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vlan: Propagate MAC address to VLANs

PATCH Applied Mike Manning 2 participants 2 messages May 27, 2016 – May 31, 2016 1 message not in the archive

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Networking Network drivers
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A message that is not in the archive (sent off-list or not yet received): [email protected]

Mike Manning

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#1 lore raw

PATCH v5 1/1 vlan: Propagate MAC address to VLANs

The MAC address of the physical interface is only copied to the VLAN when it is first created, resulting in an inconsistency after MAC address changes of only newly created VLANs having an up-to-date MAC.

The VLANs should continue inheriting the MAC address of the physical interface until the VLAN MAC address is explicitly set to any value. This allows IPv6 EUI64 addresses for the VLAN to reflect any changes to the MAC of the physical interface and thus for DAD to behave as expected.

Signed-off-by Mike Manning <[email protected]>
---
 net/8021q/vlan.c     |    5 +++++
 net/8021q/vlan.h     |    2 ++
 net/8021q/vlan_dev.c |   20 +++++++++++++++++---
 3 files changed, 24 insertions(+), 3 deletions(-)
net/8021q/vlan.c +5 -0
@@ -291,6 +291,10 @@ static void vlan_sync_address(struct net
 	if (ether_addr_equal(vlan->real_dev_addr, dev->dev_addr))
 		return;
 
+	/* vlan continues to inherit address of lower device */
+	if (vlan_dev_inherit_address(vlandev, dev))
+		goto out;
+
 	/* vlan address was different from the old address and is equal to
 	 * the new address */
 	if (!ether_addr_equal(vlandev->dev_addr, vlan->real_dev_addr) &&

@@ -303,6 +307,7 @@ static void vlan_sync_address(struct net
 	    !ether_addr_equal(vlandev->dev_addr, dev->dev_addr))
 		dev_uc_add(dev, vlandev->dev_addr);
 
+out:
 	ether_addr_copy(vlan->real_dev_addr, dev->dev_addr);
 }
net/8021q/vlan.h +2 -0
@@ -109,6 +109,8 @@ int vlan_check_real_dev(struct net_devic
 void vlan_setup(struct net_device *dev);
 int register_vlan_dev(struct net_device *dev);
 void unregister_vlan_dev(struct net_device *dev, struct list_head *head);
+bool vlan_dev_inherit_address(struct net_device *dev,
+			      struct net_device *real_dev);
 
 static inline u32 vlan_get_ingress_priority(struct net_device *dev,
 					    u16 vlan_tci)
net/8021q/vlan_dev.c +17 -3
@@ -244,6 +244,17 @@ void vlan_dev_get_realdev_name(const str
 	strncpy(result, vlan_dev_priv(dev)->real_dev->name, 23);
 }
 
+bool vlan_dev_inherit_address(struct net_device *dev,
+			      struct net_device *real_dev)
+{
+	if (dev->addr_assign_type != NET_ADDR_STOLEN)
+		return false;
+
+	ether_addr_copy(dev->dev_addr, real_dev->dev_addr);
+	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
+	return true;
+}
+
 static int vlan_dev_open(struct net_device *dev)
 {
 	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);

@@ -254,7 +265,8 @@ static int vlan_dev_open(struct net_devi
 	    !(vlan->flags & VLAN_FLAG_LOOSE_BINDING))
 		return -ENETDOWN;
 
-	if (!ether_addr_equal(dev->dev_addr, real_dev->dev_addr)) {
+	if (!ether_addr_equal(dev->dev_addr, real_dev->dev_addr) &&
+	    !vlan_dev_inherit_address(dev, real_dev)) {
 		err = dev_uc_add(real_dev, dev->dev_addr);
 		if (err < 0)
 			goto out;

@@ -558,8 +570,10 @@ static int vlan_dev_init(struct net_devi
 	/* ipv6 shared card related stuff */
 	dev->dev_id = real_dev->dev_id;
 
-	if (is_zero_ether_addr(dev->dev_addr))
-		eth_hw_addr_inherit(dev, real_dev);
+	if (is_zero_ether_addr(dev->dev_addr)) {
+		ether_addr_copy(dev->dev_addr, real_dev->dev_addr);
+		dev->addr_assign_type = NET_ADDR_STOLEN;
+	}
 	if (is_zero_ether_addr(dev->broadcast))
 		memcpy(dev->broadcast, real_dev->broadcast, dev->addr_len);
Signature · 1 line
1.7.10.4
maintainer Applied
#2 lore raw

From: Mike Manning <[email protected]>
Date: Fri, 27 May 2016 17:45:07 +0100

Quoted 11 lines

The MAC address of the physical interface is only copied to the VLAN when it is first created, resulting in an inconsistency after MAC address changes of only newly created VLANs having an up-to-date MAC.

The VLANs should continue inheriting the MAC address of the physical interface until the VLAN MAC address is explicitly set to any value. This allows IPv6 EUI64 addresses for the VLAN to reflect any changes to the MAC of the physical interface and thus for DAD to behave as expected.

Signed-off-by Mike Manning <[email protected]>

Applied, thanks Mike.