string.c 3.7 KB

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  1. /*
  2. * linux/fs/hfs/string.c
  3. *
  4. * Copyright (C) 1995-1997 Paul H. Hargrove
  5. * (C) 2003 Ardis Technologies <roman@ardistech.com>
  6. * This file may be distributed under the terms of the GNU General Public License.
  7. *
  8. * This file contains the string comparison function for the
  9. * Macintosh character set.
  10. *
  11. * The code in this file is derived from code which is copyright
  12. * 1986, 1989, 1990 by Abacus Research and Development, Inc. (ARDI)
  13. * It is used here by the permission of ARDI's president Cliff Matthews.
  14. */
  15. #include "hfs_fs.h"
  16. #include <linux/dcache.h>
  17. /*================ File-local variables ================*/
  18. /*
  19. * unsigned char caseorder[]
  20. *
  21. * Defines the lexical ordering of characters on the Macintosh
  22. *
  23. * Composition of the 'casefold' and 'order' tables from ARDI's code
  24. * with the entry for 0x20 changed to match that for 0xCA to remove
  25. * special case for those two characters.
  26. */
  27. static unsigned char caseorder[256] = {
  28. 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
  29. 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
  30. 0x20,0x22,0x23,0x28,0x29,0x2A,0x2B,0x2C,0x2F,0x30,0x31,0x32,0x33,0x34,0x35,0x36,
  31. 0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,0x40,0x41,0x42,0x43,0x44,0x45,0x46,
  32. 0x47,0x48,0x57,0x59,0x5D,0x5F,0x66,0x68,0x6A,0x6C,0x72,0x74,0x76,0x78,0x7A,0x7E,
  33. 0x8C,0x8E,0x90,0x92,0x95,0x97,0x9E,0xA0,0xA2,0xA4,0xA7,0xA9,0xAA,0xAB,0xAC,0xAD,
  34. 0x4E,0x48,0x57,0x59,0x5D,0x5F,0x66,0x68,0x6A,0x6C,0x72,0x74,0x76,0x78,0x7A,0x7E,
  35. 0x8C,0x8E,0x90,0x92,0x95,0x97,0x9E,0xA0,0xA2,0xA4,0xA7,0xAF,0xB0,0xB1,0xB2,0xB3,
  36. 0x4A,0x4C,0x5A,0x60,0x7B,0x7F,0x98,0x4F,0x49,0x51,0x4A,0x4B,0x4C,0x5A,0x60,0x63,
  37. 0x64,0x65,0x6E,0x6F,0x70,0x71,0x7B,0x84,0x85,0x86,0x7F,0x80,0x9A,0x9B,0x9C,0x98,
  38. 0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0x94,0xBB,0xBC,0xBD,0xBE,0xBF,0xC0,0x4D,0x81,
  39. 0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xCB,0x55,0x8A,0xCC,0x4D,0x81,
  40. 0xCD,0xCE,0xCF,0xD0,0xD1,0xD2,0xD3,0x26,0x27,0xD4,0x20,0x49,0x4B,0x80,0x82,0x82,
  41. 0xD5,0xD6,0x24,0x25,0x2D,0x2E,0xD7,0xD8,0xA6,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,
  42. 0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,
  43. 0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF
  44. };
  45. /*================ Global functions ================*/
  46. /*
  47. * Hash a string to an integer in a case-independent way
  48. */
  49. int hfs_hash_dentry(struct dentry *dentry, struct qstr *this)
  50. {
  51. const unsigned char *name = this->name;
  52. unsigned int hash, len = this->len;
  53. if (len > HFS_NAMELEN)
  54. len = HFS_NAMELEN;
  55. hash = init_name_hash();
  56. for (; len; len--)
  57. hash = partial_name_hash(caseorder[*name++], hash);
  58. this->hash = end_name_hash(hash);
  59. return 0;
  60. }
  61. /*
  62. * Compare two strings in the HFS filename character ordering
  63. * Returns positive, negative, or zero, not just 0 or (+/-)1
  64. *
  65. * Equivalent to ARDI's call:
  66. * ROMlib_RelString(s1+1, s2+1, true, false, (s1[0]<<16) | s2[0])
  67. */
  68. int hfs_strcmp(const unsigned char *s1, unsigned int len1,
  69. const unsigned char *s2, unsigned int len2)
  70. {
  71. int len, tmp;
  72. len = (len1 > len2) ? len2 : len1;
  73. while (len--) {
  74. tmp = (int)caseorder[*(s1++)] - (int)caseorder[*(s2++)];
  75. if (tmp)
  76. return tmp;
  77. }
  78. return len1 - len2;
  79. }
  80. /*
  81. * Test for equality of two strings in the HFS filename character ordering.
  82. * return 1 on failure and 0 on success
  83. */
  84. int hfs_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2)
  85. {
  86. const unsigned char *n1, *n2;
  87. int len;
  88. len = s1->len;
  89. if (len >= HFS_NAMELEN) {
  90. if (s2->len < HFS_NAMELEN)
  91. return 1;
  92. len = HFS_NAMELEN;
  93. } else if (len != s2->len)
  94. return 1;
  95. n1 = s1->name;
  96. n2 = s2->name;
  97. while (len--) {
  98. if (caseorder[*n1++] != caseorder[*n2++])
  99. return 1;
  100. }
  101. return 0;
  102. }