Initial version1.0

8 files changed, 2200 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100755
index 0000000..d2d947f
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,48 @@
+
+#########################################################################
+#
+#  $Id: Makefile 1.1 2014/04/01 13:02:21 martin REL_M $
+#
+#  Description:
+#    Makefile for ntptest.
+#
+# -----------------------------------------------------------------------
+#  $Log: Makefile $
+#  Revision 1.1  2014/04/01 13:02:21  martin
+#  Initial revision.
+#
+#########################################################################
+
+TARGET = ntptest
+
+MBGLIB = mbglib
+MBGLIB_DIRS = common
+
+OBJS = $(TARGET).o
+OBJS += mbg_ntp_test_util.o
+
+ifdef DEBUG
+  CPPFLAGS += -g2
+  CPPFLAGS += -DDEBUG=$(DEBUG)
+else
+  CPPFLAGS += -O2
+endif
+
+CPPFLAGS += -Wall
+CPPFLAGS += $(foreach dir,$(MBGLIB_DIRS),-I$(MBGLIB)/$(dir))
+
+LDFLAGS += -lrt
+
+VPATH += $(foreach dir,$(MBGLIB_DIRS),$(MBGLIB)/$(dir))
+
+
+.PHONY: all
+all: $(TARGET)
+
+$(TARGET): $(OBJS)
+
+.PHONY: clean
+clean:
+	rm -f *.o *~ core
+	rm -f $(TARGET)
+
diff --git a/README b/README
new file mode 100755
index 0000000..063f3f1
--- /dev/null
+++ b/README
@@ -0,0 +1,103 @@
+$Id: README 1.1 2014/04/01 15:13:58 martin REL_M $
+
+This is the README file for the ntptest tool which is similar to ntpdate
+which comes with the NTP software package. It sends an NTP request packet
+to an NTP server, receives the response packet, and evaluates the returned
+information.
+
+Just unpack the tar.gz source code archive, cd into the extracted directory
+and run "make" to build the executable.
+
+Then type "./ntptest -?" to get some usage information.
+
+At least the hostname or IP address of a remote NTP server has to be
+specified on the command line, e.g.:
+
+------------------------------------------------------------------------------
+#ntptest> ./ntptest 172.16.100.43
+
+ntptest v1.0, (c) Meinberg 2014, contact: <martin.burnicki@meinberg.de>
+
+Host 172.16.100.43
+Request packet:
+  mode 3, version 4, leap_ind 3, stratum 0, poll 6, prec 238
+  root delay:      00000000 (0.0000 s)
+  root dispersion: 00000000 (0.0000 s/s)
+  reference id:    00000000 ()
+  Ref time:       00000000.00000000  1900-01-01 00:00:00.000000000
+  Org time (T1):  00000000.00000000  1900-01-01 00:00:00.000000000
+  Rcv time (T2):  00000000.00000000  1900-01-01 00:00:00.000000000
+  Xmt time (T3):  D6E541C5.A4A2B11A  2014-04-01 13:46:45.643107479
+  Curr time (T4): D6E541C5.A4A2B11A  2014-04-01 13:46:45.643107479
+
+Response packet:
+  mode 4, version 4, leap_ind 0, stratum 1, poll 6, prec 237
+  root delay:      00000000 (0.0000 s)
+  root dispersion: 00000008 (0.0001 s/s)
+  reference id:    0053524D (MRS)
+  Ref time:       D6E541C4.09622D44  2014-04-01 13:46:44.036654309
+  Org time (T1):  D6E541C5.A4A2B11A  2014-04-01 13:46:45.643107479
+  Rcv time (T2):  D6E541C5.A4AEDE9B  2014-04-01 13:46:45.643293297
+  Xmt time (T3):  D6E541C5.A4B2FEF1  2014-04-01 13:46:45.643356260
+  Curr time (T4): D6E541C5.A4BF6278  2014-04-01 13:46:45.643545297
+
+turnaround:         437.818 (437.818..437.818) us  (T4 - T1)
+server latency:      62.963 (0.000..62.963) us  (T3 - T2)
+computed delay:     374.855 (374.855..374.855) us  ((T4 – T1) – (T3 – T2))
+computed offset:     -1.610 (-1.610..-1.610) us  (((T2 – T1) + (T3 – T4)) / 2)
+------------------------------------------------------------------------------
+
+The output shows the contents of the request packet sent to the NTP server,
+and the response packet received from the server.
+
+The values T1..T4 from the response packet are evaluated as suggested by the
+NTP algorithms.
+
+The "turnaround" time (T4 - T1) tells how long it takes on the client until
+a response is received after the request has been sent.
+
+The "server latency" value (T3 - T2) indicates the time interval on the server
+until it sends the reply after it has received the request.
+
+The computed "delay" and "offset" numbers are the estimated packet delay
+and time offset between the client and the server.
+
+If called with parameter -c the program runs continuously and sends one
+request per second. The minimum and maximum numbers for the computed values
+from several pollings are recorded and displayed.
+
+
+Please note:
+
+- The only relevant number in the request packet is the transmit time (T3).
+
+- Upon receipt of the request packet the NTP server copies T3 into the
+  "originate time" field, which becomes T1 in the response packet seen
+  by the client. So T3 of the request packet should always match T1 of
+  the response packet.
+
+- The server latency may vary with the load on the NTP server. However,
+  this doesn't really matter since it is elimiated in the calculation
+  of the delay and offset on the client.
+
+- The computed delay and time offset can only be accurate if the packet
+  propagation delay is constant all the time, and the same for packets
+  in both directions.
+
+- In reality the packet propagation delay to or from the NTP server
+  *does* vary mor or less for each packet exchange (polling), and
+  there can be "spikes" where single packet in either direction are
+  delayed significantly longer than usual, in which case the computec
+  delay and offset are significantly off their mean values.
+
+- The NTP daemon has been designed to cope with such spikes, and the
+  "delay"  and "offset" values displayed by "ntpq -p" are filtered values
+  based on weighted avarages from subsequent poll, so the results displayed
+  by this program will vary more than those displayed by "ntpq -p".
+
+- Don't run this program only with parameter -c against public NTP server.
+  Polling at 1 request per second can be considered as abusive.
+  Use the -s parameter to increase the sleep interval betweent to pollings
+  to at least 64 seconds (-s 64), which is the minimum polling interval
+  used by the NTP reference implementation.
+
diff --git a/mbglib/common/mbg_ntp_test_util.c b/mbglib/common/mbg_ntp_test_util.c
new file mode 100755
index 0000000..59e6bcc
--- /dev/null
+++ b/mbglib/common/mbg_ntp_test_util.c
@@ -0,0 +1,286 @@
+
+/**************************************************************************
+ *
+ *  $Id: mbg_ntp_test_util.c 1.1 2014/04/01 13:02:21 martin REL_M $
+ *
+ *  Copyright (c) Meinberg Funkuhren, Bad Pyrmont, Germany
+ *
+ *  Description:
+ *    Functions useful to test NTP implementations.
+ *
+ * -----------------------------------------------------------------------
+ *  $Log: mbg_ntp_test_util.c $
+ *  Revision 1.1  2014/04/01 13:02:21  martin
+ *  Initial revision.
+ *
+ **************************************************************************/
+
+#define _MBG_NTP_TEST_UTIL
+  #include <mbg_ntp_test_util.h>
+#undef _MBG_NTP_TEST_UTIL
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <time.h>
+#include <values.h>
+
+
+
+/*HDR*/
+void reset_query_stats( QUERY_STATS *p )
+{
+  memset( p, 0, sizeof( *p ) );
+  p->turnaround.min = MAXLONG;
+  p->turnaround.max = MINLONG;
+  p->ntp_delay.min = MAXDOUBLE;
+  p->ntp_delay.max = -MAXDOUBLE;
+  p->ntp_offs.min = MAXDOUBLE;
+  p->ntp_offs.max = -MAXDOUBLE;
+
+}  // reset_query_stats
+
+
+
+/*HDR*/
+void print_stats_double( const char *info, int info_width,
+                         double curr, int curr_width, double scale,
+                         const MIN_MAX_DOUBLE *p, const char *hint )
+{
+  if ( info )
+    printf( "%-*s", info_width, info );
+
+  printf( "%*.3f", curr_width, curr * scale );
+
+  if ( p )
+    printf( " (%.3f..%.3f)", p->min * scale, p->max * scale );
+
+  if ( hint )
+    printf( "%s", hint );
+
+  printf( "\n" );
+
+}  // print_stats_double
+
+
+
+/*HDR*/
+void print_timespec_date_time( const struct timespec *p_ts )
+{
+  time_t t = p_ts->tv_sec;
+  struct tm *tmp = gmtime( &t );
+
+  printf( "%04i-%02i-%02i %02i:%02i:%02i.%09li",
+          tmp->tm_year + 1900, tmp->tm_mon + 1, tmp->tm_mday,
+          tmp->tm_hour, tmp->tm_min, tmp->tm_sec,
+          (long) p_ts->tv_nsec
+        );
+
+}  // print_timespec_date_time
+
+
+
+/*HDR*/
+/**
+ * @brief Print date and time of an NTP time stamp
+ */
+void print_ntp_date_time( const NTP_TSTAMP *t_ntp )
+{
+  struct timespec ts;
+
+  ntp_tstamp_to_timespec( &ts, t_ntp );
+  print_timespec_date_time( &ts );
+
+}  // print_ntp_date_time
+
+
+
+/*HDR*/
+/**
+ * @brief Print an NTP timestamp and optionally converted date and time
+ */
+void print_ntp_time( const char *msg, const NTP_TSTAMP *t, const char *tail )
+{
+  printf( "%s%08lX.%08lX", msg, (long) (uint32_t) t->integer, (long) (uint32_t) t->fraction );
+
+  printf( "  " );
+  print_ntp_date_time( t );
+
+  if ( tail )
+    printf( tail );
+
+}  // print_ntp_time
+
+
+
+//
+// print contents of an NTP packet
+//
+/*HDR*/
+/**
+ * @brief Print contents of an NTP packet
+ */
+void print_ntp_packet( const char *msg, const NTP_PACKET *p, const NTP_TSTAMP *t_rcv )
+{
+  int i;
+  char ref_id_str[80];
+  char *cp = ref_id_str;
+
+  printf( "%s\n", msg );
+
+  printf( INDENT
+    "mode %u, version %u, leap_ind %u, "
+    "stratum %u, poll %u, prec %u\n"
+    ,
+    p->packet.flags.mode,
+    p->packet.flags.version,
+    p->packet.flags.leap_ind,
+    p->packet.flags.stratum,
+    p->packet.flags.poll,
+    p->packet.flags.precision
+  );
+
+
+  for ( i = 0; ; )
+  {
+    unsigned char uc;
+    uc = BYTE_OF( p->packet.reference_id, i );
+
+    if ( !isdigit( uc ) )
+    {
+      sprintf( ref_id_str, "%.*s",
+               (int) sizeof( p->packet.reference_id ),
+               (char *) &p->packet.reference_id
+              ); 
+      break;
+    }
+
+    cp += sprintf( cp, "%u", uc );
+
+    if ( ++i >= sizeof( p->packet.reference_id ) )
+    {
+      *cp = 0;
+      break;
+    }
+
+    *cp++ = '.';
+  }
+
+  printf(
+    INDENT "root delay:      %08lX (%.4f s)\n"
+    INDENT "root dispersion: %08lX (%.4f s/s)\n"
+    INDENT "reference id:    %08lX (%s)\n"
+    ,
+    (long) p->packet.root_delay, _u_fp_to_d( p->packet.root_delay ),
+    (long) p->packet.root_dispersion, _u_fp_to_d( p->packet.root_dispersion ),
+    (long) p->packet.reference_id,
+    ref_id_str
+  );
+
+  print_ntp_time( INDENT "Ref time:       ", &p->packet.reference_time, newline );
+  print_ntp_time( INDENT "Org time (T1):  ", &p->packet.originate_time, newline );
+  print_ntp_time( INDENT "Rcv time (T2):  ", &p->packet.receive_time, newline );
+  print_ntp_time( INDENT "Xmt time (T3):  ", &p->packet.transmit_time, newline );
+
+
+  if ( t_rcv )
+    print_ntp_time( INDENT "Curr time (T4): ", t_rcv, newline );
+
+  printf( "\n" );
+
+}  // print_ntp_packet
+
+
+
+/*HDR*/
+void init_ntp_req_packet( NTP_PACKET *p, int req_mode, int prot_version )
+{
+  memset( p, 0, sizeof( *p ) );
+
+  p->packet.flags.mode = req_mode;
+  p->packet.flags.version = prot_version;
+  p->packet.flags.leap_ind = 3;
+  p->packet.flags.stratum = 0;
+  p->packet.flags.poll = 6;
+  p->packet.flags.precision = 238;
+
+}  // init_ntp_req_packet
+
+
+
+/*HDR*/
+int eval_ntp_packet( NTP_PACKET *p_rcv_packet, NTP_PACKET *p_req_packet,
+                     const struct timespec *p_tsr_rcv, const struct timespec *p_tsr_req,
+                     const NTP_TSTAMP *p_t_req_ntp, QUERY_STATS *p_stats )
+{
+  double turnaround;
+  double latency;
+  double ntp_delay;
+  double ntp_offs;
+  double t34;
+  double t21;
+  NTP_TSTAMP t_rcv;       // *p_tv_rcv converted to NTP format
+
+  timespec_to_ntp_tstamp( &t_rcv, p_tsr_rcv );
+
+  ntoh_ntp_packet( p_req_packet );
+  ntoh_ntp_packet( p_rcv_packet );
+
+
+  // delay = (T4 – T1) – (T3 – T2)
+  // offset = ((T2 – T1) + (T3 – T4)) / 2
+
+  turnaround = delta_tstamps( &t_rcv, &p_rcv_packet->packet.originate_time );                          // (T4 - T1)
+  latency = delta_tstamps( &p_rcv_packet->packet.transmit_time, &p_rcv_packet->packet.receive_time );  // (T3 - T2)
+  ntp_delay = turnaround - latency;
+
+  t21 = delta_tstamps( &p_rcv_packet->packet.receive_time, &p_rcv_packet->packet.originate_time );     // (T2 - T1)
+  t34 = delta_tstamps( &p_rcv_packet->packet.transmit_time, &t_rcv );                                  // (T3 - T4)
+  ntp_offs = ( t21 + t34 ) / 2.0;
+
+
+  // update statistics begins
+
+  p_stats->replies++;
+
+  update_min_max_double( turnaround, &p_stats->turnaround );
+  update_min_max_double( latency, &p_stats->latency );
+  update_min_max_double( ntp_offs, &p_stats->ntp_offs );
+  update_min_max_double( ntp_delay, &p_stats->ntp_delay );
+
+  // update statistics ended
+
+
+  // print results, if appropriate
+
+
+  print_ntp_packet( "Request packet:", p_req_packet, p_t_req_ntp );
+  print_ntp_packet( "Response packet:", p_rcv_packet, &t_rcv );
+
+  {
+    int info_width = 17;
+    int val_width = 10;
+    double scale = 1e6;
+
+    print_stats_double( "turnaround: ", info_width, turnaround, val_width, scale,
+                        &p_stats->turnaround, " us  (T4 - T1)" );
+
+    print_stats_double( "server latency: ", info_width, latency, val_width, scale,
+                        &p_stats->latency, " us  (T3 - T2)" );
+
+    print_stats_double( "computed delay: ", info_width, ntp_delay, val_width, scale,
+                        &p_stats->ntp_delay, " us  ((T4 – T1) – (T3 – T2))" );
+
+    print_stats_double( "computed offset: ", info_width, ntp_offs, val_width, scale,
+                        &p_stats->ntp_offs, " us  (((T2 – T1) + (T3 – T4)) / 2)" );
+  }
+
+  printf( "\n" );
+
+  return 1;
+
+}  // eval_ntp_packet
+
+
+
diff --git a/mbglib/common/mbg_ntp_test_util.h b/mbglib/common/mbg_ntp_test_util.h
new file mode 100755
index 0000000..2ef6241
--- /dev/null
+++ b/mbglib/common/mbg_ntp_test_util.h
@@ -0,0 +1,292 @@
+
+/**************************************************************************
+ *
+ *  $Id: mbg_ntp_test_util.h 1.1 2014/04/01 13:02:21 martin REL_M $
+ *
+ *  Copyright (c) Meinberg Funkuhren, Bad Pyrmont, Germany
+ *
+ *  Description:
+ *    Definitions and prototypes used with mbg_ntp_test_util.h
+ *
+ * -----------------------------------------------------------------------
+ *  $Log: mbg_ntp_test_util.h $
+ *  Revision 1.1  2014/04/01 13:02:21  martin
+ *  Initial revision.
+ *
+ **************************************************************************/
+
+#ifndef _MBG_NTP_TEST_UTIL_H
+#define _MBG_NTP_TEST_UTIL_H
+
+
+/* Other headers to be included */
+
+#include <mbg_tgt.h>
+#include <mbgntp.h>
+
+#if defined( MBG_TGT_POSIX )
+  #include <syslog.h>
+  #include <arpa/inet.h>
+#endif
+
+
+#ifdef _MBG_NTP_TEST_UTIL
+ #define _ext
+ #define _DO_INIT
+#else
+ #define _ext extern
+#endif
+
+
+
+#if defined( _USE_PACK )
+// not used here
+// #pragma pack( 1 )      // set byte alignment
+// #define _USING_BYTE_ALIGNMENT
+#endif
+
+/* Start of header body */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define INDENT   "  "
+
+void mbglog( int priority, const char *fmt, ... );
+
+_ext const char *newline
+#ifdef _DO_INIT
+ = "\n"
+#endif
+;
+
+
+typedef struct
+{
+  double min;
+  double max;
+
+} MIN_MAX_DOUBLE;
+
+
+
+// query mode statistics
+
+typedef struct
+{
+  unsigned long long requests;
+  unsigned long long replies;
+  unsigned long long timeouts;
+
+  MIN_MAX_DOUBLE turnaround;
+  MIN_MAX_DOUBLE latency;
+  MIN_MAX_DOUBLE ntp_delay;
+  MIN_MAX_DOUBLE ntp_offs;
+
+} QUERY_STATS;
+
+
+
+static __mbg_inline /*HDR*/
+void update_min_max_double( double curr, MIN_MAX_DOUBLE *p )
+{
+  if ( curr > p->max )
+    p->max = curr;
+
+  if ( curr < p->min )
+    p->min = curr;
+
+}  // update_min_max_double
+
+
+
+static __mbg_inline /*HDR*/
+double ntp_tstamp_to_double( const NTP_TSTAMP *t )
+{
+  return (double) t->integer + ( ( (double) t->fraction ) / NTP_FRAC_PER_SEC );
+
+}  // ntp_tstamp_to_double
+
+
+
+static __mbg_inline /*HDR*/
+ulong ntp_frac_to_nsec( uint32_t frac )
+{
+  unsigned long long tmp = ( (unsigned long long) frac * NSECS_PER_SEC ) / NTP_FRAC_PER_SEC;
+
+  if ( tmp >= NSECS_PER_SEC )
+    mbglog( LOG_WARNING, "Range overflow in ntp_frac_to_nsec: 0x%X -> %Lu",
+            frac, tmp );
+
+  return (ulong) tmp;
+
+}  // ntp_frac_to_nsec
+
+
+
+static __mbg_inline /*HDR*/
+uint32_t nsec_to_ntp_frac( ulong nsec )
+{
+  unsigned long long tmp;
+
+  tmp = ( (unsigned long long) nsec * NTP_FRAC_PER_SEC ) / NSECS_PER_SEC;
+
+  if ( tmp >= NTP_FRAC_PER_SEC )
+    mbglog( LOG_WARNING, "Range overflow in nsec_to_ntp_frac: %lu -> 0x%LX",
+           (ulong) nsec, tmp );
+
+  return (uint32_t) tmp;
+
+}  // nsec_to_ntp_frac
+
+
+
+static __mbg_inline /*HDR*/
+void timespec_to_ntp_tstamp( NTP_TSTAMP *t_ntp, const struct timespec *t_ts )
+{
+  t_ntp->integer = t_ts->tv_sec + NTP_OFFS;
+  t_ntp->fraction = nsec_to_ntp_frac( t_ts->tv_nsec );
+
+}  // timespec_to_ntp_tstamp
+
+
+
+static __mbg_inline /*HDR*/
+void ntp_tstamp_to_timespec( struct timespec *t_ts, const NTP_TSTAMP *t_ntp )
+{
+  t_ts->tv_sec = ( (uint32_t) t_ntp->integer ) - NTP_OFFS;
+  t_ts->tv_nsec = ntp_frac_to_nsec( t_ntp->fraction );
+
+}  // ntp_tstamp_to_timespec
+
+
+
+//
+// convert the byte order of an NTP time stamp
+// from net to host
+//
+static __mbg_inline /*HDR*/
+void ntoh_ntp_time( NTP_TSTAMP *t )
+{
+  t->integer = ntohl( t->integer );
+  t->fraction = ntohl( t->fraction );
+
+}  // ntoh_ntp_time
+
+
+//
+// convert the byte order of an NTP packet
+// from net to host
+//
+static __mbg_inline /*HDR*/
+void ntoh_ntp_packet( NTP_PACKET *p )
+{
+  ntoh_ntp_time( &p->packet.reference_time );
+  ntoh_ntp_time( &p->packet.originate_time );
+  ntoh_ntp_time( &p->packet.receive_time );
+  ntoh_ntp_time( &p->packet.transmit_time );
+
+  p->packet.root_delay = ntohl( p->packet.root_delay );
+  p->packet.root_dispersion = ntohl( p->packet.root_dispersion );
+
+}  // ntoh_ntp_packet
+
+
+
+static __mbg_inline /*HDR*/
+double delta_tstamps( const NTP_TSTAMP *t,
+                      const NTP_TSTAMP *t_ref )
+{
+  return ( (double) t->integer - (double) t_ref->integer )
+       + ( (double) t->fraction - (double) t_ref->fraction ) / NTP_FRAC_PER_SEC;
+
+}  // delta_tstamps
+
+
+
+//
+// compute the difference of two timespec variables
+//
+static __mbg_inline /*HDR*/
+double delta_timespec_d_s( const struct timespec *ts,
+                           const struct timespec *ts_ref )
+{
+  return ( (double) ts->tv_sec - (double) ts_ref->tv_sec )
+       + ( (double) ts->tv_nsec - (double) ts_ref->tv_nsec ) / NSECS_PER_SEC;
+
+}  // delta_timespec_d_s
+
+
+
+static __mbg_inline /*HDR*/
+long long delta_timespec_ll_ns( const struct timespec *ts,
+                                const struct timespec *ts_ref )
+{
+  return ( ts->tv_sec - ts_ref->tv_sec ) * NSECS_PER_SEC
+       + ( ts->tv_nsec - ts_ref->tv_nsec );
+
+}  // delta_timespec_ll_ns
+
+
+
+static __mbg_inline /*HDR*/
+int check_bounds( int opt_val, int min_val, int max_val, int default_val )
+{
+  return ( ( opt_val < min_val ) || ( opt_val > max_val ) ) ? default_val : opt_val;
+
+}  // check_bounds
+
+
+
+
+/* function prototypes: */
+
+/* ----- function prototypes begin ----- */
+
+/* This section was generated automatically */
+/* by MAKEHDR, do not remove the comments. */
+
+ void reset_query_stats( QUERY_STATS *p ) ;
+ void print_stats_double( const char *info, int info_width, double curr, int curr_width, double scale, const MIN_MAX_DOUBLE *p, const char *hint ) ;
+ void print_timespec_date_time( const struct timespec *p_ts ) ;
+ /**
+ * @brief Print date and time of an NTP time stamp
+ */
+ void print_ntp_date_time( const NTP_TSTAMP *t_ntp ) ;
+
+ /**
+ * @brief Print an NTP timestamp and optionally converted date and time
+ */
+ void print_ntp_time( const char *msg, const NTP_TSTAMP *t, const char *tail ) ;
+
+ /**
+ * @brief Print contents of an NTP packet
+ */
+ void print_ntp_packet( const char *msg, const NTP_PACKET *p, const NTP_TSTAMP *t_rcv ) ;
+
+ void init_ntp_req_packet( NTP_PACKET *p, int req_mode, int prot_version ) ;
+ int eval_ntp_packet( NTP_PACKET *p_rcv_packet, NTP_PACKET *p_req_packet, const struct timespec *p_tsr_rcv, const struct timespec *p_tsr_req, const NTP_TSTAMP *p_t_req_ntp, QUERY_STATS *p_stats ) ;
+
+/* ----- function prototypes end ----- */
+
+#ifdef __cplusplus
+}
+#endif
+
+
+
+
+#if defined( _USING_BYTE_ALIGNMENT )
+  #pragma pack()      // set default alignment
+  #undef _USING_BYTE_ALIGNMENT
+#endif
+
+/* End of header body */
+
+
+#undef _ext
+#undef _DO_INIT
+
+#endif  /* _MBG_NTP_TEST_UTIL_H */
+
diff --git a/mbglib/common/mbg_tgt.h b/mbglib/common/mbg_tgt.h
new file mode 100755
index 0000000..91b4d09
--- /dev/null
+++ b/mbglib/common/mbg_tgt.h
@@ -0,0 +1,590 @@
+
+/**************************************************************************
+ *
+ *  $Id: mbg_tgt.h 1.30 2014/04/01 12:55:58 martin REL_M $
+ *
+ *  Copyright (c) Meinberg Funkuhren, Bad Pyrmont, Germany
+ *
+ *  Description:
+ *    Check the build environment and setup control definitions
+ *    for the Meinberg library modules.
+ *
+ * -----------------------------------------------------------------------
+ *  $Log: mbg_tgt.h $
+ *  Revision 1.30  2014/04/01 12:55:58  martin
+ *  Define MBG_TGT_WIN32 also for MS resource compiler.
+ *  New target MBG_TGT_POSIX.
+ *  Always include winsock2.h and windows.h for MBG_TGT_WIN32.
+ *  Always include unistd.h for MBG_TGT_POSIX.
+ *  Define empty __attribute__ macro for non-gcc environments.
+ *  Revision 1.29  2013/02/01 14:50:46  martin
+ *  Fixed a typo which caused an error under Borland CBuilder 5.
+ *  Revision 1.28  2012/12/12 10:03:16Z  martin
+ *  Fix for Borland C 3.1.
+ *  Revision 1.27  2012/11/29 12:03:14Z  martin
+ *  Moved definition of _no_macro_fnc() to words.h.
+ *  Revision 1.26  2012/11/02 09:01:47Z  martin
+ *  Merged some stuff depending on the build environment here
+ *  and cleaned up.
+ *  Revision 1.25  2012/04/04 07:17:18  martin
+ *  Treat QNX Neutrino as Unix target.
+ *  Revision 1.24  2011/08/23 10:21:23  martin
+ *  New symbol _NO_MBG_API_ATTR which can be used with functions
+ *  which are going to be exported by a DLL, but actually aren't, yet.
+ *  Revision 1.23  2011/08/19 10:47:00  martin
+ *  Don't include stddef.h.
+ *  Distinguish between different gcc target platforms.
+ *  Initial support for IA64 platform.
+ *  Support wchar_t for BSD.
+ *  Defined _NO_USE_PACK_INTF for Sparc and IA64.
+ *  Fixed typo in comment.
+ *  Revision 1.22  2009/10/01 08:20:50  martin
+ *  Fixed inline code support with different BC versions.
+ *  Revision 1.21  2009/09/01 10:34:23Z  martin
+ *  Don't define __mbg_inline for CVI and undefined targets.
+ *  Revision 1.20  2009/08/18 15:14:26  martin
+ *  Defined default MBG_INVALID_PORT_HANDLE for non-Windows targets.
+ *  Revision 1.19  2009/06/09 10:03:58  daniel
+ *  Preliminary support for ARM architecture.
+ *  Revision 1.18  2009/04/01 14:10:55  martin
+ *  Cleanup for CVI.
+ *  Revision 1.17  2009/03/19 15:21:07Z  martin
+ *  Conditionally define DWORD_PTR type for old MS C compilers.
+ *  Revision 1.16  2008/12/08 16:42:30  martin
+ *  Defined _GNU_SOURCE for Linux.
+ *  Revision 1.15  2008/11/19 15:31:49  martin
+ *  Added symbol MBG_ARCH_I386.
+ *  Revision 1.14  2008/09/03 15:06:04  martin
+ *  Support DOS protected mode target.
+ *  Support SUN SPARC architecture.
+ *  Specified handle types for common host environments.
+ *  Added macro MBG_USE_MM_IO_FOR_PCI.
+ *  Added macro _nop_macro_fnc().
+ *  Revision 1.13  2008/01/30 15:52:22  martin
+ *  Modified checking for availability of wchar_t.
+ *  Revision 1.13  2008/01/29 15:18:07Z  martin
+ *  Recognize DOS target under Watcom compilers.
+ *  Flag Watcom C always supports wchar_t.
+ *  Revision 1.12  2008/01/17 09:38:50Z  daniel
+ *  Added macros to determine whether C language extensions 
+ *  (e.g. C94, C99) are supported by the target environment.
+ *  Added macro to check whether wchar_t and friends are 
+ *  supported, and some compatibility stuff.
+ *  Revision 1.11  2007/10/31 16:58:03  martin
+ *  Fixed __mbg_inline for Borland C (DOS).
+ *  Revision 1.10  2007/09/25 08:10:27Z  martin
+ *  Support CVI target environment.
+ *  Added MBG_PORT_HANDLE type for serial ports.
+ *  Added macros for unified inline code syntax.
+ *  Revision 1.9  2006/12/08 12:45:54Z  martin
+ *  Under Windows include ntddk.h rather than windows.h 
+ *  if building kernel driver .
+ *  Revision 1.8  2006/10/25 12:20:45Z  martin
+ *  Initial support for FreeBSD, NetBSD, and OpenBSD.
+ *  Added definitions for generic handle types.
+ *  Revision 1.7  2006/08/23 13:43:55  martin
+ *  Added definition for MBG_TGT_UNIX.
+ *  Minor syntax fixes.
+ *  Revision 1.6  2006/01/25 14:37:06  martin
+ *  Added definitions for 64 bit Windows environments.
+ *  Revision 1.5  2003/12/17 16:11:41Z  martin
+ *  Split API modifiers into _MBG_API and _MBG_API_ATTR.
+ *  Revision 1.4  2003/06/19 08:20:22Z  martin
+ *  Added WINAPI attribute for DLL exported functions.
+ *  Revision 1.3  2003/04/09 13:37:20Z  martin
+ *  Added definition for _MBG_API.
+ *  Revision 1.2  2003/02/24 16:08:45Z  martin
+ *  Don't setup for Win32 PNP if explicitely configured non-PNP.
+ *  Revision 1.1  2002/02/19 13:46:20Z  MARTIN
+ *  Initial revision
+ *
+ **************************************************************************/
+
+#ifndef _MBG_TGT_H
+#define _MBG_TGT_H
+
+
+/* Other headers to be included */
+
+#ifdef _MBG_TGT
+ #define _ext
+#else
+ #define _ext extern
+#endif
+
+
+/* Start of header body */
+
+#if defined( _CVI_ )
+
+  #define MBG_TGT_CVI
+
+  #if defined( _NI_mswin_ )
+    #define MBG_TGT_WIN32
+  #else
+    #error Unsupported CVI target platform.
+  #endif
+
+#elif defined( _WIN32_WINNT )
+
+  // MS platform SDK
+  // WinNT 4.0 and above
+  #define MBG_TGT_WIN32
+
+  #if ( _WIN32_WINNT >= 0x0500 )
+    // Win2k and above
+    #if !defined( MBG_TGT_WIN32_NON_PNP )
+      // only if not explicitely disabled
+      #define MBG_TGT_WIN32_PNP
+    #endif
+  #endif
+
+#elif defined( WINVER )
+
+  // MS platform SDK
+  // Win95, WinNT 4.0 and above
+  #define MBG_TGT_WIN32
+
+  #if ( WINVER >= 0x0500 )
+    // Win98, Win2k and above
+    // #define ...
+  #endif
+
+#elif defined( __WIN32__ )
+
+  // Borland C++ Builder
+  #define MBG_TGT_WIN32
+
+#elif defined( _WIN32 )
+
+  // MS Visual C++
+  #define MBG_TGT_WIN32
+
+#elif defined( RC_INVOKED )
+
+  //MS resource compiler
+  #define MBG_TGT_WIN32
+
+#elif defined( __WINDOWS_386__ )
+
+  // Watcom C/C++ for target Win32
+  #define MBG_TGT_WIN32
+
+#elif defined( __NETWARE_386__ )
+
+  // Watcom C/C++ for target NetWare
+  #define MBG_TGT_NETWARE
+
+#elif defined( __OS2__ )
+
+  // Watcom C/C++ for target OS/2
+  #define MBG_TGT_OS2
+
+#elif defined( __linux )
+
+  // GCC for target Linux
+  #define MBG_TGT_LINUX
+  #define _GNU_SOURCE    1
+
+  #if defined( __KERNEL__ )
+    #define MBG_TGT_KERNEL
+  #endif
+
+#elif defined( __FreeBSD__ )
+
+  // GCC for target FreeBSD
+  #define MBG_TGT_FREEBSD
+
+#elif defined( __NetBSD__ )
+
+  // GCC for target NetBSD
+  #define MBG_TGT_NETBSD
+
+#elif defined( __OpenBSD__ )
+
+  // GCC for target OpenBSD
+  #define MBG_TGT_OPENBSD
+
+#elif defined( __QNX__ )
+
+  // any compiler for target QNX
+  #define MBG_TGT_QNX
+
+  #if defined( __QNXNTO__ )
+    // target QNX Neutrino
+    #define MBG_TGT_QNX_NTO
+  #endif
+
+#elif defined( __MSDOS__ ) || defined( __DOS__ )
+
+  // any compiler for target DOS
+  #define MBG_TGT_DOS
+
+  #if defined( __WATCOMC__ ) && defined( __386__ )
+
+    #define MBG_TGT_DOS_PM  // protected mode DOS
+
+  #endif
+
+#endif
+
+
+
+#if defined( MBG_TGT_FREEBSD ) \
+ || defined( MBG_TGT_NETBSD ) \
+ || defined( MBG_TGT_OPENBSD )
+  #define MBG_TGT_BSD
+
+  #if defined( _KERNEL )
+    #define MBG_TGT_KERNEL
+  #endif
+
+#endif
+
+#if defined( MBG_TGT_LINUX ) \
+ || defined( MBG_TGT_BSD )
+  #define MBG_TGT_POSIX
+  #define MBG_TGT_UNIX
+#endif
+
+
+
+// Some definitions depending on the build environment ...
+
+#if defined( __GNUC__ )
+
+  #if defined( __i386__ )
+
+    #define MBG_ARCH_I386
+    #define MBG_ARCH_X86
+
+  #elif defined( __x86_64__ )
+
+    #define MBG_ARCH_X86_64
+    #define MBG_ARCH_X86
+
+  #elif defined( __ia64__ )
+
+    #define MBG_ARCH_IA64
+
+    #define _NO_USE_PACK_INTF
+
+  #elif defined( __sparc__ )
+
+    #define MBG_ARCH_SPARC
+    #define MBG_USE_MM_IO_FOR_PCI  1
+
+    #define _NO_USE_PACK_INTF
+
+  #elif defined( __arm__ )
+
+    #define MBG_ARCH_ARM
+
+  #endif
+
+  #if defined( MBG_TGT_LINUX )
+
+    #if defined( __KERNEL__ )
+      #include <linux/types.h>
+    #else
+      #include <sys/types.h>
+      #include <stdint.h>
+      #include <stdbool.h>
+    #endif
+
+  #elif defined( MBG_TGT_BSD )
+
+    #include <sys/types.h>
+
+  #elif defined( MBG_TGT_QNX_NTO )  // QNX 6.x (Neutrino)
+
+    #include <stdint.h>
+    #include <stdbool.h>
+
+  #else
+
+    #include <stdint.h>
+    #include <stdbool.h>
+
+  #endif
+
+  #define MBG_TGT_HAS_EXACT_SIZE_TYPES     1
+
+  #define MBG_TGT_HAS_WCHAR_T              1
+
+  #define __mbg_inline __inline__
+
+#elif defined( _MSC_VER )
+
+  // Known predifined MS compiler version codes:
+  // 1700: MSVC++ 11.0 (Visual Studio 2012)
+  // 1600: MSVC++ 10.0 (Visual Studio 2010)
+  // 1500: MSVC++ 9.0  (Visual Studio 2008)
+  // 1400: MSVC++ 8.0  (Visual Studio 2005)
+  // 1310: MSVC++ 7.1  (Visual Studio 2003)
+  // 1300: MSVC++ 7.0
+  // 1200: MSVC++ 6.0
+  // 1100: MSVC++ 5.0
+
+  #if ( _MSC_VER >= 1600 )
+    #include <stdint.h>
+    #define MBG_TGT_HAS_EXACT_SIZE_TYPES   1
+  #else
+    #define MBG_TGT_HAS_INT_8_16_32        1
+  #endif
+
+  // no bool support anyway
+  #define MBG_TGT_MISSING_BOOL_TYPE        1
+
+  #define MBG_TGT_HAS_WCHAR_T              1
+
+  #define __mbg_inline __forceinline
+
+#elif defined( _CVI_ )
+
+  // 1000 for CVI v10.0 (CVI 2010)
+  // 911 for CVI v9.1.1 (CVI 2009 SP1)
+  // 910 for CVI v9.1 (CVI 2009)
+  // 310 for CVI v3.1
+  // 301 for CVI v3.0.1
+  // 1 for CVI v3.0
+
+  #if ( _CVI_ >= 910 )
+    // LabWindows/CVI 2009 is the first version providing stdint.h.
+    #include <stdint.h>
+    #define MBG_TGT_HAS_EXACT_SIZE_TYPES   1
+  #else
+    #define USE_LONG_FOR_INT32  1
+  #endif
+
+  // As of LabWindows/CVI 2010, stdbool.h is still missing.
+  #define MBG_TGT_MISSING_BOOL_TYPE        1
+
+  #define MBG_TGT_HAS_WCHAR_T              0
+
+  // Inline code is not supported, though the inline keyword
+  // is silently accepted since CVI v9.0
+
+#elif defined( __BORLANDC__ )
+
+  // 0x0570 Borland Developer Studio 2006
+  // 0x0550 Borland C/C++ 5.5 (C++ Builder 5.0)
+  // 0x0410 Borland C/C++ 3.1
+  // 0x0400 Borland C/C++ 3.0
+  // 0x0200 Borland C/C++ 2.0
+
+  #if ( __BORLANDC__ >= 0x570 )
+    // at least Borland Developer Studio 2006 supports C99
+    #include <stdint.h>
+    #include <stdbool.h>
+    #define MBG_TGT_HAS_EXACT_SIZE_TYPES   1
+  #elif ( __BORLANDC__ >= 0x0550 )
+    #define MBG_TGT_HAS_INT_8_16_32        1
+    #define MBG_TGT_MISSING_BOOL_TYPE      1
+  #else  // e.g. BC 3.1 or earlier
+    #if ( __BORLANDC__ <= 0x410 )
+      #define MBG_TGT_MISSING_64_BIT_TYPES 1
+      #define MBG_TGT_MISSING_BOOL_TYPE    1
+      #define USE_LONG_FOR_INT32           1
+    #endif
+  #endif
+
+  #define MBG_TGT_HAS_WCHAR_T  defined( MBG_TGT_WIN32 )
+
+  #if defined( __cplusplus )
+    #define __mbg_inline inline    // standard C++ syntax
+  #elif ( __BORLANDC__ > 0x410 )   // BC3.1 defines 0x410 !
+    #define __mbg_inline __inline  // newer BC versions support this for C
+  #else
+    #define __mbg_inline           // up to BC3.1 not supported for C
+  #endif
+
+#elif defined( __WATCOMC__ )
+
+  // 1050  v10.5
+  // 1100  v11.0
+  // 1200  Open Watcom C++ v1.0
+  // 1230  Open Watcom C++ v1.3
+  // 1270  Open Watcom C++ v1.7
+
+  #if defined( MBG_TGT_QNX )    // QNX 4.x
+
+    #include <sys/types.h>
+
+    #define MBG_TGT_MISSING_64_BIT_TYPES  1
+
+  #elif ( __WATCOMC__ > 1230 )  // Open Watcom C 1.3 and above
+
+    #include <stdint.h>
+
+  #elif !defined( __WATCOM_INT64__ )  // Watcom C 11
+
+    #define MBG_TGT_MISSING_64_BIT_TYPES  1
+
+  #endif
+
+  #define MBG_TGT_HAS_WCHAR_T  defined( MBG_TGT_WIN32 )
+
+  #define __mbg_inline _inline
+
+#endif
+
+
+#if !defined( __GNUC__ ) && !defined( __attribute__ )
+  #define __attribute__( _x )
+#endif
+
+
+#if defined( MBG_TGT_WIN32 )
+
+  #if defined( _AMD64_ )
+    // This is used for AMD64 architecture and for 
+    // Intel XEON CPUs with 64 bit extension.
+    #define MBG_TGT_WIN32_PNP_X64
+    #define WIN32_FLAVOR "x64"
+  #elif defined( _IA64_ )
+    #define MBG_TGT_WIN32_PNP_IA64
+    #define WIN32_FLAVOR "ia64"
+  #endif
+
+  #if defined( _KDD_ )
+    #define MBG_TGT_KERNEL
+    #include <ntddk.h>
+  #else
+    // This must not be used for kernel drivers.
+    #define WIN32_LEAN_AND_MEAN 1
+    #define _WINSOCKAPI_   /* Prevent inclusion of winsock.h in windows.h */
+    #include <winsock2.h>
+    #include <windows.h>
+
+    typedef HANDLE MBG_HANDLE;
+
+    #define MBG_INVALID_HANDLE  INVALID_HANDLE_VALUE
+
+    #if defined( MBG_TGT_CVI )
+      // CVI uses an own set of functions to support serial ports
+      typedef int MBG_PORT_HANDLE;
+      #define MBG_INVALID_PORT_HANDLE -1
+    #else
+      typedef HANDLE MBG_PORT_HANDLE;
+    #endif
+
+    // The DWORD_PTR type is not defined in the headers shipping
+    // with VC6. However, if the SDK is installed then the SDK's
+    // headers may declare this type. This is at least the case
+    // in the Oct 2001 SDK which also defines the symbol _W64.
+    #if !defined( _W64 )
+      typedef DWORD DWORD_PTR;
+    #endif
+
+  #endif
+
+  #define _MBG_API  WINAPI
+
+  #if defined( MBG_LIB_EXPORT )
+    #define _MBG_API_ATTR __declspec( dllexport )
+  #else
+    #define _MBG_API_ATTR __declspec( dllimport )
+  #endif
+
+#elif defined( MBG_TGT_POSIX )
+
+  #if !defined( MBG_TGT_KERNEL )
+    #include <unistd.h>
+  #endif
+
+  typedef int MBG_HANDLE;
+  typedef int MBG_PORT_HANDLE;
+
+  #define MBG_INVALID_HANDLE  -1
+
+#else
+
+  typedef int MBG_HANDLE;
+  typedef int MBG_PORT_HANDLE;
+
+  #define MBG_INVALID_HANDLE  -1
+
+#endif
+
+
+#if !defined( _MBG_API )
+  #define _MBG_API
+#endif
+
+#if !defined( _MBG_API_ATTR )
+  #define _MBG_API_ATTR
+#endif
+
+#if !defined( _NO_MBG_API_ATTR )
+  #define _NO_MBG_API_ATTR
+#endif
+
+#if !defined( MBG_INVALID_PORT_HANDLE )
+  #define MBG_INVALID_PORT_HANDLE   MBG_INVALID_HANDLE
+#endif
+
+#if !defined( MBG_USE_MM_IO_FOR_PCI )
+  #define MBG_USE_MM_IO_FOR_PCI  0
+#endif
+
+
+// The macros below are defined in order to be able to check if
+// certain C language extensions are available on the target system:
+#if defined( __STDC_VERSION__ ) && ( __STDC_VERSION__ >= 199409L )
+  #define MBG_TGT_C94    1
+#else
+  #define MBG_TGT_C94    0
+#endif
+
+
+#if defined( __STDC_VERSION__ ) && ( __STDC_VERSION__ >= 199901L )
+  #define MBG_TGT_C99    1
+#else
+  #define MBG_TGT_C99    0
+#endif
+
+// Check if wchar_t is supported
+#if !defined( MBG_TGT_HAS_WCHAR_T )
+  #define MBG_TGT_HAS_WCHAR_T  ( MBG_TGT_C94 || defined( WCHAR_MAX ) )
+#endif
+
+#if !MBG_TGT_HAS_WCHAR_T
+  // Even if wchar_t is not natively supported by the target platform
+  // there may already be a compatibility define (e.g. BC3.1)
+  // However, some functions may be missing (e.g. snwprintf()).
+  #if !defined( _WCHAR_T )          /* BC3.1 */ \
+   && !defined( _WCHAR_T_DEFINED_ ) /* WC11 */
+    #define _WCHAR_T
+    #define wchar_t char
+  #endif
+#endif
+
+
+
+/* End of header body */
+
+#undef _ext
+
+
+/* function prototypes: */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* ----- function prototypes begin ----- */
+
+/* This section was generated automatically */
+/* by MAKEHDR, do not remove the comments. */
+
+/* (no header definitions found) */
+
+/* ----- function prototypes end ----- */
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif  /* _MBG_TGT_H */
diff --git a/mbglib/common/mbgntp.h b/mbglib/common/mbgntp.h
new file mode 100755
index 0000000..a464b59
--- /dev/null
+++ b/mbglib/common/mbgntp.h
@@ -0,0 +1,208 @@
+
+/**************************************************************************
+ *
+ *  $Id: mbgntp.h 1.4 2014/04/01 12:30:30 martin REL_M $
+ *
+ *  Copyright (c) Meinberg Funkuhren, Bad Pyrmont, Germany
+ *
+ *  Description:
+ *    Definitions and prototypes for mbgntp.h.
+ *
+ * -----------------------------------------------------------------------
+ *  $Log: mbgntp.h $
+ *  Revision 1.4  2014/04/01 12:30:30  martin
+ *  Include mbg_tgt.h.
+ *  MD5 auth support disabled by default.
+ *  Moved some definitions here.
+ *  Revision 1.3  2005/11/15 13:51:15  martin
+ *  Changed NTP_TSTAMP::fraction to unsigned.
+ *  Conditional preliminary union for NTP_TSTAMP using 64 bit type.
+ *  Revision 1.2  2005/05/19 14:42:07  martin
+ *  Use C99 fixed with data types.
+ *  Support MD5 symmetric key authentication.
+ *  Revision 1.1  2000/05/23 12:04:21  martin
+ *  Initial revision
+ *
+ **************************************************************************/
+ 
+#ifndef _MBGNTP_H
+#define _MBGNTP_H
+
+
+/* Other headers to be included */
+
+#include <mbg_tgt.h>
+#include <words.h>
+
+#ifdef _MBGNTP
+ #define _ext
+ #define _DO_INIT
+#else
+ #define _ext extern
+#endif
+
+
+/* Start of header body */
+
+#ifndef MBG_MD5_AUTH
+  #define MBG_MD5_AUTH   0
+#endif
+
+
+#define NTP_PORT 123
+
+#define NTP_OFFS 2208988800UL
+
+
+#define NTP_FRAC_PER_SEC         (uint64_t) 4294967296.0
+#define NSECS_PER_SEC            1000000000L
+
+#define MIN_REQ_NTP_VERSION      3
+#define MAX_REQ_NTP_VERSION      4
+#define DEFAULT_REQ_NTP_VERSION  MAX_REQ_NTP_VERSION
+
+// From NTP's ntp.h:
+#define MODE_UNSPEC     0        /* unspecified (old version) */
+#define MODE_ACTIVE     1        /* symmetric active mode */
+#define MODE_PASSIVE    2        /* symmetric passive mode */
+#define MODE_CLIENT     3        /* client mode */
+#define MODE_SERVER     4        /* server mode */
+#define MODE_BROADCAST  5        /* broadcast mode */
+
+#define DEFAULT_REQ_NTP_MODE     MODE_CLIENT
+
+
+
+typedef struct
+{
+  int32_t integer;
+  uint32_t fraction;
+} NTP_TSTAMP;
+
+
+
+typedef int32_t NTP_S_FP;   // signed floating point in integer representation
+typedef uint32_t NTP_U_FP;  // unsigned floating point in integer representation
+
+
+/*
+ * s_fp/double and u_fp/double conversions
+ */
+#define FRIC              65536  /* 2^16 as a double */
+
+#if 1
+
+static __mbg_inline /*HDR*/
+NTP_S_FP d_to_s_fp( double d )
+{
+  return (NTP_S_FP) ( d * FRIC );
+}
+
+static __mbg_inline /*HDR*/
+NTP_S_FP d_to_u_fp( double d )
+{
+  return (NTP_U_FP) ( d * FRIC );
+}
+
+static __mbg_inline /*HDR*/
+double s_fp_to_d( NTP_S_FP s_fp )
+{
+  return (double) s_fp / FRIC;
+}
+
+static __mbg_inline /*HDR*/
+double u_fp_to_d( NTP_U_FP u_fp )
+{
+  return (double) u_fp / FRIC;
+}
+
+
+#define _d_to_s_fp( _r )  d_to_s_fp( _r )
+#define _d_to_u_fp( _r )  d_to_u_fp( _r )
+#define _s_fp_to_d( _r )  s_fp_to_d( _r )
+#define _u_fp_to_d( _r )  u_fp_to_d( _r )
+
+#else
+
+#define _d_to_s_fp( _r )  ( (NTP_S_FP) ( (_r) * FRIC ) )
+#define _d_to_u_fp( _r )  ( (NTP_U_FP) ( (_r) * FRIC ) )
+#define _s_fp_to_d( _r )  _u_fp_to_d( _r )
+#define _u_fp_to_d( _r )  ( (double) ( _r ) / FRIC )
+
+#endif
+
+typedef struct
+{
+  unsigned int mode      : 3;
+  unsigned int version   : 3;
+  unsigned int leap_ind  : 2;
+  unsigned int stratum   : 8;
+  unsigned int poll      : 8;
+  unsigned int precision : 8;
+} NTP_FLAGS;
+
+
+
+typedef struct
+{
+  NTP_FLAGS flags;
+  NTP_U_FP root_delay;
+  NTP_U_FP root_dispersion;
+  uint32_t reference_id;
+  NTP_TSTAMP reference_time;
+  NTP_TSTAMP originate_time;
+  NTP_TSTAMP receive_time;
+  NTP_TSTAMP transmit_time;
+} NTP_BASE_PACKET;
+
+
+#if MBG_MD5_AUTH
+
+#define N_NTP_MAC_BYTES   16
+
+typedef struct
+{
+  uint32_t key_id;
+  uint8_t mac[N_NTP_MAC_BYTES];    // message authenticator
+} NTP_AUTH_INFO;
+
+#endif
+
+
+typedef struct
+{
+  NTP_BASE_PACKET packet;
+  #if MBG_MD5_AUTH
+    NTP_AUTH_INFO auth_info;
+  #endif
+} NTP_PACKET;
+
+
+
+/* function prototypes: */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* ----- function prototypes begin ----- */
+
+/* This section was generated automatically */
+/* by MAKEHDR, do not remove the comments. */
+
+/* (no header definitions found) */
+
+/* ----- function prototypes end ----- */
+
+#ifdef __cplusplus
+}
+#endif
+
+
+/* End of header body */
+
+#undef _ext
+#undef _DO_INIT
+
+#endif  /* _MBGNTP_H */
+
diff --git a/mbglib/common/words.h b/mbglib/common/words.h
new file mode 100755
index 0000000..5047f16
--- /dev/null
+++ b/mbglib/common/words.h
@@ -0,0 +1,363 @@
+
+/**************************************************************************
+ *
+ *  $Id: words.h 1.32 2014/01/07 15:43:52 martin REL_M $
+ *
+ *  Copyright (c) Meinberg Funkuhren, Bad Pyrmont, Germany
+ *
+ *  Description:
+ *    Definitions of commonly used data types.
+ *
+ * -----------------------------------------------------------------------
+ *  $Log: words.h $
+ *  Revision 1.32  2014/01/07 15:43:52  martin
+ *  Define __mbg_inline for ARM firmware targets.
+ *  Revision 1.31  2012/11/29 11:54:39Z  martin
+ *  Removed #if sizeof() definitions which may cause build errors
+ *  with some older compilers.
+ *  Include stdbool.h for __ARMCC_VERSION targets.
+ *  Moved _nop_macro_fnc() definition here.
+ *  Revision 1.30  2012/11/02 09:12:29Z  martin
+ *  Moved most feature detection code to mbg_tgt.h.
+ *  Tried to define missing features most flexibly and portably.
+ *  Revision 1.29  2012/07/11 16:45:45Z  martin
+ *  New macros to access individual bytes of long constants.
+ *  Revision 1.28  2012/04/05 14:36:18Z  martin
+ *  Support CVI 2010 compiler which provides C99 types.
+ *  Revision 1.27  2011/07/18 10:21:38Z  martin
+ *  Added definition for MBG_CODE_NAME_TABLE_ENTRY which can
+ *  be used to define tables assigning strings to numeric codes.
+ *  Revision 1.26  2011/04/06 10:23:03  martin
+ *  Added FBYTE_OF() and FWORD_OF() macros.
+ *  Modifications required for *BSD.
+ *  Revision 1.25  2010/11/17 10:23:09  martin
+ *  Define _BIT_REDEFINED if bit type is redefined.
+ *  Revision 1.24  2010/11/17 08:44:56Z  martin
+ *  If supported, use type "bool" to implement "bit".
+ *  Revision 1.23  2010/05/27 08:54:30Z  martin
+ *  Support fixed size data types with Keil RealView compiler for ARM.
+ *  Keil RealView ARM targets are always considered as firmware.
+ *  Revision 1.22  2009/10/21 07:53:55  martin
+ *  Undid changes introduced in 1.21 since they were not consistent
+ *  across glibc and/or Linux kernel header versions.
+ *  Revision 1.21  2009/10/01 14:00:17  martin
+ *  Conditionally define ulong and friends also for Linux/glibc.
+ *  Revision 1.20  2009/07/02 15:38:12  martin
+ *  Added new macro _wswap32().
+ *  Revision 1.19  2009/04/14 14:45:45Z  martin
+ *  Added BYTE_OF_P() and WORD_OF_P() macros.
+ *  Revision 1.18  2009/03/27 14:05:18  martin
+ *  Cleanup for CVI.
+ *  Revision 1.17  2009/03/13 09:06:03Z  martin
+ *  Declared bit type for non-firmware environments.
+ *  Revision 1.16  2008/12/05 12:05:41Z  martin
+ *  Define dummy int64_t/uint64_t types for targets
+ *  which don't support 64 bit data types.
+ *  Revision 1.15  2008/07/14 14:44:00Z  martin
+ *  Use fixed size C99 types which come with GCC and newer Borland compilers.
+ *  Revision 1.14  2008/01/30 10:27:50Z  martin
+ *  Moved some macro definitions here.
+ *  Revision 1.13  2007/03/08 15:00:30Z  martin
+ *  Fixed incompatibility of macro _IS_MBG_FIRMWARE.
+ *  Added a workaround for _IS_MBG_FIRMWARE under CVI.
+ *  Support for BSD.
+ *  Revision 1.12  2006/12/15 10:45:46  martin
+ *  Added macro _IS_MBG_FIRMWARE.
+ *  Cleanup for Linux, QNX, and Watcom C.
+ *  Include mbg_tgt.h for non-firmware targets.
+ *  Revision 1.11  2004/11/10 10:45:34  martin
+ *  Added C99 fixed-type handling for QNX.
+ *  Revision 1.10  2004/11/09 13:12:56  martin
+ *  Redefined C99 integer types with fixed sizes as standard types
+ *  if required, depending on the environment.
+ *  Revision 1.9  2003/02/07 11:36:54  MARTIN
+ *  New macros _hilo_16() and _hilo_32() for endian conversion.
+ *  Revision 1.8  2002/05/28 10:09:54  MARTIN
+ *  Added new macros _var_bswap16() and _var_bswap32().
+ *  Revision 1.7  2001/03/14 11:30:48  MARTIN
+ *  Removed definitions for UINT8, UINT16, UINT32.
+ *  Redefined preprocessor control for Win32.
+ *  Revision 1.6  2001/02/28 15:43:20  MARTIN
+ *  Modified preprocessor syntax.
+ *  Revision 1.5  2001/02/05 10:20:53  MARTIN
+ *  Include different Linux types for user space and kernel space programs.
+ *  Source code cleanup.
+ *  Revision 1.4  2000/09/15 08:34:11  MARTIN
+ *  Exclude some definitions if compiling under Win NT.
+ *  Revision 1.3  2000/08/22 15:04:28  MARTIN
+ *  Added new file header.
+ *  Added macros to revert endianess of 16 and 32 bit values.
+ *
+ **************************************************************************/
+
+#ifndef _WORDS_H
+#define _WORDS_H
+
+
+/* Other headers to be included */
+
+
+#if !defined( _IS_MBG_FIRMWARE )
+
+  #if defined( _C166 ) ||    \
+      defined( _CC51 ) ||    \
+      defined( __ARM ) ||    \
+      defined( __ARMCC_VERSION )
+    #define _IS_MBG_FIRMWARE 1
+  #else
+    #define _IS_MBG_FIRMWARE 0
+  #endif
+
+#endif
+
+
+#if !_IS_MBG_FIRMWARE
+  #include <mbg_tgt.h>
+#else
+  #if defined( __ARMCC_VERSION )  // Keil RealView Compiler for ARM
+    #define __mbg_inline __inline
+    #include <stdint.h>
+    #include <stdbool.h>
+    #define MBG_TGT_HAS_EXACT_SIZE_TYPES  1
+  #else
+    #define MBG_TGT_MISSING_64_BIT_TYPES 1
+  #endif
+#endif
+
+
+
+#ifdef _WORDS
+ #define _ext
+#else
+ #define _ext extern
+#endif
+
+
+/* Start of header body */
+
+#if defined( _C166 ) \
+ || defined( _CC51 )
+  #define _BIT_DEFINED        1  // these compilers natively support the "bit" type
+  #define USE_LONG_FOR_INT32  1
+#endif
+
+
+
+#if !defined( MBG_TGT_HAS_EXACT_SIZE_TYPES )
+
+  #if defined( MBG_TGT_HAS_INT_8_16_32 )
+
+    // Define C99 exact size types using non-standard exact-size types
+    typedef __int8 int8_t;
+    typedef unsigned __int8 uint8_t;
+
+    typedef __int16 int16_t;
+    typedef unsigned __int16 uint16_t;
+
+    typedef __int32 int32_t;
+    typedef unsigned __int32 uint32_t;
+
+  #else
+
+    // Assume a 16 or 32 bit compiler which doesn't
+    // support exact-size types.
+
+    typedef char int8_t;
+    typedef unsigned char uint8_t;
+
+    typedef short int16_t;
+    typedef unsigned short uint16_t;
+
+    // Using #if sizeof() to determine the size of a type may not
+    // be supported by all preprocessors, and may even result in
+    // build errors if used in a conditional preprocessor section,
+    // so we can't use this here without compatibility problems.
+
+    #if defined( USE_LONG_FOR_INT32 )
+      typedef long int32_t;
+      typedef unsigned long uint32_t;
+    #elif defined( USE_INT_FOR_INT32 )
+      typedef int int32_t;
+      typedef unsigned int uint32_t;
+    #else
+      #error Need to define int32_t and uint32_t
+    #endif
+
+  #endif
+
+  #if defined( MBG_TGT_MISSING_64_BIT_TYPES )
+
+    // The build environment does not support 64 bit types. However,
+    // 64 bit types need to be defined to avoid build errors
+    // if these types are formally used in function prototypes.
+    // We explicitely use abnormal data types to hopefully
+    // cause compiler errors in case these types are
+    // unexpectedly used to generate real code for a target
+    // platform which does not support 64 bit types.
+    typedef void *int64_t;
+    typedef void *uint64_t;
+
+  #else
+
+    // Define C99 types using non-standard exact-size types
+    // which are usually supported by build envonronments
+    // supporting 64 bit types but no C99 types.
+    typedef __int64 int64_t;
+    typedef unsigned __int64 uint64_t;
+
+  #endif
+
+#endif
+
+
+
+#if defined( MBG_TGT_MISSING_64_BIT_TYPES )
+
+  #define MBG_TGT_HAS_64BIT_TYPES    0
+
+#else
+
+  #define MBG_TGT_HAS_64BIT_TYPES    1
+
+#endif
+
+
+
+// Some commonly used types
+
+typedef unsigned char uchar;
+
+#if !defined( MBG_TGT_LINUX ) \
+  && !( defined ( MBG_TGT_NETBSD ) \
+  && defined ( MBG_TGT_KERNEL ) )
+  typedef unsigned short ushort;
+  typedef unsigned int uint;
+  typedef unsigned long ulong;
+#endif
+
+typedef double udouble;
+
+typedef unsigned char byte;
+typedef unsigned short word;
+typedef unsigned long longword;
+typedef unsigned long dword;
+
+
+#if !defined( _BIT_DEFINED )
+
+  // We need to implement a "bit" type. Preferably we use "bool"
+  // to do this, but this is only supported by C++ compilers, and
+  // by C compilers supporting the C99 standard.
+
+  #if !defined( MBG_TGT_MISSING_BOOL_TYPE ) && \
+    ( defined( __cplusplus ) || defined( __bool_true_false_are_defined ) )
+
+    typedef bool bit;
+
+  #else  // C99 types not supported
+
+    // Falling back to use "int" for "bit". This prevents error
+    // messages if "bit" is used in function prototypes, but may
+    // yield unexpected results for code like:
+    //   return (bit) ( val & 0x10 );
+    typedef int bit;
+
+  #endif
+
+  #define _BIT_REDEFINED  1
+
+#endif
+
+
+#define BYTE_0( _x )  ( ( (ulong) (_x) ) & 0xFF )
+#define BYTE_1( _x )  ( ( ( (ulong) (_x) ) >> 8 ) & 0xFF )
+#define BYTE_2( _x )  ( ( ( (ulong) (_x) ) >> 16 ) & 0xFF )
+#define BYTE_3( _x )  ( ( ( (ulong) (_x) ) >> 24 ) & 0xFF )
+
+
+#define HI_BYTE( _x )      ( (_x) >> 8 )
+#define LO_BYTE( _x )      ( (_x) & 0xFF )
+
+#define HI_WORD( _x )      ( (_x) >> 16 )
+#define LO_WORD( _x )      ( (_x) & 0xFFFF )
+
+// the macros below assume little endianess
+// these macros expect the name of a variable
+#define BYTE_OF( _v, _n )  *( ( (uint8_t *) &(_v) ) + (_n) )
+#define WORD_OF( _v, _n )  *( ( (uint16_t *) &(_v) ) + (_n) )
+
+#define FBYTE_OF( _v, _n )  *( ( (uint8_t far *) &(_v) ) + (_n) )
+#define FWORD_OF( _v, _n )  *( ( (uint16_t far *) &(_v) ) + (_n) )
+
+// same as above, but taking pointers
+#define BYTE_OF_P( _p, _n )  *( ( (uint8_t *) (_p) ) + (_n) )
+#define WORD_OF_P( _p, _n )  *( ( (uint16_t *) (_p) ) + (_n) )
+
+
+// a macro to swap the byte order of a 16 bit value
+#define _bswap16( _x )                        \
+(                                             \
+  ( ( ( (uint16_t) (_x) ) & 0x00FF ) << 8 ) | \
+  ( ( ( (uint16_t) (_x) ) & 0xFF00 ) >> 8 )   \
+)
+
+// a macro to swap the byte order of a 32 bit value
+#define _bswap32( _x )                               \
+(                                                    \
+  ( ( ( (uint32_t) (_x) ) & 0x000000FFUL ) << 24 ) | \
+  ( ( ( (uint32_t) (_x) ) & 0x0000FF00UL ) << 8 )  | \
+  ( ( ( (uint32_t) (_x) ) & 0x00FF0000UL ) >> 8 )  | \
+  ( ( ( (uint32_t) (_x) ) & 0xFF000000UL ) >> 24 )   \
+)
+
+// a macro to swap the word order of a 32 bit value
+#define _wswap32( _x )                               \
+(                                                    \
+  ( ( ( (uint32_t) (_x) ) & 0x0000FFFFUL ) << 16 ) | \
+  ( ( ( (uint32_t) (_x) ) >> 16 ) & 0x0000FFFFUL )   \
+)
+
+#define _var_bswap16( _v )   (_v) = _bswap16( _v )
+#define _var_bswap32( _v )   (_v) = _bswap32( _v )
+
+
+// The C51 compiler is big-endian, that means the most
+// significant byte of a 16 or 32 bit value is stored in
+// the lowest memory location. Most other systems are
+// little-endian, so we must use macros to adjust the
+// byte order if the C51 is used.
+
+#if defined( _CC51 )
+  #define _hilo_16( _x )  _bswap16( _x )
+  #define _hilo_32( _x )  _bswap32( _x )
+#else
+  #define _hilo_16( _x )  (_x)
+  #define _hilo_32( _x )  (_x)
+#endif
+
+
+// A macro function which can safely be used without
+// side effects as a macro doing nothing.
+// This is useful to define debug macros away in 
+// release builds, etc.
+#if !defined( _nop_macro_fnc )
+  #define _nop_macro_fnc()     do {} while (0)
+#endif
+
+
+/**
+ * @brief A table entry which can be used to map codes to names.
+ */
+typedef struct
+{
+  ulong code;
+  const char *name;
+} MBG_CODE_NAME_TABLE_ENTRY;
+
+
+
+/* End of header body */
+
+#undef _ext
+
+#endif  /* _WORDS_H */
diff --git a/ntptest.c b/ntptest.c
new file mode 100755
index 0000000..1066b08
--- /dev/null
+++ b/ntptest.c
@@ -0,0 +1,310 @@
+
+/**************************************************************************
+ *
+ *  $Id: ntptest.c 1.1 2014/04/01 13:02:21 martin REL_M $
+ *
+ *  Copyright (c) Meinberg Funkuhren, Bad Pyrmont, Germany
+ *
+ *  Description:
+ *    Main module for ntptest program. Sends one or several client
+ *    request packets to an NTP server, receives the replies and
+ *    prints NTP statistics.
+ *
+ * -----------------------------------------------------------------------
+ *  $Log: ntptest.c $
+ *  Revision 1.1  2014/04/01 13:02:21  martin
+ *  Initial revision.
+ *
+ **************************************************************************/
+
+#include <mbg_ntp_test_util.h>
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <time.h>
+#include <errno.h>
+#include <netdb.h>
+
+
+static const char program_name[] = "ntptest";
+
+static const char program_version[] = "v1.0";
+static const char program_copyright[] = "(c) Meinberg 2014";
+static const char program_contact[] = "contact: <martin.burnicki@meinberg.de>";
+
+
+#define RCV_TIMEOUT              400  // [msec]
+
+
+
+// parameters which can to some extent be modified via command
+// line options to control the program's behaviour
+
+static int run_continuously;         // -c
+static int sleep_intv = 1;           // -s, [sec], sleep interval between requests, default 1
+static int prot_version;             // -V, protocol version to be used
+static unsigned long rcv_timeout;    // -T, [msec] receive timeout after request sent
+
+static const char *tgt_host;            // target hostname or IP address
+static struct sockaddr_in tgt_addr;     // target address
+
+static int must_print_usage;
+static NTP_PACKET default_ntp_req_packet;       // template of request packet
+
+static QUERY_STATS glb_query_stats;
+
+
+
+/*HDR*/
+void mbglog( int priority, const char *fmt, ... )
+{
+  char s[300];
+
+  va_list ap;
+
+  va_start( ap, fmt);
+  vsnprintf( s, sizeof( s ), fmt, ap );
+  va_end(ap);
+
+  fprintf( stderr, "%s\n", s );
+
+}  // mbglog
+
+
+
+//
+// send query packet(s) to a host, wait for a response
+// and evaluate the response packet
+//
+static /*HDR*/
+void do_ntp_queries( void )
+{
+  fd_set read_set;
+  struct timeval tv_timeout;
+  struct timespec tsr_req;  // time stamp when request was sent
+  struct timespec tsr_rcv;  // time stamp when response arrived
+  NTP_TSTAMP t_req_ntp;     // tv_req converted to NTP format
+  NTP_PACKET ntp_req_packet;  // set up from template
+  NTP_PACKET rcv_buffer;
+  void *req_packet;
+  int req_packet_size;
+  ssize_t rcv_packet_size;
+  int sockfd;
+  int rc;
+  struct sockaddr_in si_src;
+  socklen_t slen_src;
+
+
+  sockfd = socket( AF_INET, SOCK_DGRAM, IPPROTO_UDP );   // create socket on which to send
+
+  if ( sockfd < 0 )
+  {
+    mbglog( LOG_ERR, "Failed to open UDP socket in %s: %s", __func__, strerror( errno ) );
+    exit( 1 );
+  }
+
+
+  ntp_req_packet = default_ntp_req_packet;
+
+  for (;;)
+  {
+    // get time stamp when request packet was sent
+    clock_gettime( CLOCK_REALTIME, &tsr_req );
+
+    timespec_to_ntp_tstamp( &t_req_ntp, &tsr_req );
+
+    ntp_req_packet.packet.transmit_time = t_req_ntp;
+    ntoh_ntp_time( &ntp_req_packet.packet.transmit_time );
+
+    req_packet = &ntp_req_packet;
+    req_packet_size = sizeof( ntp_req_packet );
+
+    // send request packet
+    if ( sendto( sockfd, req_packet, req_packet_size, 0,
+                 (__const__ struct sockaddr *) &tgt_addr,
+                 sizeof( tgt_addr ) ) < 0 )
+    {
+      mbglog( LOG_ERR, "Failed to send UDP packet in %s: %s", __func__, strerror( errno ) );
+      exit( 1 );
+    }
+
+    glb_query_stats.requests++;
+
+
+    FD_ZERO( &read_set );
+    FD_SET( sockfd, &read_set );
+
+    tv_timeout.tv_sec = 0;
+    tv_timeout.tv_usec = rcv_timeout * 1000;
+
+    rc = select( sockfd + 1, &read_set, NULL, NULL, &tv_timeout );
+
+    if ( rc < 0 )  // select() failed
+    {
+      mbglog( LOG_ERR, "Select failed in %s: %s", __func__, strerror( errno ) );
+      break;
+    }
+
+    if ( rc == 0 )  // select() timed out
+    {
+      mbglog( LOG_ERR, "Timeout waiting for reply packet, exiting." );
+      exit( 1 );
+    }
+
+    // read response packet
+    slen_src = sizeof( si_src ) ;
+    rcv_packet_size = recvfrom( sockfd, &rcv_buffer, sizeof( rcv_buffer ), 0,
+                                (struct sockaddr *) &si_src, &slen_src );
+
+    if ( rcv_packet_size < 0 )
+    {
+      mbglog( LOG_ERR, "Failed to receive from UDP socket in %s: %s", __func__, strerror( errno ) );
+      continue;
+    }
+
+    // get time stamp when response was received
+    clock_gettime( CLOCK_REALTIME, &tsr_rcv );
+
+    rc = eval_ntp_packet( &rcv_buffer, &ntp_req_packet, &tsr_rcv,
+                          &tsr_req, &t_req_ntp, &glb_query_stats );
+
+    if ( !run_continuously )
+      break;
+
+    sleep( sleep_intv );
+  }
+
+  close( sockfd );
+
+}  // do_ntp_queries
+
+
+
+static /*HDR*/
+void usage( void )
+{
+  printf( "\n" );
+  printf( "Usage:  %s [[OPTION]...] <host>\n", program_name );
+  printf( "\n" );
+  printf( "Send NTP client requests to an NTP server with IP address or\n"
+          "hostname <host>, show the sent and received packets,\n"
+          "and evaluate the results.\n" );
+  printf( "\n" );
+  printf( "[OPTION] can be one of the following:\n" );
+  printf( "  -c          run continuously\n" );
+  printf( "  -s n        n seconds delay between queries, default: %i s\n", sleep_intv );
+  printf( "  -V n        NTP protocol version, %i..%i, default: %i\n",
+                         MIN_REQ_NTP_VERSION, MAX_REQ_NTP_VERSION, DEFAULT_REQ_NTP_VERSION );
+  printf( "  -T n        packet receive timeout [ms], default: %u\n", RCV_TIMEOUT );
+  printf( "  -?, -h      print this usage information\n"
+          "\n" );
+
+}  // usage
+
+
+
+static /*HDR*/
+void check_options( int argc, char *argv[] )
+{
+  char c;
+
+  while ( ( c = getopt( argc, argv, "cs:V:T:h?" ) ) != -1 )
+  {
+    switch ( c )
+    {
+      case 'c':
+        run_continuously = 1;
+        break;
+
+
+      case 's':
+        sleep_intv = strtol( optarg, NULL, 10 );
+
+        if ( sleep_intv < 1 )
+          sleep_intv = 1;
+
+        break;
+
+
+      case 'V':
+        prot_version = strtol( optarg, NULL, 10 );
+        break;
+
+
+      case 'T':
+        rcv_timeout = strtoul( optarg, NULL, 10 );
+        break;
+
+      case 'h':
+      case '?':
+      default:
+        must_print_usage = 1;
+    }
+  }
+
+}  // check_options
+
+
+
+int main( int argc, char *argv[] )
+{
+  struct hostent *p_hostent;
+
+  fprintf( stderr, "\n%s %s, %s, %s\n\n", program_name, program_version,
+           program_copyright, program_contact );
+
+  check_options( argc, argv );
+
+  if ( rcv_timeout == 0 )
+    rcv_timeout = RCV_TIMEOUT;
+
+  prot_version = check_bounds( prot_version, MIN_REQ_NTP_VERSION,
+                               MAX_REQ_NTP_VERSION, DEFAULT_REQ_NTP_VERSION );
+
+  if ( ( argc - optind ) > 0 )  // a host name has been specified
+    tgt_host = argv[optind];
+  else
+    must_print_usage = 1;       // required in client mode
+
+  if ( must_print_usage )
+  {
+    usage();
+    return 1;
+  }
+
+
+  if ( tgt_host )
+  {
+    // Construct name, with no wildcards, of the socket to send to.
+    // getnostbyname() returns a structure including the network address
+    // of the specified host.
+    p_hostent = gethostbyname( tgt_host );
+
+    if ( p_hostent == 0 )
+    {
+      mbglog( LOG_ERR, "Unknown host %s: (error code %i)", tgt_host, h_errno );
+      exit( 2 );
+    }
+
+    // set up host info for sending
+    memset( &tgt_addr, 0, sizeof( tgt_addr ) );
+    memcpy( &tgt_addr.sin_addr, p_hostent->h_addr, p_hostent->h_length );
+    tgt_addr.sin_family = AF_INET;
+    tgt_addr.sin_port = htons( NTP_PORT );
+  }
+
+
+  reset_query_stats( &glb_query_stats );
+
+  // setup packet templates
+  init_ntp_req_packet( &default_ntp_req_packet, MODE_CLIENT, prot_version );
+
+  printf( "Host %s%s\n", tgt_host, run_continuously ? ", running continuously" : "" );
+
+  do_ntp_queries();
+
+  return 0;
+}