[PATCH BlueZ 3/3] gatt: Do not always attempt to connect EATT immediately

[Luiz Augusto von Dentz <luiz.dentz@gmail.com>]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Wait the bt_gatt_client becomes ready (has performed service discovery)
before attempting to connect EATT when acting as peripheral/acceptor
since the central/initiator might actually attempt to connect EATT
channels in the same way which can potentially cause a collisions.
---
 src/device.c      |  7 +++++
 src/gatt-client.c | 74 +++++++++++++++++++++++------------------------
 src/gatt-client.h |  1 +
 3 files changed, 44 insertions(+), 38 deletions(-)

diff --git a/src/device.c b/src/device.c
index 998485be7..6253edc77 100644
--- a/src/device.c
+++ b/src/device.c
@@ -5304,6 +5304,13 @@ static void gatt_client_init(struct btd_device *device)
 	}
 
 	btd_gatt_client_connected(device->client_dbus);
+
+	/* Only initiate EATT connection when acting as initiator, as acceptor
+	 * it shall be triggered only when ready to avoid possible clashes where
+	 * both sides attempt to connection at same time.
+	 */
+	if (device->connect)
+		bt_gatt_client_eatt_connect(device->client_dbus);
 }
 
 static void gatt_server_init(struct btd_device *device,
diff --git a/src/gatt-client.c b/src/gatt-client.c
index bec6e1ec0..6cf96365d 100644
--- a/src/gatt-client.c
+++ b/src/gatt-client.c
@@ -2156,6 +2156,38 @@ static void register_notify(void *data, void *user_data)
 	notify_client_free(notify_client);
 }
 
+void btd_gatt_client_ready(struct btd_gatt_client *client)
+{
+	if (!client)
+		return;
+
+	if (!client->gatt) {
+		struct bt_gatt_client *gatt;
+
+		gatt = btd_device_get_gatt_client(client->device);
+		client->gatt = bt_gatt_client_clone(gatt);
+		if (!client->gatt) {
+			error("GATT client not initialized");
+			return;
+		}
+	}
+
+	client->ready = true;
+
+	DBG("GATT client ready");
+
+	create_services(client);
+
+	DBG("Features 0x%02x", client->features);
+
+	if (!client->features) {
+		client->features = bt_gatt_client_get_features(client->gatt);
+		DBG("Update Features 0x%02x", client->features);
+		if (client->features & BT_GATT_CHRC_CLI_FEAT_EATT)
+			bt_gatt_client_eatt_connect(client);
+	}
+}
+
 static void eatt_connect_cb(GIOChannel *io, GError *gerr, gpointer user_data)
 {
 	struct btd_gatt_client *client = user_data;
@@ -2166,7 +2198,7 @@ static void eatt_connect_cb(GIOChannel *io, GError *gerr, gpointer user_data)
 	device_attach_att(client->device, io);
 }
 
-static void eatt_connect(struct btd_gatt_client *client)
+void bt_gatt_client_eatt_connect(struct btd_gatt_client *client)
 {
 	struct bt_att *att = bt_gatt_client_get_att(client->gatt);
 	struct btd_device *dev = client->device;
@@ -2176,6 +2208,9 @@ static void eatt_connect(struct btd_gatt_client *client)
 	char addr[18];
 	int i;
 
+	if (!(client->features & BT_GATT_CHRC_CLI_FEAT_EATT))
+		return;
+
 	if (bt_att_get_channels(att) == btd_opts.gatt_channels)
 		return;
 
@@ -2232,38 +2267,6 @@ static void eatt_connect(struct btd_gatt_client *client)
 	}
 }
 
-void btd_gatt_client_ready(struct btd_gatt_client *client)
-{
-	if (!client)
-		return;
-
-	if (!client->gatt) {
-		struct bt_gatt_client *gatt;
-
-		gatt = btd_device_get_gatt_client(client->device);
-		client->gatt = bt_gatt_client_clone(gatt);
-		if (!client->gatt) {
-			error("GATT client not initialized");
-			return;
-		}
-	}
-
-	client->ready = true;
-
-	DBG("GATT client ready");
-
-	create_services(client);
-
-	DBG("Features 0x%02x", client->features);
-
-	if (!client->features) {
-		client->features = bt_gatt_client_get_features(client->gatt);
-		DBG("Update Features 0x%02x", client->features);
-		if (client->features & BT_GATT_CHRC_CLI_FEAT_EATT)
-			eatt_connect(client);
-	}
-}
-
 void btd_gatt_client_connected(struct btd_gatt_client *client)
 {
 	struct bt_gatt_client *gatt;
@@ -2284,11 +2287,6 @@ void btd_gatt_client_connected(struct btd_gatt_client *client)
 	 * for any pre-registered notification sessions.
 	 */
 	queue_foreach(client->all_notify_clients, register_notify, client);
-
-	if (!(client->features & BT_GATT_CHRC_CLI_FEAT_EATT))
-		return;
-
-	eatt_connect(client);
 }
 
 void btd_gatt_client_service_added(struct btd_gatt_client *client,
diff --git a/src/gatt-client.h b/src/gatt-client.h
index b6539207e..672c5e72f 100644
--- a/src/gatt-client.h
+++ b/src/gatt-client.h
@@ -20,6 +20,7 @@ void btd_gatt_client_service_added(struct btd_gatt_client *client,
 void btd_gatt_client_service_removed(struct btd_gatt_client *client,
 					struct gatt_db_attribute *attrib);
 void btd_gatt_client_disconnected(struct btd_gatt_client *client);
+void bt_gatt_client_eatt_connect(struct btd_gatt_client *client);
 
 typedef void (*btd_gatt_client_service_path_t)(const char *service_path,
 							void *user_data);
-- 
2.31.1