busybox/e2fsprogs/blkid/probe.c

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/*
* probe.c - identify a block device by its contents, and return a dev
* struct with the details
*
* Copyright (C) 1999 by Andries Brouwer
* Copyright (C) 1999, 2000, 2003 by Theodore Ts'o
* Copyright (C) 2001 by Andreas Dilger
*
* %Begin-Header%
* This file may be redistributed under the terms of the
* GNU Lesser General Public License.
* %End-Header%
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_SYS_MKDEV_H
#include <sys/mkdev.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include "blkidP.h"
#include "uuid/uuid.h"
#include "probe.h"
/*
* This is a special case code to check for an MDRAID device. We do
* this special since it requires checking for a superblock at the end
* of the device.
*/
static int check_mdraid(int fd, unsigned char *ret_uuid)
{
struct mdp_superblock_s *md;
blkid_loff_t offset;
char buf[4096];
if (fd < 0)
return -BLKID_ERR_PARAM;
offset = (blkid_get_dev_size(fd) & ~((blkid_loff_t)65535)) - 65536;
if (blkid_llseek(fd, offset, 0) < 0 ||
read(fd, buf, 4096) != 4096)
return -BLKID_ERR_IO;
/* Check for magic number */
if (memcmp("\251+N\374", buf, 4))
return -BLKID_ERR_PARAM;
if (!ret_uuid)
return 0;
*ret_uuid = 0;
/* The MD UUID is not contiguous in the superblock, make it so */
md = (struct mdp_superblock_s *)buf;
if (md->set_uuid0 || md->set_uuid1 || md->set_uuid2 || md->set_uuid3) {
memcpy(ret_uuid, &md->set_uuid0, 4);
memcpy(ret_uuid, &md->set_uuid1, 12);
}
return 0;
}
static void set_uuid(blkid_dev dev, uuid_t uuid)
{
char str[37];
if (!uuid_is_null(uuid)) {
uuid_unparse(uuid, str);
blkid_set_tag(dev, "UUID", str, sizeof(str));
}
}
static void get_ext2_info(blkid_dev dev, unsigned char *buf)
{
struct ext2_super_block *es = (struct ext2_super_block *) buf;
const char *label = 0;
DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n",
blkid_le32(es->s_feature_compat),
blkid_le32(es->s_feature_incompat),
blkid_le32(es->s_feature_ro_compat)));
if (strlen(es->s_volume_name))
label = es->s_volume_name;
blkid_set_tag(dev, "LABEL", label, sizeof(es->s_volume_name));
set_uuid(dev, es->s_uuid);
}
static int probe_ext3(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id, unsigned char *buf)
{
struct ext2_super_block *es;
es = (struct ext2_super_block *)buf;
/* Distinguish between jbd and ext2/3 fs */
if (blkid_le32(es->s_feature_incompat) &
EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
return -BLKID_ERR_PARAM;
/* Distinguish between ext3 and ext2 */
if (!(blkid_le32(es->s_feature_compat) &
EXT3_FEATURE_COMPAT_HAS_JOURNAL))
return -BLKID_ERR_PARAM;
get_ext2_info(dev, buf);
blkid_set_tag(dev, "SEC_TYPE", "ext2", sizeof("ext2"));
return 0;
}
static int probe_ext2(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id, unsigned char *buf)
{
struct ext2_super_block *es;
// const char *sec_type = 0, *label = 0;
es = (struct ext2_super_block *)buf;
/* Distinguish between jbd and ext2/3 fs */
if (blkid_le32(es->s_feature_incompat) &
EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
return -BLKID_ERR_PARAM;
get_ext2_info(dev, buf);
return 0;
}
static int probe_jbd(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf)
{
struct ext2_super_block *es = (struct ext2_super_block *) buf;
if (!(blkid_le32(es->s_feature_incompat) &
EXT3_FEATURE_INCOMPAT_JOURNAL_DEV))
return -BLKID_ERR_PARAM;
get_ext2_info(dev, buf);
return 0;
}
static int probe_vfat(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf)
{
struct vfat_super_block *vs;
char serno[10];
const char *label = 0;
int label_len = 0;
vs = (struct vfat_super_block *)buf;
if (strncmp(vs->vs_label, "NO NAME", 7)) {
char *end = vs->vs_label + sizeof(vs->vs_label) - 1;
while (*end == ' ' && end >= vs->vs_label)
--end;
if (end >= vs->vs_label) {
label = vs->vs_label;
label_len = end - vs->vs_label + 1;
}
}
/* We can't just print them as %04X, because they are unaligned */
sprintf(serno, "%02X%02X-%02X%02X", vs->vs_serno[3], vs->vs_serno[2],
vs->vs_serno[1], vs->vs_serno[0]);
blkid_set_tag(dev, "LABEL", label, label_len);
blkid_set_tag(dev, "UUID", serno, sizeof(serno));
return 0;
}
static int probe_msdos(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf)
{
struct msdos_super_block *ms = (struct msdos_super_block *) buf;
char serno[10];
const char *label = 0;
int label_len = 0;
if (strncmp(ms->ms_label, "NO NAME", 7)) {
char *end = ms->ms_label + sizeof(ms->ms_label) - 1;
while (*end == ' ' && end >= ms->ms_label)
--end;
if (end >= ms->ms_label) {
label = ms->ms_label;
label_len = end - ms->ms_label + 1;
}
}
/* We can't just print them as %04X, because they are unaligned */
sprintf(serno, "%02X%02X-%02X%02X", ms->ms_serno[3], ms->ms_serno[2],
ms->ms_serno[1], ms->ms_serno[0]);
blkid_set_tag(dev, "UUID", serno, 0);
blkid_set_tag(dev, "LABEL", label, label_len);
blkid_set_tag(dev, "SEC_TYPE", "msdos", sizeof("msdos"));
return 0;
}
static int probe_xfs(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf)
{
struct xfs_super_block *xs;
const char *label = 0;
xs = (struct xfs_super_block *)buf;
if (strlen(xs->xs_fname))
label = xs->xs_fname;
blkid_set_tag(dev, "LABEL", label, sizeof(xs->xs_fname));
set_uuid(dev, xs->xs_uuid);
return 0;
}
static int probe_reiserfs(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id, unsigned char *buf)
{
struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
unsigned int blocksize;
const char *label = 0;
blocksize = blkid_le16(rs->rs_blocksize);
/* If the superblock is inside the journal, we have the wrong one */
if (id->bim_kboff/(blocksize>>10) > blkid_le32(rs->rs_journal_block))
return -BLKID_ERR_BIG;
/* LABEL/UUID are only valid for later versions of Reiserfs v3.6. */
if (!strcmp(id->bim_magic, "ReIsEr2Fs") ||
!strcmp(id->bim_magic, "ReIsEr3Fs")) {
if (strlen(rs->rs_label))
label = rs->rs_label;
set_uuid(dev, rs->rs_uuid);
}
blkid_set_tag(dev, "LABEL", label, sizeof(rs->rs_label));
return 0;
}
static int probe_jfs(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf)
{
struct jfs_super_block *js;
const char *label = 0;
js = (struct jfs_super_block *)buf;
if (strlen((char *) js->js_label))
label = (char *) js->js_label;
blkid_set_tag(dev, "LABEL", label, sizeof(js->js_label));
set_uuid(dev, js->js_uuid);
return 0;
}
static int probe_romfs(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf)
{
struct romfs_super_block *ros;
const char *label = 0;
ros = (struct romfs_super_block *)buf;
if (strlen((char *) ros->ros_volume))
label = (char *) ros->ros_volume;
blkid_set_tag(dev, "LABEL", label, 0);
return 0;
}
static int probe_swap0(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf __BLKID_ATTR((unused)))
{
blkid_set_tag(dev, "UUID", 0, 0);
blkid_set_tag(dev, "LABEL", 0, 0);
return 0;
}
static int probe_swap1(int fd,
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf __BLKID_ATTR((unused)))
{
struct swap_id_block *sws;
// const char *label = 0;
probe_swap0(fd, cache, dev, id, buf);
/*
* Version 1 swap headers are always located at offset of 1024
* bytes, although the swap signature itself is located at the
* end of the page (which may vary depending on hardware
* pagesize).
*/
if (lseek(fd, 1024, SEEK_SET) < 0) return 1;
if (!(sws = (struct swap_id_block *)malloc(1024))) return 1;
if (read(fd, sws, 1024) != 1024) {
free(sws);
return 1;
}
/* arbitrary sanity check.. is there any garbage down there? */
if (sws->sws_pad[32] == 0 && sws->sws_pad[33] == 0) {
if (sws->sws_volume[0])
blkid_set_tag(dev, "LABEL", sws->sws_volume,
sizeof(sws->sws_volume));
if (sws->sws_uuid[0])
set_uuid(dev, sws->sws_uuid);
}
free(sws);
return 0;
}
static const char
*udf_magic[] = { "BEA01", "BOOT2", "CD001", "CDW02", "NSR02",
"NSR03", "TEA01", 0 };
static int probe_udf(int fd, blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev __BLKID_ATTR((unused)),
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf __BLKID_ATTR((unused)))
{
int j, bs;
struct iso_volume_descriptor isosb;
const char ** m;
/* determine the block size by scanning in 2K increments
(block sizes larger than 2K will be null padded) */
for (bs = 1; bs < 16; bs++) {
lseek(fd, bs*2048+32768, SEEK_SET);
if (read(fd, (char *)&isosb, sizeof(isosb)) != sizeof(isosb))
return 1;
if (isosb.id[0])
break;
}
/* Scan up to another 64 blocks looking for additional VSD's */
for (j = 1; j < 64; j++) {
if (j > 1) {
lseek(fd, j*bs*2048+32768, SEEK_SET);
if (read(fd, (char *)&isosb, sizeof(isosb))
!= sizeof(isosb))
return 1;
}
/* If we find NSR0x then call it udf:
NSR01 for UDF 1.00
NSR02 for UDF 1.50
NSR03 for UDF 2.00 */
if (!strncmp(isosb.id, "NSR0", 4))
return 0;
for (m = udf_magic; *m; m++)
if (!strncmp(*m, isosb.id, 5))
break;
if (*m == 0)
return 1;
}
return 1;
}
static int probe_ocfs(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf)
{
struct ocfs_volume_header ovh;
struct ocfs_volume_label ovl;
__u32 major;
memcpy(&ovh, buf, sizeof(ovh));
memcpy(&ovl, buf+512, sizeof(ovl));
major = ocfsmajor(ovh);
if (major == 1)
blkid_set_tag(dev,"SEC_TYPE","ocfs1",sizeof("ocfs1"));
else if (major >= 9)
blkid_set_tag(dev,"SEC_TYPE","ntocfs",sizeof("ntocfs"));
blkid_set_tag(dev, "LABEL", ovl.label, ocfslabellen(ovl));
blkid_set_tag(dev, "MOUNT", ovh.mount, ocfsmountlen(ovh));
set_uuid(dev, ovl.vol_id);
return 0;
}
static int probe_ocfs2(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf)
{
struct ocfs2_super_block *osb;
osb = (struct ocfs2_super_block *)buf;
blkid_set_tag(dev, "LABEL", osb->s_label, sizeof(osb->s_label));
set_uuid(dev, osb->s_uuid);
return 0;
}
static int probe_oracleasm(int fd __BLKID_ATTR((unused)),
blkid_cache cache __BLKID_ATTR((unused)),
blkid_dev dev,
struct blkid_magic *id __BLKID_ATTR((unused)),
unsigned char *buf)
{
struct oracle_asm_disk_label *dl;
dl = (struct oracle_asm_disk_label *)buf;
blkid_set_tag(dev, "LABEL", dl->dl_id, sizeof(dl->dl_id));
return 0;
}
/*
* BLKID_BLK_OFFS is at least as large as the highest bim_kboff defined
* in the type_array table below + bim_kbalign.
*
* When probing for a lot of magics, we handle everything in 1kB buffers so
* that we don't have to worry about reading each combination of block sizes.
*/
#define BLKID_BLK_OFFS 64 /* currently reiserfs */
/*
* Various filesystem magics that we can check for. Note that kboff and
* sboff are in kilobytes and bytes respectively. All magics are in
* byte strings so we don't worry about endian issues.
*/
static struct blkid_magic type_array[] = {
/* type kboff sboff len magic probe */
{ "oracleasm", 0, 32, 8, "ORCLDISK", probe_oracleasm },
{ "ntfs", 0, 3, 8, "NTFS ", 0 },
{ "jbd", 1, 0x38, 2, "\123\357", probe_jbd },
{ "ext3", 1, 0x38, 2, "\123\357", probe_ext3 },
{ "ext2", 1, 0x38, 2, "\123\357", probe_ext2 },
{ "reiserfs", 8, 0x34, 8, "ReIsErFs", probe_reiserfs },
{ "reiserfs", 64, 0x34, 9, "ReIsEr2Fs", probe_reiserfs },
{ "reiserfs", 64, 0x34, 9, "ReIsEr3Fs", probe_reiserfs },
{ "reiserfs", 64, 0x34, 8, "ReIsErFs", probe_reiserfs },
{ "reiserfs", 8, 20, 8, "ReIsErFs", probe_reiserfs },
{ "vfat", 0, 0x52, 5, "MSWIN", probe_vfat },
{ "vfat", 0, 0x52, 8, "FAT32 ", probe_vfat },
{ "vfat", 0, 0x36, 5, "MSDOS", probe_msdos },
{ "vfat", 0, 0x36, 8, "FAT16 ", probe_msdos },
{ "vfat", 0, 0x36, 8, "FAT12 ", probe_msdos },
{ "minix", 1, 0x10, 2, "\177\023", 0 },
{ "minix", 1, 0x10, 2, "\217\023", 0 },
{ "minix", 1, 0x10, 2, "\150\044", 0 },
{ "minix", 1, 0x10, 2, "\170\044", 0 },
{ "vxfs", 1, 0, 4, "\365\374\001\245", 0 },
{ "xfs", 0, 0, 4, "XFSB", probe_xfs },
{ "romfs", 0, 0, 8, "-rom1fs-", probe_romfs },
{ "bfs", 0, 0, 4, "\316\372\173\033", 0 },
{ "cramfs", 0, 0, 4, "E=\315\034", 0 },
{ "qnx4", 0, 4, 6, "QNX4FS", 0 },
{ "udf", 32, 1, 5, "BEA01", probe_udf },
{ "udf", 32, 1, 5, "BOOT2", probe_udf },
{ "udf", 32, 1, 5, "CD001", probe_udf },
{ "udf", 32, 1, 5, "CDW02", probe_udf },
{ "udf", 32, 1, 5, "NSR02", probe_udf },
{ "udf", 32, 1, 5, "NSR03", probe_udf },
{ "udf", 32, 1, 5, "TEA01", probe_udf },
{ "iso9660", 32, 1, 5, "CD001", 0 },
{ "iso9660", 32, 9, 5, "CDROM", 0 },
{ "jfs", 32, 0, 4, "JFS1", probe_jfs },
{ "hfs", 1, 0, 2, "BD", 0 },
{ "ufs", 8, 0x55c, 4, "T\031\001\000", 0 },
{ "hpfs", 8, 0, 4, "I\350\225\371", 0 },
{ "sysv", 0, 0x3f8, 4, "\020~\030\375", 0 },
{ "swap", 0, 0xff6, 10, "SWAP-SPACE", probe_swap0 },
{ "swap", 0, 0xff6, 10, "SWAPSPACE2", probe_swap1 },
{ "swap", 0, 0x1ff6, 10, "SWAP-SPACE", probe_swap0 },
{ "swap", 0, 0x1ff6, 10, "SWAPSPACE2", probe_swap1 },
{ "swap", 0, 0x3ff6, 10, "SWAP-SPACE", probe_swap0 },
{ "swap", 0, 0x3ff6, 10, "SWAPSPACE2", probe_swap1 },
{ "swap", 0, 0x7ff6, 10, "SWAP-SPACE", probe_swap0 },
{ "swap", 0, 0x7ff6, 10, "SWAPSPACE2", probe_swap1 },
{ "swap", 0, 0xfff6, 10, "SWAP-SPACE", probe_swap0 },
{ "swap", 0, 0xfff6, 10, "SWAPSPACE2", probe_swap1 },
{ "ocfs", 0, 8, 9, "OracleCFS", probe_ocfs },
{ "ocfs2", 1, 0, 6, "OCFSV2", probe_ocfs2 },
{ "ocfs2", 2, 0, 6, "OCFSV2", probe_ocfs2 },
{ "ocfs2", 4, 0, 6, "OCFSV2", probe_ocfs2 },
{ "ocfs2", 8, 0, 6, "OCFSV2", probe_ocfs2 },
{ NULL, 0, 0, 0, NULL, NULL }
};
/*
* Verify that the data in dev is consistent with what is on the actual
* block device (using the devname field only). Normally this will be
* called when finding items in the cache, but for long running processes
* is also desirable to revalidate an item before use.
*
* If we are unable to revalidate the data, we return the old data and
* do not set the BLKID_BID_FL_VERIFIED flag on it.
*/
blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
{
struct blkid_magic *id;
unsigned char *bufs[BLKID_BLK_OFFS + 1], *buf;
const char *type;
struct stat st;
time_t diff, now;
int fd, idx;
if (!dev)
return NULL;
now = time(0);
diff = now - dev->bid_time;
if ((now < dev->bid_time) ||
(diff < BLKID_PROBE_MIN) ||
(dev->bid_flags & BLKID_BID_FL_VERIFIED &&
diff < BLKID_PROBE_INTERVAL))
return dev;
DBG(DEBUG_PROBE,
printf("need to revalidate %s (time since last check %lu)\n",
dev->bid_name, diff));
if (((fd = open(dev->bid_name, O_RDONLY)) < 0) ||
(fstat(fd, &st) < 0)) {
if (errno == ENXIO || errno == ENODEV || errno == ENOENT) {
blkid_free_dev(dev);
return NULL;
}
/* We don't have read permission, just return cache data. */
DBG(DEBUG_PROBE,
printf("returning unverified data for %s\n",
dev->bid_name));
return dev;
}
memset(bufs, 0, sizeof(bufs));
/*
* Iterate over the type array. If we already know the type,
* then try that first. If it doesn't work, then blow away
* the type information, and try again.
*
*/
try_again:
type = 0;
if (!dev->bid_type || !strcmp(dev->bid_type, "mdraid")) {
uuid_t uuid;
if (check_mdraid(fd, uuid) == 0) {
set_uuid(dev, uuid);
type = "mdraid";
goto found_type;
}
}
for (id = type_array; id->bim_type; id++) {
if (dev->bid_type &&
strcmp(id->bim_type, dev->bid_type))
continue;
idx = id->bim_kboff + (id->bim_sboff >> 10);
if (idx > BLKID_BLK_OFFS || idx < 0)
continue;
buf = bufs[idx];
if (!buf) {
if (lseek(fd, idx << 10, SEEK_SET) < 0)
continue;
if (!(buf = (unsigned char *)malloc(1024)))
continue;
if (read(fd, buf, 1024) != 1024) {
free(buf);
continue;
}
bufs[idx] = buf;
}
if (memcmp(id->bim_magic, buf + (id->bim_sboff&0x3ff),
id->bim_len))
continue;
if ((id->bim_probe == NULL) ||
(id->bim_probe(fd, cache, dev, id, buf) == 0)) {
type = id->bim_type;
goto found_type;
}
}
if (!id->bim_type && dev->bid_type) {
/*
* Zap the device filesystem type and try again
*/
blkid_set_tag(dev, "TYPE", 0, 0);
blkid_set_tag(dev, "SEC_TYPE", 0, 0);
blkid_set_tag(dev, "LABEL", 0, 0);
blkid_set_tag(dev, "UUID", 0, 0);
goto try_again;
}
if (!dev->bid_type) {
blkid_free_dev(dev);
return NULL;
}
found_type:
if (dev && type) {
dev->bid_devno = st.st_rdev;
dev->bid_time = time(0);
dev->bid_flags |= BLKID_BID_FL_VERIFIED;
cache->bic_flags |= BLKID_BIC_FL_CHANGED;
blkid_set_tag(dev, "TYPE", type, 0);
DBG(DEBUG_PROBE, printf("%s: devno 0x%04Lx, type %s\n",
dev->bid_name, st.st_rdev, type));
}
close(fd);
return dev;
}
int blkid_known_fstype(const char *fstype)
{
struct blkid_magic *id;
for (id = type_array; id->bim_type; id++) {
if (strcmp(fstype, id->bim_type) == 0)
return 1;
}
return 0;
}
#ifdef TEST_PROGRAM
int main(int argc, char **argv)
{
blkid_dev dev;
blkid_cache cache;
int ret;
blkid_debug_mask = DEBUG_ALL;
if (argc != 2) {
fprintf(stderr, "Usage: %s device\n"
"Probe a single device to determine type\n", argv[0]);
exit(1);
}
if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
fprintf(stderr, "%s: error creating cache (%d)\n",
argv[0], ret);
exit(1);
}
dev = blkid_get_dev(cache, argv[1], BLKID_DEV_NORMAL);
if (!dev) {
printf("%s: %s has an unsupported type\n", argv[0], argv[1]);
return (1);
}
printf("%s is type %s\n", argv[1], dev->bid_type ?
dev->bid_type : "(null)");
if (dev->bid_label)
printf("\tlabel is '%s'\n", dev->bid_label);
if (dev->bid_uuid)
printf("\tuuid is %s\n", dev->bid_uuid);
blkid_free_dev(dev);
return (0);
}
#endif