From 6bc506b4fb065eac3d89ca1ce37082e174493d9e Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Thu, 25 Aug 2016 18:42:37 +0200 Subject: bridge: switchdev: Add forward mark support for stacked devices switchdev_port_fwd_mark_set() is used to set the 'offload_fwd_mark' of port netdevs so that packets being flooded by the device won't be flooded twice. It works by assigning a unique identifier (the ifindex of the first bridge port) to bridge ports sharing the same parent ID. This prevents packets from being flooded twice by the same switch, but will flood packets through bridge ports belonging to a different switch. This method is problematic when stacked devices are taken into account, such as VLANs. In such cases, a physical port netdev can have upper devices being members in two different bridges, thus requiring two different 'offload_fwd_mark's to be configured on the port netdev, which is impossible. The main problem is that packet and netdev marking is performed at the physical netdev level, whereas flooding occurs between bridge ports, which are not necessarily port netdevs. Instead, packet and netdev marking should really be done in the bridge driver with the switch driver only telling it which packets it already forwarded. The bridge driver will mark such packets using the mark assigned to the ingress bridge port and will prevent the packet from being forwarded through any bridge port sharing the same mark (i.e. having the same parent ID). Remove the current switchdev 'offload_fwd_mark' implementation and instead implement the proposed method. In addition, make rocker - the sole user of the mark - use the proposed method. Signed-off-by: Ido Schimmel Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- net/bridge/br_switchdev.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 net/bridge/br_switchdev.c (limited to 'net/bridge/br_switchdev.c') diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c new file mode 100644 index 000000000000..f4097b900de1 --- /dev/null +++ b/net/bridge/br_switchdev.c @@ -0,0 +1,57 @@ +#include +#include +#include +#include +#include +#include + +#include "br_private.h" + +static int br_switchdev_mark_get(struct net_bridge *br, struct net_device *dev) +{ + struct net_bridge_port *p; + + /* dev is yet to be added to the port list. */ + list_for_each_entry(p, &br->port_list, list) { + if (switchdev_port_same_parent_id(dev, p->dev)) + return p->offload_fwd_mark; + } + + return ++br->offload_fwd_mark; +} + +int nbp_switchdev_mark_set(struct net_bridge_port *p) +{ + struct switchdev_attr attr = { + .orig_dev = p->dev, + .id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID, + }; + int err; + + ASSERT_RTNL(); + + err = switchdev_port_attr_get(p->dev, &attr); + if (err) { + if (err == -EOPNOTSUPP) + return 0; + return err; + } + + p->offload_fwd_mark = br_switchdev_mark_get(p->br, p->dev); + + return 0; +} + +void nbp_switchdev_frame_mark(const struct net_bridge_port *p, + struct sk_buff *skb) +{ + if (skb->offload_fwd_mark && !WARN_ON_ONCE(!p->offload_fwd_mark)) + BR_INPUT_SKB_CB(skb)->offload_fwd_mark = p->offload_fwd_mark; +} + +bool nbp_switchdev_allowed_egress(const struct net_bridge_port *p, + const struct sk_buff *skb) +{ + return !skb->offload_fwd_mark || + BR_INPUT_SKB_CB(skb)->offload_fwd_mark != p->offload_fwd_mark; +} -- cgit v1.2.3