xref: /openbmc/linux/fs/hfs/trans.c (revision d5532ee7)
1 /*
2  *  linux/fs/hfs/trans.c
3  *
4  * Copyright (C) 1995-1997  Paul H. Hargrove
5  * This file may be distributed under the terms of the GNU General Public License.
6  *
7  * This file contains routines for converting between the Macintosh
8  * character set and various other encodings.  This includes dealing
9  * with ':' vs. '/' as the path-element separator.
10  */
11 
12 #include <linux/types.h>
13 #include <linux/nls.h>
14 
15 #include "hfs_fs.h"
16 
17 /*================ Global functions ================*/
18 
19 /*
20  * hfs_mac2asc()
21  *
22  * Given a 'Pascal String' (a string preceded by a length byte) in
23  * the Macintosh character set produce the corresponding filename using
24  * the 'trivial' name-mangling scheme, returning the length of the
25  * mangled filename.  Note that the output string is not NULL
26  * terminated.
27  *
28  * The name-mangling works as follows:
29  * The character '/', which is illegal in Linux filenames is replaced
30  * by ':' which never appears in HFS filenames.	 All other characters
31  * are passed unchanged from input to output.
32  */
33 int hfs_mac2asc(struct super_block *sb, char *out, const struct hfs_name *in)
34 {
35 	struct nls_table *nls_disk = HFS_SB(sb)->nls_disk;
36 	struct nls_table *nls_io = HFS_SB(sb)->nls_io;
37 	const char *src;
38 	char *dst;
39 	int srclen, dstlen, size;
40 
41 	src = in->name;
42 	srclen = in->len;
43 	dst = out;
44 	dstlen = HFS_MAX_NAMELEN;
45 	if (nls_io) {
46 		wchar_t ch;
47 
48 		while (srclen > 0) {
49 			if (nls_disk) {
50 				size = nls_disk->char2uni(src, srclen, &ch);
51 				if (size <= 0) {
52 					ch = '?';
53 					size = 1;
54 				}
55 				src += size;
56 				srclen -= size;
57 			} else {
58 				ch = *src++;
59 				srclen--;
60 			}
61 			if (ch == '/')
62 				ch = ':';
63 			size = nls_io->uni2char(ch, dst, dstlen);
64 			if (size < 0) {
65 				if (size == -ENAMETOOLONG)
66 					goto out;
67 				*dst = '?';
68 				size = 1;
69 			}
70 			dst += size;
71 			dstlen -= size;
72 		}
73 	} else {
74 		char ch;
75 
76 		while (--srclen >= 0)
77 			*dst++ = (ch = *src++) == '/' ? ':' : ch;
78 	}
79 out:
80 	return dst - out;
81 }
82 
83 /*
84  * hfs_asc2mac()
85  *
86  * Given an ASCII string (not null-terminated) and its length,
87  * generate the corresponding filename in the Macintosh character set
88  * using the 'trivial' name-mangling scheme, returning the length of
89  * the mangled filename.  Note that the output string is not NULL
90  * terminated.
91  *
92  * This routine is a inverse to hfs_mac2triv().
93  * A ':' is replaced by a '/'.
94  */
95 void hfs_asc2mac(struct super_block *sb, struct hfs_name *out, struct qstr *in)
96 {
97 	struct nls_table *nls_disk = HFS_SB(sb)->nls_disk;
98 	struct nls_table *nls_io = HFS_SB(sb)->nls_io;
99 	const char *src;
100 	char *dst;
101 	int srclen, dstlen, size;
102 
103 	src = in->name;
104 	srclen = in->len;
105 	dst = out->name;
106 	dstlen = HFS_NAMELEN;
107 	if (nls_io) {
108 		wchar_t ch;
109 
110 		while (srclen > 0) {
111 			size = nls_io->char2uni(src, srclen, &ch);
112 			if (size < 0) {
113 				ch = '?';
114 				size = 1;
115 			}
116 			src += size;
117 			srclen -= size;
118 			if (ch == ':')
119 				ch = '/';
120 			if (nls_disk) {
121 				size = nls_disk->uni2char(ch, dst, dstlen);
122 				if (size < 0) {
123 					if (size == -ENAMETOOLONG)
124 						goto out;
125 					*dst = '?';
126 					size = 1;
127 				}
128 				dst += size;
129 				dstlen -= size;
130 			} else {
131 				*dst++ = ch > 0xff ? '?' : ch;
132 				dstlen--;
133 			}
134 		}
135 	} else {
136 		char ch;
137 
138 		if (dstlen > srclen)
139 			dstlen = srclen;
140 		while (--dstlen >= 0)
141 			*dst++ = (ch = *src++) == ':' ? '/' : ch;
142 	}
143 out:
144 	out->len = dst - (char *)out->name;
145 	dstlen = HFS_NAMELEN - out->len;
146 	while (--dstlen >= 0)
147 		*dst++ = 0;
148 }
149