[mirror_ubuntu-artful-kernel.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 {
			struct udf_sb_info *sbi = UDF_SB(inode->i_sb);

			size -= sizeof(struct extendedAttrHeaderDesc);
			UDF_I_LENEATTR(inode) += 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(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;
	struct udf_sb_info *sbi = UDF_SB(sb);

	/* Read the block */
	if (block == 0xFFFFFFFF)
		return NULL;

	bh = udf_tread(sb, block + sbi->s_session);
	if (!bh) {
		udf_debug("block=%d, location=%d: read failed\n",
			  block + sbi->s_session, 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 + sbi->s_session, 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 + sbi->s_session, 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 {
6c79e987 MS	84	struct udf_sb_info *sbi = UDF_SB(inode->i_sb);
6c79e987 MS	85
1da177e4	86	size -= sizeof(struct extendedAttrHeaderDesc);
28de7948	87	UDF_I_LENEATTR(inode) += sizeof(struct extendedAttrHeaderDesc);
1da177e4	88	eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD);
6c79e987	89	if (sbi->s_udfrev >= 0x0200)
1da177e4 LT	90	eahd->descTag.descVersion = cpu_to_le16(3);
	91	else
	92	eahd->descTag.descVersion = cpu_to_le16(2);
6c79e987	93	eahd->descTag.tagSerialNum = cpu_to_le16(sbi->s_serial_number);
28de7948	94	eahd->descTag.tagLocation = cpu_to_le32(UDF_I_LOCATION(inode).logicalBlockNum);
1da177e4 LT	95	eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF);
	96	eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF);
	97	}
	98
	99	offset = UDF_I_LENEATTR(inode);
cb00ea35	100	if (type < 2048) {
28de7948 CG	101	if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode)) {
	102	uint32_t aal = le32_to_cpu(eahd->appAttrLocation);
	103	memmove(&ea[offset - aal + size],
	104	&ea[aal], offset - aal);
1da177e4 LT	105	offset -= aal;
	106	eahd->appAttrLocation = cpu_to_le32(aal + size);
	107	}
28de7948 CG	108	if (le32_to_cpu(eahd->impAttrLocation) < UDF_I_LENEATTR(inode)) {
	109	uint32_t ial = le32_to_cpu(eahd->impAttrLocation);
	110	memmove(&ea[offset - ial + size],
	111	&ea[ial], offset - ial);
1da177e4 LT	112	offset -= ial;
	113	eahd->impAttrLocation = cpu_to_le32(ial + size);
	114	}
cb00ea35	115	} else if (type < 65536) {
28de7948 CG	116	if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode)) {
	117	uint32_t aal = le32_to_cpu(eahd->appAttrLocation);
	118	memmove(&ea[offset - aal + size],
	119	&ea[aal], offset - aal);
1da177e4 LT	120	offset -= aal;
	121	eahd->appAttrLocation = cpu_to_le32(aal + size);
	122	}
	123	}
	124	/* rewrite CRC + checksum of eahd */
	125	crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(tag);
	126	eahd->descTag.descCRCLength = cpu_to_le16(crclen);
28de7948 CG	127	eahd->descTag.descCRC = cpu_to_le16(udf_crc((char *)eahd +
28de7948 CG	128	sizeof(tag), crclen, 0));
1da177e4	129	eahd->descTag.tagChecksum = 0;
cb00ea35	130	for (i = 0; i < 16; i++)
1da177e4	131	if (i != 4)
28de7948	132	eahd->descTag.tagChecksum += ((uint8_t *)&(eahd->descTag))[i];
1da177e4 LT	133	UDF_I_LENEATTR(inode) += size;
	134	return (struct genericFormat *)&ea[offset];
	135	}
cb00ea35	136	if (loc & 0x02) {
1da177e4	137	}
28de7948	138
1da177e4 LT	139	return NULL;
	140	}
	141
cb00ea35 CG	142	struct genericFormat udf_get_extendedattr(struct inode inode, uint32_t type,
cb00ea35 CG	143	uint8_t subtype)
1da177e4 LT	144	{
	145	struct genericFormat *gaf;
	146	uint8_t *ea = NULL;
	147	uint32_t offset;
	148
	149	ea = UDF_I_DATA(inode);
	150
cb00ea35	151	if (UDF_I_LENEATTR(inode)) {
1da177e4 LT	152	struct extendedAttrHeaderDesc *eahd;
	153	eahd = (struct extendedAttrHeaderDesc *)ea;
	154
	155	/* check checksum/crc */
	156	if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD \|\|
28de7948	157	le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum) {
1da177e4 LT	158	return NULL;
1da177e4 LT	159	}
cb00ea35	160
1da177e4 LT	161	if (type < 2048)
	162	offset = sizeof(struct extendedAttrHeaderDesc);
	163	else if (type < 65536)
	164	offset = le32_to_cpu(eahd->impAttrLocation);
	165	else
	166	offset = le32_to_cpu(eahd->appAttrLocation);
	167
cb00ea35	168	while (offset < UDF_I_LENEATTR(inode)) {
1da177e4	169	gaf = (struct genericFormat *)&ea[offset];
28de7948	170	if (le32_to_cpu(gaf->attrType) == type && gaf->attrSubtype == subtype)
1da177e4 LT	171	return gaf;
	172	else
	173	offset += le32_to_cpu(gaf->attrLength);
	174	}
	175	}
28de7948	176
1da177e4 LT	177	return NULL;
	178	}
	179
	180	/*
	181	* udf_read_tagged
	182	*
	183	* PURPOSE
	184	* Read the first block of a tagged descriptor.
	185	*
	186	* HISTORY
	187	* July 1, 1997 - Andrew E. Mileski
	188	* Written, tested, and released.
	189	*/
cb00ea35 CG	190	struct buffer_head udf_read_tagged(struct super_block sb, uint32_t block,
cb00ea35 CG	191	uint32_t location, uint16_t * ident)
1da177e4 LT	192	{
	193	tag *tag_p;
	194	struct buffer_head *bh = NULL;
	195	register uint8_t checksum;
	196	register int i;
6c79e987	197	struct udf_sb_info *sbi = UDF_SB(sb);
1da177e4 LT	198
	199	/* Read the block */
	200	if (block == 0xFFFFFFFF)
	201	return NULL;
	202
6c79e987	203	bh = udf_tread(sb, block + sbi->s_session);
cb00ea35 CG	204	if (!bh) {
cb00ea35 CG	205	udf_debug("block=%d, location=%d: read failed\n",
6c79e987	206	block + sbi->s_session, location);
1da177e4 LT	207	return NULL;
	208	}
	209
28de7948	210	tag_p = (tag *)(bh->b_data);
1da177e4 LT	211
	212	*ident = le16_to_cpu(tag_p->tagIdent);
	213
cb00ea35	214	if (location != le32_to_cpu(tag_p->tagLocation)) {
1da177e4	215	udf_debug("location mismatch block %u, tag %u != %u\n",
6c79e987	216	block + sbi->s_session, le32_to_cpu(tag_p->tagLocation), location);
1da177e4 LT	217	goto error_out;
1da177e4 LT	218	}
cb00ea35	219
1da177e4 LT	220	/* Verify the tag checksum */
	221	checksum = 0U;
	222	for (i = 0; i < 4; i++)
28de7948	223	checksum += (uint8_t)(bh->b_data[i]);
1da177e4	224	for (i = 5; i < 16; i++)
28de7948	225	checksum += (uint8_t)(bh->b_data[i]);
1da177e4 LT	226	if (checksum != tag_p->tagChecksum) {
	227	printk(KERN_ERR "udf: tag checksum failed block %d\n", block);
	228	goto error_out;
	229	}
	230
	231	/* Verify the tag version */
	232	if (le16_to_cpu(tag_p->descVersion) != 0x0002U &&
cb00ea35	233	le16_to_cpu(tag_p->descVersion) != 0x0003U) {
1da177e4	234	udf_debug("tag version 0x%04x != 0x0002 \|\| 0x0003 block %d\n",
cb00ea35	235	le16_to_cpu(tag_p->descVersion), block);
1da177e4 LT	236	goto error_out;
	237	}
	238
	239	/* Verify the descriptor CRC */
	240	if (le16_to_cpu(tag_p->descCRCLength) + sizeof(tag) > sb->s_blocksize \|\|
cb00ea35	241	le16_to_cpu(tag_p->descCRC) == udf_crc(bh->b_data + sizeof(tag),
28de7948	242	le16_to_cpu(tag_p->descCRCLength), 0)) {
1da177e4 LT	243	return bh;
	244	}
	245	udf_debug("Crc failure block %d: crc = %d, crclen = %d\n",
6c79e987	246	block + sbi->s_session, le16_to_cpu(tag_p->descCRC),
cb00ea35	247	le16_to_cpu(tag_p->descCRCLength));
1da177e4	248
28de7948	249	error_out:
1da177e4 LT	250	brelse(bh);
	251	return NULL;
	252	}
	253
cb00ea35 CG	254	struct buffer_head udf_read_ptagged(struct super_block sb, kernel_lb_addr loc,
cb00ea35 CG	255	uint32_t offset, uint16_t * ident)
1da177e4 LT	256	{
1da177e4 LT	257	return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset),
cb00ea35	258	loc.logicalBlockNum + offset, ident);
1da177e4 LT	259	}
1da177e4 LT	260
1da177e4 LT	261	void udf_update_tag(char *data, int length)
1da177e4 LT	262	{
28de7948	263	tag tptr = (tag )data;
1da177e4 LT	264	int i;
	265
	266	length -= sizeof(tag);
	267
	268	tptr->tagChecksum = 0;
	269	tptr->descCRCLength = cpu_to_le16(length);
	270	tptr->descCRC = cpu_to_le16(udf_crc(data + sizeof(tag), length, 0));
	271
cb00ea35	272	for (i = 0; i < 16; i++)
1da177e4	273	if (i != 4)
28de7948	274	tptr->tagChecksum += (uint8_t)(data[i]);
1da177e4 LT	275	}
	276
	277	void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum,
cb00ea35	278	uint32_t loc, int length)
1da177e4	279	{
28de7948	280	tag tptr = (tag )data;
1da177e4 LT	281	tptr->tagIdent = cpu_to_le16(ident);
	282	tptr->descVersion = cpu_to_le16(version);
	283	tptr->tagSerialNum = cpu_to_le16(snum);
	284	tptr->tagLocation = cpu_to_le32(loc);
	285	udf_update_tag(data, length);
	286	}