1 files changed, 69 insertions, 0 deletions

diff --git a/src/mqtt.c b/src/mqtt.c
new file mode 100644
index 0000000..50cfa6a
--- /dev/null
+++ b/src/mqtt.c
@@ -0,0 +1,69 @@
+// Standard C
+#include <stdio.h>
+
+// System
+#include <unistd.h>
+
+// Project
+#include "config.h"
+#include "mqtt.h"
+
+struct mosquitto *
+connect(const char *clientid, // NOLINT
+        const char *username, // NOLINT
+        const char *password, // NOLINT
+        const char *hostname, // NOLINT
+        int         port,
+        void        callback(struct mosquitto *, void *, const struct mosquitto_message *),
+        void       *userdata)
+{
+        struct mosquitto *client = mosquitto_new(clientid, true, userdata);
+        if ( client == NULL ) {
+                (void) fprintf(stderr, "error on new client...\n");
+                return NULL;
+        }
+
+        int err = mosquitto_username_pw_set(client, username, password);
+        if ( err != MOSQ_ERR_SUCCESS ) {
+                (void) fprintf(stderr, "error: %s\n", mosquitto_strerror(err));
+                mosquitto_destroy(client);
+                return NULL;
+        }
+
+        mosquitto_message_callback_set(client, callback);
+
+        err = mosquitto_connect(client, hostname, port, KEEPALIVE);
+        if ( err != MOSQ_ERR_SUCCESS ) {
+                (void) fprintf(stderr, "error: %s\n", mosquitto_strerror(err));
+                mosquitto_destroy(client);
+                return NULL;
+        }
+
+        return client;
+}
+
+void
+run(struct mosquitto *client, const char *topics[], const volatile bool *quit)
+{
+        for ( size_t idx = 0; topics[idx] != NULL; ++idx ) {
+                mosquitto_subscribe(client, NULL, topics[idx], 0);
+        }
+
+        while ( !*quit ) {
+                static const int defaultTimeout = -1; // 1000ms
+
+                int err = mosquitto_loop(client, defaultTimeout, 1);
+                if ( !*quit && err ) {
+                        (void) fprintf(stderr, "connection error: %s\n", mosquitto_strerror(err));
+                        sleep(WAIT_UNTIL_RECONNECT); // NOLINT
+                        mosquitto_reconnect(client);
+                }
+        }
+}
+
+void
+shutdown(struct mosquitto *client)
+{
+        mosquitto_disconnect(client);
+        mosquitto_destroy(client);
+}