Re: [net-next 06/12] i40e/ixgbe/igb: fail on new WoL flag setting WAKE_MAGICSECURE

[Jeff Kirsher <jeffrey.t.kirsher@intel.com>]

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On Thu, 2018-11-08 at 07:42 +0100, Michal Kubecek wrote:
> On Thu, Nov 08, 2018 at 06:05:26AM +0000, Kevin Easton wrote:
> > On Wed, Nov 07, 2018 at 02:48:24PM -0800, Jeff Kirsher wrote:
> > > From: Todd Fujinaka <todd.fujinaka@intel.com>
> > > 
> > > There's a new flag for setting WoL filters that is only
> > > enabled on one manufacturer's NICs, and it's not ours. Fail
> > > with EOPNOTSUPP.
> > > 
> > > Signed-off-by: Todd Fujinaka <todd.fujinaka@intel.com>
> > > Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
> > > Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> > > ---
> > >  drivers/net/ethernet/intel/i40e/i40e_ethtool.c   | 3 ++-
> > >  drivers/net/ethernet/intel/igb/igb_ethtool.c     | 2 +-
> > >  drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c | 3 ++-
> > >  3 files changed, 5 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> > > b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> > > index 9f8464f80783..9c1211ad2c6b 100644
> > > --- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> > > +++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> > > @@ -2377,7 +2377,8 @@ static int i40e_set_wol(struct net_device
> > > *netdev, struct ethtool_wolinfo *wol)
> > >  		return -EOPNOTSUPP;
> > >  
> > >  	/* only magic packet is supported */
> > > -	if (wol->wolopts && (wol->wolopts != WAKE_MAGIC))
> > > +	if (wol->wolopts && (wol->wolopts != WAKE_MAGIC)
> > > +			  | (wol->wolopts != WAKE_FILTER))
> > >  		return -EOPNOTSUPP;
> > 
> > This doesn't look right.  WAKE_MAGIC and WAKE_FILTER are distinct, so
> > 
> > (wol->wolopts != WAKE_MAGIC) | (wol->wolopts != WAKE_FILTER)
> > 
> > will always be 1.
> 
> Right. Also, using "|" with logical values is rather confusing. While
> the result works as expected, its priority is higher than priority of
> && (which would not be true for ||), making the code counterintuitive.
> 
> BtW, the patch subject is also wrong, the newly added flag it is dealing
> with is WAKE_FILTER, not WAKE_MAGICSECURE.

After looking into this this more, this does appear to be incorrect.  The
author of this change is currently out on vacation, so once he gets back, I
will address both Kevin's and your concerns.

> 
> > It looks like the existing test in this driver was fine - it *only*
> > accepted wol->wolopts of either 0 or WAKE_MAGIC, it was already
> > rejecting everything else including WAKE_FILTER.
> 
> Another way to write the check would be
> 
> 	if (wol->wolopts & ~WAKE_MAGIC)
> 
> > > diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c
> > > b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> > > index 5acf3b743876..c57671068245 100644
> > > --- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
> > > +++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
> > > @@ -2113,7 +2113,7 @@ static int igb_set_wol(struct net_device
> > > *netdev, struct ethtool_wolinfo *wol)
> > >  {
> > >  	struct igb_adapter *adapter = netdev_priv(netdev);
> > >  
> > > -	if (wol->wolopts & (WAKE_ARP | WAKE_MAGICSECURE))
> > > +	if (wol->wolopts & (WAKE_ARP | WAKE_MAGICSECURE | WAKE_FILTER))
> > >  		return -EOPNOTSUPP;
> > >  
> > >  	if (!(adapter->flags & IGB_FLAG_WOL_SUPPORTED))
> 
> I would also suggest taking the opposite approach here, i.e. listing the
> flags which _are_ supported so that we don't have to update the code if
> another wol flag is added (or userspace sends an invalid one):
> 
> #define SUPPORTED_WOL_MODES \
> 	(WAKE_PHY | WAKE_UCAST | WAKE_MCAST | WAKE_BCAST | WAKE_MAGIC)
> ...
> 	if (wol->wolopts & ~SUPPORTED_WOL_MODES)
> 		return -EOPNOTSUPP;
> 
> 
> > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
> > > b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
> > > index 732b1e6ecc43..acba067cc15a 100644
> > > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
> > > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
> > > @@ -2206,7 +2206,8 @@ static int ixgbe_set_wol(struct net_device
> > > *netdev, struct ethtool_wolinfo *wol)
> > >  {
> > >  	struct ixgbe_adapter *adapter = netdev_priv(netdev);
> > >  
> > > -	if (wol->wolopts & (WAKE_PHY | WAKE_ARP | WAKE_MAGICSECURE))
> > > +	if (wol->wolopts & (WAKE_PHY | WAKE_ARP | WAKE_MAGICSECURE |
> > > +			    WAKE_FILTER))
> > >  		return -EOPNOTSUPP;
> > >  
> > >  	if (ixgbe_wol_exclusion(adapter, wol))
> 
> ...and here.
> 
> Michal Kubecek


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