[linux-2.6-block.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/crc-itu-t.h>

#include "udf_i.h"
#include "udf_sb.h"

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_data;
	if (iinfo->i_lenEAttr) {
		ad = iinfo->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(struct tag);
		eahd->descTag.descCRCLength = cpu_to_le16(crclen);
		eahd->descTag.descCRC = cpu_to_le16(crc_itu_t(0, (char *)eahd +
						sizeof(struct tag), crclen));
		eahd->descTag.tagChecksum = udf_tag_checksum(&eahd->descTag);
		iinfo->i_lenEAttr += size;
		return (struct genericFormat *)&ea[offset];
	}

	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_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 + sizeof(*gaf) < iinfo->i_lenEAttr) {
			uint32_t attrLength;

			gaf = (struct genericFormat *)&ea[offset];
			attrLength = le32_to_cpu(gaf->attrLength);

			/* Detect undersized elements and buffer overflows */
			if ((attrLength < sizeof(*gaf)) ||
			    (attrLength > (iinfo->i_lenEAttr - offset)))
				break;

			if (le32_to_cpu(gaf->attrType) == type &&
					gaf->attrSubtype == subtype)
				return gaf;
			else
				offset += 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)
{
	struct tag *tag_p;
	struct buffer_head *bh = NULL;
	u8 checksum;

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

	bh = sb_bread(sb, block);
	if (!bh) {
		udf_err(sb, "read failed, block=%u, location=%u\n",
			block, location);
		return NULL;
	}

	tag_p = (struct 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 */
	checksum = udf_tag_checksum(tag_p);
	if (checksum != tag_p->tagChecksum) {
		udf_err(sb, "tag checksum failed, block %u: 0x%02x != 0x%02x\n",
			block, checksum, tag_p->tagChecksum);
		goto error_out;
	}

	/* Verify the tag version */
	if (tag_p->descVersion != cpu_to_le16(0x0002U) &&
	    tag_p->descVersion != cpu_to_le16(0x0003U)) {
		udf_err(sb, "tag version 0x%04x != 0x0002 || 0x0003, block %u\n",
			le16_to_cpu(tag_p->descVersion), block);
		goto error_out;
	}

	/* Verify the descriptor CRC */
	if (le16_to_cpu(tag_p->descCRCLength) + sizeof(struct tag) > sb->s_blocksize ||
	    le16_to_cpu(tag_p->descCRC) == crc_itu_t(0,
					bh->b_data + sizeof(struct tag),
					le16_to_cpu(tag_p->descCRCLength)))
		return bh;

	udf_debug("Crc failure block %u: crc = %u, crclen = %u\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,
				     struct 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)
{
	struct tag *tptr = (struct tag *)data;
	length -= sizeof(struct tag);

	tptr->descCRCLength = cpu_to_le16(length);
	tptr->descCRC = cpu_to_le16(crc_itu_t(0, data + sizeof(struct 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)
{
	struct tag *tptr = (struct 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 struct tag *t)
{
	u8 *data = (u8 *)t;
	u8 checksum = 0;
	int i;
	for (i = 0; i < sizeof(struct tag); ++i)
		if (i != 4) /* position of checksum */
			checksum += data[i];
	return checksum;
}
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>
f845fced	26	#include <linux/crc-itu-t.h>
1da177e4 LT	27
	28	#include "udf_i.h"
	29	#include "udf_sb.h"
	30
cb00ea35 CG	31	struct genericFormat udf_add_extendedattr(struct inode inode, uint32_t size,
cb00ea35 CG	32	uint32_t type, uint8_t loc)
1da177e4 LT	33	{
	34	uint8_t ea = NULL, ad = NULL;
	35	int offset;
	36	uint16_t crclen;
48d6d8ff	37	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	38
382a2287	39	ea = iinfo->i_data;
48d6d8ff	40	if (iinfo->i_lenEAttr) {
382a2287	41	ad = iinfo->i_data + iinfo->i_lenEAttr;
28de7948	42	} else {
1da177e4 LT	43	ad = ea;
	44	size += sizeof(struct extendedAttrHeaderDesc);
	45	}
	46
	47	offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) -
48d6d8ff	48	iinfo->i_lenAlloc;
1da177e4 LT	49
	50	/* TODO - Check for FreeEASpace */
	51
cb00ea35	52	if (loc & 0x01 && offset >= size) {
1da177e4 LT	53	struct extendedAttrHeaderDesc *eahd;
	54	eahd = (struct extendedAttrHeaderDesc *)ea;
	55
48d6d8ff MS	56	if (iinfo->i_lenAlloc)
48d6d8ff MS	57	memmove(&ad[size], ad, iinfo->i_lenAlloc);
1da177e4	58
48d6d8ff	59	if (iinfo->i_lenEAttr) {
1da177e4	60	/* check checksum/crc */
5e0f0017 MS	61	if (eahd->descTag.tagIdent !=
5e0f0017 MS	62	cpu_to_le16(TAG_IDENT_EAHD) \|\|
4b11111a	63	le32_to_cpu(eahd->descTag.tagLocation) !=
48d6d8ff	64	iinfo->i_location.logicalBlockNum)
1da177e4	65	return NULL;
cb00ea35	66	} else {
6c79e987 MS	67	struct udf_sb_info *sbi = UDF_SB(inode->i_sb);
6c79e987 MS	68
1da177e4	69	size -= sizeof(struct extendedAttrHeaderDesc);
48d6d8ff	70	iinfo->i_lenEAttr +=
4b11111a	71	sizeof(struct extendedAttrHeaderDesc);
1da177e4	72	eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD);
6c79e987	73	if (sbi->s_udfrev >= 0x0200)
1da177e4 LT	74	eahd->descTag.descVersion = cpu_to_le16(3);
	75	else
	76	eahd->descTag.descVersion = cpu_to_le16(2);
4b11111a MS	77	eahd->descTag.tagSerialNum =
	78	cpu_to_le16(sbi->s_serial_number);
	79	eahd->descTag.tagLocation = cpu_to_le32(
48d6d8ff	80	iinfo->i_location.logicalBlockNum);
1da177e4 LT	81	eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF);
	82	eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF);
	83	}
	84
48d6d8ff	85	offset = iinfo->i_lenEAttr;
cb00ea35	86	if (type < 2048) {
4b11111a	87	if (le32_to_cpu(eahd->appAttrLocation) <
48d6d8ff	88	iinfo->i_lenEAttr) {
4b11111a MS	89	uint32_t aal =
4b11111a MS	90	le32_to_cpu(eahd->appAttrLocation);
28de7948 CG	91	memmove(&ea[offset - aal + size],
28de7948 CG	92	&ea[aal], offset - aal);
1da177e4	93	offset -= aal;
4b11111a MS	94	eahd->appAttrLocation =
4b11111a MS	95	cpu_to_le32(aal + size);
1da177e4	96	}
4b11111a	97	if (le32_to_cpu(eahd->impAttrLocation) <
48d6d8ff	98	iinfo->i_lenEAttr) {
4b11111a MS	99	uint32_t ial =
4b11111a MS	100	le32_to_cpu(eahd->impAttrLocation);
28de7948 CG	101	memmove(&ea[offset - ial + size],
28de7948 CG	102	&ea[ial], offset - ial);
1da177e4	103	offset -= ial;
4b11111a MS	104	eahd->impAttrLocation =
4b11111a MS	105	cpu_to_le32(ial + size);
1da177e4	106	}
cb00ea35	107	} else if (type < 65536) {
4b11111a	108	if (le32_to_cpu(eahd->appAttrLocation) <
48d6d8ff	109	iinfo->i_lenEAttr) {
4b11111a MS	110	uint32_t aal =
4b11111a MS	111	le32_to_cpu(eahd->appAttrLocation);
28de7948 CG	112	memmove(&ea[offset - aal + size],
28de7948 CG	113	&ea[aal], offset - aal);
1da177e4	114	offset -= aal;
4b11111a MS	115	eahd->appAttrLocation =
4b11111a MS	116	cpu_to_le32(aal + size);
1da177e4 LT	117	}
	118	}
	119	/* rewrite CRC + checksum of eahd */
5ca4e4be	120	crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(struct tag);
1da177e4	121	eahd->descTag.descCRCLength = cpu_to_le16(crclen);
f845fced	122	eahd->descTag.descCRC = cpu_to_le16(crc_itu_t(0, (char *)eahd +
5ca4e4be	123	sizeof(struct tag), crclen));
3f2587bb	124	eahd->descTag.tagChecksum = udf_tag_checksum(&eahd->descTag);
48d6d8ff	125	iinfo->i_lenEAttr += size;
1da177e4 LT	126	return (struct genericFormat *)&ea[offset];
1da177e4 LT	127	}
28de7948	128
1da177e4 LT	129	return NULL;
	130	}
	131
cb00ea35 CG	132	struct genericFormat udf_get_extendedattr(struct inode inode, uint32_t type,
cb00ea35 CG	133	uint8_t subtype)
1da177e4 LT	134	{
	135	struct genericFormat *gaf;
	136	uint8_t *ea = NULL;
	137	uint32_t offset;
48d6d8ff	138	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	139
382a2287	140	ea = iinfo->i_data;
1da177e4	141
48d6d8ff	142	if (iinfo->i_lenEAttr) {
1da177e4 LT	143	struct extendedAttrHeaderDesc *eahd;
	144	eahd = (struct extendedAttrHeaderDesc *)ea;
	145
	146	/* check checksum/crc */
5e0f0017 MS	147	if (eahd->descTag.tagIdent !=
5e0f0017 MS	148	cpu_to_le16(TAG_IDENT_EAHD) \|\|
4b11111a	149	le32_to_cpu(eahd->descTag.tagLocation) !=
48d6d8ff	150	iinfo->i_location.logicalBlockNum)
1da177e4	151	return NULL;
cb00ea35	152
1da177e4 LT	153	if (type < 2048)
	154	offset = sizeof(struct extendedAttrHeaderDesc);
	155	else if (type < 65536)
	156	offset = le32_to_cpu(eahd->impAttrLocation);
	157	else
	158	offset = le32_to_cpu(eahd->appAttrLocation);
	159
58bc6d1b SS	160	while (offset + sizeof(*gaf) < iinfo->i_lenEAttr) {
	161	uint32_t attrLength;
	162
1da177e4	163	gaf = (struct genericFormat *)&ea[offset];
58bc6d1b SS	164	attrLength = le32_to_cpu(gaf->attrLength);
	165
	166	/* Detect undersized elements and buffer overflows */
	167	if ((attrLength < sizeof(*gaf)) \|\|
	168	(attrLength > (iinfo->i_lenEAttr - offset)))
	169	break;
	170
4b11111a MS	171	if (le32_to_cpu(gaf->attrType) == type &&
4b11111a MS	172	gaf->attrSubtype == subtype)
1da177e4 LT	173	return gaf;
1da177e4 LT	174	else
58bc6d1b	175	offset += attrLength;
1da177e4 LT	176	}
1da177e4 LT	177	}
28de7948	178
1da177e4 LT	179	return NULL;
	180	}
	181
	182	/*
	183	* udf_read_tagged
	184	*
	185	* PURPOSE
	186	* Read the first block of a tagged descriptor.
	187	*
	188	* HISTORY
	189	* July 1, 1997 - Andrew E. Mileski
	190	* Written, tested, and released.
	191	*/
cb00ea35	192	struct buffer_head udf_read_tagged(struct super_block sb, uint32_t block,
4b11111a	193	uint32_t location, uint16_t *ident)
1da177e4	194	{
5ca4e4be	195	struct tag *tag_p;
1da177e4	196	struct buffer_head *bh = NULL;
7e273e3b	197	u8 checksum;
1da177e4 LT	198
	199	/* Read the block */
	200	if (block == 0xFFFFFFFF)
	201	return NULL;
	202
101ee137	203	bh = sb_bread(sb, block);
cb00ea35	204	if (!bh) {
fcbf7637	205	udf_err(sb, "read failed, block=%u, location=%u\n",
8076c363	206	block, location);
1da177e4 LT	207	return NULL;
	208	}
	209
5ca4e4be	210	tag_p = (struct 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",
f4bcbbd9	216	block, le32_to_cpu(tag_p->tagLocation), location);
1da177e4 LT	217	goto error_out;
1da177e4 LT	218	}
cb00ea35	219
1da177e4	220	/* Verify the tag checksum */
7e273e3b JP	221	checksum = udf_tag_checksum(tag_p);
7e273e3b JP	222	if (checksum != tag_p->tagChecksum) {
8076c363 JP	223	udf_err(sb, "tag checksum failed, block %u: 0x%02x != 0x%02x\n",
8076c363 JP	224	block, checksum, tag_p->tagChecksum);
1da177e4 LT	225	goto error_out;
	226	}
	227
	228	/* Verify the tag version */
5e0f0017 MS	229	if (tag_p->descVersion != cpu_to_le16(0x0002U) &&
5e0f0017 MS	230	tag_p->descVersion != cpu_to_le16(0x0003U)) {
8076c363 JP	231	udf_err(sb, "tag version 0x%04x != 0x0002 \|\| 0x0003, block %u\n",
8076c363 JP	232	le16_to_cpu(tag_p->descVersion), block);
1da177e4 LT	233	goto error_out;
	234	}
	235
	236	/* Verify the descriptor CRC */
5ca4e4be	237	if (le16_to_cpu(tag_p->descCRCLength) + sizeof(struct tag) > sb->s_blocksize \|\|
f845fced	238	le16_to_cpu(tag_p->descCRC) == crc_itu_t(0,
5ca4e4be	239	bh->b_data + sizeof(struct tag),
f845fced	240	le16_to_cpu(tag_p->descCRCLength)))
1da177e4	241	return bh;
4b11111a	242
fcbf7637	243	udf_debug("Crc failure block %u: crc = %u, crclen = %u\n", block,
8076c363 JP	244	le16_to_cpu(tag_p->descCRC),
8076c363 JP	245	le16_to_cpu(tag_p->descCRCLength));
28de7948	246	error_out:
1da177e4 LT	247	brelse(bh);
	248	return NULL;
	249	}
	250
97e961fd PE	251	struct buffer_head udf_read_ptagged(struct super_block sb,
97e961fd PE	252	struct kernel_lb_addr *loc,
4b11111a	253	uint32_t offset, uint16_t *ident)
1da177e4 LT	254	{
1da177e4 LT	255	return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset),
97e961fd	256	loc->logicalBlockNum + offset, ident);
1da177e4 LT	257	}
1da177e4 LT	258
1da177e4 LT	259	void udf_update_tag(char *data, int length)
1da177e4 LT	260	{
5ca4e4be PE	261	struct tag tptr = (struct tag )data;
5ca4e4be PE	262	length -= sizeof(struct tag);
1da177e4	263
1da177e4	264	tptr->descCRCLength = cpu_to_le16(length);
5ca4e4be	265	tptr->descCRC = cpu_to_le16(crc_itu_t(0, data + sizeof(struct tag), length));
3f2587bb	266	tptr->tagChecksum = udf_tag_checksum(tptr);
1da177e4 LT	267	}
	268
	269	void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum,
cb00ea35	270	uint32_t loc, int length)
1da177e4	271	{
5ca4e4be	272	struct tag tptr = (struct tag )data;
1da177e4 LT	273	tptr->tagIdent = cpu_to_le16(ident);
	274	tptr->descVersion = cpu_to_le16(version);
	275	tptr->tagSerialNum = cpu_to_le16(snum);
	276	tptr->tagLocation = cpu_to_le32(loc);
	277	udf_update_tag(data, length);
	278	}
3f2587bb	279
5ca4e4be	280	u8 udf_tag_checksum(const struct tag *t)
3f2587bb MS	281	{
	282	u8 data = (u8 )t;
	283	u8 checksum = 0;
	284	int i;
5ca4e4be	285	for (i = 0; i < sizeof(struct tag); ++i)
3f2587bb MS	286	if (i != 4) /* position of checksum */
	287	checksum += data[i];
	288	return checksum;
	289	}