[nrf fromtree] openthread: map Thread network interface state

The current mapping gets the network interface into dormant state when
Thread is not attached. While the node is not capable of doing multi-hop
communication when it's not attached, it should be able to do link-local
communication. This commit changes the mapping to look at OpenThread's
own network interface state instead without further checking Thread's
device role, so that link-local communication is supported when a node
in detached state.

Signed-off-by: Yakun Xu <[email protected]>
(cherry picked from commit eddb1af)

Author: bukepo

subsys/net/l2/openthread/Kconfig

@@ -353,4 +353,14 @@ config OPENTHREAD_PLATFORM_KEYS_EXPORTABLE_ENABLE
 	help
 	  Enable the creation of exportable MAC keys in the OpenThread Key Manager.
 
+config OPENTHREAD_INTERFACE_EARLY_UP
+	bool "Make OpenThread interface ready as soon as Thread is enabled"
+	help
+	  When enabled, OpenThread interface will be marked ready (operational
+	  UP) as soon as Thread has been enabled. This means the interface will
+	  be ready to transmit application packets during the Mesh Link
+	  Establishment phase.
+	  Otherwise, OpenThread interface will be marked operational UP only
+	  after the device joins a Thread network.
+
 endif # NET_L2_OPENTHREAD_IMPLEMENTATION_ZEPHYR

subsys/net/l2/openthread/openthread.c

@@ -187,12 +187,20 @@ static void ot_state_changed_handler(uint32_t flags, void *context)
 {
 	struct openthread_state_changed_cb *entry, *next;
 	struct openthread_context *ot_context = context;
+	bool is_up = otIp6IsEnabled(ot_context->instance);
 
-	NET_INFO("State changed! Flags: 0x%08" PRIx32 " Current role: %s",
+	NET_INFO("State changed! Flags: 0x%08" PRIx32 " Current role: %s Ip6: %s",
 		flags,
-		otThreadDeviceRoleToString(otThreadGetDeviceRole(ot_context->instance))
-		);
+		otThreadDeviceRoleToString(otThreadGetDeviceRole(ot_context->instance)),
+		(is_up ? "up" : "down"));
 
+#if defined(CONFIG_OPENTHREAD_INTERFACE_EARLY_UP)
+	if (is_up) {
+		net_if_dormant_off(ot_context->iface);
+	} else {
+		net_if_dormant_on(ot_context->iface);
+	}
+#else
 	if (flags & OT_CHANGED_THREAD_ROLE) {
 		switch (otThreadGetDeviceRole(ot_context->instance)) {
 		case OT_DEVICE_ROLE_CHILD:
@@ -208,6 +216,7 @@ static void ot_state_changed_handler(uint32_t flags, void *context)
 			break;
 		}
 	}
+#endif
 
 	if (flags & OT_CHANGED_IP6_ADDRESS_REMOVED) {
 		NET_DBG("Ipv6 address removed");