macvlan: Allow setting multicast filter on all macvlan types

Currently, macvlan code restricts multicast and unicast
filter setting only to passthru devices.  As a result,
if a guest using macvtap wants to receive multicast
traffic, it has to set IFF_ALLMULTI or IFF_PROMISC.

This patch makes it possible to use the fdb interface
to add multicast addresses to the filter thus allowing
a guest to receive only targeted multicast traffic.

CC: John Fastabend <john.r.fastabend@intel.com>
CC: Michael S. Tsirkin <mst@redhat.com>
CC: Jason Wang <jasowang@redhat.com>
Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 60e4ca01ccbb..a96955597755 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -739,7 +739,10 @@ static int macvlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
         struct macvlan_dev *vlan = netdev_priv(dev);
         int err = -EINVAL;
 
-        if (!vlan->port->passthru)
+        /* Support unicast filter only on passthru devices.
+         * Multicast filter should be allowed on all devices.
+         */
+        if (!vlan->port->passthru && is_unicast_ether_addr(addr))
                 return -EOPNOTSUPP;
 
         if (flags & NLM_F_REPLACE)
@@ -760,7 +763,10 @@ static int macvlan_fdb_del(struct ndmsg *ndm, struct nlattr *tb[],
         struct macvlan_dev *vlan = netdev_priv(dev);
         int err = -EINVAL;
 
-        if (!vlan->port->passthru)
+        /* Support unicast filter only on passthru devices.
+         * Multicast filter should be allowed on all devices.
+         */
+        if (!vlan->port->passthru && is_unicast_ether_addr(addr))
                 return -EOPNOTSUPP;
 
         if (is_unicast_ether_addr(addr))