[RFC PATCH net-next 2/5] net: 8021q: vlan_dev: add vid tag for uc and mc address lists

[Ivan Khoronzhuk]

Update vlan mc and uc addresses with VID tag while propagating address
set to lower devices, do this only if address is not synched. It allows
on end driver level to distinguish address belonging to vlans.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
---
 include/linux/if_vlan.h |  1 +
 net/8021q/vlan_core.c   | 10 ++++++++++
 net/8021q/vlan_dev.c    | 26 ++++++++++++++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 4cca4da7a6de..94657f3c483a 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -136,6 +136,7 @@ extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev,
 extern int vlan_for_each(struct net_device *dev,
 			 int (*action)(struct net_device *dev, int vid,
 				       void *arg), void *arg);
+extern u16 vlan_dev_get_addr_vid(struct net_device *dev, const u8 *addr);
 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 extern __be16 vlan_dev_vlan_proto(const struct net_device *dev);
diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c
index a313165e7a67..5d17947d6988 100644
--- a/net/8021q/vlan_core.c
+++ b/net/8021q/vlan_core.c
@@ -454,6 +454,16 @@ bool vlan_uses_dev(const struct net_device *dev)
 }
 EXPORT_SYMBOL(vlan_uses_dev);
 
+u16 vlan_dev_get_addr_vid(struct net_device *dev, const u8 *addr)
+{
+	u16 vid = 0;
+
+	vid = addr[dev->addr_len];
+	vid |= (addr[dev->addr_len + 1] & 0xf) << 8;
+	return vid;
+}
+EXPORT_SYMBOL(vlan_dev_get_addr_vid);
+
 static struct sk_buff *vlan_gro_receive(struct list_head *head,
 					struct sk_buff *skb)
 {
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index b2d9c8f27cd7..c05b313314b7 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -250,6 +250,14 @@ void vlan_dev_get_realdev_name(const struct net_device *dev, char *result)
 	strncpy(result, vlan_dev_priv(dev)->real_dev->name, 23);
 }
 
+static void vlan_dev_set_addr_vid(struct net_device *vlan_dev, u8 *addr)
+{
+	u16 vid = vlan_dev_vlan_id(vlan_dev);
+
+	addr[vlan_dev->addr_len] = vid & 0xff;
+	addr[vlan_dev->addr_len + 1] = (vid >> 8) & 0xf;
+}
+
 bool vlan_dev_inherit_address(struct net_device *dev,
 			      struct net_device *real_dev)
 {
@@ -481,8 +489,26 @@ static void vlan_dev_change_rx_flags(struct net_device *dev, int change)
 	}
 }
 
+static void vlan_dev_align_addr_vid(struct net_device *vlan_dev)
+{
+	struct net_device *real_dev = vlan_dev_real_dev(vlan_dev);
+	struct netdev_hw_addr *ha;
+
+	if (!real_dev->vid_len)
+		return;
+
+	netdev_for_each_mc_addr(ha, vlan_dev)
+		if (!ha->sync_cnt)
+			vlan_dev_set_addr_vid(vlan_dev, ha->addr);
+
+	netdev_for_each_uc_addr(ha, vlan_dev)
+		if (!ha->sync_cnt)
+			vlan_dev_set_addr_vid(vlan_dev, ha->addr);
+}
+
 static void vlan_dev_set_rx_mode(struct net_device *vlan_dev)
 {
+	vlan_dev_align_addr_vid(vlan_dev);
 	dev_mc_sync(vlan_dev_priv(vlan_dev)->real_dev, vlan_dev);
 	dev_uc_sync(vlan_dev_priv(vlan_dev)->real_dev, vlan_dev);
 }
-- 
2.17.1