setup.con commit Merge branch 'lt/racy-empty' into maint (c636d0e)
   1#include "cache.h"
   2#include "dir.h"
   3
   4static int inside_git_dir = -1;
   5static int inside_work_tree = -1;
   6
   7static 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
  90const 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 */
 126const 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 */
 143void 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 */
 164void 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
 181const 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 */
 226static 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
 253int 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
 260int 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 */
 273static 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
 285void 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                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        set_git_dir(make_relative_path(git_dir, work_tree));
 299        initialized = 1;
 300}
 301
 302static int check_repository_format_gently(int *nongit_ok)
 303{
 304        git_config(check_repository_format_version, NULL);
 305        if (GIT_REPO_VERSION < repository_format_version) {
 306                if (!nongit_ok)
 307                        die ("Expected git repo version <= %d, found %d",
 308                             GIT_REPO_VERSION, repository_format_version);
 309                warning("Expected git repo version <= %d, found %d",
 310                        GIT_REPO_VERSION, repository_format_version);
 311                warning("Please upgrade Git");
 312                *nongit_ok = -1;
 313                return -1;
 314        }
 315        return 0;
 316}
 317
 318/*
 319 * Try to read the location of the git directory from the .git file,
 320 * return path to git directory if found.
 321 */
 322const char *read_gitfile_gently(const char *path)
 323{
 324        char *buf;
 325        struct stat st;
 326        int fd;
 327        size_t len;
 328
 329        if (stat(path, &st))
 330                return NULL;
 331        if (!S_ISREG(st.st_mode))
 332                return NULL;
 333        fd = open(path, O_RDONLY);
 334        if (fd < 0)
 335                die("Error opening %s: %s", path, strerror(errno));
 336        buf = xmalloc(st.st_size + 1);
 337        len = read_in_full(fd, buf, st.st_size);
 338        close(fd);
 339        if (len != st.st_size)
 340                die("Error reading %s", path);
 341        buf[len] = '\0';
 342        if (prefixcmp(buf, "gitdir: "))
 343                die("Invalid gitfile format: %s", path);
 344        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 345                len--;
 346        if (len < 9)
 347                die("No path in gitfile: %s", path);
 348        buf[len] = '\0';
 349        if (!is_git_directory(buf + 8))
 350                die("Not a git repository: %s", buf + 8);
 351        path = make_absolute_path(buf + 8);
 352        free(buf);
 353        return path;
 354}
 355
 356/*
 357 * We cannot decide in this function whether we are in the work tree or
 358 * not, since the config can only be read _after_ this function was called.
 359 */
 360const char *setup_git_directory_gently(int *nongit_ok)
 361{
 362        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 363        static char cwd[PATH_MAX+1];
 364        const char *gitdirenv;
 365        const char *gitfile_dir;
 366        int len, offset;
 367
 368        /*
 369         * Let's assume that we are in a git repository.
 370         * If it turns out later that we are somewhere else, the value will be
 371         * updated accordingly.
 372         */
 373        if (nongit_ok)
 374                *nongit_ok = 0;
 375
 376        /*
 377         * If GIT_DIR is set explicitly, we're not going
 378         * to do any discovery, but we still do repository
 379         * validation.
 380         */
 381        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 382        if (gitdirenv) {
 383                if (PATH_MAX - 40 < strlen(gitdirenv))
 384                        die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 385                if (is_git_directory(gitdirenv)) {
 386                        static char buffer[1024 + 1];
 387                        const char *retval;
 388
 389                        if (!work_tree_env) {
 390                                retval = set_work_tree(gitdirenv);
 391                                /* config may override worktree */
 392                                if (check_repository_format_gently(nongit_ok))
 393                                        return NULL;
 394                                return retval;
 395                        }
 396                        if (check_repository_format_gently(nongit_ok))
 397                                return NULL;
 398                        retval = get_relative_cwd(buffer, sizeof(buffer) - 1,
 399                                        get_git_work_tree());
 400                        if (!retval || !*retval)
 401                                return NULL;
 402                        set_git_dir(make_absolute_path(gitdirenv));
 403                        if (chdir(work_tree_env) < 0)
 404                                die ("Could not chdir to %s", work_tree_env);
 405                        strcat(buffer, "/");
 406                        return retval;
 407                }
 408                if (nongit_ok) {
 409                        *nongit_ok = 1;
 410                        return NULL;
 411                }
 412                die("Not a git repository: '%s'", gitdirenv);
 413        }
 414
 415        if (!getcwd(cwd, sizeof(cwd)-1))
 416                die("Unable to read current working directory");
 417
 418        /*
 419         * Test in the following order (relative to the cwd):
 420         * - .git (file containing "gitdir: <path>")
 421         * - .git/
 422         * - ./ (bare)
 423         * - ../.git
 424         * - ../.git/
 425         * - ../ (bare)
 426         * - ../../.git/
 427         *   etc.
 428         */
 429        offset = len = strlen(cwd);
 430        for (;;) {
 431                gitfile_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
 432                if (gitfile_dir) {
 433                        if (set_git_dir(gitfile_dir))
 434                                die("Repository setup failed");
 435                        break;
 436                }
 437                if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 438                        break;
 439                if (is_git_directory(".")) {
 440                        inside_git_dir = 1;
 441                        if (!work_tree_env)
 442                                inside_work_tree = 0;
 443                        setenv(GIT_DIR_ENVIRONMENT, ".", 1);
 444                        check_repository_format_gently(nongit_ok);
 445                        return NULL;
 446                }
 447                chdir("..");
 448                do {
 449                        if (!offset) {
 450                                if (nongit_ok) {
 451                                        if (chdir(cwd))
 452                                                die("Cannot come back to cwd");
 453                                        *nongit_ok = 1;
 454                                        return NULL;
 455                                }
 456                                die("Not a git repository");
 457                        }
 458                } while (cwd[--offset] != '/');
 459        }
 460
 461        inside_git_dir = 0;
 462        if (!work_tree_env)
 463                inside_work_tree = 1;
 464        git_work_tree_cfg = xstrndup(cwd, offset);
 465        if (check_repository_format_gently(nongit_ok))
 466                return NULL;
 467        if (offset == len)
 468                return NULL;
 469
 470        /* Make "offset" point to past the '/', and add a '/' at the end */
 471        offset++;
 472        cwd[len++] = '/';
 473        cwd[len] = 0;
 474        return cwd + offset;
 475}
 476
 477int git_config_perm(const char *var, const char *value)
 478{
 479        int i;
 480        char *endptr;
 481
 482        if (value == NULL)
 483                return PERM_GROUP;
 484
 485        if (!strcmp(value, "umask"))
 486                return PERM_UMASK;
 487        if (!strcmp(value, "group"))
 488                return PERM_GROUP;
 489        if (!strcmp(value, "all") ||
 490            !strcmp(value, "world") ||
 491            !strcmp(value, "everybody"))
 492                return PERM_EVERYBODY;
 493
 494        /* Parse octal numbers */
 495        i = strtol(value, &endptr, 8);
 496
 497        /* If not an octal number, maybe true/false? */
 498        if (*endptr != 0)
 499                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 500
 501        /*
 502         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 503         * a chmod value.
 504         */
 505        switch (i) {
 506        case PERM_UMASK:               /* 0 */
 507                return PERM_UMASK;
 508        case OLD_PERM_GROUP:           /* 1 */
 509                return PERM_GROUP;
 510        case OLD_PERM_EVERYBODY:       /* 2 */
 511                return PERM_EVERYBODY;
 512        }
 513
 514        /* A filemode value was given: 0xxx */
 515
 516        if ((i & 0600) != 0600)
 517                die("Problem with core.sharedRepository filemode value "
 518                    "(0%.3o).\nThe owner of files must always have "
 519                    "read and write permissions.", i);
 520
 521        /*
 522         * Mask filemode value. Others can not get write permission.
 523         * x flags for directories are handled separately.
 524         */
 525        return i & 0666;
 526}
 527
 528int check_repository_format_version(const char *var, const char *value, void *cb)
 529{
 530        if (strcmp(var, "core.repositoryformatversion") == 0)
 531                repository_format_version = git_config_int(var, value);
 532        else if (strcmp(var, "core.sharedrepository") == 0)
 533                shared_repository = git_config_perm(var, value);
 534        else if (strcmp(var, "core.bare") == 0) {
 535                is_bare_repository_cfg = git_config_bool(var, value);
 536                if (is_bare_repository_cfg == 1)
 537                        inside_work_tree = -1;
 538        } else if (strcmp(var, "core.worktree") == 0) {
 539                if (!value)
 540                        return config_error_nonbool(var);
 541                free(git_work_tree_cfg);
 542                git_work_tree_cfg = xstrdup(value);
 543                inside_work_tree = -1;
 544        }
 545        return 0;
 546}
 547
 548int check_repository_format(void)
 549{
 550        return check_repository_format_gently(NULL);
 551}
 552
 553const char *setup_git_directory(void)
 554{
 555        const char *retval = setup_git_directory_gently(NULL);
 556
 557        /* If the work tree is not the default one, recompute prefix */
 558        if (inside_work_tree < 0) {
 559                static char buffer[PATH_MAX + 1];
 560                char *rel;
 561                if (retval && chdir(retval))
 562                        die ("Could not jump back into original cwd");
 563                rel = get_relative_cwd(buffer, PATH_MAX, get_git_work_tree());
 564                return rel && *rel ? strcat(rel, "/") : NULL;
 565        }
 566
 567        return retval;
 568}