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 0x%x: %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 {
256 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
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 _dbus_make_file_world_readable (tmp_filename_c);
279
280 _dbus_verbose ("tmp file %s hnd %p opened\n", tmp_filename_c, hnd);
281
282 need_unlink = TRUE;
283
284 total = 0;
285 bytes_to_write = _dbus_string_get_length (str);
286 str_c = _dbus_string_get_const_data (str);
287
288 while (total < bytes_to_write)
289 {
290 DWORD bytes_written;
291 BOOL res;
292
293 res = WriteFile (hnd, str_c + total, bytes_to_write - total,
294 &bytes_written, NULL);
295
296 if (res == 0 || bytes_written <= 0)
297 {
298 char *emsg = _dbus_win_error_string (GetLastError ());
299 dbus_set_error (error, _dbus_win_error_from_last_error (),
300 "Could not write to %s: %s", tmp_filename_c, emsg);
301 _dbus_win_free_error_string (emsg);
302 goto out;
303 }
304
305 total += bytes_written;
306 }
307
308 if (CloseHandle (hnd) == 0)
309 {
310 char *emsg = _dbus_win_error_string (GetLastError ());
311 dbus_set_error (error, _dbus_win_error_from_last_error (),
312 "Could not close file %s: %s", tmp_filename_c, emsg);
313 _dbus_win_free_error_string (emsg);
314 goto out;
315 }
316
317 hnd = INVALID_HANDLE_VALUE;
318
319 /* Unlike rename(), MoveFileEx() can replace existing files */
320 if (!MoveFileExA (tmp_filename_c, filename_c, MOVEFILE_REPLACE_EXISTING))
321 {
322 char *emsg = _dbus_win_error_string (GetLastError ());
323 dbus_set_error (error, _dbus_win_error_from_last_error (),
324 "Could not rename %s to %s: %s",
325 tmp_filename_c, filename_c, emsg);
326 _dbus_win_free_error_string (emsg);
327
328 goto out;
329 }
330
331 need_unlink = FALSE;
332
333 retval = TRUE;
334
335 out:
336 /* close first, then unlink */
337
338 if (hnd != INVALID_HANDLE_VALUE)
339 CloseHandle (hnd);
340
341 if (need_unlink && DeleteFileA (tmp_filename_c) == 0)
342 {
343 char *emsg = _dbus_win_error_string (GetLastError ());
344 _dbus_verbose ("Failed to unlink temp file %s: %s", tmp_filename_c,
345 emsg);
346 _dbus_win_free_error_string (emsg);
347 }
348
349 _dbus_string_free (&tmp_filename);
350
351 if (!retval)
352 _DBUS_ASSERT_ERROR_IS_SET (error);
353
354 return retval;
355 }
356
357
358 /** Creates the given file, failing if the file already exists.
359 *
360 * @param filename the filename
361 * @param error error location
362 * @returns #TRUE if we created the file and it didn't exist
363 */
364 dbus_bool_t
_dbus_create_file_exclusively(const DBusString * filename,DBusError * error)365 _dbus_create_file_exclusively (const DBusString *filename,
366 DBusError *error)
367 {
368 HANDLE hnd;
369 const char *filename_c;
370
371 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
372
373 filename_c = _dbus_string_get_const_data (filename);
374
375 hnd = CreateFileA (filename_c, GENERIC_WRITE,
376 FILE_SHARE_READ | FILE_SHARE_WRITE,
377 NULL, CREATE_NEW, FILE_ATTRIBUTE_NORMAL,
378 INVALID_HANDLE_VALUE);
379 if (hnd == INVALID_HANDLE_VALUE)
380 {
381 char *emsg = _dbus_win_error_string (GetLastError ());
382 dbus_set_error (error, _dbus_win_error_from_last_error (),
383 "Could not create file %s: %s",
384 filename_c, emsg);
385 _dbus_win_free_error_string (emsg);
386 return FALSE;
387 }
388
389 _dbus_verbose ("exclusive file %s hnd %p opened\n", filename_c, hnd);
390
391 if (CloseHandle (hnd) == 0)
392 {
393 char *emsg = _dbus_win_error_string (GetLastError ());
394 dbus_set_error (error, _dbus_win_error_from_last_error (),
395 "Could not close file %s: %s",
396 filename_c, emsg);
397 _dbus_win_free_error_string (emsg);
398
399 return FALSE;
400 }
401
402 return TRUE;
403 }
404
405