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 const char *prefix_path(const char *prefix, int len, const char *path)
   8 {
   9         const char *orig = path;
  10         char *sanitized = xmalloc(len + strlen(path) + 1);
  11         if (is_absolute_path(orig))
  12                 strcpy(sanitized, path);
  13         else {
  14                 if (len)
  15                         memcpy(sanitized, prefix, len);
  16                 strcpy(sanitized + len, path);
  17         }
  18         if (normalize_path_copy(sanitized, sanitized))
  19                 goto error_out;
  20         if (is_absolute_path(orig)) {
  21                 size_t len, total;
  22                 const char *work_tree = get_git_work_tree();
  23                 if (!work_tree)
  24                         goto error_out;
  25                 len = strlen(work_tree);
  26                 total = strlen(sanitized) + 1;
  27                 if (strncmp(sanitized, work_tree, len) ||
  28                     (sanitized[len] != '\0' && sanitized[len] != '/')) {
  29                 error_out:
  30                         die("'%s' is outside repository", orig);
  31                 }
  32                 if (sanitized[len] == '/')
  33                         len++;
  34                 memmove(sanitized, sanitized + len, total - len);
  35         }
  36         return sanitized;
  37 }
  38
  39 /*
  40  * Unlike prefix_path, this should be used if the named file does
  41  * not have to interact with index entry; i.e. name of a random file
  42  * on the filesystem.
  43  */
  44 const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
  45 {
  46         static char path[PATH_MAX];
  47 #ifndef WIN32
  48         if (!pfx || !*pfx || is_absolute_path(arg))
  49                 return arg;
  50         memcpy(path, pfx, pfx_len);
  51         strcpy(path + pfx_len, arg);
  52 #else
  53         char *p;
  54         /* don't add prefix to absolute paths, but still replace '\' by '/' */
  55         if (is_absolute_path(arg))
  56                 pfx_len = 0;
  57         else
  58                 memcpy(path, pfx, pfx_len);
  59         strcpy(path + pfx_len, arg);
  60         for (p = path + pfx_len; *p; p++)
  61                 if (*p == '\\')
  62                         *p = '/';
  63 #endif
  64         return path;
  65 }
  66
  67 /*
  68  * Verify a filename that we got as an argument for a pathspec
  69  * entry. Note that a filename that begins with "-" never verifies
  70  * as true, because even if such a filename were to exist, we want
  71  * it to be preceded by the "--" marker (or we want the user to
  72  * use a format like "./-filename")
  73  */
  74 void verify_filename(const char *prefix, const char *arg)
  75 {
  76         const char *name;
  77         struct stat st;
  78
  79         if (*arg == '-')
  80                 die("bad flag '%s' used after filename", arg);
  81         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
  82         if (!lstat(name, &st))
  83                 return;
  84         if (errno == ENOENT)
  85                 die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
  86                     "Use '--' to separate paths from revisions", arg);
  87         die_errno("failed to stat '%s'", arg);
  88 }
  89
  90 /*
  91  * Opposite of the above: the command line did not have -- marker
  92  * and we parsed the arg as a refname.  It should not be interpretable
  93  * as a filename.
  94  */
  95 void verify_non_filename(const char *prefix, const char *arg)
  96 {
  97         const char *name;
  98         struct stat st;
  99
 100         if (!is_inside_work_tree() || is_inside_git_dir())
 101                 return;
 102         if (*arg == '-')
 103                 return; /* flag */
 104         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
 105         if (!lstat(name, &st))
 106                 die("ambiguous argument '%s': both revision and filename\n"
 107                     "Use '--' to separate filenames from revisions", arg);
 108         if (errno != ENOENT && errno != ENOTDIR)
 109                 die_errno("failed to stat '%s'", arg);
 110 }
 111
 112 const char **get_pathspec(const char *prefix, const char **pathspec)
 113 {
 114         const char *entry = *pathspec;
 115         const char **src, **dst;
 116         int prefixlen;
 117
 118         if (!prefix && !entry)
 119                 return NULL;
 120
 121         if (!entry) {
 122                 static const char *spec[2];
 123                 spec[0] = prefix;
 124                 spec[1] = NULL;
 125                 return spec;
 126         }
 127
 128         /* Otherwise we have to re-write the entries.. */
 129         src = pathspec;
 130         dst = pathspec;
 131         prefixlen = prefix ? strlen(prefix) : 0;
 132         while (*src) {
 133                 const char *p = prefix_path(prefix, prefixlen, *src);
 134                 *(dst++) = p;
 135                 src++;
 136         }
 137         *dst = NULL;
 138         if (!*pathspec)
 139                 return NULL;
 140         return pathspec;
 141 }
 142
 143 /*
 144  * Test if it looks like we're at a git directory.
 145  * We want to see:
 146  *
 147  *  - either an objects/ directory _or_ the proper
 148  *    GIT_OBJECT_DIRECTORY environment variable
 149  *  - a refs/ directory
 150  *  - either a HEAD symlink or a HEAD file that is formatted as
 151  *    a proper "ref:", or a regular file HEAD that has a properly
 152  *    formatted sha1 object name.
 153  */
 154 static int is_git_directory(const char *suspect)
 155 {
 156         char path[PATH_MAX];
 157         size_t len = strlen(suspect);
 158
 159         strcpy(path, suspect);
 160         if (getenv(DB_ENVIRONMENT)) {
 161                 if (access(getenv(DB_ENVIRONMENT), X_OK))
 162                         return 0;
 163         }
 164         else {
 165                 strcpy(path + len, "/objects");
 166                 if (access(path, X_OK))
 167                         return 0;
 168         }
 169
 170         strcpy(path + len, "/refs");
 171         if (access(path, X_OK))
 172                 return 0;
 173
 174         strcpy(path + len, "/HEAD");
 175         if (validate_headref(path))
 176                 return 0;
 177
 178         return 1;
 179 }
 180
 181 int is_inside_git_dir(void)
 182 {
 183         if (inside_git_dir < 0)
 184                 inside_git_dir = is_inside_dir(get_git_dir());
 185         return inside_git_dir;
 186 }
 187
 188 int is_inside_work_tree(void)
 189 {
 190         if (inside_work_tree < 0)
 191                 inside_work_tree = is_inside_dir(get_git_work_tree());
 192         return inside_work_tree;
 193 }
 194
 195 /*
 196  * set_work_tree() is only ever called if you set GIT_DIR explicitely.
 197  * The old behaviour (which we retain here) is to set the work tree root
 198  * to the cwd, unless overridden by the config, the command line, or
 199  * GIT_WORK_TREE.
 200  */
 201 static const char *set_work_tree(const char *dir)
 202 {
 203         char buffer[PATH_MAX + 1];
 204
 205         if (!getcwd(buffer, sizeof(buffer)))
 206                 die ("Could not get the current working directory");
 207         git_work_tree_cfg = xstrdup(buffer);
 208         inside_work_tree = 1;
 209
 210         return NULL;
 211 }
 212
 213 void setup_work_tree(void)
 214 {
 215         const char *work_tree, *git_dir;
 216         static int initialized = 0;
 217
 218         if (initialized)
 219                 return;
 220         work_tree = get_git_work_tree();
 221         git_dir = get_git_dir();
 222         if (!is_absolute_path(git_dir))
 223                 git_dir = make_absolute_path(git_dir);
 224         if (!work_tree || chdir(work_tree))
 225                 die("This operation must be run in a work tree");
 226         set_git_dir(make_relative_path(git_dir, work_tree));
 227         initialized = 1;
 228 }
 229
 230 static int check_repository_format_gently(int *nongit_ok)
 231 {
 232         git_config(check_repository_format_version, NULL);
 233         if (GIT_REPO_VERSION < repository_format_version) {
 234                 if (!nongit_ok)
 235                         die ("Expected git repo version <= %d, found %d",
 236                              GIT_REPO_VERSION, repository_format_version);
 237                 warning("Expected git repo version <= %d, found %d",
 238                         GIT_REPO_VERSION, repository_format_version);
 239                 warning("Please upgrade Git");
 240                 *nongit_ok = -1;
 241                 return -1;
 242         }
 243         return 0;
 244 }
 245
 246 /*
 247  * Try to read the location of the git directory from the .git file,
 248  * return path to git directory if found.
 249  */
 250 const char *read_gitfile_gently(const char *path)
 251 {
 252         char *buf;
 253         struct stat st;
 254         int fd;
 255         size_t len;
 256
 257         if (stat(path, &st))
 258                 return NULL;
 259         if (!S_ISREG(st.st_mode))
 260                 return NULL;
 261         fd = open(path, O_RDONLY);
 262         if (fd < 0)
 263                 die_errno("Error opening '%s'", path);
 264         buf = xmalloc(st.st_size + 1);
 265         len = read_in_full(fd, buf, st.st_size);
 266         close(fd);
 267         if (len != st.st_size)
 268                 die("Error reading %s", path);
 269         buf[len] = '\0';
 270         if (prefixcmp(buf, "gitdir: "))
 271                 die("Invalid gitfile format: %s", path);
 272         while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 273                 len--;
 274         if (len < 9)
 275                 die("No path in gitfile: %s", path);
 276         buf[len] = '\0';
 277         if (!is_git_directory(buf + 8))
 278                 die("Not a git repository: %s", buf + 8);
 279         path = make_absolute_path(buf + 8);
 280         free(buf);
 281         return path;
 282 }
 283
 284 /*
 285  * We cannot decide in this function whether we are in the work tree or
 286  * not, since the config can only be read _after_ this function was called.
 287  */
 288 const char *setup_git_directory_gently(int *nongit_ok)
 289 {
 290         const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 291         const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 292         static char cwd[PATH_MAX+1];
 293         const char *gitdirenv;
 294         const char *gitfile_dir;
 295         int len, offset, ceil_offset;
 296
 297         /*
 298          * Let's assume that we are in a git repository.
 299          * If it turns out later that we are somewhere else, the value will be
 300          * updated accordingly.
 301          */
 302         if (nongit_ok)
 303                 *nongit_ok = 0;
 304
 305         /*
 306          * If GIT_DIR is set explicitly, we're not going
 307          * to do any discovery, but we still do repository
 308          * validation.
 309          */
 310         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 311         if (gitdirenv) {
 312                 if (PATH_MAX - 40 < strlen(gitdirenv))
 313                         die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 314                 if (is_git_directory(gitdirenv)) {
 315                         static char buffer[1024 + 1];
 316                         const char *retval;
 317
 318                         if (!work_tree_env) {
 319                                 retval = set_work_tree(gitdirenv);
 320                                 /* config may override worktree */
 321                                 if (check_repository_format_gently(nongit_ok))
 322                                         return NULL;
 323                                 return retval;
 324                         }
 325                         if (check_repository_format_gently(nongit_ok))
 326                                 return NULL;
 327                         retval = get_relative_cwd(buffer, sizeof(buffer) - 1,
 328                                         get_git_work_tree());
 329                         if (!retval || !*retval)
 330                                 return NULL;
 331                         set_git_dir(make_absolute_path(gitdirenv));
 332                         if (chdir(work_tree_env) < 0)
 333                                 die_errno ("Could not chdir to '%s'", work_tree_env);
 334                         strcat(buffer, "/");
 335                         return retval;
 336                 }
 337                 if (nongit_ok) {
 338                         *nongit_ok = 1;
 339                         return NULL;
 340                 }
 341                 die("Not a git repository: '%s'", gitdirenv);
 342         }
 343
 344         if (!getcwd(cwd, sizeof(cwd)-1))
 345                 die_errno("Unable to read current working directory");
 346
 347         ceil_offset = longest_ancestor_length(cwd, env_ceiling_dirs);
 348         if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
 349                 ceil_offset = 1;
 350
 351         /*
 352          * Test in the following order (relative to the cwd):
 353          * - .git (file containing "gitdir: <path>")
 354          * - .git/
 355          * - ./ (bare)
 356          * - ../.git
 357          * - ../.git/
 358          * - ../ (bare)
 359          * - ../../.git/
 360          *   etc.
 361          */
 362         offset = len = strlen(cwd);
 363         for (;;) {
 364                 gitfile_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
 365                 if (gitfile_dir) {
 366                         if (set_git_dir(gitfile_dir))
 367                                 die("Repository setup failed");
 368                         break;
 369                 }
 370                 if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 371                         break;
 372                 if (is_git_directory(".")) {
 373                         inside_git_dir = 1;
 374                         if (!work_tree_env)
 375                                 inside_work_tree = 0;
 376                         if (offset != len) {
 377                                 cwd[offset] = '\0';
 378                                 setenv(GIT_DIR_ENVIRONMENT, cwd, 1);
 379                         } else
 380                                 setenv(GIT_DIR_ENVIRONMENT, ".", 1);
 381                         check_repository_format_gently(nongit_ok);
 382                         return NULL;
 383                 }
 384                 while (--offset > ceil_offset && cwd[offset] != '/');
 385                 if (offset <= ceil_offset) {
 386                         if (nongit_ok) {
 387                                 if (chdir(cwd))
 388                                         die_errno("Cannot come back to cwd");
 389                                 *nongit_ok = 1;
 390                                 return NULL;
 391                         }
 392                         die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
 393                 }
 394                 if (chdir(".."))
 395                         die_errno("Cannot change to '%s/..'", cwd);
 396         }
 397
 398         inside_git_dir = 0;
 399         if (!work_tree_env)
 400                 inside_work_tree = 1;
 401         git_work_tree_cfg = xstrndup(cwd, offset);
 402         if (check_repository_format_gently(nongit_ok))
 403                 return NULL;
 404         if (offset == len)
 405                 return NULL;
 406
 407         /* Make "offset" point to past the '/', and add a '/' at the end */
 408         offset++;
 409         cwd[len++] = '/';
 410         cwd[len] = 0;
 411         return cwd + offset;
 412 }
 413
 414 int git_config_perm(const char *var, const char *value)
 415 {
 416         int i;
 417         char *endptr;
 418
 419         if (value == NULL)
 420                 return PERM_GROUP;
 421
 422         if (!strcmp(value, "umask"))
 423                 return PERM_UMASK;
 424         if (!strcmp(value, "group"))
 425                 return PERM_GROUP;
 426         if (!strcmp(value, "all") ||
 427             !strcmp(value, "world") ||
 428             !strcmp(value, "everybody"))
 429                 return PERM_EVERYBODY;
 430
 431         /* Parse octal numbers */
 432         i = strtol(value, &endptr, 8);
 433
 434         /* If not an octal number, maybe true/false? */
 435         if (*endptr != 0)
 436                 return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 437
 438         /*
 439          * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 440          * a chmod value to restrict to.
 441          */
 442         switch (i) {
 443         case PERM_UMASK:               /* 0 */
 444                 return PERM_UMASK;
 445         case OLD_PERM_GROUP:           /* 1 */
 446                 return PERM_GROUP;
 447         case OLD_PERM_EVERYBODY:       /* 2 */
 448                 return PERM_EVERYBODY;
 449         }
 450
 451         /* A filemode value was given: 0xxx */
 452
 453         if ((i & 0600) != 0600)
 454                 die("Problem with core.sharedRepository filemode value "
 455                     "(0%.3o).\nThe owner of files must always have "
 456                     "read and write permissions.", i);
 457
 458         /*
 459          * Mask filemode value. Others can not get write permission.
 460          * x flags for directories are handled separately.
 461          */
 462         return -(i & 0666);
 463 }
 464
 465 int check_repository_format_version(const char *var, const char *value, void *cb)
 466 {
 467         if (strcmp(var, "core.repositoryformatversion") == 0)
 468                 repository_format_version = git_config_int(var, value);
 469         else if (strcmp(var, "core.sharedrepository") == 0)
 470                 shared_repository = git_config_perm(var, value);
 471         else if (strcmp(var, "core.bare") == 0) {
 472                 is_bare_repository_cfg = git_config_bool(var, value);
 473                 if (is_bare_repository_cfg == 1)
 474                         inside_work_tree = -1;
 475         } else if (strcmp(var, "core.worktree") == 0) {
 476                 if (!value)
 477                         return config_error_nonbool(var);
 478                 free(git_work_tree_cfg);
 479                 git_work_tree_cfg = xstrdup(value);
 480                 inside_work_tree = -1;
 481         }
 482         return 0;
 483 }
 484
 485 int check_repository_format(void)
 486 {
 487         return check_repository_format_gently(NULL);
 488 }
 489
 490 const char *setup_git_directory(void)
 491 {
 492         const char *retval = setup_git_directory_gently(NULL);
 493
 494         /* If the work tree is not the default one, recompute prefix */
 495         if (inside_work_tree < 0) {
 496                 static char buffer[PATH_MAX + 1];
 497                 char *rel;
 498                 if (retval && chdir(retval))
 499                         die_errno ("Could not jump back into original cwd");
 500                 rel = get_relative_cwd(buffer, PATH_MAX, get_git_work_tree());
 501                 if (rel && *rel && chdir(get_git_work_tree()))
 502                         die_errno ("Could not jump to working directory");
 503                 return rel && *rel ? strcat(rel, "/") : NULL;
 504         }
 505
 506         return retval;
 507 }