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 static struct string_list unknown_extensions = STRING_LIST_INIT_DUP;
   9
  10 /*
  11  * The input parameter must contain an absolute path, and it must already be
  12  * normalized.
  13  *
  14  * Find the part of an absolute path that lies inside the work tree by
  15  * dereferencing symlinks outside the work tree, for example:
  16  * /dir1/repo/dir2/file   (work tree is /dir1/repo)      -> dir2/file
  17  * /dir/file              (work tree is /)               -> dir/file
  18  * /dir/symlink1/symlink2 (symlink1 points to work tree) -> symlink2
  19  * /dir/repolink/file     (repolink points to /dir/repo) -> file
  20  * /dir/repo              (exactly equal to work tree)   -> (empty string)
  21  */
  22 static int abspath_part_inside_repo(char *path)
  23 {
  24         size_t len;
  25         size_t wtlen;
  26         char *path0;
  27         int off;
  28         const char *work_tree = get_git_work_tree();
  29
  30         if (!work_tree)
  31                 return -1;
  32         wtlen = strlen(work_tree);
  33         len = strlen(path);
  34         off = offset_1st_component(path);
  35
  36         /* check if work tree is already the prefix */
  37         if (wtlen <= len && !strncmp(path, work_tree, wtlen)) {
  38                 if (path[wtlen] == '/') {
  39                         memmove(path, path + wtlen + 1, len - wtlen);
  40                         return 0;
  41                 } else if (path[wtlen - 1] == '/' || path[wtlen] == '\0') {
  42                         /* work tree is the root, or the whole path */
  43                         memmove(path, path + wtlen, len - wtlen + 1);
  44                         return 0;
  45                 }
  46                 /* work tree might match beginning of a symlink to work tree */
  47                 off = wtlen;
  48         }
  49         path0 = path;
  50         path += off;
  51
  52         /* check each '/'-terminated level */
  53         while (*path) {
  54                 path++;
  55                 if (*path == '/') {
  56                         *path = '\0';
  57                         if (strcmp(real_path(path0), work_tree) == 0) {
  58                                 memmove(path0, path + 1, len - (path - path0));
  59                                 return 0;
  60                         }
  61                         *path = '/';
  62                 }
  63         }
  64
  65         /* check whole path */
  66         if (strcmp(real_path(path0), work_tree) == 0) {
  67                 *path0 = '\0';
  68                 return 0;
  69         }
  70
  71         return -1;
  72 }
  73
  74 /*
  75  * Normalize "path", prepending the "prefix" for relative paths. If
  76  * remaining_prefix is not NULL, return the actual prefix still
  77  * remains in the path. For example, prefix = sub1/sub2/ and path is
  78  *
  79  *  foo          -> sub1/sub2/foo  (full prefix)
  80  *  ../foo       -> sub1/foo       (remaining prefix is sub1/)
  81  *  ../../bar    -> bar            (no remaining prefix)
  82  *  ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix)
  83  *  `pwd`/../bar -> sub1/bar       (no remaining prefix)
  84  */
  85 char *prefix_path_gently(const char *prefix, int len,
  86                          int *remaining_prefix, const char *path)
  87 {
  88         const char *orig = path;
  89         char *sanitized;
  90         if (is_absolute_path(orig)) {
  91                 sanitized = xmalloc(strlen(path) + 1);
  92                 if (remaining_prefix)
  93                         *remaining_prefix = 0;
  94                 if (normalize_path_copy_len(sanitized, path, remaining_prefix)) {
  95                         free(sanitized);
  96                         return NULL;
  97                 }
  98                 if (abspath_part_inside_repo(sanitized)) {
  99                         free(sanitized);
 100                         return NULL;
 101                 }
 102         } else {
 103                 sanitized = xmalloc(len + strlen(path) + 1);
 104                 if (len)
 105                         memcpy(sanitized, prefix, len);
 106                 strcpy(sanitized + len, path);
 107                 if (remaining_prefix)
 108                         *remaining_prefix = len;
 109                 if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
 110                         free(sanitized);
 111                         return NULL;
 112                 }
 113         }
 114         return sanitized;
 115 }
 116
 117 char *prefix_path(const char *prefix, int len, const char *path)
 118 {
 119         char *r = prefix_path_gently(prefix, len, NULL, path);
 120         if (!r)
 121                 die("'%s' is outside repository", path);
 122         return r;
 123 }
 124
 125 int path_inside_repo(const char *prefix, const char *path)
 126 {
 127         int len = prefix ? strlen(prefix) : 0;
 128         char *r = prefix_path_gently(prefix, len, NULL, path);
 129         if (r) {
 130                 free(r);
 131                 return 1;
 132         }
 133         return 0;
 134 }
 135
 136 int check_filename(const char *prefix, const char *arg)
 137 {
 138         const char *name;
 139         struct stat st;
 140
 141         if (starts_with(arg, ":/")) {
 142                 if (arg[2] == '\0') /* ":/" is root dir, always exists */
 143                         return 1;
 144                 name = arg + 2;
 145         } else if (!no_wildcard(arg))
 146                 return 1;
 147         else if (prefix)
 148                 name = prefix_filename(prefix, strlen(prefix), arg);
 149         else
 150                 name = arg;
 151         if (!lstat(name, &st))
 152                 return 1; /* file exists */
 153         if (errno == ENOENT || errno == ENOTDIR)
 154                 return 0; /* file does not exist */
 155         die_errno("failed to stat '%s'", arg);
 156 }
 157
 158 static void NORETURN die_verify_filename(const char *prefix,
 159                                          const char *arg,
 160                                          int diagnose_misspelt_rev)
 161 {
 162         if (!diagnose_misspelt_rev)
 163                 die("%s: no such path in the working tree.\n"
 164                     "Use 'git <command> -- <path>...' to specify paths that do not exist locally.",
 165                     arg);
 166         /*
 167          * Saying "'(icase)foo' does not exist in the index" when the
 168          * user gave us ":(icase)foo" is just stupid.  A magic pathspec
 169          * begins with a colon and is followed by a non-alnum; do not
 170          * let maybe_die_on_misspelt_object_name() even trigger.
 171          */
 172         if (!(arg[0] == ':' && !isalnum(arg[1])))
 173                 maybe_die_on_misspelt_object_name(arg, prefix);
 174
 175         /* ... or fall back the most general message. */
 176         die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 177             "Use '--' to separate paths from revisions, like this:\n"
 178             "'git <command> [<revision>...] -- [<file>...]'", arg);
 179
 180 }
 181
 182 /*
 183  * Verify a filename that we got as an argument for a pathspec
 184  * entry. Note that a filename that begins with "-" never verifies
 185  * as true, because even if such a filename were to exist, we want
 186  * it to be preceded by the "--" marker (or we want the user to
 187  * use a format like "./-filename")
 188  *
 189  * The "diagnose_misspelt_rev" is used to provide a user-friendly
 190  * diagnosis when dying upon finding that "name" is not a pathname.
 191  * If set to 1, the diagnosis will try to diagnose "name" as an
 192  * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
 193  * will only complain about an inexisting file.
 194  *
 195  * This function is typically called to check that a "file or rev"
 196  * argument is unambiguous. In this case, the caller will want
 197  * diagnose_misspelt_rev == 1 when verifying the first non-rev
 198  * argument (which could have been a revision), and
 199  * diagnose_misspelt_rev == 0 for the next ones (because we already
 200  * saw a filename, there's not ambiguity anymore).
 201  */
 202 void verify_filename(const char *prefix,
 203                      const char *arg,
 204                      int diagnose_misspelt_rev)
 205 {
 206         if (*arg == '-')
 207                 die("bad flag '%s' used after filename", arg);
 208         if (check_filename(prefix, arg))
 209                 return;
 210         die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 211 }
 212
 213 /*
 214  * Opposite of the above: the command line did not have -- marker
 215  * and we parsed the arg as a refname.  It should not be interpretable
 216  * as a filename.
 217  */
 218 void verify_non_filename(const char *prefix, const char *arg)
 219 {
 220         if (!is_inside_work_tree() || is_inside_git_dir())
 221                 return;
 222         if (*arg == '-')
 223                 return; /* flag */
 224         if (!check_filename(prefix, arg))
 225                 return;
 226         die("ambiguous argument '%s': both revision and filename\n"
 227             "Use '--' to separate paths from revisions, like this:\n"
 228             "'git <command> [<revision>...] -- [<file>...]'", arg);
 229 }
 230
 231 int get_common_dir(struct strbuf *sb, const char *gitdir)
 232 {
 233         const char *git_env_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
 234         if (git_env_common_dir) {
 235                 strbuf_addstr(sb, git_env_common_dir);
 236                 return 1;
 237         } else {
 238                 return get_common_dir_noenv(sb, gitdir);
 239         }
 240 }
 241
 242 int get_common_dir_noenv(struct strbuf *sb, const char *gitdir)
 243 {
 244         struct strbuf data = STRBUF_INIT;
 245         struct strbuf path = STRBUF_INIT;
 246         int ret = 0;
 247
 248         strbuf_addf(&path, "%s/commondir", gitdir);
 249         if (file_exists(path.buf)) {
 250                 if (strbuf_read_file(&data, path.buf, 0) <= 0)
 251                         die_errno(_("failed to read %s"), path.buf);
 252                 while (data.len && (data.buf[data.len - 1] == '\n' ||
 253                                     data.buf[data.len - 1] == '\r'))
 254                         data.len--;
 255                 data.buf[data.len] = '\0';
 256                 strbuf_reset(&path);
 257                 if (!is_absolute_path(data.buf))
 258                         strbuf_addf(&path, "%s/", gitdir);
 259                 strbuf_addbuf(&path, &data);
 260                 strbuf_addstr(sb, real_path(path.buf));
 261                 ret = 1;
 262         } else
 263                 strbuf_addstr(sb, gitdir);
 264         strbuf_release(&data);
 265         strbuf_release(&path);
 266         return ret;
 267 }
 268
 269 /*
 270  * Test if it looks like we're at a git directory.
 271  * We want to see:
 272  *
 273  *  - either an objects/ directory _or_ the proper
 274  *    GIT_OBJECT_DIRECTORY environment variable
 275  *  - a refs/ directory
 276  *  - either a HEAD symlink or a HEAD file that is formatted as
 277  *    a proper "ref:", or a regular file HEAD that has a properly
 278  *    formatted sha1 object name.
 279  */
 280 int is_git_directory(const char *suspect)
 281 {
 282         struct strbuf path = STRBUF_INIT;
 283         int ret = 0;
 284         size_t len;
 285
 286         /* Check worktree-related signatures */
 287         strbuf_addf(&path, "%s/HEAD", suspect);
 288         if (validate_headref(path.buf))
 289                 goto done;
 290
 291         strbuf_reset(&path);
 292         get_common_dir(&path, suspect);
 293         len = path.len;
 294
 295         /* Check non-worktree-related signatures */
 296         if (getenv(DB_ENVIRONMENT)) {
 297                 if (access(getenv(DB_ENVIRONMENT), X_OK))
 298                         goto done;
 299         }
 300         else {
 301                 strbuf_setlen(&path, len);
 302                 strbuf_addstr(&path, "/objects");
 303                 if (access(path.buf, X_OK))
 304                         goto done;
 305         }
 306
 307         strbuf_setlen(&path, len);
 308         strbuf_addstr(&path, "/refs");
 309         if (access(path.buf, X_OK))
 310                 goto done;
 311
 312         ret = 1;
 313 done:
 314         strbuf_release(&path);
 315         return ret;
 316 }
 317
 318 int is_inside_git_dir(void)
 319 {
 320         if (inside_git_dir < 0)
 321                 inside_git_dir = is_inside_dir(get_git_dir());
 322         return inside_git_dir;
 323 }
 324
 325 int is_inside_work_tree(void)
 326 {
 327         if (inside_work_tree < 0)
 328                 inside_work_tree = is_inside_dir(get_git_work_tree());
 329         return inside_work_tree;
 330 }
 331
 332 void setup_work_tree(void)
 333 {
 334         const char *work_tree, *git_dir;
 335         static int initialized = 0;
 336
 337         if (initialized)
 338                 return;
 339
 340         if (work_tree_config_is_bogus)
 341                 die("unable to set up work tree using invalid config");
 342
 343         work_tree = get_git_work_tree();
 344         git_dir = get_git_dir();
 345         if (!is_absolute_path(git_dir))
 346                 git_dir = real_path(get_git_dir());
 347         if (!work_tree || chdir(work_tree))
 348                 die("This operation must be run in a work tree");
 349
 350         /*
 351          * Make sure subsequent git processes find correct worktree
 352          * if $GIT_WORK_TREE is set relative
 353          */
 354         if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 355                 setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 356
 357         set_git_dir(remove_leading_path(git_dir, work_tree));
 358         initialized = 1;
 359 }
 360
 361 static int check_repo_format(const char *var, const char *value, void *cb)
 362 {
 363         const char *ext;
 364
 365         if (strcmp(var, "core.repositoryformatversion") == 0)
 366                 repository_format_version = git_config_int(var, value);
 367         else if (strcmp(var, "core.sharedrepository") == 0)
 368                 shared_repository = git_config_perm(var, value);
 369         else if (skip_prefix(var, "extensions.", &ext)) {
 370                 /*
 371                  * record any known extensions here; otherwise,
 372                  * we fall through to recording it as unknown, and
 373                  * check_repository_format will complain
 374                  */
 375                 if (!strcmp(ext, "noop"))
 376                         ;
 377                 else if (!strcmp(ext, "preciousobjects"))
 378                         repository_format_precious_objects = git_config_bool(var, value);
 379                 else
 380                         string_list_append(&unknown_extensions, ext);
 381         }
 382         return 0;
 383 }
 384
 385 static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 386 {
 387         struct strbuf sb = STRBUF_INIT;
 388         const char *repo_config;
 389         config_fn_t fn;
 390         int ret = 0;
 391
 392         string_list_clear(&unknown_extensions, 0);
 393
 394         if (get_common_dir(&sb, gitdir))
 395                 fn = check_repo_format;
 396         else
 397                 fn = check_repository_format_version;
 398         strbuf_addstr(&sb, "/config");
 399         repo_config = sb.buf;
 400
 401         /*
 402          * git_config() can't be used here because it calls git_pathdup()
 403          * to get $GIT_CONFIG/config. That call will make setup_git_env()
 404          * set git_dir to ".git".
 405          *
 406          * We are in gitdir setup, no git dir has been found useable yet.
 407          * Use a gentler version of git_config() to check if this repo
 408          * is a good one.
 409          */
 410         git_config_early(fn, NULL, repo_config);
 411         if (GIT_REPO_VERSION_READ < repository_format_version) {
 412                 if (!nongit_ok)
 413                         die ("Expected git repo version <= %d, found %d",
 414                              GIT_REPO_VERSION_READ, repository_format_version);
 415                 warning("Expected git repo version <= %d, found %d",
 416                         GIT_REPO_VERSION_READ, repository_format_version);
 417                 warning("Please upgrade Git");
 418                 *nongit_ok = -1;
 419                 ret = -1;
 420         }
 421
 422         if (repository_format_version >= 1 && unknown_extensions.nr) {
 423                 int i;
 424
 425                 if (!nongit_ok)
 426                         die("unknown repository extension: %s",
 427                             unknown_extensions.items[0].string);
 428
 429                 for (i = 0; i < unknown_extensions.nr; i++)
 430                         warning("unknown repository extension: %s",
 431                                 unknown_extensions.items[i].string);
 432                 *nongit_ok = -1;
 433                 ret = -1;
 434         }
 435
 436         strbuf_release(&sb);
 437         return ret;
 438 }
 439
 440 static void update_linked_gitdir(const char *gitfile, const char *gitdir)
 441 {
 442         struct strbuf path = STRBUF_INIT;
 443         struct stat st;
 444
 445         strbuf_addf(&path, "%s/gitdir", gitdir);
 446         if (stat(path.buf, &st) || st.st_mtime + 24 * 3600 < time(NULL))
 447                 write_file(path.buf, "%s", gitfile);
 448         strbuf_release(&path);
 449 }
 450
 451 /*
 452  * Try to read the location of the git directory from the .git file,
 453  * return path to git directory if found.
 454  *
 455  * On failure, if return_error_code is not NULL, return_error_code
 456  * will be set to an error code and NULL will be returned. If
 457  * return_error_code is NULL the function will die instead (for most
 458  * cases).
 459  */
 460 const char *read_gitfile_gently(const char *path, int *return_error_code)
 461 {
 462         const int max_file_size = 1 << 20;  /* 1MB */
 463         int error_code = 0;
 464         char *buf = NULL;
 465         char *dir = NULL;
 466         const char *slash;
 467         struct stat st;
 468         int fd;
 469         ssize_t len;
 470
 471         if (stat(path, &st)) {
 472                 error_code = READ_GITFILE_ERR_STAT_FAILED;
 473                 goto cleanup_return;
 474         }
 475         if (!S_ISREG(st.st_mode)) {
 476                 error_code = READ_GITFILE_ERR_NOT_A_FILE;
 477                 goto cleanup_return;
 478         }
 479         if (st.st_size > max_file_size) {
 480                 error_code = READ_GITFILE_ERR_TOO_LARGE;
 481                 goto cleanup_return;
 482         }
 483         fd = open(path, O_RDONLY);
 484         if (fd < 0) {
 485                 error_code = READ_GITFILE_ERR_OPEN_FAILED;
 486                 goto cleanup_return;
 487         }
 488         buf = xmalloc(st.st_size + 1);
 489         len = read_in_full(fd, buf, st.st_size);
 490         close(fd);
 491         if (len != st.st_size) {
 492                 error_code = READ_GITFILE_ERR_READ_FAILED;
 493                 goto cleanup_return;
 494         }
 495         buf[len] = '\0';
 496         if (!starts_with(buf, "gitdir: ")) {
 497                 error_code = READ_GITFILE_ERR_INVALID_FORMAT;
 498                 goto cleanup_return;
 499         }
 500         while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 501                 len--;
 502         if (len < 9) {
 503                 error_code = READ_GITFILE_ERR_NO_PATH;
 504                 goto cleanup_return;
 505         }
 506         buf[len] = '\0';
 507         dir = buf + 8;
 508
 509         if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 510                 size_t pathlen = slash+1 - path;
 511                 size_t dirlen = pathlen + len - 8;
 512                 dir = xmalloc(dirlen + 1);
 513                 strncpy(dir, path, pathlen);
 514                 strncpy(dir + pathlen, buf + 8, len - 8);
 515                 dir[dirlen] = '\0';
 516                 free(buf);
 517                 buf = dir;
 518         }
 519         if (!is_git_directory(dir)) {
 520                 error_code = READ_GITFILE_ERR_NOT_A_REPO;
 521                 goto cleanup_return;
 522         }
 523         update_linked_gitdir(path, dir);
 524         path = real_path(dir);
 525
 526 cleanup_return:
 527         if (return_error_code)
 528                 *return_error_code = error_code;
 529         else if (error_code) {
 530                 switch (error_code) {
 531                 case READ_GITFILE_ERR_STAT_FAILED:
 532                 case READ_GITFILE_ERR_NOT_A_FILE:
 533                         /* non-fatal; follow return path */
 534                         break;
 535                 case READ_GITFILE_ERR_OPEN_FAILED:
 536                         die_errno("Error opening '%s'", path);
 537                 case READ_GITFILE_ERR_TOO_LARGE:
 538                         die("Too large to be a .git file: '%s'", path);
 539                 case READ_GITFILE_ERR_READ_FAILED:
 540                         die("Error reading %s", path);
 541                 case READ_GITFILE_ERR_INVALID_FORMAT:
 542                         die("Invalid gitfile format: %s", path);
 543                 case READ_GITFILE_ERR_NO_PATH:
 544                         die("No path in gitfile: %s", path);
 545                 case READ_GITFILE_ERR_NOT_A_REPO:
 546                         die("Not a git repository: %s", dir);
 547                 default:
 548                         assert(0);
 549                 }
 550         }
 551
 552         free(buf);
 553         return error_code ? NULL : path;
 554 }
 555
 556 static const char *setup_explicit_git_dir(const char *gitdirenv,
 557                                           struct strbuf *cwd,
 558                                           int *nongit_ok)
 559 {
 560         const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 561         const char *worktree;
 562         char *gitfile;
 563         int offset;
 564
 565         if (PATH_MAX - 40 < strlen(gitdirenv))
 566                 die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 567
 568         gitfile = (char*)read_gitfile(gitdirenv);
 569         if (gitfile) {
 570                 gitfile = xstrdup(gitfile);
 571                 gitdirenv = gitfile;
 572         }
 573
 574         if (!is_git_directory(gitdirenv)) {
 575                 if (nongit_ok) {
 576                         *nongit_ok = 1;
 577                         free(gitfile);
 578                         return NULL;
 579                 }
 580                 die("Not a git repository: '%s'", gitdirenv);
 581         }
 582
 583         if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 584                 free(gitfile);
 585                 return NULL;
 586         }
 587
 588         /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 589         if (work_tree_env)
 590                 set_git_work_tree(work_tree_env);
 591         else if (is_bare_repository_cfg > 0) {
 592                 if (git_work_tree_cfg) {
 593                         /* #22.2, #30 */
 594                         warning("core.bare and core.worktree do not make sense");
 595                         work_tree_config_is_bogus = 1;
 596                 }
 597
 598                 /* #18, #26 */
 599                 set_git_dir(gitdirenv);
 600                 free(gitfile);
 601                 return NULL;
 602         }
 603         else if (git_work_tree_cfg) { /* #6, #14 */
 604                 if (is_absolute_path(git_work_tree_cfg))
 605                         set_git_work_tree(git_work_tree_cfg);
 606                 else {
 607                         char *core_worktree;
 608                         if (chdir(gitdirenv))
 609                                 die_errno("Could not chdir to '%s'", gitdirenv);
 610                         if (chdir(git_work_tree_cfg))
 611                                 die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 612                         core_worktree = xgetcwd();
 613                         if (chdir(cwd->buf))
 614                                 die_errno("Could not come back to cwd");
 615                         set_git_work_tree(core_worktree);
 616                         free(core_worktree);
 617                 }
 618         }
 619         else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 620                 /* #16d */
 621                 set_git_dir(gitdirenv);
 622                 free(gitfile);
 623                 return NULL;
 624         }
 625         else /* #2, #10 */
 626                 set_git_work_tree(".");
 627
 628         /* set_git_work_tree() must have been called by now */
 629         worktree = get_git_work_tree();
 630
 631         /* both get_git_work_tree() and cwd are already normalized */
 632         if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
 633                 set_git_dir(gitdirenv);
 634                 free(gitfile);
 635                 return NULL;
 636         }
 637
 638         offset = dir_inside_of(cwd->buf, worktree);
 639         if (offset >= 0) {      /* cwd inside worktree? */
 640                 set_git_dir(real_path(gitdirenv));
 641                 if (chdir(worktree))
 642                         die_errno("Could not chdir to '%s'", worktree);
 643                 strbuf_addch(cwd, '/');
 644                 free(gitfile);
 645                 return cwd->buf + offset;
 646         }
 647
 648         /* cwd outside worktree */
 649         set_git_dir(gitdirenv);
 650         free(gitfile);
 651         return NULL;
 652 }
 653
 654 static const char *setup_discovered_git_dir(const char *gitdir,
 655                                             struct strbuf *cwd, int offset,
 656                                             int *nongit_ok)
 657 {
 658         if (check_repository_format_gently(gitdir, nongit_ok))
 659                 return NULL;
 660
 661         /* --work-tree is set without --git-dir; use discovered one */
 662         if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 663                 if (offset != cwd->len && !is_absolute_path(gitdir))
 664                         gitdir = xstrdup(real_path(gitdir));
 665                 if (chdir(cwd->buf))
 666                         die_errno("Could not come back to cwd");
 667                 return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 668         }
 669
 670         /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 671         if (is_bare_repository_cfg > 0) {
 672                 set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
 673                 if (chdir(cwd->buf))
 674                         die_errno("Could not come back to cwd");
 675                 return NULL;
 676         }
 677
 678         /* #0, #1, #5, #8, #9, #12, #13 */
 679         set_git_work_tree(".");
 680         if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 681                 set_git_dir(gitdir);
 682         inside_git_dir = 0;
 683         inside_work_tree = 1;
 684         if (offset == cwd->len)
 685                 return NULL;
 686
 687         /* Make "offset" point to past the '/', and add a '/' at the end */
 688         offset++;
 689         strbuf_addch(cwd, '/');
 690         return cwd->buf + offset;
 691 }
 692
 693 /* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 694 static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 695                                       int *nongit_ok)
 696 {
 697         int root_len;
 698
 699         if (check_repository_format_gently(".", nongit_ok))
 700                 return NULL;
 701
 702         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 703
 704         /* --work-tree is set without --git-dir; use discovered one */
 705         if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 706                 const char *gitdir;
 707
 708                 gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
 709                 if (chdir(cwd->buf))
 710                         die_errno("Could not come back to cwd");
 711                 return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 712         }
 713
 714         inside_git_dir = 1;
 715         inside_work_tree = 0;
 716         if (offset != cwd->len) {
 717                 if (chdir(cwd->buf))
 718                         die_errno("Cannot come back to cwd");
 719                 root_len = offset_1st_component(cwd->buf);
 720                 strbuf_setlen(cwd, offset > root_len ? offset : root_len);
 721                 set_git_dir(cwd->buf);
 722         }
 723         else
 724                 set_git_dir(".");
 725         return NULL;
 726 }
 727
 728 static const char *setup_nongit(const char *cwd, int *nongit_ok)
 729 {
 730         if (!nongit_ok)
 731                 die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
 732         if (chdir(cwd))
 733                 die_errno("Cannot come back to cwd");
 734         *nongit_ok = 1;
 735         return NULL;
 736 }
 737
 738 static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 739 {
 740         struct stat buf;
 741         if (stat(path, &buf)) {
 742                 die_errno("failed to stat '%*s%s%s'",
 743                                 prefix_len,
 744                                 prefix ? prefix : "",
 745                                 prefix ? "/" : "", path);
 746         }
 747         return buf.st_dev;
 748 }
 749
 750 /*
 751  * A "string_list_each_func_t" function that canonicalizes an entry
 752  * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 753  * discards it if unusable.  The presence of an empty entry in
 754  * GIT_CEILING_DIRECTORIES turns off canonicalization for all
 755  * subsequent entries.
 756  */
 757 static int canonicalize_ceiling_entry(struct string_list_item *item,
 758                                       void *cb_data)
 759 {
 760         int *empty_entry_found = cb_data;
 761         char *ceil = item->string;
 762
 763         if (!*ceil) {
 764                 *empty_entry_found = 1;
 765                 return 0;
 766         } else if (!is_absolute_path(ceil)) {
 767                 return 0;
 768         } else if (*empty_entry_found) {
 769                 /* Keep entry but do not canonicalize it */
 770                 return 1;
 771         } else {
 772                 const char *real_path = real_path_if_valid(ceil);
 773                 if (!real_path)
 774                         return 0;
 775                 free(item->string);
 776                 item->string = xstrdup(real_path);
 777                 return 1;
 778         }
 779 }
 780
 781 /*
 782  * We cannot decide in this function whether we are in the work tree or
 783  * not, since the config can only be read _after_ this function was called.
 784  */
 785 static const char *setup_git_directory_gently_1(int *nongit_ok)
 786 {
 787         const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 788         struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 789         static struct strbuf cwd = STRBUF_INIT;
 790         const char *gitdirenv, *ret;
 791         char *gitfile;
 792         int offset, offset_parent, ceil_offset = -1;
 793         dev_t current_device = 0;
 794         int one_filesystem = 1;
 795
 796         /*
 797          * We may have read an incomplete configuration before
 798          * setting-up the git directory. If so, clear the cache so
 799          * that the next queries to the configuration reload complete
 800          * configuration (including the per-repo config file that we
 801          * ignored previously).
 802          */
 803         git_config_clear();
 804
 805         /*
 806          * Let's assume that we are in a git repository.
 807          * If it turns out later that we are somewhere else, the value will be
 808          * updated accordingly.
 809          */
 810         if (nongit_ok)
 811                 *nongit_ok = 0;
 812
 813         if (strbuf_getcwd(&cwd))
 814                 die_errno("Unable to read current working directory");
 815         offset = cwd.len;
 816
 817         /*
 818          * If GIT_DIR is set explicitly, we're not going
 819          * to do any discovery, but we still do repository
 820          * validation.
 821          */
 822         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 823         if (gitdirenv)
 824                 return setup_explicit_git_dir(gitdirenv, &cwd, nongit_ok);
 825
 826         if (env_ceiling_dirs) {
 827                 int empty_entry_found = 0;
 828
 829                 string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 830                 filter_string_list(&ceiling_dirs, 0,
 831                                    canonicalize_ceiling_entry, &empty_entry_found);
 832                 ceil_offset = longest_ancestor_length(cwd.buf, &ceiling_dirs);
 833                 string_list_clear(&ceiling_dirs, 0);
 834         }
 835
 836         if (ceil_offset < 0 && has_dos_drive_prefix(cwd.buf))
 837                 ceil_offset = 1;
 838
 839         /*
 840          * Test in the following order (relative to the cwd):
 841          * - .git (file containing "gitdir: <path>")
 842          * - .git/
 843          * - ./ (bare)
 844          * - ../.git
 845          * - ../.git/
 846          * - ../ (bare)
 847          * - ../../.git/
 848          *   etc.
 849          */
 850         one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 851         if (one_filesystem)
 852                 current_device = get_device_or_die(".", NULL, 0);
 853         for (;;) {
 854                 gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
 855                 if (gitfile)
 856                         gitdirenv = gitfile = xstrdup(gitfile);
 857                 else {
 858                         if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 859                                 gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 860                 }
 861
 862                 if (gitdirenv) {
 863                         ret = setup_discovered_git_dir(gitdirenv,
 864                                                        &cwd, offset,
 865                                                        nongit_ok);
 866                         free(gitfile);
 867                         return ret;
 868                 }
 869                 free(gitfile);
 870
 871                 if (is_git_directory("."))
 872                         return setup_bare_git_dir(&cwd, offset, nongit_ok);
 873
 874                 offset_parent = offset;
 875                 while (--offset_parent > ceil_offset && cwd.buf[offset_parent] != '/');
 876                 if (offset_parent <= ceil_offset)
 877                         return setup_nongit(cwd.buf, nongit_ok);
 878                 if (one_filesystem) {
 879                         dev_t parent_device = get_device_or_die("..", cwd.buf,
 880                                                                 offset);
 881                         if (parent_device != current_device) {
 882                                 if (nongit_ok) {
 883                                         if (chdir(cwd.buf))
 884                                                 die_errno("Cannot come back to cwd");
 885                                         *nongit_ok = 1;
 886                                         return NULL;
 887                                 }
 888                                 strbuf_setlen(&cwd, offset);
 889                                 die("Not a git repository (or any parent up to mount point %s)\n"
 890                                 "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).",
 891                                     cwd.buf);
 892                         }
 893                 }
 894                 if (chdir("..")) {
 895                         strbuf_setlen(&cwd, offset);
 896                         die_errno("Cannot change to '%s/..'", cwd.buf);
 897                 }
 898                 offset = offset_parent;
 899         }
 900 }
 901
 902 const char *setup_git_directory_gently(int *nongit_ok)
 903 {
 904         const char *prefix;
 905
 906         prefix = setup_git_directory_gently_1(nongit_ok);
 907         if (prefix)
 908                 setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
 909         else
 910                 setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
 911
 912         if (startup_info) {
 913                 startup_info->have_repository = !nongit_ok || !*nongit_ok;
 914                 startup_info->prefix = prefix;
 915         }
 916         return prefix;
 917 }
 918
 919 int git_config_perm(const char *var, const char *value)
 920 {
 921         int i;
 922         char *endptr;
 923
 924         if (value == NULL)
 925                 return PERM_GROUP;
 926
 927         if (!strcmp(value, "umask"))
 928                 return PERM_UMASK;
 929         if (!strcmp(value, "group"))
 930                 return PERM_GROUP;
 931         if (!strcmp(value, "all") ||
 932             !strcmp(value, "world") ||
 933             !strcmp(value, "everybody"))
 934                 return PERM_EVERYBODY;
 935
 936         /* Parse octal numbers */
 937         i = strtol(value, &endptr, 8);
 938
 939         /* If not an octal number, maybe true/false? */
 940         if (*endptr != 0)
 941                 return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 942
 943         /*
 944          * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 945          * a chmod value to restrict to.
 946          */
 947         switch (i) {
 948         case PERM_UMASK:               /* 0 */
 949                 return PERM_UMASK;
 950         case OLD_PERM_GROUP:           /* 1 */
 951                 return PERM_GROUP;
 952         case OLD_PERM_EVERYBODY:       /* 2 */
 953                 return PERM_EVERYBODY;
 954         }
 955
 956         /* A filemode value was given: 0xxx */
 957
 958         if ((i & 0600) != 0600)
 959                 die("Problem with core.sharedRepository filemode value "
 960                     "(0%.3o).\nThe owner of files must always have "
 961                     "read and write permissions.", i);
 962
 963         /*
 964          * Mask filemode value. Others can not get write permission.
 965          * x flags for directories are handled separately.
 966          */
 967         return -(i & 0666);
 968 }
 969
 970 int check_repository_format_version(const char *var, const char *value, void *cb)
 971 {
 972         int ret = check_repo_format(var, value, cb);
 973         if (ret)
 974                 return ret;
 975         if (strcmp(var, "core.bare") == 0) {
 976                 is_bare_repository_cfg = git_config_bool(var, value);
 977                 if (is_bare_repository_cfg == 1)
 978                         inside_work_tree = -1;
 979         } else if (strcmp(var, "core.worktree") == 0) {
 980                 if (!value)
 981                         return config_error_nonbool(var);
 982                 free(git_work_tree_cfg);
 983                 git_work_tree_cfg = xstrdup(value);
 984                 inside_work_tree = -1;
 985         }
 986         return 0;
 987 }
 988
 989 int check_repository_format(void)
 990 {
 991         return check_repository_format_gently(get_git_dir(), NULL);
 992 }
 993
 994 /*
 995  * Returns the "prefix", a path to the current working directory
 996  * relative to the work tree root, or NULL, if the current working
 997  * directory is not a strict subdirectory of the work tree root. The
 998  * prefix always ends with a '/' character.
 999  */
1000 const char *setup_git_directory(void)
1001 {
1002         return setup_git_directory_gently(NULL);
1003 }
1004
1005 const char *resolve_gitdir(const char *suspect)
1006 {
1007         if (is_git_directory(suspect))
1008                 return suspect;
1009         return read_gitfile(suspect);
1010 }
1011
1012 /* if any standard file descriptor is missing open it to /dev/null */
1013 void sanitize_stdfds(void)
1014 {
1015         int fd = open("/dev/null", O_RDWR, 0);
1016         while (fd != -1 && fd < 2)
1017                 fd = dup(fd);
1018         if (fd == -1)
1019                 die_errno("open /dev/null or dup failed");
1020         if (fd > 2)
1021                 close(fd);
1022 }
1023
1024 int daemonize(void)
1025 {
1026 #ifdef NO_POSIX_GOODIES
1027         errno = ENOSYS;
1028         return -1;
1029 #else
1030         switch (fork()) {
1031                 case 0:
1032                         break;
1033                 case -1:
1034                         die_errno("fork failed");
1035                 default:
1036                         exit(0);
1037         }
1038         if (setsid() == -1)
1039                 die_errno("setsid failed");
1040         close(0);
1041         close(1);
1042         close(2);
1043         sanitize_stdfds();
1044         return 0;
1045 #endif
1046 }