tor: Add option to toggle bridge relay

actions/tor

@@ -53,6 +53,8 @@ def parse_arguments():
     configure = subparsers.add_parser('configure', help='Configure Tor')
     configure.add_argument('--service', choices=['enable', 'disable'],
                            help='Configure Tor service')
+    configure.add_argument('--relay', choices=['enable', 'disable'],
+                           help='Configure relay')
     configure.add_argument('--hidden-service', choices=['enable', 'disable'],
                            help='Configure hidden service')
     configure.add_argument('--apt-transport-tor',
@@ -123,6 +125,12 @@ def subcommand_configure(arguments):
     if arguments.service == 'disable':
         _disable()
 
+    restart = arguments.service == None and arguments.hidden_service == None
+    if arguments.relay == 'enable':
+        _enable_relay(restart=restart)
+    elif arguments.relay == 'disable':
+        _disable_relay(restart=restart)
+
     restart = arguments.service == None
     if arguments.hidden_service == 'enable':
         _enable_hs(restart=restart)
@@ -140,7 +148,17 @@ def subcommand_configure(arguments):
 
 def get_status():
     """Return dict with Tor status."""
-    return {'ports': get_ports(), 'hidden_service': get_hidden_service()}
+    return {'relay_enabled': is_relay_enabled(),
+            'ports': get_ports(),
+            'hidden_service': get_hidden_service()}
+
+
+def is_relay_enabled():
+    """Return whether bridge relay is enabled."""
+    aug = augeas_load()
+    orport = aug.get(TOR_CONFIG + '/ORPort')
+    bridge = aug.get(TOR_CONFIG + '/BridgeRelay')
+    return orport == 'auto' and bridge == '1'
 
 
 def get_ports():
@@ -227,6 +245,30 @@ def _disable():
     action_utils.service_disable('tor')
 
 
+def _enable_relay(restart=True):
+    """Enable Tor bridge relay."""
+    aug = augeas_load()
+    aug.set(TOR_CONFIG + '/ORPort', 'auto')
+    aug.set(TOR_CONFIG + '/BridgeRelay', '1')
+    aug.save()
+
+    if restart:
+        if is_enabled() and is_running():
+            action_utils.service_restart('tor')
+
+
+def _disable_relay(restart=False):
+    """Disable Tor bridge relay."""
+    aug = augeas_load()
+    aug.remove(TOR_CONFIG + '/ORPort')
+    aug.set(TOR_CONFIG + '/BridgeRelay', '0')
+    aug.save()
+
+    if restart:
+        if is_enabled() and is_running():
+            action_utils.service_restart('tor')
+
+
 def _enable_hs(restart=True):
     """Enable Tor hidden service"""
     if get_hidden_service()['enabled']:

plinth/modules/tor/forms.py

@@ -31,6 +31,13 @@ class TorForm(forms.Form):  # pylint: disable=W0232
     enabled = forms.BooleanField(
         label=_('Enable Tor'),
         required=False)
+    relay_enabled = forms.BooleanField(
+        label=_('Enable Tor bridge relay'),
+        required=False,
+        help_text=format_lazy(_(
+            'When enabled, your {box_name} will run a Tor bridge relay with '
+            'obfsproxy, so it can help circumvent censorship.'),
+                              box_name=_(cfg.box_name)))
     hs_enabled = forms.BooleanField(
         label=_('Enable Tor Hidden Service'),
         required=False,

plinth/modules/tor/templates/tor.html

@@ -93,17 +93,15 @@
              value="{% trans "Update setup" %}"/>
     </form>
 
-    <h3>{% trans "Bridge" %}</h3>
-
+    {% if status.relay_enabled %}
+    <h3>{% trans "Bridge Relay" %}</h3>
     <p>
       {% blocktrans trimmed %}
-        Your {{ box_name }} is configured as a Tor bridge with obfsproxy,
-        so it can help circumvent censorship. If your {{ box_name }} is
-        behind a router or firewall, you should make sure the following
-        ports are open, and port-forwarded, if necessary:
+        If your {{ box_name }} is behind a router or firewall, you should
+        make sure the following ports are open, and port-forwarded, if
+        necessary:
       {% endblocktrans %}
     </p>
-
     <div class="row">
       <div class="col-sm-3">
         <table class="table table-bordered table-condensed table-striped">
@@ -124,6 +122,7 @@
         </table>
       </div>
     </div>
+    {% endif %}
 
     <h3>{% trans "SOCKS" %}</h3>
 

plinth/modules/tor/utils.py

@@ -59,6 +59,7 @@ def get_status():
 
     return {'enabled': is_enabled(),
             'is_running': is_running(),
+            'relay_enabled': status['relay_enabled'],
             'ports': ports,
             'hs_enabled': hs_info['enabled'],
             'hs_status': hs_info['status'],

plinth/modules/tor/views.py

@@ -80,6 +80,10 @@ def __apply_changes(request, old_status, new_status):
         arg_value = 'enable' if new_status['enabled'] else 'disable'
         arguments.extend(['--service', arg_value])
 
+    if old_status['relay_enabled'] != new_status['relay_enabled']:
+        arg_value = 'enable' if new_status['relay_enabled'] else 'disable'
+        arguments.extend(['--relay', arg_value])
+
     if old_status['hs_enabled'] != new_status['hs_enabled']:
         arg_value = 'enable' if new_status['hs_enabled'] else 'disable'
         arguments.extend(['--hidden-service', arg_value])