IEEE 802.11u: Allow Interworking and HESSID to be configured

The new wpa_supplicant.conf file global parameters interworking and
hessid can be used to configure wpa_supplicant to include
Interworking element in Probe Request frames.

src/common/ieee802_11_defs.h

@@ -282,6 +282,15 @@
 #define INTERWORKING_ANO_ESR 0x40
 #define INTERWORKING_ANO_UESA 0x80
 
+#define INTERWORKING_ANT_PRIVATE 0
+#define INTERWORKING_ANT_PRIVATE_WITH_GUEST 1
+#define INTERWORKING_ANT_CHARGEABLE_PUBLIC 2
+#define INTERWORKING_ANT_FREE_PUBLIC 3
+#define INTERWORKING_ANT_PERSONAL_DEVICE 4
+#define INTERWORKING_ANT_EMERGENCY_SERVICES 5
+#define INTERWORKING_ANT_TEST 6
+#define INTERWORKING_ANT_WILDCARD 15
+
 /* Advertisement Protocol ID definitions (IEEE Std 802.11u-2011) */
 enum adv_proto_id {
 	ACCESS_NETWORK_QUERY_PROTOCOL = 0,

wpa_supplicant/Makefile

@@ -209,6 +209,11 @@ CFLAGS += -DCONFIG_P2P_STRICT
 endif
 endif
 
+ifdef CONFIG_INTERWORKING
+CFLAGS += -DCONFIG_INTERWORKING
+NEED_GAS=y
+endif
+
 ifdef CONFIG_NO_WPA2
 CFLAGS += -DCONFIG_NO_WPA2
 endif

wpa_supplicant/config.c

@@ -2381,6 +2381,20 @@ static int wpa_config_process_sec_device_type(
 #endif /* CONFIG_P2P */
 
 
+static int wpa_config_process_hessid(
+	const struct global_parse_data *data,
+	struct wpa_config *config, int line, const char *pos)
+{
+	if (hwaddr_aton2(pos, config->hessid) < 0) {
+		wpa_printf(MSG_ERROR, "Line %d: Invalid hessid '%s'",
+			   line, pos);
+		return -1;
+	}
+
+	return 0;
+}
+
+
 #ifdef OFFSET
 #undef OFFSET
 #endif /* OFFSET */
@@ -2445,7 +2459,9 @@ static const struct global_parse_data global_fields[] = {
 	{ INT(bss_expiration_scan_count), 0 },
 	{ INT_RANGE(filter_ssids, 0, 1), 0 },
 	{ INT(max_num_sta), 0 },
-	{ INT_RANGE(disassoc_low_ack, 0, 1), 0 }
+	{ INT_RANGE(disassoc_low_ack, 0, 1), 0 },
+	{ INT_RANGE(interworking, 0, 1), 0 },
+	{ FUNC(hessid), 0 }
 };
 
 #undef FUNC

wpa_supplicant/config.h

@@ -426,6 +426,20 @@ struct wpa_config {
 	 * disassoc_low_ack - Disassocicate stations with massive packet loss
 	 */
 	int disassoc_low_ack;
+
+	/**
+	 * interworking - Whether Interworking (IEEE 802.11u) is enabled
+	 */
+	int interworking;
+
+	/**
+	 * hessid - Homogenous ESS identifier
+	 *
+	 * If this is set (any octet is non-zero), scans will be used to
+	 * request response only from BSSes belonging to the specified
+	 * Homogeneous ESS. This is used only if interworking is enabled.
+	 */
+	u8 hessid[ETH_ALEN];
 };
 
 

wpa_supplicant/config_file.c

@@ -703,6 +703,10 @@ static void wpa_config_write_global(FILE *f, struct wpa_config *config)
 		fprintf(f, "max_num_sta=%u\n", config->max_num_sta);
 	if (config->disassoc_low_ack)
 		fprintf(f, "disassoc_low_ack=%u\n", config->disassoc_low_ack);
+	if (config->interworking)
+		fprintf(f, "interworking=%u\n", config->interworking);
+	if (!is_zero_ether_addr(config->hessid))
+		fprintf(f, "hessid=" MACSTR "\n", MAC2STR(config->hessid));
 }
 
 #endif /* CONFIG_NO_CONFIG_WRITE */

wpa_supplicant/defconfig

@@ -457,3 +457,9 @@ CONFIG_PEERKEY=y
 
 # IEEE 802.11n (High Throughput) support (mainly for AP mode)
 #CONFIG_IEEE80211N=y
+
+# Interworking (IEEE 802.11u)
+# This can be used to enable functionality to improve interworking with
+# external networks (GAS/ANQP to learn more about the networks and network
+# selection based on available credentials).
+#CONFIG_INTERWORKING=y

wpa_supplicant/scan.c

@@ -354,41 +354,73 @@ static void wpa_supplicant_optimize_freqs(
 }
 
 
+#ifdef CONFIG_INTERWORKING
+static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
+					   struct wpabuf *buf)
+{
+	if (wpa_s->conf->interworking == 0)
+		return;
+
+	wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
+	wpabuf_put_u8(buf, 4);
+	wpabuf_put_u8(buf, 0x00);
+	wpabuf_put_u8(buf, 0x00);
+	wpabuf_put_u8(buf, 0x00);
+	wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
+
+	wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
+	wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
+		      1 + ETH_ALEN);
+	wpabuf_put_u8(buf, INTERWORKING_ANT_WILDCARD);
+	/* No Venue Info */
+	if (!is_zero_ether_addr(wpa_s->conf->hessid))
+		wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
+}
+#endif /* CONFIG_INTERWORKING */
+
+
 static struct wpabuf *
 wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s,
 			 struct wpa_driver_scan_params *params)
 {
-	struct wpabuf *wps_ie = NULL;
+	struct wpabuf *extra_ie = NULL;
 #ifdef CONFIG_WPS
 	int wps = 0;
 	enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
+#endif /* CONFIG_WPS */
 
+#ifdef CONFIG_INTERWORKING
+	if (wpa_s->conf->interworking &&
+	    wpabuf_resize(&extra_ie, 100) == 0)
+		wpas_add_interworking_elements(wpa_s, extra_ie);
+#endif /* CONFIG_INTERWORKING */
+
+#ifdef CONFIG_WPS
 	wps = wpas_wps_in_use(wpa_s, &req_type);
 
 	if (wps) {
+		struct wpabuf *wps_ie;
 		wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
 						wpa_s->wps->uuid, req_type,
 						0, NULL);
 		if (wps_ie) {
-			params->extra_ies = wpabuf_head(wps_ie);
-			params->extra_ies_len = wpabuf_len(wps_ie);
+			if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
+				wpabuf_put_buf(extra_ie, wps_ie);
+			wpabuf_free(wps_ie);
 		}
 	}
 
 #ifdef CONFIG_P2P
-	if (wps_ie) {
+	if (wps) {
 		size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
-		if (wpabuf_resize(&wps_ie, ielen) == 0) {
-			wpas_p2p_scan_ie(wpa_s, wps_ie);
-			params->extra_ies = wpabuf_head(wps_ie);
-			params->extra_ies_len = wpabuf_len(wps_ie);
-		}
+		if (wpabuf_resize(&extra_ie, ielen) == 0)
+			wpas_p2p_scan_ie(wpa_s, extra_ie);
 	}
 #endif /* CONFIG_P2P */
 
 #endif /* CONFIG_WPS */
 
-	return wps_ie;
+	return extra_ie;
 }
 
 
@@ -397,7 +429,7 @@ static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 	struct wpa_supplicant *wpa_s = eloop_ctx;
 	struct wpa_ssid *ssid;
 	int scan_req = 0, ret;
-	struct wpabuf *wps_ie;
+	struct wpabuf *extra_ie;
 	struct wpa_driver_scan_params params;
 	size_t max_ssids;
 	enum wpa_states prev_state;
@@ -558,7 +590,7 @@ static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 	}
 
 	wpa_supplicant_optimize_freqs(wpa_s, &params);
-	wps_ie = wpa_supplicant_extra_ies(wpa_s, &params);
+	extra_ie = wpa_supplicant_extra_ies(wpa_s, &params);
 
 	if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 		wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
@@ -570,10 +602,14 @@ static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 
 	params.filter_ssids = wpa_supplicant_build_filter_ssids(
 		wpa_s->conf, &params.num_filter_ssids);
+	if (extra_ie) {
+		params.extra_ies = wpabuf_head(extra_ie);
+		params.extra_ies_len = wpabuf_len(extra_ie);
+	}
 
 	ret = wpa_supplicant_trigger_scan(wpa_s, &params);
 
-	wpabuf_free(wps_ie);
+	wpabuf_free(extra_ie);
 	os_free(params.freqs);
 	os_free(params.filter_ssids);
 

wpa_supplicant/wpa_supplicant.conf

@@ -228,6 +228,17 @@ fast_reauth=1
 #filter_ssids=0
 
 
+# Interworking (IEEE 802.11u)
+
+# Enable Interworking
+# interworking=1
+
+# Homogenous ESS identifier
+# If this is set, scans will be used to request response only from BSSes
+# belonging to the specified Homogeneous ESS. This is used only if interworking
+# is enabled.
+# hessid=00:11:22:33:44:55
+
 # network block
 #
 # Each network (usually AP's sharing the same SSID) is configured as a separate