| 1 | /* |
| 2 | * misc.c |
| 3 | * |
| 4 | * PURPOSE |
| 5 | * Miscellaneous routines for the OSTA-UDF(tm) filesystem. |
| 6 | * |
| 7 | * COPYRIGHT |
| 8 | * This file is distributed under the terms of the GNU General Public |
| 9 | * License (GPL). Copies of the GPL can be obtained from: |
| 10 | * ftp://prep.ai.mit.edu/pub/gnu/GPL |
| 11 | * Each contributing author retains all rights to their own work. |
| 12 | * |
| 13 | * (C) 1998 Dave Boynton |
| 14 | * (C) 1998-2004 Ben Fennema |
| 15 | * (C) 1999-2000 Stelias Computing Inc |
| 16 | * |
| 17 | * HISTORY |
| 18 | * |
| 19 | * 04/19/99 blf partial support for reading/writing specific EA's |
| 20 | */ |
| 21 | |
| 22 | #include "udfdecl.h" |
| 23 | |
| 24 | #include <linux/fs.h> |
| 25 | #include <linux/string.h> |
| 26 | #include <linux/crc-itu-t.h> |
| 27 | |
| 28 | #include "udf_i.h" |
| 29 | #include "udf_sb.h" |
| 30 | |
| 31 | struct buffer_head *udf_tgetblk(struct super_block *sb, int block) |
| 32 | { |
| 33 | if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV)) |
| 34 | return sb_getblk(sb, udf_fixed_to_variable(block)); |
| 35 | else |
| 36 | return sb_getblk(sb, block); |
| 37 | } |
| 38 | |
| 39 | struct buffer_head *udf_tread(struct super_block *sb, int block) |
| 40 | { |
| 41 | if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV)) |
| 42 | return sb_bread(sb, udf_fixed_to_variable(block)); |
| 43 | else |
| 44 | return sb_bread(sb, block); |
| 45 | } |
| 46 | |
| 47 | struct genericFormat *udf_add_extendedattr(struct inode *inode, uint32_t size, |
| 48 | uint32_t type, uint8_t loc) |
| 49 | { |
| 50 | uint8_t *ea = NULL, *ad = NULL; |
| 51 | int offset; |
| 52 | uint16_t crclen; |
| 53 | struct udf_inode_info *iinfo = UDF_I(inode); |
| 54 | |
| 55 | ea = iinfo->i_ext.i_data; |
| 56 | if (iinfo->i_lenEAttr) { |
| 57 | ad = iinfo->i_ext.i_data + iinfo->i_lenEAttr; |
| 58 | } else { |
| 59 | ad = ea; |
| 60 | size += sizeof(struct extendedAttrHeaderDesc); |
| 61 | } |
| 62 | |
| 63 | offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) - |
| 64 | iinfo->i_lenAlloc; |
| 65 | |
| 66 | /* TODO - Check for FreeEASpace */ |
| 67 | |
| 68 | if (loc & 0x01 && offset >= size) { |
| 69 | struct extendedAttrHeaderDesc *eahd; |
| 70 | eahd = (struct extendedAttrHeaderDesc *)ea; |
| 71 | |
| 72 | if (iinfo->i_lenAlloc) |
| 73 | memmove(&ad[size], ad, iinfo->i_lenAlloc); |
| 74 | |
| 75 | if (iinfo->i_lenEAttr) { |
| 76 | /* check checksum/crc */ |
| 77 | if (eahd->descTag.tagIdent != |
| 78 | cpu_to_le16(TAG_IDENT_EAHD) || |
| 79 | le32_to_cpu(eahd->descTag.tagLocation) != |
| 80 | iinfo->i_location.logicalBlockNum) |
| 81 | return NULL; |
| 82 | } else { |
| 83 | struct udf_sb_info *sbi = UDF_SB(inode->i_sb); |
| 84 | |
| 85 | size -= sizeof(struct extendedAttrHeaderDesc); |
| 86 | iinfo->i_lenEAttr += |
| 87 | sizeof(struct extendedAttrHeaderDesc); |
| 88 | eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD); |
| 89 | if (sbi->s_udfrev >= 0x0200) |
| 90 | eahd->descTag.descVersion = cpu_to_le16(3); |
| 91 | else |
| 92 | eahd->descTag.descVersion = cpu_to_le16(2); |
| 93 | eahd->descTag.tagSerialNum = |
| 94 | cpu_to_le16(sbi->s_serial_number); |
| 95 | eahd->descTag.tagLocation = cpu_to_le32( |
| 96 | iinfo->i_location.logicalBlockNum); |
| 97 | eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF); |
| 98 | eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF); |
| 99 | } |
| 100 | |
| 101 | offset = iinfo->i_lenEAttr; |
| 102 | if (type < 2048) { |
| 103 | if (le32_to_cpu(eahd->appAttrLocation) < |
| 104 | iinfo->i_lenEAttr) { |
| 105 | uint32_t aal = |
| 106 | le32_to_cpu(eahd->appAttrLocation); |
| 107 | memmove(&ea[offset - aal + size], |
| 108 | &ea[aal], offset - aal); |
| 109 | offset -= aal; |
| 110 | eahd->appAttrLocation = |
| 111 | cpu_to_le32(aal + size); |
| 112 | } |
| 113 | if (le32_to_cpu(eahd->impAttrLocation) < |
| 114 | iinfo->i_lenEAttr) { |
| 115 | uint32_t ial = |
| 116 | le32_to_cpu(eahd->impAttrLocation); |
| 117 | memmove(&ea[offset - ial + size], |
| 118 | &ea[ial], offset - ial); |
| 119 | offset -= ial; |
| 120 | eahd->impAttrLocation = |
| 121 | cpu_to_le32(ial + size); |
| 122 | } |
| 123 | } else if (type < 65536) { |
| 124 | if (le32_to_cpu(eahd->appAttrLocation) < |
| 125 | iinfo->i_lenEAttr) { |
| 126 | uint32_t aal = |
| 127 | le32_to_cpu(eahd->appAttrLocation); |
| 128 | memmove(&ea[offset - aal + size], |
| 129 | &ea[aal], offset - aal); |
| 130 | offset -= aal; |
| 131 | eahd->appAttrLocation = |
| 132 | cpu_to_le32(aal + size); |
| 133 | } |
| 134 | } |
| 135 | /* rewrite CRC + checksum of eahd */ |
| 136 | crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(struct tag); |
| 137 | eahd->descTag.descCRCLength = cpu_to_le16(crclen); |
| 138 | eahd->descTag.descCRC = cpu_to_le16(crc_itu_t(0, (char *)eahd + |
| 139 | sizeof(struct tag), crclen)); |
| 140 | eahd->descTag.tagChecksum = udf_tag_checksum(&eahd->descTag); |
| 141 | iinfo->i_lenEAttr += size; |
| 142 | return (struct genericFormat *)&ea[offset]; |
| 143 | } |
| 144 | |
| 145 | return NULL; |
| 146 | } |
| 147 | |
| 148 | struct genericFormat *udf_get_extendedattr(struct inode *inode, uint32_t type, |
| 149 | uint8_t subtype) |
| 150 | { |
| 151 | struct genericFormat *gaf; |
| 152 | uint8_t *ea = NULL; |
| 153 | uint32_t offset; |
| 154 | struct udf_inode_info *iinfo = UDF_I(inode); |
| 155 | |
| 156 | ea = iinfo->i_ext.i_data; |
| 157 | |
| 158 | if (iinfo->i_lenEAttr) { |
| 159 | struct extendedAttrHeaderDesc *eahd; |
| 160 | eahd = (struct extendedAttrHeaderDesc *)ea; |
| 161 | |
| 162 | /* check checksum/crc */ |
| 163 | if (eahd->descTag.tagIdent != |
| 164 | cpu_to_le16(TAG_IDENT_EAHD) || |
| 165 | le32_to_cpu(eahd->descTag.tagLocation) != |
| 166 | iinfo->i_location.logicalBlockNum) |
| 167 | return NULL; |
| 168 | |
| 169 | if (type < 2048) |
| 170 | offset = sizeof(struct extendedAttrHeaderDesc); |
| 171 | else if (type < 65536) |
| 172 | offset = le32_to_cpu(eahd->impAttrLocation); |
| 173 | else |
| 174 | offset = le32_to_cpu(eahd->appAttrLocation); |
| 175 | |
| 176 | while (offset < iinfo->i_lenEAttr) { |
| 177 | gaf = (struct genericFormat *)&ea[offset]; |
| 178 | if (le32_to_cpu(gaf->attrType) == type && |
| 179 | gaf->attrSubtype == subtype) |
| 180 | return gaf; |
| 181 | else |
| 182 | offset += le32_to_cpu(gaf->attrLength); |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | return NULL; |
| 187 | } |
| 188 | |
| 189 | /* |
| 190 | * udf_read_tagged |
| 191 | * |
| 192 | * PURPOSE |
| 193 | * Read the first block of a tagged descriptor. |
| 194 | * |
| 195 | * HISTORY |
| 196 | * July 1, 1997 - Andrew E. Mileski |
| 197 | * Written, tested, and released. |
| 198 | */ |
| 199 | struct buffer_head *udf_read_tagged(struct super_block *sb, uint32_t block, |
| 200 | uint32_t location, uint16_t *ident) |
| 201 | { |
| 202 | struct tag *tag_p; |
| 203 | struct buffer_head *bh = NULL; |
| 204 | u8 checksum; |
| 205 | |
| 206 | /* Read the block */ |
| 207 | if (block == 0xFFFFFFFF) |
| 208 | return NULL; |
| 209 | |
| 210 | bh = udf_tread(sb, block); |
| 211 | if (!bh) { |
| 212 | udf_err(sb, "read failed, block=%u, location=%d\n", |
| 213 | block, location); |
| 214 | return NULL; |
| 215 | } |
| 216 | |
| 217 | tag_p = (struct tag *)(bh->b_data); |
| 218 | |
| 219 | *ident = le16_to_cpu(tag_p->tagIdent); |
| 220 | |
| 221 | if (location != le32_to_cpu(tag_p->tagLocation)) { |
| 222 | udf_debug("location mismatch block %u, tag %u != %u\n", |
| 223 | block, le32_to_cpu(tag_p->tagLocation), location); |
| 224 | goto error_out; |
| 225 | } |
| 226 | |
| 227 | /* Verify the tag checksum */ |
| 228 | checksum = udf_tag_checksum(tag_p); |
| 229 | if (checksum != tag_p->tagChecksum) { |
| 230 | udf_err(sb, "tag checksum failed, block %u: 0x%02x != 0x%02x\n", |
| 231 | block, checksum, tag_p->tagChecksum); |
| 232 | goto error_out; |
| 233 | } |
| 234 | |
| 235 | /* Verify the tag version */ |
| 236 | if (tag_p->descVersion != cpu_to_le16(0x0002U) && |
| 237 | tag_p->descVersion != cpu_to_le16(0x0003U)) { |
| 238 | udf_err(sb, "tag version 0x%04x != 0x0002 || 0x0003, block %u\n", |
| 239 | le16_to_cpu(tag_p->descVersion), block); |
| 240 | goto error_out; |
| 241 | } |
| 242 | |
| 243 | /* Verify the descriptor CRC */ |
| 244 | if (le16_to_cpu(tag_p->descCRCLength) + sizeof(struct tag) > sb->s_blocksize || |
| 245 | le16_to_cpu(tag_p->descCRC) == crc_itu_t(0, |
| 246 | bh->b_data + sizeof(struct tag), |
| 247 | le16_to_cpu(tag_p->descCRCLength))) |
| 248 | return bh; |
| 249 | |
| 250 | udf_debug("Crc failure block %d: crc = %d, crclen = %d\n", block, |
| 251 | le16_to_cpu(tag_p->descCRC), |
| 252 | le16_to_cpu(tag_p->descCRCLength)); |
| 253 | error_out: |
| 254 | brelse(bh); |
| 255 | return NULL; |
| 256 | } |
| 257 | |
| 258 | struct buffer_head *udf_read_ptagged(struct super_block *sb, |
| 259 | struct kernel_lb_addr *loc, |
| 260 | uint32_t offset, uint16_t *ident) |
| 261 | { |
| 262 | return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset), |
| 263 | loc->logicalBlockNum + offset, ident); |
| 264 | } |
| 265 | |
| 266 | void udf_update_tag(char *data, int length) |
| 267 | { |
| 268 | struct tag *tptr = (struct tag *)data; |
| 269 | length -= sizeof(struct tag); |
| 270 | |
| 271 | tptr->descCRCLength = cpu_to_le16(length); |
| 272 | tptr->descCRC = cpu_to_le16(crc_itu_t(0, data + sizeof(struct tag), length)); |
| 273 | tptr->tagChecksum = udf_tag_checksum(tptr); |
| 274 | } |
| 275 | |
| 276 | void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum, |
| 277 | uint32_t loc, int length) |
| 278 | { |
| 279 | struct tag *tptr = (struct tag *)data; |
| 280 | tptr->tagIdent = cpu_to_le16(ident); |
| 281 | tptr->descVersion = cpu_to_le16(version); |
| 282 | tptr->tagSerialNum = cpu_to_le16(snum); |
| 283 | tptr->tagLocation = cpu_to_le32(loc); |
| 284 | udf_update_tag(data, length); |
| 285 | } |
| 286 | |
| 287 | u8 udf_tag_checksum(const struct tag *t) |
| 288 | { |
| 289 | u8 *data = (u8 *)t; |
| 290 | u8 checksum = 0; |
| 291 | int i; |
| 292 | for (i = 0; i < sizeof(struct tag); ++i) |
| 293 | if (i != 4) /* position of checksum */ |
| 294 | checksum += data[i]; |
| 295 | return checksum; |
| 296 | } |