qcacld-3.0: Validate hidden ssid after roaming to avoid disconnection

After roam synch indication is received, the driver compares the
SSID of the current AP and SSID of the roamed AP. If there is a
mismatch, driver issues disassociate to current connected AP.
This causes data path queues to be stopped and M2 to the roamed
AP from userspace will fail. The SSID of the current AP is
parsed from the beacon IEs stored in the connected bss
description. In hidden ssid case the SSID IE has 0 length
and the host receives unicast probe with SSID of the
AP in the roam synch indication. So SSID mismatch happens
and validation fails.

Check if the current SSID in the bss description is NULL.
If its NULL, get the SSID from the connected profile in csr
session.

Change-Id: I30c41b821c0fc506d763eb33f8bb706dd26b405a
CRs-Fixed: 2544915

core/sme/src/csr/csr_api_roam.c

@@ -5125,6 +5125,74 @@ QDF_STATUS csr_roam_set_bss_config_cfg(struct mac_context *mac, uint32_t session
 	return QDF_STATUS_SUCCESS;
 }
 
+/**
+ * csr_check_for_hidden_ssid_match() - Check if the current connected SSID
+ * is hidden ssid and if it matches with the roamed AP ssid.
+ * @mac: Global mac context pointer
+ * @session: csr session pointer
+ * @roamed_bss_desc: pointer to bss descriptor of roamed bss
+ * @roamed_bss_ies: Roamed AP beacon/probe IEs pointer
+ *
+ * Return: True if the SSID is hidden and matches with roamed SSID else false
+ */
+static bool
+csr_check_for_hidden_ssid_match(struct mac_context *mac,
+				struct csr_roam_session *session,
+				struct bss_description *roamed_bss_desc,
+				tDot11fBeaconIEs *roamed_bss_ies)
+{
+	QDF_STATUS status;
+	bool is_null_ssid_match = false;
+	tDot11fBeaconIEs *connected_profile_ies = NULL;
+
+	if (!session || !roamed_bss_ies)
+		return false;
+
+	status = csr_get_parsed_bss_description_ies(mac,
+						    session->pConnectBssDesc,
+						    &connected_profile_ies);
+	if (QDF_IS_STATUS_ERROR(status)) {
+		sme_err("Unable to get IES");
+		goto error;
+	}
+
+	if (!csr_is_nullssid(connected_profile_ies->SSID.ssid,
+			     connected_profile_ies->SSID.num_ssid))
+		goto error;
+
+	/*
+	 * After roam synch indication is received, the driver compares
+	 * the SSID of the current AP and SSID of the roamed AP. If
+	 * there is a mismatch, driver issues disassociate to current
+	 * connected AP. This causes data path queues to be stopped and
+	 * M2 to the roamed AP from userspace will fail if EAPOL is
+	 * offloaded to userspace. The SSID of the current AP is
+	 * parsed from the beacon IEs stored in the connected bss
+	 * description. In hidden ssid case the SSID IE has 0 length
+	 * and the host receives unicast probe with SSID of the
+	 * AP in the roam synch indication. So SSID mismatch happens
+	 * and validation fails. So fetch if the connected bss
+	 * description has hidden ssid, fill the ssid from the
+	 * csr_session connected_profile structure which will
+	 * have the SSID.
+	 */
+	if (!roamed_bss_ies->SSID.present)
+		goto error;
+
+	if (roamed_bss_ies->SSID.num_ssid !=
+	    session->connectedProfile.SSID.length)
+		goto error;
+
+	is_null_ssid_match = !qdf_mem_cmp(session->connectedProfile.SSID.ssId,
+					  roamed_bss_ies->SSID.ssid,
+					  roamed_bss_ies->SSID.num_ssid);
+error:
+	if (connected_profile_ies)
+		qdf_mem_free(connected_profile_ies);
+
+	return is_null_ssid_match;
+}
+
 static
 QDF_STATUS csr_roam_stop_network(struct mac_context *mac, uint32_t sessionId,
 				 struct csr_roam_profile *roam_profile,
@@ -5134,6 +5202,7 @@ QDF_STATUS csr_roam_stop_network(struct mac_context *mac, uint32_t sessionId,
 	QDF_STATUS status;
 	struct bss_config_param *pBssConfig;
 	struct csr_roam_session *pSession = CSR_GET_SESSION(mac, sessionId);
+	bool ssid_match;
 
 	if (!pSession) {
 		sme_err("session %d not found", sessionId);
@@ -5175,10 +5244,16 @@ QDF_STATUS csr_roam_stop_network(struct mac_context *mac, uint32_t sessionId,
 			 * (roaming to a new SSID)...
 			 * Not worry about WDS connection for now
 			 */
+			ssid_match =
+				csr_check_for_hidden_ssid_match(mac, pSession,
+								bss_desc, pIes);
+			if (!ssid_match)
+				ssid_match = csr_is_ssid_equal(
+						mac, pSession->pConnectBssDesc,
+						bss_desc, pIes);
+
 			if (bss_desc &&
-			    (csr_is_ibss_bss_desc(bss_desc) ||
-			     !csr_is_ssid_equal(mac, pSession->pConnectBssDesc,
-						bss_desc, pIes)))
+			    (csr_is_ibss_bss_desc(bss_desc) || !ssid_match))
 				status = csr_roam_issue_disassociate(mac,
 						sessionId, substate, false);
 			else if (bss_desc)