On Mon, Jun 3, 2019 at 11:22 AM Young Xiao <92siuy...@gmail.com> wrote:
>
> Clearing the IFF_ALLMULTI flag on a down interface could cause an allmulti
> overflow on the underlying interface.
>
> Attempting the set IFF_ALLMULTI on the underlying interface would cause an
> error and the log message:
>
> "allmulti touches root, set allmulti failed."
s/root/roof
I guess this patch was inspired by:
commit bbeb0eadcf9fe74fb2b9b1a6fea82cd538b1e556
Author: Peter Christensen <p...@ordbogen.com>
Date: Thu May 8 11:15:37 2014 +0200
macvlan: Don't propagate IFF_ALLMULTI changes on down interfaces.
I could trigger this error on macvlan prior to this patch with:
# ip link add mymacvlan1 link eth2 type macvlan mode bridge
# ip link set mymacvlan1 up
# ip link set mymacvlan1 allmulticast on
# ip link set mymacvlan1 down
# ip link set mymacvlan1 allmulticast off
# ip link set mymacvlan1 allmulticast on
but not on ipvlan, could you?
macvlan had this problem, as lowerdev's allmulticast is cleared when doing
dev_stop and set when doing dev_open, which doesn't happen on ipvlan.
So I'd think this patch fixes nothing unless you want to add
dev_set_allmulti(1/-1) in ipvlan_open/stop(), but that's another topic.
did I miss something?
>
> Signed-off-by: Young Xiao <92siuy...@gmail.com>
> ---
> drivers/net/ipvlan/ipvlan_main.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ipvlan/ipvlan_main.c
> b/drivers/net/ipvlan/ipvlan_main.c
> index bbeb162..523bb83 100644
> --- a/drivers/net/ipvlan/ipvlan_main.c
> +++ b/drivers/net/ipvlan/ipvlan_main.c
> @@ -242,8 +242,10 @@ static void ipvlan_change_rx_flags(struct net_device
> *dev, int change)
> struct ipvl_dev *ipvlan = netdev_priv(dev);
> struct net_device *phy_dev = ipvlan->phy_dev;
>
> - if (change & IFF_ALLMULTI)
> - dev_set_allmulti(phy_dev, dev->flags & IFF_ALLMULTI? 1 : -1);
> + if (dev->flags & IFF_UP) {
> + if (change & IFF_ALLMULTI)
> + dev_set_allmulti(phy_dev, dev->flags & IFF_ALLMULTI ?
> 1 : -1);
> + }
> }
>
> static void ipvlan_set_multicast_mac_filter(struct net_device *dev)
> --
> 2.7.4
>
