[winpr,timezone] refactor timezone mapping

* update windowsZones.xml update url
* add option to use ICU as a fallback mapping (eliminate need for
  WindowsZones mapping list)
* extract timezone related settings from localtime_r and eliminate the
  need to parse the complex TimeZones table
* Add new TimeZoneNameMap to map IANA to windows names (Id, Stnadard,
  Daylight and Display names)
* Implement GetDynamicTimeZoneInformation

winpr/include/winpr/timezone.h

@@ -57,6 +57,10 @@ extern "C"
 	} DYNAMIC_TIME_ZONE_INFORMATION, *PDYNAMIC_TIME_ZONE_INFORMATION,
 	    *LPDYNAMIC_TIME_ZONE_INFORMATION;
 
+#define TIME_ZONE_ID_UNKNOWN 0
+#define TIME_ZONE_ID_STANDARD 1
+#define TIME_ZONE_ID_DAYLIGHT 2
+
 	WINPR_API DWORD GetTimeZoneInformation(LPTIME_ZONE_INFORMATION lpTimeZoneInformation);
 	WINPR_API BOOL SetTimeZoneInformation(const TIME_ZONE_INFORMATION* lpTimeZoneInformation);
 	WINPR_API BOOL SystemTimeToFileTime(const SYSTEMTIME* lpSystemTime, LPFILETIME lpFileTime);

winpr/libwinpr/timezone/CMakeLists.txt

@@ -15,4 +15,28 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-winpr_module_add(timezone.c TimeZones.c WindowsZones.c TimeZones.h WindowsZones.h)
+set(SRCS
+		TimeZoneNameMap.c
+		TimeZoneNameMap.h
+		TimeZoneNameMapUtils.c
+	)
+if (NOT WIN32)
+	list(APPEND SRCS
+		timezone.c
+	)
+endif()
+
+option(WITH_TIMEZONE_ICU "Use ICU for improved timezone mapping" OFF)
+if (WITH_TIMEZONE_ICU)
+	find_package(ICU COMPONENTS i18n uc REQUIRED)
+	winpr_include_directory_add(${ICU_INCLUDE_DIRS})
+	winpr_library_add_private(${ICU_LIBRARIES})
+	winpr_definition_add(-DWITH_TIMEZONE_ICU)
+else()
+	list(APPEND SRCS
+		WindowsZones.c
+		WindowsZones.h
+	)
+endif()
+
+winpr_module_add(${SRCS})

winpr/libwinpr/timezone/TimeZoneNameMap.h

@@ -0,0 +1,30 @@
+
+#ifndef WINPR_TIME_NAME_MAP_H_
+#define WINPR_TIME_NAME_MAP_H_
+
+#include <winpr/wtypes.h>
+
+typedef enum
+{
+	TIME_ZONE_NAME_ID,
+	TIME_ZONE_NAME_STANDARD,
+	TIME_ZONE_NAME_DISPLAY,
+	TIME_ZONE_NAME_DAYLIGHT,
+	TIME_ZONE_NAME_IANA,
+} TimeZoneNameType;
+
+typedef struct
+{
+	const char* Id;
+	const char* StandardName;
+	const char* DisplayName;
+	const char* DaylightName;
+	const char* Iana;
+} TimeZoneNameMapEntry;
+
+extern const TimeZoneNameMapEntry TimeZoneNameMap[];
+extern const size_t TimeZoneNameMapSize;
+
+const char* TimeZoneIanaToWindows(const char* iana, TimeZoneNameType type);
+
+#endif

winpr/libwinpr/timezone/TimeZoneNameMapUtils.c

@@ -0,0 +1,130 @@
+#include <winpr/config.h>
+#include <winpr/assert.h>
+#include <winpr/string.h>
+
+#include <string.h>
+
+#if defined(WITH_TIMEZONE_ICU)
+#include <unicode/ucal.h>
+#else
+#include "WindowsZones.h"
+#endif
+
+#include "TimeZoneNameMap.h"
+
+static const char* return_type(const TimeZoneNameMapEntry* entry, TimeZoneNameType type)
+{
+	WINPR_ASSERT(entry);
+	switch (type)
+	{
+		case TIME_ZONE_NAME_IANA:
+			return entry->Iana;
+		case TIME_ZONE_NAME_ID:
+			return entry->Id;
+		case TIME_ZONE_NAME_STANDARD:
+			return entry->StandardName;
+		case TIME_ZONE_NAME_DISPLAY:
+			return entry->DisplayName;
+		case TIME_ZONE_NAME_DAYLIGHT:
+			return entry->DaylightName;
+		default:
+			return NULL;
+	}
+}
+
+#if defined(WITH_TIMEZONE_ICU)
+static char* get_wzid_icu(const UChar* utzid, size_t utzid_len)
+{
+	char* res = NULL;
+	UErrorCode error = U_ZERO_ERROR;
+
+	int32_t rc = ucal_getWindowsTimeZoneID(utzid, utzid_len, NULL, 0, &error);
+	if ((error == U_BUFFER_OVERFLOW_ERROR) && (rc > 0))
+	{
+		rc++; // make space for '\0'
+		UChar* wzid = calloc((size_t)rc + 1, sizeof(UChar));
+		if (wzid)
+		{
+			UErrorCode error2 = U_ZERO_ERROR;
+			int32_t rc2 = ucal_getWindowsTimeZoneID(utzid, utzid_len, wzid, rc, &error2);
+			if (U_SUCCESS(error2) && (rc2 > 0))
+				res = ConvertWCharNToUtf8Alloc(wzid, (size_t)rc, NULL);
+			free(wzid);
+		}
+	}
+	return res;
+}
+
+static char* get(const char* iana)
+{
+	size_t utzid_len = 0;
+	UChar* utzid = ConvertUtf8ToWCharAlloc(iana, &utzid_len);
+	if (!utzid)
+		return NULL;
+
+	char* wzid = get_wzid_icu(utzid, utzid_len);
+	free(utzid);
+	return wzid;
+}
+
+static const char* map_fallback(const char* iana, TimeZoneNameType type)
+{
+	const char* res = NULL;
+	char* wzid = get(iana);
+	if (!wzid)
+		return NULL;
+
+	for (size_t x = 0; x < TimeZoneNameMapSize; x++)
+	{
+		const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[x];
+		if (strcmp(wzid, entry->Id) == 0)
+		{
+			res = return_type(entry, type);
+			break;
+		}
+	}
+
+	free(wzid);
+	return res;
+}
+#else
+static const char* map_fallback(const char* iana, TimeZoneNameType type)
+{
+	if (!iana)
+		return NULL;
+
+	for (size_t x = 0; x < WindowsTimeZoneIdTableNrElements; x++)
+	{
+		const WINDOWS_TZID_ENTRY* const entry = &WindowsTimeZoneIdTable[x];
+		if (strcmp(entry->tzid, iana) == 0)
+			return entry->windows;
+	}
+
+	return NULL;
+}
+#endif
+
+const char* TimeZoneIanaToWindows(const char* iana, TimeZoneNameType type)
+{
+	if (!iana)
+		return NULL;
+
+	for (size_t x = 0; x < TimeZoneNameMapSize; x++)
+	{
+		const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[x];
+		if (strcmp(iana, entry->Iana) == 0)
+			return return_type(entry, type);
+	}
+
+	const char* wzid = map_fallback(iana, type);
+	if (!wzid)
+		return NULL;
+
+	for (size_t x = 0; x < TimeZoneNameMapSize; x++)
+	{
+		const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[x];
+		if (strcmp(wzid, entry->Id) == 0)
+			return return_type(entry, type);
+	}
+	return NULL;
+}