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