From 7569459a52c95bc6e82c0b4075c4380df55cd343 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Wed, 2 Mar 2022 21:14:12 +0200 Subject: net: dsa: manage flooding on the CPU ports DSA can treat IFF_PROMISC and IFF_ALLMULTI on standalone user ports as signifying whether packets with an unknown MAC DA will be received or not. Since known MAC DAs are handled by FDB/MDB entries, this means that promiscuity is analogous to including/excluding the CPU port from the flood domain of those packets. There are two ways to signal CPU flooding to drivers. The first (chosen here) is to synthesize a call to ds->ops->port_bridge_flags() for the CPU port, with a mask of BR_FLOOD | BR_MCAST_FLOOD. This has the effect of turning on egress flooding on the CPU port regardless of source. The alternative would be to create a new ds->ops->port_host_flood() which is called per user port. Some switches (sja1105) have a flood domain that is managed per {ingress port, egress port} pair, so it would make more sense for this kind of switch to not flood the CPU from port A if just port B requires it. Nonetheless, the sja1105 has other quirks that prevent it from making use of unicast filtering, and without a concrete user making use of this feature, I chose not to implement it. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller --- net/dsa/slave.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'net/dsa/slave.c') diff --git a/net/dsa/slave.c b/net/dsa/slave.c index 6eb728efac43..42436ac6993b 100644 --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -229,9 +229,44 @@ static int dsa_slave_close(struct net_device *dev) return 0; } +/* Keep flooding enabled towards this port's CPU port as long as it serves at + * least one port in the tree that requires it. + */ +static void dsa_port_manage_cpu_flood(struct dsa_port *dp) +{ + struct switchdev_brport_flags flags = { + .mask = BR_FLOOD | BR_MCAST_FLOOD, + }; + struct dsa_switch_tree *dst = dp->ds->dst; + struct dsa_port *cpu_dp = dp->cpu_dp; + struct dsa_port *other_dp; + int err; + + list_for_each_entry(other_dp, &dst->ports, list) { + if (!dsa_port_is_user(other_dp)) + continue; + + if (other_dp->cpu_dp != cpu_dp) + continue; + + if (other_dp->slave->flags & IFF_ALLMULTI) + flags.val |= BR_MCAST_FLOOD; + if (other_dp->slave->flags & IFF_PROMISC) + flags.val |= BR_FLOOD; + } + + err = dsa_port_pre_bridge_flags(dp, flags, NULL); + if (err) + return; + + dsa_port_bridge_flags(cpu_dp, flags, NULL); +} + static void dsa_slave_change_rx_flags(struct net_device *dev, int change) { struct net_device *master = dsa_slave_to_master(dev); + struct dsa_port *dp = dsa_slave_to_port(dev); + struct dsa_switch *ds = dp->ds; if (change & IFF_ALLMULTI) dev_set_allmulti(master, @@ -239,6 +274,10 @@ static void dsa_slave_change_rx_flags(struct net_device *dev, int change) if (change & IFF_PROMISC) dev_set_promiscuity(master, dev->flags & IFF_PROMISC ? 1 : -1); + + if (dsa_switch_supports_uc_filtering(ds) && + dsa_switch_supports_mc_filtering(ds)) + dsa_port_manage_cpu_flood(dp); } static void dsa_slave_set_rx_mode(struct net_device *dev) -- cgit v1.2.3-59-g8ed1b