1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-file-win.c windows related file implementation (internal to D-Bus implementation)
3 *
4 * Copyright (C) 2002, 2003, 2006 Red Hat, Inc.
5 * Copyright (C) 2003 CodeFactory AB
6 *
7 * Licensed under the Academic Free License version 2.1
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 *
23 */
24
25 #include <config.h>
26 #include "dbus-protocol.h"
27 #include "dbus-string.h"
28 #include "dbus-internals.h"
29 #include "dbus-sysdeps-win.h"
30 #include "dbus-pipe.h"
31
32 #include <windows.h>
33
34
35 /**
36 * Thin wrapper around the read() system call that appends
37 * the data it reads to the DBusString buffer. It appends
38 * up to the given count.
39 *
40 * @param hnd the HANDLE to read from
41 * @param buffer the buffer to append data to
42 * @param count the amount of data to read
43 * @param error place to set an error
44 * @returns the number of bytes read or -1
45 */
46 static int
_dbus_file_read(HANDLE hnd,DBusString * buffer,int count,DBusError * error)47 _dbus_file_read (HANDLE hnd,
48 DBusString *buffer,
49 int count,
50 DBusError *error)
51 {
52 BOOL result;
53 DWORD bytes_read;
54 int start;
55 char *data;
56
57 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
58
59 _dbus_assert (count >= 0);
60
61 start = _dbus_string_get_length (buffer);
62
63 if (!_dbus_string_lengthen (buffer, count))
64 {
65 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
66 return -1;
67 }
68
69 data = _dbus_string_get_data_len (buffer, start, count);
70
71 result = ReadFile (hnd, data, count, &bytes_read, NULL);
72 if (result == 0)
73 {
74 char *emsg = _dbus_win_error_string (GetLastError ());
75 dbus_set_error (error, _dbus_win_error_from_last_error (),
76 "Failed to read from %p: %s", hnd, emsg);
77 _dbus_win_free_error_string (emsg);
78 return -1;
79 }
80
81 if (bytes_read)
82 {
83 /* put length back (doesn't actually realloc) */
84 _dbus_string_set_length (buffer, start + bytes_read);
85
86 #if 0
87 if (bytes_read > 0)
88 _dbus_verbose_bytes_of_string (buffer, start, bytes_read);
89 #endif
90 }
91
92 return bytes_read;
93 }
94
95
96 /**
97 * Appends the contents of the given file to the string,
98 * returning error code. At the moment, won't open a file
99 * more than a megabyte in size.
100 *
101 * @param str the string to append to
102 * @param filename filename to load
103 * @param error place to set an error
104 * @returns #FALSE if error was set
105 */
106 dbus_bool_t
_dbus_file_get_contents(DBusString * str,const DBusString * filename,DBusError * error)107 _dbus_file_get_contents (DBusString *str,
108 const DBusString *filename,
109 DBusError *error)
110 {
111 HANDLE hnd;
112 DWORD fsize;
113 DWORD fsize_hi;
114 int orig_len;
115 unsigned int total;
116 const char *filename_c;
117
118 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
119
120 filename_c = _dbus_string_get_const_data (filename);
121
122 hnd = CreateFileA (filename_c, GENERIC_READ,
123 FILE_SHARE_READ | FILE_SHARE_WRITE,
124 NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
125 if (hnd == INVALID_HANDLE_VALUE)
126 {
127 char *emsg = _dbus_win_error_string (GetLastError ());
128 dbus_set_error (error, _dbus_win_error_from_last_error (),
129 "Failed to open \"%s\": %s", filename_c, emsg);
130 _dbus_win_free_error_string (emsg);
131 return FALSE;
132 }
133
134 _dbus_verbose ("file %s hnd %p opened\n", filename_c, hnd);
135
136 fsize = GetFileSize (hnd, &fsize_hi);
137 if (fsize == 0xFFFFFFFF && GetLastError() != NO_ERROR)
138 {
139 char *emsg = _dbus_win_error_string (GetLastError ());
140 dbus_set_error (error, _dbus_win_error_from_last_error (),
141 "Failed to get file size for \"%s\": %s",
142 filename_c, emsg);
143 _dbus_win_free_error_string (emsg);
144
145 _dbus_verbose ("GetFileSize() failed: %s", emsg);
146
147 CloseHandle (hnd);
148
149 return FALSE;
150 }
151
152 if (fsize_hi != 0 || fsize > _DBUS_ONE_MEGABYTE)
153 {
154 dbus_set_error (error, DBUS_ERROR_FAILED,
155 "File size %lu/%lu of \"%s\" is too large.",
156 (unsigned long) fsize_hi,
157 (unsigned long) fsize, filename_c);
158 CloseHandle (hnd);
159 return FALSE;
160 }
161
162 total = 0;
163 orig_len = _dbus_string_get_length (str);
164 if (fsize > 0)
165 {
166 int bytes_read;
167
168 while (total < fsize)
169 {
170 bytes_read = _dbus_file_read (hnd, str, fsize - total, error);
171 if (bytes_read <= 0)
172 {
173 if (bytes_read == 0)
174 {
175 dbus_set_error (error, DBUS_ERROR_FAILED,
176 "Premature EOF reading \"%s\"",
177 filename_c);
178 }
179 else
180 _DBUS_ASSERT_ERROR_IS_SET (error);
181
182 CloseHandle (hnd);
183 _dbus_string_set_length (str, orig_len);
184 return FALSE;
185 }
186 else
187 total += bytes_read;
188 }
189
190 CloseHandle (hnd);
191 return TRUE;
192 }
193 else
194 {
195 CloseHandle (hnd);
196 return TRUE;
197 }
198 }
199
200
201 /**
202 * Writes a string out to a file. If the file exists,
203 * it will be atomically overwritten by the new data.
204 *
205 * @param str the string to write out
206 * @param filename the file to save string to
207 * @param world_readable if true, ensure file is world readable
208 * @param error error to be filled in on failure
209 * @returns #FALSE on failure
210 */
211 dbus_bool_t
_dbus_string_save_to_file(const DBusString * str,const DBusString * filename,dbus_bool_t world_readable,DBusError * error)212 _dbus_string_save_to_file (const DBusString *str,
213 const DBusString *filename,
214 dbus_bool_t world_readable,
215 DBusError *error)
216 {
217 HANDLE hnd;
218 int bytes_to_write;
219 const char *filename_c;
220 DBusString tmp_filename;
221 const char *tmp_filename_c;
222 int total;
223 const char *str_c;
224 dbus_bool_t need_unlink;
225 dbus_bool_t retval;
226
227 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
228
229 hnd = INVALID_HANDLE_VALUE;
230 retval = FALSE;
231 need_unlink = FALSE;
232
233 if (!_dbus_string_init (&tmp_filename))
234 {
235 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
236 return FALSE;
237 }
238
239 if (!_dbus_string_copy (filename, 0, &tmp_filename, 0))
240 {
241 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
242 _dbus_string_free (&tmp_filename);
243 return FALSE;
244 }
245
246 if (!_dbus_string_append (&tmp_filename, "."))
247 {
248 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
249 _dbus_string_free (&tmp_filename);
250 return FALSE;
251 }
252
253 #define N_TMP_FILENAME_RANDOM_BYTES 8
254 if (!_dbus_generate_random_ascii (&tmp_filename, N_TMP_FILENAME_RANDOM_BYTES,
255 error))
256 {
257 _dbus_string_free (&tmp_filename);
258 return FALSE;
259 }
260
261 filename_c = _dbus_string_get_const_data (filename);
262 tmp_filename_c = _dbus_string_get_const_data (&tmp_filename);
263
264 /* TODO - support world-readable in an atomic fashion */
265 hnd = CreateFileA (tmp_filename_c, GENERIC_WRITE,
266 FILE_SHARE_READ | FILE_SHARE_WRITE,
267 NULL, CREATE_NEW, FILE_ATTRIBUTE_NORMAL,
268 INVALID_HANDLE_VALUE);
269 if (hnd == INVALID_HANDLE_VALUE)
270 {
271 char *emsg = _dbus_win_error_string (GetLastError ());
272 dbus_set_error (error, _dbus_win_error_from_last_error (),
273 "Could not create \"%s\": %s", filename_c, emsg);
274 _dbus_win_free_error_string (emsg);
275 goto out;
276 }
277 if (world_readable)
278 {
279 if (! _dbus_make_file_world_readable (&tmp_filename, error))
280 goto out;
281 }
282
283 _dbus_verbose ("tmp file %s hnd %p opened\n", tmp_filename_c, hnd);
284
285 need_unlink = TRUE;
286
287 total = 0;
288 bytes_to_write = _dbus_string_get_length (str);
289 str_c = _dbus_string_get_const_data (str);
290
291 while (total < bytes_to_write)
292 {
293 DWORD bytes_written;
294 BOOL res;
295
296 res = WriteFile (hnd, str_c + total, bytes_to_write - total,
297 &bytes_written, NULL);
298
299 if (res == 0 || bytes_written <= 0)
300 {
301 char *emsg = _dbus_win_error_string (GetLastError ());
302 dbus_set_error (error, _dbus_win_error_from_last_error (),
303 "Could not write to %s: %s", tmp_filename_c, emsg);
304 _dbus_win_free_error_string (emsg);
305 goto out;
306 }
307
308 total += bytes_written;
309 }
310
311 if (CloseHandle (hnd) == 0)
312 {
313 char *emsg = _dbus_win_error_string (GetLastError ());
314 dbus_set_error (error, _dbus_win_error_from_last_error (),
315 "Could not close file %s: %s", tmp_filename_c, emsg);
316 _dbus_win_free_error_string (emsg);
317 goto out;
318 }
319
320 hnd = INVALID_HANDLE_VALUE;
321
322 /* Unlike rename(), MoveFileEx() can replace existing files */
323 if (!MoveFileExA (tmp_filename_c, filename_c, MOVEFILE_REPLACE_EXISTING))
324 {
325 char *emsg = _dbus_win_error_string (GetLastError ());
326 dbus_set_error (error, _dbus_win_error_from_last_error (),
327 "Could not rename %s to %s: %s",
328 tmp_filename_c, filename_c, emsg);
329 _dbus_win_free_error_string (emsg);
330
331 goto out;
332 }
333
334 need_unlink = FALSE;
335
336 retval = TRUE;
337
338 out:
339 /* close first, then unlink */
340
341 if (hnd != INVALID_HANDLE_VALUE)
342 CloseHandle (hnd);
343
344 if (need_unlink && DeleteFileA (tmp_filename_c) == 0)
345 {
346 char *emsg = _dbus_win_error_string (GetLastError ());
347 _dbus_verbose ("Failed to unlink temp file %s: %s", tmp_filename_c,
348 emsg);
349 _dbus_win_free_error_string (emsg);
350 }
351
352 _dbus_string_free (&tmp_filename);
353
354 if (!retval)
355 _DBUS_ASSERT_ERROR_IS_SET (error);
356
357 return retval;
358 }
359
360
361 /** Creates the given file, failing if the file already exists.
362 *
363 * @param filename the filename
364 * @param error error location
365 * @returns #TRUE if we created the file and it didn't exist
366 */
367 dbus_bool_t
_dbus_create_file_exclusively(const DBusString * filename,DBusError * error)368 _dbus_create_file_exclusively (const DBusString *filename,
369 DBusError *error)
370 {
371 HANDLE hnd;
372 const char *filename_c;
373
374 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
375
376 filename_c = _dbus_string_get_const_data (filename);
377
378 hnd = CreateFileA (filename_c, GENERIC_WRITE,
379 FILE_SHARE_READ | FILE_SHARE_WRITE,
380 NULL, CREATE_NEW, FILE_ATTRIBUTE_NORMAL,
381 INVALID_HANDLE_VALUE);
382 if (hnd == INVALID_HANDLE_VALUE)
383 {
384 char *emsg = _dbus_win_error_string (GetLastError ());
385 dbus_set_error (error, _dbus_win_error_from_last_error (),
386 "Could not create file %s: %s",
387 filename_c, emsg);
388 _dbus_win_free_error_string (emsg);
389 return FALSE;
390 }
391
392 _dbus_verbose ("exclusive file %s hnd %p opened\n", filename_c, hnd);
393
394 if (CloseHandle (hnd) == 0)
395 {
396 char *emsg = _dbus_win_error_string (GetLastError ());
397 dbus_set_error (error, _dbus_win_error_from_last_error (),
398 "Could not close file %s: %s",
399 filename_c, emsg);
400 _dbus_win_free_error_string (emsg);
401
402 return FALSE;
403 }
404
405 return TRUE;
406 }
407
408