/* * 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_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 = 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; }