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