File: /usr/src/linux/fs/isofs/joliet.c

1     /*
2      *  linux/fs/isofs/joliet.c
3      *
4      *  (C) 1996 Gordon Chaffee
5      *
6      *  Joliet: Microsoft's Unicode extensions to iso9660
7      */
8     
9     #include <linux/string.h>
10     #include <linux/nls.h>
11     #include <linux/slab.h>
12     #include <linux/iso_fs.h>
13     #include <asm/unaligned.h>
14     
15     /*
16      * Convert Unicode 16 to UTF8 or ASCII.
17      */
18     static int
19     uni16_to_x8(unsigned char *ascii, u16 *uni, int len, struct nls_table *nls)
20     {
21     	wchar_t *ip, ch;
22     	unsigned char *op;
23     
24     	ip = uni;
25     	op = ascii;
26     
27     	while ((ch = get_unaligned(ip)) && len) {
28     		int llen;
29     		ch = be16_to_cpu(ch);
30     		if ((llen = nls->uni2char(ch, op, NLS_MAX_CHARSET_SIZE)) > 0)
31     			op += llen;
32     		else
33     			*op++ = '?';
34     		ip++;
35     
36     		len--;
37     	}
38     	*op = 0;
39     	return (op - ascii);
40     }
41     
42     /* Convert big endian wide character string to utf8 */
43     static int
44     wcsntombs_be(__u8 *s, const __u8 *pwcs, int inlen, int maxlen)
45     {
46     	const __u8 *ip;
47     	__u8 *op;
48     	int size;
49     	__u16 c;
50     
51     	op = s;
52     	ip = pwcs;
53     	while ((*ip || ip[1]) && (maxlen > 0) && (inlen > 0)) {
54     		c = (*ip << 8) | ip[1];
55     		if (c > 0x7f) {
56     			size = utf8_wctomb(op, c, maxlen);
57     			if (size == -1) {
58     				/* Ignore character and move on */
59     				maxlen--;
60     			} else {
61     				op += size;
62     				maxlen -= size;
63     			}
64     		} else {
65     			*op++ = (__u8) c;
66     		}
67     		ip += 2;
68     		inlen--;
69     	}
70     	return (op - s);
71     }
72     
73     int
74     get_joliet_filename(struct iso_directory_record * de, unsigned char *outname, struct inode * inode)
75     {
76     	unsigned char utf8;
77     	struct nls_table *nls;
78     	unsigned char len = 0;
79     
80     	utf8 = inode->i_sb->u.isofs_sb.s_utf8;
81     	nls = inode->i_sb->u.isofs_sb.s_nls_iocharset;
82     
83     	if (utf8) {
84     		len = wcsntombs_be(outname, de->name,
85     				   de->name_len[0] >> 1, PAGE_SIZE);
86     	} else {
87     		len = uni16_to_x8(outname, (u16 *) de->name,
88     				  de->name_len[0] >> 1, nls);
89     	}
90     	if ((len > 2) && (outname[len-2] == ';') && (outname[len-1] == '1')) {
91     		len -= 2;
92     	}
93     
94     	/*
95     	 * Windows doesn't like periods at the end of a name,
96     	 * so neither do we
97     	 */
98     	while (len >= 2 && (outname[len-1] == '.')) {
99     		len--;
100     	}
101     
102     	return len;
103     }
104