Diff: ntp.cpp

Revision:

5:01e1e68309ae

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ntp.cpp	Mon Oct 15 18:30:20 2018 +0000
@@ -0,0 +1,63 @@
+#include "ntp.h"
+#include "mbed.h"
+
+//this code has been taken from https://github.com/ARMmbed/ntp-client
+
+NTPClient::NTPClient(NetworkInterface *iface)
+: iface(iface), nist_server_address((char *)NTP_DEFULT_NIST_SERVER_ADDRESS), nist_server_port(NTP_DEFULT_NIST_SERVER_PORT) {
+}
+
+void NTPClient::set_server(char* server, int port){
+    nist_server_address = server;
+    nist_server_port = port;
+}
+
+time_t NTPClient::get_timestamp(int timeout) {
+    const time_t TIME1970 = (time_t)2208988800UL;
+    int ntp_send_values[12] = {0};
+    int ntp_recv_values[12] = {0};
+
+    SocketAddress nist;
+    int ret_gethostbyname = iface->gethostbyname(nist_server_address, &nist);
+
+    if (ret_gethostbyname < 0) {
+        // Network error on DNS lookup
+        return ret_gethostbyname;
+    }
+
+    nist.set_port(nist_server_port);
+
+    memset(ntp_send_values, 0x00, sizeof(ntp_send_values));
+    ntp_send_values[0] = '\x1b';
+
+    memset(ntp_recv_values, 0x00, sizeof(ntp_recv_values));
+
+    UDPSocket sock;
+    sock.open(iface);
+    sock.set_timeout(timeout);
+
+    sock.sendto(nist, (void*)ntp_send_values, sizeof(ntp_send_values));
+
+    SocketAddress source;
+    const int n = sock.recvfrom(&source, (void*)ntp_recv_values, sizeof(ntp_recv_values));
+
+    if (n > 10) {
+        return ntohl(ntp_recv_values[10]) - TIME1970;
+    } else {
+        if (n < 0) {
+            // Network error
+            return n;
+        } else {
+            // No or partial data returned
+            return -1;
+        }
+    }
+}
+
+uint32_t NTPClient::ntohl(uint32_t x) {
+    uint32_t ret = (x & 0xff) << 24;
+    ret |= (x & 0xff00) << 8;
+    ret |= (x & 0xff0000UL) >> 8;
+    ret |= (x & 0xff000000UL) >> 24;
+    return ret;
+}
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