1 /*
2 * Copyright (C) 1999-2001 Free Software Foundation, Inc.
3 * This file is part of the GNU LIBICONV Library.
4 *
5 * The GNU LIBICONV Library is free software; you can redistribute it
6 * and/or modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
9 *
10 * The GNU LIBICONV Library is distributed in the hope that it will be
11 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public
16 * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
17 * If not, write to the Free Software Foundation, Inc., 51 Franklin Street,
18 * Fifth Floor, Boston, MA 02110-1301, USA.
19 */
20
21 /*
22 * UCS-2
23 */
24
25 /* Here we accept FFFE/FEFF marks as endianness indicators everywhere
26 in the stream, not just at the beginning. The default is big-endian. */
27 /* The state is 0 if big-endian, 1 if little-endian. */
28 static int
ucs2_mbtowc(conv_t conv,ucs4_t * pwc,const unsigned char * s,int n)29 ucs2_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
30 {
31 conv_state_t state = conv->istate;
32 int count = 0;
33 for (; n >= 2;) {
34 ucs4_t wc = (state ? s[0] + (s[1] << 8) : (s[0] << 8) + s[1]);
35 s += 2; n -= 2; count += 2;
36 if (wc == 0xfeff) {
37 } else if (wc == 0xfffe) {
38 state ^= 1;
39 } else if (wc >= 0xd800 && wc < 0xe000) {
40 return RET_ILSEQ;
41 } else {
42 *pwc = wc;
43 conv->istate = state;
44 return count;
45 }
46 }
47 conv->istate = state;
48 return RET_TOOFEW(count);
49 }
50
51 /* But we output UCS-2 in big-endian order, without byte-order mark. */
52 /* RFC 2152 says:
53 "ISO/IEC 10646-1:1993(E) specifies that when characters the UCS-2 form are
54 serialized as octets, that the most significant octet appear first." */
55 static int
ucs2_wctomb(conv_t conv,unsigned char * r,ucs4_t wc,int n)56 ucs2_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
57 {
58 if (wc < 0x10000 && wc != 0xfffe && !(wc >= 0xd800 && wc < 0xe000)) {
59 if (n >= 2) {
60 r[0] = (unsigned char) (wc >> 8);
61 r[1] = (unsigned char) wc;
62 return 2;
63 } else
64 return RET_TOOSMALL;
65 } else
66 return RET_ILUNI;
67 }
68