From 8dac05c59bf79ec6f88ca07187677fa43d737642 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 13 Jun 2013 10:07:29 +0300 Subject: [PATCH] macvlan: don't touch promisc without passthrough commit a3e17141dde26b498f4a33e8139dfe0fc2e874d2 "macvlan: add FDB bridge ops and macvlan flags" added a way to control NOPROMISC macvlan flag through netlink. However, with a non passthrough device we never set promisc on open, even if NOPROMISC is off. As a result: If userspace clears NOPROMISC on open, then does not clear it on a netlink command, promisc counter is not decremented on stop and there will be no way to clear it once macvlan is detached. If userspace does not clear NOPROMISC on open, then sets NOPROMISC on a netlink command, promisc counter will be decremented from 0 and overflow to fffffffff with no way to clear promisc. To fix, simply ignore NOPROMISC flag in a netlink command for non-passthrough devices, same as we do at open/close. Since we touch this code anyway - check dev_set_promiscuity return code and pass it to users (though an error here is unlikely). Cc: "David S. Miller" Reviewed-by: John Fastabend Signed-off-by: Michael S. Tsirkin Signed-off-by: David S. Miller --- drivers/net/macvlan.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index 1c502bb0c916f..6e91931a1c2ca 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -853,18 +853,24 @@ static int macvlan_changelink(struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { struct macvlan_dev *vlan = netdev_priv(dev); - if (data && data[IFLA_MACVLAN_MODE]) - vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]); + if (data && data[IFLA_MACVLAN_FLAGS]) { __u16 flags = nla_get_u16(data[IFLA_MACVLAN_FLAGS]); bool promisc = (flags ^ vlan->flags) & MACVLAN_FLAG_NOPROMISC; - - if (promisc && (flags & MACVLAN_FLAG_NOPROMISC)) - dev_set_promiscuity(vlan->lowerdev, -1); - else if (promisc && !(flags & MACVLAN_FLAG_NOPROMISC)) - dev_set_promiscuity(vlan->lowerdev, 1); + if (vlan->port->passthru && promisc) { + int err; + + if (flags & MACVLAN_FLAG_NOPROMISC) + err = dev_set_promiscuity(vlan->lowerdev, -1); + else + err = dev_set_promiscuity(vlan->lowerdev, 1); + if (err < 0) + return err; + } vlan->flags = flags; } + if (data && data[IFLA_MACVLAN_MODE]) + vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]); return 0; } -- 2.39.5