Subject: Re: [net-next PATCH v1 7/7] macvlan: add FDB bridge ops and new macvlan mode

From: "Michael S. Tsirkin" <[email-masked]>
Date: Tue, 10 Apr 2012 11:14:18 +0300

On Tue, Apr 10, 2012 at 11:09:16AM +0300, Michael S. Tsirkin wrote:
> On Mon, Apr 09, 2012 at 03:00:54PM -0700, John Fastabend wrote:
> > This adds a new macvlan mode MACVLAN_PASSTHRU_NOPROMISC
> > this mode acts the same as the original passthru mode _except_
> > it does not set promiscuous mode on the lowerdev. Because the
> > lowerdev is not put in promiscuous mode any unicast or multicast
> > addresses the device should receive must be explicitely added
> > with the FDB bridge ops. In many use cases the management stack
> > will know the mac addresses needed (maybe negotiated via EVB/VDP)
> > or may require only receiving known "good" mac addresses. This
> > mode with the FDB ops supports this usage model.
> 
> 
> Looks good to me. Some questions below:
> 
> > This patch is a result of Roopa Prabhu's work. Follow up
> > patches are needed for VEPA and VEB macvlan modes.
> 
> And bridge too?
> 
> Also, my understanding is that other modes won't need a flag
> like this since they don't put the device in promisc mode initially,
> so no assumptions are broken if we require all addresses
> to be declared, right?
> 
> A final question: I think we'll later add a macvlan mode
> that does not flood all multicasts. This would change behaviour
> in an incompatible way so we'll probably need yet another
> flag. Would it make sense to combine this functionality
> with nopromisc so we have less modes to support?

One other question I forgot:

> > CC: Roopa Prabhu <[email-masked]>
> > CC: Michael S. Tsirkin <[email-masked]>
> > Signed-off-by: John Fastabend <[email-masked]>
> > ---
> > 
> >  drivers/net/macvlan.c   |   60 ++++++++++++++++++++++++++++++++++++++++++-----
> >  include/linux/if_link.h |    1 +
> >  2 files changed, 55 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> > index b17fc90..9892d8d 100644
> > --- a/drivers/net/macvlan.c
> > +++ b/drivers/net/macvlan.c
> > @@ -181,6 +181,7 @@ static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb)
> >  					  MACVLAN_MODE_PRIVATE |
> >  					  MACVLAN_MODE_VEPA    |
> >  					  MACVLAN_MODE_PASSTHRU|
> > +					  MACVLAN_MODE_PASSTHRU_NOPROMISC |
> >  					  MACVLAN_MODE_BRIDGE);
> >  		else if (src->mode == MACVLAN_MODE_VEPA)
> >  			/* flood to everyone except source */
> > @@ -312,7 +313,8 @@ static int macvlan_open(struct net_device *dev)
> >  	int err;
> >  
> >  	if (vlan->port->passthru) {
> > -		dev_set_promiscuity(lowerdev, 1);
> > +		if (vlan->mode == MACVLAN_MODE_PASSTHRU)
> > +			dev_set_promiscuity(lowerdev, 1);
> >  		goto hash_add;
> >  	}
> >  
> > @@ -344,12 +346,15 @@ static int macvlan_stop(struct net_device *dev)
> >  	struct macvlan_dev *vlan = netdev_priv(dev);
> >  	struct net_device *lowerdev = vlan->lowerdev;
> >  
> > +	dev_uc_unsync(lowerdev, dev);
> > +	dev_mc_unsync(lowerdev, dev);
> > +
> >  	if (vlan->port->passthru) {
> > -		dev_set_promiscuity(lowerdev, -1);
> > +		if (vlan->mode == MACVLAN_MODE_PASSTHRU)
> > +			dev_set_promiscuity(lowerdev, 1);
> >  		goto hash_del;
> >  	}
> >  
> > -	dev_mc_unsync(lowerdev, dev);
> >  	if (dev->flags & IFF_ALLMULTI)
> >  		dev_set_allmulti(lowerdev, -1);
> >  
> > @@ -399,10 +404,11 @@ static void macvlan_change_rx_flags(struct net_device *dev, int change)
> >  		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);

In the new mode, do we want to have promisc on lowerdev follow whatever
is set on the macvlan, like we do for allmulti?
I'm not sure at this point - what do others think?

> >  }
> >  
> > -static void macvlan_set_multicast_list(struct net_device *dev)
> > +static void macvlan_set_mac_lists(struct net_device *dev)
> >  {
> >  	struct macvlan_dev *vlan = netdev_priv(dev);
> >  
> > +	dev_uc_sync(vlan->lowerdev, dev);
> >  	dev_mc_sync(vlan->lowerdev, dev);
> >  }
> >  
> > @@ -542,6 +548,43 @@ static int macvlan_vlan_rx_kill_vid(struct net_device *dev,
> >  	return 0;
> >  }
> >  
> > +static int macvlan_fdb_add(struct ndmsg *ndm,
> > +			   struct net_device *dev,
> > +			   unsigned char *addr,
> > +			   u16 flags)
> > +{
> > +	struct macvlan_dev *vlan = netdev_priv(dev);
> > +	int err = -EINVAL;
> > +
> > +	if (!vlan->port->passthru)
> > +		return -EOPNOTSUPP;
> > +
> > +	if (is_unicast_ether_addr(addr))
> > +		err = dev_uc_add_excl(dev, addr);
> > +	else if (is_multicast_ether_addr(addr))
> > +		err = dev_mc_add_excl(dev, addr);
> > +
> > +	return err;
> > +}
> > +
> > +static int macvlan_fdb_del(struct ndmsg *ndm,
> > +			   struct net_device *dev,
> > +			   unsigned char *addr)
> > +{
> > +	struct macvlan_dev *vlan = netdev_priv(dev);
> > +	int err = -EINVAL;
> > +
> > +	if (!vlan->port->passthru)
> > +		return -EOPNOTSUPP;
> > +
> > +	if (is_unicast_ether_addr(addr))
> > +		err = dev_uc_del(dev, addr);
> > +	else if (is_multicast_ether_addr(addr))
> > +		err = dev_mc_del(dev, addr);
> > +
> > +	return err;
> > +}
> > +
> >  static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
> >  					struct ethtool_drvinfo *drvinfo)
> >  {
> > @@ -572,11 +615,14 @@ static const struct net_device_ops macvlan_netdev_ops = {
> >  	.ndo_change_mtu		= macvlan_change_mtu,
> >  	.ndo_change_rx_flags	= macvlan_change_rx_flags,
> >  	.ndo_set_mac_address	= macvlan_set_mac_address,
> > -	.ndo_set_rx_mode	= macvlan_set_multicast_list,
> > +	.ndo_set_rx_mode	= macvlan_set_mac_lists,
> >  	.ndo_get_stats64	= macvlan_dev_get_stats64,
> >  	.ndo_validate_addr	= eth_validate_addr,
> >  	.ndo_vlan_rx_add_vid	= macvlan_vlan_rx_add_vid,
> >  	.ndo_vlan_rx_kill_vid	= macvlan_vlan_rx_kill_vid,
> > +	.ndo_fdb_add		= macvlan_fdb_add,
> > +	.ndo_fdb_del		= macvlan_fdb_del,
> > +	.ndo_fdb_dump		= ndo_dflt_fdb_dump,
> >  };
> >  
> >  void macvlan_common_setup(struct net_device *dev)
> > @@ -648,6 +694,7 @@ static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
> >  		case MACVLAN_MODE_VEPA:
> >  		case MACVLAN_MODE_BRIDGE:
> >  		case MACVLAN_MODE_PASSTHRU:
> > +		case MACVLAN_MODE_PASSTHRU_NOPROMISC:
> >  			break;
> >  		default:
> >  			return -EINVAL;
> > @@ -711,7 +758,8 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
> >  	if (data && data[IFLA_MACVLAN_MODE])
> >  		vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
> >  
> > -	if (vlan->mode == MACVLAN_MODE_PASSTHRU) {
> > +	if ((vlan->mode == MACVLAN_MODE_PASSTHRU) ||
> > +	    (vlan->mode == MACVLAN_MODE_PASSTHRU_NOPROMISC)) {
> >  		if (port->count)
> >  			return -EINVAL;
> >  		port->passthru = true;
> > diff --git a/include/linux/if_link.h b/include/linux/if_link.h
> > index 2f4fa93..db67b9d 100644
> > --- a/include/linux/if_link.h
> > +++ b/include/linux/if_link.h
> > @@ -265,6 +265,7 @@ enum macvlan_mode {
> >  	MACVLAN_MODE_VEPA    = 2, /* talk to other ports through ext bridge */
> >  	MACVLAN_MODE_BRIDGE  = 4, /* talk to bridge ports directly */
> >  	MACVLAN_MODE_PASSTHRU = 8,/* take over the underlying device */
> > +	MACVLAN_MODE_PASSTHRU_NOPROMISC = 16, /* passthru without promisc */
> >  };
> >  
> >  /* SR-IOV virtual function management section */