Support MAVLink usage in simulation

gazebo/wifi.h

@@ -0,0 +1,44 @@
+// Copyright (c) 2023 Oleg Kalachev <okalachev@gmail.com>
+// Repository: https://github.com/okalachev/flix
+
+// sendWiFi and receiveWiFi implementations for the simulation
+
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <sys/poll.h>
+#include <gazebo/gazebo.hh>
+
+#define WIFI_UDP_PORT_LOCAL 14580
+#define WIFI_UDP_PORT_REMOTE 14550
+
+int wifiSocket;
+
+void setupWiFi() {
+	wifiSocket = socket(AF_INET, SOCK_DGRAM, 0);
+	sockaddr_in addr;
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = INADDR_ANY;
+	addr.sin_port = htons(WIFI_UDP_PORT_LOCAL);
+	bind(wifiSocket, (sockaddr *)&addr, sizeof(addr));
+	int broadcast = 1;
+	setsockopt(wifiSocket, SOL_SOCKET, SO_BROADCAST, &broadcast, sizeof(broadcast)); // enable broadcast
+	gzmsg << "WiFi UDP socket initialized on port " << WIFI_UDP_PORT_LOCAL << std::endl;
+}
+
+void sendWiFi(const uint8_t *buf, int len) {
+	if (wifiSocket == 0) setupWiFi();
+	sockaddr_in addr;
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = INADDR_BROADCAST; // send UDP broadcast
+	addr.sin_port = htons(WIFI_UDP_PORT_REMOTE);
+	sendto(wifiSocket, buf, len, 0, (sockaddr *)&addr, sizeof(addr));
+}
+
+int receiveWiFi(uint8_t *buf, int len) {
+	struct pollfd pfd = { .fd = wifiSocket, .events = POLLIN };
+	if (poll(&pfd, 1, 0) <= 0) return 0; // check if there is data to read
+	return recv(wifiSocket, buf, len, 0);
+}