Add disable_scan_offload parameter to disable automatic scan offloading

This new configuration parameter can be used to disable automatic
offloading of scan requests to the driver which was previously used
by default if the driver supported sched_scan.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>

wpa_supplicant/config.c

@@ -2822,6 +2822,7 @@ static const struct global_parse_data global_fields[] = {
 #endif /* CONFIG_CTRL_IFACE */
 	{ INT_RANGE(eapol_version, 1, 2), 0 },
 	{ INT(ap_scan), 0 },
+	{ INT(disable_scan_offload), 0 },
 	{ INT(fast_reauth), 0 },
 	{ STR(opensc_engine_path), 0 },
 	{ STR(pkcs11_engine_path), 0 },

wpa_supplicant/config.h

@@ -243,6 +243,15 @@ struct wpa_config {
 	 */
 	int ap_scan;
 
+	/**
+	 * disable_scan_offload - Disable automatic offloading of scan requests
+	 *
+	 * By default, %wpa_supplicant tries to offload scanning if the driver
+	 * indicates support for this (sched_scan). This configuration
+	 * parameter can be used to disable this offloading mechanism.
+	 */
+	int disable_scan_offload;
+
 	/**
 	 * ctrl_interface - Parameters for the control interface
 	 *

wpa_supplicant/config_file.c

@@ -710,6 +710,9 @@ static void wpa_config_write_global(FILE *f, struct wpa_config *config)
 		fprintf(f, "eapol_version=%d\n", config->eapol_version);
 	if (config->ap_scan != DEFAULT_AP_SCAN)
 		fprintf(f, "ap_scan=%d\n", config->ap_scan);
+	if (config->disable_scan_offload)
+		fprintf(f, "disable_scan_offload=%d\n",
+			config->disable_scan_offload);
 	if (config->fast_reauth != DEFAULT_FAST_REAUTH)
 		fprintf(f, "fast_reauth=%d\n", config->fast_reauth);
 	if (config->opensc_engine_path)

wpa_supplicant/scan.c

@@ -755,7 +755,7 @@ int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 		max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 	else
 		max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
-	if (max_sched_scan_ssids < 1)
+	if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 		return -1;
 
 	if (wpa_s->sched_scanning) {