lib/makepath.c

   1 /* makepath.c -- Ensure that a directory path exists.
   2    Copyright (C) 1990, 1997 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 #if STDC_HEADERS
  54 # include <stdlib.h>
  55 #endif
  56
  57 #if HAVE_ERRNO_H
  58 # include <errno.h>
  59 #endif
  60
  61 #ifndef errno
  62 extern int errno;
  63 #endif
  64
  65 #if HAVE_STRING_H
  66 # include <string.h>
  67 #else
  68 # include <strings.h>
  69 # ifndef strchr
  70 #  define strchr index
  71 # endif
  72 #endif
  73
  74 #ifdef __MSDOS__
  75 typedef int uid_t;
  76 typedef int gid_t;
  77 #endif
  78
  79 #include "save-cwd.h"
  80 #include "makepath.h"
  81 #include "error.h"
  82
  83 void strip_trailing_slashes ();
  84
  85 #define CLEANUP_CWD                                     \
  86   do                                                    \
  87     {                                                   \
  88       /* We're done operating on basename_dir.          \
  89          Restore working directory.  */                 \
  90       if (saved_cwd)                                    \
  91         {                                               \
  92           int fail = restore_cwd (&cwd, NULL, NULL);    \
  93           free_cwd (&cwd);                              \
  94           if (fail)                                     \
  95             return 1;                                   \
  96         }                                               \
  97     }                                                   \
  98   while (0)
  99
 100 #define CLEANUP                                         \
 101   do                                                    \
 102     {                                                   \
 103       umask (oldmask);                                  \
 104       CLEANUP_CWD;                                      \
 105     }                                                   \
 106   while (0)
 107
 108 /* Ensure that the directory ARGPATH exists.
 109    Remove any trailing slashes from ARGPATH before calling this function.
 110
 111    Create any leading directories that don't already exist, with
 112    permissions PARENT_MODE.
 113    If the last element of ARGPATH does not exist, create it as
 114    a new directory with permissions MODE.
 115    If OWNER and GROUP are non-negative, use them to set the UID and GID of
 116    any created directories.
 117    If VERBOSE_FMT_STRING is nonzero, use it as a printf format
 118    string for printing a message after successfully making a directory,
 119    with the name of the directory that was just made as an argument.
 120    If PRESERVE_EXISTING is non-zero and ARGPATH is an existing directory,
 121    then do not attempt to set its permissions and ownership.
 122
 123    Return 0 if ARGPATH exists as a directory with the proper
 124    ownership and permissions when done, otherwise 1.  */
 125
 126 #if __STDC__
 127 int
 128 make_path (const char *argpath,
 129            int mode,
 130            int parent_mode,
 131            uid_t owner,
 132            gid_t group,
 133            int preserve_existing,
 134            const char *verbose_fmt_string)
 135 #else
 136 int
 137 make_path (argpath, mode, parent_mode, owner, group, preserve_existing,
 138            verbose_fmt_string)
 139      const char *argpath;
 140      int mode;
 141      int parent_mode;
 142      uid_t owner;
 143      gid_t group;
 144      int preserve_existing;
 145      const char *verbose_fmt_string;
 146 #endif
 147 {
 148   struct stat stats;
 149   int retval = 0;
 150
 151   if (stat (argpath, &stats))
 152     {
 153       char *slash;
 154       int tmp_mode;             /* Initial perms for leading dirs.  */
 155       int re_protect;           /* Should leading dirs be unwritable? */
 156       struct ptr_list
 157       {
 158         char *dirname_end;
 159         struct ptr_list *next;
 160       };
 161       struct ptr_list *p, *leading_dirs = NULL;
 162       int saved_cwd = 0;
 163       struct saved_cwd cwd;
 164       char *basename_dir;
 165       int first_subdir = 1;
 166       char *dirpath;
 167
 168       /* Temporarily relax umask in case it's overly restrictive.  */
 169       int oldmask = umask (0);
 170
 171       /* Make a copy of ARGPATH that we can scribble NULs on.  */
 172       dirpath = (char *) alloca (strlen (argpath) + 1);
 173       strcpy (dirpath, argpath);
 174       strip_trailing_slashes (dirpath);
 175
 176       /* If leading directories shouldn't be writable or executable,
 177          or should have set[ug]id or sticky bits set and we are setting
 178          their owners, we need to fix their permissions after making them.  */
 179       if (((parent_mode & 0300) != 0300)
 180           || (owner != (uid_t) -1 && group != (gid_t) -1
 181               && (parent_mode & 07000) != 0))
 182         {
 183           tmp_mode = 0700;
 184           re_protect = 1;
 185         }
 186       else
 187         {
 188           tmp_mode = parent_mode;
 189           re_protect = 0;
 190         }
 191
 192       slash = dirpath;
 193
 194       /* Skip over leading slashes.  */
 195       while (*slash == '/')
 196         slash++;
 197
 198       while (1)
 199         {
 200           /* slash points to the leftmost unprocessed component of dirpath.  */
 201           basename_dir = slash;
 202
 203           slash = strchr (slash, '/');
 204           if (slash == NULL)
 205             break;
 206
 207           if (first_subdir)
 208             {
 209               first_subdir = 0;
 210               saved_cwd = !save_cwd (&cwd);
 211             }
 212
 213           if (!saved_cwd)
 214             basename_dir = dirpath;
 215
 216           *slash = '\0';
 217           if (mkdir (basename_dir, tmp_mode))
 218             {
 219               if (stat (basename_dir, &stats))
 220                 {
 221                   error (0, errno, "cannot create directory `%s'", dirpath);
 222                   CLEANUP;
 223                   return 1;
 224                 }
 225               else if (!S_ISDIR (stats.st_mode))
 226                 {
 227                   error (0, 0, "`%s' exists but is not a directory", dirpath);
 228                   CLEANUP;
 229                   return 1;
 230                 }
 231               else
 232                 {
 233                   /* DIRPATH already exists and is a directory. */
 234                 }
 235             }
 236
 237           if (verbose_fmt_string != NULL)
 238             error (0, 0, verbose_fmt_string, dirpath);
 239
 240           if (owner != (uid_t) -1 && group != (gid_t) -1
 241               && chown (basename_dir, owner, group)
 242 #if defined(AFS) && defined (EPERM)
 243               && errno != EPERM
 244 #endif
 245               )
 246             {
 247               error (0, errno, "%s", dirpath);
 248               CLEANUP;
 249               return 1;
 250             }
 251
 252           if (re_protect)
 253             {
 254               struct ptr_list *new = (struct ptr_list *)
 255                 alloca (sizeof (struct ptr_list));
 256               new->dirname_end = slash;
 257               new->next = leading_dirs;
 258               leading_dirs = new;
 259             }
 260
 261           if (saved_cwd && chdir (basename_dir) < 0)
 262             {
 263               error (0, errno, "cannot chdir to directory, %s", dirpath);
 264               CLEANUP;
 265               return 1;
 266             }
 267
 268           *slash++ = '/';
 269
 270           /* Avoid unnecessary calls to `stat' when given
 271              pathnames containing multiple adjacent slashes.  */
 272           while (*slash == '/')
 273             slash++;
 274         }
 275
 276       if (!saved_cwd)
 277         basename_dir = dirpath;
 278
 279       /* We're done making leading directories.
 280          Create the final component of the path.  */
 281
 282       /* The path could end in "/." or contain "/..", so test
 283          if we really have to create the directory.  */
 284
 285       if (stat (basename_dir, &stats) && mkdir (basename_dir, mode))
 286         {
 287           error (0, errno, "cannot create directory `%s'", dirpath);
 288           CLEANUP;
 289           return 1;
 290         }
 291
 292       /* Done creating directories.  Restore original umask.  */
 293       umask (oldmask);
 294
 295       if (verbose_fmt_string != NULL)
 296         error (0, 0, verbose_fmt_string, dirpath);
 297
 298       if (owner != (uid_t) -1 && group != (gid_t) -1)
 299         {
 300           if (chown (basename_dir, owner, group)
 301 #ifdef AFS
 302               && errno != EPERM
 303 #endif
 304               )
 305             {
 306               error (0, errno, "cannot chown %s", dirpath);
 307               retval = 1;
 308             }
 309           /* chown may have turned off some permission bits we wanted.  */
 310           if ((mode & 07000) != 0 && chmod (basename_dir, mode))
 311             {
 312               error (0, errno, "cannot chmod %s", dirpath);
 313               retval = 1;
 314             }
 315         }
 316
 317       CLEANUP_CWD;
 318
 319       /* If the mode for leading directories didn't include owner "wx"
 320          privileges, we have to reset their protections to the correct
 321          value.  */
 322       for (p = leading_dirs; p != NULL; p = p->next)
 323         {
 324           *(p->dirname_end) = '\0';
 325           if (chmod (dirpath, parent_mode))
 326             {
 327               error (0, errno, "%s", dirpath);
 328               retval = 1;
 329             }
 330         }
 331     }
 332   else
 333     {
 334       /* We get here if the entire path already exists.  */
 335
 336       const char *dirpath = argpath;
 337
 338       if (!S_ISDIR (stats.st_mode))
 339         {
 340           error (0, 0, "`%s' exists but is not a directory", dirpath);
 341           return 1;
 342         }
 343
 344       if (!preserve_existing)
 345         {
 346           /* chown must precede chmod because on some systems,
 347              chown clears the set[ug]id bits for non-superusers,
 348              resulting in incorrect permissions.
 349              On System V, users can give away files with chown and then not
 350              be able to chmod them.  So don't give files away.  */
 351
 352           if (owner != (uid_t) -1 && group != (gid_t) -1
 353               && chown (dirpath, owner, group)
 354 #ifdef AFS
 355               && errno != EPERM
 356 #endif
 357               )
 358             {
 359               error (0, errno, "%s", dirpath);
 360               retval = 1;
 361             }
 362           if (chmod (dirpath, mode))
 363             {
 364               error (0, errno, "%s", dirpath);
 365               retval = 1;
 366             }
 367         }
 368     }
 369
 370   return retval;
 371 }