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