[PATCHv3 net 2/2] team: reset team's flags when down link is P2P device

[Hangbin Liu <liuhangbin@gmail.com>]

When adding a point to point downlink to team device, we neglected to reset
the team's flags, which were still using flags like BROADCAST and
MULTICAST. Consequently, this would initiate ARP/DAD for P2P downlink
interfaces, such as when adding a GRE device to team device. Fix this by
remove multicast/broadcast flags and add p2p and noarp flags.

After removing the none ethernet interface and adding an ethernet interface
to team, we need to reset team interface flags and hw address back. Unlike
bonding interface, team do not need restore IFF_MASTER, IFF_SLAVE flags.

Reported-by: Liang Li <liali@redhat.com>
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2221438
Fixes: 1d76efe1577b ("team: add support for non-ethernet devices")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
v3: add function team_ether_setup to reset team back to ethernet.
v2: Add the missed {} after if checking.
---
 drivers/net/team/team.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 555b0b1e9a78..2e124a3b81d1 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -2135,6 +2135,20 @@ static void team_setup_by_port(struct net_device *dev,
 	dev->mtu = port_dev->mtu;
 	memcpy(dev->broadcast, port_dev->broadcast, port_dev->addr_len);
 	eth_hw_addr_inherit(dev, port_dev);
+
+	if (port_dev->flags & IFF_POINTOPOINT) {
+		dev->flags &= ~(IFF_BROADCAST | IFF_MULTICAST);
+		dev->flags |= (IFF_POINTOPOINT | IFF_NOARP);
+	}
+}
+
+static void team_ether_setup(struct net_device *dev)
+{
+	unsigned int flags = dev->flags & IFF_UP;
+
+	ether_setup(dev);
+	dev->flags |= flags;
+	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 }
 
 static int team_dev_type_check_change(struct net_device *dev,
@@ -2158,7 +2172,14 @@ static int team_dev_type_check_change(struct net_device *dev,
 	}
 	dev_uc_flush(dev);
 	dev_mc_flush(dev);
-	team_setup_by_port(dev, port_dev);
+
+	if (port_dev->type != ARPHRD_ETHER) {
+		team_setup_by_port(dev, port_dev);
+	} else {
+		team_ether_setup(dev);
+		eth_hw_addr_inherit(dev, port_dev);
+	}
+
 	call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
 	return 0;
 }
-- 
2.38.1