1 files changed, 313 insertions, 0 deletions
diff --git a/fs/udf/misc.c b/fs/udf/misc.c
new file mode 100644
index 000000000000..fd321f9ace83
--- /dev/null
+++ b/fs/udf/misc.c
@@ -0,0 +1,313 @@
+/*
+ * misc.c
+ *
+ * PURPOSE
+ *	Miscellaneous routines for the OSTA-UDF(tm) filesystem.
+ *
+ * CONTACTS
+ *	E-mail regarding any portion of the Linux UDF file system should be
+ *	directed to the development team mailing list (run by majordomo):
+ *		linux_udf@hpesjro.fc.hp.com
+ *
+ * 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);
+}