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                 set_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         initialized = 1;
 299 }
 300
 301 static int check_repository_format_gently(int *nongit_ok)
 302 {
 303         git_config(check_repository_format_version);
 304         if (GIT_REPO_VERSION < repository_format_version) {
 305                 if (!nongit_ok)
 306                         die ("Expected git repo version <= %d, found %d",
 307                              GIT_REPO_VERSION, repository_format_version);
 308                 warning("Expected git repo version <= %d, found %d",
 309                         GIT_REPO_VERSION, repository_format_version);
 310                 warning("Please upgrade Git");
 311                 *nongit_ok = -1;
 312                 return -1;
 313         }
 314         return 0;
 315 }
 316
 317 /*
 318  * We cannot decide in this function whether we are in the work tree or
 319  * not, since the config can only be read _after_ this function was called.
 320  */
 321 const char *setup_git_directory_gently(int *nongit_ok)
 322 {
 323         const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 324         static char cwd[PATH_MAX+1];
 325         const char *gitdirenv;
 326         int len, offset;
 327
 328         /*
 329          * Let's assume that we are in a git repository.
 330          * If it turns out later that we are somewhere else, the value will be
 331          * updated accordingly.
 332          */
 333         if (nongit_ok)
 334                 *nongit_ok = 0;
 335
 336         /*
 337          * If GIT_DIR is set explicitly, we're not going
 338          * to do any discovery, but we still do repository
 339          * validation.
 340          */
 341         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 342         if (gitdirenv) {
 343                 if (PATH_MAX - 40 < strlen(gitdirenv))
 344                         die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 345                 if (is_git_directory(gitdirenv)) {
 346                         static char buffer[1024 + 1];
 347                         const char *retval;
 348
 349                         if (!work_tree_env) {
 350                                 retval = set_work_tree(gitdirenv);
 351                                 /* config may override worktree */
 352                                 if (check_repository_format_gently(nongit_ok))
 353                                         return NULL;
 354                                 return retval;
 355                         }
 356                         if (check_repository_format_gently(nongit_ok))
 357                                 return NULL;
 358                         retval = get_relative_cwd(buffer, sizeof(buffer) - 1,
 359                                         get_git_work_tree());
 360                         if (!retval || !*retval)
 361                                 return NULL;
 362                         set_git_dir(make_absolute_path(gitdirenv));
 363                         if (chdir(work_tree_env) < 0)
 364                                 die ("Could not chdir to %s", work_tree_env);
 365                         strcat(buffer, "/");
 366                         return retval;
 367                 }
 368                 if (nongit_ok) {
 369                         *nongit_ok = 1;
 370                         return NULL;
 371                 }
 372                 die("Not a git repository: '%s'", gitdirenv);
 373         }
 374
 375         if (!getcwd(cwd, sizeof(cwd)-1))
 376                 die("Unable to read current working directory");
 377
 378         /*
 379          * Test in the following order (relative to the cwd):
 380          * - .git/
 381          * - ./ (bare)
 382          * - ../.git/
 383          * - ../ (bare)
 384          * - ../../.git/
 385          *   etc.
 386          */
 387         offset = len = strlen(cwd);
 388         for (;;) {
 389                 if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 390                         break;
 391                 if (is_git_directory(".")) {
 392                         inside_git_dir = 1;
 393                         if (!work_tree_env)
 394                                 inside_work_tree = 0;
 395                         setenv(GIT_DIR_ENVIRONMENT, ".", 1);
 396                         check_repository_format_gently(nongit_ok);
 397                         return NULL;
 398                 }
 399                 chdir("..");
 400                 do {
 401                         if (!offset) {
 402                                 if (nongit_ok) {
 403                                         if (chdir(cwd))
 404                                                 die("Cannot come back to cwd");
 405                                         *nongit_ok = 1;
 406                                         return NULL;
 407                                 }
 408                                 die("Not a git repository");
 409                         }
 410                 } while (cwd[--offset] != '/');
 411         }
 412
 413         inside_git_dir = 0;
 414         if (!work_tree_env)
 415                 inside_work_tree = 1;
 416         git_work_tree_cfg = xstrndup(cwd, offset);
 417         if (check_repository_format_gently(nongit_ok))
 418                 return NULL;
 419         if (offset == len)
 420                 return NULL;
 421
 422         /* Make "offset" point to past the '/', and add a '/' at the end */
 423         offset++;
 424         cwd[len++] = '/';
 425         cwd[len] = 0;
 426         return cwd + offset;
 427 }
 428
 429 int git_config_perm(const char *var, const char *value)
 430 {
 431         if (value) {
 432                 int i;
 433                 if (!strcmp(value, "umask"))
 434                         return PERM_UMASK;
 435                 if (!strcmp(value, "group"))
 436                         return PERM_GROUP;
 437                 if (!strcmp(value, "all") ||
 438                     !strcmp(value, "world") ||
 439                     !strcmp(value, "everybody"))
 440                         return PERM_EVERYBODY;
 441                 i = atoi(value);
 442                 if (i > 1)
 443                         return i;
 444         }
 445         return git_config_bool(var, value);
 446 }
 447
 448 int check_repository_format_version(const char *var, const char *value)
 449 {
 450         if (strcmp(var, "core.repositoryformatversion") == 0)
 451                 repository_format_version = git_config_int(var, value);
 452         else if (strcmp(var, "core.sharedrepository") == 0)
 453                 shared_repository = git_config_perm(var, value);
 454         else if (strcmp(var, "core.bare") == 0) {
 455                 is_bare_repository_cfg = git_config_bool(var, value);
 456                 if (is_bare_repository_cfg == 1)
 457                         inside_work_tree = -1;
 458         } else if (strcmp(var, "core.worktree") == 0) {
 459                 if (!value)
 460                         return config_error_nonbool(var);
 461                 free(git_work_tree_cfg);
 462                 git_work_tree_cfg = xstrdup(value);
 463                 inside_work_tree = -1;
 464         }
 465         return 0;
 466 }
 467
 468 int check_repository_format(void)
 469 {
 470         return check_repository_format_gently(NULL);
 471 }
 472
 473 const char *setup_git_directory(void)
 474 {
 475         const char *retval = setup_git_directory_gently(NULL);
 476
 477         /* If the work tree is not the default one, recompute prefix */
 478         if (inside_work_tree < 0) {
 479                 static char buffer[PATH_MAX + 1];
 480                 char *rel;
 481                 if (retval && chdir(retval))
 482                         die ("Could not jump back into original cwd");
 483                 rel = get_relative_cwd(buffer, PATH_MAX, get_git_work_tree());
 484                 return rel && *rel ? strcat(rel, "/") : NULL;
 485         }
 486
 487         return retval;
 488 }