openthread: add NAT64 and DNS64 support

* Add required configs and headers for NAT64 and DNS64
* Add hook for DNS name resolution
* Add NAT64 and DNS64 example commands

components/lwip/Kconfig

@@ -965,7 +965,8 @@ menu "LWIP"
 
         choice LWIP_HOOK_NETCONN_EXTERNAL_RESOLVE
             prompt "Netconn external resolve Hook"
-            default LWIP_HOOK_NETCONN_EXT_RESOLVE_NONE
+            default LWIP_HOOK_NETCONN_EXT_RESOLVE_DEFAULT if OPENTHREAD_DNS64_CLIENT
+            default LWIP_HOOK_NETCONN_EXT_RESOLVE_NONE if !OPENTHREAD_DNS64_CLIENT
             help
                 Enables custom DNS resolve hook.
                 Setting this to "default" provides weak implementation

components/openthread/CMakeLists.txt

@@ -33,6 +33,7 @@ if(CONFIG_OPENTHREAD_ENABLED)
 
     if(CONFIG_OPENTHREAD_FTD OR CONFIG_OPENTHREAD_MTD)
         list(APPEND src_dirs
+            "src"
             "openthread/examples/apps/cli"
             "openthread/src/core/backbone_router"
             "openthread/src/core/coap"
@@ -141,7 +142,7 @@ idf_component_register(SRC_DIRS "${src_dirs}"
                        EXCLUDE_SRCS "${exclude_srcs}"
                        INCLUDE_DIRS "${public_include_dirs}"
                        PRIV_INCLUDE_DIRS "${private_include_dirs}"
-                       REQUIRES mbedtls ieee802154 console lwip)
+                       REQUIRES esp_event mbedtls ieee802154 console lwip)
 
 if(CONFIG_OPENTHREAD_ENABLED)
     if(CONFIG_OPENTHREAD_RADIO)

components/openthread/Kconfig

@@ -98,4 +98,11 @@ menu "OpenThread"
         default 65
         range 50 100
 
+    config OPENTHREAD_DNS64_CLIENT
+        bool "Use dns64 client"
+        depends on OPENTHREAD_ENABLED
+        default n
+        help
+            Select this option to acquire NAT64 address from dns servers.
+
 endmenu

components/openthread/include/esp_openthread.h

@@ -1,16 +1,8 @@
-// Copyright 2021 Espressif Systems (Shanghai) CO LTD
-//
-// 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
+/*
+ * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
 
 #pragma once
 
@@ -18,6 +10,7 @@
 #include "esp_openthread_types.h"
 #include "openthread/error.h"
 #include "openthread/instance.h"
+#include "lwip/ip_addr.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -72,6 +65,7 @@ esp_err_t esp_openthread_deinit(void);
  */
 otInstance *esp_openthread_get_instance(void);
 
+
 #ifdef __cplusplus
 } // end of extern "C"
 #endif

components/openthread/include/esp_openthread_dns64.h

@@ -0,0 +1,43 @@
+/*
+ * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include "esp_openthread.h"
+#include "lwip/netdb.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief This function acquires the NAT64 prefix in the Thread network.
+ *
+ * @param[out]  nat64_prefix    The NAT64 prefix output.
+ *
+ * @return
+ *      - ESP_OK on success
+ *      - ESP_ERR_NOT_FOUND if NAT64 prefix available
+ *
+ */
+esp_err_t esp_openthread_get_nat64_prefix(ip6_addr_t *nat64_prefix);
+
+
+/**
+ * @brief The alternative function for gethostbyname and adds the NAT64 prefix.
+ *
+ */
+struct hostent *esp_openthread_gethostbyname_dns64(const char *name);
+
+/**
+ * @brief The alternative function for getaddrinfo and adds the NAT64 prefix.
+ *
+ */
+int esp_openthread_getaddrinfo_dns64(const char *nodename, const char *servname, const struct addrinfo *hints, struct addrinfo **res);
+
+#ifdef __cplusplus
+}
+#endif

components/openthread/include/esp_openthread_types.h

@@ -21,8 +21,7 @@ extern "C" {
  * @brief OpenThread event declarations
  *
  */
-typedef enum
-{
+typedef enum {
     OPENTHREAD_EVENT_START,                     /*!< OpenThread stack start */
     OPENTHREAD_EVENT_STOP,                      /*!< OpenThread stack stop */
     OPENTHREAD_EVENT_IF_UP,                     /*!< OpenThread network interface up */
@@ -69,8 +68,7 @@ typedef struct {
  * @brief The radio mode of OpenThread.
  *
  */
-typedef enum
-{
+typedef enum {
     RADIO_MODE_NATIVE = 0x0,   /*!< Use the native 15.4 radio */
     RADIO_MODE_UART_RCP = 0x1, /*!< UART connection to a 15.4 capable radio co-processor (RCP) */
     RADIO_MODE_SPI_RCP = 0x2,  /*!< SPI connection to a 15.4 capable radio co-processor (RCP) */
@@ -80,8 +78,7 @@ typedef enum
  * @brief How OpenThread connects to the host.
  *
  */
-typedef enum
-{
+typedef enum {
     HOST_CONNECTION_MODE_NONE = 0x0,     /*!< Disable host connection */
     HOST_CONNECTION_MODE_CLI_UART = 0x1, /*!< CLI UART connection to the host */
     HOST_CONNECTION_MODE_RCP_UART = 0x2, /*!< RCP UART connection to the host */

components/openthread/lib

@@ -1 +1 @@
-Subproject commit 9fabccb43c2318d45d7d893902a614d94d0f2e2a
+Subproject commit af1ac2b3770335db96702bcb06ca793a1425dc86

components/openthread/private_include/openthread-core-esp32x-ftd-config.h

@@ -149,6 +149,16 @@
 #define OPENTHREAD_CONFIG_PLATFORM_UDP_ENABLE 1
 #endif
 
+/**
+ * @def OPENTHREAD_CONFIG_BORDER_ROUTING_NAT64_ENABLE
+ *
+ * Define to 1 to enable Border Routing NAT64 support.
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_BORDER_ROUTING_NAT64_ENABLE
+#define OPENTHREAD_CONFIG_BORDER_ROUTING_NAT64_ENABLE 1
+#endif
+
 /**
  * @def OPENTHREAD_CONFIG_ECDSA_ENABLE
  *

components/openthread/src/esp_openthread_dns64.c

@@ -0,0 +1,63 @@
+/*
+ * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "esp_openthread_dns64.h"
+
+#include "esp_log.h"
+#include "openthread/instance.h"
+#include "openthread/netdata.h"
+#include "lwip_default_hooks.h"
+#include "lwip/api.h"
+
+#define TAG "OT_DNS64"
+
+esp_err_t esp_openthread_get_nat64_prefix(ip6_addr_t *nat64_prefix)
+{
+    otNetworkDataIterator iter = OT_NETWORK_DATA_ITERATOR_INIT;
+    otInstance *instance = esp_openthread_get_instance();
+    otExternalRouteConfig route;
+
+    memset(&route, 0, sizeof(route));
+    while (otNetDataGetNextRoute(instance, &iter, &route) == OT_ERROR_NONE) {
+        if (route.mNat64) {
+            break;
+        }
+    }
+
+    if (route.mNat64) {
+        memcpy(nat64_prefix->addr, route.mPrefix.mPrefix.mFields.m8, sizeof(nat64_prefix->addr));
+        return ESP_OK;
+    } else {
+        return ESP_ERR_NOT_FOUND;
+    }
+}
+
+int lwip_hook_netconn_external_resolve(const char *name, ip_addr_t *addr, u8_t addrtype, err_t *err)
+{
+    if (addrtype == NETCONN_DNS_IPV4) {
+        return 0;
+    }
+
+    ip6_addr_t nat64_prefix;
+    if (esp_openthread_get_nat64_prefix(&nat64_prefix) != ESP_OK) {
+        ESP_LOGE(TAG, "Cannot find NAT64 prefix\n");
+        *err = ERR_ABRT;
+        return 1;
+    }
+
+    *err = netconn_gethostbyname_addrtype(name, addr, NETCONN_DNS_IPV4);
+    if (*err != ERR_OK) {
+        return 1;
+    }
+    if (addr->type == IPADDR_TYPE_V4) {
+        ip4_addr_t addr_copy = addr->u_addr.ip4;
+        addr->type = IPADDR_TYPE_V6;
+        memcpy(addr->u_addr.ip6.addr, nat64_prefix.addr, sizeof(nat64_prefix.addr));
+        addr->u_addr.ip6.addr[3] = addr_copy.addr;
+        addr->u_addr.ip6.zone = IP6_NO_ZONE;
+    }
+    return 1;
+}

examples/openthread/README_nat64.md

@@ -0,0 +1,48 @@
+# Visiting the Internet on the Thread network with NAT64
+
+The Espressif Thread border router supports NAT64 which allows Thread devices to visit the IPv4 Internet.
+
+## Building the Thread border router with NAT64
+
+The Thread border router supports NAT64 by default. After the Wi-Fi and the Thread network is launched, we can fetch the NAT64 prefix:
+
+```
+> br nat64prefix
+fd97:83ad:debc:2:0:0::/96
+Done
+```
+
+This prefix will be used for translating the IPv4 addresses.
+
+## Visiting IPv4 UDP servers
+
+Build and run the OpenThread cli example with the default configuration and join the Thread network formed by the border router.
+On the local machine, setup a basic UDP echo server. The destination UDP address will be the hexadecimal IPv4 address added to the NAT64 prefix.
+Say the host has address 192.168.1.2 and the NAT64 prefix is fd97:83ad:debc:2:0:0::/96, the destination address will be fd97:83ad:debc:2:0:0:c0a8:0102.
+
+```
+> udp send fd97:83ad:debc:2:0:0:c0a8:0102 4388 hello
+
+Done
+> 5 bytes from fd97:83ad:debc:2:0:0:c0a8:102 4388 hello
+```
+
+## Visiting IPv4 HTTP servers
+
+For visiting HTTP servers with domain names, we need to first set the DNS server:
+
+```
+> dns64server 8.8.8.8
+Done
+```
+
+Now we can curl the HTTP server
+
+```
+> curl http://www.google.com
+
+Done
+> I (33809) HTTP_CLIENT: Body received in fetch header state, 0x3fca4025, 111
+<!doctype html><html itemscope="" itemtype="http://schema.org/WebPage" lang="zh-HK"><head><meta content="text/html; charset=UTF-8" http-equiv="Content-Type"> ...
+// Other HTTP response to follow
+```

examples/openthread/ot_br/main/esp_ot_br.c

@@ -10,7 +10,7 @@
  * Unless required by applicable law or agreed to in writing, this
  * software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
  * CONDITIONS OF ANY KIND, either express or implied.
-*/
+ */
 
 #include <stdio.h>
 #include <string.h>
@@ -28,7 +28,10 @@
 #include "esp_openthread_lock.h"
 #include "esp_openthread_netif_glue.h"
 #include "esp_openthread_types.h"
+#include "esp_ot_cli_extension.h"
 #include "esp_ot_config.h"
+#include "esp_ot_wifi_cmd.h"
+#include "esp_vfs_dev.h"
 #include "esp_vfs_eventfd.h"
 #include "esp_wifi.h"
 #include "mdns.h"
@@ -51,8 +54,6 @@
 #include "openthread/logging.h"
 #include "openthread/tasklet.h"
 #include "openthread/thread_ftd.h"
-#include "esp_ot_wifi_cmd.h"
-#include "esp_ot_cli_extension.h"
 
 #define TAG "esp_ot_br"
 
@@ -211,6 +212,7 @@ void app_main(void)
     ESP_ERROR_CHECK(nvs_flash_init());
     ESP_ERROR_CHECK(esp_netif_init());
     ESP_ERROR_CHECK(esp_event_loop_create_default());
+
 #if CONFIG_OPENTHREAD_BR_AUTO_START
     ESP_ERROR_CHECK(example_connect());
     ESP_ERROR_CHECK(esp_wifi_set_ps(WIFI_PS_NONE));

examples/openthread/ot_cli/sdkconfig.defaults

@@ -5,6 +5,8 @@ CONFIG_IDF_TARGET="esp32h2"
 CONFIG_LIBSODIUM_USE_MBEDTLS_SHA=y
 # end of libsodium
 
+CONFIG_FREERTOS_IDLE_TASK_STACKSIZE=2048
+
 #
 # Partition Table
 #
@@ -33,6 +35,8 @@ CONFIG_MBEDTLS_ECJPAKE_C=y
 #
 CONFIG_OPENTHREAD_ENABLED=y
 CONFIG_OPENTHREAD_BORDER_ROUTER=n
+CONFIG_OPENTHREAD_SRP_CLIENT=y
+CONFIG_OPENTHREAD_DNS64_CLIENT=y
 # end of OpenThread
 
 #

tools/ci/check_copyright_ignore.txt

@@ -949,7 +949,6 @@ components/nvs_flash/test_nvs_host/test_nvs_handle.cpp
 components/nvs_flash/test_nvs_host/test_nvs_initialization.cpp
 components/nvs_flash/test_nvs_host/test_nvs_partition.cpp
 components/nvs_flash/test_nvs_host/test_nvs_storage.cpp
-components/openthread/include/esp_openthread.h
 components/openthread/include/esp_openthread_lock.h
 components/protocomm/include/transports/protocomm_console.h
 components/protocomm/include/transports/protocomm_httpd.h