/* * 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/udf_fs.h>#include <linux/buffer_head.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;	int i; 	ea = UDF_I_DATA(inode);	if (UDF_I_LENEATTR(inode))		ad = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode);	else	{		ad = ea;		size += sizeof(struct extendedAttrHeaderDesc);	} 	offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) -		UDF_I_LENALLOC(inode); 	/* TODO - Check for FreeEASpace */ 	if (loc & 0x01 && offset >= size)	{		struct extendedAttrHeaderDesc *eahd;		eahd = (struct extendedAttrHeaderDesc *)ea; 		if (UDF_I_LENALLOC(inode))		{			memmove(&ad[size], ad, UDF_I_LENALLOC(inode));		} 		if (UDF_I_LENEATTR(inode))		{			/* check checksum/crc */			if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD ||				le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum)			{				return NULL;			}		}		else		{			size -= sizeof(struct extendedAttrHeaderDesc);			UDF_I_LENEATTR(inode) += sizeof(struct extendedAttrHeaderDesc);			eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD);			if (UDF_SB_UDFREV(inode->i_sb) >= 0x0200)				eahd->descTag.descVersion = cpu_to_le16(3);			else				eahd->descTag.descVersion = cpu_to_le16(2);			eahd->descTag.tagSerialNum = cpu_to_le16(UDF_SB_SERIALNUM(inode->i_sb));			eahd->descTag.tagLocation = cpu_to_le32(UDF_I_LOCATION(inode).logicalBlockNum);			eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF);			eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF);		} 		offset = UDF_I_LENEATTR(inode);		if (type < 2048)		{			if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode))			{				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) < UDF_I_LENEATTR(inode))			{				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) < UDF_I_LENEATTR(inode))			{				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(udf_crc((char *)eahd + sizeof(tag), crclen, 0));		eahd->descTag.tagChecksum = 0;		for (i=0; i<16; i++)			if (i != 4)				eahd->descTag.tagChecksum += ((uint8_t *)&(eahd->descTag))[i];		UDF_I_LENEATTR(inode) += 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; 	ea = UDF_I_DATA(inode); 	if (UDF_I_LENEATTR(inode))	{		struct extendedAttrHeaderDesc *eahd;		eahd = (struct extendedAttrHeaderDesc *)ea; 		/* check checksum/crc */		if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD ||			le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).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 < UDF_I_LENEATTR(inode))		{			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;	register uint8_t checksum;	register int i; 	/* Read the block */	if (block == 0xFFFFFFFF)		return NULL; 	bh = udf_tread(sb, block + UDF_SB_SESSION(sb));	if (!bh)	{		udf_debug("block=%d, location=%d: read failed\n", block + UDF_SB_SESSION(sb), 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 + UDF_SB_SESSION(sb), le32_to_cpu(tag_p->tagLocation), location);		goto error_out;	}		/* Verify the tag checksum */	checksum = 0U;	for (i = 0; i < 4; i++)		checksum += (uint8_t)(bh->b_data[i]);	for (i = 5; i < 16; i++)		checksum += (uint8_t)(bh->b_data[i]);	if (checksum != tag_p->tagChecksum) {		printk(KERN_ERR "udf: tag checksum failed block %d\n", block);		goto error_out;	} 	/* Verify the tag version */	if (le16_to_cpu(tag_p->descVersion) != 0x0002U &&		le16_to_cpu(tag_p->descVersion) != 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) == udf_crc(bh->b_data + sizeof(tag),			le16_to_cpu(tag_p->descCRCLength), 0))	{		return bh;	}	udf_debug("Crc failure block %d: crc = %d, crclen = %d\n",		block + UDF_SB_SESSION(sb), 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_release_data(struct buffer_head *bh){	if (bh)		brelse(bh);} void udf_update_tag(char *data, int length){	tag *tptr = (tag *)data;	int i; 	length -= sizeof(tag); 	tptr->tagChecksum = 0;	tptr->descCRCLength = cpu_to_le16(length);	tptr->descCRC = cpu_to_le16(udf_crc(data + sizeof(tag), length, 0)); 	for (i=0; i<16; i++)		if (i != 4)			tptr->tagChecksum += (uint8_t)(data[i]);} 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);}