path: convert strbuf_git_common_path to take a 'struct repository'
[git/git.git] / path.c
1 /*
2 * Utilities for paths and pathnames
3 */
4 #include "cache.h"
5 #include "repository.h"
6 #include "strbuf.h"
7 #include "string-list.h"
8 #include "dir.h"
9 #include "worktree.h"
10 #include "submodule-config.h"
11 #include "path.h"
12
13 static int get_st_mode_bits(const char *path, int *mode)
14 {
15 struct stat st;
16 if (lstat(path, &st) < 0)
17 return -1;
18 *mode = st.st_mode;
19 return 0;
20 }
21
22 static char bad_path[] = "/bad-path/";
23
24 static struct strbuf *get_pathname(void)
25 {
26 static struct strbuf pathname_array[4] = {
27 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
28 };
29 static int index;
30 struct strbuf *sb = &pathname_array[index];
31 index = (index + 1) % ARRAY_SIZE(pathname_array);
32 strbuf_reset(sb);
33 return sb;
34 }
35
36 static char *cleanup_path(char *path)
37 {
38 /* Clean it up */
39 if (!memcmp(path, "./", 2)) {
40 path += 2;
41 while (*path == '/')
42 path++;
43 }
44 return path;
45 }
46
47 static void strbuf_cleanup_path(struct strbuf *sb)
48 {
49 char *path = cleanup_path(sb->buf);
50 if (path > sb->buf)
51 strbuf_remove(sb, 0, path - sb->buf);
52 }
53
54 char *mksnpath(char *buf, size_t n, const char *fmt, ...)
55 {
56 va_list args;
57 unsigned len;
58
59 va_start(args, fmt);
60 len = vsnprintf(buf, n, fmt, args);
61 va_end(args);
62 if (len >= n) {
63 strlcpy(buf, bad_path, n);
64 return buf;
65 }
66 return cleanup_path(buf);
67 }
68
69 static int dir_prefix(const char *buf, const char *dir)
70 {
71 int len = strlen(dir);
72 return !strncmp(buf, dir, len) &&
73 (is_dir_sep(buf[len]) || buf[len] == '\0');
74 }
75
76 /* $buf =~ m|$dir/+$file| but without regex */
77 static int is_dir_file(const char *buf, const char *dir, const char *file)
78 {
79 int len = strlen(dir);
80 if (strncmp(buf, dir, len) || !is_dir_sep(buf[len]))
81 return 0;
82 while (is_dir_sep(buf[len]))
83 len++;
84 return !strcmp(buf + len, file);
85 }
86
87 static void replace_dir(struct strbuf *buf, int len, const char *newdir)
88 {
89 int newlen = strlen(newdir);
90 int need_sep = (buf->buf[len] && !is_dir_sep(buf->buf[len])) &&
91 !is_dir_sep(newdir[newlen - 1]);
92 if (need_sep)
93 len--; /* keep one char, to be replaced with '/' */
94 strbuf_splice(buf, 0, len, newdir, newlen);
95 if (need_sep)
96 buf->buf[newlen] = '/';
97 }
98
99 struct common_dir {
100 /* Not considered garbage for report_linked_checkout_garbage */
101 unsigned ignore_garbage:1;
102 unsigned is_dir:1;
103 /* Not common even though its parent is */
104 unsigned exclude:1;
105 const char *dirname;
106 };
107
108 static struct common_dir common_list[] = {
109 { 0, 1, 0, "branches" },
110 { 0, 1, 0, "hooks" },
111 { 0, 1, 0, "info" },
112 { 0, 0, 1, "info/sparse-checkout" },
113 { 1, 1, 0, "logs" },
114 { 1, 1, 1, "logs/HEAD" },
115 { 0, 1, 1, "logs/refs/bisect" },
116 { 0, 1, 0, "lost-found" },
117 { 0, 1, 0, "objects" },
118 { 0, 1, 0, "refs" },
119 { 0, 1, 1, "refs/bisect" },
120 { 0, 1, 0, "remotes" },
121 { 0, 1, 0, "worktrees" },
122 { 0, 1, 0, "rr-cache" },
123 { 0, 1, 0, "svn" },
124 { 0, 0, 0, "config" },
125 { 1, 0, 0, "gc.pid" },
126 { 0, 0, 0, "packed-refs" },
127 { 0, 0, 0, "shallow" },
128 { 0, 0, 0, NULL }
129 };
130
131 /*
132 * A compressed trie. A trie node consists of zero or more characters that
133 * are common to all elements with this prefix, optionally followed by some
134 * children. If value is not NULL, the trie node is a terminal node.
135 *
136 * For example, consider the following set of strings:
137 * abc
138 * def
139 * definite
140 * definition
141 *
142 * The trie would look like:
143 * root: len = 0, children a and d non-NULL, value = NULL.
144 * a: len = 2, contents = bc, value = (data for "abc")
145 * d: len = 2, contents = ef, children i non-NULL, value = (data for "def")
146 * i: len = 3, contents = nit, children e and i non-NULL, value = NULL
147 * e: len = 0, children all NULL, value = (data for "definite")
148 * i: len = 2, contents = on, children all NULL,
149 * value = (data for "definition")
150 */
151 struct trie {
152 struct trie *children[256];
153 int len;
154 char *contents;
155 void *value;
156 };
157
158 static struct trie *make_trie_node(const char *key, void *value)
159 {
160 struct trie *new_node = xcalloc(1, sizeof(*new_node));
161 new_node->len = strlen(key);
162 if (new_node->len) {
163 new_node->contents = xmalloc(new_node->len);
164 memcpy(new_node->contents, key, new_node->len);
165 }
166 new_node->value = value;
167 return new_node;
168 }
169
170 /*
171 * Add a key/value pair to a trie. The key is assumed to be \0-terminated.
172 * If there was an existing value for this key, return it.
173 */
174 static void *add_to_trie(struct trie *root, const char *key, void *value)
175 {
176 struct trie *child;
177 void *old;
178 int i;
179
180 if (!*key) {
181 /* we have reached the end of the key */
182 old = root->value;
183 root->value = value;
184 return old;
185 }
186
187 for (i = 0; i < root->len; i++) {
188 if (root->contents[i] == key[i])
189 continue;
190
191 /*
192 * Split this node: child will contain this node's
193 * existing children.
194 */
195 child = malloc(sizeof(*child));
196 memcpy(child->children, root->children, sizeof(root->children));
197
198 child->len = root->len - i - 1;
199 if (child->len) {
200 child->contents = xstrndup(root->contents + i + 1,
201 child->len);
202 }
203 child->value = root->value;
204 root->value = NULL;
205 root->len = i;
206
207 memset(root->children, 0, sizeof(root->children));
208 root->children[(unsigned char)root->contents[i]] = child;
209
210 /* This is the newly-added child. */
211 root->children[(unsigned char)key[i]] =
212 make_trie_node(key + i + 1, value);
213 return NULL;
214 }
215
216 /* We have matched the entire compressed section */
217 if (key[i]) {
218 child = root->children[(unsigned char)key[root->len]];
219 if (child) {
220 return add_to_trie(child, key + root->len + 1, value);
221 } else {
222 child = make_trie_node(key + root->len + 1, value);
223 root->children[(unsigned char)key[root->len]] = child;
224 return NULL;
225 }
226 }
227
228 old = root->value;
229 root->value = value;
230 return old;
231 }
232
233 typedef int (*match_fn)(const char *unmatched, void *data, void *baton);
234
235 /*
236 * Search a trie for some key. Find the longest /-or-\0-terminated
237 * prefix of the key for which the trie contains a value. Call fn
238 * with the unmatched portion of the key and the found value, and
239 * return its return value. If there is no such prefix, return -1.
240 *
241 * The key is partially normalized: consecutive slashes are skipped.
242 *
243 * For example, consider the trie containing only [refs,
244 * refs/worktree] (both with values).
245 *
246 * | key | unmatched | val from node | return value |
247 * |-----------------|------------|---------------|--------------|
248 * | a | not called | n/a | -1 |
249 * | refs | \0 | refs | as per fn |
250 * | refs/ | / | refs | as per fn |
251 * | refs/w | /w | refs | as per fn |
252 * | refs/worktree | \0 | refs/worktree | as per fn |
253 * | refs/worktree/ | / | refs/worktree | as per fn |
254 * | refs/worktree/a | /a | refs/worktree | as per fn |
255 * |-----------------|------------|---------------|--------------|
256 *
257 */
258 static int trie_find(struct trie *root, const char *key, match_fn fn,
259 void *baton)
260 {
261 int i;
262 int result;
263 struct trie *child;
264
265 if (!*key) {
266 /* we have reached the end of the key */
267 if (root->value && !root->len)
268 return fn(key, root->value, baton);
269 else
270 return -1;
271 }
272
273 for (i = 0; i < root->len; i++) {
274 /* Partial path normalization: skip consecutive slashes. */
275 if (key[i] == '/' && key[i+1] == '/') {
276 key++;
277 continue;
278 }
279 if (root->contents[i] != key[i])
280 return -1;
281 }
282
283 /* Matched the entire compressed section */
284 key += i;
285 if (!*key)
286 /* End of key */
287 return fn(key, root->value, baton);
288
289 /* Partial path normalization: skip consecutive slashes */
290 while (key[0] == '/' && key[1] == '/')
291 key++;
292
293 child = root->children[(unsigned char)*key];
294 if (child)
295 result = trie_find(child, key + 1, fn, baton);
296 else
297 result = -1;
298
299 if (result >= 0 || (*key != '/' && *key != 0))
300 return result;
301 if (root->value)
302 return fn(key, root->value, baton);
303 else
304 return -1;
305 }
306
307 static struct trie common_trie;
308 static int common_trie_done_setup;
309
310 static void init_common_trie(void)
311 {
312 struct common_dir *p;
313
314 if (common_trie_done_setup)
315 return;
316
317 for (p = common_list; p->dirname; p++)
318 add_to_trie(&common_trie, p->dirname, p);
319
320 common_trie_done_setup = 1;
321 }
322
323 /*
324 * Helper function for update_common_dir: returns 1 if the dir
325 * prefix is common.
326 */
327 static int check_common(const char *unmatched, void *value, void *baton)
328 {
329 struct common_dir *dir = value;
330
331 if (!dir)
332 return 0;
333
334 if (dir->is_dir && (unmatched[0] == 0 || unmatched[0] == '/'))
335 return !dir->exclude;
336
337 if (!dir->is_dir && unmatched[0] == 0)
338 return !dir->exclude;
339
340 return 0;
341 }
342
343 static void update_common_dir(struct strbuf *buf, int git_dir_len,
344 const char *common_dir)
345 {
346 char *base = buf->buf + git_dir_len;
347 init_common_trie();
348 if (trie_find(&common_trie, base, check_common, NULL) > 0)
349 replace_dir(buf, git_dir_len, common_dir);
350 }
351
352 void report_linked_checkout_garbage(void)
353 {
354 struct strbuf sb = STRBUF_INIT;
355 const struct common_dir *p;
356 int len;
357
358 if (!the_repository->different_commondir)
359 return;
360 strbuf_addf(&sb, "%s/", get_git_dir());
361 len = sb.len;
362 for (p = common_list; p->dirname; p++) {
363 const char *path = p->dirname;
364 if (p->ignore_garbage)
365 continue;
366 strbuf_setlen(&sb, len);
367 strbuf_addstr(&sb, path);
368 if (file_exists(sb.buf))
369 report_garbage(PACKDIR_FILE_GARBAGE, sb.buf);
370 }
371 strbuf_release(&sb);
372 }
373
374 static void adjust_git_path(struct strbuf *buf, int git_dir_len)
375 {
376 const char *base = buf->buf + git_dir_len;
377 if (is_dir_file(base, "info", "grafts"))
378 strbuf_splice(buf, 0, buf->len,
379 get_graft_file(), strlen(get_graft_file()));
380 else if (!strcmp(base, "index"))
381 strbuf_splice(buf, 0, buf->len,
382 get_index_file(), strlen(get_index_file()));
383 else if (dir_prefix(base, "objects"))
384 replace_dir(buf, git_dir_len + 7, get_object_directory());
385 else if (git_hooks_path && dir_prefix(base, "hooks"))
386 replace_dir(buf, git_dir_len + 5, git_hooks_path);
387 else if (the_repository->different_commondir)
388 update_common_dir(buf, git_dir_len, get_git_common_dir());
389 }
390
391 static void do_git_path(const struct worktree *wt, struct strbuf *buf,
392 const char *fmt, va_list args)
393 {
394 int gitdir_len;
395 strbuf_addstr(buf, get_worktree_git_dir(wt));
396 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
397 strbuf_addch(buf, '/');
398 gitdir_len = buf->len;
399 strbuf_vaddf(buf, fmt, args);
400 adjust_git_path(buf, gitdir_len);
401 strbuf_cleanup_path(buf);
402 }
403
404 char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
405 {
406 va_list args;
407 strbuf_reset(buf);
408 va_start(args, fmt);
409 do_git_path(NULL, buf, fmt, args);
410 va_end(args);
411 return buf->buf;
412 }
413
414 void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
415 {
416 va_list args;
417 va_start(args, fmt);
418 do_git_path(NULL, sb, fmt, args);
419 va_end(args);
420 }
421
422 const char *git_path(const char *fmt, ...)
423 {
424 struct strbuf *pathname = get_pathname();
425 va_list args;
426 va_start(args, fmt);
427 do_git_path(NULL, pathname, fmt, args);
428 va_end(args);
429 return pathname->buf;
430 }
431
432 char *git_pathdup(const char *fmt, ...)
433 {
434 struct strbuf path = STRBUF_INIT;
435 va_list args;
436 va_start(args, fmt);
437 do_git_path(NULL, &path, fmt, args);
438 va_end(args);
439 return strbuf_detach(&path, NULL);
440 }
441
442 char *mkpathdup(const char *fmt, ...)
443 {
444 struct strbuf sb = STRBUF_INIT;
445 va_list args;
446 va_start(args, fmt);
447 strbuf_vaddf(&sb, fmt, args);
448 va_end(args);
449 strbuf_cleanup_path(&sb);
450 return strbuf_detach(&sb, NULL);
451 }
452
453 const char *mkpath(const char *fmt, ...)
454 {
455 va_list args;
456 struct strbuf *pathname = get_pathname();
457 va_start(args, fmt);
458 strbuf_vaddf(pathname, fmt, args);
459 va_end(args);
460 return cleanup_path(pathname->buf);
461 }
462
463 const char *worktree_git_path(const struct worktree *wt, const char *fmt, ...)
464 {
465 struct strbuf *pathname = get_pathname();
466 va_list args;
467 va_start(args, fmt);
468 do_git_path(wt, pathname, fmt, args);
469 va_end(args);
470 return pathname->buf;
471 }
472
473 /* Returns 0 on success, negative on failure. */
474 static int do_submodule_path(struct strbuf *buf, const char *path,
475 const char *fmt, va_list args)
476 {
477 struct strbuf git_submodule_common_dir = STRBUF_INIT;
478 struct strbuf git_submodule_dir = STRBUF_INIT;
479 int ret;
480
481 ret = submodule_to_gitdir(&git_submodule_dir, path);
482 if (ret)
483 goto cleanup;
484
485 strbuf_complete(&git_submodule_dir, '/');
486 strbuf_addbuf(buf, &git_submodule_dir);
487 strbuf_vaddf(buf, fmt, args);
488
489 if (get_common_dir_noenv(&git_submodule_common_dir, git_submodule_dir.buf))
490 update_common_dir(buf, git_submodule_dir.len, git_submodule_common_dir.buf);
491
492 strbuf_cleanup_path(buf);
493
494 cleanup:
495 strbuf_release(&git_submodule_dir);
496 strbuf_release(&git_submodule_common_dir);
497 return ret;
498 }
499
500 char *git_pathdup_submodule(const char *path, const char *fmt, ...)
501 {
502 int err;
503 va_list args;
504 struct strbuf buf = STRBUF_INIT;
505 va_start(args, fmt);
506 err = do_submodule_path(&buf, path, fmt, args);
507 va_end(args);
508 if (err) {
509 strbuf_release(&buf);
510 return NULL;
511 }
512 return strbuf_detach(&buf, NULL);
513 }
514
515 int strbuf_git_path_submodule(struct strbuf *buf, const char *path,
516 const char *fmt, ...)
517 {
518 int err;
519 va_list args;
520 va_start(args, fmt);
521 err = do_submodule_path(buf, path, fmt, args);
522 va_end(args);
523
524 return err;
525 }
526
527 static void do_git_common_path(const struct repository *repo,
528 struct strbuf *buf,
529 const char *fmt,
530 va_list args)
531 {
532 strbuf_addstr(buf, repo->commondir);
533 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
534 strbuf_addch(buf, '/');
535 strbuf_vaddf(buf, fmt, args);
536 strbuf_cleanup_path(buf);
537 }
538
539 const char *git_common_path(const char *fmt, ...)
540 {
541 struct strbuf *pathname = get_pathname();
542 va_list args;
543 va_start(args, fmt);
544 do_git_common_path(the_repository, pathname, fmt, args);
545 va_end(args);
546 return pathname->buf;
547 }
548
549 void strbuf_git_common_path(struct strbuf *sb,
550 const struct repository *repo,
551 const char *fmt, ...)
552 {
553 va_list args;
554 va_start(args, fmt);
555 do_git_common_path(repo, sb, fmt, args);
556 va_end(args);
557 }
558
559 int validate_headref(const char *path)
560 {
561 struct stat st;
562 char *buf, buffer[256];
563 unsigned char sha1[20];
564 int fd;
565 ssize_t len;
566
567 if (lstat(path, &st) < 0)
568 return -1;
569
570 /* Make sure it is a "refs/.." symlink */
571 if (S_ISLNK(st.st_mode)) {
572 len = readlink(path, buffer, sizeof(buffer)-1);
573 if (len >= 5 && !memcmp("refs/", buffer, 5))
574 return 0;
575 return -1;
576 }
577
578 /*
579 * Anything else, just open it and try to see if it is a symbolic ref.
580 */
581 fd = open(path, O_RDONLY);
582 if (fd < 0)
583 return -1;
584 len = read_in_full(fd, buffer, sizeof(buffer)-1);
585 close(fd);
586
587 /*
588 * Is it a symbolic ref?
589 */
590 if (len < 4)
591 return -1;
592 if (!memcmp("ref:", buffer, 4)) {
593 buf = buffer + 4;
594 len -= 4;
595 while (len && isspace(*buf))
596 buf++, len--;
597 if (len >= 5 && !memcmp("refs/", buf, 5))
598 return 0;
599 }
600
601 /*
602 * Is this a detached HEAD?
603 */
604 if (!get_sha1_hex(buffer, sha1))
605 return 0;
606
607 return -1;
608 }
609
610 static struct passwd *getpw_str(const char *username, size_t len)
611 {
612 struct passwd *pw;
613 char *username_z = xmemdupz(username, len);
614 pw = getpwnam(username_z);
615 free(username_z);
616 return pw;
617 }
618
619 /*
620 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
621 * then it is a newly allocated string. Returns NULL on getpw failure or
622 * if path is NULL.
623 *
624 * If real_home is true, real_path($HOME) is used in the expansion.
625 */
626 char *expand_user_path(const char *path, int real_home)
627 {
628 struct strbuf user_path = STRBUF_INIT;
629 const char *to_copy = path;
630
631 if (path == NULL)
632 goto return_null;
633 if (path[0] == '~') {
634 const char *first_slash = strchrnul(path, '/');
635 const char *username = path + 1;
636 size_t username_len = first_slash - username;
637 if (username_len == 0) {
638 const char *home = getenv("HOME");
639 if (!home)
640 goto return_null;
641 if (real_home)
642 strbuf_addstr(&user_path, real_path(home));
643 else
644 strbuf_addstr(&user_path, home);
645 #ifdef GIT_WINDOWS_NATIVE
646 convert_slashes(user_path.buf);
647 #endif
648 } else {
649 struct passwd *pw = getpw_str(username, username_len);
650 if (!pw)
651 goto return_null;
652 strbuf_addstr(&user_path, pw->pw_dir);
653 }
654 to_copy = first_slash;
655 }
656 strbuf_addstr(&user_path, to_copy);
657 return strbuf_detach(&user_path, NULL);
658 return_null:
659 strbuf_release(&user_path);
660 return NULL;
661 }
662
663 /*
664 * First, one directory to try is determined by the following algorithm.
665 *
666 * (0) If "strict" is given, the path is used as given and no DWIM is
667 * done. Otherwise:
668 * (1) "~/path" to mean path under the running user's home directory;
669 * (2) "~user/path" to mean path under named user's home directory;
670 * (3) "relative/path" to mean cwd relative directory; or
671 * (4) "/absolute/path" to mean absolute directory.
672 *
673 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
674 * in this order. We select the first one that is a valid git repository, and
675 * chdir() to it. If none match, or we fail to chdir, we return NULL.
676 *
677 * If all goes well, we return the directory we used to chdir() (but
678 * before ~user is expanded), avoiding getcwd() resolving symbolic
679 * links. User relative paths are also returned as they are given,
680 * except DWIM suffixing.
681 */
682 const char *enter_repo(const char *path, int strict)
683 {
684 static struct strbuf validated_path = STRBUF_INIT;
685 static struct strbuf used_path = STRBUF_INIT;
686
687 if (!path)
688 return NULL;
689
690 if (!strict) {
691 static const char *suffix[] = {
692 "/.git", "", ".git/.git", ".git", NULL,
693 };
694 const char *gitfile;
695 int len = strlen(path);
696 int i;
697 while ((1 < len) && (path[len-1] == '/'))
698 len--;
699
700 /*
701 * We can handle arbitrary-sized buffers, but this remains as a
702 * sanity check on untrusted input.
703 */
704 if (PATH_MAX <= len)
705 return NULL;
706
707 strbuf_reset(&used_path);
708 strbuf_reset(&validated_path);
709 strbuf_add(&used_path, path, len);
710 strbuf_add(&validated_path, path, len);
711
712 if (used_path.buf[0] == '~') {
713 char *newpath = expand_user_path(used_path.buf, 0);
714 if (!newpath)
715 return NULL;
716 strbuf_attach(&used_path, newpath, strlen(newpath),
717 strlen(newpath));
718 }
719 for (i = 0; suffix[i]; i++) {
720 struct stat st;
721 size_t baselen = used_path.len;
722 strbuf_addstr(&used_path, suffix[i]);
723 if (!stat(used_path.buf, &st) &&
724 (S_ISREG(st.st_mode) ||
725 (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
726 strbuf_addstr(&validated_path, suffix[i]);
727 break;
728 }
729 strbuf_setlen(&used_path, baselen);
730 }
731 if (!suffix[i])
732 return NULL;
733 gitfile = read_gitfile(used_path.buf);
734 if (gitfile) {
735 strbuf_reset(&used_path);
736 strbuf_addstr(&used_path, gitfile);
737 }
738 if (chdir(used_path.buf))
739 return NULL;
740 path = validated_path.buf;
741 }
742 else {
743 const char *gitfile = read_gitfile(path);
744 if (gitfile)
745 path = gitfile;
746 if (chdir(path))
747 return NULL;
748 }
749
750 if (is_git_directory(".")) {
751 set_git_dir(".");
752 check_repository_format();
753 return path;
754 }
755
756 return NULL;
757 }
758
759 static int calc_shared_perm(int mode)
760 {
761 int tweak;
762
763 if (get_shared_repository() < 0)
764 tweak = -get_shared_repository();
765 else
766 tweak = get_shared_repository();
767
768 if (!(mode & S_IWUSR))
769 tweak &= ~0222;
770 if (mode & S_IXUSR)
771 /* Copy read bits to execute bits */
772 tweak |= (tweak & 0444) >> 2;
773 if (get_shared_repository() < 0)
774 mode = (mode & ~0777) | tweak;
775 else
776 mode |= tweak;
777
778 return mode;
779 }
780
781
782 int adjust_shared_perm(const char *path)
783 {
784 int old_mode, new_mode;
785
786 if (!get_shared_repository())
787 return 0;
788 if (get_st_mode_bits(path, &old_mode) < 0)
789 return -1;
790
791 new_mode = calc_shared_perm(old_mode);
792 if (S_ISDIR(old_mode)) {
793 /* Copy read bits to execute bits */
794 new_mode |= (new_mode & 0444) >> 2;
795 new_mode |= FORCE_DIR_SET_GID;
796 }
797
798 if (((old_mode ^ new_mode) & ~S_IFMT) &&
799 chmod(path, (new_mode & ~S_IFMT)) < 0)
800 return -2;
801 return 0;
802 }
803
804 void safe_create_dir(const char *dir, int share)
805 {
806 if (mkdir(dir, 0777) < 0) {
807 if (errno != EEXIST) {
808 perror(dir);
809 exit(1);
810 }
811 }
812 else if (share && adjust_shared_perm(dir))
813 die(_("Could not make %s writable by group"), dir);
814 }
815
816 static int have_same_root(const char *path1, const char *path2)
817 {
818 int is_abs1, is_abs2;
819
820 is_abs1 = is_absolute_path(path1);
821 is_abs2 = is_absolute_path(path2);
822 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
823 (!is_abs1 && !is_abs2);
824 }
825
826 /*
827 * Give path as relative to prefix.
828 *
829 * The strbuf may or may not be used, so do not assume it contains the
830 * returned path.
831 */
832 const char *relative_path(const char *in, const char *prefix,
833 struct strbuf *sb)
834 {
835 int in_len = in ? strlen(in) : 0;
836 int prefix_len = prefix ? strlen(prefix) : 0;
837 int in_off = 0;
838 int prefix_off = 0;
839 int i = 0, j = 0;
840
841 if (!in_len)
842 return "./";
843 else if (!prefix_len)
844 return in;
845
846 if (have_same_root(in, prefix))
847 /* bypass dos_drive, for "c:" is identical to "C:" */
848 i = j = has_dos_drive_prefix(in);
849 else {
850 return in;
851 }
852
853 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
854 if (is_dir_sep(prefix[i])) {
855 while (is_dir_sep(prefix[i]))
856 i++;
857 while (is_dir_sep(in[j]))
858 j++;
859 prefix_off = i;
860 in_off = j;
861 } else {
862 i++;
863 j++;
864 }
865 }
866
867 if (
868 /* "prefix" seems like prefix of "in" */
869 i >= prefix_len &&
870 /*
871 * but "/foo" is not a prefix of "/foobar"
872 * (i.e. prefix not end with '/')
873 */
874 prefix_off < prefix_len) {
875 if (j >= in_len) {
876 /* in="/a/b", prefix="/a/b" */
877 in_off = in_len;
878 } else if (is_dir_sep(in[j])) {
879 /* in="/a/b/c", prefix="/a/b" */
880 while (is_dir_sep(in[j]))
881 j++;
882 in_off = j;
883 } else {
884 /* in="/a/bbb/c", prefix="/a/b" */
885 i = prefix_off;
886 }
887 } else if (
888 /* "in" is short than "prefix" */
889 j >= in_len &&
890 /* "in" not end with '/' */
891 in_off < in_len) {
892 if (is_dir_sep(prefix[i])) {
893 /* in="/a/b", prefix="/a/b/c/" */
894 while (is_dir_sep(prefix[i]))
895 i++;
896 in_off = in_len;
897 }
898 }
899 in += in_off;
900 in_len -= in_off;
901
902 if (i >= prefix_len) {
903 if (!in_len)
904 return "./";
905 else
906 return in;
907 }
908
909 strbuf_reset(sb);
910 strbuf_grow(sb, in_len);
911
912 while (i < prefix_len) {
913 if (is_dir_sep(prefix[i])) {
914 strbuf_addstr(sb, "../");
915 while (is_dir_sep(prefix[i]))
916 i++;
917 continue;
918 }
919 i++;
920 }
921 if (!is_dir_sep(prefix[prefix_len - 1]))
922 strbuf_addstr(sb, "../");
923
924 strbuf_addstr(sb, in);
925
926 return sb->buf;
927 }
928
929 /*
930 * A simpler implementation of relative_path
931 *
932 * Get relative path by removing "prefix" from "in". This function
933 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
934 * to increase performance when traversing the path to work_tree.
935 */
936 const char *remove_leading_path(const char *in, const char *prefix)
937 {
938 static struct strbuf buf = STRBUF_INIT;
939 int i = 0, j = 0;
940
941 if (!prefix || !prefix[0])
942 return in;
943 while (prefix[i]) {
944 if (is_dir_sep(prefix[i])) {
945 if (!is_dir_sep(in[j]))
946 return in;
947 while (is_dir_sep(prefix[i]))
948 i++;
949 while (is_dir_sep(in[j]))
950 j++;
951 continue;
952 } else if (in[j] != prefix[i]) {
953 return in;
954 }
955 i++;
956 j++;
957 }
958 if (
959 /* "/foo" is a prefix of "/foo" */
960 in[j] &&
961 /* "/foo" is not a prefix of "/foobar" */
962 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
963 )
964 return in;
965 while (is_dir_sep(in[j]))
966 j++;
967
968 strbuf_reset(&buf);
969 if (!in[j])
970 strbuf_addstr(&buf, ".");
971 else
972 strbuf_addstr(&buf, in + j);
973 return buf.buf;
974 }
975
976 /*
977 * It is okay if dst == src, but they should not overlap otherwise.
978 *
979 * Performs the following normalizations on src, storing the result in dst:
980 * - Ensures that components are separated by '/' (Windows only)
981 * - Squashes sequences of '/' except "//server/share" on Windows
982 * - Removes "." components.
983 * - Removes ".." components, and the components the precede them.
984 * Returns failure (non-zero) if a ".." component appears as first path
985 * component anytime during the normalization. Otherwise, returns success (0).
986 *
987 * Note that this function is purely textual. It does not follow symlinks,
988 * verify the existence of the path, or make any system calls.
989 *
990 * prefix_len != NULL is for a specific case of prefix_pathspec():
991 * assume that src == dst and src[0..prefix_len-1] is already
992 * normalized, any time "../" eats up to the prefix_len part,
993 * prefix_len is reduced. In the end prefix_len is the remaining
994 * prefix that has not been overridden by user pathspec.
995 *
996 * NEEDSWORK: This function doesn't perform normalization w.r.t. trailing '/'.
997 * For everything but the root folder itself, the normalized path should not
998 * end with a '/', then the callers need to be fixed up accordingly.
999 *
1000 */
1001 int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
1002 {
1003 char *dst0;
1004 const char *end;
1005
1006 /*
1007 * Copy initial part of absolute path: "/", "C:/", "//server/share/".
1008 */
1009 end = src + offset_1st_component(src);
1010 while (src < end) {
1011 char c = *src++;
1012 if (is_dir_sep(c))
1013 c = '/';
1014 *dst++ = c;
1015 }
1016 dst0 = dst;
1017
1018 while (is_dir_sep(*src))
1019 src++;
1020
1021 for (;;) {
1022 char c = *src;
1023
1024 /*
1025 * A path component that begins with . could be
1026 * special:
1027 * (1) "." and ends -- ignore and terminate.
1028 * (2) "./" -- ignore them, eat slash and continue.
1029 * (3) ".." and ends -- strip one and terminate.
1030 * (4) "../" -- strip one, eat slash and continue.
1031 */
1032 if (c == '.') {
1033 if (!src[1]) {
1034 /* (1) */
1035 src++;
1036 } else if (is_dir_sep(src[1])) {
1037 /* (2) */
1038 src += 2;
1039 while (is_dir_sep(*src))
1040 src++;
1041 continue;
1042 } else if (src[1] == '.') {
1043 if (!src[2]) {
1044 /* (3) */
1045 src += 2;
1046 goto up_one;
1047 } else if (is_dir_sep(src[2])) {
1048 /* (4) */
1049 src += 3;
1050 while (is_dir_sep(*src))
1051 src++;
1052 goto up_one;
1053 }
1054 }
1055 }
1056
1057 /* copy up to the next '/', and eat all '/' */
1058 while ((c = *src++) != '\0' && !is_dir_sep(c))
1059 *dst++ = c;
1060 if (is_dir_sep(c)) {
1061 *dst++ = '/';
1062 while (is_dir_sep(c))
1063 c = *src++;
1064 src--;
1065 } else if (!c)
1066 break;
1067 continue;
1068
1069 up_one:
1070 /*
1071 * dst0..dst is prefix portion, and dst[-1] is '/';
1072 * go up one level.
1073 */
1074 dst--; /* go to trailing '/' */
1075 if (dst <= dst0)
1076 return -1;
1077 /* Windows: dst[-1] cannot be backslash anymore */
1078 while (dst0 < dst && dst[-1] != '/')
1079 dst--;
1080 if (prefix_len && *prefix_len > dst - dst0)
1081 *prefix_len = dst - dst0;
1082 }
1083 *dst = '\0';
1084 return 0;
1085 }
1086
1087 int normalize_path_copy(char *dst, const char *src)
1088 {
1089 return normalize_path_copy_len(dst, src, NULL);
1090 }
1091
1092 /*
1093 * path = Canonical absolute path
1094 * prefixes = string_list containing normalized, absolute paths without
1095 * trailing slashes (except for the root directory, which is denoted by "/").
1096 *
1097 * Determines, for each path in prefixes, whether the "prefix"
1098 * is an ancestor directory of path. Returns the length of the longest
1099 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1100 * is an ancestor. (Note that this means 0 is returned if prefixes is
1101 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
1102 * are not considered to be their own ancestors. path must be in a
1103 * canonical form: empty components, or "." or ".." components are not
1104 * allowed.
1105 */
1106 int longest_ancestor_length(const char *path, struct string_list *prefixes)
1107 {
1108 int i, max_len = -1;
1109
1110 if (!strcmp(path, "/"))
1111 return -1;
1112
1113 for (i = 0; i < prefixes->nr; i++) {
1114 const char *ceil = prefixes->items[i].string;
1115 int len = strlen(ceil);
1116
1117 if (len == 1 && ceil[0] == '/')
1118 len = 0; /* root matches anything, with length 0 */
1119 else if (!strncmp(path, ceil, len) && path[len] == '/')
1120 ; /* match of length len */
1121 else
1122 continue; /* no match */
1123
1124 if (len > max_len)
1125 max_len = len;
1126 }
1127
1128 return max_len;
1129 }
1130
1131 /* strip arbitrary amount of directory separators at end of path */
1132 static inline int chomp_trailing_dir_sep(const char *path, int len)
1133 {
1134 while (len && is_dir_sep(path[len - 1]))
1135 len--;
1136 return len;
1137 }
1138
1139 /*
1140 * If path ends with suffix (complete path components), returns the
1141 * part before suffix (sans trailing directory separators).
1142 * Otherwise returns NULL.
1143 */
1144 char *strip_path_suffix(const char *path, const char *suffix)
1145 {
1146 int path_len = strlen(path), suffix_len = strlen(suffix);
1147
1148 while (suffix_len) {
1149 if (!path_len)
1150 return NULL;
1151
1152 if (is_dir_sep(path[path_len - 1])) {
1153 if (!is_dir_sep(suffix[suffix_len - 1]))
1154 return NULL;
1155 path_len = chomp_trailing_dir_sep(path, path_len);
1156 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
1157 }
1158 else if (path[--path_len] != suffix[--suffix_len])
1159 return NULL;
1160 }
1161
1162 if (path_len && !is_dir_sep(path[path_len - 1]))
1163 return NULL;
1164 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
1165 }
1166
1167 int daemon_avoid_alias(const char *p)
1168 {
1169 int sl, ndot;
1170
1171 /*
1172 * This resurrects the belts and suspenders paranoia check by HPA
1173 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
1174 * does not do getcwd() based path canonicalization.
1175 *
1176 * sl becomes true immediately after seeing '/' and continues to
1177 * be true as long as dots continue after that without intervening
1178 * non-dot character.
1179 */
1180 if (!p || (*p != '/' && *p != '~'))
1181 return -1;
1182 sl = 1; ndot = 0;
1183 p++;
1184
1185 while (1) {
1186 char ch = *p++;
1187 if (sl) {
1188 if (ch == '.')
1189 ndot++;
1190 else if (ch == '/') {
1191 if (ndot < 3)
1192 /* reject //, /./ and /../ */
1193 return -1;
1194 ndot = 0;
1195 }
1196 else if (ch == 0) {
1197 if (0 < ndot && ndot < 3)
1198 /* reject /.$ and /..$ */
1199 return -1;
1200 return 0;
1201 }
1202 else
1203 sl = ndot = 0;
1204 }
1205 else if (ch == 0)
1206 return 0;
1207 else if (ch == '/') {
1208 sl = 1;
1209 ndot = 0;
1210 }
1211 }
1212 }
1213
1214 static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
1215 {
1216 if (len < skip)
1217 return 0;
1218 len -= skip;
1219 path += skip;
1220 while (len-- > 0) {
1221 char c = *(path++);
1222 if (c != ' ' && c != '.')
1223 return 0;
1224 }
1225 return 1;
1226 }
1227
1228 int is_ntfs_dotgit(const char *name)
1229 {
1230 int len;
1231
1232 for (len = 0; ; len++)
1233 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
1234 if (only_spaces_and_periods(name, len, 4) &&
1235 !strncasecmp(name, ".git", 4))
1236 return 1;
1237 if (only_spaces_and_periods(name, len, 5) &&
1238 !strncasecmp(name, "git~1", 5))
1239 return 1;
1240 if (name[len] != '\\')
1241 return 0;
1242 name += len + 1;
1243 len = -1;
1244 }
1245 }
1246
1247 char *xdg_config_home(const char *filename)
1248 {
1249 const char *home, *config_home;
1250
1251 assert(filename);
1252 config_home = getenv("XDG_CONFIG_HOME");
1253 if (config_home && *config_home)
1254 return mkpathdup("%s/git/%s", config_home, filename);
1255
1256 home = getenv("HOME");
1257 if (home)
1258 return mkpathdup("%s/.config/git/%s", home, filename);
1259 return NULL;
1260 }
1261
1262 char *xdg_cache_home(const char *filename)
1263 {
1264 const char *home, *cache_home;
1265
1266 assert(filename);
1267 cache_home = getenv("XDG_CACHE_HOME");
1268 if (cache_home && *cache_home)
1269 return mkpathdup("%s/git/%s", cache_home, filename);
1270
1271 home = getenv("HOME");
1272 if (home)
1273 return mkpathdup("%s/.cache/git/%s", home, filename);
1274 return NULL;
1275 }
1276
1277 GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
1278 GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
1279 GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
1280 GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
1281 GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
1282 GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
1283 GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
1284 GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
1285 GIT_PATH_FUNC(git_path_shallow, "shallow")