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