summaryrefslogtreecommitdiff
path: root/source3/smbd/vfs.c
blob: 71ebf9b506b99c1b3ff84196e3de756f78d4d878 (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
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
/*
   Unix SMB/Netbios implementation.
   Version 3.0
   VFS initialisation and support functions
   Copyright (C) Tim Potter 1999

   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 of the License, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

extern int DEBUGLEVEL;

/* Some structures to help us initialise the vfs operations table */

struct vfs_syminfo {
	char *name;
	void *fptr;
};

/* Default vfs hooks.  WARNING: The order of these initialisers is
   very important.  They must be in the same order as defined in
   vfs.h.  Change at your own peril. */

struct vfs_ops default_vfs_ops = {

	/* Disk operations */

	vfswrap_dummy_connect,
	vfswrap_dummy_disconnect,
	vfswrap_disk_free,

	/* Directory operations */

	vfswrap_opendir,
	vfswrap_readdir,
	vfswrap_mkdir,
	vfswrap_rmdir,
	vfswrap_closedir,

	/* File operations */

	vfswrap_open,
	vfswrap_close,
	vfswrap_read,
	vfswrap_write,
	vfswrap_lseek,
	vfswrap_rename,
	vfswrap_fsync,
	vfswrap_stat,
	vfswrap_fstat,
	vfswrap_lstat,
	vfswrap_unlink,
	vfswrap_chmod,
	vfswrap_fchmod,
	vfswrap_chown,
	vfswrap_fchown,
	vfswrap_chdir,
	vfswrap_getwd,
	vfswrap_utime,
	vfswrap_ftruncate,
	vfswrap_lock,
	vfswrap_symlink,
	vfswrap_readlink,

	vfswrap_fget_nt_acl,
	vfswrap_get_nt_acl,
	vfswrap_fset_nt_acl,
	vfswrap_set_nt_acl,

#if defined(HAVE_NO_ACLS)
	NULL,
	NULL
#else
	vfswrap_chmod_acl,
	vfswrap_fchmod_acl
#endif
};

/****************************************************************************
  initialise default vfs hooks
****************************************************************************/

static BOOL vfs_init_default(connection_struct *conn)
{
    DEBUG(3, ("Initialising default vfs hooks\n"));

    memcpy(&conn->vfs_ops, &default_vfs_ops, sizeof(struct vfs_ops));
    return True;
}

/****************************************************************************
  initialise custom vfs hooks
****************************************************************************/

#ifdef HAVE_LIBDL
static BOOL vfs_init_custom(connection_struct *conn)
{
	int vfs_version = -1;
	struct vfs_ops *ops, *(*init_fptr)(int *, struct vfs_ops *);

	DEBUG(3, ("Initialising custom vfs hooks from %s\n",
		  lp_vfsobj(SNUM(conn))));

	/* Open object file */
	if ((conn->dl_handle = sys_dlopen(lp_vfsobj(SNUM(conn)), 
					  RTLD_NOW | RTLD_GLOBAL)) == NULL) {
		DEBUG(0, ("Error opening %s: %s\n", lp_vfsobj(SNUM(conn)), dlerror()));
		return False;
	}

	/* Get handle on vfs_init() symbol */
	init_fptr = (struct vfs_ops *(*)(int *, struct vfs_ops *))sys_dlsym(conn->dl_handle, "vfs_init");

	if (init_fptr == NULL) {
		DEBUG(0, ("No vfs_init() symbol found in %s\n",
			  lp_vfsobj(SNUM(conn))));
		return False;
	}

	/* Initialise vfs_ops structure */
	conn->vfs_ops = default_vfs_ops;

	if ((ops = init_fptr(&vfs_version, &conn->vfs_ops)) == NULL) {
		DEBUG(0, ("vfs_init function from %s failed\n", lp_vfsobj(SNUM(conn))));
		return False;
	}
	
	if (vfs_version != SMB_VFS_INTERFACE_VERSION) {
		DEBUG(0, ("vfs_init returned wrong interface version info (was %d, should be %d)\n",
			  vfs_version, SMB_VFS_INTERFACE_VERSION ));
		return False;
	}
	
	if (ops != &conn->vfs_ops) {
		memcpy(&conn->vfs_ops, ops, sizeof(struct vfs_ops));
	}

	return True;
}
#endif

/*****************************************************************
 Generic VFS init.
******************************************************************/

BOOL vfs_init(connection_struct *conn)
{
	if (*lp_vfsobj(SNUM(conn))) {
#ifdef HAVE_LIBDL
 
		/* Loadable object file */
 
		if (!vfs_init_custom(conn)) {
			DEBUG(0, ("vfs_init: vfs_init_custom failed\n"));
			return False;
		}

		return True;
#else
		DEBUG(0, ("vfs_init: No libdl present - cannot use VFS objects\n"));
		return False;
#endif
	}
 
	/* Normal share - initialise with disk access functions */
 
	return vfs_init_default(conn);
}

/*******************************************************************
 Check if directory exists.
********************************************************************/

BOOL vfs_directory_exist(connection_struct *conn, const char *dname, SMB_STRUCT_STAT *st)
{
	SMB_STRUCT_STAT st2;
	BOOL ret;

	if (!st)
		st = &st2;

	if (vfs_stat(conn,dname,st) != 0)
		return(False);

	ret = S_ISDIR(st->st_mode);
	if(!ret)
		errno = ENOTDIR;

	return ret;
}

/*******************************************************************
 vfs getwd wrapper 
********************************************************************/
char *vfs_getwd(connection_struct *conn, char *path)
{
	return conn->vfs_ops.getwd(conn,path);
}

/*******************************************************************
 vfs mkdir wrapper 
********************************************************************/

int vfs_mkdir(connection_struct *conn, const char *name, mode_t mode)
{
	int ret;
	SMB_STRUCT_STAT sbuf;

	if(!(ret=conn->vfs_ops.mkdir(conn,name,mode))) {
		/*
		 * Check if high bits should have been set,
		 * then (if bits are missing): add them.
		 * Consider bits automagically set by UNIX, i.e. SGID bit from parent dir.
		 */
		if(mode & ~(S_IRWXU|S_IRWXG|S_IRWXO) &&
				!vfs_stat(conn,name,&sbuf) && (mode & ~sbuf.st_mode))
			vfs_chmod(conn,name,sbuf.st_mode | (mode & ~sbuf.st_mode));
	}
	return ret;
}

/*******************************************************************
 Check if a vfs file exists.
********************************************************************/

BOOL vfs_file_exist(connection_struct *conn,const char *fname,SMB_STRUCT_STAT *sbuf)
{
	SMB_STRUCT_STAT st;

	if (!sbuf)
		sbuf = &st;

	ZERO_STRUCTP(sbuf);

	if (vfs_stat(conn,fname,sbuf) != 0)
		return(False);

	return(S_ISREG(sbuf->st_mode));
}

/****************************************************************************
 Read data from fsp on the vfs. (note: EINTR re-read differs from vfs_write_data)
****************************************************************************/

ssize_t vfs_read_data(files_struct *fsp, char *buf, size_t byte_count)
{
	size_t total=0;

	while (total < byte_count)
	{
		ssize_t ret = fsp->conn->vfs_ops.read(fsp, fsp->fd, buf + total,
											  byte_count - total);

		if (ret == 0) return total;
		if (ret == -1) {
			if (errno == EINTR)
				continue;
			else
				return -1;
		}
		total += ret;
	}
	return (ssize_t)total;
}

/****************************************************************************
 Write data to a fd on the vfs.
****************************************************************************/

ssize_t vfs_write_data(files_struct *fsp,const char *buffer,size_t N)
{
  size_t total=0;
  ssize_t ret;

  while (total < N)
  {
    ret = fsp->conn->vfs_ops.write(fsp,fsp->fd,buffer + total,N - total);

    if (ret == -1) return -1;
    if (ret == 0) return total;

    total += ret;
  }
  return (ssize_t)total;
}

/****************************************************************************
 A vfs set_filelen call.
 set the length of a file from a filedescriptor.
 Returns 0 on success, -1 on failure.
****************************************************************************/

int vfs_set_filelen(files_struct *fsp, SMB_OFF_T len)
{
	int ret;

	release_level_2_oplocks_on_change(fsp);
	if ((ret = fsp->conn->vfs_ops.ftruncate(fsp, fsp->fd, len)) != -1) {
		set_filelen_write_cache(fsp, len);
	}

	return ret;
}

/****************************************************************************
 Transfer some data between two file_struct's.
****************************************************************************/

SMB_OFF_T vfs_transfer_file(int in_fd, files_struct *in_fsp,
			    int out_fd, files_struct *out_fsp,
			    SMB_OFF_T n, char *header, int headlen, int align)
{
  static char *buf=NULL;
  static int size=0;
  char *buf1,*abuf;
  SMB_OFF_T total = 0;

  DEBUG(4,("vfs_transfer_file n=%.0f  (head=%d) called\n",(double)n,headlen));

  /* Check we have at least somewhere to read from */

  SMB_ASSERT((in_fd != -1) || (in_fsp != NULL));

  if (size == 0) {
    size = lp_readsize();
    size = MAX(size,1024);
  }

  while (!buf && size>0) {
    buf = (char *)Realloc(buf,size+8);
    if (!buf) size /= 2;
  }

  if (!buf) {
    DEBUG(0,("Can't allocate transfer buffer!\n"));
    exit(1);
  }

  abuf = buf + (align%8);

  if (header)
    n += headlen;

  while (n > 0)
  {
    int s = (int)MIN(n,(SMB_OFF_T)size);
    int ret,ret2=0;

    ret = 0;

    if (header && (headlen >= MIN(s,1024))) {
      buf1 = header;
      s = headlen;
      ret = headlen;
      headlen = 0;
      header = NULL;
    } else {
      buf1 = abuf;
    }

    if (header && headlen > 0)
    {
      ret = MIN(headlen,size);
      memcpy(buf1,header,ret);
      headlen -= ret;
      header += ret;
      if (headlen <= 0) header = NULL;
    }

    if (s > ret) {
      ret += in_fsp ?
	  in_fsp->conn->vfs_ops.read(in_fsp,in_fsp->fd,buf1+ret,s-ret) : read(in_fd,buf1+ret,s-ret);
    }

    if (ret > 0) {
		if (out_fsp)
		    ret2 = out_fsp->conn->vfs_ops.write(out_fsp,out_fsp->fd,buf1,ret);
		else
		    ret2= (out_fd != -1) ? write_data(out_fd,buf1,ret) : ret;
    }

      if (ret2 > 0) total += ret2;
      /* if we can't write then dump excess data */
      if (ret2 != ret)
        vfs_transfer_file(in_fd, in_fsp, -1,NULL,n-(ret+headlen),NULL,0,0);

    if (ret <= 0 || ret2 != ret)
      return(total);
    n -= ret;
  }
  return(total);
}

/*******************************************************************
 A vfs_readdir wrapper which just returns the file name.
********************************************************************/

char *vfs_readdirname(connection_struct *conn, void *p)
{
	struct dirent *ptr;
	char *dname;

	if (!p)
		return(NULL);

	ptr = (struct dirent *)conn->vfs_ops.readdir(conn,p);
	if (!ptr)
		return(NULL);

	dname = ptr->d_name;

#ifdef NEXT2
	if (telldir(p) < 0)
		return(NULL);
#endif

#ifdef HAVE_BROKEN_READDIR
	/* using /usr/ucb/cc is BAD */
	dname = dname - 2;
#endif

	return(dname);
}

/* VFS options not quite working yet */

#if 0

/***************************************************************************
  handle the interpretation of the vfs option parameter
 *************************************************************************/
static BOOL handle_vfs_option(char *pszParmValue, char **ptr)
{
    struct vfs_options *new_option, **options = (struct vfs_options **)ptr;
    int i;

    /* Create new vfs option */

    new_option = (struct vfs_options *)malloc(sizeof(*new_option));
    if (new_option == NULL) {
	return False;
    }

    ZERO_STRUCTP(new_option);

    /* Get name and value */

    new_option->name = strtok(pszParmValue, "=");

    if (new_option->name == NULL) {
	return False;
    }

    while(isspace(*new_option->name)) {
	new_option->name++;
    }

    for (i = strlen(new_option->name); i > 0; i--) {
	if (!isspace(new_option->name[i - 1])) break;
    }

    new_option->name[i] = '\0';
    new_option->name = strdup(new_option->name);

    new_option->value = strtok(NULL, "=");

    if (new_option->value != NULL) {

	while(isspace(*new_option->value)) {
	    new_option->value++;
	}
	
	for (i = strlen(new_option->value); i > 0; i--) {
	    if (!isspace(new_option->value[i - 1])) break;
	}
	
	new_option->value[i] = '\0';
	new_option->value = strdup(new_option->value);
    }

    /* Add to list */

    DLIST_ADD(*options, new_option);

    return True;
}

#endif


/*******************************************************************
 A wrapper for vfs_chdir().
********************************************************************/

int vfs_ChDir(connection_struct *conn, char *path)
{
	int res;
	static pstring LastDir="";

	if (strcsequal(path,"."))
		return(0);

	if (*path == '/' && strcsequal(LastDir,path))
		return(0);

	DEBUG(3,("vfs_ChDir to %s\n",path));

	res = vfs_chdir(conn,path);
	if (!res)
		pstrcpy(LastDir,path);
	return(res);
}

/* number of list structures for a caching GetWd function. */
#define MAX_GETWDCACHE (50)

struct
{
  SMB_DEV_T dev; /* These *must* be compatible with the types returned in a stat() call. */
  SMB_INO_T inode; /* These *must* be compatible with the types returned in a stat() call. */
  char *dos_path; /* The pathname in DOS format. */
  BOOL valid;
} ino_list[MAX_GETWDCACHE];

extern BOOL use_getwd_cache;

/****************************************************************************
 Prompte a ptr (to make it recently used)
****************************************************************************/

static void array_promote(char *array,int elsize,int element)
{
	char *p;
	if (element == 0)
		return;

	p = (char *)malloc(elsize);

	if (!p) {
		DEBUG(5,("array_promote: malloc fail\n"));
		return;
	}

	memcpy(p,array + element * elsize, elsize);
	memmove(array + elsize,array,elsize*element);
	memcpy(array,p,elsize);
	free(p);
}

/*******************************************************************
 Return the absolute current directory path - given a UNIX pathname.
 Note that this path is returned in DOS format, not UNIX
 format. Note this can be called with conn == NULL.
********************************************************************/

char *vfs_GetWd(connection_struct *conn, char *path)
{
  pstring s;
  static BOOL getwd_cache_init = False;
  SMB_STRUCT_STAT st, st2;
  int i;

  *s = 0;

  if (!use_getwd_cache)
    return(vfs_getwd(conn,path));

  /* init the cache */
  if (!getwd_cache_init)
  {
    getwd_cache_init = True;
    for (i=0;i<MAX_GETWDCACHE;i++)
    {
      string_set(&ino_list[i].dos_path,"");
      ino_list[i].valid = False;
    }
  }

  /*  Get the inode of the current directory, if this doesn't work we're
      in trouble :-) */

  if (vfs_stat(conn, ".",&st) == -1)
  {
    DEBUG(0,("Very strange, couldn't stat \".\" path=%s\n", path));
    return(vfs_getwd(conn,path));
  }


  for (i=0; i<MAX_GETWDCACHE; i++)
    if (ino_list[i].valid)
    {

      /*  If we have found an entry with a matching inode and dev number
          then find the inode number for the directory in the cached string.
          If this agrees with that returned by the stat for the current
          directory then all is o.k. (but make sure it is a directory all
          the same...) */

      if (st.st_ino == ino_list[i].inode &&
          st.st_dev == ino_list[i].dev)
      {
        if (vfs_stat(conn,ino_list[i].dos_path,&st2) == 0)
        {
          if (st.st_ino == st2.st_ino &&
              st.st_dev == st2.st_dev &&
              (st2.st_mode & S_IFMT) == S_IFDIR)
          {
            pstrcpy (path, ino_list[i].dos_path);

            /* promote it for future use */
            array_promote((char *)&ino_list[0],sizeof(ino_list[0]),i);
            return (path);
          }
          else
          {
            /*  If the inode is different then something's changed,
                scrub the entry and start from scratch. */
            ino_list[i].valid = False;
          }
        }
      }
    }


  /*  We don't have the information to hand so rely on traditional methods.
      The very slow getcwd, which spawns a process on some systems, or the
      not quite so bad getwd. */

  if (!vfs_getwd(conn,s))
  {
    DEBUG(0,("vfs_GetWd: vfs_getwd call failed, errno %s\n",strerror(errno)));
    return (NULL);
  }

  pstrcpy(path,s);

  DEBUG(5,("vfs_GetWd %s, inode %.0f, dev %.0f\n",s,(double)st.st_ino,(double)st.st_dev));

  /* add it to the cache */
  i = MAX_GETWDCACHE - 1;
  string_set(&ino_list[i].dos_path,s);
  ino_list[i].dev = st.st_dev;
  ino_list[i].inode = st.st_ino;
  ino_list[i].valid = True;

  /* put it at the top of the list */
  array_promote((char *)&ino_list[0],sizeof(ino_list[0]),i);

  return (path);
}

/*******************************************************************
 Reduce a file name, removing .. elements and checking that
 it is below dir in the heirachy. This uses vfs_GetWd() and so must be run
 on the system that has the referenced file system.
 Widelinks are allowed if widelinks is true.
********************************************************************/

BOOL reduce_name(connection_struct *conn, char *s,char *dir,BOOL widelinks)
{
#ifndef REDUCE_PATHS
  return True;
#else
  pstring dir2;
  pstring wd;
  pstring base_name;
  pstring newname;
  char *p=NULL;
  BOOL relative = (*s != '/');

  *dir2 = *wd = *base_name = *newname = 0;

  if (widelinks)
  {
    unix_clean_name(s);
    /* can't have a leading .. */
    if (strncmp(s,"..",2) == 0 && (s[2]==0 || s[2]=='/'))
    {
      DEBUG(3,("Illegal file name? (%s)\n",s));
      return(False);
    }

    if (strlen(s) == 0)
      pstrcpy(s,"./");

    return(True);
  }

  DEBUG(3,("reduce_name [%s] [%s]\n",s,dir));

  /* remove any double slashes */
  all_string_sub(s,"//","/",0);

  pstrcpy(base_name,s);
  p = strrchr_m(base_name,'/');

  if (!p)
    return(True);

  if (!vfs_GetWd(conn,wd))
  {
    DEBUG(0,("couldn't vfs_GetWd for %s %s\n",s,dir));
    return(False);
  }

  if (vfs_ChDir(conn,dir) != 0)
  {
    DEBUG(0,("couldn't vfs_ChDir to %s\n",dir));
    return(False);
  }

  if (!vfs_GetWd(conn,dir2))
  {
    DEBUG(0,("couldn't vfs_GetWd for %s\n",dir));
    vfs_ChDir(conn,wd);
    return(False);
  }

  if (p && (p != base_name))
  {
    *p = 0;
    if (strcmp(p+1,".")==0)
      p[1]=0;
    if (strcmp(p+1,"..")==0)
      *p = '/';
  }

  if (vfs_ChDir(conn,base_name) != 0)
  {
    vfs_ChDir(conn,wd);
    DEBUG(3,("couldn't vfs_ChDir for %s %s basename=%s\n",s,dir,base_name));
    return(False);
  }

  if (!vfs_GetWd(conn,newname))
  {
    vfs_ChDir(conn,wd);
    DEBUG(2,("couldn't get vfs_GetWd for %s %s\n",s,dir2));
    return(False);
  }

  if (p && (p != base_name))
  {
    pstrcat(newname,"/");
    pstrcat(newname,p+1);
  }

  {
    size_t l = strlen(dir2);
    if (dir2[l-1] == '/')
      l--;

    if (strncmp(newname,dir2,l) != 0)
    {
      vfs_ChDir(conn,wd);
      DEBUG(2,("Bad access attempt? s=%s dir=%s newname=%s l=%d\n",s,dir2,newname,(int)l));
      return(False);
    }

    if (relative)
    {
      if (newname[l] == '/')
        pstrcpy(s,newname + l + 1);
      else
        pstrcpy(s,newname+l);
    }
    else
      pstrcpy(s,newname);
  }

  vfs_ChDir(conn,wd);

  if (strlen(s) == 0)
    pstrcpy(s,"./");

  DEBUG(3,("reduced to %s\n",s));
  return(True);
#endif
}