qcacld-3.0: Move SAP from dfs to non-dfs if sta is coming up

Currently STA will fail to start on 5G channel if SAP is up on
dfs channel already. So moving SAP from dfs to non-dfs channel
first to make sure STA connection can happen.

Change-Id: I1761debdd33b0b60755f159d598fd3c9b080ceee
CRs-Fixed: 3103726

core/hdd/src/wlan_hdd_cm_connect.c

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2012-2021, The Linux Foundation. All rights reserved.
- * Copyright (c) 2021 Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2021-2022, Qualcomm Innovation Center, Inc. All rights reserved.
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -49,6 +49,7 @@
 #include <wlan_mlme_twt_ucfg_api.h>
 #include "wlan_roam_debug.h"
 #include <wlan_hdd_regulatory.h>
+#include "wlan_hdd_hostapd.h"
 
 bool hdd_cm_is_vdev_associated(struct hdd_adapter *adapter)
 {
@@ -385,6 +386,189 @@ hdd_get_dot11mode_filter(struct hdd_context *hdd_ctx)
 		return ALLOW_ALL;
 }
 
+/**
+ * hdd_get_sap_adapter_of_dfs - Get sap adapter on dfs channel
+ * @hdd_ctx: HDD context
+ *
+ * This function is used to get the sap adapter on dfs channel.
+ *
+ * Return: pointer to adapter or null
+ */
+static struct hdd_adapter
+*hdd_get_sap_adapter_of_dfs(struct hdd_context *hdd_ctx)
+{
+	struct hdd_adapter *adapter, *next_adapter = NULL;
+	wlan_net_dev_ref_dbgid dbgid = NET_DEV_HOLD_GET_ADAPTER;
+	qdf_freq_t chan_freq = 0;
+
+	hdd_for_each_adapter_dev_held_safe(hdd_ctx, adapter, next_adapter,
+					   dbgid) {
+		if (adapter->device_mode != QDF_SAP_MODE)
+			goto loop_next;
+
+		/*
+		 * sap is not in started state and also not under doing CAC,
+		 * so it is fine to go ahead with sta.
+		 */
+		if (!test_bit(SOFTAP_BSS_STARTED, &(adapter)->event_flags) &&
+		    (hdd_ctx->dev_dfs_cac_status != DFS_CAC_IN_PROGRESS))
+			goto loop_next;
+
+		chan_freq = wlan_get_operation_chan_freq_vdev_id(hdd_ctx->pdev,
+							adapter->vdev_id);
+
+		if (chan_freq && wlan_reg_is_dfs_for_freq(hdd_ctx->pdev,
+							  chan_freq)) {
+			hdd_adapter_dev_put_debug(adapter, dbgid);
+			if (next_adapter)
+				hdd_adapter_dev_put_debug(next_adapter, dbgid);
+
+			return adapter;
+		}
+loop_next:
+		hdd_adapter_dev_put_debug(adapter, dbgid);
+	}
+
+	return NULL;
+}
+
+/**
+ * wlan_hdd_cm_handle_sap_sta_dfs_conc() - to handle SAP STA DFS conc
+ * @hdd_ctx: hdd_ctx
+ * @req: connect req
+ *
+ * This routine will move SAP from dfs to non-dfs, if sta is coming up.
+ *
+ * Return: false if sta-sap conc is not allowed, else return true
+ */
+static
+bool wlan_hdd_cm_handle_sap_sta_dfs_conc(struct hdd_context *hdd_ctx,
+					 struct cfg80211_connect_params *req)
+{
+	struct hdd_adapter *ap_adapter;
+	struct hdd_ap_ctx *hdd_ap_ctx;
+	struct hdd_hostapd_state *hostapd_state;
+	QDF_STATUS status;
+	qdf_freq_t ch_freq = 0;
+	struct scan_filter *scan_filter;
+	qdf_list_t *list = NULL;
+	qdf_list_node_t *cur_lst = NULL;
+	struct scan_cache_node *cur_node = NULL;
+
+	ap_adapter = hdd_get_sap_adapter_of_dfs(hdd_ctx);
+	/* probably no dfs sap running, no handling required */
+	if (!ap_adapter)
+		return true;
+
+	/* if sap is currently doing CAC then don't allow sta to go further */
+	if (hdd_ctx->dev_dfs_cac_status == DFS_CAC_IN_PROGRESS) {
+		hdd_err("Concurrent SAP is in CAC state, STA is not allowed");
+		return false;
+	}
+
+	/*
+	 * log and return error, if we allow STA to go through, we don't
+	 * know what is going to happen better stop sta connection
+	 */
+	hdd_ap_ctx = WLAN_HDD_GET_AP_CTX_PTR(ap_adapter);
+	if (!hdd_ap_ctx) {
+		hdd_err("AP context not found");
+		return false;
+	}
+
+	if (req->channel && req->channel->center_freq) {
+		ch_freq = req->channel->center_freq;
+		goto def_chan;
+	}
+	/*
+	 * find out by looking in to scan cache where sta is going to
+	 * connect by passing its ssid amd bssid.
+	 */
+	scan_filter = qdf_mem_malloc(sizeof(*scan_filter));
+	if (!scan_filter)
+		goto def_chan;
+
+	if (req->bssid) {
+		scan_filter->num_of_bssid = 1;
+		qdf_mem_copy(scan_filter->bssid_list[0].bytes, req->bssid,
+			     QDF_MAC_ADDR_SIZE);
+	}
+	scan_filter->num_of_ssid = 1;
+	scan_filter->ssid_list[0].length =
+				QDF_MIN(req->ssid_len, QDF_MAC_ADDR_SIZE);
+	qdf_mem_copy(scan_filter->ssid_list[0].ssid, req->ssid,
+		     scan_filter->ssid_list[0].length);
+	scan_filter->ignore_auth_enc_type = true;
+	list = ucfg_scan_get_result(hdd_ctx->pdev, scan_filter);
+	qdf_mem_free(scan_filter);
+
+	if (!list || (list && !qdf_list_size(list))) {
+		hdd_debug("scan list empty");
+		goto purge_list;
+	}
+	qdf_list_peek_front(list, &cur_lst);
+	if (!cur_lst)
+		goto purge_list;
+
+	cur_node = qdf_container_of(cur_lst, struct scan_cache_node, node);
+	ch_freq = cur_node->entry->channel.chan_freq;
+purge_list:
+	if (list)
+		ucfg_scan_purge_results(list);
+def_chan:
+	/*
+	 * If the STA's channel is 2.4 GHz, then set pcl with only 2.4 GHz
+	 * channels for roaming case.
+	 */
+	if (WLAN_REG_IS_24GHZ_CH_FREQ(ch_freq)) {
+		hdd_info("sap is on dfs, new sta conn on 2.4 is allowed");
+		return true;
+	}
+
+	/*
+	 * If channel is 0 or DFS or LTE unsafe then better to call pcl and
+	 * find out the best channel. If channel is non-dfs 5 GHz then
+	 * better move SAP to STA's channel to make scc, so we have room
+	 * for 3port MCC scenario.
+	 */
+	if (!ch_freq || wlan_reg_is_dfs_for_freq(hdd_ctx->pdev, ch_freq) ||
+	    !policy_mgr_is_safe_channel(hdd_ctx->psoc, ch_freq))
+		ch_freq = policy_mgr_get_nondfs_preferred_channel(
+			hdd_ctx->psoc, PM_SAP_MODE, true);
+
+	hostapd_state = WLAN_HDD_GET_HOSTAP_STATE_PTR(ap_adapter);
+	qdf_event_reset(&hostapd_state->qdf_event);
+	wlan_hdd_set_sap_csa_reason(hdd_ctx->psoc, ap_adapter->vdev_id,
+				    CSA_REASON_STA_CONNECT_DFS_TO_NON_DFS);
+
+	status = wlansap_set_channel_change_with_csa(
+			WLAN_HDD_GET_SAP_CTX_PTR(ap_adapter), ch_freq,
+			hdd_ap_ctx->sap_config.ch_width_orig, false);
+
+	if (QDF_STATUS_SUCCESS != status) {
+		hdd_err("Set channel with CSA IE failed, can't allow STA");
+		return false;
+	}
+
+	/*
+	 * wait here for SAP to finish the channel switch. When channel
+	 * switch happens, SAP sends few beacons with CSA_IE. After
+	 * successfully Transmission of those beacons, it will move its
+	 * state from started to disconnected and move to new channel.
+	 * once it moves to new channel, sap again moves its state
+	 * machine from disconnected to started and set this event.
+	 * wait for 10 secs to finish this.
+	 */
+	status = qdf_wait_for_event_completion(&hostapd_state->qdf_event,
+					       10000);
+	if (!QDF_IS_STATUS_SUCCESS(status)) {
+		hdd_err("wait for qdf_event failed, STA not allowed!!");
+		return false;
+	}
+
+	return true;
+}
+
 int wlan_hdd_cm_connect(struct wiphy *wiphy,
 			struct net_device *ndev,
 			struct cfg80211_connect_params *req)
@@ -427,6 +611,12 @@ int wlan_hdd_cm_connect(struct wiphy *wiphy,
 
 	hdd_reg_wait_for_country_change(hdd_ctx);
 
+	if (policy_mgr_is_hw_dbs_capable(hdd_ctx->psoc) &&
+	    !wlan_hdd_cm_handle_sap_sta_dfs_conc(hdd_ctx, req)) {
+		hdd_err("sap-sta conc will fail, can't allow sta");
+		return -EINVAL;
+	}
+
 	qdf_mem_zero(&params, sizeof(params));
 	ucfg_blm_dump_black_list_ap(hdd_ctx->pdev);
 	vdev = hdd_objmgr_get_vdev_by_user(adapter, WLAN_OSIF_CM_ID);