[RFC PATCH] macvlan: add FDB bridge ops

[John Fastabend <john.r.fastabend@intel.com>]

Add support to add/del and dump the forwarding database
for macvlan passthru mode. The macvlan driver acts like
a Two Port Mac Relay (TPMR 802.1Q-2011) in the passthru
case so adding forwarding rules is just adding the addr
to the uc or mc lists.

By default the passthru mode puts the lowerdev into a
promiscuous mode to receive all packets. This behavior
is not changed by this patch. This is a bit problematic
and needs to be solved without IMHO breaking existing
mechanics. Maybe on the first add_fdb we can decrement
the promisc mode? That seems to work reasonable well and
keep existing functionality in place... but requires
an initial add to set things up which is a bit annoying
so maybe a flag is better. I haven't thought too hard
about it yet so any ideas welcome

This patch is a result of Roopa Prabhu's work. Follow up
patches are needed for VEPA and VEB macvlan modes.

Only lightly touch tested at this point.

CC: Roopa Prabhu <roprabhu@cisco.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
---

 drivers/net/macvlan.c |   42 ++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 42 insertions(+), 0 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index f975afd..86af56b 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -349,6 +349,7 @@ static int macvlan_stop(struct net_device *dev)
 		goto hash_del;
 	}
 
+	dev_uc_unsync(lowerdev, dev);
 	dev_mc_unsync(lowerdev, dev);
 	if (dev->flags & IFF_ALLMULTI)
 		dev_set_allmulti(lowerdev, -1);
@@ -403,6 +404,7 @@ static void macvlan_set_multicast_list(struct net_device *dev)
 {
 	struct macvlan_dev *vlan = netdev_priv(dev);
 
+	dev_uc_sync(vlan->lowerdev, dev);
 	dev_mc_sync(vlan->lowerdev, dev);
 }
 
@@ -542,6 +544,43 @@ static int macvlan_vlan_rx_kill_vid(struct net_device *dev,
 	return 0;
 }
 
+static int macvlan_fdb_add(struct ndmsg *ndm,
+			   struct net_device *dev,
+			   unsigned char *addr,
+			   u16 flags)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	int err = -EINVAL;
+
+	if (!vlan->port->passthru)
+		return -EOPNOTSUPP;
+
+	if (is_unicast_ether_addr(addr))
+		err = dev_uc_add(dev, addr);
+	else if (is_multicast_ether_addr(addr))
+		err = dev_mc_add(dev, addr);
+
+	return err;
+}
+
+static int macvlan_fdb_del(struct ndmsg *ndm,
+			   struct net_device *dev,
+			   unsigned char *addr)
+{
+	struct macvlan_dev *vlan = netdev_priv(dev);
+	int err = -EINVAL;
+
+	if (!vlan->port->passthru)
+		return -EOPNOTSUPP;
+
+	if (is_unicast_ether_addr(addr))
+		err = dev_uc_del(dev, addr);
+	else if (is_multicast_ether_addr(addr))
+		err = dev_mc_del(dev, addr);
+
+	return err;
+}
+
 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
 					struct ethtool_drvinfo *drvinfo)
 {
@@ -577,6 +616,9 @@ static const struct net_device_ops macvlan_netdev_ops = {
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_vlan_rx_add_vid	= macvlan_vlan_rx_add_vid,
 	.ndo_vlan_rx_kill_vid	= macvlan_vlan_rx_kill_vid,
+	.ndo_fdb_add		= macvlan_fdb_add,
+	.ndo_fdb_del		= macvlan_fdb_del,
+	.ndo_fdb_dump		= ndo_dflt_fdb_dump,
 };
 
 void macvlan_common_setup(struct net_device *dev)