303 строки
7.6 KiB
C
303 строки
7.6 KiB
C
/*
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* misc.c
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*
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* PURPOSE
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* Miscellaneous routines for the OSTA-UDF(tm) filesystem.
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*
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* COPYRIGHT
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* This file is distributed under the terms of the GNU General Public
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* License (GPL). Copies of the GPL can be obtained from:
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* ftp://prep.ai.mit.edu/pub/gnu/GPL
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* Each contributing author retains all rights to their own work.
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*
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* (C) 1998 Dave Boynton
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* (C) 1998-2004 Ben Fennema
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* (C) 1999-2000 Stelias Computing Inc
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*
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* HISTORY
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*
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* 04/19/99 blf partial support for reading/writing specific EA's
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*/
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#include "udfdecl.h"
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#include <linux/fs.h>
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#include <linux/string.h>
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#include <linux/udf_fs.h>
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#include <linux/buffer_head.h>
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#include "udf_i.h"
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#include "udf_sb.h"
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struct buffer_head *
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udf_tgetblk(struct super_block *sb, int block)
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{
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if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
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return sb_getblk(sb, udf_fixed_to_variable(block));
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else
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return sb_getblk(sb, block);
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}
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struct buffer_head *
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udf_tread(struct super_block *sb, int block)
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{
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if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
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return sb_bread(sb, udf_fixed_to_variable(block));
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else
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return sb_bread(sb, block);
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}
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struct genericFormat *
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udf_add_extendedattr(struct inode * inode, uint32_t size, uint32_t type,
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uint8_t loc)
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{
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uint8_t *ea = NULL, *ad = NULL;
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int offset;
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uint16_t crclen;
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int i;
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ea = UDF_I_DATA(inode);
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if (UDF_I_LENEATTR(inode))
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ad = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode);
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else
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{
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ad = ea;
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size += sizeof(struct extendedAttrHeaderDesc);
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}
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offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) -
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UDF_I_LENALLOC(inode);
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/* TODO - Check for FreeEASpace */
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if (loc & 0x01 && offset >= size)
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{
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struct extendedAttrHeaderDesc *eahd;
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eahd = (struct extendedAttrHeaderDesc *)ea;
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if (UDF_I_LENALLOC(inode))
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{
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memmove(&ad[size], ad, UDF_I_LENALLOC(inode));
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}
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if (UDF_I_LENEATTR(inode))
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{
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/* check checksum/crc */
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if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD ||
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le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum)
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{
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return NULL;
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}
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}
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else
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{
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size -= sizeof(struct extendedAttrHeaderDesc);
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UDF_I_LENEATTR(inode) += sizeof(struct extendedAttrHeaderDesc);
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eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD);
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if (UDF_SB_UDFREV(inode->i_sb) >= 0x0200)
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eahd->descTag.descVersion = cpu_to_le16(3);
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else
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eahd->descTag.descVersion = cpu_to_le16(2);
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eahd->descTag.tagSerialNum = cpu_to_le16(UDF_SB_SERIALNUM(inode->i_sb));
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eahd->descTag.tagLocation = cpu_to_le32(UDF_I_LOCATION(inode).logicalBlockNum);
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eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF);
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eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF);
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}
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offset = UDF_I_LENEATTR(inode);
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if (type < 2048)
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{
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if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode))
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{
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uint32_t aal = le32_to_cpu(eahd->appAttrLocation);
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memmove(&ea[offset - aal + size],
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&ea[aal], offset - aal);
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offset -= aal;
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eahd->appAttrLocation = cpu_to_le32(aal + size);
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}
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if (le32_to_cpu(eahd->impAttrLocation) < UDF_I_LENEATTR(inode))
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{
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uint32_t ial = le32_to_cpu(eahd->impAttrLocation);
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memmove(&ea[offset - ial + size],
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&ea[ial], offset - ial);
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offset -= ial;
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eahd->impAttrLocation = cpu_to_le32(ial + size);
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}
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}
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else if (type < 65536)
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{
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if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode))
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{
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uint32_t aal = le32_to_cpu(eahd->appAttrLocation);
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memmove(&ea[offset - aal + size],
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&ea[aal], offset - aal);
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offset -= aal;
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eahd->appAttrLocation = cpu_to_le32(aal + size);
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}
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}
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/* rewrite CRC + checksum of eahd */
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crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(tag);
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eahd->descTag.descCRCLength = cpu_to_le16(crclen);
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eahd->descTag.descCRC = cpu_to_le16(udf_crc((char *)eahd + sizeof(tag), crclen, 0));
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eahd->descTag.tagChecksum = 0;
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for (i=0; i<16; i++)
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if (i != 4)
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eahd->descTag.tagChecksum += ((uint8_t *)&(eahd->descTag))[i];
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UDF_I_LENEATTR(inode) += size;
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return (struct genericFormat *)&ea[offset];
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}
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if (loc & 0x02)
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{
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}
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return NULL;
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}
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struct genericFormat *
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udf_get_extendedattr(struct inode *inode, uint32_t type, uint8_t subtype)
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{
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struct genericFormat *gaf;
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uint8_t *ea = NULL;
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uint32_t offset;
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ea = UDF_I_DATA(inode);
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if (UDF_I_LENEATTR(inode))
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{
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struct extendedAttrHeaderDesc *eahd;
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eahd = (struct extendedAttrHeaderDesc *)ea;
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/* check checksum/crc */
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if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD ||
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le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum)
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{
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return NULL;
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}
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if (type < 2048)
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offset = sizeof(struct extendedAttrHeaderDesc);
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else if (type < 65536)
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offset = le32_to_cpu(eahd->impAttrLocation);
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else
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offset = le32_to_cpu(eahd->appAttrLocation);
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while (offset < UDF_I_LENEATTR(inode))
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{
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gaf = (struct genericFormat *)&ea[offset];
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if (le32_to_cpu(gaf->attrType) == type && gaf->attrSubtype == subtype)
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return gaf;
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else
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offset += le32_to_cpu(gaf->attrLength);
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}
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}
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return NULL;
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}
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/*
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* udf_read_tagged
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*
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* PURPOSE
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* Read the first block of a tagged descriptor.
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*
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* HISTORY
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* July 1, 1997 - Andrew E. Mileski
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* Written, tested, and released.
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*/
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struct buffer_head *
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udf_read_tagged(struct super_block *sb, uint32_t block, uint32_t location, uint16_t *ident)
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{
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tag *tag_p;
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struct buffer_head *bh = NULL;
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register uint8_t checksum;
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register int i;
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/* Read the block */
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if (block == 0xFFFFFFFF)
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return NULL;
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bh = udf_tread(sb, block + UDF_SB_SESSION(sb));
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if (!bh)
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{
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udf_debug("block=%d, location=%d: read failed\n", block + UDF_SB_SESSION(sb), location);
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return NULL;
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}
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tag_p = (tag *)(bh->b_data);
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*ident = le16_to_cpu(tag_p->tagIdent);
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if ( location != le32_to_cpu(tag_p->tagLocation) )
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{
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udf_debug("location mismatch block %u, tag %u != %u\n",
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block + UDF_SB_SESSION(sb), le32_to_cpu(tag_p->tagLocation), location);
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goto error_out;
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}
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/* Verify the tag checksum */
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checksum = 0U;
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for (i = 0; i < 4; i++)
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checksum += (uint8_t)(bh->b_data[i]);
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for (i = 5; i < 16; i++)
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checksum += (uint8_t)(bh->b_data[i]);
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if (checksum != tag_p->tagChecksum) {
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printk(KERN_ERR "udf: tag checksum failed block %d\n", block);
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goto error_out;
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}
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/* Verify the tag version */
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if (le16_to_cpu(tag_p->descVersion) != 0x0002U &&
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le16_to_cpu(tag_p->descVersion) != 0x0003U)
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{
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udf_debug("tag version 0x%04x != 0x0002 || 0x0003 block %d\n",
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le16_to_cpu(tag_p->descVersion), block);
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goto error_out;
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}
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/* Verify the descriptor CRC */
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if (le16_to_cpu(tag_p->descCRCLength) + sizeof(tag) > sb->s_blocksize ||
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le16_to_cpu(tag_p->descCRC) == udf_crc(bh->b_data + sizeof(tag),
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le16_to_cpu(tag_p->descCRCLength), 0))
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{
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return bh;
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}
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udf_debug("Crc failure block %d: crc = %d, crclen = %d\n",
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block + UDF_SB_SESSION(sb), le16_to_cpu(tag_p->descCRC), le16_to_cpu(tag_p->descCRCLength));
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error_out:
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brelse(bh);
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return NULL;
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}
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struct buffer_head *
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udf_read_ptagged(struct super_block *sb, kernel_lb_addr loc, uint32_t offset, uint16_t *ident)
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{
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return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset),
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loc.logicalBlockNum + offset, ident);
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}
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void udf_update_tag(char *data, int length)
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{
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tag *tptr = (tag *)data;
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int i;
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length -= sizeof(tag);
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tptr->tagChecksum = 0;
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tptr->descCRCLength = cpu_to_le16(length);
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tptr->descCRC = cpu_to_le16(udf_crc(data + sizeof(tag), length, 0));
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for (i=0; i<16; i++)
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if (i != 4)
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tptr->tagChecksum += (uint8_t)(data[i]);
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}
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void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum,
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uint32_t loc, int length)
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{
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tag *tptr = (tag *)data;
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tptr->tagIdent = cpu_to_le16(ident);
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tptr->descVersion = cpu_to_le16(version);
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tptr->tagSerialNum = cpu_to_le16(snum);
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tptr->tagLocation = cpu_to_le32(loc);
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udf_update_tag(data, length);
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}
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