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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * misc.c
 *
 * PURPOSE
 *	Miscellaneous routines for the OSTA-UDF(tm) filesystem.
 *
 * COPYRIGHT
 *  (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
5ce34554	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* misc.c
	4	*
	5	* PURPOSE
	6	* Miscellaneous routines for the OSTA-UDF(tm) filesystem.
	7	*
1da177e4	8	* COPYRIGHT
1da177e4 LT	9	* (C) 1998 Dave Boynton
	10	* (C) 1998-2004 Ben Fennema
	11	* (C) 1999-2000 Stelias Computing Inc
	12	*
	13	* HISTORY
	14	*
	15	* 04/19/99 blf partial support for reading/writing specific EA's
	16	*/
	17
	18	#include "udfdecl.h"
	19
	20	#include <linux/fs.h>
	21	#include <linux/string.h>
f845fced	22	#include <linux/crc-itu-t.h>
1da177e4 LT	23
	24	#include "udf_i.h"
	25	#include "udf_sb.h"
	26
cb00ea35 CG	27	struct genericFormat udf_add_extendedattr(struct inode inode, uint32_t size,
cb00ea35 CG	28	uint32_t type, uint8_t loc)
1da177e4 LT	29	{
	30	uint8_t ea = NULL, ad = NULL;
	31	int offset;
	32	uint16_t crclen;
48d6d8ff	33	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	34
382a2287	35	ea = iinfo->i_data;
48d6d8ff	36	if (iinfo->i_lenEAttr) {
382a2287	37	ad = iinfo->i_data + iinfo->i_lenEAttr;
28de7948	38	} else {
1da177e4 LT	39	ad = ea;
	40	size += sizeof(struct extendedAttrHeaderDesc);
	41	}
	42
	43	offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) -
48d6d8ff	44	iinfo->i_lenAlloc;
1da177e4 LT	45
	46	/* TODO - Check for FreeEASpace */
	47
cb00ea35	48	if (loc & 0x01 && offset >= size) {
1da177e4 LT	49	struct extendedAttrHeaderDesc *eahd;
	50	eahd = (struct extendedAttrHeaderDesc *)ea;
	51
48d6d8ff MS	52	if (iinfo->i_lenAlloc)
48d6d8ff MS	53	memmove(&ad[size], ad, iinfo->i_lenAlloc);
1da177e4	54
48d6d8ff	55	if (iinfo->i_lenEAttr) {
1da177e4	56	/* check checksum/crc */
5e0f0017 MS	57	if (eahd->descTag.tagIdent !=
5e0f0017 MS	58	cpu_to_le16(TAG_IDENT_EAHD) \|\|
4b11111a	59	le32_to_cpu(eahd->descTag.tagLocation) !=
48d6d8ff	60	iinfo->i_location.logicalBlockNum)
1da177e4	61	return NULL;
cb00ea35	62	} else {
6c79e987 MS	63	struct udf_sb_info *sbi = UDF_SB(inode->i_sb);
6c79e987 MS	64
1da177e4	65	size -= sizeof(struct extendedAttrHeaderDesc);
48d6d8ff	66	iinfo->i_lenEAttr +=
4b11111a	67	sizeof(struct extendedAttrHeaderDesc);
1da177e4	68	eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD);
6c79e987	69	if (sbi->s_udfrev >= 0x0200)
1da177e4 LT	70	eahd->descTag.descVersion = cpu_to_le16(3);
	71	else
	72	eahd->descTag.descVersion = cpu_to_le16(2);
4b11111a MS	73	eahd->descTag.tagSerialNum =
	74	cpu_to_le16(sbi->s_serial_number);
	75	eahd->descTag.tagLocation = cpu_to_le32(
48d6d8ff	76	iinfo->i_location.logicalBlockNum);
1da177e4 LT	77	eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF);
	78	eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF);
	79	}
	80
48d6d8ff	81	offset = iinfo->i_lenEAttr;
cb00ea35	82	if (type < 2048) {
4b11111a	83	if (le32_to_cpu(eahd->appAttrLocation) <
48d6d8ff	84	iinfo->i_lenEAttr) {
4b11111a MS	85	uint32_t aal =
4b11111a MS	86	le32_to_cpu(eahd->appAttrLocation);
28de7948 CG	87	memmove(&ea[offset - aal + size],
28de7948 CG	88	&ea[aal], offset - aal);
1da177e4	89	offset -= aal;
4b11111a MS	90	eahd->appAttrLocation =
4b11111a MS	91	cpu_to_le32(aal + size);
1da177e4	92	}
4b11111a	93	if (le32_to_cpu(eahd->impAttrLocation) <
48d6d8ff	94	iinfo->i_lenEAttr) {
4b11111a MS	95	uint32_t ial =
4b11111a MS	96	le32_to_cpu(eahd->impAttrLocation);
28de7948 CG	97	memmove(&ea[offset - ial + size],
28de7948 CG	98	&ea[ial], offset - ial);
1da177e4	99	offset -= ial;
4b11111a MS	100	eahd->impAttrLocation =
4b11111a MS	101	cpu_to_le32(ial + size);
1da177e4	102	}
cb00ea35	103	} else if (type < 65536) {
4b11111a	104	if (le32_to_cpu(eahd->appAttrLocation) <
48d6d8ff	105	iinfo->i_lenEAttr) {
4b11111a MS	106	uint32_t aal =
4b11111a MS	107	le32_to_cpu(eahd->appAttrLocation);
28de7948 CG	108	memmove(&ea[offset - aal + size],
28de7948 CG	109	&ea[aal], offset - aal);
1da177e4	110	offset -= aal;
4b11111a MS	111	eahd->appAttrLocation =
4b11111a MS	112	cpu_to_le32(aal + size);
1da177e4 LT	113	}
	114	}
	115	/* rewrite CRC + checksum of eahd */
5ca4e4be	116	crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(struct tag);
1da177e4	117	eahd->descTag.descCRCLength = cpu_to_le16(crclen);
f845fced	118	eahd->descTag.descCRC = cpu_to_le16(crc_itu_t(0, (char *)eahd +
5ca4e4be	119	sizeof(struct tag), crclen));
3f2587bb	120	eahd->descTag.tagChecksum = udf_tag_checksum(&eahd->descTag);
48d6d8ff	121	iinfo->i_lenEAttr += size;
1da177e4 LT	122	return (struct genericFormat *)&ea[offset];
1da177e4 LT	123	}
28de7948	124
1da177e4 LT	125	return NULL;
	126	}
	127
cb00ea35 CG	128	struct genericFormat udf_get_extendedattr(struct inode inode, uint32_t type,
cb00ea35 CG	129	uint8_t subtype)
1da177e4 LT	130	{
	131	struct genericFormat *gaf;
	132	uint8_t *ea = NULL;
	133	uint32_t offset;
48d6d8ff	134	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	135
382a2287	136	ea = iinfo->i_data;
1da177e4	137
48d6d8ff	138	if (iinfo->i_lenEAttr) {
1da177e4 LT	139	struct extendedAttrHeaderDesc *eahd;
	140	eahd = (struct extendedAttrHeaderDesc *)ea;
	141
	142	/* check checksum/crc */
5e0f0017 MS	143	if (eahd->descTag.tagIdent !=
5e0f0017 MS	144	cpu_to_le16(TAG_IDENT_EAHD) \|\|
4b11111a	145	le32_to_cpu(eahd->descTag.tagLocation) !=
48d6d8ff	146	iinfo->i_location.logicalBlockNum)
1da177e4	147	return NULL;
cb00ea35	148
1da177e4 LT	149	if (type < 2048)
	150	offset = sizeof(struct extendedAttrHeaderDesc);
	151	else if (type < 65536)
	152	offset = le32_to_cpu(eahd->impAttrLocation);
	153	else
	154	offset = le32_to_cpu(eahd->appAttrLocation);
	155
58bc6d1b SS	156	while (offset + sizeof(*gaf) < iinfo->i_lenEAttr) {
	157	uint32_t attrLength;
	158
1da177e4	159	gaf = (struct genericFormat *)&ea[offset];
58bc6d1b SS	160	attrLength = le32_to_cpu(gaf->attrLength);
	161
	162	/* Detect undersized elements and buffer overflows */
	163	if ((attrLength < sizeof(*gaf)) \|\|
	164	(attrLength > (iinfo->i_lenEAttr - offset)))
	165	break;
	166
4b11111a MS	167	if (le32_to_cpu(gaf->attrType) == type &&
4b11111a MS	168	gaf->attrSubtype == subtype)
1da177e4 LT	169	return gaf;
1da177e4 LT	170	else
58bc6d1b	171	offset += attrLength;
1da177e4 LT	172	}
1da177e4 LT	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	188	struct buffer_head udf_read_tagged(struct super_block sb, uint32_t block,
4b11111a	189	uint32_t location, uint16_t *ident)
1da177e4	190	{
5ca4e4be	191	struct tag *tag_p;
1da177e4	192	struct buffer_head *bh = NULL;
7e273e3b	193	u8 checksum;
1da177e4 LT	194
	195	/* Read the block */
	196	if (block == 0xFFFFFFFF)
	197	return NULL;
	198
101ee137	199	bh = sb_bread(sb, block);
cb00ea35	200	if (!bh) {
fcbf7637	201	udf_err(sb, "read failed, block=%u, location=%u\n",
8076c363	202	block, location);
1da177e4 LT	203	return NULL;
	204	}
	205
5ca4e4be	206	tag_p = (struct tag *)(bh->b_data);
1da177e4 LT	207
	208	*ident = le16_to_cpu(tag_p->tagIdent);
	209
cb00ea35	210	if (location != le32_to_cpu(tag_p->tagLocation)) {
1da177e4	211	udf_debug("location mismatch block %u, tag %u != %u\n",
f4bcbbd9	212	block, le32_to_cpu(tag_p->tagLocation), location);
1da177e4 LT	213	goto error_out;
1da177e4 LT	214	}
cb00ea35	215
1da177e4	216	/* Verify the tag checksum */
7e273e3b JP	217	checksum = udf_tag_checksum(tag_p);
7e273e3b JP	218	if (checksum != tag_p->tagChecksum) {
8076c363 JP	219	udf_err(sb, "tag checksum failed, block %u: 0x%02x != 0x%02x\n",
8076c363 JP	220	block, checksum, tag_p->tagChecksum);
1da177e4 LT	221	goto error_out;
	222	}
	223
	224	/* Verify the tag version */
5e0f0017 MS	225	if (tag_p->descVersion != cpu_to_le16(0x0002U) &&
5e0f0017 MS	226	tag_p->descVersion != cpu_to_le16(0x0003U)) {
8076c363 JP	227	udf_err(sb, "tag version 0x%04x != 0x0002 \|\| 0x0003, block %u\n",
8076c363 JP	228	le16_to_cpu(tag_p->descVersion), block);
1da177e4 LT	229	goto error_out;
	230	}
	231
	232	/* Verify the descriptor CRC */
5ca4e4be	233	if (le16_to_cpu(tag_p->descCRCLength) + sizeof(struct tag) > sb->s_blocksize \|\|
f845fced	234	le16_to_cpu(tag_p->descCRC) == crc_itu_t(0,
5ca4e4be	235	bh->b_data + sizeof(struct tag),
f845fced	236	le16_to_cpu(tag_p->descCRCLength)))
1da177e4	237	return bh;
4b11111a	238
fcbf7637	239	udf_debug("Crc failure block %u: crc = %u, crclen = %u\n", block,
8076c363 JP	240	le16_to_cpu(tag_p->descCRC),
8076c363 JP	241	le16_to_cpu(tag_p->descCRCLength));
28de7948	242	error_out:
1da177e4 LT	243	brelse(bh);
	244	return NULL;
	245	}
	246
97e961fd PE	247	struct buffer_head udf_read_ptagged(struct super_block sb,
97e961fd PE	248	struct kernel_lb_addr *loc,
4b11111a	249	uint32_t offset, uint16_t *ident)
1da177e4 LT	250	{
1da177e4 LT	251	return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset),
97e961fd	252	loc->logicalBlockNum + offset, ident);
1da177e4 LT	253	}
1da177e4 LT	254
1da177e4 LT	255	void udf_update_tag(char *data, int length)
1da177e4 LT	256	{
5ca4e4be PE	257	struct tag tptr = (struct tag )data;
5ca4e4be PE	258	length -= sizeof(struct tag);
1da177e4	259
1da177e4	260	tptr->descCRCLength = cpu_to_le16(length);
5ca4e4be	261	tptr->descCRC = cpu_to_le16(crc_itu_t(0, data + sizeof(struct tag), length));
3f2587bb	262	tptr->tagChecksum = udf_tag_checksum(tptr);
1da177e4 LT	263	}
	264
	265	void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum,
cb00ea35	266	uint32_t loc, int length)
1da177e4	267	{
5ca4e4be	268	struct tag tptr = (struct tag )data;
1da177e4 LT	269	tptr->tagIdent = cpu_to_le16(ident);
	270	tptr->descVersion = cpu_to_le16(version);
	271	tptr->tagSerialNum = cpu_to_le16(snum);
	272	tptr->tagLocation = cpu_to_le32(loc);
	273	udf_update_tag(data, length);
	274	}
3f2587bb	275
5ca4e4be	276	u8 udf_tag_checksum(const struct tag *t)
3f2587bb MS	277	{
	278	u8 data = (u8 )t;
	279	u8 checksum = 0;
	280	int i;
5ca4e4be	281	for (i = 0; i < sizeof(struct tag); ++i)
3f2587bb MS	282	if (i != 4) /* position of checksum */
	283	checksum += data[i];
	284	return checksum;
	285	}