From 9eb484b21b0bb1153c9a900ea56c994b7e717958 Mon Sep 17 00:00:00 2001
From: akallabeth <akallabeth@posteo.net>
Date: Thu, 18 Jul 2024 16:10:10 +0200
Subject: [PATCH 1/3] [winpr,timezone] implement EnumDynamicTimeZoneInformation

---
 winpr/libwinpr/timezone/CMakeLists.txt |  2 +-
 winpr/libwinpr/timezone/timezone.c     | 94 +++++++++++++++++++++++---
 2 files changed, 86 insertions(+), 10 deletions(-)

diff --git a/winpr/libwinpr/timezone/CMakeLists.txt b/winpr/libwinpr/timezone/CMakeLists.txt
index a60c2e8df..c877e1890 100644
--- a/winpr/libwinpr/timezone/CMakeLists.txt
+++ b/winpr/libwinpr/timezone/CMakeLists.txt
@@ -19,12 +19,12 @@ set(SRCS
 		TimeZoneNameMap.c
 		TimeZoneNameMap.h
 		TimeZoneNameMapUtils.c
+		timezone.c
 	)
 if (NOT WIN32)
 	list(APPEND SRCS
             TimeZoneIanaAbbrevMap.c
             TimeZoneIanaAbbrevMap.h
-            timezone.c
 	)
 endif()
 
diff --git a/winpr/libwinpr/timezone/timezone.c b/winpr/libwinpr/timezone/timezone.c
index d22358bb5..4b013445d 100644
--- a/winpr/libwinpr/timezone/timezone.c
+++ b/winpr/libwinpr/timezone/timezone.c
@@ -38,7 +38,9 @@
 #include "TimeZoneNameMap.h"
 #include "TimeZoneIanaAbbrevMap.h"
 
-#ifndef _WIN32
+#ifdef _WIN32
+#pragma comment(lib, "advapi32")
+#else
 
 #include <time.h>
 #include <unistd.h>
@@ -710,6 +712,34 @@ BOOL TzSpecificLocalTimeToSystemTime(LPTIME_ZONE_INFORMATION lpTimeZoneInformati
     (defined(_WIN32) && (defined(NTDDI_WIN8) && _WIN32_WINNT < 0x0600 || \
                          !defined(NTDDI_WIN8) && _WIN32_WINNT < 0x0501)) /* Windows Vista */
 
+typedef enum
+{
+	HAVE_TRANSITION_DATES = 0,
+	HAVE_NO_STANDARD_TRANSITION_DATE = 1,
+	HAVE_NO_DAYLIGHT_TRANSITION_DATE = 2
+} dyn_transition_result;
+
+static int dynamic_time_zone_from_localtime(const struct tm* local_time,
+                                            PDYNAMIC_TIME_ZONE_INFORMATION tz)
+{
+	WINPR_ASSERT(local_time);
+	WINPR_ASSERT(tz);
+	int rc = HAVE_TRANSITION_DATES;
+
+	tz->Bias = get_bias(local_time, FALSE);
+	if (local_time->tm_isdst >= 0)
+	{
+		/* DST bias is the difference between standard time and DST in minutes */
+		const LONG d = get_bias(local_time, TRUE);
+		tz->DaylightBias = -1 * labs(tz->Bias - d);
+		if (!get_transition_date(local_time, FALSE, &tz->StandardDate))
+			rc |= HAVE_NO_STANDARD_TRANSITION_DATE;
+		if (!get_transition_date(local_time, TRUE, &tz->DaylightDate))
+			rc |= HAVE_NO_DAYLIGHT_TRANSITION_DATE;
+	}
+	return rc;
+}
+
 DWORD GetDynamicTimeZoneInformation(PDYNAMIC_TIME_ZONE_INFORMATION tz)
 {
 	BOOL doesNotHaveStandardDate = FALSE;
@@ -734,12 +764,10 @@ DWORD GetDynamicTimeZoneInformation(PDYNAMIC_TIME_ZONE_INFORMATION tz)
 	tz->Bias = get_bias(local_time, FALSE);
 	if (local_time->tm_isdst >= 0)
 	{
-		/* DST bias is the difference between standard time and DST in minutes */
-		const LONG d = get_bias(local_time, TRUE);
-		tz->DaylightBias = -1 * labs(tz->Bias - d);
-		if (!get_transition_date(local_time, FALSE, &tz->StandardDate))
+		const int rc = dynamic_time_zone_from_localtime(local_time, tz);
+		if (rc & HAVE_NO_STANDARD_TRANSITION_DATE)
 			doesNotHaveStandardDate = TRUE;
-		if (!get_transition_date(local_time, TRUE, &tz->DaylightDate))
+		if (rc & HAVE_NO_DAYLIGHT_TRANSITION_DATE)
 			doesNotHaveDaylightDate = TRUE;
 	}
 
@@ -822,9 +850,57 @@ BOOL TzSpecificLocalTimeToSystemTimeEx(const DYNAMIC_TIME_ZONE_INFORMATION* lpTi
 DWORD EnumDynamicTimeZoneInformation(const DWORD dwIndex,
                                      PDYNAMIC_TIME_ZONE_INFORMATION lpTimeZoneInformation)
 {
-	WINPR_UNUSED(dwIndex);
-	WINPR_UNUSED(lpTimeZoneInformation);
-	return 0;
+	if (!lpTimeZoneInformation)
+		return ERROR_INVALID_PARAMETER;
+	const DYNAMIC_TIME_ZONE_INFORMATION empty = { 0 };
+	*lpTimeZoneInformation = empty;
+
+	if (dwIndex >= TimeZoneNameMapSize)
+		return ERROR_NO_MORE_ITEMS;
+
+	const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[dwIndex];
+	if (entry->DaylightName)
+		ConvertUtf8ToWChar(entry->DaylightName, lpTimeZoneInformation->DaylightName,
+		                   ARRAYSIZE(lpTimeZoneInformation->DaylightName));
+	if (entry->StandardName)
+		ConvertUtf8ToWChar(entry->StandardName, lpTimeZoneInformation->StandardName,
+		                   ARRAYSIZE(lpTimeZoneInformation->StandardName));
+	if (entry->Id)
+		ConvertUtf8ToWChar(entry->Id, lpTimeZoneInformation->TimeZoneKeyName,
+		                   ARRAYSIZE(lpTimeZoneInformation->TimeZoneKeyName));
+
+	const time_t t = time(NULL);
+	struct tm tres = { 0 };
+
+	const char* tz = getenv("TZ");
+	char* tzcopy = NULL;
+	if (tz)
+	{
+		size_t tzianalen = 0;
+		winpr_asprintf(&tzcopy, &tzianalen, "TZ=%s", tz);
+	}
+
+	char* tziana = NULL;
+	{
+		size_t tzianalen = 0;
+		winpr_asprintf(&tziana, &tzianalen, "TZ=%s", entry->Iana);
+	}
+	if (tziana)
+		putenv(tziana);
+
+	tzset();
+	struct tm* local_time = localtime_r(&t, &tres);
+	free(tziana);
+	if (tzcopy)
+		putenv(tzcopy);
+	else
+		unsetenv("TZ");
+	free(tzcopy);
+
+	if (local_time)
+		dynamic_time_zone_from_localtime(local_time, lpTimeZoneInformation);
+
+	return ERROR_SUCCESS;
 }
 
 DWORD GetDynamicTimeZoneInformationEffectiveYears(

From 6c682c84180bedb229133789ee316b86a30540e6 Mon Sep 17 00:00:00 2001
From: akallabeth <akallabeth@posteo.net>
Date: Tue, 23 Apr 2024 15:40:04 +0200
Subject: [PATCH 2/3] [client,common] add option to set timezone

* /timezone now allows setting the timezone used from a windows timezone
  key name
* /list:timezones now lists all available windows timezone key names
---
 client/common/cmdline.c            | 57 ++++++++++++++++++++++++++++--
 client/common/cmdline.h            |  5 ++-
 winpr/include/winpr/timezone.h     |  2 ++
 winpr/libwinpr/timezone/timezone.c | 25 ++++++++++---
 4 files changed, 81 insertions(+), 8 deletions(-)

diff --git a/client/common/cmdline.c b/client/common/cmdline.c
index e17c40dc3..f5ac643b1 100644
--- a/client/common/cmdline.c
+++ b/client/common/cmdline.c
@@ -30,6 +30,7 @@
 #include <winpr/path.h>
 #include <winpr/ncrypt.h>
 #include <winpr/environment.h>
+#include <winpr/timezone.h>
 
 #include <freerdp/freerdp.h>
 #include <freerdp/addin.h>
@@ -1666,11 +1667,24 @@ static void freerdp_client_print_keyboard_list(void)
 	                                        RDP_KEYBOARD_LAYOUT_TYPE_IME);
 }
 
+static void freerdp_client_print_timezone_list(void)
+{
+	DWORD index = 0;
+	DYNAMIC_TIME_ZONE_INFORMATION info = { 0 };
+	while (EnumDynamicTimeZoneInformation(index++, &info) != ERROR_NO_MORE_ITEMS)
+	{
+		char TimeZoneKeyName[ARRAYSIZE(info.TimeZoneKeyName) + 1] = { 0 };
+
+		ConvertWCharNToUtf8(info.TimeZoneKeyName, ARRAYSIZE(info.TimeZoneKeyName), TimeZoneKeyName,
+		                    ARRAYSIZE(TimeZoneKeyName));
+		printf("%" PRIu32 ": '%s'\n", index, TimeZoneKeyName);
+	}
+}
+
 static void freerdp_client_print_tune_list(const rdpSettings* settings)
 {
 	SSIZE_T type = 0;
 
-	printf("%s\t%50s\t%s\t%s", "<index>", "<key>", "<type>", "<default value>\n");
 	for (size_t x = 0; x < FreeRDP_Settings_StableAPI_MAX; x++)
 	{
 		const char* name = freerdp_settings_get_name_for_key(x);
@@ -1755,7 +1769,9 @@ int freerdp_client_settings_command_line_status_print_ex(rdpSettings* settings,
 
 		if (arg->Flags & COMMAND_LINE_ARGUMENT_PRESENT)
 		{
-			if (option_equals("tune", arg->Value))
+			if (option_equals("timezones", arg->Value))
+				freerdp_client_print_timezone_list();
+			else if (option_equals("tune", arg->Value))
 				freerdp_client_print_tune_list(settings);
 			else if (option_equals("kbd", arg->Value))
 				freerdp_client_print_keyboard_list();
@@ -4718,6 +4734,43 @@ static int freerdp_client_settings_parse_command_line_arguments_int(
 			if (!freerdp_settings_set_uint32(settings, FreeRDP_TcpAckTimeout, (UINT32)val))
 				return fail_at(arg, COMMAND_LINE_ERROR_UNEXPECTED_VALUE);
 		}
+		CommandLineSwitchCase(arg, "timezone")
+		{
+			BOOL found = FALSE;
+			DWORD index = 0;
+			DYNAMIC_TIME_ZONE_INFORMATION info = { 0 };
+			char TimeZoneKeyName[ARRAYSIZE(info.TimeZoneKeyName) + 1] = { 0 };
+			while (EnumDynamicTimeZoneInformation(index++, &info) != ERROR_NO_MORE_ITEMS)
+			{
+				ConvertWCharNToUtf8(info.TimeZoneKeyName, ARRAYSIZE(info.TimeZoneKeyName),
+				                    TimeZoneKeyName, ARRAYSIZE(TimeZoneKeyName));
+
+				if (strncmp(TimeZoneKeyName, arg->Value, ARRAYSIZE(TimeZoneKeyName)) == 0)
+				{
+					found = TRUE;
+					break;
+				}
+			}
+			if (!found)
+				return fail_at(arg, COMMAND_LINE_ERROR_UNEXPECTED_VALUE);
+
+			if (!freerdp_settings_set_string(settings, FreeRDP_DynamicDSTTimeZoneKeyName,
+			                                 TimeZoneKeyName))
+				return fail_at(arg, COMMAND_LINE_ERROR);
+
+			TIME_ZONE_INFORMATION* tz =
+			    freerdp_settings_get_pointer_writable(settings, FreeRDP_ClientTimeZone);
+			if (!tz)
+				return fail_at(arg, COMMAND_LINE_ERROR_MEMORY);
+
+			tz->Bias = info.Bias;
+			tz->DaylightBias = info.DaylightBias;
+			tz->DaylightDate = info.DaylightDate;
+			memcpy(tz->DaylightName, info.DaylightName, sizeof(tz->DaylightName));
+			tz->StandardBias = info.StandardBias;
+			tz->StandardDate = info.StandardDate;
+			memcpy(tz->StandardName, info.StandardName, sizeof(tz->StandardName));
+		}
 		CommandLineSwitchCase(arg, "aero")
 		{
 			if (!freerdp_settings_set_bool(settings, FreeRDP_AllowDesktopComposition, enable))
diff --git a/client/common/cmdline.h b/client/common/cmdline.h
index fe116202e..a4232052c 100644
--- a/client/common/cmdline.h
+++ b/client/common/cmdline.h
@@ -297,7 +297,7 @@ static const COMMAND_LINE_ARGUMENT_A global_cmd_args[] = {
 	{ "list", COMMAND_LINE_VALUE_REQUIRED | COMMAND_LINE_PRINT,
 	  "[kbd|kbd-scancode|kbd-lang[:<value>]|smartcard[:[pkinit-anchors:<path>][,pkcs11-module:<"
 	  "name>]]|"
-	  "monitor|tune]",
+	  "monitor|tune|timezones]",
 	  "List available options for subcommand", NULL, -1, NULL,
 	  "List available options for subcommand" },
 	{ "log-filters", COMMAND_LINE_VALUE_REQUIRED, "<tag>:<level>[,<tag>:<level>[,...]]", NULL, NULL,
@@ -453,6 +453,9 @@ static const COMMAND_LINE_ARGUMENT_A global_cmd_args[] = {
 	{ "timeout", COMMAND_LINE_VALUE_REQUIRED, "<time in ms>", "9000", NULL, -1, "timeout",
 	  "Advanced setting for high latency links: Adjust connection timeout, use if you encounter "
 	  "timeout failures with your connection" },
+	{ "timezone", COMMAND_LINE_VALUE_REQUIRED, "<windows timezone>", NULL, NULL, -1, NULL,
+	  "Use supplied windows timezone for connection (requires server support), see /list:timezones "
+	  "for allowed values" },
 	{ "tls", COMMAND_LINE_VALUE_REQUIRED, "[ciphers|seclevel|secrets-file|enforce]", NULL, NULL, -1,
 	  NULL,
 	  "TLS configuration options:"
diff --git a/winpr/include/winpr/timezone.h b/winpr/include/winpr/timezone.h
index 5170407b6..7afbf64f3 100644
--- a/winpr/include/winpr/timezone.h
+++ b/winpr/include/winpr/timezone.h
@@ -110,6 +110,8 @@ extern "C"
 	    const PDYNAMIC_TIME_ZONE_INFORMATION lpTimeZoneInformation, LPDWORD FirstYear,
 	    LPDWORD LastYear);
 
+#else
+#pragma comment(lib, "advapi32")
 #endif
 
 #ifdef __cplusplus
diff --git a/winpr/libwinpr/timezone/timezone.c b/winpr/libwinpr/timezone/timezone.c
index 4b013445d..2a68fac04 100644
--- a/winpr/libwinpr/timezone/timezone.c
+++ b/winpr/libwinpr/timezone/timezone.c
@@ -38,9 +38,7 @@
 #include "TimeZoneNameMap.h"
 #include "TimeZoneIanaAbbrevMap.h"
 
-#ifdef _WIN32
-#pragma comment(lib, "advapi32")
-#else
+#ifndef _WIN32
 
 #include <time.h>
 #include <unistd.h>
@@ -845,7 +843,7 @@ BOOL TzSpecificLocalTimeToSystemTimeEx(const DYNAMIC_TIME_ZONE_INFORMATION* lpTi
 
 #endif
 
-#if !defined(_WIN32) || (defined(_WIN32) && (_WIN32_WINNT < 0x0602)) /* Windows 8 */
+#if !defined(_WIN32)
 
 DWORD EnumDynamicTimeZoneInformation(const DWORD dwIndex,
                                      PDYNAMIC_TIME_ZONE_INFORMATION lpTimeZoneInformation)
@@ -909,7 +907,24 @@ DWORD GetDynamicTimeZoneInformationEffectiveYears(
 	WINPR_UNUSED(lpTimeZoneInformation);
 	WINPR_UNUSED(FirstYear);
 	WINPR_UNUSED(LastYear);
-	return 0;
+	return ERROR_FILE_NOT_FOUND;
 }
 
+#elif _WIN32_WINNT < 0x0602 /* Windows 8 */
+DWORD EnumDynamicTimeZoneInformation(const DWORD dwIndex,
+                                     PDYNAMIC_TIME_ZONE_INFORMATION lpTimeZoneInformation)
+{
+	WINPR_UNUSED(dwIndex);
+	WINPR_UNUSED(lpTimeZoneInformation);
+	return ERROR_NO_MORE_ITEMS;
+}
+
+DWORD GetDynamicTimeZoneInformationEffectiveYears(
+    const PDYNAMIC_TIME_ZONE_INFORMATION lpTimeZoneInformation, LPDWORD FirstYear, LPDWORD LastYear)
+{
+	WINPR_UNUSED(lpTimeZoneInformation);
+	WINPR_UNUSED(FirstYear);
+	WINPR_UNUSED(LastYear);
+	return ERROR_FILE_NOT_FOUND;
+}
 #endif

From 962a996dd9adc0ae499cef023fa9470f41905e24 Mon Sep 17 00:00:00 2001
From: akallabeth <akallabeth@posteo.net>
Date: Fri, 19 Jul 2024 10:08:46 +0200
Subject: [PATCH 3/3] [winpr,timezone] encapsulate timezonemap

---
 winpr/libwinpr/timezone/TimeZoneNameMap.h     |  4 +-
 .../libwinpr/timezone/TimeZoneNameMapUtils.c  | 91 ++++++++++++++-----
 winpr/libwinpr/timezone/timezone.c            |  4 +-
 3 files changed, 70 insertions(+), 29 deletions(-)

diff --git a/winpr/libwinpr/timezone/TimeZoneNameMap.h b/winpr/libwinpr/timezone/TimeZoneNameMap.h
index 405f73a89..bd5f8fe87 100644
--- a/winpr/libwinpr/timezone/TimeZoneNameMap.h
+++ b/winpr/libwinpr/timezone/TimeZoneNameMap.h
@@ -41,9 +41,7 @@ typedef struct
 	const char* Iana;
 } TimeZoneNameMapEntry;
 
-extern const TimeZoneNameMapEntry TimeZoneNameMap[];
-extern const size_t TimeZoneNameMapSize;
-
+const TimeZoneNameMapEntry* TimeZoneGetAt(size_t index);
 const char* TimeZoneIanaToWindows(const char* iana, TimeZoneNameType type);
 
 #endif
diff --git a/winpr/libwinpr/timezone/TimeZoneNameMapUtils.c b/winpr/libwinpr/timezone/TimeZoneNameMapUtils.c
index efd3d0f0f..70660db2a 100644
--- a/winpr/libwinpr/timezone/TimeZoneNameMapUtils.c
+++ b/winpr/libwinpr/timezone/TimeZoneNameMapUtils.c
@@ -20,6 +20,7 @@
 #include <winpr/config.h>
 #include <winpr/assert.h>
 #include <winpr/string.h>
+#include <winpr/synch.h>
 
 #include <string.h>
 
@@ -31,6 +32,36 @@
 
 #include "TimeZoneNameMap.h"
 
+typedef struct
+{
+	size_t count;
+	TimeZoneNameMapEntry* entries;
+} TimeZoneNameMapContext;
+
+static BOOL CALLBACK load_timezones(PINIT_ONCE once, PVOID param, PVOID* pvcontext)
+{
+	// Do not expose these, only used internally.
+	extern const TimeZoneNameMapEntry TimeZoneNameMap[];
+	extern const size_t TimeZoneNameMapSize;
+
+	TimeZoneNameMapContext* context = pvcontext;
+	WINPR_ASSERT(context);
+
+	context->count = TimeZoneNameMapSize;
+	context->entries = TimeZoneNameMap;
+}
+
+const TimeZoneNameMapEntry* TimeZoneGetAt(size_t index)
+{
+	static INIT_ONCE init_guard = INIT_ONCE_STATIC_INIT;
+	static TimeZoneNameMapContext context = { 0 };
+
+	InitOnceExecuteOnce(&init_guard, load_timezones, NULL, &context);
+	if (index >= context.count)
+		return NULL;
+	return &context.entries[index];
+}
+
 static const char* return_type(const TimeZoneNameMapEntry* entry, TimeZoneNameType type)
 {
 	WINPR_ASSERT(entry);
@@ -51,6 +82,37 @@ static const char* return_type(const TimeZoneNameMapEntry* entry, TimeZoneNameTy
 	}
 }
 
+static BOOL iana_cmp(const TimeZoneNameMapEntry* entry, const char* iana)
+{
+	if (!entry || !iana || !entry->Iana)
+		return FALSE;
+	return strcmp(iana, entry->Iana) == 0;
+}
+
+static BOOL id_cmp(const TimeZoneNameMapEntry* entry, const char* id)
+{
+	if (!entry || !id || !entry->Id)
+		return FALSE;
+	return strcmp(id, entry->Id) == 0;
+}
+
+static const char* get_for_type(const char* val, TimeZoneNameType type,
+                                BOOL (*cmp)(const TimeZoneNameMapEntry*, const char*))
+{
+	WINPR_ASSERT(val);
+	WINPR_ASSERT(cmp);
+
+	size_t index = 0;
+	while (TRUE)
+	{
+		const TimeZoneNameMapEntry* entry = TimeZoneGetAt(index++);
+		if (!entry)
+			return NULL;
+		if (cmp(entry, val))
+			return return_type(entry, type);
+	}
+}
+
 #if defined(WITH_TIMEZONE_ICU)
 static char* get_wzid_icu(const UChar* utzid, size_t utzid_len)
 {
@@ -88,21 +150,11 @@ static char* get(const char* iana)
 
 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;
-		}
-	}
-
+	const char* res = get_for_type(wzid, type, id_cmp);
 	free(wzid);
 	return res;
 }
@@ -149,22 +201,13 @@ 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* val = get_for_type(iana, type, iana_cmp);
+	if (val)
+		return val;
 
 	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;
+	return get_for_type(wzid, type, id_cmp);
 }
diff --git a/winpr/libwinpr/timezone/timezone.c b/winpr/libwinpr/timezone/timezone.c
index 2a68fac04..081516bce 100644
--- a/winpr/libwinpr/timezone/timezone.c
+++ b/winpr/libwinpr/timezone/timezone.c
@@ -853,10 +853,10 @@ DWORD EnumDynamicTimeZoneInformation(const DWORD dwIndex,
 	const DYNAMIC_TIME_ZONE_INFORMATION empty = { 0 };
 	*lpTimeZoneInformation = empty;
 
-	if (dwIndex >= TimeZoneNameMapSize)
+	const TimeZoneNameMapEntry* entry = TimeZoneGetAt(dwIndex);
+	if (!entry)
 		return ERROR_NO_MORE_ITEMS;
 
-	const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[dwIndex];
 	if (entry->DaylightName)
 		ConvertUtf8ToWChar(entry->DaylightName, lpTimeZoneInformation->DaylightName,
 		                   ARRAYSIZE(lpTimeZoneInformation->DaylightName));