aboutsummaryrefslogtreecommitdiffstats
path: root/fs/isofs/dir.c
blob: e0aca9a0ac68b9f5a75764a570df2c3d0bd81a72 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
/*
 *  linux/fs/isofs/dir.c
 *
 *  (C) 1992, 1993, 1994  Eric Youngdale Modified for ISO 9660 filesystem.
 *
 *  (C) 1991  Linus Torvalds - minix filesystem
 *
 *  Steve Beynon		       : Missing last directory entries fixed
 *  (stephen@askone.demon.co.uk)      : 21st June 1996
 *
 *  isofs directory handling functions
 */
#include <linux/smp_lock.h>
#include <linux/gfp.h>
#include "isofs.h"

int isofs_name_translate(struct iso_directory_record *de, char *new, struct inode *inode)
{
	char * old = de->name;
	int len = de->name_len[0];
	int i;

	for (i = 0; i < len; i++) {
		unsigned char c = old[i];
		if (!c)
			break;

		if (c >= 'A' && c <= 'Z')
			c |= 0x20;	/* lower case */

		/* Drop trailing '.;1' (ISO 9660:1988 7.5.1 requires period) */
		if (c == '.' && i == len - 3 && old[i + 1] == ';' && old[i + 2] == '1')
			break;

		/* Drop trailing ';1' */
		if (c == ';' && i == len - 2 && old[i + 1] == '1')
			break;

		/* Convert remaining ';' to '.' */
		/* Also '/' to '.' (broken Acorn-generated ISO9660 images) */
		if (c == ';' || c == '/')
			c = '.';

		new[i] = c;
	}
	return i;
}

/* Acorn extensions written by Matthew Wilcox <willy@bofh.ai> 1998 */
int get_acorn_filename(struct iso_directory_record *de,
			    char *retname, struct inode *inode)
{
	int std;
	unsigned char *chr;
	int retnamlen = isofs_name_translate(de, retname, inode);

	if (retnamlen == 0)
		return 0;
	std = sizeof(struct iso_directory_record) + de->name_len[0];
	if (std & 1)
		std++;
	if ((*((unsigned char *) de) - std) != 32)
		return retnamlen;
	chr = ((unsigned char *) de) + std;
	if (strncmp(chr, "ARCHIMEDES", 10))
		return retnamlen;
	if ((*retname == '_') && ((chr[19] & 1) == 1))
		*retname = '!';
	if (((de->flags[0] & 2) == 0) && (chr[13] == 0xff)
		&& ((chr[12] & 0xf0) == 0xf0)) {
		retname[retnamlen] = ',';
		sprintf(retname+retnamlen+1, "%3.3x",
			((chr[12] & 0xf) << 8) | chr[11]);
		retnamlen += 4;
	}
	return retnamlen;
}

/*
 * This should _really_ be cleaned up some day..
 */
static int do_isofs_readdir(struct inode *inode, struct file *filp,
		void *dirent, filldir_t filldir,
		char *tmpname, struct iso_directory_record *tmpde)
{
	unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
	unsigned char bufbits = ISOFS_BUFFER_BITS(inode);
	unsigned long block, offset, block_saved, offset_saved;
	unsigned long inode_number = 0;	/* Quiet GCC */
	struct buffer_head *bh = NULL;
	int len;
	int map;
	int first_de = 1;
	char *p = NULL;		/* Quiet GCC */
	struct iso_directory_record *de;
	struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);

	offset = filp->f_pos & (bufsize - 1);
	block = filp->f_pos >> bufbits;

	while (filp->f_pos < inode->i_size) {
		int de_len;

		if (!bh) {
			bh = isofs_bread(inode, block);
			if (!bh)
				return 0;
		}

		de = (struct iso_directory_record *) (bh->b_data + offset);

		de_len = *(unsigned char *) de;

		/*
		 * If the length byte is zero, we should move on to the next
		 * CDROM sector.  If we are at the end of the directory, we
		 * kick out of the while loop.
		 */

		if (de_len == 0) {
			brelse(bh);
			bh = NULL;
			filp->f_pos = (filp->f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
			block = filp->f_pos >> bufbits;
			offset = 0;
			continue;
		}

		block_saved = block;
		offset_saved = offset;
		offset += de_len;

		/* Make sure we have a full directory entry */
		if (offset >= bufsize) {
			int slop = bufsize - offset + de_len;
			memcpy(tmpde, de, slop);
			offset &= bufsize - 1;
			block++;
			brelse(bh);
			bh = NULL;
			if (offset) {
				bh = isofs_bread(inode, block);
				if (!bh)
					return 0;
				memcpy((void *) tmpde + slop, bh->b_data, offset);
			}
			de = tmpde;
		}
		/* Basic sanity check, whether name doesn't exceed dir entry */
		if (de_len < de->name_len[0] +
					sizeof(struct iso_directory_record)) {
			printk(KERN_NOTICE "iso9660: Corrupted directory entry"
			       " in block %lu of inode %lu\n", block,
			       inode->i_ino);
			return -EIO;
		}

		if (first_de) {
			isofs_normalize_block_and_offset(de,
							&block_saved,
							&offset_saved);
			inode_number = isofs_get_ino(block_saved,
							offset_saved, bufbits);
		}

		if (de->flags[-sbi->s_high_sierra] & 0x80) {
			first_de = 0;
			filp->f_pos += de_len;
			continue;
		}
		first_de = 1;

		/* Handle the case of the '.' directory */
		if (de->name_len[0] == 1 && de->name[0] == 0) {
			if (filldir(dirent, ".", 1, filp->f_pos, inode->i_ino, DT_DIR) < 0)
				break;
			filp->f_pos += de_len;
			continue;
		}

		len = 0;

		/* Handle the case of the '..' directory */
		if (de->name_len[0] == 1 && de->name[0] == 1) {
			inode_number = parent_ino(filp->f_path.dentry);
			if (filldir(dirent, "..", 2, filp->f_pos, inode_number, DT_DIR) < 0)
				break;
			filp->f_pos += de_len;
			continue;
		}

		/* Handle everything else.  Do name translation if there
		   is no Rock Ridge NM field. */

		/*
		 * Do not report hidden files if so instructed, or associated
		 * files unless instructed to do so
		 */
		if ((sbi->s_hide && (de->flags[-sbi->s_high_sierra] & 1)) ||
		    (!sbi->s_showassoc &&
				(de->flags[-sbi->s_high_sierra] & 4))) {
			filp->f_pos += de_len;
			continue;
		}

		map = 1;
		if (sbi->s_rock) {
			len = get_rock_ridge_filename(de, tmpname, inode);
			if (len != 0) {		/* may be -1 */
				p = tmpname;
				map = 0;
			}
		}
		if (map) {
#ifdef CONFIG_JOLIET
			if (sbi->s_joliet_level) {
				len = get_joliet_filename(de, tmpname, inode);
				p = tmpname;
			} else
#endif
			if (sbi->s_mapping == 'a') {
				len = get_acorn_filename(de, tmpname, inode);
				p = tmpname;
			} else
			if (sbi->s_mapping == 'n') {
				len = isofs_name_translate(de, tmpname, inode);
				p = tmpname;
			} else {
				p = de->name;
				len = de->name_len[0];
			}
		}
		if (len > 0) {
			if (filldir(dirent, p, len, filp->f_pos, inode_number, DT_UNKNOWN) < 0)
				break;
		}
		filp->f_pos += de_len;

		continue;
	}
	if (bh)
		brelse(bh);
	return 0;
}

/*
 * Handle allocation of temporary space for name translation and
 * handling split directory entries.. The real work is done by
 * "do_isofs_readdir()".
 */
static int isofs_readdir(struct file *filp,
		void *dirent, filldir_t filldir)
{
	int result;
	char *tmpname;
	struct iso_directory_record *tmpde;
	struct inode *inode = filp->f_path.dentry->d_inode;

	tmpname = (char *)__get_free_page(GFP_KERNEL);
	if (tmpname == NULL)
		return -ENOMEM;

	lock_kernel();
	tmpde = (struct iso_directory_record *) (tmpname+1024);

	result = do_isofs_readdir(inode, filp, dirent, filldir, tmpname, tmpde);

	free_page((unsigned long) tmpname);
	unlock_kernel();
	return result;
}

const struct file_operations isofs_dir_operations =
{
	.llseek = generic_file_llseek,
	.read = generic_read_dir,
	.readdir = isofs_readdir,
};

/*
 * directories can handle most operations...
 */
const struct inode_operations isofs_dir_inode_operations =
{
	.lookup = isofs_lookup,
};