[PATCH 3/3] tests: MLD reassociation with stale per-link BSS entries

[Louis Kotze]

Verify that an affiliated link whose BSS table entry is older than the
kernel accepts for association gets refreshed with an ML probe on
reconnection, instead of the association failing in the kernel ("Error
fetching BSS for link") and the connection degrading to a single link.

Signed-off-by: Louis Kotze <loukot at gmail.com>
---
 tests/hwsim/test_eht.py | 49 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/tests/hwsim/test_eht.py b/tests/hwsim/test_eht.py
index 5767213fb..f0281d3f1 100644
--- a/tests/hwsim/test_eht.py
+++ b/tests/hwsim/test_eht.py
@@ -1043,6 +1043,55 @@ def test_eht_mld_connect_probes_hidden(dev, apdev, params):
     """MLD client sends ML probe with SSID to connect to not discovered links"""
     _eht_mld_connect_probes(params, hidden=True)
 
+def test_eht_mld_reconnect_stale_links(dev, apdev, params):
+    """MLD client uses ML probe to refresh stale link entries on reconnection"""
+    with HWSimRadio(use_mlo=True) as (hapd_radio, hapd_iface), \
+        HWSimRadio(use_mlo=True) as (wpas_radio, wpas_iface):
+
+        wpas = WpaSupplicant(global_iface='/tmp/wpas-wlan5')
+        wpas.interface_add(wpas_iface)
+        check_sae_capab(wpas)
+
+        ssid = "mld_ap"
+        passphrase = 'qwertyuiop'
+        link_params = eht_mld_ap_wpa2_params(ssid, passphrase, mfp="2",
+                                             key_mgmt="SAE", pwe='2')
+        link_params['channel'] = '1'
+        link_params['bssid'] = '00:11:22:33:44:01'
+        hapd0 = eht_mld_enable_ap(hapd_iface, 0, link_params)
+
+        link_params['channel'] = '6'
+        link_params['bssid'] = '00:11:22:33:44:02'
+        hapd1 = eht_mld_enable_ap(hapd_iface, 1, link_params)
+
+        wpas.set("sae_pwe", "1")
+        # Make sure the BSS entries do not get removed from wpa_supplicant's
+        # BSS table while aging them below, so that the stale entry handling
+        # (and not the missing entry handling) gets exercised.
+        wpas.set("bss_expiration_age", "3600")
+        wpas.connect(ssid, sae_password=passphrase, ieee80211w="2",
+                     key_mgmt="SAE", scan_freq="2412")
+        eht_verify_status(wpas, hapd0, 2412, 20, is_ht=True, mld=True,
+                          valid_links=3, active_links=3)
+
+        wpas.request("DISCONNECT")
+        wpas.wait_disconnected()
+
+        # Age the BSS table entries beyond the kernel's freshness limit for
+        # association (IEEE80211_SCAN_RESULT_EXPIRE = 30 seconds) while
+        # keeping them in wpa_supplicant's BSS table (bss_expiration_age is
+        # 180 seconds by default). The reconnection scan covers only the
+        # first link (scan_freq=2412), so the second link needs to be
+        # refreshed with an ML probe before association can succeed.
+        time.sleep(35)
+
+        wpas.request("RECONNECT")
+        wpas.wait_connected()
+        eht_verify_status(wpas, hapd0, 2412, 20, is_ht=True, mld=True,
+                          valid_links=3, active_links=3)
+        traffic_test(wpas, hapd0)
+        traffic_test(wpas, hapd1)
+
 def test_eht_tx_link_rejected_connect_other(dev, apdev, params):
     """EHT MLD AP with MLD client being rejected on TX link, but then connecting on second link"""
     with HWSimRadio(use_mlo=True) as (hapd_radio, hapd_iface), \
-- 
2.55.0