From fbd65421d0922f0b11534a8cc7590928bf09aae5 Mon Sep 17 00:00:00 2001
From: Olivier Martin <olivier@labapart.com>
Date: Tue, 20 Feb 2024 23:23:39 +0100
Subject: [PATCH] Ensure adapter is present

---
 dbus/gattlib.c                  |  4 ++++
 dbus/gattlib_adapter.c          |  8 ++++++++
 gattlib-py/gattlib/adapter.py   | 10 ++++++++++
 gattlib-py/gattlib/exception.py | 11 +++++++----
 include/gattlib.h               |  1 +
 5 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/dbus/gattlib.c b/dbus/gattlib.c
index 316a4c5..50ada2e 100644
--- a/dbus/gattlib.c
+++ b/dbus/gattlib.c
@@ -931,6 +931,10 @@ int get_bluez_device_from_mac(struct gattlib_adapter *adapter, const char *mac_a
 	char object_path[100];
 	int ret;
 
+	if (adapter->adapter_proxy == NULL) {
+		return GATTLIB_NO_ADAPTER;
+	}
+
 	if (adapter != NULL) {
 		get_device_path_from_mac_with_adapter(adapter->adapter_proxy, mac_address, object_path, sizeof(object_path));
 	} else {
diff --git a/dbus/gattlib_adapter.c b/dbus/gattlib_adapter.c
index 6a0cefd..c9002b9 100644
--- a/dbus/gattlib_adapter.c
+++ b/dbus/gattlib_adapter.c
@@ -313,6 +313,10 @@ static int _gattlib_adapter_scan_enable_with_filter(void *adapter, uuid_t **uuid
 	GVariant *rssi_variant = NULL;
 	int ret;
 
+	if ((gattlib_adapter == NULL) || (gattlib_adapter->adapter_proxy == NULL)) {
+		return GATTLIB_NO_ADAPTER;
+	}
+
 	g_variant_builder_init(&arg_properties_builder, G_VARIANT_TYPE("a{sv}"));
 
 	if (enabled_filters & GATTLIB_DISCOVER_FILTER_USE_UUID) {
@@ -444,6 +448,10 @@ int gattlib_adapter_scan_disable(void* adapter) {
 	struct gattlib_adapter *gattlib_adapter = adapter;
 	GError *error = NULL;
 
+	if (gattlib_adapter->adapter_proxy == NULL) {
+		return GATTLIB_NO_ADAPTER;
+	}
+
 	org_bluez_adapter1_call_stop_discovery_sync(gattlib_adapter->adapter_proxy, NULL, &error);
 	// Ignore the error
 
diff --git a/gattlib-py/gattlib/adapter.py b/gattlib-py/gattlib/adapter.py
index 0160f07..9087181 100644
--- a/gattlib-py/gattlib/adapter.py
+++ b/gattlib-py/gattlib/adapter.py
@@ -4,6 +4,7 @@
 # Copyright (c) 2016-2024, Olivier Martin <olivier@labapart.org>
 #
 
+import threading
 from uuid import UUID
 
 from gattlib import *
@@ -42,6 +43,7 @@ class Adapter:
         self._name = name
         self._adapter = c_void_p(None)
         self._is_opened = False  # Note: 'self._adapter != c_void_p(None)' does not seem to return the expected result
+        self._lock = threading.Lock()
 
     def __str__(self) -> str:
         if self._name:
@@ -59,20 +61,28 @@ class Adapter:
         return []
 
     def open(self):
+        self._lock.acquire()
+        if self._is_opened:
+            self._lock.release()
+            return 0
+
         self._adapter = c_void_p(None)
         ret = gattlib_adapter_open(self._name, byref(self._adapter))
         if ret == 0:
             self._is_opened = True
             if self._name is None:
                 self._name = gattlib_adapter_get_name(self._adapter)
+        self._lock.release()
         return ret
 
     def close(self):
+        self._lock.acquire()
         ret = 0
         if self._adapter:
             ret = gattlib.gattlib_adapter_close(self._adapter)
         self._is_opened = False
         self._adapter = None
+        self._lock.release()
         return ret
 
     # Use a closure to return a method that can be called by the C-library (see: https://stackoverflow.com/a/7261524/6267288)
diff --git a/gattlib-py/gattlib/exception.py b/gattlib-py/gattlib/exception.py
index 8f03843..5777199 100644
--- a/gattlib-py/gattlib/exception.py
+++ b/gattlib-py/gattlib/exception.py
@@ -12,6 +12,7 @@ GATTLIB_OUT_OF_MEMORY = 4
 GATTLIB_NOT_SUPPORTED = 5
 GATTLIB_DEVICE_ERROR = 6
 GATTLIB_DEVICE_NOT_CONNECTED = 7
+GATTLIB_NO_ADAPTER = 8
 
 GATTLIB_ERROR_MODULE_MASK      = 0xF0000000
 GATTLIB_ERROR_DBUS             = 0x10000000
@@ -22,23 +23,21 @@ GATTLIB_ERROR_INTERNAL         = 0x80000000
 class GattlibException(Exception):
     pass
 
+class NoAdapter(GattlibException):
+    pass
 
 class AdapterNotOpened(GattlibException):
     pass
 
-
 class InvalidParameter(GattlibException):
     pass
 
-
 class NotFound(GattlibException):
     pass
 
-
 class OutOfMemory(GattlibException):
     pass
 
-
 class NotSupported(GattlibException):
     pass
 
@@ -61,6 +60,8 @@ class DBusError(GattlibException):
     def __str__(self) -> str:
         if self.domain == 238 and self.code == 60964:
             return f"DBus Error: le-connection-abort-by-local"
+        elif self.domain == 238 and self.code == 60964:
+            return f"DBus Error: Timeout was reached"
         else:
             return f"DBus Error domain={self.domain},code={self.code}"
 
@@ -79,6 +80,8 @@ def handle_return(ret):
         raise DeviceError()
     elif ret == GATTLIB_DEVICE_NOT_CONNECTED:
         raise NotConnected()
+    elif ret == GATTLIB_NO_ADAPTER:
+        raise NoAdapter()
     elif (ret & GATTLIB_ERROR_MODULE_MASK) == GATTLIB_ERROR_DBUS:
         raise DBusError((ret >> 8) & 0xFFF, ret & 0xFFFF)
     elif ret == -22: # From '-EINVAL'
diff --git a/include/gattlib.h b/include/gattlib.h
index e8acf3b..2bf7fad 100644
--- a/include/gattlib.h
+++ b/include/gattlib.h
@@ -43,6 +43,7 @@ extern "C" {
 #define GATTLIB_NOT_SUPPORTED          5
 #define GATTLIB_DEVICE_ERROR           6
 #define GATTLIB_DEVICE_NOT_CONNECTED   7
+#define GATTLIB_NO_ADAPTER             8
 #define GATTLIB_ERROR_MODULE_MASK      0xF0000000
 #define GATTLIB_ERROR_DBUS             0x10000000
 #define GATTLIB_ERROR_BLUEZ            0x20000000