Bluetooth: Classic: OBEX: Optimize MOPL configuration

Set the MOPL of RX and TX to `BT_OBEX_MIN_MTU` when registering OBEX
server.

Set the TX MOPL to `BT_OBEX_MIN_MTU` when sending OBEX connection
request.

Check if the MOPL of client exceeds MTU of transport when server
receives the connection request.

Check if the MOPL of server exceeds MTU of transport when client
receives the connection response.

Signed-off-by: Lyle Zhu <[email protected]>

Author: lylezhu2012

subsys/bluetooth/host/classic/obex.c

@@ -212,7 +212,13 @@ static int obex_server_connect(struct bt_obex_server *server, uint16_t len, stru
 	LOG_DBG("version %u, flags %u, mopl %u", version, flags, mopl);
 
 	if (mopl < BT_OBEX_MIN_MTU) {
-		LOG_WRN("Invalid MTU length (%d < %d)", mopl, BT_OBEX_MIN_MTU);
+		LOG_WRN("Invalid MOPL (%d < %d)", mopl, BT_OBEX_MIN_MTU);
+		rsp_code = BT_OBEX_RSP_CODE_PRECON_FAIL;
+		goto failed;
+	}
+
+	if (mopl > server->obex->tx.mtu) {
+		LOG_WRN("MOPL exceeds MTU (%d > %d)", mopl, server->obex->tx.mtu);
 		rsp_code = BT_OBEX_RSP_CODE_PRECON_FAIL;
 		goto failed;
 	}
@@ -949,9 +955,15 @@ static int obex_client_connect(struct bt_obex_client *client, uint8_t rsp_code,
 	}
 
 	if (mopl < BT_OBEX_MIN_MTU) {
-		LOG_WRN("Invalid MTU length (%d < %d)", mopl, BT_OBEX_MIN_MTU);
+		LOG_WRN("Invalid MOPL (%d < %d)", mopl, BT_OBEX_MIN_MTU);
 		goto failed;
 	}
+
+	if (mopl > client->obex->tx.mtu) {
+		LOG_WRN("MOPL exceeds MTU (%d > %d)", mopl, client->obex->tx.mtu);
+		goto failed;
+	}
+
 	client->tx.mopl = mopl;
 
 	atomic_set(&client->_state,
@@ -1374,9 +1386,9 @@ int bt_obex_server_register(struct bt_obex_server *server, const struct bt_uuid_
 		return -EINVAL;
 	}
 
-	server->rx.mopl = server->obex->rx.mtu;
+	server->rx.mopl = BT_OBEX_MIN_MTU;
 	/* Set MOPL of TX to MTU by default to avoid the OBEX connect rsp cannot be sent. */
-	server->tx.mopl = server->obex->tx.mtu;
+	server->tx.mopl = BT_OBEX_MIN_MTU;
 
 	server->uuid = uuid;
 
@@ -1485,7 +1497,7 @@ int bt_obex_connect(struct bt_obex_client *client, uint16_t mopl, struct net_buf
 
 	client->rx.mopl = mopl;
 	/* Set MOPL of TX to MTU by default to avoid the OBEX connect req cannot be sent. */
-	client->tx.mopl = client->obex->tx.mtu;
+	client->tx.mopl = BT_OBEX_MIN_MTU;
 	atomic_set(&client->_state, BT_OBEX_CONNECTING);
 
 	if (!sys_slist_find(&client->obex->_clients, &client->_node, NULL)) {