1/*
2 * Utilities for paths and pathnames
3 */
4#include "cache.h"
5#include "strbuf.h"
6#include "string-list.h"
7static int get_st_mode_bits(const char *path, int *mode)
9{
10 struct stat st;
11 if (lstat(path, &st) < 0)
12 return -1;
13 *mode = st.st_mode;
14 return 0;
15}
16static char bad_path[] = "/bad-path/";
18static char *get_pathname(void)
20{
21 static char pathname_array[4][PATH_MAX];
22 static int index;
23 return pathname_array[3 & ++index];
24}
25static char *cleanup_path(char *path)
27{
28 /* Clean it up */
29 if (!memcmp(path, "./", 2)) {
30 path += 2;
31 while (*path == '/')
32 path++;
33 }
34 return path;
35}
36char *mksnpath(char *buf, size_t n, const char *fmt, ...)
38{
39 va_list args;
40 unsigned len;
41 va_start(args, fmt);
43 len = vsnprintf(buf, n, fmt, args);
44 va_end(args);
45 if (len >= n) {
46 strlcpy(buf, bad_path, n);
47 return buf;
48 }
49 return cleanup_path(buf);
50}
51static char *vsnpath(char *buf, size_t n, const char *fmt, va_list args)
53{
54 const char *git_dir = get_git_dir();
55 size_t len;
56 len = strlen(git_dir);
58 if (n < len + 1)
59 goto bad;
60 memcpy(buf, git_dir, len);
61 if (len && !is_dir_sep(git_dir[len-1]))
62 buf[len++] = '/';
63 len += vsnprintf(buf + len, n - len, fmt, args);
64 if (len >= n)
65 goto bad;
66 return cleanup_path(buf);
67bad:
68 strlcpy(buf, bad_path, n);
69 return buf;
70}
71char *git_snpath(char *buf, size_t n, const char *fmt, ...)
73{
74 char *ret;
75 va_list args;
76 va_start(args, fmt);
77 ret = vsnpath(buf, n, fmt, args);
78 va_end(args);
79 return ret;
80}
81char *git_pathdup(const char *fmt, ...)
83{
84 char path[PATH_MAX], *ret;
85 va_list args;
86 va_start(args, fmt);
87 ret = vsnpath(path, sizeof(path), fmt, args);
88 va_end(args);
89 return xstrdup(ret);
90}
91char *mkpathdup(const char *fmt, ...)
93{
94 char *path;
95 struct strbuf sb = STRBUF_INIT;
96 va_list args;
97 va_start(args, fmt);
99 strbuf_vaddf(&sb, fmt, args);
100 va_end(args);
101 path = xstrdup(cleanup_path(sb.buf));
102 strbuf_release(&sb);
104 return path;
105}
106char *mkpath(const char *fmt, ...)
108{
109 va_list args;
110 unsigned len;
111 char *pathname = get_pathname();
112 va_start(args, fmt);
114 len = vsnprintf(pathname, PATH_MAX, fmt, args);
115 va_end(args);
116 if (len >= PATH_MAX)
117 return bad_path;
118 return cleanup_path(pathname);
119}
120char *git_path(const char *fmt, ...)
122{
123 char *pathname = get_pathname();
124 va_list args;
125 char *ret;
126 va_start(args, fmt);
128 ret = vsnpath(pathname, PATH_MAX, fmt, args);
129 va_end(args);
130 return ret;
131}
132void home_config_paths(char **global, char **xdg, char *file)
134{
135 char *xdg_home = getenv("XDG_CONFIG_HOME");
136 char *home = getenv("HOME");
137 char *to_free = NULL;
138 if (!home) {
140 if (global)
141 *global = NULL;
142 } else {
143 if (!xdg_home) {
144 to_free = mkpathdup("%s/.config", home);
145 xdg_home = to_free;
146 }
147 if (global)
148 *global = mkpathdup("%s/.gitconfig", home);
149 }
150 if (xdg) {
152 if (!xdg_home)
153 *xdg = NULL;
154 else
155 *xdg = mkpathdup("%s/git/%s", xdg_home, file);
156 }
157 free(to_free);
159}
160char *git_path_submodule(const char *path, const char *fmt, ...)
162{
163 char *pathname = get_pathname();
164 struct strbuf buf = STRBUF_INIT;
165 const char *git_dir;
166 va_list args;
167 unsigned len;
168 len = strlen(path);
170 if (len > PATH_MAX-100)
171 return bad_path;
172 strbuf_addstr(&buf, path);
174 if (len && path[len-1] != '/')
175 strbuf_addch(&buf, '/');
176 strbuf_addstr(&buf, ".git");
177 git_dir = read_gitfile(buf.buf);
179 if (git_dir) {
180 strbuf_reset(&buf);
181 strbuf_addstr(&buf, git_dir);
182 }
183 strbuf_addch(&buf, '/');
184 if (buf.len >= PATH_MAX)
186 return bad_path;
187 memcpy(pathname, buf.buf, buf.len + 1);
188 strbuf_release(&buf);
190 len = strlen(pathname);
191 va_start(args, fmt);
193 len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
194 va_end(args);
195 if (len >= PATH_MAX)
196 return bad_path;
197 return cleanup_path(pathname);
198}
199int validate_headref(const char *path)
201{
202 struct stat st;
203 char *buf, buffer[256];
204 unsigned char sha1[20];
205 int fd;
206 ssize_t len;
207 if (lstat(path, &st) < 0)
209 return -1;
210 /* Make sure it is a "refs/.." symlink */
212 if (S_ISLNK(st.st_mode)) {
213 len = readlink(path, buffer, sizeof(buffer)-1);
214 if (len >= 5 && !memcmp("refs/", buffer, 5))
215 return 0;
216 return -1;
217 }
218 /*
220 * Anything else, just open it and try to see if it is a symbolic ref.
221 */
222 fd = open(path, O_RDONLY);
223 if (fd < 0)
224 return -1;
225 len = read_in_full(fd, buffer, sizeof(buffer)-1);
226 close(fd);
227 /*
229 * Is it a symbolic ref?
230 */
231 if (len < 4)
232 return -1;
233 if (!memcmp("ref:", buffer, 4)) {
234 buf = buffer + 4;
235 len -= 4;
236 while (len && isspace(*buf))
237 buf++, len--;
238 if (len >= 5 && !memcmp("refs/", buf, 5))
239 return 0;
240 }
241 /*
243 * Is this a detached HEAD?
244 */
245 if (!get_sha1_hex(buffer, sha1))
246 return 0;
247 return -1;
249}
250static struct passwd *getpw_str(const char *username, size_t len)
252{
253 struct passwd *pw;
254 char *username_z = xmemdupz(username, len);
255 pw = getpwnam(username_z);
256 free(username_z);
257 return pw;
258}
259/*
261 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
262 * then it is a newly allocated string. Returns NULL on getpw failure or
263 * if path is NULL.
264 */
265char *expand_user_path(const char *path)
266{
267 struct strbuf user_path = STRBUF_INIT;
268 const char *to_copy = path;
269 if (path == NULL)
271 goto return_null;
272 if (path[0] == '~') {
273 const char *first_slash = strchrnul(path, '/');
274 const char *username = path + 1;
275 size_t username_len = first_slash - username;
276 if (username_len == 0) {
277 const char *home = getenv("HOME");
278 if (!home)
279 goto return_null;
280 strbuf_addstr(&user_path, home);
281 } else {
282 struct passwd *pw = getpw_str(username, username_len);
283 if (!pw)
284 goto return_null;
285 strbuf_addstr(&user_path, pw->pw_dir);
286 }
287 to_copy = first_slash;
288 }
289 strbuf_addstr(&user_path, to_copy);
290 return strbuf_detach(&user_path, NULL);
291return_null:
292 strbuf_release(&user_path);
293 return NULL;
294}
295/*
297 * First, one directory to try is determined by the following algorithm.
298 *
299 * (0) If "strict" is given, the path is used as given and no DWIM is
300 * done. Otherwise:
301 * (1) "~/path" to mean path under the running user's home directory;
302 * (2) "~user/path" to mean path under named user's home directory;
303 * (3) "relative/path" to mean cwd relative directory; or
304 * (4) "/absolute/path" to mean absolute directory.
305 *
306 * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git"
307 * in this order. We select the first one that is a valid git repository, and
308 * chdir() to it. If none match, or we fail to chdir, we return NULL.
309 *
310 * If all goes well, we return the directory we used to chdir() (but
311 * before ~user is expanded), avoiding getcwd() resolving symbolic
312 * links. User relative paths are also returned as they are given,
313 * except DWIM suffixing.
314 */
315const char *enter_repo(const char *path, int strict)
316{
317 static char used_path[PATH_MAX];
318 static char validated_path[PATH_MAX];
319 if (!path)
321 return NULL;
322 if (!strict) {
324 static const char *suffix[] = {
325 "/.git", "", ".git/.git", ".git", NULL,
326 };
327 const char *gitfile;
328 int len = strlen(path);
329 int i;
330 while ((1 < len) && (path[len-1] == '/'))
331 len--;
332 if (PATH_MAX <= len)
334 return NULL;
335 strncpy(used_path, path, len); used_path[len] = 0 ;
336 strcpy(validated_path, used_path);
337 if (used_path[0] == '~') {
339 char *newpath = expand_user_path(used_path);
340 if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
341 free(newpath);
342 return NULL;
343 }
344 /*
345 * Copy back into the static buffer. A pity
346 * since newpath was not bounded, but other
347 * branches of the if are limited by PATH_MAX
348 * anyway.
349 */
350 strcpy(used_path, newpath); free(newpath);
351 }
352 else if (PATH_MAX - 10 < len)
353 return NULL;
354 len = strlen(used_path);
355 for (i = 0; suffix[i]; i++) {
356 struct stat st;
357 strcpy(used_path + len, suffix[i]);
358 if (!stat(used_path, &st) &&
359 (S_ISREG(st.st_mode) ||
360 (S_ISDIR(st.st_mode) && is_git_directory(used_path)))) {
361 strcat(validated_path, suffix[i]);
362 break;
363 }
364 }
365 if (!suffix[i])
366 return NULL;
367 gitfile = read_gitfile(used_path) ;
368 if (gitfile)
369 strcpy(used_path, gitfile);
370 if (chdir(used_path))
371 return NULL;
372 path = validated_path;
373 }
374 else if (chdir(path))
375 return NULL;
376 if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
378 validate_headref("HEAD") == 0) {
379 set_git_dir(".");
380 check_repository_format();
381 return path;
382 }
383 return NULL;
385}
386static int calc_shared_perm(int mode)
388{
389 int tweak;
390 if (shared_repository < 0)
392 tweak = -shared_repository;
393 else
394 tweak = shared_repository;
395 if (!(mode & S_IWUSR))
397 tweak &= ~0222;
398 if (mode & S_IXUSR)
399 /* Copy read bits to execute bits */
400 tweak |= (tweak & 0444) >> 2;
401 if (shared_repository < 0)
402 mode = (mode & ~0777) | tweak;
403 else
404 mode |= tweak;
405 return mode;
407}
408int adjust_shared_perm(const char *path)
411{
412 int old_mode, new_mode;
413 if (!shared_repository)
415 return 0;
416 if (get_st_mode_bits(path, &old_mode) < 0)
417 return -1;
418 new_mode = calc_shared_perm(old_mode);
420 if (S_ISDIR(old_mode)) {
421 /* Copy read bits to execute bits */
422 new_mode |= (new_mode & 0444) >> 2;
423 new_mode |= FORCE_DIR_SET_GID;
424 }
425 if (((old_mode ^ new_mode) & ~S_IFMT) &&
427 chmod(path, (new_mode & ~S_IFMT)) < 0)
428 return -2;
429 return 0;
430}
431static int have_same_root(const char *path1, const char *path2)
433{
434 int is_abs1, is_abs2;
435 is_abs1 = is_absolute_path(path1);
437 is_abs2 = is_absolute_path(path2);
438 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
439 (!is_abs1 && !is_abs2);
440}
441/*
443 * Give path as relative to prefix.
444 *
445 * The strbuf may or may not be used, so do not assume it contains the
446 * returned path.
447 */
448const char *relative_path(const char *in, const char *prefix,
449 struct strbuf *sb)
450{
451 int in_len = in ? strlen(in) : 0;
452 int prefix_len = prefix ? strlen(prefix) : 0;
453 int in_off = 0;
454 int prefix_off = 0;
455 int i = 0, j = 0;
456 if (!in_len)
458 return "./";
459 else if (!prefix_len)
460 return in;
461 if (have_same_root(in, prefix)) {
463 /* bypass dos_drive, for "c:" is identical to "C:" */
464 if (has_dos_drive_prefix(in)) {
465 i = 2;
466 j = 2;
467 }
468 } else {
469 return in;
470 }
471 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
473 if (is_dir_sep(prefix[i])) {
474 while (is_dir_sep(prefix[i]))
475 i++;
476 while (is_dir_sep(in[j]))
477 j++;
478 prefix_off = i;
479 in_off = j;
480 } else {
481 i++;
482 j++;
483 }
484 }
485 if (
487 /* "prefix" seems like prefix of "in" */
488 i >= prefix_len &&
489 /*
490 * but "/foo" is not a prefix of "/foobar"
491 * (i.e. prefix not end with '/')
492 */
493 prefix_off < prefix_len) {
494 if (j >= in_len) {
495 /* in="/a/b", prefix="/a/b" */
496 in_off = in_len;
497 } else if (is_dir_sep(in[j])) {
498 /* in="/a/b/c", prefix="/a/b" */
499 while (is_dir_sep(in[j]))
500 j++;
501 in_off = j;
502 } else {
503 /* in="/a/bbb/c", prefix="/a/b" */
504 i = prefix_off;
505 }
506 } else if (
507 /* "in" is short than "prefix" */
508 j >= in_len &&
509 /* "in" not end with '/' */
510 in_off < in_len) {
511 if (is_dir_sep(prefix[i])) {
512 /* in="/a/b", prefix="/a/b/c/" */
513 while (is_dir_sep(prefix[i]))
514 i++;
515 in_off = in_len;
516 }
517 }
518 in += in_off;
519 in_len -= in_off;
520 if (i >= prefix_len) {
522 if (!in_len)
523 return "./";
524 else
525 return in;
526 }
527 strbuf_reset(sb);
529 strbuf_grow(sb, in_len);
530 while (i < prefix_len) {
532 if (is_dir_sep(prefix[i])) {
533 strbuf_addstr(sb, "../");
534 while (is_dir_sep(prefix[i]))
535 i++;
536 continue;
537 }
538 i++;
539 }
540 if (!is_dir_sep(prefix[prefix_len - 1]))
541 strbuf_addstr(sb, "../");
542 strbuf_addstr(sb, in);
544 return sb->buf;
546}
547/*
549 * A simpler implementation of relative_path
550 *
551 * Get relative path by removing "prefix" from "in". This function
552 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
553 * to increase performance when traversing the path to work_tree.
554 */
555const char *remove_leading_path(const char *in, const char *prefix)
556{
557 static char buf[PATH_MAX + 1];
558 int i = 0, j = 0;
559 if (!prefix || !prefix[0])
561 return in;
562 while (prefix[i]) {
563 if (is_dir_sep(prefix[i])) {
564 if (!is_dir_sep(in[j]))
565 return in;
566 while (is_dir_sep(prefix[i]))
567 i++;
568 while (is_dir_sep(in[j]))
569 j++;
570 continue;
571 } else if (in[j] != prefix[i]) {
572 return in;
573 }
574 i++;
575 j++;
576 }
577 if (
578 /* "/foo" is a prefix of "/foo" */
579 in[j] &&
580 /* "/foo" is not a prefix of "/foobar" */
581 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
582 )
583 return in;
584 while (is_dir_sep(in[j]))
585 j++;
586 if (!in[j])
587 strcpy(buf, ".");
588 else
589 strcpy(buf, in + j);
590 return buf;
591}
592/*
594 * It is okay if dst == src, but they should not overlap otherwise.
595 *
596 * Performs the following normalizations on src, storing the result in dst:
597 * - Ensures that components are separated by '/' (Windows only)
598 * - Squashes sequences of '/'.
599 * - Removes "." components.
600 * - Removes ".." components, and the components the precede them.
601 * Returns failure (non-zero) if a ".." component appears as first path
602 * component anytime during the normalization. Otherwise, returns success (0).
603 *
604 * Note that this function is purely textual. It does not follow symlinks,
605 * verify the existence of the path, or make any system calls.
606 *
607 * prefix_len != NULL is for a specific case of prefix_pathspec():
608 * assume that src == dst and src[0..prefix_len-1] is already
609 * normalized, any time "../" eats up to the prefix_len part,
610 * prefix_len is reduced. In the end prefix_len is the remaining
611 * prefix that has not been overridden by user pathspec.
612 */
613int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
614{
615 char *dst0;
616 if (has_dos_drive_prefix(src)) {
618 *dst++ = *src++;
619 *dst++ = *src++;
620 }
621 dst0 = dst;
622 if (is_dir_sep(*src)) {
624 *dst++ = '/';
625 while (is_dir_sep(*src))
626 src++;
627 }
628 for (;;) {
630 char c = *src;
631 /*
633 * A path component that begins with . could be
634 * special:
635 * (1) "." and ends -- ignore and terminate.
636 * (2) "./" -- ignore them, eat slash and continue.
637 * (3) ".." and ends -- strip one and terminate.
638 * (4) "../" -- strip one, eat slash and continue.
639 */
640 if (c == '.') {
641 if (!src[1]) {
642 /* (1) */
643 src++;
644 } else if (is_dir_sep(src[1])) {
645 /* (2) */
646 src += 2;
647 while (is_dir_sep(*src))
648 src++;
649 continue;
650 } else if (src[1] == '.') {
651 if (!src[2]) {
652 /* (3) */
653 src += 2;
654 goto up_one;
655 } else if (is_dir_sep(src[2])) {
656 /* (4) */
657 src += 3;
658 while (is_dir_sep(*src))
659 src++;
660 goto up_one;
661 }
662 }
663 }
664 /* copy up to the next '/', and eat all '/' */
666 while ((c = *src++) != '\0' && !is_dir_sep(c))
667 *dst++ = c;
668 if (is_dir_sep(c)) {
669 *dst++ = '/';
670 while (is_dir_sep(c))
671 c = *src++;
672 src--;
673 } else if (!c)
674 break;
675 continue;
676 up_one:
678 /*
679 * dst0..dst is prefix portion, and dst[-1] is '/';
680 * go up one level.
681 */
682 dst--; /* go to trailing '/' */
683 if (dst <= dst0)
684 return -1;
685 /* Windows: dst[-1] cannot be backslash anymore */
686 while (dst0 < dst && dst[-1] != '/')
687 dst--;
688 if (prefix_len && *prefix_len > dst - dst0)
689 *prefix_len = dst - dst0;
690 }
691 *dst = '\0';
692 return 0;
693}
694int normalize_path_copy(char *dst, const char *src)
696{
697 return normalize_path_copy_len(dst, src, NULL);
698}
699/*
701 * path = Canonical absolute path
702 * prefixes = string_list containing normalized, absolute paths without
703 * trailing slashes (except for the root directory, which is denoted by "/").
704 *
705 * Determines, for each path in prefixes, whether the "prefix"
706 * is an ancestor directory of path. Returns the length of the longest
707 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
708 * is an ancestor. (Note that this means 0 is returned if prefixes is
709 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
710 * are not considered to be their own ancestors. path must be in a
711 * canonical form: empty components, or "." or ".." components are not
712 * allowed.
713 */
714int longest_ancestor_length(const char *path, struct string_list *prefixes)
715{
716 int i, max_len = -1;
717 if (!strcmp(path, "/"))
719 return -1;
720 for (i = 0; i < prefixes->nr; i++) {
722 const char *ceil = prefixes->items[i].string;
723 int len = strlen(ceil);
724 if (len == 1 && ceil[0] == '/')
726 len = 0; /* root matches anything, with length 0 */
727 else if (!strncmp(path, ceil, len) && path[len] == '/')
728 ; /* match of length len */
729 else
730 continue; /* no match */
731 if (len > max_len)
733 max_len = len;
734 }
735 return max_len;
737}
738/* strip arbitrary amount of directory separators at end of path */
740static inline int chomp_trailing_dir_sep(const char *path, int len)
741{
742 while (len && is_dir_sep(path[len - 1]))
743 len--;
744 return len;
745}
746/*
748 * If path ends with suffix (complete path components), returns the
749 * part before suffix (sans trailing directory separators).
750 * Otherwise returns NULL.
751 */
752char *strip_path_suffix(const char *path, const char *suffix)
753{
754 int path_len = strlen(path), suffix_len = strlen(suffix);
755 while (suffix_len) {
757 if (!path_len)
758 return NULL;
759 if (is_dir_sep(path[path_len - 1])) {
761 if (!is_dir_sep(suffix[suffix_len - 1]))
762 return NULL;
763 path_len = chomp_trailing_dir_sep(path, path_len);
764 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
765 }
766 else if (path[--path_len] != suffix[--suffix_len])
767 return NULL;
768 }
769 if (path_len && !is_dir_sep(path[path_len - 1]))
771 return NULL;
772 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
773}
774int daemon_avoid_alias(const char *p)
776{
777 int sl, ndot;
778 /*
780 * This resurrects the belts and suspenders paranoia check by HPA
781 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
782 * does not do getcwd() based path canonicalization.
783 *
784 * sl becomes true immediately after seeing '/' and continues to
785 * be true as long as dots continue after that without intervening
786 * non-dot character.
787 */
788 if (!p || (*p != '/' && *p != '~'))
789 return -1;
790 sl = 1; ndot = 0;
791 p++;
792 while (1) {
794 char ch = *p++;
795 if (sl) {
796 if (ch == '.')
797 ndot++;
798 else if (ch == '/') {
799 if (ndot < 3)
800 /* reject //, /./ and /../ */
801 return -1;
802 ndot = 0;
803 }
804 else if (ch == 0) {
805 if (0 < ndot && ndot < 3)
806 /* reject /.$ and /..$ */
807 return -1;
808 return 0;
809 }
810 else
811 sl = ndot = 0;
812 }
813 else if (ch == 0)
814 return 0;
815 else if (ch == '/') {
816 sl = 1;
817 ndot = 0;
818 }
819 }
820}
821static int only_spaces_and_periods(const char *path, size_t len, size_t skip)
823{
824 if (len < skip)
825 return 0;
826 len -= skip;
827 path += skip;
828 while (len-- > 0) {
829 char c = *(path++);
830 if (c != ' ' && c != '.')
831 return 0;
832 }
833 return 1;
834}
835int is_ntfs_dotgit(const char *name)
837{
838 int len;
839 for (len = 0; ; len++)
841 if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) {
842 if (only_spaces_and_periods(name, len, 4) &&
843 !strncasecmp(name, ".git", 4))
844 return 1;
845 if (only_spaces_and_periods(name, len, 5) &&
846 !strncasecmp(name, "git~1", 5))
847 return 1;
848 if (name[len] != '\\')
849 return 0;
850 name += len + 1;
851 len = -1;
852 }
853}