Add NTP Local Server Library

lib/ArduinoNTPd/NTPPacket.cpp

@@ -0,0 +1,39 @@
+/*
+ * File: NTPPacket.cpp
+ * Description:
+ *   NTP packet representation.
+ * Author: Mooneer Salem <mooneer@gmail.com>
+ * License: New BSD License
+ */
+ 
+#include "NTPPacket.h"
+
+void NtpPacket::swapEndian()
+{
+    reverseBytes_(&rootDelay);
+    reverseBytes_(&rootDispersion);
+    reverseBytes_(&referenceTimestampSeconds);
+    reverseBytes_(&referenceTimestampFraction);
+    reverseBytes_(&originTimestampSeconds);
+    reverseBytes_(&originTimestampFraction);
+    reverseBytes_(&receiveTimestampSeconds);
+    reverseBytes_(&receiveTimestampFraction);
+    reverseBytes_(&transmitTimestampSeconds);
+    reverseBytes_(&transmitTimestampFraction);
+}
+
+void NtpPacket::reverseBytes_(uint32_t *number)
+{
+    char buf[4];
+    char *numberAsChar = (char*)number;
+    
+    buf[0] = numberAsChar[3];
+    buf[1] = numberAsChar[2];
+    buf[2] = numberAsChar[1];
+    buf[3] = numberAsChar[0];
+    
+    numberAsChar[0] = buf[0];
+    numberAsChar[1] = buf[1];
+    numberAsChar[2] = buf[2];
+    numberAsChar[3] = buf[3];
+}

lib/ArduinoNTPd/NTPPacket.h

@@ -0,0 +1,75 @@
+/*
+ * File: NTPPacket.h
+ * Description:
+ *   NTP packet representation.
+ * Author: Mooneer Salem <mooneer@gmail.com>
+ * License: New BSD License
+ */
+ 
+#ifndef NTP_PACKET_H
+#define NTP_PACKET_H
+
+#include "Arduino.h"
+
+
+/*
+ * Contains the data in a typical NTP packet.
+ */
+struct NtpPacket
+{
+    static const int PACKET_SIZE = 48;
+    
+    unsigned char leapVersionMode;
+    
+    unsigned int leapIndicator() const { return leapVersionMode >> 6; }
+    void leapIndicator(unsigned int newValue) { leapVersionMode = (0x3F & leapVersionMode) | ((newValue & 0x03) << 6); }
+    
+    unsigned int versionNumber() const { return (leapVersionMode >> 3) & 0x07; }
+    void versionNumber(unsigned int newValue) { leapVersionMode = (0xC7 & leapVersionMode) | ((newValue & 0x07) << 3); }
+    
+    unsigned int mode() const { return (leapVersionMode & 0x07); }
+    void mode(unsigned int newValue) { leapVersionMode = (leapVersionMode & 0xF8) | (newValue & 0x07); }
+    
+    char stratum;
+    char poll;
+    char precision;
+    uint32_t rootDelay;
+    uint32_t rootDispersion;
+    char referenceId[4];
+    uint32_t referenceTimestampSeconds;
+    uint32_t referenceTimestampFraction;
+    uint32_t originTimestampSeconds;
+    uint32_t originTimestampFraction;
+    uint32_t receiveTimestampSeconds;
+    uint32_t receiveTimestampFraction;
+    uint32_t transmitTimestampSeconds;
+    uint32_t transmitTimestampFraction;
+    
+    /*
+     * Rearranges bytes in 32 bit values from big-endian (NTP protocol)
+     * to little-endian (Arduino/PC), or vice versa. Must be called before 
+     * modifying the structure or sending the packet.
+     */
+    void swapEndian();
+
+    /*
+     * Returns packet as a char array for transmission via network.
+     * WARNING: modifying the return value is unsafe.
+     */
+    const char *packet() { return (const char*)this; }
+    
+    /*
+     * Copies packet buffer to packet object.
+     */
+    void populatePacket(const char *buffer)
+    {
+        memcpy(this, buffer, PACKET_SIZE);
+    }
+private:
+    /*
+     * Reverses bytes in a number.
+     */
+    void reverseBytes_(uint32_t *number);
+};
+
+#endif // NTP_PACKET_H

lib/ArduinoNTPd/NTPServer.cpp

@@ -0,0 +1,79 @@
+/*
+ * File: NTPServer.cpp
+ * Description:
+ *   NTP server implementation.
+ * Author: Mooneer Salem <mooneer@gmail.com>
+ * License: New BSD License
+ */
+
+
+#include <WiFiUdp.h>
+
+#include "NTPPacket.h"
+#include "NTPServer.h"
+
+#define NTP_PORT 123
+#define NTP_TIMESTAMP_DIFF     (2208988800)    // 1900 to 1970 in seconds
+
+bool NtpServer::beginListening()
+{
+    if (timeServerPort_.begin(NTP_PORT)){
+      return true;
+    }
+    return false;
+}
+
+bool NtpServer::processOneRequest(uint32_t utc, uint32_t millisecs) 
+{
+    // We need the time we've received the packet in our response.
+    uint32_t recvSecs =  utc + NTP_TIMESTAMP_DIFF;
+    double recvFractDouble = (double)millisecs/0.00023283064365386963; // millisec/((10^6)/(2^32))
+    uint32_t recvFract = (double)recvFractDouble; //TODO: really handle this!!!
+    bool processed = false;
+    
+    int packetDataSize = timeServerPort_.parsePacket();
+    if (packetDataSize && packetDataSize >= NtpPacket::PACKET_SIZE)
+    {
+        // Received what is probably an NTP packet. Read it in and verify
+        // that it's legit.
+        NtpPacket packet;
+        timeServerPort_.read((char*)&packet, NtpPacket::PACKET_SIZE);
+        // TODO: verify packet.
+
+        // Populate response.
+        packet.swapEndian();        
+        packet.leapIndicator(0);
+        packet.versionNumber(4);
+        packet.mode(4);
+        packet.stratum = 2; // I guess stratum 1 is too optimistic
+        packet.poll = 10; // 6-10 per RFC 5905.
+        packet.precision = -21; // ~0.5 microsecond precision.
+        packet.rootDelay = 0; //60 * (0xFFFF / 1000); // ~60 milliseconds, TBD
+        packet.rootDispersion = 0; //10 * (0xFFFF / 1000); // ~10 millisecond dispersion, TBD
+        packet.referenceId[0] = 'G';
+        packet.referenceId[1] = 'P';
+        packet.referenceId[2] = 'S';
+        packet.referenceId[3] = 0;
+        packet.referenceTimestampSeconds = utc;
+        packet.referenceTimestampFraction = recvFract;
+        packet.originTimestampSeconds = packet.transmitTimestampSeconds;
+        packet.originTimestampFraction = packet.transmitTimestampFraction;
+        packet.receiveTimestampSeconds = recvSecs;
+        packet.receiveTimestampFraction = recvFract;
+        
+        // ...and the transmit time.
+        // timeSource_.now(&packet.transmitTimestampSeconds, &packet.transmitTimestampFraction);
+        
+        // Now transmit the response to the client.
+        packet.swapEndian();
+        timeServerPort_.beginPacket(timeServerPort_.remoteIP(), timeServerPort_.remotePort());
+        for (int count = 0; count < NtpPacket::PACKET_SIZE; count++)
+        {
+            timeServerPort_.write(packet.packet()[count]);
+        }
+        timeServerPort_.endPacket();
+        processed = true;
+    } 
+    
+    return processed;
+}

lib/ArduinoNTPd/NTPServer.h

@@ -0,0 +1,35 @@
+/*
+ * File: NTPServer.h
+ * Description:
+ *   NTP server implementation.
+ * Author: Mooneer Salem <mooneer@gmail.com>
+ * License: New BSD License
+ */
+ 
+#ifndef NTP_SERVER_H
+#define NTP_SERVER_H
+
+class NtpServer
+{
+public:
+    NtpServer(WiFiUDP Port)
+    {
+        timeServerPort_=Port;
+    }
+    
+    /*
+     * Begins listening for NTP requests.
+     */
+    bool beginListening(void);
+    
+    
+    /*
+     * Processes a single NTP request.
+     */
+    bool processOneRequest(uint32_t utc, uint32_t millisecs);
+    
+private:
+    WiFiUDP timeServerPort_;
+};
+
+#endif // NTP_SERVER_H

tasmota/xsns_58_GPS.ino

@@ -1,5 +1,5 @@
 /*
-  xsns_92_GPS_UBX.ino - GPS UBLOX support for Sonoff-Tasmota
+  xsns_58_GPS_UBX.ino - GPS UBLOX support for Sonoff-Tasmota
 
   Copyright (C) 2019  Theo Arends, Christian Baars and Adrian Scillato