Diff: features/netsocket/DNS.h

Revision:

0:5b88d5760320

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/features/netsocket/DNS.h	Tue Dec 17 23:23:45 2019 +0000
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2018 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/** @file DNS.h Domain Name Service */
+/** @addtogroup netsocket
+ * @{ */
+
+#ifndef DNS_H
+#define DNS_H
+
+/** Base class for DNS provider */
+class DNS {
+public:
+
+    /** Translate a hostname to an IP address with specific version using network interface name.
+     *
+     *  The hostname may be either a domain name or an IP address. If the
+     *  hostname is an IP address, no network transactions will be performed.
+     *
+     *  If no stack-specific DNS resolution is provided, the hostname
+     *  will be resolve using a UDP socket on the stack.
+     *
+     *  @param host     Hostname to resolve.
+     *  @param address  Pointer to a SocketAddress to store the result.
+     *  @param version  IP version of address to resolve, NSAPI_UNSPEC indicates
+     *                  version is chosen by the stack (defaults to NSAPI_UNSPEC).
+     *  @param interface_name  Network interface name
+     *  @return         NSAPI_ERROR_OK on success, negative error code on failure.
+     */
+    virtual nsapi_error_t gethostbyname(const char *host,
+                                        SocketAddress *address, nsapi_version_t version = NSAPI_UNSPEC, const char *interface_name = NULL) = 0;
+    /** Hostname translation callback for gethostbyname_async.
+     *
+     *  The callback is called after DNS resolution completes, or a failure occurs.
+     *
+     *  Callback should not take more than 10ms to execute, otherwise it might
+     *  prevent underlying thread processing. A portable user of the callback
+     *  should not make calls to network operations due to stack size limitations.
+     *  The callback should not perform expensive operations such as socket recv/send
+     *  calls or blocking operations.
+     *
+     *  @param result  NSAPI_ERROR_OK on success, negative error code on failure.
+     *  @param address On success, destination for the host SocketAddress.
+     */
+    typedef mbed::Callback<void (nsapi_error_t result, SocketAddress *address)> hostbyname_cb_t;
+
+    /** Translate a hostname to an IP address (asynchronous)
+     *
+     *  The hostname may be either a domain name or an IP address. If the
+     *  hostname is an IP address, no network transactions will be performed.
+     *
+     *  If no stack-specific DNS resolution is provided, the hostname
+     *  will be resolved using a UDP socket on the stack.
+     *
+     *  The call is non-blocking. The result of the DNS operation is returned by the callback.
+     *  If this function returns failure, the callback will not be called. If it is successful,
+     *  (the IP address was found from the DNS cache), the callback will be called
+     *  before the function returns.
+     *
+     *  @param host     Hostname to resolve.
+     *  @param callback Callback that is called to return the result.
+     *  @param version  IP version of address to resolve. NSAPI_UNSPEC indicates that the
+     *                  version is chosen by the stack (defaults to NSAPI_UNSPEC).
+     *  @param interface_name  Network interface name
+     *  @return         NSAPI_ERROR_OK on immediate success,
+     *                  negative error code on immediate failure or
+     *                  a positive unique ID that represents the hostname translation operation
+     *                  and can be passed to cancel.
+     */
+    virtual nsapi_value_or_error_t gethostbyname_async(const char *host, hostbyname_cb_t callback, nsapi_version_t version = NSAPI_UNSPEC,
+                                                       const char *interface_name = NULL) = 0;
+
+    /** Cancel asynchronous hostname translation.
+     *
+     *  When translation is canceled, callback is not called.
+     *
+     *  @param id       Unique ID of the hostname translation operation returned by gethostbyname_async.
+     *  @return         NSAPI_ERROR_OK on success, negative error code on failure.
+     */
+    virtual nsapi_error_t gethostbyname_async_cancel(int id) = 0;
+
+    /** Add a domain name server to list of servers to query.
+     *
+     *  @param address  DNS server host address.
+     *  @param interface_name  Network interface name
+     *  @return         NSAPI_ERROR_OK on success, negative error code on failure.
+     */
+    virtual nsapi_error_t add_dns_server(const SocketAddress &address, const char *interface_name = NULL) = 0;
+};
+
+#endif
+
+/** @} */