P2P: Optimize join scan frequency

Allow clients to specify the BSSID of an auto GO. If the auto GO has been
discovered on another interface, optimize scan frequency by performing
a single channel scan first. Android and ChromeOS use this to streamline
auto GO discovery.

Signed-off-by: Matthew Wang <matthewmwang@chromium.org>

wpa_supplicant/bss.c

@@ -240,7 +240,7 @@ void wpa_bss_remove(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
 /**
  * wpa_bss_get - Fetch a BSS table entry based on BSSID and SSID
  * @wpa_s: Pointer to wpa_supplicant data
- * @bssid: BSSID
+ * @bssid: BSSID, or %NULL to match any BSSID
  * @ssid: SSID
  * @ssid_len: Length of @ssid
  * Returns: Pointer to the BSS entry or %NULL if not found
@@ -249,10 +249,11 @@ struct wpa_bss * wpa_bss_get(struct wpa_supplicant *wpa_s, const u8 *bssid,
 			     const u8 *ssid, size_t ssid_len)
 {
 	struct wpa_bss *bss;
-	if (!wpa_supplicant_filter_bssid_match(wpa_s, bssid))
+
+	if (bssid && !wpa_supplicant_filter_bssid_match(wpa_s, bssid))
 		return NULL;
 	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
-		if (os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0 &&
+		if ((!bssid || os_memcmp(bss->bssid, bssid, ETH_ALEN) == 0) &&
 		    bss->ssid_len == ssid_len &&
 		    os_memcmp(bss->ssid, ssid, ssid_len) == 0)
 			return bss;

wpa_supplicant/ctrl_iface.c

@@ -7128,7 +7128,7 @@ static int p2p_ctrl_group_add_persistent(struct wpa_supplicant *wpa_s,
 	return wpas_p2p_group_add_persistent(wpa_s, ssid, 0, freq,
 					     vht_center_freq2, 0, ht40, vht,
 					     vht_chwidth, he, edmg,
-					     NULL, 0, 0, allow_6ghz, 0);
+					     NULL, 0, 0, allow_6ghz, 0, NULL);
 }
 
 

wpa_supplicant/dbus/dbus_new_handlers_p2p.c

@@ -359,6 +359,7 @@ DBusMessage * wpas_dbus_handler_p2p_group_add(DBusMessage *message,
 	char *iface = NULL;
 	unsigned int group_id = 0;
 	struct wpa_ssid *ssid;
+	u8 go_bssid_buf[ETH_ALEN], *go_bssid = NULL;
 
 	dbus_message_iter_init(message, &iter);
 
@@ -384,10 +385,16 @@ DBusMessage * wpas_dbus_handler_p2p_group_add(DBusMessage *message,
 				goto inv_args_clear;
 		} else if (os_strcmp(entry.key, "persistent_group_object") ==
 			   0 &&
-			   entry.type == DBUS_TYPE_OBJECT_PATH)
+			   entry.type == DBUS_TYPE_OBJECT_PATH) {
 			pg_object_path = os_strdup(entry.str_value);
-		else
+		} else if (os_strcmp(entry.key, "go_bssid") == 0 &&
+			   entry.type == DBUS_TYPE_STRING) {
+			if (hwaddr_aton(entry.str_value, go_bssid_buf))
 				goto inv_args_clear;
+			go_bssid = go_bssid_buf;
+		} else {
+			goto inv_args_clear;
+		}
 
 		wpa_dbus_dict_entry_clear(&entry);
 	}
@@ -432,7 +439,8 @@ DBusMessage * wpas_dbus_handler_p2p_group_add(DBusMessage *message,
 
 		if (wpas_p2p_group_add_persistent(wpa_s, ssid, 0, freq, 0, 0, 0,
 						  0, 0, 0, 0, NULL, 0, 0,
-						  false, retry_limit)) {
+						  false, retry_limit,
+						  go_bssid)) {
 			reply = wpas_dbus_error_unknown_error(
 				message,
 				"Failed to reinvoke a persistent group");

wpa_supplicant/events.c

@@ -1163,7 +1163,7 @@ static void owe_trans_ssid(struct wpa_supplicant *wpa_s, struct wpa_bss *bss,
 }
 
 
-static int disabled_freq(struct wpa_supplicant *wpa_s, int freq)
+int disabled_freq(struct wpa_supplicant *wpa_s, int freq)
 {
 	int i, j;
 

wpa_supplicant/p2p_supplicant.c

@@ -3373,7 +3373,8 @@ static void wpas_invitation_received(void *ctx, const u8 *sa, const u8 *bssid,
 				wpa_s->conf->p2p_go_he,
 				wpa_s->conf->p2p_go_edmg, NULL,
 				go ? P2P_MAX_INITIAL_CONN_WAIT_GO_REINVOKE : 0,
-				1, is_p2p_allow_6ghz(wpa_s->global->p2p), 0);
+				1, is_p2p_allow_6ghz(wpa_s->global->p2p), 0,
+				NULL);
 		} else if (bssid) {
 			wpa_s->user_initiated_pd = 0;
 			wpa_msg_global(wpa_s, MSG_INFO,
@@ -3603,7 +3604,8 @@ static void wpas_invitation_result(void *ctx, int status, const u8 *bssid,
 				      ssid->mode == WPAS_MODE_P2P_GO ?
 				      P2P_MAX_INITIAL_CONN_WAIT_GO_REINVOKE :
 				      0, 1,
-				      is_p2p_allow_6ghz(wpa_s->global->p2p), 0);
+				      is_p2p_allow_6ghz(wpa_s->global->p2p), 0,
+				      NULL);
 }
 
 
@@ -4689,7 +4691,7 @@ static void wpas_p2ps_prov_complete(void *ctx, u8 status, const u8 *dev,
 					persistent_go->mode ==
 					WPAS_MODE_P2P_GO ?
 					P2P_MAX_INITIAL_CONN_WAIT_GO_REINVOKE :
-					0, 0, false, 0);
+					0, 0, false, 0, NULL);
 			} else if (response_done) {
 				wpas_p2p_group_add(wpa_s, 1, freq,
 						   0, 0, 0, 0, 0, 0, false);
@@ -4812,7 +4814,7 @@ static int wpas_prov_disc_resp_cb(void *ctx)
 			NULL,
 			persistent_go->mode == WPAS_MODE_P2P_GO ?
 			P2P_MAX_INITIAL_CONN_WAIT_GO_REINVOKE : 0, 0,
-			is_p2p_allow_6ghz(wpa_s->global->p2p), 0);
+			is_p2p_allow_6ghz(wpa_s->global->p2p), 0, NULL);
 	} else {
 		wpas_p2p_group_add(wpa_s, 1, freq, 0, 0, 0, 0, 0, 0,
 				   is_p2p_allow_6ghz(wpa_s->global->p2p));
@@ -6946,7 +6948,8 @@ int wpas_p2p_group_add(struct wpa_supplicant *wpa_s, int persistent_group,
 
 static int wpas_start_p2p_client(struct wpa_supplicant *wpa_s,
 				 struct wpa_ssid *params, int addr_allocated,
-				 int freq, int force_scan, int retry_limit)
+				 int freq, int force_scan, int retry_limit,
+				 const u8 *go_bssid)
 {
 	struct wpa_ssid *ssid;
 	int other_iface_found = 0;
@@ -6999,6 +7002,11 @@ static int wpas_start_p2p_client(struct wpa_supplicant *wpa_s,
 	if (params->passphrase)
 		ssid->passphrase = os_strdup(params->passphrase);
 
+	if (go_bssid) {
+		ssid->bssid_set = 1;
+		os_memcpy(ssid->bssid, go_bssid, ETH_ALEN);
+	}
+
 	wpa_s->show_group_started = 1;
 	wpa_s->p2p_in_invitation = 1;
 	wpa_s->p2p_retry_limit = retry_limit;
@@ -7045,7 +7053,8 @@ int wpas_p2p_group_add_persistent(struct wpa_supplicant *wpa_s,
 				  int edmg,
 				  const struct p2p_channels *channels,
 				  int connection_timeout, int force_scan,
-				  bool allow_6ghz, int retry_limit)
+				  bool allow_6ghz, int retry_limit,
+				  const u8 *go_bssid)
 {
 	struct p2p_go_neg_results params;
 	int go = 0, freq;
@@ -7113,7 +7122,7 @@ int wpas_p2p_group_add_persistent(struct wpa_supplicant *wpa_s,
 		}
 
 		return wpas_start_p2p_client(wpa_s, ssid, addr_allocated, freq,
-					     force_scan, retry_limit);
+					     force_scan, retry_limit, go_bssid);
 	} else {
 		return -1;
 	}

wpa_supplicant/p2p_supplicant.h

@@ -52,7 +52,8 @@ int wpas_p2p_group_add_persistent(struct wpa_supplicant *wpa_s,
 				  int max_oper_chwidth, int he, int edmg,
 				  const struct p2p_channels *channels,
 				  int connection_timeout, int force_scan,
-				  bool allow_6ghz, int retry_limit);
+				  bool allow_6ghz, int retry_limit,
+				  const u8 *go_bssid);
 struct p2p_group * wpas_p2p_group_init(struct wpa_supplicant *wpa_s,
 				       struct wpa_ssid *ssid);
 enum wpas_p2p_prov_disc_use {

wpa_supplicant/scan.c

@@ -445,11 +445,43 @@ static void wpa_supplicant_optimize_freqs(
 	}
 
 	if (params->freqs == NULL && wpa_s->p2p_in_invitation) {
+		struct wpa_ssid *ssid = wpa_s->current_ssid;
+
+		/*
+		 * Perform a single-channel scan if the GO has already been
+		 * discovered on another non-P2P interface. Note that a scan
+		 * initiated by a P2P interface (e.g., the device interface)
+		 * should already have sufficient IEs and scan results will be
+		 * fetched on interface creation in that case.
+		 */
+		if (wpa_s->p2p_in_invitation == 1 && ssid) {
+			struct wpa_supplicant *ifs;
+			struct wpa_bss *bss = NULL;
+			const u8 *bssid = ssid->bssid_set ? ssid->bssid : NULL;
+
+			dl_list_for_each(ifs, &wpa_s->radio->ifaces,
+					 struct wpa_supplicant, radio_list) {
+				bss = wpa_bss_get(ifs, bssid, ssid->ssid,
+						  ssid->ssid_len);
+				if (bss)
+					break;
+			}
+			if (bss && !disabled_freq(wpa_s, bss->freq)) {
+				params->freqs = os_calloc(2, sizeof(int));
+				if (params->freqs) {
+					wpa_dbg(wpa_s, MSG_DEBUG,
+						"P2P: Scan only the known GO frequency %d MHz during invitation",
+						bss->freq);
+					params->freqs[0] = bss->freq;
+				}
+			}
+		}
+
 		/*
 		 * Optimize scan based on GO information during persistent
 		 * group reinvocation
 		 */
-		if (wpa_s->p2p_in_invitation < 5 &&
+		if (!params->freqs && wpa_s->p2p_in_invitation < 5 &&
 		    wpa_s->p2p_invite_go_freq > 0) {
 			if (wpa_s->p2p_invite_go_freq == 2 ||
 			    wpa_s->p2p_invite_go_freq == 5) {

wpa_supplicant/wpa_supplicant_i.h

@@ -1826,6 +1826,7 @@ int get_shared_radio_freqs_data(struct wpa_supplicant *wpa_s,
 int get_shared_radio_freqs(struct wpa_supplicant *wpa_s,
 			   int *freq_array, unsigned int len,
 			   bool exclude_current);
+int disabled_freq(struct wpa_supplicant *wpa_s, int freq);
 
 void wpas_network_reenabled(void *eloop_ctx, void *timeout_ctx);