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
|
/**
* @file
*
* @brief Untar an Image
* @ingroup libmisc_untar_img Untar Image
*
* FIXME:
* 1. Symbolic links are not created.
* 2. Untar_FromMemory uses FILE *fp.
* 3. How to determine end of archive?
*
*/
/*
* Written by: Jake Janovetz <janovetz@tempest.ece.uiuc.edu>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <rtems/untar.h>
#include <rtems/bspIo.h>
/**************************************************************************
* TAR file format:
*
* Offset Length Contents
* 0 100 bytes File name ('\0' terminated, 99 maxmum length)
* 100 8 bytes File mode (in octal ascii)
* 108 8 bytes User ID (in octal ascii)
* 116 8 bytes Group ID (in octal ascii)
* 124 12 bytes File size (s) (in octal ascii)
* 136 12 bytes Modify time (in octal ascii)
* 148 8 bytes Header checksum (in octal ascii)
* 156 1 bytes Link flag
* 157 100 bytes Linkname ('\0' terminated, 99 maxmum length)
* 257 8 bytes Magic PAX ("ustar\0" + 2 bytes padding)
* 257 8 bytes Magic GNU tar ("ustar \0")
* 265 32 bytes User name ('\0' terminated, 31 maxmum length)
* 297 32 bytes Group name ('\0' terminated, 31 maxmum length)
* 329 8 bytes Major device ID (in octal ascii)
* 337 8 bytes Minor device ID (in octal ascii)
* 345 155 bytes Prefix
* 512 (s+p)bytes File contents (s+p) := (((s) + 511) & ~511),
* round up to 512 bytes
*
* Checksum:
* int i, sum;
* char* header = tar_header_pointer;
* sum = 0;
* for(i = 0; i < 512; i++)
* sum += 0xFF & header[i];
*************************************************************************/
#define MAX_NAME_FIELD_SIZE 99
#define MIN(a,b) ((a)>(b)?(b):(a))
/**************************************************************************
* This converts octal ASCII number representations into an
* unsigned long. Only support 32-bit numbers for now.
*************************************************************************/
unsigned long
_rtems_octal2ulong(
const char *octascii,
size_t len
)
{
size_t i;
unsigned long num;
num = 0;
for (i=0; i < len; i++)
{
if ((octascii[i] < '0') || (octascii[i] > '9'))
{
continue;
}
num = num * 8 + ((unsigned long)(octascii[i] - '0'));
}
return(num);
}
/**************************************************************************
* Function: Untar_FromMemory *
**************************************************************************
* Description: *
* *
* This is a simple subroutine used to rip links, directories, and *
* files out of a block of memory. *
* *
* *
* Inputs: *
* *
* void * tar_buf - Pointer to TAR buffer. *
* size_t size - Length of TAR buffer. *
* *
* *
* Output: *
* *
* int - UNTAR_SUCCESSFUL (0) on successful completion. *
* UNTAR_INVALID_CHECKSUM for an invalid header checksum. *
* UNTAR_INVALID_HEADER for an invalid header. *
* *
**************************************************************************/
int
Untar_FromMemory(
void *tar_buf,
size_t size
)
{
FILE *fp;
const char *tar_ptr = (const char *)tar_buf;
const char *bufr;
size_t n;
char fname[100];
char linkname[100];
int sum;
int hdr_chksum;
int retval;
unsigned long ptr;
unsigned long i;
unsigned long nblocks;
unsigned long file_size;
unsigned char linkflag;
ptr = 0;
while (1)
{
if (ptr + 512 > size)
{
retval = UNTAR_SUCCESSFUL;
break;
}
/* Read the header */
bufr = &tar_ptr[ptr];
ptr += 512;
if (strncmp(&bufr[257], "ustar", 5))
{
retval = UNTAR_SUCCESSFUL;
break;
}
strncpy(fname, bufr, MAX_NAME_FIELD_SIZE);
fname[MAX_NAME_FIELD_SIZE] = '\0';
linkflag = bufr[156];
file_size = _rtems_octal2ulong(&bufr[124], 12);
/******************************************************************
* Compute the TAR checksum and check with the value in
* the archive. The checksum is computed over the entire
* header, but the checksum field is substituted with blanks.
******************************************************************/
hdr_chksum = _rtems_octal2ulong(&bufr[148], 8);
sum = _rtems_tar_header_checksum(bufr);
if (sum != hdr_chksum)
{
retval = UNTAR_INVALID_CHECKSUM;
break;
}
/******************************************************************
* We've decoded the header, now figure out what it contains and
* do something with it.
*****************************************************************/
if (linkflag == SYMTYPE)
{
strncpy(linkname, &bufr[157], MAX_NAME_FIELD_SIZE);
linkname[MAX_NAME_FIELD_SIZE] = '\0';
symlink(linkname, fname);
}
else if (linkflag == REGTYPE)
{
nblocks = (((file_size) + 511) & ~511) / 512;
if ((fp = fopen(fname, "w")) == NULL)
{
printk("Untar: failed to create file %s\n", fname);
ptr += 512 * nblocks;
}
else
{
unsigned long sizeToGo = file_size;
size_t len;
/***************************************************************
* Read out the data. There are nblocks of data where nblocks
* is the file_size rounded to the nearest 512-byte boundary.
**************************************************************/
for (i=0; i<nblocks; i++)
{
len = ((sizeToGo < 512L)?(sizeToGo):(512L));
n = fwrite(&tar_ptr[ptr], 1, len, fp);
if (n != len)
{
printk("untar: Error during write\n");
retval = UNTAR_FAIL;
break;
}
ptr += 512;
sizeToGo -= n;
}
fclose(fp);
}
}
else if (linkflag == DIRTYPE)
{
mkdir(fname, S_IRWXU | S_IRWXG | S_IRWXO);
}
}
return(retval);
}
/**************************************************************************
* Function: Untar_FromFile *
**************************************************************************
* Description: *
* *
* This is a simple subroutine used to rip links, directories, and *
* files out of a TAR file. *
* *
* *
* Inputs: *
* *
* const char *tar_name - TAR filename. *
* *
* *
* Output: *
* *
* int - UNTAR_SUCCESSFUL (0) on successful completion. *
* UNTAR_INVALID_CHECKSUM for an invalid header checksum. *
* UNTAR_INVALID_HEADER for an invalid header. *
* *
**************************************************************************
* Change History: *
* 12/30/1998 - Creation (JWJ) *
*************************************************************************/
int
Untar_FromFile(
const char *tar_name
)
{
int fd;
char *bufr;
ssize_t n;
char fname[100];
char linkname[100];
int sum;
int hdr_chksum;
int retval;
unsigned long i;
unsigned long nblocks;
unsigned long size;
unsigned char linkflag;
retval = UNTAR_SUCCESSFUL;
if ((fd = open(tar_name, O_RDONLY)) < 0) {
return UNTAR_FAIL;
}
bufr = (char *)malloc(512);
if (bufr == NULL) {
close(fd);
return(UNTAR_FAIL);
}
while (1)
{
/* Read the header */
/* If the header read fails, we just consider it the end
of the tarfile. */
if ((n = read(fd, bufr, 512)) != 512)
{
break;
}
if (strncmp(&bufr[257], "ustar", 5))
{
break;
}
strncpy(fname, bufr, MAX_NAME_FIELD_SIZE);
fname[MAX_NAME_FIELD_SIZE] = '\0';
linkflag = bufr[156];
size = _rtems_octal2ulong(&bufr[124], 12);
/******************************************************************
* Compute the TAR checksum and check with the value in
* the archive. The checksum is computed over the entire
* header, but the checksum field is substituted with blanks.
******************************************************************/
hdr_chksum = _rtems_octal2ulong(&bufr[148], 8);
sum = _rtems_tar_header_checksum(bufr);
if (sum != hdr_chksum)
{
retval = UNTAR_INVALID_CHECKSUM;
break;
}
/******************************************************************
* We've decoded the header, now figure out what it contains and
* do something with it.
*****************************************************************/
if (linkflag == SYMTYPE)
{
strncpy(linkname, &bufr[157], MAX_NAME_FIELD_SIZE);
linkname[MAX_NAME_FIELD_SIZE] = '\0';
symlink(linkname,fname);
}
else if (linkflag == REGTYPE)
{
int out_fd;
/******************************************************************
* Read out the data. There are nblocks of data where nblocks
* is the size rounded to the nearest 512-byte boundary.
*****************************************************************/
nblocks = (((size) + 511) & ~511) / 512;
if ((out_fd = creat(fname, 0644)) == -1)
{
for (i=0; i<nblocks; i++)
{
n = read(fd, bufr, 512);
}
}
else
{
for (i=0; i<nblocks; i++)
{
n = read(fd, bufr, 512);
n = MIN(n, size - i*512);
write(out_fd, bufr, n);
}
close(out_fd);
}
}
else if (linkflag == DIRTYPE)
{
mkdir(fname, S_IRWXU | S_IRWXG | S_IRWXO);
}
}
free(bufr);
close(fd);
return(retval);
}
/************************************************************************
* Compute the TAR checksum and check with the value in
* the archive. The checksum is computed over the entire
* header, but the checksum field is substituted with blanks.
************************************************************************/
int
_rtems_tar_header_checksum(
const char *bufr
)
{
int i, sum;
sum = 0;
for (i=0; i<512; i++)
{
if ((i >= 148) && (i < 156))
sum += 0xff & ' ';
else
sum += 0xff & bufr[i];
}
return(sum);
}
|
