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