1 | /* Verify that ftell returns the correct value at various points before and |
2 | after the handler on which it is called becomes active. |
3 | Copyright (C) 2014-2022 Free Software Foundation, Inc. |
4 | This file is part of the GNU C Library. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either |
9 | version 2.1 of the License, or (at your option) any later version. |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <https://www.gnu.org/licenses/>. */ |
19 | |
20 | #include <stdio.h> |
21 | #include <stdlib.h> |
22 | #include <string.h> |
23 | #include <errno.h> |
24 | #include <unistd.h> |
25 | #include <fcntl.h> |
26 | #include <locale.h> |
27 | #include <wchar.h> |
28 | |
29 | static int do_test (void); |
30 | |
31 | #define TEST_FUNCTION do_test () |
32 | #include "../test-skeleton.c" |
33 | |
34 | #define get_handles_fdopen(filename, fd, fp, fd_mode, mode) \ |
35 | ({ \ |
36 | int ret = 0; \ |
37 | (fd) = open ((filename), (fd_mode), 0); \ |
38 | if ((fd) == -1) \ |
39 | { \ |
40 | printf ("open failed: %m\n"); \ |
41 | ret = 1; \ |
42 | } \ |
43 | else \ |
44 | { \ |
45 | (fp) = fdopen ((fd), (mode)); \ |
46 | if ((fp) == NULL) \ |
47 | { \ |
48 | printf ("fdopen failed: %m\n"); \ |
49 | close (fd); \ |
50 | ret = 1; \ |
51 | } \ |
52 | } \ |
53 | ret; \ |
54 | }) |
55 | |
56 | #define get_handles_fopen(filename, fd, fp, mode) \ |
57 | ({ \ |
58 | int ret = 0; \ |
59 | (fp) = fopen ((filename), (mode)); \ |
60 | if ((fp) == NULL) \ |
61 | { \ |
62 | printf ("fopen failed: %m\n"); \ |
63 | ret = 1; \ |
64 | } \ |
65 | else \ |
66 | { \ |
67 | (fd) = fileno (fp); \ |
68 | if ((fd) == -1) \ |
69 | { \ |
70 | printf ("fileno failed: %m\n"); \ |
71 | ret = 1; \ |
72 | } \ |
73 | } \ |
74 | ret; \ |
75 | }) |
76 | |
77 | /* data points to either char_data or wide_data, depending on whether we're |
78 | testing regular file mode or wide mode respectively. Similarly, |
79 | fputs_func points to either fputs or fputws. data_len keeps track of the |
80 | length of the current data and file_len maintains the current file |
81 | length. */ |
82 | static const void *data; |
83 | static const char *char_data = "abcdef" ; |
84 | static const wchar_t *wide_data = L"abcdef" ; |
85 | static size_t data_len; |
86 | static size_t file_len; |
87 | |
88 | typedef int (*fputs_func_t) (const void *data, FILE *fp); |
89 | typedef void *(*fgets_func_t) (void *ws, int n, FILE *fp); |
90 | fputs_func_t fputs_func; |
91 | fgets_func_t fgets_func; |
92 | |
93 | /* This test verifies that the offset reported by ftell is correct after the |
94 | file is truncated using ftruncate. ftruncate does not change the file |
95 | offset on truncation and hence, SEEK_CUR should continue to point to the |
96 | old offset and not be changed to the new offset. */ |
97 | static int |
98 | do_ftruncate_test (const char *filename) |
99 | { |
100 | FILE *fp = NULL; |
101 | int fd; |
102 | int ret = 0; |
103 | struct test |
104 | { |
105 | const char *mode; |
106 | int fd_mode; |
107 | } test_modes[] = { |
108 | {"r+" , O_RDWR}, |
109 | {"w" , O_WRONLY | O_TRUNC}, |
110 | {"w+" , O_RDWR | O_TRUNC}, |
111 | {"a" , O_WRONLY}, |
112 | {"a+" , O_RDWR} |
113 | }; |
114 | |
115 | for (int j = 0; j < 2; j++) |
116 | { |
117 | for (int i = 0; i < sizeof (test_modes) / sizeof (struct test); i++) |
118 | { |
119 | int fileret; |
120 | printf (format: "\tftruncate: %s (file, \"%s\"): " , |
121 | j == 0 ? "fopen" : "fdopen" , |
122 | test_modes[i].mode); |
123 | |
124 | if (j == 0) |
125 | fileret = get_handles_fopen (filename, fd, fp, test_modes[i].mode); |
126 | else |
127 | fileret = get_handles_fdopen (filename, fd, fp, |
128 | test_modes[i].fd_mode, |
129 | test_modes[i].mode); |
130 | |
131 | if (fileret != 0) |
132 | return fileret; |
133 | |
134 | /* Write some data. */ |
135 | size_t written = fputs_func (data, fp); |
136 | |
137 | if (written == EOF) |
138 | { |
139 | printf (format: "fputs[1] failed to write data\n" ); |
140 | ret |= 1; |
141 | } |
142 | |
143 | /* Record the offset. */ |
144 | long offset = ftell (stream: fp); |
145 | |
146 | /* Flush data to allow switching active handles. */ |
147 | if (fflush (fp)) |
148 | { |
149 | printf (format: "Flush failed: %m\n" ); |
150 | ret |= 1; |
151 | } |
152 | |
153 | /* Now truncate the file. */ |
154 | if (ftruncate (fd: fd, length: 0) != 0) |
155 | { |
156 | printf (format: "Failed to truncate file: %m\n" ); |
157 | ret |= 1; |
158 | } |
159 | |
160 | /* ftruncate does not change the offset, so there is no need to call |
161 | anything to be able to switch active handles. */ |
162 | long new_offset = ftell (stream: fp); |
163 | |
164 | /* The offset should remain unchanged since ftruncate does not update |
165 | it. */ |
166 | if (offset != new_offset) |
167 | { |
168 | printf (format: "Incorrect offset. Expected %ld, but got %ld\n" , |
169 | offset, new_offset); |
170 | |
171 | ret |= 1; |
172 | } |
173 | else |
174 | printf (format: "offset = %ld\n" , offset); |
175 | |
176 | fclose (fp); |
177 | } |
178 | } |
179 | |
180 | return ret; |
181 | } |
182 | /* Test that ftell output after a rewind is correct. */ |
183 | static int |
184 | do_rewind_test (const char *filename) |
185 | { |
186 | int ret = 0; |
187 | struct test |
188 | { |
189 | const char *mode; |
190 | int fd_mode; |
191 | size_t old_off; |
192 | size_t new_off; |
193 | } test_modes[] = { |
194 | {"w" , O_WRONLY | O_TRUNC, 0, data_len}, |
195 | {"w+" , O_RDWR | O_TRUNC, 0, data_len}, |
196 | {"r+" , O_RDWR, 0, data_len}, |
197 | /* The new offsets for 'a' and 'a+' modes have to factor in the |
198 | previous writes since they always append to the end of the |
199 | file. */ |
200 | {"a" , O_WRONLY, 0, 3 * data_len}, |
201 | {"a+" , O_RDWR, 0, 4 * data_len}, |
202 | }; |
203 | |
204 | /* Empty the file before the test so that our offsets are simple to |
205 | calculate. */ |
206 | FILE *fp = fopen (filename, "w" ); |
207 | if (fp == NULL) |
208 | { |
209 | printf (format: "Failed to open file for emptying\n" ); |
210 | return 1; |
211 | } |
212 | fclose (fp); |
213 | |
214 | for (int j = 0; j < 2; j++) |
215 | { |
216 | for (int i = 0; i < sizeof (test_modes) / sizeof (struct test); i++) |
217 | { |
218 | FILE *fp; |
219 | int fd; |
220 | int fileret; |
221 | |
222 | printf (format: "\trewind: %s (file, \"%s\"): " , j == 0 ? "fdopen" : "fopen" , |
223 | test_modes[i].mode); |
224 | |
225 | if (j == 0) |
226 | fileret = get_handles_fdopen (filename, fd, fp, |
227 | test_modes[i].fd_mode, |
228 | test_modes[i].mode); |
229 | else |
230 | fileret = get_handles_fopen (filename, fd, fp, test_modes[i].mode); |
231 | |
232 | if (fileret != 0) |
233 | return fileret; |
234 | |
235 | /* Write some content to the file, rewind and ensure that the ftell |
236 | output after the rewind is 0. POSIX does not specify what the |
237 | behavior is when a file is rewound in 'a' mode, so we retain |
238 | current behavior, which is to keep the 0 offset. */ |
239 | size_t written = fputs_func (data, fp); |
240 | |
241 | if (written == EOF) |
242 | { |
243 | printf (format: "fputs[1] failed to write data\n" ); |
244 | ret |= 1; |
245 | } |
246 | |
247 | rewind (fp); |
248 | long offset = ftell (stream: fp); |
249 | |
250 | if (offset != test_modes[i].old_off) |
251 | { |
252 | printf (format: "Incorrect old offset. Expected %zu, but got %ld, " , |
253 | test_modes[i].old_off, offset); |
254 | ret |= 1; |
255 | } |
256 | else |
257 | printf (format: "old offset = %ld, " , offset); |
258 | |
259 | written = fputs_func (data, fp); |
260 | |
261 | if (written == EOF) |
262 | { |
263 | printf (format: "fputs[1] failed to write data\n" ); |
264 | ret |= 1; |
265 | } |
266 | |
267 | /* After this write, the offset in append modes should factor in the |
268 | implicit lseek to the end of file. */ |
269 | offset = ftell (stream: fp); |
270 | if (offset != test_modes[i].new_off) |
271 | { |
272 | printf (format: "Incorrect new offset. Expected %zu, but got %ld\n" , |
273 | test_modes[i].new_off, offset); |
274 | ret |= 1; |
275 | } |
276 | else |
277 | printf (format: "new offset = %ld\n" , offset); |
278 | } |
279 | } |
280 | return ret; |
281 | } |
282 | |
283 | /* Test that the value of ftell is not cached when the stream handle is not |
284 | active. */ |
285 | static int |
286 | do_ftell_test (const char *filename) |
287 | { |
288 | int ret = 0; |
289 | struct test |
290 | { |
291 | const char *mode; |
292 | int fd_mode; |
293 | size_t old_off; |
294 | size_t new_off; |
295 | size_t eof_off; |
296 | } test_modes[] = { |
297 | /* In w, w+ and r+ modes, the file position should be at the |
298 | beginning of the file. After the write, the offset should be |
299 | updated to data_len. We don't use eof_off in w and a modes since |
300 | they don't allow reading. */ |
301 | {"w" , O_WRONLY | O_TRUNC, 0, data_len, 0}, |
302 | {"w+" , O_RDWR | O_TRUNC, 0, data_len, 2 * data_len}, |
303 | {"r+" , O_RDWR, 0, data_len, 3 * data_len}, |
304 | /* For the 'a' mode, the initial file position should be the |
305 | current end of file. After the write, the offset has data_len |
306 | added to the old value. For a+ mode however, the initial file |
307 | position is the file position of the underlying file descriptor, |
308 | since it is initially assumed to be in read mode. */ |
309 | {"a" , O_WRONLY, 3 * data_len, 4 * data_len, 5 * data_len}, |
310 | {"a+" , O_RDWR, 0, 5 * data_len, 6 * data_len}, |
311 | }; |
312 | for (int j = 0; j < 2; j++) |
313 | { |
314 | for (int i = 0; i < sizeof (test_modes) / sizeof (struct test); i++) |
315 | { |
316 | FILE *fp; |
317 | int fd; |
318 | int fileret; |
319 | |
320 | printf (format: "\tftell: %s (file, \"%s\"): " , j == 0 ? "fdopen" : "fopen" , |
321 | test_modes[i].mode); |
322 | |
323 | if (j == 0) |
324 | fileret = get_handles_fdopen (filename, fd, fp, |
325 | test_modes[i].fd_mode, |
326 | test_modes[i].mode); |
327 | else |
328 | fileret = get_handles_fopen (filename, fd, fp, test_modes[i].mode); |
329 | |
330 | if (fileret != 0) |
331 | return fileret; |
332 | |
333 | long off = ftell (stream: fp); |
334 | if (off != test_modes[i].old_off) |
335 | { |
336 | printf (format: "Incorrect old offset. Expected %zu but got %ld, " , |
337 | test_modes[i].old_off, off); |
338 | ret |= 1; |
339 | } |
340 | else |
341 | printf (format: "old offset = %ld, " , off); |
342 | |
343 | /* The effect of this write on the offset should be seen in the ftell |
344 | call that follows it. */ |
345 | int write_ret = write (fd, data, data_len); |
346 | if (write_ret != data_len) |
347 | { |
348 | printf (format: "write failed (%m)\n" ); |
349 | ret |= 1; |
350 | } |
351 | off = ftell (stream: fp); |
352 | |
353 | if (off != test_modes[i].new_off) |
354 | { |
355 | printf (format: "Incorrect new offset. Expected %zu but got %ld" , |
356 | test_modes[i].new_off, off); |
357 | ret |= 1; |
358 | } |
359 | else |
360 | printf (format: "new offset = %ld" , off); |
361 | |
362 | /* Read to the end, write some data to the fd and check if ftell can |
363 | see the new ofset. Do this test only for files that allow |
364 | reading. */ |
365 | if (test_modes[i].fd_mode != O_WRONLY) |
366 | { |
367 | wchar_t tmpbuf[data_len]; |
368 | |
369 | rewind (fp); |
370 | |
371 | while (fgets_func (tmpbuf, data_len, fp) && !feof (stream: fp)); |
372 | |
373 | write_ret = write (fd, data, data_len); |
374 | if (write_ret != data_len) |
375 | { |
376 | printf (format: "write failed (%m)\n" ); |
377 | ret |= 1; |
378 | } |
379 | off = ftell (stream: fp); |
380 | |
381 | if (off != test_modes[i].eof_off) |
382 | { |
383 | printf (format: ", Incorrect offset after read EOF. " |
384 | "Expected %zu but got %ld\n" , |
385 | test_modes[i].eof_off, off); |
386 | ret |= 1; |
387 | } |
388 | else |
389 | printf (format: ", offset after EOF = %ld\n" , off); |
390 | } |
391 | else |
392 | putc (c: '\n', stdout); |
393 | |
394 | fclose (fp); |
395 | } |
396 | } |
397 | |
398 | return ret; |
399 | } |
400 | |
401 | /* This test opens the file for writing, moves the file offset of the |
402 | underlying file, writes out data and then checks if ftell trips on it. */ |
403 | static int |
404 | do_write_test (const char *filename) |
405 | { |
406 | FILE *fp = NULL; |
407 | int fd; |
408 | int ret = 0; |
409 | struct test |
410 | { |
411 | const char *mode; |
412 | int fd_mode; |
413 | } test_modes[] = { |
414 | {"w" , O_WRONLY | O_TRUNC}, |
415 | {"w+" , O_RDWR | O_TRUNC}, |
416 | {"r+" , O_RDWR} |
417 | }; |
418 | |
419 | for (int j = 0; j < 2; j++) |
420 | { |
421 | for (int i = 0; i < sizeof (test_modes) / sizeof (struct test); i++) |
422 | { |
423 | int fileret; |
424 | printf (format: "\twrite: %s (file, \"%s\"): " , j == 0 ? "fopen" : "fdopen" , |
425 | test_modes[i].mode); |
426 | |
427 | if (j == 0) |
428 | fileret = get_handles_fopen (filename, fd, fp, test_modes[i].mode); |
429 | else |
430 | fileret = get_handles_fdopen (filename, fd, fp, |
431 | test_modes[i].fd_mode, |
432 | test_modes[i].mode); |
433 | |
434 | if (fileret != 0) |
435 | return fileret; |
436 | |
437 | /* Move offset to just before the end of the file. */ |
438 | off_t seek_ret = lseek (fd: fd, offset: file_len - 1, SEEK_SET); |
439 | if (seek_ret == -1) |
440 | { |
441 | printf (format: "lseek failed: %m\n" ); |
442 | ret |= 1; |
443 | } |
444 | |
445 | /* Write some data. */ |
446 | size_t written = fputs_func (data, fp); |
447 | |
448 | if (written == EOF) |
449 | { |
450 | printf (format: "fputs[1] failed to write data\n" ); |
451 | ret |= 1; |
452 | } |
453 | |
454 | /* Verify that the offset points to the end of the file. The length |
455 | of the file would be the original length + the length of data |
456 | written to it - the amount by which we moved the offset using |
457 | lseek. */ |
458 | long offset = ftell (stream: fp); |
459 | file_len = file_len - 1 + data_len; |
460 | |
461 | if (offset != file_len) |
462 | { |
463 | printf (format: "Incorrect offset. Expected %zu, but got %ld\n" , |
464 | file_len, offset); |
465 | |
466 | ret |= 1; |
467 | } |
468 | |
469 | printf (format: "offset = %ld\n" , offset); |
470 | fclose (fp); |
471 | } |
472 | } |
473 | |
474 | return ret; |
475 | } |
476 | |
477 | /* This test opens a file in append mode, writes some data, and then verifies |
478 | that ftell does not trip over it. */ |
479 | static int |
480 | do_append_test (const char *filename) |
481 | { |
482 | FILE *fp = NULL; |
483 | int ret = 0; |
484 | int fd; |
485 | |
486 | struct test |
487 | { |
488 | const char *mode; |
489 | int fd_mode; |
490 | } test_modes[] = { |
491 | {"a" , O_WRONLY}, |
492 | {"a+" , O_RDWR} |
493 | }; |
494 | |
495 | for (int j = 0; j < 2; j++) |
496 | { |
497 | for (int i = 0; i < sizeof (test_modes) / sizeof (struct test); i++) |
498 | { |
499 | int fileret; |
500 | |
501 | printf (format: "\tappend: %s (file, \"%s\"): " , j == 0 ? "fopen" : "fdopen" , |
502 | test_modes[i].mode); |
503 | |
504 | if (j == 0) |
505 | fileret = get_handles_fopen (filename, fd, fp, test_modes[i].mode); |
506 | else |
507 | fileret = get_handles_fdopen (filename, fd, fp, |
508 | test_modes[i].fd_mode, |
509 | test_modes[i].mode); |
510 | |
511 | if (fileret != 0) |
512 | return fileret; |
513 | |
514 | /* Write some data. */ |
515 | size_t written = fputs_func (data, fp); |
516 | |
517 | if (written == EOF) |
518 | { |
519 | printf (format: "fputs[1] failed to write all data\n" ); |
520 | ret |= 1; |
521 | } |
522 | |
523 | /* Verify that the offset points to the end of the file. The file |
524 | len is maintained by adding data_len each time to reflect the data |
525 | written to it. */ |
526 | long offset = ftell (stream: fp); |
527 | file_len += data_len; |
528 | |
529 | if (offset != file_len) |
530 | { |
531 | printf (format: "Incorrect offset. Expected %zu, but got %ld\n" , |
532 | file_len, offset); |
533 | |
534 | ret |= 1; |
535 | } |
536 | |
537 | printf (format: "offset = %ld\n" , offset); |
538 | fclose (fp); |
539 | } |
540 | } |
541 | |
542 | /* For fdopen in 'a' mode, the file descriptor should not change if the file |
543 | is already open with the O_APPEND flag set. */ |
544 | fd = open (file: filename, O_WRONLY | O_APPEND, 0); |
545 | if (fd == -1) |
546 | { |
547 | printf (format: "open(O_APPEND) failed: %m\n" ); |
548 | return 1; |
549 | } |
550 | |
551 | off_t seek_ret = lseek (fd: fd, offset: file_len - 1, SEEK_SET); |
552 | if (seek_ret == -1) |
553 | { |
554 | printf (format: "lseek[O_APPEND][0] failed: %m\n" ); |
555 | ret |= 1; |
556 | } |
557 | |
558 | fp = fdopen (fd, "a" ); |
559 | if (fp == NULL) |
560 | { |
561 | printf (format: "fdopen(O_APPEND) failed: %m\n" ); |
562 | close (fd: fd); |
563 | return 1; |
564 | } |
565 | |
566 | off_t new_seek_ret = lseek (fd: fd, offset: 0, SEEK_CUR); |
567 | if (seek_ret == -1) |
568 | { |
569 | printf (format: "lseek[O_APPEND][1] failed: %m\n" ); |
570 | ret |= 1; |
571 | } |
572 | |
573 | printf (format: "\tappend: fdopen (file, \"a\"): O_APPEND: " ); |
574 | |
575 | if (seek_ret != new_seek_ret) |
576 | { |
577 | printf (format: "incorrectly modified file offset to %jd, should be %jd" , |
578 | (intmax_t) new_seek_ret, (intmax_t) seek_ret); |
579 | ret |= 1; |
580 | } |
581 | else |
582 | printf (format: "retained current file offset %jd" , (intmax_t) seek_ret); |
583 | |
584 | new_seek_ret = ftello (stream: fp); |
585 | |
586 | if (seek_ret != new_seek_ret) |
587 | { |
588 | printf (format: ", ftello reported incorrect offset %jd, should be %jd\n" , |
589 | (intmax_t) new_seek_ret, (intmax_t) seek_ret); |
590 | ret |= 1; |
591 | } |
592 | else |
593 | printf (format: ", ftello reported correct offset %jd\n" , (intmax_t) seek_ret); |
594 | |
595 | fclose (fp); |
596 | |
597 | return ret; |
598 | } |
599 | |
600 | static int |
601 | do_one_test (const char *filename) |
602 | { |
603 | int ret = 0; |
604 | |
605 | ret |= do_ftell_test (filename); |
606 | ret |= do_write_test (filename); |
607 | ret |= do_append_test (filename); |
608 | ret |= do_rewind_test (filename); |
609 | ret |= do_ftruncate_test (filename); |
610 | |
611 | return ret; |
612 | } |
613 | |
614 | /* Run a set of tests for ftell for regular files and wide mode files. */ |
615 | static int |
616 | do_test (void) |
617 | { |
618 | int ret = 0; |
619 | FILE *fp = NULL; |
620 | char *filename; |
621 | size_t written; |
622 | int fd = create_temp_file (base: "tst-active-handler-tmp." , filename: &filename); |
623 | |
624 | if (fd == -1) |
625 | { |
626 | printf (format: "create_temp_file: %m\n" ); |
627 | return 1; |
628 | } |
629 | |
630 | fp = fdopen (fd, "w" ); |
631 | if (fp == NULL) |
632 | { |
633 | printf (format: "fdopen[0]: %m\n" ); |
634 | close (fd: fd); |
635 | return 1; |
636 | } |
637 | |
638 | data = char_data; |
639 | data_len = strlen (char_data); |
640 | file_len = strlen (char_data); |
641 | written = fputs (data, fp); |
642 | |
643 | if (written == EOF) |
644 | { |
645 | printf (format: "fputs[1] failed to write data\n" ); |
646 | ret = 1; |
647 | } |
648 | |
649 | fclose (fp); |
650 | if (ret) |
651 | return ret; |
652 | |
653 | /* Tests for regular files. */ |
654 | puts (s: "Regular mode:" ); |
655 | fputs_func = (fputs_func_t) fputs; |
656 | fgets_func = (fgets_func_t) fgets; |
657 | data = char_data; |
658 | data_len = strlen (char_data); |
659 | ret |= do_one_test (filename); |
660 | |
661 | /* Truncate the file before repeating the tests in wide mode. */ |
662 | fp = fopen (filename, "w" ); |
663 | if (fp == NULL) |
664 | { |
665 | printf (format: "fopen failed %m\n" ); |
666 | return 1; |
667 | } |
668 | fclose (fp); |
669 | |
670 | /* Tests for wide files. */ |
671 | puts (s: "Wide mode:" ); |
672 | if (setlocale (LC_ALL, "en_US.UTF-8" ) == NULL) |
673 | { |
674 | printf (format: "Cannot set en_US.UTF-8 locale.\n" ); |
675 | return 1; |
676 | } |
677 | fputs_func = (fputs_func_t) fputws; |
678 | fgets_func = (fgets_func_t) fgetws; |
679 | data = wide_data; |
680 | data_len = wcslen (s: wide_data); |
681 | ret |= do_one_test (filename); |
682 | |
683 | return ret; |
684 | } |
685 | |