/*
 * 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) 1999 by Sun Microsystems, Inc.
 * All rights reserved.
 */


#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/isa_defs.h>
#include "utf_ebcdic_to_utf8.h"

void *
_icv_open()
{
        return((void *)MAGIC_NUMBER);
}


void
_icv_close(int *cd)
{
        if (! cd || cd != (int *)MAGIC_NUMBER)
                errno = EBADF;
}


#define OUTBUF_SIZE_CHECK(sz) \
        if ((obtail - ob) < (sz)) { \
                ib = ib_org;\
                errno = E2BIG; \
                ret_val = (size_t)-1; \
                break; \
        }

#define UTFEBICDIC_I8(utfe) utf_ebcdic_to_i8[(utfe)]

size_t
_icv_iconv(int *cd, char **inbuf, size_t *inbufleft, char **outbuf,
                size_t *outbufleft)
{
        size_t ret_val = 0;
        uchar_t *ib;
        uchar_t *ob;
        uchar_t *ibtail;
        uchar_t *obtail;

        if (cd != (int *)MAGIC_NUMBER) {
                errno = EBADF;
                return((size_t)-1);
        }

        if (!inbuf || !(*inbuf))
                return((size_t)0);

        ib = (uchar_t *)*inbuf;
        ob = (uchar_t *)*outbuf;
        ibtail = ib + *inbufleft;
        obtail = ob + *outbufleft;

        while (ib < ibtail) {
                uchar_t *ib_org;
                uint_t u4;
                signed char sz; /* must be signed for loop condition */

                sz = number_of_bytes_in_utf_ebcidc[*ib];
                if ((sz > UTF_EBCDIC_LEAD_OCTET_MAX) ||
                        (sz < UTF_EBCDIC_LEAD_OCTET_MIN)) {
                        errno = EILSEQ;
                        ret_val = (size_t)-1;
                        break;
                }
                /* sz == 0 means control character. and it need 1 byte */
                if ((ibtail - ib) < ((sz == 0)? 1: sz)) {
                        errno = EINVAL;
                        ret_val = (size_t)-1;
                        break;
                }

                ib_org = ib;

                u4 = (UTFEBICDIC_I8(*ib++) & utf_ebcdic_masks_tbl[sz]);

                /* correct size */
                if (sz == 0){
                        sz = 1;
                }
                for (; sz > 1; sz--) {
                        if (number_of_bytes_in_utf_ebcidc[*ib] !=
                                UTF_EBCDIC_TRAILING_OCTET) {
                                ib = ib_org;
                                errno = EILSEQ;
                                ret_val = (size_t)-1;
                                goto illegal_char_err;
                        }
                        u4 = ((u4 << UTF_EBCDIC_BIT_SHIFT) |
                                (((uint_t)(UTFEBICDIC_I8(*ib)))
                                & UTF_EBCDIC_BIT_MASK));
                        ib++;
                }

                if (u4 <= 0x7f) {
                        OUTBUF_SIZE_CHECK(1);
                        *ob++ = (uchar_t)u4;
                } else if (u4 <= 0x7ff) {
                        OUTBUF_SIZE_CHECK(2);
                        *ob++ = (uchar_t)(0xc0 | ((u4 & 0x07c0) >> 6));
                        *ob++ = (uchar_t)(0x80 |  (u4 & 0x003f));
                } else if (u4 <= 0xd7ff) {
                        OUTBUF_SIZE_CHECK(3);
                        *ob++ = (uchar_t)(0xe0 | ((u4 & 0x0f000) >> 12));
                        *ob++ = (uchar_t)(0x80 | ((u4 & 0x00fc0) >> 6));
                        *ob++ = (uchar_t)(0x80 |  (u4 & 0x0003f));
                } else if (u4 <= 0x00dfff) {
                        /* S zone */
                        errno = EILSEQ;
                        ret_val = (size_t)-1;
                        break;
                } else if (u4 <= 0x00fffd) {
                        OUTBUF_SIZE_CHECK(3);
                        *ob++ = (uchar_t)(0xe0 | ((u4 & 0x0f000) >> 12));
                        *ob++ = (uchar_t)(0x80 | ((u4 & 0x00fc0) >> 6));
                        *ob++ = (uchar_t)(0x80 |  (u4 & 0x0003f));
                } else if (u4 <= 0x00ffff) {
                        errno = EILSEQ;
                        ret_val = (size_t)-1;
                        break;
                } else if (u4 <= 0x1fffff) {
                        OUTBUF_SIZE_CHECK(4);
                        *ob++ = (uchar_t)(0xf0 | ((u4 & 0x01c0000) >> 18));
                        *ob++ = (uchar_t)(0x80 | ((u4 & 0x003f000) >> 12));
                        *ob++ = (uchar_t)(0x80 | ((u4 & 0x0000fc0) >> 6));
                        *ob++ = (uchar_t)(0x80 |  (u4 & 0x000003f));
                } else if (u4 <= 0x3ffffff) {
                        OUTBUF_SIZE_CHECK(5);
                        *ob++ = (uchar_t)(0xf8 | ((u4 & 0x03000000) >> 24));
                        *ob++ = (uchar_t)(0x80 | ((u4 & 0x00fc0000) >> 18));
                        *ob++ = (uchar_t)(0x80 | ((u4 & 0x0003f000) >> 12));
                        *ob++ = (uchar_t)(0x80 | ((u4 & 0x00000fc0) >> 6));
                        *ob++ = (uchar_t)(0x80 |  (u4 & 0x0000003f));
                } else if (u4 <= 0x7fffffff) {
                        OUTBUF_SIZE_CHECK(6);
                        *ob++ = (uchar_t)(0xfc | ((u4 & 0x40000000) >> 30));
                        *ob++ = (uchar_t)(0x80 | ((u4 & 0x3f000000) >> 24));
                        *ob++ = (uchar_t)(0x80 | ((u4 & 0x00fc0000) >> 18));
                        *ob++ = (uchar_t)(0x80 | ((u4 & 0x0003f000) >> 12));
                        *ob++ = (uchar_t)(0x80 | ((u4 & 0x00000fc0) >> 6));
                        *ob++ = (uchar_t)(0x80 |  (u4 & 0x0000003f));

                } else {
                        ib = ib_org;
                        errno = EILSEQ;
                        ret_val = (size_t)-1;
                        break;
                }
        }

illegal_char_err:
        *inbuf = (char *)ib;
        *inbufleft = ibtail - ib;
        *outbuf = (char *)ob;
        *outbufleft = obtail - ob;

        return(ret_val);
}