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/*
* 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) 1995, by Sun Microsystems, Inc.
* All rights reserved.
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include "big5_cns11643.h" /* Big-5 to CNS 11643 mapping table */
#define MSB 0x80 /* most significant bit */
#define MBYTE 0x8e /* multi-byte (4 byte character) */
#define PMASK 0xa0 /* plane number mask */
#define ONEBYTE 0xff /* right most byte */
#define NON_ID_CHAR '_' /* non-identified character */
typedef struct _icv_state {
char keepc[2]; /* maximum # byte of Big-5 code */
short cstate; /* state machine id */
int _errno; /* internal errno */
} _iconv_st;
enum _CSTATE { C0, C1 };
static int big5_2nd_byte(char);
static int get_plane_no_by_big5(const char, const char, int*, unsigned long*);
static int big5_to_cns(int, int, unsigned long, char*, size_t);
static int binsearch(unsigned long, table_t[], int);
/*
* 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->cstate = C0;
st->_errno = 0;
#ifdef DEBUG
fprintf(stderr, "========== iconv(): Big-5 --> CNS 11643 ==========\n");
#endif
return ((void *) st);
}
/*
* Close; called from iconv_close()
*/
void
_icv_close(_iconv_st *st)
{
if (!st)
errno = EBADF;
else
free(st);
}
/*
* Actual conversion; called from iconv()
*/
/*=======================================================
*
* State Machine for interpreting Big-5 code
*
*=======================================================
*
* 1st C
* +--------> C0 ----------> C1
* | ascii | 2nd C |
* ^ v v
* +----<-----+-----<--------+
*
*=======================================================*/
/*
* Big-5 encoding range:
* High byte: 0xA1 - 0xFE ( 94 encoding space)
* Low byte: 0x40 - 0x7E, 0xA1 - 0xFE ( 157 encoding space)
* Plane #1: 0xA140 - 0xC8FE ( 6280 encoding space)
* Plane #2: 0xC940 - 0xFEFE ( 8478 encoding space)
* Total: 94 * 157 = 14,758 (14758 encoding space)
*/
size_t
_icv_iconv(_iconv_st *st, char **inbuf, size_t *inbytesleft,
char **outbuf, size_t *outbytesleft)
{
int plane_no, n, unidx;
unsigned long cnscode;
#ifdef DEBUG
fprintf(stderr, "=== (Re-entry) iconv(): Big-5 --> CNS 11643 ===\n");
#endif
if (st == NULL) {
errno = EBADF;
return ((size_t) -1);
}
if (inbuf == NULL || *inbuf == NULL) { /* Reset request. */
st->cstate = C0;
st->_errno = 0;
return ((size_t) 0);
}
st->_errno = 0; /* reset internal errno */
errno = 0; /* reset external errno */
/* a state machine for interpreting Big-5 code */
while (*inbytesleft > 0 && *outbytesleft > 0) {
switch (st->cstate) {
case C0: /* assuming ASCII in the beginning */
if (**inbuf & MSB) {
st->keepc[0] = (**inbuf);
st->cstate = C1;
} else { /* real ASCII */
**outbuf = **inbuf;
(*outbuf)++;
(*outbytesleft)--;
}
break;
case C1: /* Chinese characters: 2nd byte */
if (big5_2nd_byte(**inbuf) == 0) {
st->keepc[1] = (**inbuf);
plane_no = get_plane_no_by_big5(st->keepc[0],
st->keepc[1], &unidx, &cnscode);
/* comment these lines, it is legal BIG5 character, but no corresponding CNS character
if (plane_no < 0) {
st->_errno = errno = EILSEQ;
break;
}
*/
n = big5_to_cns(plane_no, unidx, cnscode,
*outbuf, *outbytesleft);
if (n > 0) {
(*outbuf) += n;
(*outbytesleft) -= n;
st->cstate = C0;
} else { /* don't reset state */
st->_errno = errno = E2BIG;
}
} else { /* input char doesn't belong
* to the input code set
*/
st->_errno = errno = EILSEQ;
}
break;
default: /* should never come here */
st->_errno = errno = EILSEQ;
st->cstate = C0; /* reset state */
break;
}
if (st->_errno) {
#ifdef DEBUG
fprintf(stderr, "!!!!!\tst->_errno = %d\tst->cstate = %d\n",
st->_errno, st->cstate);
#endif
break;
}
(*inbuf)++;
(*inbytesleft)--;
}
if (errno) return ((size_t) -1);
if (*inbytesleft == 0 && st->cstate != C0) {
errno = EINVAL;
return ((size_t) -1);
}
if (*inbytesleft > 0 && *outbytesleft == 0) {
errno = E2BIG;
return((size_t)-1);
}
return (*inbytesleft);
}
/*
* Test whether inbuf is a valid character for 2nd byte Big-5 code
* Return: = 0 - valid Big-5 2nd byte
* = 1 - invalid Big-5 2nd byte
*/
static int big5_2nd_byte(char inbuf)
{
unsigned int buf = (unsigned int) (inbuf & ONEBYTE);
if ((buf >= 0x40) && (buf <= 0x7E))
return (0);
if ((buf >= 0xA1) && (buf <= 0xFE))
return (0);
return(1);
}
/*
* Get plane number by Big-5 code; i.e. plane #1 returns 1, #2 returns 2, etc.
* Returns -1 on error conditions
*
* Since binary search of the Big-5 to CNS table is necessary, might as well
* return index and CNS code matching to the unicode.
*/
static int get_plane_no_by_big5(const char c1, const char c2,
int *unidx, unsigned long *cnscode)
{
int ret;
unsigned long big5code;
big5code = (unsigned long) ((c1 & ONEBYTE) << 8) + (c2 & ONEBYTE);
*unidx = binsearch(big5code, big5_cns_tab, MAX_BIG5_NUM);
if ((*unidx) >= 0)
*cnscode = big5_cns_tab[*unidx].value;
else
return(0); /* match from Big-5 to CNS not found */
#ifdef DEBUG
fprintf(stderr, "Big-5=%04x, idx=%5d, CNS=%x ", big5code, *unidx, *cnscode);
#endif
ret = (int) (*cnscode >> 16);
switch (ret) {
case 0x21: /* 0x8EA1 - G */
case 0x22: /* 0x8EA2 - H */
case 0x23: /* 0x8EA3 - I */
case 0x24: /* 0x8EA4 - J */
case 0x25: /* 0x8EA5 - K */
case 0x26: /* 0x8EA6 - L */
case 0x27: /* 0x8EA7 - M */
case 0x28: /* 0x8EA8 - N */
case 0x29: /* 0x8EA9 - O */
case 0x2a: /* 0x8EAA - P */
case 0x2b: /* 0x8EAB - Q */
case 0x2c: /* 0x8EAC - R */
case 0x2d: /* 0x8EAD - S */
case 0x2f: /* 0x8EAF - U */
case 0x30: /* 0x8EB0 - V */
return (ret - 0x20); /* so that we can use GET_PLANEC() */
case 0x2e: /* 0x8EAE - T */
return (3); /* CNS 11643-1992 */
default:
return (-1);
}
}
/*
* Big-5 code --> CNS 11643 (Chinese EUC)
* Return: > 0 - converted with enough space in output buffer
* = 0 - no space in outbuf
*/
static int big5_to_cns(int plane_no, int unidx, unsigned long cnscode,
char *buf, size_t buflen)
{
unsigned long val; /* CNS 11643 value */
unsigned char c1 = '\0', c2 = '\0', cns_str[5];
int ret_size; /* return buffer size */
if (unidx < 0) { /* no match from UTF8 to CNS 11643 */
if ( buflen < 2 ) goto err;
*buf = *(buf+1) = NON_ID_CHAR;
ret_size = 2;
} else {
val = cnscode & 0xffff;
c1 = ((val & 0xff00) >> 8) | MSB;
c2 = (val & 0xff) | MSB;
}
switch (plane_no) {
case 1:
if ( buflen < 2 ) goto err;
*buf = cns_str[0] = c1;
*(buf+1) = cns_str[1] = c2;
cns_str[2] = cns_str[3] = cns_str[4] = NULL;
ret_size = 2;
break;
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
case 8:
case 9:
case 10:
case 11:
case 12:
case 13:
case 14:
case 15:
case 16:
if ( buflen < 4 ) goto err;
*(unsigned char*) buf = cns_str[0] = MBYTE;
*(unsigned char*)(buf+1) = cns_str[1] = PMASK + plane_no;
*(unsigned char*) (buf+2) = cns_str[2] = c1;
*(unsigned char*) (buf+3) = cns_str[3] = c2;
cns_str[4] = NULL;
ret_size = 4;
break;
}
#ifdef DEBUG
fprintf(stderr, "\t#%d ->%s<-\n", plane_no, cns_str);
#endif
return(ret_size);
err:
errno = E2BIG;
return(0);
}
/* binsearch: find x in v[0] <= v[1] <= ... <= v[n-1] */
static int binsearch(unsigned long x, table_t v[], int n)
{
int low, high, mid;
low = 0;
high = n - 1;
while (low <= high) {
mid = (low + high) / 2;
if (x < v[mid].key)
high = mid - 1;
else if (x > v[mid].key)
low = mid + 1;
else /* found match */
return mid;
}
return (-1); /* no match */
}