xref: /openbmc/linux/fs/hfs/trans.c (revision 84764a41)
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 	if (srclen > HFS_NAMELEN)
44 		srclen = HFS_NAMELEN;
45 	dst = out;
46 	dstlen = HFS_MAX_NAMELEN;
47 	if (nls_io) {
48 		wchar_t ch;
49 
50 		while (srclen > 0) {
51 			if (nls_disk) {
52 				size = nls_disk->char2uni(src, srclen, &ch);
53 				if (size <= 0) {
54 					ch = '?';
55 					size = 1;
56 				}
57 				src += size;
58 				srclen -= size;
59 			} else {
60 				ch = *src++;
61 				srclen--;
62 			}
63 			if (ch == '/')
64 				ch = ':';
65 			size = nls_io->uni2char(ch, dst, dstlen);
66 			if (size < 0) {
67 				if (size == -ENAMETOOLONG)
68 					goto out;
69 				*dst = '?';
70 				size = 1;
71 			}
72 			dst += size;
73 			dstlen -= size;
74 		}
75 	} else {
76 		char ch;
77 
78 		while (--srclen >= 0)
79 			*dst++ = (ch = *src++) == '/' ? ':' : ch;
80 	}
81 out:
82 	return dst - out;
83 }
84 
85 /*
86  * hfs_asc2mac()
87  *
88  * Given an ASCII string (not null-terminated) and its length,
89  * generate the corresponding filename in the Macintosh character set
90  * using the 'trivial' name-mangling scheme, returning the length of
91  * the mangled filename.  Note that the output string is not NULL
92  * terminated.
93  *
94  * This routine is a inverse to hfs_mac2triv().
95  * A ':' is replaced by a '/'.
96  */
97 void hfs_asc2mac(struct super_block *sb, struct hfs_name *out, struct qstr *in)
98 {
99 	struct nls_table *nls_disk = HFS_SB(sb)->nls_disk;
100 	struct nls_table *nls_io = HFS_SB(sb)->nls_io;
101 	const char *src;
102 	char *dst;
103 	int srclen, dstlen, size;
104 
105 	src = in->name;
106 	srclen = in->len;
107 	dst = out->name;
108 	dstlen = HFS_NAMELEN;
109 	if (nls_io) {
110 		wchar_t ch;
111 
112 		while (srclen > 0) {
113 			size = nls_io->char2uni(src, srclen, &ch);
114 			if (size < 0) {
115 				ch = '?';
116 				size = 1;
117 			}
118 			src += size;
119 			srclen -= size;
120 			if (ch == ':')
121 				ch = '/';
122 			if (nls_disk) {
123 				size = nls_disk->uni2char(ch, dst, dstlen);
124 				if (size < 0) {
125 					if (size == -ENAMETOOLONG)
126 						goto out;
127 					*dst = '?';
128 					size = 1;
129 				}
130 				dst += size;
131 				dstlen -= size;
132 			} else {
133 				*dst++ = ch > 0xff ? '?' : ch;
134 				dstlen--;
135 			}
136 		}
137 	} else {
138 		char ch;
139 
140 		if (dstlen > srclen)
141 			dstlen = srclen;
142 		while (--dstlen >= 0)
143 			*dst++ = (ch = *src++) == ':' ? '/' : ch;
144 	}
145 out:
146 	out->len = dst - (char *)out->name;
147 	dstlen = HFS_NAMELEN - out->len;
148 	while (--dstlen >= 0)
149 		*dst++ = 0;
150 }
151