summaryrefslogtreecommitdiff
path: root/examples/VFS/block/block.c
blob: 6566bf3d8cff4db4ac6e268bfc85f8e01b32e781 (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
/* 
 * 
 * Block access from links to dev mount points specified in PARAMCONF file
 *
 * Copyright (C) Ronald Kuetemeier, 2001
 * Copyright (C) Alexander Bokovoy, 2002
 *
 * 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 "config.h"
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>


#ifdef HAVE_UTIME_H
#include <utime.h>
#endif
#ifdef HAVE_DIRENT_H
#include <dirent.h>
#endif
#include <syslog.h>
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif


#include <includes.h>
#include <vfs.h>



static DIR *block_opendir(connection_struct *conn, char *fname);
static int block_connect(connection_struct *conn, const char *service, const char *user);    
static void block_disconnect(connection_struct *conn);    

static struct smb_vfs_handle_struct *block_handle;

/* VFS operations */


static struct vfs_ops default_vfs_ops;   /* For passthrough operation */

static vfs_op_tuple block_vfs_ops[] = {
    
	/* Disk operations */

	{block_connect,		SMB_VFS_OP_CONNECT,	SMB_VFS_LAYER_TRANSPARENT},
	{block_disconnect,	SMB_VFS_OP_DISCONNECT,	SMB_VFS_LAYER_TRANSPARENT},

	/* Directory operations */

	{block_opendir,		SMB_VFS_OP_OPENDIR,	SMB_VFS_LAYER_TRANSPARENT},
	
	{NULL,			SMB_VFS_OP_NOOP,	SMB_VFS_LAYER_NOOP}
};


#ifndef PARAMCONF
#define PARAMCONF "/etc/samba-block.conf"
#endif

extern BOOL pm_process(char *FileName, BOOL (*sfunc)(char *), BOOL(*pfunc)(char * , char *));

//functions

static BOOL enter_pblock_mount(char *dir);
static BOOL get_section(char *sect);
static BOOL get_parameter_value(char *param, char *value);
static BOOL load_param(void);
static BOOL search(struct stat *stat_buf);
static BOOL dir_search(char *linkstr, char *dir);
static BOOL enter_pblock_dir(char *dir);



typedef struct block_dir
{
	dev_t st_dev;
	int str_len;	
	char *dir_name;
	struct block_dir *next;
} block_dir;


static char *params[] = {"mount_point","dir_name"};
enum                    { MOUNT_POINT , DIR_NAME };

static struct block_dir *pblock_mountp = NULL;
static struct block_dir *pblock_dir = NULL;



/*
 * Load the conf file into a table
 */

static BOOL load_param(void)
{

	if ((pm_process(PARAMCONF,&get_section,&get_parameter_value)) == TRUE)
	{
		return TRUE;
		
	}
	return FALSE;	
}



/*
 * Enter the key and data into the list
 * 
 */

static BOOL enter_pblock_mount(char *dir)
{
	struct stat stat_buf;
	static struct block_dir *tmp_pblock;
	

	if((stat(dir,&stat_buf)) != 0)
	{
		return FALSE;
	}
	
	if(pblock_mountp == NULL)
	{
		pblock_mountp = calloc(1, sizeof(block_dir));
		if( pblock_mountp == NULL)
		{
			return FALSE;
		}
		tmp_pblock = pblock_mountp;
		tmp_pblock->next = NULL;
		
	}else
	{
		tmp_pblock->next = calloc(1, sizeof(block_dir));
		if(tmp_pblock->next == NULL)
		{
			return FALSE;
		}
		tmp_pblock = tmp_pblock->next;
		tmp_pblock->next = NULL;
		
	}
	

	tmp_pblock->st_dev = stat_buf.st_dev;
	tmp_pblock->dir_name = strdup(dir);
	

      return TRUE;
		
}


/*
 * Enter the key and data into the list
 * 
 */

static BOOL enter_pblock_dir(char *dir)
{
	static struct block_dir *tmp_pblock;
	

	if(pblock_dir == NULL)
	{
		pblock_dir = calloc(1, sizeof(block_dir));
		if( pblock_dir == NULL)
		{
			return FALSE;
		}
		tmp_pblock = pblock_dir;
		tmp_pblock->next = NULL;
		
	}else
	{
		tmp_pblock->next = calloc(1, sizeof(block_dir));
		if(tmp_pblock->next == NULL)
		{
			return FALSE;
		}
		tmp_pblock = tmp_pblock->next;
		tmp_pblock->next = NULL;
		
	}
	

	tmp_pblock->dir_name = strdup(dir);
	tmp_pblock->str_len = strlen(dir);
	

      return TRUE;
		
}




/*
 * Function callback for config section names 
 */

static BOOL get_section(char *sect)
{
	return TRUE;	
}



/* 
 * Function callback for config parameter value pairs
 *
 */

static BOOL get_parameter_value(char *param, char *value)
{
	int i = 0, maxargs = sizeof(params) / sizeof(char *);

	
	for( i= 0; i < maxargs; i++)
	{
		if (strcmp(param,params[i]) == 0)
		{
			switch(i)
			{
			case MOUNT_POINT :				
				enter_pblock_mount(value);				
				break;
			case DIR_NAME :				
				enter_pblock_dir(value);				
				break;
			default :
				break;
			}
		}
	}
       				
	return TRUE;
	
}




/* VFS initialisation function.  Return initialised vfs_op_tuple array
   back to SAMBA. */

vfs_op_tuple *vfs_init(int *vfs_version, struct vfs_ops *def_vfs_ops,
			struct smb_vfs_handle_struct *vfs_handle)
{
	*vfs_version = SMB_VFS_INTERFACE_VERSION;
	
	memcpy(&default_vfs_ops, def_vfs_ops, sizeof(struct vfs_ops));
	
	block_handle = vfs_handle;

	return block_vfs_ops;
}


/* VFS finalization function. */
void vfs_done(connection_struct *conn)
{
}


/*
 * VFS connect and param file loading
 */

static int block_connect(connection_struct *conn, const char *service, const char *user)
{
	if((load_param()) == FALSE)
	{

		return -1;
		
	}	

        DEBUG(0,("%s connecting \n",conn->user));
	
	return (default_vfs_ops.connect(conn, service,user));
}

/*
 * Free allocated structures and disconnect
 *
 */


static void block_disconnect(struct connection_struct *conn)
{
	
	struct block_dir *tmp_pblock = (pblock_mountp == NULL ? pblock_dir : pblock_mountp);
	struct block_dir *free_pblock = NULL;

	while(tmp_pblock != NULL)
	{
		free(tmp_pblock->dir_name);		
		free_pblock = tmp_pblock;		
		tmp_pblock = tmp_pblock->next;
		free(free_pblock);	

		if(tmp_pblock == NULL && pblock_dir != NULL)
		{
			tmp_pblock = (pblock_mountp == NULL ? pblock_dir : NULL);
			pblock_dir = NULL;
			
		}
		
	}
		
	

	default_vfs_ops.disconnect(conn);
}

/*
 * VFS opendir
 */

static DIR *block_opendir(struct connection_struct *conn, char *fname)
{

	char *dir_name = NULL; 
	struct stat stat_buf;
	size_t len;

	len = strlen(conn->origpath) + 1 + strcspn(fname, "/");
	asprintf(&dir_name, "%s/%s", conn->origpath, fname);
	dir_name[len] = '\0';

	if((lstat(dir_name,&stat_buf)) == 0)
	{
		if((S_ISLNK(stat_buf.st_mode)) == 1)
		{
			stat(dir_name,&stat_buf);			
			if((search(&stat_buf) || dir_search(dir_name, fname) ) == TRUE)			
			{			
				DEBUG(0,("%s used link to blocked dir: %s \n", conn->user, dir_name));				
				errno = EACCES;				
				return NULL;
			}
		}
	} 
		
	return (default_vfs_ops.opendir(conn, fname));	
}


/*
 * Find mount point to block in list
 */

static BOOL search(struct stat *stat_buf)
{
	struct block_dir *tmp_pblock = pblock_mountp;

	while(tmp_pblock != NULL)
	{

		if(tmp_pblock->st_dev == stat_buf->st_dev)
		{
			return TRUE;
		}
		tmp_pblock = tmp_pblock->next;
	}
		
	return FALSE;	
	
}

/*
 * Find dir in list to block id the starting point is link from a share
 */

static BOOL dir_search(char *linkstr, char *dir)
{
	char buf[PATH_MAX +1], *ext_path;
	int len = 0;
	struct block_dir *tmp_pblock = pblock_dir;
	
	if((len = readlink(linkstr, buf, sizeof(buf))) == -1)
	{
		return TRUE;

	}else
	{
		buf[len] = '\0';
	}
	
	
        if((ext_path = strchr(dir, '/')) != NULL)
	{
		pstrcat(buf, &ext_path[1]);
		len = strlen(buf);		
	}
	
	while(tmp_pblock != NULL)
	{
		if(len < tmp_pblock->str_len)
		{
			tmp_pblock = tmp_pblock->next;
			continue;
		}
		
		if((strstr(buf, tmp_pblock->dir_name)) != NULL)
		{
			return TRUE;
		}
		tmp_pblock = tmp_pblock->next;
	}


	return FALSE;
	
}