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 29 ucs2_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n) 30 { 31 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 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