mqtt tests: adding weekend test for mqtt library to exercise publishing/receiving different data and references esp-mqtt commits to pass these tests

testing conditions:
transports (tcp, ssl, ws..)
qos (0, 1, 2)
short repeated messages (packed packets)
oversized messages (fragmented packets)
publish from a different thread

Closes https://github.com/espressif/esp-idf/issues/2870 by means of including commit 815623dfe5 from esp-mqtt
Closes https://github.com/espressif/esp-idf/issues/2975 by means of including commit 752953dc3b from esp-mqtt
Closes https://github.com/espressif/esp-idf/issues/2850 by means of including commits df455d2a5f 17fd713bce from esp-mqtt

examples/protocols/mqtt/publish_test/CMakeLists.txt

@@ -0,0 +1,9 @@
+# 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)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+
+project(mqtt_publish)
+
+target_add_binary_data(mqtt_publish.elf "main/iot_eclipse_org.pem" TEXT)

examples/protocols/mqtt/publish_test/Makefile

@@ -0,0 +1,7 @@
+#
+# This is a project Makefile. It is assumed the directory this Makefile resides in is a
+# project subdirectory.
+#
+PROJECT_NAME := mqtt_publish
+
+include $(IDF_PATH)/make/project.mk

examples/protocols/mqtt/publish_test/README.md

@@ -0,0 +1,91 @@
+# ESP-MQTT advanced published test
+(See the README.md file in the upper level 'examples' directory for more information about examples.)
+
+Main purpose of this example is to test the MQTT library to correctly publish and receive messages (of different size and sequences) over different transports. 
+It is possible to run this example manually without any test to exercise how the MQTT library deals with
+
+- reception of fragmented messages
+- runtime updates of URI
+
+## How to use example
+
+This example waits for user input to provide these parameters:
+- transport: string parameter, one of: tcp, ssl, ws, wss
+- pattern: sample string to be transmitted as message
+- pattern repeats: number of repeats of pattern in one MQTT message
+- repeated: number of repeats ESP32 publishes the message, also ESP32 expects to receive the same message the same number of repeats
+- qos: number specifying qos, one of: 0, 1, 2
+
+### Hardware Required
+
+This example can be executed on any ESP32 board, the only required interface is WiFi and connection to internet.
+
+### Configure the project
+
+```
+make menuconfig
+```
+
+* Set serial port under Serial Flasher Options.
+
+* Set ssid and password for the board to connect to AP.
+
+* Set brokers for all 4 transports (TCP, SSL, WS, WSS), also set certificate if needed
+
+* Set topics for publishing from and to ESP32
+
+### Build and Flash
+
+Build the project and flash it to the board, then run monitor tool to view serial output:
+
+```
+make -j4 flash monitor
+```
+
+(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 (4730) event: sta ip: 192.168.0.125, mask: 255.255.255.0, gw: 192.168.0.2
+I (4730) PUBLISH_TEST: [APP] Free memory: 236728 bytes
+I (4730) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
+D (4740) MQTT_CLIENT: MQTT client_id=ESP32_09885C
+I (31360) PUBLISH_TEST: PATTERN:1234 REPEATED:10 PUBLISHED:10
+```
+- User enters "tcp 1234 10 10 1"
+```
+EXPECTED STRING 1234123412341234123412341234123412341234, SIZE:40
+W (31360) MQTT_CLIENT: Client asked to stop, but was not started
+I (31360) PUBLISH_TEST: [TCP transport] Startup..
+D (31370) MQTT_CLIENT: Core selection disabled
+I (31370) PUBLISH_TEST: Note free memory: 224652 bytes
+I (31370) PUBLISH_TEST: Other event id:7
+D (31390) MQTT_CLIENT: Transport connected to mqtt://192.168.0.163:1883
+I (31400) MQTT_CLIENT: Sending MQTT CONNECT message, type: 1, id: 0000
+D (31410) MQTT_CLIENT: Connected
+I (31410) PUBLISH_TEST: MQTT_EVENT_CONNECTED
+D (31410) MQTT_CLIENT: mqtt_enqueue id: 31184, type=8 successful
+D (31410) OUTBOX: ENQUEUE msgid=31184, msg_type=8, len=20, size=20
+D (31420) MQTT_CLIENT: Sent subscribe topic=/xxx.topic123, id: 31184, type=8 successful
+I (31430) PUBLISH_TEST: sent subscribe successful, msg_id=31184
+D (31440) MQTT_CLIENT: mqtt_enqueue id: 16584, type=3 successful
+D (31440) OUTBOX: ENQUEUE msgid=16584, msg_type=3, len=59, size=79
+I (31450) PUBLISH_TEST: [16584] Publishing...
+D (31450) MQTT_CLIENT: msg_type=9, msg_id=31184
+D (31460) MQTT_CLIENT: pending_id=16584, pending_msg_count = 2
+D (31460) OUTBOX: DELETED msgid=31184, msg_type=8, remain size=59
+D (31470) MQTT_CLIENT: Subscribe successful
+I (31470) PUBLISH_TEST: MQTT_EVENT_SUBSCRIBED, msg_id=31184
+D (31480) MQTT_CLIENT: msg_type=4, msg_id=16584
+D (31480) MQTT_CLIENT: pending_id=16584, pending_msg_count = 1
+D (31490) OUTBOX: DELETED msgid=16584, msg_type=3, remain size=0
+D (31500) MQTT_CLIENT: received MQTT_MSG_TYPE_PUBACK, finish QoS1 publish
+I (31500) PUBLISH_TEST: MQTT_EVENT_PUBLISHED, msg_id=16584
+D (31510) MQTT_CLIENT: mqtt_enqueue id: 44615, type=3 successful
+D (31520) OUTBOX: ENQUEUE msgid=44615, msg_type=3, len=59, size=59
+I (31530) PUBLISH_TEST: [44615] Publishing...
+...
+```

examples/protocols/mqtt/publish_test/main/CMakeLists.txt

@@ -0,0 +1,4 @@
+set(COMPONENT_SRCS "publish_test.c")
+set(COMPONENT_ADD_INCLUDEDIRS ".")
+
+register_component()

examples/protocols/mqtt/publish_test/main/Kconfig.projbuild

@@ -0,0 +1,62 @@
+menu "Example Configuration"
+
+    config WIFI_SSID
+        string "WiFi SSID"
+        default "myssid"
+        help
+            SSID (network name) for the example to connect to.
+
+    config WIFI_PASSWORD
+        string "WiFi Password"
+        default "mypassword"
+        help
+            WiFi password (WPA or WPA2) for the example to use.
+
+    config BROKER_SSL_URI
+        string "Broker SSL URL"
+        default "mqtts://iot.eclipse.org:8883"
+        help
+            URL of an mqtt broker for ssl transport
+
+    config BROKER_TCP_URI
+        string "Broker TCP URL"
+        default "mqtt://iot.eclipse.org:1883"
+        help
+            URL of an mqtt broker for tcp transport
+
+    config BROKER_WS_URI
+        string "Broker WS URL"
+        default "ws://iot.eclipse.org:80/ws"
+        help
+            URL of an mqtt broker for ws transport
+
+    config BROKER_WSS_URI
+        string "Broker WSS URL"
+        default "wss://iot.eclipse.org:443/ws"
+        help
+            URL of an mqtt broker for wss transport
+
+    config PUBLISH_TOPIC
+        string "publish topic"
+        default "/topic/publish/esp2py"
+        help
+            topic to which esp32 client publishes
+
+    config SUBSCIBE_TOPIC
+        string "subscribe topic"
+        default "/topic/subscribe/py2esp"
+        help
+            topic to which esp32 client subsribes (and expects data)
+
+    config BROKER_CERTIFICATE_OVERRIDE
+        string "Broker certificate override"
+        default ""
+        help
+            Please leave empty if broker certificate included from a textfile; otherwise fill in a base64 part of PEM
+            format certificate
+
+    config BROKER_CERTIFICATE_OVERRIDDEN
+        bool
+        default y if BROKER_CERTIFICATE_OVERRIDE != ""
+
+endmenu

examples/protocols/mqtt/publish_test/main/component.mk

@@ -0,0 +1 @@
+COMPONENT_EMBED_TXTFILES := iot_eclipse_org.pem

examples/protocols/mqtt/publish_test/main/iot_eclipse_org.pem

@@ -0,0 +1,27 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

examples/protocols/mqtt/publish_test/main/publish_test.c

@@ -0,0 +1,258 @@
+/* MQTT publish test
+
+   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 <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include "esp_wifi.h"
+#include "esp_system.h"
+#include "nvs_flash.h"
+#include "esp_event_loop.h"
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "freertos/semphr.h"
+#include "freertos/queue.h"
+#include "freertos/event_groups.h"
+
+#include "lwip/sockets.h"
+#include "lwip/dns.h"
+#include "lwip/netdb.h"
+
+#include "esp_log.h"
+#include "mqtt_client.h"
+
+static const char *TAG = "PUBLISH_TEST";
+
+static EventGroupHandle_t wifi_event_group;
+static EventGroupHandle_t mqtt_event_group;
+const static int CONNECTED_BIT = BIT0;
+
+static esp_mqtt_client_handle_t mqtt_client = NULL;
+
+static char *expected_data = NULL;
+static char *actual_data = NULL;
+static size_t expected_size = 0;
+static size_t expected_published = 0;
+static size_t actual_published = 0;
+static int qos_test = 0;
+
+static esp_err_t wifi_event_handler(void *ctx, system_event_t *event)
+{
+    switch (event->event_id) {
+    case SYSTEM_EVENT_STA_START:
+        esp_wifi_connect();
+        break;
+    case SYSTEM_EVENT_STA_GOT_IP:
+        xEventGroupSetBits(wifi_event_group, CONNECTED_BIT);
+
+        break;
+    case SYSTEM_EVENT_STA_DISCONNECTED:
+        esp_wifi_connect();
+        xEventGroupClearBits(wifi_event_group, CONNECTED_BIT);
+        break;
+    default:
+        break;
+    }
+    return ESP_OK;
+}
+
+static void wifi_init(void)
+{
+    tcpip_adapter_init();
+    wifi_event_group = xEventGroupCreate();
+    ESP_ERROR_CHECK(esp_event_loop_init(wifi_event_handler, NULL));
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+    ESP_ERROR_CHECK(esp_wifi_set_storage(WIFI_STORAGE_RAM));
+    wifi_config_t wifi_config = {
+        .sta = {
+            .ssid = CONFIG_WIFI_SSID,
+            .password = CONFIG_WIFI_PASSWORD,
+        },
+    };
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config));
+    ESP_LOGI(TAG, "start the WIFI SSID:[%s]", CONFIG_WIFI_SSID);
+    ESP_ERROR_CHECK(esp_wifi_start());
+    ESP_LOGI(TAG, "Waiting for wifi");
+    xEventGroupWaitBits(wifi_event_group, CONNECTED_BIT, false, true, portMAX_DELAY);
+}
+
+#if CONFIG_BROKER_CERTIFICATE_OVERRIDDEN == 1
+static const uint8_t iot_eclipse_org_pem_start[]  = "-----BEGIN CERTIFICATE-----\n" CONFIG_BROKER_CERTIFICATE_OVERRIDE "\n-----END CERTIFICATE-----";
+#else
+extern const uint8_t iot_eclipse_org_pem_start[]   asm("_binary_iot_eclipse_org_pem_start");
+#endif
+extern const uint8_t iot_eclipse_org_pem_end[]   asm("_binary_iot_eclipse_org_pem_end");
+
+static esp_err_t mqtt_event_handler(esp_mqtt_event_handle_t event)
+{
+    esp_mqtt_client_handle_t client = event->client;
+    static int msg_id = 0;
+    static int actual_len = 0;
+    // your_context_t *context = event->context;
+    switch (event->event_id) {
+    case MQTT_EVENT_CONNECTED:
+        ESP_LOGI(TAG, "MQTT_EVENT_CONNECTED");
+        xEventGroupSetBits(mqtt_event_group, CONNECTED_BIT);
+        msg_id = esp_mqtt_client_subscribe(client, CONFIG_SUBSCIBE_TOPIC, qos_test);
+        ESP_LOGI(TAG, "sent subscribe successful, msg_id=%d", msg_id);
+
+        break;
+    case MQTT_EVENT_DISCONNECTED:
+        ESP_LOGI(TAG, "MQTT_EVENT_DISCONNECTED");
+        break;
+
+    case MQTT_EVENT_SUBSCRIBED:
+        ESP_LOGI(TAG, "MQTT_EVENT_SUBSCRIBED, msg_id=%d", event->msg_id);
+        break;
+    case MQTT_EVENT_UNSUBSCRIBED:
+        ESP_LOGI(TAG, "MQTT_EVENT_UNSUBSCRIBED, msg_id=%d", event->msg_id);
+        break;
+    case MQTT_EVENT_PUBLISHED:
+        ESP_LOGI(TAG, "MQTT_EVENT_PUBLISHED, msg_id=%d", event->msg_id);
+        break;
+    case MQTT_EVENT_DATA:
+        ESP_LOGI(TAG, "MQTT_EVENT_DATA");
+        printf("TOPIC=%.*s\r\n", event->topic_len, event->topic);
+        printf("DATA=%.*s\r\n", event->data_len, event->data);
+        printf("ID=%d, total_len=%d, data_len=%d, current_data_offset=%d\n", event->msg_id, event->total_data_len, event->data_len, event->current_data_offset);
+        if (event->topic) {
+            actual_len = event->data_len;
+            msg_id = event->msg_id;
+        } else {
+            actual_len += event->data_len;
+            // check consisency with msg_id across multiple data events for single msg
+            if (msg_id != event->msg_id) {
+                ESP_LOGI(TAG, "Wrong msg_id in chunked message %d != %d", msg_id, event->msg_id);
+                abort();
+            }
+        }
+        memcpy(actual_data + event->current_data_offset, event->data, event->data_len);
+        if (actual_len == event->total_data_len) {
+            if (0 == memcmp(actual_data, expected_data, expected_size)) {
+                printf("OK!");
+                memset(actual_data, 0, expected_size);
+                actual_published ++;
+                if (actual_published == expected_published) {
+                    printf("Correct pattern received exactly x times\n");
+                    ESP_LOGI(TAG, "Test finished correctly!");
+                }
+            } else {
+                printf("FAILED!");
+                abort();
+            }
+        }
+        break;
+    case MQTT_EVENT_ERROR:
+        ESP_LOGI(TAG, "MQTT_EVENT_ERROR");
+        break;
+    default:
+        ESP_LOGI(TAG, "Other event id:%d", event->event_id);
+        break;
+    }
+    return ESP_OK;
+}
+
+
+static void mqtt_app_start(void)
+{
+    mqtt_event_group = xEventGroupCreate();
+    const esp_mqtt_client_config_t mqtt_cfg = {
+        .event_handle = mqtt_event_handler,
+        .cert_pem = (const char *)iot_eclipse_org_pem_start,
+    };
+
+    ESP_LOGI(TAG, "[APP] Free memory: %d bytes", esp_get_free_heap_size());
+    mqtt_client = esp_mqtt_client_init(&mqtt_cfg);
+}
+
+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(10 / portTICK_PERIOD_MS);
+    }
+}
+
+void app_main()
+{
+    char line[256];
+    char pattern[32];
+    char transport[32];
+    int repeat = 0;
+
+    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_log_level_set("*", ESP_LOG_INFO);
+    esp_log_level_set("MQTT_CLIENT", ESP_LOG_VERBOSE);
+    esp_log_level_set("TRANSPORT_TCP", ESP_LOG_VERBOSE);
+    esp_log_level_set("TRANSPORT_SSL", ESP_LOG_VERBOSE);
+    esp_log_level_set("TRANSPORT", ESP_LOG_VERBOSE);
+    esp_log_level_set("OUTBOX", ESP_LOG_VERBOSE);
+
+    nvs_flash_init();
+    wifi_init();
+    mqtt_app_start();
+
+    while (1) {
+        get_string(line, sizeof(line));
+        sscanf(line, "%s %s %d %d %d", transport, pattern, &repeat, &expected_published, &qos_test);
+        ESP_LOGI(TAG, "PATTERN:%s REPEATED:%d PUBLISHED:%d\n", pattern, repeat, expected_published);
+        int pattern_size = strlen(pattern);
+        free(expected_data);
+        free(actual_data);
+        actual_published = 0;
+        expected_size = pattern_size * repeat;
+        expected_data = malloc(expected_size);
+        actual_data = malloc(expected_size);
+        for (int i = 0; i < repeat; i++) {
+            memcpy(expected_data + i * pattern_size, pattern, pattern_size);
+        }
+        printf("EXPECTED STRING %.*s, SIZE:%d\n", expected_size, expected_data, expected_size);
+        esp_mqtt_client_stop(mqtt_client);
+
+        if (0 == strcmp(transport, "tcp")) {
+            ESP_LOGI(TAG, "[TCP transport] Startup..");
+            esp_mqtt_client_set_uri(mqtt_client, CONFIG_BROKER_TCP_URI);
+        } else if (0 == strcmp(transport, "ssl")) {
+            ESP_LOGI(TAG, "[SSL transport] Startup..");
+            esp_mqtt_client_set_uri(mqtt_client, CONFIG_BROKER_SSL_URI);
+        } else if (0 == strcmp(transport, "ws")) {
+            ESP_LOGI(TAG, "[WS transport] Startup..");
+            esp_mqtt_client_set_uri(mqtt_client, CONFIG_BROKER_WS_URI);
+        } else if (0 == strcmp(transport, "wss")) {
+            ESP_LOGI(TAG, "[WSS transport] Startup..");
+            esp_mqtt_client_set_uri(mqtt_client, CONFIG_BROKER_WSS_URI);
+        } else {
+            ESP_LOGE(TAG, "Unexpected transport");
+            abort();
+        }
+        xEventGroupClearBits(mqtt_event_group, CONNECTED_BIT);
+        esp_mqtt_client_start(mqtt_client);
+        ESP_LOGI(TAG, "Note free memory: %d bytes", esp_get_free_heap_size());
+        xEventGroupWaitBits(mqtt_event_group, CONNECTED_BIT, false, true, portMAX_DELAY);
+
+        for (int i = 0; i < expected_published; i++) {
+            int msg_id = esp_mqtt_client_publish(mqtt_client, CONFIG_PUBLISH_TOPIC, expected_data, expected_size, qos_test, 0);
+            ESP_LOGI(TAG, "[%d] Publishing...", msg_id);
+        }
+    }
+}

examples/protocols/mqtt/publish_test/sdkconfig.ci

@@ -0,0 +1,5 @@
+CONFIG_BROKER_SSL_URI="mqtts://${EXAMPLE_MQTT_BROKER_SSL}"
+CONFIG_BROKER_TCP_URI="mqtt://${EXAMPLE_MQTT_BROKER_TCP}"
+CONFIG_BROKER_WS_URI="ws://${EXAMPLE_MQTT_BROKER_WS}/ws"
+CONFIG_BROKER_WSS_URI="wss://${EXAMPLE_MQTT_BROKER_WSS}/ws"
+CONFIG_BROKER_CERTIFICATE_OVERRIDE="${EXAMPLE_MQTT_BROKER_CERTIFICATE}"