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/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, __be16 *uni, int len, struct nls_table *nls)
  18 {
  19         __be16 *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                 llen = nls->uni2char(be16_to_cpu(ch), op, NLS_MAX_CHARSET_SIZE);
  28                 if (llen > 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, (__be16 *) 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          * Windows doesn't like periods at the end of a name,
  93          * so neither do we
  94          */
  95         while (len >= 2 && (outname[len-1] == '.'))
  96                 len--;
  97
  98         return len;
  99 }