[linux.git] / fs / udf / misc.c

/*
 * 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_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);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* misc.c
	3	*
	4	* PURPOSE
	5	* Miscellaneous routines for the OSTA-UDF(tm) filesystem.
	6	*
1da177e4 LT	7	* COPYRIGHT
	8	* This file is distributed under the terms of the GNU General Public
	9	* License (GPL). Copies of the GPL can be obtained from:
	10	* ftp://prep.ai.mit.edu/pub/gnu/GPL
	11	* Each contributing author retains all rights to their own work.
	12	*
	13	* (C) 1998 Dave Boynton
	14	* (C) 1998-2004 Ben Fennema
	15	* (C) 1999-2000 Stelias Computing Inc
	16	*
	17	* HISTORY
	18	*
	19	* 04/19/99 blf partial support for reading/writing specific EA's
	20	*/
	21
	22	#include "udfdecl.h"
	23
	24	#include <linux/fs.h>
	25	#include <linux/string.h>
	26	#include <linux/udf_fs.h>
	27	#include <linux/buffer_head.h>
	28
	29	#include "udf_i.h"
	30	#include "udf_sb.h"
	31
cb00ea35	32	struct buffer_head udf_tgetblk(struct super_block sb, int block)
1da177e4 LT	33	{
	34	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
	35	return sb_getblk(sb, udf_fixed_to_variable(block));
	36	else
	37	return sb_getblk(sb, block);
	38	}
	39
cb00ea35	40	struct buffer_head udf_tread(struct super_block sb, int block)
1da177e4 LT	41	{
	42	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
	43	return sb_bread(sb, udf_fixed_to_variable(block));
	44	else
	45	return sb_bread(sb, block);
	46	}
	47
cb00ea35 CG	48	struct genericFormat udf_add_extendedattr(struct inode inode, uint32_t size,
cb00ea35 CG	49	uint32_t type, uint8_t loc)
1da177e4 LT	50	{
	51	uint8_t ea = NULL, ad = NULL;
	52	int offset;
	53	uint16_t crclen;
	54	int i;
	55
	56	ea = UDF_I_DATA(inode);
28de7948	57	if (UDF_I_LENEATTR(inode)) {
1da177e4	58	ad = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode);
28de7948	59	} else {
1da177e4 LT	60	ad = ea;
	61	size += sizeof(struct extendedAttrHeaderDesc);
	62	}
	63
	64	offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) -
28de7948	65	UDF_I_LENALLOC(inode);
1da177e4 LT	66
	67	/* TODO - Check for FreeEASpace */
	68
cb00ea35	69	if (loc & 0x01 && offset >= size) {
1da177e4 LT	70	struct extendedAttrHeaderDesc *eahd;
	71	eahd = (struct extendedAttrHeaderDesc *)ea;
	72
cb00ea35	73	if (UDF_I_LENALLOC(inode)) {
1da177e4 LT	74	memmove(&ad[size], ad, UDF_I_LENALLOC(inode));
	75	}
	76
cb00ea35	77	if (UDF_I_LENEATTR(inode)) {
1da177e4	78	/* check checksum/crc */
28de7948 CG	79	if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD \|\|
28de7948 CG	80	le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum) {
1da177e4 LT	81	return NULL;
1da177e4 LT	82	}
cb00ea35	83	} else {
1da177e4	84	size -= sizeof(struct extendedAttrHeaderDesc);
28de7948	85	UDF_I_LENEATTR(inode) += sizeof(struct extendedAttrHeaderDesc);
1da177e4 LT	86	eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD);
	87	if (UDF_SB_UDFREV(inode->i_sb) >= 0x0200)
	88	eahd->descTag.descVersion = cpu_to_le16(3);
	89	else
	90	eahd->descTag.descVersion = cpu_to_le16(2);
28de7948 CG	91	eahd->descTag.tagSerialNum = cpu_to_le16(UDF_SB_SERIALNUM(inode->i_sb));
28de7948 CG	92	eahd->descTag.tagLocation = cpu_to_le32(UDF_I_LOCATION(inode).logicalBlockNum);
1da177e4 LT	93	eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF);
	94	eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF);
	95	}
	96
	97	offset = UDF_I_LENEATTR(inode);
cb00ea35	98	if (type < 2048) {
28de7948 CG	99	if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode)) {
	100	uint32_t aal = le32_to_cpu(eahd->appAttrLocation);
	101	memmove(&ea[offset - aal + size],
	102	&ea[aal], offset - aal);
1da177e4 LT	103	offset -= aal;
	104	eahd->appAttrLocation = cpu_to_le32(aal + size);
	105	}
28de7948 CG	106	if (le32_to_cpu(eahd->impAttrLocation) < UDF_I_LENEATTR(inode)) {
	107	uint32_t ial = le32_to_cpu(eahd->impAttrLocation);
	108	memmove(&ea[offset - ial + size],
	109	&ea[ial], offset - ial);
1da177e4 LT	110	offset -= ial;
	111	eahd->impAttrLocation = cpu_to_le32(ial + size);
	112	}
cb00ea35	113	} else if (type < 65536) {
28de7948 CG	114	if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode)) {
	115	uint32_t aal = le32_to_cpu(eahd->appAttrLocation);
	116	memmove(&ea[offset - aal + size],
	117	&ea[aal], offset - aal);
1da177e4 LT	118	offset -= aal;
	119	eahd->appAttrLocation = cpu_to_le32(aal + size);
	120	}
	121	}
	122	/* rewrite CRC + checksum of eahd */
	123	crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(tag);
	124	eahd->descTag.descCRCLength = cpu_to_le16(crclen);
28de7948 CG	125	eahd->descTag.descCRC = cpu_to_le16(udf_crc((char *)eahd +
28de7948 CG	126	sizeof(tag), crclen, 0));
1da177e4	127	eahd->descTag.tagChecksum = 0;
cb00ea35	128	for (i = 0; i < 16; i++)
1da177e4	129	if (i != 4)
28de7948	130	eahd->descTag.tagChecksum += ((uint8_t *)&(eahd->descTag))[i];
1da177e4 LT	131	UDF_I_LENEATTR(inode) += size;
	132	return (struct genericFormat *)&ea[offset];
	133	}
cb00ea35	134	if (loc & 0x02) {
1da177e4	135	}
28de7948	136
1da177e4 LT	137	return NULL;
	138	}
	139
cb00ea35 CG	140	struct genericFormat udf_get_extendedattr(struct inode inode, uint32_t type,
cb00ea35 CG	141	uint8_t subtype)
1da177e4 LT	142	{
	143	struct genericFormat *gaf;
	144	uint8_t *ea = NULL;
	145	uint32_t offset;
	146
	147	ea = UDF_I_DATA(inode);
	148
cb00ea35	149	if (UDF_I_LENEATTR(inode)) {
1da177e4 LT	150	struct extendedAttrHeaderDesc *eahd;
	151	eahd = (struct extendedAttrHeaderDesc *)ea;
	152
	153	/* check checksum/crc */
	154	if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD \|\|
28de7948	155	le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum) {
1da177e4 LT	156	return NULL;
1da177e4 LT	157	}
cb00ea35	158
1da177e4 LT	159	if (type < 2048)
	160	offset = sizeof(struct extendedAttrHeaderDesc);
	161	else if (type < 65536)
	162	offset = le32_to_cpu(eahd->impAttrLocation);
	163	else
	164	offset = le32_to_cpu(eahd->appAttrLocation);
	165
cb00ea35	166	while (offset < UDF_I_LENEATTR(inode)) {
1da177e4	167	gaf = (struct genericFormat *)&ea[offset];
28de7948	168	if (le32_to_cpu(gaf->attrType) == type && gaf->attrSubtype == subtype)
1da177e4 LT	169	return gaf;
	170	else
	171	offset += le32_to_cpu(gaf->attrLength);
	172	}
	173	}
28de7948	174
1da177e4 LT	175	return NULL;
	176	}
	177
	178	/*
	179	* udf_read_tagged
	180	*
	181	* PURPOSE
	182	* Read the first block of a tagged descriptor.
	183	*
	184	* HISTORY
	185	* July 1, 1997 - Andrew E. Mileski
	186	* Written, tested, and released.
	187	*/
cb00ea35 CG	188	struct buffer_head udf_read_tagged(struct super_block sb, uint32_t block,
cb00ea35 CG	189	uint32_t location, uint16_t * ident)
1da177e4 LT	190	{
	191	tag *tag_p;
	192	struct buffer_head *bh = NULL;
	193	register uint8_t checksum;
	194	register int i;
	195
	196	/* Read the block */
	197	if (block == 0xFFFFFFFF)
	198	return NULL;
	199
	200	bh = udf_tread(sb, block + UDF_SB_SESSION(sb));
cb00ea35 CG	201	if (!bh) {
	202	udf_debug("block=%d, location=%d: read failed\n",
	203	block + UDF_SB_SESSION(sb), location);
1da177e4 LT	204	return NULL;
	205	}
	206
28de7948	207	tag_p = (tag *)(bh->b_data);
1da177e4 LT	208
	209	*ident = le16_to_cpu(tag_p->tagIdent);
	210
cb00ea35	211	if (location != le32_to_cpu(tag_p->tagLocation)) {
1da177e4	212	udf_debug("location mismatch block %u, tag %u != %u\n",
28de7948	213	block + UDF_SB_SESSION(sb), le32_to_cpu(tag_p->tagLocation), location);
1da177e4 LT	214	goto error_out;
1da177e4 LT	215	}
cb00ea35	216
1da177e4 LT	217	/* Verify the tag checksum */
	218	checksum = 0U;
	219	for (i = 0; i < 4; i++)
28de7948	220	checksum += (uint8_t)(bh->b_data[i]);
1da177e4	221	for (i = 5; i < 16; i++)
28de7948	222	checksum += (uint8_t)(bh->b_data[i]);
1da177e4 LT	223	if (checksum != tag_p->tagChecksum) {
	224	printk(KERN_ERR "udf: tag checksum failed block %d\n", block);
	225	goto error_out;
	226	}
	227
	228	/* Verify the tag version */
	229	if (le16_to_cpu(tag_p->descVersion) != 0x0002U &&
cb00ea35	230	le16_to_cpu(tag_p->descVersion) != 0x0003U) {
1da177e4	231	udf_debug("tag version 0x%04x != 0x0002 \|\| 0x0003 block %d\n",
cb00ea35	232	le16_to_cpu(tag_p->descVersion), block);
1da177e4 LT	233	goto error_out;
	234	}
	235
	236	/* Verify the descriptor CRC */
	237	if (le16_to_cpu(tag_p->descCRCLength) + sizeof(tag) > sb->s_blocksize \|\|
cb00ea35	238	le16_to_cpu(tag_p->descCRC) == udf_crc(bh->b_data + sizeof(tag),
28de7948	239	le16_to_cpu(tag_p->descCRCLength), 0)) {
1da177e4 LT	240	return bh;
	241	}
	242	udf_debug("Crc failure block %d: crc = %d, crclen = %d\n",
cb00ea35 CG	243	block + UDF_SB_SESSION(sb), le16_to_cpu(tag_p->descCRC),
cb00ea35 CG	244	le16_to_cpu(tag_p->descCRCLength));
1da177e4	245
28de7948	246	error_out:
1da177e4 LT	247	brelse(bh);
	248	return NULL;
	249	}
	250
cb00ea35 CG	251	struct buffer_head udf_read_ptagged(struct super_block sb, kernel_lb_addr loc,
cb00ea35 CG	252	uint32_t offset, uint16_t * ident)
1da177e4 LT	253	{
1da177e4 LT	254	return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset),
cb00ea35	255	loc.logicalBlockNum + offset, ident);
1da177e4 LT	256	}
1da177e4 LT	257
1da177e4 LT	258	void udf_update_tag(char *data, int length)
1da177e4 LT	259	{
28de7948	260	tag tptr = (tag )data;
1da177e4 LT	261	int i;
	262
	263	length -= sizeof(tag);
	264
	265	tptr->tagChecksum = 0;
	266	tptr->descCRCLength = cpu_to_le16(length);
	267	tptr->descCRC = cpu_to_le16(udf_crc(data + sizeof(tag), length, 0));
	268
cb00ea35	269	for (i = 0; i < 16; i++)
1da177e4	270	if (i != 4)
28de7948	271	tptr->tagChecksum += (uint8_t)(data[i]);
1da177e4 LT	272	}
	273
	274	void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum,
cb00ea35	275	uint32_t loc, int length)
1da177e4	276	{
28de7948	277	tag tptr = (tag )data;
1da177e4 LT	278	tptr->tagIdent = cpu_to_le16(ident);
	279	tptr->descVersion = cpu_to_le16(version);
	280	tptr->tagSerialNum = cpu_to_le16(snum);
	281	tptr->tagLocation = cpu_to_le32(loc);
	282	udf_update_tag(data, length);
	283	}