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/mm.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 = ISOFS_SB(inode->i_sb)->s_utf8;
  81         nls = ISOFS_SB(inode->i_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 }