bridge: only overwrite implicit vlan assignment if vlans are configured

When VLAN filtering is enabled, but no vlans are defined, the implicit
VLANs should stay, so that forwarding between ports still works.
This is useful for setups where VLANs are assigned by external scripts
instead of being configured via netifd

Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 16 insertions, 6 deletions

diff --git a/config.c b/config.c
index 3546787..8122a95 100644
--- a/config.c
+++ b/config.c
@@ -76,18 +76,15 @@ config_bridge_has_vlans(const char *br_name)
 }
 
 static void
-config_fixup_bridge_vlan_filtering(struct uci_section *s, const char *name)
+config_fixup_bridge_var(struct uci_section *s, const char *name, const char *val)
 {
 	struct uci_ptr ptr = {
 		.p = s->package,
 		.s = s,
-		.option = "vlan_filtering",
-		.value = "1",
+		.option = name,
+		.value = val,
 	};
 
-	if (!config_bridge_has_vlans(name))
-		return;
-
 	uci_lookup_ptr(uci_ctx, &ptr, NULL, false);
 	if (ptr.o)
 		return;
@@ -95,6 +92,19 @@ config_fixup_bridge_vlan_filtering(struct uci_section *s, const char *name)
 	uci_set(uci_ctx, &ptr);
 }
 
+static void
+config_fixup_bridge_vlan_filtering(struct uci_section *s, const char *name)
+{
+	bool has_vlans = config_bridge_has_vlans(name);
+
+	config_fixup_bridge_var(s, "__has_vlans", has_vlans ? "1" : "0");
+
+	if (!has_vlans)
+		return;
+
+	config_fixup_bridge_var(s, "vlan_filtering", "1");
+}
+
 static int
 config_parse_bridge_interface(struct uci_section *s, struct device_type *devtype)
 {