summaryrefslogtreecommitdiff
path: root/lib/makepath.c
blob: 1dc5dae5f166929a46b5dac5130fe126b2074342 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
/* makepath.c -- Ensure that a directory path exists.
   Copyright (C) 1990, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* Written by David MacKenzie <djm@gnu.ai.mit.edu> and Jim Meyering.  */

#if HAVE_CONFIG_H
# include <config.h>
#endif

#if __GNUC__
# define alloca __builtin_alloca
#else
# if HAVE_ALLOCA_H
#  include <alloca.h>
# else
#  ifdef _AIX
 #  pragma alloca
#  else
char *alloca ();
#  endif
# endif
#endif

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#if HAVE_UNISTD_H
# include <unistd.h>
#endif

#if STAT_MACROS_BROKEN
# undef S_ISDIR
#endif

#if !defined(S_ISDIR) && defined(S_IFDIR)
# define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif

#ifndef S_IRWXUGO
# define S_IRWXUGO (S_IRWXU | S_IRWXG | S_IRWXO)
#endif

#if STDC_HEADERS
# include <stdlib.h>
#endif

#if HAVE_ERRNO_H
# include <errno.h>
#endif

#ifndef errno
extern int errno;
#endif

#if HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
# ifndef strchr
#  define strchr index
# endif
#endif

#ifndef S_ISUID
# define S_ISUID 04000
#endif
#ifndef S_ISGID
# define S_ISGID 02000
#endif
#ifndef S_ISVTX
# define S_ISVTX 01000
#endif
#ifndef S_IRUSR
# define S_IRUSR 0200
#endif
#ifndef S_IWUSR
# define S_IWUSR 0200
#endif
#ifndef S_IXUSR
# define S_IXUSR 0100
#endif

#ifndef S_IRWXU
# define S_IRWXU (S_IRUSR | S_IWUSR | S_IXUSR)
#endif

#define WX_USR (S_IWUSR | S_IXUSR)

/* Include this before libintl.h so we get our definition of PARAMS. */
#include "makepath.h"

#if HAVE_LOCALE_H
# include <locale.h>
#endif

#if ENABLE_NLS
# include <libintl.h>
# define _(Text) gettext (Text)
#else
# define _(Text) Text
#endif

#include "save-cwd.h"
#include "error.h"
#include "quote.h"

void strip_trailing_slashes ();

#define CLEANUP_CWD					\
  do							\
    {							\
      /* We're done operating on basename_dir.		\
	 Restore working directory.  */			\
      if (do_chdir)					\
	{						\
	  int _fail = restore_cwd (&cwd, NULL, NULL);	\
	  free_cwd (&cwd);				\
	  if (_fail)					\
	    return 1;					\
	}						\
    }							\
  while (0)

#define CLEANUP						\
  do							\
    {							\
      umask (oldmask);					\
      CLEANUP_CWD;					\
    }							\
  while (0)

/* Attempt to create directory DIR (aka DIRPATH) with the specified MODE.
   If CREATED_DIR_P is non-NULL, set *CREATED_DIR_P to non-zero if this
   function creates DIR and to zero otherwise.  Give a diagnostic and
   return non-zero if DIR cannot be created or cannot be determined to
   exist already.  Use DIRPATH in any diagnostic, not DIR.
   Note that if DIR already exists, this function will return zero
   (indicating success) and will set *CREATED_DIR_P to zero.  */

static int
make_dir (const char *dir, const char *dirpath, mode_t mode, int *created_dir_p)
{
  int fail = 0;
  int created_dir;

  created_dir = (mkdir (dir, mode) == 0);

  if (!created_dir)
    {
      struct stat stats;
      int saved_errno = errno;

      /* The mkdir and stat calls below may appear to be reversed.
	 They are not.  It is important to call mkdir first and then to
	 call stat (to distinguish the three cases) only if mkdir fails.
	 The alternative to this approach is to `stat' each directory,
	 then to call mkdir if it doesn't exist.  But if some other process
	 were to create the directory between the stat & mkdir, the mkdir
	 would fail with EEXIST.  */

      if (stat (dir, &stats))
	{
	  error (0, saved_errno, _("cannot create directory %s"),
		 quote (dirpath));
	  fail = 1;
	}
      else if (!S_ISDIR (stats.st_mode))
	{
	  error (0, 0, _("%s exists but is not a directory"), quote (dirpath));
	  fail = 1;
	}
      else
	{
	  /* DIR (aka DIRPATH) already exists and is a directory. */
	}
    }

  if (created_dir_p)
    *created_dir_p = created_dir;

  return fail;
}

/* Ensure that the directory ARGPATH exists.
   Remove any trailing slashes from ARGPATH before calling this function.

   Create any leading directories that don't already exist, with
   permissions PARENT_MODE.
   If the last element of ARGPATH does not exist, create it as
   a new directory with permissions MODE.
   If OWNER and GROUP are non-negative, use them to set the UID and GID of
   any created directories.
   If VERBOSE_FMT_STRING is nonzero, use it as a printf format
   string for printing a message after successfully making a directory,
   with the name of the directory that was just made as an argument.
   If PRESERVE_EXISTING is non-zero and ARGPATH is an existing directory,
   then do not attempt to set its permissions and ownership.

   Return 0 if ARGPATH exists as a directory with the proper
   ownership and permissions when done, otherwise 1.  */

int
make_path (const char *argpath,
	   int mode,
	   int parent_mode,
	   uid_t owner,
	   gid_t group,
	   int preserve_existing,
	   const char *verbose_fmt_string)
{
  struct stat stats;
  int retval = 0;

  if (stat (argpath, &stats))
    {
      char *slash;
      int tmp_mode;		/* Initial perms for leading dirs.  */
      int re_protect;		/* Should leading dirs be unwritable? */
      struct ptr_list
      {
	char *dirname_end;
	struct ptr_list *next;
      };
      struct ptr_list *p, *leading_dirs = NULL;
      int do_chdir;		/* Whether to chdir before each mkdir.  */
      struct saved_cwd cwd;
      char *basename_dir;
      char *dirpath;

      /* Temporarily relax umask in case it's overly restrictive.  */
      mode_t oldmask = umask (0);

      /* Make a copy of ARGPATH that we can scribble NULs on.  */
      dirpath = (char *) alloca (strlen (argpath) + 1);
      strcpy (dirpath, argpath);
      strip_trailing_slashes (dirpath);

      /* If leading directories shouldn't be writable or executable,
	 or should have set[ug]id or sticky bits set and we are setting
	 their owners, we need to fix their permissions after making them.  */
      if (((parent_mode & WX_USR) != WX_USR)
	  || ((owner != (uid_t) -1 || group != (gid_t) -1)
	      && (parent_mode & (S_ISUID | S_ISGID | S_ISVTX)) != 0))
	{
	  tmp_mode = S_IRWXU;
	  re_protect = 1;
	}
      else
	{
	  tmp_mode = parent_mode;
	  re_protect = 0;
	}

      /* If we can record the current working directory, we may be able
	 to do the chdir optimization.  */
      do_chdir = !save_cwd (&cwd);

      /* If we've saved the cwd and DIRPATH is an absolute pathname,
	 we must chdir to `/' in order to enable the chdir optimization.
         So if chdir ("/") fails, turn off the optimization.  */
      if (do_chdir && *dirpath == '/' && chdir ("/") < 0)
	do_chdir = 0;

      slash = dirpath;

      /* Skip over leading slashes.  */
      while (*slash == '/')
	slash++;

      while (1)
	{
	  int newly_created_dir;
	  int fail;

	  /* slash points to the leftmost unprocessed component of dirpath.  */
	  basename_dir = slash;

	  slash = strchr (slash, '/');
	  if (slash == NULL)
	    break;

	  /* If we're *not* doing chdir before each mkdir, then we have to refer
	     to the target using the full (multi-component) directory name.  */
	  if (!do_chdir)
	    basename_dir = dirpath;

	  *slash = '\0';
	  fail = make_dir (basename_dir, dirpath, tmp_mode, &newly_created_dir);
	  if (fail)
	    {
	      CLEANUP;
	      return 1;
	    }

	  if (newly_created_dir)
	    {
	      if (verbose_fmt_string)
		error (0, 0, verbose_fmt_string, quote (dirpath));

	      if ((owner != (uid_t) -1 || group != (gid_t) -1)
		  && chown (basename_dir, owner, group)
#if defined(AFS) && defined (EPERM)
		  && errno != EPERM
#endif
		  )
		{
		  error (0, errno, _("cannot change owner and/or group of %s"),
			 quote (dirpath));
		  CLEANUP;
		  return 1;
		}

	      if (re_protect)
		{
		  struct ptr_list *new = (struct ptr_list *)
		    alloca (sizeof (struct ptr_list));
		  new->dirname_end = slash;
		  new->next = leading_dirs;
		  leading_dirs = new;
		}
	    }

	  /* If we were able to save the initial working directory,
	     then we can use chdir to change into each directory before
	     creating an entry in that directory.  This avoids making
	     stat and mkdir process O(n^2) file name components.  */
	  if (do_chdir && chdir (basename_dir) < 0)
	    {
	      error (0, errno, _("cannot chdir to directory, %s"),
		     quote (dirpath));
	      CLEANUP;
	      return 1;
	    }

	  *slash++ = '/';

	  /* Avoid unnecessary calls to `stat' when given
	     pathnames containing multiple adjacent slashes.  */
	  while (*slash == '/')
	    slash++;
	}

      if (!do_chdir)
	basename_dir = dirpath;

      /* We're done making leading directories.
	 Create the final component of the path.  */

      if (make_dir (basename_dir, dirpath, mode, NULL))
	{
	  CLEANUP;
	  return 1;
	}

      /* Done creating directories.  Restore original umask.  */
      umask (oldmask);

      if (verbose_fmt_string != NULL)
	error (0, 0, verbose_fmt_string, quote (dirpath));

      if (owner != (uid_t) -1 || group != (gid_t) -1)
	{
	  if (chown (basename_dir, owner, group)
#ifdef AFS
	      && errno != EPERM
#endif
	      )
	    {
	      error (0, errno, _("cannot change owner and/or group of %s"),
		     quote (dirpath));
	      retval = 1;
	    }
	}

      /* The above chown may have turned off some permission bits in MODE.
	 Another reason we may have to use chmod here is that mkdir(2) is
	 required to honor only the file permission bits.  In particular,
	 it need not honor the `special' bits, so if MODE includes any
	 special bits, set them here.  */
      if ((mode & ~S_IRWXUGO)
	  && chmod (basename_dir, mode))
	{
	  error (0, errno, _("cannot change permissions of %s"), quote (dirpath));
	  retval = 1;
	}

      CLEANUP_CWD;

      /* If the mode for leading directories didn't include owner "wx"
	 privileges, we have to reset their protections to the correct
	 value.  */
      for (p = leading_dirs; p != NULL; p = p->next)
	{
	  *(p->dirname_end) = '\0';
	  if (chmod (dirpath, parent_mode))
	    {
	      error (0, errno, "cannot change permissions of %s",
		     quote (dirpath));
	      retval = 1;
	    }
	}
    }
  else
    {
      /* We get here if the entire path already exists.  */

      const char *dirpath = argpath;

      if (!S_ISDIR (stats.st_mode))
	{
	  error (0, 0, _("%s exists but is not a directory"), quote (dirpath));
	  return 1;
	}

      if (!preserve_existing)
	{
	  /* chown must precede chmod because on some systems,
	     chown clears the set[ug]id bits for non-superusers,
	     resulting in incorrect permissions.
	     On System V, users can give away files with chown and then not
	     be able to chmod them.  So don't give files away.  */

	  if ((owner != (uid_t) -1 || group != (gid_t) -1)
	      && chown (dirpath, owner, group)
#ifdef AFS
	      && errno != EPERM
#endif
	      )
	    {
	      error (0, errno, _("cannot change owner and/or group of %s"),
		     quote (dirpath));
	      retval = 1;
	    }
	  if (chmod (dirpath, mode))
	    {
	      error (0, errno, _("cannot change permissions of %s"),
				 quote (dirpath));
	      retval = 1;
	    }
	}
    }

  return retval;
}