lib/makepath.c

   1 /* makepath.c -- Ensure that a directory path exists.
   2    Copyright (C) 1990, 1997, 1998, 1999, 2000, 2002 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Written by David MacKenzie <djm@gnu.ai.mit.edu> and Jim Meyering.  */
  19
  20 #if HAVE_CONFIG_H
  21 # include <config.h>
  22 #endif
  23
  24 #if __GNUC__
  25 # define alloca __builtin_alloca
  26 #else
  27 # if HAVE_ALLOCA_H
  28 #  include <alloca.h>
  29 # else
  30 #  ifdef _AIX
  31  #  pragma alloca
  32 #  else
  33 char *alloca ();
  34 #  endif
  35 # endif
  36 #endif
  37
  38 #include <stdio.h>
  39 #include <sys/types.h>
  40 #include <sys/stat.h>
  41 #if HAVE_UNISTD_H
  42 # include <unistd.h>
  43 #endif
  44
  45 #if STAT_MACROS_BROKEN
  46 # undef S_ISDIR
  47 #endif
  48
  49 #if !defined(S_ISDIR) && defined(S_IFDIR)
  50 # define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
  51 #endif
  52
  53 #ifndef S_IRWXUGO
  54 # define S_IRWXUGO (S_IRWXU | S_IRWXG | S_IRWXO)
  55 #endif
  56
  57 #if STDC_HEADERS
  58 # include <stdlib.h>
  59 #endif
  60
  61 #if HAVE_ERRNO_H
  62 # include <errno.h>
  63 #endif
  64
  65 #ifndef errno
  66 extern int errno;
  67 #endif
  68
  69 #if HAVE_STRING_H
  70 # include <string.h>
  71 #else
  72 # include <strings.h>
  73 # ifndef strchr
  74 #  define strchr index
  75 # endif
  76 #endif
  77
  78 #ifndef S_ISUID
  79 # define S_ISUID 04000
  80 #endif
  81 #ifndef S_ISGID
  82 # define S_ISGID 02000
  83 #endif
  84 #ifndef S_ISVTX
  85 # define S_ISVTX 01000
  86 #endif
  87 #ifndef S_IRUSR
  88 # define S_IRUSR 0200
  89 #endif
  90 #ifndef S_IWUSR
  91 # define S_IWUSR 0200
  92 #endif
  93 #ifndef S_IXUSR
  94 # define S_IXUSR 0100
  95 #endif
  96
  97 #ifndef S_IRWXU
  98 # define S_IRWXU (S_IRUSR | S_IWUSR | S_IXUSR)
  99 #endif
 100
 101 #define WX_USR (S_IWUSR | S_IXUSR)
 102
 103 /* Include this before libintl.h so we get our definition of PARAMS. */
 104 #include "makepath.h"
 105
 106 #if HAVE_LOCALE_H
 107 # include <locale.h>
 108 #endif
 109
 110 #if ENABLE_NLS
 111 # include <libintl.h>
 112 # define _(Text) gettext (Text)
 113 #else
 114 # define _(Text) Text
 115 #endif
 116
 117 #include "save-cwd.h"
 118 #include "dirname.h"
 119 #include "error.h"
 120 #include "quote.h"
 121
 122 #define CLEANUP_CWD                                     \
 123   do                                                    \
 124     {                                                   \
 125       /* We're done operating on basename_dir.          \
 126          Restore working directory.  */                 \
 127       if (do_chdir)                                     \
 128         {                                               \
 129           int _fail = restore_cwd (&cwd, NULL, NULL);   \
 130           free_cwd (&cwd);                              \
 131           if (_fail)                                    \
 132             return 1;                                   \
 133         }                                               \
 134     }                                                   \
 135   while (0)
 136
 137 #define CLEANUP                                         \
 138   do                                                    \
 139     {                                                   \
 140       umask (oldmask);                                  \
 141       CLEANUP_CWD;                                      \
 142     }                                                   \
 143   while (0)
 144
 145 /* Attempt to create directory DIR (aka DIRPATH) with the specified MODE.
 146    If CREATED_DIR_P is non-NULL, set *CREATED_DIR_P to non-zero if this
 147    function creates DIR and to zero otherwise.  Give a diagnostic and
 148    return non-zero if DIR cannot be created or cannot be determined to
 149    exist already.  Use DIRPATH in any diagnostic, not DIR.
 150    Note that if DIR already exists, this function returns zero
 151    (indicating success) and sets *CREATED_DIR_P to zero.  */
 152
 153 int
 154 make_dir (const char *dir, const char *dirpath, mode_t mode, int *created_dir_p)
 155 {
 156   int fail = 0;
 157   int created_dir;
 158
 159   created_dir = (mkdir (dir, mode) == 0);
 160
 161   if (!created_dir)
 162     {
 163       struct stat stats;
 164       int saved_errno = errno;
 165
 166       /* The mkdir and stat calls below may appear to be reversed.
 167          They are not.  It is important to call mkdir first and then to
 168          call stat (to distinguish the three cases) only if mkdir fails.
 169          The alternative to this approach is to `stat' each directory,
 170          then to call mkdir if it doesn't exist.  But if some other process
 171          were to create the directory between the stat & mkdir, the mkdir
 172          would fail with EEXIST.  */
 173
 174       if (stat (dir, &stats))
 175         {
 176           error (0, saved_errno, _("cannot create directory %s"),
 177                  quote (dirpath));
 178           fail = 1;
 179         }
 180       else if (!S_ISDIR (stats.st_mode))
 181         {
 182           error (0, 0, _("%s exists but is not a directory"), quote (dirpath));
 183           fail = 1;
 184         }
 185       else
 186         {
 187           /* DIR (aka DIRPATH) already exists and is a directory. */
 188         }
 189     }
 190
 191   if (created_dir_p)
 192     *created_dir_p = created_dir;
 193
 194   return fail;
 195 }
 196
 197 /* Ensure that the directory ARGPATH exists.
 198
 199    Create any leading directories that don't already exist, with
 200    permissions PARENT_MODE.
 201    If the last element of ARGPATH does not exist, create it as
 202    a new directory with permissions MODE.
 203    If OWNER and GROUP are non-negative, use them to set the UID and GID of
 204    any created directories.
 205    If VERBOSE_FMT_STRING is nonzero, use it as a printf format
 206    string for printing a message after successfully making a directory,
 207    with the name of the directory that was just made as an argument.
 208    If PRESERVE_EXISTING is non-zero and ARGPATH is an existing directory,
 209    then do not attempt to set its permissions and ownership.
 210
 211    Return 0 if ARGPATH exists as a directory with the proper
 212    ownership and permissions when done, otherwise 1.  */
 213
 214 int
 215 make_path (const char *argpath,
 216            int mode,
 217            int parent_mode,
 218            uid_t owner,
 219            gid_t group,
 220            int preserve_existing,
 221            const char *verbose_fmt_string)
 222 {
 223   struct stat stats;
 224   int retval = 0;
 225
 226   if (stat (argpath, &stats))
 227     {
 228       char *slash;
 229       int tmp_mode;             /* Initial perms for leading dirs.  */
 230       int re_protect;           /* Should leading dirs be unwritable? */
 231       struct ptr_list
 232       {
 233         char *dirname_end;
 234         struct ptr_list *next;
 235       };
 236       struct ptr_list *p, *leading_dirs = NULL;
 237       int do_chdir;             /* Whether to chdir before each mkdir.  */
 238       struct saved_cwd cwd;
 239       char *basename_dir;
 240       char *dirpath;
 241
 242       /* Temporarily relax umask in case it's overly restrictive.  */
 243       mode_t oldmask = umask (0);
 244
 245       /* Make a copy of ARGPATH that we can scribble NULs on.  */
 246       dirpath = (char *) alloca (strlen (argpath) + 1);
 247       strcpy (dirpath, argpath);
 248       strip_trailing_slashes (dirpath);
 249
 250       /* If leading directories shouldn't be writable or executable,
 251          or should have set[ug]id or sticky bits set and we are setting
 252          their owners, we need to fix their permissions after making them.  */
 253       if (((parent_mode & WX_USR) != WX_USR)
 254           || ((owner != (uid_t) -1 || group != (gid_t) -1)
 255               && (parent_mode & (S_ISUID | S_ISGID | S_ISVTX)) != 0))
 256         {
 257           tmp_mode = S_IRWXU;
 258           re_protect = 1;
 259         }
 260       else
 261         {
 262           tmp_mode = parent_mode;
 263           re_protect = 0;
 264         }
 265
 266       /* If we can record the current working directory, we may be able
 267          to do the chdir optimization.  */
 268       do_chdir = !save_cwd (&cwd);
 269
 270       /* If we've saved the cwd and DIRPATH is an absolute pathname,
 271          we must chdir to `/' in order to enable the chdir optimization.
 272          So if chdir ("/") fails, turn off the optimization.  */
 273       if (do_chdir && *dirpath == '/' && chdir ("/") < 0)
 274         do_chdir = 0;
 275
 276       slash = dirpath;
 277
 278       /* Skip over leading slashes.  */
 279       while (*slash == '/')
 280         slash++;
 281
 282       while (1)
 283         {
 284           int newly_created_dir;
 285           int fail;
 286
 287           /* slash points to the leftmost unprocessed component of dirpath.  */
 288           basename_dir = slash;
 289
 290           slash = strchr (slash, '/');
 291           if (slash == NULL)
 292             break;
 293
 294           /* If we're *not* doing chdir before each mkdir, then we have to refer
 295              to the target using the full (multi-component) directory name.  */
 296           if (!do_chdir)
 297             basename_dir = dirpath;
 298
 299           *slash = '\0';
 300           fail = make_dir (basename_dir, dirpath, tmp_mode, &newly_created_dir);
 301           if (fail)
 302             {
 303               CLEANUP;
 304               return 1;
 305             }
 306
 307           if (newly_created_dir)
 308             {
 309               if (verbose_fmt_string)
 310                 error (0, 0, verbose_fmt_string, quote (dirpath));
 311
 312               if ((owner != (uid_t) -1 || group != (gid_t) -1)
 313                   && chown (basename_dir, owner, group)
 314 #if defined(AFS) && defined (EPERM)
 315                   && errno != EPERM
 316 #endif
 317                   )
 318                 {
 319                   error (0, errno, _("cannot change owner and/or group of %s"),
 320                          quote (dirpath));
 321                   CLEANUP;
 322                   return 1;
 323                 }
 324
 325               if (re_protect)
 326                 {
 327                   struct ptr_list *new = (struct ptr_list *)
 328                     alloca (sizeof (struct ptr_list));
 329                   new->dirname_end = slash;
 330                   new->next = leading_dirs;
 331                   leading_dirs = new;
 332                 }
 333             }
 334
 335           /* If we were able to save the initial working directory,
 336              then we can use chdir to change into each directory before
 337              creating an entry in that directory.  This avoids making
 338              stat and mkdir process O(n^2) file name components.  */
 339           if (do_chdir && chdir (basename_dir) < 0)
 340             {
 341               error (0, errno, _("cannot chdir to directory %s"),
 342                      quote (dirpath));
 343               CLEANUP;
 344               return 1;
 345             }
 346
 347           *slash++ = '/';
 348
 349           /* Avoid unnecessary calls to `stat' when given
 350              pathnames containing multiple adjacent slashes.  */
 351           while (*slash == '/')
 352             slash++;
 353         }
 354
 355       if (!do_chdir)
 356         basename_dir = dirpath;
 357
 358       /* We're done making leading directories.
 359          Create the final component of the path.  */
 360
 361       if (make_dir (basename_dir, dirpath, mode, NULL))
 362         {
 363           CLEANUP;
 364           return 1;
 365         }
 366
 367       /* Done creating directories.  Restore original umask.  */
 368       umask (oldmask);
 369
 370       if (verbose_fmt_string != NULL)
 371         error (0, 0, verbose_fmt_string, quote (dirpath));
 372
 373       if (owner != (uid_t) -1 || group != (gid_t) -1)
 374         {
 375           if (chown (basename_dir, owner, group)
 376 #ifdef AFS
 377               && errno != EPERM
 378 #endif
 379               )
 380             {
 381               error (0, errno, _("cannot change owner and/or group of %s"),
 382                      quote (dirpath));
 383               retval = 1;
 384             }
 385         }
 386
 387       /* The above chown may have turned off some permission bits in MODE.
 388          Another reason we may have to use chmod here is that mkdir(2) is
 389          required to honor only the file permission bits.  In particular,
 390          it need not honor the `special' bits, so if MODE includes any
 391          special bits, set them here.  */
 392       if ((mode & ~S_IRWXUGO)
 393           && chmod (basename_dir, mode))
 394         {
 395           error (0, errno, _("cannot change permissions of %s"), quote (dirpath));
 396           retval = 1;
 397         }
 398
 399       CLEANUP_CWD;
 400
 401       /* If the mode for leading directories didn't include owner "wx"
 402          privileges, we have to reset their protections to the correct
 403          value.  */
 404       for (p = leading_dirs; p != NULL; p = p->next)
 405         {
 406           *(p->dirname_end) = '\0';
 407           if (chmod (dirpath, parent_mode))
 408             {
 409               error (0, errno, "cannot change permissions of %s",
 410                      quote (dirpath));
 411               retval = 1;
 412             }
 413         }
 414     }
 415   else
 416     {
 417       /* We get here if the entire path already exists.  */
 418
 419       const char *dirpath = argpath;
 420
 421       if (!S_ISDIR (stats.st_mode))
 422         {
 423           error (0, 0, _("%s exists but is not a directory"), quote (dirpath));
 424           return 1;
 425         }
 426
 427       if (!preserve_existing)
 428         {
 429           /* chown must precede chmod because on some systems,
 430              chown clears the set[ug]id bits for non-superusers,
 431              resulting in incorrect permissions.
 432              On System V, users can give away files with chown and then not
 433              be able to chmod them.  So don't give files away.  */
 434
 435           if ((owner != (uid_t) -1 || group != (gid_t) -1)
 436               && chown (dirpath, owner, group)
 437 #ifdef AFS
 438               && errno != EPERM
 439 #endif
 440               )
 441             {
 442               error (0, errno, _("cannot change owner and/or group of %s"),
 443                      quote (dirpath));
 444               retval = 1;
 445             }
 446           if (chmod (dirpath, mode))
 447             {
 448               error (0, errno, _("cannot change permissions of %s"),
 449                                  quote (dirpath));
 450               retval = 1;
 451             }
 452         }
 453     }
 454
 455   return retval;
 456 }