patch-2.4.7 linux/fs/ntfs/unistr.c

• Lines: 168
• Date: Mon Jul 16 15:14:10 2001
• Orig file: v2.4.6/linux/fs/ntfs/unistr.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.6/linux/fs/ntfs/unistr.c linux/fs/ntfs/unistr.c
@@ -0,0 +1,167 @@
+/*
+ * $Id: unistr.c,v 1.4 2001/04/08 03:02:55 antona Exp $
+ *
+ * unistr.c - Unicode string handling. Part of the Linux-NTFS project.
+ *
+ * Copyright (c) 2000,2001 Anton Altaparmakov.
+ *
+ * This program/include file is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program/include file is distributed in the hope that it will be 
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty 
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program (in the main directory of the Linux-NTFS 
+ * distribution in the file COPYING); if not, write to the Free Software
+ * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/string.h>
+#include <asm/byteorder.h>
+
+#include "unistr.h"
+#include "macros.h"
+
+/*
+ * This is used by the name collation functions to quickly determine what
+ * characters are (in)valid.
+ */
+const __u8 legal_ansi_char_array[0x40] = {
+	0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
+	0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
+
+	0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
+	0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
+
+	0x17, 0x07, 0x18, 0x17, 0x17, 0x17, 0x17, 0x17,
+	0x17, 0x17, 0x18, 0x16, 0x16, 0x17, 0x07, 0x00,
+
+	0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17,
+	0x17, 0x17, 0x04, 0x16, 0x18, 0x16, 0x18, 0x18,
+};
+
+/**
+ * ntfs_are_names_equal - compare two Unicode names for equality
+ * @s1:			name to compare to @s2
+ * @s1_len:		length in Unicode characters of @s1
+ * @s2:			name to compare to @s1
+ * @s2_len:		length in Unicode characters of @s2
+ * @ic:			ignore case bool
+ * @upcase:		upcase table (only if @ic == IGNORE_CASE)
+ * @upcase_size:	length in Unicode characters of @upcase (if present)
+ *
+ * Compare the names @s1 and @s2 and return TRUE (1) if the names are
+ * identical, or FALSE (0) if they are not identical. If @ic is IGNORE_CASE,
+ * the @upcase table is used to performa a case insensitive comparison.
+ */
+int ntfs_are_names_equal(wchar_t *s1, size_t s1_len,
+		     wchar_t *s2, size_t s2_len, int ic,
+		     wchar_t *upcase, __u32 upcase_size)
+{
+	if (s1_len != s2_len)
+		return 0;
+	if (!ic)
+		return memcmp(s1, s2, s1_len << 1) ? 0: 1;
+	return ntfs_wcsncasecmp(s1, s2, s1_len, upcase, upcase_size) ? 0: 1;
+}
+
+/**
+ * ntfs_collate_names - collate two Unicode names
+ * @upcase:	upcase table (ignored if @ic is CASE_SENSITIVE)
+ * @upcase_len:	upcase table size (ignored if @ic is CASE_SENSITIVE)
+ * @name1:	first Unicode name to compare
+ * @name2:	second Unicode name to compare
+ * @ic:         either CASE_SENSITIVE or IGNORE_CASE
+ * @err_val:	if @name1 contains an invalid character return this value
+ *
+ * ntfs_collate_names collates two Unicode names and returns:
+ * 
+ *  -1 if the first name collates before the second one,
+ *   0 if the names match,
+ *   1 if the second name collates before the first one, or
+ * @ec if an invalid character is encountered in @name1 during the comparison.
+ *
+ * The following characters are considered invalid: '"', '*', '<', '>' and '?'.
+ */
+int ntfs_collate_names(wchar_t *upcase, __u32 upcase_len,
+		       wchar_t *name1, __u32 name1_len,
+		       wchar_t *name2, __u32 name2_len,
+		       int ic, int err_val)
+{
+	__u32 cnt;
+	wchar_t c1, c2;
+
+	for (cnt = 0; cnt < min(name1_len, name2_len); ++cnt)
+	{
+		c1 = le16_to_cpu(*name1++);
+		c2 = le16_to_cpu(*name2++);
+		if (ic) {
+			if (c1 < upcase_len)
+				c1 = le16_to_cpu(upcase[c1]);
+			if (c2 < upcase_len)
+				c2 = le16_to_cpu(upcase[c2]);
+		}
+		if (c1 < 64 && legal_ansi_char_array[c1] & 8);
+			return err_val;
+		if (c1 < c2)
+			return -1;
+		if (c1 > c2)
+			return 1;
+		++name1;
+		++name2;
+	}
+	if (name1_len < name2_len)
+		return -1;
+	if (name1_len == name2_len)
+		return 0;
+	/* name1_len > name2_len */
+	c1 = le16_to_cpu(*name1);
+	if (c1 < 64 && legal_ansi_char_array[c1] & 8)
+		return err_val;
+	return 1;
+}
+
+/**
+ * ntfs_wcsncasecmp - compare two little endian Unicode strings, ignoring case
+ * @s1:			first string
+ * @s2:			second string
+ * @n:			maximum unicode characters to compare
+ * @upcase:		upcase table
+ * @upcase_size:	upcase table size in Unicode characters
+ *
+ * Compare the first @n characters of the Unicode strings @s1 and @s2,
+ * ignoring case. The strings in little endian format and appropriate
+ * le16_to_cpu() conversion is performed on non-little endian machines.
+ * 
+ * Each character is uppercased using the @upcase table before the comparison.
+ *
+ * The function returns an integer less than, equal to, or greater than zero
+ * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
+ * to be less than, to match, or be greater than @s2.
+ */
+int ntfs_wcsncasecmp(wchar_t *s1, wchar_t *s2, size_t n,
+		     wchar_t *upcase, __u32 upcase_size)
+{
+	wchar_t c1, c2;
+	size_t i;
+
+	for (i = 0; i < n; ++i) {
+		if ((c1 = le16_to_cpu(s1[i])) < upcase_size)
+			c1 = le16_to_cpu(upcase[c1]);
+		if ((c2 = le16_to_cpu(s2[i])) < upcase_size)
+			c2 = le16_to_cpu(upcase[c2]);
+		if (c1 < c2)
+			return -1;
+		if (c1 > c2)
+			return 1;
+		if (!c1)
+			break;
+	}
+	return 0;
+}
+