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authorVladimir Oltean <vladimir.oltean@nxp.com>2021-08-24 00:22:56 +0300
committerDavid S. Miller <davem@davemloft.net>2021-08-24 09:30:58 +0100
commit67b5fb5db76dbbdbd7bbed220134c7be4217aed9 (patch)
tree6863c4fac8c845b0c84dc9ddba5ff197f8cd0024 /net/dsa
parent09dba21b432a13369d6d600941c4902237218f20 (diff)
downloadlinux-67b5fb5db76dbbdbd7bbed220134c7be4217aed9.tar.bz2
net: dsa: properly fall back to software bridging
If the driver does not implement .port_bridge_{join,leave}, then we must fall back to standalone operation on that port, and trigger the error path of dsa_port_bridge_join. This sets dp->bridge_dev = NULL. In turn, having a non-NULL dp->bridge_dev when there is no offloading support makes the following things go wrong: - dsa_default_offload_fwd_mark make the wrong decision in setting skb->offload_fwd_mark. It should set skb->offload_fwd_mark = 0 for ports that don't offload the bridge, which should instruct the bridge to forward in software. But this does not happen, dp->bridge_dev is incorrectly set to point to the bridge, so the bridge is told that packets have been forwarded in hardware, which they haven't. - switchdev objects (MDBs, VLANs) should not be offloaded by ports that don't offload the bridge. Standalone ports should behave as packet-in, packet-out and the bridge should not be able to manipulate the pvid of the port, or tag stripping on egress, or ingress filtering. This should already work fine because dsa_slave_port_obj_add has: case SWITCHDEV_OBJ_ID_PORT_VLAN: if (!dsa_port_offloads_bridge_port(dp, obj->orig_dev)) return -EOPNOTSUPP; err = dsa_slave_vlan_add(dev, obj, extack); but since dsa_port_offloads_bridge_port works based on dp->bridge_dev, this is again sabotaging us. All the above work in case the port has an unoffloaded LAG interface, so this is well exercised code, we should apply it for plain unoffloaded bridge ports too. Reported-by: Alvin Šipraga <alsi@bang-olufsen.dk> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dsa')
-rw-r--r--net/dsa/slave.c5
-rw-r--r--net/dsa/switch.c6
2 files changed, 9 insertions, 2 deletions
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index eb9d9e53c536..f785d24fcf23 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -2009,6 +2009,11 @@ static int dsa_slave_changeupper(struct net_device *dev,
err = dsa_port_bridge_join(dp, info->upper_dev, extack);
if (!err)
dsa_bridge_mtu_normalization(dp);
+ if (err == -EOPNOTSUPP) {
+ NL_SET_ERR_MSG_MOD(extack,
+ "Offloading not supported");
+ err = 0;
+ }
err = notifier_from_errno(err);
} else {
dsa_port_bridge_leave(dp, info->upper_dev);
diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index fd1a1c6bf9cf..dd042fd7f800 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -92,8 +92,10 @@ static int dsa_switch_bridge_join(struct dsa_switch *ds,
struct dsa_switch_tree *dst = ds->dst;
int err;
- if (dst->index == info->tree_index && ds->index == info->sw_index &&
- ds->ops->port_bridge_join) {
+ if (dst->index == info->tree_index && ds->index == info->sw_index) {
+ if (!ds->ops->port_bridge_join)
+ return -EOPNOTSUPP;
+
err = ds->ops->port_bridge_join(ds, info->port, info->br);
if (err)
return err;