diff options
Diffstat (limited to 'kernel/fs/udf/misc.c')
| -rw-r--r-- | kernel/fs/udf/misc.c | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/kernel/fs/udf/misc.c b/kernel/fs/udf/misc.c new file mode 100644 index 000000000..71d1c25f3 --- /dev/null +++ b/kernel/fs/udf/misc.c @@ -0,0 +1,298 @@ +/* + * 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, 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; + 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]; + } + 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; + 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 < iinfo->i_lenEAttr) { + 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) +{ + 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=%d\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 %d: crc = %d, crclen = %d\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; +} |