Adding upstream version 4.0.upstream/4.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

109 files changed, 8622 insertions, 0 deletions

diff --git a/test/compilation/001-features b/test/compilation/001-features
new file mode 100755
index 0000000..9bd340f
--- /dev/null
+++ b/test/compilation/001-features
@@ -0,0 +1,36 @@
+#!/bin/sh
+
+# Try to compile chrony in various combinations of disabled features
+
+cd ../..
+
+export CFLAGS="-O2 -Werror -Wpointer-arith -Wformat-signedness -Wno-unknown-warning-option -D_FORTIFY_SOURCE=2"
+
+for opts in \
+	"--enable-debug" \
+	"--enable-ntp-signd" \
+	"--enable-scfilter" \
+	"--disable-asyncdns" \
+	"--disable-ipv6" \
+	"--disable-privdrop" \
+	"--disable-readline" \
+	"--disable-rtc" \
+	"--disable-sechash" \
+	"--disable-cmdmon" \
+	"--disable-cmdmon --enable-scfilter" \
+	"--disable-ntp" \
+	"--disable-ntp --enable-scfilter" \
+	"--disable-nts" \
+	"--disable-refclock" \
+	"--disable-timestamping" \
+	"--disable-timestamping --disable-ntp" \
+	"--disable-cmdmon --disable-ntp" \
+	"--disable-cmdmon --disable-ntp --enable-scfilter" \
+	"--disable-cmdmon --disable-refclock" \
+	"--disable-cmdmon --disable-ntp --disable-refclock"
+do
+	./configure $opts || exit 1
+	make clean
+	make "$@" || exit 1
+	make -C test/unit check || exit 1
+done
diff --git a/test/compilation/002-scanbuild b/test/compilation/002-scanbuild
new file mode 100755
index 0000000..da87407
--- /dev/null
+++ b/test/compilation/002-scanbuild
@@ -0,0 +1,15 @@
+#!/bin/sh
+
+cd ../..
+
+for opts in \
+	"--host-system=Linux" \
+	"--host-system=NetBSD" \
+	"--host-system=FreeBSD" \
+	"--without-nettle" \
+	"--without-nettle --without-nss" \
+	"--without-nettle --without-nss --without-tomcrypt"
+do
+	./configure $opts
+	scan-build make "$@" || exit 1
+done
diff --git a/test/compilation/003-sanitizers b/test/compilation/003-sanitizers
new file mode 100755
index 0000000..4da9aa3
--- /dev/null
+++ b/test/compilation/003-sanitizers
@@ -0,0 +1,88 @@
+#!/bin/bash
+# Run the unit and simulation tests with different compiler sanitizers
+# and under valgrind
+
+cd ../..
+
+if [ "$(uname -sm)" != "Linux x86_64" ]; then
+  echo Test supported on Linux x86_64 only
+  exit 1
+fi
+
+[ -f /etc/os-release ] && . /etc/os-release
+
+if [ "$ID" = "fedora" ]; then
+  echo Checking test dependencies:
+  rpm -q {valgrind,gcc,clang}.x86_64 {libgcc,clang-libs}.{x86_64,i686} || exit 1
+  rpm -q {libseccomp,nettle,nss-softokn-freebl,libtomcrypt,gnutls}-devel.{x86_64,i686} || exit 1
+  echo
+fi
+
+touch Makefile
+
+for CC in gcc clang; do
+  export CC
+
+  for arch_opts in "-m32" ""; do
+    pushd test/simulation/clknetsim || exit 1
+    make clean > /dev/null 2>&1
+    CFLAGS="$arch_opts -DCLKNETSIM_DISABLE_SYSCALL" make "$@" || exit 1
+    echo
+
+    popd
+
+    for extra_config_opts in \
+      "--all-privops" \
+      "--disable-scfilter" \
+      "--without-gnutls" \
+      "--without-nettle" \
+      "--without-nettle --without-nss" \
+      "--without-nettle --without-nss --without-tomcrypt"; \
+    do
+      for san_options in "" "-fsanitize=address" "-fsanitize=memory"; do
+        export CFLAGS="-O2 -g -fsanitize=undefined -fsanitize=float-divide-by-zero -fno-sanitize-recover=undefined,float-divide-by-zero $san_options $arch_opts"
+
+        # clang msan doesn't work on i686 and otherwise requires patches
+        echo $CFLAGS | grep -q 'sanitize=memory' && continue
+
+        # build fails with clang ubsan on i686 (Fedora only?)
+        [ "$arch_opts" = "-m32" -a "$CC" = "clang" ] && continue
+
+        [ "$CC" = "gcc" ] && echo $CFLAGS | grep -q 'sanitize=address' && CFLAGS="$CFLAGS -static-libasan"
+
+        config_opts="--with-user=chrony --enable-debug --enable-scfilter --enable-ntp-signd $extra_config_opts"
+
+        echo -----------------------------------------------------------------------------
+        echo CC=\"$CC\" CFLAGS=\"$CFLAGS\" ./configure $config_opts
+
+        make distclean > /dev/null 2>&1
+
+        ./configure $config_opts || exit 1
+
+        if echo "$config_opts" | grep -q all-privops; then
+          for op in ADJUSTTIME ADJUSTTIMEX SETTIME BINDSOCKET; do
+            echo "#define PRIVOPS_$op 1" >> config.h
+          done
+        fi
+
+        make "$@" || exit 1
+
+        [ -n "$BUILD_TEST_ONLY" ] && continue
+
+        echo
+        pushd test/unit || exit 1
+        if [ "$san_options" = "" ]; then
+          make check TEST_WRAPPER="valgrind --error-exitcode=1" || exit 1
+        else
+          make check || exit 1
+        fi
+        popd
+
+        echo
+        pushd test/simulation || exit 1
+        CLKNETSIM_RANDOM_SEED=101 ./run -i 1 || exit 1
+        popd
+      done
+    done
+  done
+done
diff --git a/test/kernel/Makefile b/test/kernel/Makefile
new file mode 100644
index 0000000..6ec8341
--- /dev/null
+++ b/test/kernel/Makefile
@@ -0,0 +1,7 @@
+CFLAGS=-O2 -Wall
+PROGS=adjtime ntpadjtime
+
+all: $(PROGS)
+
+clean:
+	rm -f $(PROGS)
diff --git a/test/kernel/adjtime.c b/test/kernel/adjtime.c
new file mode 100644
index 0000000..0ca8ff2
--- /dev/null
+++ b/test/kernel/adjtime.c
@@ -0,0 +1,185 @@
+/*
+ * Copyright (C) Miroslav Lichvar  2015
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+/* Test the system adjtime() function. Check the range of supported offset,
+   support for readonly operation, and slew rate with different update
+   intervals and offsets. */
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+static int
+diff_tv(struct timeval *tv1, struct timeval *tv2)
+{
+  return 1000000 * (tv1->tv_sec - tv2->tv_sec) + (tv1->tv_usec - tv2->tv_usec);
+}
+
+static struct timeval
+usec_to_tv(int usec)
+{
+  struct timeval tv;
+
+  tv.tv_sec = usec / 1000000;
+  tv.tv_usec = usec % 1000000;
+
+  return tv;
+}
+
+static int
+try_adjtime(struct timeval *new, struct timeval *old)
+{
+  int r;
+
+  r = adjtime(new, old);
+  if (r)
+    printf("adjtime() failed : %s ", strerror(errno));
+  return r;
+}
+
+static void
+reset_adjtime(void)
+{
+  struct timeval tv;
+
+  tv = usec_to_tv(0);
+  try_adjtime(&tv, NULL);
+}
+
+static void
+test_range(void)
+{
+  struct timeval tv;
+  int i;
+
+  printf("range:\n");
+
+  for (i = 0; i < sizeof (time_t) * 8; i++) {
+    tv.tv_usec = 0;
+    tv.tv_sec = (1ULL << i) - 1;
+    printf("%20lld s : ", (long long)tv.tv_sec);
+    printf("%s\n", !try_adjtime(&tv, NULL) ? "ok" : "");
+    tv.tv_sec = ~tv.tv_sec;
+    printf("%20lld s : ", (long long)tv.tv_sec);
+    printf("%s\n", !try_adjtime(&tv, NULL) ? "ok" : "");
+  }
+}
+
+static void
+test_readonly(void)
+{
+  struct timeval tv1, tv2;
+  int i, r;
+
+  printf("readonly:\n");
+
+  for (i = 0; i <= 20; i++) {
+    tv1 = usec_to_tv(1 << i);
+
+    printf("%9d us : ", 1 << i);
+    try_adjtime(&tv1, NULL);
+    r = !try_adjtime(NULL, &tv2) && !diff_tv(&tv1, &tv2);
+    printf("%s\n", r ? "ok" : "fail");
+  }
+}
+
+static void
+test_readwrite(void)
+{
+  struct timeval tv1, tv2, tv3;
+  int i, r;
+
+  printf("readwrite:\n");
+
+  for (i = 0; i <= 20; i++) {
+    tv1 = usec_to_tv(1 << i);
+    tv3 = usec_to_tv(0);
+
+    printf("%9d us : ", 1 << i);
+    try_adjtime(&tv1, NULL);
+    r = !try_adjtime(&tv3, &tv2) && !diff_tv(&tv1, &tv2);
+    printf("%s\n", r ? "ok" : "fail");
+  }
+}
+
+static void
+xusleep(int usec)
+{
+  struct timeval tv;
+
+  tv = usec_to_tv(usec);
+  select(0, NULL, NULL, NULL, &tv);
+}
+
+static void
+test_slew(void)
+{
+  struct timeval tv1, tv2, tv3;
+  int i, j, k, diff, min, has_min;
+
+  printf("slew:\n");
+
+  for (i = 9; i <= 20; i++) {
+    printf("%9d us : ", 1 << i);
+    for (j = 4; j <= 20; j += 4) {
+      for (min = has_min = 0, k = 4; k < 16; k += 2) {
+
+        tv1 = usec_to_tv(1 << j);
+        tv3 = usec_to_tv(0);
+
+        xusleep(1 << i);
+        reset_adjtime();
+
+        xusleep(1 << i);
+        if (try_adjtime(&tv1, NULL))
+          continue;
+
+        xusleep(1 << i);
+        if (try_adjtime(&tv3, &tv2))
+          continue;
+
+        diff = diff_tv(&tv1, &tv2);
+        if (!has_min || min > diff) {
+          min = diff;
+          has_min = 1;
+        }
+      }
+
+      if (!has_min)
+        continue;
+
+      printf(" %5d (%d)", min, 1 << j);
+      fflush(stdout);
+    }
+    printf("\n");
+  }
+}
+
+int
+main()
+{
+  test_range();
+  test_readonly();
+  test_readwrite();
+  test_slew();
+
+  reset_adjtime();
+
+  return 0;
+}
diff --git a/test/kernel/ntpadjtime.c b/test/kernel/ntpadjtime.c
new file mode 100644
index 0000000..4af96b4
--- /dev/null
+++ b/test/kernel/ntpadjtime.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) Miroslav Lichvar  2015
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+/* Check the frequency range of the system ntp_adjtime() implementation */
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/timex.h>
+
+static int
+try_ntpadjtime(struct timex *t)
+{
+  int r;
+  r = ntp_adjtime(t);
+  if (r < 0)
+    printf("ntp_adjtime() failed : %s ", strerror(errno));
+  return r;
+}
+
+static void
+reset_ntpadjtime(void)
+{
+  struct timex t;
+
+  t.modes = MOD_OFFSET | MOD_FREQUENCY;
+  t.offset = 0;
+  t.freq = 0;
+  try_ntpadjtime(&t);
+}
+
+static void
+test_freqrange(void)
+{
+  struct timex t;
+  int i;
+
+  printf("freq range:\n");
+
+  for (i = -1000; i <= 1000; i += 50) {
+    t.modes = MOD_FREQUENCY;
+    t.freq = i * (1 << 16);
+    printf("%4d ppm => ", i);
+    if (try_ntpadjtime(&t) < 0)
+      continue;
+
+    printf("%4ld ppm : ", t.freq / (1 << 16));
+    printf("%s\n", t.freq == i * (1 << 16) ? "ok" : "fail");
+  }
+}
+
+int
+main()
+{
+  test_freqrange();
+
+  reset_ntpadjtime();
+
+  return 0;
+}
diff --git a/test/simulation/001-defaults b/test/simulation/001-defaults
new file mode 100755
index 0000000..541cdad
--- /dev/null
+++ b/test/simulation/001-defaults
@@ -0,0 +1,13 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "default test settings"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/002-largenetwork b/test/simulation/002-largenetwork
new file mode 100755
index 0000000..fd41106
--- /dev/null
+++ b/test/simulation/002-largenetwork
@@ -0,0 +1,22 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "large network"
+
+time_rms_limit=5e-4
+
+server_strata=3
+servers=4
+clients=5
+
+client_start=2000
+min_sync_time=2100
+max_sync_time=2300
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/003-largefreqoffset b/test/simulation/003-largefreqoffset
new file mode 100755
index 0000000..7210662
--- /dev/null
+++ b/test/simulation/003-largefreqoffset
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "large frequency offset"
+
+max_sync_time=1000
+
+for freq_offset in -5e-2 -5e-3 5e-3 5e-2; do
+	# Adjust offset so it's close to 0 on first clock update
+	time_offset=$(awk "BEGIN {print -($freq_offset * 130)}")
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/004-largetimeoffset b/test/simulation/004-largetimeoffset
new file mode 100755
index 0000000..5d8e2b6
--- /dev/null
+++ b/test/simulation/004-largetimeoffset
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "large time offset"
+
+min_sync_time=1300
+max_sync_time=1400
+
+for time_offset in -1e2 1e2; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/005-externalstep b/test/simulation/005-externalstep
new file mode 100755
index 0000000..709c8a8
--- /dev/null
+++ b/test/simulation/005-externalstep
@@ -0,0 +1,46 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "external time step"
+
+min_sync_time=1500
+max_sync_time=1550
+
+for step in -1e2 1e2; do
+	# Make one step in 150th second
+	client_step="(* $step (equal 0.1 (sum 1.0) 150))"
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+min_sync_time=5120
+max_sync_time=6200
+client_conf="makestep 1 -1"
+
+for step in -1e8 -1e5 1e5 1e8; do
+	# Make one step in 5000th second
+	client_step="(* $step (equal 0.1 (sum 1.0) 5000))"
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+min_sync_time=$default_min_sync_time
+max_sync_time=$default_max_sync_time
+time_max_limit=2e4
+time_rms_limit=8e3
+
+for step in -1e4 1e4; do
+	# Make a step every 500 seconds
+	client_step="(* $step (equal 0.1 (% (sum 1.0) 500) 0))"
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/006-largejitter b/test/simulation/006-largejitter
new file mode 100755
index 0000000..f70e63c
--- /dev/null
+++ b/test/simulation/006-largejitter
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "large jitter"
+
+time_offset=1e0
+jitter=1e-1
+
+time_max_limit=5e-1
+freq_max_limit=2e-1
+time_rms_limit=1e-1
+freq_rms_limit=5e-3
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/007-largewander b/test/simulation/007-largewander
new file mode 100755
index 0000000..5572cbc
--- /dev/null
+++ b/test/simulation/007-largewander
@@ -0,0 +1,20 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "large wander"
+
+wander=1e-7
+
+time_max_limit=5e-3
+freq_max_limit=5e-3
+time_rms_limit=1e-3
+freq_rms_limit=1e-4
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/008-ntpera b/test/simulation/008-ntpera
new file mode 100755
index 0000000..360a97d
--- /dev/null
+++ b/test/simulation/008-ntpera
@@ -0,0 +1,40 @@
+#!/bin/bash
+
+. ./test.common
+test_start "NTP eras"
+
+# Assume NTP_ERA_SPLIT is between years 1960 and 1990
+
+# Set date to 500 seconds before NTP second overflows, this should
+# work correctly with both 32-bit and 64-bit time_t
+export CLKNETSIM_START_DATE=$(date -d 'Feb  7 06:19:56 UTC 2036' +'%s')
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+# The following tests need 64-bit time_t
+check_config_h 'HAVE_LONG_TIME_T 1' || test_skip
+
+for year in 1990 2090; do
+	export CLKNETSIM_START_DATE=$(date -d "Jan  1 00:00:00 UTC $year" +'%s')
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+for year in 1950 2130; do
+	export CLKNETSIM_START_DATE=$(date -d "Jan  1 00:00:00 UTC $year" +'%s')
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	# This check is expected to fail
+	check_sync && test_fail
+done
+
+test_pass
diff --git a/test/simulation/009-sourceselection b/test/simulation/009-sourceselection
new file mode 100755
index 0000000..7e60931
--- /dev/null
+++ b/test/simulation/009-sourceselection
@@ -0,0 +1,40 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "source selection"
+
+# Falsetickers should be detected if their number is less than half of all
+
+base_delay=1e-3
+servers=5
+
+for falsetickers in 1 2; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+for falsetickers in 3 4; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	# These check are expected to fail
+	check_source_selection && test_fail
+	check_sync && test_fail
+done
+
+# Sources with large asymmetric delay should be excluded
+
+servers=3
+falsetickers=0
+base_delay="(+ 1e-3 (equal 0.1 to 2) (equal 0.1 to 3))"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/010-multrecv b/test/simulation/010-multrecv
new file mode 100755
index 0000000..8adfab6
--- /dev/null
+++ b/test/simulation/010-multrecv
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+. ./test.common
+
+export CLKNETSIM_RECV_MULTIPLY=4
+
+test_start "multiple received packets"
+
+limit=50000
+client_server_options="minpoll 6 maxpoll 6"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/011-asymjitter b/test/simulation/011-asymjitter
new file mode 100755
index 0000000..18e6ec1
--- /dev/null
+++ b/test/simulation/011-asymjitter
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "asymmetric jitter"
+
+jitter=5e-4
+jitter_asymmetry=0.47
+limit=100000
+max_sync_time=2000
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/012-daemonts b/test/simulation/012-daemonts
new file mode 100755
index 0000000..b883516
--- /dev/null
+++ b/test/simulation/012-daemonts
@@ -0,0 +1,15 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "daemon timestamping"
+
+export CLKNETSIM_TIMESTAMPING=0
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/013-nameserv b/test/simulation/013-nameserv
new file mode 100755
index 0000000..84f0c8d
--- /dev/null
+++ b/test/simulation/013-nameserv
@@ -0,0 +1,15 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "name resolving"
+
+dns=1
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/101-poll b/test/simulation/101-poll
new file mode 100755
index 0000000..cb3647f
--- /dev/null
+++ b/test/simulation/101-poll
@@ -0,0 +1,30 @@
+#!/bin/bash
+
+. ./test.common
+test_start "minpoll/maxpoll options"
+
+wander=0.0
+jitter=1e-6
+
+time_max_limit=1e-5
+freq_max_limit=1e-5
+time_rms_limit=5e-6
+freq_rms_limit=5e-6
+client_conf="makestep 1e-2 1"
+
+for poll in $(seq 1 14); do
+	client_server_options="minpoll $poll maxpoll $poll"
+	limit=$[2**$poll * 10]
+	min_sync_time=$[2**$poll * 2]
+	max_sync_time=$[2**$poll * 21 / 10 + 1]
+	client_max_min_out_interval=$(awk "BEGIN {print 2^$poll * 1.1}")
+	client_min_mean_out_interval=$(awk "BEGIN {print 2^$poll * 0.99}")
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/102-iburst b/test/simulation/102-iburst
new file mode 100755
index 0000000..bd82530
--- /dev/null
+++ b/test/simulation/102-iburst
@@ -0,0 +1,23 @@
+#!/bin/bash
+
+. ./test.common
+test_start "iburst option"
+
+freq_offset=1e-4
+
+client_conf="makestep 1e-2 1
+driftfile tmp/drift"
+client_server_options="iburst"
+
+min_sync_time=4
+max_sync_time=6
+
+echo "100 1.0" > tmp/drift
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/103-initstepslew b/test/simulation/103-initstepslew
new file mode 100755
index 0000000..303020e
--- /dev/null
+++ b/test/simulation/103-initstepslew
@@ -0,0 +1,32 @@
+#!/bin/bash
+
+. ./test.common
+test_start "initstepslew directive"
+
+freq_offset=0.0
+wander=0.0
+time_rms_limit=1e-3
+limit=100
+
+client_conf="initstepslew 5 192.168.123.1"
+
+min_sync_time=6
+max_sync_time=35
+
+for time_offset in -2.0 -0.2 0.2 2.0; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+min_sync_time=5
+max_sync_time=5
+
+for time_offset in -1e8 -1e2 1e2 1e8; do
+	run_test || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/104-driftfile b/test/simulation/104-driftfile
new file mode 100755
index 0000000..703dad7
--- /dev/null
+++ b/test/simulation/104-driftfile
@@ -0,0 +1,23 @@
+#!/bin/bash
+
+. ./test.common
+test_start "driftfile directive"
+
+servers=0
+time_offset=0.0
+wander=0.0
+limit=10
+freq_max_limit=1e-9
+min_sync_time=1
+max_sync_time=1
+client_conf="driftfile tmp/drift"
+
+for freq_offset in -5e-2 -5e-4 -5e-6 5e-6 5e-4 5e-2; do
+	awk "BEGIN {printf \"%.9e 1\", 1e6 - 1 / (1 + $freq_offset) * 1e6}" > tmp/drift
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/105-ntpauth b/test/simulation/105-ntpauth
new file mode 100755
index 0000000..9503138
--- /dev/null
+++ b/test/simulation/105-ntpauth
@@ -0,0 +1,96 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "NTP authentication"
+
+server_conf="keyfile tmp/server.keys"
+client_conf="keyfile tmp/client.keys"
+
+cat > tmp/server.keys <<-EOF
+1 MD5 HEX:6B5D3C6A2E4A74775E4F6F3B7A35453E6E5C5F302D783D2979505C663C295A5E
+2 MD5 HEX:6B5D3C6A2E4A74775E4F6F3B7A35453E6E5C5F302D783D2979505C663C295A5E
+3 MD5 HEX:6B5D3C6A2E4A74775E4F6F3B7A35453E6E5C5F302D783D2979505C663C295A5E
+4 MD5 HEX:6B5D3C6A2E4A74775E4F6F3B7A35453E6E5C5F302D783D2979505C663C295A5E
+EOF
+
+cat > tmp/client.keys <<-EOF
+1 k]<j.Jtw^Oo;z5E>n\_0-x=)yP\f<)Z^
+2 ASCII:k]<j.Jtw^Oo;z5E>n\_0-x=)yP\f<)Z^
+3 MD5 ASCII:k]<j.Jtw^Oo;z5E>n\_0-x=)yP\f<)Z^
+4 MD5 HEX:6B5D3C6A2E4A74775E4F6F3B7A35453E6E5C5F302D783D2979505C663C295A5E
+EOF
+
+keys=4
+
+types="MD5"
+check_config_h 'FEAT_SECHASH 1' && types="$types SHA1 SHA256 SHA384 SHA512"
+check_config_h 'HAVE_CMAC 1' && types="$types AES128 AES256"
+
+for type in $types; do
+	keys=$[$keys + 1]
+	case $type in
+		AES128)	length=16;;
+		AES256)	length=32;;
+		*)	length=$[$RANDOM % 32 + 1];;
+	esac
+
+	key=$(echo $keys $type HEX:$(tr -c -d '0-9A-F' < /dev/urandom 2> /dev/null | \
+		head -c $[$length * 2]))
+	echo "$key" >> tmp/server.keys
+	echo "$key" >> tmp/client.keys
+done
+
+for version in 3 4; do
+	for key in $(seq $keys); do
+		client_server_options="version $version key $key"
+		run_test || test_fail
+		check_chronyd_exit || test_fail
+		check_source_selection || test_fail
+		check_packet_interval || test_fail
+		check_sync || test_fail
+	done
+done
+
+server_conf=""
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+# This check must fail as the server doesn't know the key
+check_sync && test_fail
+check_packet_interval || test_fail
+
+server_conf="keyfile tmp/server.keys"
+client_conf=""
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+# This check must fail as the client doesn't know the key
+check_sync && test_fail
+check_packet_interval || test_fail
+
+client_conf="keyfile tmp/client.keys"
+clients=2
+peers=2
+max_sync_time=500
+base_delay="$default_base_delay (* -1 (equal 0.1 from 3) (equal 0.1 to 1))"
+
+for versions in "3 3" "3 4" "4 3" "4 4"; do
+	for key in 1 $keys; do
+		client_lpeer_options="version ${versions% *} key $key"
+		client_rpeer_options="version ${versions#* } key $key"
+		run_test || test_fail
+		check_chronyd_exit || test_fail
+		check_sync || test_fail
+	done
+done
+
+client_lpeer_options="key 1"
+client_rpeer_options="key 2"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+# This check must fail as the peers are using different keys"
+check_sync && test_fail
+
+test_pass
diff --git a/test/simulation/106-refclock b/test/simulation/106-refclock
new file mode 100755
index 0000000..c4cec20
--- /dev/null
+++ b/test/simulation/106-refclock
@@ -0,0 +1,34 @@
+#!/bin/bash
+
+. ./test.common
+test_start "SHM refclock"
+
+check_config_h 'FEAT_REFCLOCK 1' || test_skip
+check_config_h 'FEAT_PHC 1' || test_skip
+check_config_h 'FEAT_CMDMON 1' || test_skip
+
+servers=0
+limit=1000
+refclock_jitter=$jitter
+min_sync_time=45
+max_sync_time=70
+chronyc_start=70
+chronyc_conf="tracking"
+
+for refclock in "SHM 0" "PHC /dev/ptp0"; do
+	client_conf="refclock $refclock stratum 3 delay 1e-3 refid GPS"
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
+	check_chronyc_output "^Reference ID.*47505300 \(GPS\)
+Stratum.*: 4
+.*
+Root delay      : 0.001000000 seconds
+.*
+Update interval : 16\.. seconds
+.*$" || test_fail
+done
+
+test_pass
diff --git a/test/simulation/107-allowdeny b/test/simulation/107-allowdeny
new file mode 100755
index 0000000..3ab83ff
--- /dev/null
+++ b/test/simulation/107-allowdeny
@@ -0,0 +1,48 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "allow/deny directives"
+
+check_config_h 'FEAT_CMDMON 1' || test_skip
+
+limit=500
+
+# Note that start_client in clknetsim.bash always adds allow to the config
+
+for server_conf in \
+	"deny" \
+	"deny all" \
+	"deny 192.168.0.0/16" \
+	"deny 192.168.123" \
+	"deny 192.168.123.2" \
+	"deny all
+allow 192.168.124.0/24"
+do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	# These checks are expected to fail
+	check_source_selection && test_fail
+	check_sync && test_fail
+done
+
+for server_conf in \
+	"deny all
+allow" \
+	"deny all
+allow all" \
+	"deny all
+allow 192.168.123" \
+	"deny all
+allow 192.168.123/24" \
+	"deny 192.168.124.0/24"
+do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/108-peer b/test/simulation/108-peer
new file mode 100755
index 0000000..20e2254
--- /dev/null
+++ b/test/simulation/108-peer
@@ -0,0 +1,54 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "NTP peers"
+
+# Allow and drop packets to the server in 1000 second intervals, so only one
+# client has access to it and the other is forced to switch to the peer.
+base_delay=$(cat <<-EOF | tr -d '\n'
+  (+ 1e-4
+     (* -1
+        (equal 0.1 from 2)
+        (equal 0.1 to 1)
+        (equal 0.1 (min (% time 2000) 1000) 1000))
+     (* -1
+        (equal 0.1 from 3)
+        (equal 0.1 to 1)
+	(equal 0.1 (max (% time 2000) 1000) 1000)))
+EOF
+)
+
+clients=2
+peers=2
+max_sync_time=1000
+client_server_options="minpoll 6 maxpoll 6"
+client_peer_options="minpoll 6 maxpoll 6"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+base_delay="(+ 1e-4 (* -1 (equal 0.1 from 3) (equal 0.1 to 1)))"
+client_peer_options=""
+
+while read lminpoll lmaxpoll rminpoll rmaxpoll max_sync_time; do
+	client_lpeer_options="minpoll $lminpoll maxpoll $lmaxpoll"
+	client_rpeer_options="minpoll $rminpoll maxpoll $rmaxpoll"
+	limit=$[$max_sync_time * 10]
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_sync || test_fail
+done <<-EOF
+	3 6 3 6 400
+	3 3 6 6 450
+	6 6 3 3 450
+	3 6 6 6 450
+	6 6 3 6 450
+	-2 -2 2 2 220
+	2 2 -2 -2 220
+EOF
+
+test_pass
diff --git a/test/simulation/109-makestep b/test/simulation/109-makestep
new file mode 100755
index 0000000..f984f72
--- /dev/null
+++ b/test/simulation/109-makestep
@@ -0,0 +1,41 @@
+#!/bin/bash
+
+. ./test.common
+test_start "makestep directive"
+
+client_conf="makestep 0 -1
+corrtimeratio 1e10"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+limit=200
+jitter=1e-5
+client_conf="makestep 2 1"
+
+min_sync_time=130
+max_sync_time=150
+
+for time_offset in -1.0 -0.1 0.1 1.0; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+min_sync_time=120
+max_sync_time=140
+
+for time_offset in -1e8 -1e2 1e2 1e8; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/110-chronyc b/test/simulation/110-chronyc
new file mode 100755
index 0000000..d578bf2
--- /dev/null
+++ b/test/simulation/110-chronyc
@@ -0,0 +1,226 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "chronyc"
+
+check_config_h 'FEAT_REFCLOCK 1' || test_skip
+check_config_h 'FEAT_CMDMON 1' || test_skip
+
+refclock_jitter=$jitter
+client_server_conf="
+server node1.net1.clk
+server 192.168.123.2"
+client_conf="
+refclock SHM 0 noselect
+smoothtime 400 0.001 leaponly"
+
+chronyc_conf="activity
+tracking
+sourcename 192.168.123.1
+sourcename 192.168.123.2
+sources
+sourcestats
+manual list
+smoothing
+waitsync
+rtcdata"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+
+check_chronyc_output "^200 OK
+2 sources online
+0 sources offline
+0 sources doing burst \(return to online\)
+0 sources doing burst \(return to offline\)
+0 sources with unknown address
+Reference ID    : C0A87B01 \(192\.168\.123\.1\)
+Stratum         : 2
+Ref time \(UTC\)  : Fri Jan 01 00:1.:.. 2010
+System time     : 0\.0000..... seconds (slow|fast) of NTP time
+Last offset     : [+-]0\.000...... seconds
+RMS offset      : 0\.000...... seconds
+Frequency       : (99|100)\.... ppm fast
+Residual freq   : [+-][0-9]\.... ppm
+Skew            : [0-9]\.... ppm
+Root delay      : 0\.000...... seconds
+Root dispersion : 0\.000...... seconds
+Update interval : [0-9]+\.. seconds
+Leap status     : Normal
+node1\.net1\.clk
+192\.168\.123\.2
+MS Name/IP address         Stratum Poll Reach LastRx Last sample               
+===============================================================================
+#\? SHM0                          0   4   377    [0-9]+ [0-9 +-]+[un]s\[[0-9 +-]+[un]s\] \+/-[ 0-9]+[un]s
+\^\* 192\.168\.123\.1                 1   [67]   377    [0-9]+ [0-9 +-]+[un]s\[[0-9 +-]+[un]s\] \+/-[ 0-9]+[un]s
+\^\? 192\.168\.123\.2                 0   [0-9]+     0     -     \+0ns\[   \+0ns\] \+/-    0ns
+Name/IP Address            NP  NR  Span  Frequency  Freq Skew  Offset  Std Dev
+==============================================================================
+SHM0                       [0-9 ]+ [0-9 ]+ [0-9 ]+ [ +-][01]\.... [0-9 ]+\....  [0-9 +-]+[un]s [0-9 ]+[un]s
+192\.168\.123\.1              [0-9 ]+ [0-9 ]+ [0-9 ]+ [ +-][01]\.... [0-9 ]+\....  [0-9 +-]+[un]s [0-9 ]+[un]s
+192\.168\.123\.2               0   0     0     \+0\.000   2000\.000     \+0ns  4000ms
+210 n_samples = 0
+#    Date     Time\(UTC\)    Slewed   Original   Residual
+=======================================================
+Active         : Yes \(leap second only\)
+Offset         : \+0\.000000000 seconds
+Frequency      : \+0\.000000 ppm
+Wander         : \+0\.000000 ppm per second
+Last update    : [0-9]+\.. seconds ago
+Remaining time : 0\.0 seconds
+try: 1, refid: C0A87B01, correction: 0\.000......, skew: .\....
+513 RTC driver not running$" \
+|| test_fail
+
+chronyc_conf="tracking"
+dns=1
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+
+check_chronyc_output "^Reference ID    : C0A87B01 \(node1\.net1\.clk\)" \
+	|| test_fail
+
+chronyc_options="-c"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+
+check_chronyc_output "^C0A87B01,192\.168\.123\.1,2,12623049..\..........,-?0\.0000.....,-?0\.000......,0\.000......,(99|100)\....,-?[0-9]\....,[0-9]\....,0\.000......,0\.000......,[0-9]+\..,Normal$" \
+	|| test_fail
+
+chronyc_options=""
+server_strata=0
+chronyc_start=0
+client_server_conf=""
+client_conf=""
+server_conf="server 192.168.123.1"
+limit=1
+
+for chronyc_conf in \
+	"accheck 1.2.3.4" \
+	"add peer 10.0.0.0 minpoll 2 maxpoll 6" \
+	"add server 10.0.0.0 minpoll 6 maxpoll 10 iburst burst key 1 maxdelay 1e-3 maxdelayratio 10.0 maxdelaydevratio 10.0 mindelay 1e-4 asymmetry 0.5 offset 1e-5 minsamples 6 maxsamples 6 filter 3 offline auto_offline prefer noselect trust require xleave polltarget 20 port 123 presend 7 minstratum 3 version 4" \
+	"add server node1.net1.clk" \
+	"allow 1.2.3.4" \
+	"allow 1.2" \
+	"allow 3.4.5" \
+	"allow 6.7.8/22" \
+	"allow 6.7.8.9/22" \
+	"allow 2001:db8::/32" \
+	"allow 0/0" \
+	"allow ::/0" \
+	"allow" \
+	"allow all 10/24" \
+	"authdata" \
+	"burst 5/10" \
+	"burst 3/5 255.255.255.0/1.2.3.0" \
+	"burst 1/2 1.2.3.0/24" \
+	"clients" \
+	"clients -k" \
+	"clients -p 100" \
+	"clients -r" \
+	"cmdaccheck 1.2.3.4" \
+	"cmdallow 1.2.3.4" \
+	"cmdallow all 1.2.3.0/24" \
+	"cmddeny 1.2.3.4" \
+	"cmddeny all 1.2.3.0/24" \
+	"cyclelogs" \
+	"delete 10.0.0.0" \
+	"delete ID#0000000001" \
+	"deny 1.2.3.4" \
+	"deny all 1.2.3.0/24" \
+	"dfreq 1.0e-3" \
+	"doffset -1.0" \
+	"dump" \
+	"local stratum 5 distance 1.0 orphan" \
+	"local off" \
+	"makestep 10.0 3" \
+	"makestep" \
+	"manual delete 0" \
+	"manual off" \
+	"manual on" \
+	"manual reset" \
+	"maxdelay 1.2.3.4 1e-2" \
+	"maxdelaydevratio 1.2.3.4 5.0" \
+	"maxdelayratio 1.2.3.4 3.0" \
+	"maxpoll 1.2.3.4 5" \
+	"maxupdateskew 1.2.3.4 10.0" \
+	"minpoll 1.2.3.4 3" \
+	"minstratum 1.2.3.4 1" \
+	"minstratum ID#0000000001 1" \
+	"ntpdata 1.2.3.4" \
+	"offline" \
+	"offline 255.255.255.0/1.2.3.0" \
+	"offline 1.2.3.0/24" \
+	"online" \
+	"online 1.2.3.0/24" \
+	"onoffline" \
+	"polltarget 1.2.3.4 10" \
+	"refresh" \
+	"rekey" \
+	"reload sources" \
+	"reselect" \
+	"reselectdist 1e-3" \
+	"reset sources" \
+	"selectdata" \
+	"settime 16:30" \
+	"settime 16:30:05" \
+	"settime Nov 21, 2015 16:30:05" \
+	"serverstats" \
+	"shutdown" \
+	"smoothtime reset" \
+	"smoothtime activate" \
+	"trimrtc" \
+	"writertc"
+do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_chronyc_output "501 Not authorised$" || test_fail
+done
+
+chronyc_conf="dns -n
+dns +n
+dns -4
+dns -6
+dns -46
+timeout 200
+retries 1
+keygen
+keygen 10 MD5 128
+keygen 11 MD5 40
+help
+quit
+nosuchcommand"
+
+run_test || test_fail
+
+check_chronyc_output "^1 (MD5|SHA1) HEX:........................................
+10 MD5 HEX:................................
+11 MD5 HEX:....................
+System clock:.*this help
+ *$" || test_fail
+
+chronyc_conf="keygen 10 NOSUCHTYPE 128
+help"
+run_test || test_fail
+check_chronyc_output "^Unknown hash function or cipher NOSUCHTYPE\$" || test_fail
+
+if check_config_h 'FEAT_SECHASH 1'; then
+	for hash in MD5 SHA1 SHA256 SHA384 SHA512; do
+		chronyc_conf="keygen 5 $hash"
+		run_test || test_fail
+		check_chronyc_output "^5 $hash HEX:........................................\$" || test_fail
+	done
+fi
+
+if check_config_h 'HAVE_CMAC 1'; then
+	chronyc_conf="keygen 6 AES128
+keygen 7 AES256"
+	run_test || test_fail
+	check_chronyc_output "^6 AES128 HEX:................................
+7 AES256 HEX:................................................................\$" || test_fail
+fi
+
+test_pass
diff --git a/test/simulation/111-knownclient b/test/simulation/111-knownclient
new file mode 100755
index 0000000..3d3fd87
--- /dev/null
+++ b/test/simulation/111-knownclient
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "reply to client configured as server"
+
+server_conf="server 192.168.123.2 noselect
+acquisitionport 123"
+client_conf="acquisitionport 123"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_port || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/112-port b/test/simulation/112-port
new file mode 100755
index 0000000..a8efabd
--- /dev/null
+++ b/test/simulation/112-port
@@ -0,0 +1,57 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "port and acquisitionport directives"
+
+check_config_h 'FEAT_CMDMON 1' || test_skip
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+# This check is expected to fail
+check_packet_port && test_fail
+
+client_conf="acquisitionport 123"
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_port || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+client_conf=""
+for server_conf in \
+	"port 0" \
+	"acquisitionport 123
+port 0"
+do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_port || test_fail
+	check_packet_interval || test_fail
+	# These checks are expected to fail
+	check_source_selection && test_fail
+	check_sync && test_fail
+done
+
+server_conf="port 124
+acquisitionport 123"
+client_server_options="port 124"
+for client_conf in \
+	"acquisitionport 0" \
+	"acquisitionport 123" \
+	"acquisitionport 124"
+do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+	# This check is expected to fail
+	check_packet_port && test_fail
+done
+
+test_pass
diff --git a/test/simulation/113-leapsecond b/test/simulation/113-leapsecond
new file mode 100755
index 0000000..2fb81b8
--- /dev/null
+++ b/test/simulation/113-leapsecond
@@ -0,0 +1,61 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "leap second"
+
+check_config_h 'FEAT_REFCLOCK 1' || test_skip
+
+export CLKNETSIM_START_DATE=$(TZ=UTC date -d 'Dec 30 2008 0:00:00' +'%s')
+
+leap=$[2 * 24 * 3600]
+limit=$[4 * 24 * 3600]
+client_start=$[2 * 3600]
+server_conf="refclock SHM 0 dpoll 10 poll 10
+leapsectz right/UTC"
+refclock_jitter=1e-9
+refclock_offset="(* -1.0 (equal 0.1 (max (sum 1.0) $leap) $leap))"
+
+for leapmode in system step slew; do
+	client_conf="leapsecmode $leapmode"
+	if [ $leapmode = slew ]; then
+		max_sync_time=$[$leap + 12]
+	else
+		max_sync_time=$[$leap]
+	fi
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+client_server_options="trust"
+client_conf="refclock SHM 0 dpoll 10 poll 10 delay 1e-3"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+client_server_options=""
+client_conf="leapsecmode system"
+min_sync_time=230000
+max_sync_time=240000
+
+for smoothmode in "" "leaponly"; do
+	server_conf="refclock SHM 0 dpoll 10 poll 10
+	leapsectz right/UTC
+	leapsecmode slew
+	smoothtime 400 0.001 $smoothmode"
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/114-presend b/test/simulation/114-presend
new file mode 100755
index 0000000..3113253
--- /dev/null
+++ b/test/simulation/114-presend
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+. ./test.common
+test_start "presend option"
+
+min_sync_time=136
+max_sync_time=260
+client_server_options="presend 6 maxdelay 16"
+client_conf="maxdistance 10"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+base_delay=5
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/115-cmdmontime b/test/simulation/115-cmdmontime
new file mode 100755
index 0000000..ea79b26
--- /dev/null
+++ b/test/simulation/115-cmdmontime
@@ -0,0 +1,24 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "cmdmon timestamps"
+
+# The following tests need 64-bit time_t
+check_config_h 'HAVE_LONG_TIME_T 1' || test_skip
+check_config_h 'FEAT_CMDMON 1' || test_skip
+
+limit=2
+client_server_options="noselect"
+client_conf="local stratum 1"
+chronyc_start="1.5"
+chronyc_conf="tracking"
+
+for year in `seq 1850 100 2300`; do
+	export CLKNETSIM_START_DATE=$(date -d "Jan 01 00:00:05 $year UTC" +'%s')
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_chronyc_output "^.*Ref time \(UTC\).*Jan 01 00:00:0. $year.*$" || test_fail
+done
+
+test_pass
diff --git a/test/simulation/116-minsources b/test/simulation/116-minsources
new file mode 100755
index 0000000..392f360
--- /dev/null
+++ b/test/simulation/116-minsources
@@ -0,0 +1,24 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "minsources directive"
+
+client_conf="minsources 3"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_interval || test_fail
+# These check are expected to fail
+check_source_selection && test_fail
+check_sync && test_fail
+
+servers=3
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_interval || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/117-fallbackdrift b/test/simulation/117-fallbackdrift
new file mode 100755
index 0000000..22270c9
--- /dev/null
+++ b/test/simulation/117-fallbackdrift
@@ -0,0 +1,24 @@
+#!/bin/bash
+
+. ./test.common
+test_start "fallback drift"
+
+limit=100000
+wander=0.0
+jitter=1e-6
+time_offset=10
+freq_offset="(* 1e-4 (sine 1000))"
+base_delay="(* -1.0 (equal 0.1 (min time 4250) 4250))"
+client_server_options="minpoll 4 maxpoll 4"
+client_conf="fallbackdrift 6 10"
+max_sync_time=4500
+time_max_limit=1e0
+time_rms_limit=1e0
+freq_max_limit=2e-4
+freq_rms_limit=1e-4
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/118-maxdelay b/test/simulation/118-maxdelay
new file mode 100755
index 0000000..22b9a50
--- /dev/null
+++ b/test/simulation/118-maxdelay
@@ -0,0 +1,28 @@
+#!/bin/bash
+
+. ./test.common
+test_start "maxdelay options"
+
+max_sync_time=2000
+base_delay=1e-5
+jitter=1e-5
+wander=0.0
+freq_offset="(sum 1e-10)"
+time_rms_limit=2e-4
+
+client_server_options="maxpoll 6 maxdelay 3e-5 maxdelayratio 2.0 maxdelaydevratio 2.0"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+for client_server_options in "maxpoll 6 maxdelay 2e-5"; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_packet_interval || test_fail
+	check_sync && test_fail
+done
+
+test_pass
diff --git a/test/simulation/119-smoothtime b/test/simulation/119-smoothtime
new file mode 100755
index 0000000..3f90715
--- /dev/null
+++ b/test/simulation/119-smoothtime
@@ -0,0 +1,82 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "smoothtime option"
+
+check_config_h 'FEAT_REFCLOCK 1' || test_skip
+
+server_strata=2
+server_conf="smoothtime 400 0.001"
+server_server_options="minpoll 8"
+min_sync_time=600
+max_sync_time=800
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+limit=10000
+refclock_jitter=1e-4
+refclock_offset="(* 10.0 (equal 0.1 (max (sum 1.0) 1000) 1000))"
+server_step="(* -10.0 (equal 0.1 (sum 1.0) 1))"
+server_strata=1
+server_conf="refclock SHM 0 dpoll 4 poll 6
+smoothtime 2000 1
+maxjitter 10.0"
+time_offset=-10
+server_server_options=""
+client_server_options="minpoll 6 maxpoll 6"
+client_conf="corrtimeratio 100"
+min_sync_time=8000
+max_sync_time=9000
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+client_server_options="minpoll 6 maxpoll 6 xleave maxdelay 1e-1"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+client_server_options="minpoll 6 maxpoll 6"
+min_sync_time=$default_min_sync_time
+max_sync_time=$default_max_sync_time
+time_max_limit=11
+time_rms_limit=11
+freq_max_limit=1e-2
+freq_rms_limit=2e-3
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+refclock_jitter=1e-9
+refclock_offset="(* 1e-1 (triangle 1000) (+ -1.0 (pulse 1000 10000)))"
+server_step=""
+server_conf="refclock SHM 0 dpoll 4 poll 6 minsamples 4 maxsamples 4
+smoothtime 1e4 1e-6"
+client_server_options="minpoll 4 maxpoll 4"
+time_offset=0.1
+jitter=1e-6
+wander=0.0
+min_sync_time=30
+max_sync_time=40
+time_max_limit=1e-5
+time_rms_limit=5e-6
+freq_max_limit=1e-6
+freq_rms_limit=1e-7
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/120-selectoptions b/test/simulation/120-selectoptions
new file mode 100755
index 0000000..a6b1e14
--- /dev/null
+++ b/test/simulation/120-selectoptions
@@ -0,0 +1,92 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "source selection options"
+
+servers=3
+falsetickers=2
+
+base_delay=0.6
+client_server_conf="
+server 192.168.123.1
+server 192.168.123.2
+server 192.168.123.3 trust"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+client_server_conf="
+server 192.168.123.1
+server 192.168.123.2
+server 192.168.123.3 prefer"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+# This check is expected to fail
+check_sync && test_fail
+
+base_delay=1.1
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+base_delay=$default_base_delay
+falsetickers=1
+
+client_server_conf="
+server 192.168.123.1
+server 192.168.123.2
+server 192.168.123.3 require"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+client_server_conf="
+server 192.168.123.1 require
+server 192.168.123.2
+server 192.168.123.3"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_interval || test_fail
+# These checks are expected to fail
+check_source_selection && test_fail
+check_sync && test_fail
+
+cat > tmp/keys <<-EOF
+1 MD5 HEX:1B81CBF88D4A73F2E8CE59647F6E5C1719B6CAF5
+EOF
+
+server_conf="keyfile tmp/keys"
+client_server_conf="
+server 192.168.123.1 key 1
+server 192.168.123.2
+server 192.168.123.3"
+
+for authselectmode in require prefer mix ignore; do
+	client_conf="keyfile tmp/keys
+		     authselectmode $authselectmode"
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	if [ $authselectmode = ignore ]; then
+		check_sync || test_fail
+	else
+		check_sync && test_fail
+	fi
+done
+
+test_pass
diff --git a/test/simulation/121-orphan b/test/simulation/121-orphan
new file mode 100755
index 0000000..c3d043f
--- /dev/null
+++ b/test/simulation/121-orphan
@@ -0,0 +1,26 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "orphan option"
+
+check_config_h 'FEAT_CMDMON 1' || test_skip
+
+server_strata=3
+server_conf="local stratum 5 orphan
+server 192.168.123.1
+server 192.168.123.2
+server 192.168.123.3"
+max_sync_time=900
+client_start=140
+chronyc_start=700
+chronyc_conf="tracking"
+time_rms_limit=5e-4
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+check_chronyc_output "^.*Stratum *: 7.*$" || test_fail
+
+test_pass
diff --git a/test/simulation/122-xleave b/test/simulation/122-xleave
new file mode 100755
index 0000000..66eef5c
--- /dev/null
+++ b/test/simulation/122-xleave
@@ -0,0 +1,55 @@
+#!/bin/bash
+
+. ./test.common
+test_start "interleaved mode"
+
+client_server_options="xleave"
+client_conf="
+logdir tmp
+log rawmeasurements"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+check_file_messages "111 111 1111.* 4B [DKH] [DKH]\$" 2 2 measurements.log || test_fail
+check_file_messages "111 111 1111.* 4I [DKH] [DKH]\$" 30 200 measurements.log || test_fail
+rm -f tmp/measurements.log
+
+clients=2
+peers=2
+max_sync_time=500
+base_delay="(+ 1e-4 (* -1 (equal 0.1 from 2) (equal 0.1 to 1)))"
+
+client_lpeer_options="xleave minpoll 5 maxpoll 5"
+client_rpeer_options="minpoll 5 maxpoll 5"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+# These checks are expected to fail
+check_source_selection && test_fail
+check_sync && test_fail
+
+rm -f tmp/measurements.log
+
+for rpoll in 4 5 6; do
+	client_rpeer_options="xleave minpoll $rpoll maxpoll $rpoll"
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
+
+	if [ $rpoll -le 5 ]; then
+		check_file_messages "111 111 1111.* 1B [DKH] [DKH]\$" 0 0 measurements.log || test_fail
+		check_file_messages "111 111 1111.* 1I [DKH] [DKH]\$" 200 310 measurements.log || test_fail
+	else
+		check_file_messages "111 111 1111.* 1B [DKH] [DKH]\$" 125 135 measurements.log || test_fail
+		check_file_messages "111 111 1111.* 1I [DKH] [DKH]\$" 20 30 measurements.log || test_fail
+	fi
+	rm -f tmp/measurements.log
+done
+
+test_pass
diff --git a/test/simulation/123-mindelay b/test/simulation/123-mindelay
new file mode 100755
index 0000000..cde214a
--- /dev/null
+++ b/test/simulation/123-mindelay
@@ -0,0 +1,27 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "mindelay and asymmetry options"
+
+jitter_asymmetry=0.499
+time_rms_limit=1e-6
+time_freq_limit=1e-9
+wander=1e-12
+
+for client_server_options in "mindelay 2e-4 asymmetry 0.499"; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+for client_server_options in "mindelay 1e-4 asymmetry 0.499" "mindelay 2e-4 asymmetry 0.0"; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync && test_fail
+done
+
+test_pass
diff --git a/test/simulation/124-tai b/test/simulation/124-tai
new file mode 100755
index 0000000..d41d29d
--- /dev/null
+++ b/test/simulation/124-tai
@@ -0,0 +1,45 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "tai option"
+
+check_config_h 'FEAT_REFCLOCK 1' || test_skip
+
+export CLKNETSIM_START_DATE=$(TZ=UTC date -d 'Dec 31 2008 23:50:00' +'%s')
+
+leap=$[10 * 60]
+limit=$[20 * 60]
+min_sync_time=2
+max_sync_time=15
+refclock_jitter=1e-6
+servers=0
+
+refclock_offset="(+ -34 (equal 0.1 (max (sum 1.0) $leap) $leap))"
+client_conf="
+refclock SHM 0 dpoll 0 poll 0 tai
+leapsectz right/UTC
+leapsecmode ignore
+maxchange 1e-3 1 0"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+export CLKNETSIM_START_DATE=$(TZ=UTC date -d 'Jan 01 2009 00:10:00' +'%s')
+
+time_offset=-1000
+refclock_offset="(+ -34)"
+client_conf="
+refclock SHM 0 dpoll 0 poll 0 tai
+leapsectz right/UTC
+makestep 1 1
+maxchange 1e-3 1 0"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/125-packetloss b/test/simulation/125-packetloss
new file mode 100755
index 0000000..95604da
--- /dev/null
+++ b/test/simulation/125-packetloss
@@ -0,0 +1,29 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "packet loss"
+
+# Drop 33% of packets by default and 100% on the 3->1 path
+base_delay=$(cat <<-EOF | tr -d '\n'
+  (+ 1e-4
+     (* -1 (equal 0.33 (uniform) 1.0))
+     (* -1 (equal 0.1 from 3) (equal 0.1 to 1)))
+EOF
+)
+clients=2
+peers=2
+jitter=1e-5
+limit=20000
+max_sync_time=10000
+
+for options in "maxpoll 8" "maxpoll 8 xleave"; do
+	client_server_options=$options
+	client_peer_options=$options
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/126-burst b/test/simulation/126-burst
new file mode 100755
index 0000000..d63f290
--- /dev/null
+++ b/test/simulation/126-burst
@@ -0,0 +1,45 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "burst option"
+
+# Pass every fourth packet on the 2->1 path
+base_delay=$(cat <<-EOF | tr -d '\n'
+  (+ 1e-4
+     (* -1
+        (equal 0.1 from 2)
+        (equal 0.1 to 1)
+        (equal 0.1 (min (% (sum 1) 4) 1) 1)))
+EOF
+)
+
+client_server_options="burst polltarget 1"
+min_sync_time=700
+max_sync_time=730
+client_max_min_out_interval=2.2
+client_min_mean_out_interval=150.0
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+# Add a significant delay to 70% of packets on the 2->1 path after 6th packet
+base_delay=$(cat <<-EOF | tr -d '\n'
+  (+ 1e-4
+     (* 0.15
+        (equal 0.1 from 2)
+        (equal 0.1 to 1)
+        (equal 0.1 (min (sum 1) 7) 7)
+        (equal 0.7 (uniform) 0.0)))
+EOF
+)
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+
+test_pass
diff --git a/test/simulation/127-filter b/test/simulation/127-filter
new file mode 100755
index 0000000..737d1f9
--- /dev/null
+++ b/test/simulation/127-filter
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "filter option"
+
+client_server_options="minpoll 4 maxpoll 4 filter 15"
+min_sync_time=710
+max_sync_time=720
+client_max_min_out_interval=16.1
+client_min_mean_out_interval=15.9
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/128-nocontrol b/test/simulation/128-nocontrol
new file mode 100755
index 0000000..cca82f4
--- /dev/null
+++ b/test/simulation/128-nocontrol
@@ -0,0 +1,27 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "-x option"
+
+check_config_h 'FEAT_CMDMON 1' || test_skip
+
+wander=0.0
+time_offset=0.0
+freq_offset=0.0
+time_max_limit=1e-6
+freq_max_limit=1e-9
+min_sync_time=0
+max_sync_time=0
+client_chronyd_options="-x"
+chronyc_start=300
+chronyc_conf="tracking"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+check_chronyc_output "^.*Stratum *: 2.*$" || test_fail
+
+test_pass
diff --git a/test/simulation/129-reload b/test/simulation/129-reload
new file mode 100755
index 0000000..7a346a4
--- /dev/null
+++ b/test/simulation/129-reload
@@ -0,0 +1,26 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "-r option"
+
+wander=0.0
+limit=100
+min_sync_time=100
+max_sync_time=104
+client_chronyd_options="-r"
+client_conf="dumpdir tmp
+maxupdateskew 10000"
+
+run_test || test_fail
+
+client_start=$limit
+limit=1000
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/130-quit b/test/simulation/130-quit
new file mode 100755
index 0000000..f5f7766
--- /dev/null
+++ b/test/simulation/130-quit
@@ -0,0 +1,31 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "-q/-Q option"
+
+wander=0.0
+freq_offset=0.0
+min_sync_time=5
+max_sync_time=10
+client_chronyd_options="-q"
+client_server_options="iburst"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+min_sync_time=1
+max_sync_time=1
+client_server_options="iburst maxsamples 1"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_sync || test_fail
+
+client_chronyd_options="-Q"
+run_test || test_fail
+check_sync && test_fail
+
+test_pass
diff --git a/test/simulation/131-maxchange b/test/simulation/131-maxchange
new file mode 100755
index 0000000..969f71f
--- /dev/null
+++ b/test/simulation/131-maxchange
@@ -0,0 +1,20 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "maxchange directive"
+
+time_offset=2
+max_sync_time=5000
+client_conf="maxchange 0.1 1 3"
+client_step="(* $step (equal 0.1 (sum 1.0) 300))"
+
+run_test || test_fail
+check_chronyd_exit && test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync && test_fail
+check_log_messages "seconds exceeds.*ignored" 3 3 || test_fail
+check_log_messages "seconds exceeds.*exiting" 1 1 || test_fail
+
+test_pass
diff --git a/test/simulation/132-logchange b/test/simulation/132-logchange
new file mode 100755
index 0000000..8db1741
--- /dev/null
+++ b/test/simulation/132-logchange
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "logchange directive"
+
+time_offset=2
+min_sync_time=590
+max_sync_time=700
+client_server_options="maxsamples 6"
+client_conf="logchange 0.1"
+client_step="(* $step (equal 0.1 (sum 1.0) 300))"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+check_log_messages "clock wrong by" 4 8 || test_fail
+
+test_pass
diff --git a/test/simulation/133-hwtimestamp b/test/simulation/133-hwtimestamp
new file mode 100755
index 0000000..e4896fc
--- /dev/null
+++ b/test/simulation/133-hwtimestamp
@@ -0,0 +1,39 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "hwtimestamp directive"
+
+check_config_h 'HAVE_LINUX_TIMESTAMPING 1' || test_skip
+
+export CLKNETSIM_TIMESTAMPING=2
+
+refclock_jitter=1e-8
+refclock_offset=10.0
+min_sync_time=4
+max_sync_time=20
+limit=200
+server_conf="hwtimestamp eth0"
+client_server_options="minpoll 0 maxpoll 0 minsamples 32 xleave"
+client_chronyd_options="-d"
+
+for client_conf in "hwtimestamp eth0" "hwtimestamp eth0
+acquisitionport 123"; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
+
+	if check_config_h 'FEAT_DEBUG 1'; then
+		check_log_messages "HW clock samples" 190 200 || test_fail
+		check_log_messages "HW clock reset" 0 0 || test_fail
+		check_log_messages "Received message.*tss=KH" 195 200 || test_fail
+		check_log_messages "Received error.*message.*tss=KH" 195 200 || test_fail
+		check_log_messages "Updated RX timestamp.*tss=1" 1 1 || test_fail
+		check_log_messages "Updated RX timestamp.*tss=2" 195 200 || test_fail
+		check_log_messages "update_tx_timestamp.*Updated" 50 140 || test_fail
+		check_log_messages "update_tx_timestamp.*Unacceptable" 50 140 || test_fail
+	fi
+done
+
+test_pass
diff --git a/test/simulation/134-log b/test/simulation/134-log
new file mode 100755
index 0000000..0a6ef76
--- /dev/null
+++ b/test/simulation/134-log
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "log directive"
+
+check_config_h 'FEAT_PHC 1' || test_skip
+
+refclock_jitter=$jitter
+client_server_options="maxpoll 6"
+client_conf="refclock PHC /dev/ptp0 dpoll 4 poll 6 noselect
+logbanner 10
+logdir tmp
+log tracking rawmeasurements measurements statistics rtc refclocks tempcomp
+tempcomp tmp/tempcomp 64 0.0 0.0 0.0 0.0"
+
+echo 0.0 > tmp/tempcomp
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+check_file_messages "=============" 31 33 \
+	tracking.log measurements.log tempcomp.log || test_fail
+check_file_messages "20.*192\.168\.123\.1" 150 160 \
+	tracking.log measurements.log statistics.log || test_fail
+check_file_messages "20.*PHC0" 150 160 statistics.log || test_fail
+check_file_messages "20.*PHC0" 750 800 refclocks.log || test_fail
+check_file_messages "20.* 0\.0000" 150 160 tempcomp.log || test_fail
+
+test_pass
diff --git a/test/simulation/135-ratelimit b/test/simulation/135-ratelimit
new file mode 100755
index 0000000..cfa5eab
--- /dev/null
+++ b/test/simulation/135-ratelimit
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+. ./test.common
+test_start "ratelimit directive"
+
+server_conf="ratelimit interval 6 burst 2 leak 4"
+client_server_options="minpoll 3 maxpoll 3"
+min_sync_time=16
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+check_file_messages "	2	1	" 1200 1300 log.packets || test_fail
+check_file_messages "	1	2	" 180 220 log.packets || test_fail
+
+test_pass
diff --git a/test/simulation/136-broadcast b/test/simulation/136-broadcast
new file mode 100755
index 0000000..d60d678
--- /dev/null
+++ b/test/simulation/136-broadcast
@@ -0,0 +1,16 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "broadcast directive"
+
+server_conf="broadcast 64 192.168.123.255"
+client_server_options="offline"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_interval && test_fail
+
+check_file_messages "	1	2	" 150 160 log.packets || test_fail
+
+test_pass
diff --git a/test/simulation/137-pool b/test/simulation/137-pool
new file mode 100755
index 0000000..32f44ec
--- /dev/null
+++ b/test/simulation/137-pool
@@ -0,0 +1,49 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "pool directive"
+
+limit=500
+client_conf="logdir tmp
+log measurements"
+
+servers=3
+client_server_conf="pool nodes-1-2-3.net1.clk"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+check_file_messages "20.*192.168.123.1" 5 10 measurements.log || test_fail
+check_file_messages "20.*192.168.123.2" 5 10 measurements.log || test_fail
+check_file_messages "20.*192.168.123.3" 5 10 measurements.log || test_fail
+rm -f tmp/measurements.log
+
+servers=6
+client_server_conf="pool nodes-1-2-3-4-5-6.net1.clk minpoll 6 maxpoll 6"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+check_file_messages "20.*192.168.123.*" 30 35 measurements.log || test_fail
+rm -f tmp/measurements.log
+
+servers=6
+client_server_conf="pool nodes-1-2-3-4-5-6.net1.clk maxsources 2 minpoll 6 maxpoll 6"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+check_file_messages "20.*192.168.123.*" 15 17 measurements.log || test_fail
+rm -f tmp/measurements.log
+
+test_pass
diff --git a/test/simulation/138-syncloop b/test/simulation/138-syncloop
new file mode 100755
index 0000000..8edeec6
--- /dev/null
+++ b/test/simulation/138-syncloop
@@ -0,0 +1,34 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "loop prevention"
+
+mkdir tmp/logdir1 tmp/logdir2
+
+server_conf="
+server 192.168.123.1
+server 192.168.123.2
+logdir tmp/logdir1
+log measurements"
+client_server_conf="
+server 192.168.123.1
+server 192.168.123.2
+logdir tmp/logdir2
+log measurements
+allow"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+check_file_messages "20.*123\.1.* 111 111 1110" 30 200 logdir1/measurements.log || test_fail
+check_file_messages "20.*123\.2.* 111 111 1110" 30 200 logdir1/measurements.log || test_fail
+check_file_messages "20.*123\...* 111 111 1111" 0 0 logdir1/measurements.log || test_fail
+check_file_messages "20.*123\.1.* 111 111 1111" 30 200 logdir2/measurements.log || test_fail
+check_file_messages "20.*123\.1.* 111 111 1110" 0 0 logdir2/measurements.log || test_fail
+check_file_messages "20.*123\.2.* 111 111 1110" 30 200 logdir2/measurements.log || test_fail
+check_file_messages "20.*123\.2.* 111 111 1111" 0 0 logdir1/measurements.log || test_fail
+
+test_pass
diff --git a/test/simulation/139-nts b/test/simulation/139-nts
new file mode 100755
index 0000000..74b8981
--- /dev/null
+++ b/test/simulation/139-nts
@@ -0,0 +1,173 @@
+#!/bin/bash
+
+. ./test.common
+
+test_start "NTP authentication with NTS"
+
+check_config_h 'FEAT_NTS 1' || test_skip
+certtool --help &> /dev/null || test_skip
+
+export CLKNETSIM_START_DATE=$(date -d 'Jan  1 00:00:00 UTC 2010' +'%s')
+
+cat > tmp/cert.cfg <<EOF
+cn = "node1.net1.clk"
+serial = 001
+activation_date = "2010-01-01 00:00:00 UTC"
+expiration_date = "2010-01-02 00:00:00 UTC"
+#dns_name = "node1.net1.clk"
+signing_key
+encryption_key
+EOF
+
+certtool --generate-privkey --key-type=ed25519 --outfile tmp/server.key &> tmp/log.certtool
+certtool --generate-self-signed --load-privkey tmp/server.key \
+	--template tmp/cert.cfg --outfile tmp/server.crt &>> tmp/log.certtool
+
+max_sync_time=400
+dns=1
+server_conf="
+ntsserverkey tmp/server.key
+ntsservercert tmp/server.crt
+ntsprocesses 0
+ntsrotate 66
+ntsdumpdir tmp
+"
+client_server_options="minpoll 6 maxpoll 6 nts"
+client_conf="
+nosystemcert
+ntstrustedcerts tmp/server.crt
+logdir tmp
+log rawmeasurements"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+check_file_messages "20.*123\.1.* 111 111 1111" 75 80 measurements.log || test_fail
+check_file_messages "20.*123\.1.* 111 001 0000" 37 39 measurements.log || test_fail
+check_file_messages "	2	1	.*	4460	" 260 300 log.packets || test_fail
+check_file_messages "." 6 6 ntskeys || test_fail
+rm -f tmp/measurements.log
+
+client_conf+="
+ntsrefresh 120
+ntsdumpdir tmp"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+check_file_messages "20.*123\.1.* 111 111 1111" 99 103 measurements.log || test_fail
+check_file_messages "20.*123\.1.* 111 001 0000" 0 0 measurements.log || test_fail
+check_file_messages "	2	1	.*	4460	" 350 390 log.packets || test_fail
+check_file_messages "." 6 6 ntskeys || test_fail
+check_file_messages "." 12 13 192.168.123.1.nts || test_fail
+rm -f tmp/measurements.log
+
+export CLKNETSIM_START_DATE=$(date -d 'Jan  1 00:00:00 UTC 2010 + 40000 sec' +'%s')
+
+server_conf+="
+ntsrotate 100000"
+client_conf+="
+ntsrefresh 39500"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+check_file_messages "20.*123\.1.* 111 111 1111" 150 160 measurements.log || test_fail
+check_file_messages "20.*123\.1.* 111 001 0000" 0 0 measurements.log || test_fail
+check_file_messages "	2	1	.*	4460	" 6 10 log.packets || test_fail
+check_file_messages "^9\.......e+03	2	1	.*	4460	" 6 10 log.packets || test_fail
+check_file_messages "." 6 6 ntskeys || test_fail
+check_file_messages "." 12 13 192.168.123.1.nts || test_fail
+rm -f tmp/measurements.log
+
+client_conf="
+nosystemcert"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection && test_fail
+check_sync && test_fail
+
+check_file_messages "	2	1	.*	123	" 0 0 log.packets || test_fail
+check_file_messages "	2	1	.*	4460	" 10 20 log.packets || test_fail
+
+export CLKNETSIM_START_DATE=$(date -d 'Jan  2 00:00:01 UTC 2010' +'%s')
+
+client_conf="
+nosystemcert
+ntstrustedcerts tmp/server.crt"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection && test_fail
+check_sync && test_fail
+
+check_file_messages "	2	1	.*	123	" 0 0 log.packets || test_fail
+check_file_messages "	2	1	.*	4460	" 10 20 log.packets || test_fail
+check_log_messages "expired certificate" 4 4 || test_fail
+
+client_conf+="
+nocerttimecheck 1"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+export CLKNETSIM_START_DATE=$(date -d 'Jan  1 00:00:00 UTC 2010' +'%s')
+
+server_conf="
+ntsserverkey tmp/server.key
+ntsservercert tmp/server.crt
+ntsprocesses 0
+ntsrotate 0
+ntsdumpdir tmp
+ntsntpserver 192.168.123.2"
+client_conf="
+nosystemcert
+ntstrustedcerts tmp/server.crt
+ntsrefresh 500"
+client_server_conf="server node1.net1.clk $client_server_options"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection && test_fail
+check_sync && test_fail
+
+check_file_messages "	2	1	.*	4460	" 50 100 log.packets || test_fail
+check_file_messages "	2	2	.*	4460	" 0 0 log.packets || test_fail
+check_log_messages "Source 192.168.123.1 changed to 192.168.123.2" 6 8 || test_fail
+check_log_messages "Source 192.168.123.2 replaced with 192.168.123.1" 6 8 || test_fail
+
+servers=2
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+check_file_messages "	3	1	.*	4460	" 100 150 log.packets || test_fail
+check_file_messages "	3	2	.*	4460	" 0 0 log.packets || test_fail
+check_log_messages "Source 192.168.123.1 changed to 192.168.123.2" 1 1 || test_fail
+check_log_messages "Source 192.168.123.2 replaced with 192.168.123.1" 0 0 || test_fail
+
+server_conf+="
+ntsratelimit interval 12 burst 1 leak 4"
+
+client_chronyd_options="-d -d"
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection && test_fail
+
+check_file_messages "	3	1	.*	4460	1	0	2" 25 50 log.packets || test_fail
+check_file_messages "	3	2	.*	4460	" 0 0 log.packets || test_fail
+check_log_messages "Source 192.168.123.1 changed to 192.168.123.2" 2 6 || test_fail
+check_log_messages "Source 192.168.123.2 replaced with 192.168.123.1" 1 6 || test_fail
+
+test_pass
diff --git a/test/simulation/140-noclientlog b/test/simulation/140-noclientlog
new file mode 100755
index 0000000..c456647
--- /dev/null
+++ b/test/simulation/140-noclientlog
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+. ./test.common
+test_start "noclientlog option"
+
+server_conf="noclientlog"
+client_server_options="xleave"
+client_conf="
+logdir tmp
+log rawmeasurements"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+check_file_messages "111 111 1111.* 4B " 30 200 measurements.log || test_fail
+check_file_messages "111 111 1111.* 4I " 0 0 measurements.log || test_fail
+
+test_pass
diff --git a/test/simulation/201-freqaccumulation b/test/simulation/201-freqaccumulation
new file mode 100755
index 0000000..7a9c22c
--- /dev/null
+++ b/test/simulation/201-freqaccumulation
@@ -0,0 +1,35 @@
+#!/bin/bash
+
+. ./test.common
+
+# Test fix in commit 60d0fa299307076143da94d36deb7b908fa9bdb7
+
+test_start "frequency accumulation"
+
+time_offset=100.0
+jitter=1e-6
+base_delay=1e-6
+wander=0.0
+
+limit=180
+time_max_limit=1e-5
+freq_max_limit=1e-7
+time_rms_limit=1e-5
+freq_rms_limit=1e-7
+min_sync_time=120
+max_sync_time=140
+
+client_server_options="minpoll 6 maxpoll 6"
+client_conf="driftfile tmp/drift
+makestep 1 1"
+
+for freq_offset in -5e-2 -5e-4 5e-4 5e-2; do
+	for drift in -1e+4 -1e+2 1e+2 1e+4; do
+		echo "$drift 100000" > tmp/drift
+		run_test || test_fail
+		check_chronyd_exit || test_fail
+		check_sync || test_fail
+	done
+done
+
+test_pass
diff --git a/test/simulation/202-prefer b/test/simulation/202-prefer
new file mode 100755
index 0000000..ae24848
--- /dev/null
+++ b/test/simulation/202-prefer
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+. ./test.common
+
+# Test fix in commit 4253075a97141edfa62043ab71bd0673587e6629
+
+test_start "prefer option"
+
+servers=3
+client_server_conf="
+server 192.168.123.1
+server 192.168.123.2
+server 192.168.123.3 prefer"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/README b/test/simulation/README
new file mode 100644
index 0000000..e174500
--- /dev/null
+++ b/test/simulation/README
@@ -0,0 +1,11 @@
+This is a collection of simulation tests using the clknetsim simulator
+(supported on Linux only).
+
+https://github.com/mlichvar/clknetsim
+
+The CLKNETSIM_PATH environment variable should point to the directory where
+clknetsim was downloaded and compiled. If the variable is not set, the tests
+will look for clknetsim in ./clknetsim in the current directory.
+
+The tests are written in bash and they can be run directly. The ./run script
+runs all tests.
diff --git a/test/simulation/run b/test/simulation/run
new file mode 100755
index 0000000..463e8dd
--- /dev/null
+++ b/test/simulation/run
@@ -0,0 +1,90 @@
+#!/bin/bash
+
+print_help() {
+	echo "$1 [-a] [-i ITERATIONS] [-m MAXFAILS] [-s SEED] [TEST]..."
+}
+
+run_test() {
+	local result name=$1 seed=$2
+
+	CLKNETSIM_RANDOM_SEED=$seed ./$name
+	result=$?
+
+	if [ $result -ne 0 -a $result -ne 9 ]; then
+		if [ $abort_on_fail -ne 0 ]; then
+			echo 1>&2
+			echo Failed with random seed $seed 1>&2
+			exit 1
+		fi
+		failed_seeds=(${failed_seeds[@]} $seed)
+	fi
+
+	return $result
+}
+
+abort_on_fail=0
+iterations=1
+max_fails=0
+random_seed=${CLKNETSIM_RANDOM_SEED:-$RANDOM}
+
+while getopts ":ai:m:s:" opt; do
+	case $opt in
+		a) abort_on_fail=1;;
+		i) iterations=$OPTARG;;
+		m) max_fails=$OPTARG;;
+		s) random_seed=$OPTARG;;
+		*) print_help "$0"; exit 3;;
+	esac
+done
+
+shift $[$OPTIND - 1]
+
+passed=() failed=() skipped=() failed_seeds=()
+
+[ $# -gt 0 ] && tests=($@) || tests=([0-9]*-*[^_])
+
+for test in "${tests[@]}"; do
+	if [ $iterations -gt 1 ]; then
+		printf "%-30s" "$test"
+		fails=0
+		for i in $(seq 1 $iterations); do
+			run_test $test $[$random_seed + $i - 1] > /dev/null
+			case $? in
+				0) echo -n ".";;
+				9) break;;
+				*) echo -n "x"; fails=$[$fails + 1];;
+			esac
+		done
+		if [ $i -lt $iterations ]; then
+			printf "%${iterations}s" ""
+			echo " SKIP"
+			result=9
+		elif [ $fails -gt $max_fails ]; then
+			echo " FAIL"
+			result=1
+		else
+			echo " PASS"
+			result=0
+		fi
+	else
+		printf "%s   " "$test"
+		run_test $test $random_seed
+		result=$?
+		echo
+	fi
+
+	case $result in
+		0) passed=(${passed[@]} $test);;
+		9) skipped=(${skipped[@]} $test);;
+		*) failed=(${failed[@]} $test);;
+	esac
+done
+
+echo
+echo "SUMMARY:"
+echo "  TOTAL  $[${#passed[@]} + ${#failed[@]} + ${#skipped[@]}]"
+echo "  PASSED ${#passed[@]}"
+echo "  FAILED ${#failed[@]}    (${failed[@]}) (${failed_seeds[@]})"
+echo "  SKIPPED ${#skipped[@]}   (${skipped[@]})"
+
+[ ${#failed[@]} -eq 0 ]
diff --git a/test/simulation/test.common b/test/simulation/test.common
new file mode 100644
index 0000000..9d85a5c
--- /dev/null
+++ b/test/simulation/test.common
@@ -0,0 +1,516 @@
+# Copyright (C) 2013-2014  Miroslav Lichvar <mlichvar@redhat.com>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+export LC_ALL=C
+export PATH=../../:$PATH
+export CLKNETSIM_PATH=${CLKNETSIM_PATH:-clknetsim}
+
+if [ ! -x $CLKNETSIM_PATH/clknetsim ]; then
+	echo "SKIP (clknetsim not found)"
+	exit 9
+fi
+
+. $CLKNETSIM_PATH/clknetsim.bash
+
+# Default test testings
+
+default_limit=10000
+default_time_offset=1e-1
+default_freq_offset=1e-4
+default_base_delay=1e-4
+default_jitter=1e-4
+default_jitter_asymmetry=0.0
+default_wander=1e-9
+default_refclock_jitter=""
+default_refclock_offset=0.0
+
+default_update_interval=0
+default_shift_pll=2
+
+default_server_strata=1
+default_servers=1
+default_clients=1
+default_peers=0
+default_falsetickers=0
+default_server_start=0.0
+default_client_start=0.0
+default_chronyc_start=1000.0
+default_server_step=""
+default_client_step=""
+
+default_client_server_conf=""
+default_server_server_options=""
+default_client_server_options=""
+default_server_peer_options=""
+default_server_lpeer_options=""
+default_server_rpeer_options=""
+default_client_peer_options=""
+default_client_lpeer_options=""
+default_client_rpeer_options=""
+default_server_conf=""
+default_client_conf=""
+default_chronyc_conf=""
+default_server_chronyd_options=""
+default_client_chronyd_options=""
+default_chronyc_options=""
+
+default_time_max_limit=1e-3
+default_freq_max_limit=5e-4
+default_time_rms_limit=3e-4
+default_freq_rms_limit=1e-5
+default_min_sync_time=120
+default_max_sync_time=210
+
+default_client_min_mean_out_interval=0.0
+default_client_max_min_out_interval=inf
+
+default_dns=0
+
+# Initialize test settings from their defaults
+for defoptname in ${!default_*}; do
+	optname=${defoptname#default_}
+	[ -z "${!optname}" ] && declare "$optname"="${!defoptname}"
+done
+
+test_start() {
+	rm -rf tmp/*
+	echo "Testing $@:"
+
+	check_config_h 'FEAT_NTP 1' || test_skip
+}
+
+test_pass() {
+	echo "PASS"
+	exit 0
+}
+
+test_fail() {
+	echo "FAIL"
+	exit 1
+}
+
+test_skip() {
+	echo "SKIP"
+	exit 9
+}
+
+test_ok() {
+	pad_line
+	echo -e "\tOK"
+	return 0
+}
+
+test_bad() {
+	pad_line
+	echo -e "\tBAD"
+	return 1
+}
+
+test_error() {
+	pad_line
+	echo -e "\tERROR"
+	return 1
+}
+
+msg_length=0
+pad_line() {
+	local line_length=56
+	[ $msg_length -lt $line_length ] && \
+		printf "%$[$line_length - $msg_length]s" ""
+	msg_length=0
+}
+
+# Print aligned message
+test_message() {
+	local level=$1 eol=$2
+	shift 2
+	local msg="$*"
+
+	while [ $level -gt 0 ]; do
+		echo -n "  "
+		level=$[$level - 1]
+		msg_length=$[$msg_length + 2]
+	done
+	echo -n "$msg"
+
+	msg_length=$[$msg_length + ${#msg}]
+	if [ $eol -ne 0 ]; then
+		echo
+		msg_length=0
+	fi
+}
+
+get_wander_expr() {
+	local scaled_wander
+
+	scaled_wander=$(awk "BEGIN {print $wander / \
+		sqrt($update_interval < 0 ? 2^-($update_interval) : 1)}")
+
+	echo "(+ $freq_offset (sum (* $scaled_wander (normal))))"
+}
+
+
+get_delay_expr() {
+	local direction=$1 asym
+
+	if [ $jitter_asymmetry == "0.0" ]; then
+		asym=""
+	elif [ $direction = "up" ]; then
+		asym=$(awk "BEGIN {print 1 - 2 * $jitter_asymmetry}")
+	elif [ $direction = "down" ]; then
+		asym=$(awk "BEGIN {print 1 + 2 * $jitter_asymmetry}")
+	fi
+	echo "(+ $base_delay (* $asym $jitter (exponential)))"
+}
+
+get_refclock_expr() {
+	echo "(+ $refclock_offset (* $refclock_jitter (normal)))"
+}
+
+get_chronyd_nodes() {
+	echo $[$servers * $server_strata + $clients]
+}
+
+get_node_name() {
+	local index=$1
+
+	if [ $dns -ne 0 ]; then
+		echo "node$index.net1.clk"
+	else
+		echo "192.168.123.$index"
+	fi
+}
+
+get_chronyd_conf() {
+	local i stratum=$1 peer=$2
+
+	if [ $stratum -eq 1 ]; then
+		echo "local stratum 1"
+		echo "$server_conf"
+	elif [ $stratum -le $server_strata ]; then
+		for i in $(seq 1 $servers); do
+			echo "server $(get_node_name $[$servers * ($stratum - 2) + $i]) $server_server_options"
+		done
+		for i in $(seq 1 $peers); do
+			[ $i -eq $peer -o $i -gt $servers ] && continue
+			echo -n "peer $(get_node_name $[$servers * ($stratum - 1) + $i]) $server_peer_options "
+			[ $i -lt $peer ] && echo "$server_lpeer_options" || echo "$server_rpeer_options"
+		done
+		echo "$server_conf"
+	else
+		echo "deny"
+		if [ -n "$client_server_conf" ]; then
+			echo "$client_server_conf"
+		else
+			for i in $(seq 1 $servers); do
+				echo "server $(get_node_name $[$servers * ($stratum - 2) + $i]) $client_server_options"
+			done
+		fi
+		for i in $(seq 1 $peers); do
+			[ $i -eq $peer -o $i -gt $clients ] && continue
+			echo -n "peer $(get_node_name $[$servers * ($stratum - 1) + $i]) $client_peer_options "
+			[ $i -lt $peer ] && echo "$client_lpeer_options" || echo "$client_rpeer_options"
+		done
+		echo "$client_conf"
+	fi
+}
+
+# Check if chrony was built with specified option in config.h
+check_config_h() {
+	local pattern=$1
+	grep -q "^#define $pattern" ../../config.h
+}
+
+# Check if the clock was well synchronized
+check_sync() {
+	local i sync_time max_time_error max_freq_error ret=0
+	local rms_time_error rms_freq_error
+
+	test_message 2 1 "checking clock sync time, max/rms time/freq error:"
+
+	for i in $(seq 1 $(get_chronyd_nodes)); do
+		[ $i -gt $[$servers * $server_strata] ] || continue
+
+		sync_time=$(find_sync tmp/log.offset tmp/log.freq $i \
+			$time_max_limit $freq_max_limit 1.0)
+		max_time_error=$(get_stat 'Maximum absolute offset' $i)
+		max_freq_error=$(get_stat 'Maximum absolute frequency' $i)
+		rms_time_error=$(get_stat 'RMS offset' $i)
+		rms_freq_error=$(get_stat 'RMS frequency' $i)
+
+		test_message 3 0 "node $i: $sync_time $(printf '%.2e %.2e %.2e %.2e' \
+			$max_time_error $max_freq_error $rms_time_error $rms_freq_error)"
+
+		check_stat $sync_time $min_sync_time $max_sync_time && \
+			check_stat $max_time_error 0.0 $time_max_limit && \
+			check_stat $max_freq_error 0.0 $freq_max_limit && \
+			check_stat $rms_time_error 0.0 $time_rms_limit && \
+			check_stat $rms_freq_error 0.0 $freq_rms_limit && \
+			test_ok || test_bad
+
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Check if chronyd exited properly
+check_chronyd_exit() {
+	local i ret=0
+
+	test_message 2 1 "checking chronyd exit:"
+
+	for i in $(seq 1 $(get_chronyd_nodes)); do
+		test_message 3 0 "node $i:"
+
+		grep -q 'chronyd exiting' tmp/log.$i && \
+			! grep -q 'Adjustment.*exceeds.*exiting' tmp/log.$i && \
+			! grep -q 'Assertion.*failed' tmp/log.$i && \
+			test_ok || test_bad
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Check for problems in source selection
+check_source_selection() {
+	local i ret=0
+
+	test_message 2 1 "checking source selection:"
+
+	for i in $(seq $[$servers * $server_strata + 1] $(get_chronyd_nodes)); do
+		test_message 3 0 "node $i:"
+
+		! grep -q 'no majority\|no selectable sources' tmp/log.$i && \
+			grep -q 'Selected source' tmp/log.$i && \
+			test_ok || test_bad
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Check if incoming and outgoing packet intervals are sane
+check_packet_interval() {
+	local i ret=0 mean_in_interval mean_out_interval min_in_interval min_out_interval
+
+	test_message 2 1 "checking mean/min incoming/outgoing packet interval:"
+
+	for i in $(seq 1 $(get_chronyd_nodes)); do
+		mean_in_interval=$(get_stat 'Mean incoming packet interval' $i)
+		mean_out_interval=$(get_stat 'Mean outgoing packet interval' $i)
+		min_in_interval=$(get_stat 'Minimum incoming packet interval' $i)
+		min_out_interval=$(get_stat 'Minimum outgoing packet interval' $i)
+
+		test_message 3 0 "node $i: $(printf '%.2e %.2e %.2e %.2e' \
+			$mean_in_interval $mean_out_interval $min_in_interval $min_out_interval)"
+
+		# Check that the mean intervals are non-zero and shorter than
+		# limit, incoming is not longer than outgoing for stratum 1
+		# servers, outgoing is not longer than incoming for clients,
+		# and the minimum outgoing interval is not shorter than the NTP
+		# sampling separation or iburst interval for clients
+		nodes=$[$servers * $server_strata + $clients]
+		check_stat $mean_in_interval 0.1 inf && \
+			check_stat $mean_out_interval 0.1 inf && \
+			([ $i -gt $servers ] || \
+				check_stat $mean_in_interval 0.0 $mean_out_interval 10*$jitter) && \
+			([ $i -le $[$servers * $server_strata] ] || \
+				check_stat $mean_out_interval $client_min_mean_out_interval \
+					$mean_in_interval 10*$jitter) && \
+			([ $i -le $[$servers * $server_strata] ] || \
+				check_stat $min_out_interval \
+					$([ $servers -gt 1 ] && echo 0.18 || echo 1.8) \
+					$client_max_min_out_interval) && \
+			test_ok || test_bad
+
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Compare chronyc output with specified pattern
+check_chronyc_output() {
+	local i ret=0 pattern=$1
+
+	test_message 2 1 "checking chronyc output:"
+
+	for i in $(seq $[$(get_chronyd_nodes) + 1] $[$(get_chronyd_nodes) + $clients]); do
+		test_message 3 0 "node $i:"
+
+		[[ "$(cat tmp/log.$i)" =~ $pattern ]] && \
+			test_ok || test_bad
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Check the number of messages matching a pattern in the client logs
+check_log_messages() {
+	local i count ret=0 pattern=$1 min=$2 max=$3
+
+	test_message 2 1 "checking number of messages \"$pattern\":"
+
+	for i in $(seq $[$servers * $server_strata + 1] $(get_chronyd_nodes)); do
+		count=$(grep "$pattern" tmp/log.$i | wc -l)
+		test_message 3 0 "node $i: $count"
+
+		[ "$min" -le "$count" ] && [ "$count" -le "$max" ] && \
+			test_ok || test_bad
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Check the number of messages matching a pattern in a specified file
+check_file_messages() {
+	local i count ret=0 pattern=$1 min=$2 max=$3
+	shift 3
+
+	test_message 2 1 "checking number of messages \"$pattern\":"
+
+	for i; do
+		count=$(grep "$pattern" tmp/$i | wc -l)
+		test_message 3 0 "$i: $count"
+
+		[ "$min" -le "$count" ] && [ "$count" -le "$max" ] && \
+			test_ok || test_bad
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Check if only NTP port (123) was used
+check_packet_port() {
+	local i ret=0 port=123
+
+	test_message 2 1 "checking port numbers in packet log:"
+
+	for i in $(seq 1 $(get_chronyd_nodes)); do
+		test_message 3 0 "node $i:"
+
+		grep -E -q "^([0-9e.+-]+	){5}$port	" tmp/log.packets && \
+			! grep -E "^[0-9e.+-]+	$i	" tmp/log.packets | \
+			grep -E -q -v "^([0-9e.+-]+	){5}$port	" && \
+			test_ok || test_bad
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Print test settings which differ from default value
+print_nondefaults() {
+	local defoptname optname
+
+	test_message 2 1 "non-default settings:"
+	for defoptname in ${!default_*}; do
+		optname=${defoptname#default_}
+		[ "${!defoptname}" = "${!optname}" ] || \
+			test_message 3 1 $optname=${!optname}
+	done
+}
+
+run_simulation() {
+	local nodes=$1
+
+	test_message 2 0 "running simulation:"
+
+	start_server $nodes \
+		-o tmp/log.offset -f tmp/log.freq -p tmp/log.packets \
+		-R $(awk "BEGIN {print $update_interval < 0 ? 2^-($update_interval) : 1}") \
+		-r $(awk "BEGIN {print $max_sync_time * 2^$update_interval}") \
+		-l $(awk "BEGIN {print $limit * 2^$update_interval}") && test_ok || test_error
+}
+
+run_test() {
+	local i j n stratum node nodes step start freq offset conf options
+
+	test_message 1 1 "network with $servers*$server_strata servers and $clients clients:"
+	print_nondefaults
+
+	nodes=$(get_chronyd_nodes)
+	[ -n "$chronyc_conf" ] && nodes=$[$nodes + $clients]
+
+	for i in $(seq 1 $nodes); do
+		echo "node${i}_shift_pll = $shift_pll"
+		for j in $(seq 1 $nodes); do
+			echo "node${i}_delay${j} = $(get_delay_expr up)"
+			echo "node${j}_delay${i} = $(get_delay_expr down)"
+		done
+	done > tmp/conf
+
+	node=1
+
+	for stratum in $(seq 1 $[$server_strata + 1]); do
+		[ $stratum -le $server_strata ] && n=$servers || n=$clients
+
+		for i in $(seq 1 $n); do
+			test_message 2 0 "starting node $node:"
+			if [ $stratum -eq 1 ]; then
+				step=$server_step
+				start=$server_start
+				freq=""
+				[ $i -le $falsetickers ] && offset=$i.0 || offset=0.0
+				options=$server_chronyd_options
+			elif [ $stratum -le $server_strata ]; then
+				step=$server_step
+				start=$server_start
+				freq=$(get_wander_expr)
+				offset=0.0
+				options=$server_chronyd_options
+			else
+				step=$client_step
+				start=$client_start
+				freq=$(get_wander_expr)
+				offset=$time_offset
+				options=$client_chronyd_options
+			fi
+
+			conf=$(get_chronyd_conf $stratum $i $n)
+
+			[ -z "$freq" ] || echo "node${node}_freq = $freq" >> tmp/conf
+			[ -z "$step" ] || echo "node${node}_step = $step" >> tmp/conf
+			[ -z "$refclock_jitter" ] || \
+				echo "node${node}_refclock = $(get_refclock_expr)" >> tmp/conf
+			echo "node${node}_offset = $offset" >> tmp/conf
+			echo "node${node}_start = $start" >> tmp/conf
+			start_client $node chronyd "$conf" "" "$options" && \
+				test_ok || test_error
+
+			[ $? -ne 0 ] && return 1
+			node=$[$node + 1]
+		done
+	done
+
+	for i in $(seq 1 $[$nodes - $node + 1]); do
+		test_message 2 0 "starting node $node:"
+
+		echo "node${node}_start = $chronyc_start" >> tmp/conf
+		start_client $node chronyc "$chronyc_conf" "" \
+			"$([ $dns -eq 0 ] && printf "%s" "-n") -h $(get_node_name $[$node - $clients]) $chronyc_options" && \
+			test_ok || test_error
+
+		[ $? -ne 0 ] && return 1
+		node=$[$node + 1]
+	done
+
+	run_simulation $nodes
+}
diff --git a/test/system/001-minimal b/test/system/001-minimal
new file mode 100755
index 0000000..107fa3f
--- /dev/null
+++ b/test/system/001-minimal
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+test_start "minimal configuration"
+
+minimal_config=1
+
+start_chronyd || test_fail
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+
+test_pass
diff --git a/test/system/002-extended b/test/system/002-extended
new file mode 100755
index 0000000..7a6734f
--- /dev/null
+++ b/test/system/002-extended
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+test_start "extended configuration"
+
+start_chronyd || test_fail
+wait_for_sync || test_fail
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+check_chronyd_files || test_fail
+
+test_pass
diff --git a/test/system/003-memlock b/test/system/003-memlock
new file mode 100755
index 0000000..e4ab1bf
--- /dev/null
+++ b/test/system/003-memlock
@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+test_start "memory locking"
+
+extra_chronyd_options="-m"
+
+start_chronyd || test_fail
+wait_for_sync || test_fail
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+check_chronyd_files || test_fail
+
+test_pass
diff --git a/test/system/004-priority b/test/system/004-priority
new file mode 100755
index 0000000..bf8a04b
--- /dev/null
+++ b/test/system/004-priority
@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+test_start "process priority"
+
+extra_chronyd_options="-P 1"
+
+start_chronyd || test_fail
+wait_for_sync || test_fail
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+check_chronyd_files || test_fail
+
+test_pass
diff --git a/test/system/005-scfilter b/test/system/005-scfilter
new file mode 100755
index 0000000..778a688
--- /dev/null
+++ b/test/system/005-scfilter
@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+check_chronyd_features SCFILTER || test_skip "SCFILTER support disabled"
+
+test_start "system call filter"
+
+for extra_chronyd_options in "-F -1" "-F 1"; do
+	start_chronyd || test_fail
+	wait_for_sync || test_fail
+	stop_chronyd || test_fail
+	check_chronyd_messages || test_fail
+	check_chronyd_files || test_fail
+done
+
+test_pass
diff --git a/test/system/006-privdrop b/test/system/006-privdrop
new file mode 100755
index 0000000..6d7b0c9
--- /dev/null
+++ b/test/system/006-privdrop
@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+check_chronyd_features PRIVDROP || test_skip "PRIVDROP support disabled"
+
+user="nobody"
+
+test_start "dropping of root privileges"
+
+minimal_config=1
+
+start_chronyd || test_fail
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+
+test_pass
diff --git a/test/system/007-cmdmon b/test/system/007-cmdmon
new file mode 100755
index 0000000..37a1d34
--- /dev/null
+++ b/test/system/007-cmdmon
@@ -0,0 +1,157 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+test_start "chronyc commands"
+
+start_chronyd || test_fail
+wait_for_sync || test_fail
+
+for command in \
+	"allow 1.2.3.4" \
+	"deny 1.2.3.4" \
+	"cmddeny" \
+	"cmdallow" \
+	"cmddeny 1.2.3.4" \
+	"cmdallow 1.2.3.4" \
+	"add server 127.123.1.1" \
+	"delete 127.123.1.1" \
+	"burst 1/1" \
+	"cyclelogs" \
+	"dfreq 1.0e-3" \
+	"doffset -0.1" \
+	"dump" \
+	"local off" \
+	"local" \
+	"maxdelay $server 1e-1" \
+	"maxdelaydevratio $server 5.0" \
+	"maxdelayratio $server 3.0" \
+	"maxpoll $server 5" \
+	"maxupdateskew $server 10.0" \
+	"minpoll $server 3" \
+	"minstratum $server 1" \
+	"offline" \
+	"online" \
+	"onoffline" \
+	"polltarget $server 10" \
+	"refresh" \
+	"rekey" \
+	"reload sources" \
+	"reselect" \
+	"reselectdist 1e-3" \
+	"reset sources" \
+	"smoothtime reset" \
+	"smoothtime activate" \
+; do
+	run_chronyc "$command" || test_fail
+	check_chronyc_output "^200 OK$" || test_fail
+done
+
+run_chronyc "accheck $server" || test_fail
+check_chronyc_output "^208 Access allowed$" || test_fail
+run_chronyc "accheck 1.2.3.4" || test_fail
+check_chronyc_output "^209 Access denied$" || test_fail
+
+run_chronyc "cmdaccheck 1.2.3.4" || test_fail
+check_chronyc_output "^208 Access allowed$" || test_fail
+
+run_chronyc "authdata" || test_fail
+check_chronyc_output "^Name/IP address             Mode KeyID Type KLen Last Atmp  NAK Cook CLen
+=========================================================================
+127\.0\.0\.1                      -     0    0    0    -    0    0    0    0$" \
+	|| test_chronyc
+
+run_chronyc "clients" || test_fail
+check_chronyc_output "^Hostname                      NTP   Drop Int IntL Last     Cmd   Drop Int  Last
+===============================================================================
+127\.0\.0\.1                       [0-9 ]+    0 [-0-9 ]+   -     [0-9]       0      0   -     -$" \
+	|| test_fail
+
+run_chronyc "ntpdata $server" || test_fail
+check_chronyc_output "^Remote address  : 127\.0\.0\.1 \(7F000001\)
+Remote port     : [0-9]+
+Local address   : 127\.0\.0\.1 \(7F000001\)
+Leap status     : Normal
+Version         : 4
+Mode            : Server
+Stratum         : 10
+Poll interval   : (-6|[0345]) \([0-9]+ seconds\)
+Precision       : [0-9 +-]+ \(0\.[0-9]+ seconds\)
+Root delay      : 0\.000000 seconds
+Root dispersion : 0\.000000 seconds
+Reference ID    : 7F7F0101 \(\)
+Reference time  : [A-Za-z0-9: ]+
+Offset          : [+-]0\.......... seconds
+Peer delay      : 0\.......... seconds
+Peer dispersion : 0\.......... seconds
+Response time   : 0\.......... seconds
+Jitter asymmetry: \+0\.00
+NTP tests       : 111 111 1110
+Interleaved     : No
+Authenticated   : No
+TX timestamping : (Daemon|Kernel)
+RX timestamping : (Daemon|Kernel)
+Total TX        : [0-9]+
+Total RX        : [0-9]+
+Total valid RX  : [0-9]+$" || test_fail
+
+run_chronyc "selectdata" || test_fail
+check_chronyc_output "^S Name/IP Address        Auth COpts EOpts Last Score     Interval  Leap
+=======================================================================
+M 127\.0\.0\.1                 N ----- -----    0   1\.0    \+0ns    \+0ns  \?$" || test_fail
+
+run_chronyc "serverstats" || test_fail
+check_chronyc_output "^NTP packets received       : [0-9]+
+NTP packets dropped        : 0
+Command packets received   : [0-9]+
+Command packets dropped    : 0
+Client log records dropped : 0
+NTS-KE connections accepted: 0
+NTS-KE connections dropped : 0
+Authenticated NTP packets  : 0$" || test_fail
+
+run_chronyc "manual on" || test_fail
+check_chronyc_output "^200 OK$" || test_fail
+
+run_chronyc "settime now" || test_fail
+check_chronyc_output "^200 OK
+Clock was.*$" || test_fail
+
+run_chronyc "manual delete 0" || test_fail
+check_chronyc_output "^200 OK$" || test_fail
+
+run_chronyc "settime now" || test_fail
+check_chronyc_output "^200 OK
+Clock was.*$" || test_fail
+
+run_chronyc "manual list" || test_fail
+check_chronyc_output "^210 n_samples = 1
+#    Date     Time\(UTC\)    Slewed   Original   Residual
+=======================================================
+ 0.*$" || test_fail
+
+run_chronyc "manual reset" || test_fail
+check_chronyc_output "^200 OK$" || test_fail
+
+run_chronyc "manual off" || test_fail
+check_chronyc_output "^200 OK$" || test_fail
+
+run_chronyc "shutdown" || test_fail
+check_chronyc_output "^200 OK$" || test_fail
+
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+start_chronyd || test_fail
+
+run_chronyc "makestep" && test_fail
+check_chronyc_output "500 Failure" || test_fail
+
+run_chronyc "trimrtc" && test_fail
+check_chronyc_output "513 RTC driver not running" || test_fail
+
+run_chronyc "writertc" && test_fail
+check_chronyc_output "513 RTC driver not running" || test_fail
+
+stop_chronyd || test_fail
+
+test_pass
diff --git a/test/system/008-confload b/test/system/008-confload
new file mode 100755
index 0000000..689e38b
--- /dev/null
+++ b/test/system/008-confload
@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+test_start "loading of configuration"
+
+minimal_config=1
+extra_chronyd_directives="
+include $TEST_DIR/conf1.d/conf.1
+confdir $TEST_DIR/conf1.d
+confdir $TEST_DIR/conf2.d $TEST_DIR/conf3.d $TEST_DIR/conf4.d
+sourcedir $TEST_DIR/conf5.d
+include $TEST_DIR/conf1.d/conf.2"
+
+mkdir $TEST_DIR/conf{1,2,3,4,5}.d
+
+echo "server 127.123.1.1" > $TEST_DIR/conf1.d/conf.1
+echo "server 127.123.1.2" > $TEST_DIR/conf1.d/conf.2
+echo "server 127.123.1.3" > $TEST_DIR/conf1.d/3.conf
+echo "server 127.123.1.4" > $TEST_DIR/conf1.d/4.conf
+echo "server 127.123.2.2" > $TEST_DIR/conf2.d/2.conf
+echo "server 127.123.2.3" > $TEST_DIR/conf2.d/3.conf
+echo "server 127.123.3.1" > $TEST_DIR/conf3.d/1.conf
+echo "server 127.123.3.2" > $TEST_DIR/conf3.d/2.conf
+echo "server 127.123.3.3" > $TEST_DIR/conf3.d/3.conf
+echo "server 127.123.4.1" > $TEST_DIR/conf4.d/1.conf
+echo "server 127.123.4.2" > $TEST_DIR/conf4.d/2.conf
+echo "server 127.123.4.3" > $TEST_DIR/conf4.d/3.conf
+echo "server 127.123.4.4" > $TEST_DIR/conf4.d/4.conf
+echo "server 127.123.5.1" > $TEST_DIR/conf5.d/1.sources
+echo "server 127.123.5.2" > $TEST_DIR/conf5.d/2.sources
+echo "server 127.123.5.3" > $TEST_DIR/conf5.d/3.sources
+
+start_chronyd || test_fail
+wait_for_sync || test_fail
+
+run_chronyc "sources" || test_fail
+check_chronyc_output "^[^=]*
+=*
+.. 127\.123\.1\.1 [^^]*
+.. 127\.123\.1\.3 [^^]*
+.. 127\.123\.1\.4 [^^]*
+.. 127\.123\.3\.1 [^^]*
+.. 127\.123\.2\.2 [^^]*
+.. 127\.123\.2\.3 [^^]*
+.. 127\.123\.4\.4 [^^]*
+.. 127\.123\.1\.2 [^^]*
+.. 127\.123\.5\.1 [^^]*
+.. 127\.123\.5\.2 [^^]*
+.. 127\.123\.5\.3 [^^]*$" || test_fail
+
+rm $TEST_DIR/conf5.d/1.sources
+echo "server 127.123.5.2 minpoll 7" > $TEST_DIR/conf5.d/2.sources
+echo > $TEST_DIR/conf5.d/3.sources
+echo "server 127.123.5.4" > $TEST_DIR/conf5.d/4.sources
+
+run_chronyc "reload sources" || test_fail
+
+run_chronyc "sources" || test_fail
+check_chronyc_output "^[^=]*
+=*
+.. 127\.123\.1\.1 [^^]*
+.. 127\.123\.1\.3 [^^]*
+.. 127\.123\.1\.4 [^^]*
+.. 127\.123\.3\.1 [^^]*
+.. 127\.123\.2\.2 [^^]*
+.. 127\.123\.2\.3 [^^]*
+.. 127\.123\.4\.4 [^^]*
+.. 127\.123\.1\.2 *0   6 [^^]*
+.. 127\.123\.5\.2 *0   7 [^^]*
+.. 127\.123\.5\.4 [^^]*$" || test_fail
+
+stop_chronyd || test_fail
+
+test_pass
diff --git a/test/system/009-binddevice b/test/system/009-binddevice
new file mode 100755
index 0000000..fc64ae2
--- /dev/null
+++ b/test/system/009-binddevice
@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+[ "$(uname -s)" = "Linux" ] || test_skip "non-Linux system"
+
+test_start "binddevice directives"
+
+extra_chronyd_directives="
+binddevice lo
+bindacqdevice lo
+bindcmddevice lo"
+
+start_chronyd || test_fail
+wait_for_sync || test_fail
+
+run_chronyc "ntpdata $server" || test_fail
+check_chronyc_output "^Remote address" || test_fail
+
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+check_chronyd_files || test_fail
+
+test_pass
diff --git a/test/system/100-clockupdate b/test/system/100-clockupdate
new file mode 100755
index 0000000..191e461
--- /dev/null
+++ b/test/system/100-clockupdate
@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+test_start "update of system clock"
+
+clock_control=1
+minimal_config=1
+
+start_chronyd || test_fail
+run_chronyc "dfreq 1e-3" || test_fail
+check_chronyc_output "200 OK" || test_fail
+
+before=$(date '+%s')
+run_chronyc "doffset -1.0" || test_fail
+check_chronyc_output "200 OK" || test_fail
+run_chronyc "makestep" || test_fail
+check_chronyc_output "200 OK" || test_fail
+after=$(date '+%s')
+
+test_message 1 0 "checking system clock"
+[ "$before" -lt "$after" ] && test_ok || test_bad || test_fail
+
+run_chronyc "doffset 1.0" || test_fail
+run_chronyc "makestep" || test_fail
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+check_chronyd_message_count "System clock was stepped by" 2 2 || test_fail
+
+test_pass
diff --git a/test/system/101-rtc b/test/system/101-rtc
new file mode 100755
index 0000000..68bce68
--- /dev/null
+++ b/test/system/101-rtc
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+check_chronyd_features RTC || test_skip "RTC support disabled"
+[ -c "/dev/rtc" ] || test_skip "missing /dev/rtc"
+
+test_start "real-time clock"
+
+minimal_config=1
+extra_chronyd_options="-s"
+extra_chronyd_directives="rtcfile $TEST_DIR/rtcfile"
+echo "1 $(date +%s) 0.0 0.0" > "$TEST_DIR/rtcfile"
+
+start_chronyd || test_fail
+stop_chronyd || test_fail
+check_chronyd_message_count "\(clock off from RTC\|RTC time before last\|Could not \(enable\|disable\) RTC interrupt\)" 1 1 || test_fail
+
+test_pass
diff --git a/test/system/102-hwtimestamp b/test/system/102-hwtimestamp
new file mode 100755
index 0000000..6b86d20
--- /dev/null
+++ b/test/system/102-hwtimestamp
@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+[ "$(uname -s)" = "Linux" ] || test_skip "non-Linux system"
+
+hwts_iface=""
+for iface_path in /sys/class/net/*; do
+	iface=$(basename "$iface_path")
+	if ethtool -T "$iface" 2> /dev/null | grep -q '	all\($\| \)'; then
+		hwts_iface="$iface"
+		break
+	fi
+done
+
+[ -n "$hwts_iface" ] || test_skip "no HW timestamping interface found"
+
+test_start "hardware timestamping"
+
+minimal_config=1
+extra_chronyd_directives="hwtimestamp $hwts_iface"
+
+start_chronyd || test_fail
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+check_chronyd_message_count "Enabled HW timestamping on $hwts_iface" 1 1 || test_fail
+
+test_pass
diff --git a/test/system/103-refclock b/test/system/103-refclock
new file mode 100755
index 0000000..e5b74e0
--- /dev/null
+++ b/test/system/103-refclock
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+check_chronyd_features REFCLOCK || test_skip "refclock support disabled"
+
+test_start "reference clocks"
+
+extra_chronyd_directives="
+refclock SOCK $TEST_DIR/refclock.sock
+refclock SHM 100"
+
+start_chronyd || test_fail
+wait_for_sync || test_fail
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+check_chronyd_files || test_fail
+
+test_pass
diff --git a/test/system/104-systemdirs b/test/system/104-systemdirs
new file mode 100755
index 0000000..15508dc
--- /dev/null
+++ b/test/system/104-systemdirs
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+TEST_LIBDIR=${CHRONY_LIBDIR:-/var/lib/chrony}
+TEST_LOGDIR=${CHRONY_LOGDIR:-/var/log/chrony}
+TEST_RUNDIR=${CHRONY_RUNDIR:-/var/run/chrony}
+
+. ./test.common
+
+user=$(ls -ld "$TEST_RUNDIR" 2> /dev/null | awk '{print $3}')
+
+test_start "system directories"
+
+start_chronyd || test_fail
+wait_for_sync || test_fail
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+check_chronyd_files || test_fail
+
+test_pass
diff --git a/test/system/105-nts b/test/system/105-nts
new file mode 100755
index 0000000..5833b2f
--- /dev/null
+++ b/test/system/105-nts
@@ -0,0 +1,72 @@
+#!/usr/bin/env bash
+
+. ./test.common
+
+server_name="chrony-nts-test"
+
+check_chronyd_features NTS || test_skip "NTS support disabled"
+certtool --help &> /dev/null || test_skip "certtool missing"
+sed -i "/ $server_name\$/d" /etc/hosts && echo "$server $server_name" >> /etc/hosts || \
+	test_skip "Cannot modify /etc/hosts"
+
+check_chronyd_features PRIVDROP && user="nobody"
+
+test_start "NTS authentication"
+
+cat > $TEST_DIR/cert.cfg <<EOF
+cn = "$server_name"
+serial = 001
+activation_date = "$(date -d '1 year ago' +'%Y-%m-%d') 00:00:00 UTC"
+expiration_date = "$(date -d '1 year' +'%Y-%m-%d') 00:00:00 UTC"
+signing_key
+encryption_key
+EOF
+
+certtool --generate-privkey --key-type=ed25519 --outfile $TEST_DIR/server.key \
+	&> $TEST_DIR/certtool.log
+certtool --generate-self-signed --load-privkey $TEST_DIR/server.key \
+	--template $TEST_DIR/cert.cfg --outfile $TEST_DIR/server.crt &>> $TEST_DIR/certtool.log
+chown $user $TEST_DIR/server.*
+
+ntpport=$(get_free_port)
+ntsport=$(get_free_port)
+
+server_options="port $ntpport nts ntsport $ntsport"
+extra_chronyd_directives="
+port $ntpport
+ntsport $ntsport
+ntsserverkey $TEST_DIR/server.key
+ntsservercert $TEST_DIR/server.crt
+ntstrustedcerts $TEST_DIR/server.crt
+ntsdumpdir $TEST_LIBDIR
+ntsprocesses 3"
+
+start_chronyd || test_fail
+sleep 3
+
+run_chronyc "authdata" || test_fail
+check_chronyc_output "^Name/IP address             Mode KeyID Type KLen Last Atmp  NAK Cook CLen
+=========================================================================
+127\.0\.0\.1                    NTS     1   15  256    [0-9]    0    0    [78]  100$" || test_fail
+
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+check_chronyd_files || test_fail
+
+rm -f $TEST_LOGDIR/measurements.log
+
+server_options="port $ntpport nts ntsport $((ntsport + 1))"
+
+start_chronyd || test_fail
+sleep 2
+
+run_chronyc "authdata" || test_fail
+check_chronyc_output "^Name/IP address             Mode KeyID Type KLen Last Atmp  NAK Cook CLen
+=========================================================================
+127\.0\.0\.1                    NTS     1   15  256    [0-9]    0    0    [78]  100$" || test_fail
+
+stop_chronyd || test_fail
+check_chronyd_messages || test_fail
+check_chronyd_files || test_fail
+
+test_pass
diff --git a/test/system/run b/test/system/run
new file mode 100755
index 0000000..5516ed4
--- /dev/null
+++ b/test/system/run
@@ -0,0 +1,64 @@
+#!/usr/bin/env bash
+
+print_help() {
+	echo "$1 [-a] [-d] [TEST]..."
+}
+
+run_test() {
+	local result name=$1
+
+	if [ $destructive -ne 1 ] && [[ "$name" == 1[0-9][0-9]-* ]]; then
+		echo "SKIP (destructive test)"
+		return 9
+	fi
+
+	./$name
+	result=$?
+
+	if [ $result -ne 0 -a $result -ne 9 ]; then
+		if [ $abort_on_fail -ne 0 ]; then
+			exit 1
+		fi
+	fi
+
+	return $result
+}
+
+passed=() failed=() skipped=()
+
+abort_on_fail=0
+destructive=0
+
+while getopts ":ad" opt; do
+	case $opt in
+		a) abort_on_fail=1;;
+		d) destructive=1;;
+		*) print_help "$0"; exit 3;;
+	esac
+done
+
+shift $[$OPTIND - 1]
+
+[ $# -gt 0 ] && tests=($@) || tests=([0-9]*-*[^_])
+
+for test in "${tests[@]}"; do
+	printf "%s   " "$test"
+	run_test $test
+	result=$?
+	echo
+
+	case $result in
+		0) passed=(${passed[@]} $test);;
+		9) skipped=(${skipped[@]} $test);;
+		*) failed=(${failed[@]} $test);;
+	esac
+done
+
+echo
+echo "SUMMARY:"
+echo "  TOTAL  $[${#passed[@]} + ${#failed[@]} + ${#skipped[@]}]"
+echo "  PASSED ${#passed[@]}"
+echo "  FAILED ${#failed[@]}    (${failed[@]})"
+echo "  SKIPPED ${#skipped[@]}   (${skipped[@]})"
+
+[ ${#failed[@]} -eq 0 ]
diff --git a/test/system/test.common b/test/system/test.common
new file mode 100644
index 0000000..1e48819
--- /dev/null
+++ b/test/system/test.common
@@ -0,0 +1,338 @@
+# Copyright (C) Miroslav Lichvar  2009
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of version 2 of the GNU General Public License as
+# published by the Free Software Foundation.
+# 
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+export LC_ALL=C
+export PATH=${CHRONY_PATH:-../..}:$PATH
+
+TEST_DIR=${TEST_DIR:-$(pwd)/tmp}
+TEST_LIBDIR=${TEST_LIBDIR:-$TEST_DIR}
+TEST_LOGDIR=${TEST_LOGDIR:-$TEST_DIR}
+TEST_RUNDIR=${TEST_RUNDIR:-$TEST_DIR}
+
+test_start() {
+	check_chronyd_features NTP CMDMON || test_skip "NTP/CMDMON support disabled"
+
+	[ "${#TEST_DIR}" -ge 5 ] || test_skip "invalid TEST_DIR"
+
+	rm -rf "$TEST_DIR"
+	mkdir -p "$TEST_DIR" && chmod 700 "$TEST_DIR" || test_skip "could not create $TEST_DIR"
+
+	[ -d "$TEST_LIBDIR" ] || test_skip "missing $TEST_LIBDIR"
+	[ -d "$TEST_LOGDIR" ] || test_skip "missing $TEST_LOGDIR"
+	[ -d "$TEST_RUNDIR" ] || test_skip "missing $TEST_RUNDIR"
+
+	rm -f "$TEST_LIBDIR"/* "$TEST_LOGDIR"/* "$TEST_RUNDIR"/*
+
+	if [ "$user" != "root" ]; then
+		id -u "$user" > /dev/null 2> /dev/null || test_skip "missing user $user"
+		chown "$user:$(id -g "$user")" "$TEST_DIR" || test_skip "could not chown $TEST_DIR"
+		su "$user" -s /bin/sh -c "touch $TEST_DIR/test" 2> /dev/null || \
+			test_skip "$user cannot access $TEST_DIR"
+		rm "$TEST_DIR/test"
+	fi
+
+	echo "Testing $*:"
+}
+
+test_pass() {
+	echo "PASS"
+	exit 0
+}
+
+test_fail() {
+	echo "FAIL"
+	exit 1
+}
+
+test_skip() {
+	local msg=$1
+
+	[ -n "$msg" ] && echo "SKIP ($msg)" || echo "SKIP"
+	exit 9
+}
+
+test_ok() {
+	pad_line
+	echo -e "\tOK"
+	return 0
+}
+
+test_bad() {
+	pad_line
+	echo -e "\tBAD"
+	return 1
+}
+
+test_error() {
+	pad_line
+	echo -e "\tERROR"
+	return 1
+}
+
+chronyd=$(command -v chronyd)
+chronyc=$(command -v chronyc)
+
+[ $EUID -eq 0 ] || test_skip "not root"
+
+[ -x "$chronyd" ] || test_skip "chronyd not found"
+[ -x "$chronyc" ] || test_skip "chronyc not found"
+
+netstat -aln > /dev/null 2> /dev/null || test_skip "missing netstat"
+
+# Default test testings
+default_minimal_config=0
+default_extra_chronyd_directives=""
+default_extra_chronyd_options=""
+default_clock_control=0
+default_server=127.0.0.1
+default_server_name=127.0.0.1
+default_server_options=""
+default_user=root
+
+# Initialize test settings from their defaults
+for defoptname in ${!default_*}; do
+	optname=${defoptname#default_}
+	[ -z "${!optname}" ] && declare "$optname"="${!defoptname}"
+done
+
+msg_length=0
+pad_line() {
+	local line_length=56
+	[ $msg_length -lt $line_length ] && \
+		printf "%$((line_length - msg_length))s" ""
+	msg_length=0
+}
+
+# Print aligned message
+test_message() {
+	local level=$1 eol=$2
+	shift 2
+	local msg="$*"
+
+	while [ "$level" -gt 0 ]; do
+		echo -n "  "
+		level=$((level - 1))
+		msg_length=$((msg_length + 2))
+	done
+	echo -n "$msg"
+
+	msg_length=$((msg_length + ${#msg}))
+	if [ "$eol" -ne 0 ]; then
+		echo
+		msg_length=0
+	fi
+}
+
+# Check if chronyd has specified features
+check_chronyd_features() {
+	local feature features
+
+	features=$($chronyd -v | sed 's/.*(\(.*\)).*/\1/')
+
+	for feature; do
+		echo "$features" | grep -q "+$feature" || return 1
+	done
+}
+
+# Print test settings which differ from default value
+print_nondefaults() {
+	local defoptname optname
+
+	test_message 1 1 "non-default settings:"
+	for defoptname in ${!default_*}; do
+		optname=${defoptname#default_}
+		[ "${!defoptname}" = "${!optname}" ] || \
+			test_message 2 1 "$optname"=${!optname}
+	done
+}
+
+get_conffile() {
+	echo "$TEST_DIR/chronyd.conf"
+}
+
+get_pidfile() {
+	echo "$TEST_RUNDIR/chronyd.pid"
+}
+
+get_logfile() {
+	echo "$TEST_LOGDIR/chronyd.log"
+}
+
+get_cmdsocket() {
+	echo "$TEST_RUNDIR/chronyd.sock"
+}
+
+# Find a free port in the 10000-20000 range (their use is racy)
+get_free_port() {
+	local port
+
+	while true; do
+		port=$((RANDOM % 10000 + 10000))
+		netstat -aln | grep '^\(tcp\|udp\).*[:.]'"$port " && continue
+		break
+	done
+
+	echo $port
+}
+
+generate_chrony_conf() {
+	local ntpport cmdport
+
+	ntpport=$(get_free_port)
+	cmdport=$(get_free_port)
+
+	echo "0.0 10000" > "$TEST_LIBDIR/driftfile"
+	echo "1 MD5 abcdefghijklmnopq" > "$TEST_DIR/keys"
+	chown "$user:$(id -g "$user")" "$TEST_LIBDIR/driftfile" "$TEST_DIR/keys"
+	echo "0.0" > "$TEST_DIR/tempcomp"
+
+	(
+		echo "pidfile $(get_pidfile)"
+		echo "bindcmdaddress $(get_cmdsocket)"
+		echo "port $ntpport"
+		echo "cmdport $cmdport"
+
+		echo "$extra_chronyd_directives"
+
+		[ "$minimal_config" -ne 0 ] && exit 0
+
+		echo "allow"
+		echo "cmdallow"
+		echo "local"
+
+		echo "server $server_name port $ntpport minpoll -6 maxpoll -6 $server_options"
+
+		[ "$server" = "127.0.0.1" ] && echo "bindacqaddress $server"
+		echo "bindaddress 127.0.0.1"
+		echo "bindcmdaddress 127.0.0.1"
+		echo "dumpdir $TEST_RUNDIR"
+		echo "logdir $TEST_LOGDIR"
+		echo "log tempcomp rawmeasurements refclocks statistics tracking rtc"
+		echo "logbanner 0"
+		echo "smoothtime 100.0 0.001"
+
+		echo "include /dev/null"
+		echo "keyfile $TEST_DIR/keys"
+		echo "driftfile $TEST_LIBDIR/driftfile"
+		echo "tempcomp $TEST_DIR/tempcomp 0.1 0 0 0 0"
+
+	) > "$(get_conffile)"
+}
+
+get_chronyd_options() {
+	[ "$clock_control" -eq 0 ] && echo "-x"
+	echo "-l $(get_logfile)"
+	echo "-f $(get_conffile)"
+	echo "-u $user"
+	echo "$extra_chronyd_options"
+}
+
+# Start a chronyd instance
+start_chronyd() {
+	local pid pidfile=$(get_pidfile)
+
+	print_nondefaults
+	test_message 1 0 "starting chronyd"
+
+	generate_chrony_conf
+
+	trap stop_chronyd EXIT
+
+	$CHRONYD_WRAPPER "$chronyd" $(get_chronyd_options) > "$TEST_DIR/chronyd.out" 2>&1
+
+	[ $? -eq 0 ] && [ -f "$pidfile" ] && ps -p "$(cat "$pidfile")" > /dev/null && test_ok || test_error
+}
+
+wait_for_sync() {
+	test_message 1 0 "waiting for synchronization"
+	sleep 1 && test_ok || test_error
+}
+
+# Stop the chronyd instance
+stop_chronyd() {
+	local pid pidfile
+
+	pidfile=$(get_pidfile)
+	[ -f "$pidfile" ] || return 0
+
+	pid=$(cat "$pidfile")
+
+	test_message 1 0 "stopping chronyd"
+
+	if ! kill "$pid" 2> /dev/null; then
+		test_error
+		return
+	fi
+
+	# Wait for the process to terminate (we cannot use "wait")
+	while ps -p "$pid" > /dev/null; do
+		sleep 0.1
+	done
+
+	test_ok
+}
+
+# Check chronyd log for expected and unexpected messages
+check_chronyd_messages() {
+	local logfile=$(get_logfile)
+
+	test_message 1 0 "checking chronyd messages"
+
+	grep -q 'chronyd exiting' "$logfile" && \
+		([ "$clock_control" -eq 0 ] || ! grep -q 'Disabled control of system clock' "$logfile") && \
+		([ "$clock_control" -ne 0 ] || grep -q 'Disabled control of system clock' "$logfile") && \
+		([ "$minimal_config" -ne 0 ] || grep -q 'Frequency .* read from' "$logfile") && \
+		grep -q 'chronyd exiting' "$logfile" && \
+		! grep -q 'Could not' "$logfile" && \
+		! grep -q 'Disabled command socket' "$logfile" && \
+		test_ok || test_bad
+}
+
+# Check the number of messages matching a pattern in a specified file
+check_chronyd_message_count() {
+	local count pattern=$1 min=$2 max=$3 logfile=$(get_logfile)
+
+	test_message 1 0 "checking message \"$pattern\""
+
+	count=$(grep "$pattern" "$(get_logfile)" | wc -l)
+
+	[ "$min" -le "$count" ] && [ "$count" -le "$max" ] && test_ok || test_bad
+}
+
+# Check the logs and dump file for measurements and a clock update
+check_chronyd_files() {
+	test_message 1 0 "checking chronyd files"
+
+	grep -q " $server .* 111 111 1110 " "$TEST_LOGDIR/measurements.log" && \
+		[ -f "$TEST_LOGDIR/tempcomp.log" ] && [ "$(wc -l < "$TEST_LOGDIR/tempcomp.log")" -ge 2 ] && \
+		test_ok || test_bad
+}
+
+# Run a chronyc command
+run_chronyc() {
+	test_message 1 0 "running chronyc $*"
+
+	$CHRONYC_WRAPPER "$chronyc" -h "$(get_cmdsocket)" -n -m "$@" > "$TEST_DIR/chronyc.out" && \
+		test_ok || test_error
+}
+
+# Compare chronyc output with specified pattern
+check_chronyc_output() {
+	local pattern=$1
+
+	test_message 1 0 "checking chronyc output"
+
+	[[ "$(cat "$TEST_DIR/chronyc.out")" =~ $pattern ]] && test_ok || test_bad
+}
diff --git a/test/unit/Makefile.in b/test/unit/Makefile.in
new file mode 100644
index 0000000..9979840
--- /dev/null
+++ b/test/unit/Makefile.in
@@ -0,0 +1,48 @@
+TEST_WRAPPER =
+CHRONY_SRCDIR = ../..
+
+CC = @CC@
+CFLAGS = @CFLAGS@
+CPPFLAGS = -I$(CHRONY_SRCDIR) @CPPFLAGS@
+LDFLAGS = @LDFLAGS@ @LIBS@ @EXTRA_LIBS@
+
+SHARED_OBJS = test.o
+
+TEST_OBJS := $(sort $(patsubst %.c,%.o,$(wildcard *.c)))
+TESTS := $(patsubst %.o,%.test,$(filter-out $(SHARED_OBJS),$(TEST_OBJS)))
+
+CHRONYD_OBJS := $(patsubst %.o,$(CHRONY_SRCDIR)/%.o,$(filter-out main.o,\
+		  $(filter %.o,$(shell $(MAKE) -f $(CHRONY_SRCDIR)/Makefile \
+					print-chronyd-objects NODEPS=1))))
+
+all: $(TESTS)
+
+$(CHRONYD_OBJS): ;
+
+%.test: %.o $(SHARED_OBJS) $(CHRONYD_OBJS)
+	$(CC) $(CFLAGS) -o $@ $(filter-out $(CHRONY_SRCDIR)/$<,$^) $(LDFLAGS)
+
+%.o: %.c
+	$(CC) $(CPPFLAGS) $(CFLAGS) -c $<
+
+check: $(TESTS)
+	@ret=0; \
+	for t in $^; do \
+	  $(TEST_WRAPPER) ./$$t || ret=1; \
+	done; \
+	exit $$ret
+
+clean:
+	rm -f *.o *.gcda *.gcno core.* $(TESTS)
+	rm -rf .deps
+
+distclean: clean
+	rm -f Makefile
+
+.deps:
+	@mkdir .deps
+
+.deps/%.d: %.c | .deps
+	@$(CC) -MM $(CPPFLAGS) -MT '$(<:%.c=%.o) $@' $< -o $@
+
+-include $(TEST_OBJS:%.o=.deps/%.d)
diff --git a/test/unit/addrfilt.c b/test/unit/addrfilt.c
new file mode 100644
index 0000000..b236073
--- /dev/null
+++ b/test/unit/addrfilt.c
@@ -0,0 +1,83 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <addrfilt.c>
+#include <logging.h>
+#include <util.h>
+#include "test.h"
+
+void
+test_unit(void)
+{
+  int i, j, sub, maxsub;
+  IPAddr ip;
+  ADF_AuthTable table;
+
+  table = ADF_CreateTable();
+
+  for (i = 0; i < 100; i++) {
+    for (j = 0; j < 1000; j++) {
+      if (j % 2) {
+        maxsub = 32;
+        TST_GetRandomAddress(&ip, IPADDR_INET4, -1);
+      } else {
+        maxsub = 128;
+        TST_GetRandomAddress(&ip, IPADDR_INET6, -1);
+      }
+
+      DEBUG_LOG("address %s", UTI_IPToString(&ip));
+
+      sub = random() % (maxsub + 1);
+
+      TEST_CHECK(!ADF_IsAllowed(table, &ip));
+      ADF_Allow(table, &ip, sub);
+      TEST_CHECK(ADF_IsAllowed(table, &ip));
+
+      if (sub < maxsub) {
+        TST_SwapAddressBit(&ip, sub);
+        TEST_CHECK(ADF_IsAllowed(table, &ip));
+      }
+
+      if (sub > 0) {
+        TST_SwapAddressBit(&ip, sub - 1);
+        TEST_CHECK(!ADF_IsAllowed(table, &ip));
+        if (sub % 4 != 1) {
+          ADF_Deny(table, &ip, sub - 1);
+          TST_SwapAddressBit(&ip, sub - 1);
+          TEST_CHECK(!ADF_IsAllowed(table, &ip));
+        }
+      }
+
+      if (sub > 4) {
+        ADF_AllowAll(table, &ip, sub - 4);
+        TEST_CHECK(ADF_IsAllowed(table, &ip));
+      }
+
+      ADF_DenyAll(table, &ip, 0);
+    }
+
+    ip.family = IPADDR_INET4;
+    ADF_DenyAll(table, &ip, 0);
+    ip.family = IPADDR_INET6;
+    ADF_DenyAll(table, &ip, 0);
+  }
+
+  ADF_DestroyTable(table);
+}
diff --git a/test/unit/clientlog.c b/test/unit/clientlog.c
new file mode 100644
index 0000000..850cedf
--- /dev/null
+++ b/test/unit/clientlog.c
@@ -0,0 +1,94 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include "test.h"
+
+#if defined(FEAT_NTP) || defined(FEAT_CMDMON)
+
+#include <clientlog.c>
+
+void
+test_unit(void)
+{
+  int i, j, index;
+  CLG_Service s;
+  struct timespec ts;
+  IPAddr ip;
+  char conf[][100] = {
+    "clientloglimit 10000",
+    "ratelimit interval 3 burst 4 leak 3",
+    "cmdratelimit interval 3 burst 4 leak 3",
+    "ntsratelimit interval 6 burst 8 leak 3",
+  };
+
+  CNF_Initialise(0, 0);
+  for (i = 0; i < sizeof conf / sizeof conf[0]; i++)
+    CNF_ParseLine(NULL, i + 1, conf[i]);
+
+  CLG_Initialise();
+
+  TEST_CHECK(ARR_GetSize(records) == 16);
+
+  for (i = 0; i < 500; i++) {
+    DEBUG_LOG("iteration %d", i);
+
+    ts.tv_sec = (time_t)random() & 0x0fffffff;
+    ts.tv_nsec = 0;
+
+    for (j = 0; j < 1000; j++) {
+      TST_GetRandomAddress(&ip, IPADDR_UNSPEC, i % 8 ? -1 : i / 8 % 9);
+      DEBUG_LOG("address %s", UTI_IPToString(&ip));
+
+      s = random() % MAX_SERVICES;
+      index = CLG_LogServiceAccess(s, &ip, &ts);
+      TEST_CHECK(index >= 0);
+      CLG_LimitServiceRate(s, index);
+
+      UTI_AddDoubleToTimespec(&ts, (1 << random() % 14) / 100.0, &ts);
+    }
+  }
+
+  DEBUG_LOG("records %u", ARR_GetSize(records));
+  TEST_CHECK(ARR_GetSize(records) == 64);
+
+  s = CLG_NTP;
+
+  for (i = j = 0; i < 10000; i++) {
+    ts.tv_sec += 1;
+    index = CLG_LogServiceAccess(s, &ip, &ts);
+    TEST_CHECK(index >= 0);
+    if (!CLG_LimitServiceRate(s, index))
+      j++;
+  }
+
+  DEBUG_LOG("requests %d responses %d", i, j);
+  TEST_CHECK(j * 4 < i && j * 6 > i);
+
+  CLG_Finalise();
+  CNF_Finalise();
+}
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/cmac.c b/test/unit/cmac.c
new file mode 100644
index 0000000..be4ffbb
--- /dev/null
+++ b/test/unit/cmac.c
@@ -0,0 +1,109 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2019
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include <sysincl.h>
+#include <cmac.h>
+#include <logging.h>
+#include <util.h>
+#include "test.h"
+
+#define MAX_KEY_LENGTH 64
+#define MAX_HASH_LENGTH 64
+
+struct cmac_test {
+  const char *name;
+  const unsigned char key[MAX_KEY_LENGTH];
+  int key_length;
+  const unsigned char hash[MAX_HASH_LENGTH];
+  int hash_length;
+};
+
+void
+test_unit(void)
+{
+  unsigned char data[] = "abcdefghijklmnopqrstuvwxyz0123456789";
+  unsigned char hash[MAX_HASH_LENGTH];
+  struct cmac_test tests[] = {
+    { "AES128", "\xfc\x24\x97\x1b\x52\x66\xdc\x46\xef\xe0\xe8\x08\x46\x89\xb6\x88", 16,
+                "\xaf\x3c\xfe\xc2\x66\x71\x08\x04\xd4\xaf\x5b\x16\x2b\x11\xf4\x85", 16 },
+    { "AES256", "\x14\x02\x8e\x7d\x17\x3c\x2f\x4e\x17\x0f\x37\x96\xc3\x2c\xc5\x99"
+                "\x18\xdd\x55\x23\xb7\xd7\x9b\xc5\x76\x36\x88\x3f\xc5\x82\xb5\x83", 32,
+                "\xfe\xf7\x94\x96\x14\x04\x11\x0b\x87\xe4\xd4\x3f\x81\xb3\xb2\x2d", 16 },
+    { "", "", 0, "", 0 }
+  };
+
+  CMC_Algorithm algorithm;
+  CMC_Instance inst;
+  int i, j, length;
+
+#ifndef HAVE_CMAC
+  TEST_REQUIRE(0);
+#endif
+
+  TEST_CHECK(CMC_INVALID == 0);
+
+  for (i = 0; tests[i].name[0] != '\0'; i++) {
+    algorithm = UTI_CmacNameToAlgorithm(tests[i].name);
+    TEST_CHECK(algorithm != 0);
+    TEST_CHECK(CMC_GetKeyLength(algorithm) == tests[i].key_length);
+
+    DEBUG_LOG("testing %s", tests[i].name);
+
+    for (j = -1; j <= 128; j++) {
+      if (j == tests[i].key_length)
+        continue;
+      TEST_CHECK(!CMC_CreateInstance(algorithm, tests[i].key, j));
+    }
+
+    inst = CMC_CreateInstance(algorithm, tests[i].key, tests[i].key_length);
+    TEST_CHECK(inst);
+
+    TEST_CHECK(!CMC_CreateInstance(0, tests[i].key, tests[i].key_length));
+
+    TEST_CHECK(CMC_Hash(inst, data, -1, hash, sizeof (hash)) == 0);
+    TEST_CHECK(CMC_Hash(inst, data, sizeof (data) - 1, hash, -1) == 0);
+
+    for (j = 0; j <= sizeof (hash); j++) {
+      memset(hash, 0, sizeof (hash));
+      length = CMC_Hash(inst, data, sizeof (data) - 1, hash, j);
+
+#if 0
+      for (int k = 0; k < length; k++)
+        printf("\\x%02x", hash[k]);
+      printf("\n");
+#endif
+
+      if (j >= tests[i].hash_length)
+        TEST_CHECK(length == tests[i].hash_length);
+      else
+        TEST_CHECK(length == j);
+
+      TEST_CHECK(!memcmp(hash, tests[i].hash, length));
+    }
+
+    for (j = 0; j < sizeof (data); j++) {
+      length = CMC_Hash(inst, data, j, hash, sizeof (hash));
+      TEST_CHECK(length == tests[i].hash_length);
+    }
+
+    CMC_DestroyInstance(inst);
+  }
+}
diff --git a/test/unit/hash.c b/test/unit/hash.c
new file mode 100644
index 0000000..d57c915
--- /dev/null
+++ b/test/unit/hash.c
@@ -0,0 +1,124 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2018
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include <sysincl.h>
+#include <hash.h>
+#include <logging.h>
+#include <util.h>
+#include "test.h"
+
+struct hash_test {
+  const char *name;
+  const unsigned char out[MAX_HASH_LENGTH];
+  int length;
+};
+
+void
+test_unit(void)
+{
+  unsigned char data1[] = "abcdefghijklmnopqrstuvwxyz";
+  unsigned char data2[] = "12345678910";
+  unsigned char out[MAX_HASH_LENGTH];
+  struct hash_test tests[] = {
+    { "MD5",       "\xfc\x24\x97\x1b\x52\x66\xdc\x46\xef\xe0\xe8\x08\x46\x89\xb6\x88", 16 },
+    { "SHA1",      "\xd8\x85\xb3\x86\xce\xea\x93\xeb\x92\xcd\x7b\x94\xb9\x8d\xc2\x8e"
+                   "\x3e\x31\x13\xdd", 20},
+    { "SHA256",    "\x0e\x35\x14\xe7\x15\x7a\x1d\xdd\xea\x11\x78\xd3\x41\xf6\xb9\x3e"
+                   "\xa0\x42\x96\x73\x3c\x54\x74\x0b\xfa\x6b\x9e\x29\x59\xad\x69\xd3", 32 },
+    { "SHA384",    "\x2c\xeb\xbd\x4d\x95\xed\xad\x03\xed\x80\xc4\xf3\xa6\x10\x21\xde"
+                   "\x40\x69\x54\xed\x42\x70\xb8\x95\xb0\x6f\x01\x1d\x04\xdf\x57\xbc"
+                   "\x1d\xb5\x85\xbf\x4f\x03\x88\xd5\x83\x93\xbc\x81\x90\xb0\xa9\x9b", 48 },
+    { "SHA512",    "\x20\xba\xec\xcb\x68\x98\x33\x5b\x70\x26\x63\x13\xe2\xf7\x0e\x67"
+                   "\x08\xf3\x77\x4f\xbd\xeb\xc4\xa8\xc5\x94\xe2\x39\x40\x7e\xed\x0b"
+                   "\x69\x0e\x18\xa5\xa2\x03\x73\xe7\x1d\x20\x7d\x3f\xc8\x70\x2d\x64"
+                   "\x9e\x89\x6d\x20\x6a\x4a\x5a\x46\xe7\x4f\x2c\xf9\x0f\x0a\x54\xdc", 64 },
+    { "SHA3-224",  "\x3b\xa2\x22\x28\xdd\x26\x18\xec\x3b\xb9\x25\x39\x5e\xbd\x94\x25"
+                   "\xd4\x20\x8a\x76\x76\xc0\x3c\x5d\x9e\x0a\x06\x46", 28},
+    { "SHA3-256",  "\x26\xd1\x19\xb2\xc1\x64\xc8\xb8\x10\xd8\xa8\x1c\xb6\xa4\x0d\x29"
+                   "\x09\xc9\x8e\x2e\x2d\xde\x7a\x74\x8c\x43\x70\xb8\xaa\x0f\x09\x17", 32 },
+    { "SHA3-384",  "\x6a\x64\xb9\x89\x08\x29\xd0\xa7\x4b\x84\xba\xa6\x65\xf5\xe7\x54"
+                   "\xe2\x18\x12\xc3\x63\x34\xc6\xba\x26\xf5\x6e\x99\xe2\x54\xcc\x9d"
+                   "\x01\x10\x9d\xee\x35\x38\x04\x83\xe5\x71\x70\xd8\xc8\x99\x96\xd8", 48 },
+    { "SHA3-512",  "\xa8\xe3\x2b\x65\x1f\x87\x90\x73\x19\xc8\xa0\x3f\xe3\x85\x60\x3c"
+                   "\x39\xfc\xcb\xc1\x29\xe1\x23\x7d\x8b\x56\x54\xe3\x08\x9d\xf9\x74"
+                   "\x78\x69\x2e\x3c\x7e\x51\x1e\x9d\xab\x09\xbe\xe7\x6b\x1a\xa1\x22"
+                   "\x93\xb1\x2b\x82\x9d\x1e\xcf\xa8\x99\xc5\xec\x7b\x1d\x89\x07\x2b", 64 },
+    { "TIGER",     "\x1c\xcd\x68\x74\xca\xd6\xd5\x17\xba\x3e\x82\xaf\xbd\x70\xdc\x66"
+                   "\x99\xaa\xae\x16\x72\x59\xd1\x64", 24},
+    { "WHIRLPOOL", "\xe3\xcd\xe6\xbf\xe1\x8c\xe4\x4d\xc8\xb4\xa5\x7c\x36\x8d\xc8\x8a"
+                   "\x8b\xad\x52\x24\xc0\x4e\x99\x5b\x7e\x86\x94\x2d\x10\x56\x12\xa3"
+                   "\x29\x2a\x65\x0f\x9e\x07\xbc\x15\x21\x14\xe6\x07\xfc\xe6\xb9\x2f"
+                   "\x13\xe2\x57\xe9\x0a\xb0\xd2\xf4\xa3\x20\x36\x9c\x88\x92\x8e\xc9", 64 },
+    { "", "", 0 }
+  };
+
+  HSH_Algorithm algorithm;
+  int i, j, hash_id, length;
+
+  TEST_CHECK(HSH_INVALID == 0);
+
+  for (i = 0; tests[i].name[0] != '\0'; i++) {
+    algorithm = UTI_HashNameToAlgorithm(tests[i].name);
+    TEST_CHECK(algorithm != 0);
+    hash_id = HSH_GetHashId(algorithm);
+    if (hash_id < 0) {
+      TEST_CHECK(algorithm != HSH_MD5);
+#ifdef FEAT_SECHASH
+      TEST_CHECK(algorithm != HSH_SHA1);
+      TEST_CHECK(algorithm != HSH_SHA256);
+      TEST_CHECK(algorithm != HSH_SHA384);
+      TEST_CHECK(algorithm != HSH_SHA512);
+#endif
+      continue;
+    }
+
+    DEBUG_LOG("testing %s", tests[i].name);
+
+    TEST_CHECK(HSH_Hash(hash_id, data1, -1, NULL, 0, out, sizeof (out)) == 0);
+    TEST_CHECK(HSH_Hash(hash_id, data1, sizeof (data1) - 1, data2, -1, out, sizeof (out)) == 0);
+    TEST_CHECK(HSH_Hash(hash_id, data1, sizeof (data1) - 1, NULL, 0, out, -1) == 0);
+
+    for (j = 0; j <= sizeof (out); j++) {
+      TEST_CHECK(HSH_GetHashId(algorithm) == hash_id);
+      TEST_CHECK(HSH_GetHashId(0) < 0);
+
+      memset(out, 0, sizeof (out));
+      length = HSH_Hash(hash_id, data1, sizeof (data1) - 1, data2, sizeof (data2) - 1,
+                        out, j);
+
+      if (j >= tests[i].length)
+        TEST_CHECK(length == tests[i].length);
+      else
+        TEST_CHECK(length == j);
+
+      TEST_CHECK(!memcmp(out, tests[i].out, length));
+    }
+
+    for (j = 0; j < 10000; j++) {
+      length = HSH_Hash(hash_id, data1, random() % sizeof (data1),
+                        random() % 2 ? data2 : NULL, random() % sizeof (data2),
+                        out, sizeof (out));
+      TEST_CHECK(length == tests[i].length);
+    }
+  }
+
+  HSH_Finalise();
+}
diff --git a/test/unit/hwclock.c b/test/unit/hwclock.c
new file mode 100644
index 0000000..6462c5c
--- /dev/null
+++ b/test/unit/hwclock.c
@@ -0,0 +1,84 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016-2018
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <hwclock.c>
+#include "test.h"
+
+void
+test_unit(void)
+{
+  struct timespec start_hw_ts, start_local_ts, hw_ts, local_ts, ts;
+  HCL_Instance clock;
+  double freq, jitter, interval, dj, sum;
+  int i, j, k, count;
+
+  LCL_Initialise();
+
+  for (i = 1; i <= 8; i++) {
+    clock = HCL_CreateInstance(random() % (1 << i), 1 << i, 1.0);
+
+    for (j = 0, count = 0, sum = 0.0; j < 100; j++) {
+      UTI_ZeroTimespec(&start_hw_ts);
+      UTI_ZeroTimespec(&start_local_ts);
+      UTI_AddDoubleToTimespec(&start_hw_ts, TST_GetRandomDouble(0.0, 1e9), &start_hw_ts);
+      UTI_AddDoubleToTimespec(&start_local_ts, TST_GetRandomDouble(0.0, 1e9), &start_local_ts);
+
+      DEBUG_LOG("iteration %d", j);
+
+      freq = TST_GetRandomDouble(0.9, 1.1);
+      jitter = TST_GetRandomDouble(10.0e-9, 1000.0e-9);
+      interval = TST_GetRandomDouble(0.1, 10.0);
+
+      clock->n_samples = 0;
+      clock->valid_coefs = 0;
+
+      for (k = 0; k < 100; k++) {
+        UTI_AddDoubleToTimespec(&start_hw_ts, k * interval * freq, &hw_ts);
+        UTI_AddDoubleToTimespec(&start_local_ts, k * interval, &local_ts);
+        if (HCL_CookTime(clock, &hw_ts, &ts, NULL)) {
+          dj = fabs(UTI_DiffTimespecsToDouble(&ts, &local_ts) / jitter);
+          DEBUG_LOG("delta/jitter %f", dj);
+          if (clock->n_samples >= clock->max_samples / 2)
+            sum += dj, count++;
+          TEST_CHECK(clock->n_samples < 4 || dj <= 4.0);
+          TEST_CHECK(clock->n_samples < 8 || dj <= 3.0);
+        }
+
+        UTI_AddDoubleToTimespec(&start_hw_ts, k * interval * freq + TST_GetRandomDouble(-jitter, jitter), &hw_ts);
+
+        if (HCL_NeedsNewSample(clock, &local_ts))
+          HCL_AccumulateSample(clock, &hw_ts, &local_ts, 2.0 * jitter);
+
+        TEST_CHECK(clock->valid_coefs || clock->n_samples < 2);
+
+        if (!clock->valid_coefs)
+          continue;
+
+        TEST_CHECK(fabs(clock->offset) <= 2.0 * jitter);
+      }
+    }
+
+    TEST_CHECK(sum / count < 2.4 / sqrt(clock->max_samples));
+
+    HCL_DestroyInstance(clock);
+  }
+
+  LCL_Finalise();
+}
diff --git a/test/unit/keys.c b/test/unit/keys.c
new file mode 100644
index 0000000..aa5e649
--- /dev/null
+++ b/test/unit/keys.c
@@ -0,0 +1,173 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2017
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include "test.h"
+
+#if defined(FEAT_NTP) || defined(FEAT_CMDMON)
+
+#include <keys.c>
+
+#define KEYS 100
+#define KEYFILE "keys.test-keys"
+
+static
+uint32_t write_random_key(FILE *f)
+{
+  const char *type, *prefix;
+  char key[128];
+  uint32_t id;
+  int i, length;
+
+  length = random() % sizeof (key) + 1;
+  length = MAX(length, 4);
+  prefix = random() % 2 ? "HEX:" : "";
+
+  switch (random() % 8) {
+#ifdef FEAT_SECHASH
+    case 0:
+      type = "SHA1";
+      break;
+    case 1:
+      type = "SHA256";
+      break;
+    case 2:
+      type = "SHA384";
+      break;
+    case 3:
+      type = "SHA512";
+      break;
+#endif
+#ifdef HAVE_CMAC
+    case 4:
+      type = "AES128";
+      length = prefix[0] == '\0' ? 8 : 16;
+      break;
+    case 5:
+      type = "AES256";
+      length = prefix[0] == '\0' ? 16 : 32;
+      break;
+#endif
+    case 6:
+      type = "MD5";
+      break;
+    default:
+      type = "";
+  }
+
+  UTI_GetRandomBytes(&id, sizeof (id));
+  UTI_GetRandomBytes(key, length);
+
+  fprintf(f, "%u %s %s", id, type, prefix);
+  for (i = 0; i < length; i++)
+    fprintf(f, "%02hhX", key[i]);
+  fprintf(f, "\n");
+
+  return id;
+}
+
+static void
+generate_key_file(const char *name, uint32_t *keys)
+{
+  FILE *f;
+  int i;
+
+  f = fopen(name, "w");
+  TEST_CHECK(f);
+  for (i = 0; i < KEYS; i++)
+    keys[i] = write_random_key(f);
+  fclose(f);
+}
+
+void
+test_unit(void)
+{
+  int i, j, data_len, auth_len, type, bits;
+  uint32_t keys[KEYS], key;
+  unsigned char data[100], auth[MAX_HASH_LENGTH];
+  char conf[][100] = {
+    "keyfile "KEYFILE
+  };
+
+  CNF_Initialise(0, 0);
+  for (i = 0; i < sizeof conf / sizeof conf[0]; i++)
+    CNF_ParseLine(NULL, i + 1, conf[i]);
+
+  generate_key_file(KEYFILE, keys);
+  KEY_Initialise();
+
+  for (i = 0; i < 100; i++) {
+    DEBUG_LOG("iteration %d", i);
+
+    if (i) {
+      generate_key_file(KEYFILE, keys);
+      KEY_Reload();
+    }
+
+    UTI_GetRandomBytes(data, sizeof (data));
+
+    for (j = 0; j < KEYS; j++) {
+      TEST_CHECK(KEY_KeyKnown(keys[j]));
+      TEST_CHECK(KEY_GetAuthLength(keys[j]) >= 16);
+
+      data_len = random() % (sizeof (data) + 1);
+      auth_len = KEY_GenerateAuth(keys[j], data, data_len, auth, sizeof (auth));
+      TEST_CHECK(auth_len >= 16);
+
+      TEST_CHECK(KEY_CheckAuth(keys[j], data, data_len, auth, auth_len, auth_len));
+
+      if (j > 0 && keys[j - 1] != keys[j])
+        TEST_CHECK(!KEY_CheckAuth(keys[j - 1], data, data_len, auth, auth_len, auth_len));
+
+      auth_len = random() % auth_len + 1;
+      if (auth_len < MAX_HASH_LENGTH)
+        auth[auth_len]++;
+      TEST_CHECK(KEY_CheckAuth(keys[j], data, data_len, auth, auth_len, auth_len));
+
+      auth[auth_len - 1]++;
+      TEST_CHECK(!KEY_CheckAuth(keys[j], data, data_len, auth, auth_len, auth_len));
+
+      TEST_CHECK(KEY_GetKeyInfo(keys[j], &type, &bits));
+      TEST_CHECK(type > 0 && bits > 0);
+    }
+
+    for (j = 0; j < 1000; j++) {
+      UTI_GetRandomBytes(&key, sizeof (key));
+      if (KEY_KeyKnown(key))
+        continue;
+      TEST_CHECK(!KEY_GetKeyInfo(key, &type, &bits));
+      TEST_CHECK(!KEY_GenerateAuth(key, data, data_len, auth, sizeof (auth)));
+      TEST_CHECK(!KEY_CheckAuth(key, data, data_len, auth, auth_len, auth_len));
+    }
+  }
+
+  unlink(KEYFILE);
+
+  KEY_Finalise();
+  CNF_Finalise();
+  HSH_Finalise();
+}
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/ntp_auth.c b/test/unit/ntp_auth.c
new file mode 100644
index 0000000..c83cf29
--- /dev/null
+++ b/test/unit/ntp_auth.c
@@ -0,0 +1,305 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2020
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ **********************************************************************
+ */
+
+#include <config.h>
+#include <sysincl.h>
+#include <conf.h>
+#include <keys.h>
+#include <local.h>
+#include <ntp_ext.h>
+#include <ntp_signd.h>
+#include <nts_ntp_server.h>
+#include <socket.h>
+#include "test.h"
+
+#ifdef FEAT_NTP
+
+#include <ntp_auth.c>
+
+static void
+prepare_packet(NTP_AuthMode auth_mode, NTP_Packet *packet, NTP_PacketInfo *info, int req)
+{
+  unsigned char buf[64];
+  int i, version;
+  NTP_Mode mode;
+
+  switch (auth_mode) {
+    case NTP_AUTH_MSSNTP:
+    case NTP_AUTH_MSSNTP_EXT:
+      version = 3;
+      mode = random() % 2 ? (req ? MODE_CLIENT : MODE_SERVER) :
+                            (req ? MODE_ACTIVE : MODE_PASSIVE);
+      break;
+    case NTP_AUTH_NTS:
+      version = 4;
+      mode = req ? MODE_CLIENT : MODE_SERVER;
+      break;
+    default:
+      version = 3 + random() % 2;
+      mode = random() % 2 ? (req ? MODE_CLIENT : MODE_SERVER) :
+                            (req ? MODE_ACTIVE : MODE_PASSIVE);
+      break;
+  }
+
+  memset(packet, 0, sizeof (*packet));
+  memset(info, 0, sizeof (*info));
+  packet->lvm = NTP_LVM(LEAP_Normal, version, mode);
+  info->length = NTP_HEADER_LENGTH;
+  info->version = version;
+  info->mode = mode;
+
+  if (version == 4) {
+    memset(buf, 0, sizeof (buf));
+    for (i = random() % 5; i > 0; i--)
+      TEST_CHECK(NEF_AddField(packet, info, 0, buf, sizeof (buf)));
+  }
+}
+
+static void
+add_dummy_auth(NTP_AuthMode auth_mode, uint32_t key_id, NTP_Packet *packet, NTP_PacketInfo *info)
+{
+  unsigned char buf[64];
+  int len, fill;
+
+  info->auth.mode = auth_mode;
+
+  switch (auth_mode) {
+    case NTP_AUTH_NONE:
+      break;
+    case NTP_AUTH_SYMMETRIC:
+    case NTP_AUTH_MSSNTP:
+    case NTP_AUTH_MSSNTP_EXT:
+      switch (auth_mode) {
+        case NTP_AUTH_SYMMETRIC:
+          len = 16 + random() % 2 * 4;
+          fill = 1 + random() % 255;
+          break;
+        case NTP_AUTH_MSSNTP:
+          len = 16;
+          fill = 0;
+          break;
+        case NTP_AUTH_MSSNTP_EXT:
+          len = 68;
+          fill = 0;
+          break;
+        default:
+          assert(0);
+      }
+
+      assert(info->length + 4 + len <= sizeof (*packet));
+
+      *(uint32_t *)((unsigned char *)packet + info->length) = htonl(key_id);
+      info->auth.mac.key_id = key_id;
+      info->length += 4;
+
+      memset((unsigned char *)packet + info->length, fill, len);
+      info->length += len;
+      break;
+    case NTP_AUTH_NTS:
+      memset(buf, 0, sizeof (buf));
+      TEST_CHECK(NEF_AddField(packet, info, NTP_EF_NTS_AUTH_AND_EEF, buf, sizeof (buf)));
+      break;
+    default:
+      assert(0);
+  }
+}
+
+void
+test_unit(void)
+{
+  int i, j, can_auth_req, can_auth_res;
+  NTP_PacketInfo req_info, res_info;
+  NTP_Packet req, res;
+  NAU_Instance inst;
+  RPT_AuthReport report;
+  NTP_AuthMode mode;
+  IPSockAddr nts_addr;
+  uint32_t key_id, kod;
+  char conf[][100] = {
+    "keyfile ntp_core.keys"
+  };
+
+  CNF_Initialise(0, 0);
+  for (i = 0; i < sizeof conf / sizeof conf[0]; i++)
+    CNF_ParseLine(NULL, i + 1, conf[i]);
+
+  LCL_Initialise();
+
+  TST_SuspendLogging();
+  KEY_Initialise();
+  TST_ResumeLogging();
+
+  NSD_Initialise();
+  NNS_Initialise();
+
+  SCK_GetAnyLocalIPAddress(IPADDR_INET4, &nts_addr.ip_addr);
+  nts_addr.port = 0;
+
+  for (i = 0; i < 1000; i++) {
+    TST_SuspendLogging();
+
+    key_id = INACTIVE_AUTHKEY;
+
+    switch (i % 5) {
+      case 0:
+        inst = NAU_CreateNoneInstance();
+        TEST_CHECK(!NAU_IsAuthEnabled(inst));
+        TEST_CHECK(NAU_GetSuggestedNtpVersion(inst) == 4);
+        mode = NTP_AUTH_NONE;
+        can_auth_req = 1;
+        can_auth_res = 1;
+        break;
+      case 1:
+        key_id = random() % 7 + 2;
+        inst = NAU_CreateSymmetricInstance(key_id);
+        TEST_CHECK(NAU_IsAuthEnabled(inst));
+        TEST_CHECK(NAU_GetSuggestedNtpVersion(inst) ==
+                   (KEY_KeyKnown(inst->key_id) && KEY_GetAuthLength(inst->key_id) > 20 ? 3 : 4));
+        mode = NTP_AUTH_SYMMETRIC;
+        can_auth_req = KEY_KeyKnown(key_id);
+        can_auth_res = can_auth_req;
+        break;
+      case 2:
+        inst = NAU_CreateNtsInstance(&nts_addr, "test", &nts_addr);
+        TEST_CHECK(NAU_IsAuthEnabled(inst));
+        TEST_CHECK(NAU_GetSuggestedNtpVersion(inst) == 4);
+        mode = NTP_AUTH_NTS;
+        can_auth_req = 0;
+        can_auth_res = 0;
+        break;
+      case 3:
+        key_id = 1 + random() % 100;
+        inst = NULL;
+        mode = NTP_AUTH_MSSNTP;
+        can_auth_req = 1;
+        can_auth_res = 0;
+        break;
+      case 4:
+        key_id = 1 + random() % 100;
+        inst = NULL;
+        mode = NTP_AUTH_MSSNTP_EXT;
+        can_auth_req = 0;
+        can_auth_res = 0;
+        break;
+      default:
+        assert(0);
+    }
+
+    TST_ResumeLogging();
+
+    DEBUG_LOG("iteration %d auth=%d key_id=%d", i, (int)mode, (int)key_id);
+
+    prepare_packet(mode, &req, &req_info, 1);
+
+    if (inst) {
+      TEST_CHECK(inst->mode == mode);
+      TEST_CHECK(inst->key_id == key_id);
+
+      NAU_DumpData(inst);
+      NAU_GetReport(inst, &report);
+      if (random() % 2)
+        NAU_ChangeAddress(inst, &nts_addr.ip_addr);
+
+      if (inst->mode == NTP_AUTH_NTS) {
+        TST_SuspendLogging();
+        for (j = random() % 5; j > 0; j--)
+#ifdef FEAT_NTS
+          TEST_CHECK(!NAU_PrepareRequestAuth(inst));
+#else
+          TEST_CHECK(NAU_PrepareRequestAuth(inst));
+#endif
+        TEST_CHECK(!NAU_GenerateRequestAuth(inst, &req, &req_info));
+        TST_ResumeLogging();
+      } else if (can_auth_req) {
+        TEST_CHECK(NAU_PrepareRequestAuth(inst));
+        TEST_CHECK(NAU_GenerateRequestAuth(inst, &req, &req_info));
+      } else {
+        TEST_CHECK(NAU_PrepareRequestAuth(inst));
+        TEST_CHECK(!NAU_GenerateRequestAuth(inst, &req, &req_info));
+      }
+    }
+
+    if (!inst || !can_auth_req)
+      add_dummy_auth(mode, key_id, &req, &req_info);
+
+    TEST_CHECK(req_info.auth.mode == mode);
+
+    memset(&req_info.auth, 0, sizeof (req_info.auth));
+    TEST_CHECK(NAU_ParsePacket(&req, &req_info));
+    TEST_CHECK(req_info.auth.mode == mode);
+    TEST_CHECK(req_info.auth.mac.key_id == key_id);
+
+    kod = 1;
+    TEST_CHECK(NAU_CheckRequestAuth(&req, &req_info, &kod) == can_auth_req);
+    TEST_CHECK(kod == 0);
+
+    if (inst) {
+      for (j = NTP_AUTH_NONE; j <= NTP_AUTH_NTS; j++) {
+        if (j == mode && j == NTP_AUTH_NONE)
+          continue;
+
+        prepare_packet(j, &res, &res_info, 0);
+        add_dummy_auth(j, key_id ? key_id : 1, &res, &res_info);
+
+        TEST_CHECK(res_info.auth.mode == j);
+        TEST_CHECK(!NAU_CheckResponseAuth(inst, &res, &res_info));
+      }
+    }
+
+    prepare_packet(mode, &res, &res_info, 0);
+    TEST_CHECK(NAU_GenerateResponseAuth(&req, &req_info, &res, &res_info, NULL, NULL, kod) ==
+               can_auth_res);
+    if (!can_auth_res)
+      add_dummy_auth(mode, key_id, &res, &res_info);
+
+    memset(&res_info.auth, 0, sizeof (res_info.auth));
+    TEST_CHECK(NAU_ParsePacket(&res, &res_info));
+    TEST_CHECK(res_info.auth.mode == mode);
+    TEST_CHECK(res_info.auth.mac.key_id == key_id);
+
+    if (inst) {
+      if (mode == NTP_AUTH_SYMMETRIC) {
+        res_info.auth.mac.key_id ^= 1;
+        TEST_CHECK(!NAU_CheckResponseAuth(inst, &res, &res_info));
+        res_info.auth.mac.key_id ^= 1;
+      }
+
+      TEST_CHECK(NAU_CheckResponseAuth(inst, &res, &res_info) == can_auth_res);
+
+      NAU_GetReport(inst, &report);
+      NAU_DestroyInstance(inst);
+    }
+  }
+
+  NNS_Finalise();
+  NSD_Finalise();
+  KEY_Finalise();
+  LCL_Finalise();
+  CNF_Finalise();
+  HSH_Finalise();
+}
+
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/ntp_core.c b/test/unit/ntp_core.c
new file mode 100644
index 0000000..b5c148a
--- /dev/null
+++ b/test/unit/ntp_core.c
@@ -0,0 +1,527 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2017-2018
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include <sysincl.h>
+#include <cmdparse.h>
+#include <conf.h>
+#include <keys.h>
+#include <ntp_ext.h>
+#include <ntp_io.h>
+#include <sched.h>
+#include <local.h>
+#include "test.h"
+
+#ifdef FEAT_NTP
+
+static struct timespec current_time;
+static NTP_Packet req_buffer, res_buffer;
+static int req_length, res_length;
+
+#define NIO_OpenServerSocket(addr) ((addr)->ip_addr.family != IPADDR_UNSPEC ? 100 : 0)
+#define NIO_CloseServerSocket(fd) assert(fd == 100)
+#define NIO_OpenClientSocket(addr) ((addr)->ip_addr.family != IPADDR_UNSPEC ? 101 : 0)
+#define NIO_CloseClientSocket(fd) assert(fd == 101)
+#define NIO_IsServerSocket(fd) (fd == 100)
+#define NIO_IsServerSocketOpen() 1
+#define NIO_SendPacket(msg, to, from, len, process_tx) (memcpy(&req_buffer, msg, len), req_length = len, 1)
+#define SCH_AddTimeoutByDelay(delay, handler, arg) (1 ? 102 : (handler(arg), 1))
+#define SCH_AddTimeoutInClass(delay, separation, randomness, class, handler, arg) \
+  add_timeout_in_class(delay, separation, randomness, class, handler, arg)
+#define SCH_RemoveTimeout(id) assert(!id || id == 102)
+#define LCL_ReadRawTime(ts) (*ts = current_time)
+#define LCL_ReadCookedTime(ts, err) do {double *p = err; *ts = current_time; if (p) *p = 0.0;} while (0)
+#define LCL_GetSysPrecisionAsLog() (random() % 10 - 30)
+#define SRC_UpdateReachability(inst, reach)
+#define SRC_ResetReachability(inst)
+
+static SCH_TimeoutID
+add_timeout_in_class(double min_delay, double separation, double randomness,
+                     SCH_TimeoutClass class, SCH_TimeoutHandler handler, SCH_ArbitraryArgument arg)
+{
+  return 102;
+}
+
+#include <ntp_core.c>
+
+static void
+advance_time(double x)
+{
+  UTI_AddDoubleToTimespec(&current_time, x, &current_time);
+}
+
+static uint32_t
+get_random_key_id(void)
+{
+  uint32_t id;
+
+  do {
+    id = random() % 8 + 2;
+  } while (!KEY_KeyKnown(id));
+
+  return id;
+}
+
+static void
+send_request(NCR_Instance inst)
+{
+  NTP_Local_Address local_addr;
+  NTP_Local_Timestamp local_ts;
+  uint32_t prev_tx_count;
+
+  prev_tx_count = inst->report.total_tx_count;
+
+  transmit_timeout(inst);
+  TEST_CHECK(!inst->valid_rx);
+  TEST_CHECK(prev_tx_count + 1 == inst->report.total_tx_count);
+
+  advance_time(1e-5);
+
+  if (random() % 2) {
+    local_addr.ip_addr.family = IPADDR_UNSPEC;
+    local_addr.if_index = INVALID_IF_INDEX;
+    local_addr.sock_fd = 101;
+    local_ts.ts = current_time;
+    local_ts.err = 0.0;
+    local_ts.source = NTP_TS_KERNEL;
+
+    NCR_ProcessTxKnown(inst, &local_addr, &local_ts, &req_buffer, req_length);
+  }
+}
+
+static void
+process_request(NTP_Remote_Address *remote_addr)
+{
+  NTP_Local_Address local_addr;
+  NTP_Local_Timestamp local_ts;
+
+  local_addr.ip_addr.family = IPADDR_UNSPEC;
+  local_addr.if_index = INVALID_IF_INDEX;
+  local_addr.sock_fd = 100;
+  local_ts.ts = current_time;
+  local_ts.err = 0.0;
+  local_ts.source = NTP_TS_KERNEL;
+
+  res_length = 0;
+  NCR_ProcessRxUnknown(remote_addr, &local_addr, &local_ts,
+                       &req_buffer, req_length);
+  res_length = req_length;
+  res_buffer = req_buffer;
+
+  advance_time(1e-5);
+
+  if (random() % 2) {
+    local_ts.ts = current_time;
+    NCR_ProcessTxUnknown(remote_addr, &local_addr, &local_ts,
+                         &res_buffer, res_length);
+  }
+}
+
+static void
+send_response(int interleaved, int authenticated, int allow_update, int valid_ts, int valid_auth)
+{
+  NTP_Packet *req, *res;
+  uint32_t key_id = 0;
+  int i, auth_len = 0, ef_len, efs;
+
+  req = &req_buffer;
+  res = &res_buffer;
+
+  TEST_CHECK(req_length >= NTP_HEADER_LENGTH);
+
+  res->lvm = NTP_LVM(LEAP_Normal, NTP_LVM_TO_VERSION(req->lvm),
+                     NTP_LVM_TO_MODE(req->lvm) == MODE_CLIENT ? MODE_SERVER : MODE_ACTIVE);
+  res->stratum = 1;
+  res->poll = req->poll;
+  res->precision = -20;
+  res->root_delay = UTI_DoubleToNtp32(0.1);
+  res->root_dispersion = UTI_DoubleToNtp32(0.1);
+  res->reference_id = 0;
+  UTI_ZeroNtp64(&res->reference_ts);
+  res->originate_ts = interleaved ? req->receive_ts : req->transmit_ts;
+
+  advance_time(TST_GetRandomDouble(1e-4, 1e-2));
+  UTI_TimespecToNtp64(&current_time, &res->receive_ts, NULL);
+  advance_time(TST_GetRandomDouble(-1e-4, 1e-3));
+  UTI_TimespecToNtp64(&current_time, &res->transmit_ts, NULL);
+  advance_time(TST_GetRandomDouble(1e-4, 1e-2));
+
+  if (!valid_ts) {
+    switch (random() % (allow_update ? 4 : 5)) {
+      case 0:
+        res->originate_ts.hi = random();
+        break;
+      case 1:
+        res->originate_ts.lo = random();
+        break;
+      case 2:
+        UTI_ZeroNtp64(&res->originate_ts);
+        break;
+      case 3:
+        UTI_ZeroNtp64(&res->receive_ts);
+        break;
+      case 4:
+        UTI_ZeroNtp64(&res->transmit_ts);
+        break;
+      default:
+        assert(0);
+    }
+  }
+
+  res_length = NTP_HEADER_LENGTH;
+
+  if (NTP_LVM_TO_VERSION(res->lvm) == 4 && random() % 2) {
+    unsigned char buf[128];
+
+    memset(buf, 0, sizeof (buf));
+    efs = random() % 5;
+
+    for (i = 0; i < efs; i++) {
+      ef_len = (i + 1 == efs ? NTP_MAX_V4_MAC_LENGTH + 4 : NTP_MIN_EF_LENGTH) +
+               4 * (random() % 10);
+      TEST_CHECK(NEF_SetField((unsigned char *)res, sizeof (*res), res_length, 0,
+                              buf, ef_len - 4, &ef_len));
+      res_length += ef_len;
+    }
+  }
+
+  if (authenticated) {
+    key_id = ntohl(*(uint32_t *)req->extensions);
+    if (key_id == 0)
+      key_id = get_random_key_id();
+    auth_len = KEY_GetAuthLength(key_id);
+    assert(auth_len);
+    if (NTP_LVM_TO_VERSION(res->lvm) == 4)
+      auth_len = MIN(auth_len, NTP_MAX_V4_MAC_LENGTH - 4);
+
+    if (KEY_GenerateAuth(key_id, res, res_length,
+                         (unsigned char *)res + res_length + 4, auth_len) != auth_len)
+      assert(0);
+    res_length += 4 + auth_len;
+  }
+
+  if (!valid_auth && authenticated) {
+    assert(auth_len);
+
+    switch (random() % 5) {
+      case 0:
+        key_id++;
+        break;
+      case 1:
+        key_id ^= 1;
+        if (KEY_GenerateAuth(key_id, res, res_length - auth_len - 4,
+                             (unsigned char *)res + res_length - auth_len, auth_len) != auth_len)
+          assert(0);
+        break;
+      case 2:
+        ((unsigned char *)res)[res_length - auth_len + random() % auth_len]++;
+        break;
+      case 3:
+        res_length -= 4 + auth_len;
+        auth_len = 4 * (random() % (auth_len / 4));
+        res_length += 4 + auth_len;
+        break;
+      case 4:
+        if (NTP_LVM_TO_VERSION(res->lvm) == 4 && random() % 2 &&
+            KEY_GetAuthLength(key_id) > NTP_MAX_V4_MAC_LENGTH - 4) {
+          res_length -= 4 + auth_len;
+          auth_len += 4 + 4 * (random() %
+                               ((KEY_GetAuthLength(key_id) - NTP_MAX_V4_MAC_LENGTH - 4) / 4));
+          if (KEY_GenerateAuth(key_id, res, res_length,
+                               (unsigned char *)res + res_length + 4, auth_len) != auth_len)
+              assert(0);
+          res_length += 4 + auth_len;
+        } else {
+          memset((unsigned char *)res + res_length, 0, 4);
+          auth_len += 4;
+          res_length += 4;
+        }
+        break;
+      default:
+        assert(0);
+    }
+  }
+
+  assert(res_length <= sizeof (*res));
+  assert(res_length >= NTP_HEADER_LENGTH + auth_len);
+
+  if (authenticated)
+    *(uint32_t *)((unsigned char *)res + res_length - auth_len - 4) = htonl(key_id);
+}
+
+static void
+proc_response(NCR_Instance inst, int good, int valid, int updated_sync, int updated_init)
+{
+  NTP_Local_Address local_addr;
+  NTP_Local_Timestamp local_ts;
+  NTP_Packet *res;
+  uint32_t prev_rx_count, prev_valid_count;
+  struct timespec prev_rx_ts, prev_init_rx_ts;
+  int ret;
+
+  res = &res_buffer;
+
+  local_addr.ip_addr.family = IPADDR_UNSPEC;
+  local_addr.if_index = INVALID_IF_INDEX;
+  local_addr.sock_fd = NTP_LVM_TO_MODE(res->lvm) != MODE_SERVER ? 100 : 101;
+  local_ts.ts = current_time;
+  local_ts.err = 0.0;
+  local_ts.source = NTP_TS_KERNEL;
+
+  prev_rx_count = inst->report.total_rx_count;
+  prev_valid_count = inst->report.total_valid_count;
+  prev_rx_ts = inst->local_rx.ts;
+  prev_init_rx_ts = inst->init_local_rx.ts;
+
+  ret = NCR_ProcessRxKnown(inst, &local_addr, &local_ts, res, res_length);
+
+  if (good > 0)
+    TEST_CHECK(ret);
+  else if (!good)
+    TEST_CHECK(!ret);
+
+  TEST_CHECK(prev_rx_count + 1 == inst->report.total_rx_count);
+
+  if (valid)
+    TEST_CHECK(prev_valid_count + 1 == inst->report.total_valid_count);
+  else
+    TEST_CHECK(prev_valid_count == inst->report.total_valid_count);
+
+  if (updated_sync)
+    TEST_CHECK(UTI_CompareTimespecs(&inst->local_rx.ts, &prev_rx_ts));
+  else
+    TEST_CHECK(!UTI_CompareTimespecs(&inst->local_rx.ts, &prev_rx_ts));
+
+  if (updated_init > 0)
+    TEST_CHECK(UTI_CompareTimespecs(&inst->init_local_rx.ts, &prev_init_rx_ts));
+  else if (!updated_init)
+    TEST_CHECK(!UTI_CompareTimespecs(&inst->init_local_rx.ts, &prev_init_rx_ts));
+
+  if (valid) {
+    TEST_CHECK(UTI_IsZeroTimespec(&inst->init_local_rx.ts));
+    TEST_CHECK(UTI_IsZeroNtp64(&inst->init_remote_ntp_tx));
+  }
+}
+
+static void
+process_replay(NCR_Instance inst, NTP_Packet *packet_queue,
+               int queue_length, int updated_init)
+{
+  do {
+    res_buffer = packet_queue[random() % queue_length];
+  } while (!UTI_CompareNtp64(&res_buffer.transmit_ts, &inst->remote_ntp_tx));
+  proc_response(inst, 0, 0, 0, updated_init);
+  advance_time(1e-6);
+}
+
+#define PACKET_QUEUE_LENGTH 10
+
+void
+test_unit(void)
+{
+  char source_line[] = "127.0.0.1 maxdelaydevratio 1e6";
+  char conf[][100] = {
+    "allow",
+    "port 0",
+    "local",
+    "keyfile ntp_core.keys"
+  };
+  int i, j, k, interleaved, authenticated, valid, updated, has_updated;
+  CPS_NTP_Source source;
+  NTP_Remote_Address remote_addr;
+  NCR_Instance inst1, inst2;
+  NTP_Packet packet_queue[PACKET_QUEUE_LENGTH];
+
+  CNF_Initialise(0, 0);
+  for (i = 0; i < sizeof conf / sizeof conf[0]; i++)
+    CNF_ParseLine(NULL, i + 1, conf[i]);
+
+  LCL_Initialise();
+  TST_RegisterDummyDrivers();
+  SCH_Initialise();
+  SRC_Initialise();
+  NIO_Initialise();
+  NCR_Initialise();
+  REF_Initialise();
+
+  TST_SuspendLogging();
+  KEY_Initialise();
+  TST_ResumeLogging();
+
+  CNF_SetupAccessRestrictions();
+
+  CPS_ParseNTPSourceAdd(source_line, &source);
+
+  for (i = 0; i < 1000; i++) {
+    source.params.interleaved = random() % 2;
+    source.params.authkey = random() % 2 ? get_random_key_id() : INACTIVE_AUTHKEY;
+    source.params.version = random() % 4 + 1;
+
+    UTI_ZeroTimespec(&current_time);
+    advance_time(TST_GetRandomDouble(1.0, 1e9));
+
+    TST_GetRandomAddress(&remote_addr.ip_addr, IPADDR_UNSPEC, -1);
+    remote_addr.port = 123;
+
+    inst1 = NCR_CreateInstance(&remote_addr, random() % 2 ? NTP_SERVER : NTP_PEER,
+                               &source.params, NULL);
+    NCR_StartInstance(inst1);
+    has_updated = 0;
+
+    for (j = 0; j < 50; j++) {
+      DEBUG_LOG("client/peer test iteration %d/%d", i, j);
+
+      interleaved = random() % 2 && (inst1->mode != MODE_CLIENT ||
+                                     inst1->tx_count < MAX_CLIENT_INTERLEAVED_TX);
+      authenticated = random() % 2;
+      valid = (!interleaved || (source.params.interleaved && has_updated)) &&
+              ((source.params.authkey == INACTIVE_AUTHKEY) == !authenticated);
+      updated = (valid || inst1->mode == MODE_ACTIVE) &&
+                ((source.params.authkey == INACTIVE_AUTHKEY) == !authenticated);
+      has_updated = has_updated || updated;
+      if (inst1->mode == MODE_CLIENT)
+        updated = 0;
+
+      DEBUG_LOG("authkey=%d version=%d interleaved=%d authenticated=%d valid=%d updated=%d has_updated=%d",
+                (int)source.params.authkey, source.params.version,
+                interleaved, authenticated, valid, updated, has_updated);
+
+      send_request(inst1);
+
+      send_response(interleaved, authenticated, 1, 0, 1);
+      DEBUG_LOG("response 1");
+      proc_response(inst1, 0, 0, 0, updated);
+
+      if (source.params.authkey) {
+        send_response(interleaved, authenticated, 1, 1, 0);
+        DEBUG_LOG("response 2");
+        proc_response(inst1, 0, 0, 0, 0);
+      }
+
+      send_response(interleaved, authenticated, 1, 1, 1);
+      DEBUG_LOG("response 3");
+      proc_response(inst1, -1, valid, valid, updated);
+      DEBUG_LOG("response 4");
+      proc_response(inst1, 0, 0, 0, 0);
+
+      advance_time(-1.0);
+
+      send_response(interleaved, authenticated, 1, 1, 1);
+      DEBUG_LOG("response 5");
+      proc_response(inst1, 0, 0, 0, updated && valid);
+
+      advance_time(1.0);
+
+      send_response(interleaved, authenticated, 1, 1, 1);
+      DEBUG_LOG("response 6");
+      proc_response(inst1, 0, 0, valid && updated, updated);
+    }
+
+    NCR_DestroyInstance(inst1);
+
+    inst1 = NCR_CreateInstance(&remote_addr, random() % 2 ? NTP_SERVER : NTP_PEER,
+                               &source.params, NULL);
+    NCR_StartInstance(inst1);
+
+    for (j = 0; j < 20; j++) {
+      DEBUG_LOG("server test iteration %d/%d", i, j);
+
+      send_request(inst1);
+      process_request(&remote_addr);
+      proc_response(inst1, 1, 1, 1, 0);
+      advance_time(1 << inst1->local_poll);
+    }
+
+    NCR_DestroyInstance(inst1);
+
+    inst1 = NCR_CreateInstance(&remote_addr, NTP_PEER, &source.params, NULL);
+    NCR_StartInstance(inst1);
+    inst2 = NCR_CreateInstance(&remote_addr, NTP_PEER, &source.params, NULL);
+    NCR_StartInstance(inst2);
+
+    res_length = req_length = 0;
+
+    for (j = 0; j < 20; j++) {
+      DEBUG_LOG("peer replay test iteration %d/%d", i, j);
+
+      send_request(inst1);
+      res_buffer = req_buffer;
+      assert(!res_length || res_length == req_length);
+      res_length = req_length;
+
+      TEST_CHECK(inst1->valid_timestamps == (j > 0));
+
+      DEBUG_LOG("response 1->2");
+      proc_response(inst2, j > source.params.interleaved, j > 0, j > 0, 1);
+
+      packet_queue[(j * 2) % PACKET_QUEUE_LENGTH] = res_buffer;
+
+      for (k = 0; k < j % 4 + 1; k++) {
+        DEBUG_LOG("replay ?->1 %d", k);
+        process_replay(inst1, packet_queue, MIN(j * 2 + 1, PACKET_QUEUE_LENGTH), k ? -1 : 1);
+        DEBUG_LOG("replay ?->2 %d", k);
+        process_replay(inst2, packet_queue, MIN(j * 2 + 1, PACKET_QUEUE_LENGTH), -1);
+      }
+
+      advance_time(1 << (source.params.minpoll - 1));
+
+      send_request(inst2);
+      res_buffer = req_buffer;
+      assert(res_length == req_length);
+
+      TEST_CHECK(inst2->valid_timestamps == (j > 0));
+
+      DEBUG_LOG("response 2->1");
+      proc_response(inst1, 1, 1, 1, 1);
+
+      packet_queue[(j * 2 + 1) % PACKET_QUEUE_LENGTH] = res_buffer;
+
+      for (k = 0; k < j % 4 + 1; k++) {
+        DEBUG_LOG("replay ?->1 %d", k);
+        process_replay(inst1, packet_queue, MIN(j * 2 + 2, PACKET_QUEUE_LENGTH), k ? -1 : 1);
+        DEBUG_LOG("replay ?->2 %d", k);
+        process_replay(inst2, packet_queue, MIN(j * 2 + 2, PACKET_QUEUE_LENGTH), -1);
+      }
+
+      advance_time(1 << (source.params.minpoll - 1));
+    }
+
+    NCR_DestroyInstance(inst1);
+    NCR_DestroyInstance(inst2);
+  }
+
+  KEY_Finalise();
+  REF_Finalise();
+  NCR_Finalise();
+  NIO_Finalise();
+  SRC_Finalise();
+  SCH_Finalise();
+  LCL_Finalise();
+  CNF_Finalise();
+  HSH_Finalise();
+}
+
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/ntp_core.keys b/test/unit/ntp_core.keys
new file mode 100644
index 0000000..a3e4f6c
--- /dev/null
+++ b/test/unit/ntp_core.keys
@@ -0,0 +1,8 @@
+2 MD5 HEX:38979C567358C0896F4D9D459A3C8B8478654579
+3 MD5 HEX:38979C567358C0896F4D9D459A3C8B8478654579
+4 SHA1 HEX:B71744EA01FBF01CA30D173ECDDF901952AE356A
+5 SHA1 HEX:B71744EA01FBF01CA30D173ECDDF901952AE356A
+6 SHA512 HEX:DE027482F22B201FC20863F58C74095E7906089F
+7 SHA512 HEX:DE027482F22B201FC20863F58C74095E7906089F
+8 AES128 HEX:5D5E8A31D4B459A66D445259E147CFB5
+9 AES128 HEX:5D5E8A31D4B459A66D445259E147CFB5
diff --git a/test/unit/ntp_ext.c b/test/unit/ntp_ext.c
new file mode 100644
index 0000000..c37e702
--- /dev/null
+++ b/test/unit/ntp_ext.c
@@ -0,0 +1,167 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2020
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include "test.h"
+
+#ifdef FEAT_NTP
+
+#include <util.h>
+#include <logging.h>
+
+#include <ntp_ext.c>
+
+void
+test_unit(void)
+{
+  unsigned char *buffer, body[NTP_MAX_EXTENSIONS_LENGTH];
+  void *bodyp;
+  NTP_PacketInfo info;
+  NTP_Packet packet;
+  int i, j, start, length, type, type2, body_length, body_length2;
+
+  assert(sizeof (uint16_t) == 2);
+  assert(sizeof (body) == sizeof (packet.extensions));
+
+  buffer = (unsigned char *)packet.extensions;
+
+  for (i = 0; i < 10000; i++) {
+    body_length = random() % (sizeof (body) - 4 + 1) / 4 * 4;
+    start = random() % (sizeof (packet.extensions) - body_length - 4 + 1) / 4 * 4;
+    type = random() % 0x10000;
+
+    DEBUG_LOG("body_length=%d start=%d type=%d", body_length, start, type);
+    assert(body_length + start <= sizeof (packet.extensions));
+
+    UTI_GetRandomBytes(body, body_length);
+
+    TEST_CHECK(!NEF_SetField(buffer, body_length + start + 4, start,
+                             type, body, body_length + 4, &length));
+    TEST_CHECK(!NEF_SetField(buffer, body_length + start + 4, start + 4,
+                             type, body, body_length, &length));
+    TEST_CHECK(!NEF_SetField(buffer, body_length + start + 4, start,
+                             type, body, body_length - 1, &length));
+    TEST_CHECK(!NEF_SetField(buffer, body_length + start + 4, start,
+                             type, body, body_length - 2, &length));
+    TEST_CHECK(!NEF_SetField(buffer, body_length + start + 4, start,
+                             type, body, body_length - 3, &length));
+    TEST_CHECK(!NEF_SetField(buffer, body_length + start + 3, start,
+                             type, body, body_length, &length));
+    TEST_CHECK(!NEF_SetField(buffer, body_length + start + 5, start + 1,
+                             type, body, body_length, &length));
+
+    TEST_CHECK(NEF_SetField(buffer, body_length + start + 4, start,
+                            type, body, body_length, &length));
+    TEST_CHECK(length == body_length + 4);
+    TEST_CHECK(((uint16_t *)buffer)[start / 2] == htons(type));
+    TEST_CHECK(((uint16_t *)buffer)[start / 2 + 1] == htons(length));
+    TEST_CHECK(memcmp(buffer + start + 4, body, body_length) == 0);
+
+    memset(&packet, 0, sizeof (packet));
+    packet.lvm = NTP_LVM(0, 4, MODE_CLIENT);
+    memset(&info, 0, sizeof (info));
+
+    info.version = 3;
+    info.length = NTP_HEADER_LENGTH;
+    TEST_CHECK(!NEF_AddBlankField(&packet, &info, type, body_length, &bodyp));
+
+    info.version = 4;
+    info.length = NTP_HEADER_LENGTH - 4;
+    TEST_CHECK(!NEF_AddBlankField(&packet, &info, type, body_length, &bodyp));
+
+    info.length = sizeof (packet) - body_length;
+    TEST_CHECK(!NEF_AddBlankField(&packet, &info, type, body_length, &bodyp));
+
+    info.length = NTP_HEADER_LENGTH + start;
+
+    if (body_length < 12) {
+      TEST_CHECK(!NEF_AddBlankField(&packet, &info, type, body_length, &bodyp));
+      continue;
+    }
+
+    TEST_CHECK(NEF_AddBlankField(&packet, &info, type, body_length, &bodyp));
+    TEST_CHECK(info.length == NTP_HEADER_LENGTH + start + body_length + 4);
+    TEST_CHECK(((uint16_t *)buffer)[start / 2] == htons(type));
+    TEST_CHECK(((uint16_t *)buffer)[start / 2 + 1] == htons(length));
+    TEST_CHECK(bodyp == buffer + start + 4);
+    TEST_CHECK(info.ext_fields == 1);
+
+    memset(buffer, 0, sizeof (packet.extensions));
+    info.length = NTP_HEADER_LENGTH + start;
+    info.ext_fields = 0;
+
+    TEST_CHECK(NEF_AddField(&packet, &info, type, body, body_length));
+    TEST_CHECK(info.length == NTP_HEADER_LENGTH + start + body_length + 4);
+    TEST_CHECK(((uint16_t *)buffer)[start / 2] == htons(type));
+    TEST_CHECK(((uint16_t *)buffer)[start / 2 + 1] == htons(length));
+    TEST_CHECK(memcmp(buffer + start + 4, body, body_length) == 0);
+    TEST_CHECK(info.ext_fields == 1);
+
+    for (j = 1; j <= 4; j++) {
+      TEST_CHECK(((uint16_t *)buffer)[start / 2 + 1] = htons(length + j));
+      TEST_CHECK(!NEF_ParseSingleField(buffer, start + body_length + 4, start,
+                                       &length, &type2, &bodyp, &body_length2));
+    }
+
+    TEST_CHECK(((uint16_t *)buffer)[start / 2 + 1] = htons(length));
+
+    TEST_CHECK(NEF_ParseSingleField(buffer, sizeof (packet.extensions), start,
+                                    &length, &type2, &bodyp, &body_length2));
+    TEST_CHECK(length == body_length + 4);
+    TEST_CHECK(type2 == type);
+    TEST_CHECK(bodyp == buffer + start + 4);
+    TEST_CHECK(body_length2 == body_length);
+
+    TEST_CHECK(!NEF_ParseField(&packet, sizeof (packet) + 4,
+                               NTP_HEADER_LENGTH + start,
+                               &length, &type2, &bodyp, &body_length2));
+
+    if (body_length < 24) {
+      TEST_CHECK(!NEF_ParseField(&packet, NTP_HEADER_LENGTH + start + length, 
+                                 NTP_HEADER_LENGTH + start,
+                                 &length, &type2, &bodyp, &body_length2));
+      if (sizeof (packet.extensions) - start <= 24) {
+        TEST_CHECK(!NEF_ParseField(&packet, sizeof (packet), NTP_HEADER_LENGTH + start,
+                                   &length, &type2, &bodyp, &body_length2));
+        continue;
+      } else {
+        TEST_CHECK(NEF_ParseField(&packet, sizeof (packet), NTP_HEADER_LENGTH + start,
+                                  &length, &type2, &bodyp, &body_length2));
+      }
+    } else {
+      TEST_CHECK(NEF_ParseField(&packet, NTP_HEADER_LENGTH + start + length, 
+                                NTP_HEADER_LENGTH + start,
+                                &length, &type2, &bodyp, &body_length2));
+    }
+    TEST_CHECK(length == body_length + 4);
+    TEST_CHECK(type2 == type);
+    TEST_CHECK(bodyp == buffer + start + 4);
+    TEST_CHECK(body_length2 == body_length);
+
+  }
+}
+
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/ntp_sources.c b/test/unit/ntp_sources.c
new file mode 100644
index 0000000..f824316
--- /dev/null
+++ b/test/unit/ntp_sources.c
@@ -0,0 +1,112 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include "test.h"
+
+#ifdef FEAT_NTP
+
+#include <ntp_sources.c>
+#include <conf.h>
+#include <ntp_io.h>
+
+void
+test_unit(void)
+{
+  int i, j, k, slot, found;
+  uint32_t hash = 0;
+  NTP_Remote_Address addrs[256], addr;
+  SourceParameters params;
+  char conf[] = "port 0";
+
+  memset(&params, 0, sizeof (params));
+
+  CNF_Initialise(0, 0);
+  CNF_ParseLine(NULL, 1, conf);
+
+  LCL_Initialise();
+  SCH_Initialise();
+  SRC_Initialise();
+  NIO_Initialise();
+  NCR_Initialise();
+  NSR_Initialise();
+
+  for (i = 0; i < 6; i++) {
+    TEST_CHECK(ARR_GetSize(records) == 1);
+
+    DEBUG_LOG("collision mod %u", 1U << i);
+
+    for (j = 0; j < sizeof (addrs) / sizeof (addrs[0]); j++) {
+      do {
+        TST_GetRandomAddress(&addrs[j].ip_addr, IPADDR_UNSPEC, -1);
+      } while (UTI_IPToHash(&addrs[j].ip_addr) % (1U << i) != hash % (1U << i));
+
+      addrs[j].port = random() % 1024;
+
+      if (!j)
+        hash = UTI_IPToHash(&addrs[j].ip_addr);
+
+      DEBUG_LOG("adding source %s hash %"PRIu32, UTI_IPToString(&addrs[j].ip_addr),
+                UTI_IPToHash(&addrs[j].ip_addr) % (1U << i));
+
+      NSR_AddSource(&addrs[j], random() % 2 ? NTP_SERVER : NTP_PEER, &params, NULL);
+
+      for (k = 0; k < j; k++) {
+        addr = addrs[k];
+        found = find_slot2(&addr, &slot);
+        TEST_CHECK(found == 2);
+        TEST_CHECK(!UTI_CompareIPs(&get_record(slot)->remote_addr->ip_addr,
+                                   &addr.ip_addr, NULL));
+        addr.port++;
+        found = find_slot2(&addr, &slot);
+        TEST_CHECK(found == 1);
+        TEST_CHECK(!UTI_CompareIPs(&get_record(slot)->remote_addr->ip_addr,
+                                   &addr.ip_addr, NULL));
+      }
+    }
+
+    for (j = 0; j < sizeof (addrs) / sizeof (addrs[0]); j++) {
+      DEBUG_LOG("removing source %s", UTI_IPToString(&addrs[j].ip_addr));
+      NSR_RemoveSource(&addrs[j].ip_addr);
+
+      for (k = 0; k < sizeof (addrs) / sizeof (addrs[0]); k++) {
+        found = find_slot2(&addrs[k], &slot);
+        TEST_CHECK(found == (k <= j ? 0 : 2));
+      }
+    }
+  }
+
+  NSR_Finalise();
+  NCR_Finalise();
+  NIO_Finalise();
+  SRC_Finalise();
+  SCH_Finalise();
+  LCL_Finalise();
+  CNF_Finalise();
+  HSH_Finalise();
+}
+
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/nts_ke.crt b/test/unit/nts_ke.crt
new file mode 100644
index 0000000..8165287
--- /dev/null
+++ b/test/unit/nts_ke.crt
@@ -0,0 +1,8 @@
+-----BEGIN CERTIFICATE-----
+MIIBDjCBwaADAgECAgEBMAUGAytlcDAPMQ0wCwYDVQQDEwR0ZXN0MCAXDTcwMDEw
+MTAwMDAwMFoYDzIxMDAwMTAyMDAwMDAwWjAPMQ0wCwYDVQQDEwR0ZXN0MCowBQYD
+K2VwAyEA3oh/FZeOxRYvJVLfCDEwGI6Oe23gTgLHx8a87tvwgfyjQDA+MAwGA1Ud
+EwEB/wQCMAAwDwYDVR0PAQH/BAUDAweAADAdBgNVHQ4EFgQUYwAqF9q3jxUk68m1
+cuz8DueOHeMwBQYDK2VwA0EAne0dCRXb0dW8bn2v3RhVTqeTJWXfl74x8MTQMTM7
+/uGTqoYOA0YJffypd+p27pvx2BEoNQWRYM6pqBg55KbwDw==
+-----END CERTIFICATE-----
diff --git a/test/unit/nts_ke.key b/test/unit/nts_ke.key
new file mode 100644
index 0000000..6414c64
--- /dev/null
+++ b/test/unit/nts_ke.key
@@ -0,0 +1,25 @@
+Public Key Info:
+	Public Key Algorithm: EdDSA (Ed25519)
+	Key Security Level: High (256 bits)
+
+curve:	Ed25519
+private key:
+	01:d9:75:42:7c:52:cc:29:9e:90:01:f3:da:26:f6:d7
+	ad:af:a5:2a:82:36:1d:86:c6:57:a7:b4:99:9b:6c:6d
+	
+
+x:
+	de:88:7f:15:97:8e:c5:16:2f:25:52:df:08:31:30:18
+	8e:8e:7b:6d:e0:4e:02:c7:c7:c6:bc:ee:db:f0:81:fc
+	
+
+
+Public Key PIN:
+	pin-sha256:C4LBJP2cRxvLcZ6pjowcOEQhcW3ZPMVTpLgRGsBDeMw=
+Public Key ID:
+	sha256:0b82c124fd9c471bcb719ea98e8c1c384421716dd93cc553a4b8111ac04378cc
+	sha1:63002a17dab78f1524ebc9b572ecfc0ee78e1de3
+
+-----BEGIN PRIVATE KEY-----
+MC4CAQAwBQYDK2VwBCIEIAHZdUJ8UswpnpAB89om9tetr6UqgjYdhsZXp7SZm2xt
+-----END PRIVATE KEY-----
diff --git a/test/unit/nts_ke_client.c b/test/unit/nts_ke_client.c
new file mode 100644
index 0000000..a907573
--- /dev/null
+++ b/test/unit/nts_ke_client.c
@@ -0,0 +1,144 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2020
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include "test.h"
+
+#ifdef FEAT_NTS
+
+#include <nts_ke_client.c>
+#include <local.h>
+
+static void
+prepare_response(NKSN_Instance session, int valid)
+{
+  uint16_t data[16];
+  int i, index, length;
+
+  if (valid)
+    index = -1;
+  else
+    index = random() % 10;
+  DEBUG_LOG("index=%d", index);
+
+  NKSN_BeginMessage(session);
+
+  memset(data, 0, sizeof (data));
+  length = 2;
+  assert(sizeof (data[0]) == 2);
+
+  if (index == 0) {
+    data[0] = htons(random() % 100);
+    TEST_CHECK(NKSN_AddRecord(session, 1, random() % 2 ? NKE_RECORD_ERROR : NKE_RECORD_WARNING,
+                              data, length));
+  } else if (index == 1) {
+    TEST_CHECK(NKSN_AddRecord(session, 1, NKE_RECORD_ERROR + 1000, data, length));
+  }
+
+  if (index != 2) {
+    if (index == 3)
+      data[0] = htons(NKE_NEXT_PROTOCOL_NTPV4 + random() % 10 + 1);
+    else
+      data[0] = htons(NKE_NEXT_PROTOCOL_NTPV4);
+    if (index == 4)
+      length = 3 + random() % 10;
+    TEST_CHECK(NKSN_AddRecord(session, 1, NKE_RECORD_NEXT_PROTOCOL, data, length));
+  }
+
+  if (index != 5) {
+    if (index == 6)
+      data[0] = htons(AEAD_AES_SIV_CMAC_256 + random() % 10 + 1);
+    else
+      data[0] = htons(AEAD_AES_SIV_CMAC_256);
+    if (index == 7)
+      length = 3 + random() % 10;
+    TEST_CHECK(NKSN_AddRecord(session, 1, NKE_RECORD_AEAD_ALGORITHM, data, length));
+  }
+
+  if (random() % 2) {
+    const char server[] = "127.0.0.1";
+    TEST_CHECK(NKSN_AddRecord(session, 1, NKE_RECORD_NTPV4_SERVER_NEGOTIATION,
+                              server, sizeof (server) - 1));
+  }
+
+  if (random() % 2) {
+    data[0] = htons(123);
+    TEST_CHECK(NKSN_AddRecord(session, 1, NKE_RECORD_NTPV4_PORT_NEGOTIATION, data, length));
+  }
+
+  if (random() % 2) {
+    length = random() % (sizeof (data) + 1);
+    TEST_CHECK(NKSN_AddRecord(session, 0, 1000 + random() % 1000, data, length));
+  }
+
+  if (index != 8) {
+    for (i = 0; i < NKE_MAX_COOKIES; i++) {
+      length = (random() % sizeof (data) + 1) / 4 * 4;
+      if (index == 9)
+        length += (length < sizeof (data) ? 1 : -1) * (random() % 3 + 1);
+      TEST_CHECK(NKSN_AddRecord(session, 0, NKE_RECORD_COOKIE, data, length));
+    }
+  }
+
+  TEST_CHECK(NKSN_EndMessage(session));
+}
+
+void
+test_unit(void)
+{
+  NKC_Instance inst;
+  IPSockAddr addr;
+  int i, r, valid;
+
+  char conf[][100] = {
+    "nosystemcert",
+  };
+
+  CNF_Initialise(0, 0);
+  for (i = 0; i < sizeof conf / sizeof conf[0]; i++)
+    CNF_ParseLine(NULL, i + 1, conf[i]);
+
+  LCL_Initialise();
+
+  SCK_GetLoopbackIPAddress(AF_INET, &addr.ip_addr);
+  addr.port = 0;
+
+  inst = NKC_CreateInstance(&addr, "test");
+  TEST_CHECK(inst);
+
+  for (i = 0; i < 10000; i++) {
+    valid = random() % 2;
+    prepare_response(inst->session, valid);
+    r = process_response(inst);
+    TEST_CHECK(r == valid);
+  }
+
+  NKC_DestroyInstance(inst);
+
+  LCL_Finalise();
+  CNF_Finalise();
+}
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/nts_ke_server.c b/test/unit/nts_ke_server.c
new file mode 100644
index 0000000..f4f03a1
--- /dev/null
+++ b/test/unit/nts_ke_server.c
@@ -0,0 +1,230 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2020
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include "test.h"
+
+#ifdef FEAT_NTS
+
+#include <local.h>
+#include <nts_ke_session.h>
+#include <util.h>
+
+#define NKSN_GetKeys get_keys
+
+static int
+get_keys(NKSN_Instance session, SIV_Algorithm siv, NKE_Key *c2s, NKE_Key *s2c)
+{
+  c2s->length = SIV_GetKeyLength(siv);
+  UTI_GetRandomBytes(c2s->key, c2s->length);
+  s2c->length = SIV_GetKeyLength(siv);
+  UTI_GetRandomBytes(s2c->key, s2c->length);
+  return 1;
+}
+
+#include <nts_ke_server.c>
+
+static void
+prepare_request(NKSN_Instance session, int valid)
+{
+  uint16_t data[16];
+  int index, length;
+
+  if (valid)
+    index = -1;
+  else
+    index = random() % 9;
+  DEBUG_LOG("index=%d", index);
+
+  NKSN_BeginMessage(session);
+
+  memset(data, 0, sizeof (data));
+  length = 2;
+  assert(sizeof (data[0]) == 2);
+
+  if (index != 0) {
+    memset(data, NKE_NEXT_PROTOCOL_NTPV4 + 1, sizeof (data));
+    data[0] = htons(NKE_NEXT_PROTOCOL_NTPV4);
+    if (index == 1)
+      length = 0;
+    else if (index == 2)
+      length = 3 + random() % 15 * 2;
+    else
+      length = 2 + random() % 16 * 2;
+    TEST_CHECK(NKSN_AddRecord(session, 1, NKE_RECORD_NEXT_PROTOCOL, data, length));
+  }
+
+  if (index == 3)
+    TEST_CHECK(NKSN_AddRecord(session, 1, NKE_RECORD_NEXT_PROTOCOL, data, length));
+
+  if (index != 4) {
+    data[0] = htons(AEAD_AES_SIV_CMAC_256);
+    if (index == 5)
+      length = 0;
+    else if (index == 6)
+      length = 3 + random() % 15 * 2;
+    else
+      length = 2 + random() % 16 * 2;
+    TEST_CHECK(NKSN_AddRecord(session, 1, NKE_RECORD_AEAD_ALGORITHM, data, length));
+  }
+
+  if (index == 7)
+    TEST_CHECK(NKSN_AddRecord(session, 1, NKE_RECORD_AEAD_ALGORITHM, data, length));
+
+  if (index == 8) {
+    length = random() % (sizeof (data) + 1);
+    TEST_CHECK(NKSN_AddRecord(session, 1, 1000 + random() % 1000, data, length));
+  }
+
+  if (random() % 2) {
+    const char server[] = "127.0.0.1";
+    TEST_CHECK(NKSN_AddRecord(session, 0, NKE_RECORD_NTPV4_SERVER_NEGOTIATION,
+                              server, sizeof (server) - 1));
+  }
+
+  if (random() % 2) {
+    data[0] = htons(123);
+    TEST_CHECK(NKSN_AddRecord(session, 0, NKE_RECORD_NTPV4_PORT_NEGOTIATION, data, length));
+  }
+
+  if (random() % 2) {
+    length = random() % (sizeof (data) + 1);
+    TEST_CHECK(NKSN_AddRecord(session, 0, 1000 + random() % 1000, data, length));
+  }
+
+  TEST_CHECK(NKSN_EndMessage(session));
+}
+
+static void
+process_response(NKSN_Instance session, int valid)
+{
+  int records, errors, critical, type, length;
+
+  for (records = errors = 0; ; records++) {
+    if (!NKSN_GetRecord(session, &critical, &type, &length, NULL, 0))
+      break;
+    if (type == NKE_RECORD_ERROR)
+      errors++;
+  }
+
+  if (valid) {
+    TEST_CHECK(records >= 2);
+  } else {
+    TEST_CHECK(records == 1);
+    TEST_CHECK(errors == 1);
+  }
+}
+
+void
+test_unit(void)
+{
+  NKSN_Instance session;
+  NKE_Context context, context2;
+  NKE_Cookie cookie;
+  int i, valid, l;
+  uint32_t sum, sum2;
+
+  char conf[][100] = {
+    "ntsdumpdir .",
+    "ntsport 0",
+    "ntsprocesses 0",
+    "ntsserverkey nts_ke.key",
+    "ntsservercert nts_ke.crt",
+  };
+
+  CNF_Initialise(0, 0);
+  for (i = 0; i < sizeof conf / sizeof conf[0]; i++)
+    CNF_ParseLine(NULL, i + 1, conf[i]);
+
+  LCL_Initialise();
+  TST_RegisterDummyDrivers();
+  SCH_Initialise();
+
+  unlink("ntskeys");
+  NKS_PreInitialise(0, 0, 0);
+  NKS_Initialise();
+
+  session = NKSN_CreateInstance(1, NULL, handle_message, NULL);
+
+  for (i = 0; i < 10000; i++) {
+    valid = random() % 2;
+    prepare_request(session, valid);
+    TEST_CHECK(process_request(session));
+    process_response(session, valid);
+  }
+
+
+  for (i = 0; i < 10000; i++) {
+    context.algorithm = AEAD_AES_SIV_CMAC_256;
+    get_keys(session, context.algorithm, &context.c2s, &context.s2c);
+    memset(&cookie, 0, sizeof (cookie));
+    TEST_CHECK(NKS_GenerateCookie(&context, &cookie));
+    TEST_CHECK(NKS_DecodeCookie(&cookie, &context2));
+    TEST_CHECK(context.algorithm == context2.algorithm);
+    TEST_CHECK(context.c2s.length == context2.c2s.length);
+    TEST_CHECK(context.s2c.length == context2.s2c.length);
+    TEST_CHECK(memcmp(context.c2s.key, context2.c2s.key, context.c2s.length) == 0);
+    TEST_CHECK(memcmp(context.s2c.key, context2.s2c.key, context.s2c.length) == 0);
+
+    if (random() % 4) {
+      cookie.cookie[random() % (cookie.length)]++;
+    } else if (random() % 4) {
+      generate_key(current_server_key);
+    } else {
+      l = cookie.length;
+      while (l == cookie.length)
+        cookie.length = random() % (sizeof (cookie.cookie) + 1);
+    }
+    TEST_CHECK(!NKS_DecodeCookie(&cookie, &context2));
+  }
+
+  unlink("ntskeys");
+  save_keys();
+
+  for (i = 0, sum = 0; i < MAX_SERVER_KEYS; i++) {
+    sum += server_keys[i].id + server_keys[i].key[0];
+    generate_key(i);
+  }
+
+  load_keys();
+  TEST_CHECK(unlink("ntskeys") == 0);
+
+  for (i = 0, sum2 = 0; i < MAX_SERVER_KEYS; i++) {
+    sum2 += server_keys[i].id + server_keys[i].key[0];
+  }
+
+  TEST_CHECK(sum == sum2);
+
+  NKSN_DestroyInstance(session);
+
+  NKS_Finalise();
+  TEST_CHECK(unlink("ntskeys") == 0);
+
+  SCH_Finalise();
+  LCL_Finalise();
+  CNF_Finalise();
+}
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/nts_ke_session.c b/test/unit/nts_ke_session.c
new file mode 100644
index 0000000..adcade6
--- /dev/null
+++ b/test/unit/nts_ke_session.c
@@ -0,0 +1,218 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2020
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include "test.h"
+
+#ifdef FEAT_NTS
+
+#include <nts_ke_session.c>
+
+#include <local.h>
+#include <socket.h>
+#include <sched.h>
+
+static NKSN_Instance client, server;
+static unsigned char record[NKE_MAX_MESSAGE_LENGTH];
+static int record_length, critical, type_start, records;
+static int request_received;
+static int response_received;
+
+static void
+send_message(NKSN_Instance inst)
+{
+  int i;
+
+  record_length = random() % (NKE_MAX_MESSAGE_LENGTH - 4 + 1);
+  for (i = 0; i < record_length; i++)
+    record[i] = random() % 256;
+  critical = random() % 2;
+  type_start = random() % 30000 + 1;
+  assert(sizeof (struct RecordHeader) == 4);
+  records = random() % ((NKE_MAX_MESSAGE_LENGTH - 4) / (4 + record_length) + 1);
+
+  DEBUG_LOG("critical=%d type_start=%d records=%d*%d",
+            critical, type_start, records, record_length);
+
+  NKSN_BeginMessage(inst);
+
+  TEST_CHECK(check_message_format(&inst->message, 0));
+  TEST_CHECK(!check_message_format(&inst->message, 1));
+
+  TEST_CHECK(!NKSN_AddRecord(inst, 0, 1, record, NKE_MAX_MESSAGE_LENGTH - 4 + 1));
+
+  TEST_CHECK(check_message_format(&inst->message, 0));
+  TEST_CHECK(!check_message_format(&inst->message, 1));
+
+  for (i = 0; i < records; i++) {
+    TEST_CHECK(NKSN_AddRecord(inst, critical, type_start + i, record, record_length));
+    TEST_CHECK(!NKSN_AddRecord(inst, 0, 1, &record,
+                               NKE_MAX_MESSAGE_LENGTH - inst->message.length - 4 + 1));
+
+    TEST_CHECK(check_message_format(&inst->message, 0));
+    TEST_CHECK(!check_message_format(&inst->message, 1));
+  }
+
+  TEST_CHECK(NKSN_EndMessage(inst));
+
+  TEST_CHECK(check_message_format(&inst->message, 0));
+  TEST_CHECK(check_message_format(&inst->message, 1));
+}
+
+static void
+verify_message(NKSN_Instance inst)
+{
+  unsigned char buffer[NKE_MAX_MESSAGE_LENGTH];
+  int i, c, t, length, buffer_length, msg_length, prev_parsed;
+  NKE_Key c2s, s2c;
+
+  for (i = 0; i < records; i++) {
+    memset(buffer, 0, sizeof (buffer));
+    buffer_length = random() % (record_length + 1);
+    assert(buffer_length <= sizeof (buffer));
+
+    prev_parsed = inst->message.parsed;
+    msg_length = inst->message.length;
+
+    TEST_CHECK(NKSN_GetRecord(inst, &c, &t, &length, buffer, buffer_length));
+    TEST_CHECK(c == critical);
+    TEST_CHECK(t == type_start + i);
+    TEST_CHECK(length == record_length);
+    TEST_CHECK(memcmp(record, buffer, buffer_length) == 0);
+    if (buffer_length < record_length)
+      TEST_CHECK(buffer[buffer_length] == 0);
+
+    inst->message.length = inst->message.parsed - 1;
+    inst->message.parsed = prev_parsed;
+    TEST_CHECK(!get_record(&inst->message, NULL, NULL, NULL, buffer, buffer_length));
+    TEST_CHECK(inst->message.parsed == prev_parsed);
+    inst->message.length = msg_length;
+    if (msg_length < 0x8000) {
+      inst->message.data[prev_parsed + 2] ^= 0x80;
+      TEST_CHECK(!get_record(&inst->message, NULL, NULL, NULL, buffer, buffer_length));
+      TEST_CHECK(inst->message.parsed == prev_parsed);
+      inst->message.data[prev_parsed + 2] ^= 0x80;
+    }
+    TEST_CHECK(get_record(&inst->message, NULL, NULL, NULL, buffer, buffer_length));
+    TEST_CHECK(inst->message.parsed > prev_parsed);
+  }
+
+  TEST_CHECK(!NKSN_GetRecord(inst, &critical, &t, &length, buffer, sizeof (buffer)));
+
+  TEST_CHECK(NKSN_GetKeys(inst, AEAD_AES_SIV_CMAC_256, &c2s, &s2c));
+  TEST_CHECK(c2s.length == SIV_GetKeyLength(AEAD_AES_SIV_CMAC_256));
+  TEST_CHECK(s2c.length == SIV_GetKeyLength(AEAD_AES_SIV_CMAC_256));
+}
+
+static int
+handle_request(void *arg)
+{
+  NKSN_Instance server = arg;
+
+  verify_message(server);
+
+  request_received = 1;
+
+  send_message(server);
+
+  return 1;
+}
+
+static int
+handle_response(void *arg)
+{
+  NKSN_Instance client = arg;
+
+  response_received = 1;
+
+  verify_message(client);
+
+  return 1;
+}
+
+static void
+check_finished(void *arg)
+{
+  DEBUG_LOG("checking for stopped sessions");
+  if (!NKSN_IsStopped(server) || !NKSN_IsStopped(client)) {
+    SCH_AddTimeoutByDelay(0.001, check_finished, NULL);
+    return;
+  }
+
+  SCH_QuitProgram();
+}
+
+void
+test_unit(void)
+{
+  void *client_cred, *server_cred;
+  int sock_fds[2], i;
+
+  LCL_Initialise();
+  TST_RegisterDummyDrivers();
+
+  for (i = 0; i < 50; i++) {
+    SCH_Initialise();
+
+    server = NKSN_CreateInstance(1, NULL, handle_request, NULL);
+    client = NKSN_CreateInstance(0, "test", handle_response, NULL);
+
+    server_cred = NKSN_CreateCertCredentials("nts_ke.crt", "nts_ke.key", NULL);
+    client_cred = NKSN_CreateCertCredentials(NULL, NULL, "nts_ke.crt");
+
+    TEST_CHECK(socketpair(AF_UNIX, SOCK_STREAM, 0, sock_fds) == 0);
+    TEST_CHECK(fcntl(sock_fds[0], F_SETFL, O_NONBLOCK) == 0);
+    TEST_CHECK(fcntl(sock_fds[1], F_SETFL, O_NONBLOCK) == 0);
+
+    TEST_CHECK(NKSN_StartSession(server, sock_fds[0], "client", server_cred, 4.0));
+    TEST_CHECK(NKSN_StartSession(client, sock_fds[1], "server", client_cred, 4.0));
+
+    send_message(client);
+
+    request_received = response_received = 0;
+
+    check_finished(NULL);
+
+    SCH_MainLoop();
+
+    TEST_CHECK(NKSN_IsStopped(server));
+    TEST_CHECK(NKSN_IsStopped(client));
+
+    TEST_CHECK(request_received);
+    TEST_CHECK(response_received);
+
+    NKSN_DestroyInstance(server);
+    NKSN_DestroyInstance(client);
+
+    NKSN_DestroyCertCredentials(server_cred);
+    NKSN_DestroyCertCredentials(client_cred);
+
+    SCH_Finalise();
+  }
+
+  LCL_Finalise();
+}
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/nts_ntp_auth.c b/test/unit/nts_ntp_auth.c
new file mode 100644
index 0000000..307b93b
--- /dev/null
+++ b/test/unit/nts_ntp_auth.c
@@ -0,0 +1,112 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2020
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include "test.h"
+
+#ifdef FEAT_NTS
+
+#include <nts_ntp_auth.c>
+
+#include "ntp_ext.h"
+#include "siv.h"
+
+void
+test_unit(void)
+{
+  unsigned char key[SIV_MAX_KEY_LENGTH], nonce[256], plaintext[256], plaintext2[256];
+  NTP_PacketInfo info;
+  NTP_Packet packet;
+  SIV_Instance siv;
+  int i, j, r, packet_length, nonce_length, key_length;
+  int plaintext_length, plaintext2_length, min_ef_length;
+
+  siv = SIV_CreateInstance(AEAD_AES_SIV_CMAC_256);
+  TEST_CHECK(siv);
+
+  for (i = 0; i < 10000; i++) {
+    key_length = SIV_GetKeyLength(AEAD_AES_SIV_CMAC_256);
+    for (j = 0; j < key_length; j++)
+      key[j] = random() % 256;
+    TEST_CHECK(SIV_SetKey(siv, key, key_length));
+
+    nonce_length = random() % sizeof (nonce) + 1;
+    for (j = 0; j < nonce_length; j++)
+      nonce[j] = random() % 256;
+
+    plaintext_length = random() % (sizeof (plaintext) + 1);
+    for (j = 0; j < plaintext_length; j++)
+      plaintext[j] = random() % 256;
+
+    packet_length = NTP_HEADER_LENGTH + random() % 100 * 4;
+    min_ef_length = random() % (sizeof (packet) - packet_length);
+
+    memset(&packet, 0, sizeof (packet));
+    packet.lvm = NTP_LVM(0, 4, 0);
+    memset(&info, 0, sizeof (info));
+    info.version = 4;
+    info.length = packet_length;
+
+    DEBUG_LOG("packet_length=%d nonce_length=%d plaintext_length=%d min_ef_length=%d",
+              packet_length, nonce_length, plaintext_length, min_ef_length);
+
+    r = NNA_GenerateAuthEF(&packet, &info, siv, nonce, nonce_length, plaintext,
+                           -1, 0);
+    TEST_CHECK(!r);
+    r = NNA_GenerateAuthEF(&packet, &info, siv, nonce, 0, plaintext,
+                           plaintext_length, 0);
+    TEST_CHECK(!r);
+    r = NNA_GenerateAuthEF(&packet, &info, siv, nonce, nonce_length, plaintext,
+                           plaintext_length, sizeof (packet) - info.length + 1);
+    TEST_CHECK(!r);
+
+    r = NNA_GenerateAuthEF(&packet, &info, siv, nonce, nonce_length, plaintext,
+                           plaintext_length, min_ef_length);
+    TEST_CHECK(r);
+    TEST_CHECK(info.length - packet_length >= min_ef_length);
+
+    r = NNA_DecryptAuthEF(&packet, &info, siv, packet_length, plaintext2,
+                          -1, &plaintext2_length);
+    TEST_CHECK(!r);
+
+    r = NNA_DecryptAuthEF(&packet, &info, siv, packet_length, plaintext2,
+                          sizeof (plaintext2), &plaintext2_length);
+    TEST_CHECK(r);
+    TEST_CHECK(plaintext_length == plaintext2_length);
+    TEST_CHECK(memcmp(plaintext, plaintext2, plaintext_length) == 0);
+
+    j = random() % (packet_length + plaintext_length +
+                    nonce_length + SIV_GetTagLength(siv) + 8) / 4 * 4;
+    ((unsigned char *)&packet)[j]++;
+    r = NNA_DecryptAuthEF(&packet, &info, siv, packet_length, plaintext2,
+                          sizeof (plaintext2), &plaintext2_length);
+    TEST_CHECK(!r);
+    ((unsigned char *)&packet)[j]--;
+  }
+
+  SIV_DestroyInstance(siv);
+}
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/nts_ntp_client.c b/test/unit/nts_ntp_client.c
new file mode 100644
index 0000000..4ee33b0
--- /dev/null
+++ b/test/unit/nts_ntp_client.c
@@ -0,0 +1,284 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2020
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include "test.h"
+
+#ifdef FEAT_NTS
+
+#include "socket.h"
+#include "ntp.h"
+#include "nts_ke_client.h"
+
+#define NKC_CreateInstance(address, name) Malloc(1)
+#define NKC_DestroyInstance(inst) Free(inst)
+#define NKC_Start(inst) (random() % 2)
+#define NKC_IsActive(inst) (random() % 2)
+#define NKC_GetRetryFactor(inst) (1)
+
+static int get_nts_data(NKC_Instance inst, NKE_Context *context,
+                        NKE_Cookie *cookies, int *num_cookies, int max_cookies,
+                        IPSockAddr *ntp_address);
+#define NKC_GetNtsData get_nts_data
+
+#include <nts_ntp_client.c>
+
+static int
+get_nts_data(NKC_Instance inst, NKE_Context *context,
+             NKE_Cookie *cookies, int *num_cookies, int max_cookies,
+             IPSockAddr *ntp_address)
+{
+  int i;
+
+  if (random() % 2)
+    return 0;
+
+  context->algorithm = AEAD_AES_SIV_CMAC_256;
+
+  context->c2s.length = SIV_GetKeyLength(context->algorithm);
+  UTI_GetRandomBytes(context->c2s.key, context->c2s.length);
+  context->s2c.length = SIV_GetKeyLength(context->algorithm);
+  UTI_GetRandomBytes(context->s2c.key, context->s2c.length);
+
+  *num_cookies = random() % max_cookies + 1;
+  for (i = 0; i < *num_cookies; i++) {
+    cookies[i].length = random() % (sizeof (cookies[i].cookie) + 1);
+    if (random() % 4 != 0)
+      cookies[i].length = cookies[i].length / 4 * 4;
+    memset(cookies[i].cookie, random(), cookies[i].length);
+  }
+
+  ntp_address->ip_addr.family = IPADDR_UNSPEC;
+  ntp_address->port = 0;
+
+  return 1;
+}
+
+static int
+get_request(NNC_Instance inst)
+{
+  unsigned char nonce[NTS_MIN_UNPADDED_NONCE_LENGTH], uniq_id[NTS_MIN_UNIQ_ID_LENGTH];
+  NTP_PacketInfo info;
+  NTP_Packet packet;
+  int expected_length, req_cookies;
+
+  memset(&packet, 0, sizeof (packet));
+  memset(&info, 0, sizeof (info));
+  info.version = 4;
+  info.mode = MODE_CLIENT;
+  info.length = random() % (sizeof (packet) + 1);
+  if (random() % 4 != 0)
+    info.length = info.length / 4 * 4;
+
+  if (inst->num_cookies > 0 && random() % 2) {
+    inst->num_cookies = 0;
+
+    TEST_CHECK(!NNC_GenerateRequestAuth(inst, &packet, &info));
+  }
+
+  while (!NNC_PrepareForAuth(inst)) {
+    inst->next_nke_attempt = SCH_GetLastEventMonoTime() + random() % 10 - 7;
+  }
+
+  TEST_CHECK(inst->num_cookies > 0);
+  TEST_CHECK(inst->siv);
+
+  memcpy(nonce, inst->nonce, sizeof (nonce));
+  memcpy(uniq_id, inst->uniq_id, sizeof (uniq_id));
+  TEST_CHECK(NNC_PrepareForAuth(inst));
+  TEST_CHECK(memcmp(nonce, inst->nonce, sizeof (nonce)) != 0);
+  TEST_CHECK(memcmp(uniq_id, inst->uniq_id, sizeof (uniq_id)) != 0);
+
+  req_cookies = MIN(NTS_MAX_COOKIES - inst->num_cookies + 1,
+                    MAX_TOTAL_COOKIE_LENGTH /
+                      (inst->cookies[inst->cookie_index].length + 4));
+  expected_length = info.length + 4 + sizeof (inst->uniq_id) +
+                    req_cookies * (4 + inst->cookies[inst->cookie_index].length) +
+                    4 + 4 + sizeof (inst->nonce) + SIV_GetTagLength(inst->siv);
+  DEBUG_LOG("length=%d cookie_length=%d expected_length=%d",
+            info.length, inst->cookies[inst->cookie_index].length, expected_length);
+
+  if (info.length % 4 == 0 && info.length >= NTP_HEADER_LENGTH &&
+      inst->cookies[inst->cookie_index].length % 4 == 0 &&
+      inst->cookies[inst->cookie_index].length >= (NTP_MIN_EF_LENGTH - 4) &&
+      expected_length <= sizeof (packet)) {
+    TEST_CHECK(NNC_GenerateRequestAuth(inst, &packet, &info));
+    TEST_CHECK(info.length == expected_length);
+    return 1;
+  } else {
+    TEST_CHECK(!NNC_GenerateRequestAuth(inst, &packet, &info));
+    return 0;
+  }
+}
+
+static void
+prepare_response(NNC_Instance inst, NTP_Packet *packet, NTP_PacketInfo *info, int valid, int nak)
+{
+  unsigned char cookie[508], plaintext[528], nonce[448];
+  int nonce_length, ef_length, cookie_length, plaintext_length, min_auth_length;
+  int i, index, auth_start;
+  SIV_Instance siv;
+
+  memset(packet, 0, sizeof (*packet));
+  packet->lvm = NTP_LVM(0, 4, MODE_SERVER);
+  memset(info, 0, sizeof (*info));
+  info->version = 4;
+  info->mode = MODE_SERVER;
+  info->length = NTP_HEADER_LENGTH;
+
+  if (valid)
+    index = -1;
+  else
+    index = random() % (nak ? 2 : 8);
+
+  DEBUG_LOG("index=%d nak=%d", index, nak);
+
+  if (index != 0)
+    TEST_CHECK(NEF_AddField(packet, info, NTP_EF_NTS_UNIQUE_IDENTIFIER, inst->uniq_id,
+                            sizeof (inst->uniq_id)));
+  if (index == 1)
+    ((unsigned char *)packet)[NTP_HEADER_LENGTH + 4]++;
+
+  if (nak) {
+    packet->stratum = NTP_INVALID_STRATUM;
+    packet->reference_id = htonl(NTP_KOD_NTS_NAK);
+    return;
+  }
+
+  nonce_length = random() % (sizeof (nonce)) + 1;
+
+  do {
+    cookie_length = random() % (sizeof (cookie) + 1);
+  } while (cookie_length % 4 != 0 ||
+           ((index != 2) == (cookie_length < NTP_MIN_EF_LENGTH - 4 ||
+                             cookie_length > NKE_MAX_COOKIE_LENGTH)));
+
+  min_auth_length = random() % (512 + 1);
+
+  DEBUG_LOG("nonce_length=%d cookie_length=%d min_auth_length=%d",
+            nonce_length, cookie_length, min_auth_length);
+
+  UTI_GetRandomBytes(nonce, nonce_length);
+  UTI_GetRandomBytes(cookie, cookie_length);
+
+  if (cookie_length >= 12 && cookie_length <= 32 && random() % 2 == 0)
+    TEST_CHECK(NEF_AddField(packet, info, NTP_EF_NTS_COOKIE, cookie, cookie_length));
+
+  plaintext_length = 0;
+  if (index != 3) {
+    for (i = random() % ((sizeof (plaintext) - 16) / (cookie_length + 4)); i >= 0; i--) {
+      TEST_CHECK(NEF_SetField(plaintext, sizeof (plaintext), plaintext_length,
+                              NTP_EF_NTS_COOKIE, cookie,
+                              i == 0 ? cookie_length : random() % (cookie_length + 1) / 4 * 4,
+                              &ef_length));
+      plaintext_length += ef_length;
+    }
+  }
+  auth_start = info->length;
+  if (index != 4) {
+    if (index == 5) {
+      assert(plaintext_length + 16 <= sizeof (plaintext));
+      memset(plaintext + plaintext_length, 0, 16);
+      plaintext_length += 16;
+    }
+    siv = SIV_CreateInstance(inst->context.algorithm);
+    TEST_CHECK(siv);
+    TEST_CHECK(SIV_SetKey(siv, inst->context.s2c.key, inst->context.s2c.length));
+    TEST_CHECK(NNA_GenerateAuthEF(packet, info, siv,
+                                  nonce, nonce_length, plaintext, plaintext_length,
+                                  min_auth_length));
+    SIV_DestroyInstance(siv);
+  }
+  if (index == 6)
+    ((unsigned char *)packet)[auth_start + 8]++;
+  if (index == 7)
+    TEST_CHECK(NEF_AddField(packet, info, 0x7000, inst->uniq_id, sizeof (inst->uniq_id)));
+}
+
+void
+test_unit(void)
+{
+  NNC_Instance inst;
+  NTP_PacketInfo info;
+  NTP_Packet packet;
+  IPSockAddr addr;
+  IPAddr ip_addr;
+  int i, j, prev_num_cookies, valid;
+
+  TEST_CHECK(SIV_GetKeyLength(AEAD_AES_SIV_CMAC_256) > 0);
+
+  SCK_GetLoopbackIPAddress(AF_INET, &addr.ip_addr);
+  addr.port = 0;
+
+  inst = NNC_CreateInstance(&addr, "test", &addr);
+  TEST_CHECK(inst);
+
+  for (i = 0; i < 100000; i++) {
+    if (!get_request(inst))
+      continue;
+
+    valid = random() % 2;
+
+    TEST_CHECK(!inst->nak_response);
+    TEST_CHECK(!inst->ok_response);
+
+    if (random() % 2) {
+      prepare_response(inst, &packet, &info, 0, 1);
+      TEST_CHECK(!NNC_CheckResponseAuth(inst, &packet, &info));
+      TEST_CHECK(!inst->nak_response);
+      TEST_CHECK(!inst->ok_response);
+      for (j = random() % 3; j > 0; j--) {
+        prepare_response(inst, &packet, &info, 1, 1);
+        TEST_CHECK(!NNC_CheckResponseAuth(inst, &packet, &info));
+        TEST_CHECK(inst->nak_response);
+        TEST_CHECK(!inst->ok_response);
+      }
+    }
+
+    prev_num_cookies = inst->num_cookies;
+    prepare_response(inst, &packet, &info, valid, 0);
+
+    if (valid) {
+      TEST_CHECK(NNC_CheckResponseAuth(inst, &packet, &info));
+      TEST_CHECK(inst->num_cookies >= MIN(NTS_MAX_COOKIES, prev_num_cookies + 1));
+      TEST_CHECK(inst->ok_response);
+    }
+
+    prev_num_cookies = inst->num_cookies;
+    TEST_CHECK(!NNC_CheckResponseAuth(inst, &packet, &info));
+    TEST_CHECK(inst->num_cookies == prev_num_cookies);
+    TEST_CHECK(inst->ok_response == valid);
+
+    if (random() % 10 == 0) {
+      TST_GetRandomAddress(&ip_addr, IPADDR_INET4, 32);
+      NNC_ChangeAddress(inst, &ip_addr);
+      TEST_CHECK(UTI_CompareIPs(&inst->nts_address.ip_addr, &ip_addr, NULL) == 0);
+    }
+  }
+
+  NNC_DestroyInstance(inst);
+}
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/nts_ntp_server.c b/test/unit/nts_ntp_server.c
new file mode 100644
index 0000000..40938d6
--- /dev/null
+++ b/test/unit/nts_ntp_server.c
@@ -0,0 +1,176 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2020
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include "test.h"
+
+#ifdef FEAT_NTS
+
+#include <local.h>
+#include <sched.h>
+
+#include <nts_ntp_server.c>
+
+static void
+prepare_request(NTP_Packet *packet, NTP_PacketInfo *info, int valid, int nak)
+{
+  unsigned char uniq_id[NTS_MIN_UNIQ_ID_LENGTH], nonce[NTS_MIN_UNPADDED_NONCE_LENGTH];
+  SIV_Instance siv;
+  NKE_Context context;
+  NKE_Cookie cookie;
+  int i, index, cookie_start, auth_start;
+
+  context.algorithm = SERVER_SIV;
+  context.c2s.length = SIV_GetKeyLength(context.algorithm);
+  UTI_GetRandomBytes(&context.c2s.key, context.c2s.length);
+  context.s2c.length = SIV_GetKeyLength(context.algorithm);
+  UTI_GetRandomBytes(&context.s2c.key, context.s2c.length);
+
+  TEST_CHECK(NKS_GenerateCookie(&context, &cookie));
+
+  UTI_GetRandomBytes(uniq_id, sizeof (uniq_id));
+  UTI_GetRandomBytes(nonce, sizeof (nonce));
+
+  memset(packet, 0, sizeof (*packet));
+  packet->lvm = NTP_LVM(0, 4, MODE_CLIENT);
+  memset(info, 0, sizeof (*info));
+  info->version = 4;
+  info->mode = MODE_CLIENT;
+  info->length = NTP_HEADER_LENGTH;
+
+  if (valid)
+    index = -1;
+  else
+    index = random() % 3;
+
+  DEBUG_LOG("valid=%d nak=%d index=%d", valid, nak, index);
+
+  if (index != 0)
+    TEST_CHECK(NEF_AddField(packet, info, NTP_EF_NTS_UNIQUE_IDENTIFIER,
+                            uniq_id, sizeof (uniq_id)));
+
+  cookie_start = info->length;
+
+  if (index != 1)
+    TEST_CHECK(NEF_AddField(packet, info, NTP_EF_NTS_COOKIE,
+                            cookie.cookie, cookie.length));
+
+  for (i = random() % 4; i > 0; i--)
+    TEST_CHECK(NEF_AddField(packet, info, NTP_EF_NTS_COOKIE_PLACEHOLDER,
+                            cookie.cookie, cookie.length));
+
+  auth_start = info->length;
+
+  if (index != 2) {
+    siv = SIV_CreateInstance(context.algorithm);
+    TEST_CHECK(SIV_SetKey(siv, context.c2s.key, context.c2s.length));
+    TEST_CHECK(NNA_GenerateAuthEF(packet, info, siv, nonce, sizeof (nonce),
+                                  (const unsigned char *)"", 0, 0));
+    SIV_DestroyInstance(siv);
+  }
+
+  if (nak)
+    ((unsigned char *)packet)[(index == 2 ? cookie_start :
+                               (index == 1 ? auth_start :
+                                (random() % 2 ? cookie_start : auth_start))) +
+                              4 + random() % 16]++;
+}
+
+static void
+init_response(NTP_Packet *packet, NTP_PacketInfo *info)
+{
+  memset(packet, 0, sizeof (*packet));
+  packet->lvm = NTP_LVM(0, 4, MODE_SERVER);
+  memset(info, 0, sizeof (*info));
+  info->version = 4;
+  info->mode = MODE_SERVER;
+  info->length = NTP_HEADER_LENGTH;
+}
+
+void
+test_unit(void)
+{
+  NTP_PacketInfo req_info, res_info;
+  NTP_Packet request, response;
+  int i, valid, nak;
+  uint32_t kod;
+
+  char conf[][100] = {
+    "ntsport 0",
+    "ntsprocesses 0",
+    "ntsserverkey nts_ke.key",
+    "ntsservercert nts_ke.crt",
+  };
+
+  CNF_Initialise(0, 0);
+  for (i = 0; i < sizeof conf / sizeof conf[0]; i++)
+    CNF_ParseLine(NULL, i + 1, conf[i]);
+
+  LCL_Initialise();
+  TST_RegisterDummyDrivers();
+  SCH_Initialise();
+  NKS_PreInitialise(0, 0, 0);
+  NKS_Initialise();
+  NNS_Initialise();
+
+  for (i = 0; i < 50000; i++) {
+    valid = random() % 2;
+    nak = random() % 2;
+    prepare_request(&request, &req_info, valid, nak);
+
+    TEST_CHECK(NNS_CheckRequestAuth(&request, &req_info, &kod) == (valid && !nak));
+
+    if (valid && !nak) {
+      TEST_CHECK(kod == 0);
+      TEST_CHECK(server->num_cookies > 0);
+
+      init_response(&response, &res_info);
+      TEST_CHECK(NNS_GenerateResponseAuth(&request, &req_info, &response, &res_info, kod));
+
+      TEST_CHECK(res_info.ext_fields == 2);
+      TEST_CHECK(server->num_cookies == 0);
+    } else if (valid && nak) {
+      TEST_CHECK(kod == NTP_KOD_NTS_NAK);
+      TEST_CHECK(server->num_cookies == 0);
+
+      init_response(&response, &res_info);
+      TEST_CHECK(NNS_GenerateResponseAuth(&request, &req_info, &response, &res_info, kod));
+
+      TEST_CHECK(res_info.ext_fields == 1);
+      TEST_CHECK(server->num_cookies == 0);
+    } else {
+      TEST_CHECK(kod == 0);
+      TEST_CHECK(server->num_cookies == 0);
+    }
+  }
+
+  NNS_Finalise();
+  NKS_Finalise();
+  SCH_Finalise();
+  LCL_Finalise();
+  CNF_Finalise();
+}
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/regress.c b/test/unit/regress.c
new file mode 100644
index 0000000..f47d1c4
--- /dev/null
+++ b/test/unit/regress.c
@@ -0,0 +1,119 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2017
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+#include <regress.c>
+#include "test.h"
+
+#define POINTS 64
+
+void
+test_unit(void)
+{
+  double x[POINTS], x2[POINTS], y[POINTS], w[POINTS];
+  double b0, b1, b2, s2, sb0, sb1, slope, slope2, intercept, sd, median;
+  double xrange, yrange, wrange, x2range;
+  int i, j, n, m, c1, c2, c3, runs, best_start, dof;
+
+  for (n = 3; n <= POINTS; n++) {
+    for (i = 0; i < 200; i++) {
+      slope = TST_GetRandomDouble(-0.1, 0.1);
+      intercept = TST_GetRandomDouble(-1.0, 1.0);
+      sd = TST_GetRandomDouble(1e-6, 1e-4);
+      slope2 = (random() % 2 ? 1 : -1) * TST_GetRandomDouble(0.1, 0.5);
+
+      DEBUG_LOG("iteration %d n=%d intercept=%e slope=%e sd=%e",
+                i, n, intercept, slope, sd);
+
+      for (j = 0; j < n; j++) {
+        x[j] = -j;
+        y[j] = intercept + slope * x[j] + (j % 2 ? 1 : -1) * TST_GetRandomDouble(1e-6, sd);
+        w[j] = TST_GetRandomDouble(1.0, 2.0);
+        x2[j] = (y[j] - intercept - slope * x[j]) / slope2;
+      }
+
+      RGR_WeightedRegression(x, y, w, n, &b0, &b1, &s2, &sb0, &sb1);
+      DEBUG_LOG("WR b0=%e b1=%e s2=%e sb0=%e sb1=%e", b0, b1, s2, sb0, sb1);
+      TEST_CHECK(fabs(b0 - intercept) < sd + 1e-3);
+      TEST_CHECK(fabs(b1 - slope) < sd);
+
+      if (RGR_FindBestRegression(x, y, w, n, 0, 3, &b0, &b1, &s2, &sb0, &sb1,
+                                 &best_start, &runs, &dof)) {
+        DEBUG_LOG("BR b0=%e b1=%e s2=%e sb0=%e sb1=%e runs=%d bs=%d dof=%d",
+                  b0, b1, s2, sb0, sb1, runs, best_start, dof);
+
+        TEST_CHECK(fabs(b0 - intercept) < sd + 1e-3);
+        TEST_CHECK(fabs(b1 - slope) < sd);
+      }
+
+      if (RGR_MultipleRegress(x, x2, y, n, &b2)) {
+        DEBUG_LOG("MR b2=%e", b2);
+        TEST_CHECK(fabs(b2 - slope2) < 1e-6);
+      }
+
+      for (j = 0; j < n / 7; j++)
+        y[random() % n] += 100 * sd;
+
+      if (RGR_FindBestRobustRegression(x, y, n, 1e-8, &b0, &b1, &runs, &best_start)) {
+        DEBUG_LOG("BRR b0=%e b1=%e runs=%d bs=%d", b0, b1, runs, best_start);
+
+        TEST_CHECK(fabs(b0 - intercept) < sd + 1e-2);
+        TEST_CHECK(fabs(b1 - slope) < 5.0 * sd);
+      }
+
+      for (j = 0; j < n; j++)
+        x[j] = random() % 4 * TST_GetRandomDouble(-1000, 1000);
+
+      median = RGR_FindMedian(x, n);
+
+      for (j = c1 = c2 = c3 = 0; j < n; j++) {
+        if (x[j] < median)
+          c1++;
+        if (x[j] > median)
+          c3++;
+        else
+          c2++;
+      }
+
+      TEST_CHECK(c1 + c2 >= c3 && c1 <= c2 + c3);
+
+      xrange = TST_GetRandomDouble(1e-6, pow(10.0, random() % 10));
+      yrange = random() % 3 * TST_GetRandomDouble(0.0, pow(10.0, random() % 10));
+      wrange = random() % 3 * TST_GetRandomDouble(0.0, pow(10.0, random() % 10));
+      x2range = random() % 3 * TST_GetRandomDouble(0.0, pow(10.0, random() % 10));
+      m = random() % n;
+
+      for (j = 0; j < n; j++) {
+        x[j] = (j ? x[j - 1] : 0.0) + TST_GetRandomDouble(1e-6, xrange);
+        y[j] = TST_GetRandomDouble(-yrange, yrange);
+        w[j] = 1.0 + TST_GetRandomDouble(0.0, wrange);
+        x2[j] = TST_GetRandomDouble(-x2range, x2range);
+      }
+
+      RGR_WeightedRegression(x, y, w, n, &b0, &b1, &s2, &sb0, &sb1);
+
+      if (RGR_FindBestRegression(x + m, y + m, w, n - m, m, 3, &b0, &b1, &s2, &sb0, &sb1,
+                                 &best_start, &runs, &dof))
+        ;
+      if (RGR_MultipleRegress(x, x2, y, n, &b2))
+        ;
+      if (RGR_FindBestRobustRegression(x, y, n, 1e-8, &b0, &b1, &runs, &best_start))
+        ;
+    }
+  }
+}
diff --git a/test/unit/samplefilt.c b/test/unit/samplefilt.c
new file mode 100644
index 0000000..d8d2975
--- /dev/null
+++ b/test/unit/samplefilt.c
@@ -0,0 +1,118 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2018
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <local.h>
+#include "test.h"
+
+#define LCL_GetSysPrecisionAsQuantum() (1.0e-6)
+
+#include <samplefilt.c>
+
+void
+test_unit(void)
+{
+  NTP_Sample sample_in, sample_out;
+  SPF_Instance filter;
+  int i, j, k, sum_count, min_samples, max_samples;
+  double mean, combine_ratio, sum_err;
+
+  LCL_Initialise();
+
+  memset(&sample_in, 0, sizeof (sample_in));
+  memset(&sample_out, 0, sizeof (sample_out));
+
+  for (i = 0; i <= 100; i++) {
+    max_samples = random() % 20 + 1;
+    min_samples = random() % (max_samples) + 1;
+    combine_ratio = TST_GetRandomDouble(0.0, 1.0);
+
+    filter = SPF_CreateInstance(min_samples, max_samples, 2.0, combine_ratio);
+
+    for (j = 0, sum_count = 0, sum_err = 0.0; j < 100; j++) {
+      DEBUG_LOG("iteration %d/%d", i, j);
+
+      mean = TST_GetRandomDouble(-1.0e3, 1.0e3);
+      UTI_ZeroTimespec(&sample_in.time);
+
+      for (k = 0; k < 100; k++) {
+        UTI_AddDoubleToTimespec(&sample_in.time, TST_GetRandomDouble(1.0e-1, 1.0e2),
+                                &sample_in.time);
+        sample_in.offset = mean + TST_GetRandomDouble(-1.0, 1.0);
+        sample_in.peer_dispersion = TST_GetRandomDouble(1.0e-4, 2.0e-4);
+        sample_in.root_dispersion = TST_GetRandomDouble(1.0e-3, 2.0e-3);
+        sample_in.peer_delay = TST_GetRandomDouble(1.0e-2, 2.0e-2);
+        sample_in.root_delay = TST_GetRandomDouble(1.0e-1, 2.0e-1);
+        sample_in.stratum = random() % 16;
+
+        TEST_CHECK(SPF_AccumulateSample(filter, &sample_in));
+        TEST_CHECK(!SPF_AccumulateSample(filter, &sample_in));
+
+        TEST_CHECK(SPF_GetNumberOfSamples(filter) == MIN(k + 1, max_samples));
+
+        SPF_GetLastSample(filter, &sample_out);
+        TEST_CHECK(!memcmp(&sample_in, &sample_out, sizeof (sample_in)));
+
+        SPF_SlewSamples(filter, &sample_in.time, 0.0, 0.0);
+        SPF_AddDispersion(filter, 0.0);
+
+        if (k + 1 < min_samples)
+          TEST_CHECK(!SPF_GetFilteredSample(filter, &sample_out));
+
+        TEST_CHECK(SPF_GetNumberOfSamples(filter) == MIN(k + 1, max_samples));
+      }
+
+      if (random() % 10) {
+        TEST_CHECK(SPF_GetFilteredSample(filter, &sample_out));
+
+        TEST_CHECK(SPF_GetAvgSampleDispersion(filter) <= 2.0);
+
+        sum_err += sample_out.offset - mean;
+        sum_count++;
+
+        TEST_CHECK(UTI_CompareTimespecs(&sample_out.time, &sample_in.time) <= 0 &&
+                   sample_out.time.tv_sec >= 0);
+        TEST_CHECK(fabs(sample_out.offset - mean) <= 1.0);
+        TEST_CHECK(sample_out.peer_dispersion >= 1.0e-4 &&
+                   (sample_out.peer_dispersion <= 2.0e-4 || filter->max_samples > 1));
+        TEST_CHECK(sample_out.root_dispersion >= 1.0e-3 &&
+                   (sample_out.root_dispersion <= 2.0e-3 || filter->max_samples > 1));
+        TEST_CHECK(sample_out.peer_delay >= 1.0e-2 &&
+                   sample_out.peer_delay <= 2.0e-2);
+        TEST_CHECK(sample_out.root_delay >= 1.0e-1 &&
+                   sample_out.root_delay <= 2.0e-1);
+        TEST_CHECK(sample_out.stratum >= 0 && sample_out.stratum <= 15);
+
+        if (max_samples == 1)
+          TEST_CHECK(!memcmp(&sample_in, &sample_out, sizeof (sample_in)));
+
+      } else {
+        SPF_DropSamples(filter);
+      }
+
+      TEST_CHECK(SPF_GetNumberOfSamples(filter) == 0);
+    }
+
+    TEST_CHECK(fabs(sum_err / sum_count) < 0.3);
+
+    SPF_DestroyInstance(filter);
+  }
+
+  LCL_Finalise();
+}
diff --git a/test/unit/siv.c b/test/unit/siv.c
new file mode 100644
index 0000000..76846c8
--- /dev/null
+++ b/test/unit/siv.c
@@ -0,0 +1,321 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2019
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include <sysincl.h>
+#include <logging.h>
+#include <siv.h>
+#include "test.h"
+
+#ifdef HAVE_SIV
+
+struct siv_test {
+  SIV_Algorithm algorithm;
+  const unsigned char key[64];
+  int key_length;
+  const unsigned char nonce[128];
+  int nonce_length;
+  const unsigned char assoc[128];
+  int assoc_length;
+  const unsigned char plaintext[128];
+  int plaintext_length;
+  const unsigned char ciphertext[128];
+  int ciphertext_length;
+};
+
+void
+test_unit(void)
+{
+  struct siv_test tests[] = {
+    { AEAD_AES_SIV_CMAC_256,
+      "\x01\x23\x45\x67\x89\xab\xcd\xef\xf0\x12\x34\x56\x78\x9a\xbc\xde"
+      "\xef\x01\x23\x45\x67\x89\xab\xcd\xde\xf0\x12\x34\x56\x78\x9a\xbc", 32,
+      "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f", 16,
+      "", 0,
+      "", 0,
+      "\x22\x3e\xb5\x94\xe0\xe0\x25\x4b\x00\x25\x8e\x21\x9a\x1c\xa4\x21", 16
+    },
+    { AEAD_AES_SIV_CMAC_256,
+      "\x01\x23\x45\x67\x89\xab\xcd\xef\xf0\x12\x34\x56\x78\x9a\xbc\xde"
+      "\xef\x01\x23\x45\x67\x89\xab\xcd\xde\xf0\x12\x34\x56\x78\x9a\xbc", 32,
+      "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f", 16,
+      "\x4c\x9d\x4f\xca\xed\x8a\xe2\xba\xad\x3f\x3e\xa6\xe9\x3c\x8c\x8b", 16,
+      "", 0,
+      "\xd7\x20\x19\x89\xc6\xdb\xc6\xd6\x61\xfc\x62\xbc\x86\x5e\xee\xef", 16
+    },
+    { AEAD_AES_SIV_CMAC_256,
+      "\x01\x23\x45\x67\x89\xab\xcd\xef\xf0\x12\x34\x56\x78\x9a\xbc\xde"
+      "\xef\x01\x23\x45\x67\x89\xab\xcd\xde\xf0\x12\x34\x56\x78\x9a\xbc", 32,
+      "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f", 16,
+      "", 0,
+      "\x4c\x9d\x4f\xca\xed\x8a\xe2\xba\xad\x3f\x3e\xa6\xe9\x3c\x8c\x8b", 16,
+      "\xb6\xc1\x60\xe9\xc2\xfd\x2a\xe8\xde\xc5\x36\x8b\x2a\x33\xed\xe1"
+      "\x14\xff\xb3\x97\x34\x5c\xcb\xe4\x4a\xa4\xde\xac\xd9\x36\x90\x46", 32
+    },
+    { AEAD_AES_SIV_CMAC_256,
+      "\x01\x23\x45\x67\x89\xab\xcd\xef\xf0\x12\x34\x56\x78\x9a\xbc\xde"
+      "\xef\x01\x23\x45\x67\x89\xab\xcd\xde\xf0\x12\x34\x56\x78\x9a\xbc", 32,
+      "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e", 15,
+      "\x4c\x9d\x4f\xca\xed\x8a\xe2\xba\xad\x3f\x3e\xa6\xe9\x3c\x8c", 15,
+      "\xba\x99\x79\x31\x23\x7e\x3c\x53\x58\x7e\xd4\x93\x02\xab\xe4", 15,
+      "\x03\x8c\x41\x51\xba\x7a\x8f\x77\x6e\x56\x31\x99\x42\x0b\xc7\x03"
+      "\xe7\x6c\x67\xc9\xda\xb7\x0d\x5b\x44\x06\x26\x5a\xd0\xd2\x3b", 31
+    },
+    { AEAD_AES_SIV_CMAC_256,
+      "\x01\x23\x45\x67\x89\xab\xcd\xef\xf0\x12\x34\x56\x78\x9a\xbc\xde"
+      "\xef\x01\x23\x45\x67\x89\xab\xcd\xde\xf0\x12\x34\x56\x78\x9a\xbc", 32,
+      "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f", 16,
+      "\x4c\x9d\x4f\xca\xed\x8a\xe2\xba\xad\x3f\x3e\xa6\xe9\x3c\x8c\x8b", 16,
+      "\xba\x99\x79\x31\x23\x7e\x3c\x53\x58\x7e\xd4\x93\x02\xab\xe4\xa7", 16,
+      "\x5c\x05\x23\x65\xf4\x57\x0a\xa0\xfb\x38\x3e\xce\x9b\x75\x85\xeb"
+      "\x68\x85\x19\x36\x0c\x7c\x48\x11\x40\xcb\x9b\x57\x9a\x0e\x65\x32", 32
+    },
+    { AEAD_AES_SIV_CMAC_256,
+      "\x01\x23\x45\x67\x89\xab\xcd\xef\xf0\x12\x34\x56\x78\x9a\xbc\xde"
+      "\xef\x01\x23\x45\x67\x89\xab\xcd\xde\xf0\x12\x34\x56\x78\x9a\xbc", 32,
+      "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
+      "\xd5", 17,
+      "\x4c\x9d\x4f\xca\xed\x8a\xe2\xba\xad\x3f\x3e\xa6\xe9\x3c\x8c\x8b"
+      "\xa0", 17,
+      "\xba\x99\x79\x31\x23\x7e\x3c\x53\x58\x7e\xd4\x93\x02\xab\xe4\xa7"
+      "\x08", 17,
+      "\xaf\x58\x4b\xe7\x82\x1e\x96\x19\x29\x91\x25\xe0\xdd\x80\x3b\x49"
+      "\xa5\x11\xcd\xb6\x08\xf3\x76\xa0\xb6\xfa\x15\x82\xf3\x95\xe1\xeb"
+      "\xbd", 33
+    },
+    { AEAD_AES_SIV_CMAC_256,
+      "\x01\x23\x45\x67\x89\xab\xcd\xef\xf0\x12\x34\x56\x78\x9a\xbc\xde"
+      "\xef\x01\x23\x45\x67\x89\xab\xcd\xde\xf0\x12\x34\x56\x78\x9a\xbc", 32,
+      "\xb0\x5a\x1b\xc7\x56\xe7\xb6\x2c\xb4\x85\xe5\x56\xa5\x28\xc0\x6c"
+      "\x2f\x3b\x0b\x9d\x1a\x0c\xdf\x69\x47\xe0\xcc\xc0\x87\xaa\x5c\x09"
+      "\x98\x48\x8d\x6a\x8e\x1e\x05\xd7\x8b\x68\x74\x83\xb5\x1d\xf1\x2c", 48,
+      "\xe5\x8b\xd2\x6a\x30\xc5\xc5\x61\xcc\xbd\x7c\x27\xbf\xfe\xf9\x06"
+      "\x00\x5b\xd7\xfc\x11\x0b\xcf\x16\x61\xef\xac\x05\xa7\xaf\xec\x27"
+      "\x41\xc8\x5e\x9e\x0d\xf9\x2f\xaf\x20\x79\x17\xe5\x17\x91\x2a\x27"
+      "\x34\x1c\xbc\xaf\xeb\xef\x7f\x52\xe7\x1e\x4c\x2a\xca\xbd\x2b\xbe"
+      "\x34\xd6\xfb\x69\xd3\x3e\x49\x59\x60\xb4\x26\xc9\xb8\xce\xba", 79,
+      "\x6c\xe7\xcf\x7e\xab\x7b\xa0\xe1\xa7\x22\xcb\x88\xde\x5e\x42\xd2"
+      "\xec\x79\xe0\xa2\xcf\x5f\x0f\x6f\x6b\x89\x57\xcd\xae\x17\xd4\xc2"
+      "\xf3\x1b\xa2\xa8\x13\x78\x23\x2f\x83\xa8\xd4\x0c\xc0\xd2\xf3\x99"
+      "\xae\x81\xa1\xca\x5b\x5f\x45\xa6\x6f\x0c\x8a\xf3\xd4\x67\x40\x81"
+      "\x26\xe2\x01\x86\xe8\x5a\xd5\xf8\x58\x80\x9f\x56\xaa\x76\x96\xbf"
+      "\x31", 81,
+      "\x9a\x06\x33\xe0\xee\x00\x6a\x9b\xc8\x20\xd5\xe2\xc2\xed\xb5\x75"
+      "\xfa\x9e\x42\x2a\x31\x6b\xda\xca\xaa\x7d\x31\x8b\x84\x7a\xb8\xd7"
+      "\x8a\x81\x25\x64\xed\x41\x9b\xa9\x77\x10\xbd\x05\x0c\x4e\xc5\x31"
+      "\x0c\xa2\x86\xec\x8a\x94\xc8\x24\x23\x3c\x13\xee\xa5\x51\xc9\xdf"
+      "\x48\xc9\x55\xc5\x2f\x40\x73\x3f\x98\xbb\x8d\x69\x78\x46\x64\x17"
+      "\x8d\x49\x2f\x14\x62\xa4\x7c\x2a\x57\x38\x87\xce\xc6\x72\xd3\x5c"
+      "\xa1", 97
+    },
+    { 0, "", 0 }
+  };
+
+  unsigned char plaintext[sizeof (((struct siv_test *)NULL)->plaintext)];
+  unsigned char ciphertext[sizeof (((struct siv_test *)NULL)->ciphertext)];
+  SIV_Instance siv;
+  int i, j, r;
+
+  TEST_CHECK(SIV_CreateInstance(0) == NULL);
+
+  for (i = 0; tests[i].algorithm != 0; i++) {
+    DEBUG_LOG("testing %d (%d)", (int)tests[i].algorithm, i);
+
+    assert(tests[i].key_length <= sizeof (tests[i].key));
+    assert(tests[i].nonce_length <= sizeof (tests[i].nonce));
+    assert(tests[i].assoc_length <= sizeof (tests[i].assoc));
+    assert(tests[i].plaintext_length <= sizeof (tests[i].plaintext));
+    assert(tests[i].ciphertext_length <= sizeof (tests[i].ciphertext));
+
+    siv = SIV_CreateInstance(tests[i].algorithm);
+    TEST_CHECK(siv != NULL);
+
+    TEST_CHECK(SIV_GetKeyLength(tests[i].algorithm) == tests[i].key_length);
+
+    r = SIV_Encrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                    tests[i].assoc, tests[i].assoc_length,
+                    tests[i].plaintext, tests[i].plaintext_length,
+                    ciphertext, tests[i].ciphertext_length);
+    TEST_CHECK(!r);
+    r = SIV_Decrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                    tests[i].assoc, tests[i].assoc_length,
+                    tests[i].ciphertext, tests[i].ciphertext_length,
+                    plaintext, tests[i].plaintext_length);
+    TEST_CHECK(!r);
+
+    for (j = -1; j < 1024; j++) {
+      r = SIV_SetKey(siv, tests[i].key, j);
+      TEST_CHECK(r == (j == tests[i].key_length));
+    }
+
+    TEST_CHECK(SIV_GetTagLength(siv) == tests[i].ciphertext_length - tests[i].plaintext_length);
+
+    r = SIV_Encrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                    tests[i].assoc, tests[i].assoc_length,
+                    tests[i].plaintext, tests[i].plaintext_length,
+                    ciphertext, tests[i].ciphertext_length);
+    TEST_CHECK(r);
+
+#if 0
+    for (j = 0; j < tests[i].ciphertext_length; j++) {
+      printf("\\x%02x", ciphertext[j]);
+      if (j % 16 == 15)
+        printf("\n");
+    }
+    printf("\n");
+#endif
+    TEST_CHECK(memcmp(ciphertext, tests[i].ciphertext, tests[i].ciphertext_length) == 0);
+
+    for (j = -1; j < tests[i].nonce_length; j++) {
+      r = SIV_Encrypt(siv, tests[i].nonce, j,
+                      tests[i].assoc, tests[i].assoc_length,
+                      tests[i].plaintext, tests[i].plaintext_length,
+                      ciphertext, tests[i].ciphertext_length);
+      if (j > 0) {
+        TEST_CHECK(r);
+        TEST_CHECK(memcmp(ciphertext, tests[i].ciphertext, tests[i].ciphertext_length) != 0);
+      } else {
+        TEST_CHECK(!r);
+      }
+    }
+
+    for (j = -1; j < tests[i].assoc_length; j++) {
+      r = SIV_Encrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                      tests[i].assoc, j,
+                      tests[i].plaintext, tests[i].plaintext_length,
+                      ciphertext, tests[i].ciphertext_length);
+      if (j >= 0) {
+        TEST_CHECK(r);
+        TEST_CHECK(memcmp(ciphertext, tests[i].ciphertext, tests[i].ciphertext_length) != 0);
+      } else {
+        TEST_CHECK(!r);
+      }
+    }
+
+    for (j = -1; j < tests[i].plaintext_length; j++) {
+      r = SIV_Encrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                      tests[i].assoc, tests[i].assoc_length,
+                      tests[i].plaintext, j,
+                      ciphertext, j + SIV_GetTagLength(siv));
+      if (j >= 0) {
+        TEST_CHECK(r);
+        TEST_CHECK(memcmp(ciphertext, tests[i].ciphertext, j + SIV_GetTagLength(siv)) != 0);
+      } else {
+        TEST_CHECK(!r);
+      }
+    }
+
+    for (j = -1; j < 2 * tests[i].plaintext_length; j++) {
+      if (j == tests[i].plaintext_length)
+        continue;
+      r = SIV_Encrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                      tests[i].assoc, tests[i].assoc_length,
+                      tests[i].plaintext, j,
+                      ciphertext, tests[i].ciphertext_length);
+      TEST_CHECK(!r);
+    }
+
+    for (j = -1; j < 2 * tests[i].ciphertext_length; j++) {
+      if (j == tests[i].ciphertext_length)
+        continue;
+      r = SIV_Encrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                      tests[i].assoc, tests[i].assoc_length,
+                      tests[i].plaintext, tests[i].plaintext_length,
+                      ciphertext, j);
+      TEST_CHECK(!r);
+    }
+
+    r = SIV_Decrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                    tests[i].assoc, tests[i].assoc_length,
+                    tests[i].ciphertext, tests[i].ciphertext_length,
+                    plaintext, tests[i].plaintext_length);
+    TEST_CHECK(r);
+    TEST_CHECK(memcmp(plaintext, tests[i].plaintext, tests[i].plaintext_length) == 0);
+
+    for (j = -1; j < tests[i].nonce_length; j++) {
+      r = SIV_Decrypt(siv, tests[i].nonce, j,
+                      tests[i].assoc, tests[i].assoc_length,
+                      tests[i].ciphertext, tests[i].ciphertext_length,
+                      plaintext, tests[i].plaintext_length);
+      TEST_CHECK(!r);
+    }
+
+    for (j = -1; j < tests[i].assoc_length; j++) {
+      r = SIV_Decrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                      tests[i].assoc, j,
+                      tests[i].ciphertext, tests[i].ciphertext_length,
+                      plaintext, tests[i].plaintext_length);
+      TEST_CHECK(!r);
+    }
+
+    for (j = -1; j < 2 * tests[i].ciphertext_length; j++) {
+      if (j == tests[i].ciphertext_length)
+        continue;
+
+      r = SIV_Decrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                      tests[i].assoc, tests[i].assoc_length,
+                      tests[i].ciphertext, j,
+                      plaintext, tests[i].plaintext_length);
+      TEST_CHECK(!r);
+    }
+
+    for (j = -1; j < tests[i].plaintext_length; j++) {
+      r = SIV_Decrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                      tests[i].assoc, tests[i].assoc_length,
+                      tests[i].ciphertext, tests[i].ciphertext_length,
+                      plaintext, j);
+      TEST_CHECK(!r);
+
+      r = SIV_Decrypt(siv, tests[i].nonce, tests[i].nonce_length,
+                      tests[i].assoc, tests[i].assoc_length,
+                      tests[i].ciphertext, j + SIV_GetTagLength(siv),
+                      plaintext, j);
+      TEST_CHECK(!r);
+    }
+
+    SIV_DestroyInstance(siv);
+  }
+
+  siv = SIV_CreateInstance(tests[0].algorithm);
+  for (i = 0; i < 1000; i++) {
+    for (j = 0; tests[j].algorithm == tests[0].algorithm; j++) {
+      r = SIV_SetKey(siv, tests[j].key, tests[j].key_length);
+      TEST_CHECK(r);
+      r = SIV_Encrypt(siv, tests[j].nonce, tests[j].nonce_length,
+                      tests[j].assoc, tests[j].assoc_length,
+                      tests[j].plaintext, tests[j].plaintext_length,
+                      ciphertext, tests[j].ciphertext_length);
+      TEST_CHECK(r);
+      r = SIV_Decrypt(siv, tests[j].nonce, tests[j].nonce_length,
+                      tests[j].assoc, tests[j].assoc_length,
+                      tests[j].ciphertext, tests[j].ciphertext_length,
+                      plaintext, tests[j].plaintext_length);
+      TEST_CHECK(r);
+    }
+  }
+  SIV_DestroyInstance(siv);
+}
+#else
+void
+test_unit(void)
+{
+  TEST_REQUIRE(0);
+}
+#endif
diff --git a/test/unit/smooth.c b/test/unit/smooth.c
new file mode 100644
index 0000000..998a4d1
--- /dev/null
+++ b/test/unit/smooth.c
@@ -0,0 +1,63 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <smooth.c>
+#include "test.h"
+
+void
+test_unit(void)
+{
+  int i, j;
+  struct timespec ts;
+  double offset, freq, wander;
+  char conf[] = "smoothtime 300 0.01";
+
+  CNF_Initialise(0, 0);
+  CNF_ParseLine(NULL, 1, conf);
+
+  LCL_Initialise();
+  SMT_Initialise();
+  locked = 0;
+
+  for (i = 0; i < 500; i++) {
+    UTI_ZeroTimespec(&ts);
+    SMT_Reset(&ts);
+
+    DEBUG_LOG("iteration %d", i);
+
+    offset = (random() % 1000000 - 500000) / 1.0e6;
+    freq = (random() % 1000000 - 500000) / 1.0e9;
+    update_smoothing(&ts, offset, freq);
+
+    for (j = 0; j < 10000; j++) {
+      update_smoothing(&ts, 0.0, 0.0);
+      UTI_AddDoubleToTimespec(&ts, 16.0, &ts);
+      get_smoothing(&ts, &offset, &freq, &wander);
+    }
+
+    TEST_CHECK(fabs(offset) < 1e-12);
+    TEST_CHECK(fabs(freq) < 1e-12);
+    TEST_CHECK(fabs(wander) < 1e-12);
+  }
+
+  SMT_Finalise();
+  LCL_Finalise();
+  CNF_Finalise();
+}
diff --git a/test/unit/sources.c b/test/unit/sources.c
new file mode 100644
index 0000000..621b79c
--- /dev/null
+++ b/test/unit/sources.c
@@ -0,0 +1,243 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016, 2018
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <sources.c>
+#include "test.h"
+
+static SRC_Instance
+create_source(SRC_Type type, IPAddr *addr, int authenticated, int sel_options)
+{
+  TST_GetRandomAddress(addr, IPADDR_UNSPEC, -1);
+
+  return SRC_CreateNewInstance(UTI_IPToRefid(addr), type, authenticated, sel_options,
+                               type == SRC_NTP ? addr : NULL,
+                               SRC_DEFAULT_MINSAMPLES, SRC_DEFAULT_MAXSAMPLES, 0.0, 1.0);
+}
+
+void
+test_unit(void)
+{
+  SRC_AuthSelectMode sel_mode;
+  SRC_Instance srcs[16];
+  IPAddr addrs[16];
+  RPT_SourceReport report;
+  NTP_Sample sample;
+  int i, j, k, l, n1, n2, n3, n4, samples, sel_options;
+  char conf[128];
+
+  CNF_Initialise(0, 0);
+  LCL_Initialise();
+  TST_RegisterDummyDrivers();
+  SCH_Initialise();
+  SRC_Initialise();
+  REF_Initialise();
+  NSR_Initialise();
+
+  REF_SetMode(REF_ModeIgnore);
+
+  for (i = 0; i < 1000; i++) {
+    DEBUG_LOG("iteration %d", i);
+
+    for (j = 0; j < sizeof (srcs) / sizeof (srcs[0]); j++) {
+      TEST_CHECK(n_sources == j);
+
+      sel_options = i & random() & (SRC_SELECT_NOSELECT | SRC_SELECT_PREFER |
+                                    SRC_SELECT_TRUST | SRC_SELECT_REQUIRE);
+
+      DEBUG_LOG("added source %d options %d", j, sel_options);
+      srcs[j] = create_source(SRC_NTP, &addrs[j], 0, sel_options);
+      SRC_UpdateReachability(srcs[j], 1);
+
+      samples = (i + j) % 5 + 3;
+
+      sample.offset = TST_GetRandomDouble(-1.0, 1.0);
+
+      for (k = 0; k < samples; k++) {
+        SCH_GetLastEventTime(&sample.time, NULL, NULL);
+        UTI_AddDoubleToTimespec(&sample.time, TST_GetRandomDouble(k - samples, k - samples + 1),
+                                &sample.time);
+
+        sample.offset += TST_GetRandomDouble(-1.0e-2, 1.0e-2);
+        sample.peer_delay = TST_GetRandomDouble(1.0e-6, 1.0e-1);
+        sample.peer_dispersion = TST_GetRandomDouble(1.0e-6, 1.0e-1);
+        sample.root_delay = sample.peer_delay;
+        sample.root_dispersion = sample.peer_dispersion;
+        sample.stratum = 1;
+
+        if (random() % 2)
+          SRC_SetLeapStatus(srcs[j], random() % 4);
+
+        DEBUG_LOG("source %d sample %d offset %f delay %f disp %f", j, k,
+                  sample.offset, sample.peer_delay, sample.peer_dispersion);
+
+        SRC_AccumulateSample(srcs[j], &sample);
+      }
+
+      for (k = 0; k <= j; k++) {
+        int passed = 0, trusted = 0, trusted_passed = 0, required = 0, required_passed = 0;
+        double trusted_lo = DBL_MAX, trusted_hi = DBL_MIN;
+        double passed_lo = DBL_MAX, passed_hi = DBL_MIN;
+
+        SRC_SelectSource(srcs[k]);
+        DEBUG_LOG("source %d status %u", k, sources[k]->status);
+
+        for (l = 0; l <= j; l++) {
+          TEST_CHECK(sources[l]->status > SRC_OK && sources[l]->status <= SRC_SELECTED);
+          if (sources[l]->sel_options & SRC_SELECT_NOSELECT) {
+            TEST_CHECK(sources[l]->status == SRC_UNSELECTABLE);
+          } else if (sources[l]->status != SRC_BAD_DISTANCE) {
+            if (sources[l]->status >= SRC_NONPREFERRED) {
+              passed++;
+              if (passed_lo > sources[l]->sel_info.lo_limit)
+                passed_lo = sources[l]->sel_info.lo_limit;
+              if (passed_hi < sources[l]->sel_info.hi_limit)
+                passed_hi = sources[l]->sel_info.hi_limit;
+            }
+            if (sources[l]->sel_options & SRC_SELECT_TRUST) {
+              trusted++;
+              if (trusted_lo > sources[l]->sel_info.lo_limit)
+                trusted_lo = sources[l]->sel_info.lo_limit;
+              if (trusted_hi < sources[l]->sel_info.hi_limit)
+                trusted_hi = sources[l]->sel_info.hi_limit;
+              if (sources[l]->status >= SRC_NONPREFERRED)
+                trusted_passed++;
+            }
+            if (sources[l]->sel_options & SRC_SELECT_REQUIRE) {
+              required++;
+              if (sources[l]->status >= SRC_NONPREFERRED)
+                required_passed++;
+            }
+            if (sources[l]->sel_options & SRC_SELECT_PREFER)
+              TEST_CHECK(sources[l]->status != SRC_NONPREFERRED);
+          }
+        }
+
+        DEBUG_LOG("sources %d passed %d trusted %d/%d required %d/%d", j + 1, passed,
+                  trusted_passed, trusted, required_passed, required);
+
+        TEST_CHECK(!trusted || !passed || (passed_lo >= trusted_lo && passed_hi <= trusted_hi));
+        TEST_CHECK(!passed || !trusted || trusted_passed >= 1);
+        TEST_CHECK(!passed || !required || required_passed > 0);
+
+        for (l = 0; l <= j; l++) {
+          TEST_CHECK(sources[l]->leap_vote ==
+                     (sources[l]->status >= SRC_NONPREFERRED &&
+                      (!trusted || sources[l]->sel_options & SRC_SELECT_TRUST)));
+        }
+      }
+    }
+
+    for (j = 0; j < sizeof (srcs) / sizeof (srcs[0]); j++) {
+      SRC_ReportSource(j, &report, &sample.time);
+      SRC_DestroyInstance(srcs[j]);
+    }
+  }
+
+  TEST_CHECK(CNF_GetAuthSelectMode() == SRC_AUTHSELECT_MIX);
+
+  for (i = 0; i < 1000; i++) {
+    DEBUG_LOG("iteration %d", i);
+
+    switch (i % 4) {
+      case 0:
+        snprintf(conf, sizeof (conf), "authselectmode require");
+        sel_mode = SRC_AUTHSELECT_REQUIRE;
+        break;
+      case 1:
+        snprintf(conf, sizeof (conf), "authselectmode prefer");
+        sel_mode = SRC_AUTHSELECT_PREFER;
+        break;
+      case 2:
+        snprintf(conf, sizeof (conf), "authselectmode mix");
+        sel_mode = SRC_AUTHSELECT_MIX;
+        break;
+      case 3:
+        snprintf(conf, sizeof (conf), "authselectmode ignore");
+        sel_mode = SRC_AUTHSELECT_IGNORE;
+        break;
+    }
+
+    CNF_ParseLine(NULL, 0, conf);
+    TEST_CHECK(CNF_GetAuthSelectMode() == sel_mode);
+
+    sel_options = random() & (SRC_SELECT_PREFER | SRC_SELECT_TRUST | SRC_SELECT_REQUIRE);
+
+    n1 = random() % 3;
+    n2 = random() % 3;
+    n3 = random() % 3;
+    n4 = random() % 3;
+    assert(n1 + n2 + n3 < sizeof (srcs) / sizeof (srcs[0]));
+
+    for (j = 0; j < n1; j++)
+      srcs[j] = create_source(SRC_REFCLOCK, &addrs[j], random() % 2, sel_options);
+    for (; j < n1 + n2; j++)
+      srcs[j] = create_source(SRC_NTP, &addrs[j], 1, sel_options);
+    for (; j < n1 + n2 + n3; j++)
+      srcs[j] = create_source(SRC_NTP, &addrs[j], 0, sel_options);
+    for (; j < n1 + n2 + n3 + n4; j++)
+      srcs[j] = create_source(random() % 2 ? SRC_REFCLOCK : SRC_NTP, &addrs[j],
+                              random() % 2, sel_options | SRC_SELECT_NOSELECT);
+
+    switch (sel_mode) {
+      case SRC_AUTHSELECT_IGNORE:
+        for (j = 0; j < n1 + n2 + n3; j++)
+          TEST_CHECK(srcs[j]->sel_options == sel_options);
+        break;
+      case SRC_AUTHSELECT_MIX:
+        for (j = 0; j < n1 + n2; j++)
+          TEST_CHECK(srcs[j]->sel_options ==
+                     (sel_options | (n2 > 0 && n3 > 0 ? SRC_SELECT_REQUIRE | SRC_SELECT_TRUST : 0)));
+        for (; j < n1 + n2 + n3; j++)
+          TEST_CHECK(srcs[j]->sel_options == sel_options);
+        break;
+      case SRC_AUTHSELECT_PREFER:
+        for (j = 0; j < n1 + n2; j++)
+          TEST_CHECK(srcs[j]->sel_options == sel_options);
+        for (; j < n1 + n2 + n3; j++)
+          TEST_CHECK(srcs[j]->sel_options == (sel_options | (n2 > 0 ? SRC_SELECT_NOSELECT : 0)));
+        break;
+      case SRC_AUTHSELECT_REQUIRE:
+        for (j = 0; j < n1 + n2; j++)
+          TEST_CHECK(srcs[j]->sel_options == sel_options);
+        for (; j < n1 + n2 + n3; j++)
+          TEST_CHECK(srcs[j]->sel_options == (sel_options | SRC_SELECT_NOSELECT));
+        break;
+      default:
+        assert(0);
+    }
+
+    for (j = n1 + n2 + n3; j < n1 + n2 + n3 + n4; j++)
+      TEST_CHECK(srcs[j]->sel_options == (sel_options | SRC_SELECT_NOSELECT));
+
+    for (j = n1 + n2 + n3 + n4 - 1; j >= 0; j--) {
+      if (j < n1 + n2)
+        TEST_CHECK(srcs[j]->sel_options == sel_options);
+      SRC_DestroyInstance(srcs[j]);
+    }
+  }
+
+  NSR_Finalise();
+  REF_Finalise();
+  SRC_Finalise();
+  SCH_Finalise();
+  LCL_Finalise();
+  CNF_Finalise();
+  HSH_Finalise();
+}
diff --git a/test/unit/test.c b/test/unit/test.c
new file mode 100644
index 0000000..482d83f
--- /dev/null
+++ b/test/unit/test.c
@@ -0,0 +1,187 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <config.h>
+#include <sysincl.h>
+#include <logging.h>
+#include <localp.h>
+#include <util.h>
+
+#include "test.h"
+
+void
+TST_Fail(int line)
+{
+  printf("FAIL (on line %d)\n", line);
+  exit(1);
+}
+
+void
+TST_Skip(int line)
+{
+  printf("SKIP (on line %d)\n", line);
+  exit(0);
+}
+
+int
+main(int argc, char **argv)
+{
+  char *test_name, *s;
+  int i, seed = 0;
+  struct timeval tv;
+
+  test_name = argv[0];
+  s = strrchr(test_name, '.');
+  if (s)
+    *s = '\0';
+  s = strrchr(test_name, '/');
+  if (s)
+    test_name = s + 1;
+
+  for (i = 1; i < argc; i++) {
+    if (!strcmp(argv[i], "-d")) {
+      LOG_SetMinSeverity(LOGS_DEBUG);
+    } else if (!strcmp(argv[i], "-s") && i + 1 < argc) {
+      seed = atoi(argv[++i]);
+    } else {
+      fprintf(stderr, "Unknown option\n");
+      exit(1);
+    }
+  }
+
+  gettimeofday(&tv, NULL);
+  srandom(seed ? seed : tv.tv_sec ^ (tv.tv_usec << 10));
+
+  printf("Testing %-30s ", test_name);
+  fflush(stdout);
+
+  LOG_Initialise();
+
+  test_unit();
+
+  LOG_Finalise();
+
+  printf("PASS\n");
+
+  return 0;
+}
+
+void TST_SuspendLogging(void)
+{
+  LOG_OpenFileLog("/dev/null");
+}
+
+void TST_ResumeLogging(void)
+{
+  LOG_OpenFileLog(NULL);
+}
+
+double
+TST_GetRandomDouble(double min, double max)
+{
+  return min + (double)random() / RAND_MAX * (max - min);
+}
+
+void
+TST_GetRandomAddress(IPAddr *ip, int family, int bits)
+{
+  if (family != IPADDR_INET4 && family != IPADDR_INET6)
+    family = random() % 2 ? IPADDR_INET4 : IPADDR_INET6;
+
+  ip->family = family;
+
+  if (family == IPADDR_INET4) {
+    if (bits < 0)
+      bits = 32;
+    assert(bits <= 32);
+
+    if (bits > 16)
+      ip->addr.in4 = (uint32_t)random() % (1U << (bits - 16)) << 16 |
+                     (uint32_t)random() % (1U << 16);
+    else
+      ip->addr.in4 = (uint32_t)random() % (1U << bits);
+  } else {
+    int i, b;
+
+    if (bits < 0)
+      bits = 128;
+    assert(bits <= 128);
+
+    for (i = 0, b = 120; i < 16; i++, b -= 8) {
+      if (b >= bits) {
+        ip->addr.in6[i] = 0;
+      } else {
+        ip->addr.in6[i] = random() % (1U << MIN(bits - b, 8));
+      }
+    }
+  }
+}
+
+void
+TST_SwapAddressBit(IPAddr *ip, unsigned int b)
+{
+  if (ip->family == IPADDR_INET4) {
+    assert(b < 32);
+    ip->addr.in4 ^= 1U << (31 - b);
+  } else if (ip->family == IPADDR_INET6) {
+    assert(b < 128);
+    ip->addr.in6[b / 8] ^= 1U << (7 - b % 8);
+  } else {
+    assert(0);
+  }
+}
+
+static double
+read_frequency(void)
+{
+  return 0.0;
+}
+
+static double
+set_frequency(double freq_ppm)
+{
+  return 0.0;
+}
+
+static void
+accrue_offset(double offset, double corr_rate)
+{
+}
+
+static int
+apply_step_offset(double offset)
+{
+  return 0;
+}
+
+static void
+offset_convert(struct timespec *raw, double *corr, double *err)
+{
+  *corr = 0.0;
+  if (err)
+    *err = 0.0;
+}
+
+void
+TST_RegisterDummyDrivers(void)
+{
+  lcl_RegisterSystemDrivers(read_frequency, set_frequency, accrue_offset,
+                            apply_step_offset, offset_convert, NULL, NULL);
+}
diff --git a/test/unit/test.h b/test/unit/test.h
new file mode 100644
index 0000000..2d3637b
--- /dev/null
+++ b/test/unit/test.h
@@ -0,0 +1,55 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2016
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#ifndef GOT_TEST_H
+#define GOT_TEST_H
+
+#include <addressing.h>
+
+extern void test_unit(void);
+
+#define TEST_CHECK(expr) \
+  do { \
+    if (!(expr)) { \
+      TST_Fail(__LINE__); \
+      exit(1); \
+    } \
+  } while (0)
+
+#define TEST_REQUIRE(expr) \
+  do { \
+    if (!(expr)) { \
+      TST_Skip(__LINE__); \
+      exit(0); \
+    } \
+  } while (0)
+
+extern void TST_Fail(int line);
+extern void TST_Skip(int line);
+
+extern void TST_SuspendLogging(void);
+extern void TST_ResumeLogging(void);
+
+extern double TST_GetRandomDouble(double min, double max);
+extern void TST_GetRandomAddress(IPAddr *ip, int family, int bits);
+extern void TST_SwapAddressBit(IPAddr *ip, unsigned int b);
+extern void TST_RegisterDummyDrivers(void);
+
+#endif
diff --git a/test/unit/util.c b/test/unit/util.c
new file mode 100644
index 0000000..052eb31
--- /dev/null
+++ b/test/unit/util.c
@@ -0,0 +1,372 @@
+/*
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2017-2018
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+ */
+
+#include <util.c>
+#include "test.h"
+
+void test_unit(void) {
+  NTP_int64 ntp_ts, ntp_fuzz;
+  NTP_int32 ntp32_ts;
+  struct timespec ts, ts2;
+  struct timeval tv;
+  double x, y, nan, inf;
+  Timespec tspec;
+  Float f;
+  int i, j, c;
+  char buf[16], *s, *words[3];
+  uid_t uid;
+  gid_t gid;
+  struct stat st;
+  FILE *file;
+
+  for (i = -31; i < 31; i++) {
+    x = pow(2.0, i);
+    y = UTI_Log2ToDouble(i);
+    TEST_CHECK(y / x > 0.99999 && y / x < 1.00001);
+  }
+
+  for (i = -89; i < 63; i++) {
+    x = pow(2.0, i);
+    y = UTI_FloatNetworkToHost(UTI_FloatHostToNetwork(x));
+    TEST_CHECK(y / x > 0.99999 && y / x < 1.00001);
+  }
+
+  for (i = 0; i < 100000; i++) {
+    x = TST_GetRandomDouble(-1000.0, 1000.0);
+    y = UTI_FloatNetworkToHost(UTI_FloatHostToNetwork(x));
+    TEST_CHECK(y / x > 0.99999 && y / x < 1.00001);
+
+    UTI_GetRandomBytes(&f, sizeof (f));
+    x = UTI_FloatNetworkToHost(f);
+    TEST_CHECK(x > 0.0 || x <= 0.0);
+  }
+
+  for (i = 0; i < 100000; i++) {
+    UTI_GetRandomBytes(&ntp32_ts, sizeof (ntp32_ts));
+    TEST_CHECK(UTI_DoubleToNtp32(UTI_Ntp32ToDouble(ntp32_ts)) == ntp32_ts);
+  }
+
+  TEST_CHECK(UTI_DoubleToNtp32(1.0) == htonl(65536));
+  TEST_CHECK(UTI_DoubleToNtp32(0.0) == htonl(0));
+  TEST_CHECK(UTI_DoubleToNtp32(1.0 / (65536.0)) == htonl(1));
+  TEST_CHECK(UTI_DoubleToNtp32(1.000001 / (65536.0)) == htonl(2));
+  TEST_CHECK(UTI_DoubleToNtp32(1.000001) == htonl(65537));
+  TEST_CHECK(UTI_DoubleToNtp32(1000000) == htonl(0xffffffff));
+  TEST_CHECK(UTI_DoubleToNtp32(-1.0) == htonl(0));
+
+  UTI_DoubleToTimeval(0.4e-6, &tv);
+  TEST_CHECK(tv.tv_sec == 0);
+  TEST_CHECK(tv.tv_usec == 0);
+  UTI_DoubleToTimeval(-0.4e-6, &tv);
+  TEST_CHECK(tv.tv_sec == 0);
+  TEST_CHECK(tv.tv_usec == 0);
+  UTI_DoubleToTimeval(0.5e-6, &tv);
+  TEST_CHECK(tv.tv_sec == 0);
+  TEST_CHECK(tv.tv_usec == 1);
+  UTI_DoubleToTimeval(-0.5e-6, &tv);
+  TEST_CHECK(tv.tv_sec == -1);
+  TEST_CHECK(tv.tv_usec == 999999);
+
+  UTI_DoubleToTimespec(0.9e-9, &ts);
+  TEST_CHECK(ts.tv_sec == 0);
+  TEST_CHECK(ts.tv_nsec == 0);
+  UTI_DoubleToTimespec(1.0e-9, &ts);
+  TEST_CHECK(ts.tv_sec == 0);
+  TEST_CHECK(ts.tv_nsec == 1);
+  UTI_DoubleToTimespec(-0.9e-9, &ts);
+  TEST_CHECK(ts.tv_sec == 0);
+  TEST_CHECK(ts.tv_nsec == 0);
+  UTI_DoubleToTimespec(-1.0e-9, &ts);
+  TEST_CHECK(ts.tv_sec == -1);
+  TEST_CHECK(ts.tv_nsec == 999999999);
+
+  ntp_ts.hi = htonl(JAN_1970);
+  ntp_ts.lo = 0xffffffff;
+  UTI_Ntp64ToTimespec(&ntp_ts, &ts);
+#if defined(HAVE_LONG_TIME_T) && NTP_ERA_SPLIT > 0
+  TEST_CHECK(ts.tv_sec == 0x100000000LL * (1 + (NTP_ERA_SPLIT - 1) / 0x100000000LL));
+#else
+  TEST_CHECK(ts.tv_sec == 0);
+#endif
+  TEST_CHECK(ts.tv_nsec == 999999999);
+
+  UTI_AddDoubleToTimespec(&ts, 1e-9, &ts);
+#if defined(HAVE_LONG_TIME_T) && NTP_ERA_SPLIT > 0
+  TEST_CHECK(ts.tv_sec == 1 + 0x100000000LL * (1 + (NTP_ERA_SPLIT - 1) / 0x100000000LL));
+#else
+  TEST_CHECK(ts.tv_sec == 1);
+#endif
+  TEST_CHECK(ts.tv_nsec == 0);
+
+  ntp_fuzz.hi = 0;
+  ntp_fuzz.lo = htonl(0xff1234ff);
+
+  UTI_TimespecToNtp64(&ts, &ntp_ts, &ntp_fuzz);
+  TEST_CHECK(ntp_ts.hi == htonl(JAN_1970 + 1));
+  TEST_CHECK(ntp_ts.lo == ntp_fuzz.lo);
+
+  ts.tv_sec = ts.tv_nsec = 0;
+  UTI_TimespecToNtp64(&ts, &ntp_ts, &ntp_fuzz);
+  TEST_CHECK(ntp_ts.hi == 0);
+  TEST_CHECK(ntp_ts.lo == 0);
+
+  TEST_CHECK(UTI_IsZeroTimespec(&ts));
+  TEST_CHECK(UTI_IsZeroNtp64(&ntp_ts));
+
+  ts.tv_sec = 1;
+  ntp_ts.hi = htonl(1);
+
+  TEST_CHECK(!UTI_IsZeroTimespec(&ts));
+  TEST_CHECK(!UTI_IsZeroNtp64(&ntp_ts));
+
+  ts.tv_sec = 0;
+  ntp_ts.hi = 0;
+  ts.tv_nsec = 1;
+  ntp_ts.lo = htonl(1);
+
+  TEST_CHECK(!UTI_IsZeroTimespec(&ts));
+  TEST_CHECK(!UTI_IsZeroNtp64(&ntp_ts));
+
+  ntp_ts.hi = 0;
+  ntp_ts.lo = 0;
+
+  UTI_Ntp64ToTimespec(&ntp_ts, &ts);
+  TEST_CHECK(UTI_IsZeroTimespec(&ts));
+  UTI_TimespecToNtp64(&ts, &ntp_ts, NULL);
+  TEST_CHECK(UTI_IsZeroNtp64(&ntp_ts));
+
+  ntp_fuzz.hi = htonl(1);
+  ntp_fuzz.lo = htonl(3);
+  ntp_ts.hi = htonl(1);
+  ntp_ts.lo = htonl(2);
+
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_ts) == 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_fuzz) < 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_fuzz, &ntp_ts) > 0);
+
+  ntp_ts.hi = htonl(0x80000002);
+  ntp_ts.lo = htonl(2);
+
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_ts) == 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_fuzz) < 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_fuzz, &ntp_ts) > 0);
+
+  ntp_fuzz.hi = htonl(0x90000001);
+
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_ts) == 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_fuzz) < 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_fuzz, &ntp_ts) > 0);
+
+  TEST_CHECK(UTI_IsEqualAnyNtp64(&ntp_ts, &ntp_ts, NULL, NULL));
+  TEST_CHECK(UTI_IsEqualAnyNtp64(&ntp_ts, NULL, &ntp_ts, NULL));
+  TEST_CHECK(UTI_IsEqualAnyNtp64(&ntp_ts, NULL, NULL, &ntp_ts));
+  TEST_CHECK(!UTI_IsEqualAnyNtp64(&ntp_ts, &ntp_fuzz, &ntp_fuzz, &ntp_fuzz));
+
+  ts.tv_sec = 1;
+  ts.tv_nsec = 2;
+  ts2.tv_sec = 1;
+  ts2.tv_nsec = 3;
+
+  TEST_CHECK(UTI_CompareTimespecs(&ts, &ts) == 0);
+  TEST_CHECK(UTI_CompareTimespecs(&ts, &ts2) < 0);
+  TEST_CHECK(UTI_CompareTimespecs(&ts2, &ts) > 0);
+
+  ts2.tv_sec = 2;
+
+  TEST_CHECK(UTI_CompareTimespecs(&ts, &ts) == 0);
+  TEST_CHECK(UTI_CompareTimespecs(&ts, &ts2) < 0);
+  TEST_CHECK(UTI_CompareTimespecs(&ts2, &ts) > 0);
+
+  for (i = -32; i <= 32; i++) {
+    for (j = c = 0; j < 1000; j++) {
+      UTI_GetNtp64Fuzz(&ntp_fuzz, i);
+      if (i <= 0)
+        TEST_CHECK(ntp_fuzz.hi == 0);
+      if (i < 0)
+        TEST_CHECK(ntohl(ntp_fuzz.lo) < 1U << (32 + i));
+      else if (i < 32)
+        TEST_CHECK(ntohl(ntp_fuzz.hi) < 1U << i);
+      if (ntohl(ntp_fuzz.lo) >= 1U << (31 + CLAMP(-31, i, 0)))
+        c++;
+    }
+
+    if (i == -32)
+      TEST_CHECK(c == 0);
+    else
+      TEST_CHECK(c > 400 && c < 600);
+  }
+
+  ts.tv_nsec = 0;
+
+  ts.tv_sec = 10;
+  TEST_CHECK(!UTI_IsTimeOffsetSane(&ts, -20.0));
+
+#ifdef HAVE_LONG_TIME_T
+  ts.tv_sec = NTP_ERA_SPLIT + (1LL << 32);
+#else
+  ts.tv_sec = 0x7fffffff - MIN_ENDOFTIME_DISTANCE;
+#endif
+  TEST_CHECK(!UTI_IsTimeOffsetSane(&ts, 10.0));
+  TEST_CHECK(UTI_IsTimeOffsetSane(&ts, -20.0));
+
+  UTI_TimespecHostToNetwork(&ts, &tspec);
+  UTI_TimespecNetworkToHost(&tspec, &ts2);
+  TEST_CHECK(!UTI_CompareTimespecs(&ts, &ts2));
+
+  for (i = c = 0; i < 100000; i++) {
+    j = random() % (sizeof (buf) + 1);
+    UTI_GetRandomBytes(buf, j);
+    if (j && buf[j - 1] % 2)
+      c++;
+  }
+  TEST_CHECK(c > 46000 && c < 48000);
+
+  s = UTI_PathToDir("/aaa/bbb/ccc/ddd");
+  TEST_CHECK(!strcmp(s, "/aaa/bbb/ccc"));
+  Free(s);
+  s = UTI_PathToDir("aaa");
+  TEST_CHECK(!strcmp(s, "."));
+  Free(s);
+  s = UTI_PathToDir("/aaaa");
+  TEST_CHECK(!strcmp(s, "/"));
+  Free(s);
+
+  nan = strtod("nan", NULL);
+  inf = strtod("inf", NULL);
+
+  TEST_CHECK(MIN(2.0, -1.0) == -1.0);
+  TEST_CHECK(MIN(-1.0, 2.0) == -1.0);
+  TEST_CHECK(MIN(inf, 2.0) == 2.0);
+
+  TEST_CHECK(MAX(2.0, -1.0) == 2.0);
+  TEST_CHECK(MAX(-1.0, 2.0) == 2.0);
+  TEST_CHECK(MAX(inf, 2.0) == inf);
+
+  TEST_CHECK(CLAMP(1.0, -1.0, 2.0) == 1.0);
+  TEST_CHECK(CLAMP(1.0, 3.0, 2.0) == 2.0);
+  TEST_CHECK(CLAMP(1.0, inf, 2.0) == 2.0);
+  TEST_CHECK(CLAMP(1.0, nan, 2.0) == 2.0);
+
+  TEST_CHECK(SQUARE(3.0) == 3.0 * 3.0);
+
+  rmdir("testdir");
+
+  uid = geteuid();
+  gid = getegid();
+
+  TEST_CHECK(UTI_CreateDirAndParents("testdir", 0700, uid, gid));
+
+  TST_SuspendLogging();
+  TEST_CHECK(UTI_CheckDirPermissions("testdir", 0700, uid, gid));
+  TEST_CHECK(!UTI_CheckDirPermissions("testdir", 0300, uid, gid));
+  TEST_CHECK(!UTI_CheckDirPermissions("testdir", 0700, uid + 1, gid));
+  TEST_CHECK(!UTI_CheckDirPermissions("testdir", 0700, uid, gid + 1));
+  TST_ResumeLogging();
+
+  umask(0);
+
+  unlink("testfile");
+  file = UTI_OpenFile(NULL, "testfile", NULL, 'r', 0);
+  TEST_CHECK(!file);
+  TEST_CHECK(stat("testfile", &st) < 0);
+
+  file = UTI_OpenFile(NULL, "testfile", NULL, 'w', 0644);
+  TEST_CHECK(file);
+  TEST_CHECK(stat("testfile", &st) == 0);
+  TEST_CHECK((st.st_mode & 0777) == 0644);
+  fclose(file);
+
+  file = UTI_OpenFile(".", "test", "file", 'W', 0640);
+  TEST_CHECK(file);
+  TEST_CHECK(stat("testfile", &st) == 0);
+  TEST_CHECK((st.st_mode & 0777) == 0640);
+  fclose(file);
+
+  file = UTI_OpenFile(NULL, "test", "file", 'r', 0);
+  TEST_CHECK(file);
+  fclose(file);
+
+  TEST_CHECK(UTI_RenameTempFile(NULL, "testfil", "e", NULL));
+  TEST_CHECK(stat("testfil", &st) == 0);
+  file = UTI_OpenFile(NULL, "testfil", NULL, 'R', 0);
+  TEST_CHECK(file);
+  fclose(file);
+
+  TEST_CHECK(UTI_RenameTempFile(NULL, "test", "fil", "file"));
+  TEST_CHECK(stat("testfile", &st) == 0);
+  file = UTI_OpenFile(NULL, "testfile", NULL, 'R', 0);
+  TEST_CHECK(file);
+  fclose(file);
+
+  TEST_CHECK(UTI_RemoveFile(NULL, "testfile", NULL));
+  TEST_CHECK(stat("testfile", &st) < 0);
+  TEST_CHECK(!UTI_RemoveFile(NULL, "testfile", NULL));
+
+  assert(sizeof (buf) >= 16);
+  TEST_CHECK(UTI_HexToBytes("", buf, sizeof (buf)) == 0);
+  TEST_CHECK(UTI_HexToBytes("0", buf, sizeof (buf)) == 0);
+  TEST_CHECK(UTI_HexToBytes("00123456789ABCDEF", buf, sizeof (buf)) == 0);
+  TEST_CHECK(UTI_HexToBytes("00123456789ABCDEF0", buf, 8) == 0);
+  TEST_CHECK(UTI_HexToBytes("00123456789ABCDEF0", buf, sizeof (buf)) == 9);
+  TEST_CHECK(memcmp(buf, "\x00\x12\x34\x56\x78\x9A\xBC\xDE\xF0", 9) == 0);
+  memcpy(buf, "AB123456780001", 15);
+  TEST_CHECK(UTI_HexToBytes(buf, buf, sizeof (buf)) == 7);
+  TEST_CHECK(memcmp(buf, "\xAB\x12\x34\x56\x78\x00\x01", 7) == 0);
+
+  TEST_CHECK(UTI_BytesToHex("", 0, buf, 0) == 0);
+  TEST_CHECK(UTI_BytesToHex("\xAB\x12\x34\x56\x78\x00\x01", 7, buf, 14) == 0);
+  TEST_CHECK(UTI_BytesToHex("\xAB\x12\x34\x56\x78\x00\x01", 7, buf, 15) == 1);
+  TEST_CHECK(strcmp(buf, "AB123456780001") == 0);
+  TEST_CHECK(UTI_BytesToHex("\xAB\x12\x34\x56\x78\x00\x01", 0, buf, 15) == 1);
+  TEST_CHECK(strcmp(buf, "") == 0);
+
+  TEST_CHECK(snprintf(buf, sizeof (buf), "%s", "") < sizeof (buf));
+  TEST_CHECK(UTI_SplitString(buf, words, 3) == 0);
+  TEST_CHECK(!words[0]);
+  TEST_CHECK(snprintf(buf, sizeof (buf), "%s", "     ") < sizeof (buf));
+  TEST_CHECK(UTI_SplitString(buf, words, 3) == 0);
+  TEST_CHECK(!words[0]);
+  TEST_CHECK(snprintf(buf, sizeof (buf), "%s", "a  \n ") < sizeof (buf));
+  TEST_CHECK(UTI_SplitString(buf, words, 3) == 1);
+  TEST_CHECK(words[0] == buf + 0);
+  TEST_CHECK(strcmp(words[0], "a") == 0);
+  TEST_CHECK(snprintf(buf, sizeof (buf), "%s", "  a  ") < sizeof (buf));
+  TEST_CHECK(UTI_SplitString(buf, words, 3) == 1);
+  TEST_CHECK(words[0] == buf + 2);
+  TEST_CHECK(strcmp(words[0], "a") == 0);
+  TEST_CHECK(snprintf(buf, sizeof (buf), "%s", " \n  a") < sizeof (buf));
+  TEST_CHECK(UTI_SplitString(buf, words, 3) == 1);
+  TEST_CHECK(words[0] == buf + 4);
+  TEST_CHECK(strcmp(words[0], "a") == 0);
+  TEST_CHECK(snprintf(buf, sizeof (buf), "%s", "a   b") < sizeof (buf));
+  TEST_CHECK(UTI_SplitString(buf, words, 1) == 2);
+  TEST_CHECK(snprintf(buf, sizeof (buf), "%s", "a   b") < sizeof (buf));
+  TEST_CHECK(UTI_SplitString(buf, words, 2) == 2);
+  TEST_CHECK(words[0] == buf + 0);
+  TEST_CHECK(words[1] == buf + 4);
+  TEST_CHECK(strcmp(words[0], "a") == 0);
+  TEST_CHECK(strcmp(words[1], "b") == 0);
+  TEST_CHECK(snprintf(buf, sizeof (buf), "%s", " a b ") < sizeof (buf));
+  TEST_CHECK(UTI_SplitString(buf, words, 3) == 2);
+  TEST_CHECK(words[0] == buf + 1);
+  TEST_CHECK(words[1] == buf + 3);
+  TEST_CHECK(strcmp(words[0], "a") == 0);
+  TEST_CHECK(strcmp(words[1], "b") == 0);
+}