1 /*
2 ********************************************************************************
3 * Copyright (C) 2005-2012, International Business Machines
4 * Corporation and others. All Rights Reserved.
5 ********************************************************************************
6 *
7 * File WINTZ.CPP
8 *
9 ********************************************************************************
10 */
11
12 #include "unicode/utypes.h"
13
14 #if U_PLATFORM_HAS_WIN32_API
15
16 #include "wintz.h"
17 #include "cmemory.h"
18 #include "cstring.h"
19
20 #include "unicode/ustring.h"
21 #include "unicode/ures.h"
22
23 # define WIN32_LEAN_AND_MEAN
24 # define VC_EXTRALEAN
25 # define NOUSER
26 # define NOSERVICE
27 # define NOIME
28 # define NOMCX
29 #include <windows.h>
30
31 #define MAX_LENGTH_ID 40
32
33 /* The layout of the Tzi value in the registry */
34 typedef struct
35 {
36 int32_t bias;
37 int32_t standardBias;
38 int32_t daylightBias;
39 SYSTEMTIME standardDate;
40 SYSTEMTIME daylightDate;
41 } TZI;
42
43 /**
44 * Various registry keys and key fragments.
45 */
46 static const char CURRENT_ZONE_REGKEY[] = "SYSTEM\\CurrentControlSet\\Control\\TimeZoneInformation\\";
47 static const char STANDARD_NAME_REGKEY[] = "StandardName";
48 static const char STANDARD_TIME_REGKEY[] = " Standard Time";
49 static const char TZI_REGKEY[] = "TZI";
50 static const char STD_REGKEY[] = "Std";
51
52 /**
53 * HKLM subkeys used to probe for the flavor of Windows. Note that we
54 * specifically check for the "GMT" zone subkey; this is present on
55 * NT, but on XP has become "GMT Standard Time". We need to
56 * discriminate between these cases.
57 */
58 static const char* const WIN_TYPE_PROBE_REGKEY[] = {
59 /* WIN_9X_ME_TYPE */
60 "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Time Zones",
61
62 /* WIN_NT_TYPE */
63 "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Time Zones\\GMT"
64
65 /* otherwise: WIN_2K_XP_TYPE */
66 };
67
68 /**
69 * The time zone root subkeys (under HKLM) for different flavors of
70 * Windows.
71 */
72 static const char* const TZ_REGKEY[] = {
73 /* WIN_9X_ME_TYPE */
74 "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Time Zones\\",
75
76 /* WIN_NT_TYPE | WIN_2K_XP_TYPE */
77 "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Time Zones\\"
78 };
79
80 /**
81 * Flavor of Windows, from our perspective. Not a real OS version,
82 * but rather the flavor of the layout of the time zone information in
83 * the registry.
84 */
85 enum {
86 WIN_9X_ME_TYPE = 1,
87 WIN_NT_TYPE = 2,
88 WIN_2K_XP_TYPE = 3
89 };
90
91 static int32_t gWinType = 0;
92
detectWindowsType()93 static int32_t detectWindowsType()
94 {
95 int32_t winType;
96 LONG result;
97 HKEY hkey;
98
99 /* Detect the version of windows by trying to open a sequence of
100 probe keys. We don't use the OS version API because what we
101 really want to know is how the registry is laid out.
102 Specifically, is it 9x/Me or not, and is it "GMT" or "GMT
103 Standard Time". */
104 for (winType = 0; winType < 2; winType++) {
105 result = RegOpenKeyExA(HKEY_LOCAL_MACHINE,
106 WIN_TYPE_PROBE_REGKEY[winType],
107 0,
108 KEY_QUERY_VALUE,
109 &hkey);
110 RegCloseKey(hkey);
111
112 if (result == ERROR_SUCCESS) {
113 break;
114 }
115 }
116
117 return winType+1; /* +1 to bring it inline with the enum */
118 }
119
openTZRegKey(HKEY * hkey,const char * winid)120 static LONG openTZRegKey(HKEY *hkey, const char *winid)
121 {
122 char subKeyName[110]; /* TODO: why 96?? */
123 char *name;
124 LONG result;
125
126 /* This isn't thread safe, but it's good enough because the result should be constant per system. */
127 if (gWinType <= 0) {
128 gWinType = detectWindowsType();
129 }
130
131 uprv_strcpy(subKeyName, TZ_REGKEY[(gWinType != WIN_9X_ME_TYPE)]);
132 name = &subKeyName[strlen(subKeyName)];
133 uprv_strcat(subKeyName, winid);
134
135 if (gWinType == WIN_9X_ME_TYPE) {
136 /* Remove " Standard Time" */
137 char *pStd = uprv_strstr(subKeyName, STANDARD_TIME_REGKEY);
138 if (pStd) {
139 *pStd = 0;
140 }
141 }
142
143 result = RegOpenKeyExA(HKEY_LOCAL_MACHINE,
144 subKeyName,
145 0,
146 KEY_QUERY_VALUE,
147 hkey);
148 return result;
149 }
150
getTZI(const char * winid,TZI * tzi)151 static LONG getTZI(const char *winid, TZI *tzi)
152 {
153 DWORD cbData = sizeof(TZI);
154 LONG result;
155 HKEY hkey;
156
157 result = openTZRegKey(&hkey, winid);
158
159 if (result == ERROR_SUCCESS) {
160 result = RegQueryValueExA(hkey,
161 TZI_REGKEY,
162 NULL,
163 NULL,
164 (LPBYTE)tzi,
165 &cbData);
166
167 }
168
169 RegCloseKey(hkey);
170
171 return result;
172 }
173
getSTDName(const char * winid,char * regStdName,int32_t length)174 static LONG getSTDName(const char *winid, char *regStdName, int32_t length) {
175 DWORD cbData = length;
176 LONG result;
177 HKEY hkey;
178
179 result = openTZRegKey(&hkey, winid);
180
181 if (result == ERROR_SUCCESS) {
182 result = RegQueryValueExA(hkey,
183 STD_REGKEY,
184 NULL,
185 NULL,
186 (LPBYTE)regStdName,
187 &cbData);
188
189 }
190
191 RegCloseKey(hkey);
192
193 return result;
194 }
195
196 /*
197 This code attempts to detect the Windows time zone, as set in the
198 Windows Date and Time control panel. It attempts to work on
199 multiple flavors of Windows (9x, Me, NT, 2000, XP) and on localized
200 installs. It works by directly interrogating the registry and
201 comparing the data there with the data returned by the
202 GetTimeZoneInformation API, along with some other strategies. The
203 registry contains time zone data under one of two keys (depending on
204 the flavor of Windows):
205
206 HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Time Zones\
207 HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\
208
209 Under this key are several subkeys, one for each time zone. These
210 subkeys are named "Pacific" on Win9x/Me and "Pacific Standard Time"
211 on WinNT/2k/XP. There are some other wrinkles; see the code for
212 details. The subkey name is NOT LOCALIZED, allowing us to support
213 localized installs.
214
215 Under the subkey are data values. We care about:
216
217 Std Standard time display name, localized
218 TZI Binary block of data
219
220 The TZI data is of particular interest. It contains the offset, two
221 more offsets for standard and daylight time, and the start and end
222 rules. This is the same data returned by the GetTimeZoneInformation
223 API. The API may modify the data on the way out, so we have to be
224 careful, but essentially we do a binary comparison against the TZI
225 blocks of various registry keys. When we find a match, we know what
226 time zone Windows is set to. Since the registry key is not
227 localized, we can then translate the key through a simple table
228 lookup into the corresponding ICU time zone.
229
230 This strategy doesn't always work because there are zones which
231 share an offset and rules, so more than one TZI block will match.
232 For example, both Tokyo and Seoul are at GMT+9 with no DST rules;
233 their TZI blocks are identical. For these cases, we fall back to a
234 name lookup. We attempt to match the display name as stored in the
235 registry for the current zone to the display name stored in the
236 registry for various Windows zones. By comparing the registry data
237 directly we avoid conversion complications.
238
239 Author: Alan Liu
240 Since: ICU 2.6
241 Based on original code by Carl Brown <cbrown@xnetinc.com>
242 */
243
244 /**
245 * Main Windows time zone detection function. Returns the Windows
246 * time zone, translated to an ICU time zone, or NULL upon failure.
247 */
248 U_CFUNC const char* U_EXPORT2
uprv_detectWindowsTimeZone()249 uprv_detectWindowsTimeZone() {
250 UErrorCode status = U_ZERO_ERROR;
251 UResourceBundle* bundle = NULL;
252 char* icuid = NULL;
253 UChar apiStd[MAX_LENGTH_ID];
254 char apiStdName[MAX_LENGTH_ID];
255 char regStdName[MAX_LENGTH_ID];
256 char tmpid[MAX_LENGTH_ID];
257 int32_t apiStdLength = 0;
258 int32_t len;
259 int id;
260 int errorCode;
261 char ISOcode[3]; /* 2 letter iso code */
262
263 LONG result;
264 TZI tziKey;
265 TZI tziReg;
266 TIME_ZONE_INFORMATION apiTZI;
267
268 /* Obtain TIME_ZONE_INFORMATION from the API, and then convert it
269 to TZI. We could also interrogate the registry directly; we do
270 this below if needed. */
271 uprv_memset(&apiTZI, 0, sizeof(apiTZI));
272 uprv_memset(&tziKey, 0, sizeof(tziKey));
273 uprv_memset(&tziReg, 0, sizeof(tziReg));
274 GetTimeZoneInformation(&apiTZI);
275 tziKey.bias = apiTZI.Bias;
276 uprv_memcpy((char *)&tziKey.standardDate, (char*)&apiTZI.StandardDate,
277 sizeof(apiTZI.StandardDate));
278 uprv_memcpy((char *)&tziKey.daylightDate, (char*)&apiTZI.DaylightDate,
279 sizeof(apiTZI.DaylightDate));
280
281 /* Convert the wchar_t* standard name to char* */
282 uprv_memset(apiStdName, 0, sizeof(apiStdName));
283 u_strFromWCS(apiStd, MAX_LENGTH_ID, &apiStdLength, apiTZI.StandardName, -1, &status);
284 u_austrncpy(apiStdName, apiStd, apiStdLength);
285
286 tmpid[0] = 0;
287
288 id = GetUserGeoID(GEOCLASS_NATION);
289 errorCode = GetGeoInfo(id,GEO_ISO2,ISOcode,3,0);
290
291 bundle = ures_openDirect(NULL, "windowsZones", &status);
292 ures_getByKey(bundle, "mapTimezones", bundle, &status);
293
294 /* Note: We get the winid not from static tables but from resource bundle. */
295 while (U_SUCCESS(status) && ures_hasNext(bundle)) {
296 UBool idFound = FALSE;
297 const char* winid;
298 UResourceBundle* winTZ = ures_getNextResource(bundle, NULL, &status);
299 if (U_FAILURE(status)) {
300 break;
301 }
302 winid = ures_getKey(winTZ);
303 result = getTZI(winid, &tziReg);
304
305 if (result == ERROR_SUCCESS) {
306 /* Windows alters the DaylightBias in some situations.
307 Using the bias and the rules suffices, so overwrite
308 these unreliable fields. */
309 tziKey.standardBias = tziReg.standardBias;
310 tziKey.daylightBias = tziReg.daylightBias;
311
312 if (uprv_memcmp((char *)&tziKey, (char*)&tziReg, sizeof(tziKey)) == 0) {
313 const UChar* icuTZ = NULL;
314 if (errorCode != 0) {
315 icuTZ = ures_getStringByKey(winTZ, ISOcode, &len, &status);
316 }
317 if (errorCode==0 || icuTZ==NULL) {
318 /* fallback to default "001" and reset status */
319 status = U_ZERO_ERROR;
320 icuTZ = ures_getStringByKey(winTZ, "001", &len, &status);
321 }
322
323 if (U_SUCCESS(status)) {
324 /* Get the standard name from the registry key to compare with
325 the one from Windows API call. */
326 uprv_memset(regStdName, 0, sizeof(regStdName));
327 result = getSTDName(winid, regStdName, sizeof(regStdName));
328 if (result == ERROR_SUCCESS) {
329 if (uprv_strcmp(apiStdName, regStdName) == 0) {
330 idFound = TRUE;
331 }
332 }
333
334 /* tmpid buffer holds the ICU timezone ID corresponding to the timezone ID from Windows.
335 * If none is found, tmpid buffer will contain a fallback ID (i.e. the time zone ID matching
336 * the current time zone information)
337 */
338 if (idFound || tmpid[0] == 0) {
339 /* if icuTZ has more than one city, take only the first (i.e. terminate icuTZ at first space) */
340 int index=0;
341 while (! (*icuTZ == '\0' || *icuTZ ==' ')) {
342 tmpid[index++]=(char)(*icuTZ++); /* safe to assume 'char' is ASCII compatible on windows */
343 }
344 tmpid[index]='\0';
345 }
346 }
347 }
348 }
349 ures_close(winTZ);
350 if (idFound) {
351 break;
352 }
353 }
354
355 /*
356 * Copy the timezone ID to icuid to be returned.
357 */
358 if (tmpid[0] != 0) {
359 len = uprv_strlen(tmpid);
360 icuid = (char*)uprv_calloc(len + 1, sizeof(char));
361 if (icuid != NULL) {
362 uprv_strcpy(icuid, tmpid);
363 }
364 }
365
366 ures_close(bundle);
367
368 return icuid;
369 }
370
371 #endif /* U_PLATFORM_HAS_WIN32_API */
372