Checkbox 417/wireless detect (#507)

* add test_network_device_info.py for unit test

* modify get_ipv6_address function

* fix import issue

* fix line too long (89 > 79 characters)

* modify space

* update network_device_info.py

move dbus import to where it belong

* Update test_network_device_info.py

modify mocked input

* fix flake8 issue

* remove old comments

* modify the error msg

* modify error msg display

providers/base/bin/network_device_info.py

@@ -28,8 +28,6 @@
 from subprocess import check_output, CalledProcessError, STDOUT
 import sys
 
-import dbus
-
 from checkbox_support.parsers.modinfo import ModinfoParser
 from checkbox_support.parsers.udevadm import UdevadmParser
 
@@ -82,14 +80,14 @@ def is_iface_connected(cls, iface):
     def get_ipv4_address(interface):
         s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
         try:
-            ipv4_addr = socket.inet_ntoa(fcntl.ioctl(
-                s.fileno(),
-                0x8915,  # SIOCGIFADDR
-                struct.pack('256s', interface[:15].encode())
-            )[20:24])
-        except Exception as e:
-            print("ERROR: getting the IPv4 address for %s: %s" %
-                  (interface, repr(e)))
+
+            buffer = struct.pack('256s', interface[:15].encode())
+            # retrieve the IP address associated with a network interface.
+            data = fcntl.ioctl(s.fileno(), 0x8915, buffer)
+            ipv4_addr = socket.inet_ntoa(data[20:24])
+        except OSError as e:
+            print("OSError: failed to get the IPv4 address for %s: %s" %
+                  (interface, repr(e)), file=sys.stderr)
             ipv4_addr = "***NOT CONFIGURED***"
         finally:
             return ipv4_addr
@@ -99,7 +97,14 @@ def get_ipv6_address(interface):
         cmd = ['/sbin/ip', '-6', '-o', 'addr', 'show', 'dev', interface,
                'scope', 'link']
         proc = check_output(cmd, universal_newlines=True)
-        return proc.split()[3].strip()
+        try:
+            # If it failed at split(), it means there is no output from cmd.
+            ipv6_addr = proc.split()[3].strip()
+        except IndexError as e:
+            print("IndexError: failed to get the IPv6 address for %s: %s" %
+                  (interface, repr(e)), file=sys.stderr)
+            ipv6_addr = "***NOT CONFIGURED***"
+        return ipv6_addr
 
     @classmethod
     def get_mac_address(cls, interface):
@@ -278,7 +283,6 @@ def _driver_populate(self):
 
 
 class NMDevices():
-
     # This example lists basic information about network interfaces known to NM
     devtypes = {1: "Ethernet",
                 2: "WiFi",
@@ -296,6 +300,7 @@ def __len__(self):
         return len(self._devices)
 
     def _collect_devices(self):
+        import dbus
         bus = dbus.SystemBus()
         proxy = bus.get_object("org.freedesktop.NetworkManager",
                                "/org/freedesktop/NetworkManager")
@@ -304,6 +309,7 @@ def _collect_devices(self):
 
     def devices(self):
         """Convert to list of NetworkDevice with NM derived attrs set"""
+        import dbus
         for d in self._devices:
             bus = dbus.SystemBus()
             dev_proxy = bus.get_object("org.freedesktop.NetworkManager", d)

providers/base/tests/test_network_device_info.py

@@ -0,0 +1,92 @@
+#!/usr/bin/env python3
+# Copyright 2020 Canonical Ltd.
+# Written by:
+#   Dio He <dio.he@canonical.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3,
+# as published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import unittest
+from io import StringIO
+from unittest.mock import Mock, patch
+from contextlib import redirect_stderr
+
+from network_device_info import Utils
+
+class GetIpv4AddressTests(unittest.TestCase):
+    # There are 2 output we could get from fcntl.ioctl():
+    # 1. No WiFi connected 
+    #    (It pulls out bytes data directly from kernel, so if the given SIOCGIFADDR doesn't exist, it raise a OSError)
+
+    # 2. Connected with WiFi
+    #    It will pulls out a 256 bytes data into buffer, then we get to parse the IP address
+    @patch("fcntl.ioctl")
+    def test_get_ipv4_address_without_connection(self, mock_ioctl):
+        mock_ioctl.side_effect = OSError()
+        interface = "wlo1"
+        with redirect_stderr(StringIO()) as stderr:
+            addr = Utils.get_ipv4_address(interface)
+
+        self.assertEqual(addr, "***NOT CONFIGURED***")
+
+    def test_get_ipv4_address_with_connection(self):
+        test_input = (b'wlo1\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x02\x00\x00\x00\xc0\xa8De\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
+        mock_inet_ntoa = Mock(return_value=test_input)
+        with patch("fcntl.ioctl", mock_inet_ntoa):
+            interface = "wlo1"
+            addr = Utils.get_ipv4_address(interface)
+            self.assertEqual(addr, "192.168.68.101")
+
+class GetIpv6AddressTests(unittest.TestCase):
+    # There are 3 kind of output it could return, but only 2 will happen in this case.
+    # 1. No WiFi connected 
+
+    # 2. Connected with WiFi
+
+    # 3. Connected with WiFi, but we ask the wrong interface name 
+    #    (This would not happen in our case, because the name is given by NetworkManager)
+    def test_get_ipv6_address_without_connection(self):
+        test_input = ""
+        mock_check_output = Mock(return_value=test_input)
+        with patch("network_device_info.check_output", mock_check_output):
+            interface = "wlo1"
+            with redirect_stderr(StringIO()) as stderr:
+                addr = Utils.get_ipv6_address(interface)
+
+            self.assertEqual(addr, "***NOT CONFIGURED***")
+
+    def test_get_ipv6_address_with_connection(self):
+        test_input = "2: wlo1    inet6 fe80::d9eb:3f93:c7b2:86ba/64 scope link noprefixroute \       valid_lft forever preferred_lft forever"
+        mock_check_output = Mock(return_value=test_input)
+        with patch("network_device_info.check_output", mock_check_output):
+            interface = "wlo1"
+            addr = Utils.get_ipv6_address(interface)
+            self.assertEqual(addr, "fe80::d9eb:3f93:c7b2:86ba/64")
+
+if __name__ == '__main__':
+    unittest.main()