_64bits(port->dev->dev_addr, addr))
 		return true;
 
 	if (macvlan_hash_lookup(port, addr))
@@ -445,7 +475,7 @@ static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb)
 	}
 
 	macvlan_forward_source(skb, port, eth->h_source);
-	if (port->passthru)
+	if (macvlan_passthru(port))
 		vlan = list_first_or_null_rcu(&port->vlans,
 					      struct macvlan_dev, list);
 	else
@@ -574,7 +604,7 @@ static int macvlan_open(struct net_device *dev)
 	struct net_device *lowerdev = vlan->lowerdev;
 	int err;
 
-	if (vlan->port->passthru) {
+	if (macvlan_passthru(vlan->port)) {
 		if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC)) {
 			err = dev_set_promiscuity(lowerdev, 1);
 			if (err < 0)
@@ -649,7 +679,7 @@ static int macvlan_stop(struct net_device *dev)
 	dev_uc_unsync(lowerdev, dev);
 	dev_mc_unsync(lowerdev, dev);
 
-	if (vlan->port->passthru) {
+	if (macvlan_passthru(vlan->port)) {
 		if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC))
 			dev_set_promiscuity(lowerdev, -1);
 		goto hash_del;
@@ -672,6 +702,7 @@ static int macvlan_sync_address(struct net_device *dev, unsigned char *addr)
 {
 	struct macvlan_dev *vlan = netdev_priv(dev);
 	struct net_device *lowerdev = vlan->lowerdev;
+	struct macvlan_port *port = vlan->port;
 	int err;
 
 	if (!(dev->flags & IFF_UP)) {
@@ -682,7 +713,7 @@ static int macvlan_sync_address(struct net_device *dev, unsigned char *addr)
 		if (macvlan_addr_busy(vlan->port, addr))
 			return -EBUSY;
 
-		if (!vlan->port->passthru) {
+		if (!macvlan_passthru(port)) {
 			err = dev_uc_add(lowerdev, addr);
 			if (err)
 				return err;
@@ -692,6 +723,15 @@ static int macvlan_sync_address(struct net_device *dev, unsigned char *addr)
 
 		macvlan_hash_change_addr(vlan, addr);
 	}
+	if (macvlan_passthru(port) && !macvlan_addr_change(port)) {
+		/* Since addr_change isn't set, we are here due to lower
+		 * device change.  Save the lower-dev address so we can
+		 * restore it later.
+		 */
+		ether_addr_copy(vlan->port->perm_addr,
+				lowerdev->dev_addr);
+	}
+	macvlan_clear_addr_change(port);
 	return 0;
 }
 
@@ -703,7 +743,12 @@ static int macvlan_set_mac_address(struct net_device *dev, void *p)
 	if (!is_valid_ether_addr(addr->sa_data))
 		return -EADDRNOTAVAIL;
 
+	/* If the addresses are the same, this is a no-op */
+	if (ether_addr_equal(dev->dev_addr, addr->sa_data))
+		return 0;
+
 	if (vlan->mode == MACVLAN_MODE_PASSTHRU) {
+		macvlan_set_addr_change(vlan->port);
 		dev_set_mac_address(vlan->lowerdev, addr);
 		return 0;
 	}
@@ -928,7 +973,7 @@ static int macvlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 	/* Support unicast filter only on passthru devices.
 	 * Multicast filter should be allowed on all devices.
 	 */
-	if (!vlan->port->passthru && is_unicast_ether_addr(addr))
+	if (!macvlan_passthru(vlan->port) && is_unicast_ether_addr(addr))
 		return -EOPNOTSUPP;
 
 	if (flags & NLM_F_REPLACE)
@@ -952,7 +997,7 @@ static int macvlan_fdb_del(struct ndmsg *ndm, struct nlattr *tb[],
 	/* Support unicast filter only on passthru devices.
 	 * Multicast filter should be allowed on all devices.
 	 */
-	if (!vlan->port->passthru && is_unicast_ether_addr(addr))
+	if (!macvlan_passthru(vlan->port) && is_unicast_ether_addr(addr))
 		return -EOPNOTSUPP;
 
 	if (is_unicast_ether_addr(addr))
@@ -1120,8 +1165,8 @@ static int macvlan_port_create(struct net_device *dev)
 	if (port == NULL)
 		return -ENOMEM;
 
-	port->passthru = false;
 	port->dev = dev;
+	ether_addr_copy(port->perm_addr, dev->dev_addr);
 	INIT_LIST_HEAD(&port->vlans);
 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
@@ -1161,6 +1206,18 @@ static void macvlan_port_destroy(struct net_device *dev)
 		kfree_skb(skb);
 	}
 
+	/* If the lower device address has been changed by passthru
+	 * macvlan, put it back.
+	 */
+	if (macvlan_passthru(port) &&
+	    !ether_addr_equal(port->dev->dev_addr, port->perm_addr)) {
+		struct sockaddr sa;
+
+		sa.sa_family = port->dev->type;
+		memcpy(&sa.sa_data, port->perm_addr, port->dev->addr_len);
+		dev_set_mac_address(port->dev, &sa);
+	}
+
 	kfree(port);
 }
 
@@ -1326,7 +1383,7 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
 	port = macvlan_port_get_rtnl(lowerdev);
 
 	/* Only 1 macvlan device can be created in passthru mode */
-	if (port->passthru) {
+	if (macvlan_passthru(port)) {
 		/* The macvlan port must be not created this time,
 		 * still goto destroy_macvlan_port for readability.
 		 */
@@ -1352,7 +1409,7 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
 			err = -EINVAL;
 			goto destroy_macvlan_port;
 		}
-		port->passthru = true;
+		macvlan_set_passthru(port);
 		eth_hw_addr_inherit(dev, lowerdev);
 	}
 
@@ -1434,7 +1491,7 @@ static int macvlan_changelink(struct net_device *dev,
 	if (data && data[IFLA_MACVLAN_FLAGS]) {
 		__u16 flags = nla_get_u16(data[IFLA_MACVLAN_FLAGS]);
 		bool promisc = (flags ^ vlan->flags) & MACVLAN_FLAG_NOPROMISC;
-		if (vlan->port->passthru && promisc) {
+		if (macvlan_passthru(vlan->port) && promisc) {
 			int err;
 
 			if (flags & MACVLAN_FLAG_NOPROMISC)
@@ -1597,7 +1654,7 @@ static int macvlan_device_event(struct notifier_block *unused,
 		}
 		break;
 	case NETDEV_CHANGEADDR:
-		if (!port->passthru)
+		if (!macvlan_passthru(port))
 			return NOTIFY_DONE;
 
 		vlan = list_first_entry_or_null(&port->vlans,