xref: /linux/fs/isofs/joliet.c (revision f01c18456993bab43067b678f56c87ca954aa43b)
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/types.h>
10 #include <linux/nls.h>
11 #include "isofs.h"
12 
13 /*
14  * Convert Unicode 16 to UTF-8 or ASCII.
15  */
16 static int
17 uni16_to_x8(unsigned char *ascii, u16 *uni, int len, struct nls_table *nls)
18 {
19 	wchar_t *ip, ch;
20 	unsigned char *op;
21 
22 	ip = uni;
23 	op = ascii;
24 
25 	while ((ch = get_unaligned(ip)) && len) {
26 		int llen;
27 		ch = be16_to_cpu(ch);
28 		if ((llen = nls->uni2char(ch, op, NLS_MAX_CHARSET_SIZE)) > 0)
29 			op += llen;
30 		else
31 			*op++ = '?';
32 		ip++;
33 
34 		len--;
35 	}
36 	*op = 0;
37 	return (op - ascii);
38 }
39 
40 /* Convert big endian wide character string to utf8 */
41 static int
42 wcsntombs_be(__u8 *s, const __u8 *pwcs, int inlen, int maxlen)
43 {
44 	const __u8 *ip;
45 	__u8 *op;
46 	int size;
47 	__u16 c;
48 
49 	op = s;
50 	ip = pwcs;
51 	while ((*ip || ip[1]) && (maxlen > 0) && (inlen > 0)) {
52 		c = (*ip << 8) | ip[1];
53 		if (c > 0x7f) {
54 			size = utf8_wctomb(op, c, maxlen);
55 			if (size == -1) {
56 				/* Ignore character and move on */
57 				maxlen--;
58 			} else {
59 				op += size;
60 				maxlen -= size;
61 			}
62 		} else {
63 			*op++ = (__u8) c;
64 		}
65 		ip += 2;
66 		inlen--;
67 	}
68 	return (op - s);
69 }
70 
71 int
72 get_joliet_filename(struct iso_directory_record * de, unsigned char *outname, struct inode * inode)
73 {
74 	unsigned char utf8;
75 	struct nls_table *nls;
76 	unsigned char len = 0;
77 
78 	utf8 = ISOFS_SB(inode->i_sb)->s_utf8;
79 	nls = ISOFS_SB(inode->i_sb)->s_nls_iocharset;
80 
81 	if (utf8) {
82 		len = wcsntombs_be(outname, de->name,
83 				   de->name_len[0] >> 1, PAGE_SIZE);
84 	} else {
85 		len = uni16_to_x8(outname, (u16 *) de->name,
86 				  de->name_len[0] >> 1, nls);
87 	}
88 	if ((len > 2) && (outname[len-2] == ';') && (outname[len-1] == '1')) {
89 		len -= 2;
90 	}
91 
92 	/*
93 	 * Windows doesn't like periods at the end of a name,
94 	 * so neither do we
95 	 */
96 	while (len >= 2 && (outname[len-1] == '.')) {
97 		len--;
98 	}
99 
100 	return len;
101 }
102