Extract our code for answering "what time is it right now".

The other time stuff is higher-level

6 files changed, 178 insertions, 0 deletions

diff --git a/src/lib/wallclock/.may_include b/src/lib/wallclock/.may_include
new file mode 100644
index 0000000000..686d9196fd
--- /dev/null
+++ b/src/lib/wallclock/.may_include
@@ -0,0 +1,4 @@
+orconfig.h
+lib/err/*.h
+lib/wallclock/*.h
+lib/testsupport/*.h
diff --git a/src/lib/wallclock/approx_time.c b/src/lib/wallclock/approx_time.c
new file mode 100644
index 0000000000..2528954f13
--- /dev/null
+++ b/src/lib/wallclock/approx_time.c
@@ -0,0 +1,38 @@
+/* Copyright (c) 2003, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#include "orconfig.h"
+#include "lib/wallclock/approx_time.h"
+
+/* =====
+ * Cached time
+ * ===== */
+
+#ifndef TIME_IS_FAST
+/** Cached estimate of the current time.  Updated around once per second;
+ * may be a few seconds off if we are really busy.  This is a hack to avoid
+ * calling time(NULL) (which not everybody has optimized) on critical paths.
+ */
+static time_t cached_approx_time = 0;
+
+/** Return a cached estimate of the current time from when
+ * update_approx_time() was last called.  This is a hack to avoid calling
+ * time(NULL) on critical paths: please do not even think of calling it
+ * anywhere else. */
+time_t
+approx_time(void)
+{
+  return cached_approx_time;
+}
+
+/** Update the cached estimate of the current time.  This function SHOULD be
+ * called once per second, and MUST be called before the first call to
+ * get_approx_time. */
+void
+update_approx_time(time_t now)
+{
+  cached_approx_time = now;
+}
+#endif /* !defined(TIME_IS_FAST) */
diff --git a/src/lib/wallclock/approx_time.h b/src/lib/wallclock/approx_time.h
new file mode 100644
index 0000000000..c57ff5bcd3
--- /dev/null
+++ b/src/lib/wallclock/approx_time.h
@@ -0,0 +1,20 @@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#ifndef TOR_APPROX_TIME_H
+#define TOR_APPROX_TIME_H
+
+#include <time.h>
+
+/* Cached time */
+#ifdef TIME_IS_FAST
+#define approx_time() time(NULL)
+#define update_approx_time(t) STMT_NIL
+#else
+time_t approx_time(void);
+void update_approx_time(time_t now);
+#endif /* defined(TIME_IS_FAST) */
+
+#endif
diff --git a/src/lib/wallclock/include.am b/src/lib/wallclock/include.am
new file mode 100644
index 0000000000..d414eb4688
--- /dev/null
+++ b/src/lib/wallclock/include.am
@@ -0,0 +1,19 @@
+
+noinst_LIBRARIES += src/lib/libtor-wallclock.a
+
+if UNITTESTS_ENABLED
+noinst_LIBRARIES += src/lib/libtor-wallclock-testing.a
+endif
+
+src_lib_libtor_wallclock_a_SOURCES =			\
+	src/lib/wallclock/approx_time.c			\
+	src/lib/wallclock/tor_gettimeofday.c
+
+src_lib_libtor_wallclock_testing_a_SOURCES = \
+	$(src_lib_libtor_wallclock_a_SOURCES)
+src_lib_libtor_wallclock_testing_a_CPPFLAGS = $(AM_CPPFLAGS) $(TEST_CPPFLAGS)
+src_lib_libtor_wallclock_testing_a_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)
+
+noinst_HEADERS +=					\
+	src/lib/wallclock/approx_time.h			\
+	src/lib/wallclock/tor_gettimeofday.h
diff --git a/src/lib/wallclock/tor_gettimeofday.c b/src/lib/wallclock/tor_gettimeofday.c
new file mode 100644
index 0000000000..83081d9c98
--- /dev/null
+++ b/src/lib/wallclock/tor_gettimeofday.c
@@ -0,0 +1,82 @@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file compat_time.c
+ * \brief Portable wrappers for finding out the current time, running
+ *   timers, etc.
+ **/
+
+#include "orconfig.h"
+#include "lib/err/torerr.h"
+#include "lib/wallclock/tor_gettimeofday.h"
+
+#include <stddef.h>
+#include <stdlib.h>
+
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#ifndef HAVE_GETTIMEOFDAY
+#ifdef HAVE_FTIME
+#include <sys/timeb.h>
+#endif
+#endif
+
+/** Set *timeval to the current time of day.  On error, log and terminate.
+ * (Same as gettimeofday(timeval,NULL), but never returns -1.)
+ */
+MOCK_IMPL(void,
+tor_gettimeofday, (struct timeval *timeval))
+{
+#ifdef _WIN32
+  /* Epoch bias copied from perl: number of units between windows epoch and
+   * Unix epoch. */
+#define EPOCH_BIAS U64_LITERAL(116444736000000000)
+#define UNITS_PER_SEC U64_LITERAL(10000000)
+#define USEC_PER_SEC U64_LITERAL(1000000)
+#define UNITS_PER_USEC U64_LITERAL(10)
+  union {
+    uint64_t ft_64;
+    FILETIME ft_ft;
+  } ft;
+  /* number of 100-nsec units since Jan 1, 1601 */
+  GetSystemTimeAsFileTime(&ft.ft_ft);
+  if (ft.ft_64 < EPOCH_BIAS) {
+    /* LCOV_EXCL_START */
+    log_err(LD_GENERAL,"System time is before 1970; failing.");
+    exit(1); // exit ok: system clock is broken.
+    /* LCOV_EXCL_STOP */
+  }
+  ft.ft_64 -= EPOCH_BIAS;
+  timeval->tv_sec = (unsigned) (ft.ft_64 / UNITS_PER_SEC);
+  timeval->tv_usec = (unsigned) ((ft.ft_64 / UNITS_PER_USEC) % USEC_PER_SEC);
+#elif defined(HAVE_GETTIMEOFDAY)
+  if (gettimeofday(timeval, NULL)) {
+    /* LCOV_EXCL_START */
+    /* If gettimeofday dies, we have either given a bad timezone (we didn't),
+       or segfaulted.*/
+    raw_assert_unreached_msg("gettimeofday failed");
+    /* LCOV_EXCL_STOP */
+  }
+#elif defined(HAVE_FTIME)
+  struct timeb tb;
+  ftime(&tb);
+  timeval->tv_sec = tb.time;
+  timeval->tv_usec = tb.millitm * 1000;
+#else
+#error "No way to get time."
+#endif /* defined(_WIN32) || ... */
+  return;
+}
diff --git a/src/lib/wallclock/tor_gettimeofday.h b/src/lib/wallclock/tor_gettimeofday.h
new file mode 100644
index 0000000000..728ad9565d
--- /dev/null
+++ b/src/lib/wallclock/tor_gettimeofday.h
@@ -0,0 +1,15 @@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#ifndef TOR_GETTIMEOFDAY_H
+#define TOR_GETTIMEOFDAY_H
+
+#include "lib/testsupport/testsupport.h"
+
+struct timeval;
+
+MOCK_DECL(void, tor_gettimeofday, (struct timeval *timeval));
+
+#endif