setup.c

   1 #include "cache.h"
   2
   3 const char *prefix_path(const char *prefix, int len, const char *path)
   4 {
   5         const char *orig = path;
   6         for (;;) {
   7                 char c;
   8                 if (*path != '.')
   9                         break;
  10                 c = path[1];
  11                 /* "." */
  12                 if (!c) {
  13                         path++;
  14                         break;
  15                 }
  16                 /* "./" */
  17                 if (c == '/') {
  18                         path += 2;
  19                         continue;
  20                 }
  21                 if (c != '.')
  22                         break;
  23                 c = path[2];
  24                 if (!c)
  25                         path += 2;
  26                 else if (c == '/')
  27                         path += 3;
  28                 else
  29                         break;
  30                 /* ".." and "../" */
  31                 /* Remove last component of the prefix */
  32                 do {
  33                         if (!len)
  34                                 die("'%s' is outside repository", orig);
  35                         len--;
  36                 } while (len && prefix[len-1] != '/');
  37                 continue;
  38         }
  39         if (len) {
  40                 int speclen = strlen(path);
  41                 char *n = xmalloc(speclen + len + 1);
  42
  43                 memcpy(n, prefix, len);
  44                 memcpy(n + len, path, speclen+1);
  45                 path = n;
  46         }
  47         return path;
  48 }
  49
  50 /*
  51  * Unlike prefix_path, this should be used if the named file does
  52  * not have to interact with index entry; i.e. name of a random file
  53  * on the filesystem.
  54  */
  55 const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
  56 {
  57         static char path[PATH_MAX];
  58         if (!pfx || !*pfx || arg[0] == '/')
  59                 return arg;
  60         memcpy(path, pfx, pfx_len);
  61         strcpy(path + pfx_len, arg);
  62         return path;
  63 }
  64
  65 /*
  66  * Verify a filename that we got as an argument for a pathspec
  67  * entry. Note that a filename that begins with "-" never verifies
  68  * as true, because even if such a filename were to exist, we want
  69  * it to be preceded by the "--" marker (or we want the user to
  70  * use a format like "./-filename")
  71  */
  72 void verify_filename(const char *prefix, const char *arg)
  73 {
  74         const char *name;
  75         struct stat st;
  76
  77         if (*arg == '-')
  78                 die("bad flag '%s' used after filename", arg);
  79         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
  80         if (!lstat(name, &st))
  81                 return;
  82         if (errno == ENOENT)
  83                 die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
  84                     "Use '--' to separate paths from revisions", arg);
  85         die("'%s': %s", arg, strerror(errno));
  86 }
  87
  88 /*
  89  * Opposite of the above: the command line did not have -- marker
  90  * and we parsed the arg as a refname.  It should not be interpretable
  91  * as a filename.
  92  */
  93 void verify_non_filename(const char *prefix, const char *arg)
  94 {
  95         const char *name;
  96         struct stat st;
  97
  98         if (!is_inside_work_tree() || is_inside_git_dir())
  99                 return;
 100         if (*arg == '-')
 101                 return; /* flag */
 102         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
 103         if (!lstat(name, &st))
 104                 die("ambiguous argument '%s': both revision and filename\n"
 105                     "Use '--' to separate filenames from revisions", arg);
 106         if (errno != ENOENT)
 107                 die("'%s': %s", arg, strerror(errno));
 108 }
 109
 110 const char **get_pathspec(const char *prefix, const char **pathspec)
 111 {
 112         const char *entry = *pathspec;
 113         const char **p;
 114         int prefixlen;
 115
 116         if (!prefix && !entry)
 117                 return NULL;
 118
 119         if (!entry) {
 120                 static const char *spec[2];
 121                 spec[0] = prefix;
 122                 spec[1] = NULL;
 123                 return spec;
 124         }
 125
 126         /* Otherwise we have to re-write the entries.. */
 127         p = pathspec;
 128         prefixlen = prefix ? strlen(prefix) : 0;
 129         do {
 130                 *p = prefix_path(prefix, prefixlen, entry);
 131         } while ((entry = *++p) != NULL);
 132         return (const char **) pathspec;
 133 }
 134
 135 /*
 136  * Test if it looks like we're at a git directory.
 137  * We want to see:
 138  *
 139  *  - either a objects/ directory _or_ the proper
 140  *    GIT_OBJECT_DIRECTORY environment variable
 141  *  - a refs/ directory
 142  *  - either a HEAD symlink or a HEAD file that is formatted as
 143  *    a proper "ref:", or a regular file HEAD that has a properly
 144  *    formatted sha1 object name.
 145  */
 146 static int is_git_directory(const char *suspect)
 147 {
 148         char path[PATH_MAX];
 149         size_t len = strlen(suspect);
 150
 151         strcpy(path, suspect);
 152         if (getenv(DB_ENVIRONMENT)) {
 153                 if (access(getenv(DB_ENVIRONMENT), X_OK))
 154                         return 0;
 155         }
 156         else {
 157                 strcpy(path + len, "/objects");
 158                 if (access(path, X_OK))
 159                         return 0;
 160         }
 161
 162         strcpy(path + len, "/refs");
 163         if (access(path, X_OK))
 164                 return 0;
 165
 166         strcpy(path + len, "/HEAD");
 167         if (validate_headref(path))
 168                 return 0;
 169
 170         return 1;
 171 }
 172
 173 static int inside_git_dir = -1;
 174
 175 int is_inside_git_dir(void)
 176 {
 177         if (inside_git_dir >= 0)
 178                 return inside_git_dir;
 179         die("BUG: is_inside_git_dir called before setup_git_directory");
 180 }
 181
 182 static int inside_work_tree = -1;
 183
 184 int is_inside_work_tree(void)
 185 {
 186         if (inside_git_dir >= 0)
 187                 return inside_work_tree;
 188         die("BUG: is_inside_work_tree called before setup_git_directory");
 189 }
 190
 191 static char *gitworktree_config;
 192
 193 static int git_setup_config(const char *var, const char *value)
 194 {
 195         if (!strcmp(var, "core.worktree")) {
 196                 if (gitworktree_config)
 197                         strlcpy(gitworktree_config, value, PATH_MAX);
 198                 return 0;
 199         }
 200         return git_default_config(var, value);
 201 }
 202
 203 const char *setup_git_directory_gently(int *nongit_ok)
 204 {
 205         static char cwd[PATH_MAX+1];
 206         char worktree[PATH_MAX+1], gitdir[PATH_MAX+1];
 207         const char *gitdirenv, *gitworktree;
 208         int wt_rel_gitdir = 0;
 209
 210         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 211         if (!gitdirenv) {
 212                 int len, offset;
 213
 214                 if (!getcwd(cwd, sizeof(cwd)-1))
 215                         die("Unable to read current working directory");
 216
 217                 offset = len = strlen(cwd);
 218                 for (;;) {
 219                         if (is_git_directory(".git"))
 220                                 break;
 221                         if (offset == 0) {
 222                                 offset = -1;
 223                                 break;
 224                         }
 225                         chdir("..");
 226                         while (cwd[--offset] != '/')
 227                                 ; /* do nothing */
 228                 }
 229
 230                 if (offset >= 0) {
 231                         inside_work_tree = 1;
 232                         git_config(git_default_config);
 233                         if (offset == len) {
 234                                 inside_git_dir = 0;
 235                                 return NULL;
 236                         }
 237
 238                         cwd[len++] = '/';
 239                         cwd[len] = '\0';
 240                         inside_git_dir = !prefixcmp(cwd + offset + 1, ".git/");
 241                         return cwd + offset + 1;
 242                 }
 243
 244                 if (chdir(cwd))
 245                         die("Cannot come back to cwd");
 246                 if (!is_git_directory(".")) {
 247                         if (nongit_ok) {
 248                                 *nongit_ok = 1;
 249                                 return NULL;
 250                         }
 251                         die("Not a git repository");
 252                 }
 253                 setenv(GIT_DIR_ENVIRONMENT, cwd, 1);
 254                 gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 255                 if (!gitdirenv)
 256                         die("getenv after setenv failed");
 257         }
 258
 259         if (PATH_MAX - 40 < strlen(gitdirenv)) {
 260                 if (nongit_ok) {
 261                         *nongit_ok = 1;
 262                         return NULL;
 263                 }
 264                 die("$%s too big", GIT_DIR_ENVIRONMENT);
 265         }
 266         if (!is_git_directory(gitdirenv)) {
 267                 if (nongit_ok) {
 268                         *nongit_ok = 1;
 269                         return NULL;
 270                 }
 271                 die("Not a git repository: '%s'", gitdirenv);
 272         }
 273
 274         if (!getcwd(cwd, sizeof(cwd)-1))
 275                 die("Unable to read current working directory");
 276         if (chdir(gitdirenv)) {
 277                 if (nongit_ok) {
 278                         *nongit_ok = 1;
 279                         return NULL;
 280                 }
 281                 die("Cannot change directory to $%s '%s'",
 282                         GIT_DIR_ENVIRONMENT, gitdirenv);
 283         }
 284         if (!getcwd(gitdir, sizeof(gitdir)-1))
 285                 die("Unable to read current working directory");
 286         if (chdir(cwd))
 287                 die("Cannot come back to cwd");
 288
 289         /*
 290          * In case there is a work tree we may change the directory,
 291          * therefore make GIT_DIR an absolute path.
 292          */
 293         if (gitdirenv[0] != '/') {
 294                 setenv(GIT_DIR_ENVIRONMENT, gitdir, 1);
 295                 gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 296                 if (!gitdirenv)
 297                         die("getenv after setenv failed");
 298                 if (PATH_MAX - 40 < strlen(gitdirenv)) {
 299                         if (nongit_ok) {
 300                                 *nongit_ok = 1;
 301                                 return NULL;
 302                         }
 303                         die("$%s too big after expansion to absolute path",
 304                                 GIT_DIR_ENVIRONMENT);
 305                 }
 306         }
 307
 308         strcat(cwd, "/");
 309         strcat(gitdir, "/");
 310         inside_git_dir = !prefixcmp(cwd, gitdir);
 311
 312         gitworktree = getenv(GIT_WORK_TREE_ENVIRONMENT);
 313         if (!gitworktree) {
 314                 gitworktree_config = worktree;
 315                 worktree[0] = '\0';
 316         }
 317         git_config(git_setup_config);
 318         if (!gitworktree) {
 319                 gitworktree_config = NULL;
 320                 if (worktree[0])
 321                         gitworktree = worktree;
 322                 if (gitworktree && gitworktree[0] != '/')
 323                         wt_rel_gitdir = 1;
 324         }
 325
 326         if (wt_rel_gitdir && chdir(gitdirenv))
 327                 die("Cannot change directory to $%s '%s'",
 328                         GIT_DIR_ENVIRONMENT, gitdirenv);
 329         if (gitworktree && chdir(gitworktree)) {
 330                 if (nongit_ok) {
 331                         if (wt_rel_gitdir && chdir(cwd))
 332                                 die("Cannot come back to cwd");
 333                         *nongit_ok = 1;
 334                         return NULL;
 335                 }
 336                 if (wt_rel_gitdir)
 337                         die("Cannot change directory to working tree '%s'"
 338                                 " from $%s", gitworktree, GIT_DIR_ENVIRONMENT);
 339                 else
 340                         die("Cannot change directory to working tree '%s'",
 341                                 gitworktree);
 342         }
 343         if (!getcwd(worktree, sizeof(worktree)-1))
 344                 die("Unable to read current working directory");
 345         strcat(worktree, "/");
 346         inside_work_tree = !prefixcmp(cwd, worktree);
 347
 348         if (gitworktree && inside_work_tree && !prefixcmp(worktree, gitdir) &&
 349             strcmp(worktree, gitdir)) {
 350                 inside_git_dir = 0;
 351         }
 352
 353         if (!inside_work_tree) {
 354                 if (chdir(cwd))
 355                         die("Cannot come back to cwd");
 356                 return NULL;
 357         }
 358
 359         if (!strcmp(cwd, worktree))
 360                 return NULL;
 361         return cwd+strlen(worktree);
 362 }
 363
 364 int git_config_perm(const char *var, const char *value)
 365 {
 366         if (value) {
 367                 if (!strcmp(value, "umask"))
 368                         return PERM_UMASK;
 369                 if (!strcmp(value, "group"))
 370                         return PERM_GROUP;
 371                 if (!strcmp(value, "all") ||
 372                     !strcmp(value, "world") ||
 373                     !strcmp(value, "everybody"))
 374                         return PERM_EVERYBODY;
 375         }
 376         return git_config_bool(var, value);
 377 }
 378
 379 int check_repository_format_version(const char *var, const char *value)
 380 {
 381        if (strcmp(var, "core.repositoryformatversion") == 0)
 382                repository_format_version = git_config_int(var, value);
 383         else if (strcmp(var, "core.sharedrepository") == 0)
 384                 shared_repository = git_config_perm(var, value);
 385        return 0;
 386 }
 387
 388 int check_repository_format(void)
 389 {
 390         git_config(check_repository_format_version);
 391         if (GIT_REPO_VERSION < repository_format_version)
 392                 die ("Expected git repo version <= %d, found %d",
 393                      GIT_REPO_VERSION, repository_format_version);
 394         return 0;
 395 }
 396
 397 const char *setup_git_directory(void)
 398 {
 399         const char *retval = setup_git_directory_gently(NULL);
 400         check_repository_format();
 401         return retval;
 402 }