auto-t: add test for roaming retry timing

Recent changes make iwd more eager to retry roaming if it has detected a
high RSSI since the last attempt. Add an autotest to verify this
behaviour.

autotests/testRoamRetry/fast_retry_test.py

@@ -0,0 +1,145 @@
+#!/usr/bin/python3
+
+import unittest
+import sys
+
+sys.path.append('../util')
+import iwd
+from iwd import IWD
+from iwd import PSKAgent
+from iwd import NetworkType
+
+import testutil
+
+from hostapd import HostapdCLI
+from hwsim import Hwsim
+
+class Test(unittest.TestCase):
+    # Normally the time between a failed roam attempt and the next roam attempt
+    # is 60 seconds (default RoamRetryInterval). Test that we retry roaming
+    # faster if the transision looks like this: LOW [roam] [same bss] HIGH LOW.
+    def test_fast_retry(self):
+        hwsim = Hwsim()
+
+        bss_hostapd = [ HostapdCLI(config='ssid1.conf'),
+                        HostapdCLI(config='ssid2.conf') ]
+        bss_radio =  [ hwsim.get_radio('rad0'),
+                       hwsim.get_radio('rad1') ]
+
+        rule0 = hwsim.rules.create()
+        rule0.source = bss_radio[0].addresses[0]
+        rule0.bidirectional = True
+
+        rule1 = hwsim.rules.create()
+        rule1.source = bss_radio[1].addresses[0]
+        rule1.bidirectional = True
+
+        # Fill in the neighbor AP tables in both BSSes.  By default each
+        # instance knows only about current BSS, even inside one hostapd
+        # process.
+        # Roaming still works without the neighbor AP table but neighbor
+        # reports have to be disabled in the .conf files
+        bss0_nr = ''.join(bss_radio[0].addresses[0].split(':')) + \
+                '8f0000005101060603000000'
+        bss1_nr = ''.join(bss_radio[1].addresses[0].split(':')) + \
+                '8f0000005102060603000000'
+
+        bss_hostapd[0].set_neighbor(bss_radio[1].addresses[0], 'TestRoamRetry',
+                bss1_nr)
+        bss_hostapd[1].set_neighbor(bss_radio[0].addresses[0], 'TestRoamRetry',
+                bss0_nr)
+
+        # Start in the vicinity of BSS 0, check that iwd connects to BSS 0
+        rule0.signal = -2000
+        rule1.signal = -8500
+
+        wd = IWD()
+
+        psk_agent = PSKAgent("secret123")
+        wd.register_psk_agent(psk_agent)
+
+        devices = wd.list_devices(1)
+        device = devices[0]
+
+        condition = 'not obj.scanning'
+        wd.wait_for_object_condition(device, condition)
+
+        device.scan()
+
+        condition = 'not obj.scanning'
+        wd.wait_for_object_condition(device, condition)
+
+        ordered_network = device.get_ordered_network('TestRoamRetry')
+
+        self.assertEqual(ordered_network.type, NetworkType.psk)
+
+        condition = 'not obj.connected'
+        wd.wait_for_object_condition(ordered_network.network_object, condition)
+
+        ordered_network.network_object.connect()
+
+        condition = 'obj.state == DeviceState.connected'
+        wd.wait_for_object_condition(device, condition)
+
+        self.assertTrue(bss_hostapd[0].list_sta())
+        self.assertFalse(bss_hostapd[1].list_sta())
+
+        wd.wait(5)
+
+        # Now push the signal LOW, wait for iwd to attempt a roam, fail, and
+        # schedule another attempt for 60 seconds later
+        rule0.signal = -8000
+
+        wd.wait(20)
+
+        self.assertEqual(device.state, iwd.DeviceState.connected)
+        self.assertTrue(bss_hostapd[0].list_sta())
+        self.assertFalse(bss_hostapd[1].list_sta())
+
+        testutil.test_iface_operstate(device.name)
+        testutil.test_ifaces_connected(bss_hostapd[0].ifname, device.name)
+
+        # Assert high signal for BSS 0 again. This clears the way for a faster
+        # roam attempt on LOW again
+        rule0.signal = -5000
+
+        # Wait a little for signal recognition
+        wd.wait(1)
+
+        # Assert low signal for BSS 0, check that iwd starts transition to BSS 1
+        # in less than 10 seconds. Because of the neighbor report a scan should
+        # not be necessary.
+        rule0.signal = -8000
+        rule1.signal = -2000
+
+        condition = 'obj.state == DeviceState.roaming'
+        wd.wait_for_object_condition(device, condition, max_wait=10)
+
+        # Check that iwd is on BSS 1 once out of roaming state and doesn't
+        # go through 'disconnected', 'autoconnect', 'connecting' in between
+        condition = 'obj.state != DeviceState.roaming'
+        wd.wait_for_object_condition(device, condition, max_wait=5)
+
+        self.assertEqual(device.state, iwd.DeviceState.connected)
+        self.assertTrue(bss_hostapd[1].list_sta())
+
+        device.disconnect()
+
+        condition = 'not obj.connected'
+        wd.wait_for_object_condition(ordered_network.network_object, condition)
+
+        wd.unregister_psk_agent(psk_agent)
+
+        rule0.remove()
+        rule1.remove()
+
+    @classmethod
+    def setUpClass(cls):
+        pass
+
+    @classmethod
+    def tearDownClass(cls):
+        IWD.clear_storage()
+
+if __name__ == '__main__':
+    unittest.main(exit=True)

autotests/testRoamRetry/hw.conf

@@ -0,0 +1,7 @@
+[SETUP]
+num_radios=3
+needs_hwsim=1
+
+[HOSTAPD]
+rad0=ssid1.conf
+rad1=ssid2.conf

autotests/testRoamRetry/ssid1.conf

@@ -0,0 +1,11 @@
+hw_mode=g
+channel=1
+ssid=TestRoamRetry
+
+wpa=2
+wpa_pairwise=CCMP
+wpa_passphrase=secret123
+
+ctrl_interface=/var/run/hostapd
+
+rrm_neighbor_report=1

autotests/testRoamRetry/ssid2.conf

@@ -0,0 +1,11 @@
+hw_mode=g
+channel=2
+ssid=TestRoamRetry
+
+wpa=2
+wpa_pairwise=CCMP
+wpa_passphrase=secret123
+
+ctrl_interface=/var/run/hostapd
+
+rrm_neighbor_report=1