xref: /illumos-gate/usr/src/lib/iconv_modules/zh/common/UTF-8%zh_CN.iso2022-7.c (revision 16d8656330ae5622ec32e5007f62145ebafdc50f)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright(c) 1998 Sun Microsystems, Inc.
 */

#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unicode_gb2312.h>
#include "common_defs.h"

#define SI	0x0f
#define SO	0x0e
#define ESC	0x1b
#define MSB	0x80

#define NON_ID_CHAR '?'

typedef struct _icv_state {
	short	_ustate;
	short	_istate;
	short	_gstate;
	char	_cbuf[3];
} _iconv_st;

enum	_USTATE	{ U0, U1, U2, U3, U4, U5, U6 };
enum	_ISTATE	{ IN, OUT };
enum	_GSTATE	{ G0, G1 };

int unicode_to_iso(char in_byte1, char in_byte2, char *buf, int	buflen);

/*
 * Open; called from iconv_open()
 */
void *
_icv_open()
{
	_iconv_st *st;

	if ((st = (_iconv_st *)malloc(sizeof(_iconv_st))) == NULL) {
		errno = ENOMEM;
		return ((void *) -1);
	}

	st->_ustate = U0;
	st->_istate = IN;
	st->_gstate = G0;

	return ((void *)st);
}


/*
 * Close; called from iconv_close()
 */
void
_icv_close(_iconv_st *st)
{
	if (st == NULL)
		errno = EBADF;
	else
		free(st);
}


/*
 * Actual conversion; called from iconv()
 */
size_t
_icv_iconv(_iconv_st *st, char **inbuf, size_t*inbytesleft,
			char **outbuf, size_t*outbytesleft)
{
	char	c1, c2;
	int	n;

	if (st == NULL) {
		errno = EBADF;
		return ((size_t)-1);
	}

	if (inbuf == NULL || *inbuf == NULL) { /* Reset request. */
		st->_ustate = U0;
		st->_istate = IN;
		st->_gstate = G0;
		return ((size_t)0);
	}

	errno = 0;

	while (*inbytesleft > 0 && *outbytesleft > 0) {

	    uchar_t  first_byte;

	    switch (st->_ustate) {
	    case U0:
		if ((**inbuf & MSB) == 0) {	/* ASCII */
		    if (st->_istate == OUT) {
			st->_istate = IN;
			**outbuf = SI;
			(*outbuf)++, (*outbytesleft)--;
			if (*outbytesleft <= 0) {
			    errno = E2BIG;
			    return ((size_t)-1);
			}
		    }
		    **outbuf = **inbuf;
		    (*outbuf)++, (*outbytesleft)--;
	        } else {
		    if ((**inbuf & 0xe0) == 0xc0) { /* 0xc2..0xdf */

		        /* invalid sequence if the first char is either 0xc0 or 0xc1 */
		        if ( number_of_bytes_in_utf8_char[((uchar_t)**inbuf)] == ICV_TYPE_ILLEGAL_CHAR )
			 {
			    errno = EILSEQ;
		            break;
			 }
		        else
			 {
			     st->_ustate = U1;
			     st->_cbuf[0] = **inbuf;
			 }
		    } else if ((**inbuf & 0xf0) == 0xe0) { /* 0xe0..0xef */
			st->_ustate = U2;
			st->_cbuf[0] = **inbuf;
		    } else {
		        /* four bytes of UTF-8 sequences */
		        if ( number_of_bytes_in_utf8_char[((uchar_t)**inbuf)] == ICV_TYPE_ILLEGAL_CHAR )
			  {
			    errno = EILSEQ;
		            break;
		           }
		        else {
			   st->_ustate = U4;
			   st->_cbuf[0] = **inbuf;
			}
		    }
		    if (st->_istate == IN) {
			if (st->_gstate == G0) {
			    if (*outbytesleft < 4) {
				errno = E2BIG;
				return ((size_t)-1);
			    }
			    st->_gstate = G1;
			    **outbuf = ESC;
			    *(*outbuf+1) = '$';
			    *(*outbuf+2) = ')';
			    *(*outbuf+3) = 'A';
			    (*outbuf) += 4, (*outbytesleft) -= 4;
			    if (*outbytesleft <= 0) {
				errno = E2BIG;
				return ((size_t)-1);
			    }
			}
			st->_istate = OUT;
			**outbuf = SO;
			(*outbuf)++, (*outbytesleft)--;
		    }
		}
		break;
	    case U1:
		if ((**inbuf & 0xc0) == MSB) {	/* two-byte UTF */
		    c1 = (st->_cbuf[0]&0x1c)>>2;
		    c2 = ((st->_cbuf[0]&0x03)<<6) | ((**inbuf)&0x3f);
		    n = unicode_to_iso(c1, c2, *outbuf, *outbytesleft);
		    if (n > 0) {
			(*outbuf) += n, (*outbytesleft) -= n;
		    } else {
			errno = E2BIG;
			return ((size_t)-1);
		    }
		    st->_ustate = U0;
		} else {
		    errno = EILSEQ;
		}
		break;
	    case U2:

	        first_byte = st->_cbuf[0];

	        /* if the first byte is 0xed, it is illegal sequence if the second
		 * one is one between 0xa0 and 0xbf because surrogate section is ill-formed
		 */
	        if (((uchar_t)**inbuf) < valid_min_2nd_byte[first_byte] ||
		    ((uchar_t)**inbuf) > valid_max_2nd_byte[first_byte] )
		     errno = EILSEQ;
	        else {
		     st->_ustate = U3;
		     st->_cbuf[1] = **inbuf;
		}
		break;
	    case U3:
		if ((**inbuf & 0xc0) == MSB) {	/* three-byte UTF */
		    c1 = ((st->_cbuf[0]&0x0f)<<4) | ((st->_cbuf[1]&0x3c)>>2);
		    c2 = ((st->_cbuf[1]&0x03)<<6) | ((**inbuf)&0x3f);
		    n = unicode_to_iso(c1, c2, *outbuf, *outbytesleft);
		    if (n > 0) {
			(*outbuf) += n, (*outbytesleft) -= n;
		    } else if ( n == -1 ) {
		        errno = EILSEQ; /* unicode is either 0xfffe or 0xffff */
		    } else {
			errno = E2BIG;
			return ((size_t)-1);
		    }
		    st->_ustate = U0;
		} else {
		    errno = EILSEQ;
		}
		break;
	     case U4:
	        first_byte = st->_cbuf[0];

	        /* if the first byte is 0xf0, it is illegal sequence if
		 * the second one is between 0x80 and 0x8f
		 * for Four-Byte UTF: U+10000..U+10FFFF
		 */
	        if (((uchar_t)**inbuf) < valid_min_2nd_byte[first_byte] ||
		    ((uchar_t)**inbuf) > valid_max_2nd_byte[first_byte] )
		     errno = EILSEQ;
		else {
		     st->_ustate = U5;
		     st->_cbuf[1] = **inbuf;
		}
	        break;
	     case U5:
		if ((**inbuf & 0xc0) == MSB) /* 0x80..0xbf */
		  {
		     st->_ustate = U6;
		     st->_cbuf[2] = **inbuf;
	          }
		else
		     errno = EILSEQ;
	        break;
	     case U6:
	        if ((**inbuf & 0xc0) == MSB) /* 0x80..0xbf */
		   {
		      /* replace with double NON_ID_CHARs */
		      if ( *outbytesleft < 2 )
			 errno = E2BIG;
		      else
			{
			   **outbuf = NON_ID_CHAR;
			   *(*outbuf+1) = NON_ID_CHAR;
			   (*outbytesleft) -= 2;

			   st->_ustate = U0;
			}
	           }
		else
		     errno = EILSEQ;
	        break;
	    }

	    if (errno)
		return ((size_t)-1);

	    (*inbuf)++; (*inbytesleft)--;
	}

	if (*inbytesleft == 0 && st->_ustate != U0) {
	        errno = EINVAL;
	        return ((size_t) -1);
	}

	if (*inbytesleft > 0 && *outbytesleft == 0) {
		errno = E2BIG;
		return ((size_t)-1);
	}
	return ((size_t)(*inbytesleft));
}


int unicode_to_iso(in_byte1, in_byte2, buf, buflen)
char	in_byte1, in_byte2;
char	*buf;
int	buflen;
{
	int	gb, unicode;
	int	i, l, h;

	if (buflen < 2)
		return 0;
	unicode = ((in_byte1 & 0xff) << 8) + (in_byte2 & 0xff);

        /* 0xfffe and 0xffff should not be allowed */
        if ( unicode == 0xFFFE || unicode == 0xFFFF ) return -1;

	for (l = 0, h = UNICODEMAX; l < h; ) {
		if (unicode_gb_tab[l].key == unicode) {
			i = l;
			break;
		}
		if (unicode_gb_tab[h].key == unicode) {
			i = h;
			break;
		}
		i = (l + h) / 2;
		if (unicode_gb_tab[i].key == unicode)
			break;
		if (unicode_gb_tab[i].key < unicode)
			l = i + 1;
		else	h = i - 1;
	}
	if (unicode == unicode_gb_tab[i].key) {
		gb = unicode_gb_tab[i].value;
		*buf = (gb & 0xff00) >> 8;
		*(buf+1) = gb & 0xff;
	} else {
		*buf = *(buf+1) = NON_ID_CHAR;
	}
	return 2;
}