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/malloc.h>
  12 #include <linux/iso_fs.h>
  13
  14 /*
  15  * Convert Unicode 16 to UTF8 or ASCII.
  16  */
  17 static int
  18 uni16_to_x8(unsigned char *ascii, unsigned char *uni, int len,
  19             struct nls_table *nls)
  20 {
  21         unsigned char *ip, *op;
  22         unsigned char ch, cl;
  23         unsigned char *uni_page;
  24
  25         ip = uni;
  26         op = ascii;
  27
  28         while ((*ip || ip[1]) && len) {
  29                 ch = *ip++;
  30                 cl = *ip++;
  31
  32                 uni_page = nls->page_uni2charset[ch];
  33                 if (uni_page && uni_page[cl]) {
  34                         *op++ = uni_page[cl];
  35                 } else {
  36                         *op++ = '?';
  37                 }
  38                 len--;
  39         }
  40         *op = 0;
  41         return (op - ascii);
  42 }
  43
  44 /* Convert big endian wide character string to utf8 */
  45 static int
  46 wcsntombs_be(__u8 *s, const __u8 *pwcs, int inlen, int maxlen)
  47 {
  48         const __u8 *ip;
  49         __u8 *op;
  50         int size;
  51         __u16 c;
  52
  53         op = s;
  54         ip = pwcs;
  55         while ((*ip || ip[1]) && (maxlen > 0) && (inlen > 0)) {
  56                 c = (*ip << 8) | ip[1];
  57                 if (c > 0x7f) {
  58                         size = utf8_wctomb(op, c, maxlen);
  59                         if (size == -1) {
  60                                 /* Ignore character and move on */
  61                                 maxlen--;
  62                         } else {
  63                                 op += size;
  64                                 maxlen -= size;
  65                         }
  66                 } else {
  67                         *op++ = (__u8) c;
  68                 }
  69                 ip += 2;
  70                 inlen--;
  71         }
  72         return (op - s);
  73 }
  74
  75 int
  76 get_joliet_filename(struct iso_directory_record * de, struct inode * inode,
  77                     unsigned char *outname)
  78 {
  79         unsigned char utf8;
  80         struct nls_table *nls;
  81         unsigned char len = 0;
  82
  83         utf8 = inode->i_sb->u.isofs_sb.s_utf8;
  84         nls = inode->i_sb->u.isofs_sb.s_nls_iocharset;
  85
  86         if (utf8) {
  87                 len = wcsntombs_be(outname, de->name,
  88                                    de->name_len[0] >> 1, PAGE_SIZE);
  89         } else {
  90                 len = uni16_to_x8(outname, de->name,
  91                                   de->name_len[0] >> 1, nls);
  92         }
  93         if ((len > 2) && (outname[len-2] == ';') && (outname[len-1] == '1')) {
  94                 len -= 2;
  95         }
  96
  97         /*
  98          * Windows doesn't like periods at the end of a name,
  99          * so neither do we
 100          */
 101         while (len >= 2 && (outname[len-1] == '.')) {
 102                 len--;
 103         }
 104
 105         return len;
 106 }