Commit 920a33cd authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Paolo Abeni
Browse files

net: bridge: move DSA master bridging restriction to DSA 



When DSA gains support for multiple CPU ports in a LAG, it will become
mandatory to monitor the changeupper events for the DSA master.

In fact, there are already some restrictions to be imposed in that area,
namely that a DSA master cannot be a bridge port except in some special
circumstances.

Centralize the restrictions at the level of the DSA layer as a
preliminary step.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: default avatarNikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 0498277e

net/bridge/br_if.c

+0 −20
Original line number Diff line number Diff line
@@ -568,26 +568,6 @@ int br_add_if(struct net_bridge *br, struct net_device *dev, 
	    !is_valid_ether_addr(dev->dev_addr))

		return -EINVAL;



	/* Also don't allow bridging of net devices that are DSA masters, since

	 * the bridge layer rx_handler prevents the DSA fake ethertype handler

	 * to be invoked, so we don't get the chance to strip off and parse the

	 * DSA switch tag protocol header (the bridge layer just returns

	 * RX_HANDLER_CONSUMED, stopping RX processing for these frames).

	 * The only case where that would not be an issue is when bridging can

	 * already be offloaded, such as when the DSA master is itself a DSA

	 * or plain switchdev port, and is bridged only with other ports from

	 * the same hardware device.

	 */

	if (netdev_uses_dsa(dev)) {

		list_for_each_entry(p, &br->port_list, list) {

			if (!netdev_port_same_parent_id(dev, p->dev)) {

				NL_SET_ERR_MSG(extack,

					       "Cannot do software bridging with a DSA master");

				return -EINVAL;

			}

		}

	}



	/* No bridging of bridges */

	if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) {

		NL_SET_ERR_MSG(extack,

net/dsa/slave.c

+44 −0
Original line number Diff line number Diff line
@@ -2699,6 +2699,46 @@ dsa_slave_prechangeupper_sanity_check(struct net_device *dev, 
	return NOTIFY_DONE;

}



/* Don't allow bridging of DSA masters, since the bridge layer rx_handler

 * prevents the DSA fake ethertype handler to be invoked, so we don't get the

 * chance to strip off and parse the DSA switch tag protocol header (the bridge

 * layer just returns RX_HANDLER_CONSUMED, stopping RX processing for these

 * frames).

 * The only case where that would not be an issue is when bridging can already

 * be offloaded, such as when the DSA master is itself a DSA or plain switchdev

 * port, and is bridged only with other ports from the same hardware device.

 */

static int

dsa_bridge_prechangelower_sanity_check(struct net_device *new_lower,

				       struct netdev_notifier_changeupper_info *info)

{

	struct net_device *br = info->upper_dev;

	struct netlink_ext_ack *extack;

	struct net_device *lower;

	struct list_head *iter;



	if (!netif_is_bridge_master(br))

		return NOTIFY_DONE;



	if (!info->linking)

		return NOTIFY_DONE;



	extack = netdev_notifier_info_to_extack(&info->info);



	netdev_for_each_lower_dev(br, lower, iter) {

		if (!netdev_uses_dsa(new_lower) && !netdev_uses_dsa(lower))

			continue;



		if (!netdev_port_same_parent_id(lower, new_lower)) {

			NL_SET_ERR_MSG(extack,

				       "Cannot do software bridging with a DSA master");

			return notifier_from_errno(-EINVAL);

		}

	}



	return NOTIFY_DONE;

}



static int dsa_slave_netdevice_event(struct notifier_block *nb,

				     unsigned long event, void *ptr)

{
@@ -2713,6 +2753,10 @@ static int dsa_slave_netdevice_event(struct notifier_block *nb, 
		if (notifier_to_errno(err))

			return err;



		err = dsa_bridge_prechangelower_sanity_check(dev, info);

		if (notifier_to_errno(err))

			return err;



		err = dsa_slave_prechangeupper(dev, ptr);

		if (notifier_to_errno(err))

			return err;