a7ceea26fbdee5b8f94c5023d1a8de5f1f4a9fa8
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 struct strbuf *get_pathname(void)
20{
21 static struct strbuf pathname_array[4] = {
22 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
23 };
24 static int index;
25 struct strbuf *sb = &pathname_array[3 & ++index];
26 strbuf_reset(sb);
27 return sb;
28}
29static char *cleanup_path(char *path)
31{
32 /* Clean it up */
33 if (!memcmp(path, "./", 2)) {
34 path += 2;
35 while (*path == '/')
36 path++;
37 }
38 return path;
39}
40static void strbuf_cleanup_path(struct strbuf *sb)
42{
43 char *path = cleanup_path(sb->buf);
44 if (path > sb->buf)
45 strbuf_remove(sb, 0, path - sb->buf);
46}
47char *mksnpath(char *buf, size_t n, const char *fmt, ...)
49{
50 va_list args;
51 unsigned len;
52 va_start(args, fmt);
54 len = vsnprintf(buf, n, fmt, args);
55 va_end(args);
56 if (len >= n) {
57 strlcpy(buf, bad_path, n);
58 return buf;
59 }
60 return cleanup_path(buf);
61}
62static void vsnpath(struct strbuf *buf, const char *fmt, va_list args)
64{
65 const char *git_dir = get_git_dir();
66 strbuf_addstr(buf, git_dir);
67 if (buf->len && !is_dir_sep(buf->buf[buf->len - 1]))
68 strbuf_addch(buf, '/');
69 strbuf_vaddf(buf, fmt, args);
70 strbuf_cleanup_path(buf);
71}
72char *git_snpath(char *buf, size_t n, const char *fmt, ...)
74{
75 struct strbuf sb = STRBUF_INIT;
76 va_list args;
77 va_start(args, fmt);
78 vsnpath(&sb, fmt, args);
79 va_end(args);
80 if (sb.len >= n)
81 strlcpy(buf, bad_path, n);
82 else
83 memcpy(buf, sb.buf, sb.len + 1);
84 strbuf_release(&sb);
85 return buf;
86}
87char *git_pathdup(const char *fmt, ...)
89{
90 struct strbuf path = STRBUF_INIT;
91 va_list args;
92 va_start(args, fmt);
93 vsnpath(&path, fmt, args);
94 va_end(args);
95 return strbuf_detach(&path, NULL);
96}
97char *mkpathdup(const char *fmt, ...)
99{
100 struct strbuf sb = STRBUF_INIT;
101 va_list args;
102 va_start(args, fmt);
103 strbuf_vaddf(&sb, fmt, args);
104 va_end(args);
105 strbuf_cleanup_path(&sb);
106 return strbuf_detach(&sb, NULL);
107}
108const char *mkpath(const char *fmt, ...)
110{
111 va_list args;
112 struct strbuf *pathname = get_pathname();
113 va_start(args, fmt);
114 strbuf_vaddf(pathname, fmt, args);
115 va_end(args);
116 return cleanup_path(pathname->buf);
117}
118const char *git_path(const char *fmt, ...)
120{
121 struct strbuf *pathname = get_pathname();
122 va_list args;
123 va_start(args, fmt);
124 vsnpath(pathname, fmt, args);
125 va_end(args);
126 return pathname->buf;
127}
128void home_config_paths(char **global, char **xdg, char *file)
130{
131 char *xdg_home = getenv("XDG_CONFIG_HOME");
132 char *home = getenv("HOME");
133 char *to_free = NULL;
134 if (!home) {
136 if (global)
137 *global = NULL;
138 } else {
139 if (!xdg_home) {
140 to_free = mkpathdup("%s/.config", home);
141 xdg_home = to_free;
142 }
143 if (global)
144 *global = mkpathdup("%s/.gitconfig", home);
145 }
146 if (xdg) {
148 if (!xdg_home)
149 *xdg = NULL;
150 else
151 *xdg = mkpathdup("%s/git/%s", xdg_home, file);
152 }
153 free(to_free);
155}
156const char *git_path_submodule(const char *path, const char *fmt, ...)
158{
159 struct strbuf *buf = get_pathname();
160 const char *git_dir;
161 va_list args;
162 strbuf_addstr(buf, path);
164 if (buf->len && buf->buf[buf->len - 1] != '/')
165 strbuf_addch(buf, '/');
166 strbuf_addstr(buf, ".git");
167 git_dir = read_gitfile(buf->buf);
169 if (git_dir) {
170 strbuf_reset(buf);
171 strbuf_addstr(buf, git_dir);
172 }
173 strbuf_addch(buf, '/');
174 va_start(args, fmt);
176 strbuf_vaddf(buf, fmt, args);
177 va_end(args);
178 strbuf_cleanup_path(buf);
179 return buf->buf;
180}
181int validate_headref(const char *path)
183{
184 struct stat st;
185 char *buf, buffer[256];
186 unsigned char sha1[20];
187 int fd;
188 ssize_t len;
189 if (lstat(path, &st) < 0)
191 return -1;
192 /* Make sure it is a "refs/.." symlink */
194 if (S_ISLNK(st.st_mode)) {
195 len = readlink(path, buffer, sizeof(buffer)-1);
196 if (len >= 5 && !memcmp("refs/", buffer, 5))
197 return 0;
198 return -1;
199 }
200 /*
202 * Anything else, just open it and try to see if it is a symbolic ref.
203 */
204 fd = open(path, O_RDONLY);
205 if (fd < 0)
206 return -1;
207 len = read_in_full(fd, buffer, sizeof(buffer)-1);
208 close(fd);
209 /*
211 * Is it a symbolic ref?
212 */
213 if (len < 4)
214 return -1;
215 if (!memcmp("ref:", buffer, 4)) {
216 buf = buffer + 4;
217 len -= 4;
218 while (len && isspace(*buf))
219 buf++, len--;
220 if (len >= 5 && !memcmp("refs/", buf, 5))
221 return 0;
222 }
223 /*
225 * Is this a detached HEAD?
226 */
227 if (!get_sha1_hex(buffer, sha1))
228 return 0;
229 return -1;
231}
232static struct passwd *getpw_str(const char *username, size_t len)
234{
235 struct passwd *pw;
236 char *username_z = xmemdupz(username, len);
237 pw = getpwnam(username_z);
238 free(username_z);
239 return pw;
240}
241/*
243 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
244 * then it is a newly allocated string. Returns NULL on getpw failure or
245 * if path is NULL.
246 */
247char *expand_user_path(const char *path)
248{
249 struct strbuf user_path = STRBUF_INIT;
250 const char *to_copy = path;
251 if (path == NULL)
253 goto return_null;
254 if (path[0] == '~') {
255 const char *first_slash = strchrnul(path, '/');
256 const char *username = path + 1;
257 size_t username_len = first_slash - username;
258 if (username_len == 0) {
259 const char *home = getenv("HOME");
260 if (!home)
261 goto return_null;
262 strbuf_addstr(&user_path, home);
263 } else {
264 struct passwd *pw = getpw_str(username, username_len);
265 if (!pw)
266 goto return_null;
267 strbuf_addstr(&user_path, pw->pw_dir);
268 }
269 to_copy = first_slash;
270 }
271 strbuf_addstr(&user_path, to_copy);
272 return strbuf_detach(&user_path, NULL);
273return_null:
274 strbuf_release(&user_path);
275 return NULL;
276}
277/*
279 * First, one directory to try is determined by the following algorithm.
280 *
281 * (0) If "strict" is given, the path is used as given and no DWIM is
282 * done. Otherwise:
283 * (1) "~/path" to mean path under the running user's home directory;
284 * (2) "~user/path" to mean path under named user's home directory;
285 * (3) "relative/path" to mean cwd relative directory; or
286 * (4) "/absolute/path" to mean absolute directory.
287 *
288 * Unless "strict" is given, we try access() for existence of "%s.git/.git",
289 * "%s/.git", "%s.git", "%s" in this order. The first one that exists is
290 * what we try.
291 *
292 * Second, we try chdir() to that. Upon failure, we return NULL.
293 *
294 * Then, we try if the current directory is a valid git repository.
295 * Upon failure, we return NULL.
296 *
297 * If all goes well, we return the directory we used to chdir() (but
298 * before ~user is expanded), avoiding getcwd() resolving symbolic
299 * links. User relative paths are also returned as they are given,
300 * except DWIM suffixing.
301 */
302const char *enter_repo(const char *path, int strict)
303{
304 static char used_path[PATH_MAX];
305 static char validated_path[PATH_MAX];
306 if (!path)
308 return NULL;
309 if (!strict) {
311 static const char *suffix[] = {
312 "/.git", "", ".git/.git", ".git", NULL,
313 };
314 const char *gitfile;
315 int len = strlen(path);
316 int i;
317 while ((1 < len) && (path[len-1] == '/'))
318 len--;
319 if (PATH_MAX <= len)
321 return NULL;
322 strncpy(used_path, path, len); used_path[len] = 0 ;
323 strcpy(validated_path, used_path);
324 if (used_path[0] == '~') {
326 char *newpath = expand_user_path(used_path);
327 if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
328 free(newpath);
329 return NULL;
330 }
331 /*
332 * Copy back into the static buffer. A pity
333 * since newpath was not bounded, but other
334 * branches of the if are limited by PATH_MAX
335 * anyway.
336 */
337 strcpy(used_path, newpath); free(newpath);
338 }
339 else if (PATH_MAX - 10 < len)
340 return NULL;
341 len = strlen(used_path);
342 for (i = 0; suffix[i]; i++) {
343 struct stat st;
344 strcpy(used_path + len, suffix[i]);
345 if (!stat(used_path, &st) &&
346 (S_ISREG(st.st_mode) ||
347 (S_ISDIR(st.st_mode) && is_git_directory(used_path)))) {
348 strcat(validated_path, suffix[i]);
349 break;
350 }
351 }
352 if (!suffix[i])
353 return NULL;
354 gitfile = read_gitfile(used_path) ;
355 if (gitfile)
356 strcpy(used_path, gitfile);
357 if (chdir(used_path))
358 return NULL;
359 path = validated_path;
360 }
361 else if (chdir(path))
362 return NULL;
363 if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
365 validate_headref("HEAD") == 0) {
366 set_git_dir(".");
367 check_repository_format();
368 return path;
369 }
370 return NULL;
372}
373static int calc_shared_perm(int mode)
375{
376 int tweak;
377 if (shared_repository < 0)
379 tweak = -shared_repository;
380 else
381 tweak = shared_repository;
382 if (!(mode & S_IWUSR))
384 tweak &= ~0222;
385 if (mode & S_IXUSR)
386 /* Copy read bits to execute bits */
387 tweak |= (tweak & 0444) >> 2;
388 if (shared_repository < 0)
389 mode = (mode & ~0777) | tweak;
390 else
391 mode |= tweak;
392 return mode;
394}
395int adjust_shared_perm(const char *path)
398{
399 int old_mode, new_mode;
400 if (!shared_repository)
402 return 0;
403 if (get_st_mode_bits(path, &old_mode) < 0)
404 return -1;
405 new_mode = calc_shared_perm(old_mode);
407 if (S_ISDIR(old_mode)) {
408 /* Copy read bits to execute bits */
409 new_mode |= (new_mode & 0444) >> 2;
410 new_mode |= FORCE_DIR_SET_GID;
411 }
412 if (((old_mode ^ new_mode) & ~S_IFMT) &&
414 chmod(path, (new_mode & ~S_IFMT)) < 0)
415 return -2;
416 return 0;
417}
418static int have_same_root(const char *path1, const char *path2)
420{
421 int is_abs1, is_abs2;
422 is_abs1 = is_absolute_path(path1);
424 is_abs2 = is_absolute_path(path2);
425 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
426 (!is_abs1 && !is_abs2);
427}
428/*
430 * Give path as relative to prefix.
431 *
432 * The strbuf may or may not be used, so do not assume it contains the
433 * returned path.
434 */
435const char *relative_path(const char *in, const char *prefix,
436 struct strbuf *sb)
437{
438 int in_len = in ? strlen(in) : 0;
439 int prefix_len = prefix ? strlen(prefix) : 0;
440 int in_off = 0;
441 int prefix_off = 0;
442 int i = 0, j = 0;
443 if (!in_len)
445 return "./";
446 else if (!prefix_len)
447 return in;
448 if (have_same_root(in, prefix)) {
450 /* bypass dos_drive, for "c:" is identical to "C:" */
451 if (has_dos_drive_prefix(in)) {
452 i = 2;
453 j = 2;
454 }
455 } else {
456 return in;
457 }
458 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
460 if (is_dir_sep(prefix[i])) {
461 while (is_dir_sep(prefix[i]))
462 i++;
463 while (is_dir_sep(in[j]))
464 j++;
465 prefix_off = i;
466 in_off = j;
467 } else {
468 i++;
469 j++;
470 }
471 }
472 if (
474 /* "prefix" seems like prefix of "in" */
475 i >= prefix_len &&
476 /*
477 * but "/foo" is not a prefix of "/foobar"
478 * (i.e. prefix not end with '/')
479 */
480 prefix_off < prefix_len) {
481 if (j >= in_len) {
482 /* in="/a/b", prefix="/a/b" */
483 in_off = in_len;
484 } else if (is_dir_sep(in[j])) {
485 /* in="/a/b/c", prefix="/a/b" */
486 while (is_dir_sep(in[j]))
487 j++;
488 in_off = j;
489 } else {
490 /* in="/a/bbb/c", prefix="/a/b" */
491 i = prefix_off;
492 }
493 } else if (
494 /* "in" is short than "prefix" */
495 j >= in_len &&
496 /* "in" not end with '/' */
497 in_off < in_len) {
498 if (is_dir_sep(prefix[i])) {
499 /* in="/a/b", prefix="/a/b/c/" */
500 while (is_dir_sep(prefix[i]))
501 i++;
502 in_off = in_len;
503 }
504 }
505 in += in_off;
506 in_len -= in_off;
507 if (i >= prefix_len) {
509 if (!in_len)
510 return "./";
511 else
512 return in;
513 }
514 strbuf_reset(sb);
516 strbuf_grow(sb, in_len);
517 while (i < prefix_len) {
519 if (is_dir_sep(prefix[i])) {
520 strbuf_addstr(sb, "../");
521 while (is_dir_sep(prefix[i]))
522 i++;
523 continue;
524 }
525 i++;
526 }
527 if (!is_dir_sep(prefix[prefix_len - 1]))
528 strbuf_addstr(sb, "../");
529 strbuf_addstr(sb, in);
531 return sb->buf;
533}
534/*
536 * A simpler implementation of relative_path
537 *
538 * Get relative path by removing "prefix" from "in". This function
539 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
540 * to increase performance when traversing the path to work_tree.
541 */
542const char *remove_leading_path(const char *in, const char *prefix)
543{
544 static char buf[PATH_MAX + 1];
545 int i = 0, j = 0;
546 if (!prefix || !prefix[0])
548 return in;
549 while (prefix[i]) {
550 if (is_dir_sep(prefix[i])) {
551 if (!is_dir_sep(in[j]))
552 return in;
553 while (is_dir_sep(prefix[i]))
554 i++;
555 while (is_dir_sep(in[j]))
556 j++;
557 continue;
558 } else if (in[j] != prefix[i]) {
559 return in;
560 }
561 i++;
562 j++;
563 }
564 if (
565 /* "/foo" is a prefix of "/foo" */
566 in[j] &&
567 /* "/foo" is not a prefix of "/foobar" */
568 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
569 )
570 return in;
571 while (is_dir_sep(in[j]))
572 j++;
573 if (!in[j])
574 strcpy(buf, ".");
575 else
576 strcpy(buf, in + j);
577 return buf;
578}
579/*
581 * It is okay if dst == src, but they should not overlap otherwise.
582 *
583 * Performs the following normalizations on src, storing the result in dst:
584 * - Ensures that components are separated by '/' (Windows only)
585 * - Squashes sequences of '/'.
586 * - Removes "." components.
587 * - Removes ".." components, and the components the precede them.
588 * Returns failure (non-zero) if a ".." component appears as first path
589 * component anytime during the normalization. Otherwise, returns success (0).
590 *
591 * Note that this function is purely textual. It does not follow symlinks,
592 * verify the existence of the path, or make any system calls.
593 *
594 * prefix_len != NULL is for a specific case of prefix_pathspec():
595 * assume that src == dst and src[0..prefix_len-1] is already
596 * normalized, any time "../" eats up to the prefix_len part,
597 * prefix_len is reduced. In the end prefix_len is the remaining
598 * prefix that has not been overridden by user pathspec.
599 */
600int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
601{
602 char *dst0;
603 if (has_dos_drive_prefix(src)) {
605 *dst++ = *src++;
606 *dst++ = *src++;
607 }
608 dst0 = dst;
609 if (is_dir_sep(*src)) {
611 *dst++ = '/';
612 while (is_dir_sep(*src))
613 src++;
614 }
615 for (;;) {
617 char c = *src;
618 /*
620 * A path component that begins with . could be
621 * special:
622 * (1) "." and ends -- ignore and terminate.
623 * (2) "./" -- ignore them, eat slash and continue.
624 * (3) ".." and ends -- strip one and terminate.
625 * (4) "../" -- strip one, eat slash and continue.
626 */
627 if (c == '.') {
628 if (!src[1]) {
629 /* (1) */
630 src++;
631 } else if (is_dir_sep(src[1])) {
632 /* (2) */
633 src += 2;
634 while (is_dir_sep(*src))
635 src++;
636 continue;
637 } else if (src[1] == '.') {
638 if (!src[2]) {
639 /* (3) */
640 src += 2;
641 goto up_one;
642 } else if (is_dir_sep(src[2])) {
643 /* (4) */
644 src += 3;
645 while (is_dir_sep(*src))
646 src++;
647 goto up_one;
648 }
649 }
650 }
651 /* copy up to the next '/', and eat all '/' */
653 while ((c = *src++) != '\0' && !is_dir_sep(c))
654 *dst++ = c;
655 if (is_dir_sep(c)) {
656 *dst++ = '/';
657 while (is_dir_sep(c))
658 c = *src++;
659 src--;
660 } else if (!c)
661 break;
662 continue;
663 up_one:
665 /*
666 * dst0..dst is prefix portion, and dst[-1] is '/';
667 * go up one level.
668 */
669 dst--; /* go to trailing '/' */
670 if (dst <= dst0)
671 return -1;
672 /* Windows: dst[-1] cannot be backslash anymore */
673 while (dst0 < dst && dst[-1] != '/')
674 dst--;
675 if (prefix_len && *prefix_len > dst - dst0)
676 *prefix_len = dst - dst0;
677 }
678 *dst = '\0';
679 return 0;
680}
681int normalize_path_copy(char *dst, const char *src)
683{
684 return normalize_path_copy_len(dst, src, NULL);
685}
686/*
688 * path = Canonical absolute path
689 * prefixes = string_list containing normalized, absolute paths without
690 * trailing slashes (except for the root directory, which is denoted by "/").
691 *
692 * Determines, for each path in prefixes, whether the "prefix"
693 * is an ancestor directory of path. Returns the length of the longest
694 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
695 * is an ancestor. (Note that this means 0 is returned if prefixes is
696 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
697 * are not considered to be their own ancestors. path must be in a
698 * canonical form: empty components, or "." or ".." components are not
699 * allowed.
700 */
701int longest_ancestor_length(const char *path, struct string_list *prefixes)
702{
703 int i, max_len = -1;
704 if (!strcmp(path, "/"))
706 return -1;
707 for (i = 0; i < prefixes->nr; i++) {
709 const char *ceil = prefixes->items[i].string;
710 int len = strlen(ceil);
711 if (len == 1 && ceil[0] == '/')
713 len = 0; /* root matches anything, with length 0 */
714 else if (!strncmp(path, ceil, len) && path[len] == '/')
715 ; /* match of length len */
716 else
717 continue; /* no match */
718 if (len > max_len)
720 max_len = len;
721 }
722 return max_len;
724}
725/* strip arbitrary amount of directory separators at end of path */
727static inline int chomp_trailing_dir_sep(const char *path, int len)
728{
729 while (len && is_dir_sep(path[len - 1]))
730 len--;
731 return len;
732}
733/*
735 * If path ends with suffix (complete path components), returns the
736 * part before suffix (sans trailing directory separators).
737 * Otherwise returns NULL.
738 */
739char *strip_path_suffix(const char *path, const char *suffix)
740{
741 int path_len = strlen(path), suffix_len = strlen(suffix);
742 while (suffix_len) {
744 if (!path_len)
745 return NULL;
746 if (is_dir_sep(path[path_len - 1])) {
748 if (!is_dir_sep(suffix[suffix_len - 1]))
749 return NULL;
750 path_len = chomp_trailing_dir_sep(path, path_len);
751 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
752 }
753 else if (path[--path_len] != suffix[--suffix_len])
754 return NULL;
755 }
756 if (path_len && !is_dir_sep(path[path_len - 1]))
758 return NULL;
759 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
760}
761int daemon_avoid_alias(const char *p)
763{
764 int sl, ndot;
765 /*
767 * This resurrects the belts and suspenders paranoia check by HPA
768 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
769 * does not do getcwd() based path canonicalization.
770 *
771 * sl becomes true immediately after seeing '/' and continues to
772 * be true as long as dots continue after that without intervening
773 * non-dot character.
774 */
775 if (!p || (*p != '/' && *p != '~'))
776 return -1;
777 sl = 1; ndot = 0;
778 p++;
779 while (1) {
781 char ch = *p++;
782 if (sl) {
783 if (ch == '.')
784 ndot++;
785 else if (ch == '/') {
786 if (ndot < 3)
787 /* reject //, /./ and /../ */
788 return -1;
789 ndot = 0;
790 }
791 else if (ch == 0) {
792 if (0 < ndot && ndot < 3)
793 /* reject /.$ and /..$ */
794 return -1;
795 return 0;
796 }
797 else
798 sl = ndot = 0;
799 }
800 else if (ch == 0)
801 return 0;
802 else if (ch == '/') {
803 sl = 1;
804 ndot = 0;
805 }
806 }
807}