path.c: group git_path(), git_pathdup() and strbuf_git_path() together
[git/git.git] / path.c
CommitLineData
26c8a533 1/*
3a429d3b 2 * Utilities for paths and pathnames
26c8a533
LT
3 */
4#include "cache.h"
395de250 5#include "strbuf.h"
a5ccdbe4 6#include "string-list.h"
26c8a533 7
f66450ae 8static int get_st_mode_bits(const char *path, int *mode)
0117c2f0
TB
9{
10 struct stat st;
11 if (lstat(path, &st) < 0)
12 return -1;
13 *mode = st.st_mode;
14 return 0;
15}
0117c2f0 16
26c8a533
LT
17static char bad_path[] = "/bad-path/";
18
4ef9caf5 19static struct strbuf *get_pathname(void)
e7676d2f 20{
4ef9caf5
NTND
21 static struct strbuf pathname_array[4] = {
22 STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
23 };
e7676d2f 24 static int index;
4ef9caf5
NTND
25 struct strbuf *sb = &pathname_array[3 & ++index];
26 strbuf_reset(sb);
27 return sb;
e7676d2f
LT
28}
29
26c8a533
LT
30static 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}
40
4ef9caf5
NTND
41static 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}
47
108bebea
AR
48char *mksnpath(char *buf, size_t n, const char *fmt, ...)
49{
50 va_list args;
51 unsigned len;
52
53 va_start(args, fmt);
54 len = vsnprintf(buf, n, fmt, args);
55 va_end(args);
56 if (len >= n) {
9db56f71 57 strlcpy(buf, bad_path, n);
108bebea
AR
58 return buf;
59 }
60 return cleanup_path(buf);
61}
62
8afdaf39 63static void do_git_path(struct strbuf *buf, const char *fmt, va_list args)
fe2d7776
AR
64{
65 const char *git_dir = get_git_dir();
4ef9caf5
NTND
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);
fe2d7776
AR
71}
72
1a83c240 73void strbuf_git_path(struct strbuf *sb, const char *fmt, ...)
aba13e7c
AR
74{
75 va_list args;
76 va_start(args, fmt);
8afdaf39 77 do_git_path(sb, fmt, args);
aba13e7c 78 va_end(args);
aba13e7c
AR
79}
80
57a23b77
NTND
81const char *git_path(const char *fmt, ...)
82{
83 struct strbuf *pathname = get_pathname();
84 va_list args;
85 va_start(args, fmt);
86 do_git_path(pathname, fmt, args);
87 va_end(args);
88 return pathname->buf;
89}
90
aba13e7c
AR
91char *git_pathdup(const char *fmt, ...)
92{
4ef9caf5 93 struct strbuf path = STRBUF_INIT;
aba13e7c
AR
94 va_list args;
95 va_start(args, fmt);
8afdaf39 96 do_git_path(&path, fmt, args);
aba13e7c 97 va_end(args);
4ef9caf5 98 return strbuf_detach(&path, NULL);
aba13e7c
AR
99}
100
21cf3227
HKNN
101char *mkpathdup(const char *fmt, ...)
102{
21cf3227
HKNN
103 struct strbuf sb = STRBUF_INIT;
104 va_list args;
21cf3227
HKNN
105 va_start(args, fmt);
106 strbuf_vaddf(&sb, fmt, args);
107 va_end(args);
4ef9caf5
NTND
108 strbuf_cleanup_path(&sb);
109 return strbuf_detach(&sb, NULL);
21cf3227
HKNN
110}
111
dcf69262 112const char *mkpath(const char *fmt, ...)
26c8a533
LT
113{
114 va_list args;
4ef9caf5 115 struct strbuf *pathname = get_pathname();
26c8a533 116 va_start(args, fmt);
4ef9caf5 117 strbuf_vaddf(pathname, fmt, args);
26c8a533 118 va_end(args);
4ef9caf5 119 return cleanup_path(pathname->buf);
26c8a533
LT
120}
121
21cf3227
HKNN
122void home_config_paths(char **global, char **xdg, char *file)
123{
124 char *xdg_home = getenv("XDG_CONFIG_HOME");
125 char *home = getenv("HOME");
126 char *to_free = NULL;
127
128 if (!home) {
129 if (global)
130 *global = NULL;
131 } else {
132 if (!xdg_home) {
133 to_free = mkpathdup("%s/.config", home);
134 xdg_home = to_free;
135 }
136 if (global)
137 *global = mkpathdup("%s/.gitconfig", home);
138 }
139
06b2d872
MM
140 if (xdg) {
141 if (!xdg_home)
142 *xdg = NULL;
143 else
144 *xdg = mkpathdup("%s/git/%s", xdg_home, file);
145 }
21cf3227
HKNN
146
147 free(to_free);
148}
149
dcf69262 150const char *git_path_submodule(const char *path, const char *fmt, ...)
0bad611b 151{
4ef9caf5 152 struct strbuf *buf = get_pathname();
0bad611b
HV
153 const char *git_dir;
154 va_list args;
0bad611b 155
4ef9caf5
NTND
156 strbuf_addstr(buf, path);
157 if (buf->len && buf->buf[buf->len - 1] != '/')
158 strbuf_addch(buf, '/');
159 strbuf_addstr(buf, ".git");
0bad611b 160
4ef9caf5 161 git_dir = read_gitfile(buf->buf);
0bad611b 162 if (git_dir) {
4ef9caf5
NTND
163 strbuf_reset(buf);
164 strbuf_addstr(buf, git_dir);
0bad611b 165 }
4ef9caf5 166 strbuf_addch(buf, '/');
0bad611b
HV
167
168 va_start(args, fmt);
4ef9caf5 169 strbuf_vaddf(buf, fmt, args);
0bad611b 170 va_end(args);
4ef9caf5
NTND
171 strbuf_cleanup_path(buf);
172 return buf->buf;
0bad611b 173}
f2db68ed 174
c847f537 175int validate_headref(const char *path)
0870ca7f
JH
176{
177 struct stat st;
178 char *buf, buffer[256];
c847f537 179 unsigned char sha1[20];
0104ca09
HO
180 int fd;
181 ssize_t len;
0870ca7f
JH
182
183 if (lstat(path, &st) < 0)
184 return -1;
185
186 /* Make sure it is a "refs/.." symlink */
187 if (S_ISLNK(st.st_mode)) {
188 len = readlink(path, buffer, sizeof(buffer)-1);
222b1673 189 if (len >= 5 && !memcmp("refs/", buffer, 5))
0870ca7f
JH
190 return 0;
191 return -1;
192 }
193
194 /*
195 * Anything else, just open it and try to see if it is a symbolic ref.
196 */
197 fd = open(path, O_RDONLY);
198 if (fd < 0)
199 return -1;
93d26e4c 200 len = read_in_full(fd, buffer, sizeof(buffer)-1);
0870ca7f
JH
201 close(fd);
202
203 /*
204 * Is it a symbolic ref?
205 */
c847f537 206 if (len < 4)
0870ca7f 207 return -1;
c847f537
JH
208 if (!memcmp("ref:", buffer, 4)) {
209 buf = buffer + 4;
210 len -= 4;
211 while (len && isspace(*buf))
212 buf++, len--;
222b1673 213 if (len >= 5 && !memcmp("refs/", buf, 5))
c847f537
JH
214 return 0;
215 }
216
217 /*
218 * Is this a detached HEAD?
219 */
220 if (!get_sha1_hex(buffer, sha1))
0870ca7f 221 return 0;
c847f537 222
0870ca7f
JH
223 return -1;
224}
225
395de250 226static struct passwd *getpw_str(const char *username, size_t len)
54f4b874 227{
d79374c7 228 struct passwd *pw;
5c0b13f8 229 char *username_z = xmemdupz(username, len);
395de250
MM
230 pw = getpwnam(username_z);
231 free(username_z);
232 return pw;
233}
54f4b874 234
395de250
MM
235/*
236 * Return a string with ~ and ~user expanded via getpw*. If buf != NULL,
237 * then it is a newly allocated string. Returns NULL on getpw failure or
238 * if path is NULL.
239 */
240char *expand_user_path(const char *path)
241{
242 struct strbuf user_path = STRBUF_INIT;
395de250
MM
243 const char *to_copy = path;
244
245 if (path == NULL)
246 goto return_null;
247 if (path[0] == '~') {
53ec551c 248 const char *first_slash = strchrnul(path, '/');
395de250
MM
249 const char *username = path + 1;
250 size_t username_len = first_slash - username;
df2a79f4
MM
251 if (username_len == 0) {
252 const char *home = getenv("HOME");
79bf1490
JN
253 if (!home)
254 goto return_null;
cedc61a9 255 strbuf_addstr(&user_path, home);
df2a79f4
MM
256 } else {
257 struct passwd *pw = getpw_str(username, username_len);
258 if (!pw)
259 goto return_null;
cedc61a9 260 strbuf_addstr(&user_path, pw->pw_dir);
54f4b874 261 }
395de250 262 to_copy = first_slash;
d79374c7 263 }
cedc61a9 264 strbuf_addstr(&user_path, to_copy);
395de250
MM
265 return strbuf_detach(&user_path, NULL);
266return_null:
267 strbuf_release(&user_path);
268 return NULL;
54f4b874
AE
269}
270
d79374c7
JH
271/*
272 * First, one directory to try is determined by the following algorithm.
273 *
274 * (0) If "strict" is given, the path is used as given and no DWIM is
275 * done. Otherwise:
276 * (1) "~/path" to mean path under the running user's home directory;
277 * (2) "~user/path" to mean path under named user's home directory;
278 * (3) "relative/path" to mean cwd relative directory; or
279 * (4) "/absolute/path" to mean absolute directory.
280 *
281 * Unless "strict" is given, we try access() for existence of "%s.git/.git",
282 * "%s/.git", "%s.git", "%s" in this order. The first one that exists is
283 * what we try.
284 *
285 * Second, we try chdir() to that. Upon failure, we return NULL.
286 *
287 * Then, we try if the current directory is a valid git repository.
288 * Upon failure, we return NULL.
289 *
290 * If all goes well, we return the directory we used to chdir() (but
291 * before ~user is expanded), avoiding getcwd() resolving symbolic
292 * links. User relative paths are also returned as they are given,
293 * except DWIM suffixing.
294 */
1c64b48e 295const char *enter_repo(const char *path, int strict)
54f4b874 296{
d79374c7
JH
297 static char used_path[PATH_MAX];
298 static char validated_path[PATH_MAX];
299
300 if (!path)
54f4b874
AE
301 return NULL;
302
d79374c7
JH
303 if (!strict) {
304 static const char *suffix[] = {
b3256eb8 305 "/.git", "", ".git/.git", ".git", NULL,
d79374c7 306 };
03106768 307 const char *gitfile;
d79374c7
JH
308 int len = strlen(path);
309 int i;
1c64b48e 310 while ((1 < len) && (path[len-1] == '/'))
d79374c7 311 len--;
1c64b48e 312
d79374c7 313 if (PATH_MAX <= len)
54f4b874 314 return NULL;
1c64b48e
EFL
315 strncpy(used_path, path, len); used_path[len] = 0 ;
316 strcpy(validated_path, used_path);
317
318 if (used_path[0] == '~') {
319 char *newpath = expand_user_path(used_path);
395de250
MM
320 if (!newpath || (PATH_MAX - 10 < strlen(newpath))) {
321 free(newpath);
d79374c7 322 return NULL;
395de250
MM
323 }
324 /*
325 * Copy back into the static buffer. A pity
326 * since newpath was not bounded, but other
327 * branches of the if are limited by PATH_MAX
328 * anyway.
329 */
330 strcpy(used_path, newpath); free(newpath);
d79374c7
JH
331 }
332 else if (PATH_MAX - 10 < len)
333 return NULL;
1c64b48e 334 len = strlen(used_path);
d79374c7 335 for (i = 0; suffix[i]; i++) {
b3256eb8 336 struct stat st;
1c64b48e 337 strcpy(used_path + len, suffix[i]);
b3256eb8
JK
338 if (!stat(used_path, &st) &&
339 (S_ISREG(st.st_mode) ||
340 (S_ISDIR(st.st_mode) && is_git_directory(used_path)))) {
d79374c7
JH
341 strcat(validated_path, suffix[i]);
342 break;
343 }
344 }
03106768
PH
345 if (!suffix[i])
346 return NULL;
347 gitfile = read_gitfile(used_path) ;
348 if (gitfile)
349 strcpy(used_path, gitfile);
350 if (chdir(used_path))
0870ca7f 351 return NULL;
d79374c7 352 path = validated_path;
0870ca7f 353 }
d79374c7
JH
354 else if (chdir(path))
355 return NULL;
54f4b874 356
d79374c7 357 if (access("objects", X_OK) == 0 && access("refs", X_OK) == 0 &&
c847f537 358 validate_headref("HEAD") == 0) {
717c3972 359 set_git_dir(".");
1644162a 360 check_repository_format();
d79374c7 361 return path;
54f4b874
AE
362 }
363
364 return NULL;
365}
138086a7 366
cbe43b84 367static int calc_shared_perm(int mode)
138086a7 368{
cbe43b84 369 int tweak;
138086a7 370
5a688fe4 371 if (shared_repository < 0)
cbe43b84 372 tweak = -shared_repository;
5a688fe4 373 else
cbe43b84 374 tweak = shared_repository;
5a688fe4
JH
375
376 if (!(mode & S_IWUSR))
377 tweak &= ~0222;
378 if (mode & S_IXUSR)
379 /* Copy read bits to execute bits */
380 tweak |= (tweak & 0444) >> 2;
381 if (shared_repository < 0)
382 mode = (mode & ~0777) | tweak;
383 else
8c6202d8 384 mode |= tweak;
06cbe855 385
cbe43b84
TB
386 return mode;
387}
388
389
390int adjust_shared_perm(const char *path)
391{
392 int old_mode, new_mode;
393
394 if (!shared_repository)
395 return 0;
396 if (get_st_mode_bits(path, &old_mode) < 0)
397 return -1;
398
399 new_mode = calc_shared_perm(old_mode);
400 if (S_ISDIR(old_mode)) {
06cbe855 401 /* Copy read bits to execute bits */
cbe43b84
TB
402 new_mode |= (new_mode & 0444) >> 2;
403 new_mode |= FORCE_DIR_SET_GID;
06cbe855
HO
404 }
405
cbe43b84
TB
406 if (((old_mode ^ new_mode) & ~S_IFMT) &&
407 chmod(path, (new_mode & ~S_IFMT)) < 0)
138086a7
JH
408 return -2;
409 return 0;
410}
e5392c51 411
7fbd4221
JX
412static int have_same_root(const char *path1, const char *path2)
413{
414 int is_abs1, is_abs2;
415
416 is_abs1 = is_absolute_path(path1);
417 is_abs2 = is_absolute_path(path2);
418 return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) ||
419 (!is_abs1 && !is_abs2);
420}
421
e02ca72f
JX
422/*
423 * Give path as relative to prefix.
424 *
425 * The strbuf may or may not be used, so do not assume it contains the
426 * returned path.
427 */
428const char *relative_path(const char *in, const char *prefix,
429 struct strbuf *sb)
044bbbcb 430{
e02ca72f
JX
431 int in_len = in ? strlen(in) : 0;
432 int prefix_len = prefix ? strlen(prefix) : 0;
433 int in_off = 0;
434 int prefix_off = 0;
288123f0
JH
435 int i = 0, j = 0;
436
e02ca72f
JX
437 if (!in_len)
438 return "./";
439 else if (!prefix_len)
440 return in;
441
7fbd4221
JX
442 if (have_same_root(in, prefix)) {
443 /* bypass dos_drive, for "c:" is identical to "C:" */
444 if (has_dos_drive_prefix(in)) {
445 i = 2;
446 j = 2;
447 }
448 } else {
449 return in;
450 }
451
e02ca72f
JX
452 while (i < prefix_len && j < in_len && prefix[i] == in[j]) {
453 if (is_dir_sep(prefix[i])) {
454 while (is_dir_sep(prefix[i]))
288123f0 455 i++;
e02ca72f
JX
456 while (is_dir_sep(in[j]))
457 j++;
458 prefix_off = i;
459 in_off = j;
460 } else {
461 i++;
462 j++;
463 }
464 }
465
466 if (
467 /* "prefix" seems like prefix of "in" */
468 i >= prefix_len &&
469 /*
470 * but "/foo" is not a prefix of "/foobar"
471 * (i.e. prefix not end with '/')
472 */
473 prefix_off < prefix_len) {
474 if (j >= in_len) {
475 /* in="/a/b", prefix="/a/b" */
476 in_off = in_len;
477 } else if (is_dir_sep(in[j])) {
478 /* in="/a/b/c", prefix="/a/b" */
479 while (is_dir_sep(in[j]))
288123f0 480 j++;
e02ca72f
JX
481 in_off = j;
482 } else {
483 /* in="/a/bbb/c", prefix="/a/b" */
484 i = prefix_off;
485 }
486 } else if (
487 /* "in" is short than "prefix" */
488 j >= in_len &&
489 /* "in" not end with '/' */
490 in_off < in_len) {
491 if (is_dir_sep(prefix[i])) {
492 /* in="/a/b", prefix="/a/b/c/" */
493 while (is_dir_sep(prefix[i]))
494 i++;
495 in_off = in_len;
496 }
497 }
498 in += in_off;
499 in_len -= in_off;
500
501 if (i >= prefix_len) {
502 if (!in_len)
503 return "./";
504 else
505 return in;
506 }
507
508 strbuf_reset(sb);
509 strbuf_grow(sb, in_len);
510
511 while (i < prefix_len) {
512 if (is_dir_sep(prefix[i])) {
513 strbuf_addstr(sb, "../");
514 while (is_dir_sep(prefix[i]))
515 i++;
288123f0 516 continue;
288123f0
JH
517 }
518 i++;
288123f0 519 }
e02ca72f
JX
520 if (!is_dir_sep(prefix[prefix_len - 1]))
521 strbuf_addstr(sb, "../");
522
523 strbuf_addstr(sb, in);
524
525 return sb->buf;
044bbbcb 526}
ae299be0 527
41894ae3
JX
528/*
529 * A simpler implementation of relative_path
530 *
531 * Get relative path by removing "prefix" from "in". This function
532 * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
533 * to increase performance when traversing the path to work_tree.
534 */
535const char *remove_leading_path(const char *in, const char *prefix)
536{
537 static char buf[PATH_MAX + 1];
538 int i = 0, j = 0;
539
540 if (!prefix || !prefix[0])
541 return in;
542 while (prefix[i]) {
543 if (is_dir_sep(prefix[i])) {
544 if (!is_dir_sep(in[j]))
545 return in;
546 while (is_dir_sep(prefix[i]))
547 i++;
548 while (is_dir_sep(in[j]))
549 j++;
550 continue;
551 } else if (in[j] != prefix[i]) {
552 return in;
553 }
554 i++;
555 j++;
556 }
557 if (
558 /* "/foo" is a prefix of "/foo" */
559 in[j] &&
560 /* "/foo" is not a prefix of "/foobar" */
561 !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
562 )
563 return in;
564 while (is_dir_sep(in[j]))
565 j++;
566 if (!in[j])
567 strcpy(buf, ".");
568 else
569 strcpy(buf, in + j);
570 return buf;
571}
572
ae299be0 573/*
f2a782b8 574 * It is okay if dst == src, but they should not overlap otherwise.
ae299be0 575 *
f2a782b8
JS
576 * Performs the following normalizations on src, storing the result in dst:
577 * - Ensures that components are separated by '/' (Windows only)
578 * - Squashes sequences of '/'.
ae299be0
DR
579 * - Removes "." components.
580 * - Removes ".." components, and the components the precede them.
f2a782b8
JS
581 * Returns failure (non-zero) if a ".." component appears as first path
582 * component anytime during the normalization. Otherwise, returns success (0).
ae299be0
DR
583 *
584 * Note that this function is purely textual. It does not follow symlinks,
585 * verify the existence of the path, or make any system calls.
645a29c4
NTND
586 *
587 * prefix_len != NULL is for a specific case of prefix_pathspec():
588 * assume that src == dst and src[0..prefix_len-1] is already
589 * normalized, any time "../" eats up to the prefix_len part,
590 * prefix_len is reduced. In the end prefix_len is the remaining
591 * prefix that has not been overridden by user pathspec.
ae299be0 592 */
645a29c4 593int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
ae299be0 594{
f3cad0ad 595 char *dst0;
ae299be0 596
f3cad0ad
JS
597 if (has_dos_drive_prefix(src)) {
598 *dst++ = *src++;
599 *dst++ = *src++;
ae299be0 600 }
f3cad0ad 601 dst0 = dst;
ae299be0 602
f3cad0ad 603 if (is_dir_sep(*src)) {
ae299be0 604 *dst++ = '/';
f3cad0ad
JS
605 while (is_dir_sep(*src))
606 src++;
607 }
608
609 for (;;) {
610 char c = *src;
611
612 /*
613 * A path component that begins with . could be
614 * special:
615 * (1) "." and ends -- ignore and terminate.
616 * (2) "./" -- ignore them, eat slash and continue.
617 * (3) ".." and ends -- strip one and terminate.
618 * (4) "../" -- strip one, eat slash and continue.
619 */
620 if (c == '.') {
621 if (!src[1]) {
622 /* (1) */
623 src++;
624 } else if (is_dir_sep(src[1])) {
625 /* (2) */
626 src += 2;
627 while (is_dir_sep(*src))
628 src++;
629 continue;
630 } else if (src[1] == '.') {
631 if (!src[2]) {
632 /* (3) */
633 src += 2;
634 goto up_one;
635 } else if (is_dir_sep(src[2])) {
636 /* (4) */
637 src += 3;
638 while (is_dir_sep(*src))
639 src++;
640 goto up_one;
641 }
642 }
643 }
ae299be0 644
f3cad0ad
JS
645 /* copy up to the next '/', and eat all '/' */
646 while ((c = *src++) != '\0' && !is_dir_sep(c))
647 *dst++ = c;
648 if (is_dir_sep(c)) {
649 *dst++ = '/';
650 while (is_dir_sep(c))
651 c = *src++;
652 src--;
653 } else if (!c)
654 break;
655 continue;
656
657 up_one:
658 /*
659 * dst0..dst is prefix portion, and dst[-1] is '/';
660 * go up one level.
661 */
f42302b4
JS
662 dst--; /* go to trailing '/' */
663 if (dst <= dst0)
f3cad0ad 664 return -1;
f42302b4
JS
665 /* Windows: dst[-1] cannot be backslash anymore */
666 while (dst0 < dst && dst[-1] != '/')
667 dst--;
645a29c4
NTND
668 if (prefix_len && *prefix_len > dst - dst0)
669 *prefix_len = dst - dst0;
f3cad0ad 670 }
ae299be0 671 *dst = '\0';
f3cad0ad 672 return 0;
ae299be0 673}
0454dd93 674
645a29c4
NTND
675int normalize_path_copy(char *dst, const char *src)
676{
677 return normalize_path_copy_len(dst, src, NULL);
678}
679
0454dd93
DR
680/*
681 * path = Canonical absolute path
9e2326c7
MH
682 * prefixes = string_list containing normalized, absolute paths without
683 * trailing slashes (except for the root directory, which is denoted by "/").
0454dd93 684 *
9e2326c7 685 * Determines, for each path in prefixes, whether the "prefix"
0454dd93
DR
686 * is an ancestor directory of path. Returns the length of the longest
687 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
31171d9e
MH
688 * is an ancestor. (Note that this means 0 is returned if prefixes is
689 * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories
0454dd93
DR
690 * are not considered to be their own ancestors. path must be in a
691 * canonical form: empty components, or "." or ".." components are not
9e2326c7 692 * allowed.
0454dd93 693 */
31171d9e 694int longest_ancestor_length(const char *path, struct string_list *prefixes)
0454dd93 695{
a5ccdbe4 696 int i, max_len = -1;
0454dd93 697
31171d9e 698 if (!strcmp(path, "/"))
0454dd93
DR
699 return -1;
700
31171d9e
MH
701 for (i = 0; i < prefixes->nr; i++) {
702 const char *ceil = prefixes->items[i].string;
a5ccdbe4
MH
703 int len = strlen(ceil);
704
9e2326c7
MH
705 if (len == 1 && ceil[0] == '/')
706 len = 0; /* root matches anything, with length 0 */
707 else if (!strncmp(path, ceil, len) && path[len] == '/')
708 ; /* match of length len */
709 else
710 continue; /* no match */
0454dd93 711
9e2326c7 712 if (len > max_len)
0454dd93 713 max_len = len;
0454dd93
DR
714 }
715
716 return max_len;
717}
4fcc86b0
JS
718
719/* strip arbitrary amount of directory separators at end of path */
720static inline int chomp_trailing_dir_sep(const char *path, int len)
721{
722 while (len && is_dir_sep(path[len - 1]))
723 len--;
724 return len;
725}
726
727/*
728 * If path ends with suffix (complete path components), returns the
729 * part before suffix (sans trailing directory separators).
730 * Otherwise returns NULL.
731 */
732char *strip_path_suffix(const char *path, const char *suffix)
733{
734 int path_len = strlen(path), suffix_len = strlen(suffix);
735
736 while (suffix_len) {
737 if (!path_len)
738 return NULL;
739
740 if (is_dir_sep(path[path_len - 1])) {
741 if (!is_dir_sep(suffix[suffix_len - 1]))
742 return NULL;
743 path_len = chomp_trailing_dir_sep(path, path_len);
744 suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
745 }
746 else if (path[--path_len] != suffix[--suffix_len])
747 return NULL;
748 }
749
750 if (path_len && !is_dir_sep(path[path_len - 1]))
751 return NULL;
752 return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
753}
34b6cb8b
SP
754
755int daemon_avoid_alias(const char *p)
756{
757 int sl, ndot;
758
759 /*
760 * This resurrects the belts and suspenders paranoia check by HPA
761 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
9517e6b8 762 * does not do getcwd() based path canonicalization.
34b6cb8b
SP
763 *
764 * sl becomes true immediately after seeing '/' and continues to
765 * be true as long as dots continue after that without intervening
766 * non-dot character.
767 */
768 if (!p || (*p != '/' && *p != '~'))
769 return -1;
770 sl = 1; ndot = 0;
771 p++;
772
773 while (1) {
774 char ch = *p++;
775 if (sl) {
776 if (ch == '.')
777 ndot++;
778 else if (ch == '/') {
779 if (ndot < 3)
780 /* reject //, /./ and /../ */
781 return -1;
782 ndot = 0;
783 }
784 else if (ch == 0) {
785 if (0 < ndot && ndot < 3)
786 /* reject /.$ and /..$ */
787 return -1;
788 return 0;
789 }
790 else
791 sl = ndot = 0;
792 }
793 else if (ch == 0)
794 return 0;
795 else if (ch == '/') {
796 sl = 1;
797 ndot = 0;
798 }
799 }
800}