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
|
/****************************************************************************
* fs/nxffs/nxffs_inode.c
*
* Copyright (C) 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* References: Linux/Documentation/filesystems/romfs.txt
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <crc32.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/mtd.h>
#include "nxffs.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Public Types
****************************************************************************/
/****************************************************************************
* Public Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: nxffs_rdentry
*
* Description:
* Read the inode entry at this offset. Called only from nxffs_nextentry().
*
* Input Parameters:
* volume - Describes the current volume.
* offset - The byte offset from the beginning of FLASH where the inode
* header is expected.
* entry - A memory location to return the expanded inode header
* information.
*
* Returned Value:
* Zero on success. Otherwise, a negater errno value is returned
* indicating the nature of the failure.
*
****************************************************************************/
static int nxffs_rdentry(FAR struct nxffs_volume_s *volume, off_t offset,
FAR struct nxffs_entry_s *entry)
{
struct nxffs_inode_s inode;
uint32_t ecrc;
uint32_t crc;
int namelen;
int ret;
DEBUGASSERT(volume && entry);
memset(entry, 0, sizeof(struct nxffs_entry_s));
/* Read the header at the FLASH offset */
nxffs_ioseek(volume, offset);
ret = nxffs_rddata(volume, (FAR uint8_t *)&inode, SIZEOF_NXFFS_INODE_HDR);
if (ret < 0)
{
fdbg("Failed to read inode, offset %d: %d\n", offset, -ret);
return -EIO;
}
/* Check if the file is marked as deleted. */
if (inode.state != INODE_STATE_FILE)
{
return -ENOENT;
}
/* Copy the packed header into the user-friendly buffer */
entry->hoffset = offset;
entry->doffset = offset + inode.doffset;
entry->utc = nxffs_rdle32(inode.utc);
entry->datlen = nxffs_rdle32(inode.datlen);
/* Modify the packed header and perform the (partial) CRC calculation */
ecrc = nxffs_rdle32(inode.crc);
inode.state = CONFIG_NXFFS_ERASEDSTATE;
memset(inode.crc, 0, 4);
crc = crc32((FAR const uint8_t *)&inode, SIZEOF_NXFFS_INODE_HDR);
/* Allocate memory to hold the variable-length file name */
namelen = (int)inode.doffset - (int)inode.noffset;
if (namelen < 0)
{
fdbg("Bad offsets, name: %d data: %d\n", inode.noffset, inode.doffset);
return -EIO;
}
entry->name = (FAR char *)kmalloc(namelen+1);
if (!entry->name)
{
fdbg("Failed to allocate name, namelen: %d\n", namelen);
return -ENOMEM;
}
/* Read the file name from the expected offset in FLASH */
nxffs_ioseek(volume, offset + inode.noffset);
ret = nxffs_rddata(volume, (FAR uint8_t*)entry->name, namelen);
if (ret < 0)
{
fdbg("Failed to read inode, offset %d: %d\n", offset, -ret);
return -EIO;
}
entry->name[namelen] = '\0';
/* Finish the CRC calculation and verify the entry */
crc = crc32part(entry->name, namelen, crc);
if (crc != ecrc)
{
fdbg("CRC entry: %08x CRC calculated: %08x\n", ecrc, crc);
nxffs_freeentry(entry);
return -EIO;
}
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxffs_freeentry
*
* Description:
* The inode values returned by nxffs_nextentry() include allocated memory
* (specifically, the file name string). This function should be called
* to dispose of that memory when the inode entry is no longer needed.
*
* Note that the nxffs_entry_s containing structure is not freed. The
* caller may call kfree upon return of this function if necessary to
* free the entry container.
*
* Input parameters:
* entry - The entry to be freed.
*
* Returned Value:
* None
*
****************************************************************************/
void nxffs_freeentry(FAR struct nxffs_entry_s *entry)
{
if (entry->name)
{
kfree(entry->name);
entry->name = NULL;
}
}
/****************************************************************************
* Name: nxffs_nextentry
*
* Description:
* Search for the next valid inode starting at the provided FLASH offset.
*
* Input Parameters:
* volume - Describes the NXFFS volume.
* offset - The FLASH memory offset to begin searching.
* entry - A pointer to memory provided by the caller in which to return
* the inode description.
*
* Returned Value:
* Zero is returned on success. Otherwise, a negated errno is returned
* that indicates the nature of the failure.
*
****************************************************************************/
int nxffs_nextentry(FAR struct nxffs_volume_s *volume, off_t offset,
FAR struct nxffs_entry_s *entry)
{
int nmagic;
int ch;
int nerased;
int ret;
/* Seek to the first FLASH offset provided by the caller. */
nxffs_ioseek(volume, offset);
/* Then begin searching */
nerased = 0;
nmagic = 0;
for (;;)
{
/* Read the next character */
ch = nxffs_getc(volume);
if (ch < 0)
{
fvdbg("nxffs_getc failed: %d\n", -ch);
return ch;
}
/* Check for another erased byte */
else if (ch == CONFIG_NXFFS_ERASEDSTATE)
{
/* If we have encountered NXFFS_NERASED number of consecutive
* erased bytes, then presume we have reached the end of valid
* data.
*/
if (++nerased >= NXFFS_NERASED)
{
fvdbg("No entry found\n");
return -ENOENT;
}
}
else
{
nerased = 0;
/* Check for the magic sequence indicating the start of an NXFFS
* inode. There is the possibility of this magic sequnce occurring
* in FLASH data. However, the header CRC should distinguish
* between real NXFFS inode headers and such false alarms.
*/
if (ch != g_inodemagic[nmagic])
{
nmagic = 0;
}
else if (nmagic < NXFFS_MAGICSIZE - 1)
{
nmagic++;
}
/* We have found the magic sequence in the FLASH data that may
* indicate the beginning of an NXFFS inode.
*/
else
{
ret = nxffs_rdentry(volume, offset, entry);
if (ret == OK)
{
fdbg("Found a valid fileheader\n");
return OK;
}
/* False alarm.. keep looking */
nmagic = 0;
}
}
}
/* We won't get here, but to keep some compilers happy: */
return -ENOENT;
}
/****************************************************************************
* Name: nxffs_findinode
*
* Description:
* Search for an inode with the provided name starting with the first
* valid inode and proceeding to the end FLASH or until the matching
* inode is found.
*
* Input Parameters:
* volume - Describes the NXFFS volume
* name - The name of the inode to find
* entry - The location to return information about the inode.
*
* Returned Value:
* Zero is returned on success. Otherwise, a negated errno is returned
* that indicates the nature of the failure.
*
****************************************************************************/
int nxffs_findinode(FAR struct nxffs_volume_s *volume, FAR const char *name,
FAR struct nxffs_entry_s *entry)
{
off_t offset;
int ret;
/* Start with the first valid inode that was discovered when the volume
* was created (or modified after the last cleanup).
*/
offset = volume->inoffset;
/* Loop, checking each NXFFS inode until either: (1) we find the NXFFS inode
* with the matching name, or (2) we reach the end of data written on the
* media.
*/
for (;;)
{
/* Get the next, valid NXFFS inode entry */
ret = nxffs_nextentry(volume, offset, entry);
if (ret < 0)
{
fdbg("No inode found: %d\n", -ret);
return ret;
}
/* Is this the NXFFS inode we are looking for? */
else if (strcmp(name, entry->name) == 0)
{
/* Yes, return success with the entry data in 'enty' */
return OK;
}
/* Discard this entry and try the next one. Here we set the
* next offset using the raw data length as the offset
* increment. This is, of course, not accurate because it
* does not account for the data headers that enclose the
* data. But it is guaranteed to be less than or equal to
* the correct offset and, hence, better then searching
* byte-for-byte.
*/
offset = entry->doffset + entry->datlen;
nxffs_freeentry(entry);
}
/* We won't get here, but for some compilers: */
return -ENOENT;
}
|