• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 //     * Redistributions of source code must retain the above copyright
10 // notice, this list of conditions and the following disclaimer.
11 //     * Redistributions in binary form must reproduce the above
12 // copyright notice, this list of conditions and the following disclaimer
13 // in the documentation and/or other materials provided with the
14 // distribution.
15 //     * Neither the name of Google Inc. nor the names of its
16 // contributors may be used to endorse or promote products derived from
17 // this software without specific prior written permission.
18 //
19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 
31 // Author: laszlocsomor@google.com (Laszlo Csomor)
32 //  Based on original Protocol Buffers design by
33 //  Sanjay Ghemawat, Jeff Dean, and others.
34 
35 // Implementation for long-path-aware open/mkdir/access/etc. on Windows, as well
36 // as for the supporting utility functions.
37 //
38 // These functions convert the input path to an absolute Windows path
39 // with "\\?\" prefix, then pass that to _wopen/_wmkdir/_waccess/etc.
40 // (declared in <io.h>) respectively. This allows working with files/directories
41 // whose paths are longer than MAX_PATH (260 chars).
42 //
43 // This file is only used on Windows, it's empty on other platforms.
44 
45 #if defined(_WIN32) && !defined(_XBOX_ONE)
46 
47 // Comment this out to fall back to using the ANSI versions (open, mkdir, ...)
48 // instead of the Unicode ones (_wopen, _wmkdir, ...). Doing so can be useful to
49 // debug failing tests if that's caused by the long path support.
50 #define SUPPORT_LONGPATHS
51 
52 #include <google/protobuf/io/io_win32.h>
53 
54 #include <ctype.h>
55 #include <direct.h>
56 #include <errno.h>
57 #include <fcntl.h>
58 #include <io.h>
59 #include <sys/stat.h>
60 #include <sys/types.h>
61 #include <wctype.h>
62 
63 #ifndef WIN32_LEAN_AND_MEAN
64 #define WIN32_LEAN_AND_MEAN 1
65 #endif
66 
67 #include <windows.h>
68 
69 #include <memory>
70 #include <sstream>
71 #include <string>
72 #include <vector>
73 
74 namespace google {
75 namespace protobuf {
76 namespace io {
77 namespace win32 {
78 namespace {
79 
80 using std::string;
81 using std::wstring;
82 
83 template <typename char_type>
84 struct CharTraits {
85   static bool is_alpha(char_type ch);
86 };
87 
88 template <>
89 struct CharTraits<char> {
is_alphagoogle::protobuf::io::win32::__anon2d386eeb0111::CharTraits90   static bool is_alpha(char ch) { return isalpha(ch); }
91 };
92 
93 template <>
94 struct CharTraits<wchar_t> {
is_alphagoogle::protobuf::io::win32::__anon2d386eeb0111::CharTraits95   static bool is_alpha(wchar_t ch) { return iswalpha(ch); }
96 };
97 
98 template <typename char_type>
null_or_empty(const char_type * s)99 bool null_or_empty(const char_type* s) {
100   return s == nullptr || *s == 0;
101 }
102 
103 // Returns true if the path starts with a drive letter, e.g. "c:".
104 // Note that this won't check for the "\" after the drive letter, so this also
105 // returns true for "c:foo" (which is "c:\${PWD}\foo").
106 // This check requires that a path not have a longpath prefix ("\\?\").
107 template <typename char_type>
has_drive_letter(const char_type * ch)108 bool has_drive_letter(const char_type* ch) {
109   return CharTraits<char_type>::is_alpha(ch[0]) && ch[1] == ':';
110 }
111 
112 // Returns true if the path starts with a longpath prefix ("\\?\").
113 template <typename char_type>
has_longpath_prefix(const char_type * path)114 bool has_longpath_prefix(const char_type* path) {
115   return path[0] == '\\' && path[1] == '\\' && path[2] == '?' &&
116          path[3] == '\\';
117 }
118 
119 template <typename char_type>
is_separator(char_type c)120 bool is_separator(char_type c) {
121   return c == '/' || c == '\\';
122 }
123 
124 // Returns true if the path starts with a drive specifier (e.g. "c:\").
125 template <typename char_type>
is_path_absolute(const char_type * path)126 bool is_path_absolute(const char_type* path) {
127   return has_drive_letter(path) && is_separator(path[2]);
128 }
129 
130 template <typename char_type>
is_drive_relative(const char_type * path)131 bool is_drive_relative(const char_type* path) {
132   return has_drive_letter(path) && (path[2] == 0 || !is_separator(path[2]));
133 }
134 
join_paths(const wstring & path1,const wstring & path2)135 wstring join_paths(const wstring& path1, const wstring& path2) {
136   if (path1.empty() || is_path_absolute(path2.c_str()) ||
137       has_longpath_prefix(path2.c_str())) {
138     return path2;
139   }
140   if (path2.empty()) {
141     return path1;
142   }
143 
144   if (is_separator(path1[path1.size() - 1])) {
145     return is_separator(path2[0]) ? (path1 + path2.substr(1))
146                                        : (path1 + path2);
147   } else {
148     return is_separator(path2[0]) ? (path1 + path2)
149                                        : (path1 + L'\\' + path2);
150   }
151 }
152 
normalize(wstring path)153 wstring normalize(wstring path) {
154   if (has_longpath_prefix(path.c_str())) {
155     path = path.substr(4);
156   }
157 
158   static const wstring dot(L".");
159   static const wstring dotdot(L"..");
160   const WCHAR* p = path.c_str();
161 
162   std::vector<wstring> segments;
163   int segment_start = -1;
164   // Find the path segments in `path` (separated by "/").
165   for (int i = 0;; ++i) {
166     if (!is_separator(p[i]) && p[i] != L'\0') {
167       // The current character does not end a segment, so start one unless it's
168       // already started.
169       if (segment_start < 0) {
170         segment_start = i;
171       }
172     } else if (segment_start >= 0 && i > segment_start) {
173       // The current character is "/" or "\0", so this ends a segment.
174       // Add that to `segments` if there's anything to add; handle "." and "..".
175       wstring segment(p, segment_start, i - segment_start);
176       segment_start = -1;
177       if (segment == dotdot) {
178         if (!segments.empty() &&
179             (!has_drive_letter(segments[0].c_str()) || segments.size() > 1)) {
180           segments.pop_back();
181         }
182       } else if (segment != dot && !segment.empty()) {
183         segments.push_back(segment);
184       }
185     }
186     if (p[i] == L'\0') {
187       break;
188     }
189   }
190 
191   // Handle the case when `path` is just a drive specifier (or some degenerate
192   // form of it, e.g. "c:\..").
193   if (segments.size() == 1 && segments[0].size() == 2 &&
194       has_drive_letter(segments[0].c_str())) {
195     return segments[0] + L'\\';
196   }
197 
198   // Join all segments.
199   bool first = true;
200   std::wstringstream result;
201   for (int i = 0; i < segments.size(); ++i) {
202     if (!first) {
203       result << L'\\';
204     }
205     first = false;
206     result << segments[i];
207   }
208   // Preserve trailing separator if the input contained it.
209   if (!path.empty() && is_separator(p[path.size() - 1])) {
210     result << L'\\';
211   }
212   return result.str();
213 }
214 
as_windows_path(const char * path,wstring * result)215 bool as_windows_path(const char* path, wstring* result) {
216   if (null_or_empty(path)) {
217     result->clear();
218     return true;
219   }
220   wstring wpath;
221   if (!strings::utf8_to_wcs(path, &wpath)) {
222     return false;
223   }
224   if (has_longpath_prefix(wpath.c_str())) {
225     *result = wpath;
226     return true;
227   }
228   if (is_separator(path[0]) || is_drive_relative(path)) {
229     return false;
230   }
231 
232 
233   if (!is_path_absolute(wpath.c_str())) {
234     int size = ::GetCurrentDirectoryW(0, nullptr);
235     if (size == 0 && GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
236       return false;
237     }
238     std::unique_ptr<WCHAR[]> wcwd(new WCHAR[size]);
239     ::GetCurrentDirectoryW(size, wcwd.get());
240     wpath = join_paths(wcwd.get(), wpath);
241   }
242   wpath = normalize(wpath);
243   if (!has_longpath_prefix(wpath.c_str())) {
244     // Add the "\\?\" prefix unconditionally. This way we prevent the Win32 API
245     // from processing the path and "helpfully" removing trailing dots from the
246     // path, for example.
247     // See https://github.com/bazelbuild/bazel/issues/2935
248     wpath = wstring(L"\\\\?\\") + wpath;
249   }
250   *result = wpath;
251   return true;
252 }
253 
254 }  // namespace
255 
open(const char * path,int flags,int mode)256 int open(const char* path, int flags, int mode) {
257 #ifdef SUPPORT_LONGPATHS
258   wstring wpath;
259   if (!as_windows_path(path, &wpath)) {
260     errno = ENOENT;
261     return -1;
262   }
263   return ::_wopen(wpath.c_str(), flags, mode);
264 #else
265   return ::_open(path, flags, mode);
266 #endif
267 }
268 
mkdir(const char * path,int _mode)269 int mkdir(const char* path, int _mode) {
270 #ifdef SUPPORT_LONGPATHS
271   wstring wpath;
272   if (!as_windows_path(path, &wpath)) {
273     errno = ENOENT;
274     return -1;
275   }
276   return ::_wmkdir(wpath.c_str());
277 #else   // not SUPPORT_LONGPATHS
278   return ::_mkdir(path);
279 #endif  // not SUPPORT_LONGPATHS
280 }
281 
access(const char * path,int mode)282 int access(const char* path, int mode) {
283 #ifdef SUPPORT_LONGPATHS
284   wstring wpath;
285   if (!as_windows_path(path, &wpath)) {
286     errno = ENOENT;
287     return -1;
288   }
289   return ::_waccess(wpath.c_str(), mode);
290 #else
291   return ::_access(path, mode);
292 #endif
293 }
294 
chdir(const char * path)295 int chdir(const char* path) {
296 #ifdef SUPPORT_LONGPATHS
297   wstring wpath;
298   if (!as_windows_path(path, &wpath)) {
299     errno = ENOENT;
300     return -1;
301   }
302   return ::_wchdir(wpath.c_str());
303 #else
304   return ::_chdir(path);
305 #endif
306 }
307 
stat(const char * path,struct _stat * buffer)308 int stat(const char* path, struct _stat* buffer) {
309 #ifdef SUPPORT_LONGPATHS
310   wstring wpath;
311   if (!as_windows_path(path, &wpath)) {
312     errno = ENOENT;
313     return -1;
314   }
315   return ::_wstat(wpath.c_str(), buffer);
316 #else   // not SUPPORT_LONGPATHS
317   return ::_stat(path, buffer);
318 #endif  // not SUPPORT_LONGPATHS
319 }
320 
fopen(const char * path,const char * mode)321 FILE* fopen(const char* path, const char* mode) {
322 #ifdef SUPPORT_LONGPATHS
323   if (null_or_empty(path)) {
324     errno = EINVAL;
325     return nullptr;
326   }
327   wstring wpath;
328   if (!as_windows_path(path, &wpath)) {
329     errno = ENOENT;
330     return nullptr;
331   }
332   wstring wmode;
333   if (!strings::utf8_to_wcs(mode, &wmode)) {
334     errno = EINVAL;
335     return nullptr;
336   }
337   return ::_wfopen(wpath.c_str(), wmode.c_str());
338 #else
339   return ::fopen(path, mode);
340 #endif
341 }
342 
close(int fd)343 int close(int fd) { return ::_close(fd); }
344 
dup(int fd)345 int dup(int fd) { return ::_dup(fd); }
346 
dup2(int fd1,int fd2)347 int dup2(int fd1, int fd2) { return ::_dup2(fd1, fd2); }
348 
read(int fd,void * buffer,size_t size)349 int read(int fd, void* buffer, size_t size) {
350   return ::_read(fd, buffer, size);
351 }
352 
setmode(int fd,int mode)353 int setmode(int fd, int mode) { return ::_setmode(fd, mode); }
354 
write(int fd,const void * buffer,size_t size)355 int write(int fd, const void* buffer, size_t size) {
356   return ::_write(fd, buffer, size);
357 }
358 
testonly_utf8_to_winpath(const char * path)359 wstring testonly_utf8_to_winpath(const char* path) {
360   wstring wpath;
361   return as_windows_path(path, &wpath) ? wpath : wstring();
362 }
363 
ExpandWildcards(const string & path,std::function<void (const string &)> consume)364 ExpandWildcardsResult ExpandWildcards(
365     const string& path, std::function<void(const string&)> consume) {
366   if (path.find_first_of("*?") == string::npos) {
367     // There are no wildcards in the path, we don't need to expand it.
368     consume(path);
369     return ExpandWildcardsResult::kSuccess;
370   }
371 
372   wstring wpath;
373   if (!as_windows_path(path.c_str(), &wpath)) {
374     return ExpandWildcardsResult::kErrorInputPathConversion;
375   }
376 
377   static const wstring kDot = L".";
378   static const wstring kDotDot = L"..";
379   WIN32_FIND_DATAW metadata;
380   HANDLE handle = ::FindFirstFileW(wpath.c_str(), &metadata);
381   if (handle == INVALID_HANDLE_VALUE) {
382     // The pattern does not match any files (or directories).
383     return ExpandWildcardsResult::kErrorNoMatchingFile;
384   }
385 
386   string::size_type pos = path.find_last_of("\\/");
387   string dirname;
388   if (pos != string::npos) {
389     dirname = path.substr(0, pos + 1);
390   }
391 
392   ExpandWildcardsResult matched = ExpandWildcardsResult::kErrorNoMatchingFile;
393   do {
394     // Ignore ".", "..", and directories.
395     if ((metadata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) == 0 &&
396         kDot != metadata.cFileName && kDotDot != metadata.cFileName) {
397       matched = ExpandWildcardsResult::kSuccess;
398       string filename;
399       if (!strings::wcs_to_utf8(metadata.cFileName, &filename)) {
400         return ExpandWildcardsResult::kErrorOutputPathConversion;
401       }
402 
403       if (dirname.empty()) {
404         consume(filename);
405       } else {
406         consume(dirname + filename);
407       }
408     }
409   } while (::FindNextFileW(handle, &metadata));
410   FindClose(handle);
411   return matched;
412 }
413 
414 namespace strings {
415 
wcs_to_mbs(const WCHAR * s,string * out,bool outUtf8)416 bool wcs_to_mbs(const WCHAR* s, string* out, bool outUtf8) {
417   if (null_or_empty(s)) {
418     out->clear();
419     return true;
420   }
421   BOOL usedDefaultChar = FALSE;
422   SetLastError(0);
423   int size = WideCharToMultiByte(
424       outUtf8 ? CP_UTF8 : CP_ACP, 0, s, -1, nullptr, 0, nullptr,
425       outUtf8 ? nullptr : &usedDefaultChar);
426   if ((size == 0 && GetLastError() != ERROR_INSUFFICIENT_BUFFER)
427       || usedDefaultChar) {
428     return false;
429   }
430   std::unique_ptr<CHAR[]> astr(new CHAR[size]);
431   WideCharToMultiByte(
432       outUtf8 ? CP_UTF8 : CP_ACP, 0, s, -1, astr.get(), size, nullptr, nullptr);
433   out->assign(astr.get());
434   return true;
435 }
436 
mbs_to_wcs(const char * s,wstring * out,bool inUtf8)437 bool mbs_to_wcs(const char* s, wstring* out, bool inUtf8) {
438   if (null_or_empty(s)) {
439     out->clear();
440     return true;
441   }
442 
443   SetLastError(0);
444   int size =
445       MultiByteToWideChar(inUtf8 ? CP_UTF8 : CP_ACP, 0, s, -1, nullptr, 0);
446   if (size == 0 && GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
447     return false;
448   }
449   std::unique_ptr<WCHAR[]> wstr(new WCHAR[size]);
450   MultiByteToWideChar(
451       inUtf8 ? CP_UTF8 : CP_ACP, 0, s, -1, wstr.get(), size + 1);
452   out->assign(wstr.get());
453   return true;
454 }
455 
utf8_to_wcs(const char * input,wstring * out)456 bool utf8_to_wcs(const char* input, wstring* out) {
457   return mbs_to_wcs(input, out, true);
458 }
459 
wcs_to_utf8(const wchar_t * input,string * out)460 bool wcs_to_utf8(const wchar_t* input, string* out) {
461   return wcs_to_mbs(input, out, true);
462 }
463 
464 }  // namespace strings
465 }  // namespace win32
466 }  // namespace io
467 }  // namespace protobuf
468 }  // namespace google
469 
470 #endif  // defined(_WIN32)
471