Allow interface to be selected

Author: maggie44

README.md

@@ -16,9 +16,9 @@ Enjoy and please do feel free to feedback experiences and issues.
 You can specify a Wi-Fi connection you would like your device to try and connect to the first time it loads by using the environment variables in the docker-compose.yml file. Once this connection is established, the device will stay connected after reboots until you use the `forget` endpoint. If the network is not available, the hotspot will start instead.
 
 ````
-PWC_SSID: "network-name" # The SSID of the network you would like to try and auto-connect.
-USERNAME: "username" # Optional, for enterprise networks
-PWC_PASSWORD: "your-password" # Optional, the password associated with the Wi-Fi network. Must be 8 characters or more. 
+PWC_AC_SSID: "network-name" # The SSID of the network you would like to try and auto-connect.
+PWC_AC_USERNAME: "username" # Optional, for enterprise networks
+PWC_AC_PASSWORD: "your-password" # Optional, the password associated with the Wi-Fi network. Must be 8 characters or more. 
 ````
 
 ## Securing the API
@@ -32,6 +32,21 @@ Users will then be unable to access the API `http://your-device:9090/v1/connect`
 
 Alternatively, if you would rather have your backend use specified ports instead of the host network, you can change the `PWC_HOST` environment variable to `172.17.0.1` and access the API from `http://172.17.0.1:9090/v1/connect`.
 
+## Changing the default interface
+By default, the first available Wi-Fi interface available will be used. For the vast majority of cases there is only one Wi-Fi interface (`wlan0`) and therefore this is no issue. Similarly, if you plug in a Wi-Fi dongle to a device without its own built-in Wi-Fi, the Wi-Fi dongle will be used by default. If however, you have a device with built in Wi-Fi and a Wi-Fi dongle, you will have a device with two interfaces (usually `wlan0` and `wlan1`). For these instances, or on other occasions where you have a complex interface setup, you can specify which interface you would like Py Wi-Fi Connect to use by setting the environment variable shown in the `docker-compose.yml` file:
+
+````
+PWC_INTERFACE: "wlan0" // Optional. 
+````
+
+To allow for automatic detection, set the variable to `false` or remove the variable from your `docker-compose.yml` file:
+
+````
+PWC_INTERFACE: false
+````
+
+This setting can also be controlled using the `/set_interface` endpoint.
+
 ## LED Indicator
 Some devices - such as the Raspberry Pi series - have an LED that can be controlled. When your device is connected to Wi-Fi, Python Wi-Fi Connect turns the LED on. When disconnected or in Hotspot mode, it turns the LED off.
 
@@ -83,7 +98,7 @@ When passing `"all_networks": false` this endpoint will only touch Wi-Fi connect
 #### POST
 ````
 {
-    "all_networks": false
+    "all_networks": false // Optional. Defaults to False.
 }
 ````
 
@@ -146,3 +161,25 @@ Requests are returned immediately and then the process is executed. Otherwise us
     "message": "ok"
 }
 ````
+
+### http://your-device:9090/v1//set_interface
+
+By default the Wi-Fi interface is auto-detected. If you need to specify an interface, you can do so using this endpoint. 
+
+To set back to auto-detection, pass `false` as the value.
+
+Changing the setting will only last until the next restart of the container, when it will resort back to the default setting set by the environment variable in the container. 
+
+#### POST
+````
+{
+    "all_networks": "wlan0" // Optional.
+}
+````
+
+#### Response status 200
+````
+{
+    "message": "ok"
+}
+````

docker-compose.yml

@@ -9,17 +9,20 @@ services:
 
       ## Hotspot details ##
       PWC_HOTSPOT_SSID: "Py Wi-Fi Connect"
-      #HOTSPOT_PASSWORD: "my-hotspot-password" # Optional hotspot password. Must be 8 characters or more.
+      #PWC_HOTSPOT_PASSWORD: "my-hotspot-password" # Optional. Must be 8 characters or more.
 
       ## Try to automatically set up a Wi-Fi network on first boot ##
-      #PWC_SSID: "network-name" # Compulsory for this feature
-      #USERNAME: "username" # Optional
-      #PWC_PASSWORD: "your-password" # Optional. Must be 8 characters or more.
+      #PWC_AC_SSID: "network-name" # Compulsory for this feature
+      #PWC_AC_USERNAME: "username" # Optional
+      #PWC_AC_PASSWORD: "your-password" # Optional. Must be 8 characters or more.
+
+      ## Wi-Fi Interface ##
+      # PWC_INTERFACE: 'wlan0' # When disabled interface is auto detected
 
       ## Enable/Disable LED interaction ##
       PWC_LED: "ON"
 
-      ## Required System Variables ##
+      ## Required system variables ##
       DBUS_SYSTEM_BUS_ADDRESS: "unix:path=/host/run/dbus/system_bus_socket"
     build:
       context: .
@@ -30,4 +33,4 @@ services:
       io.balena.features.dbus: '1'
     cap_add:
       - NET_ADMIN
-    privileged: true # This can be removed if you do not need the LED indicator (see the docs for more info).
+    privileged: true # This can be removed if you do not need the LED indicator.

src/common/errors.py

@@ -27,6 +27,11 @@ class WifiConnectionFailed(Exception):
     pass
 
 
+# Error classes for Flask-Restful
+class WifiDeviceNotFound(Exception):
+    pass
+
+
 class WifiHotspotStartFailed(Exception):
     pass
 
@@ -49,6 +54,10 @@ class WifiNoSuitableDevice(Exception):
          "message": "System error while establishing Wi-Fi connection.",
          "status": 500
      },
+    "WifiDeviceNotFound": {
+         "message": "Requested device not available.",
+         "status": 500
+     },
     "WifiHotspotStartFailed": {
          "message": "System error starting hotspot.",
          "status": 500

src/common/nm_dicts.py

@@ -24,9 +24,10 @@ def get_nm_dict(conn_type, ssid, username, password):
         }
 
         # Include a key-mgmt string in hotspot if setting a password
-        if password:
+        if config.hotspot_password:
             password_key_mgmt = {'802-11-wireless-security':
-                                 {'key-mgmt': 'wpa-psk', 'psk': password}}
+                                 {'key-mgmt': 'wpa-psk',
+                                  'psk': config.hotspot_password}}
 
             hs_dict.update(password_key_mgmt)
 

src/common/wifi.py

@@ -1,10 +1,11 @@
 import config
-import NetworkManager
+import NetworkManager as Pnm  # Python NetworkManager
 import socket
 import subprocess
 import time
 from common.errors import logger
 from common.errors import WifiConnectionFailed
+from common.errors import WifiDeviceNotFound
 from common.errors import WifiHotspotStartFailed
 from common.errors import WifiNetworkManagerError
 from common.errors import WifiNoSuitableDevice
@@ -23,8 +24,8 @@ def analyse_access_point(ap):
     # Based on a subset of the AP_SEC flag settings
     # (https://developer.gnome.org/NetworkManager/1.2/nm-dbus-types.html#NM80211ApSecurityFlags)
     # to determine which type of security this AP uses.
-    AP_SEC = NetworkManager.NM_802_11_AP_SEC_NONE
-    if ap.Flags & NetworkManager.NM_802_11_AP_FLAGS_PRIVACY and \
+    AP_SEC = Pnm.NM_802_11_AP_SEC_NONE
+    if ap.Flags & Pnm.NM_802_11_AP_FLAGS_PRIVACY and \
             ap.WpaFlags == AP_SEC and \
             ap.RsnFlags == AP_SEC:
         security = config.type_wep
@@ -36,9 +37,9 @@ def analyse_access_point(ap):
         security = config.type_wpa2
 
     if ap.WpaFlags & \
-        NetworkManager.NM_802_11_AP_SEC_KEY_MGMT_802_1X or \
+        Pnm.NM_802_11_AP_SEC_KEY_MGMT_802_1X or \
             ap.RsnFlags & \
-            NetworkManager.NM_802_11_AP_SEC_KEY_MGMT_802_1X:
+            Pnm.NM_802_11_AP_SEC_KEY_MGMT_802_1X:
         security = config.type_enterprise
 
     entry = {"ssid": ap.Ssid,
@@ -69,7 +70,7 @@ def auto_connect(ssid=None,
 # Returns True when a connection to a router is made, or the Hotspot is live
 def check_device_state():
     # Save the wi-fi device object to a variable
-    if get_device().State == NetworkManager.NM_DEVICE_STATE_ACTIVATED:
+    if get_device().State == Pnm.NM_DEVICE_STATE_ACTIVATED:
         return True
     else:
         return False
@@ -112,24 +113,20 @@ def connect(conn_type=config.type_hotspot,
     # Remove any existing connection made by this app
     forget()
 
-    # If user has specified a password for their hotspot
-    if conn_type == config.type_hotspot and config.hotspot_password:
-        password = config.hotspot_password
-
     # Get the correct config based on type requested
     conn_dict = get_nm_dict(conn_type, ssid, username, password)
 
     try:
-        NetworkManager.Settings.AddConnection(conn_dict)
+        Pnm.Settings.AddConnection(conn_dict)
         logger.info(f"Adding connection of type {conn_type}")
 
         # Save the wi-fi device object to a variable
         dev = get_device()
 
         # Connect
-        NetworkManager.NetworkManager.ActivateConnection(get_connection_id(),
-                                                         dev,
-                                                         "/")
+        Pnm.NetworkManager.ActivateConnection(get_connection_id(),
+                                              dev,
+                                              "/")
 
         # If not a hotspot, log the connection SSID being attempted
         if conn_type != config.type_hotspot:
@@ -174,7 +171,7 @@ def forget(create_new_hotspot=False, all_networks=False):
     # Find and delete the hotspot connection
     try:
         if all_networks:
-            for connection in NetworkManager.Settings.ListConnections():
+            for connection in Pnm.Settings.ListConnections():
                 if connection.GetSettings()["connection"]["type"] \
                         == "802-11-wireless":
                     # Delete the identified connection
@@ -183,6 +180,8 @@ def forget(create_new_hotspot=False, all_networks=False):
                     logger.debug(f"Deleted connection: {network_id}")
         else:
             connection_id = get_connection_id()
+            # connection_id returns false if it is missing. This can be ignored
+            # as this function is often called as a precautionary clean up
             if connection_id:
                 connection_id.Delete()
                 logger.debug(f"Deleted connection: {config.ap_name}")
@@ -204,7 +203,7 @@ def forget(create_new_hotspot=False, all_networks=False):
 
 def get_connection_id():
     connection = dict([(x.GetSettings()['connection']['id'], x)
-                      for x in NetworkManager.Settings.ListConnections()])
+                      for x in Pnm.Settings.ListConnections()])
 
     if config.ap_name in connection:
         return connection[config.ap_name]
@@ -213,11 +212,26 @@ def get_connection_id():
 
 
 def get_device():
+    # Configured interface variable takes precedent.
+    if config.interface:
+        logger.debug(f"Interface {config.interface} selected.")
+        for device in Pnm.NetworkManager.GetDevices():
+            if device.DeviceType != Pnm.NM_DEVICE_TYPE_WIFI:
+                continue
+            # For each Wi-Fi network interface, check the interface name
+            # against the one configured in config.interface
+            if (device.Udi[device.Udi.rfind('/')+1:].lower()
+                    == config.interface.lower()):
+                return device
+            else:
+                raise WifiDeviceNotFound
+
+    # Fetch last Wi-Fi interface found
     devices = dict([(x.DeviceType, x)
-                   for x in NetworkManager.NetworkManager.GetDevices()])
+                   for x in Pnm.NetworkManager.GetDevices()])
 
-    if NetworkManager.NM_DEVICE_TYPE_WIFI in devices:
-        return devices[NetworkManager.NM_DEVICE_TYPE_WIFI]
+    if Pnm.NM_DEVICE_TYPE_WIFI in devices:
+        return devices[Pnm.NM_DEVICE_TYPE_WIFI]
     else:
         logger.error("No suitable or available device found.")
         raise WifiNoSuitableDevice

src/config.py

@@ -1,3 +1,4 @@
+import json
 import os
 
 # Set default Wi-Fi SSID.
@@ -25,17 +26,24 @@
     port = 9090
 
 # Compile kwargs for automatic connection
-if "PWC_SSID" in os.environ:
+if "PWC_AC_SSID" in os.environ:
     auto_connect_kargs = \
-        {"ssid": os.environ['PWC_SSID']}
+        {"ssid": os.environ['PWC_AC_SSID']}
 
-    if "PWC_USERNAME" in os.environ:
-        auto_connect_kargs.update(username=os.environ['PWC_USERNAME'])
-    if "PWC_PASSWORD" in os.environ:
-        auto_connect_kargs.update(password=os.environ['PWC_PASSWORD'])
+    if "PWC_AC_USERNAME" in os.environ:
+        auto_connect_kargs.update(username=os.environ['PWC_AC_USERNAME'])
+    if "PWC_AC_PASSWORD" in os.environ:
+        auto_connect_kargs.update(password=os.environ['PWC_AC_PASSWORD'])
 else:
     auto_connect_kargs = False
 
+# Set default interface
+if "PWC_INTERFACE" in os.environ and \
+        json.loads(os.environ['PWC_INTERFACE']) is not False:
+    interface = os.environ['PWC_INTERFACE']
+else:
+    interface = False
+
 # Default access point name. No need to change these under usual operation as
 # they are for use inside the app only. PWC is acronym for 'Py Wi-Fi Connect'.
 ap_name = 'PWC'

src/resources/wifi_routes.py

@@ -1,3 +1,4 @@
+import config
 import threading
 from common.errors import logger
 from common.wifi import check_internet_status
@@ -49,21 +50,20 @@ def post(self):
         if not check_wifi_status():
             return {'message': 'Device is already disconnected.'}, 409
 
-        # Check the all_networks boolean is valid
+        # Check the all_networks boolean
         if (not request.get_json() or
-            'all_networks' not in request.get_json()
-                or type(request.get_json()['all_networks']) is not bool):
-            return {'message': "all_networks boolean missing or is not "
-                               "a boolean."}, 202
+                'all_networks' not in request.get_json()):
+            forget_mode = False
+        else:
+            forget_mode = request.get_json()['all_networks']
 
         # Use threading so the response can be returned before the user is
         # disconnected.
         wifi_forget_thread = threading.Thread(target=forget,
                                               kwargs={'create_new_hotspot':
                                                       True,
                                                       'all_networks':
-                                                      request.get_json()
-                                                      ['all_networks']})
+                                                      forget_mode})
 
         logger.info('Removing connetion...')
         wifi_forget_thread.start()
@@ -76,3 +76,15 @@ def get(self):
         ssids, iw_status = list_access_points()
 
         return {'ssids': ssids, 'iw_compatible': iw_status}
+
+
+class wifi_set_interface(Resource):
+    def post(self):
+        # Check entry exists
+        if (not request.get_json() or
+                'interface' not in request.get_json()):
+            return {'message': 'Interface value not provided.'}, 500
+        else:
+            config.interface = request.get_json()['interface']
+            logger.info(f"Interface changed to {config.interface}")
+            return {'message': 'ok'}, 200

src/run.py

@@ -18,6 +18,7 @@
 from resources.wifi_routes import wifi_connection_status
 from resources.wifi_routes import wifi_forget
 from resources.wifi_routes import wifi_list_access_points
+from resources.wifi_routes import wifi_set_interface
 from waitress import serve
 
 
@@ -35,6 +36,7 @@
 api.add_resource(wifi_connection_status, '/v1/connection_status')
 api.add_resource(wifi_forget, '/v1/forget')
 api.add_resource(wifi_list_access_points, '/v1/list_access_points')
+api.add_resource(wifi_set_interface, '/v1/set_interface')
 
 if __name__ == '__main__':
     # Begin loading program
@@ -46,6 +48,10 @@
     # Allow time for an exsiting saved Wi-Fi connection to connect.
     time.sleep(10)
 
+    # Log interface status
+    if config.interface:
+        logger.info(f"Interface set to {config.interface}")
+
     # If the Wi-Fi connection or device is already active, do nothing
     if check_wifi_status() or check_device_state():
         led(1)