bridge: vlan: learn to count

Add support for per-VLAN Tx/Rx statistics. Every global vlan context gets
allocated a per-cpu stats which is then set in each per-port vlan context
for quick access. The br_allowed_ingress() common function is used to
account for Rx packets and the br_handle_vlan() common function is used
to account for Tx packets. Stats accounting is performed only if the
bridge-wide vlan_stats_enabled option is set either via sysfs or netlink.
A struct hole between vlan_enabled and vlan_proto is used for the new
option so it is in the same cache line. Currently it is binary (on/off)
but it is intentionally restricted to exactly 0 and 1 since other values
will be used in the future for different purposes (e.g. per-port stats).

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 0 deletions

diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index 70bddfd0f3e9..beb47071e38d 100644
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -731,6 +731,22 @@ static ssize_t default_pvid_store(struct device *d,
 	return store_bridge_parm(d, buf, len, br_vlan_set_default_pvid);
 }
 static DEVICE_ATTR_RW(default_pvid);
+
+static ssize_t vlan_stats_enabled_show(struct device *d,
+				       struct device_attribute *attr,
+				       char *buf)
+{
+	struct net_bridge *br = to_bridge(d);
+	return sprintf(buf, "%u\n", br->vlan_stats_enabled);
+}
+
+static ssize_t vlan_stats_enabled_store(struct device *d,
+					struct device_attribute *attr,
+					const char *buf, size_t len)
+{
+	return store_bridge_parm(d, buf, len, br_vlan_set_stats);
+}
+static DEVICE_ATTR_RW(vlan_stats_enabled);
 #endif
 
 static struct attribute *bridge_attrs[] = {
@@ -778,6 +794,7 @@ static struct attribute *bridge_attrs[] = {
 	&dev_attr_vlan_filtering.attr,
 	&dev_attr_vlan_protocol.attr,
 	&dev_attr_default_pvid.attr,
+	&dev_attr_vlan_stats_enabled.attr,
 #endif
 	NULL
 };