Root/fs/ntfs/unistr.c

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 */
40static 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 */
68bool 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 */
97int 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 */
149int 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 */
185int 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
206void 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
217void 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
224int 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 */
259int 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;
295name_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 */
336int 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++) {
358retry: 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;
386conversion_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;
395mem_err_out:
396    ntfs_error(vol->sb, "Failed to allocate name!");
397    return -ENOMEM;
398}
399

Archive Download this file



interactive