/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2000-2001 Boris Popov
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#ifndef _SYS_ICONV_H_
#define _SYS_ICONV_H_

#define ICONV_CSNMAXLEN         31      /* maximum length of charset name */
#define ICONV_CNVNMAXLEN        31      /* maximum length of converter name */
/* maximum size of data associated with cs pair */
#define ICONV_CSMAXDATALEN      (sizeof(caddr_t) * 0x200 + sizeof(uint32_t) * 0x200 * 0x80)

#define XLAT16_ACCEPT_NULL_OUT          0x01000000
#define XLAT16_ACCEPT_NULL_IN           0x02000000
#define XLAT16_HAS_LOWER_CASE           0x04000000
#define XLAT16_HAS_UPPER_CASE           0x08000000
#define XLAT16_HAS_FROM_LOWER_CASE      0x10000000
#define XLAT16_HAS_FROM_UPPER_CASE      0x20000000
#define XLAT16_IS_3BYTE_CHR             0x40000000

#define KICONV_LOWER            1       /* tolower converted character */
#define KICONV_UPPER            2       /* toupper converted character */
#define KICONV_FROM_LOWER       4       /* tolower source character, then convert */
#define KICONV_FROM_UPPER       8       /* toupper source character, then convert */
#define KICONV_WCTYPE           16      /* towlower/towupper characters */

#define ENCODING_UNICODE        "UTF-16BE"
#define KICONV_WCTYPE_NAME      "_wctype"

/*
 * Entry for cslist sysctl
 */
#define ICONV_CSPAIR_INFO_VER   1

struct iconv_cspair_info {
        int     cs_version;
        int     cs_id;
        int     cs_base;
        int     cs_refcount;
        char    cs_to[ICONV_CSNMAXLEN];
        char    cs_from[ICONV_CSNMAXLEN];
};

/*
 * Parameters for 'add' sysctl
 */
#define ICONV_ADD_VER   1

struct iconv_add_in {
        int     ia_version;
        char    ia_converter[ICONV_CNVNMAXLEN];
        char    ia_to[ICONV_CSNMAXLEN];
        char    ia_from[ICONV_CSNMAXLEN];
        int     ia_datalen;
        const void *ia_data;
};

struct iconv_add_out {
        int     ia_csid;
};

#ifndef _KERNEL

__BEGIN_DECLS

#define KICONV_VENDOR_MICSFT    1       /* Microsoft Vendor Code for quirk */

int   kiconv_add_xlat_table(const char *, const char *, const u_char *);
int   kiconv_add_xlat16_cspair(const char *, const char *, int);
int   kiconv_add_xlat16_cspairs(const char *, const char *);
int   kiconv_add_xlat16_table(const char *, const char *, const void *, int);
int   kiconv_lookupconv(const char *drvname);
int   kiconv_lookupcs(const char *tocode, const char *fromcode);
const char *kiconv_quirkcs(const char *, int);

__END_DECLS

#else /* !_KERNEL */

#include <sys/kobj.h>
#include <sys/module.h>                 /* can't avoid that */
#include <sys/queue.h>                  /* can't avoid that */
#include <sys/sysctl.h>                 /* can't avoid that */

struct iconv_cspair;
struct iconv_cspairdata;

/*
 * iconv converter class definition
 */
struct iconv_converter_class {
        KOBJ_CLASS_FIELDS;
        TAILQ_ENTRY(iconv_converter_class)      cc_link;
};

struct iconv_cspair {
        int             cp_id;          /* unique id of charset pair */
        int             cp_refcount;    /* number of references from other pairs */
        const char *    cp_from;
        const char *    cp_to;
        void *          cp_data;
        struct iconv_converter_class * cp_dcp;
        struct iconv_cspair *cp_base;
        TAILQ_ENTRY(iconv_cspair)       cp_link;
};

#define KICONV_CONVERTER(name,size)                     \
    static struct iconv_converter_class iconv_ ## name ## _class = { \
        "iconv_"#name, iconv_ ## name ## _methods, size, NULL \
    };                                                  \
    static moduledata_t iconv_ ## name ## _mod = {      \
        "iconv_"#name, iconv_converter_handler,         \
        (void*)&iconv_ ## name ## _class                \
    };                                                  \
    DECLARE_MODULE(iconv_ ## name, iconv_ ## name ## _mod, SI_SUB_DRIVERS, SI_ORDER_ANY);

#define KICONV_CES(name,size)                           \
    static DEFINE_CLASS(iconv_ces_ ## name, iconv_ces_ ## name ## _methods, (size)); \
    static moduledata_t iconv_ces_ ## name ## _mod = {  \
        "iconv_ces_"#name, iconv_cesmod_handler,        \
        (void*)&iconv_ces_ ## name ## _class            \
    };                                                  \
    DECLARE_MODULE(iconv_ces_ ## name, iconv_ces_ ## name ## _mod, SI_SUB_DRIVERS, SI_ORDER_ANY);

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_ICONV);
#endif

/*
 * Basic conversion functions
 */
int iconv_open(const char *to, const char *from, void **handle);
int iconv_close(void *handle);
int iconv_conv(void *handle, const char **inbuf,
        size_t *inbytesleft, char **outbuf, size_t *outbytesleft);
int iconv_conv_case(void *handle, const char **inbuf,
        size_t *inbytesleft, char **outbuf, size_t *outbytesleft, int casetype);
int iconv_convchr(void *handle, const char **inbuf,
        size_t *inbytesleft, char **outbuf, size_t *outbytesleft);
int iconv_convchr_case(void *handle, const char **inbuf,
        size_t *inbytesleft, char **outbuf, size_t *outbytesleft, int casetype);
int iconv_add(const char *converter, const char *to, const char *from);
char* iconv_convstr(void *handle, char *dst, const char *src);
void* iconv_convmem(void *handle, void *dst, const void *src, int size);
int iconv_vfs_refcount(const char *fsname);

int towlower(int c, void *handle);
int towupper(int c, void *handle);

/*
 * Bridge struct of iconv functions
 */
struct iconv_functions {
        int (*open)(const char *to, const char *from, void **handle);
        int (*close)(void *handle);
        int (*conv)(void *handle, const char **inbuf, size_t *inbytesleft,
                char **outbuf, size_t *outbytesleft);
        int (*conv_case)(void *handle, const char **inbuf, size_t *inbytesleft,
                char **outbuf, size_t *outbytesleft, int casetype);
        int (*convchr)(void *handle, const char **inbuf, size_t *inbytesleft,
                char **outbuf, size_t *outbytesleft);
        int (*convchr_case)(void *handle, const char **inbuf, size_t *inbytesleft,
                char **outbuf, size_t *outbytesleft, int casetype);
};

#define VFS_DECLARE_ICONV(fsname)                                       \
        static struct iconv_functions fsname ## _iconv_core = {         \
                iconv_open,                                             \
                iconv_close,                                            \
                iconv_conv,                                             \
                iconv_conv_case,                                        \
                iconv_convchr,                                          \
                iconv_convchr_case                                      \
        };                                                              \
        extern struct iconv_functions *fsname ## _iconv;                \
        static int fsname ## _iconv_mod_handler(module_t mod,           \
                int type, void *d);                                     \
        static int                                                      \
        fsname ## _iconv_mod_handler(module_t mod, int type, void *d)   \
        {                                                               \
                int error = 0;                                          \
                switch(type) {                                          \
                case MOD_LOAD:                                          \
                        fsname ## _iconv = & fsname ## _iconv_core;     \
                        break;                                          \
                case MOD_UNLOAD:                                        \
                        error = iconv_vfs_refcount(#fsname);            \
                        if (error)                                      \
                                return (EBUSY);                         \
                        fsname ## _iconv = NULL;                        \
                        break;                                          \
                default:                                                \
                        error = EINVAL;                                 \
                        break;                                          \
                }                                                       \
                return (error);                                         \
        }                                                               \
        static moduledata_t fsname ## _iconv_mod = {                    \
                #fsname"_iconv",                                        \
                fsname ## _iconv_mod_handler,                           \
                NULL                                                    \
        };                                                              \
        DECLARE_MODULE(fsname ## _iconv, fsname ## _iconv_mod,          \
                       SI_SUB_DRIVERS, SI_ORDER_ANY);                   \
        MODULE_DEPEND(fsname ## _iconv, fsname, 1, 1, 1);               \
        MODULE_DEPEND(fsname ## _iconv, libiconv, 2, 2, 2);             \
        MODULE_VERSION(fsname ## _iconv, 1)

/*
 * Internal functions
 */
int iconv_lookupcp(char **cpp, const char *s);

int iconv_converter_initstub(struct iconv_converter_class *dp);
int iconv_converter_donestub(struct iconv_converter_class *dp);
int iconv_converter_tolowerstub(int c, void *handle);
int iconv_converter_handler(module_t mod, int type, void *data);

#ifdef ICONV_DEBUG
#define ICDEBUG(format, ...) printf("%s: "format, __func__ , ## __VA_ARGS__)
#else
#define ICDEBUG(format, ...)
#endif

#endif /* !_KERNEL */

#endif /* !_SYS_ICONV_H_ */