mirror of
https://github.com/torvalds/linux.git
synced 2024-12-15 07:33:56 +00:00
0f43158cad
This patch (as1234) fixes a bug in the UTF8 -> UTF-16 conversion routine in the gadget/usbstring library. In a UTF-8 multi-byte sequence, all bytes after the first should have their high-order two bits set to 10, not 11. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
137 lines
3.4 KiB
C
137 lines
3.4 KiB
C
/*
|
|
* Copyright (C) 2003 David Brownell
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU Lesser General Public License as published
|
|
* by the Free Software Foundation; either version 2.1 of the License, or
|
|
* (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/list.h>
|
|
#include <linux/string.h>
|
|
#include <linux/device.h>
|
|
#include <linux/init.h>
|
|
|
|
#include <linux/usb/ch9.h>
|
|
#include <linux/usb/gadget.h>
|
|
|
|
#include <asm/unaligned.h>
|
|
|
|
|
|
static int utf8_to_utf16le(const char *s, __le16 *cp, unsigned len)
|
|
{
|
|
int count = 0;
|
|
u8 c;
|
|
u16 uchar;
|
|
|
|
/* this insists on correct encodings, though not minimal ones.
|
|
* BUT it currently rejects legit 4-byte UTF-8 code points,
|
|
* which need surrogate pairs. (Unicode 3.1 can use them.)
|
|
*/
|
|
while (len != 0 && (c = (u8) *s++) != 0) {
|
|
if (unlikely(c & 0x80)) {
|
|
// 2-byte sequence:
|
|
// 00000yyyyyxxxxxx = 110yyyyy 10xxxxxx
|
|
if ((c & 0xe0) == 0xc0) {
|
|
uchar = (c & 0x1f) << 6;
|
|
|
|
c = (u8) *s++;
|
|
if ((c & 0xc0) != 0x80)
|
|
goto fail;
|
|
c &= 0x3f;
|
|
uchar |= c;
|
|
|
|
// 3-byte sequence (most CJKV characters):
|
|
// zzzzyyyyyyxxxxxx = 1110zzzz 10yyyyyy 10xxxxxx
|
|
} else if ((c & 0xf0) == 0xe0) {
|
|
uchar = (c & 0x0f) << 12;
|
|
|
|
c = (u8) *s++;
|
|
if ((c & 0xc0) != 0x80)
|
|
goto fail;
|
|
c &= 0x3f;
|
|
uchar |= c << 6;
|
|
|
|
c = (u8) *s++;
|
|
if ((c & 0xc0) != 0x80)
|
|
goto fail;
|
|
c &= 0x3f;
|
|
uchar |= c;
|
|
|
|
/* no bogus surrogates */
|
|
if (0xd800 <= uchar && uchar <= 0xdfff)
|
|
goto fail;
|
|
|
|
// 4-byte sequence (surrogate pairs, currently rare):
|
|
// 11101110wwwwzzzzyy + 110111yyyyxxxxxx
|
|
// = 11110uuu 10uuzzzz 10yyyyyy 10xxxxxx
|
|
// (uuuuu = wwww + 1)
|
|
// FIXME accept the surrogate code points (only)
|
|
|
|
} else
|
|
goto fail;
|
|
} else
|
|
uchar = c;
|
|
put_unaligned_le16(uchar, cp++);
|
|
count++;
|
|
len--;
|
|
}
|
|
return count;
|
|
fail:
|
|
return -1;
|
|
}
|
|
|
|
|
|
/**
|
|
* usb_gadget_get_string - fill out a string descriptor
|
|
* @table: of c strings encoded using UTF-8
|
|
* @id: string id, from low byte of wValue in get string descriptor
|
|
* @buf: at least 256 bytes
|
|
*
|
|
* Finds the UTF-8 string matching the ID, and converts it into a
|
|
* string descriptor in utf16-le.
|
|
* Returns length of descriptor (always even) or negative errno
|
|
*
|
|
* If your driver needs stings in multiple languages, you'll probably
|
|
* "switch (wIndex) { ... }" in your ep0 string descriptor logic,
|
|
* using this routine after choosing which set of UTF-8 strings to use.
|
|
* Note that US-ASCII is a strict subset of UTF-8; any string bytes with
|
|
* the eighth bit set will be multibyte UTF-8 characters, not ISO-8859/1
|
|
* characters (which are also widely used in C strings).
|
|
*/
|
|
int
|
|
usb_gadget_get_string (struct usb_gadget_strings *table, int id, u8 *buf)
|
|
{
|
|
struct usb_string *s;
|
|
int len;
|
|
|
|
/* descriptor 0 has the language id */
|
|
if (id == 0) {
|
|
buf [0] = 4;
|
|
buf [1] = USB_DT_STRING;
|
|
buf [2] = (u8) table->language;
|
|
buf [3] = (u8) (table->language >> 8);
|
|
return 4;
|
|
}
|
|
for (s = table->strings; s && s->s; s++)
|
|
if (s->id == id)
|
|
break;
|
|
|
|
/* unrecognized: stall. */
|
|
if (!s || !s->s)
|
|
return -EINVAL;
|
|
|
|
/* string descriptors have length, tag, then UTF16-LE text */
|
|
len = min ((size_t) 126, strlen (s->s));
|
|
memset (buf + 2, 0, 2 * len); /* zero all the bytes */
|
|
len = utf8_to_utf16le(s->s, (__le16 *)&buf[2], len);
|
|
if (len < 0)
|
|
return -EINVAL;
|
|
buf [0] = (len + 1) * 2;
|
|
buf [1] = USB_DT_STRING;
|
|
return buf [0];
|
|
}
|
|
|