send rref to mqtt

.gitignore

@@ -1,2 +1,3 @@
 bin/
-.vscode/
+.vscode/
+config.h

Makefile

@@ -6,7 +6,7 @@ command:
 	gcc -o ${BIN}/command network.c command.c
 
 readref:
-	gcc -o ${BIN}/readref network.c readref.c
+	gcc -o ${BIN}/readref network.c mqtt.c -lmosquitto readref.c
 
 .PHONY: clean dirs
 clean:

mqtt.c

@@ -0,0 +1,74 @@
+#include <stdio.h>
+
+#include <errno.h>
+#include <string.h>
+
+// https://mosquitto.org/api/files/mosquitto-h.html
+#include <mosquitto.h>
+
+struct mosquitto *connectMqtt(char *user, char *pass)
+{
+    int err;
+    struct mosquitto *mqtt;
+
+    err = mosquitto_lib_init();
+    if (err)
+    {
+        fprintf(stderr, "Error initalizing mosquitto lib (%d): %s\n", err, mosquitto_strerror(err));
+        return NULL;
+    }
+
+    mqtt = mosquitto_new(user, true, NULL);
+    if (mqtt == NULL)
+    {
+        fprintf(stderr, "Error creating mosquitto instance (%d): %s\n", errno, strerror(errno));
+        return NULL;
+    }
+
+    err = mosquitto_username_pw_set(mqtt, user, pass);
+    if (err)
+    {
+        fprintf(stderr, "Error setting username & password (%d): %s\n", err, mosquitto_strerror(err));
+        return NULL;
+    }
+
+    err = mosquitto_connect(mqtt, "openhab.sugarland.lan", 1883, 10);
+    if (err)
+    {
+        fprintf(stderr, "Error on connection of type ");
+        if (err == MOSQ_ERR_ERRNO)
+        {
+            fprintf(stderr, "system (%d): %s\n", errno, strerror(errno));
+        }
+        else
+        {
+            fprintf(stderr, "mosquitto (%d): %s\n", err, mosquitto_strerror(err));
+        }
+        return NULL;
+    }
+
+    return mqtt;
+}
+
+int sendMqtt(struct mosquitto *mqtt, char *topic, char *payload, int payloadLength)
+{
+    int err;
+
+    err = mosquitto_publish(mqtt, NULL, topic, payloadLength, payload, 0, false);
+    if (err)
+    {
+        fprintf(stderr, "Error publishing message (%d): %s\n", err, mosquitto_strerror(err));
+        return -1;
+    }
+    else
+    {
+        return 0;
+    }
+}
+
+void disconnectMqtt(struct mosquitto *mqtt)
+{
+    // ignore errors
+    mosquitto_disconnect(mqtt);
+    mosquitto_destroy(mqtt);
+}

mqtt.h

@@ -0,0 +1,3 @@
+struct mosquitto * connectMqtt(char *user, char *pass);
+int sendMqtt(struct mosquitto *mqtt, char *topic, char *payload, int payloadLength);
+void disconnectMqtt(struct mosquitto *mqtt);

readref.c

@@ -4,6 +4,9 @@
 #include <inttypes.h>
 
 #include "network.h"
+#include "mqtt.h"
+
+#include "config.h"
 
 struct dref_struct_in
 {
@@ -21,6 +24,7 @@ struct dref_struct_out
 int main(int argc, char *argv[])
 {
     int xPlaneSocket;
+    struct mosquitto *mqtt;
     char *wtf;
 
     // check argument
@@ -37,8 +41,10 @@ int main(int argc, char *argv[])
         exit(EXIT_FAILURE);
     }
 
-    //    char drefsToRead[413 * ((argc - 1) / 3)];
-    //    memset(drefsToRead, 0, sizeof(drefsToRead));
+    // mqtt
+    mqtt = connectMqtt(MQTT_USER, MQTT_PASS);
+
+    // request every dref from arguments
     for (int i = 1; i < argc; i = i + 3)
     {
         // prepare struct to send, make sure padding is with NULL bytes
@@ -53,13 +59,13 @@ int main(int argc, char *argv[])
         {
             exit(EXIT_FAILURE);
         }
-
-        //        memcpy(&drefsToRead[((i - 1) / 3) * 413], &drefToRead, sizeof(drefToRead));
     }
 
     // read from network
     char msg[DGRAM_MSG_LENGTH + 1];
     char payload[RECV_BUFFER];
+
+    char mqttTopic[100], mqttPayload[512];
     while (1)
     {
         int payloadBytes = recvFromXPlane(xPlaneSocket, msg, payload, RECV_BUFFER);
@@ -74,13 +80,21 @@ int main(int argc, char *argv[])
             printf("\n");
             if (strcmp(msg, "RREF") == 0)
             {
+                // XXX: loop throught multiple drefs
                 if ((payloadBytes - 1) % 8 == 0)
                 {
-                    // XXX: loop
+                    memset(mqttTopic, 0, sizeof(mqttTopic));
+                    memset(mqttPayload, 0, sizeof(mqttPayload));
+
                     struct dref_struct_out drefRead;
                     memcpy(&drefRead, &payload[1], 8);
 
                     printf("%d: %f\n", drefRead.dref_sender_index, drefRead.dref_flt_value);
+
+                    sprintf(mqttTopic, "/xplane/rref/%d", drefRead.dref_sender_index);
+                    sprintf(mqttPayload, "%f", drefRead.dref_flt_value);
+
+                    sendMqtt(mqtt, mqttTopic, mqttPayload, strlen(mqttPayload));
                 }
                 else
                 {
@@ -99,6 +113,7 @@ int main(int argc, char *argv[])
     }
 
     // bye bye (and no, I don't care about error anymore; I'll exit anyway?!)
+    disconnectMqtt(mqtt);
     closeSocket(xPlaneSocket);
     exit(EXIT_SUCCESS);
 }