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