mDNS: Initial version based on IDF 5.0

components/mdns/README.md

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+# mDNS Service
+
+mDNS is a multicast UDP service that is used to provide local network service and host discovery.
+
+## Examples
+
+Get started with example test [Example](examples/README.md):
+
+## Documentation
+
+* View the full [html documentation](https://espressif.github.io/esp-protocols/mdns/index.html)

components/mdns/docs/Doxyfile

@@ -0,0 +1,75 @@
+# This is Doxygen configuration file
+#
+# Doxygen provides over 260 configuration statements
+# To make this file easier to follow,
+# it contains only statements that are non-default
+#
+# NOTE:
+# It is recommended not to change defaults unless specifically required
+# Test any changes how they affect generated documentation
+# Make sure that correct warnings are generated to flag issues with documented code
+#
+# For the complete list of configuration statements see:
+# http://doxygen.nl/manual/config.html
+
+
+PROJECT_NAME = "ESP Protocols Programming Guide"
+
+## The 'INPUT' statement below is used as input by script 'gen-df-input.py'
+## to automatically generate API reference list files heder_file.inc
+## These files are placed in '_inc' directory
+## and used to include in API reference documentation
+
+INPUT = \
+   $(PROJECT_PATH)/include/mdns.h
+
+## Get warnings for functions that have no documentation for their parameters or return value
+##
+WARN_NO_PARAMDOC = YES
+
+## Enable preprocessing and remove __attribute__(...) expressions from the INPUT files
+##
+ENABLE_PREPROCESSING   = YES
+MACRO_EXPANSION        = YES
+EXPAND_ONLY_PREDEF     = YES
+PREDEFINED             = \
+    $(ENV_DOXYGEN_DEFINES) \
+    __DOXYGEN__=1 \
+    __attribute__(x)= \
+	_Static_assert()= \
+    IDF_DEPRECATED(X)= \
+    IRAM_ATTR= \
+    configSUPPORT_DYNAMIC_ALLOCATION=1 \
+    configSUPPORT_STATIC_ALLOCATION=1 \
+    configQUEUE_REGISTRY_SIZE=1 \
+    configUSE_RECURSIVE_MUTEXES=1 \
+    configTHREAD_LOCAL_STORAGE_DELETE_CALLBACKS=1 \
+    configNUM_THREAD_LOCAL_STORAGE_POINTERS=1 \
+    configUSE_APPLICATION_TASK_TAG=1 \
+    configTASKLIST_INCLUDE_COREID=1 \
+    "ESP_EVENT_DECLARE_BASE(x)=extern esp_event_base_t x"
+
+## Do not complain about not having dot
+##
+HAVE_DOT = NO
+
+## Generate XML that is required for Breathe
+##
+GENERATE_XML    = YES
+XML_OUTPUT      = xml
+
+GENERATE_HTML   = NO
+HAVE_DOT        = NO
+GENERATE_LATEX  = NO
+GENERATE_MAN    = YES
+GENERATE_RTF    = NO
+
+## Skip distracting progress messages
+##
+QUIET = YES
+
+## Enable Section Tags for conditional documentation
+##
+ENABLED_SECTIONS += \
+    DOC_EXCLUDE_HEADER_SECTION \   ## To conditionally remove doc sections from IDF source files without affecting documentation in upstream files.
+    DOC_SINGLE_GROUP        ## To conditionally remove groups from the documentation and create a 'flat' document without affecting documentation in upstream files.

components/mdns/docs/conf_common.py

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+from esp_docs.conf_docs import *  # noqa: F403,F401
+
+extensions += ['sphinx_copybutton',
+               # Needed as a trigger for running doxygen
+               'esp_docs.esp_extensions.dummy_build_system',
+               'esp_docs.esp_extensions.run_doxygen',
+               ]
+
+# link roles config
+github_repo = 'espressif/esp-protocols'
+
+# context used by sphinx_idf_theme
+html_context['github_user'] = 'espressif'
+html_context['github_repo'] = 'esp-protocols'
+
+# Extra options required by sphinx_idf_theme
+project_slug = 'esp-idf' # >=5.0
+versions_url = 'https://github.com/espressif/esp-protocols/docs/docs_versions.js'
+
+idf_targets = ['esp32']
+languages = ['en', 'zh_CN']

components/mdns/docs/en/conf.py

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+# -*- coding: utf-8 -*-
+#
+# English Language RTD & Sphinx config file
+#
+# Uses ../conf_common.py for most non-language-specific settings.
+
+# Importing conf_common adds all the non-language-specific
+# parts to this conf module
+
+try:
+    from conf_common import *  # noqa: F403,F401
+except ImportError:
+    import os
+    import sys
+    sys.path.insert(0, os.path.abspath('../'))
+    from conf_common import *  # noqa: F403,F401
+
+# General information about the project.
+project = u'ESP-Protocols'
+copyright = u'2016 - 2022, Espressif Systems (Shanghai) Co., Ltd'
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+language = 'en'

components/mdns/docs/en/index.rst

@@ -0,0 +1,205 @@
+mDNS Service
+============
+:link_to_translation:`zh_CN:[中文]`
+
+Overview
+--------
+
+mDNS is a multicast UDP service that is used to provide local network service and host discovery.
+
+mDNS is installed by default on most operating systems or is available as separate package. On ``Mac OS`` it is installed by default and is called ``Bonjour``. Apple releases an installer for ``Windows`` that can be found `on Apple's support page <https://support.apple.com/downloads/bonjour%2520for%2520windows>`_. On ``Linux``, mDNS is provided by `avahi <https://github.com/lathiat/avahi>`_ and is usually installed by default.
+
+mDNS Properties
+^^^^^^^^^^^^^^^
+
+    * ``hostname``: the hostname that the device will respond to. If not set, the ``hostname`` will be read from the interface. Example: ``my-{IDF_TARGET_PATH_NAME}`` will resolve to ``my-{IDF_TARGET_PATH_NAME}.local``
+    * ``default_instance``: friendly name for your device, like ``Jhon's {IDF_TARGET_NAME} Thing``. If not set, ``hostname`` will be used.
+
+Example method to start mDNS for the STA interface and set ``hostname`` and ``default_instance``:
+
+.. highlight:: c
+
+::
+
+    void start_mdns_service()
+    {
+        //initialize mDNS service
+        esp_err_t err = mdns_init();
+        if (err) {
+            printf("MDNS Init failed: %d\n", err);
+            return;
+        }
+
+        //set hostname
+        mdns_hostname_set("my-{IDF_TARGET_PATH_NAME}");
+        //set default instance
+        mdns_instance_name_set("Jhon's {IDF_TARGET_NAME} Thing");
+    }
+
+mDNS Services
+^^^^^^^^^^^^^
+
+mDNS can advertise information about network services that your device offers. Each service is defined by a few properties.
+
+    * ``instance_name``: friendly name for your service, like ``Jhon's E{IDF_TARGET_NAME} Web Server``. If not defined, ``default_instance`` will be used.
+    * ``service_type``: (required) service type, prepended with underscore. Some common types can be found `here <http://www.dns-sd.org/serviceTypes.html>`_.
+    * ``proto``: (required) protocol that the service runs on, prepended with underscore. Example: ``_tcp`` or ``_udp``
+    * ``port``: (required) network port that the service runs on
+    * ``txt``: ``{var, val}`` array of strings, used to define properties for your service
+
+Example method to add a few services and different properties::
+
+    void add_mdns_services()
+    {
+        //add our services
+        mdns_service_add(NULL, "_http", "_tcp", 80, NULL, 0);
+        mdns_service_add(NULL, "_arduino", "_tcp", 3232, NULL, 0);
+        mdns_service_add(NULL, "_myservice", "_udp", 1234, NULL, 0);
+
+        //NOTE: services must be added before their properties can be set
+        //use custom instance for the web server
+        mdns_service_instance_name_set("_http", "_tcp", "Jhon's {IDF_TARGET_NAME} Web Server");
+
+        mdns_txt_item_t serviceTxtData[3] = {
+            {"board","{{IDF_TARGET_PATH_NAME}}"},
+            {"u","user"},
+            {"p","password"}
+        };
+        //set txt data for service (will free and replace current data)
+        mdns_service_txt_set("_http", "_tcp", serviceTxtData, 3);
+
+        //change service port
+        mdns_service_port_set("_myservice", "_udp", 4321);
+    }
+
+mDNS Query
+^^^^^^^^^^
+
+mDNS provides methods for browsing for services and resolving host's IP/IPv6 addresses.
+
+Results for services are returned as a linked list of ``mdns_result_t`` objects.
+
+Example method to resolve host IPs::
+
+    void resolve_mdns_host(const char * host_name)
+    {
+        printf("Query A: %s.local", host_name);
+
+        struct ip4_addr addr;
+        addr.addr = 0;
+
+        esp_err_t err = mdns_query_a(host_name, 2000,  &addr);
+        if(err){
+            if(err == ESP_ERR_NOT_FOUND){
+                printf("Host was not found!");
+                return;
+            }
+            printf("Query Failed");
+            return;
+        }
+
+        printf(IPSTR, IP2STR(&addr));
+    }
+
+Example method to resolve local services::
+
+    static const char * if_str[] = {"STA", "AP", "ETH", "MAX"};
+    static const char * ip_protocol_str[] = {"V4", "V6", "MAX"};
+
+    void mdns_print_results(mdns_result_t * results){
+        mdns_result_t * r = results;
+        mdns_ip_addr_t * a = NULL;
+        int i = 1, t;
+        while(r){
+            printf("%d: Interface: %s, Type: %s\n", i++, if_str[r->tcpip_if], ip_protocol_str[r->ip_protocol]);
+            if(r->instance_name){
+                printf("  PTR : %s\n", r->instance_name);
+            }
+            if(r->hostname){
+                printf("  SRV : %s.local:%u\n", r->hostname, r->port);
+            }
+            if(r->txt_count){
+                printf("  TXT : [%u] ", r->txt_count);
+                for(t=0; t<r->txt_count; t++){
+                    printf("%s=%s; ", r->txt[t].key, r->txt[t].value);
+                }
+                printf("\n");
+            }
+            a = r->addr;
+            while(a){
+                if(a->addr.type == IPADDR_TYPE_V6){
+                    printf("  AAAA: " IPV6STR "\n", IPV62STR(a->addr.u_addr.ip6));
+                } else {
+                    printf("  A   : " IPSTR "\n", IP2STR(&(a->addr.u_addr.ip4)));
+                }
+                a = a->next;
+            }
+            r = r->next;
+        }
+
+    }
+
+    void find_mdns_service(const char * service_name, const char * proto)
+    {
+        ESP_LOGI(TAG, "Query PTR: %s.%s.local", service_name, proto);
+
+        mdns_result_t * results = NULL;
+        esp_err_t err = mdns_query_ptr(service_name, proto, 3000, 20,  &results);
+        if(err){
+            ESP_LOGE(TAG, "Query Failed");
+            return;
+        }
+        if(!results){
+            ESP_LOGW(TAG, "No results found!");
+            return;
+        }
+
+        mdns_print_results(results);
+        mdns_query_results_free(results);
+    }
+
+Example of using the methods above::
+
+    void my_app_some_method(){
+        //search for {IDF_TARGET_PATH_NAME}-mdns.local
+        resolve_mdns_host("{IDF_TARGET_PATH_NAME}-mdns");
+
+        //search for HTTP servers
+        find_mdns_service("_http", "_tcp");
+        //or file servers
+        find_mdns_service("_smb", "_tcp"); //windows sharing
+        find_mdns_service("_afpovertcp", "_tcp"); //apple sharing
+        find_mdns_service("_nfs", "_tcp"); //NFS server
+        find_mdns_service("_ftp", "_tcp"); //FTP server
+        //or networked printer
+        find_mdns_service("_printer", "_tcp");
+        find_mdns_service("_ipp", "_tcp");
+    }
+
+
+Performance Optimization
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+Execution Speed
+^^^^^^^^^^^^^^^
+
+ - mDNS creates a task with default low priority 1 ``CONFIG_MDNS_TASK_PRIORITY`` (If ``CONFIG_FREERTOS_UNICORE`` enabeled it pinned to CPU0 (``CONFIG_MDNS_TASK_AFFINITY``).
+ Please check `Maximizing Execution Speed <https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-guides/performance/speed.html>`_ for more details.
+
+Minimizing RAM Usage
+^^^^^^^^^^^^^^^^^^^^
+
+- mDNS creates a tasks with stack sizes configured by ``CONFIG_MDNS_TASK_STACK_SIZE``.
+Please check `Minimizing RAM Usage <https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-guides/performance/ram-usage.html>`_ for more details.
+
+Application Example
+-------------------
+
+mDNS server/scanner example: :example:`<../examples>`.
+
+API Reference
+-------------
+
+.. include-build-file:: inc/mdns.inc
+
+

components/mdns/docs/generate_docs

@@ -0,0 +1,28 @@
+build-docs --target esp32 --language en
+build-docs --target esp32 --language zh_CN
+
+cp -rf _build/en/esp32/html html_en
+cp -rf _build/zh_CN/esp32/html html_zh_CN
+rm -rf _build __pycache__ tee
+
+# Modifes some version and target fields of index.html
+echo "<script type="text/javascript">
+window.onload =(function() {
+    var myAnchor = document.getElementById('version-select');
+    var mySpan = document.createElement('input');
+    mySpan.setAttribute('type', 'text');
+    mySpan.setAttribute('maxLength', '10');
+    mySpan.value = 'latest';
+    mySpan.setAttribute('disabled', true);
+    myAnchor.parentNode.replaceChild(mySpan, myAnchor);
+ 
+    var myAnchor = document.getElementById('target-select');
+    var mySpan = document.createElement('input');
+    mySpan.setAttribute('type', 'text');
+    mySpan.setAttribute('maxLength', '10');
+    mySpan.value = 'all targets';
+    mySpan.setAttribute('disabled', true);
+    myAnchor.parentNode.replaceChild(mySpan, myAnchor);
+
+})();
+</script>" | tee -a html_en/index.html html_zh_CN/index.html > /dev/null

components/mdns/docs/zh_CN/conf.py

@@ -0,0 +1,27 @@
+# -*- coding: utf-8 -*-
+#
+# English Language RTD & Sphinx config file
+#
+# Uses ../conf_common.py for most non-language-specific settings.
+
+# Importing conf_common adds all the non-language-specific
+# parts to this conf module
+try:
+    from conf_common import *  # noqa: F403,F401
+except ImportError:
+    import os
+    import sys
+    sys.path.insert(0, os.path.abspath('..'))
+    from conf_common import *  # noqa: F403,F401
+
+import datetime
+
+current_year = datetime.datetime.now().year
+
+# General information about the project.
+project = u'ESP-IDF 编程指南'
+copyright = u'2016 - {} 乐鑫信息科技（上海）股份有限公司'.format(current_year)
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+language = 'zh_CN'

components/mdns/docs/zh_CN/index.rst

@@ -0,0 +1,189 @@
+mDNS 服务
+=========
+:link_to_translation:`en:[English]`
+
+概述
+----
+
+mDNS 是一种组播 UDP 服务，用来提供本地网络服务和主机发现。
+
+绝大多数的操作系统默认都会安装 mDNS 服务，或者提供单独的安装包。``Mac OS`` 默认会安装名为 ``Bonjour`` 的服务（该服务基于 mDNS），此外 Apple 还发布了适用于 Windows 系统的安装程序，可以在 `官方支持 <https://support.apple.com/downloads/bonjour%2520for%2520windows>`_ 找到。在 ``Linux`` 上，mDNS 服务由 `avahi <https://github.com/lathiat/avahi>`_ 提供，通常也会被默认安装。
+
+mDNS 属性
+^^^^^^^^^
+
+    * ``hostname``：设备会去响应的主机名，如果没有设置，会根据设备的网络接口名定义 ``hostname`` 。例如，``my-{IDF_TARGET_PATH_NAME}`` 会被解析为 ``my-{IDF_TARGET_PATH_NAME}.local``。
+    * ``default_instance``：默认实例名（即易记的设备名），例如 ``Jhon's {IDF_TARGET_NAME} Thing``。如果没有设置，将会使用 ``hostname``。
+
+以下为 STA 接口启动 mDNS 服务并设置 ``hostname`` 和 ``default_instance`` 的示例方法：
+
+.. highlight:: c
+
+::
+
+    void start_mdns_service()
+    {
+        // 初始化 mDNS 服务
+        esp_err_t err = mdns_init();
+        if (err) {
+            printf("MDNS Init failed: %d\n", err);
+            return;
+        }
+
+        // 设置 hostname
+        mdns_hostname_set("my-{IDF_TARGET_PATH_NAME}");
+        // 设置默认实例
+        mdns_instance_name_set("Jhon's {IDF_TARGET_NAME} Thing");
+    }
+
+mDNS 服务
+^^^^^^^^^
+
+mDNS 可以广播设备能够提供的网络服务的相关信息，每个服务会由以下属性构成。
+
+    * ``instance_name``：实例名（即易记的服务名），例如 ``Jhon's {IDF_TARGET_NAME} Web Server``。如果没有定义，会使用 ``default_instance``。
+    * ``service_type``：（必需）服务类型，以下划线为前缀，`这里 <http://www.dns-sd.org/serviceTypes.html>`_ 列出了常见的类型。
+    * ``proto``：（必需）服务运行所依赖的协议，以下划线为前缀，例如 ``_tcp`` 或者 ``_udp``。
+    * ``port``：（必需）服务运行所用的端口号。
+    * ``txt``：形如 ``{var, val}`` 的字符串数组，用于定义服务的属性。
+
+添加一些服务和不同属性的示例方法::
+
+    void add_mdns_services()
+    {
+        // 添加服务
+        mdns_service_add(NULL, "_http", "_tcp", 80, NULL, 0);
+        mdns_service_add(NULL, "_arduino", "_tcp", 3232, NULL, 0);
+        mdns_service_add(NULL, "_myservice", "_udp", 1234, NULL, 0);
+
+        // 注意：必须先添加服务，然后才能设置其属性
+        // web 服务器使用自定义的实例名
+        mdns_service_instance_name_set("_http", "_tcp", "Jhon's {IDF_TARGET_NAME} Web Server");
+
+        mdns_txt_item_t serviceTxtData[3] = {
+            {"board","{IDF_TARGET_PATH_NAME}"},
+            {"u","user"},
+            {"p","password"}
+        };
+        // 设置服务的文本数据（会释放并替换当前数据）
+        mdns_service_txt_set("_http", "_tcp", serviceTxtData, 3);
+
+        // 修改服务端口号
+        mdns_service_port_set("_myservice", "_udp", 4321);
+    }
+
+mDNS 查询
+^^^^^^^^^
+
+mDNS 提供查询服务和解析主机 IP/IPv6 地址的方法。
+
+服务查询的结果会作为 ``mdns_result_t`` 类型对象的链表返回。
+
+解析主机 IP 地址的示例方法::
+
+    void resolve_mdns_host(const char * host_name)
+    {
+        printf("Query A: %s.local", host_name);
+
+        struct ip4_addr addr;
+        addr.addr = 0;
+
+        esp_err_t err = mdns_query_a(host_name, 2000,  &addr);
+        if(err){
+            if(err == ESP_ERR_NOT_FOUND){
+                printf("Host was not found!");
+                return;
+            }
+            printf("Query Failed");
+            return;
+        }
+
+        printf(IPSTR, IP2STR(&addr));
+    }
+
+解析本地服务的示例方法::
+
+    static const char * if_str[] = {"STA", "AP", "ETH", "MAX"};
+    static const char * ip_protocol_str[] = {"V4", "V6", "MAX"};
+
+    void mdns_print_results(mdns_result_t * results){
+        mdns_result_t * r = results;
+        mdns_ip_addr_t * a = NULL;
+        int i = 1, t;
+        while(r){
+            printf("%d: Interface: %s, Type: %s\n", i++, if_str[r->tcpip_if], ip_protocol_str[r->ip_protocol]);
+            if(r->instance_name){
+                printf("  PTR : %s\n", r->instance_name);
+            }
+            if(r->hostname){
+                printf("  SRV : %s.local:%u\n", r->hostname, r->port);
+            }
+            if(r->txt_count){
+                printf("  TXT : [%u] ", r->txt_count);
+                for(t=0; t<r->txt_count; t++){
+                    printf("%s=%s; ", r->txt[t].key, r->txt[t].value);
+                }
+                printf("\n");
+            }
+            a = r->addr;
+            while(a){
+                if(a->addr.type == IPADDR_TYPE_V6){
+                    printf("  AAAA: " IPV6STR "\n", IPV62STR(a->addr.u_addr.ip6));
+                } else {
+                    printf("  A   : " IPSTR "\n", IP2STR(&(a->addr.u_addr.ip4)));
+                }
+                a = a->next;
+            }
+            r = r->next;
+        }
+
+    }
+
+    void find_mdns_service(const char * service_name, const char * proto)
+    {
+        ESP_LOGI(TAG, "Query PTR: %s.%s.local", service_name, proto);
+
+        mdns_result_t * results = NULL;
+        esp_err_t err = mdns_query_ptr(service_name, proto, 3000, 20,  &results);
+        if(err){
+            ESP_LOGE(TAG, "Query Failed");
+            return;
+        }
+        if(!results){
+            ESP_LOGW(TAG, "No results found!");
+            return;
+        }
+
+        mdns_print_results(results);
+        mdns_query_results_free(results);
+    }
+
+使用上述方法的示例::
+
+    void my_app_some_method(){
+        // 搜索 {IDF_TARGET_PATH_NAME}-mdns.local
+        resolve_mdns_host("{IDF_TARGET_PATH_NAME}-mdns");
+
+        // 搜索 HTTP 服务器
+        find_mdns_service("_http", "_tcp");
+        // 或者搜索文件服务器
+        find_mdns_service("_smb", "_tcp"); // Windows 系统的共享服务
+        find_mdns_service("_afpovertcp", "_tcp"); // Apple AFP 文件共享服务
+        find_mdns_service("_nfs", "_tcp"); // NFS 服务器
+        find_mdns_service("_ftp", "_tcp"); // FTP 服务器
+        // 或者网络打印机
+        find_mdns_service("_printer", "_tcp");
+        find_mdns_service("_ipp", "_tcp");
+    }
+
+应用示例
+--------
+
+有关 mDNS 服务器和查询器的应用示例请参考 :example:`<../examples>`。
+
+API 参考
+--------
+
+.. include-build-file:: inc/mdns.inc
+
+

components/mdns/examples/CMakeLists.txt

@@ -0,0 +1,10 @@
+# The following lines of boilerplate have to be in your project's CMakeLists
+# in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.5)
+
+set(EXTRA_COMPONENT_DIRS "../..")
+# This example uses an extra component for common functions such as Wi-Fi and Ethernet connection.
+list(APPEND EXTRA_COMPONENT_DIRS "../../../common_components/protocol_examples_common")
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(mdns_test)

components/mdns/examples/README.md

@@ -0,0 +1,91 @@
+# mDNS example
+
+Shows how to use mDNS to advertise lookup services and hosts
+
+## Example workflow
+
+- mDNS is initialized with host name and instance name defined through the project configuration and `_http._tcp` service is added to be advertised
+- A delegated host `esp32-delegated._local` is added and another `_http._tcp` service is added for this host.
+- WiFi STA is started and trying to connect to the access point defined through the project configuration
+- The system event handler is used to pass the network events to mDNS so the service is aware when the interface comes up or down
+- GPIO0 (BOOT Button) is initialized as pulled-up input that can be monitored for button press
+- Example task is started to check if the button is pressed so it can execute the mDNS queries defined
+
+### Configure the project
+
+* Open the project configuration menu (`idf.py menuconfig`)
+
+* Configure Wi-Fi or Ethernet under "Example Connection Configuration" menu
+* Set `mDNS Hostname` as host name prefix for the device and its instance name in `mDNS Instance Name`
+* Disable `Resolve test services` to prevent the example from querying defined names/services on startup (cause warnings in example logs, as illustrated below)
+
+### Build and Flash
+
+Build the project and flash it to the board, then run monitor tool to view serial output:
+
+```
+idf.py -p PORT flash monitor
+```
+
+- Wait for WiFi to connect to your access point
+- You can now ping the device at `[board-hostname].local`, where `[board-hostname]` is preconfigured hostname, `esp32-mdns` by default.
+- You can also browse for `_http._tcp` on the same network to find the advertised service
+- Pressing the BOOT button will start querying the local network for the predefined in `check_button` hosts and services
+- Note that for purpose of CI tests, configuration options of `MDNS_RESOLVE_TEST_SERVICES` and `MDNS_ADD_MAC_TO_HOSTNAME` are available, but disabled by default. If enabled, then the hostname suffix of last 3 bytes from device MAC address is added, e.g. `esp32-mdns-80FFFF`, and a query for test service is issued.
+
+
+(To exit the serial monitor, type ``Ctrl-]``.)
+
+See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
+
+## Example Output
+```
+I (0) cpu_start: Starting scheduler on APP CPU.
+I (276) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
+I (276) mdns-test: mdns hostname set to: [esp32-mdns]
+I (286) wifi: wifi driver task: 3ffc2fa4, prio:23, stack:3584, core=0
+I (286) wifi: wifi firmware version: a3be639
+I (286) wifi: config NVS flash: enabled
+I (296) wifi: config nano formating: disabled
+I (296) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
+I (306) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
+I (336) wifi: Init dynamic tx buffer num: 32
+I (336) wifi: Init data frame dynamic rx buffer num: 32
+I (336) wifi: Init management frame dynamic rx buffer num: 32
+I (346) wifi: Init static rx buffer size: 1600
+I (346) wifi: Init static rx buffer num: 10
+I (346) wifi: Init dynamic rx buffer num: 32
+I (356) mdns-test: Setting WiFi configuration SSID myssid...
+I (426) phy: phy_version: 4000, b6198fa, Sep  3 2018, 15:11:06, 0, 0
+I (426) wifi: mode : sta (30:ae:a4:80:FF:FF)
+I (426) gpio: GPIO[0]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0
+I (1756) wifi: n:11 0, o:1 0, ap:255 255, sta:11 0, prof:1
+I (2736) wifi: state: init -> auth (b0)
+I (2756) wifi: state: auth -> assoc (0)
+I (2766) wifi: state: assoc -> run (10)
+I (2786) wifi: connected with myssid, channel 11
+I (2786) wifi: pm start, type: 1
+
+I (4786) event: sta ip: 192.168.0.139, mask: 255.255.255.0, gw: 192.168.0.2
+I (21126) mdns-test: Query A: esp32.local
+W (23176) mdns-test: ESP_ERR_NOT_FOUND: Host was not found!
+I (23176) mdns-test: Query PTR: _arduino._tcp.local
+W (26276) mdns-test: No results found!
+I (26276) mdns-test: Query PTR: _http._tcp.local
+1: Interface: STA, Type: V6
+  PTR : HP Color LaserJet MFP M277dw (7C2E10)
+  SRV : NPI7C2E10.local:80
+  A   : 254.128.0.0
+2: Interface: STA, Type: V4
+  PTR : switch4e4919
+  SRV : switch4e4919.local:80
+  TXT : [1] path=/config/authentication_page.htm;
+  A   : 192.168.0.118
+I (29396) mdns-test: Query PTR: _printer._tcp.local
+1: Interface: STA, Type: V6
+  PTR : HP Color LaserJet MFP M277dw (7C2E10)
+  SRV : NPI7C2E10.local:515
+  A   : 254.128.0.0
+2: Interface: STA, Type: V4
+  PTR : HP Color LaserJet MFP M277dw (7C2E10)
+```

components/mdns/examples/main/CMakeLists.txt

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "mdns_example_main.c"
+                    INCLUDE_DIRS ".")

components/mdns/examples/main/Kconfig.projbuild

@@ -0,0 +1,55 @@
+menu "Example Configuration"
+
+    orsource "$IDF_PATH/examples/common_components/env_caps/$IDF_TARGET/Kconfig.env_caps"
+
+    config MDNS_HOSTNAME
+        string "mDNS Hostname"
+        default "esp32-mdns"
+        help
+            mDNS Hostname for example to use
+
+    config MDNS_INSTANCE
+        string "mDNS Instance Name"
+        default "ESP32 with mDNS"
+        help
+            mDNS Instance Name for example to use
+
+    config MDNS_PUBLISH_DELEGATE_HOST
+        bool "Publish a delegated host"
+        help
+            Enable publishing a delegated host other than ESP32.
+            The example will also add a mock service for this host.
+
+    config MDNS_RESOLVE_TEST_SERVICES
+        bool "Resolve test services"
+        default n
+        help
+            Enable resolving test services on startup.
+            These services are advertized and evaluated in automated tests.
+            When executed locally, these will not be resolved and warnings appear in the log.
+            Please set to false to disable initial querying to avoid warnings.
+
+    config MDNS_ADD_MAC_TO_HOSTNAME
+        bool "Add mac suffix to hostname"
+        default n
+        help
+            If enabled, a portion of MAC address is added to the hostname, this is used
+            for evaluation of tests in CI
+
+    config MDNS_BUTTON_GPIO
+        int "Button GPIO to trigger querries"
+        range ENV_GPIO_RANGE_MIN ENV_GPIO_IN_RANGE_MAX
+        default 0
+        help
+            Set the GPIO number used as mDNS test button
+
+    config MDNS_ADD_CUSTOM_NETIF
+        bool "Add user netif to mdns service"
+        default n
+        help
+            If enabled, we try to add a custom netif to mdns service.
+            Note that for using with common connection example code, we have to disable
+            all predefined interfaces in mdns component setup (since we're adding one
+            of the default interfaces)
+
+endmenu

components/mdns/examples/main/mdns_example_main.c

@@ -0,0 +1,343 @@
+/* MDNS-SD Query and advertise Example
+
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   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 <string.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "esp_netif_ip_addr.h"
+#include "esp_mac.h"
+#include "esp_event.h"
+#include "esp_log.h"
+#include "nvs_flash.h"
+#include "esp_netif.h"
+#include "protocol_examples_common.h"
+#include "mdns.h"
+#include "driver/gpio.h"
+#include "netdb.h"
+
+
+#define EXAMPLE_MDNS_INSTANCE CONFIG_MDNS_INSTANCE
+#define EXAMPLE_BUTTON_GPIO   CONFIG_MDNS_BUTTON_GPIO
+
+static const char * TAG = "mdns-test";
+static char * generate_hostname(void);
+
+#if CONFIG_MDNS_RESOLVE_TEST_SERVICES == 1
+static void  query_mdns_host_with_gethostbyname(char * host);
+static void  query_mdns_host_with_getaddrinfo(char * host);
+#endif
+
+static void initialise_mdns(void)
+{
+    char * hostname = generate_hostname();
+
+    //initialize mDNS
+    ESP_ERROR_CHECK( mdns_init() );
+    //set mDNS hostname (required if you want to advertise services)
+    ESP_ERROR_CHECK( mdns_hostname_set(hostname) );
+    ESP_LOGI(TAG, "mdns hostname set to: [%s]", hostname);
+    //set default mDNS instance name
+    ESP_ERROR_CHECK( mdns_instance_name_set(EXAMPLE_MDNS_INSTANCE) );
+
+    //structure with TXT records
+    mdns_txt_item_t serviceTxtData[3] = {
+        {"board", "esp32"},
+        {"u", "user"},
+        {"p", "password"}
+    };
+
+    //initialize service
+    ESP_ERROR_CHECK( mdns_service_add("ESP32-WebServer", "_http", "_tcp", 80, serviceTxtData, 3) );
+    ESP_ERROR_CHECK( mdns_service_subtype_add_for_host("ESP32-WebServer", "_http", "_tcp", NULL, "_server") );
+#if CONFIG_MDNS_MULTIPLE_INSTANCE
+    ESP_ERROR_CHECK( mdns_service_add("ESP32-WebServer1", "_http", "_tcp", 80, NULL, 0) );
+#endif
+
+#if CONFIG_MDNS_PUBLISH_DELEGATE_HOST
+    char *delegated_hostname;
+    if (-1 == asprintf(&delegated_hostname, "%s-delegated", hostname)) {
+        abort();
+    }
+
+    mdns_ip_addr_t addr4, addr6;
+    esp_netif_str_to_ip4("10.0.0.1", &addr4.addr.u_addr.ip4);
+    addr4.addr.type = ESP_IPADDR_TYPE_V4;
+    esp_netif_str_to_ip6("fd11:22::1", &addr6.addr.u_addr.ip6);
+    addr6.addr.type = ESP_IPADDR_TYPE_V6;
+    addr4.next = &addr6;
+    addr6.next = NULL;
+    ESP_ERROR_CHECK( mdns_delegate_hostname_add(delegated_hostname, &addr4) );
+    ESP_ERROR_CHECK( mdns_service_add_for_host("test0", "_http", "_tcp", delegated_hostname, 1234, serviceTxtData, 3) );
+    free(delegated_hostname);
+#endif // CONFIG_MDNS_PUBLISH_DELEGATE_HOST
+
+    //add another TXT item
+    ESP_ERROR_CHECK( mdns_service_txt_item_set("_http", "_tcp", "path", "/foobar") );
+    //change TXT item value
+    ESP_ERROR_CHECK( mdns_service_txt_item_set_with_explicit_value_len("_http", "_tcp", "u", "admin", strlen("admin")) );
+    free(hostname);
+}
+
+/* these strings match mdns_ip_protocol_t enumeration */
+static const char * ip_protocol_str[] = {"V4", "V6", "MAX"};
+
+static void mdns_print_results(mdns_result_t *results)
+{
+    mdns_result_t *r = results;
+    mdns_ip_addr_t *a = NULL;
+    int i = 1, t;
+    while (r) {
+        printf("%d: Interface: %s, Type: %s, TTL: %u\n", i++, esp_netif_get_ifkey(r->esp_netif), ip_protocol_str[r->ip_protocol],
+               r->ttl);
+        if (r->instance_name) {
+            printf("  PTR : %s.%s.%s\n", r->instance_name, r->service_type, r->proto);
+        }
+        if (r->hostname) {
+            printf("  SRV : %s.local:%u\n", r->hostname, r->port);
+        }
+        if (r->txt_count) {
+            printf("  TXT : [%zu] ", r->txt_count);
+            for (t = 0; t < r->txt_count; t++) {
+                printf("%s=%s(%d); ", r->txt[t].key, r->txt[t].value ? r->txt[t].value : "NULL", r->txt_value_len[t]);
+            }
+            printf("\n");
+        }
+        a = r->addr;
+        while (a) {
+            if (a->addr.type == ESP_IPADDR_TYPE_V6) {
+                printf("  AAAA: " IPV6STR "\n", IPV62STR(a->addr.u_addr.ip6));
+            } else {
+                printf("  A   : " IPSTR "\n", IP2STR(&(a->addr.u_addr.ip4)));
+            }
+            a = a->next;
+        }
+        r = r->next;
+    }
+}
+
+static void query_mdns_service(const char * service_name, const char * proto)
+{
+    ESP_LOGI(TAG, "Query PTR: %s.%s.local", service_name, proto);
+
+    mdns_result_t * results = NULL;
+    esp_err_t err = mdns_query_ptr(service_name, proto, 3000, 20,  &results);
+    if(err){
+        ESP_LOGE(TAG, "Query Failed: %s", esp_err_to_name(err));
+        return;
+    }
+    if(!results){
+        ESP_LOGW(TAG, "No results found!");
+        return;
+    }
+
+    mdns_print_results(results);
+    mdns_query_results_free(results);
+}
+
+static bool check_and_print_result(mdns_search_once_t *search)
+{
+    // Check if any result is available
+    mdns_result_t * result = NULL;
+    if (!mdns_query_async_get_results(search, 0, &result, NULL)) {
+        return false;
+    }
+
+    if (!result) {   // search timeout, but no result
+        return true;
+    }
+
+    // If yes, print the result
+    mdns_ip_addr_t * a = result->addr;
+    while (a) {
+        if(a->addr.type == ESP_IPADDR_TYPE_V6){
+            printf("  AAAA: " IPV6STR "\n", IPV62STR(a->addr.u_addr.ip6));
+        } else {
+            printf("  A   : " IPSTR "\n", IP2STR(&(a->addr.u_addr.ip4)));
+        }
+        a = a->next;
+    }
+    // and free the result
+    mdns_query_results_free(result);
+    return true;
+}
+
+static void query_mdns_hosts_async(const char * host_name)
+{
+    ESP_LOGI(TAG, "Query both A and AAA: %s.local", host_name);
+
+    mdns_search_once_t *s_a = mdns_query_async_new(host_name, NULL, NULL, MDNS_TYPE_A, 1000, 1, NULL);
+    mdns_search_once_t *s_aaaa = mdns_query_async_new(host_name, NULL, NULL, MDNS_TYPE_AAAA, 1000, 1, NULL);
+    while (s_a || s_aaaa) {
+        if (s_a && check_and_print_result(s_a)) {
+            ESP_LOGI(TAG, "Query A %s.local finished", host_name);
+            mdns_query_async_delete(s_a);
+            s_a = NULL;
+        }
+        if (s_aaaa && check_and_print_result(s_aaaa)) {
+            ESP_LOGI(TAG, "Query AAAA %s.local finished", host_name);
+            mdns_query_async_delete(s_aaaa);
+            s_aaaa = NULL;
+        }
+        vTaskDelay(50 / portTICK_PERIOD_MS);
+    }
+}
+
+static void query_mdns_host(const char * host_name)
+{
+    ESP_LOGI(TAG, "Query A: %s.local", host_name);
+
+    struct esp_ip4_addr addr;
+    addr.addr = 0;
+
+    esp_err_t err = mdns_query_a(host_name, 2000,  &addr);
+    if(err){
+        if(err == ESP_ERR_NOT_FOUND){
+            ESP_LOGW(TAG, "%s: Host was not found!", esp_err_to_name(err));
+            return;
+        }
+        ESP_LOGE(TAG, "Query Failed: %s", esp_err_to_name(err));
+        return;
+    }
+
+    ESP_LOGI(TAG, "Query A: %s.local resolved to: " IPSTR, host_name, IP2STR(&addr));
+}
+
+static void initialise_button(void)
+{
+    gpio_config_t io_conf = {0};
+    io_conf.intr_type = GPIO_INTR_DISABLE;
+    io_conf.pin_bit_mask = BIT64(EXAMPLE_BUTTON_GPIO);
+    io_conf.mode = GPIO_MODE_INPUT;
+    io_conf.pull_up_en = 1;
+    io_conf.pull_down_en = 0;
+    gpio_config(&io_conf);
+}
+
+static void check_button(void)
+{
+    static bool old_level = true;
+    bool new_level = gpio_get_level(EXAMPLE_BUTTON_GPIO);
+    if (!new_level && old_level) {
+        query_mdns_hosts_async("esp32-mdns");
+        query_mdns_host("esp32");
+        query_mdns_service("_arduino", "_tcp");
+        query_mdns_service("_http", "_tcp");
+        query_mdns_service("_printer", "_tcp");
+        query_mdns_service("_ipp", "_tcp");
+        query_mdns_service("_afpovertcp", "_tcp");
+        query_mdns_service("_smb", "_tcp");
+        query_mdns_service("_ftp", "_tcp");
+        query_mdns_service("_nfs", "_tcp");
+    }
+    old_level = new_level;
+}
+
+static void mdns_example_task(void *pvParameters)
+{
+#if CONFIG_MDNS_RESOLVE_TEST_SERVICES == 1
+    /* Send initial queries that are started by CI tester */
+    query_mdns_host("tinytester");
+    query_mdns_host_with_gethostbyname("tinytester-lwip.local");
+    query_mdns_host_with_getaddrinfo("tinytester-lwip.local");
+#endif
+
+    while (1) {
+        check_button();
+        vTaskDelay(50 / portTICK_PERIOD_MS);
+    }
+}
+
+void app_main(void)
+{
+    ESP_ERROR_CHECK(nvs_flash_init());
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+
+    initialise_mdns();
+
+    /* This helper function configures Wi-Fi or Ethernet, as selected in menuconfig.
+     * Read "Establishing Wi-Fi or Ethernet Connection" section in
+     * examples/protocols/README.md for more information about this function.
+     */
+    ESP_ERROR_CHECK(example_connect());
+
+#if defined(CONFIG_MDNS_ADD_CUSTOM_NETIF) && !defined(CONFIG_MDNS_PREDEF_NETIF_STA) && !defined(CONFIG_MDNS_PREDEF_NETIF_ETH)
+    /* Demonstration of adding a custom netif to mdns service, but we're adding the default example one,
+     * so we must disable all predefined interfaces (PREDEF_NETIF_STA, AP and ETH) first
+     */
+    ESP_ERROR_CHECK(mdns_register_netif(EXAMPLE_INTERFACE));
+    /* It is not enough to just register the interface, we have to enable is manually.
+     * This is typically performed in "GOT_IP" event handler, but we call it here directly
+     * since the `EXAMPLE_INTERFACE` netif is connected already, to keep the example simple.
+     */
+    ESP_ERROR_CHECK(mdns_netif_action(EXAMPLE_INTERFACE, MDNS_EVENT_ENABLE_IP4));
+    ESP_ERROR_CHECK(mdns_netif_action(EXAMPLE_INTERFACE, MDNS_EVENT_ANNOUNCE_IP4));
+#endif
+    initialise_button();
+    xTaskCreate(&mdns_example_task, "mdns_example_task", 2048, NULL, 5, NULL);
+}
+
+/** Generate host name based on sdkconfig, optionally adding a portion of MAC address to it.
+ *  @return host name string allocated from the heap
+ */
+static char* generate_hostname(void)
+{
+#ifndef CONFIG_MDNS_ADD_MAC_TO_HOSTNAME
+    return strdup(CONFIG_MDNS_HOSTNAME);
+#else
+    uint8_t mac[6];
+    char   *hostname;
+    esp_read_mac(mac, ESP_MAC_WIFI_STA);
+    if (-1 == asprintf(&hostname, "%s-%02X%02X%02X", CONFIG_MDNS_HOSTNAME, mac[3], mac[4], mac[5])) {
+        abort();
+    }
+    return hostname;
+#endif
+}
+
+#if CONFIG_MDNS_RESOLVE_TEST_SERVICES == 1
+/**
+ *  @brief Executes gethostbyname and displays list of resolved addresses.
+ *  Note: This function is used only to test advertised mdns hostnames resolution
+ */
+static void  query_mdns_host_with_gethostbyname(char * host)
+{
+    struct hostent *res = gethostbyname(host);
+    if (res) {
+        unsigned int i = 0;
+        while (res->h_addr_list[i] != NULL) {
+            ESP_LOGI(TAG, "gethostbyname: %s resolved to: %s", host, inet_ntoa(*(struct in_addr *) (res->h_addr_list[i])));
+            i++;
+        }
+    }
+}
+
+/**
+ *  @brief Executes getaddrinfo and displays list of resolved addresses.
+ *  Note: This function is used only to test advertised mdns hostnames resolution
+ */
+static void  query_mdns_host_with_getaddrinfo(char * host)
+{
+    struct addrinfo hints;
+    struct addrinfo * res;
+
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_socktype = SOCK_STREAM;
+
+    if (!getaddrinfo(host, NULL, &hints, &res)) {
+        while (res) {
+            ESP_LOGI(TAG, "getaddrinfo: %s resolved to: %s", host,
+                     res->ai_family == AF_INET?
+                     inet_ntoa(((struct sockaddr_in *) res->ai_addr)->sin_addr):
+                     inet_ntoa(((struct sockaddr_in6 *) res->ai_addr)->sin6_addr));
+            res = res->ai_next;
+        }
+    }
+}
+#endif

components/mdns/examples/mdns_example_test.py

@@ -0,0 +1,166 @@
+import os
+import re
+import select
+import socket
+import struct
+import subprocess
+import time
+from threading import Event, Thread
+
+import dpkt
+import dpkt.dns
+import ttfw_idf
+from tiny_test_fw import DUT
+from tiny_test_fw.Utility import console_log
+
+
+def get_dns_query_for_esp(esp_host):
+    dns = dpkt.dns.DNS(b'\x00\x00\x01\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x01')
+    dns.qd[0].name = esp_host + u'.local'
+    console_log('Created query for esp host: {} '.format(dns.__repr__()))
+    return dns.pack()
+
+
+def get_dns_answer_to_mdns(tester_host):
+    dns = dpkt.dns.DNS(b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
+    dns.op = dpkt.dns.DNS_QR | dpkt.dns.DNS_AA
+    dns.rcode = dpkt.dns.DNS_RCODE_NOERR
+    arr = dpkt.dns.DNS.RR()
+    arr.cls = dpkt.dns.DNS_IN
+    arr.type = dpkt.dns.DNS_A
+    arr.name = tester_host
+    arr.ip = socket.inet_aton('127.0.0.1')
+    dns.an.append(arr)
+    console_log('Created answer to mdns query: {} '.format(dns.__repr__()))
+    return dns.pack()
+
+
+def get_dns_answer_to_mdns_lwip(tester_host, id):
+    dns = dpkt.dns.DNS(b'\x5e\x39\x84\x00\x00\x01\x00\x01\x00\x00\x00\x00\x0a\x64\x61\x76\x69\x64'
+                       b'\x2d\x63\x6f\x6d\x70\x05\x6c\x6f\x63\x61\x6c\x00\x00\x01\x00\x01\xc0\x0c'
+                       b'\x00\x01\x00\x01\x00\x00\x00\x0a\x00\x04\xc0\xa8\x0a\x6c')
+    dns.qd[0].name = tester_host
+    dns.an[0].name = tester_host
+    dns.an[0].ip = socket.inet_aton('127.0.0.1')
+    dns.an[0].rdata = socket.inet_aton('127.0.0.1')
+    dns.id = id
+    print('Created answer to mdns (lwip) query: {} '.format(dns.__repr__()))
+    return dns.pack()
+
+
+def mdns_server(esp_host, events):
+    UDP_IP = '0.0.0.0'
+    UDP_PORT = 5353
+    MCAST_GRP = '224.0.0.251'
+    TESTER_NAME = u'tinytester.local'
+    TESTER_NAME_LWIP = u'tinytester-lwip.local'
+    QUERY_TIMEOUT = 0.2
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
+    sock.setblocking(False)
+    sock.bind((UDP_IP, UDP_PORT))
+    mreq = struct.pack('4sl', socket.inet_aton(MCAST_GRP), socket.INADDR_ANY)
+    sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
+    last_query_timepoint = time.time()
+    while not events['stop'].is_set():
+        try:
+            current_time = time.time()
+            if current_time - last_query_timepoint > QUERY_TIMEOUT:
+                last_query_timepoint = current_time
+                if not events['esp_answered'].is_set():
+                    sock.sendto(get_dns_query_for_esp(esp_host), (MCAST_GRP, UDP_PORT))
+                if not events['esp_delegated_answered'].is_set():
+                    sock.sendto(get_dns_query_for_esp(esp_host + '-delegated'), (MCAST_GRP, UDP_PORT))
+            timeout = max(0, QUERY_TIMEOUT - (current_time - last_query_timepoint))
+            read_socks, _, _ = select.select([sock], [], [], timeout)
+            if not read_socks:
+                continue
+            data, addr = sock.recvfrom(1024)
+            dns = dpkt.dns.DNS(data)
+            if len(dns.qd) > 0 and dns.qd[0].type == dpkt.dns.DNS_A:
+                if dns.qd[0].name == TESTER_NAME:
+                    console_log('Received query: {} '.format(dns.__repr__()))
+                    sock.sendto(get_dns_answer_to_mdns(TESTER_NAME), (MCAST_GRP, UDP_PORT))
+                elif dns.qd[0].name == TESTER_NAME_LWIP:
+                    console_log('Received query: {} '.format(dns.__repr__()))
+                    sock.sendto(get_dns_answer_to_mdns_lwip(TESTER_NAME_LWIP, dns.id), addr)
+            if len(dns.an) > 0 and dns.an[0].type == dpkt.dns.DNS_A:
+                console_log('Received answer from {}'.format(dns.an[0].name))
+                if dns.an[0].name == esp_host + u'.local':
+                    console_log('Received answer to esp32-mdns query: {}'.format(dns.__repr__()))
+                    events['esp_answered'].set()
+                if dns.an[0].name == esp_host + u'-delegated.local':
+                    console_log('Received answer to esp32-mdns-delegate query: {}'.format(dns.__repr__()))
+                    events['esp_delegated_answered'].set()
+        except socket.timeout:
+            break
+        except dpkt.UnpackError:
+            continue
+
+
+def test_examples_protocol_mdns(env, config):
+    """
+    steps: |
+      1. obtain IP address + init mdns example
+      2. get the dut host name (and IP address)
+      3. check the mdns name is accessible
+      4. check DUT output if mdns advertized host is resolved
+    """
+    dut1 = env.get_dut('mdns-test', 'examples/protocols/mdns', dut_class=ttfw_idf.ESP32DUT, app_config_name=config)
+    # check and log bin size
+    binary_file = os.path.join(dut1.app.binary_path, 'mdns_test.bin')
+    bin_size = os.path.getsize(binary_file)
+    ttfw_idf.log_performance('mdns-test_bin_size', '{}KB'.format(bin_size // 1024))
+    # 1. start mdns application
+    dut1.start_app()
+    # 2. get the dut host name (and IP address)
+    specific_host = dut1.expect(re.compile(r'mdns hostname set to: \[([^\]]+)\]'), timeout=30)[0]
+
+    mdns_server_events = {'stop': Event(), 'esp_answered': Event(), 'esp_delegated_answered': Event()}
+    mdns_responder = Thread(target=mdns_server, args=(str(specific_host), mdns_server_events))
+    try:
+        ip_address = dut1.expect(re.compile(r' eth ip: ([^,]+),'), timeout=30)[0]
+        console_log('Connected to AP with IP: {}'.format(ip_address))
+    except DUT.ExpectTimeout:
+        raise ValueError('ENV_TEST_FAILURE: Cannot connect to AP')
+    try:
+        # 3. check the mdns name is accessible
+        mdns_responder.start()
+        if not mdns_server_events['esp_answered'].wait(timeout=30):
+            raise ValueError('Test has failed: did not receive mdns answer within timeout')
+        if not mdns_server_events['esp_delegated_answered'].wait(timeout=30):
+            raise ValueError('Test has failed: did not receive mdns answer for delegated host within timeout')
+        # 4. check DUT output if mdns advertized host is resolved
+        dut1.expect(re.compile(r'mdns-test: Query A: tinytester.local resolved to: 127.0.0.1'), timeout=30)
+        dut1.expect(re.compile(r'mdns-test: gethostbyname: tinytester-lwip.local resolved to: 127.0.0.1'), timeout=30)
+        dut1.expect(re.compile(r'mdns-test: getaddrinfo: tinytester-lwip.local resolved to: 127.0.0.1'), timeout=30)
+        # 5. check the DUT answers to `dig` command
+        dig_output = subprocess.check_output(['dig', '+short', '-p', '5353', '@224.0.0.251',
+                                              '{}.local'.format(specific_host)])
+        console_log('Resolving {} using "dig" succeeded with:\n{}'.format(specific_host, dig_output))
+        if not ip_address.encode('utf-8') in dig_output:
+            raise ValueError('Test has failed: Incorrectly resolved DUT hostname using dig'
+                             "Output should've contained DUT's IP address:{}".format(ip_address))
+    finally:
+        mdns_server_events['stop'].set()
+        mdns_responder.join()
+
+
+@ttfw_idf.idf_example_test(env_tag='Example_EthKitV1')
+def test_examples_protocol_mdns_default(env, _):
+    test_examples_protocol_mdns(env, 'eth_def')
+
+
+@ttfw_idf.idf_example_test(env_tag='Example_EthKitV1')
+def test_examples_protocol_mdns_socket(env, _):
+    test_examples_protocol_mdns(env, 'eth_socket')
+
+
+@ttfw_idf.idf_example_test(env_tag='Example_EthKitV1')
+def test_examples_protocol_mdns_custom_netif(env, _):
+    test_examples_protocol_mdns(env, 'eth_custom_netif')
+
+
+if __name__ == '__main__':
+    test_examples_protocol_mdns_default()

components/mdns/examples/sdkconfig.ci.eth_custom_netif

@@ -0,0 +1,19 @@
+CONFIG_IDF_TARGET="esp32"
+CONFIG_MDNS_RESOLVE_TEST_SERVICES=y
+CONFIG_MDNS_ADD_MAC_TO_HOSTNAME=y
+CONFIG_MDNS_PUBLISH_DELEGATE_HOST=y
+CONFIG_MDNS_PREDEF_NETIF_STA=n
+CONFIG_MDNS_PREDEF_NETIF_AP=n
+CONFIG_MDNS_PREDEF_NETIF_ETH=n
+CONFIG_MDNS_ADD_CUSTOM_NETIF=y
+CONFIG_LWIP_DNS_SUPPORT_MDNS_QUERIES=y
+CONFIG_EXAMPLE_CONNECT_ETHERNET=y
+CONFIG_EXAMPLE_CONNECT_WIFI=n
+CONFIG_EXAMPLE_USE_INTERNAL_ETHERNET=y
+CONFIG_EXAMPLE_ETH_PHY_IP101=y
+CONFIG_EXAMPLE_ETH_MDC_GPIO=23
+CONFIG_EXAMPLE_ETH_MDIO_GPIO=18
+CONFIG_EXAMPLE_ETH_PHY_RST_GPIO=5
+CONFIG_EXAMPLE_ETH_PHY_ADDR=1
+CONFIG_EXAMPLE_CONNECT_IPV6=y
+CONFIG_MDNS_BUTTON_GPIO=32

components/mdns/examples/sdkconfig.ci.eth_def

@@ -0,0 +1,15 @@
+CONFIG_IDF_TARGET="esp32"
+CONFIG_MDNS_RESOLVE_TEST_SERVICES=y
+CONFIG_MDNS_ADD_MAC_TO_HOSTNAME=y
+CONFIG_MDNS_PUBLISH_DELEGATE_HOST=y
+CONFIG_LWIP_DNS_SUPPORT_MDNS_QUERIES=y
+CONFIG_EXAMPLE_CONNECT_ETHERNET=y
+CONFIG_EXAMPLE_CONNECT_WIFI=n
+CONFIG_EXAMPLE_USE_INTERNAL_ETHERNET=y
+CONFIG_EXAMPLE_ETH_PHY_IP101=y
+CONFIG_EXAMPLE_ETH_MDC_GPIO=23
+CONFIG_EXAMPLE_ETH_MDIO_GPIO=18
+CONFIG_EXAMPLE_ETH_PHY_RST_GPIO=5
+CONFIG_EXAMPLE_ETH_PHY_ADDR=1
+CONFIG_EXAMPLE_CONNECT_IPV6=y
+CONFIG_MDNS_BUTTON_GPIO=32

components/mdns/examples/sdkconfig.ci.eth_socket

@@ -0,0 +1,16 @@
+CONFIG_IDF_TARGET="esp32"
+CONFIG_MDNS_RESOLVE_TEST_SERVICES=y
+CONFIG_MDNS_ADD_MAC_TO_HOSTNAME=y
+CONFIG_MDNS_PUBLISH_DELEGATE_HOST=y
+CONFIG_MDNS_NETWORKING_SOCKET=y
+CONFIG_LWIP_DNS_SUPPORT_MDNS_QUERIES=y
+CONFIG_EXAMPLE_CONNECT_ETHERNET=y
+CONFIG_EXAMPLE_CONNECT_WIFI=n
+CONFIG_EXAMPLE_USE_INTERNAL_ETHERNET=y
+CONFIG_EXAMPLE_ETH_PHY_IP101=y
+CONFIG_EXAMPLE_ETH_MDC_GPIO=23
+CONFIG_EXAMPLE_ETH_MDIO_GPIO=18
+CONFIG_EXAMPLE_ETH_PHY_RST_GPIO=5
+CONFIG_EXAMPLE_ETH_PHY_ADDR=1
+CONFIG_EXAMPLE_CONNECT_IPV6=y
+CONFIG_MDNS_BUTTON_GPIO=32

components/mdns/tests/test_afl_fuzz_host/Makefile

@@ -1,10 +1,10 @@
 TEST_NAME=test
 FUZZ=afl-fuzz
-COMPONENTS_DIR=../..
+COMPONENTS_DIR=$(IDF_PATH)/components
 COMPILER_ICLUDE_DIR=$(shell echo `which xtensa-esp32-elf-gcc | xargs dirname | xargs dirname`/xtensa-esp32-elf)
 
 CFLAGS=-g -Wno-unused-value -Wno-missing-declarations -Wno-pointer-bool-conversion -Wno-macro-redefined -Wno-int-to-void-pointer-cast -DHOOK_MALLOC_FAILED -DESP_EVENT_H_ -D__ESP_LOG_H__ \
-                 -I. -I.. -I../include -I../private_include -I ./build/config  \
+                 -I. -I../.. -I../../include -I../../private_include -I ./build/config  \
                  -I$(COMPONENTS_DIR) \
                  -I$(COMPONENTS_DIR)/driver/include \
                  -I$(COMPONENTS_DIR)/esp_common/include \
@@ -68,7 +68,7 @@ all: $(TEST_NAME)
 	@echo "[CC] $<"
 	@$(CC) $(CFLAGS) -c $< -o $@
 
-mdns.o: ../mdns.c
+mdns.o: ../../mdns.c
 	@echo "[CC] $<"
 	@$(CC) $(CFLAGS) -include mdns_mock.h $(MDNS_C_DEPENDENCY_INJECTION) -c $< -o $@
 

components/mdns/tests/test_apps/CMakeLists.txt

@@ -0,0 +1,11 @@
+# The following four lines of boilerplate have to be in your project's CMakeLists
+# in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.5)
+
+# (Not part of the boilerplate)
+# This example uses an extra component for common functions such as Wi-Fi and Ethernet connection.
+set(EXTRA_COMPONENT_DIRS "../../../../common_components/protocol_examples_common")
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+
+project(mdns)

components/mdns/tests/test_apps/README.md

@@ -0,0 +1,49 @@
+| Supported Targets | ESP32 | ESP32-S2 | ESP32-C3 |
+| ----------------- | ----- | -------- | -------- |
+
+# mDNS test project
+
+Main purpose of this application is to test the mDNS library to correctly advertise, lookup services and hosts.
+The "app_test.py" logically separated from two sets of test cases 1. "ESP32 board sends queries -> Host sends answers" and 2. "Host sends queries" -> "ESP32 board sends answers".
+Two first sets of test cases are starting by 'test_query_' and the second ones by 'start_case'.
+
+## Runtime settings
+
+1. For first sets of test cases python creates and sends dns queries using "dpkt" library
+2. For the second sets of test cases this app waits for user input to provide test case(e.g. CONFIG_TEST_QUERY_HOST, CONFIG_TEST_QUERY_HOST_ASYNC or CONFIG_TEST_QUERY_SERVICE)
+In order to run both of them just needed to set up the project and run by 'python app_test.py'
+
+## Test app workflow
+
+- mDNS is initialized with hostname and instance name defined through the project configuration and `_http._tcp` service is added to be advertised
+- A delegated host `esp32-delegated._local` is added and another `_http._tcp` service is added for this host.
+- WiFi STA is started and tries to connect to the access point defined through the project configuration
+
+### Configure the project
+
+* Open the project configuration menu (`idf.py menuconfig`)
+
+* Configure Wi-Fi or Ethernet under "Example Connection Configuration" menu.
+
+* Set `mDNS Hostname` as host name prefix for the device and its instance name in `mDNS Instance Name`
+
+### Build and Flash
+
+Build the project and flash it to the board, then run the monitor tool to view the serial output:
+
+```
+idf.py -p PORT flash monitor
+```
+
+- Wait for WiFi to connect to your access point
+- You can now ping the device at `[board-hostname].local`, where `[board-hostname]` is preconfigured hostname, `esp32-mdns` by default.
+- You can also browse for `_http._tcp` on the same network to find the advertised service
+- Note that for purpose of CI tests, configuration options of `MDNS_RESOLVE_TEST_SERVICES` and `MDNS_ADD_MAC_TO_HOSTNAME` are available, but disabled by default. If enabled, then the hostname suffix of last 3 bytes from device MAC address is added, e.g. `esp32-mdns-80FFFF`, and a query for test service is issued.
+
+
+(To exit the serial monitor, type ``Ctrl-]``.)
+
+See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
+
+## Hardware Required
+This test-app can be executed on any ESP32 board, the only required interface is WiFi and connection to a local network and tls server.

components/mdns/tests/test_apps/app_test.py

@@ -0,0 +1,290 @@
+# SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+# SPDX-License-Identifier: Apache-2.0
+
+import re
+import select
+import socket
+import struct
+import time
+from threading import Event, Thread
+
+import dpkt
+import dpkt.dns
+import ttfw_idf
+from tiny_test_fw.Utility import console_log
+
+UDP_PORT = 5353
+MCAST_GRP = '224.0.0.251'
+
+# This service is created from esp board startup
+SERVICE_NAME = u'ESP32-WebServer._http._tcp.local'
+SUB_SERVICE_NAME = u'_server._sub._http._tcp.local'
+
+# This host name answer sent by host, when there is query from board
+HOST_NAME = u'tinytester.local'
+
+# This servce answer sent by host, when there is query from board
+MDNS_HOST_SERVICE = u'ESP32._http._tcp.local'
+
+# Number of retries to receive mdns answear
+RETRY_COUNT = 10
+
+stop_mdns_listener = Event()
+start_mdns_listener = Event()
+esp_service_answered = Event()
+esp_sub_service_answered = Event()
+esp_host_answered = Event()
+esp_delegated_host_answered = Event()
+
+
+# Get query of ESP32-WebServer._http._tcp.local service
+def get_mdns_service_query(service):  # type:(str) -> dpkt.dns.Msg
+    dns = dpkt.dns.DNS()
+    dns.op = dpkt.dns.DNS_QR | dpkt.dns.DNS_AA
+    dns.rcode = dpkt.dns.DNS_RCODE_NOERR
+    arr = dpkt.dns.DNS.RR()
+    arr.cls = dpkt.dns.DNS_IN
+    arr.type = dpkt.dns.DNS_SRV
+    arr.name = service
+    arr.target = socket.inet_aton('127.0.0.1')
+    arr.srvname = service
+    dns.qd.append(arr)
+    console_log('Created mdns service query: {} '.format(dns.__repr__()))
+    return dns.pack()
+
+
+# Get query of _server_.sub._http._tcp.local sub service
+def get_mdns_sub_service_query(sub_service):  # type:(str) -> dpkt.dns.Msg
+    dns = dpkt.dns.DNS()
+    dns.op = dpkt.dns.DNS_QR | dpkt.dns.DNS_AA
+    dns.rcode = dpkt.dns.DNS_RCODE_NOERR
+    arr = dpkt.dns.DNS.RR()
+    arr.cls = dpkt.dns.DNS_IN
+    arr.type = dpkt.dns.DNS_PTR
+    arr.name = sub_service
+    arr.target = socket.inet_aton('127.0.0.1')
+    arr.ptrname = sub_service
+    dns.qd.append(arr)
+    console_log('Created mdns subtype service query: {} '.format(dns.__repr__()))
+    return dns.pack()
+
+
+# Get query for host resolution
+def get_dns_query_for_esp(esp_host):  # type:(str) -> dpkt.dns.Msg
+    dns = dpkt.dns.DNS()
+    arr = dpkt.dns.DNS.RR()
+    arr.cls = dpkt.dns.DNS_IN
+    arr.name = esp_host + u'.local'
+    dns.qd.append(arr)
+    console_log('Created query for esp host: {} '.format(dns.__repr__()))
+    return dns.pack()
+
+
+# Get mdns answer for host resoloution
+def get_dns_answer_to_mdns(tester_host):  # type:(str) -> dpkt.dns.Msg
+    dns = dpkt.dns.DNS()
+    dns.op = dpkt.dns.DNS_QR | dpkt.dns.DNS_AA
+    dns.rcode = dpkt.dns.DNS_RCODE_NOERR
+    arr = dpkt.dns.DNS.RR()
+    arr.cls = dpkt.dns.DNS_IN
+    arr.type = dpkt.dns.DNS_A
+    arr.name = tester_host
+    arr.ip = socket.inet_aton('127.0.0.1')
+    dns. an.append(arr)
+    console_log('Created answer to mdns query: {} '.format(dns.__repr__()))
+    return dns.pack()
+
+
+# Get mdns answer for service query
+def get_dns_answer_to_service_query(mdns_service):  # type:(str) -> dpkt.dns.Msg
+    dns = dpkt.dns.DNS()
+    dns.op = dpkt.dns.DNS_QR | dpkt.dns.DNS_AA
+    dns.rcode = dpkt.dns.DNS_RCODE_NOERR
+    arr = dpkt.dns.DNS.RR()
+    arr.name = mdns_service
+    arr.cls = dpkt.dns.DNS_IN
+    arr.type = dpkt.dns.DNS_SRV
+    arr.priority = 0
+    arr.weight = 0
+    arr.port = 100
+    arr.srvname = mdns_service
+    arr.ip = socket.inet_aton('127.0.0.1')
+    dns. an.append(arr)
+    console_log('Created answer to mdns query: {} '.format(dns.__repr__()))
+    return dns.pack()
+
+
+def mdns_listener(esp_host):  # type:(str) -> None
+    print('mdns_listener thread started')
+
+    UDP_IP = '0.0.0.0'
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
+    sock.setblocking(False)
+    sock.bind((UDP_IP,UDP_PORT))
+    mreq = struct.pack('4sl', socket.inet_aton(MCAST_GRP), socket.INADDR_ANY)
+    sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
+    last_query_timepoint = time.time()
+    QUERY_TIMEOUT = 0.2
+    while not stop_mdns_listener.is_set():
+        try:
+            start_mdns_listener.set()
+            current_time = time.time()
+            if current_time - last_query_timepoint > QUERY_TIMEOUT:
+                last_query_timepoint = current_time
+            timeout = max(0, QUERY_TIMEOUT - (current_time - last_query_timepoint))
+            read_socks, _, _ = select.select([sock], [], [], timeout)
+            if not read_socks:
+                continue
+            data, _ = sock.recvfrom(1024)
+            dns = dpkt.dns.DNS(data)
+            # Receives queries from esp board and sends answers
+            if len(dns.qd) > 0:
+                if dns.qd[0].name == HOST_NAME:
+                    console_log('Received query: {} '.format(dns.__repr__()))
+                    sock.sendto(get_dns_answer_to_mdns(HOST_NAME), (MCAST_GRP,UDP_PORT))
+                if dns.qd[0].name == HOST_NAME:
+                    console_log('Received query: {} '.format(dns.__repr__()))
+                    sock.sendto(get_dns_answer_to_mdns(HOST_NAME), (MCAST_GRP,UDP_PORT))
+                if dns.qd[0].name == MDNS_HOST_SERVICE:
+                    print(dns.qd[0].name)
+                    console_log('Received query: {} '.format(dns.__repr__()))
+                    sock.sendto(get_dns_answer_to_service_query(MDNS_HOST_SERVICE), (MCAST_GRP,UDP_PORT))
+            # Receives answers from esp board and sets event flags for python test cases
+            if len(dns.an) == 1:
+                if dns.an[0].name.startswith(SERVICE_NAME):
+                    console_log('Received answer to service query: {}'.format(dns.__repr__()))
+                    esp_service_answered.set()
+            if len(dns.an) > 1:
+                if dns.an[1].name.startswith(SUB_SERVICE_NAME):
+                    console_log('Received answer for sub service query: {}'.format(dns.__repr__()))
+                    esp_sub_service_answered.set()
+            if len(dns.an) > 0 and dns.an[0].type == dpkt.dns.DNS_A:
+                if dns.an[0].name == esp_host + u'.local':
+                    console_log('Received answer to esp32-mdns query: {}'.format(dns.__repr__()))
+                    esp_host_answered.set()
+                if dns.an[0].name == esp_host + u'-delegated.local':
+                    console_log('Received answer to esp32-mdns-delegate query: {}'.format(dns.__repr__()))
+                    esp_delegated_host_answered.set()
+        except socket.timeout:
+            break
+        except dpkt.UnpackError:
+            continue
+
+
+def create_socket():  # type:() -> socket.socket
+    UDP_IP = '0.0.0.0'
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
+    sock.setblocking(False)
+    sock.bind((UDP_IP,UDP_PORT))
+    mreq = struct.pack('4sl', socket.inet_aton(MCAST_GRP), socket.INADDR_ANY)
+    sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
+    return sock
+
+
+def test_query_dns_http_service(service):  # type: (str) -> None
+    print('SRV: Query {}'.format(service))
+    sock = create_socket()
+    packet = get_mdns_service_query(service)
+    for _ in range(RETRY_COUNT):
+        if esp_service_answered.wait(timeout=25):
+            break
+        sock.sendto(packet, (MCAST_GRP,UDP_PORT))
+    else:
+        raise RuntimeError('Test has failed: did not receive mdns answer within timeout')
+
+
+def test_query_dns_sub_service(sub_service):  # type: (str) -> None
+    print('PTR: Query {}'.format(sub_service))
+    sock = create_socket()
+    packet = get_mdns_sub_service_query(sub_service)
+    for _ in range(RETRY_COUNT):
+        if esp_sub_service_answered.wait(timeout=25):
+            break
+        sock.sendto(packet, (MCAST_GRP,UDP_PORT))
+    else:
+        raise RuntimeError('Test has failed: did not receive mdns answer within timeout')
+
+
+def test_query_dns_host(esp_host):  # type: (str) -> None
+    print('A: {}'.format(esp_host))
+    sock = create_socket()
+    packet = get_dns_query_for_esp(esp_host)
+    for _ in range(RETRY_COUNT):
+        if esp_host_answered.wait(timeout=25):
+            break
+        sock.sendto(packet, (MCAST_GRP,UDP_PORT))
+    else:
+        raise RuntimeError('Test has failed: did not receive mdns answer within timeout')
+
+
+def test_query_dns_host_delegated(esp_host):  # type: (str) -> None
+    print('A: {}'.format(esp_host))
+    sock = create_socket()
+    packet = get_dns_query_for_esp(esp_host + '-delegated')
+    for _ in range(RETRY_COUNT):
+        if esp_delegated_host_answered.wait(timeout=25):
+            break
+        sock.sendto(packet, (MCAST_GRP,UDP_PORT))
+    else:
+        raise RuntimeError('Test has failed: did not receive mdns answer within timeout')
+
+
+@ttfw_idf.idf_custom_test(env_tag='Example_WIFI', group='test-apps')
+def test_app_esp_mdns(env, _):  # type: (ttfw_idf.TinyFW.Env, None) -> None
+    dut1 = env.get_dut('mdns', 'tools/test_apps/protocols/mdns', dut_class=ttfw_idf.ESP32DUT)
+
+    # 1. start mdns application
+    dut1.start_app()
+    # 2. get the dut host name (and IP address)
+    specific_host = dut1.expect(re.compile(r'mdns hostname set to: \[([^\]]+)\]'), timeout=30)[0]
+
+    esp_ip = dut1.expect(re.compile(r' IPv4 address: ([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)'), timeout=30)
+    print('Got IP={}'.format(esp_ip[0]))
+
+    mdns_responder = Thread(target=mdns_listener, args=(str(specific_host),))
+
+    def start_case(case, desc, result):  # type: (str, str, str) -> None
+        print('Starting {}: {}'.format(case, desc))
+        dut1.write(case)
+        dut1.expect(re.compile(result), timeout=30)
+
+    try:
+        # start dns listener thread
+        mdns_responder.start()
+
+        # wait untill mdns listener thred started
+        if not start_mdns_listener.wait(timeout=5):
+            raise ValueError('Test has failed: mdns listener thread did not start')
+
+        # query dns service from host, answer should be received from esp board
+        test_query_dns_http_service(SERVICE_NAME)
+
+        # query dns sub-service from host, answer should be received from esp board
+        test_query_dns_sub_service(SUB_SERVICE_NAME)
+
+        # query dns host name, answer should be received from esp board
+        test_query_dns_host(specific_host)
+
+        # query dns host name delegated, answer should be received from esp board
+        test_query_dns_host_delegated(specific_host)
+
+        # query service from esp board, answer should be received from host
+        start_case('CONFIG_TEST_QUERY_SERVICE', 'Query SRV ESP32._http._tcp.local', 'SRV:ESP32')
+
+        # query dns-host from esp board, answer should be received from host
+        start_case('CONFIG_TEST_QUERY_HOST', 'Query tinytester.local', 'tinytester.local resolved to: 127.0.0.1')
+
+        # query dns-host aynchrounusely from esp board, answer should be received from host
+        start_case('CONFIG_TEST_QUERY_HOST_ASYNC', 'Query tinytester.local async', 'Async query resolved to A:127.0.0.1')
+
+    finally:
+        stop_mdns_listener.set()
+        mdns_responder.join()
+
+
+if __name__ == '__main__':
+    test_app_esp_mdns()

components/mdns/tests/test_apps/main/CMakeLists.txt

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "main.c" "mdns_test.c"
+                        INCLUDE_DIRS ".")

components/mdns/tests/test_apps/main/Kconfig.projbuild

@@ -0,0 +1,28 @@
+menu "Example Configuration"
+
+    config TEST_MDNS_HOSTNAME
+        string "mDNS Hostname"
+        default "esp32-mdns"
+        help
+            mDNS Hostname for example to use
+
+    config TEST_MDNS_INSTANCE
+        string "mDNS Instance Name"
+        default "ESP32 with mDNS"
+        help
+            mDNS Instance Name for example to use
+
+    config TEST_MDNS_PUBLISH_DELEGATE_HOST
+        bool "Publish a delegated host"
+        help
+            Enable publishing a delegated host other than ESP32.
+            The example will also add a mock service for this host.
+
+    config TEST_MDNS_ADD_MAC_TO_HOSTNAME
+        bool "Add mac suffix to hostname"
+        default n
+        help
+            If enabled, a portion of MAC address is added to the hostname, this is used
+            for evaluation of tests in CI
+
+endmenu

components/mdns/tests/test_apps/main/main.c

@@ -0,0 +1,117 @@
+/*
+ * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include <stdio.h>
+#include <string.h>
+#include "esp_mac.h"
+#include "nvs_flash.h"
+#include "esp_event.h"
+#include "esp_netif.h"
+#include "esp_log.h"
+#include "protocol_examples_common.h"
+#include "mdns.h"
+
+static const char *TAG = "MDNS_TEST";
+void mdns_test(char *line);
+
+static void get_string(char *line, size_t size)
+{
+    int count = 0;
+    while (count < size) {
+        int c = fgetc(stdin);
+        if (c == '\n') {
+            line[count] = '\0';
+            break;
+        } else if (c > 0 && c < 127) {
+            line[count] = c;
+            ++count;
+        }
+        vTaskDelay(20 / portTICK_PERIOD_MS);
+    }
+}
+
+/** Generate host name based on sdkconfig, optionally adding a portion of MAC address to it.
+ *  @return host name string allocated from the heap
+ */
+static char* generate_hostname(void)
+{
+#ifndef CONFIG_TEST_MDNS_ADD_MAC_TO_HOSTNAME
+    return strdup(CONFIG_TEST_MDNS_HOSTNAME);
+#else
+    uint8_t mac[6];
+    char   *hostname;
+    esp_read_mac(mac, ESP_MAC_WIFI_STA);
+    if (-1 == asprintf(&hostname, "%s-%02X%02X%02X", CONFIG_TEST_MDNS_HOSTNAME, mac[3], mac[4], mac[5])) {
+        abort();
+    }
+    return hostname;
+#endif
+}
+
+static void initialise_mdns(void)
+{
+    char * hostname = generate_hostname();
+
+    //initialize mDNS
+    ESP_ERROR_CHECK( mdns_init() );
+
+    //set mDNS hostname (required if you want to advertise services)
+    ESP_ERROR_CHECK( mdns_hostname_set(hostname) );
+
+    ESP_LOGI(TAG, "mdns hostname set to: [%s]", hostname);
+    //set default mDNS instance name
+    ESP_ERROR_CHECK( mdns_instance_name_set(CONFIG_TEST_MDNS_INSTANCE) );
+
+    //initialize service
+    ESP_ERROR_CHECK( mdns_service_add("ESP32-WebServer", "_http", "_tcp", 80, NULL, 0) );
+
+#if CONFIG_TEST_MDNS_PUBLISH_DELEGATE_HOST
+    char *delegated_hostname;
+    if (-1 == asprintf(&delegated_hostname, "%s-delegated", hostname)) {
+        abort();
+    }
+
+    mdns_ip_addr_t addr4, addr6;
+    esp_netif_str_to_ip4("10.0.0.1", &addr4.addr.u_addr.ip4);
+    addr4.addr.type = ESP_IPADDR_TYPE_V4;
+    esp_netif_str_to_ip6("fd11:22::1", &addr6.addr.u_addr.ip6);
+    addr6.addr.type = ESP_IPADDR_TYPE_V6;
+    addr4.next = &addr6;
+    addr6.next = NULL;
+    ESP_ERROR_CHECK( mdns_delegate_hostname_add(delegated_hostname, &addr4) );
+    ESP_ERROR_CHECK( mdns_service_add_for_host("test0", "_http", "_tcp", delegated_hostname, 1234, NULL, 0) );
+    free(delegated_hostname);
+#endif // CONFIG_TEST_MDNS_PUBLISH_DELEGATE_HOST
+
+    ESP_ERROR_CHECK( mdns_service_subtype_add_for_host("ESP32-WebServer", "_http", "_tcp", NULL, "_server") );
+
+    free(hostname);
+}
+
+void app_main(void)
+{
+    ESP_LOGI(TAG, "[APP] Free memory: %d bytes", esp_get_free_heap_size());
+    ESP_LOGI(TAG, "[APP] IDF version: %s", esp_get_idf_version());
+
+    ESP_ERROR_CHECK(nvs_flash_init());
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+
+    initialise_mdns();
+
+    /* This helper function configures Wi-Fi or Ethernet, as selected in menuconfig.
+     * Read "Establishing Wi-Fi or Ethernet Connection" section in
+     * examples/protocols/README.md for more information about this function.
+     */
+    ESP_ERROR_CHECK(example_connect());
+
+    while (1) {
+        char line[256];
+
+        get_string(line, sizeof(line));
+        mdns_test(line);
+        continue;
+    }
+}

components/mdns/tests/test_apps/main/mdns_test.c

@@ -0,0 +1,188 @@
+/*
+ * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include <string.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "mdns.h"
+#include "esp_log.h"
+#include "esp_netif.h"
+
+static const char * TAG = "MDNS_TEST_APP";
+static const int RETRY_COUNT = 10;
+
+static void mdns_print_results(mdns_result_t *results)
+{
+    mdns_result_t *r = results;
+    mdns_ip_addr_t *a = NULL;
+    int t;
+    while (r) {
+        if (r->instance_name) {
+            printf("PTR:%s.%s.%s\n", r->instance_name, r->service_type, r->proto);
+        }
+        if (r->hostname) {
+            printf("SRV:%s.local:%u\n", r->hostname, r->port);
+        }
+        if (r->txt_count) {
+            printf("TXT:[%zu] ", r->txt_count);
+            for (t = 0; t < r->txt_count; t++) {
+                printf("%s=%s(%d); ", r->txt[t].key, r->txt[t].value ? r->txt[t].value : "NULL", r->txt_value_len[t]);
+            }
+            printf("\n");
+        }
+        a = r->addr;
+        while (a) {
+            if (a->addr.type == ESP_IPADDR_TYPE_V6) {
+                printf("  AAAA: " IPV6STR "\n", IPV62STR(a->addr.u_addr.ip6));
+            } else {
+                printf("  A   : " IPSTR "\n", IP2STR(&(a->addr.u_addr.ip4)));
+            }
+            a = a->next;
+        }
+        r = r->next;
+    }
+}
+
+static bool check_and_print_result(mdns_search_once_t *search)
+{
+    // Check if any result is available
+    mdns_result_t * result = NULL;
+    if (!mdns_query_async_get_results(search, 0, &result, NULL)) {
+        return false;
+    }
+
+    if (!result) {   // search timeout, but no result
+        return false;
+    }
+
+    // If yes, print the result
+    mdns_ip_addr_t * a = result->addr;
+    while (a) {
+        if(a->addr.type == ESP_IPADDR_TYPE_V6){
+            printf("Async query resolved to AAAA:" IPV6STR "\n", IPV62STR(a->addr.u_addr.ip6));
+        } else {
+            printf("Async query resolved to A:" IPSTR "\n", IP2STR(&(a->addr.u_addr.ip4)));
+        }
+        a = a->next;
+    }
+    // and free the result
+    mdns_query_results_free(result);
+    return true;
+}
+
+static bool query_mdns_hosts_async(const char * host_name)
+{
+    ESP_LOGI(TAG, "Query both A and AAA: %s.local", host_name);
+    bool res = false;
+
+    mdns_search_once_t *s_a = mdns_query_async_new(host_name, NULL, NULL, MDNS_TYPE_A, 1000, 1, NULL);
+    mdns_query_async_delete(s_a);
+    mdns_search_once_t *s_aaaa = mdns_query_async_new(host_name, NULL, NULL, MDNS_TYPE_AAAA, 1000, 1, NULL);
+    while (s_a || s_aaaa) {
+        if (s_a && check_and_print_result(s_a)) {
+            ESP_LOGI(TAG, "Query A %s.local finished", host_name);
+            mdns_query_async_delete(s_a);
+            s_a = NULL;
+            res = true;
+        }
+        if (s_aaaa && check_and_print_result(s_aaaa)) {
+            ESP_LOGI(TAG, "Query AAAA %s.local finished", host_name);
+            mdns_query_async_delete(s_aaaa);
+            s_aaaa = NULL;
+            res = true;
+        }
+    }
+    return res;
+}
+
+static esp_err_t query_mdns_host(const char * host_name)
+{
+    ESP_LOGI(TAG, "Query A: %s.local", host_name);
+
+    struct esp_ip4_addr addr;
+    addr.addr = 0;
+
+    esp_err_t err = mdns_query_a(host_name, 2000,  &addr);
+    if(err){
+        if(err == ESP_ERR_NOT_FOUND){
+            ESP_LOGW(TAG, "%s: Host was not found!", esp_err_to_name(err));
+        }
+        ESP_LOGE(TAG, "Query Failed: %s", esp_err_to_name(err));
+        return err;
+    }
+
+    ESP_LOGI(TAG, "Query A: %s.local resolved to: " IPSTR, host_name, IP2STR(&addr));
+    return ESP_OK;
+}
+
+static esp_err_t query_mdns_service(const char * instance, const char * service_name, const char * proto)
+{
+    ESP_LOGI(TAG, "Query SRV: %s.%s.local", service_name, proto);
+
+    mdns_result_t * results = NULL;
+    esp_err_t err = mdns_query_srv(instance, service_name, proto, 3000,  &results);
+    if(err){
+        ESP_LOGE(TAG, "Query Failed: %s", esp_err_to_name(err));
+        return err;
+    }
+    if(!results){
+        ESP_LOGW(TAG, "No results found!");
+    }
+
+    mdns_print_results(results);
+    mdns_query_results_free(results);
+    return ESP_OK;
+}
+
+void query_mdns_service_sub_type(const char * subtype, const char * service_name, const char * proto) {
+    ESP_LOGI(TAG, "Query PTR: %s.%s.local", service_name, proto);
+
+    mdns_result_t * results = NULL;
+    esp_err_t err = mdns_query_ptr(service_name, proto, 3000, 20,  &results);
+    if(err){
+        ESP_LOGE(TAG, "Query Failed: %s", esp_err_to_name(err));
+    }
+    if(!results){
+        ESP_LOGW(TAG, "No results found!");
+    }
+
+    mdns_print_results(results);
+    mdns_query_results_free(results);
+}
+
+void mdns_test(const char *line)
+{
+    char test_case[32];
+    int i = 0;
+    const TickType_t xDelay = 1000 / portTICK_PERIOD_MS;
+
+    sscanf(line, "%s", test_case);
+    ESP_LOGI(TAG, "test case = %s", test_case);
+
+    if (strcmp(test_case, "CONFIG_TEST_QUERY_HOST") == 0) {
+        i = 0;
+        while (query_mdns_host("tinytester") != ESP_OK && i != RETRY_COUNT) {
+            query_mdns_host("tinytester");
+            i++;
+            vTaskDelay(xDelay);
+        }
+    } else if (strcmp(test_case, "CONFIG_TEST_QUERY_HOST_ASYNC") == 0) {
+        i = 0;
+        while (query_mdns_hosts_async("tinytester") == false && i != RETRY_COUNT) {
+            query_mdns_hosts_async("tinytester");
+            i++;
+            vTaskDelay(xDelay);
+        }
+    } else if (strcmp(test_case, "CONFIG_TEST_QUERY_SERVICE") == 0) {
+        i = 0;
+        while (query_mdns_service("ESP32", "_http", "_tcp") != ESP_OK && i != RETRY_COUNT) {
+            query_mdns_service("ESP32", "_http", "_tcp");
+            i++;
+            vTaskDelay(xDelay);
+        }
+    } else {
+        ESP_LOGE(TAG, "%s: No such test case", test_case);
+    }
+}

components/mdns/tests/test_apps/sdkconfig.defaults

@@ -0,0 +1,2 @@
+CONFIG_TEST_MDNS_ADD_MAC_TO_HOSTNAME=y
+CONFIG_TEST_MDNS_PUBLISH_DELEGATE_HOST=y