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/smp_lock.h>
14 #include "isofs.h"
15
isofs_name_translate(struct iso_directory_record * de,char * new,struct inode * inode)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 */
get_acorn_filename(struct iso_directory_record * de,char * retname,struct inode * inode)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 */
do_isofs_readdir(struct inode * inode,struct file * filp,void * dirent,filldir_t filldir,char * tmpname,struct iso_directory_record * tmpde)81 static int do_isofs_readdir(struct inode *inode, struct file *filp,
82 void *dirent, filldir_t filldir,
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 = filp->f_pos & (bufsize - 1);
98 block = filp->f_pos >> bufbits;
99
100 while (filp->f_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 filp->f_pos = (filp->f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
123 block = filp->f_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 filp->f_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 (filldir(dirent, ".", 1, filp->f_pos, inode->i_ino, DT_DIR) < 0)
175 break;
176 filp->f_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 inode_number = parent_ino(filp->f_path.dentry);
185 if (filldir(dirent, "..", 2, filp->f_pos, inode_number, DT_DIR) < 0)
186 break;
187 filp->f_pos += de_len;
188 continue;
189 }
190
191 /* Handle everything else. Do name translation if there
192 is no Rock Ridge NM field. */
193
194 /*
195 * Do not report hidden files if so instructed, or associated
196 * files unless instructed to do so
197 */
198 if ((sbi->s_hide == 'y' &&
199 (de->flags[-sbi->s_high_sierra] & 1)) ||
200 (sbi->s_showassoc =='n' &&
201 (de->flags[-sbi->s_high_sierra] & 4))) {
202 filp->f_pos += de_len;
203 continue;
204 }
205
206 map = 1;
207 if (sbi->s_rock) {
208 len = get_rock_ridge_filename(de, tmpname, inode);
209 if (len != 0) { /* may be -1 */
210 p = tmpname;
211 map = 0;
212 }
213 }
214 if (map) {
215 #ifdef CONFIG_JOLIET
216 if (sbi->s_joliet_level) {
217 len = get_joliet_filename(de, tmpname, inode);
218 p = tmpname;
219 } else
220 #endif
221 if (sbi->s_mapping == 'a') {
222 len = get_acorn_filename(de, tmpname, inode);
223 p = tmpname;
224 } else
225 if (sbi->s_mapping == 'n') {
226 len = isofs_name_translate(de, tmpname, inode);
227 p = tmpname;
228 } else {
229 p = de->name;
230 len = de->name_len[0];
231 }
232 }
233 if (len > 0) {
234 if (filldir(dirent, p, len, filp->f_pos, inode_number, DT_UNKNOWN) < 0)
235 break;
236 }
237 filp->f_pos += de_len;
238
239 continue;
240 }
241 if (bh)
242 brelse(bh);
243 return 0;
244 }
245
246 /*
247 * Handle allocation of temporary space for name translation and
248 * handling split directory entries.. The real work is done by
249 * "do_isofs_readdir()".
250 */
isofs_readdir(struct file * filp,void * dirent,filldir_t filldir)251 static int isofs_readdir(struct file *filp,
252 void *dirent, filldir_t filldir)
253 {
254 int result;
255 char *tmpname;
256 struct iso_directory_record *tmpde;
257 struct inode *inode = filp->f_path.dentry->d_inode;
258
259 tmpname = (char *)__get_free_page(GFP_KERNEL);
260 if (tmpname == NULL)
261 return -ENOMEM;
262
263 lock_kernel();
264 tmpde = (struct iso_directory_record *) (tmpname+1024);
265
266 result = do_isofs_readdir(inode, filp, dirent, filldir, tmpname, tmpde);
267
268 free_page((unsigned long) tmpname);
269 unlock_kernel();
270 return result;
271 }
272
273 const struct file_operations isofs_dir_operations =
274 {
275 .read = generic_read_dir,
276 .readdir = isofs_readdir,
277 };
278
279 /*
280 * directories can handle most operations...
281 */
282 const struct inode_operations isofs_dir_inode_operations =
283 {
284 .lookup = isofs_lookup,
285 };
286
287
288