diff options
| -rw-r--r-- | Documentation/networking/dsa/configuration.rst | 68 | ||||
| -rw-r--r-- | net/dsa/slave.c | 23 |
2 files changed, 68 insertions, 23 deletions
diff --git a/Documentation/networking/dsa/configuration.rst b/Documentation/networking/dsa/configuration.rst index 774f0e76c746..2b08f1a772d3 100644 --- a/Documentation/networking/dsa/configuration.rst +++ b/Documentation/networking/dsa/configuration.rst @@ -292,3 +292,71 @@ configuration. # bring up the bridge devices ip link set br0 up + +Forwarding database (FDB) management +------------------------------------ + +The existing DSA switches do not have the necessary hardware support to keep +the software FDB of the bridge in sync with the hardware tables, so the two +tables are managed separately (``bridge fdb show`` queries both, and depending +on whether the ``self`` or ``master`` flags are being used, a ``bridge fdb +add`` or ``bridge fdb del`` command acts upon entries from one or both tables). + +Up until kernel v4.14, DSA only supported user space management of bridge FDB +entries using the bridge bypass operations (which do not update the software +FDB, just the hardware one) using the ``self`` flag (which is optional and can +be omitted). + + .. code-block:: sh + + bridge fdb add dev swp0 00:01:02:03:04:05 self static + # or shorthand + bridge fdb add dev swp0 00:01:02:03:04:05 static + +Due to a bug, the bridge bypass FDB implementation provided by DSA did not +distinguish between ``static`` and ``local`` FDB entries (``static`` are meant +to be forwarded, while ``local`` are meant to be locally terminated, i.e. sent +to the host port). Instead, all FDB entries with the ``self`` flag (implicit or +explicit) are treated by DSA as ``static`` even if they are ``local``. + + .. code-block:: sh + + # This command: + bridge fdb add dev swp0 00:01:02:03:04:05 static + # behaves the same for DSA as this command: + bridge fdb add dev swp0 00:01:02:03:04:05 local + # or shorthand, because the 'local' flag is implicit if 'static' is not + # specified, it also behaves the same as: + bridge fdb add dev swp0 00:01:02:03:04:05 + +The last command is an incorrect way of adding a static bridge FDB entry to a +DSA switch using the bridge bypass operations, and works by mistake. Other +drivers will treat an FDB entry added by the same command as ``local`` and as +such, will not forward it, as opposed to DSA. + +Between kernel v4.14 and v5.14, DSA has supported in parallel two modes of +adding a bridge FDB entry to the switch: the bridge bypass discussed above, as +well as a new mode using the ``master`` flag which installs FDB entries in the +software bridge too. + + .. code-block:: sh + + bridge fdb add dev swp0 00:01:02:03:04:05 master static + +Since kernel v5.14, DSA has gained stronger integration with the bridge's +software FDB, and the support for its bridge bypass FDB implementation (using +the ``self`` flag) has been removed. This results in the following changes: + + .. code-block:: sh + + # This is the only valid way of adding an FDB entry that is supported, + # compatible with v4.14 kernels and later: + bridge fdb add dev swp0 00:01:02:03:04:05 master static + # This command is no longer buggy and the entry is properly treated as + # 'local' instead of being forwarded: + bridge fdb add dev swp0 00:01:02:03:04:05 + # This command no longer installs a static FDB entry to hardware: + bridge fdb add dev swp0 00:01:02:03:04:05 static + +Script writers are therefore encouraged to use the ``master static`` set of +flags when working with bridge FDB entries on DSA switch interfaces. diff --git a/net/dsa/slave.c b/net/dsa/slave.c index 898ed9cf756f..64acb1e11cd7 100644 --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -1651,27 +1651,6 @@ static const struct ethtool_ops dsa_slave_ethtool_ops = { .self_test = dsa_slave_net_selftest, }; -/* legacy way, bypassing the bridge *****************************************/ -static int dsa_legacy_fdb_add(struct ndmsg *ndm, struct nlattr *tb[], - struct net_device *dev, - const unsigned char *addr, u16 vid, - u16 flags, - struct netlink_ext_ack *extack) -{ - struct dsa_port *dp = dsa_slave_to_port(dev); - - return dsa_port_fdb_add(dp, addr, vid); -} - -static int dsa_legacy_fdb_del(struct ndmsg *ndm, struct nlattr *tb[], - struct net_device *dev, - const unsigned char *addr, u16 vid) -{ - struct dsa_port *dp = dsa_slave_to_port(dev); - - return dsa_port_fdb_del(dp, addr, vid); -} - static struct devlink_port *dsa_slave_get_devlink_port(struct net_device *dev) { struct dsa_port *dp = dsa_slave_to_port(dev); @@ -1713,8 +1692,6 @@ static const struct net_device_ops dsa_slave_netdev_ops = { .ndo_change_rx_flags = dsa_slave_change_rx_flags, .ndo_set_rx_mode = dsa_slave_set_rx_mode, .ndo_set_mac_address = dsa_slave_set_mac_address, - .ndo_fdb_add = dsa_legacy_fdb_add, - .ndo_fdb_del = dsa_legacy_fdb_del, .ndo_fdb_dump = dsa_slave_fdb_dump, .ndo_do_ioctl = dsa_slave_ioctl, .ndo_get_iflink = dsa_slave_get_iflink, |