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-rw-r--r--fs/udf/misc.c305
1 files changed, 305 insertions, 0 deletions
diff --git a/fs/udf/misc.c b/fs/udf/misc.c
new file mode 100644
index 000000000..853bcff51
--- /dev/null
+++ b/fs/udf/misc.c
@@ -0,0 +1,305 @@
+/*
+ * 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 buffer_head *udf_tgetblk(struct super_block *sb, udf_pblk_t 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, udf_pblk_t 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;
+ struct udf_inode_info *iinfo = UDF_I(inode);
+
+ ea = iinfo->i_ext.i_data;
+ if (iinfo->i_lenEAttr) {
+ ad = iinfo->i_ext.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_ext.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 = udf_tread(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;
+}
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