[ncp] add property to instruct NCP to leave gracefully (#10337)

This commit adds a new property SPINEL_PROP_NET_LEAVE_GRACEFULLY. The
host can trigger otThreadDetachGracefully by setting this spinel
property. Hence a SetProperty handler is implemented for this
property. A GetProperty handler is also added for this property for a
property response.

src/lib/spinel/spinel.c

@@ -1287,6 +1287,7 @@ const char *spinel_prop_key_to_cstr(spinel_prop_key_t prop_key)
         {SPINEL_PROP_NET_REQUIRE_JOIN_EXISTING, "NET_REQUIRE_JOIN_EXISTING"},
         {SPINEL_PROP_NET_KEY_SWITCH_GUARDTIME, "NET_KEY_SWITCH_GUARDTIME"},
         {SPINEL_PROP_NET_PSKC, "NET_PSKC"},
+        {SPINEL_PROP_NET_LEAVE_GRACEFULLY, "NET_LEAVE_GRACEFULLY"},
         {SPINEL_PROP_THREAD_LEADER_ADDR, "THREAD_LEADER_ADDR"},
         {SPINEL_PROP_THREAD_PARENT, "THREAD_PARENT"},
         {SPINEL_PROP_THREAD_CHILD_TABLE, "THREAD_CHILD_TABLE"},

src/lib/spinel/spinel.h

@@ -2370,6 +2370,12 @@ enum
      */
     SPINEL_PROP_NET_PSKC = SPINEL_PROP_NET__BEGIN + 11,
 
+    /// Instruct NCP to leave the current network gracefully
+    /** Format Empty - Write only
+     *
+     */
+    SPINEL_PROP_NET_LEAVE_GRACEFULLY = SPINEL_PROP_NET__BEGIN + 12,
+
     SPINEL_PROP_NET__END = 0x50,
 
     SPINEL_PROP_NET_EXT__BEGIN = 0x1400,

src/ncp/changed_props_set.cpp

@@ -77,6 +77,7 @@ const ChangedPropsSet::Entry ChangedPropsSet::mSupportedProps[] = {
     {SPINEL_PROP_NET_XPANID, SPINEL_STATUS_OK, true},
     {SPINEL_PROP_NET_NETWORK_KEY, SPINEL_STATUS_OK, true},
     {SPINEL_PROP_NET_PSKC, SPINEL_STATUS_OK, true},
+    {SPINEL_PROP_NET_LEAVE_GRACEFULLY, SPINEL_STATUS_OK, false},
     {SPINEL_PROP_PHY_CHAN_SUPPORTED, SPINEL_STATUS_OK, true},
 #if OPENTHREAD_CONFIG_CHANNEL_MANAGER_ENABLE
     {SPINEL_PROP_CHANNEL_MANAGER_NEW_CHANNEL, SPINEL_STATUS_OK, true},

src/ncp/ncp_base.hpp

@@ -615,6 +615,10 @@ protected:
 
 #endif // OPENTHREAD_ENABLE_NCP_VENDOR_HOOK
 
+    static void ThreadDetachGracefullyHandler(void *aContext);
+
+    void ThreadDetachGracefullyHandler(void);
+
 protected:
     static NcpBase        *sNcpInstance;
     static spinel_status_t ThreadErrorToSpinelStatus(otError aError);

src/ncp/ncp_base_dispatcher.cpp

@@ -100,6 +100,7 @@ NcpBase::PropertyHandler NcpBase::FindGetPropertyHandler(spinel_prop_key_t aKey)
 #if OPENTHREAD_FTD
         OT_NCP_GET_HANDLER_ENTRY(SPINEL_PROP_NET_PSKC),
 #endif
+        OT_NCP_GET_HANDLER_ENTRY(SPINEL_PROP_NET_LEAVE_GRACEFULLY),
         OT_NCP_GET_HANDLER_ENTRY(SPINEL_PROP_THREAD_LEADER_ADDR),
         OT_NCP_GET_HANDLER_ENTRY(SPINEL_PROP_THREAD_PARENT),
 #if OPENTHREAD_FTD
@@ -452,6 +453,9 @@ NcpBase::PropertyHandler NcpBase::FindSetPropertyHandler(spinel_prop_key_t aKey)
         OT_NCP_SET_HANDLER_ENTRY(SPINEL_PROP_NET_KEY_SWITCH_GUARDTIME),
 #if OPENTHREAD_FTD
         OT_NCP_SET_HANDLER_ENTRY(SPINEL_PROP_NET_PSKC),
+#endif
+        OT_NCP_SET_HANDLER_ENTRY(SPINEL_PROP_NET_LEAVE_GRACEFULLY),
+#if OPENTHREAD_FTD
         OT_NCP_SET_HANDLER_ENTRY(SPINEL_PROP_THREAD_LOCAL_LEADER_WEIGHT),
 #endif
         OT_NCP_SET_HANDLER_ENTRY(SPINEL_PROP_THREAD_ASSISTING_PORTS),

src/ncp/ncp_base_mtd.cpp

@@ -4552,6 +4552,24 @@ exit:
     return error;
 }
 
+template <> otError NcpBase::HandlePropertyGet<SPINEL_PROP_NET_LEAVE_GRACEFULLY>(void) { return OT_ERROR_NONE; }
+
+template <> otError NcpBase::HandlePropertySet<SPINEL_PROP_NET_LEAVE_GRACEFULLY>(void)
+{
+    return otThreadDetachGracefully(mInstance, ThreadDetachGracefullyHandler, this);
+}
+
+void NcpBase::ThreadDetachGracefullyHandler(void *aContext)
+{
+    static_cast<NcpBase *>(aContext)->ThreadDetachGracefullyHandler();
+}
+
+void NcpBase::ThreadDetachGracefullyHandler(void)
+{
+    mChangedPropsSet.AddProperty(SPINEL_PROP_NET_LEAVE_GRACEFULLY);
+    mUpdateChangedPropsTask.Post();
+}
+
 // ----------------------------------------------------------------------------
 // MARK: Property/Status Changed
 // ----------------------------------------------------------------------------