/*
 * 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 2007 by Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/isa_defs.h>
#include "utf8_to_utf_ebcdic.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 I8_UTFEBICDIC(i8) i8_to_utf_ebcdic[(i8)]

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;
                uint_t first_byte;
                signed char sz;

                sz = number_of_bytes_in_utf8_char[*ib];
                if (sz == ICV_TYPE_ILLEGAL_CHAR) {
                        errno = EILSEQ;
                        ret_val = (size_t)-1;
                        break;
                }

                if ((ibtail - ib) < sz) {
                        errno = EINVAL;
                        ret_val = (size_t)-1;
                        break;
                }

                ib_org = ib;
                first_byte = *ib;
                u4 = (uint_t)(*ib++ & masks_tbl[sz]);
                for (; sz > 1; sz--) {
                        if (first_byte) {
                                if (((uchar_t)*ib) <
                                        valid_min_2nd_byte[first_byte] ||
                                    ((uchar_t)*ib) >
                                        valid_max_2nd_byte[first_byte]) {
                                        ib = ib_org;
                                        errno = EILSEQ;
                                        ret_val = (size_t)-1;
                                        goto ILLEGAL_CHAR_ERR;
                                }
                                first_byte = 0;
                        } else if (((uint_t)*ib) < 0x80 ||
                                   ((uint_t)*ib) > 0xbf) {
                                ib = ib_org;
                                errno = EILSEQ;
                                ret_val = (size_t)-1;
                                goto ILLEGAL_CHAR_ERR;
                        }
                        u4 = (u4 << ICV_UTF8_BIT_SHIFT) |
                                (((uint_t)*ib) & ICV_UTF8_BIT_MASK);
                        ib++;
                }

                /* Check against known non-characters. */
                if ((u4 & ICV_UTF32_NONCHAR_mask) == ICV_UTF32_NONCHAR_fffe ||
                    (u4 & ICV_UTF32_NONCHAR_mask) == ICV_UTF32_NONCHAR_ffff ||
                    u4 > ICV_UTF32_LAST_VALID_CHAR ||
                    (u4 >= ICV_UTF32_SURROGATE_START_d800 &&
                    u4 <= ICV_UTF32_SURROGATE_END_dfff) ||
                    (u4 >= ICV_UTF32_ARABIC_NONCHAR_START_fdd0 &&
                    u4 <= ICV_UTF32_ARABIC_NONCHAR_END_fdef)) {
                        ib = ib_org;
                        errno = EILSEQ;
                        ret_val = (size_t)-1;
                        goto ILLEGAL_CHAR_ERR;
                }

                if (u4 <= 0x7f) {
                        OUTBUF_SIZE_CHECK(1);
                        *ob++ = I8_UTFEBICDIC(u4);
                } else if (u4 <= 0x9f) {
                        OUTBUF_SIZE_CHECK(1);
                        *ob++ = I8_UTFEBICDIC(u4);
                } else if (u4 <= 0x3ff) {
                        OUTBUF_SIZE_CHECK(2);
                        *ob++ = I8_UTFEBICDIC(0xc0 | ((u4 & 0x03e0) >> 5));
                        *ob++ = I8_UTFEBICDIC(0xa0 |  (u4 & 0x001f));
                } else if (u4 <= 0x3fff) {
                        OUTBUF_SIZE_CHECK(3);
                        *ob++ = I8_UTFEBICDIC(0xe0 | ((u4 & 0x3c00) >> 10));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x03e0) >> 5));
                        *ob++ = I8_UTFEBICDIC(0xa0 |  (u4 & 0x001f));
                } else if (u4 <= 0x3ffff) {
                        OUTBUF_SIZE_CHECK(4);
                        *ob++ = I8_UTFEBICDIC(0xf0 | ((u4 & 0x38000) >> 15));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x07c00) >> 10));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x003e0) >> 5));
                        *ob++ = I8_UTFEBICDIC(0xa0 |  (u4 & 0x0001f));
                } else if (u4 <= 0x3fffff) {
                        OUTBUF_SIZE_CHECK(5);
                        *ob++ = I8_UTFEBICDIC(0xf8 | ((u4 & 0x300000) >> 20));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x0f8000) >> 15));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x007c00) >> 10));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x0003e0) >> 5));
                        *ob++ = I8_UTFEBICDIC(0xa0 |  (u4 & 0x00001f));
                } else if (u4 <= 0x3ffffff) {
                        OUTBUF_SIZE_CHECK(6);
                        *ob++ = I8_UTFEBICDIC(0xfc | ((u4 & 0x2000000) >> 25));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x1f00000) >> 20));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x00f8000) >> 15));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x0007c00) >> 10));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x00003e0) >> 5));
                        *ob++ = I8_UTFEBICDIC(0xa0 |  (u4 & 0x000001f));
                } else if (u4 <= 0x7fffffff) {
                        OUTBUF_SIZE_CHECK(7);
                        *ob++ = I8_UTFEBICDIC(0xfe | ((u4 & 0x40000000) >> 30));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x3e000000) >> 25));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x01f00000) >> 20));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x000f8000) >> 15));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x00007c00) >> 10));
                        *ob++ = I8_UTFEBICDIC(0xa0 | ((u4 & 0x000003e0) >> 5));
                        *ob++ = I8_UTFEBICDIC(0xa0 |  (u4 & 0x0000001f));
                } 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);
}