1 /* 2 * linux/fs/isofs/dir.c 3 * 4 * (C) 1992, 1993, 1994 Eric Youngdale Modified for ISO 9660 filesystem. 5 * 6 * (C) 1991 Linus Torvalds - minix filesystem 7 * 8 * Steve Beynon : Missing last directory entries fixed 9 * (stephen@askone.demon.co.uk) : 21st June 1996 10 * 11 * isofs directory handling functions 12 */ 13 #include <linux/gfp.h> 14 #include "isofs.h" 15 16 int isofs_name_translate(struct iso_directory_record *de, char *new, struct inode *inode) 17 { 18 char * old = de->name; 19 int len = de->name_len[0]; 20 int i; 21 22 for (i = 0; i < len; i++) { 23 unsigned char c = old[i]; 24 if (!c) 25 break; 26 27 if (c >= 'A' && c <= 'Z') 28 c |= 0x20; /* lower case */ 29 30 /* Drop trailing '.;1' (ISO 9660:1988 7.5.1 requires period) */ 31 if (c == '.' && i == len - 3 && old[i + 1] == ';' && old[i + 2] == '1') 32 break; 33 34 /* Drop trailing ';1' */ 35 if (c == ';' && i == len - 2 && old[i + 1] == '1') 36 break; 37 38 /* Convert remaining ';' to '.' */ 39 /* Also '/' to '.' (broken Acorn-generated ISO9660 images) */ 40 if (c == ';' || c == '/') 41 c = '.'; 42 43 new[i] = c; 44 } 45 return i; 46 } 47 48 /* Acorn extensions written by Matthew Wilcox <willy@bofh.ai> 1998 */ 49 int get_acorn_filename(struct iso_directory_record *de, 50 char *retname, struct inode *inode) 51 { 52 int std; 53 unsigned char *chr; 54 int retnamlen = isofs_name_translate(de, retname, inode); 55 56 if (retnamlen == 0) 57 return 0; 58 std = sizeof(struct iso_directory_record) + de->name_len[0]; 59 if (std & 1) 60 std++; 61 if ((*((unsigned char *) de) - std) != 32) 62 return retnamlen; 63 chr = ((unsigned char *) de) + std; 64 if (strncmp(chr, "ARCHIMEDES", 10)) 65 return retnamlen; 66 if ((*retname == '_') && ((chr[19] & 1) == 1)) 67 *retname = '!'; 68 if (((de->flags[0] & 2) == 0) && (chr[13] == 0xff) 69 && ((chr[12] & 0xf0) == 0xf0)) { 70 retname[retnamlen] = ','; 71 sprintf(retname+retnamlen+1, "%3.3x", 72 ((chr[12] & 0xf) << 8) | chr[11]); 73 retnamlen += 4; 74 } 75 return retnamlen; 76 } 77 78 /* 79 * This should _really_ be cleaned up some day.. 80 */ 81 static int do_isofs_readdir(struct inode *inode, struct file *file, 82 struct dir_context *ctx, 83 char *tmpname, struct iso_directory_record *tmpde) 84 { 85 unsigned long bufsize = ISOFS_BUFFER_SIZE(inode); 86 unsigned char bufbits = ISOFS_BUFFER_BITS(inode); 87 unsigned long block, offset, block_saved, offset_saved; 88 unsigned long inode_number = 0; /* Quiet GCC */ 89 struct buffer_head *bh = NULL; 90 int len; 91 int map; 92 int first_de = 1; 93 char *p = NULL; /* Quiet GCC */ 94 struct iso_directory_record *de; 95 struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb); 96 97 offset = ctx->pos & (bufsize - 1); 98 block = ctx->pos >> bufbits; 99 100 while (ctx->pos < inode->i_size) { 101 int de_len; 102 103 if (!bh) { 104 bh = isofs_bread(inode, block); 105 if (!bh) 106 return 0; 107 } 108 109 de = (struct iso_directory_record *) (bh->b_data + offset); 110 111 de_len = *(unsigned char *)de; 112 113 /* 114 * If the length byte is zero, we should move on to the next 115 * CDROM sector. If we are at the end of the directory, we 116 * kick out of the while loop. 117 */ 118 119 if (de_len == 0) { 120 brelse(bh); 121 bh = NULL; 122 ctx->pos = (ctx->pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1); 123 block = ctx->pos >> bufbits; 124 offset = 0; 125 continue; 126 } 127 128 block_saved = block; 129 offset_saved = offset; 130 offset += de_len; 131 132 /* Make sure we have a full directory entry */ 133 if (offset >= bufsize) { 134 int slop = bufsize - offset + de_len; 135 memcpy(tmpde, de, slop); 136 offset &= bufsize - 1; 137 block++; 138 brelse(bh); 139 bh = NULL; 140 if (offset) { 141 bh = isofs_bread(inode, block); 142 if (!bh) 143 return 0; 144 memcpy((void *) tmpde + slop, bh->b_data, offset); 145 } 146 de = tmpde; 147 } 148 /* Basic sanity check, whether name doesn't exceed dir entry */ 149 if (de_len < de->name_len[0] + 150 sizeof(struct iso_directory_record)) { 151 printk(KERN_NOTICE "iso9660: Corrupted directory entry" 152 " in block %lu of inode %lu\n", block, 153 inode->i_ino); 154 return -EIO; 155 } 156 157 if (first_de) { 158 isofs_normalize_block_and_offset(de, 159 &block_saved, 160 &offset_saved); 161 inode_number = isofs_get_ino(block_saved, 162 offset_saved, bufbits); 163 } 164 165 if (de->flags[-sbi->s_high_sierra] & 0x80) { 166 first_de = 0; 167 ctx->pos += de_len; 168 continue; 169 } 170 first_de = 1; 171 172 /* Handle the case of the '.' directory */ 173 if (de->name_len[0] == 1 && de->name[0] == 0) { 174 if (!dir_emit_dot(file, ctx)) 175 break; 176 ctx->pos += de_len; 177 continue; 178 } 179 180 len = 0; 181 182 /* Handle the case of the '..' directory */ 183 if (de->name_len[0] == 1 && de->name[0] == 1) { 184 if (!dir_emit_dotdot(file, ctx)) 185 break; 186 ctx->pos += de_len; 187 continue; 188 } 189 190 /* Handle everything else. Do name translation if there 191 is no Rock Ridge NM field. */ 192 193 /* 194 * Do not report hidden files if so instructed, or associated 195 * files unless instructed to do so 196 */ 197 if ((sbi->s_hide && (de->flags[-sbi->s_high_sierra] & 1)) || 198 (!sbi->s_showassoc && 199 (de->flags[-sbi->s_high_sierra] & 4))) { 200 ctx->pos += de_len; 201 continue; 202 } 203 204 map = 1; 205 if (sbi->s_rock) { 206 len = get_rock_ridge_filename(de, tmpname, inode); 207 if (len != 0) { /* may be -1 */ 208 p = tmpname; 209 map = 0; 210 } 211 } 212 if (map) { 213 #ifdef CONFIG_JOLIET 214 if (sbi->s_joliet_level) { 215 len = get_joliet_filename(de, tmpname, inode); 216 p = tmpname; 217 } else 218 #endif 219 if (sbi->s_mapping == 'a') { 220 len = get_acorn_filename(de, tmpname, inode); 221 p = tmpname; 222 } else 223 if (sbi->s_mapping == 'n') { 224 len = isofs_name_translate(de, tmpname, inode); 225 p = tmpname; 226 } else { 227 p = de->name; 228 len = de->name_len[0]; 229 } 230 } 231 if (len > 0) { 232 if (!dir_emit(ctx, p, len, inode_number, DT_UNKNOWN)) 233 break; 234 } 235 ctx->pos += de_len; 236 237 continue; 238 } 239 if (bh) 240 brelse(bh); 241 return 0; 242 } 243 244 /* 245 * Handle allocation of temporary space for name translation and 246 * handling split directory entries.. The real work is done by 247 * "do_isofs_readdir()". 248 */ 249 static int isofs_readdir(struct file *file, struct dir_context *ctx) 250 { 251 int result; 252 char *tmpname; 253 struct iso_directory_record *tmpde; 254 struct inode *inode = file_inode(file); 255 256 tmpname = (char *)__get_free_page(GFP_KERNEL); 257 if (tmpname == NULL) 258 return -ENOMEM; 259 260 tmpde = (struct iso_directory_record *) (tmpname+1024); 261 262 result = do_isofs_readdir(inode, file, ctx, tmpname, tmpde); 263 264 free_page((unsigned long) tmpname); 265 return result; 266 } 267 268 const struct file_operations isofs_dir_operations = 269 { 270 .llseek = generic_file_llseek, 271 .read = generic_read_dir, 272 .iterate = isofs_readdir, 273 }; 274 275 /* 276 * directories can handle most operations... 277 */ 278 const struct inode_operations isofs_dir_inode_operations = 279 { 280 .lookup = isofs_lookup, 281 }; 282 283 284