kernel/git/stable/linux.git/net/dsa/switch.c, branch linux-5.16.y

net: dsa: fix incorrect function pointer check for MRP ring roles

2022-01-27T11:01:54+00:00

[ Upstream commit ff91e1b68490b97c18c649b769618815eb945f11 ] The cross-chip notifier boilerplate code meant to check the presence of ds->ops->port_mrp_add_ring_role before calling it, but checked ds->ops->port_mrp_add instead, before calling ds->ops->port_mrp_add_ring_role. Therefore, a driver which implements one operation but not the other would trigger a NULL pointer dereference. There isn't any such driver in DSA yet, so there is no reason to backport the change. Issue found through code inspection. Cc: Horatiu Vultur Fixes: c595c4330da0 ("net: dsa: add MRP support") Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: dsa: introduce locking for the address lists on CPU and DSA ports

2021-10-25T11:59:42+00:00

Now that the rtnl_mutex is going away for dsa_port_{host_,}fdb_{add,del}, no one is serializing access to the address lists that DSA keeps for the purpose of reference counting on shared ports (CPU and cascade ports). It can happen for one dsa_switch_do_fdb_del to do list_del on a dp->fdbs element while another dsa_switch_do_fdb_{add,del} is traversing dp->fdbs. We need to avoid that. Currently dp->mdbs is not at risk, because dsa_switch_do_mdb_{add,del} still runs under the rtnl_mutex. But it would be nice if it would not depend on that being the case. So let's introduce a mutex per port (the address lists are per port too) and share it between dp->mdbs and dp->fdbs. The place where we put the locking is interesting. It could be tempting to put a DSA-level lock which still serializes calls to .port_fdb_{add,del}, but it would still not avoid concurrency with other driver code paths that are currently under rtnl_mutex (.port_fdb_dump, .port_fast_age). So it would add a very false sense of security (and adding a global switch-wide lock in DSA to resynchronize with the rtnl_lock is also counterproductive and hard). So the locking is intentionally done only where the dp->fdbs and dp->mdbs lists are traversed. That means, from a driver perspective, that .port_fdb_add will be called with the dp->addr_lists_lock mutex held on the CPU port, but not held on user ports. This is done so that driver writers are not encouraged to rely on any guarantee offered by dp->addr_lists_lock. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller

net: dsa: avoid refcount warnings when ->port_{fdb,mdb}_del returns error

2021-10-25T11:59:41+00:00

At present, when either of ds->ops->port_fdb_del() or ds->ops->port_mdb_del() return a non-zero error code, we attempt to save the day and keep the data structure associated with that switchdev object, as the deletion procedure did not complete. However, the way in which we do this is suspicious to the checker in lib/refcount.c, who thinks it is buggy to increment a refcount that became zero, and that this is indicative of a use-after-free. Fixes: 161ca59d39e9 ("net: dsa: reference count the MDB entries at the cross-chip notifier level") Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

Revert "Merge branch 'dsa-rtnl'"

2021-10-25T11:59:25+00:00

This reverts commit 965e6b262f48257dbdb51b565ecfd84877a0ab5f, reversing changes made to 4d98bb0d7ec2d0b417df6207b0bafe1868bad9f8.

net: dsa: introduce locking for the address lists on CPU and DSA ports

2021-10-24T12:47:44+00:00

net: dsa: convert cross-chip notifiers to iterate using dp

2021-10-21T11:44:07+00:00

The majority of cross-chip switch notifiers need to filter in some way over the type of ports: some install VLANs etc on all cascade ports. The difference is that the matching function, which filters by port type, is separate from the function where the iteration happens. So this patch needs to refactor the matching functions' prototypes as well, to take the dp as argument. In a future patch/series, I might convert dsa_towards_port to return a struct dsa_port *dp too, but at the moment it is a bit entangled with dsa_routing_port which is also used by mv88e6xxx and they both return an int port. So keep dsa_towards_port the way it is and convert it into a dp using dsa_to_port. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net: dsa: remove the "dsa_to_port in a loop" antipattern from the core

2021-10-21T11:44:06+00:00

Ever since Vivien's conversion of the ds->ports array into a dst->ports list, and the introduction of dsa_to_port, iterations through the ports of a switch became quadratic whenever dsa_to_port was needed. dsa_to_port can either be called directly, or indirectly through the dsa_is_{user,cpu,dsa,unused}_port helpers. Use the newly introduced dsa_switch_for_each_port() iteration macro that works with the iterator variable being a struct dsa_port *dp directly, and not an int i. It is an expensive variable to go from i to dp, but cheap to go from dp to i. This macro iterates through the entire ds->dst->ports list and filters by the ports belonging just to the switch provided as argument. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller

net: dsa: fix spurious error message when unoffloaded port leaves bridge

2021-10-12T23:11:23+00:00

Flip the sign of a return value check, thereby suppressing the following spurious error: port 2 failed to notify DSA_NOTIFIER_BRIDGE_LEAVE: -EOPNOTSUPP ... which is emitted when removing an unoffloaded DSA switch port from a bridge. Fixes: d371b7c92d19 ("net: dsa: Unset vlan_filtering when ports leave the bridge") Signed-off-by: Alvin Šipraga Reviewed-by: Vladimir Oltean Reviewed-by: Florian Fainelli Link: https://lore.kernel.org/r/20211012112730.3429157-1-alvin@pqrs.dk Signed-off-by: Jakub Kicinski

net: dsa: let drivers state that they need VLAN filtering while standalone

2021-08-24T08:30:58+00:00

As explained in commit e358bef7c392 ("net: dsa: Give drivers the chance to veto certain upper devices"), the hellcreek driver uses some tricks to comply with the network stack expectations: it enforces port separation in standalone mode using VLANs. For untagged traffic, bridging between ports is prevented by using different PVIDs, and for VLAN-tagged traffic, it never accepts 8021q uppers with the same VID on two ports, so packets with one VLAN cannot leak from one port to another. That is almost fine*, and has worked because hellcreek relied on an implicit behavior of the DSA core that was changed by the previous patch: the standalone ports declare the 'rx-vlan-filter' feature as 'on [fixed]'. Since most of the DSA drivers are actually VLAN-unaware in standalone mode, that feature was actually incorrectly reflecting the hardware/driver state, so there was a desire to fix it. This leaves the hellcreek driver in a situation where it has to explicitly request this behavior from the DSA framework. We configure the ports as follows: - Standalone: 'rx-vlan-filter' is on. An 8021q upper on top of a standalone hellcreek port will go through dsa_slave_vlan_rx_add_vid and will add a VLAN to the hardware tables, giving the driver the opportunity to refuse it through .port_prechangeupper. - Bridged with vlan_filtering=0: 'rx-vlan-filter' is off. An 8021q upper on top of a bridged hellcreek port will not go through dsa_slave_vlan_rx_add_vid, because there will not be any attempt to offload this VLAN. The driver already disables VLAN awareness, so that upper should receive the traffic it needs. - Bridged with vlan_filtering=1: 'rx-vlan-filter' is on. An 8021q upper on top of a bridged hellcreek port will call dsa_slave_vlan_rx_add_vid, and can again be vetoed through .port_prechangeupper. *It is not actually completely fine, because if I follow through correctly, we can have the following situation: ip link add br0 type bridge vlan_filtering 0 ip link set lan0 master br0 # lan0 now becomes VLAN-unaware ip link set lan0 nomaster # lan0 fails to become VLAN-aware again, therefore breaking isolation This patch fixes that corner case by extending the DSA core logic, based on this requested attribute, to change the VLAN awareness state of the switch (port) when it leaves the bridge. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Acked-by: Kurt Kanzenbach Signed-off-by: David S. Miller

net: dsa: properly fall back to software bridging

2021-08-24T08:30:58+00:00

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 Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller