Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  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 
 16 #include "hfs_fs.h"
 17 #include <linux/dcache.h>
 18 
 19 /*================ File-local variables ================*/
 20 
 21 /*
 22  * unsigned char caseorder[]
 23  *
 24  * Defines the lexical ordering of characters on the Macintosh
 25  *
 26  * Composition of the 'casefold' and 'order' tables from ARDI's code
 27  * with the entry for 0x20 changed to match that for 0xCA to remove
 28  * special case for those two characters.
 29  */
 30 static unsigned char caseorder[256] = {
 31         0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
 32         0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
 33         0x20,0x22,0x23,0x28,0x29,0x2A,0x2B,0x2C,0x2F,0x30,0x31,0x32,0x33,0x34,0x35,0x36,
 34         0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,0x40,0x41,0x42,0x43,0x44,0x45,0x46,
 35         0x47,0x48,0x57,0x59,0x5D,0x5F,0x66,0x68,0x6A,0x6C,0x72,0x74,0x76,0x78,0x7A,0x7E,
 36         0x8C,0x8E,0x90,0x92,0x95,0x97,0x9E,0xA0,0xA2,0xA4,0xA7,0xA9,0xAA,0xAB,0xAC,0xAD,
 37         0x4E,0x48,0x57,0x59,0x5D,0x5F,0x66,0x68,0x6A,0x6C,0x72,0x74,0x76,0x78,0x7A,0x7E,
 38         0x8C,0x8E,0x90,0x92,0x95,0x97,0x9E,0xA0,0xA2,0xA4,0xA7,0xAF,0xB0,0xB1,0xB2,0xB3,
 39         0x4A,0x4C,0x5A,0x60,0x7B,0x7F,0x98,0x4F,0x49,0x51,0x4A,0x4B,0x4C,0x5A,0x60,0x63,
 40         0x64,0x65,0x6E,0x6F,0x70,0x71,0x7B,0x84,0x85,0x86,0x7F,0x80,0x9A,0x9B,0x9C,0x98,
 41         0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0x94,0xBB,0xBC,0xBD,0xBE,0xBF,0xC0,0x4D,0x81,
 42         0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xCB,0x55,0x8A,0xCC,0x4D,0x81,
 43         0xCD,0xCE,0xCF,0xD0,0xD1,0xD2,0xD3,0x26,0x27,0xD4,0x20,0x49,0x4B,0x80,0x82,0x82,
 44         0xD5,0xD6,0x24,0x25,0x2D,0x2E,0xD7,0xD8,0xA6,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,
 45         0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,
 46         0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF
 47 };
 48 
 49 /*================ Global functions ================*/
 50 
 51 /*
 52  * Hash a string to an integer in a case-independent way
 53  */
 54 int hfs_hash_dentry(struct dentry *dentry, struct qstr *this)
 55 {
 56         const unsigned char *name = this->name;
 57         unsigned int hash, len = this->len;
 58 
 59         if (len > HFS_NAMELEN)
 60                 len = HFS_NAMELEN;
 61 
 62         hash = init_name_hash();
 63         for (; len; len--)
 64                 hash = partial_name_hash(caseorder[*name++], hash);
 65         this->hash = end_name_hash(hash);
 66         return 0;
 67 }
 68 
 69 /*
 70  * Compare two strings in the HFS filename character ordering
 71  * Returns positive, negative, or zero, not just 0 or (+/-)1
 72  *
 73  * Equivalent to ARDI's call:
 74  *      ROMlib_RelString(s1+1, s2+1, true, false, (s1[0]<<16) | s2[0])
 75  */
 76 int hfs_strcmp(const unsigned char *s1, unsigned int len1,
 77                const unsigned char *s2, unsigned int len2)
 78 {
 79         int len, tmp;
 80 
 81         len = (len1 > len2) ? len2 : len1;
 82 
 83         while (len--) {
 84                 tmp = (int)caseorder[*(s1++)] - (int)caseorder[*(s2++)];
 85                 if (tmp)
 86                         return tmp;
 87         }
 88         return len1 - len2;
 89 }
 90 
 91 /*
 92  * Test for equality of two strings in the HFS filename character ordering.
 93  * return 1 on failure and 0 on success
 94  */
 95 int hfs_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2)
 96 {
 97         const unsigned char *n1, *n2;
 98         int len;
 99 
100         len = s1->len;
101         if (len >= HFS_NAMELEN) {
102                 if (s2->len < HFS_NAMELEN)
103                         return 1;
104                 len = HFS_NAMELEN;
105         } else if (len != s2->len)
106                 return 1;
107 
108         n1 = s1->name;
109         n2 = s2->name;
110         while (len--) {
111                 if (caseorder[*n1++] != caseorder[*n2++])
112                         return 1;
113         }
114         return 0;
115 }
116 
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