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DEFINITIONS
This source file includes following definitions.
- udf_tgetblk
- udf_tread
- udf_add_extendedattr
- udf_get_extendedattr
- udf_read_tagged
- udf_read_ptagged
- udf_update_tag
- udf_new_tag
- udf_tag_checksum
/*
* misc.c
*
* PURPOSE
* Miscellaneous routines for the OSTA-UDF(tm) filesystem.
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (C) 1998 Dave Boynton
* (C) 1998-2004 Ben Fennema
* (C) 1999-2000 Stelias Computing Inc
*
* HISTORY
*
* 04/19/99 blf partial support for reading/writing specific EA's
*/
#include "udfdecl.h"
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/buffer_head.h>
#include <linux/crc-itu-t.h>
#include "udf_i.h"
#include "udf_sb.h"
struct buffer_head *udf_tgetblk(struct super_block *sb, int block)
{
if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
return sb_getblk(sb, udf_fixed_to_variable(block));
else
return sb_getblk(sb, block);
}
struct buffer_head *udf_tread(struct super_block *sb, int block)
{
if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
return sb_bread(sb, udf_fixed_to_variable(block));
else
return sb_bread(sb, block);
}
struct genericFormat *udf_add_extendedattr(struct inode *inode, uint32_t size,
uint32_t type, uint8_t loc)
{
uint8_t *ea = NULL, *ad = NULL;
int offset;
uint16_t crclen;
struct udf_inode_info *iinfo = UDF_I(inode);
ea = iinfo->i_ext.i_data;
if (iinfo->i_lenEAttr) {
ad = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
} else {
ad = ea;
size += sizeof(struct extendedAttrHeaderDesc);
}
offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) -
iinfo->i_lenAlloc;
/* TODO - Check for FreeEASpace */
if (loc & 0x01 && offset >= size) {
struct extendedAttrHeaderDesc *eahd;
eahd = (struct extendedAttrHeaderDesc *)ea;
if (iinfo->i_lenAlloc)
memmove(&ad[size], ad, iinfo->i_lenAlloc);
if (iinfo->i_lenEAttr) {
/* check checksum/crc */
if (eahd->descTag.tagIdent !=
cpu_to_le16(TAG_IDENT_EAHD) ||
le32_to_cpu(eahd->descTag.tagLocation) !=
iinfo->i_location.logicalBlockNum)
return NULL;
} else {
struct udf_sb_info *sbi = UDF_SB(inode->i_sb);
size -= sizeof(struct extendedAttrHeaderDesc);
iinfo->i_lenEAttr +=
sizeof(struct extendedAttrHeaderDesc);
eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD);
if (sbi->s_udfrev >= 0x0200)
eahd->descTag.descVersion = cpu_to_le16(3);
else
eahd->descTag.descVersion = cpu_to_le16(2);
eahd->descTag.tagSerialNum =
cpu_to_le16(sbi->s_serial_number);
eahd->descTag.tagLocation = cpu_to_le32(
iinfo->i_location.logicalBlockNum);
eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF);
eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF);
}
offset = iinfo->i_lenEAttr;
if (type < 2048) {
if (le32_to_cpu(eahd->appAttrLocation) <
iinfo->i_lenEAttr) {
uint32_t aal =
le32_to_cpu(eahd->appAttrLocation);
memmove(&ea[offset - aal + size],
&ea[aal], offset - aal);
offset -= aal;
eahd->appAttrLocation =
cpu_to_le32(aal + size);
}
if (le32_to_cpu(eahd->impAttrLocation) <
iinfo->i_lenEAttr) {
uint32_t ial =
le32_to_cpu(eahd->impAttrLocation);
memmove(&ea[offset - ial + size],
&ea[ial], offset - ial);
offset -= ial;
eahd->impAttrLocation =
cpu_to_le32(ial + size);
}
} else if (type < 65536) {
if (le32_to_cpu(eahd->appAttrLocation) <
iinfo->i_lenEAttr) {
uint32_t aal =
le32_to_cpu(eahd->appAttrLocation);
memmove(&ea[offset - aal + size],
&ea[aal], offset - aal);
offset -= aal;
eahd->appAttrLocation =
cpu_to_le32(aal + size);
}
}
/* rewrite CRC + checksum of eahd */
crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(tag);
eahd->descTag.descCRCLength = cpu_to_le16(crclen);
eahd->descTag.descCRC = cpu_to_le16(crc_itu_t(0, (char *)eahd +
sizeof(tag), crclen));
eahd->descTag.tagChecksum = udf_tag_checksum(&eahd->descTag);
iinfo->i_lenEAttr += size;
return (struct genericFormat *)&ea[offset];
}
if (loc & 0x02)
;
return NULL;
}
struct genericFormat *udf_get_extendedattr(struct inode *inode, uint32_t type,
uint8_t subtype)
{
struct genericFormat *gaf;
uint8_t *ea = NULL;
uint32_t offset;
struct udf_inode_info *iinfo = UDF_I(inode);
ea = iinfo->i_ext.i_data;
if (iinfo->i_lenEAttr) {
struct extendedAttrHeaderDesc *eahd;
eahd = (struct extendedAttrHeaderDesc *)ea;
/* check checksum/crc */
if (eahd->descTag.tagIdent !=
cpu_to_le16(TAG_IDENT_EAHD) ||
le32_to_cpu(eahd->descTag.tagLocation) !=
iinfo->i_location.logicalBlockNum)
return NULL;
if (type < 2048)
offset = sizeof(struct extendedAttrHeaderDesc);
else if (type < 65536)
offset = le32_to_cpu(eahd->impAttrLocation);
else
offset = le32_to_cpu(eahd->appAttrLocation);
while (offset < iinfo->i_lenEAttr) {
gaf = (struct genericFormat *)&ea[offset];
if (le32_to_cpu(gaf->attrType) == type &&
gaf->attrSubtype == subtype)
return gaf;
else
offset += le32_to_cpu(gaf->attrLength);
}
}
return NULL;
}
/*
* udf_read_tagged
*
* PURPOSE
* Read the first block of a tagged descriptor.
*
* HISTORY
* July 1, 1997 - Andrew E. Mileski
* Written, tested, and released.
*/
struct buffer_head *udf_read_tagged(struct super_block *sb, uint32_t block,
uint32_t location, uint16_t *ident)
{
tag *tag_p;
struct buffer_head *bh = NULL;
/* Read the block */
if (block == 0xFFFFFFFF)
return NULL;
bh = udf_tread(sb, block);
if (!bh) {
udf_debug("block=%d, location=%d: read failed\n",
block, location);
return NULL;
}
tag_p = (tag *)(bh->b_data);
*ident = le16_to_cpu(tag_p->tagIdent);
if (location != le32_to_cpu(tag_p->tagLocation)) {
udf_debug("location mismatch block %u, tag %u != %u\n",
block, le32_to_cpu(tag_p->tagLocation), location);
goto error_out;
}
/* Verify the tag checksum */
if (udf_tag_checksum(tag_p) != tag_p->tagChecksum) {
printk(KERN_ERR "udf: tag checksum failed block %d\n", block);
goto error_out;
}
/* Verify the tag version */
if (tag_p->descVersion != cpu_to_le16(0x0002U) &&
tag_p->descVersion != cpu_to_le16(0x0003U)) {
udf_debug("tag version 0x%04x != 0x0002 || 0x0003 block %d\n",
le16_to_cpu(tag_p->descVersion), block);
goto error_out;
}
/* Verify the descriptor CRC */
if (le16_to_cpu(tag_p->descCRCLength) + sizeof(tag) > sb->s_blocksize ||
le16_to_cpu(tag_p->descCRC) == crc_itu_t(0,
bh->b_data + sizeof(tag),
le16_to_cpu(tag_p->descCRCLength)))
return bh;
udf_debug("Crc failure block %d: crc = %d, crclen = %d\n", block,
le16_to_cpu(tag_p->descCRC), le16_to_cpu(tag_p->descCRCLength));
error_out:
brelse(bh);
return NULL;
}
struct buffer_head *udf_read_ptagged(struct super_block *sb, kernel_lb_addr loc,
uint32_t offset, uint16_t *ident)
{
return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset),
loc.logicalBlockNum + offset, ident);
}
void udf_update_tag(char *data, int length)
{
tag *tptr = (tag *)data;
length -= sizeof(tag);
tptr->descCRCLength = cpu_to_le16(length);
tptr->descCRC = cpu_to_le16(crc_itu_t(0, data + sizeof(tag), length));
tptr->tagChecksum = udf_tag_checksum(tptr);
}
void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum,
uint32_t loc, int length)
{
tag *tptr = (tag *)data;
tptr->tagIdent = cpu_to_le16(ident);
tptr->descVersion = cpu_to_le16(version);
tptr->tagSerialNum = cpu_to_le16(snum);
tptr->tagLocation = cpu_to_le32(loc);
udf_update_tag(data, length);
}
u8 udf_tag_checksum(const tag *t)
{
u8 *data = (u8 *)t;
u8 checksum = 0;
int i;
for (i = 0; i < sizeof(tag); ++i)
if (i != 4) /* position of checksum */
checksum += data[i];
return checksum;
}