bridge: Make Q-in-Q TPID 0x88a8 configurable.

For Q-in-Q in bridge-vlans to work properly,
the right TPID needs to be configured on the
outer tag.

This makes it possible to set the VLAN protocol
similiar to how vlan_filtering option is used.

Signed-off-by: Markus Gothe <markus.gothe@genexis.eu>

Author: Markus Gothe

bridge.c

@@ -43,6 +43,7 @@ enum {
 	BRIDGE_ATTR_HAS_VLANS,
 	BRIDGE_ATTR_STP_KERNEL,
 	BRIDGE_ATTR_STP_PROTO,
+	BRIDGE_ATTR_VLAN_PROTOCOL,
 	__BRIDGE_ATTR_MAX
 };
 
@@ -66,6 +67,7 @@ static const struct blobmsg_policy bridge_attrs[__BRIDGE_ATTR_MAX] = {
 	[BRIDGE_ATTR_HAS_VLANS] = { "__has_vlans", BLOBMSG_TYPE_BOOL }, /* internal */
 	[BRIDGE_ATTR_STP_KERNEL] = { "stp_kernel", BLOBMSG_TYPE_BOOL },
 	[BRIDGE_ATTR_STP_PROTO] = { "stp_proto", BLOBMSG_TYPE_STRING },
+	[BRIDGE_ATTR_VLAN_PROTOCOL] = { "vlan_protocol", BLOBMSG_TYPE_INT32 },
 };
 
 static const struct uci_blob_param_info bridge_attr_info[__BRIDGE_ATTR_MAX] = {
@@ -1129,6 +1131,7 @@ bridge_dump_info(struct device *dev, struct blob_buf *b)
 	blobmsg_add_u8(b, "stp_kernel", cfg->stp_kernel);
 	if (cfg->stp_proto)
 		blobmsg_add_string(b, "stp_proto", cfg->stp_proto);
+	blobmsg_add_u32(b, "vlan_protocol", cfg->vlan_protocol);
 
 	blobmsg_close_table(b, c);
 
@@ -1260,6 +1263,12 @@ bridge_apply_settings(struct bridge_state *bst, struct blob_attr **tb)
 
 	if ((cur = tb[BRIDGE_ATTR_VLAN_FILTERING]))
 		cfg->vlan_filtering = blobmsg_get_bool(cur);
+
+	if ((cur = tb[BRIDGE_ATTR_VLAN_PROTOCOL]))
+		cfg->vlan_protocol = blobmsg_get_u32(cur);
+
+	if (cfg->vlan_protocol != VLAN_PROTO_8021AD)
+		cfg->vlan_protocol = VLAN_PROTO_8021Q;
 }
 
 static enum dev_change_type

system-linux.c

@@ -1558,6 +1558,7 @@ int system_bridge_addbr(struct device *bridge, struct bridge_config *cfg)
 	}
 
 	nla_put_u8(msg, IFLA_BR_VLAN_FILTERING, !!cfg->vlan_filtering);
+	nla_put_u16(msg, IFLA_BR_VLAN_PROTOCOL, htons(cfg->vlan_protocol));
 	nla_put_u16(msg, IFLA_BR_PRIORITY, cfg->priority);
 	nla_put_u32(msg, IFLA_BR_HELLO_TIME, sec_to_jiffies(cfg->hello_time));
 	nla_put_u32(msg, IFLA_BR_MAX_AGE, sec_to_jiffies(cfg->max_age));

system.h

@@ -116,6 +116,11 @@ enum bridge_opt {
 	BRIDGE_OPT_LAST_MEMBER_INTERVAL	    = (1 << 4),
 };
 
+enum vlan_proto {
+	VLAN_PROTO_8021Q = 0x8100,
+	VLAN_PROTO_8021AD = 0x88A8
+};
+
 struct bridge_config {
 	enum bridge_opt flags;
 	bool stp;
@@ -138,6 +143,7 @@ struct bridge_config {
 	int max_age;
 	int hash_max;
 
+	enum vlan_proto vlan_protocol;
 	bool vlan_filtering;
 };
 
@@ -166,11 +172,6 @@ struct veth_config {
 	unsigned char peer_macaddr[6];
 };
 
-enum vlan_proto {
-	VLAN_PROTO_8021Q = 0x8100,
-	VLAN_PROTO_8021AD = 0x88A8
-};
-
 struct vlan_qos_mapping {
 	struct vlist_simple_node node; /* entry in vlandev_config->{e,in}gress_qos_mapping_list */
 	uint32_t from;