qcacld-3.0: Fix connect issue with hidden AP

Currently driver maintains scan cache per BSSID. For hidden
ssid ap, if beacon(null ssid) is received later than probersp
(non null ssid), the scan entry from probersp will be removed.
When connection happens, it can't get match AP by
csr_scan_get_result, which causes connection fail.

If beacon/probersp are both received in a single scan, ignore
beacon and only store probersp to tempScanResults list as it
has non-null ssid.

Change-Id: I9e9ba2fafdf3ba20d43e8b9a7068235373b4c7b3
CRs-Fixed: 2099728

1 files changed, 106 insertions, 7 deletions

diff --git a/core/sme/src/csr/csr_api_scan.c b/core/sme/src/csr/csr_api_scan.c
index 8f5390a21475..8c1e311bf8f3 100644
--- a/core/sme/src/csr/csr_api_scan.c
+++ b/core/sme/src/csr/csr_api_scan.c
@@ -2798,6 +2798,63 @@ static void csr_check_n_save_wsc_ie(tpAniSirGlobal pMac,
 	}
 }
 
+
+/**
+ * csr_check_hidden_ssid_entry() - Used for checking if probersp entry for
+ * hidden ssid ap has existed or not.
+ * @mac_ctx: pointer to Global MAC structure
+ * @bssdesc_old:  bss desc has existed in the list
+ * @bssdesc_new:  bss desc will be added to the list
+ *
+ * This function will return true if new desc's ssid is null and the existed
+ * bss desc's ssid is not null.
+ *
+ * Return:
+ *        true   - probersp entry has existed
+ *        false  - probersp entry doesn't exist
+ */
+static bool csr_check_hidden_ssid_entry(tpAniSirGlobal mac_ctx,
+				      tSirBssDescription *bssdesc_old,
+				      tSirBssDescription *bssdesc_new)
+{
+	bool is_hiddenap_probersp_entry_present = false;
+	tDot11fBeaconIEs *p_ies_old = NULL;
+	tDot11fBeaconIEs *p_ies_new = NULL;
+	QDF_STATUS status;
+
+	status = csr_get_parsed_bss_description_ies(mac_ctx, bssdesc_old,
+							&p_ies_old);
+	if (!QDF_IS_STATUS_SUCCESS(status))
+		goto free_ies;
+
+	status = csr_get_parsed_bss_description_ies(mac_ctx, bssdesc_new,
+							&p_ies_new);
+	if (!QDF_IS_STATUS_SUCCESS(status))
+		goto free_ies;
+
+
+	if (p_ies_old->SSID.present && p_ies_new->SSID.present
+		&& csr_is_nullssid(
+			p_ies_new->SSID.ssid, p_ies_new->SSID.num_ssid)
+		&& !csr_is_nullssid(
+			p_ies_old->SSID.ssid, p_ies_old->SSID.num_ssid)) {
+		/*
+		 * This is for hidden ssid. When beacon(null ssid) receives late
+		 * than probersp(non-null ssid), it should not duplicate the
+		 * non-null ssid scan entry. otherwise, it can't get match AP by
+		 * csr_scan_get_result when connection happens.
+		 */
+		is_hiddenap_probersp_entry_present = true;
+	}
+
+free_ies:
+	if (p_ies_old)
+		qdf_mem_free(p_ies_old);
+	if (p_ies_new)
+		qdf_mem_free(p_ies_new);
+	return is_hiddenap_probersp_entry_present;
+}
+
 /* pIes may be NULL */
 static bool csr_remove_dup_bss_description(tpAniSirGlobal pMac,
 					   tSirBssDescription *bss_dscp,
@@ -3417,6 +3474,7 @@ struct tag_csrscan_result *csr_scan_append_bss_description(tpAniSirGlobal pMac,
 	tmpSsid.length = 0;
 	result = csr_remove_dup_bss_description(pMac, pSirBssDescription,
 						&tmpSsid, &timer);
+
 	pCsrBssDescription = csr_scan_save_bss_description(pMac,
 					pSirBssDescription, pIes, sessionId);
 	if (result && (pCsrBssDescription != NULL)) {
@@ -4619,10 +4677,25 @@ bool csr_scan_complete(tpAniSirGlobal pMac, tSirSmeScanRsp *pScanRsp)
 	return fRemoveCommand;
 }
 
+/**
+ * csr_scan_remove_dup_bss_description_from_interim_list() - To remove duplicate
+ * entry in interim scan list
+ *
+ * @mac_ctx - MAC context
+ * @bss_dscp - new bss_dscp will be added to list
+ * @flags - flag to indicate if rssi update is needed
+ * @is_hiddenap_probersp_entry_present - value return to indicate if probersp
+ * entry for hidden ssid ap has existed
+ *
+ * To check and remove if duplicate entry existed in interim list.
+ *
+ * Return: none.
+ */
 static void
 csr_scan_remove_dup_bss_description_from_interim_list(tpAniSirGlobal mac_ctx,
-					tSirBssDescription *bss_dscp,
-					uint32_t flags)
+				tSirBssDescription *bss_dscp,
+				uint32_t flags,
+				bool *is_hiddenap_probersp_entry_present)
 {
 	tListElem *pEntry;
 	struct tag_csrscan_result *scan_bss_dscp;
@@ -4679,6 +4752,25 @@ csr_scan_remove_dup_bss_description_from_interim_list(tpAniSirGlobal mac_ctx,
 					(100 - CSR_SCAN_RESULT_RSSI_WEIGHT)))
 					/ 100);
 			}
+
+			*is_hiddenap_probersp_entry_present =
+				csr_check_hidden_ssid_entry(mac_ctx,
+					&scan_bss_dscp->Result.BssDescriptor,
+					bss_dscp);
+			if (*is_hiddenap_probersp_entry_present) {
+				/*
+				 * In the temp list we have a probe resp and we
+				 * don't want to overwrite this with beacon in
+				 * case of hidden AP scenario.
+				 * but rssi must be updated.
+				 */
+				scan_bss_dscp->Result.BssDescriptor.rssi =
+							bss_dscp->rssi;
+				scan_bss_dscp->Result.BssDescriptor.rssi_raw =
+							bss_dscp->rssi_raw;
+				break;
+			}
+
 			/* Remove the 'old' entry from the list */
 			if (csr_ll_remove_entry(&mac_ctx->scan.tempScanResults,
 				pEntry, LL_ACCESS_NOLOCK)) {
@@ -4783,7 +4875,6 @@ bool csr_is_duplicate_bss_description(tpAniSirGlobal pMac,
 	    qdf_is_macaddr_equal((struct qdf_mac_addr *) pSirBssDesc1->bssId,
 				 (struct qdf_mac_addr *) pSirBssDesc2->bssId)) {
 		fMatch = true;
-		/* Check for SSID match, if exists */
 	}
 	/* In case of P2P devices, ess and ibss will be set to zero */
 	else if (!pCap1->ess &&
@@ -4992,6 +5083,7 @@ QDF_STATUS csr_scan_process_single_bssdescr(tpAniSirGlobal mac_ctx,
 	uint32_t len = sizeof(mac_ctx->roam.validChannelList);
 	tCsrRoamInfo *roam_info;
 	uint8_t session_id;
+	bool is_hiddenap_probersp_entry_present = false;
 
 	session_id = csr_scan_get_session_id(mac_ctx);
 	sme_debug("CSR: Processing single bssdescr");
@@ -5010,7 +5102,12 @@ QDF_STATUS csr_scan_process_single_bssdescr(tpAniSirGlobal mac_ctx,
 			cnt_channels, bssdescr, &ies)) {
 
 		csr_scan_remove_dup_bss_description_from_interim_list
-			(mac_ctx, bssdescr, flags);
+			(mac_ctx, bssdescr, flags,
+			&is_hiddenap_probersp_entry_present);
+
+		if (is_hiddenap_probersp_entry_present)
+			goto exit;
+
 		csr_scan_save_bss_description_to_interim_list
 			(mac_ctx, bssdescr, ies);
 		roam_info = qdf_mem_malloc(sizeof(*roam_info));
@@ -5048,10 +5145,12 @@ QDF_STATUS csr_scan_process_single_bssdescr(tpAniSirGlobal mac_ctx,
 				csr_purge_scan_result_by_age(mac_ctx);
 		}
 		csr_update_scantype(mac_ctx, ies, bssdescr->channelId);
-		/* Free the resource */
-		if (ies != NULL)
-			qdf_mem_free(ies);
 	}
+
+exit:
+	/* Free the resource */
+	if (ies != NULL)
+		qdf_mem_free(ies);
 	return QDF_STATUS_SUCCESS;
 }