diff --git a/test_harness.h b/test_harness.h
new file mode 100644
index 0000000..405b496
--- /dev/null
+++ b/test_harness.h
@@ -0,0 +1,433 @@
+/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * test_harness.h: simple C unit test helper.
+ *
+ * Usage:
+ *   #include "test_harness.h"
+ *   TEST(standalone_test) {
+ *     do_some_stuff;
+ *     EXPECT_GT(10, stuff) {
+ *        stuff_state_t state;
+ *        enumerate_stuff_state(&state);
+ *        TH_LOG("expectation failed with state: %s", state.msg);
+ *     }
+ *     more_stuff;
+ *     ASSERT_NE(some_stuff, NULL) TH_LOG("how did it happen?!");
+ *     last_stuff;
+ *     EXPECT_EQ(0, last_stuff);
+ *   }
+ *
+ *   FIXTURE(my_fixture) {
+ *     mytype_t *data;
+ *     int awesomeness_level;
+ *   };
+ *   FIXTURE_SETUP(my_fixture) {
+ *     self->data = mytype_new();
+ *     ASSERT_NE(NULL, self->data);
+ *   }
+ *   FIXTURE_TEARDOWN(my_fixture) {
+ *     mytype_free(self->data);
+ *   }
+ *   TEST_F(my_fixture, data_is_good) {
+ *     EXPECT_EQ(1, is_my_data_good(self->data));
+ *   }
+ *
+ *   TEST_HARNESS_MAIN
+ *
+ * API inspired by code.google.com/p/googletest
+ */
+#ifndef TEST_HARNESS_H_
+#define TEST_HARNESS_H_
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+/* All exported functionality should be declared through this macro. */
+#define TEST_API(x) _##x
+
+/*
+ * Exported APIs
+ */
+
+/* TEST(name) { implementation }
+ * Defines a test by name.
+ * Names must be unique and tests must not be run in parallel.  The
+ * implementation containing block is a function and scoping should be treated
+ * as such.  Returning early may be performed with a bare "return;" statement.
+ *
+ * EXPECT_* and ASSERT_* are valid in a TEST() { } context.
+ */
+#define TEST TEST_API(TEST)
+
+/* FIXTURE(datatype name) {
+ *   type property1;
+ *   ...
+ * };
+ * Defines the data provided to TEST_F()-defined tests as |self|.  It should be
+ * populated and cleaned up using FIXTURE_SETUP and FIXTURE_TEARDOWN.
+ */
+#define FIXTURE TEST_API(FIXTURE)
+
+/* FIXTURE_DATA(datatype name)
+ * This call may be used when the type of the fixture data
+ * is needed.  In general, this should not be needed unless
+ * the |self| is being passed to a helper directly.
+ */
+#define FIXTURE_DATA TEST_API(FIXTURE_DATA)
+
+/* FIXTURE_SETUP(fixture name) { implementation }
+ * Populates the required "setup" function for a fixture.  An instance of the
+ * datatype defined with _FIXTURE_DATA will be exposed as |self| for the
+ * implementation.
+ *
+ * ASSERT_* are valid for use in this context and will prempt the execution
+ * of any dependent fixture tests.
+ *
+ * A bare "return;" statement may be used to return early.
+ */
+#define FIXTURE_SETUP TEST_API(FIXTURE_SETUP)
+
+/* FIXTURE_TEARDOWN(fixture name) { implementation }
+ * Populates the required "teardown" function for a fixture.  An instance of the
+ * datatype defined with _FIXTURE_DATA will be exposed as |self| for the
+ * implementation to clean up.
+ *
+ * A bare "return;" statement may be used to return early.
+ */
+#define FIXTURE_TEARDOWN TEST_API(FIXTURE_TEARDOWN)
+
+/* TEST_F(fixture, name) { implementation }
+ * Defines a test that depends on a fixture (e.g., is part of a test case).
+ * Very similar to TEST() except that |self| is the setup instance of fixture's
+ * datatype exposed for use by the implementation.
+ */
+#define TEST_F TEST_API(TEST_F)
+
+/* Use once to append a main() to the test file. E.g.,
+ *   TEST_HARNESS_MAIN
+ */
+#define TEST_HARNESS_MAIN TEST_API(TEST_HARNESS_MAIN)
+
+/*
+ * Operators for use in TEST and TEST_F.
+ * ASSERT_* calls will stop test execution immediately.
+ * EXPECT_* calls will emit a failure warning, note it, and continue.
+ */
+
+/* ASSERT_EQ(expected, measured): expected == measured */
+#define ASSERT_EQ TEST_API(ASSERT_EQ)
+/* ASSERT_NE(expected, measured): expected != measured */
+#define ASSERT_NE TEST_API(ASSERT_NE)
+/* ASSERT_LT(expected, measured): expected < measured */
+#define ASSERT_LT TEST_API(ASSERT_LT)
+/* ASSERT_LE(expected, measured): expected <= measured */
+#define ASSERT_LE TEST_API(ASSERT_LE)
+/* ASSERT_GT(expected, measured): expected > measured */
+#define ASSERT_GT TEST_API(ASSERT_GT)
+/* ASSERT_GE(expected, measured): expected >= measured */
+#define ASSERT_GE TEST_API(ASSERT_GE)
+/* ASSERT_NULL(measured): NULL == measured */
+#define ASSERT_NULL TEST_API(ASSERT_NULL)
+/* ASSERT_TRUE(measured): measured != 0 */
+#define ASSERT_TRUE TEST_API(ASSERT_TRUE)
+/* ASSERT_FALSE(measured): measured == 0 */
+#define ASSERT_FALSE TEST_API(ASSERT_FALSE)
+/* ASSERT_STREQ(expected, measured): !strcmp(expected, measured) */
+#define ASSERT_STREQ TEST_API(ASSERT_STREQ)
+/* ASSERT_STRNE(expected, measured): strcmp(expected, measured) */
+#define ASSERT_STRNE TEST_API(ASSERT_STRNE)
+/* EXPECT_EQ(expected, measured): expected == measured */
+#define EXPECT_EQ TEST_API(EXPECT_EQ)
+/* EXPECT_NE(expected, measured): expected != measured */
+#define EXPECT_NE TEST_API(EXPECT_NE)
+/* EXPECT_LT(expected, measured): expected < measured */
+#define EXPECT_LT TEST_API(EXPECT_LT)
+/* EXPECT_LE(expected, measured): expected <= measured */
+#define EXPECT_LE TEST_API(EXPECT_LE)
+/* EXPECT_GT(expected, measured): expected > measured */
+#define EXPECT_GT TEST_API(EXPECT_GT)
+/* EXPECT_GE(expected, measured): expected >= measured */
+#define EXPECT_GE TEST_API(EXPECT_GE)
+/* EXPECT_NULL(measured): NULL == measured */
+#define EXPECT_NULL TEST_API(EXPECT_NULL)
+/* EXPECT_TRUE(measured): 0 != measured */
+#define EXPECT_TRUE TEST_API(EXPECT_TRUE)
+/* EXPECT_FALSE(measured): 0 == measured */
+#define EXPECT_FALSE TEST_API(EXPECT_FALSE)
+/* EXPECT_STREQ(expected, measured): !strcmp(expected, measured) */
+#define EXPECT_STREQ TEST_API(EXPECT_STREQ)
+/* EXPECT_STRNE(expected, measured): strcmp(expected, measured) */
+#define EXPECT_STRNE TEST_API(EXPECT_STRNE)
+
+/* TH_LOG(format, ...)
+ * Optional debug logging function available for use in tests.
+ * Logging may be enabled or disabled by defining TH_LOG_ENABLED.
+ * E.g., #define TH_LOG_ENABLED 1
+ * If no definition is provided, logging is enabled by default.
+ */
+#define TH_LOG  TEST_API(TH_LOG)
+
+/*
+ * Internal implementation.
+ *
+ */
+
+/* Utilities exposed to the test definitions */
+#ifndef TH_LOG_STREAM
+#  define TH_LOG_STREAM stderr
+#endif
+
+#ifndef TH_LOG_ENABLED
+#  define TH_LOG_ENABLED 1
+#endif
+
+#define _TH_LOG(fmt, ...) do { \
+  if (TH_LOG_ENABLED) \
+    __TH_LOG(fmt, ##__VA_ARGS__); \
+} while (0)
+
+/* Unconditional logger for internal use. */
+#define __TH_LOG(fmt, ...) \
+    fprintf(TH_LOG_STREAM, "%s:%d:%s:" fmt "\n", \
+            __FILE__, __LINE__, _metadata->name, ##__VA_ARGS__)
+
+/* Defines the test function and creates the registration stub. */
+#define _TEST(test_name) \
+  static void test_name(struct __test_metadata *_metadata); \
+  static struct __test_metadata _##test_name##_object = \
+    { name: "global." #test_name, fn: &test_name }; \
+  static void __attribute__((constructor)) _register_##test_name(void) { \
+    __register_test(&_##test_name##_object); \
+  } \
+  static void test_name( \
+    struct __test_metadata __attribute__((unused)) *_metadata)
+
+/* Wraps the struct name so we have one less argument to pass around. */
+#define _FIXTURE_DATA(fixture_name) struct _test_data_##fixture_name
+
+/* Called once per fixture to setup the data and register. */
+#define _FIXTURE(fixture_name) \
+  static void __attribute__((constructor)) \
+      _register_##fixture_name##_data(void) { \
+    __fixture_count++; \
+  } \
+  _FIXTURE_DATA(fixture_name)
+
+/* Prepares the setup function for the fixture.  |_metadata| is included
+ * so that ASSERT_* work as a convenience.
+ */
+#define _FIXTURE_SETUP(fixture_name) \
+  void fixture_name##_setup( \
+    struct __test_metadata __attribute__((unused)) *_metadata, \
+    _FIXTURE_DATA(fixture_name) __attribute__((unused)) *self)
+#define _FIXTURE_TEARDOWN(fixture_name) \
+  void fixture_name##_teardown( \
+    struct __test_metadata __attribute__((unused)) *_metadata, \
+    _FIXTURE_DATA(fixture_name) __attribute__((unused)) *self)
+
+/* Emits test registration and helpers for fixture-based test
+ * cases.
+ * TODO(wad) register fixtures on dedicated test lists.
+ */
+#define _TEST_F(fixture_name, test_name) \
+  static void fixture_name##_##test_name( \
+    struct __test_metadata *_metadata, \
+    _FIXTURE_DATA(fixture_name) *self); \
+  static inline void wrapper_##fixture_name##_##test_name( \
+    struct __test_metadata *_metadata) { \
+    /* fixture data is allocated, setup, and torn down per call. */ \
+    _FIXTURE_DATA(fixture_name) self; \
+    memset(&self, 0, sizeof(_FIXTURE_DATA(fixture_name))); \
+    fixture_name##_setup(_metadata, &self); \
+    /* Let setup failure terminate early. */ \
+    if (!_metadata->passed) return; \
+    fixture_name##_##test_name(_metadata, &self); \
+    fixture_name##_teardown(_metadata, &self); \
+  } \
+  static struct __test_metadata _##fixture_name##_##test_name##_object = { \
+    name: #fixture_name "." #test_name, \
+    fn: &wrapper_##fixture_name##_##test_name, \
+   }; \
+  static void __attribute__((constructor)) \
+      _register_##fixture_name##_##test_name(void) { \
+    __register_test(&_##fixture_name##_##test_name##_object); \
+  } \
+  static void fixture_name##_##test_name( \
+    struct __test_metadata __attribute__((unused)) *_metadata, \
+    _FIXTURE_DATA(fixture_name) __attribute__((unused)) *self)
+
+/* Exports a simple wrapper to run the test harness. */
+#define _TEST_HARNESS_MAIN \
+  int main(int argc, char **argv) { return test_harness_run(argc, argv); }
+
+#define _ASSERT_EQ(_expected, _seen) \
+  __EXPECT(_expected, _seen, ==, 1)
+#define _ASSERT_NE(_expected, _seen) \
+  __EXPECT(_expected, _seen, !=, 1)
+#define _ASSERT_LT(_expected, _seen) \
+  __EXPECT(_expected, _seen, <, 1)
+#define _ASSERT_LE(_expected, _seen) \
+  __EXPECT(_expected, _seen, <=, 1)
+#define _ASSERT_GT(_expected, _seen) \
+  __EXPECT(_expected, _seen, >, 1)
+#define _ASSERT_GE(_expected, _seen) \
+  __EXPECT(_expected, _seen, >=, 1)
+#define _ASSERT_NULL(_seen) \
+  __EXPECT(NULL, _seen, ==, 1)
+
+#define _ASSERT_TRUE(_seen) \
+  _ASSERT_NE(0, _seen)
+#define _ASSERT_FALSE(_seen) \
+  _ASSERT_EQ(0, _seen)
+#define _ASSERT_STREQ(_expected, _seen) \
+  __EXPECT_STR(_expected, _seen, ==, 1)
+#define _ASSERT_STRNE(_expected, _seen) \
+  __EXPECT_STR(_expected, _seen, !=, 1)
+
+#define _EXPECT_EQ(_expected, _seen) \
+  __EXPECT(_expected, _seen, ==, 0)
+#define _EXPECT_NE(_expected, _seen) \
+  __EXPECT(_expected, _seen, !=, 0)
+#define _EXPECT_LT(_expected, _seen) \
+  __EXPECT(_expected, _seen, <, 0)
+#define _EXPECT_LE(_expected, _seen) \
+  __EXPECT(_expected, _seen, <=, 0)
+#define _EXPECT_GT(_expected, _seen) \
+  __EXPECT(_expected, _seen, >, 0)
+#define _EXPECT_GE(_expected, _seen) \
+  __EXPECT(_expected, _seen, >=, 0)
+
+#define _EXPECT_NULL(_seen) \
+  __EXPECT(NULL, _seen, ==, 0)
+#define _EXPECT_TRUE(_seen) \
+  _EXPECT_NE(0, _seen)
+#define _EXPECT_FALSE(_seen) \
+  _EXPECT_EQ(0, _seen)
+
+#define _EXPECT_STREQ(_expected, _seen) \
+  __EXPECT_STR(_expected, _seen, ==, 0)
+#define _EXPECT_STRNE(_expected, _seen) \
+  __EXPECT_STR(_expected, _seen, !=, 0)
+
+/* Support an optional handler after and ASSERT_* or EXPECT_*.  The approach is
+ * not thread-safe, but it should be fine in most sane test scenarios.
+ *
+ * Using __bail(), which optionally abort()s, is the easiest way to early
+ * return while still providing an optional block to the API consumer.
+ */
+#define OPTIONAL_HANDLER(_assert) \
+  for (; _metadata->trigger;  _metadata->trigger = __bail(_assert))
+
+#define __EXPECT(_expected, _seen, _t, _assert) do { \
+  /* Avoid multiple evaluation of the cases */ \
+  __typeof__(_expected) __exp = (_expected); \
+  __typeof__(_seen) __seen = (_seen); \
+  if (!(__exp _t __seen)) { \
+    unsigned long long __exp_print = 0; \
+    unsigned long long __seen_print = 0; \
+    /* Avoid casting complaints the scariest way we can. */ \
+    memcpy(&__exp_print, &__exp, sizeof(__exp)); \
+    memcpy(&__seen_print, &__seen, sizeof(__seen)); \
+    __TH_LOG("Expected %s (%llu) %s %s (%llu)", \
+            #_expected, __exp_print, #_t, \
+            #_seen, __seen_print); \
+    _metadata->passed = 0; \
+    /* Ensure the optional handler is triggered */ \
+    _metadata->trigger = 1; \
+  } \
+} while (0); OPTIONAL_HANDLER(_assert)
+
+#define __EXPECT_STR(_expected, _seen, _t, _assert) do { \
+  const char *__exp = (_expected); \
+  const char *__seen = (_seen); \
+  if (!(strcmp(__exp, __seen) _t 0))  { \
+    __TH_LOG("Expected '%s' %s '%s'.", __exp, #_t, __seen); \
+    _metadata->passed = 0; \
+    _metadata->trigger = 1; \
+  } \
+} while (0); OPTIONAL_HANDLER(_assert)
+
+/* Contains all the information for test execution and status checking. */
+struct __test_metadata {
+  const char *name;
+  void (*fn)(struct __test_metadata *);
+  int passed;
+  int trigger; /* extra handler after the evaluation */
+  struct __test_metadata *prev, *next;
+};
+
+/* Storage for the (global) tests to be run. */
+static struct __test_metadata *__test_list = NULL;
+static unsigned int __test_count = 0;
+static unsigned int __fixture_count = 0;
+
+static inline void __register_test(struct __test_metadata *t) {
+  __test_count++;
+  /* Circular linked list where only prev is circular. */
+  if (__test_list == NULL) {
+    __test_list = t;
+    t->next = NULL;
+    t->prev = t;
+    return;
+  }
+  t->next = NULL;
+  t->prev = __test_list->prev;
+  t->prev->next = t;
+  __test_list->prev = t;
+}
+
+static inline int __bail(int for_realz) {
+  if (for_realz)
+    abort();
+  return 0;
+}
+
+static int test_harness_run(int __attribute__((unused)) argc,
+                            char __attribute__((unused)) **argv) {
+  struct __test_metadata *t;
+  int ret = 0;
+  unsigned int count = 0;
+
+  /* TODO(wad) add optional arguments similar to gtest. */
+  printf("[==========] Running %u tests from %u test cases.\n",
+          __test_count, __fixture_count + 1);
+  for (t = __test_list; t; t = t->next) {
+    pid_t child_pid;
+    int status;
+    count++;
+    t->passed = 1;
+    t->trigger = 0;
+    printf("[ RUN      ] %s\n", t->name);
+    child_pid = fork();
+    if (child_pid < 0) {
+      printf("ERROR SPAWNING TEST CHILD\n");
+      t->passed = 0;
+    } else if (child_pid == 0) {
+      t->fn(t);
+      _exit(t->passed);
+    } else {
+      /* TODO(wad) add timeout support. */
+      waitpid(child_pid, &status, 0);
+      if (WIFEXITED(status))
+        t->passed = WEXITSTATUS(status);
+      if (WIFSIGNALED(status))
+        t->passed = 0;
+    }
+    printf("[     %4s ] %s\n", (t->passed ? "OK" : "FAIL"), t->name);
+    if (!t->passed)
+      ret = 1;
+  }
+  /* TODO(wad) organize by fixtures since ordering is not guaranteed now. */
+  printf("[==========] %u tests ran.\n", count);
+  printf("[  %s  ]\n", (ret ? "FAILED" : "PASSED"));
+  return ret;
+}
+
+#endif  /* TEST_HARNESS_H_ */