mirror of
https://github.com/cesanta/mongoose.git
synced 2024-12-11 15:08:59 +08:00
92 lines
3.6 KiB
C
92 lines
3.6 KiB
C
// Copyright (c) 2020 Cesanta Software Limited
|
|
// All rights reserved
|
|
//
|
|
// Example MQTT client. It performs the following steps:
|
|
// 1. Connects to the AWS IoT MQTT server
|
|
// 2. When connected, subscribes to the topic `s_rx_topic`
|
|
// 3. Publishes message `hello` to the `s_tx_topic` periodically
|
|
//
|
|
// This example requires TLS support. By default, it is built with mbedTLS,
|
|
// therefore make sure mbedTLS is installed. To build with OpenSSL, execute:
|
|
// make clean all CFLAGS="-W -Wall -DMG_ENABLE_OPENSSL=1 -lssl"
|
|
|
|
// In order to get MQTT URL, login to AWS IoT, click on "Settings" on the left
|
|
// bar, copy the "Endpoint" URL.
|
|
static const char *s_url =
|
|
"mqtts://a1pjwh2bop1ojt-ats.iot.eu-west-1.amazonaws.com";
|
|
|
|
// To create certificates:
|
|
// 1. Click Policies -> Create, fill fields:
|
|
// Name : Policy1
|
|
// Action : iot:*
|
|
// Resource ARN: *
|
|
// Effect : allow
|
|
// then, click "Create"
|
|
// 2. Click Manage -> Things -> Create things -> Create single thing -> Next
|
|
// Thing name: t1, no shadow, Next
|
|
// Auto-generate new certificate, Next
|
|
// Select policy Policy1, Create thing
|
|
// 3. From the dialog box that appears, download:
|
|
// xxx-certificate.pem.crt as cert.pem to the example directory
|
|
// xxx-private.pem.key as key.pem to the example directory
|
|
static const char *s_cert = "cert.pem";
|
|
static const char *s_key = "key.pem";
|
|
|
|
static const char *s_rx_topic = "d/rx";
|
|
static const char *s_tx_topic = "d/tx";
|
|
static int s_qos = 1;
|
|
|
|
#include "mongoose.h"
|
|
|
|
static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
|
|
if (ev == MG_EV_OPEN) {
|
|
// c->is_hexdumping = 1;
|
|
} else if (ev == MG_EV_ERROR) {
|
|
// On error, log error message
|
|
MG_ERROR(("%p %s", c->fd, (char *) ev_data));
|
|
} else if (ev == MG_EV_CONNECT) {
|
|
// Set up 2-way TLS that is required by AWS IoT
|
|
struct mg_tls_opts opts = {
|
|
.ca = "ca.pem", .cert = s_cert, .certkey = s_key};
|
|
mg_tls_init(c, &opts);
|
|
} else if (ev == MG_EV_MQTT_OPEN) {
|
|
// MQTT connect is successful
|
|
struct mg_str topic = mg_str(s_rx_topic);
|
|
MG_INFO(("Connected to %s", s_url));
|
|
MG_INFO(("Subscribing to %s", s_rx_topic));
|
|
mg_mqtt_sub(c, topic, s_qos);
|
|
c->label[0] = 'X'; // Set a label that we're logged in
|
|
} else if (ev == MG_EV_MQTT_MSG) {
|
|
// When we receive MQTT message, print it
|
|
struct mg_mqtt_message *mm = (struct mg_mqtt_message *) ev_data;
|
|
MG_INFO(("Received on %.*s : %.*s", (int) mm->topic.len, mm->topic.ptr,
|
|
(int) mm->data.len, mm->data.ptr));
|
|
} else if (ev == MG_EV_POLL && c->label[0] == 'X') {
|
|
static unsigned long prev_second;
|
|
unsigned long now_second = (*(unsigned long *) ev_data) / 1000;
|
|
if (now_second != prev_second) {
|
|
struct mg_str topic = mg_str(s_tx_topic), data = mg_str("{\"a\":123}");
|
|
MG_INFO(("Publishing to %s", s_tx_topic));
|
|
mg_mqtt_pub(c, topic, data, s_qos, false);
|
|
prev_second = now_second;
|
|
}
|
|
}
|
|
|
|
if (ev == MG_EV_ERROR || ev == MG_EV_CLOSE) {
|
|
MG_INFO(("Got event %d, stopping...", ev));
|
|
*(bool *) fn_data = true; // Signal that we're done
|
|
}
|
|
}
|
|
|
|
int main(void) {
|
|
struct mg_mgr mgr;
|
|
struct mg_mqtt_opts opts = {.clean = true};
|
|
bool done = false;
|
|
mg_mgr_init(&mgr); // Initialise event manager
|
|
MG_INFO(("Connecting to %s", s_url)); // Inform that we're starting
|
|
mg_mqtt_connect(&mgr, s_url, &opts, fn, &done); // Create client connection
|
|
while (!done) mg_mgr_poll(&mgr, 1000); // Loop until done
|
|
mg_mgr_free(&mgr); // Finished, cleanup
|
|
return 0;
|
|
}
|