basic implementation of client/server for AERPAW, whole lot of mess included

aerpaw/cpp/udp_comm.cpp

@@ -0,0 +1,32 @@
+#include "udp_comm.h"
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <cstring>
+
+static int sock = -1;
+static sockaddr_in remote_addr;
+
+void initComms(const char* ip, uint16_t port)
+{
+    if (sock != -1) return;
+
+    sock = socket(AF_INET, SOCK_DGRAM, 0);
+
+    memset(&remote_addr, 0, sizeof(remote_addr));
+    remote_addr.sin_family = AF_INET;
+    remote_addr.sin_port = htons(port);
+    inet_pton(AF_INET, ip, &remote_addr.sin_addr);
+}
+
+void sendTarget(const double* pos)
+{
+    sendto(sock, pos, 3*sizeof(double), 0,
+           (sockaddr*)&remote_addr, sizeof(remote_addr));
+}
+
+void recvOpMode(uint8_t* mode)
+{
+    recvfrom(sock, mode, sizeof(uint8_t), MSG_DONTWAIT,
+             nullptr, nullptr);
+}