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 size -= sizeof(struct extendedAttrHeaderDesc); 85 UDF_I_LENEATTR(inode) += sizeof(struct extendedAttrHeaderDesc); 86 eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD); 87 if (UDF_SB_UDFREV(inode->i_sb) >= 0x0200) 88 eahd->descTag.descVersion = cpu_to_le16(3); 89 else 90 eahd->descTag.descVersion = cpu_to_le16(2); 91 eahd->descTag.tagSerialNum = cpu_to_le16(UDF_SB_SERIALNUM(inode->i_sb)); 92 eahd->descTag.tagLocation = cpu_to_le32(UDF_I_LOCATION(inode).logicalBlockNum); 93 eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF); 94 eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF); 95 } 96 97 offset = UDF_I_LENEATTR(inode); 98 if (type < 2048) { 99 if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode)) { 100 uint32_t aal = le32_to_cpu(eahd->appAttrLocation); 101 memmove(&ea[offset - aal + size], 102 &ea[aal], offset - aal); 103 offset -= aal; 104 eahd->appAttrLocation = cpu_to_le32(aal + size); 105 } 106 if (le32_to_cpu(eahd->impAttrLocation) < UDF_I_LENEATTR(inode)) { 107 uint32_t ial = le32_to_cpu(eahd->impAttrLocation); 108 memmove(&ea[offset - ial + size], 109 &ea[ial], offset - ial); 110 offset -= ial; 111 eahd->impAttrLocation = cpu_to_le32(ial + size); 112 } 113 } else if (type < 65536) { 114 if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode)) { 115 uint32_t aal = le32_to_cpu(eahd->appAttrLocation); 116 memmove(&ea[offset - aal + size], 117 &ea[aal], offset - aal); 118 offset -= aal; 119 eahd->appAttrLocation = cpu_to_le32(aal + size); 120 } 121 } 122 /* rewrite CRC + checksum of eahd */ 123 crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(tag); 124 eahd->descTag.descCRCLength = cpu_to_le16(crclen); 125 eahd->descTag.descCRC = cpu_to_le16(udf_crc((char *)eahd + 126 sizeof(tag), crclen, 0)); 127 eahd->descTag.tagChecksum = 0; 128 for (i = 0; i < 16; i++) 129 if (i != 4) 130 eahd->descTag.tagChecksum += ((uint8_t *)&(eahd->descTag))[i]; 131 UDF_I_LENEATTR(inode) += size; 132 return (struct genericFormat *)&ea[offset]; 133 } 134 if (loc & 0x02) { 135 } 136 137 return NULL; 138 } 139 140 struct genericFormat *udf_get_extendedattr(struct inode *inode, uint32_t type, 141 uint8_t subtype) 142 { 143 struct genericFormat *gaf; 144 uint8_t *ea = NULL; 145 uint32_t offset; 146 147 ea = UDF_I_DATA(inode); 148 149 if (UDF_I_LENEATTR(inode)) { 150 struct extendedAttrHeaderDesc *eahd; 151 eahd = (struct extendedAttrHeaderDesc *)ea; 152 153 /* check checksum/crc */ 154 if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD || 155 le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum) { 156 return NULL; 157 } 158 159 if (type < 2048) 160 offset = sizeof(struct extendedAttrHeaderDesc); 161 else if (type < 65536) 162 offset = le32_to_cpu(eahd->impAttrLocation); 163 else 164 offset = le32_to_cpu(eahd->appAttrLocation); 165 166 while (offset < UDF_I_LENEATTR(inode)) { 167 gaf = (struct genericFormat *)&ea[offset]; 168 if (le32_to_cpu(gaf->attrType) == type && gaf->attrSubtype == subtype) 169 return gaf; 170 else 171 offset += le32_to_cpu(gaf->attrLength); 172 } 173 } 174 175 return NULL; 176 } 177 178 /* 179 * udf_read_tagged 180 * 181 * PURPOSE 182 * Read the first block of a tagged descriptor. 183 * 184 * HISTORY 185 * July 1, 1997 - Andrew E. Mileski 186 * Written, tested, and released. 187 */ 188 struct buffer_head *udf_read_tagged(struct super_block *sb, uint32_t block, 189 uint32_t location, uint16_t * ident) 190 { 191 tag *tag_p; 192 struct buffer_head *bh = NULL; 193 register uint8_t checksum; 194 register int i; 195 196 /* Read the block */ 197 if (block == 0xFFFFFFFF) 198 return NULL; 199 200 bh = udf_tread(sb, block + UDF_SB_SESSION(sb)); 201 if (!bh) { 202 udf_debug("block=%d, location=%d: read failed\n", 203 block + UDF_SB_SESSION(sb), location); 204 return NULL; 205 } 206 207 tag_p = (tag *)(bh->b_data); 208 209 *ident = le16_to_cpu(tag_p->tagIdent); 210 211 if (location != le32_to_cpu(tag_p->tagLocation)) { 212 udf_debug("location mismatch block %u, tag %u != %u\n", 213 block + UDF_SB_SESSION(sb), le32_to_cpu(tag_p->tagLocation), location); 214 goto error_out; 215 } 216 217 /* Verify the tag checksum */ 218 checksum = 0U; 219 for (i = 0; i < 4; i++) 220 checksum += (uint8_t)(bh->b_data[i]); 221 for (i = 5; i < 16; i++) 222 checksum += (uint8_t)(bh->b_data[i]); 223 if (checksum != tag_p->tagChecksum) { 224 printk(KERN_ERR "udf: tag checksum failed block %d\n", block); 225 goto error_out; 226 } 227 228 /* Verify the tag version */ 229 if (le16_to_cpu(tag_p->descVersion) != 0x0002U && 230 le16_to_cpu(tag_p->descVersion) != 0x0003U) { 231 udf_debug("tag version 0x%04x != 0x0002 || 0x0003 block %d\n", 232 le16_to_cpu(tag_p->descVersion), block); 233 goto error_out; 234 } 235 236 /* Verify the descriptor CRC */ 237 if (le16_to_cpu(tag_p->descCRCLength) + sizeof(tag) > sb->s_blocksize || 238 le16_to_cpu(tag_p->descCRC) == udf_crc(bh->b_data + sizeof(tag), 239 le16_to_cpu(tag_p->descCRCLength), 0)) { 240 return bh; 241 } 242 udf_debug("Crc failure block %d: crc = %d, crclen = %d\n", 243 block + UDF_SB_SESSION(sb), le16_to_cpu(tag_p->descCRC), 244 le16_to_cpu(tag_p->descCRCLength)); 245 246 error_out: 247 brelse(bh); 248 return NULL; 249 } 250 251 struct buffer_head *udf_read_ptagged(struct super_block *sb, kernel_lb_addr loc, 252 uint32_t offset, uint16_t * ident) 253 { 254 return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset), 255 loc.logicalBlockNum + offset, ident); 256 } 257 258 void udf_update_tag(char *data, int length) 259 { 260 tag *tptr = (tag *)data; 261 int i; 262 263 length -= sizeof(tag); 264 265 tptr->tagChecksum = 0; 266 tptr->descCRCLength = cpu_to_le16(length); 267 tptr->descCRC = cpu_to_le16(udf_crc(data + sizeof(tag), length, 0)); 268 269 for (i = 0; i < 16; i++) 270 if (i != 4) 271 tptr->tagChecksum += (uint8_t)(data[i]); 272 } 273 274 void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum, 275 uint32_t loc, int length) 276 { 277 tag *tptr = (tag *)data; 278 tptr->tagIdent = cpu_to_le16(ident); 279 tptr->descVersion = cpu_to_le16(version); 280 tptr->tagSerialNum = cpu_to_le16(snum); 281 tptr->tagLocation = cpu_to_le32(loc); 282 udf_update_tag(data, length); 283 } 284