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
13static 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
22static char bad_path[] = "/bad-path/";
23
24static 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
36static 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
47static 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
54char *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
69static 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 */
77static 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
87static 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
99struct 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
108static 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 */
151struct trie {
152 struct trie *children[256];
153 int len;
154 char *contents;
155 void *value;
156};
157
158static 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 */
174static 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
233typedef 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 */
258static 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
307static struct trie common_trie;
308static int common_trie_done_setup;
309
310static 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 */
327static 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
343static 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
352void 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
374static void adjust_git_path(const struct repository *repo,
375 struct strbuf *buf, int git_dir_len)
376{
377 const char *base = buf->buf + git_dir_len;
378 if (is_dir_file(base, "info", "grafts"))
379 strbuf_splice(buf, 0, buf->len,
380 repo->graft_file, strlen(repo->graft_file));
381 else if (!strcmp(base, "index"))
382 strbuf_splice(buf, 0, buf->len,
383 repo->index_file, strlen(repo->index_file));
384 else if (dir_prefix(base, "objects"))
385 replace_dir(buf, git_dir_len + 7, repo->objectdir);
386 else if (git_hooks_path && dir_prefix(base, "hooks"))
387 replace_dir(buf, git_dir_len + 5, git_hooks_path);
388 else if (repo->different_commondir)
389 update_common_dir(buf, git_dir_len, repo->commondir);
390}
391
392static void strbuf_worktree_gitdir(struct strbuf *buf,
393 const struct repository *repo,
394 const struct worktree *wt)
395{
396 if (!wt)
397 strbuf_addstr(buf, repo->gitdir);
398 else if (!wt->id)
399 strbuf_addstr(buf, repo->commondir);
400 else
401 strbuf_git_common_path(buf, repo, "worktrees/%s", wt->id);
402}
403
404static void do_git_path(const struct repository *repo,
405 const struct worktree *wt, struct strbuf *buf,
406 const char *fmt, va_list args)
407{
408 int gitdir_len;
409 strbuf_worktree_gitdir(buf, repo, wt);
410 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
411 strbuf_addch(buf, '/');
412 gitdir_len = buf->len;
413 strbuf_vaddf(buf, fmt, args);
414 if (!wt)
415 adjust_git_path(repo, buf, gitdir_len);
416 strbuf_cleanup_path(buf);
417}
418
419char *repo_git_path(const struct repository *repo,
420 const char *fmt, ...)
421{
422 struct strbuf path = STRBUF_INIT;
423 va_list args;
424 va_start(args, fmt);
425 do_git_path(repo, NULL, &path, fmt, args);
426 va_end(args);
427 return strbuf_detach(&path, NULL);
428}
429
430void strbuf_repo_git_path(struct strbuf *sb,
431 const struct repository *repo,
432 const char *fmt, ...)
433{
434 va_list args;
435 va_start(args, fmt);
436 do_git_path(repo, NULL, sb, fmt, args);
437 va_end(args);
438}
439
440char *git_path_buf(struct strbuf *buf, const char *fmt, ...)
441{
442 va_list args;
443 strbuf_reset(buf);
444 va_start(args, fmt);
445 do_git_path(the_repository, NULL, buf, fmt, args);
446 va_end(args);
447 return buf->buf;
448}
449
450void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
451{
452 va_list args;
453 va_start(args, fmt);
454 do_git_path(the_repository, NULL, sb, fmt, args);
455 va_end(args);
456}
457
458const char *git_path(const char *fmt, ...)
459{
460 struct strbuf *pathname = get_pathname();
461 va_list args;
462 va_start(args, fmt);
463 do_git_path(the_repository, NULL, pathname, fmt, args);
464 va_end(args);
465 return pathname->buf;
466}
467
468char *git_pathdup(const char *fmt, ...)
469{
470 struct strbuf path = STRBUF_INIT;
471 va_list args;
472 va_start(args, fmt);
473 do_git_path(the_repository, NULL, &path, fmt, args);
474 va_end(args);
475 return strbuf_detach(&path, NULL);
476}
477
478char *mkpathdup(const char *fmt, ...)
479{
480 struct strbuf sb = STRBUF_INIT;
481 va_list args;
482 va_start(args, fmt);
483 strbuf_vaddf(&sb, fmt, args);
484 va_end(args);
485 strbuf_cleanup_path(&sb);
486 return strbuf_detach(&sb, NULL);
487}
488
489const char *mkpath(const char *fmt, ...)
490{
491 va_list args;
492 struct strbuf *pathname = get_pathname();
493 va_start(args, fmt);
494 strbuf_vaddf(pathname, fmt, args);
495 va_end(args);
496 return cleanup_path(pathname->buf);
497}
498
499const char *worktree_git_path(const struct worktree *wt, const char *fmt, ...)
500{
501 struct strbuf *pathname = get_pathname();
502 va_list args;
503 va_start(args, fmt);
504 do_git_path(the_repository, wt, pathname, fmt, args);
505 va_end(args);
506 return pathname->buf;
507}
508
509static void do_worktree_path(const struct repository *repo,
510 struct strbuf *buf,
511 const char *fmt, va_list args)
512{
513 strbuf_addstr(buf, repo->worktree);
514 if(buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
515 strbuf_addch(buf, '/');
516
517 strbuf_vaddf(buf, fmt, args);
518 strbuf_cleanup_path(buf);
519}
520
521char *repo_worktree_path(const struct repository *repo, const char *fmt, ...)
522{
523 struct strbuf path = STRBUF_INIT;
524 va_list args;
525
526 if (!repo->worktree)
527 return NULL;
528
529 va_start(args, fmt);
530 do_worktree_path(repo, &path, fmt, args);
531 va_end(args);
532
533 return strbuf_detach(&path, NULL);
534}
535
536void strbuf_repo_worktree_path(struct strbuf *sb,
537 const struct repository *repo,
538 const char *fmt, ...)
539{
540 va_list args;
541
542 if (!repo->worktree)
543 return;
544
545 va_start(args, fmt);
546 do_worktree_path(repo, sb, fmt, args);
547 va_end(args);
548}
549
550/* Returns 0 on success, negative on failure. */
551static int do_submodule_path(struct strbuf *buf, const char *path,
552 const char *fmt, va_list args)
553{
554 struct strbuf git_submodule_common_dir = STRBUF_INIT;
555 struct strbuf git_submodule_dir = STRBUF_INIT;
556 int ret;
557
558 ret = submodule_to_gitdir(&git_submodule_dir, path);
559 if (ret)
560 goto cleanup;
561
562 strbuf_complete(&git_submodule_dir, '/');
563 strbuf_addbuf(buf, &git_submodule_dir);
564 strbuf_vaddf(buf, fmt, args);
565
566 if (get_common_dir_noenv(&git_submodule_common_dir, git_submodule_dir.buf))
567 update_common_dir(buf, git_submodule_dir.len, git_submodule_common_dir.buf);
568
569 strbuf_cleanup_path(buf);
570
571cleanup:
572 strbuf_release(&git_submodule_dir);
573 strbuf_release(&git_submodule_common_dir);
574 return ret;
575}
576
577char *git_pathdup_submodule(const char *path, const char *fmt, ...)
578{
579 int err;
580 va_list args;
581 struct strbuf buf = STRBUF_INIT;
582 va_start(args, fmt);
583 err = do_submodule_path(&buf, path, fmt, args);
584 va_end(args);
585 if (err) {
586 strbuf_release(&buf);
587 return NULL;
588 }
589 return strbuf_detach(&buf, NULL);
590}
591
592int strbuf_git_path_submodule(struct strbuf *buf, const char *path,
593 const char *fmt, ...)
594{
595 int err;
596 va_list args;
597 va_start(args, fmt);
598 err = do_submodule_path(buf, path, fmt, args);
599 va_end(args);
600
601 return err;
602}
603
604static void do_git_common_path(const struct repository *repo,
605 struct strbuf *buf,
606 const char *fmt,
607 va_list args)
608{
609 strbuf_addstr(buf, repo->commondir);
610 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
611 strbuf_addch(buf, '/');
612 strbuf_vaddf(buf, fmt, args);
613 strbuf_cleanup_path(buf);
614}
615
616const char *git_common_path(const char *fmt, ...)
617{
618 struct strbuf *pathname = get_pathname();
619 va_list args;
620 va_start(args, fmt);
621 do_git_common_path(the_repository, pathname, fmt, args);
622 va_end(args);
623 return pathname->buf;
624}
625
626void strbuf_git_common_path(struct strbuf *sb,
627 const struct repository *repo,
628 const char *fmt, ...)
629{
630 va_list args;
631 va_start(args, fmt);
632 do_git_common_path(repo, sb, fmt, args);
633 va_end(args);
634}
635
636int validate_headref(const char *path)
637{
638 struct stat st;
639 char *buf, buffer[256];
640 unsigned char sha1[20];
641 int fd;
642 ssize_t len;
643
644 if (lstat(path, &st) < 0)
645 return -1;
646
647 /* Make sure it is a "refs/.." symlink */
648 if (S_ISLNK(st.st_mode)) {
649 len = readlink(path, buffer, sizeof(buffer)-1);
650 if (len >= 5 && !memcmp("refs/", buffer, 5))
651 return 0;
652 return -1;
653 }
654
655 /*
656 * Anything else, just open it and try to see if it is a symbolic ref.
657 */
658 fd = open(path, O_RDONLY);
659 if (fd < 0)
660 return -1;
661 len = read_in_full(fd, buffer, sizeof(buffer)-1);
662 close(fd);
663
664 if (len < 0)
665 return -1;
666 buffer[len] = '\0';
667
668 /*
669 * Is it a symbolic ref?
670 */
671 if (len < 4)
672 return -1;
673 if (!memcmp("ref:", buffer, 4)) {
674 buf = buffer + 4;
675 len -= 4;
676 while (len && isspace(*buf))
677 buf++, len--;
678 if (len >= 5 && !memcmp("refs/", buf, 5))
679 return 0;
680 }
681
682 /*
683 * Is this a detached HEAD?
684 */
685 if (!get_sha1_hex(buffer, sha1))
686 return 0;
687
688 return -1;
689}
690
691static struct passwd *getpw_str(const char *username, size_t len)
692{
693 struct passwd *pw;
694 char *username_z = xmemdupz(username, len);
695 pw = getpwnam(username_z);
696 free(username_z);
697 return pw;
698}
699
700/*
701 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
702 * then it is a newly allocated string. Returns NULL on getpw failure or
703 * if path is NULL.
704 *
705 * If real_home is true, real_path($HOME) is used in the expansion.
706 */
707char *expand_user_path(const char *path, int real_home)
708{
709 struct strbuf user_path = STRBUF_INIT;
710 const char *to_copy = path;
711
712 if (path == NULL)
713 goto return_null;
714 if (path[0] == '~') {
715 const char *first_slash = strchrnul(path, '/');
716 const char *username = path + 1;
717 size_t username_len = first_slash - username;
718 if (username_len == 0) {
719 const char *home = getenv("HOME");
720 if (!home)
721 goto return_null;
722 if (real_home)
723 strbuf_addstr(&user_path, real_path(home));
724 else
725 strbuf_addstr(&user_path, home);
726#ifdef GIT_WINDOWS_NATIVE
727 convert_slashes(user_path.buf);
728#endif
729 } else {
730 struct passwd *pw = getpw_str(username, username_len);
731 if (!pw)
732 goto return_null;
733 strbuf_addstr(&user_path, pw->pw_dir);
734 }
735 to_copy = first_slash;
736 }
737 strbuf_addstr(&user_path, to_copy);
738 return strbuf_detach(&user_path, NULL);
739return_null:
740 strbuf_release(&user_path);
741 return NULL;
742}
743
744/*
745 * First, one directory to try is determined by the following algorithm.
746 *
747 * (0) If "strict" is given, the path is used as given and no DWIM is
748 * done. Otherwise:
749 * (1) "~/path" to mean path under the running user's home directory;
750 * (2) "~user/path" to mean path under named user's home directory;
751 * (3) "relative/path" to mean cwd relative directory; or
752 * (4) "/absolute/path" to mean absolute directory.
753 *
754 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
755 * in this order. We select the first one that is a valid git repository, and
756 * chdir() to it. If none match, or we fail to chdir, we return NULL.
757 *
758 * If all goes well, we return the directory we used to chdir() (but
759 * before ~user is expanded), avoiding getcwd() resolving symbolic
760 * links. User relative paths are also returned as they are given,
761 * except DWIM suffixing.
762 */
763const char *enter_repo(const char *path, int strict)
764{
765 static struct strbuf validated_path = STRBUF_INIT;
766 static struct strbuf used_path = STRBUF_INIT;
767
768 if (!path)
769 return NULL;
770
771 if (!strict) {
772 static const char *suffix[] = {
773 "/.git", "", ".git/.git", ".git", NULL,
774 };
775 const char *gitfile;
776 int len = strlen(path);
777 int i;
778 while ((1 < len) && (path[len-1] == '/'))
779 len--;
780
781 /*
782 * We can handle arbitrary-sized buffers, but this remains as a
783 * sanity check on untrusted input.
784 */
785 if (PATH_MAX <= len)
786 return NULL;
787
788 strbuf_reset(&used_path);
789 strbuf_reset(&validated_path);
790 strbuf_add(&used_path, path, len);
791 strbuf_add(&validated_path, path, len);
792
793 if (used_path.buf[0] == '~') {
794 char *newpath = expand_user_path(used_path.buf, 0);
795 if (!newpath)
796 return NULL;
797 strbuf_attach(&used_path, newpath, strlen(newpath),
798 strlen(newpath));
799 }
800 for (i = 0; suffix[i]; i++) {
801 struct stat st;
802 size_t baselen = used_path.len;
803 strbuf_addstr(&used_path, suffix[i]);
804 if (!stat(used_path.buf, &st) &&
805 (S_ISREG(st.st_mode) ||
806 (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) {
807 strbuf_addstr(&validated_path, suffix[i]);
808 break;
809 }
810 strbuf_setlen(&used_path, baselen);
811 }
812 if (!suffix[i])
813 return NULL;
814 gitfile = read_gitfile(used_path.buf);
815 if (gitfile) {
816 strbuf_reset(&used_path);
817 strbuf_addstr(&used_path, gitfile);
818 }
819 if (chdir(used_path.buf))
820 return NULL;
821 path = validated_path.buf;
822 }
823 else {
824 const char *gitfile = read_gitfile(path);
825 if (gitfile)
826 path = gitfile;
827 if (chdir(path))
828 return NULL;
829 }
830
831 if (is_git_directory(".")) {
832 set_git_dir(".");
833 check_repository_format();
834 return path;
835 }
836
837 return NULL;
838}
839
840static int calc_shared_perm(int mode)
841{
842 int tweak;
843
844 if (get_shared_repository() < 0)
845 tweak = -get_shared_repository();
846 else
847 tweak = get_shared_repository();
848
849 if (!(mode & S_IWUSR))
850 tweak &= ~0222;
851 if (mode & S_IXUSR)
852 /* Copy read bits to execute bits */
853 tweak |= (tweak & 0444) >> 2;
854 if (get_shared_repository() < 0)
855 mode = (mode & ~0777) | tweak;
856 else
857 mode |= tweak;
858
859 return mode;
860}
861
862
863int adjust_shared_perm(const char *path)
864{
865 int old_mode, new_mode;
866
867 if (!get_shared_repository())
868 return 0;
869 if (get_st_mode_bits(path, &old_mode) < 0)
870 return -1;
871
872 new_mode = calc_shared_perm(old_mode);
873 if (S_ISDIR(old_mode)) {
874 /* Copy read bits to execute bits */
875 new_mode |= (new_mode & 0444) >> 2;
876 new_mode |= FORCE_DIR_SET_GID;
877 }
878
879 if (((old_mode ^ new_mode) & ~S_IFMT) &&
880 chmod(path, (new_mode & ~S_IFMT)) < 0)
881 return -2;
882 return 0;
883}
884
885void safe_create_dir(const char *dir, int share)
886{
887 if (mkdir(dir, 0777) < 0) {
888 if (errno != EEXIST) {
889 perror(dir);
890 exit(1);
891 }
892 }
893 else if (share && adjust_shared_perm(dir))
894 die(_("Could not make %s writable by group"), dir);
895}
896
897static int have_same_root(const char *path1, const char *path2)
898{
899 int is_abs1, is_abs2;
900
901 is_abs1 = is_absolute_path(path1);
902 is_abs2 = is_absolute_path(path2);
903 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
904 (!is_abs1 && !is_abs2);
905}
906
907/*
908 * Give path as relative to prefix.
909 *
910 * The strbuf may or may not be used, so do not assume it contains the
911 * returned path.
912 */
913const char *relative_path(const char *in, const char *prefix,
914 struct strbuf *sb)
915{
916 int in_len = in ? strlen(in) : 0;
917 int prefix_len = prefix ? strlen(prefix) : 0;
918 int in_off = 0;
919 int prefix_off = 0;
920 int i = 0, j = 0;
921
922 if (!in_len)
923 return "./";
924 else if (!prefix_len)
925 return in;
926
927 if (have_same_root(in, prefix))
928 /* bypass dos_drive, for "c:" is identical to "C:" */
929 i = j = has_dos_drive_prefix(in);
930 else {
931 return in;
932 }
933
934 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
935 if (is_dir_sep(prefix[i])) {
936 while (is_dir_sep(prefix[i]))
937 i++;
938 while (is_dir_sep(in[j]))
939 j++;
940 prefix_off = i;
941 in_off = j;
942 } else {
943 i++;
944 j++;
945 }
946 }
947
948 if (
949 /* "prefix" seems like prefix of "in" */
950 i >= prefix_len &&
951 /*
952 * but "/foo" is not a prefix of "/foobar"
953 * (i.e. prefix not end with '/')
954 */
955 prefix_off < prefix_len) {
956 if (j >= in_len) {
957 /* in="/a/b", prefix="/a/b" */
958 in_off = in_len;
959 } else if (is_dir_sep(in[j])) {
960 /* in="/a/b/c", prefix="/a/b" */
961 while (is_dir_sep(in[j]))
962 j++;
963 in_off = j;
964 } else {
965 /* in="/a/bbb/c", prefix="/a/b" */
966 i = prefix_off;
967 }
968 } else if (
969 /* "in" is short than "prefix" */
970 j >= in_len &&
971 /* "in" not end with '/' */
972 in_off < in_len) {
973 if (is_dir_sep(prefix[i])) {
974 /* in="/a/b", prefix="/a/b/c/" */
975 while (is_dir_sep(prefix[i]))
976 i++;
977 in_off = in_len;
978 }
979 }
980 in += in_off;
981 in_len -= in_off;
982
983 if (i >= prefix_len) {
984 if (!in_len)
985 return "./";
986 else
987 return in;
988 }
989
990 strbuf_reset(sb);
991 strbuf_grow(sb, in_len);
992
993 while (i < prefix_len) {
994 if (is_dir_sep(prefix[i])) {
995 strbuf_addstr(sb, "../");
996 while (is_dir_sep(prefix[i]))
997 i++;
998 continue;
999 }
1000 i++;
1001 }
1002 if (!is_dir_sep(prefix[prefix_len - 1]))
1003 strbuf_addstr(sb, "../");
1004
1005 strbuf_addstr(sb, in);
1006
1007 return sb->buf;
1008}
1009
1010/*
1011 * A simpler implementation of relative_path
1012 *
1013 * Get relative path by removing "prefix" from "in". This function
1014 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
1015 * to increase performance when traversing the path to work_tree.
1016 */
1017const char *remove_leading_path(const char *in, const char *prefix)
1018{
1019 static struct strbuf buf = STRBUF_INIT;
1020 int i = 0, j = 0;
1021
1022 if (!prefix || !prefix[0])
1023 return in;
1024 while (prefix[i]) {
1025 if (is_dir_sep(prefix[i])) {
1026 if (!is_dir_sep(in[j]))
1027 return in;
1028 while (is_dir_sep(prefix[i]))
1029 i++;
1030 while (is_dir_sep(in[j]))
1031 j++;
1032 continue;
1033 } else if (in[j] != prefix[i]) {
1034 return in;
1035 }
1036 i++;
1037 j++;
1038 }
1039 if (
1040 /* "/foo" is a prefix of "/foo" */
1041 in[j] &&
1042 /* "/foo" is not a prefix of "/foobar" */
1043 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
1044 )
1045 return in;
1046 while (is_dir_sep(in[j]))
1047 j++;
1048
1049 strbuf_reset(&buf);
1050 if (!in[j])
1051 strbuf_addstr(&buf, ".");
1052 else
1053 strbuf_addstr(&buf, in + j);
1054 return buf.buf;
1055}
1056
1057/*
1058 * It is okay if dst == src, but they should not overlap otherwise.
1059 *
1060 * Performs the following normalizations on src, storing the result in dst:
1061 * - Ensures that components are separated by '/' (Windows only)
1062 * - Squashes sequences of '/' except "//server/share" on Windows
1063 * - Removes "." components.
1064 * - Removes ".." components, and the components the precede them.
1065 * Returns failure (non-zero) if a ".." component appears as first path
1066 * component anytime during the normalization. Otherwise, returns success (0).
1067 *
1068 * Note that this function is purely textual. It does not follow symlinks,
1069 * verify the existence of the path, or make any system calls.
1070 *
1071 * prefix_len != NULL is for a specific case of prefix_pathspec():
1072 * assume that src == dst and src[0..prefix_len-1] is already
1073 * normalized, any time "../" eats up to the prefix_len part,
1074 * prefix_len is reduced. In the end prefix_len is the remaining
1075 * prefix that has not been overridden by user pathspec.
1076 *
1077 * NEEDSWORK: This function doesn't perform normalization w.r.t. trailing '/'.
1078 * For everything but the root folder itself, the normalized path should not
1079 * end with a '/', then the callers need to be fixed up accordingly.
1080 *
1081 */
1082int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
1083{
1084 char *dst0;
1085 const char *end;
1086
1087 /*
1088 * Copy initial part of absolute path: "/", "C:/", "//server/share/".
1089 */
1090 end = src + offset_1st_component(src);
1091 while (src < end) {
1092 char c = *src++;
1093 if (is_dir_sep(c))
1094 c = '/';
1095 *dst++ = c;
1096 }
1097 dst0 = dst;
1098
1099 while (is_dir_sep(*src))
1100 src++;
1101
1102 for (;;) {
1103 char c = *src;
1104
1105 /*
1106 * A path component that begins with . could be
1107 * special:
1108 * (1) "." and ends -- ignore and terminate.
1109 * (2) "./" -- ignore them, eat slash and continue.
1110 * (3) ".." and ends -- strip one and terminate.
1111 * (4) "../" -- strip one, eat slash and continue.
1112 */
1113 if (c == '.') {
1114 if (!src[1]) {
1115 /* (1) */
1116 src++;
1117 } else if (is_dir_sep(src[1])) {
1118 /* (2) */
1119 src += 2;
1120 while (is_dir_sep(*src))
1121 src++;
1122 continue;
1123 } else if (src[1] == '.') {
1124 if (!src[2]) {
1125 /* (3) */
1126 src += 2;
1127 goto up_one;
1128 } else if (is_dir_sep(src[2])) {
1129 /* (4) */
1130 src += 3;
1131 while (is_dir_sep(*src))
1132 src++;
1133 goto up_one;
1134 }
1135 }
1136 }
1137
1138 /* copy up to the next '/', and eat all '/' */
1139 while ((c = *src++) != '\0' && !is_dir_sep(c))
1140 *dst++ = c;
1141 if (is_dir_sep(c)) {
1142 *dst++ = '/';
1143 while (is_dir_sep(c))
1144 c = *src++;
1145 src--;
1146 } else if (!c)
1147 break;
1148 continue;
1149
1150 up_one:
1151 /*
1152 * dst0..dst is prefix portion, and dst[-1] is '/';
1153 * go up one level.
1154 */
1155 dst--; /* go to trailing '/' */
1156 if (dst <= dst0)
1157 return -1;
1158 /* Windows: dst[-1] cannot be backslash anymore */
1159 while (dst0 < dst && dst[-1] != '/')
1160 dst--;
1161 if (prefix_len && *prefix_len > dst - dst0)
1162 *prefix_len = dst - dst0;
1163 }
1164 *dst = '\0';
1165 return 0;
1166}
1167
1168int normalize_path_copy(char *dst, const char *src)
1169{
1170 return normalize_path_copy_len(dst, src, NULL);
1171}
1172
1173/*
1174 * path = Canonical absolute path
1175 * prefixes = string_list containing normalized, absolute paths without
1176 * trailing slashes (except for the root directory, which is denoted by "/").
1177 *
1178 * Determines, for each path in prefixes, whether the "prefix"
1179 * is an ancestor directory of path. Returns the length of the longest
1180 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
1181 * is an ancestor. (Note that this means 0 is returned if prefixes is
1182 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
1183 * are not considered to be their own ancestors. path must be in a
1184 * canonical form: empty components, or "." or ".." components are not
1185 * allowed.
1186 */
1187int longest_ancestor_length(const char *path, struct string_list *prefixes)
1188{
1189 int i, max_len = -1;
1190
1191 if (!strcmp(path, "/"))
1192 return -1;
1193
1194 for (i = 0; i < prefixes->nr; i++) {
1195 const char *ceil = prefixes->items[i].string;
1196 int len = strlen(ceil);
1197
1198 if (len == 1 && ceil[0] == '/')
1199 len = 0; /* root matches anything, with length 0 */
1200 else if (!strncmp(path, ceil, len) && path[len] == '/')
1201 ; /* match of length len */
1202 else
1203 continue; /* no match */
1204
1205 if (len > max_len)
1206 max_len = len;
1207 }
1208
1209 return max_len;
1210}
1211
1212/* strip arbitrary amount of directory separators at end of path */
1213static inline int chomp_trailing_dir_sep(const char *path, int len)
1214{
1215 while (len && is_dir_sep(path[len - 1]))
1216 len--;
1217 return len;
1218}
1219
1220/*
1221 * If path ends with suffix (complete path components), returns the
1222 * part before suffix (sans trailing directory separators).
1223 * Otherwise returns NULL.
1224 */
1225char *strip_path_suffix(const char *path, const char *suffix)
1226{
1227 int path_len = strlen(path), suffix_len = strlen(suffix);
1228
1229 while (suffix_len) {
1230 if (!path_len)
1231 return NULL;
1232
1233 if (is_dir_sep(path[path_len - 1])) {
1234 if (!is_dir_sep(suffix[suffix_len - 1]))
1235 return NULL;
1236 path_len = chomp_trailing_dir_sep(path, path_len);
1237 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
1238 }
1239 else if (path[--path_len] != suffix[--suffix_len])
1240 return NULL;
1241 }
1242
1243 if (path_len && !is_dir_sep(path[path_len - 1]))
1244 return NULL;
1245 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
1246}
1247
1248int daemon_avoid_alias(const char *p)
1249{
1250 int sl, ndot;
1251
1252 /*
1253 * This resurrects the belts and suspenders paranoia check by HPA
1254 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
1255 * does not do getcwd() based path canonicalization.
1256 *
1257 * sl becomes true immediately after seeing '/' and continues to
1258 * be true as long as dots continue after that without intervening
1259 * non-dot character.
1260 */
1261 if (!p || (*p != '/' && *p != '~'))
1262 return -1;
1263 sl = 1; ndot = 0;
1264 p++;
1265
1266 while (1) {
1267 char ch = *p++;
1268 if (sl) {
1269 if (ch == '.')
1270 ndot++;
1271 else if (ch == '/') {
1272 if (ndot < 3)
1273 /* reject //, /./ and /../ */
1274 return -1;
1275 ndot = 0;
1276 }
1277 else if (ch == 0) {
1278 if (0 < ndot && ndot < 3)
1279 /* reject /.$ and /..$ */
1280 return -1;
1281 return 0;
1282 }
1283 else
1284 sl = ndot = 0;
1285 }
1286 else if (ch == 0)
1287 return 0;
1288 else if (ch == '/') {
1289 sl = 1;
1290 ndot = 0;
1291 }
1292 }
1293}
1294
1295static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
1296{
1297 if (len < skip)
1298 return 0;
1299 len -= skip;
1300 path += skip;
1301 while (len-- > 0) {
1302 char c = *(path++);
1303 if (c != ' ' && c != '.')
1304 return 0;
1305 }
1306 return 1;
1307}
1308
1309int is_ntfs_dotgit(const char *name)
1310{
1311 int len;
1312
1313 for (len = 0; ; len++)
1314 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
1315 if (only_spaces_and_periods(name, len, 4) &&
1316 !strncasecmp(name, ".git", 4))
1317 return 1;
1318 if (only_spaces_and_periods(name, len, 5) &&
1319 !strncasecmp(name, "git~1", 5))
1320 return 1;
1321 if (name[len] != '\\')
1322 return 0;
1323 name += len + 1;
1324 len = -1;
1325 }
1326}
1327
1328int looks_like_command_line_option(const char *str)
1329{
1330 return str && str[0] == '-';
1331}
1332
1333char *xdg_config_home(const char *filename)
1334{
1335 const char *home, *config_home;
1336
1337 assert(filename);
1338 config_home = getenv("XDG_CONFIG_HOME");
1339 if (config_home && *config_home)
1340 return mkpathdup("%s/git/%s", config_home, filename);
1341
1342 home = getenv("HOME");
1343 if (home)
1344 return mkpathdup("%s/.config/git/%s", home, filename);
1345 return NULL;
1346}
1347
1348char *xdg_cache_home(const char *filename)
1349{
1350 const char *home, *cache_home;
1351
1352 assert(filename);
1353 cache_home = getenv("XDG_CACHE_HOME");
1354 if (cache_home && *cache_home)
1355 return mkpathdup("%s/git/%s", cache_home, filename);
1356
1357 home = getenv("HOME");
1358 if (home)
1359 return mkpathdup("%s/.cache/git/%s", home, filename);
1360 return NULL;
1361}
1362
1363GIT_PATH_FUNC(git_path_cherry_pick_head, "CHERRY_PICK_HEAD")
1364GIT_PATH_FUNC(git_path_revert_head, "REVERT_HEAD")
1365GIT_PATH_FUNC(git_path_squash_msg, "SQUASH_MSG")
1366GIT_PATH_FUNC(git_path_merge_msg, "MERGE_MSG")
1367GIT_PATH_FUNC(git_path_merge_rr, "MERGE_RR")
1368GIT_PATH_FUNC(git_path_merge_mode, "MERGE_MODE")
1369GIT_PATH_FUNC(git_path_merge_head, "MERGE_HEAD")
1370GIT_PATH_FUNC(git_path_fetch_head, "FETCH_HEAD")
1371GIT_PATH_FUNC(git_path_shallow, "shallow")