1 /*
2  * unistr.c - NTFS Unicode string handling. Part of the Linux-NTFS project.
3  *
4  * Copyright (c) 2001-2006 Anton Altaparmakov
5  *
6  * This program/include file is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as published
8  * by the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program/include file is distributed in the hope that it will be
12  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program (in the main directory of the Linux-NTFS
18  * distribution in the file COPYING); if not, write to the Free Software
19  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
20  */
21 
22 #include <linux/slab.h>
23 
24 #include "types.h"
25 #include "debug.h"
26 #include "ntfs.h"
27 
28 /*
29  * IMPORTANT
30  * =========
31  *
32  * All these routines assume that the Unicode characters are in little endian
33  * encoding inside the strings!!!
34  */
35 
36 /*
37  * This is used by the name collation functions to quickly determine what
38  * characters are (in)valid.
39  */
40 static const u8 legal_ansi_char_array[0x40] = {
41 	0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
42 	0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
43 
44 	0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
45 	0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
46 
47 	0x17, 0x07, 0x18, 0x17, 0x17, 0x17, 0x17, 0x17,
48 	0x17, 0x17, 0x18, 0x16, 0x16, 0x17, 0x07, 0x00,
49 
50 	0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17,
51 	0x17, 0x17, 0x04, 0x16, 0x18, 0x16, 0x18, 0x18,
52 };
53 
54 /**
55  * ntfs_are_names_equal - compare two Unicode names for equality
56  * @s1:			name to compare to @s2
57  * @s1_len:		length in Unicode characters of @s1
58  * @s2:			name to compare to @s1
59  * @s2_len:		length in Unicode characters of @s2
60  * @ic:			ignore case bool
61  * @upcase:		upcase table (only if @ic == IGNORE_CASE)
62  * @upcase_size:	length in Unicode characters of @upcase (if present)
63  *
64  * Compare the names @s1 and @s2 and return 'true' (1) if the names are
65  * identical, or 'false' (0) if they are not identical. If @ic is IGNORE_CASE,
66  * the @upcase table is used to performa a case insensitive comparison.
67  */
ntfs_are_names_equal(const ntfschar * s1,size_t s1_len,const ntfschar * s2,size_t s2_len,const IGNORE_CASE_BOOL ic,const ntfschar * upcase,const u32 upcase_size)68 bool ntfs_are_names_equal(const ntfschar *s1, size_t s1_len,
69 		const ntfschar *s2, size_t s2_len, const IGNORE_CASE_BOOL ic,
70 		const ntfschar *upcase, const u32 upcase_size)
71 {
72 	if (s1_len != s2_len)
73 		return false;
74 	if (ic == CASE_SENSITIVE)
75 		return !ntfs_ucsncmp(s1, s2, s1_len);
76 	return !ntfs_ucsncasecmp(s1, s2, s1_len, upcase, upcase_size);
77 }
78 
79 /**
80  * ntfs_collate_names - collate two Unicode names
81  * @name1:	first Unicode name to compare
82  * @name2:	second Unicode name to compare
83  * @err_val:	if @name1 contains an invalid character return this value
84  * @ic:		either CASE_SENSITIVE or IGNORE_CASE
85  * @upcase:	upcase table (ignored if @ic is CASE_SENSITIVE)
86  * @upcase_len:	upcase table size (ignored if @ic is CASE_SENSITIVE)
87  *
88  * ntfs_collate_names collates two Unicode names and returns:
89  *
90  *  -1 if the first name collates before the second one,
91  *   0 if the names match,
92  *   1 if the second name collates before the first one, or
93  * @err_val if an invalid character is found in @name1 during the comparison.
94  *
95  * The following characters are considered invalid: '"', '*', '<', '>' and '?'.
96  */
ntfs_collate_names(const ntfschar * name1,const u32 name1_len,const ntfschar * name2,const u32 name2_len,const int err_val,const IGNORE_CASE_BOOL ic,const ntfschar * upcase,const u32 upcase_len)97 int ntfs_collate_names(const ntfschar *name1, const u32 name1_len,
98 		const ntfschar *name2, const u32 name2_len,
99 		const int err_val, const IGNORE_CASE_BOOL ic,
100 		const ntfschar *upcase, const u32 upcase_len)
101 {
102 	u32 cnt, min_len;
103 	u16 c1, c2;
104 
105 	min_len = name1_len;
106 	if (name1_len > name2_len)
107 		min_len = name2_len;
108 	for (cnt = 0; cnt < min_len; ++cnt) {
109 		c1 = le16_to_cpu(*name1++);
110 		c2 = le16_to_cpu(*name2++);
111 		if (ic) {
112 			if (c1 < upcase_len)
113 				c1 = le16_to_cpu(upcase[c1]);
114 			if (c2 < upcase_len)
115 				c2 = le16_to_cpu(upcase[c2]);
116 		}
117 		if (c1 < 64 && legal_ansi_char_array[c1] & 8)
118 			return err_val;
119 		if (c1 < c2)
120 			return -1;
121 		if (c1 > c2)
122 			return 1;
123 	}
124 	if (name1_len < name2_len)
125 		return -1;
126 	if (name1_len == name2_len)
127 		return 0;
128 	/* name1_len > name2_len */
129 	c1 = le16_to_cpu(*name1);
130 	if (c1 < 64 && legal_ansi_char_array[c1] & 8)
131 		return err_val;
132 	return 1;
133 }
134 
135 /**
136  * ntfs_ucsncmp - compare two little endian Unicode strings
137  * @s1:		first string
138  * @s2:		second string
139  * @n:		maximum unicode characters to compare
140  *
141  * Compare the first @n characters of the Unicode strings @s1 and @s2,
142  * The strings in little endian format and appropriate le16_to_cpu()
143  * conversion is performed on non-little endian machines.
144  *
145  * The function returns an integer less than, equal to, or greater than zero
146  * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
147  * to be less than, to match, or be greater than @s2.
148  */
ntfs_ucsncmp(const ntfschar * s1,const ntfschar * s2,size_t n)149 int ntfs_ucsncmp(const ntfschar *s1, const ntfschar *s2, size_t n)
150 {
151 	u16 c1, c2;
152 	size_t i;
153 
154 	for (i = 0; i < n; ++i) {
155 		c1 = le16_to_cpu(s1[i]);
156 		c2 = le16_to_cpu(s2[i]);
157 		if (c1 < c2)
158 			return -1;
159 		if (c1 > c2)
160 			return 1;
161 		if (!c1)
162 			break;
163 	}
164 	return 0;
165 }
166 
167 /**
168  * ntfs_ucsncasecmp - compare two little endian Unicode strings, ignoring case
169  * @s1:			first string
170  * @s2:			second string
171  * @n:			maximum unicode characters to compare
172  * @upcase:		upcase table
173  * @upcase_size:	upcase table size in Unicode characters
174  *
175  * Compare the first @n characters of the Unicode strings @s1 and @s2,
176  * ignoring case. The strings in little endian format and appropriate
177  * le16_to_cpu() conversion is performed on non-little endian machines.
178  *
179  * Each character is uppercased using the @upcase table before the comparison.
180  *
181  * The function returns an integer less than, equal to, or greater than zero
182  * if @s1 (or the first @n Unicode characters thereof) is found, respectively,
183  * to be less than, to match, or be greater than @s2.
184  */
ntfs_ucsncasecmp(const ntfschar * s1,const ntfschar * s2,size_t n,const ntfschar * upcase,const u32 upcase_size)185 int ntfs_ucsncasecmp(const ntfschar *s1, const ntfschar *s2, size_t n,
186 		const ntfschar *upcase, const u32 upcase_size)
187 {
188 	size_t i;
189 	u16 c1, c2;
190 
191 	for (i = 0; i < n; ++i) {
192 		if ((c1 = le16_to_cpu(s1[i])) < upcase_size)
193 			c1 = le16_to_cpu(upcase[c1]);
194 		if ((c2 = le16_to_cpu(s2[i])) < upcase_size)
195 			c2 = le16_to_cpu(upcase[c2]);
196 		if (c1 < c2)
197 			return -1;
198 		if (c1 > c2)
199 			return 1;
200 		if (!c1)
201 			break;
202 	}
203 	return 0;
204 }
205 
ntfs_upcase_name(ntfschar * name,u32 name_len,const ntfschar * upcase,const u32 upcase_len)206 void ntfs_upcase_name(ntfschar *name, u32 name_len, const ntfschar *upcase,
207 		const u32 upcase_len)
208 {
209 	u32 i;
210 	u16 u;
211 
212 	for (i = 0; i < name_len; i++)
213 		if ((u = le16_to_cpu(name[i])) < upcase_len)
214 			name[i] = upcase[u];
215 }
216 
ntfs_file_upcase_value(FILE_NAME_ATTR * file_name_attr,const ntfschar * upcase,const u32 upcase_len)217 void ntfs_file_upcase_value(FILE_NAME_ATTR *file_name_attr,
218 		const ntfschar *upcase, const u32 upcase_len)
219 {
220 	ntfs_upcase_name((ntfschar*)&file_name_attr->file_name,
221 			file_name_attr->file_name_length, upcase, upcase_len);
222 }
223 
ntfs_file_compare_values(FILE_NAME_ATTR * file_name_attr1,FILE_NAME_ATTR * file_name_attr2,const int err_val,const IGNORE_CASE_BOOL ic,const ntfschar * upcase,const u32 upcase_len)224 int ntfs_file_compare_values(FILE_NAME_ATTR *file_name_attr1,
225 		FILE_NAME_ATTR *file_name_attr2,
226 		const int err_val, const IGNORE_CASE_BOOL ic,
227 		const ntfschar *upcase, const u32 upcase_len)
228 {
229 	return ntfs_collate_names((ntfschar*)&file_name_attr1->file_name,
230 			file_name_attr1->file_name_length,
231 			(ntfschar*)&file_name_attr2->file_name,
232 			file_name_attr2->file_name_length,
233 			err_val, ic, upcase, upcase_len);
234 }
235 
236 /**
237  * ntfs_nlstoucs - convert NLS string to little endian Unicode string
238  * @vol:	ntfs volume which we are working with
239  * @ins:	input NLS string buffer
240  * @ins_len:	length of input string in bytes
241  * @outs:	on return contains the allocated output Unicode string buffer
242  *
243  * Convert the input string @ins, which is in whatever format the loaded NLS
244  * map dictates, into a little endian, 2-byte Unicode string.
245  *
246  * This function allocates the string and the caller is responsible for
247  * calling kmem_cache_free(ntfs_name_cache, *@outs); when finished with it.
248  *
249  * On success the function returns the number of Unicode characters written to
250  * the output string *@outs (>= 0), not counting the terminating Unicode NULL
251  * character. *@outs is set to the allocated output string buffer.
252  *
253  * On error, a negative number corresponding to the error code is returned. In
254  * that case the output string is not allocated. Both *@outs and *@outs_len
255  * are then undefined.
256  *
257  * This might look a bit odd due to fast path optimization...
258  */
ntfs_nlstoucs(const ntfs_volume * vol,const char * ins,const int ins_len,ntfschar ** outs)259 int ntfs_nlstoucs(const ntfs_volume *vol, const char *ins,
260 		const int ins_len, ntfschar **outs)
261 {
262 	struct nls_table *nls = vol->nls_map;
263 	ntfschar *ucs;
264 	wchar_t wc;
265 	int i, o, wc_len;
266 
267 	/* We do not trust outside sources. */
268 	if (likely(ins)) {
269 		ucs = kmem_cache_alloc(ntfs_name_cache, GFP_NOFS);
270 		if (likely(ucs)) {
271 			for (i = o = 0; i < ins_len; i += wc_len) {
272 				wc_len = nls->char2uni(ins + i, ins_len - i,
273 						&wc);
274 				if (likely(wc_len >= 0 &&
275 						o < NTFS_MAX_NAME_LEN)) {
276 					if (likely(wc)) {
277 						ucs[o++] = cpu_to_le16(wc);
278 						continue;
279 					} /* else if (!wc) */
280 					break;
281 				} /* else if (wc_len < 0 ||
282 						o >= NTFS_MAX_NAME_LEN) */
283 				goto name_err;
284 			}
285 			ucs[o] = 0;
286 			*outs = ucs;
287 			return o;
288 		} /* else if (!ucs) */
289 		ntfs_error(vol->sb, "Failed to allocate buffer for converted "
290 				"name from ntfs_name_cache.");
291 		return -ENOMEM;
292 	} /* else if (!ins) */
293 	ntfs_error(vol->sb, "Received NULL pointer.");
294 	return -EINVAL;
295 name_err:
296 	kmem_cache_free(ntfs_name_cache, ucs);
297 	if (wc_len < 0) {
298 		ntfs_error(vol->sb, "Name using character set %s contains "
299 				"characters that cannot be converted to "
300 				"Unicode.", nls->charset);
301 		i = -EILSEQ;
302 	} else /* if (o >= NTFS_MAX_NAME_LEN) */ {
303 		ntfs_error(vol->sb, "Name is too long (maximum length for a "
304 				"name on NTFS is %d Unicode characters.",
305 				NTFS_MAX_NAME_LEN);
306 		i = -ENAMETOOLONG;
307 	}
308 	return i;
309 }
310 
311 /**
312  * ntfs_ucstonls - convert little endian Unicode string to NLS string
313  * @vol:	ntfs volume which we are working with
314  * @ins:	input Unicode string buffer
315  * @ins_len:	length of input string in Unicode characters
316  * @outs:	on return contains the (allocated) output NLS string buffer
317  * @outs_len:	length of output string buffer in bytes
318  *
319  * Convert the input little endian, 2-byte Unicode string @ins, of length
320  * @ins_len into the string format dictated by the loaded NLS.
321  *
322  * If *@outs is NULL, this function allocates the string and the caller is
323  * responsible for calling kfree(*@outs); when finished with it. In this case
324  * @outs_len is ignored and can be 0.
325  *
326  * On success the function returns the number of bytes written to the output
327  * string *@outs (>= 0), not counting the terminating NULL byte. If the output
328  * string buffer was allocated, *@outs is set to it.
329  *
330  * On error, a negative number corresponding to the error code is returned. In
331  * that case the output string is not allocated. The contents of *@outs are
332  * then undefined.
333  *
334  * This might look a bit odd due to fast path optimization...
335  */
ntfs_ucstonls(const ntfs_volume * vol,const ntfschar * ins,const int ins_len,unsigned char ** outs,int outs_len)336 int ntfs_ucstonls(const ntfs_volume *vol, const ntfschar *ins,
337 		const int ins_len, unsigned char **outs, int outs_len)
338 {
339 	struct nls_table *nls = vol->nls_map;
340 	unsigned char *ns;
341 	int i, o, ns_len, wc;
342 
343 	/* We don't trust outside sources. */
344 	if (ins) {
345 		ns = *outs;
346 		ns_len = outs_len;
347 		if (ns && !ns_len) {
348 			wc = -ENAMETOOLONG;
349 			goto conversion_err;
350 		}
351 		if (!ns) {
352 			ns_len = ins_len * NLS_MAX_CHARSET_SIZE;
353 			ns = kmalloc(ns_len + 1, GFP_NOFS);
354 			if (!ns)
355 				goto mem_err_out;
356 		}
357 		for (i = o = 0; i < ins_len; i++) {
358 retry:			wc = nls->uni2char(le16_to_cpu(ins[i]), ns + o,
359 					ns_len - o);
360 			if (wc > 0) {
361 				o += wc;
362 				continue;
363 			} else if (!wc)
364 				break;
365 			else if (wc == -ENAMETOOLONG && ns != *outs) {
366 				unsigned char *tc;
367 				/* Grow in multiples of 64 bytes. */
368 				tc = kmalloc((ns_len + 64) &
369 						~63, GFP_NOFS);
370 				if (tc) {
371 					memcpy(tc, ns, ns_len);
372 					ns_len = ((ns_len + 64) & ~63) - 1;
373 					kfree(ns);
374 					ns = tc;
375 					goto retry;
376 				} /* No memory so goto conversion_error; */
377 			} /* wc < 0, real error. */
378 			goto conversion_err;
379 		}
380 		ns[o] = 0;
381 		*outs = ns;
382 		return o;
383 	} /* else (!ins) */
384 	ntfs_error(vol->sb, "Received NULL pointer.");
385 	return -EINVAL;
386 conversion_err:
387 	ntfs_error(vol->sb, "Unicode name contains characters that cannot be "
388 			"converted to character set %s.  You might want to "
389 			"try to use the mount option nls=utf8.", nls->charset);
390 	if (ns != *outs)
391 		kfree(ns);
392 	if (wc != -ENAMETOOLONG)
393 		wc = -EILSEQ;
394 	return wc;
395 mem_err_out:
396 	ntfs_error(vol->sb, "Failed to allocate name!");
397 	return -ENOMEM;
398 }
399