Merge branch 'dsa-vlan'

Florian Fainelli says:

====================
net: dsa: VLAN devices w/ filtering

This patch series supports having VLAN devices on top of DSA/switch
ports while the switch has VLAN filtering globally turned on (as is the
case with Broadcom switches). Whether the switch does global or per-port
VLAN filtering, having VLAN entries for these VLAN devices is
beneficial.

We take care of a few possibly problematic cases:

- adding a VLAN device while there is an existing VLAN entry created by
  a VLAN aware bridge. The entire bridge's VLAN database and not just
  the specific bridge port is being checked to be safe and conserative

- adding a bridge VLAN entry when there is an existing VLAN device
  created is also not possible because that would lead to the bridge
  being able to manipulate the VLAN device's VID/attributes under its feet

- enslaving a VLAN device into a VLAN aware bridge since that duplicates
  functionality already offered by the VLAN aware bridge

Here are the different test cases that were run to exercise this:

ip addr flush dev gphy
ip link add dev br0 type bridge
echo 1 > /sys/class/net/br0/bridge/vlan_filtering
ip link set dev gphy master br0
udhcpc -i br0

vconfig add rgmii_1 100
ifconfig rgmii_1.100 192.168.100.10
ping -c 2 192.168.100.1

vconfig add br0 42
bridge vlan add vid 42 dev gphy
bridge vlan add vid 42 dev br0 self
ifconfig br0.42 192.168.42.2
ping -c 2 192.168.42.1

ip link del rgmii_1.100
vconfig add rgmii_1 100
ifconfig rgmii_1.100 192.168.100.10
ping -c 2 192.168.100.1
echo 0 > /sys/class/net/br0/bridge/vlan_filtering
ping -c 2 192.168.100.1

ip link del rgmii_1.100
echo 1 > /sys/class/net/br0/bridge/vlan_filtering

vconfig add rgmii_1 100
brctl addif br0 rgmii_1
bridge vlan add vid 100 dev rgmii_1

vconfig rem rgmii_1.100
bridge vlan add vid 100 dev rgmii_1
vconfig add rgmii_1 100

bridge vlan del vid 100 dev rgmii_1
vconfig add rgmii_1 100
brctl addif br0 rgmii_1.100
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 42 insertions, 0 deletions

diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index 142b294d3446..e1fae969aa73 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -12,6 +12,7 @@
 
 #include <linux/netdevice.h>
 #include <linux/notifier.h>
+#include <linux/if_vlan.h>
 #include <net/switchdev.h>
 
 #include "dsa_priv.h"
@@ -168,6 +169,43 @@ static int dsa_switch_mdb_del(struct dsa_switch *ds,
         return 0;
 }
 
+static int dsa_port_vlan_device_check(struct net_device *vlan_dev,
+                                      int vlan_dev_vid,
+                                      void *arg)
+{
+        struct switchdev_obj_port_vlan *vlan = arg;
+        u16 vid;
+
+        for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
+                if (vid == vlan_dev_vid)
+                        return -EBUSY;
+        }
+
+        return 0;
+}
+
+static int dsa_port_vlan_check(struct dsa_switch *ds, int port,
+                               const struct switchdev_obj_port_vlan *vlan)
+{
+        const struct dsa_port *dp = dsa_to_port(ds, port);
+        int err = 0;
+
+        /* Device is not bridged, let it proceed with the VLAN device
+         * creation.
+         */
+        if (!dp->bridge_dev)
+                return err;
+
+        /* dsa_slave_vlan_rx_{add,kill}_vid() cannot use the prepare pharse and
+         * already checks whether there is an overlapping bridge VLAN entry
+         * with the same VID, so here we only need to check that if we are
+         * adding a bridge VLAN entry there is not an overlapping VLAN device
+         * claiming that VID.
+         */
+        return vlan_for_each(dp->slave, dsa_port_vlan_device_check,
+                             (void *)vlan);
+}
+
 static int
 dsa_switch_vlan_prepare_bitmap(struct dsa_switch *ds,
                                const struct switchdev_obj_port_vlan *vlan,
@@ -179,6 +217,10 @@ dsa_switch_vlan_prepare_bitmap(struct dsa_switch *ds,
                 return -EOPNOTSUPP;
 
         for_each_set_bit(port, bitmap, ds->num_ports) {
+                err = dsa_port_vlan_check(ds, port, vlan);
+                if (err)
+                        return err;
+
                 err = ds->ops->port_vlan_prepare(ds, port, vlan);
                 if (err)
                         return err;