[PATCH] hwsim tests: add test to check disconnect in powersave

[Johannes Berg]

From: Johannes Berg <johannes.berg at intel.com>

The kernel had two bugs (one in hwsim and one more important
one in mac80211) in this area, add a test to make sure we can
disconnect without any kernel issues while in powersave.

Also make sure that the TIM bit gets set and cleared again
(by checking with tshark.)

Change-Id: Iec74967a54926e718af2935a4c9c837c6ce3252c
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
---
 tests/hwsim/hwsim_utils.py  |  8 ++++++
 tests/hwsim/test_ap_open.py | 60 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/tests/hwsim/hwsim_utils.py b/tests/hwsim/hwsim_utils.py
index edf0a4242472..31432619811e 100644
--- a/tests/hwsim/hwsim_utils.py
+++ b/tests/hwsim/hwsim_utils.py
@@ -149,3 +149,11 @@ def test_connectivity_p2p_sta(dev1, dev2, dscp=None, tos=None):
 
 def test_connectivity_sta(dev1, dev2, dscp=None, tos=None):
     test_connectivity(dev1, dev2, dscp, tos)
+
+(PS_DISABLED, PS_ENABLED, PS_AUTO_POLL, PS_MANUAL_POLL) = range(4)
+
+def set_powersave(dev, val):
+    phy = dev.get_driver_status_field("phyname")
+    psf = open('/sys/kernel/debug/ieee80211/%s/hwsim/ps' % phy, 'w')
+    psf.write('%d\n' % val)
+    psf.close()
diff --git a/tests/hwsim/test_ap_open.py b/tests/hwsim/test_ap_open.py
index 7a646b8ab407..ea8827445e9a 100644
--- a/tests/hwsim/test_ap_open.py
+++ b/tests/hwsim/test_ap_open.py
@@ -9,6 +9,7 @@ logger = logging.getLogger()
 import struct
 import subprocess
 import time
+import os
 
 import hostapd
 import hwsim_utils
@@ -201,3 +202,62 @@ def test_ap_open_out_of_memory(dev, apdev):
     # verify that a new interface can still be added when memory allocation does
     # not fail
     hostapd.add_ap(apdev[1]['ifname'], { "ssid": "open" })
+
+def test_ap_open_disconnect_in_ps(dev, apdev, params):
+    """disconnect with the client in PS to regression-test a kernel bug"""
+    hapd = hostapd.add_ap(apdev[0]['ifname'], { "ssid": "open" })
+    dev[0].connect("open", key_mgmt="NONE", scan_freq="2412",
+                   bg_scan_period="0")
+    ev = hapd.wait_event([ "AP-STA-CONNECTED" ], timeout=5)
+    if ev is None:
+        raise Exception("No connection event received from hostapd")
+
+    hwsim_utils.set_powersave(dev[0], hwsim_utils.PS_MANUAL_POLL)
+    try:
+        # inject some traffic
+        sa = hapd.own_addr()
+        da = dev[0].own_addr()
+        hapd.request('DATA_TEST_TX {} {} 0'.format(da, sa))
+
+        # let the AP send two beacons
+        time.sleep(0.2)
+
+        # disconnect - with traffic pending - shouldn't cause kernel warnings
+        dev[0].request("DISCONNECT")
+    finally:
+        hwsim_utils.set_powersave(dev[0], hwsim_utils.PS_DISABLED)
+
+    # wait a bit to make it more likely for wlantest sniffer to have captured
+    # and written the results into a file that we can process here
+    time.sleep(1)
+
+    try:
+        arg = [ "tshark",
+                "-r", os.path.join(params['logdir'], "hwsim0.pcapng"),
+                "-Y", "wlan_mgt.tim.partial_virtual_bitmap",
+                "-Tfields", "-e", "wlan_mgt.tim.partial_virtual_bitmap" ]
+        cmd = subprocess.Popen(arg, stdout=subprocess.PIPE,
+                               stderr=open('/dev/null', 'w'))
+    except Exception, e:
+        logger.info("Could run run tshark check: " + str(e))
+        cmd = None
+
+    if cmd:
+        (out,err) = cmd.communicate()
+        res = cmd.wait()
+        if res == 1:
+            arg[3] = '-R'
+            cmd = subprocess.Popen(arg, stdout=subprocess.PIPE,
+                                   stderr=open('/dev/null', 'w'))
+            (out,err) = cmd.communicate()
+            res = cmd.wait()
+
+        state = 0
+        for l in out.splitlines():
+            pvb = int(l, 16)
+            if pvb > 0 and state == 0:
+                state = 1
+            elif pvb == 0 and state == 1:
+                state = 2
+        if state != 2:
+            raise Exception("didn't observe TIM bit getting set and unset")
-- 
2.1.1