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: Scott Feldman <sfeldma@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index d5671f1..89da893 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -157,6 +157,9 @@
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 @@
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_ */
diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
index 4e5bba5..33bafa2 100644
--- a/net/switchdev/switchdev.c
+++ b/net/switchdev/switchdev.c
@@ -1039,3 +1039,106 @@
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);
