Merge branch 'rs/strbuf-add-real-path'
[git/git.git] / setup.c
1 #include "cache.h"
2 #include "dir.h"
3 #include "string-list.h"
4
5 static int inside_git_dir = -1;
6 static int inside_work_tree = -1;
7 static int work_tree_config_is_bogus;
8
9 static struct startup_info the_startup_info;
10 struct startup_info *startup_info = &the_startup_info;
11
12 /*
13 * The input parameter must contain an absolute path, and it must already be
14 * normalized.
15 *
16 * Find the part of an absolute path that lies inside the work tree by
17 * dereferencing symlinks outside the work tree, for example:
18 * /dir1/repo/dir2/file (work tree is /dir1/repo) -> dir2/file
19 * /dir/file (work tree is /) -> dir/file
20 * /dir/symlink1/symlink2 (symlink1 points to work tree) -> symlink2
21 * /dir/repolink/file (repolink points to /dir/repo) -> file
22 * /dir/repo (exactly equal to work tree) -> (empty string)
23 */
24 static int abspath_part_inside_repo(char *path)
25 {
26 size_t len;
27 size_t wtlen;
28 char *path0;
29 int off;
30 const char *work_tree = get_git_work_tree();
31
32 if (!work_tree)
33 return -1;
34 wtlen = strlen(work_tree);
35 len = strlen(path);
36 off = offset_1st_component(path);
37
38 /* check if work tree is already the prefix */
39 if (wtlen <= len && !strncmp(path, work_tree, wtlen)) {
40 if (path[wtlen] == '/') {
41 memmove(path, path + wtlen + 1, len - wtlen);
42 return 0;
43 } else if (path[wtlen - 1] == '/' || path[wtlen] == '\0') {
44 /* work tree is the root, or the whole path */
45 memmove(path, path + wtlen, len - wtlen + 1);
46 return 0;
47 }
48 /* work tree might match beginning of a symlink to work tree */
49 off = wtlen;
50 }
51 path0 = path;
52 path += off;
53
54 /* check each '/'-terminated level */
55 while (*path) {
56 path++;
57 if (*path == '/') {
58 *path = '\0';
59 if (strcmp(real_path(path0), work_tree) == 0) {
60 memmove(path0, path + 1, len - (path - path0));
61 return 0;
62 }
63 *path = '/';
64 }
65 }
66
67 /* check whole path */
68 if (strcmp(real_path(path0), work_tree) == 0) {
69 *path0 = '\0';
70 return 0;
71 }
72
73 return -1;
74 }
75
76 /*
77 * Normalize "path", prepending the "prefix" for relative paths. If
78 * remaining_prefix is not NULL, return the actual prefix still
79 * remains in the path. For example, prefix = sub1/sub2/ and path is
80 *
81 * foo -> sub1/sub2/foo (full prefix)
82 * ../foo -> sub1/foo (remaining prefix is sub1/)
83 * ../../bar -> bar (no remaining prefix)
84 * ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix)
85 * `pwd`/../bar -> sub1/bar (no remaining prefix)
86 */
87 char *prefix_path_gently(const char *prefix, int len,
88 int *remaining_prefix, const char *path)
89 {
90 const char *orig = path;
91 char *sanitized;
92 if (is_absolute_path(orig)) {
93 sanitized = xmallocz(strlen(path));
94 if (remaining_prefix)
95 *remaining_prefix = 0;
96 if (normalize_path_copy_len(sanitized, path, remaining_prefix)) {
97 free(sanitized);
98 return NULL;
99 }
100 if (abspath_part_inside_repo(sanitized)) {
101 free(sanitized);
102 return NULL;
103 }
104 } else {
105 sanitized = xstrfmt("%.*s%s", len, len ? prefix : "", path);
106 if (remaining_prefix)
107 *remaining_prefix = len;
108 if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
109 free(sanitized);
110 return NULL;
111 }
112 }
113 return sanitized;
114 }
115
116 char *prefix_path(const char *prefix, int len, const char *path)
117 {
118 char *r = prefix_path_gently(prefix, len, NULL, path);
119 if (!r)
120 die("'%s' is outside repository", path);
121 return r;
122 }
123
124 int path_inside_repo(const char *prefix, const char *path)
125 {
126 int len = prefix ? strlen(prefix) : 0;
127 char *r = prefix_path_gently(prefix, len, NULL, path);
128 if (r) {
129 free(r);
130 return 1;
131 }
132 return 0;
133 }
134
135 int check_filename(const char *prefix, const char *arg)
136 {
137 const char *name;
138 struct stat st;
139
140 if (starts_with(arg, ":/")) {
141 if (arg[2] == '\0') /* ":/" is root dir, always exists */
142 return 1;
143 name = arg + 2;
144 } else if (prefix)
145 name = prefix_filename(prefix, strlen(prefix), arg);
146 else
147 name = arg;
148 if (!lstat(name, &st))
149 return 1; /* file exists */
150 if (errno == ENOENT || errno == ENOTDIR)
151 return 0; /* file does not exist */
152 die_errno("failed to stat '%s'", arg);
153 }
154
155 static void NORETURN die_verify_filename(const char *prefix,
156 const char *arg,
157 int diagnose_misspelt_rev)
158 {
159 if (!diagnose_misspelt_rev)
160 die(_("%s: no such path in the working tree.\n"
161 "Use 'git <command> -- <path>...' to specify paths that do not exist locally."),
162 arg);
163 /*
164 * Saying "'(icase)foo' does not exist in the index" when the
165 * user gave us ":(icase)foo" is just stupid. A magic pathspec
166 * begins with a colon and is followed by a non-alnum; do not
167 * let maybe_die_on_misspelt_object_name() even trigger.
168 */
169 if (!(arg[0] == ':' && !isalnum(arg[1])))
170 maybe_die_on_misspelt_object_name(arg, prefix);
171
172 /* ... or fall back the most general message. */
173 die(_("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
174 "Use '--' to separate paths from revisions, like this:\n"
175 "'git <command> [<revision>...] -- [<file>...]'"), arg);
176
177 }
178
179 /*
180 * Verify a filename that we got as an argument for a pathspec
181 * entry. Note that a filename that begins with "-" never verifies
182 * as true, because even if such a filename were to exist, we want
183 * it to be preceded by the "--" marker (or we want the user to
184 * use a format like "./-filename")
185 *
186 * The "diagnose_misspelt_rev" is used to provide a user-friendly
187 * diagnosis when dying upon finding that "name" is not a pathname.
188 * If set to 1, the diagnosis will try to diagnose "name" as an
189 * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
190 * will only complain about an inexisting file.
191 *
192 * This function is typically called to check that a "file or rev"
193 * argument is unambiguous. In this case, the caller will want
194 * diagnose_misspelt_rev == 1 when verifying the first non-rev
195 * argument (which could have been a revision), and
196 * diagnose_misspelt_rev == 0 for the next ones (because we already
197 * saw a filename, there's not ambiguity anymore).
198 */
199 void verify_filename(const char *prefix,
200 const char *arg,
201 int diagnose_misspelt_rev)
202 {
203 if (*arg == '-')
204 die("bad flag '%s' used after filename", arg);
205 if (check_filename(prefix, arg) || !no_wildcard(arg))
206 return;
207 die_verify_filename(prefix, arg, diagnose_misspelt_rev);
208 }
209
210 /*
211 * Opposite of the above: the command line did not have -- marker
212 * and we parsed the arg as a refname. It should not be interpretable
213 * as a filename.
214 */
215 void verify_non_filename(const char *prefix, const char *arg)
216 {
217 if (!is_inside_work_tree() || is_inside_git_dir())
218 return;
219 if (*arg == '-')
220 return; /* flag */
221 if (!check_filename(prefix, arg))
222 return;
223 die(_("ambiguous argument '%s': both revision and filename\n"
224 "Use '--' to separate paths from revisions, like this:\n"
225 "'git <command> [<revision>...] -- [<file>...]'"), arg);
226 }
227
228 int get_common_dir(struct strbuf *sb, const char *gitdir)
229 {
230 const char *git_env_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
231 if (git_env_common_dir) {
232 strbuf_addstr(sb, git_env_common_dir);
233 return 1;
234 } else {
235 return get_common_dir_noenv(sb, gitdir);
236 }
237 }
238
239 int get_common_dir_noenv(struct strbuf *sb, const char *gitdir)
240 {
241 struct strbuf data = STRBUF_INIT;
242 struct strbuf path = STRBUF_INIT;
243 int ret = 0;
244
245 strbuf_addf(&path, "%s/commondir", gitdir);
246 if (file_exists(path.buf)) {
247 if (strbuf_read_file(&data, path.buf, 0) <= 0)
248 die_errno(_("failed to read %s"), path.buf);
249 while (data.len && (data.buf[data.len - 1] == '\n' ||
250 data.buf[data.len - 1] == '\r'))
251 data.len--;
252 data.buf[data.len] = '\0';
253 strbuf_reset(&path);
254 if (!is_absolute_path(data.buf))
255 strbuf_addf(&path, "%s/", gitdir);
256 strbuf_addbuf(&path, &data);
257 strbuf_add_real_path(sb, path.buf);
258 ret = 1;
259 } else {
260 strbuf_addstr(sb, gitdir);
261 }
262
263 strbuf_release(&data);
264 strbuf_release(&path);
265 return ret;
266 }
267
268 /*
269 * Test if it looks like we're at a git directory.
270 * We want to see:
271 *
272 * - either an objects/ directory _or_ the proper
273 * GIT_OBJECT_DIRECTORY environment variable
274 * - a refs/ directory
275 * - either a HEAD symlink or a HEAD file that is formatted as
276 * a proper "ref:", or a regular file HEAD that has a properly
277 * formatted sha1 object name.
278 */
279 int is_git_directory(const char *suspect)
280 {
281 struct strbuf path = STRBUF_INIT;
282 int ret = 0;
283 size_t len;
284
285 /* Check worktree-related signatures */
286 strbuf_addf(&path, "%s/HEAD", suspect);
287 if (validate_headref(path.buf))
288 goto done;
289
290 strbuf_reset(&path);
291 get_common_dir(&path, suspect);
292 len = path.len;
293
294 /* Check non-worktree-related signatures */
295 if (getenv(DB_ENVIRONMENT)) {
296 if (access(getenv(DB_ENVIRONMENT), X_OK))
297 goto done;
298 }
299 else {
300 strbuf_setlen(&path, len);
301 strbuf_addstr(&path, "/objects");
302 if (access(path.buf, X_OK))
303 goto done;
304 }
305
306 strbuf_setlen(&path, len);
307 strbuf_addstr(&path, "/refs");
308 if (access(path.buf, X_OK))
309 goto done;
310
311 ret = 1;
312 done:
313 strbuf_release(&path);
314 return ret;
315 }
316
317 int is_nonbare_repository_dir(struct strbuf *path)
318 {
319 int ret = 0;
320 int gitfile_error;
321 size_t orig_path_len = path->len;
322 assert(orig_path_len != 0);
323 strbuf_complete(path, '/');
324 strbuf_addstr(path, ".git");
325 if (read_gitfile_gently(path->buf, &gitfile_error) || is_git_directory(path->buf))
326 ret = 1;
327 if (gitfile_error == READ_GITFILE_ERR_OPEN_FAILED ||
328 gitfile_error == READ_GITFILE_ERR_READ_FAILED)
329 ret = 1;
330 strbuf_setlen(path, orig_path_len);
331 return ret;
332 }
333
334 int is_inside_git_dir(void)
335 {
336 if (inside_git_dir < 0)
337 inside_git_dir = is_inside_dir(get_git_dir());
338 return inside_git_dir;
339 }
340
341 int is_inside_work_tree(void)
342 {
343 if (inside_work_tree < 0)
344 inside_work_tree = is_inside_dir(get_git_work_tree());
345 return inside_work_tree;
346 }
347
348 void setup_work_tree(void)
349 {
350 const char *work_tree, *git_dir;
351 static int initialized = 0;
352
353 if (initialized)
354 return;
355
356 if (work_tree_config_is_bogus)
357 die("unable to set up work tree using invalid config");
358
359 work_tree = get_git_work_tree();
360 git_dir = get_git_dir();
361 if (!is_absolute_path(git_dir))
362 git_dir = real_path(get_git_dir());
363 if (!work_tree || chdir(work_tree))
364 die("This operation must be run in a work tree");
365
366 /*
367 * Make sure subsequent git processes find correct worktree
368 * if $GIT_WORK_TREE is set relative
369 */
370 if (getenv(GIT_WORK_TREE_ENVIRONMENT))
371 setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
372
373 set_git_dir(remove_leading_path(git_dir, work_tree));
374 initialized = 1;
375 }
376
377 static int check_repo_format(const char *var, const char *value, void *vdata)
378 {
379 struct repository_format *data = vdata;
380 const char *ext;
381
382 if (strcmp(var, "core.repositoryformatversion") == 0)
383 data->version = git_config_int(var, value);
384 else if (skip_prefix(var, "extensions.", &ext)) {
385 /*
386 * record any known extensions here; otherwise,
387 * we fall through to recording it as unknown, and
388 * check_repository_format will complain
389 */
390 if (!strcmp(ext, "noop"))
391 ;
392 else if (!strcmp(ext, "preciousobjects"))
393 data->precious_objects = git_config_bool(var, value);
394 else
395 string_list_append(&data->unknown_extensions, ext);
396 } else if (strcmp(var, "core.bare") == 0) {
397 data->is_bare = git_config_bool(var, value);
398 } else if (strcmp(var, "core.worktree") == 0) {
399 if (!value)
400 return config_error_nonbool(var);
401 data->work_tree = xstrdup(value);
402 }
403 return 0;
404 }
405
406 static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
407 {
408 struct strbuf sb = STRBUF_INIT;
409 struct strbuf err = STRBUF_INIT;
410 struct repository_format candidate;
411 int has_common;
412
413 has_common = get_common_dir(&sb, gitdir);
414 strbuf_addstr(&sb, "/config");
415 read_repository_format(&candidate, sb.buf);
416 strbuf_release(&sb);
417
418 /*
419 * For historical use of check_repository_format() in git-init,
420 * we treat a missing config as a silent "ok", even when nongit_ok
421 * is unset.
422 */
423 if (candidate.version < 0)
424 return 0;
425
426 if (verify_repository_format(&candidate, &err) < 0) {
427 if (nongit_ok) {
428 warning("%s", err.buf);
429 strbuf_release(&err);
430 *nongit_ok = -1;
431 return -1;
432 }
433 die("%s", err.buf);
434 }
435
436 repository_format_precious_objects = candidate.precious_objects;
437 string_list_clear(&candidate.unknown_extensions, 0);
438 if (!has_common) {
439 if (candidate.is_bare != -1) {
440 is_bare_repository_cfg = candidate.is_bare;
441 if (is_bare_repository_cfg == 1)
442 inside_work_tree = -1;
443 }
444 if (candidate.work_tree) {
445 free(git_work_tree_cfg);
446 git_work_tree_cfg = candidate.work_tree;
447 inside_work_tree = -1;
448 }
449 } else {
450 free(candidate.work_tree);
451 }
452
453 return 0;
454 }
455
456 int read_repository_format(struct repository_format *format, const char *path)
457 {
458 memset(format, 0, sizeof(*format));
459 format->version = -1;
460 format->is_bare = -1;
461 string_list_init(&format->unknown_extensions, 1);
462 git_config_from_file(check_repo_format, path, format);
463 return format->version;
464 }
465
466 int verify_repository_format(const struct repository_format *format,
467 struct strbuf *err)
468 {
469 if (GIT_REPO_VERSION_READ < format->version) {
470 strbuf_addf(err, _("Expected git repo version <= %d, found %d"),
471 GIT_REPO_VERSION_READ, format->version);
472 return -1;
473 }
474
475 if (format->version >= 1 && format->unknown_extensions.nr) {
476 int i;
477
478 strbuf_addstr(err, _("unknown repository extensions found:"));
479
480 for (i = 0; i < format->unknown_extensions.nr; i++)
481 strbuf_addf(err, "\n\t%s",
482 format->unknown_extensions.items[i].string);
483 return -1;
484 }
485
486 return 0;
487 }
488
489 void read_gitfile_error_die(int error_code, const char *path, const char *dir)
490 {
491 switch (error_code) {
492 case READ_GITFILE_ERR_STAT_FAILED:
493 case READ_GITFILE_ERR_NOT_A_FILE:
494 /* non-fatal; follow return path */
495 break;
496 case READ_GITFILE_ERR_OPEN_FAILED:
497 die_errno("Error opening '%s'", path);
498 case READ_GITFILE_ERR_TOO_LARGE:
499 die("Too large to be a .git file: '%s'", path);
500 case READ_GITFILE_ERR_READ_FAILED:
501 die("Error reading %s", path);
502 case READ_GITFILE_ERR_INVALID_FORMAT:
503 die("Invalid gitfile format: %s", path);
504 case READ_GITFILE_ERR_NO_PATH:
505 die("No path in gitfile: %s", path);
506 case READ_GITFILE_ERR_NOT_A_REPO:
507 die("Not a git repository: %s", dir);
508 default:
509 die("BUG: unknown error code");
510 }
511 }
512
513 /*
514 * Try to read the location of the git directory from the .git file,
515 * return path to git directory if found.
516 *
517 * On failure, if return_error_code is not NULL, return_error_code
518 * will be set to an error code and NULL will be returned. If
519 * return_error_code is NULL the function will die instead (for most
520 * cases).
521 */
522 const char *read_gitfile_gently(const char *path, int *return_error_code)
523 {
524 const int max_file_size = 1 << 20; /* 1MB */
525 int error_code = 0;
526 char *buf = NULL;
527 char *dir = NULL;
528 const char *slash;
529 struct stat st;
530 int fd;
531 ssize_t len;
532
533 if (stat(path, &st)) {
534 error_code = READ_GITFILE_ERR_STAT_FAILED;
535 goto cleanup_return;
536 }
537 if (!S_ISREG(st.st_mode)) {
538 error_code = READ_GITFILE_ERR_NOT_A_FILE;
539 goto cleanup_return;
540 }
541 if (st.st_size > max_file_size) {
542 error_code = READ_GITFILE_ERR_TOO_LARGE;
543 goto cleanup_return;
544 }
545 fd = open(path, O_RDONLY);
546 if (fd < 0) {
547 error_code = READ_GITFILE_ERR_OPEN_FAILED;
548 goto cleanup_return;
549 }
550 buf = xmallocz(st.st_size);
551 len = read_in_full(fd, buf, st.st_size);
552 close(fd);
553 if (len != st.st_size) {
554 error_code = READ_GITFILE_ERR_READ_FAILED;
555 goto cleanup_return;
556 }
557 if (!starts_with(buf, "gitdir: ")) {
558 error_code = READ_GITFILE_ERR_INVALID_FORMAT;
559 goto cleanup_return;
560 }
561 while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
562 len--;
563 if (len < 9) {
564 error_code = READ_GITFILE_ERR_NO_PATH;
565 goto cleanup_return;
566 }
567 buf[len] = '\0';
568 dir = buf + 8;
569
570 if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
571 size_t pathlen = slash+1 - path;
572 dir = xstrfmt("%.*s%.*s", (int)pathlen, path,
573 (int)(len - 8), buf + 8);
574 free(buf);
575 buf = dir;
576 }
577 if (!is_git_directory(dir)) {
578 error_code = READ_GITFILE_ERR_NOT_A_REPO;
579 goto cleanup_return;
580 }
581 path = real_path(dir);
582
583 cleanup_return:
584 if (return_error_code)
585 *return_error_code = error_code;
586 else if (error_code)
587 read_gitfile_error_die(error_code, path, dir);
588
589 free(buf);
590 return error_code ? NULL : path;
591 }
592
593 static const char *setup_explicit_git_dir(const char *gitdirenv,
594 struct strbuf *cwd,
595 int *nongit_ok)
596 {
597 const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
598 const char *worktree;
599 char *gitfile;
600 int offset;
601
602 if (PATH_MAX - 40 < strlen(gitdirenv))
603 die("'$%s' too big", GIT_DIR_ENVIRONMENT);
604
605 gitfile = (char*)read_gitfile(gitdirenv);
606 if (gitfile) {
607 gitfile = xstrdup(gitfile);
608 gitdirenv = gitfile;
609 }
610
611 if (!is_git_directory(gitdirenv)) {
612 if (nongit_ok) {
613 *nongit_ok = 1;
614 free(gitfile);
615 return NULL;
616 }
617 die("Not a git repository: '%s'", gitdirenv);
618 }
619
620 if (check_repository_format_gently(gitdirenv, nongit_ok)) {
621 free(gitfile);
622 return NULL;
623 }
624
625 /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
626 if (work_tree_env)
627 set_git_work_tree(work_tree_env);
628 else if (is_bare_repository_cfg > 0) {
629 if (git_work_tree_cfg) {
630 /* #22.2, #30 */
631 warning("core.bare and core.worktree do not make sense");
632 work_tree_config_is_bogus = 1;
633 }
634
635 /* #18, #26 */
636 set_git_dir(gitdirenv);
637 free(gitfile);
638 return NULL;
639 }
640 else if (git_work_tree_cfg) { /* #6, #14 */
641 if (is_absolute_path(git_work_tree_cfg))
642 set_git_work_tree(git_work_tree_cfg);
643 else {
644 char *core_worktree;
645 if (chdir(gitdirenv))
646 die_errno("Could not chdir to '%s'", gitdirenv);
647 if (chdir(git_work_tree_cfg))
648 die_errno("Could not chdir to '%s'", git_work_tree_cfg);
649 core_worktree = xgetcwd();
650 if (chdir(cwd->buf))
651 die_errno("Could not come back to cwd");
652 set_git_work_tree(core_worktree);
653 free(core_worktree);
654 }
655 }
656 else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
657 /* #16d */
658 set_git_dir(gitdirenv);
659 free(gitfile);
660 return NULL;
661 }
662 else /* #2, #10 */
663 set_git_work_tree(".");
664
665 /* set_git_work_tree() must have been called by now */
666 worktree = get_git_work_tree();
667
668 /* both get_git_work_tree() and cwd are already normalized */
669 if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
670 set_git_dir(gitdirenv);
671 free(gitfile);
672 return NULL;
673 }
674
675 offset = dir_inside_of(cwd->buf, worktree);
676 if (offset >= 0) { /* cwd inside worktree? */
677 set_git_dir(real_path(gitdirenv));
678 if (chdir(worktree))
679 die_errno("Could not chdir to '%s'", worktree);
680 strbuf_addch(cwd, '/');
681 free(gitfile);
682 return cwd->buf + offset;
683 }
684
685 /* cwd outside worktree */
686 set_git_dir(gitdirenv);
687 free(gitfile);
688 return NULL;
689 }
690
691 static const char *setup_discovered_git_dir(const char *gitdir,
692 struct strbuf *cwd, int offset,
693 int *nongit_ok)
694 {
695 if (check_repository_format_gently(gitdir, nongit_ok))
696 return NULL;
697
698 /* --work-tree is set without --git-dir; use discovered one */
699 if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
700 if (offset != cwd->len && !is_absolute_path(gitdir))
701 gitdir = real_pathdup(gitdir);
702 if (chdir(cwd->buf))
703 die_errno("Could not come back to cwd");
704 return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
705 }
706
707 /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
708 if (is_bare_repository_cfg > 0) {
709 set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
710 if (chdir(cwd->buf))
711 die_errno("Could not come back to cwd");
712 return NULL;
713 }
714
715 /* #0, #1, #5, #8, #9, #12, #13 */
716 set_git_work_tree(".");
717 if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
718 set_git_dir(gitdir);
719 inside_git_dir = 0;
720 inside_work_tree = 1;
721 if (offset == cwd->len)
722 return NULL;
723
724 /* Make "offset" point to past the '/', and add a '/' at the end */
725 offset++;
726 strbuf_addch(cwd, '/');
727 return cwd->buf + offset;
728 }
729
730 /* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
731 static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
732 int *nongit_ok)
733 {
734 int root_len;
735
736 if (check_repository_format_gently(".", nongit_ok))
737 return NULL;
738
739 setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
740
741 /* --work-tree is set without --git-dir; use discovered one */
742 if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
743 const char *gitdir;
744
745 gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
746 if (chdir(cwd->buf))
747 die_errno("Could not come back to cwd");
748 return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
749 }
750
751 inside_git_dir = 1;
752 inside_work_tree = 0;
753 if (offset != cwd->len) {
754 if (chdir(cwd->buf))
755 die_errno("Cannot come back to cwd");
756 root_len = offset_1st_component(cwd->buf);
757 strbuf_setlen(cwd, offset > root_len ? offset : root_len);
758 set_git_dir(cwd->buf);
759 }
760 else
761 set_git_dir(".");
762 return NULL;
763 }
764
765 static const char *setup_nongit(const char *cwd, int *nongit_ok)
766 {
767 if (!nongit_ok)
768 die(_("Not a git repository (or any of the parent directories): %s"), DEFAULT_GIT_DIR_ENVIRONMENT);
769 if (chdir(cwd))
770 die_errno(_("Cannot come back to cwd"));
771 *nongit_ok = 1;
772 return NULL;
773 }
774
775 static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
776 {
777 struct stat buf;
778 if (stat(path, &buf)) {
779 die_errno("failed to stat '%*s%s%s'",
780 prefix_len,
781 prefix ? prefix : "",
782 prefix ? "/" : "", path);
783 }
784 return buf.st_dev;
785 }
786
787 /*
788 * A "string_list_each_func_t" function that canonicalizes an entry
789 * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
790 * discards it if unusable. The presence of an empty entry in
791 * GIT_CEILING_DIRECTORIES turns off canonicalization for all
792 * subsequent entries.
793 */
794 static int canonicalize_ceiling_entry(struct string_list_item *item,
795 void *cb_data)
796 {
797 int *empty_entry_found = cb_data;
798 char *ceil = item->string;
799
800 if (!*ceil) {
801 *empty_entry_found = 1;
802 return 0;
803 } else if (!is_absolute_path(ceil)) {
804 return 0;
805 } else if (*empty_entry_found) {
806 /* Keep entry but do not canonicalize it */
807 return 1;
808 } else {
809 char *real_path = real_pathdup(ceil);
810 if (!real_path) {
811 return 0;
812 }
813 free(item->string);
814 item->string = real_path;
815 return 1;
816 }
817 }
818
819 /*
820 * We cannot decide in this function whether we are in the work tree or
821 * not, since the config can only be read _after_ this function was called.
822 */
823 static const char *setup_git_directory_gently_1(int *nongit_ok)
824 {
825 const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
826 struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
827 static struct strbuf cwd = STRBUF_INIT;
828 const char *gitdirenv, *ret;
829 char *gitfile;
830 int offset, offset_parent, ceil_offset = -1;
831 dev_t current_device = 0;
832 int one_filesystem = 1;
833
834 /*
835 * We may have read an incomplete configuration before
836 * setting-up the git directory. If so, clear the cache so
837 * that the next queries to the configuration reload complete
838 * configuration (including the per-repo config file that we
839 * ignored previously).
840 */
841 git_config_clear();
842
843 /*
844 * Let's assume that we are in a git repository.
845 * If it turns out later that we are somewhere else, the value will be
846 * updated accordingly.
847 */
848 if (nongit_ok)
849 *nongit_ok = 0;
850
851 if (strbuf_getcwd(&cwd))
852 die_errno(_("Unable to read current working directory"));
853 offset = cwd.len;
854
855 /*
856 * If GIT_DIR is set explicitly, we're not going
857 * to do any discovery, but we still do repository
858 * validation.
859 */
860 gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
861 if (gitdirenv)
862 return setup_explicit_git_dir(gitdirenv, &cwd, nongit_ok);
863
864 if (env_ceiling_dirs) {
865 int empty_entry_found = 0;
866
867 string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
868 filter_string_list(&ceiling_dirs, 0,
869 canonicalize_ceiling_entry, &empty_entry_found);
870 ceil_offset = longest_ancestor_length(cwd.buf, &ceiling_dirs);
871 string_list_clear(&ceiling_dirs, 0);
872 }
873
874 if (ceil_offset < 0 && has_dos_drive_prefix(cwd.buf))
875 ceil_offset = 1;
876
877 /*
878 * Test in the following order (relative to the cwd):
879 * - .git (file containing "gitdir: <path>")
880 * - .git/
881 * - ./ (bare)
882 * - ../.git
883 * - ../.git/
884 * - ../ (bare)
885 * - ../../.git/
886 * etc.
887 */
888 one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
889 if (one_filesystem)
890 current_device = get_device_or_die(".", NULL, 0);
891 for (;;) {
892 gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
893 if (gitfile)
894 gitdirenv = gitfile = xstrdup(gitfile);
895 else {
896 if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
897 gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
898 }
899
900 if (gitdirenv) {
901 ret = setup_discovered_git_dir(gitdirenv,
902 &cwd, offset,
903 nongit_ok);
904 free(gitfile);
905 return ret;
906 }
907 free(gitfile);
908
909 if (is_git_directory("."))
910 return setup_bare_git_dir(&cwd, offset, nongit_ok);
911
912 offset_parent = offset;
913 while (--offset_parent > ceil_offset && cwd.buf[offset_parent] != '/');
914 if (offset_parent <= ceil_offset)
915 return setup_nongit(cwd.buf, nongit_ok);
916 if (one_filesystem) {
917 dev_t parent_device = get_device_or_die("..", cwd.buf,
918 offset);
919 if (parent_device != current_device) {
920 if (nongit_ok) {
921 if (chdir(cwd.buf))
922 die_errno(_("Cannot come back to cwd"));
923 *nongit_ok = 1;
924 return NULL;
925 }
926 strbuf_setlen(&cwd, offset);
927 die(_("Not a git repository (or any parent up to mount point %s)\n"
928 "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
929 cwd.buf);
930 }
931 }
932 if (chdir("..")) {
933 strbuf_setlen(&cwd, offset);
934 die_errno(_("Cannot change to '%s/..'"), cwd.buf);
935 }
936 offset = offset_parent;
937 }
938 }
939
940 const char *setup_git_directory_gently(int *nongit_ok)
941 {
942 const char *prefix;
943
944 prefix = setup_git_directory_gently_1(nongit_ok);
945 if (prefix)
946 setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
947 else
948 setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
949
950 startup_info->have_repository = !nongit_ok || !*nongit_ok;
951 startup_info->prefix = prefix;
952
953 return prefix;
954 }
955
956 int git_config_perm(const char *var, const char *value)
957 {
958 int i;
959 char *endptr;
960
961 if (value == NULL)
962 return PERM_GROUP;
963
964 if (!strcmp(value, "umask"))
965 return PERM_UMASK;
966 if (!strcmp(value, "group"))
967 return PERM_GROUP;
968 if (!strcmp(value, "all") ||
969 !strcmp(value, "world") ||
970 !strcmp(value, "everybody"))
971 return PERM_EVERYBODY;
972
973 /* Parse octal numbers */
974 i = strtol(value, &endptr, 8);
975
976 /* If not an octal number, maybe true/false? */
977 if (*endptr != 0)
978 return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
979
980 /*
981 * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
982 * a chmod value to restrict to.
983 */
984 switch (i) {
985 case PERM_UMASK: /* 0 */
986 return PERM_UMASK;
987 case OLD_PERM_GROUP: /* 1 */
988 return PERM_GROUP;
989 case OLD_PERM_EVERYBODY: /* 2 */
990 return PERM_EVERYBODY;
991 }
992
993 /* A filemode value was given: 0xxx */
994
995 if ((i & 0600) != 0600)
996 die(_("Problem with core.sharedRepository filemode value "
997 "(0%.3o).\nThe owner of files must always have "
998 "read and write permissions."), i);
999
1000 /*
1001 * Mask filemode value. Others can not get write permission.
1002 * x flags for directories are handled separately.
1003 */
1004 return -(i & 0666);
1005 }
1006
1007 void check_repository_format(void)
1008 {
1009 check_repository_format_gently(get_git_dir(), NULL);
1010 startup_info->have_repository = 1;
1011 }
1012
1013 /*
1014 * Returns the "prefix", a path to the current working directory
1015 * relative to the work tree root, or NULL, if the current working
1016 * directory is not a strict subdirectory of the work tree root. The
1017 * prefix always ends with a '/' character.
1018 */
1019 const char *setup_git_directory(void)
1020 {
1021 return setup_git_directory_gently(NULL);
1022 }
1023
1024 const char *resolve_gitdir_gently(const char *suspect, int *return_error_code)
1025 {
1026 if (is_git_directory(suspect))
1027 return suspect;
1028 return read_gitfile_gently(suspect, return_error_code);
1029 }
1030
1031 /* if any standard file descriptor is missing open it to /dev/null */
1032 void sanitize_stdfds(void)
1033 {
1034 int fd = open("/dev/null", O_RDWR, 0);
1035 while (fd != -1 && fd < 2)
1036 fd = dup(fd);
1037 if (fd == -1)
1038 die_errno("open /dev/null or dup failed");
1039 if (fd > 2)
1040 close(fd);
1041 }
1042
1043 int daemonize(void)
1044 {
1045 #ifdef NO_POSIX_GOODIES
1046 errno = ENOSYS;
1047 return -1;
1048 #else
1049 switch (fork()) {
1050 case 0:
1051 break;
1052 case -1:
1053 die_errno("fork failed");
1054 default:
1055 exit(0);
1056 }
1057 if (setsid() == -1)
1058 die_errno("setsid failed");
1059 close(0);
1060 close(1);
1061 close(2);
1062 sanitize_stdfds();
1063 return 0;
1064 #endif
1065 }