aboutsummaryrefslogtreecommitdiffstats
path: root/trunk/src/wrap-file.c
blob: db2290f39d658fca5c74225035cd31d65dce4464 (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
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
/* Copyright (C) 2003 MontaVista Software, Inc.
   Written by Daniel Jacobowitz <drow@mvista.com>, 2003.

   The chroot_canon function is copied from the GNU C Library,
   elf/chroot-canon.c, also licensed under the GPL:
   Copyright (C) 1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc.
   [and then further modified.]

   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.  */

#include <config.h>
#include <assert.h>
#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <ftw.h>
#include <stdarg.h>
#include <stddef.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include <utime.h>
#include "prelink.h"

#ifndef PATH_MAX
#define PATH_MAX 1024
#endif

#ifndef MAXSYMLINKS
#define MAXSYMLINKS 20
#endif

/* Return the canonical absolute name of file NAME as if chroot(CHROOT) was
   done first.  A canonical name does not contain any `.', `..' components
   nor any repeated path separators ('/') or symlinks.  All path components
   must exist and NAME must be absolute filename.  The result is malloc'd.
   The returned name includes the CHROOT prefix.

   If ALLOW_LAST_LINK, then symlinks in the last component won't be
   resolved.  */

static char *
chroot_canon_filename (const char * chroot, const char *name, int allow_last_link, struct stat64 *stp)
{
  char *rpath, *dest, *extra_buf = NULL;
  char *rpath_root;
  const char *start, *end, *rpath_limit;
  long int path_max;
  int num_links = 0;
  int stp_initialized = 0;
  size_t chroot_len = 0;

  if (name == NULL)
    {
      errno = EINVAL;
      return NULL;
    }

  if (name[0] == '\0')
    {
      errno = ENOENT;
      return NULL;
    }

  if (chroot == NULL)
    {
      errno = EINVAL;
      return NULL;
    }

  chroot_len = strlen (chroot);

#ifdef PATH_MAX
  path_max = PATH_MAX;
#else
  path_max = pathconf (name, _PC_PATH_MAX);
  if (path_max <= 0)
    path_max = 1024;
#endif

  rpath = malloc (chroot_len + path_max);
  if (rpath == NULL)
    return NULL;
  rpath_limit = rpath + chroot_len + path_max;

  rpath_root = (char *) mempcpy (rpath, chroot, chroot_len) - 1;
  if (*rpath_root != '/')
    *++rpath_root = '/';
  dest = rpath_root + 1;

  for (start = end = name; *start; start = end)
    {
      int n;

      /* Skip sequence of multiple path-separators.  */
      while (*start == '/')
	++start;

      /* Find end of path component.  */
      for (end = start; *end && *end != '/'; ++end)
	/* Nothing.  */;

      if (end - start == 0)
	break;
      else if (end - start == 1 && start[0] == '.')
	/* nothing */;
      else if (end - start == 2 && start[0] == '.' && start[1] == '.')
	{
	  /* Back up to previous component, ignore if at root already.  */
	  if (dest > rpath_root + 1)
	    while ((--dest)[-1] != '/');
	  stp_initialized = 0;
	}
      else
	{
	  size_t new_size;

	  if (dest[-1] != '/')
	    *dest++ = '/';

	  if (dest + (end - start) >= rpath_limit)
	    {
	      ptrdiff_t dest_offset = dest - rpath;
	      char *new_rpath;

	      new_size = rpath_limit - rpath;
	      if (end - start + 1 > path_max)
		new_size += end - start + 1;
	      else
		new_size += path_max;
	      new_rpath = (char *) realloc (rpath, new_size);
	      if (new_rpath == NULL)
		goto error;
	      rpath = new_rpath;
	      rpath_limit = rpath + new_size;

	      dest = rpath + dest_offset;
	    }

	  dest = mempcpy (dest, start, end - start);
	  *dest = '\0';

	  if (lstat64 (rpath, stp) < 0)
	    goto error;

	  stp_initialized = 1;

          if (allow_last_link && *end == '\0')
            goto done;

	  if (S_ISLNK (stp->st_mode))
	    {
	      char *buf = alloca (path_max);
	      size_t len;

	      if (++num_links > MAXSYMLINKS)
		{
		  errno = ELOOP;
		  goto error;
		}

	      n = readlink (rpath, buf, path_max);
	      if (n < 0)
		goto error;
	      buf[n] = '\0';

	      if (!extra_buf)
		extra_buf = alloca (path_max);

	      len = strlen (end);
	      if ((long int) (n + len) >= path_max)
		{
		  errno = ENAMETOOLONG;
		  goto error;
		}

	      /* Careful here, end may be a pointer into extra_buf... */
	      memmove (&extra_buf[n], end, len + 1);
	      name = end = memcpy (extra_buf, buf, n);

	      if (buf[0] == '/')
		dest = rpath_root + 1;	/* It's an absolute symlink */
	      else
		/* Back up to previous component, ignore if at root already: */
		if (dest > rpath_root + 1)
		  while ((--dest)[-1] != '/');
	    }
	  else if (!S_ISDIR (stp->st_mode) && *end != '\0')
	    {
	      errno = ENOTDIR;
	      goto error;
	    }
	}
    }
done:
  if (dest > rpath_root + 1 && dest[-1] == '/')
    --dest;
  *dest = '\0';

  if (!stp_initialized && lstat64 (rpath, stp) < 0)
    goto error;

  if (dest + 1 - rpath <= (rpath_limit - rpath) / 2)
    {
      char *new_rpath = realloc (rpath, dest + 1 - rpath);

      if (new_rpath != NULL)
	return new_rpath;
    }
  return rpath;

error:
  free (rpath);
  return NULL;
}


const char *sysroot;

char *
sysroot_file_name (const char *name, int allow_last_link, struct stat64 *stp)
{
  char *ret;
  struct stat64 st;

  if (sysroot == NULL || name == NULL)
    return (char *) name;

  if (name[0] != '/')
    {
      char *tmpname = malloc (strlen (name) + 2);
      strcpy (tmpname, "/");
      strcat (tmpname, name);
      ret = chroot_canon_filename (sysroot, tmpname, allow_last_link, stp ? stp : &st);
      free (tmpname);
    }
  else
    ret = chroot_canon_filename (sysroot, name, allow_last_link, stp ? stp : &st);

  if (ret == NULL)
  {
    char *ret_root;

    ret = malloc(strlen(sysroot) + strlen(name) + 1);
    ret_root = mempcpy(ret, sysroot, strlen(sysroot));
    ret_root = mempcpy(ret_root, name, strlen(name));
    *ret_root='\0';
  }
  return ret;
}

static char *
unsysroot_file_name (const char *name)
{
  if (name == NULL)
    return (char *)name;

  if (sysroot)
    {
      int sysroot_len = strlen (sysroot);
      if (strncmp (name, sysroot, sysroot_len) == 0)
	{
	  if (name[sysroot_len] == '/')
	    return strdup (name + sysroot_len);
	  else if (name[sysroot_len] == 0)
	    return strdup ("/");
	}
    }
  return (char *)name;
}

char *
wrap_prelink_canonicalize (const char *name, struct stat64 *stp)
{
  if (sysroot)
    {
      struct stat64 st;
      char *tmpname;
      char *ret;

      /* Use chroot_canon_filename because we want a NULL return if it doesn't exist! */
      tmpname = chroot_canon_filename (sysroot, name, 0, stp ? stp : &st);

      if (tmpname == NULL)
        return NULL;

      ret = unsysroot_file_name (tmpname);

      if (ret == tmpname)
       ret = strdup (ret);

      if (tmpname != name)
       free (tmpname);

      return ret;
    }
  else
    return prelink_canonicalize(name, stp);
}

static int
wrap_stat_body (const char *file, struct stat64 *buf, int lstat)
{
  char* file_copy;
  char *tmpname;
  int ret;
  int len;

  tmpname = sysroot_file_name (file, lstat, NULL);

  if (tmpname == NULL)
    return -1;

  file_copy = strdup (tmpname);

  if (tmpname != file)
    free (tmpname);

  if (file_copy == NULL)
    return -1;

  len = strlen (file_copy);
  if (len && (file_copy[len - 1] == '/' || file_copy[len - 1] == '\\'))
    file_copy[len - 1] = '\0';

  ret = lstat ? lstat64 (file_copy, buf) : stat64 (file_copy, buf);

  free (file_copy);

  return ret;
}

int
wrap_lstat64 (const char *file, struct stat64 *buf)
{
  return wrap_stat_body (file, buf, 1);
}

int
wrap_stat64 (const char *file, struct stat64 *buf)
{
  return wrap_stat_body (file, buf, 0);
}

int
wrap_rename (const char *old, const char *new)
{
  char *tmpold = sysroot_file_name (old, 1, NULL);
  char *tmpnew;
  int ret;

  if (tmpold == NULL)
    return -1;

  tmpnew = sysroot_file_name (new, 1, NULL);
  if (tmpnew == NULL)
    return -1;

  ret = rename (tmpold, tmpnew);

  if (tmpold != old)
    free (tmpold);
  if (tmpnew != new)
    free (tmpnew);
  return ret;
}

int
wrap_open (const char *name, int mode, ...)
{
  char *tmpname = sysroot_file_name (name, 0, NULL);
  int ret;

  if (tmpname == NULL)
    return -1;

  if (mode & O_CREAT)
    {
      va_list va;
      int flags;
      va_start (va, mode);
      flags = va_arg (va, int);
      va_end (va);
      ret = open (tmpname, mode, flags);
    }
  else
    ret = open (tmpname, mode);

  if (tmpname != name)
    free (tmpname);
  return ret;
}

int
wrap_access (const char *name, int mode)
{
  char *tmpname = sysroot_file_name (name, 0, NULL);
  int ret;

  if (tmpname == NULL)
    return -1;

  ret = access (tmpname, mode);

  if (tmpname != name)
    free (tmpname);
  return ret;
}

int
wrap_link (const char *old, const char *new)
{
  char *tmpold = sysroot_file_name (old, 1, NULL);
  char *tmpnew;
  int ret;

  if (tmpold == NULL)
    return -1;

  tmpnew = sysroot_file_name (new, 1, NULL);
  if (tmpnew == NULL)
    return -1;

  ret = link (tmpold, tmpnew);

  if (tmpold != old)
    free (tmpold);
  if (tmpnew != new)
    free (tmpnew);
  return ret;
}

/* Note that this isn't recursive safe, since nftw64 doesn't
   pass an opaque object around to use.  But that fits our needs
   for now.  */

static __nftw64_func_t nftw64_cur_func;

static int
wrap_nftw64_func (const char *filename, const struct stat64 *status,
		  int flag, struct FTW *info)
{
  char *tmpname = unsysroot_file_name (filename);
  int ret = nftw64_cur_func (tmpname, status, flag, info);

  if (tmpname != filename)
    free (tmpname);
  return ret;
}

int
wrap_nftw64 (const char *dir, __nftw64_func_t func,
	     int descriptors, int flag)
{
  char *tmpdir = sysroot_file_name (dir, 1, NULL);
  int ret;

  if (tmpdir == NULL)
    return -1;

  nftw64_cur_func = func;
  ret = nftw64 (tmpdir, wrap_nftw64_func, descriptors, flag);

  if (tmpdir != dir)
    free (tmpdir);
  return ret;
}

int
wrap_utime (const char *file, struct utimbuf *file_times)
{
  char *tmpname = sysroot_file_name (file, 0, NULL);
  int ret;

  if (tmpname == NULL)
    return -1;

  ret = utime (tmpname, file_times);

  if (tmpname != file)
    free (tmpname);
  return ret;
}

int
wrap_mkstemp (char *filename)
{
  char *tmpname = sysroot_file_name (filename, 1, NULL);
  int ret;

  if (tmpname == NULL)
    return -1;

  ret = mkstemp (tmpname);

  if (tmpname != filename)
    {
      strcpy (filename, tmpname + strlen (sysroot));
      free (tmpname);
    }
  return ret;
}

int
wrap_unlink (const char *filename)
{
  char *tmpname = sysroot_file_name (filename, 1, NULL);
  int ret;

  if (tmpname == NULL)
    return -1;

  ret = unlink (tmpname);

  if (tmpname != filename)
    free (tmpname);
  return ret;
}

int
wrap_readlink (const char *path, char *buf, int len)
{
  char *tmpname = sysroot_file_name (path, 1, NULL);
  int ret;

  if (tmpname == NULL)
    return -1;

  ret = readlink (tmpname, buf, len);

  if (tmpname != path)
    free (tmpname);
  return ret;
}