source: rtems/cpukit/libblock/src/ide_part_table.c @ b2ac8a9

4.104.11
Last change on this file since b2ac8a9 was b2ac8a9, checked in by Joel Sherrill <joel.sherrill@…>, on Jan 19, 2010 at 10:05:30 PM

2010-01-19 Joel Sherrill <joel.sherrill@…>

Coverity Id 25

  • libblock/src/ide_part_table.c: Add free(sector) on error return path to fix leak.
  • Property mode set to 100644
File size: 14.0 KB
Line 
1/*****************************************************************************
2 *
3 * ide_part_table.c
4 *
5 * The implementation of library supporting "MS-DOS-style" partition table
6 *
7 *
8 * Copyright (C) 2002 OKTET Ltd., St.-Petersburg, Russia
9 *
10 * Author: Konstantin Abramenko <Konstantin.Abramenko@oktet.ru>
11 *         Alexander Kukuta <Alexander.Kukuta@oktet.ru>
12 *
13 *  The license and distribution terms for this file may be
14 *  found in the file LICENSE in this distribution or at
15 *  http://www.rtems.com/license/LICENSE.
16 *
17 * $Id$
18 *
19 *****************************************************************************/
20
21#if HAVE_CONFIG_H
22#include "config.h"
23#endif
24
25#include <string.h>
26
27#include <rtems/ide_part_table.h>
28
29/*
30 * get_sector --
31 *      gets sector from the disk
32 *
33 * PARAMETERS:
34 *      dev        - device number
35 *      sector_num - number of sector to read
36 *      sector     - returned pointer to pointer to allocated
37 *                   sector_data_t structure
38 *
39 * RETURNS:
40 *      RTEMS_SUCCESSFUL, if success;
41 *      RTEMS_NO_MEMORY, if canot allocate memory for sector data;
42 *      other error codes returned by rtems_bdbuf_read().
43 *
44 * NOTES:
45 *      get_sector() operates with device via bdbuf library,
46 *      and does not support devices with sector size other than 512 bytes
47 */
48static rtems_status_code
49get_sector(dev_t dev, uint32_t sector_num, rtems_sector_data_t **sector)
50{
51    rtems_sector_data_t *s;
52    rtems_bdbuf_buffer  *buf;
53    rtems_status_code    rc;
54
55    if (sector == NULL)
56    {
57        return RTEMS_INTERNAL_ERROR;
58    }
59
60    s = (rtems_sector_data_t *) malloc(sizeof(rtems_sector_data_t) + RTEMS_IDE_SECTOR_SIZE);
61    if (s == NULL)
62    {
63        return RTEMS_NO_MEMORY;
64    }
65
66    rc = rtems_bdbuf_read(dev, sector_num, &buf);
67    if (rc != RTEMS_SUCCESSFUL)
68    {
69        free(s);
70        return rc;
71    }
72
73    memcpy(s->data, buf->buffer, RTEMS_IDE_SECTOR_SIZE);
74    s->sector_num = sector_num;
75
76    *sector = s;
77
78    rtems_bdbuf_release(buf);
79
80    return RTEMS_SUCCESSFUL;
81}
82
83
84/*
85 * msdos_signature_check --
86 *      checks if the partition table sector has msdos signature
87 *
88 * PARAMETERS:
89 *      sector - sector to check
90 *
91 * RETURNS:
92 *      true if sector has msdos signature, false otherwise
93 */
94static bool
95msdos_signature_check (rtems_sector_data_t *sector)
96{
97    uint8_t *p = sector->data + RTEMS_IDE_PARTITION_MSDOS_SIGNATURE_OFFSET;
98
99    return ((p[0] == RTEMS_IDE_PARTITION_MSDOS_SIGNATURE_DATA1) &&
100            (p[1] == RTEMS_IDE_PARTITION_MSDOS_SIGNATURE_DATA2));
101}
102
103
104/*
105 * is_extended --
106 *      checks if the partition type is extended
107 *
108 * PARAMETERS:
109 *      type - type of partition to check
110 *
111 * RETURNS:
112 *      true if partition type is extended, false otherwise
113 */
114static bool
115is_extended(uint8_t type)
116{
117    return ((type == EXTENDED_PARTITION) || (type == LINUX_EXTENDED));
118}
119
120/*
121 * is_fat_partition --
122 *      checks if the partition type is defined for FAT
123 *
124 * PARAMETERS:
125 *      type - type of partition to check
126 *
127 * RETURNS:
128 *      true if partition type is extended, false otherwise
129 */
130static bool
131is_fat_partition(uint8_t type)
132{
133  static const uint8_t fat_part_types[] = {
134    DOS_FAT12_PARTITION,DOS_FAT16_PARTITION,
135    DOS_P32MB_PARTITION,
136    FAT32_PARTITION    ,FAT32_LBA_PARTITION,
137    FAT16_LBA_PARTITION
138  };
139
140  return (NULL != memchr(fat_part_types,type,sizeof(fat_part_types)));
141}
142
143
144/*
145 * data_to_part_desc --
146 *      parses raw partition table sector data
147 *      to partition description structure
148 *
149 * PARAMETERS:
150 *      data          - raw partition table sector data
151 *      new_part_desc - pointer to returned partition description structure
152 *
153 * RETURNS:
154 *      RTEMS_SUCCESSFUL, if success;
155 *      RTEMS_NO_MEMOTY, if cannot allocate memory for part_desc_t strucure;
156 *      RTEMS_INTERNAL_ERROR, if other error occurs.
157 */
158static rtems_status_code
159data_to_part_desc(uint8_t *data, rtems_part_desc_t **new_part_desc)
160{
161    rtems_part_desc_t *part_desc;
162    uint32_t           temp;
163
164    if (new_part_desc == NULL)
165    {
166        return RTEMS_INTERNAL_ERROR;
167    }
168
169    *new_part_desc = NULL;
170
171    if ((part_desc = calloc(1, sizeof(rtems_part_desc_t))) == NULL)
172    {
173        return RTEMS_NO_MEMORY;
174    }
175
176    part_desc->bootable = *(data + RTEMS_IDE_PARTITION_BOOTABLE_OFFSET);
177    part_desc->sys_type = *(data + RTEMS_IDE_PARTITION_SYS_TYPE_OFFSET);
178
179    /* read the offset start position and partition size in sectors */
180
181    /* due to incorrect data alignment one have to align data first */
182    memcpy(&temp, data + RTEMS_IDE_PARTITION_START_OFFSET, sizeof(uint32_t));
183    part_desc->start = LE_TO_CPU_U32(temp);
184
185    memcpy(&temp, data + RTEMS_IDE_PARTITION_SIZE_OFFSET, sizeof(uint32_t));
186    part_desc->size = LE_TO_CPU_U32(temp);
187
188    /*
189     * use partitions that are
190     * - extended
191     * or
192     * - FAT type and non-zero
193     */
194    if (is_extended(part_desc->sys_type) ||
195       ((is_fat_partition(part_desc->sys_type)) && (part_desc->size != 0))) {
196      *new_part_desc = part_desc;
197    }
198    else {
199      /* empty partition */
200      free(part_desc);
201    }
202    return RTEMS_SUCCESSFUL;
203}
204
205
206/*
207 * read_extended_partition --
208 *      recursively reads extended partition sector from the device
209 *      and constructs the partition table tree
210 *
211 * PARAMETERS:
212 *      start    - start sector of primary extended partition, used for
213 *                 calculation of absolute partition sector address
214 *      ext_part - description of extended partition to process
215 *
216 * RETURNS:
217 *      RTEMS_SUCCESSFUL if success,
218 *      RTEMS_NO_MEMOTY if cannot allocate memory for part_desc_t strucure,
219 *      RTEMS_INTERNAL_ERROR if other error occurs.
220 */
221static rtems_status_code
222read_extended_partition(uint32_t start, rtems_part_desc_t *ext_part)
223{
224    int                  i;
225    dev_t                dev;
226    rtems_sector_data_t *sector;
227    uint32_t             here;
228    uint8_t             *data;
229    rtems_part_desc_t   *new_part_desc;
230    rtems_status_code    rc;
231
232    if ((ext_part == NULL) || (ext_part->disk_desc == NULL))
233    {
234        return RTEMS_INTERNAL_ERROR;
235    }
236
237    dev = ext_part->disk_desc->dev;
238
239    /* get start sector of current extended partition */
240    here = ext_part->start;
241
242    /* get first extended partition sector */
243
244    rc = get_sector(dev, here, &sector);
245    if (rc != RTEMS_SUCCESSFUL)
246    {
247        return rc;
248    }
249
250    if (!msdos_signature_check(sector))
251    {
252        return RTEMS_INTERNAL_ERROR;
253    }
254
255    /* read and process up to 4 logical partition descriptors */
256
257    data = sector->data + RTEMS_IDE_PARTITION_TABLE_OFFSET;
258
259    for (i = 0; i < RTEMS_IDE_PARTITION_MAX_SUB_PARTITION_NUMBER; i++)
260    {
261        /* if data_to_part_desc fails skip this partition
262         * and parse the next one
263         */
264        rc = data_to_part_desc(data, &new_part_desc);
265        if (rc != RTEMS_SUCCESSFUL)
266        {
267            free(sector);
268            return rc;
269        }
270
271        if (new_part_desc == NULL)
272        {
273            data += RTEMS_IDE_PARTITION_DESCRIPTOR_SIZE;
274            continue;
275        }
276
277        ext_part->sub_part[i] = new_part_desc;
278        new_part_desc->ext_part = ext_part;
279        new_part_desc->disk_desc = ext_part->disk_desc;
280
281        if (is_extended(new_part_desc->sys_type))
282        {
283            new_part_desc->log_id = EMPTY_PARTITION;
284            new_part_desc->start += start;
285            read_extended_partition(start, new_part_desc);
286        }
287        else
288        {
289            rtems_disk_desc_t *disk_desc = new_part_desc->disk_desc;
290            disk_desc->partitions[disk_desc->last_log_id] = new_part_desc;
291            new_part_desc->log_id = ++disk_desc->last_log_id;
292            new_part_desc->start += here;
293            new_part_desc->end = new_part_desc->start + new_part_desc->size - 1;
294        }
295        data += RTEMS_IDE_PARTITION_DESCRIPTOR_SIZE;
296    }
297
298    free(sector);
299
300    return RTEMS_SUCCESSFUL;
301}
302
303
304/*
305 * read_mbr --
306 *      reads Master Boot Record (sector 0) of physical device and
307 *      constructs disk description structure
308 *
309 * PARAMETERS:
310 *      disk_desc - returned disc description structure
311 *
312 * RETURNS:
313 *      RTEMS_SUCCESSFUL if success,
314 *      RTEMS_INTERNAL_ERROR otherwise
315 */
316static rtems_status_code
317read_mbr(rtems_disk_desc_t *disk_desc)
318{
319    int                  part_num;
320    rtems_sector_data_t *sector;
321    rtems_part_desc_t   *part_desc;
322    uint8_t             *data;
323    rtems_status_code    rc;
324    dev_t                dev = disk_desc->dev;
325
326    /* get MBR sector */
327    rc = get_sector(dev, 0, &sector);
328    if (rc != RTEMS_SUCCESSFUL)
329    {
330        return rc;
331    }
332
333    /* check if the partition table structure is MS-DOS style */
334    if (!msdos_signature_check(sector))
335    {
336        free(sector);
337        return RTEMS_INTERNAL_ERROR;
338    }
339
340    /* read and process 4 primary partition descriptors */
341
342    data = sector->data + RTEMS_IDE_PARTITION_TABLE_OFFSET;
343
344    for (part_num = 0;
345         part_num < RTEMS_IDE_PARTITION_MAX_SUB_PARTITION_NUMBER;
346         part_num++)
347    {
348        rc = data_to_part_desc(data, &part_desc);
349        if (rc != RTEMS_SUCCESSFUL)
350        {
351            free(sector);
352            return rc;
353        }
354
355        if (part_desc != NULL)
356        {
357            part_desc->log_id = part_num + 1;
358            part_desc->disk_desc = disk_desc;
359            part_desc->end = part_desc->start + part_desc->size - 1;
360            disk_desc->partitions[part_num] = part_desc;
361        }
362        else
363        {
364            disk_desc->partitions[part_num] = NULL;
365        }
366
367        data += RTEMS_IDE_PARTITION_DESCRIPTOR_SIZE;
368    }
369
370    free(sector);
371
372    disk_desc->last_log_id = RTEMS_IDE_PARTITION_MAX_SUB_PARTITION_NUMBER;
373
374    /* There cannot be more than one extended partition,
375       but we are to process each primary partition */
376    for (part_num = 0;
377         part_num < RTEMS_IDE_PARTITION_MAX_SUB_PARTITION_NUMBER;
378         part_num++)
379    {
380        part_desc = disk_desc->partitions[part_num];
381        if (part_desc != NULL && is_extended(part_desc->sys_type))
382        {
383            read_extended_partition(part_desc->start, part_desc);
384        }
385    }
386
387    return RTEMS_SUCCESSFUL;
388}
389
390
391/*
392 * partition free --
393 *      frees partition description structure
394 *
395 * PARAMETERS:
396 *      part_desc - returned disc description structure
397 *
398 * RETURNS:
399 *      N/A
400 */
401static void
402partition_free(rtems_part_desc_t *part_desc)
403{
404    int part_num;
405
406    if (part_desc == NULL)
407        return;
408
409    if (is_extended(part_desc->sys_type))
410    {
411        for (part_num = 0;
412             part_num < RTEMS_IDE_PARTITION_MAX_SUB_PARTITION_NUMBER;
413             part_num++)
414        {
415            partition_free(part_desc->sub_part[part_num]);
416        }
417    }
418
419    free(part_desc);
420}
421
422
423/*
424 * rtems_ide_part_table_free - frees disk descriptor structure
425 *
426 * PARAMETERS:
427 *      disk_desc - disc descriptor structure to free
428 *
429 * RETURNS:
430 *      N/A
431 */
432void
433rtems_ide_part_table_free(rtems_disk_desc_t *disk_desc)
434{
435    int part_num;
436
437    for (part_num = 0; part_num < RTEMS_IDE_PARTITION_MAX_SUB_PARTITION_NUMBER; part_num++)
438    {
439        partition_free(disk_desc->partitions[part_num]);
440    }
441
442    free(disk_desc);
443}
444
445
446/*
447 * rtems_ide_part_table_get - reads partition table structure from the device
448 *                            and creates disk description structure
449 *
450 * PARAMETERS:
451 *      dev_name - path to physical device in /dev filesystem
452 *      disk_desc       - returned disc description structure
453 *
454 * RETURNS:
455 *      RTEMS_SUCCESSFUL if success,
456 *      RTEMS_INTERNAL_ERROR otherwise
457 */
458rtems_status_code
459rtems_ide_part_table_get(const char *dev_name, rtems_disk_desc_t *disk_desc)
460{
461    struct stat         dev_stat;
462    rtems_status_code   rc;
463
464    rc = stat(dev_name, &dev_stat);
465    if (rc != RTEMS_SUCCESSFUL)
466    {
467        return RTEMS_INTERNAL_ERROR;
468    }
469
470    strncpy (disk_desc->dev_name, dev_name, 15);
471    disk_desc->dev = dev_stat.st_rdev;
472    disk_desc->sector_size = (dev_stat.st_blksize) ? dev_stat.st_blksize :
473                                              RTEMS_IDE_SECTOR_SIZE;
474
475    rc = read_mbr(disk_desc);
476
477    return rc;
478}
479
480
481/*
482 * rtems_ide_part_table_initialize - initializes logical devices
483 *                                   on the physical IDE drive
484 *
485 * PARAMETERS:
486 *      dev_name - path to physical device in /dev filesystem
487 *
488 * RETURNS:
489 *      RTEMS_SUCCESSFUL if success,
490 *      RTEMS_NO_MEMOTY if cannot have not enough memory,
491 *      RTEMS_INTERNAL_ERROR if other error occurs.
492 */
493rtems_status_code
494rtems_ide_part_table_initialize(char *dev_name)
495{
496    int                         part_num;
497    dev_t                       dev;
498    rtems_disk_desc_t          *disk_desc;
499    rtems_device_major_number   major;
500    rtems_device_minor_number   minor;
501    rtems_status_code           rc;
502    rtems_part_desc_t          *part_desc;
503
504    /* logical device name /dev/hdxyy */
505    char                        name[RTEMS_IDE_PARTITION_DEV_NAME_LENGTH_MAX];
506
507    disk_desc = (rtems_disk_desc_t *) calloc(1, sizeof(rtems_disk_desc_t));
508    if (disk_desc == NULL)
509    {
510        return RTEMS_NO_MEMORY;
511    }
512
513    /* get partition table */
514    rc = rtems_ide_part_table_get(dev_name, disk_desc);
515    if (rc != RTEMS_SUCCESSFUL)
516    {
517        free(disk_desc);
518        return rc;
519    }
520
521    /* To avoid device numbers conflicts we have to use for logic disk the same
522     * device major number as ATA device has, and minor number that equals to
523     * sum of logic disk partition number and the minor number of physical disk
524     */
525
526    rtems_filesystem_split_dev_t (disk_desc->dev, major, minor);
527
528    /* create logical disks on the physical one */
529    for (part_num = 0; part_num < disk_desc->last_log_id; part_num++)
530    {
531        sprintf(name, "%s%d", dev_name, part_num + 1);
532        dev = rtems_filesystem_make_dev_t(major, ++minor);
533
534        part_desc = disk_desc->partitions[part_num];
535        if (part_desc == NULL)
536        {
537            continue;
538        }
539
540        rc = rtems_disk_create_log(dev, disk_desc->dev, part_desc->start,
541                                   part_desc->size, name);
542        if (rc != RTEMS_SUCCESSFUL)
543        {
544            fprintf(stdout,"Cannot create device %s, error code %d\n", name, rc);
545            continue;
546        }
547    }
548
549    rtems_ide_part_table_free(disk_desc);
550
551    return RTEMS_SUCCESSFUL;
552}
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