netifd: Link layer state awareness support on interface level

The link layer state is monitored for a given interface; an interface will be setup
when both enabled and link layer active. Likewise an interface will be teared down
when either disabled or link layer down.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

1 files changed, 100 insertions, 30 deletions

diff --git a/interface.c b/interface.c
index b2c8baf..f0fd43f 100644
--- a/interface.c
+++ b/interface.c
@@ -207,6 +207,9 @@ mark_interface_down(struct interface *iface)
 {
 	enum interface_state state = iface->state;
 
+	if (state == IFS_DOWN)
+		return;
+
 	iface->state = IFS_DOWN;
 	if (state == IFS_UP)
 		interface_event(iface, IFEV_DOWN);
@@ -219,42 +222,112 @@ mark_interface_down(struct interface *iface)
 void
 __interface_set_down(struct interface *iface, bool force)
 {
-	if (iface->state == IFS_DOWN ||
-		iface->state == IFS_TEARDOWN)
+	switch (iface->state) {
+	case IFS_UP:
+		interface_event(iface, IFEV_DOWN);
+	case IFS_SETUP:
+		iface->state = IFS_TEARDOWN;
+		interface_proto_event(iface->proto, PROTO_CMD_TEARDOWN, force);
+		if (force)
+			interface_flush_state(iface);
+
+		if (iface->dynamic)
+			vlist_delete(&interfaces, &iface->node);
+		break;
+
+	case IFS_DOWN:
+		if (iface->main_dev.dev)
+			device_release(&iface->main_dev);
+	case IFS_TEARDOWN:
+	default:
+		break;
+	}
+}
+
+static int
+__interface_set_up(struct interface *iface)
+{
+	int ret;
+
+	netifd_log_message(L_NOTICE, "Interface '%s' is setting up now\n", iface->name);
+
+	iface->state = IFS_SETUP;
+	ret = interface_proto_event(iface->proto, PROTO_CMD_SETUP, false);
+	if (ret)
+		mark_interface_down(iface);
+
+	return ret;
+}
+
+static void
+interface_check_state(struct interface *iface)
+{
+	switch (iface->state) {
+	case IFS_UP:
+		if (!iface->enabled || !iface->link_state) {
+			mark_interface_down(iface);
+			interface_proto_event(iface->proto, PROTO_CMD_TEARDOWN, false);
+		}
+		break;
+	case IFS_DOWN:
+		if (iface->enabled && iface->link_state && !config_init)
+			__interface_set_up(iface);
+		break;
+	default:
+		break;
+	}
+}
+
+static void
+interface_set_enabled(struct interface *iface, bool new_state)
+{
+	if (iface->enabled == new_state)
 		return;
 
-	if (iface->state == IFS_UP)
-		interface_event(iface, IFEV_DOWN);
-	iface->state = IFS_TEARDOWN;
-	interface_proto_event(iface->proto, PROTO_CMD_TEARDOWN, force);
-	if (force)
-		interface_flush_state(iface);
+	netifd_log_message(L_NOTICE, "Interface '%s' is %s\n", iface->name, new_state ? "enabled" : "disabled");
+	iface->enabled = new_state;
+	interface_check_state(iface);
+}
 
-	if (iface->dynamic)
-		vlist_delete(&interfaces, &iface->node);
+static void
+interface_set_link_state(struct interface *iface, bool new_state)
+{
+	if (iface->link_state == new_state)
+		return;
+
+	netifd_log_message(L_NOTICE, "Interface '%s' has link connectivity %s\n", iface->name, new_state ? "" : "loss");
+	iface->link_state = new_state;
+	interface_check_state(iface);
 }
 
 static void
 interface_cb(struct device_user *dep, enum device_event ev)
 {
 	struct interface *iface;
-	bool new_state;
+	bool new_state = false;
 
 	iface = container_of(dep, struct interface, main_dev);
 	switch (ev) {
 	case DEV_EVENT_ADD:
 		new_state = true;
-		break;
 	case DEV_EVENT_REMOVE:
-		new_state = false;
+		interface_set_available(iface, new_state);
+		if (!new_state && dep->dev->external)
+			interface_set_main_dev(iface, NULL);
+		break;
+	case DEV_EVENT_UP:
+		new_state = true;
+	case DEV_EVENT_DOWN:
+		interface_set_enabled(iface, new_state);
+		break;
+	case DEV_EVENT_LINK_UP:
+		new_state = true;
+        case DEV_EVENT_LINK_DOWN:
+		interface_set_link_state(iface, new_state);
 		break;
 	default:
-		return;
+		break;
 	}
-
-	interface_set_available(iface, new_state);
-	if (!new_state && dep->dev->external)
-		interface_set_main_dev(iface, NULL);
 }
 
 void
@@ -684,7 +757,7 @@ interface_set_l3_dev(struct interface *iface, struct device *dev)
 void
 interface_set_main_dev(struct interface *iface, struct device *dev)
 {
-	bool set_l3 = (iface->main_dev.dev == iface->l3_dev.dev);
+	bool set_l3 = (!dev || iface->main_dev.dev == iface->l3_dev.dev);
 	bool claimed = iface->l3_dev.claimed;
 
 	if (iface->main_dev.dev == dev)
@@ -694,8 +767,10 @@ interface_set_main_dev(struct interface *iface, struct device *dev)
 		interface_set_l3_dev(iface, dev);
 
 	device_add_user(&iface->main_dev, dev);
-	if (!dev)
+	if (!dev) {
+		interface_set_link_state(iface, false);
 		return;
+	}
 
 	if (claimed)
 		device_claim(&iface->l3_dev);
@@ -794,18 +869,13 @@ interface_set_up(struct interface *iface)
 
 	if (iface->main_dev.dev) {
 		ret = device_claim(&iface->main_dev);
-		if (ret)
-			return ret;
-	}
-
-	iface->state = IFS_SETUP;
-	ret = interface_proto_event(iface->proto, PROTO_CMD_SETUP, false);
-	if (ret) {
-		mark_interface_down(iface);
-		return ret;
+		if (!ret)
+			interface_check_state(iface);
 	}
+	else
+		ret = __interface_set_up(iface);
 
-	return 0;
+	return ret;
 }
 
 int