Split the library into a linkable and an LD_PRELOAD-able part

In order to satisfy the desire of using libumberlog, specifically
ul_format(), without having to worry about syslog() & friends being
overridden, split the library into two parts:

A linkable library, which provides the new API, but does not override
the legacy syslog() functions; and a new, LD_PRELOAD-able part, which
does override the old ones.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>

5 files changed, 456 insertions, 324 deletions

diff --git a/t/Makefile.am b/t/Makefile.am
index d6a0118..3f3a973 100644
--- a/t/Makefile.am
+++ b/t/Makefile.am
@@ -1,8 +1,15 @@
 if ENABLE_TESTS
-TESTS		= test_umberlog test_perf
-check_PROGRAMS	= ${TESTS}
+TESTS				= test_umberlog_preload test_umberlog test_perf
+check_PROGRAMS			= ${TESTS}
 
-AM_CFLAGS = -I$(top_srcdir)/lib @JSON_CFLAGS@ @CHECK_CFLAGS@
-AM_LDFLAGS = -no-install
-LDADD = $(top_builddir)/lib/libumberlog.la @JSON_LIBS@ @CHECK_LIBS@
+AM_CFLAGS			= -I$(top_srcdir)/lib @JSON_CFLAGS@ @CHECK_CFLAGS@
+AM_LDFLAGS			= -no-install
+LDADD				= @JSON_LIBS@ @CHECK_LIBS@
+
+check_LTLIBRARIES		= libultest.la
+libultest_la_SOURCES		= test-common.c test-common.h
+
+test_umberlog_preload_LDADD	= ${LDADD} $(top_builddir)/lib/libumberlog_preload.la libultest.la
+test_umberlog_LDADD		= ${LDADD} $(top_builddir)/lib/libumberlog.la libultest.la
+test_perf_LDADD			= ${LDADD} $(top_builddir)/lib/libumberlog.la libultest.la
 endif
diff --git a/t/test-common.c b/t/test-common.c
new file mode 100644
index 0000000..707a5c7
--- /dev/null
+++ b/t/test-common.c
@@ -0,0 +1,66 @@
+#define _GNU_SOURCE 1
+
+#include <json.h>
+#include <assert.h>
+#include <check.h>
+
+void
+verify_value (struct json_object *jo, const char *key,
+              const char *expected_value)
+{
+  struct json_object *o;
+  const char *value;
+
+  o = json_object_object_get (jo, key);
+
+  ck_assert (o != NULL);
+
+  value = json_object_get_string (o);
+
+  ck_assert_str_eq (value, expected_value);
+}
+
+void
+verify_value_differs (struct json_object *jo, const char *key,
+                      const char *unexpected_value)
+{
+  struct json_object *o;
+  const char *value;
+
+  o = json_object_object_get (jo, key);
+
+  ck_assert (o != NULL);
+
+  value = json_object_get_string (o);
+
+  ck_assert_str_ne (value, unexpected_value);
+}
+
+void
+verify_value_exists (struct json_object *jo, const char *key)
+{
+  struct json_object *o;
+
+  o = json_object_object_get (jo, key);
+  ck_assert_msg (o != NULL, "key '%s' does not exist", key);
+}
+
+void
+verify_value_missing (struct json_object *jo, const char *key)
+{
+  struct json_object *o;
+
+  o = json_object_object_get (jo, key);
+  assert (o == NULL);
+}
+
+struct json_object *
+parse_msg (const char *msg)
+{
+  struct json_object *jo;
+
+  jo = json_tokener_parse (msg);
+  assert (jo != NULL);
+
+  return jo;
+}
diff --git a/t/test-common.h b/t/test-common.h
new file mode 100644
index 0000000..dcf6f64
--- /dev/null
+++ b/t/test-common.h
@@ -0,0 +1,14 @@
+#ifndef UMBERLOG_TEST_COMMON_H
+#define UMBERLOG_TEST_COMMON_H 1
+
+#include <json.h>
+
+void verify_value (struct json_object *jo, const char *key,
+                   const char *expected_value);
+void verify_value_differs (struct json_object *jo, const char *key,
+                           const char *unexpected_value);
+void verify_value_exists (struct json_object *jo, const char *key);
+void verify_value_missing (struct json_object *jo, const char *key);
+
+struct json_object *parse_msg (const char *msg);
+#endif
diff --git a/t/test_umberlog.c b/t/test_umberlog.c
index 88ea18f..21ac50d 100644
--- a/t/test_umberlog.c
+++ b/t/test_umberlog.c
@@ -2,6 +2,8 @@
 
 #include "umberlog.h"
 #include "config.h"
+#include "test-common.h"
+
 #include <json.h>
 #include <assert.h>
 #include <string.h>
@@ -13,74 +15,14 @@
 
 #include <check.h>
 
-static void
-verify_value (struct json_object *jo, const char *key,
-              const char *expected_value)
-{
-  struct json_object *o;
-  const char *value;
-
-  o = json_object_object_get (jo, key);
-
-  ck_assert (o != NULL);
-
-  value = json_object_get_string (o);
-
-  ck_assert_str_eq (value, expected_value);
-}
-
-static void
-verify_value_differs (struct json_object *jo, const char *key,
-                      const char *unexpected_value)
-{
-  struct json_object *o;
-  const char *value;
-
-  o = json_object_object_get (jo, key);
-
-  ck_assert (o != NULL);
-
-  value = json_object_get_string (o);
-
-  ck_assert_str_ne (value, unexpected_value);
-}
-
-static void
-verify_value_exists (struct json_object *jo, const char *key)
-{
-  struct json_object *o;
-
-  o = json_object_object_get (jo, key);
-  ck_assert_msg (o != NULL, "key '%s' does not exist", key);
-}
-
-static void
-verify_value_missing (struct json_object *jo, const char *key)
-{
-  struct json_object *o;
-
-  o = json_object_object_get (jo, key);
-  assert (o == NULL);
-}
 
-static struct json_object *
-parse_msg (const char *msg)
-{
-  struct json_object *jo;
-
-  jo = json_tokener_parse (msg);
-  assert (jo != NULL);
-
-  return jo;
-}
-
-START_TEST (test_simple)
+START_TEST (test_overrides)
 {
   char *msg;
   struct json_object *jo;
   char host[_POSIX_HOST_NAME_MAX + 1];
 
-  openlog ("umberlog/test_simple", 0, LOG_LOCAL0);
+  openlog ("umberlog/test_overrides", 0, LOG_LOCAL0);
 
   msg = ul_format (LOG_DEBUG, "hello, I'm %s!", __FUNCTION__, NULL);
   jo = parse_msg (msg);
@@ -88,10 +30,14 @@ START_TEST (test_simple)
 
   gethostname (host, _POSIX_HOST_NAME_MAX);
 
-  verify_value (jo, "msg", "hello, I'm test_simple!");
-  verify_value (jo, "facility", "local0");
+  verify_value (jo, "msg", "hello, I'm test_overrides!");
+  /* Default facility is user, and since we did not catch openlog, it
+     should not change. */
+  verify_value (jo, "facility", "user");
   verify_value (jo, "priority", "debug");
-  verify_value (jo, "program", "umberlog/test_simple");
+  /* The program is also caught by openlog(), so we'll get the
+     default back, unless we use ul_openlog(). */
+  verify_value (jo, "program", "test_umberlog");
   verify_value_exists (jo, "pid");
   verify_value_exists (jo, "uid");
   verify_value_exists (jo, "gid");
@@ -104,261 +50,33 @@ START_TEST (test_simple)
 }
 END_TEST
 
-START_TEST (test_no_discover)
+START_TEST (test_ul_openlog)
 {
   char *msg;
   struct json_object *jo;
+  char host[_POSIX_HOST_NAME_MAX + 1];
 
-  openlog ("umberlog/test_no_discover", LOG_UL_NODISCOVER, LOG_LOCAL0);
+  ul_openlog ("umberlog/test_ul_openlog", 0, LOG_LOCAL0);
 
   msg = ul_format (LOG_DEBUG, "hello, I'm %s!", __FUNCTION__, NULL);
   jo = parse_msg (msg);
   free (msg);
 
-  verify_value (jo, "msg", "hello, I'm test_no_discover!");
-  verify_value_missing (jo, "facility");
-  verify_value_missing (jo, "priority");
-  verify_value_missing (jo, "program");
-  verify_value_missing (jo, "pid");
-  verify_value_missing (jo, "uid");
-  verify_value_missing (jo, "gid");
-  verify_value_missing (jo, "host");
-  verify_value_missing (jo, "timestamp");
-
-  json_object_put (jo);
-
-  closelog ();
-}
-END_TEST
-
-START_TEST (test_additional_fields)
-{
-  char *msg;
-  struct json_object *jo;
-
-  openlog ("umberlog/test_additional_fields", 0, LOG_LOCAL0);
-
-  msg = ul_format (LOG_DEBUG, "testing 1, 2, 3...",
-                   "random_number", "%d", 42,
-                   "random_string", "fourty-two",
-                   NULL);
-  jo = parse_msg (msg);
-  free (msg);
-
-  verify_value (jo, "msg", "testing 1, 2, 3...");
-  verify_value (jo, "random_number", "42");
-  verify_value (jo, "random_string", "fourty-two");
-
-  json_object_put (jo);
-
-  closelog ();
-}
-END_TEST
-
-START_TEST (test_discover_priority)
-{
-  char *msg, *pid;
-  struct json_object *jo;
-
-  openlog ("umberlog/test_discover_priority", 0, LOG_LOCAL0);
-
-  msg = ul_format (LOG_DEBUG, "testing 1, 2, 3...",
-                   "pid", "%d", getpid () + 42,
-                   NULL);
-  jo = parse_msg (msg);
-  free (msg);
-
-  verify_value (jo, "msg", "testing 1, 2, 3...");
-
-  if (asprintf (&pid, "%d", getpid ()) == -1)
-    abort ();
-  verify_value (jo, "pid", pid);
-  free (pid);
-
-  json_object_put (jo);
-
-  closelog ();
-}
-END_TEST
-
-START_TEST (test_no_timestamp)
-{
-  char *msg;
-  struct json_object *jo;
-
-  openlog ("umberlog/test_no_timestamp", LOG_UL_NOTIME, LOG_LOCAL0);
-
-  msg = ul_format (LOG_DEBUG, "hello, I'm %s!", __FUNCTION__, NULL);
-  jo = parse_msg (msg);
-  free (msg);
+  gethostname (host, _POSIX_HOST_NAME_MAX);
 
-  verify_value (jo, "msg", "hello, I'm test_no_timestamp!");
+  verify_value (jo, "msg", "hello, I'm test_ul_openlog!");
   verify_value (jo, "facility", "local0");
   verify_value (jo, "priority", "debug");
-  verify_value (jo, "program", "umberlog/test_no_timestamp");
+  verify_value (jo, "program", "umberlog/test_ul_openlog");
   verify_value_exists (jo, "pid");
   verify_value_exists (jo, "uid");
   verify_value_exists (jo, "gid");
-  verify_value_missing (jo, "timestamp");
-  verify_value_exists (jo, "host");
-
-  json_object_put (jo);
-
-  closelog ();
-}
-END_TEST
-
-START_TEST (test_json_escape)
-{
-  static const char control_chars[] =
-    "\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
-    "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
-    "\x20";
-
-  char *msg;
-  struct json_object *jo;
-
-  openlog ("umberlog/test_json_escape", LOG_UL_NODISCOVER, LOG_LOCAL0);
-
-  msg = ul_format (LOG_DEBUG, "%s", __FUNCTION__,
-                   "quotes", "Hi, \"quoted value\" speaking!",
-                   "\"really\"", "yeah",
-                   "control", "foo\nbar",
-                   "utf8", "Árvíztűrő tükörfúrógép",
-                   "junk", "\013foo",
-                   "all_control", control_chars,
-                   NULL);
-  jo = parse_msg (msg);
-  free (msg);
-
-  verify_value (jo, "quotes", "Hi, \"quoted value\" speaking!");
-  verify_value (jo, "\"really\"", "yeah");
-  verify_value (jo, "control", "foo\nbar");
-  verify_value (jo, "utf8", "Árvíztűrő tükörfúrógép");
-  verify_value (jo, "junk", "\013foo");
-  verify_value (jo, "all_control", control_chars);
-
-  json_object_put (jo);
-
-  closelog ();
-}
-END_TEST
-
-START_TEST (test_facprio)
-{
-  char *msg;
-  struct json_object *jo;
-
-  msg = ul_format (LOG_LOCAL1 | LOG_DEBUG, "%s", __FUNCTION__,
-                   NULL);
-  jo = parse_msg (msg);
-  free (msg);
-
-  verify_value (jo, "facility", "local1");
-  verify_value (jo, "priority", "debug");
-
-  json_object_put (jo);
-}
-END_TEST
-
-START_TEST (test_closelog)
-{
-  char *msg;
-  struct json_object *jo;
-
-  openlog ("umberlog/test_closelog", LOG_UL_NODISCOVER, LOG_LOCAL0);
-  closelog ();
-
-  msg = ul_format (LOG_DEBUG, "%s", __FUNCTION__, NULL);
-  jo = parse_msg (msg);
-  free (msg);
-
-  verify_value_missing (jo, "facility");
-
-  json_object_put (jo);
-
-  openlog ("umberlog/test_closelog", 0, LOG_LOCAL0);
-  closelog ();
-
-  msg = ul_format (LOG_DEBUG, "%s", __FUNCTION__, NULL);
-  jo = parse_msg (msg);
-  free (msg);
-
-  verify_value (jo, "facility", "local0");
-#ifdef HAVE_PROGRAM_INVOCATION_SHORT_NAME
-  verify_value (jo, "program", "test_umberlog");
-#else
-  verify_value_missing (jo, "program");
-#endif
-  verify_value_differs (jo, "pid", "0");
-  if (getuid () != 0)
-    verify_value_differs (jo, "uid", "0");
-  if (getgid () != 0)
-    verify_value_differs (jo, "gid", "0");
-  verify_value_differs (jo, "host", "");
-
-  json_object_put (jo);
-}
-END_TEST
-
-#ifdef HAVE_PARSE_PRINTF_FORMAT
-START_TEST (test_positional_params)
-{
-  char *msg;
-  struct json_object *jo;
-
-  openlog ("umberlog/test_positional_params", LOG_UL_NOTIME, LOG_LOCAL0);
-
-#define COMPLEX_FORMAT \
-  "%3$*5$.*2$hhd , %1$Lf , %4$.3s , %4$s", 1.0L, 5, (char)100, "prefix", -8
-#define COMPLEX_RESULT "00100    , 1.000000 , pre , prefix"
-  msg = ul_format (LOG_DEBUG, COMPLEX_FORMAT,
-                   "simple1", "value1",
-                   "complex", COMPLEX_FORMAT,
-                   "simple2", "value2",
-                   NULL);
-  jo = parse_msg (msg);
-  free (msg);
-
-  verify_value (jo, "msg", COMPLEX_RESULT);
-  verify_value (jo, "simple1", "value1");
-  verify_value (jo, "complex", COMPLEX_RESULT);
-  verify_value (jo, "simple2", "value2");
-
-  json_object_put (jo);
-
-  closelog ();
-}
-END_TEST
-#endif
-
-/* This must be the first test! */
-START_TEST (test_openlog_defaults)
-{
-  char *msg;
-  struct json_object *jo;
-
-  /* No openlog */
-
-  msg = ul_format (LOG_ALERT, "message", NULL);
-  jo = parse_msg (msg);
-  free (msg);
+  verify_value_exists (jo, "timestamp");
+  verify_value (jo, "host", host);
 
-  verify_value (jo, "facility", "user");
-#ifdef HAVE_PROGRAM_INVOCATION_SHORT_NAME
-  verify_value (jo, "program", "test_umberlog");
-#else
-  verify_value_missing (jo, "program");
-#endif
-  verify_value_differs (jo, "pid", "0");
-  if (getuid () != 0)
-    verify_value_differs (jo, "uid", "0");
-  if (getgid () != 0)
-    verify_value_differs (jo, "gid", "0");
-  verify_value_differs (jo, "host", "");
   json_object_put (jo);
 
-  closelog ();
+  ul_closelog ();
 }
 END_TEST
 
@@ -367,29 +85,16 @@ main (void)
 {
   Suite *s;
   SRunner *sr;
-  TCase *ft, *bt;
+  TCase *ft;
   int nfailed;
 
-  s = suite_create ("Umberlog functional testsuite");
+  s = suite_create ("Umberlog (linkable) functional testsuite");
 
   ft = tcase_create ("Basic tests");
-  tcase_add_test (ft, test_openlog_defaults);
-  tcase_add_test (ft, test_simple);
-  tcase_add_test (ft, test_no_discover);
-  tcase_add_test (ft, test_additional_fields);
-  tcase_add_test (ft, test_discover_priority);
-  tcase_add_test (ft, test_no_timestamp);
-#ifdef HAVE_PARSE_PRINTF_FORMAT
-  tcase_add_test (ft, test_positional_params);
-#endif
+  tcase_add_test (ft, test_overrides);
+  tcase_add_test (ft, test_ul_openlog);
   suite_add_tcase (s, ft);
 
-  bt = tcase_create ("Bug tests");
-  tcase_add_test (bt, test_json_escape);
-  tcase_add_test (bt, test_facprio);
-  tcase_add_test (bt, test_closelog);
-  suite_add_tcase (s, bt);
-
   sr = srunner_create (s);
 
   srunner_run_all (sr, CK_ENV);
diff --git a/t/test_umberlog_preload.c b/t/test_umberlog_preload.c
new file mode 100644
index 0000000..e931210
--- /dev/null
+++ b/t/test_umberlog_preload.c
@@ -0,0 +1,340 @@
+#define _GNU_SOURCE 1
+
+#include "umberlog.h"
+#include "config.h"
+#include "test-common.h"
+#include <json.h>
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <limits.h>
+
+#include <check.h>
+
+START_TEST (test_simple)
+{
+  char *msg;
+  struct json_object *jo;
+  char host[_POSIX_HOST_NAME_MAX + 1];
+
+  openlog ("umberlog/test_simple", 0, LOG_LOCAL0);
+
+  msg = ul_format (LOG_DEBUG, "hello, I'm %s!", __FUNCTION__, NULL);
+  jo = parse_msg (msg);
+  free (msg);
+
+  gethostname (host, _POSIX_HOST_NAME_MAX);
+
+  verify_value (jo, "msg", "hello, I'm test_simple!");
+  verify_value (jo, "facility", "local0");
+  verify_value (jo, "priority", "debug");
+  verify_value (jo, "program", "umberlog/test_simple");
+  verify_value_exists (jo, "pid");
+  verify_value_exists (jo, "uid");
+  verify_value_exists (jo, "gid");
+  verify_value_exists (jo, "timestamp");
+  verify_value (jo, "host", host);
+
+  json_object_put (jo);
+
+  closelog ();
+}
+END_TEST
+
+START_TEST (test_no_discover)
+{
+  char *msg;
+  struct json_object *jo;
+
+  openlog ("umberlog/test_no_discover", LOG_UL_NODISCOVER, LOG_LOCAL0);
+
+  msg = ul_format (LOG_DEBUG, "hello, I'm %s!", __FUNCTION__, NULL);
+  jo = parse_msg (msg);
+  free (msg);
+
+  verify_value (jo, "msg", "hello, I'm test_no_discover!");
+  verify_value_missing (jo, "facility");
+  verify_value_missing (jo, "priority");
+  verify_value_missing (jo, "program");
+  verify_value_missing (jo, "pid");
+  verify_value_missing (jo, "uid");
+  verify_value_missing (jo, "gid");
+  verify_value_missing (jo, "host");
+  verify_value_missing (jo, "timestamp");
+
+  json_object_put (jo);
+
+  closelog ();
+}
+END_TEST
+
+START_TEST (test_additional_fields)
+{
+  char *msg;
+  struct json_object *jo;
+
+  openlog ("umberlog/test_additional_fields", 0, LOG_LOCAL0);
+
+  msg = ul_format (LOG_DEBUG, "testing 1, 2, 3...",
+                   "random_number", "%d", 42,
+                   "random_string", "fourty-two",
+                   NULL);
+  jo = parse_msg (msg);
+  free (msg);
+
+  verify_value (jo, "msg", "testing 1, 2, 3...");
+  verify_value (jo, "random_number", "42");
+  verify_value (jo, "random_string", "fourty-two");
+
+  json_object_put (jo);
+
+  closelog ();
+}
+END_TEST
+
+START_TEST (test_discover_priority)
+{
+  char *msg, *pid;
+  struct json_object *jo;
+
+  openlog ("umberlog/test_discover_priority", 0, LOG_LOCAL0);
+
+  msg = ul_format (LOG_DEBUG, "testing 1, 2, 3...",
+                   "pid", "%d", getpid () + 42,
+                   NULL);
+  jo = parse_msg (msg);
+  free (msg);
+
+  verify_value (jo, "msg", "testing 1, 2, 3...");
+
+  if (asprintf (&pid, "%d", getpid ()) == -1)
+    abort ();
+  verify_value (jo, "pid", pid);
+  free (pid);
+
+  json_object_put (jo);
+
+  closelog ();
+}
+END_TEST
+
+START_TEST (test_no_timestamp)
+{
+  char *msg;
+  struct json_object *jo;
+
+  openlog ("umberlog/test_no_timestamp", LOG_UL_NOTIME, LOG_LOCAL0);
+
+  msg = ul_format (LOG_DEBUG, "hello, I'm %s!", __FUNCTION__, NULL);
+  jo = parse_msg (msg);
+  free (msg);
+
+  verify_value (jo, "msg", "hello, I'm test_no_timestamp!");
+  verify_value (jo, "facility", "local0");
+  verify_value (jo, "priority", "debug");
+  verify_value (jo, "program", "umberlog/test_no_timestamp");
+  verify_value_exists (jo, "pid");
+  verify_value_exists (jo, "uid");
+  verify_value_exists (jo, "gid");
+  verify_value_missing (jo, "timestamp");
+  verify_value_exists (jo, "host");
+
+  json_object_put (jo);
+
+  closelog ();
+}
+END_TEST
+
+START_TEST (test_json_escape)
+{
+  static const char control_chars[] =
+    "\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
+    "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
+    "\x20";
+
+  char *msg;
+  struct json_object *jo;
+
+  openlog ("umberlog/test_json_escape", LOG_UL_NODISCOVER, LOG_LOCAL0);
+
+  msg = ul_format (LOG_DEBUG, "%s", __FUNCTION__,
+                   "quotes", "Hi, \"quoted value\" speaking!",
+                   "\"really\"", "yeah",
+                   "control", "foo\nbar",
+                   "utf8", "Árvíztűrő tükörfúrógép",
+                   "junk", "\013foo",
+                   "all_control", control_chars,
+                   NULL);
+  jo = parse_msg (msg);
+  free (msg);
+
+  verify_value (jo, "quotes", "Hi, \"quoted value\" speaking!");
+  verify_value (jo, "\"really\"", "yeah");
+  verify_value (jo, "control", "foo\nbar");
+  verify_value (jo, "utf8", "Árvíztűrő tükörfúrógép");
+  verify_value (jo, "junk", "\013foo");
+  verify_value (jo, "all_control", control_chars);
+
+  json_object_put (jo);
+
+  closelog ();
+}
+END_TEST
+
+START_TEST (test_facprio)
+{
+  char *msg;
+  struct json_object *jo;
+
+  msg = ul_format (LOG_LOCAL1 | LOG_DEBUG, "%s", __FUNCTION__,
+                   NULL);
+  jo = parse_msg (msg);
+  free (msg);
+
+  verify_value (jo, "facility", "local1");
+  verify_value (jo, "priority", "debug");
+
+  json_object_put (jo);
+}
+END_TEST
+
+START_TEST (test_closelog)
+{
+  char *msg;
+  struct json_object *jo;
+
+  openlog ("umberlog/test_closelog", LOG_UL_NODISCOVER, LOG_LOCAL0);
+  closelog ();
+
+  msg = ul_format (LOG_DEBUG, "%s", __FUNCTION__, NULL);
+  jo = parse_msg (msg);
+  free (msg);
+
+  verify_value_missing (jo, "facility");
+
+  json_object_put (jo);
+
+  openlog ("umberlog/test_closelog", 0, LOG_LOCAL0);
+  closelog ();
+
+  msg = ul_format (LOG_DEBUG, "%s", __FUNCTION__, NULL);
+  jo = parse_msg (msg);
+  free (msg);
+
+  verify_value (jo, "facility", "local0");
+#ifdef HAVE_PROGRAM_INVOCATION_SHORT_NAME
+  verify_value (jo, "program", "test_umberlog_preload");
+#else
+  verify_value_missing (jo, "program");
+#endif
+  verify_value_differs (jo, "pid", "0");
+  if (getuid () != 0)
+    verify_value_differs (jo, "uid", "0");
+  if (getgid () != 0)
+    verify_value_differs (jo, "gid", "0");
+  verify_value_differs (jo, "host", "");
+
+  json_object_put (jo);
+}
+END_TEST
+
+#ifdef HAVE_PARSE_PRINTF_FORMAT
+START_TEST (test_positional_params)
+{
+  char *msg;
+  struct json_object *jo;
+
+  openlog ("umberlog/test_positional_params", LOG_UL_NOTIME, LOG_LOCAL0);
+
+#define COMPLEX_FORMAT \
+  "%3$*5$.*2$hhd , %1$Lf , %4$.3s , %4$s", 1.0L, 5, (char)100, "prefix", -8
+#define COMPLEX_RESULT "00100    , 1.000000 , pre , prefix"
+  msg = ul_format (LOG_DEBUG, COMPLEX_FORMAT,
+                   "simple1", "value1",
+                   "complex", COMPLEX_FORMAT,
+                   "simple2", "value2",
+                   NULL);
+  jo = parse_msg (msg);
+  free (msg);
+
+  verify_value (jo, "msg", COMPLEX_RESULT);
+  verify_value (jo, "simple1", "value1");
+  verify_value (jo, "complex", COMPLEX_RESULT);
+  verify_value (jo, "simple2", "value2");
+
+  json_object_put (jo);
+
+  closelog ();
+}
+END_TEST
+#endif
+
+/* This must be the first test! */
+START_TEST (test_openlog_defaults)
+{
+  char *msg;
+  struct json_object *jo;
+
+  /* No openlog */
+
+  msg = ul_format (LOG_ALERT, "message", NULL);
+  jo = parse_msg (msg);
+  free (msg);
+
+  verify_value (jo, "facility", "user");
+#ifdef HAVE_PROGRAM_INVOCATION_SHORT_NAME
+  verify_value (jo, "program", "test_umberlog_preload");
+#else
+  verify_value_missing (jo, "program");
+#endif
+  verify_value_differs (jo, "pid", "0");
+  if (getuid () != 0)
+    verify_value_differs (jo, "uid", "0");
+  if (getgid () != 0)
+    verify_value_differs (jo, "gid", "0");
+  verify_value_differs (jo, "host", "");
+  json_object_put (jo);
+
+  closelog ();
+}
+END_TEST
+
+int
+main (void)
+{
+  Suite *s;
+  SRunner *sr;
+  TCase *ft, *bt;
+  int nfailed;
+
+  s = suite_create ("Umberlog (LD_PRELOAD) functional testsuite");
+
+  ft = tcase_create ("Basic tests");
+  tcase_add_test (ft, test_openlog_defaults);
+  tcase_add_test (ft, test_simple);
+  tcase_add_test (ft, test_no_discover);
+  tcase_add_test (ft, test_additional_fields);
+  tcase_add_test (ft, test_discover_priority);
+  tcase_add_test (ft, test_no_timestamp);
+#ifdef HAVE_PARSE_PRINTF_FORMAT
+  tcase_add_test (ft, test_positional_params);
+#endif
+  suite_add_tcase (s, ft);
+
+  bt = tcase_create ("Bug tests");
+  tcase_add_test (bt, test_json_escape);
+  tcase_add_test (bt, test_facprio);
+  tcase_add_test (bt, test_closelog);
+  suite_add_tcase (s, bt);
+
+  sr = srunner_create (s);
+
+  srunner_run_all (sr, CK_ENV);
+  nfailed = srunner_ntests_failed (sr);
+  srunner_free (sr);
+
+  return (nfailed == 0) ? EXIT_SUCCESS : EXIT_FAILURE;
+}