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/udf_fs.h> 27 #include <linux/buffer_head.h> 28 29 #include "udf_i.h" 30 #include "udf_sb.h" 31 32 struct buffer_head *udf_tgetblk(struct super_block *sb, int block) 33 { 34 if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV)) 35 return sb_getblk(sb, udf_fixed_to_variable(block)); 36 else 37 return sb_getblk(sb, block); 38 } 39 40 struct buffer_head *udf_tread(struct super_block *sb, int block) 41 { 42 if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV)) 43 return sb_bread(sb, udf_fixed_to_variable(block)); 44 else 45 return sb_bread(sb, block); 46 } 47 48 struct genericFormat *udf_add_extendedattr(struct inode *inode, uint32_t size, 49 uint32_t type, uint8_t loc) 50 { 51 uint8_t *ea = NULL, *ad = NULL; 52 int offset; 53 uint16_t crclen; 54 int i; 55 56 ea = UDF_I_DATA(inode); 57 if (UDF_I_LENEATTR(inode)) { 58 ad = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode); 59 } else { 60 ad = ea; 61 size += sizeof(struct extendedAttrHeaderDesc); 62 } 63 64 offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) - 65 UDF_I_LENALLOC(inode); 66 67 /* TODO - Check for FreeEASpace */ 68 69 if (loc & 0x01 && offset >= size) { 70 struct extendedAttrHeaderDesc *eahd; 71 eahd = (struct extendedAttrHeaderDesc *)ea; 72 73 if (UDF_I_LENALLOC(inode)) { 74 memmove(&ad[size], ad, UDF_I_LENALLOC(inode)); 75 } 76 77 if (UDF_I_LENEATTR(inode)) { 78 /* check checksum/crc */ 79 if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD || 80 le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum) { 81 return NULL; 82 } 83 } else { 84 struct udf_sb_info *sbi = UDF_SB(inode->i_sb); 85 86 size -= sizeof(struct extendedAttrHeaderDesc); 87 UDF_I_LENEATTR(inode) += 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 = cpu_to_le16(sbi->s_serial_number); 94 eahd->descTag.tagLocation = cpu_to_le32(UDF_I_LOCATION(inode).logicalBlockNum); 95 eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF); 96 eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF); 97 } 98 99 offset = UDF_I_LENEATTR(inode); 100 if (type < 2048) { 101 if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode)) { 102 uint32_t aal = le32_to_cpu(eahd->appAttrLocation); 103 memmove(&ea[offset - aal + size], 104 &ea[aal], offset - aal); 105 offset -= aal; 106 eahd->appAttrLocation = cpu_to_le32(aal + size); 107 } 108 if (le32_to_cpu(eahd->impAttrLocation) < UDF_I_LENEATTR(inode)) { 109 uint32_t ial = le32_to_cpu(eahd->impAttrLocation); 110 memmove(&ea[offset - ial + size], 111 &ea[ial], offset - ial); 112 offset -= ial; 113 eahd->impAttrLocation = cpu_to_le32(ial + size); 114 } 115 } else if (type < 65536) { 116 if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode)) { 117 uint32_t aal = le32_to_cpu(eahd->appAttrLocation); 118 memmove(&ea[offset - aal + size], 119 &ea[aal], offset - aal); 120 offset -= aal; 121 eahd->appAttrLocation = cpu_to_le32(aal + size); 122 } 123 } 124 /* rewrite CRC + checksum of eahd */ 125 crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(tag); 126 eahd->descTag.descCRCLength = cpu_to_le16(crclen); 127 eahd->descTag.descCRC = cpu_to_le16(udf_crc((char *)eahd + 128 sizeof(tag), crclen, 0)); 129 eahd->descTag.tagChecksum = 0; 130 for (i = 0; i < 16; i++) 131 if (i != 4) 132 eahd->descTag.tagChecksum += ((uint8_t *)&(eahd->descTag))[i]; 133 UDF_I_LENEATTR(inode) += size; 134 return (struct genericFormat *)&ea[offset]; 135 } 136 if (loc & 0x02) { 137 } 138 139 return NULL; 140 } 141 142 struct genericFormat *udf_get_extendedattr(struct inode *inode, uint32_t type, 143 uint8_t subtype) 144 { 145 struct genericFormat *gaf; 146 uint8_t *ea = NULL; 147 uint32_t offset; 148 149 ea = UDF_I_DATA(inode); 150 151 if (UDF_I_LENEATTR(inode)) { 152 struct extendedAttrHeaderDesc *eahd; 153 eahd = (struct extendedAttrHeaderDesc *)ea; 154 155 /* check checksum/crc */ 156 if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD || 157 le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum) { 158 return NULL; 159 } 160 161 if (type < 2048) 162 offset = sizeof(struct extendedAttrHeaderDesc); 163 else if (type < 65536) 164 offset = le32_to_cpu(eahd->impAttrLocation); 165 else 166 offset = le32_to_cpu(eahd->appAttrLocation); 167 168 while (offset < UDF_I_LENEATTR(inode)) { 169 gaf = (struct genericFormat *)&ea[offset]; 170 if (le32_to_cpu(gaf->attrType) == type && gaf->attrSubtype == subtype) 171 return gaf; 172 else 173 offset += le32_to_cpu(gaf->attrLength); 174 } 175 } 176 177 return NULL; 178 } 179 180 /* 181 * udf_read_tagged 182 * 183 * PURPOSE 184 * Read the first block of a tagged descriptor. 185 * 186 * HISTORY 187 * July 1, 1997 - Andrew E. Mileski 188 * Written, tested, and released. 189 */ 190 struct buffer_head *udf_read_tagged(struct super_block *sb, uint32_t block, 191 uint32_t location, uint16_t * ident) 192 { 193 tag *tag_p; 194 struct buffer_head *bh = NULL; 195 register uint8_t checksum; 196 register int i; 197 struct udf_sb_info *sbi = UDF_SB(sb); 198 199 /* Read the block */ 200 if (block == 0xFFFFFFFF) 201 return NULL; 202 203 bh = udf_tread(sb, block + sbi->s_session); 204 if (!bh) { 205 udf_debug("block=%d, location=%d: read failed\n", 206 block + sbi->s_session, location); 207 return NULL; 208 } 209 210 tag_p = (tag *)(bh->b_data); 211 212 *ident = le16_to_cpu(tag_p->tagIdent); 213 214 if (location != le32_to_cpu(tag_p->tagLocation)) { 215 udf_debug("location mismatch block %u, tag %u != %u\n", 216 block + sbi->s_session, le32_to_cpu(tag_p->tagLocation), location); 217 goto error_out; 218 } 219 220 /* Verify the tag checksum */ 221 checksum = 0U; 222 for (i = 0; i < 4; i++) 223 checksum += (uint8_t)(bh->b_data[i]); 224 for (i = 5; i < 16; i++) 225 checksum += (uint8_t)(bh->b_data[i]); 226 if (checksum != tag_p->tagChecksum) { 227 printk(KERN_ERR "udf: tag checksum failed block %d\n", block); 228 goto error_out; 229 } 230 231 /* Verify the tag version */ 232 if (le16_to_cpu(tag_p->descVersion) != 0x0002U && 233 le16_to_cpu(tag_p->descVersion) != 0x0003U) { 234 udf_debug("tag version 0x%04x != 0x0002 || 0x0003 block %d\n", 235 le16_to_cpu(tag_p->descVersion), block); 236 goto error_out; 237 } 238 239 /* Verify the descriptor CRC */ 240 if (le16_to_cpu(tag_p->descCRCLength) + sizeof(tag) > sb->s_blocksize || 241 le16_to_cpu(tag_p->descCRC) == udf_crc(bh->b_data + sizeof(tag), 242 le16_to_cpu(tag_p->descCRCLength), 0)) { 243 return bh; 244 } 245 udf_debug("Crc failure block %d: crc = %d, crclen = %d\n", 246 block + sbi->s_session, le16_to_cpu(tag_p->descCRC), 247 le16_to_cpu(tag_p->descCRCLength)); 248 249 error_out: 250 brelse(bh); 251 return NULL; 252 } 253 254 struct buffer_head *udf_read_ptagged(struct super_block *sb, kernel_lb_addr loc, 255 uint32_t offset, uint16_t * ident) 256 { 257 return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset), 258 loc.logicalBlockNum + offset, ident); 259 } 260 261 void udf_update_tag(char *data, int length) 262 { 263 tag *tptr = (tag *)data; 264 int i; 265 266 length -= sizeof(tag); 267 268 tptr->tagChecksum = 0; 269 tptr->descCRCLength = cpu_to_le16(length); 270 tptr->descCRC = cpu_to_le16(udf_crc(data + sizeof(tag), length, 0)); 271 272 for (i = 0; i < 16; i++) 273 if (i != 4) 274 tptr->tagChecksum += (uint8_t)(data[i]); 275 } 276 277 void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum, 278 uint32_t loc, int length) 279 { 280 tag *tptr = (tag *)data; 281 tptr->tagIdent = cpu_to_le16(ident); 282 tptr->descVersion = cpu_to_le16(version); 283 tptr->tagSerialNum = cpu_to_le16(snum); 284 tptr->tagLocation = cpu_to_le32(loc); 285 udf_update_tag(data, length); 286 } 287