Commit 1a3b2ec9 authored by Scott Feldman's avatar Scott Feldman Committed by David S. Miller
Browse files

switchdev: add offload_fwd_mark generator helper 



skb->offload_fwd_mark and dev->offload_fwd_mark are 32-bit and should be
unique for device and may even be unique for a sub-set of ports within
device, so add switchdev helper function to generate unique marks based on
port's switch ID and group_ifindex.  group_ifindex would typically be the
container dev's ifindex, such as the bridge's ifindex.

The generator uses a global hash table to store offload_fwd_marks hashed by
{switch ID, group_ifindex} key.

Signed-off-by: default avatarScott Feldman <sfeldma@gmail.com>
Acked-by: default avatarJiri Pirko <jiri@resnulli.us>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d754f98b

include/net/switchdev.h

+9 −0
Original line number Diff line number Diff line
@@ -157,6 +157,9 @@ int switchdev_port_fdb_del(struct ndmsg *ndm, struct nlattr *tb[], 
int switchdev_port_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,

			    struct net_device *dev,

			    struct net_device *filter_dev, int idx);

void switchdev_port_fwd_mark_set(struct net_device *dev,

				 struct net_device *group_dev,

				 bool joining);



#else
@@ -271,6 +274,12 @@ static inline int switchdev_port_fdb_dump(struct sk_buff *skb, 
	return -EOPNOTSUPP;

}



static inline void switchdev_port_fwd_mark_set(struct net_device *dev,

					       struct net_device *group_dev,

					       bool joining)

{

}



#endif



#endif /* _LINUX_SWITCHDEV_H_ */

net/switchdev/switchdev.c

+103 −0
Original line number Diff line number Diff line
@@ -1039,3 +1039,106 @@ void switchdev_fib_ipv4_abort(struct fib_info *fi) 
	fi->fib_net->ipv4.fib_offload_disabled = true;

}

EXPORT_SYMBOL_GPL(switchdev_fib_ipv4_abort);



static bool switchdev_port_same_parent_id(struct net_device *a,

					  struct net_device *b)

{

	struct switchdev_attr a_attr = {

		.id = SWITCHDEV_ATTR_PORT_PARENT_ID,

		.flags = SWITCHDEV_F_NO_RECURSE,

	};

	struct switchdev_attr b_attr = {

		.id = SWITCHDEV_ATTR_PORT_PARENT_ID,

		.flags = SWITCHDEV_F_NO_RECURSE,

	};



	if (switchdev_port_attr_get(a, &a_attr) ||

	    switchdev_port_attr_get(b, &b_attr))

		return false;



	return netdev_phys_item_id_same(&a_attr.u.ppid, &b_attr.u.ppid);

}



static u32 switchdev_port_fwd_mark_get(struct net_device *dev,

				       struct net_device *group_dev)

{

	struct net_device *lower_dev;

	struct list_head *iter;



	netdev_for_each_lower_dev(group_dev, lower_dev, iter) {

		if (lower_dev == dev)

			continue;

		if (switchdev_port_same_parent_id(dev, lower_dev))

			return lower_dev->offload_fwd_mark;

		return switchdev_port_fwd_mark_get(dev, lower_dev);

	}



	return dev->ifindex;

}



static void switchdev_port_fwd_mark_reset(struct net_device *group_dev,

					  u32 old_mark, u32 *reset_mark)

{

	struct net_device *lower_dev;

	struct list_head *iter;



	netdev_for_each_lower_dev(group_dev, lower_dev, iter) {

		if (lower_dev->offload_fwd_mark == old_mark) {

			if (!*reset_mark)

				*reset_mark = lower_dev->ifindex;

			lower_dev->offload_fwd_mark = *reset_mark;

		}

		switchdev_port_fwd_mark_reset(lower_dev, old_mark, reset_mark);

	}

}



/**

 *	switchdev_port_fwd_mark_set - Set port offload forwarding mark

 *

 *	@dev: port device

 *	@group_dev: containing device

 *	@joining: true if dev is joining group; false if leaving group

 *

 *	An ungrouped port's offload mark is just its ifindex.  A grouped

 *	port's (member of a bridge, for example) offload mark is the ifindex

 *	of one of the ports in the group with the same parent (switch) ID.

 *	Ports on the same device in the same group will have the same mark.

 *

 *	Example:

 *

 *		br0		ifindex=9

 *		  sw1p1		ifindex=2	mark=2

 *		  sw1p2		ifindex=3	mark=2

 *		  sw2p1		ifindex=4	mark=5

 *		  sw2p2		ifindex=5	mark=5

 *

 *	If sw2p2 leaves the bridge, we'll have:

 *

 *		br0		ifindex=9

 *		  sw1p1		ifindex=2	mark=2

 *		  sw1p2		ifindex=3	mark=2

 *		  sw2p1		ifindex=4	mark=4

 *		sw2p2		ifindex=5	mark=5

 */

void switchdev_port_fwd_mark_set(struct net_device *dev,

				 struct net_device *group_dev,

				 bool joining)

{

	u32 mark = dev->ifindex;

	u32 reset_mark = 0;



	if (group_dev && joining) {

		mark = switchdev_port_fwd_mark_get(dev, group_dev);

	} else if (group_dev && !joining) {

		if (dev->offload_fwd_mark == mark)

			/* Ohoh, this port was the mark reference port,

			 * but it's leaving the group, so reset the

			 * mark for the remaining ports in the group.

			 */

			switchdev_port_fwd_mark_reset(group_dev, mark,

						      &reset_mark);

	}



	dev->offload_fwd_mark = mark;

}

EXPORT_SYMBOL_GPL(switchdev_port_fwd_mark_set);

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