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_addstr(sb, real_path(path.buf));
 258                 ret = 1;
 259         } else
 260                 strbuf_addstr(sb, gitdir);
 261         strbuf_release(&data);
 262         strbuf_release(&path);
 263         return ret;
 264 }
 265
 266 /*
 267  * Test if it looks like we're at a git directory.
 268  * We want to see:
 269  *
 270  *  - either an objects/ directory _or_ the proper
 271  *    GIT_OBJECT_DIRECTORY environment variable
 272  *  - a refs/ directory
 273  *  - either a HEAD symlink or a HEAD file that is formatted as
 274  *    a proper "ref:", or a regular file HEAD that has a properly
 275  *    formatted sha1 object name.
 276  */
 277 int is_git_directory(const char *suspect)
 278 {
 279         struct strbuf path = STRBUF_INIT;
 280         int ret = 0;
 281         size_t len;
 282
 283         /* Check worktree-related signatures */
 284         strbuf_addf(&path, "%s/HEAD", suspect);
 285         if (validate_headref(path.buf))
 286                 goto done;
 287
 288         strbuf_reset(&path);
 289         get_common_dir(&path, suspect);
 290         len = path.len;
 291
 292         /* Check non-worktree-related signatures */
 293         if (getenv(DB_ENVIRONMENT)) {
 294                 if (access(getenv(DB_ENVIRONMENT), X_OK))
 295                         goto done;
 296         }
 297         else {
 298                 strbuf_setlen(&path, len);
 299                 strbuf_addstr(&path, "/objects");
 300                 if (access(path.buf, X_OK))
 301                         goto done;
 302         }
 303
 304         strbuf_setlen(&path, len);
 305         strbuf_addstr(&path, "/refs");
 306         if (access(path.buf, X_OK))
 307                 goto done;
 308
 309         ret = 1;
 310 done:
 311         strbuf_release(&path);
 312         return ret;
 313 }
 314
 315 int is_nonbare_repository_dir(struct strbuf *path)
 316 {
 317         int ret = 0;
 318         int gitfile_error;
 319         size_t orig_path_len = path->len;
 320         assert(orig_path_len != 0);
 321         strbuf_complete(path, '/');
 322         strbuf_addstr(path, ".git");
 323         if (read_gitfile_gently(path->buf, &gitfile_error) || is_git_directory(path->buf))
 324                 ret = 1;
 325         if (gitfile_error == READ_GITFILE_ERR_OPEN_FAILED ||
 326             gitfile_error == READ_GITFILE_ERR_READ_FAILED)
 327                 ret = 1;
 328         strbuf_setlen(path, orig_path_len);
 329         return ret;
 330 }
 331
 332 int is_inside_git_dir(void)
 333 {
 334         if (inside_git_dir < 0)
 335                 inside_git_dir = is_inside_dir(get_git_dir());
 336         return inside_git_dir;
 337 }
 338
 339 int is_inside_work_tree(void)
 340 {
 341         if (inside_work_tree < 0)
 342                 inside_work_tree = is_inside_dir(get_git_work_tree());
 343         return inside_work_tree;
 344 }
 345
 346 void setup_work_tree(void)
 347 {
 348         const char *work_tree, *git_dir;
 349         static int initialized = 0;
 350
 351         if (initialized)
 352                 return;
 353
 354         if (work_tree_config_is_bogus)
 355                 die("unable to set up work tree using invalid config");
 356
 357         work_tree = get_git_work_tree();
 358         git_dir = get_git_dir();
 359         if (!is_absolute_path(git_dir))
 360                 git_dir = real_path(get_git_dir());
 361         if (!work_tree || chdir(work_tree))
 362                 die("This operation must be run in a work tree");
 363
 364         /*
 365          * Make sure subsequent git processes find correct worktree
 366          * if $GIT_WORK_TREE is set relative
 367          */
 368         if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 369                 setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 370
 371         set_git_dir(remove_leading_path(git_dir, work_tree));
 372         initialized = 1;
 373 }
 374
 375 static int check_repo_format(const char *var, const char *value, void *vdata)
 376 {
 377         struct repository_format *data = vdata;
 378         const char *ext;
 379
 380         if (strcmp(var, "core.repositoryformatversion") == 0)
 381                 data->version = git_config_int(var, value);
 382         else if (skip_prefix(var, "extensions.", &ext)) {
 383                 /*
 384                  * record any known extensions here; otherwise,
 385                  * we fall through to recording it as unknown, and
 386                  * check_repository_format will complain
 387                  */
 388                 if (!strcmp(ext, "noop"))
 389                         ;
 390                 else if (!strcmp(ext, "preciousobjects"))
 391                         data->precious_objects = git_config_bool(var, value);
 392                 else
 393                         string_list_append(&data->unknown_extensions, ext);
 394         } else if (strcmp(var, "core.bare") == 0) {
 395                 data->is_bare = git_config_bool(var, value);
 396         } else if (strcmp(var, "core.worktree") == 0) {
 397                 if (!value)
 398                         return config_error_nonbool(var);
 399                 data->work_tree = xstrdup(value);
 400         }
 401         return 0;
 402 }
 403
 404 static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 405 {
 406         struct strbuf sb = STRBUF_INIT;
 407         struct strbuf err = STRBUF_INIT;
 408         struct repository_format candidate;
 409         int has_common;
 410
 411         has_common = get_common_dir(&sb, gitdir);
 412         strbuf_addstr(&sb, "/config");
 413         read_repository_format(&candidate, sb.buf);
 414         strbuf_release(&sb);
 415
 416         /*
 417          * For historical use of check_repository_format() in git-init,
 418          * we treat a missing config as a silent "ok", even when nongit_ok
 419          * is unset.
 420          */
 421         if (candidate.version < 0)
 422                 return 0;
 423
 424         if (verify_repository_format(&candidate, &err) < 0) {
 425                 if (nongit_ok) {
 426                         warning("%s", err.buf);
 427                         strbuf_release(&err);
 428                         *nongit_ok = -1;
 429                         return -1;
 430                 }
 431                 die("%s", err.buf);
 432         }
 433
 434         repository_format_precious_objects = candidate.precious_objects;
 435         string_list_clear(&candidate.unknown_extensions, 0);
 436         if (!has_common) {
 437                 if (candidate.is_bare != -1) {
 438                         is_bare_repository_cfg = candidate.is_bare;
 439                         if (is_bare_repository_cfg == 1)
 440                                 inside_work_tree = -1;
 441                 }
 442                 if (candidate.work_tree) {
 443                         free(git_work_tree_cfg);
 444                         git_work_tree_cfg = candidate.work_tree;
 445                         inside_work_tree = -1;
 446                 }
 447         } else {
 448                 free(candidate.work_tree);
 449         }
 450
 451         return 0;
 452 }
 453
 454 int read_repository_format(struct repository_format *format, const char *path)
 455 {
 456         memset(format, 0, sizeof(*format));
 457         format->version = -1;
 458         format->is_bare = -1;
 459         string_list_init(&format->unknown_extensions, 1);
 460         git_config_from_file(check_repo_format, path, format);
 461         return format->version;
 462 }
 463
 464 int verify_repository_format(const struct repository_format *format,
 465                              struct strbuf *err)
 466 {
 467         if (GIT_REPO_VERSION_READ < format->version) {
 468                 strbuf_addf(err, _("Expected git repo version <= %d, found %d"),
 469                             GIT_REPO_VERSION_READ, format->version);
 470                 return -1;
 471         }
 472
 473         if (format->version >= 1 && format->unknown_extensions.nr) {
 474                 int i;
 475
 476                 strbuf_addstr(err, _("unknown repository extensions found:"));
 477
 478                 for (i = 0; i < format->unknown_extensions.nr; i++)
 479                         strbuf_addf(err, "\n\t%s",
 480                                     format->unknown_extensions.items[i].string);
 481                 return -1;
 482         }
 483
 484         return 0;
 485 }
 486
 487 /*
 488  * Try to read the location of the git directory from the .git file,
 489  * return path to git directory if found.
 490  *
 491  * On failure, if return_error_code is not NULL, return_error_code
 492  * will be set to an error code and NULL will be returned. If
 493  * return_error_code is NULL the function will die instead (for most
 494  * cases).
 495  */
 496 const char *read_gitfile_gently(const char *path, int *return_error_code)
 497 {
 498         const int max_file_size = 1 << 20;  /* 1MB */
 499         int error_code = 0;
 500         char *buf = NULL;
 501         char *dir = NULL;
 502         const char *slash;
 503         struct stat st;
 504         int fd;
 505         ssize_t len;
 506
 507         if (stat(path, &st)) {
 508                 error_code = READ_GITFILE_ERR_STAT_FAILED;
 509                 goto cleanup_return;
 510         }
 511         if (!S_ISREG(st.st_mode)) {
 512                 error_code = READ_GITFILE_ERR_NOT_A_FILE;
 513                 goto cleanup_return;
 514         }
 515         if (st.st_size > max_file_size) {
 516                 error_code = READ_GITFILE_ERR_TOO_LARGE;
 517                 goto cleanup_return;
 518         }
 519         fd = open(path, O_RDONLY);
 520         if (fd < 0) {
 521                 error_code = READ_GITFILE_ERR_OPEN_FAILED;
 522                 goto cleanup_return;
 523         }
 524         buf = xmallocz(st.st_size);
 525         len = read_in_full(fd, buf, st.st_size);
 526         close(fd);
 527         if (len != st.st_size) {
 528                 error_code = READ_GITFILE_ERR_READ_FAILED;
 529                 goto cleanup_return;
 530         }
 531         if (!starts_with(buf, "gitdir: ")) {
 532                 error_code = READ_GITFILE_ERR_INVALID_FORMAT;
 533                 goto cleanup_return;
 534         }
 535         while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 536                 len--;
 537         if (len < 9) {
 538                 error_code = READ_GITFILE_ERR_NO_PATH;
 539                 goto cleanup_return;
 540         }
 541         buf[len] = '\0';
 542         dir = buf + 8;
 543
 544         if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 545                 size_t pathlen = slash+1 - path;
 546                 dir = xstrfmt("%.*s%.*s", (int)pathlen, path,
 547                               (int)(len - 8), buf + 8);
 548                 free(buf);
 549                 buf = dir;
 550         }
 551         if (!is_git_directory(dir)) {
 552                 error_code = READ_GITFILE_ERR_NOT_A_REPO;
 553                 goto cleanup_return;
 554         }
 555         path = real_path(dir);
 556
 557 cleanup_return:
 558         if (return_error_code)
 559                 *return_error_code = error_code;
 560         else if (error_code) {
 561                 switch (error_code) {
 562                 case READ_GITFILE_ERR_STAT_FAILED:
 563                 case READ_GITFILE_ERR_NOT_A_FILE:
 564                         /* non-fatal; follow return path */
 565                         break;
 566                 case READ_GITFILE_ERR_OPEN_FAILED:
 567                         die_errno("Error opening '%s'", path);
 568                 case READ_GITFILE_ERR_TOO_LARGE:
 569                         die("Too large to be a .git file: '%s'", path);
 570                 case READ_GITFILE_ERR_READ_FAILED:
 571                         die("Error reading %s", path);
 572                 case READ_GITFILE_ERR_INVALID_FORMAT:
 573                         die("Invalid gitfile format: %s", path);
 574                 case READ_GITFILE_ERR_NO_PATH:
 575                         die("No path in gitfile: %s", path);
 576                 case READ_GITFILE_ERR_NOT_A_REPO:
 577                         die("Not a git repository: %s", dir);
 578                 default:
 579                         assert(0);
 580                 }
 581         }
 582
 583         free(buf);
 584         return error_code ? NULL : path;
 585 }
 586
 587 static const char *setup_explicit_git_dir(const char *gitdirenv,
 588                                           struct strbuf *cwd,
 589                                           int *nongit_ok)
 590 {
 591         const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 592         const char *worktree;
 593         char *gitfile;
 594         int offset;
 595
 596         if (PATH_MAX - 40 < strlen(gitdirenv))
 597                 die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 598
 599         gitfile = (char*)read_gitfile(gitdirenv);
 600         if (gitfile) {
 601                 gitfile = xstrdup(gitfile);
 602                 gitdirenv = gitfile;
 603         }
 604
 605         if (!is_git_directory(gitdirenv)) {
 606                 if (nongit_ok) {
 607                         *nongit_ok = 1;
 608                         free(gitfile);
 609                         return NULL;
 610                 }
 611                 die("Not a git repository: '%s'", gitdirenv);
 612         }
 613
 614         if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 615                 free(gitfile);
 616                 return NULL;
 617         }
 618
 619         /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 620         if (work_tree_env)
 621                 set_git_work_tree(work_tree_env);
 622         else if (is_bare_repository_cfg > 0) {
 623                 if (git_work_tree_cfg) {
 624                         /* #22.2, #30 */
 625                         warning("core.bare and core.worktree do not make sense");
 626                         work_tree_config_is_bogus = 1;
 627                 }
 628
 629                 /* #18, #26 */
 630                 set_git_dir(gitdirenv);
 631                 free(gitfile);
 632                 return NULL;
 633         }
 634         else if (git_work_tree_cfg) { /* #6, #14 */
 635                 if (is_absolute_path(git_work_tree_cfg))
 636                         set_git_work_tree(git_work_tree_cfg);
 637                 else {
 638                         char *core_worktree;
 639                         if (chdir(gitdirenv))
 640                                 die_errno("Could not chdir to '%s'", gitdirenv);
 641                         if (chdir(git_work_tree_cfg))
 642                                 die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 643                         core_worktree = xgetcwd();
 644                         if (chdir(cwd->buf))
 645                                 die_errno("Could not come back to cwd");
 646                         set_git_work_tree(core_worktree);
 647                         free(core_worktree);
 648                 }
 649         }
 650         else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 651                 /* #16d */
 652                 set_git_dir(gitdirenv);
 653                 free(gitfile);
 654                 return NULL;
 655         }
 656         else /* #2, #10 */
 657                 set_git_work_tree(".");
 658
 659         /* set_git_work_tree() must have been called by now */
 660         worktree = get_git_work_tree();
 661
 662         /* both get_git_work_tree() and cwd are already normalized */
 663         if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
 664                 set_git_dir(gitdirenv);
 665                 free(gitfile);
 666                 return NULL;
 667         }
 668
 669         offset = dir_inside_of(cwd->buf, worktree);
 670         if (offset >= 0) {      /* cwd inside worktree? */
 671                 set_git_dir(real_path(gitdirenv));
 672                 if (chdir(worktree))
 673                         die_errno("Could not chdir to '%s'", worktree);
 674                 strbuf_addch(cwd, '/');
 675                 free(gitfile);
 676                 return cwd->buf + offset;
 677         }
 678
 679         /* cwd outside worktree */
 680         set_git_dir(gitdirenv);
 681         free(gitfile);
 682         return NULL;
 683 }
 684
 685 static const char *setup_discovered_git_dir(const char *gitdir,
 686                                             struct strbuf *cwd, int offset,
 687                                             int *nongit_ok)
 688 {
 689         if (check_repository_format_gently(gitdir, nongit_ok))
 690                 return NULL;
 691
 692         /* --work-tree is set without --git-dir; use discovered one */
 693         if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 694                 if (offset != cwd->len && !is_absolute_path(gitdir))
 695                         gitdir = xstrdup(real_path(gitdir));
 696                 if (chdir(cwd->buf))
 697                         die_errno("Could not come back to cwd");
 698                 return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 699         }
 700
 701         /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 702         if (is_bare_repository_cfg > 0) {
 703                 set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
 704                 if (chdir(cwd->buf))
 705                         die_errno("Could not come back to cwd");
 706                 return NULL;
 707         }
 708
 709         /* #0, #1, #5, #8, #9, #12, #13 */
 710         set_git_work_tree(".");
 711         if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 712                 set_git_dir(gitdir);
 713         inside_git_dir = 0;
 714         inside_work_tree = 1;
 715         if (offset == cwd->len)
 716                 return NULL;
 717
 718         /* Make "offset" point to past the '/', and add a '/' at the end */
 719         offset++;
 720         strbuf_addch(cwd, '/');
 721         return cwd->buf + offset;
 722 }
 723
 724 /* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 725 static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 726                                       int *nongit_ok)
 727 {
 728         int root_len;
 729
 730         if (check_repository_format_gently(".", nongit_ok))
 731                 return NULL;
 732
 733         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 734
 735         /* --work-tree is set without --git-dir; use discovered one */
 736         if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 737                 const char *gitdir;
 738
 739                 gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
 740                 if (chdir(cwd->buf))
 741                         die_errno("Could not come back to cwd");
 742                 return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 743         }
 744
 745         inside_git_dir = 1;
 746         inside_work_tree = 0;
 747         if (offset != cwd->len) {
 748                 if (chdir(cwd->buf))
 749                         die_errno("Cannot come back to cwd");
 750                 root_len = offset_1st_component(cwd->buf);
 751                 strbuf_setlen(cwd, offset > root_len ? offset : root_len);
 752                 set_git_dir(cwd->buf);
 753         }
 754         else
 755                 set_git_dir(".");
 756         return NULL;
 757 }
 758
 759 static const char *setup_nongit(const char *cwd, int *nongit_ok)
 760 {
 761         if (!nongit_ok)
 762                 die(_("Not a git repository (or any of the parent directories): %s"), DEFAULT_GIT_DIR_ENVIRONMENT);
 763         if (chdir(cwd))
 764                 die_errno(_("Cannot come back to cwd"));
 765         *nongit_ok = 1;
 766         return NULL;
 767 }
 768
 769 static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 770 {
 771         struct stat buf;
 772         if (stat(path, &buf)) {
 773                 die_errno("failed to stat '%*s%s%s'",
 774                                 prefix_len,
 775                                 prefix ? prefix : "",
 776                                 prefix ? "/" : "", path);
 777         }
 778         return buf.st_dev;
 779 }
 780
 781 /*
 782  * A "string_list_each_func_t" function that canonicalizes an entry
 783  * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 784  * discards it if unusable.  The presence of an empty entry in
 785  * GIT_CEILING_DIRECTORIES turns off canonicalization for all
 786  * subsequent entries.
 787  */
 788 static int canonicalize_ceiling_entry(struct string_list_item *item,
 789                                       void *cb_data)
 790 {
 791         int *empty_entry_found = cb_data;
 792         char *ceil = item->string;
 793
 794         if (!*ceil) {
 795                 *empty_entry_found = 1;
 796                 return 0;
 797         } else if (!is_absolute_path(ceil)) {
 798                 return 0;
 799         } else if (*empty_entry_found) {
 800                 /* Keep entry but do not canonicalize it */
 801                 return 1;
 802         } else {
 803                 const char *real_path = real_path_if_valid(ceil);
 804                 if (!real_path)
 805                         return 0;
 806                 free(item->string);
 807                 item->string = xstrdup(real_path);
 808                 return 1;
 809         }
 810 }
 811
 812 /*
 813  * We cannot decide in this function whether we are in the work tree or
 814  * not, since the config can only be read _after_ this function was called.
 815  */
 816 static const char *setup_git_directory_gently_1(int *nongit_ok)
 817 {
 818         const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 819         struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 820         static struct strbuf cwd = STRBUF_INIT;
 821         const char *gitdirenv, *ret;
 822         char *gitfile;
 823         int offset, offset_parent, ceil_offset = -1;
 824         dev_t current_device = 0;
 825         int one_filesystem = 1;
 826
 827         /*
 828          * We may have read an incomplete configuration before
 829          * setting-up the git directory. If so, clear the cache so
 830          * that the next queries to the configuration reload complete
 831          * configuration (including the per-repo config file that we
 832          * ignored previously).
 833          */
 834         git_config_clear();
 835
 836         /*
 837          * Let's assume that we are in a git repository.
 838          * If it turns out later that we are somewhere else, the value will be
 839          * updated accordingly.
 840          */
 841         if (nongit_ok)
 842                 *nongit_ok = 0;
 843
 844         if (strbuf_getcwd(&cwd))
 845                 die_errno(_("Unable to read current working directory"));
 846         offset = cwd.len;
 847
 848         /*
 849          * If GIT_DIR is set explicitly, we're not going
 850          * to do any discovery, but we still do repository
 851          * validation.
 852          */
 853         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 854         if (gitdirenv)
 855                 return setup_explicit_git_dir(gitdirenv, &cwd, nongit_ok);
 856
 857         if (env_ceiling_dirs) {
 858                 int empty_entry_found = 0;
 859
 860                 string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 861                 filter_string_list(&ceiling_dirs, 0,
 862                                    canonicalize_ceiling_entry, &empty_entry_found);
 863                 ceil_offset = longest_ancestor_length(cwd.buf, &ceiling_dirs);
 864                 string_list_clear(&ceiling_dirs, 0);
 865         }
 866
 867         if (ceil_offset < 0 && has_dos_drive_prefix(cwd.buf))
 868                 ceil_offset = 1;
 869
 870         /*
 871          * Test in the following order (relative to the cwd):
 872          * - .git (file containing "gitdir: <path>")
 873          * - .git/
 874          * - ./ (bare)
 875          * - ../.git
 876          * - ../.git/
 877          * - ../ (bare)
 878          * - ../../.git/
 879          *   etc.
 880          */
 881         one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 882         if (one_filesystem)
 883                 current_device = get_device_or_die(".", NULL, 0);
 884         for (;;) {
 885                 gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
 886                 if (gitfile)
 887                         gitdirenv = gitfile = xstrdup(gitfile);
 888                 else {
 889                         if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 890                                 gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 891                 }
 892
 893                 if (gitdirenv) {
 894                         ret = setup_discovered_git_dir(gitdirenv,
 895                                                        &cwd, offset,
 896                                                        nongit_ok);
 897                         free(gitfile);
 898                         return ret;
 899                 }
 900                 free(gitfile);
 901
 902                 if (is_git_directory("."))
 903                         return setup_bare_git_dir(&cwd, offset, nongit_ok);
 904
 905                 offset_parent = offset;
 906                 while (--offset_parent > ceil_offset && cwd.buf[offset_parent] != '/');
 907                 if (offset_parent <= ceil_offset)
 908                         return setup_nongit(cwd.buf, nongit_ok);
 909                 if (one_filesystem) {
 910                         dev_t parent_device = get_device_or_die("..", cwd.buf,
 911                                                                 offset);
 912                         if (parent_device != current_device) {
 913                                 if (nongit_ok) {
 914                                         if (chdir(cwd.buf))
 915                                                 die_errno(_("Cannot come back to cwd"));
 916                                         *nongit_ok = 1;
 917                                         return NULL;
 918                                 }
 919                                 strbuf_setlen(&cwd, offset);
 920                                 die(_("Not a git repository (or any parent up to mount point %s)\n"
 921                                 "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
 922                                     cwd.buf);
 923                         }
 924                 }
 925                 if (chdir("..")) {
 926                         strbuf_setlen(&cwd, offset);
 927                         die_errno(_("Cannot change to '%s/..'"), cwd.buf);
 928                 }
 929                 offset = offset_parent;
 930         }
 931 }
 932
 933 const char *setup_git_directory_gently(int *nongit_ok)
 934 {
 935         const char *prefix;
 936
 937         prefix = setup_git_directory_gently_1(nongit_ok);
 938         if (prefix)
 939                 setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
 940         else
 941                 setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
 942
 943         startup_info->have_repository = !nongit_ok || !*nongit_ok;
 944         startup_info->prefix = prefix;
 945
 946         return prefix;
 947 }
 948
 949 int git_config_perm(const char *var, const char *value)
 950 {
 951         int i;
 952         char *endptr;
 953
 954         if (value == NULL)
 955                 return PERM_GROUP;
 956
 957         if (!strcmp(value, "umask"))
 958                 return PERM_UMASK;
 959         if (!strcmp(value, "group"))
 960                 return PERM_GROUP;
 961         if (!strcmp(value, "all") ||
 962             !strcmp(value, "world") ||
 963             !strcmp(value, "everybody"))
 964                 return PERM_EVERYBODY;
 965
 966         /* Parse octal numbers */
 967         i = strtol(value, &endptr, 8);
 968
 969         /* If not an octal number, maybe true/false? */
 970         if (*endptr != 0)
 971                 return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 972
 973         /*
 974          * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 975          * a chmod value to restrict to.
 976          */
 977         switch (i) {
 978         case PERM_UMASK:               /* 0 */
 979                 return PERM_UMASK;
 980         case OLD_PERM_GROUP:           /* 1 */
 981                 return PERM_GROUP;
 982         case OLD_PERM_EVERYBODY:       /* 2 */
 983                 return PERM_EVERYBODY;
 984         }
 985
 986         /* A filemode value was given: 0xxx */
 987
 988         if ((i & 0600) != 0600)
 989                 die(_("Problem with core.sharedRepository filemode value "
 990                     "(0%.3o).\nThe owner of files must always have "
 991                     "read and write permissions."), i);
 992
 993         /*
 994          * Mask filemode value. Others can not get write permission.
 995          * x flags for directories are handled separately.
 996          */
 997         return -(i & 0666);
 998 }
 999
1000 void check_repository_format(void)
1001 {
1002         check_repository_format_gently(get_git_dir(), NULL);
1003         startup_info->have_repository = 1;
1004 }
1005
1006 /*
1007  * Returns the "prefix", a path to the current working directory
1008  * relative to the work tree root, or NULL, if the current working
1009  * directory is not a strict subdirectory of the work tree root. The
1010  * prefix always ends with a '/' character.
1011  */
1012 const char *setup_git_directory(void)
1013 {
1014         return setup_git_directory_gently(NULL);
1015 }
1016
1017 const char *resolve_gitdir(const char *suspect)
1018 {
1019         if (is_git_directory(suspect))
1020                 return suspect;
1021         return read_gitfile(suspect);
1022 }
1023
1024 /* if any standard file descriptor is missing open it to /dev/null */
1025 void sanitize_stdfds(void)
1026 {
1027         int fd = open("/dev/null", O_RDWR, 0);
1028         while (fd != -1 && fd < 2)
1029                 fd = dup(fd);
1030         if (fd == -1)
1031                 die_errno("open /dev/null or dup failed");
1032         if (fd > 2)
1033                 close(fd);
1034 }
1035
1036 int daemonize(void)
1037 {
1038 #ifdef NO_POSIX_GOODIES
1039         errno = ENOSYS;
1040         return -1;
1041 #else
1042         switch (fork()) {
1043                 case 0:
1044                         break;
1045                 case -1:
1046                         die_errno("fork failed");
1047                 default:
1048                         exit(0);
1049         }
1050         if (setsid() == -1)
1051                 die_errno("setsid failed");
1052         close(0);
1053         close(1);
1054         close(2);
1055         sanitize_stdfds();
1056         return 0;
1057 #endif
1058 }