Line Flow Count Block(s) Source
1 - /*
2 - * Copyright (C) the libgit2 contributors. All rights reserved.
3 - *
4 - * This file is part of libgit2, distributed under the GNU GPL v2 with
5 - * a Linking Exception. For full terms see the included COPYING file.
6 - */
7 -
8 - #include "filebuf.h"
9 -
10 - #include "futils.h"
11 -
12 - static const size_t WRITE_BUFFER_SIZE = (4096 * 2);
13 -
14 - enum buferr_t {
15 - BUFERR_OK = 0,
16 - BUFERR_WRITE,
17 - BUFERR_ZLIB,
18 - BUFERR_MEM
19 - };
20 -
21 - #define ENSURE_BUF_OK(buf) if ((buf)->last_error != BUFERR_OK) { return -1; }
22 -
23 12583 2 static int verify_last_error(git_filebuf *file)
24 - {
25 12583 2 switch (file->last_error) {
26 - case BUFERR_WRITE:
27 ##### 3 git_error_set(GIT_ERROR_OS, "failed to write out file");
28 ##### 4 return -1;
29 -
30 - case BUFERR_MEM:
31 ##### 5 git_error_set_oom();
32 ##### 6 return -1;
33 -
34 - case BUFERR_ZLIB:
35 ##### 7 git_error_set(GIT_ERROR_ZLIB,
36 - "Buffer error when writing out ZLib data");
37 ##### 8 return -1;
38 -
39 - default:
40 12583 9 return 0;
41 - }
42 - }
43 -
44 10356 2 static int lock_file(git_filebuf *file, int flags, mode_t mode)
45 - {
46 10356 2,3 if (git_path_exists(file->path_lock) == true) {
47 30 4 git_error_clear(); /* actual OS error code just confuses */
48 30 5 git_error_set(GIT_ERROR_OS,
49 - "failed to lock file '%s' for writing", file->path_lock);
50 30 6 return GIT_ELOCKED;
51 - }
52 -
53 - /* create path to the file buffer is required */
54 10326 7 if (flags & GIT_FILEBUF_CREATE_LEADING_DIRS) {
55 - /* XXX: Should dirmode here be configurable? Or is 0777 always fine? */
56 3495 8,9 file->fd = git_futils_creat_locked_withpath(file->path_lock, 0777, mode);
57 - } else {
58 6832 10,11 file->fd = git_futils_creat_locked(file->path_lock, mode);
59 - }
60 -
61 10326 12 if (file->fd < 0)
62 3 13 return file->fd;
63 -
64 10323 14 file->fd_is_open = true;
65 -
66 10323 14-16 if ((flags & GIT_FILEBUF_APPEND) && git_path_exists(file->path_original) == true) {
67 - git_file source;
68 - char buffer[FILEIO_BUFSIZE];
69 - ssize_t read_bytes;
70 151 17 int error = 0;
71 -
72 151 17 source = p_open(file->path_original, O_RDONLY);
73 151 18 if (source < 0) {
74 ##### 19 git_error_set(GIT_ERROR_OS,
75 - "failed to open file '%s' for reading",
76 - file->path_original);
77 ##### 20,37 return -1;
78 - }
79 -
80 230 21,27,28 while ((read_bytes = p_read(source, buffer, sizeof(buffer))) > 0) {
81 79 22,23 if ((error = p_write(file->fd, buffer, read_bytes)) < 0)
82 ##### 24 break;
83 79 25 if (file->compute_digest)
84 ##### 26 git_hash_update(&file->digest, buffer, read_bytes);
85 - }
86 -
87 151 29 p_close(source);
88 -
89 151 30 if (read_bytes < 0) {
90 ##### 31 git_error_set(GIT_ERROR_OS, "failed to read file '%s'", file->path_original);
91 ##### 32 return -1;
92 151 33 } else if (error < 0) {
93 ##### 34 git_error_set(GIT_ERROR_OS, "failed to write file '%s'", file->path_lock);
94 151 35,36 return -1;
95 - }
96 - }
97 -
98 10323 38 return 0;
99 - }
100 -
101 21314 2 void git_filebuf_cleanup(git_filebuf *file)
102 - {
103 21314 2,3 if (file->fd_is_open && file->fd >= 0)
104 2904 4 p_close(file->fd);
105 -
106 21314 5-9 if (file->created_lock && !file->did_rename && file->path_lock && git_path_exists(file->path_lock))
107 2904 10 p_unlink(file->path_lock);
108 -
109 21314 11 if (file->compute_digest) {
110 4721 12 git_hash_ctx_cleanup(&file->digest);
111 4721 13 file->compute_digest = 0;
112 - }
113 -
114 21314 14 if (file->buffer)
115 14032 15 git__free(file->buffer);
116 -
117 - /* use the presence of z_buf to decide if we need to deflateEnd */
118 21314 16 if (file->z_buf) {
119 3779 17 git__free(file->z_buf);
120 3779 18 deflateEnd(&file->zs);
121 - }
122 -
123 21314 19 if (file->path_original)
124 12004 20 git__free(file->path_original);
125 21314 21 if (file->path_lock)
126 14144 22 git__free(file->path_lock);
127 -
128 21314 23 memset(file, 0x0, sizeof(git_filebuf));
129 21314 23 file->fd = -1;
130 21314 23 }
131 -
132 19138 2 GIT_INLINE(int) flush_buffer(git_filebuf *file)
133 - {
134 19138 2 int result = file->write(file, file->buffer, file->buf_pos);
135 19138 3 file->buf_pos = 0;
136 19138 3 return result;
137 - }
138 -
139 4 2 int git_filebuf_flush(git_filebuf *file)
140 - {
141 4 2 return flush_buffer(file);
142 - }
143 -
144 11198 2 static int write_normal(git_filebuf *file, void *source, size_t len)
145 - {
146 11198 2 if (len > 0) {
147 11080 3,4 if (p_write(file->fd, (void *)source, len) < 0) {
148 ##### 5 file->last_error = BUFERR_WRITE;
149 ##### 5 return -1;
150 - }
151 -
152 11080 6 if (file->compute_digest)
153 6181 7 git_hash_update(&file->digest, source, len);
154 - }
155 -
156 11198 8 return 0;
157 - }
158 -
159 8053 2 static int write_deflate(git_filebuf *file, void *source, size_t len)
160 - {
161 8053 2 z_stream *zs = &file->zs;
162 -
163 8053 2,3 if (len > 0 || file->flush_mode == Z_FINISH) {
164 8053 4 zs->next_in = source;
165 8053 4 zs->avail_in = (uInt)len;
166 -
167 - do {
168 - size_t have;
169 -
170 8077 5 zs->next_out = file->z_buf;
171 8077 5 zs->avail_out = (uInt)file->buf_size;
172 -
173 8077 5,6 if (deflate(zs, file->flush_mode) == Z_STREAM_ERROR) {
174 ##### 7 file->last_error = BUFERR_ZLIB;
175 ##### 7 return -1;
176 - }
177 -
178 8077 8 have = file->buf_size - (size_t)zs->avail_out;
179 -
180 8077 8,9 if (p_write(file->fd, file->z_buf, have) < 0) {
181 ##### 10 file->last_error = BUFERR_WRITE;
182 ##### 10 return -1;
183 - }
184 -
185 8077 11 } while (zs->avail_out == 0);
186 -
187 8053 12,13 assert(zs->avail_in == 0);
188 -
189 8053 14 if (file->compute_digest)
190 ##### 15 git_hash_update(&file->digest, source, len);
191 - }
192 -
193 8053 16 return 0;
194 - }
195 -
196 - #define MAX_SYMLINK_DEPTH 5
197 -
198 10362 2 static int resolve_symlink(git_buf *out, const char *path)
199 - {
200 - int i, error, root;
201 - ssize_t ret;
202 - struct stat st;
203 10362 2 git_buf curpath = GIT_BUF_INIT, target = GIT_BUF_INIT;
204 -
205 10362 2-5 if ((error = git_buf_grow(&target, GIT_PATH_MAX + 1)) < 0 ||
206 - (error = git_buf_puts(&curpath, path)) < 0)
207 ##### 6 return error;
208 -
209 10370 7,42,43 for (i = 0; i < MAX_SYMLINK_DEPTH; i++) {
210 10369 8 error = p_lstat(curpath.ptr, &st);
211 10369 9-11 if (error < 0 && errno == ENOENT) {
212 3041 12 error = git_buf_puts(out, curpath.ptr);
213 3041 13 goto cleanup;
214 - }
215 -
216 7328 14 if (error < 0) {
217 ##### 15 git_error_set(GIT_ERROR_OS, "failed to stat '%s'", curpath.ptr);
218 ##### 16 error = -1;
219 ##### 16 goto cleanup;
220 - }
221 -
222 7328 17 if (!S_ISLNK(st.st_mode)) {
223 7320 18 error = git_buf_puts(out, curpath.ptr);
224 7320 19 goto cleanup;
225 - }
226 -
227 8 20 ret = p_readlink(curpath.ptr, target.ptr, GIT_PATH_MAX);
228 8 21 if (ret < 0) {
229 ##### 22 git_error_set(GIT_ERROR_OS, "failed to read symlink '%s'", curpath.ptr);
230 ##### 23 error = -1;
231 ##### 23 goto cleanup;
232 - }
233 -
234 8 24 if (ret == GIT_PATH_MAX) {
235 ##### 25 git_error_set(GIT_ERROR_INVALID, "symlink target too long");
236 ##### 26 error = -1;
237 ##### 26 goto cleanup;
238 - }
239 -
240 - /* readlink(2) won't NUL-terminate for us */
241 8 27 target.ptr[ret] = '\0';
242 8 27 target.size = ret;
243 -
244 8 27 root = git_path_root(target.ptr);
245 8 28 if (root >= 0) {
246 1 29,30 if ((error = git_buf_sets(&curpath, target.ptr)) < 0)
247 ##### 31 goto cleanup;
248 - } else {
249 7 32 git_buf dir = GIT_BUF_INIT;
250 -
251 7 32,33 if ((error = git_path_dirname_r(&dir, curpath.ptr)) < 0)
252 ##### 34,41 goto cleanup;
253 -
254 7 35 git_buf_swap(&curpath, &dir);
255 7 36 git_buf_dispose(&dir);
256 -
257 7 37,38 if ((error = git_path_apply_relative(&curpath, target.ptr)) < 0)
258 7 39,40 goto cleanup;
259 - }
260 - }
261 -
262 1 44 git_error_set(GIT_ERROR_INVALID, "maximum symlink depth reached");
263 1 45 error = -1;
264 -
265 - cleanup:
266 10362 46 git_buf_dispose(&curpath);
267 10362 47 git_buf_dispose(&target);
268 10362 48 return error;
269 - }
270 -
271 14141 2 int git_filebuf_open(git_filebuf *file, const char *path, int flags, mode_t mode)
272 - {
273 14141 2 return git_filebuf_open_withsize(file, path, flags, mode, WRITE_BUFFER_SIZE);
274 - }
275 -
276 14145 2 int git_filebuf_open_withsize(git_filebuf *file, const char *path, int flags, mode_t mode, size_t size)
277 - {
278 14145 2 int compression, error = -1;
279 - size_t path_len, alloc_len;
280 -
281 - /* opening an already open buffer is a programming error;
282 - * assert that this never happens instead of returning
283 - * an error code */
284 14145 2-5 assert(file && path && file->buffer == NULL);
285 -
286 14145 6 memset(file, 0x0, sizeof(git_filebuf));
287 -
288 14145 6 if (flags & GIT_FILEBUF_DO_NOT_BUFFER)
289 113 7 file->do_not_buffer = true;
290 -
291 14145 8 if (flags & GIT_FILEBUF_FSYNC)
292 43 9 file->do_fsync = true;
293 -
294 14145 10 file->buf_size = size;
295 14145 10 file->buf_pos = 0;
296 14145 10 file->fd = -1;
297 14145 10 file->last_error = BUFERR_OK;
298 -
299 - /* Allocate the main cache buffer */
300 14145 10 if (!file->do_not_buffer) {
301 14032 11 file->buffer = git__malloc(file->buf_size);
302 14032 12,13 GIT_ERROR_CHECK_ALLOC(file->buffer);
303 - }
304 -
305 - /* If we are hashing on-write, allocate a new hash context */
306 14145 14 if (flags & GIT_FILEBUF_HASH_CONTENTS) {
307 6102 15 file->compute_digest = 1;
308 -
309 6102 15,16 if (git_hash_ctx_init(&file->digest) < 0)
310 ##### 17 goto cleanup;
311 - }
312 -
313 14145 18 compression = flags >> GIT_FILEBUF_DEFLATE_SHIFT;
314 -
315 - /* If we are deflating on-write, */
316 14145 18 if (compression != 0) {
317 - /* Initialize the ZLib stream */
318 3779 19,20 if (deflateInit(&file->zs, compression) != Z_OK) {
319 ##### 21 git_error_set(GIT_ERROR_ZLIB, "failed to initialize zlib");
320 ##### 61 goto cleanup;
321 - }
322 -
323 - /* Allocate the Zlib cache buffer */
324 3779 22 file->z_buf = git__malloc(file->buf_size);
325 3779 23,24 GIT_ERROR_CHECK_ALLOC(file->z_buf);
326 -
327 - /* Never flush */
328 3779 25 file->flush_mode = Z_NO_FLUSH;
329 3779 25 file->write = &write_deflate;
330 - } else {
331 10366 26 file->write = &write_normal;
332 - }
333 -
334 - /* If we are writing to a temp file */
335 14145 27 if (flags & GIT_FILEBUF_TEMPORARY) {
336 3783 28 git_buf tmp_path = GIT_BUF_INIT;
337 -
338 - /* Open the file as temporary for locking */
339 3783 28 file->fd = git_futils_mktmp(&tmp_path, path, mode);
340 -
341 3783 29 if (file->fd < 0) {
342 ##### 30 git_buf_dispose(&tmp_path);
343 ##### 31 goto cleanup;
344 - }
345 3783 32 file->fd_is_open = true;
346 3783 32 file->created_lock = true;
347 -
348 - /* No original path */
349 3783 32 file->path_original = NULL;
350 3783 32 file->path_lock = git_buf_detach(&tmp_path);
351 3783 33-35 GIT_ERROR_CHECK_ALLOC(file->path_lock);
352 - } else {
353 10362 36 git_buf resolved_path = GIT_BUF_INIT;
354 -
355 10362 36,37 if ((error = resolve_symlink(&resolved_path, path)) < 0)
356 39 38,58 goto cleanup;
357 -
358 - /* Save the original path of the file */
359 10361 39 path_len = resolved_path.size;
360 10361 39 file->path_original = git_buf_detach(&resolved_path);
361 -
362 - /* create the locking path by appending ".lock" to the original */
363 10361 40-46,59 GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, path_len, GIT_FILELOCK_EXTLENGTH);
364 10361 47 file->path_lock = git__malloc(alloc_len);
365 10361 48,49 GIT_ERROR_CHECK_ALLOC(file->path_lock);
366 -
367 10361 50 memcpy(file->path_lock, file->path_original, path_len);
368 10361 50 memcpy(file->path_lock + path_len, GIT_FILELOCK_EXTENSION, GIT_FILELOCK_EXTLENGTH);
369 -
370 10361 50,51 if (git_path_isdir(file->path_original)) {
371 5 52 git_error_set(GIT_ERROR_FILESYSTEM, "path '%s' is a directory", file->path_original);
372 5 53 error = GIT_EDIRECTORY;
373 5 53 goto cleanup;
374 - }
375 -
376 - /* open the file for locking */
377 10356 54,55 if ((error = lock_file(file, flags, mode)) < 0)
378 33 56 goto cleanup;
379 -
380 10323 57 file->created_lock = true;
381 - }
382 -
383 14106 60 return 0;
384 -
385 - cleanup:
386 39 62 git_filebuf_cleanup(file);
387 39 63 return error;
388 - }
389 -
390 1381 2 int git_filebuf_hash(git_oid *oid, git_filebuf *file)
391 - {
392 1381 2-5 assert(oid && file && file->compute_digest);
393 -
394 1381 6 flush_buffer(file);
395 -
396 1381 7,8 if (verify_last_error(file) < 0)
397 ##### 9 return -1;
398 -
399 1381 10 git_hash_final(oid, &file->digest);
400 1381 11 git_hash_ctx_cleanup(&file->digest);
401 1381 12 file->compute_digest = 0;
402 -
403 1381 12 return 0;
404 - }
405 -
406 1733 2 int git_filebuf_commit_at(git_filebuf *file, const char *path)
407 - {
408 1733 2 git__free(file->path_original);
409 1733 3 file->path_original = git__strdup(path);
410 1733 4,5 GIT_ERROR_CHECK_ALLOC(file->path_original);
411 -
412 1733 6 return git_filebuf_commit(file);
413 - }
414 -
415 11202 2 int git_filebuf_commit(git_filebuf *file)
416 - {
417 - /* temporary files cannot be committed */
418 11202 2-4 assert(file && file->path_original);
419 -
420 11202 5 file->flush_mode = Z_FINISH;
421 11202 5 flush_buffer(file);
422 -
423 11202 6,7 if (verify_last_error(file) < 0)
424 ##### 8 goto on_error;
425 -
426 11202 9 file->fd_is_open = false;
427 -
428 11202 9-11 if (file->do_fsync && p_fsync(file->fd) < 0) {
429 ##### 12 git_error_set(GIT_ERROR_OS, "failed to fsync '%s'", file->path_lock);
430 ##### 27 goto on_error;
431 - }
432 -
433 11202 13,14 if (p_close(file->fd) < 0) {
434 ##### 15 git_error_set(GIT_ERROR_OS, "failed to close file at '%s'", file->path_lock);
435 ##### 16 goto on_error;
436 - }
437 -
438 11202 17 file->fd = -1;
439 -
440 11202 17,18 if (p_rename(file->path_lock, file->path_original) < 0) {
441 ##### 19 git_error_set(GIT_ERROR_OS, "failed to rename lockfile to '%s'", file->path_original);
442 ##### 20 goto on_error;
443 - }
444 -
445 11202 21-23 if (file->do_fsync && git_futils_fsync_parent(file->path_original) < 0)
446 ##### 24 goto on_error;
447 -
448 11202 25 file->did_rename = true;
449 -
450 11202 25 git_filebuf_cleanup(file);
451 11202 26 return 0;
452 -
453 - on_error:
454 ##### 28 git_filebuf_cleanup(file);
455 ##### 29 return -1;
456 - }
457 -
458 62305 2 GIT_INLINE(void) add_to_cache(git_filebuf *file, const void *buf, size_t len)
459 - {
460 62305 2 memcpy(file->buffer + file->buf_pos, buf, len);
461 62305 2 file->buf_pos += len;
462 62305 2 }
463 -
464 56004 2 int git_filebuf_write(git_filebuf *file, const void *buff, size_t len)
465 - {
466 56004 2 const unsigned char *buf = buff;
467 -
468 56004 2,3 ENSURE_BUF_OK(file);
469 -
470 56004 4 if (file->do_not_buffer)
471 113 5 return file->write(file, (void *)buff, len);
472 -
473 - for (;;) {
474 62305 6 size_t space_left = file->buf_size - file->buf_pos;
475 -
476 - /* cache if it's small */
477 62305 6 if (space_left > len) {
478 55891 7 add_to_cache(file, buf, len);
479 55891 8 return 0;
480 - }
481 -
482 6414 9 add_to_cache(file, buf, space_left);
483 6414 10,11 if (flush_buffer(file) < 0)
484 ##### 12 return -1;
485 -
486 6414 13 len -= space_left;
487 6414 13 buf += space_left;
488 6414 13 }
489 - }
490 -
491 22629 2 int git_filebuf_reserve(git_filebuf *file, void **buffer, size_t len)
492 - {
493 22629 2 size_t space_left = file->buf_size - file->buf_pos;
494 -
495 22629 2 *buffer = NULL;
496 -
497 22629 2,3 ENSURE_BUF_OK(file);
498 -
499 22629 4 if (len > file->buf_size) {
500 ##### 5 file->last_error = BUFERR_MEM;
501 ##### 5 return -1;
502 - }
503 -
504 22629 6 if (space_left <= len) {
505 137 7,8 if (flush_buffer(file) < 0)
506 ##### 9 return -1;
507 - }
508 -
509 22629 10 *buffer = (file->buffer + file->buf_pos);
510 22629 10 file->buf_pos += len;
511 -
512 22629 10 return 0;
513 - }
514 -
515 6326 2 int git_filebuf_printf(git_filebuf *file, const char *format, ...)
516 - {
517 - va_list arglist;
518 - size_t space_left, len, alloclen;
519 - int written, res;
520 - char *tmp_buffer;
521 -
522 6326 2,3 ENSURE_BUF_OK(file);
523 -
524 6326 4 space_left = file->buf_size - file->buf_pos;
525 -
526 - do {
527 6326 5 va_start(arglist, format);
528 6326 5 written = p_vsnprintf((char *)file->buffer + file->buf_pos, space_left, format, arglist);
529 6326 5 va_end(arglist);
530 -
531 6326 5 if (written < 0) {
532 ##### 6 file->last_error = BUFERR_MEM;
533 ##### 6 return -1;
534 - }
535 -
536 6326 7 len = written;
537 6326 7 if (len + 1 <= space_left) {
538 6326 8 file->buf_pos += len;
539 6326 8 return 0;
540 - }
541 -
542 ##### 9,10 if (flush_buffer(file) < 0)
543 ##### 11 return -1;
544 -
545 ##### 12 space_left = file->buf_size - file->buf_pos;
546 -
547 ##### 12 } while (len + 1 <= space_left);
548 -
549 ##### 13-17 if (GIT_ADD_SIZET_OVERFLOW(&alloclen, len, 1) ||
550 ##### 16 !(tmp_buffer = git__malloc(alloclen))) {
551 ##### 18 file->last_error = BUFERR_MEM;
552 ##### 18 return -1;
553 - }
554 -
555 ##### 19 va_start(arglist, format);
556 ##### 19 written = p_vsnprintf(tmp_buffer, len + 1, format, arglist);
557 ##### 19 va_end(arglist);
558 -
559 ##### 19 if (written < 0) {
560 ##### 20 git__free(tmp_buffer);
561 ##### 21 file->last_error = BUFERR_MEM;
562 ##### 21 return -1;
563 - }
564 -
565 ##### 22 res = git_filebuf_write(file, tmp_buffer, len);
566 ##### 23 git__free(tmp_buffer);
567 -
568 ##### 24 return res;
569 - }
570 -
571 ##### 2 int git_filebuf_stats(time_t *mtime, size_t *size, git_filebuf *file)
572 - {
573 - int res;
574 - struct stat st;
575 -
576 ##### 2 if (file->fd_is_open)
577 ##### 3 res = p_fstat(file->fd, &st);
578 - else
579 ##### 4 res = p_stat(file->path_original, &st);
580 -
581 ##### 5 if (res < 0) {
582 ##### 6 git_error_set(GIT_ERROR_OS, "could not get stat info for '%s'",
583 - file->path_original);
584 ##### 7 return res;
585 - }
586 -
587 ##### 8 if (mtime)
588 ##### 9 *mtime = st.st_mtime;
589 ##### 10 if (size)
590 ##### 11 *size = (size_t)st.st_size;
591 -
592 ##### 12 return 0;
593 - }