setup.c

   1 #include "cache.h"
   2 #include "dir.h"
   3
   4 static int inside_git_dir = -1;
   5 static int inside_work_tree = -1;
   6
   7 static int sanitary_path_copy(char *dst, const char *src)
   8 {
   9         char *dst0;
  10
  11         if (has_dos_drive_prefix(src)) {
  12                 *dst++ = *src++;
  13                 *dst++ = *src++;
  14         }
  15         dst0 = dst;
  16
  17         if (is_dir_sep(*src)) {
  18                 *dst++ = '/';
  19                 while (is_dir_sep(*src))
  20                         src++;
  21         }
  22
  23         for (;;) {
  24                 char c = *src;
  25
  26                 /*
  27                  * A path component that begins with . could be
  28                  * special:
  29                  * (1) "." and ends   -- ignore and terminate.
  30                  * (2) "./"           -- ignore them, eat slash and continue.
  31                  * (3) ".." and ends  -- strip one and terminate.
  32                  * (4) "../"          -- strip one, eat slash and continue.
  33                  */
  34                 if (c == '.') {
  35                         if (!src[1]) {
  36                                 /* (1) */
  37                                 src++;
  38                         } else if (is_dir_sep(src[1])) {
  39                                 /* (2) */
  40                                 src += 2;
  41                                 while (is_dir_sep(*src))
  42                                         src++;
  43                                 continue;
  44                         } else if (src[1] == '.') {
  45                                 if (!src[2]) {
  46                                         /* (3) */
  47                                         src += 2;
  48                                         goto up_one;
  49                                 } else if (is_dir_sep(src[2])) {
  50                                         /* (4) */
  51                                         src += 3;
  52                                         while (is_dir_sep(*src))
  53                                                 src++;
  54                                         goto up_one;
  55                                 }
  56                         }
  57                 }
  58
  59                 /* copy up to the next '/', and eat all '/' */
  60                 while ((c = *src++) != '\0' && !is_dir_sep(c))
  61                         *dst++ = c;
  62                 if (is_dir_sep(c)) {
  63                         *dst++ = '/';
  64                         while (is_dir_sep(c))
  65                                 c = *src++;
  66                         src--;
  67                 } else if (!c)
  68                         break;
  69                 continue;
  70
  71         up_one:
  72                 /*
  73                  * dst0..dst is prefix portion, and dst[-1] is '/';
  74                  * go up one level.
  75                  */
  76                 dst -= 2; /* go past trailing '/' if any */
  77                 if (dst < dst0)
  78                         return -1;
  79                 while (1) {
  80                         if (dst <= dst0)
  81                                 break;
  82                         c = *dst--;
  83                         if (c == '/') { /* MinGW: cannot be '\\' anymore */
  84                                 dst += 2;
  85                                 break;
  86                         }
  87                 }
  88         }
  89         *dst = '\0';
  90         return 0;
  91 }
  92
  93 const char *prefix_path(const char *prefix, int len, const char *path)
  94 {
  95         const char *orig = path;
  96         char *sanitized = xmalloc(len + strlen(path) + 1);
  97         if (is_absolute_path(orig))
  98                 strcpy(sanitized, path);
  99         else {
 100                 if (len)
 101                         memcpy(sanitized, prefix, len);
 102                 strcpy(sanitized + len, path);
 103         }
 104         if (sanitary_path_copy(sanitized, sanitized))
 105                 goto error_out;
 106         if (is_absolute_path(orig)) {
 107                 const char *work_tree = get_git_work_tree();
 108                 size_t len = strlen(work_tree);
 109                 size_t total = strlen(sanitized) + 1;
 110                 if (strncmp(sanitized, work_tree, len) ||
 111                     (sanitized[len] != '\0' && sanitized[len] != '/')) {
 112                 error_out:
 113                         die("'%s' is outside repository", orig);
 114                 }
 115                 if (sanitized[len] == '/')
 116                         len++;
 117                 memmove(sanitized, sanitized + len, total - len);
 118         }
 119         return sanitized;
 120 }
 121
 122 /*
 123  * Unlike prefix_path, this should be used if the named file does
 124  * not have to interact with index entry; i.e. name of a random file
 125  * on the filesystem.
 126  */
 127 const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
 128 {
 129         static char path[PATH_MAX];
 130 #ifndef __MINGW32__
 131         if (!pfx || !*pfx || is_absolute_path(arg))
 132                 return arg;
 133         memcpy(path, pfx, pfx_len);
 134         strcpy(path + pfx_len, arg);
 135 #else
 136         char *p;
 137         /* don't add prefix to absolute paths, but still replace '\' by '/' */
 138         if (is_absolute_path(arg))
 139                 pfx_len = 0;
 140         else
 141                 memcpy(path, pfx, pfx_len);
 142         strcpy(path + pfx_len, arg);
 143         for (p = path + pfx_len; *p; p++)
 144                 if (*p == '\\')
 145                         *p = '/';
 146 #endif
 147         return path;
 148 }
 149
 150 /*
 151  * Verify a filename that we got as an argument for a pathspec
 152  * entry. Note that a filename that begins with "-" never verifies
 153  * as true, because even if such a filename were to exist, we want
 154  * it to be preceded by the "--" marker (or we want the user to
 155  * use a format like "./-filename")
 156  */
 157 void verify_filename(const char *prefix, const char *arg)
 158 {
 159         const char *name;
 160         struct stat st;
 161
 162         if (*arg == '-')
 163                 die("bad flag '%s' used after filename", arg);
 164         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
 165         if (!lstat(name, &st))
 166                 return;
 167         if (errno == ENOENT)
 168                 die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 169                     "Use '--' to separate paths from revisions", arg);
 170         die("'%s': %s", arg, strerror(errno));
 171 }
 172
 173 /*
 174  * Opposite of the above: the command line did not have -- marker
 175  * and we parsed the arg as a refname.  It should not be interpretable
 176  * as a filename.
 177  */
 178 void verify_non_filename(const char *prefix, const char *arg)
 179 {
 180         const char *name;
 181         struct stat st;
 182
 183         if (!is_inside_work_tree() || is_inside_git_dir())
 184                 return;
 185         if (*arg == '-')
 186                 return; /* flag */
 187         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
 188         if (!lstat(name, &st))
 189                 die("ambiguous argument '%s': both revision and filename\n"
 190                     "Use '--' to separate filenames from revisions", arg);
 191         if (errno != ENOENT && errno != ENOTDIR)
 192                 die("'%s': %s", arg, strerror(errno));
 193 }
 194
 195 const char **get_pathspec(const char *prefix, const char **pathspec)
 196 {
 197         const char *entry = *pathspec;
 198         const char **src, **dst;
 199         int prefixlen;
 200
 201         if (!prefix && !entry)
 202                 return NULL;
 203
 204         if (!entry) {
 205                 static const char *spec[2];
 206                 spec[0] = prefix;
 207                 spec[1] = NULL;
 208                 return spec;
 209         }
 210
 211         /* Otherwise we have to re-write the entries.. */
 212         src = pathspec;
 213         dst = pathspec;
 214         prefixlen = prefix ? strlen(prefix) : 0;
 215         while (*src) {
 216                 const char *p = prefix_path(prefix, prefixlen, *src);
 217                 *(dst++) = p;
 218                 src++;
 219         }
 220         *dst = NULL;
 221         if (!*pathspec)
 222                 return NULL;
 223         return pathspec;
 224 }
 225
 226 /*
 227  * Test if it looks like we're at a git directory.
 228  * We want to see:
 229  *
 230  *  - either an objects/ directory _or_ the proper
 231  *    GIT_OBJECT_DIRECTORY environment variable
 232  *  - a refs/ directory
 233  *  - either a HEAD symlink or a HEAD file that is formatted as
 234  *    a proper "ref:", or a regular file HEAD that has a properly
 235  *    formatted sha1 object name.
 236  */
 237 static int is_git_directory(const char *suspect)
 238 {
 239         char path[PATH_MAX];
 240         size_t len = strlen(suspect);
 241
 242         strcpy(path, suspect);
 243         if (getenv(DB_ENVIRONMENT)) {
 244                 if (access(getenv(DB_ENVIRONMENT), X_OK))
 245                         return 0;
 246         }
 247         else {
 248                 strcpy(path + len, "/objects");
 249                 if (access(path, X_OK))
 250                         return 0;
 251         }
 252
 253         strcpy(path + len, "/refs");
 254         if (access(path, X_OK))
 255                 return 0;
 256
 257         strcpy(path + len, "/HEAD");
 258         if (validate_headref(path))
 259                 return 0;
 260
 261         return 1;
 262 }
 263
 264 int is_inside_git_dir(void)
 265 {
 266         if (inside_git_dir < 0)
 267                 inside_git_dir = is_inside_dir(get_git_dir());
 268         return inside_git_dir;
 269 }
 270
 271 int is_inside_work_tree(void)
 272 {
 273         if (inside_work_tree < 0)
 274                 inside_work_tree = is_inside_dir(get_git_work_tree());
 275         return inside_work_tree;
 276 }
 277
 278 /*
 279  * set_work_tree() is only ever called if you set GIT_DIR explicitely.
 280  * The old behaviour (which we retain here) is to set the work tree root
 281  * to the cwd, unless overridden by the config, the command line, or
 282  * GIT_WORK_TREE.
 283  */
 284 static const char *set_work_tree(const char *dir)
 285 {
 286         char buffer[PATH_MAX + 1];
 287
 288         if (!getcwd(buffer, sizeof(buffer)))
 289                 die ("Could not get the current working directory");
 290         git_work_tree_cfg = xstrdup(buffer);
 291         inside_work_tree = 1;
 292
 293         return NULL;
 294 }
 295
 296 void setup_work_tree(void)
 297 {
 298         const char *work_tree, *git_dir;
 299         static int initialized = 0;
 300
 301         if (initialized)
 302                 return;
 303         work_tree = get_git_work_tree();
 304         git_dir = get_git_dir();
 305         if (!is_absolute_path(git_dir))
 306                 git_dir = make_absolute_path(git_dir);
 307         if (!work_tree || chdir(work_tree))
 308                 die("This operation must be run in a work tree");
 309         set_git_dir(make_relative_path(git_dir, work_tree));
 310         initialized = 1;
 311 }
 312
 313 static int check_repository_format_gently(int *nongit_ok)
 314 {
 315         git_config(check_repository_format_version, NULL);
 316         if (GIT_REPO_VERSION < repository_format_version) {
 317                 if (!nongit_ok)
 318                         die ("Expected git repo version <= %d, found %d",
 319                              GIT_REPO_VERSION, repository_format_version);
 320                 warning("Expected git repo version <= %d, found %d",
 321                         GIT_REPO_VERSION, repository_format_version);
 322                 warning("Please upgrade Git");
 323                 *nongit_ok = -1;
 324                 return -1;
 325         }
 326         return 0;
 327 }
 328
 329 /*
 330  * Try to read the location of the git directory from the .git file,
 331  * return path to git directory if found.
 332  */
 333 const char *read_gitfile_gently(const char *path)
 334 {
 335         char *buf;
 336         struct stat st;
 337         int fd;
 338         size_t len;
 339
 340         if (stat(path, &st))
 341                 return NULL;
 342         if (!S_ISREG(st.st_mode))
 343                 return NULL;
 344         fd = open(path, O_RDONLY);
 345         if (fd < 0)
 346                 die("Error opening %s: %s", path, strerror(errno));
 347         buf = xmalloc(st.st_size + 1);
 348         len = read_in_full(fd, buf, st.st_size);
 349         close(fd);
 350         if (len != st.st_size)
 351                 die("Error reading %s", path);
 352         buf[len] = '\0';
 353         if (prefixcmp(buf, "gitdir: "))
 354                 die("Invalid gitfile format: %s", path);
 355         while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 356                 len--;
 357         if (len < 9)
 358                 die("No path in gitfile: %s", path);
 359         buf[len] = '\0';
 360         if (!is_git_directory(buf + 8))
 361                 die("Not a git repository: %s", buf + 8);
 362         path = make_absolute_path(buf + 8);
 363         free(buf);
 364         return path;
 365 }
 366
 367 /*
 368  * We cannot decide in this function whether we are in the work tree or
 369  * not, since the config can only be read _after_ this function was called.
 370  */
 371 const char *setup_git_directory_gently(int *nongit_ok)
 372 {
 373         const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 374         const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 375         static char cwd[PATH_MAX+1];
 376         const char *gitdirenv;
 377         const char *gitfile_dir;
 378         int len, offset, ceil_offset;
 379
 380         /*
 381          * Let's assume that we are in a git repository.
 382          * If it turns out later that we are somewhere else, the value will be
 383          * updated accordingly.
 384          */
 385         if (nongit_ok)
 386                 *nongit_ok = 0;
 387
 388         /*
 389          * If GIT_DIR is set explicitly, we're not going
 390          * to do any discovery, but we still do repository
 391          * validation.
 392          */
 393         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 394         if (gitdirenv) {
 395                 if (PATH_MAX - 40 < strlen(gitdirenv))
 396                         die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 397                 if (is_git_directory(gitdirenv)) {
 398                         static char buffer[1024 + 1];
 399                         const char *retval;
 400
 401                         if (!work_tree_env) {
 402                                 retval = set_work_tree(gitdirenv);
 403                                 /* config may override worktree */
 404                                 if (check_repository_format_gently(nongit_ok))
 405                                         return NULL;
 406                                 return retval;
 407                         }
 408                         if (check_repository_format_gently(nongit_ok))
 409                                 return NULL;
 410                         retval = get_relative_cwd(buffer, sizeof(buffer) - 1,
 411                                         get_git_work_tree());
 412                         if (!retval || !*retval)
 413                                 return NULL;
 414                         set_git_dir(make_absolute_path(gitdirenv));
 415                         if (chdir(work_tree_env) < 0)
 416                                 die ("Could not chdir to %s", work_tree_env);
 417                         strcat(buffer, "/");
 418                         return retval;
 419                 }
 420                 if (nongit_ok) {
 421                         *nongit_ok = 1;
 422                         return NULL;
 423                 }
 424                 die("Not a git repository: '%s'", gitdirenv);
 425         }
 426
 427         if (!getcwd(cwd, sizeof(cwd)-1))
 428                 die("Unable to read current working directory");
 429
 430         ceil_offset = longest_ancestor_length(cwd, env_ceiling_dirs);
 431         if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
 432                 ceil_offset = 1;
 433
 434         /*
 435          * Test in the following order (relative to the cwd):
 436          * - .git (file containing "gitdir: <path>")
 437          * - .git/
 438          * - ./ (bare)
 439          * - ../.git
 440          * - ../.git/
 441          * - ../ (bare)
 442          * - ../../.git/
 443          *   etc.
 444          */
 445         offset = len = strlen(cwd);
 446         for (;;) {
 447                 gitfile_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
 448                 if (gitfile_dir) {
 449                         if (set_git_dir(gitfile_dir))
 450                                 die("Repository setup failed");
 451                         break;
 452                 }
 453                 if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 454                         break;
 455                 if (is_git_directory(".")) {
 456                         inside_git_dir = 1;
 457                         if (!work_tree_env)
 458                                 inside_work_tree = 0;
 459                         if (offset != len) {
 460                                 cwd[offset] = '\0';
 461                                 setenv(GIT_DIR_ENVIRONMENT, cwd, 1);
 462                         } else
 463                                 setenv(GIT_DIR_ENVIRONMENT, ".", 1);
 464                         check_repository_format_gently(nongit_ok);
 465                         return NULL;
 466                 }
 467                 while (--offset > ceil_offset && cwd[offset] != '/');
 468                 if (offset <= ceil_offset) {
 469                         if (nongit_ok) {
 470                                 if (chdir(cwd))
 471                                         die("Cannot come back to cwd");
 472                                 *nongit_ok = 1;
 473                                 return NULL;
 474                         }
 475                         die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
 476                 }
 477                 if (chdir(".."))
 478                         die("Cannot change to %s/..: %s", cwd, strerror(errno));
 479         }
 480
 481         inside_git_dir = 0;
 482         if (!work_tree_env)
 483                 inside_work_tree = 1;
 484         git_work_tree_cfg = xstrndup(cwd, offset);
 485         if (check_repository_format_gently(nongit_ok))
 486                 return NULL;
 487         if (offset == len)
 488                 return NULL;
 489
 490         /* Make "offset" point to past the '/', and add a '/' at the end */
 491         offset++;
 492         cwd[len++] = '/';
 493         cwd[len] = 0;
 494         return cwd + offset;
 495 }
 496
 497 int git_config_perm(const char *var, const char *value)
 498 {
 499         int i;
 500         char *endptr;
 501
 502         if (value == NULL)
 503                 return PERM_GROUP;
 504
 505         if (!strcmp(value, "umask"))
 506                 return PERM_UMASK;
 507         if (!strcmp(value, "group"))
 508                 return PERM_GROUP;
 509         if (!strcmp(value, "all") ||
 510             !strcmp(value, "world") ||
 511             !strcmp(value, "everybody"))
 512                 return PERM_EVERYBODY;
 513
 514         /* Parse octal numbers */
 515         i = strtol(value, &endptr, 8);
 516
 517         /* If not an octal number, maybe true/false? */
 518         if (*endptr != 0)
 519                 return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 520
 521         /*
 522          * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 523          * a chmod value.
 524          */
 525         switch (i) {
 526         case PERM_UMASK:               /* 0 */
 527                 return PERM_UMASK;
 528         case OLD_PERM_GROUP:           /* 1 */
 529                 return PERM_GROUP;
 530         case OLD_PERM_EVERYBODY:       /* 2 */
 531                 return PERM_EVERYBODY;
 532         }
 533
 534         /* A filemode value was given: 0xxx */
 535
 536         if ((i & 0600) != 0600)
 537                 die("Problem with core.sharedRepository filemode value "
 538                     "(0%.3o).\nThe owner of files must always have "
 539                     "read and write permissions.", i);
 540
 541         /*
 542          * Mask filemode value. Others can not get write permission.
 543          * x flags for directories are handled separately.
 544          */
 545         return i & 0666;
 546 }
 547
 548 int check_repository_format_version(const char *var, const char *value, void *cb)
 549 {
 550         if (strcmp(var, "core.repositoryformatversion") == 0)
 551                 repository_format_version = git_config_int(var, value);
 552         else if (strcmp(var, "core.sharedrepository") == 0)
 553                 shared_repository = git_config_perm(var, value);
 554         else if (strcmp(var, "core.bare") == 0) {
 555                 is_bare_repository_cfg = git_config_bool(var, value);
 556                 if (is_bare_repository_cfg == 1)
 557                         inside_work_tree = -1;
 558         } else if (strcmp(var, "core.worktree") == 0) {
 559                 if (!value)
 560                         return config_error_nonbool(var);
 561                 free(git_work_tree_cfg);
 562                 git_work_tree_cfg = xstrdup(value);
 563                 inside_work_tree = -1;
 564         }
 565         return 0;
 566 }
 567
 568 int check_repository_format(void)
 569 {
 570         return check_repository_format_gently(NULL);
 571 }
 572
 573 const char *setup_git_directory(void)
 574 {
 575         const char *retval = setup_git_directory_gently(NULL);
 576
 577         /* If the work tree is not the default one, recompute prefix */
 578         if (inside_work_tree < 0) {
 579                 static char buffer[PATH_MAX + 1];
 580                 char *rel;
 581                 if (retval && chdir(retval))
 582                         die ("Could not jump back into original cwd");
 583                 rel = get_relative_cwd(buffer, PATH_MAX, get_git_work_tree());
 584                 if (rel && *rel && chdir(get_git_work_tree()))
 585                         die ("Could not jump to working directory");
 586                 return rel && *rel ? strcat(rel, "/") : NULL;
 587         }
 588
 589         return retval;
 590 }