Make maximum BSS table size configurable

New global configuration parameter bss_max_count can now be used to
change the maximum BSS table size. The old fixed size limit (200) is
used as the default value for this parameter.

wpa_supplicant/bss.c

@@ -19,15 +19,12 @@
 #include "common/ieee802_11_defs.h"
 #include "drivers/driver.h"
 #include "wpa_supplicant_i.h"
+#include "config.h"
 #include "notify.h"
 #include "scan.h"
 #include "bss.h"
 
 
-#ifndef WPA_BSS_MAX_COUNT
-#define WPA_BSS_MAX_COUNT 200
-#endif /* WPA_BSS_MAX_COUNT */
-
 /**
  * WPA_BSS_EXPIRATION_PERIOD - Period of expiration run in seconds
  */
@@ -139,7 +136,7 @@ static void wpa_bss_add(struct wpa_supplicant *wpa_s,
 	wpa_printf(MSG_DEBUG, "BSS: Add new id %u BSSID " MACSTR " SSID '%s'",
 		   bss->id, MAC2STR(bss->bssid), wpa_ssid_txt(ssid, ssid_len));
 	wpas_notify_bss_added(wpa_s, bss->bssid, bss->id);
-	if (wpa_s->num_bss > WPA_BSS_MAX_COUNT) {
+	if (wpa_s->num_bss > wpa_s->conf->bss_max_count) {
 		/* Remove the oldest entry */
 		wpa_bss_remove(wpa_s, dl_list_first(&wpa_s->bss,
 						    struct wpa_bss, list));

wpa_supplicant/config.c

@@ -2086,6 +2086,7 @@ struct wpa_config * wpa_config_alloc_empty(const char *ctrl_interface,
 	config->eapol_version = DEFAULT_EAPOL_VERSION;
 	config->ap_scan = DEFAULT_AP_SCAN;
 	config->fast_reauth = DEFAULT_FAST_REAUTH;
+	config->bss_max_count = DEFAULT_BSS_MAX_COUNT;
 
 	if (ctrl_interface)
 		config->ctrl_interface = os_strdup(ctrl_interface);

wpa_supplicant/config.h

@@ -22,6 +22,7 @@
 #define DEFAULT_AP_SCAN 1
 #endif /* CONFIG_NO_SCAN_PROCESSING */
 #define DEFAULT_FAST_REAUTH 1
+#define DEFAULT_BSS_MAX_COUNT 200
 
 #include "config_ssid.h"
 
@@ -331,6 +332,11 @@ struct wpa_config {
 	 *	ctrl_iface to external program(s)
 	 */
 	int wps_cred_processing;
+
+	/**
+	 * bss_max_count - Maximum number of BSS entries to keep in memory
+	 */
+	unsigned int bss_max_count;
 };
 
 

wpa_supplicant/config_file.c

@@ -457,7 +457,8 @@ static const struct global_parse_data global_fields[] = {
 	{ STR(config_methods) },
 	{ INT_RANGE(wps_cred_processing, 0, 2) },
 #endif /* CONFIG_WPS */
-	{ FUNC(country) }
+	{ FUNC(country) },
+	{ INT(bss_max_count) }
 };
 
 #undef FUNC
@@ -889,6 +890,8 @@ static void wpa_config_write_global(FILE *f, struct wpa_config *config)
 		fprintf(f, "country=%c%c\n",
 			config->country[0], config->country[1]);
 	}
+	if (config->bss_max_count != DEFAULT_BSS_MAX_COUNT)
+		fprintf(f, "bss_max_count=%u\n", config->bss_max_count);
 }
 
 #endif /* CONFIG_NO_CONFIG_WRITE */

wpa_supplicant/config_winreg.c

@@ -257,6 +257,9 @@ static int wpa_config_read_global(struct wpa_config *config, HKEY hk)
 				  &config->wps_cred_processing);
 #endif /* CONFIG_WPS */
 
+	wpa_config_read_reg_dword(hk, TEXT("bss_max_count"),
+				  &config->bss_max_count);
+
 	return errors ? -1 : 0;
 }
 
@@ -583,6 +586,10 @@ static int wpa_config_write_global(struct wpa_config *config, HKEY hk)
 				   config->wps_cred_processing, 0);
 #endif /* CONFIG_WPS */
 
+	wpa_config_write_reg_dword(hk, TEXT("bss_max_count"),
+				   config->bss_max_count,
+				   DEFAULT_BSS_MAX_COUNT);
+
 	return 0;
 }
 

wpa_supplicant/wpa_supplicant.conf

@@ -210,6 +210,14 @@ fast_reauth=1
 #	to external program(s)
 #wps_cred_processing=0
 
+# Maximum number of BSS entries to keep in memory
+# Default: 200
+# This can be used to limit memory use on the BSS entries (cached scan
+# results). A larger value may be needed in environments that have huge number
+# of APs when using ap_scan=1 mode.
+#bss_max_count=200
+
+
 # network block
 #
 # Each network (usually AP's sharing the same SSID) is configured as a separate