fs/hfsplus/unicode.c

   1 /*
   2  *  linux/fs/hfsplus/unicode.c
   3  *
   4  * Copyright (C) 2001
   5  * Brad Boyer (flar@allandria.com)
   6  * (C) 2003 Ardis Technologies <roman@ardistech.com>
   7  *
   8  * Handler routines for unicode strings
   9  */
  10
  11 #include <linux/types.h>
  12 #include <linux/nls.h>
  13 #include "hfsplus_fs.h"
  14 #include "hfsplus_raw.h"
  15
  16 /* Fold the case of a unicode char, given the 16 bit value */
  17 /* Returns folded char, or 0 if ignorable */
  18 static inline u16 case_fold(u16 c)
  19 {
  20         u16 tmp;
  21
  22         tmp = case_fold_table[(c>>8)];
  23         if (tmp)
  24                 tmp = case_fold_table[tmp + (c & 0xFF)];
  25         else
  26                 tmp = c;
  27         return tmp;
  28 }
  29
  30 /* Compare unicode strings, return values like normal strcmp */
  31 int hfsplus_unistrcmp(const struct hfsplus_unistr *s1, const struct hfsplus_unistr *s2)
  32 {
  33         u16 len1, len2, c1, c2;
  34         const hfsplus_unichr *p1, *p2;
  35
  36         len1 = be16_to_cpu(s1->length);
  37         len2 = be16_to_cpu(s2->length);
  38         p1 = s1->unicode;
  39         p2 = s2->unicode;
  40
  41         while (1) {
  42                 c1 = c2 = 0;
  43
  44                 while (len1 && !c1) {
  45                         c1 = case_fold(be16_to_cpu(*p1));
  46                         p1++;
  47                         len1--;
  48                 }
  49                 while (len2 && !c2) {
  50                         c2 = case_fold(be16_to_cpu(*p2));
  51                         p2++;
  52                         len2--;
  53                 }
  54
  55                 if (c1 != c2)
  56                         return (c1 < c2) ? -1 : 1;
  57                 if (!c1 && !c2)
  58                         return 0;
  59         }
  60 }
  61
  62 int hfsplus_uni2asc(const struct hfsplus_unistr *ustr, char *astr, int *len)
  63 {
  64         const hfsplus_unichr *ip;
  65         u8 *op;
  66         u16 ustrlen, cc;
  67         int size, tmp;
  68
  69         op = astr;
  70         ip = ustr->unicode;
  71         ustrlen = be16_to_cpu(ustr->length);
  72         tmp = *len;
  73         while (ustrlen > 0 && tmp > 0) {
  74                 cc = be16_to_cpu(*ip);
  75                 switch (cc) {
  76                 case 0:
  77                         cc = 0x2400;
  78                         break;
  79                 case '/':
  80                         cc = ':';
  81                         break;
  82                 }
  83                 if (cc > 0x7f) {
  84                         size = utf8_wctomb(op, cc, tmp);
  85                         if (size == -1) {
  86                                 /* ignore */
  87                         } else {
  88                                 op += size;
  89                                 tmp -= size;
  90                         }
  91                 } else {
  92                         *op++ = (u8) cc;
  93                         tmp--;
  94                 }
  95                 ip++;
  96                 ustrlen--;
  97         }
  98         *len = (char *)op - astr;
  99         if (ustrlen)
 100                 return -ENAMETOOLONG;
 101         return 0;
 102 }
 103
 104 int hfsplus_asc2uni(struct hfsplus_unistr *ustr, const char *astr, int len)
 105 {
 106         int tmp;
 107         wchar_t c;
 108         u16 outlen = 0;
 109
 110         while (outlen <= HFSPLUS_MAX_STRLEN && len > 0) {
 111                 if (*astr & 0x80) {
 112                         tmp = utf8_mbtowc(&c, astr, len);
 113                         if (tmp < 0) {
 114                                 astr++;
 115                                 len--;
 116                                 continue;
 117                         } else {
 118                                 astr += tmp;
 119                                 len -= tmp;
 120                         }
 121                 } else {
 122                         c = *astr++;
 123                         len--;
 124                 }
 125                 switch (c) {
 126                 case 0x2400:
 127                         c = 0;
 128                         break;
 129                 case ':':
 130                         c = '/';
 131                         break;
 132                 }
 133                 ustr->unicode[outlen] = cpu_to_be16(c);
 134                 outlen++;
 135         }
 136         ustr->length = cpu_to_be16(outlen);
 137         if (len > 0)
 138                 return -ENAMETOOLONG;
 139         return 0;
 140 }