source: branches/samba-3.0/source/lib/iconv.c

/* 
   Unix SMB/CIFS implementation.
   minimal iconv implementation
   Copyright (C) Andrew Tridgell 2001
   Copyright (C) Jelmer Vernooij 2002,2003
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

/*
 * We have to use strcasecmp here as the character conversions
 * haven't been initialised yet. JRA.
 */

#undef strcasecmp

/**
 * @file
 *
 * @brief Samba wrapper/stub for iconv character set conversion.
 *
 * iconv is the XPG2 interface for converting between character
 * encodings.  This file provides a Samba wrapper around it, and also
 * a simple reimplementation that is used if the system does not
 * implement iconv.
 *
 * Samba only works with encodings that are supersets of ASCII: ascii
 * characters like whitespace can be tested for directly, multibyte
 * sequences start with a byte with the high bit set, and strings are
 * terminated by a nul byte.
 *
 * Note that the only function provided by iconv is conversion between
 * characters.  It doesn't directly support operations like
 * uppercasing or comparison.  We have to convert to UCS-2 and compare
 * there.
 *
 * @sa Samba Developers Guide
 **/

static_decl_charset;

static size_t ascii_pull(void *,const char **, size_t *, char **, size_t *);
static size_t ascii_push(void *,const char **, size_t *, char **, size_t *);
static size_t latin1_push(void *,const char **, size_t *, char **, size_t *);
static size_t  utf8_pull(void *,const char **, size_t *, char **, size_t *);
static size_t  utf8_push(void *,const char **, size_t *, char **, size_t *);
static size_t ucs2hex_pull(void *,const char **, size_t *, char **, size_t *);
static size_t ucs2hex_push(void *,const char **, size_t *, char **, size_t *);
static size_t iconv_copy(void *,const char **, size_t *, char **, size_t *);
static size_t iconv_swab  (void *,const char **, size_t *, char **, size_t *);

static struct charset_functions builtin_functions[] = {
        /* windows is really neither UCS-2 not UTF-16 */
        {"UCS-2LE",  iconv_copy, iconv_copy},
        {"UTF-16LE",  iconv_copy, iconv_copy},
        {"UCS-2BE",  iconv_swab, iconv_swab},
        {"UTF-16BE",  iconv_swab, iconv_swab},

        /* we include the UTF-8 alias to cope with differing locale settings */
        {"UTF8",   utf8_pull,  utf8_push},
        {"UTF-8",   utf8_pull,  utf8_push},
        {"ASCII", ascii_pull, ascii_push},
        {"646", ascii_pull, ascii_push},
        {"ISO-8859-1", ascii_pull, latin1_push},
        {"UCS2-HEX", ucs2hex_pull, ucs2hex_push},
        {NULL, NULL, NULL}
};

static struct charset_functions *charsets = NULL;

static struct charset_functions *find_charset_functions(const char *name) 
{
        struct charset_functions *c = charsets;

        while(c) {
                if (strcasecmp(name, c->name) == 0) {
                        return c;
                }
                c = c->next;
        }

        return NULL;
}

NTSTATUS smb_register_charset(struct charset_functions *funcs) 
{
        if (!funcs) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        DEBUG(5, ("Attempting to register new charset %s\n", funcs->name));
        /* Check whether we already have this charset... */
        if (find_charset_functions(funcs->name)) {
                DEBUG(0, ("Duplicate charset %s, not registering\n", funcs->name));
                return NT_STATUS_OBJECT_NAME_COLLISION;
        }

        funcs->next = funcs->prev = NULL;
        DEBUG(5, ("Registered charset %s\n", funcs->name));
        DLIST_ADD(charsets, funcs);
        return NT_STATUS_OK;
}

static void lazy_initialize_iconv(void)
{
        static BOOL initialized;
        int i;

        if (!initialized) {
                initialized = True;
                for(i = 0; builtin_functions[i].name; i++) 
                        smb_register_charset(&builtin_functions[i]);
                static_init_charset;
        }
}

#if defined(__OS2__) && defined(__INNOTEK_LIBC__)
#include <uconv.h>

typedef struct os2_iconv_t
{
    UconvObject from;
} os2_iconv_t;

iconv_t os2_iconv_open (const char *tocode, const char *fromcode)
{
    os2_iconv_t *os2_cd = (os2_iconv_t *)iconv_open(tocode, fromcode);

    if (os2_cd != (iconv_t)(-1))
       {
        /* Assume strings contain pathnames */
        uconv_attribute_t attr;

        UniQueryUconvObject(os2_cd->from, &attr,
                            sizeof(uconv_attribute_t),
                            NULL, NULL, NULL );
        attr.converttype |= CVTTYPE_PATH;
        UniSetUconvObject(os2_cd->from, &attr);
        }

    return (iconv_t)os2_cd;
}

#define iconv_open  os2_iconv_open
#endif

#ifdef HAVE_NATIVE_ICONV
/* if there was an error then reset the internal state,
   this ensures that we don't have a shift state remaining for
   character sets like SJIS */
static size_t sys_iconv(void *cd, 
                        const char **inbuf, size_t *inbytesleft,
                        char **outbuf, size_t *outbytesleft)
{

        size_t ret = iconv((iconv_t)cd, 
                           (char **)inbuf, inbytesleft, 
                           outbuf, outbytesleft);
        if (ret == (size_t)-1) {
                int saved_errno = errno;
                iconv(cd, NULL, NULL, NULL, NULL);
                errno = saved_errno;
        }
        return ret;
}
#endif

/**
 * This is a simple portable iconv() implementaion.
 *
 * It only knows about a very small number of character sets - just
 * enough that Samba works on systems that don't have iconv.
 **/
size_t smb_iconv(smb_iconv_t cd, 
                 const char **inbuf, size_t *inbytesleft,
                 char **outbuf, size_t *outbytesleft)
{
        char cvtbuf[2048];
        char *bufp = cvtbuf;
        size_t bufsize;


        /* in many cases we can go direct */
        if (cd->direct) {
                return cd->direct(cd->cd_direct, 
                                  inbuf, inbytesleft, outbuf, outbytesleft);
        }


        /* otherwise we have to do it chunks at a time */
        while (*inbytesleft > 0) {
                bufp = cvtbuf;
                bufsize = sizeof(cvtbuf);
                
                if (cd->pull(cd->cd_pull, 
                             inbuf, inbytesleft, &bufp, &bufsize) == -1
                    && errno != E2BIG)
                        return -1;

                bufp = cvtbuf;
                bufsize = sizeof(cvtbuf) - bufsize;

                if (cd->push(cd->cd_push, 
                             (const char **)&bufp, &bufsize, 
                             outbuf, outbytesleft) == -1)
                                return -1;
        }

        return 0;
}


static BOOL is_utf16(const char *name)
{
        return strcasecmp(name, "UCS-2LE") == 0 ||
                strcasecmp(name, "UTF-16LE") == 0;
}

/*
  simple iconv_open() wrapper
 */
smb_iconv_t smb_iconv_open(const char *tocode, const char *fromcode)
{
        smb_iconv_t ret;
        struct charset_functions *from, *to;
        
        lazy_initialize_iconv();
        from = charsets;
        to = charsets;

        ret = SMB_MALLOC_P(struct _smb_iconv_t);
        if (!ret) {
                errno = ENOMEM;
                return (smb_iconv_t)-1;
        }
        memset(ret, 0, sizeof(struct _smb_iconv_t));

        ret->from_name = SMB_STRDUP(fromcode);
        ret->to_name = SMB_STRDUP(tocode);

        /* check for the simplest null conversion */
        if (strcasecmp(fromcode, tocode) == 0) {
                ret->direct = iconv_copy;
                return ret;
        }

        /* check if we have a builtin function for this conversion */
        from = find_charset_functions(fromcode);
        if(from)ret->pull = from->pull;
        
        to = find_charset_functions(tocode);
        if(to)ret->push = to->push;

        /* check if we can use iconv for this conversion */
#ifdef HAVE_NATIVE_ICONV
        if (!ret->pull) {
                ret->cd_pull = iconv_open("UTF-16LE", fromcode);
                if (ret->cd_pull == (iconv_t)-1)
                        ret->cd_pull = iconv_open("UCS-2LE", fromcode);
                if (ret->cd_pull != (iconv_t)-1)
                        ret->pull = sys_iconv;
        }

        if (!ret->push) {
                ret->cd_push = iconv_open(tocode, "UTF-16LE");
                if (ret->cd_push == (iconv_t)-1)
                        ret->cd_push = iconv_open(tocode, "UCS-2LE");
                if (ret->cd_push != (iconv_t)-1)
                        ret->push = sys_iconv;
        }
#endif
        
        /* check if there is a module available that can do this conversion */
        if (!ret->pull && NT_STATUS_IS_OK(smb_probe_module("charset", fromcode))) {
                if(!(from = find_charset_functions(fromcode)))
                        DEBUG(0, ("Module %s doesn't provide charset %s!\n", fromcode, fromcode));
                else 
                        ret->pull = from->pull;
        }

        if (!ret->push && NT_STATUS_IS_OK(smb_probe_module("charset", tocode))) {
                if(!(to = find_charset_functions(tocode)))
                        DEBUG(0, ("Module %s doesn't provide charset %s!\n", tocode, tocode));
                else 
                        ret->push = to->push;
        }

        if (!ret->push || !ret->pull) {
                SAFE_FREE(ret->from_name);
                SAFE_FREE(ret->to_name);
                SAFE_FREE(ret);
                errno = EINVAL;
                return (smb_iconv_t)-1;
        }

        /* check for conversion to/from ucs2 */
        if (is_utf16(fromcode) && to) {
                ret->direct = to->push;
                ret->push = ret->pull = NULL;
                return ret;
        }

        if (is_utf16(tocode) && from) {
                ret->direct = from->pull;
                ret->push = ret->pull = NULL;
                return ret;
        }

        /* Check if we can do the conversion direct */
#ifdef HAVE_NATIVE_ICONV
        if (is_utf16(fromcode)) {
                ret->direct = sys_iconv;
                ret->cd_direct = ret->cd_push;
                ret->cd_push = NULL;
                return ret;
        }
        if (is_utf16(tocode)) {
                ret->direct = sys_iconv;
                ret->cd_direct = ret->cd_pull;
                ret->cd_pull = NULL;
                return ret;
        }
#endif

        return ret;
}

/*
  simple iconv_close() wrapper
*/
int smb_iconv_close (smb_iconv_t cd)
{
#ifdef HAVE_NATIVE_ICONV
        if (cd->cd_direct) iconv_close((iconv_t)cd->cd_direct);
        if (cd->cd_pull) iconv_close((iconv_t)cd->cd_pull);
        if (cd->cd_push) iconv_close((iconv_t)cd->cd_push);
#endif

        SAFE_FREE(cd->from_name);
        SAFE_FREE(cd->to_name);

        memset(cd, 0, sizeof(*cd));
        SAFE_FREE(cd);
        return 0;
}


/**********************************************************************
 the following functions implement the builtin character sets in Samba
 and also the "test" character sets that are designed to test
 multi-byte character set support for english users
***********************************************************************/

static size_t ascii_pull(void *cd, const char **inbuf, size_t *inbytesleft,
                         char **outbuf, size_t *outbytesleft)
{
        while (*inbytesleft >= 1 && *outbytesleft >= 2) {
                (*outbuf)[0] = (*inbuf)[0];
                (*outbuf)[1] = 0;
                (*inbytesleft)  -= 1;
                (*outbytesleft) -= 2;
                (*inbuf)  += 1;
                (*outbuf) += 2;
        }

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

static size_t ascii_push(void *cd, const char **inbuf, size_t *inbytesleft,
                         char **outbuf, size_t *outbytesleft)
{
        int ir_count=0;

        while (*inbytesleft >= 2 && *outbytesleft >= 1) {
                (*outbuf)[0] = (*inbuf)[0] & 0x7F;
                if ((*inbuf)[1]) ir_count++;
                (*inbytesleft)  -= 2;
                (*outbytesleft) -= 1;
                (*inbuf)  += 2;
                (*outbuf) += 1;
        }

        if (*inbytesleft == 1) {
                errno = EINVAL;
                return -1;
        }

        if (*inbytesleft > 1) {
                errno = E2BIG;
                return -1;
        }
        
        return ir_count;
}

static size_t latin1_push(void *cd, const char **inbuf, size_t *inbytesleft,
                         char **outbuf, size_t *outbytesleft)
{
        int ir_count=0;

        while (*inbytesleft >= 2 && *outbytesleft >= 1) {
                (*outbuf)[0] = (*inbuf)[0];
                if ((*inbuf)[1]) ir_count++;
                (*inbytesleft)  -= 2;
                (*outbytesleft) -= 1;
                (*inbuf)  += 2;
                (*outbuf) += 1;
        }

        if (*inbytesleft == 1) {
                errno = EINVAL;
                return -1;
        }

        if (*inbytesleft > 1) {
                errno = E2BIG;
                return -1;
        }
        
        return ir_count;
}

static size_t ucs2hex_pull(void *cd, const char **inbuf, size_t *inbytesleft,
                         char **outbuf, size_t *outbytesleft)
{
        while (*inbytesleft >= 1 && *outbytesleft >= 2) {
                unsigned v;

                if ((*inbuf)[0] != '@') {
                        /* seven bit ascii case */
                        (*outbuf)[0] = (*inbuf)[0];
                        (*outbuf)[1] = 0;
                        (*inbytesleft)  -= 1;
                        (*outbytesleft) -= 2;
                        (*inbuf)  += 1;
                        (*outbuf) += 2;
                        continue;
                }
                /* it's a hex character */
                if (*inbytesleft < 5) {
                        errno = EINVAL;
                        return -1;
                }
                
                if (sscanf(&(*inbuf)[1], "%04x", &v) != 1) {
                        errno = EILSEQ;
                        return -1;
                }

                (*outbuf)[0] = v&0xff;
                (*outbuf)[1] = v>>8;
                (*inbytesleft)  -= 5;
                (*outbytesleft) -= 2;
                (*inbuf)  += 5;
                (*outbuf) += 2;
        }

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

static size_t ucs2hex_push(void *cd, const char **inbuf, size_t *inbytesleft,
                           char **outbuf, size_t *outbytesleft)
{
        while (*inbytesleft >= 2 && *outbytesleft >= 1) {
                char buf[6];

                if ((*inbuf)[1] == 0 && 
                    ((*inbuf)[0] & 0x80) == 0 &&
                    (*inbuf)[0] != '@') {
                        (*outbuf)[0] = (*inbuf)[0];
                        (*inbytesleft)  -= 2;
                        (*outbytesleft) -= 1;
                        (*inbuf)  += 2;
                        (*outbuf) += 1;
                        continue;
                }
                if (*outbytesleft < 5) {
                        errno = E2BIG;
                        return -1;
                }
                snprintf(buf, 6, "@%04x", SVAL(*inbuf, 0));
                memcpy(*outbuf, buf, 5);
                (*inbytesleft)  -= 2;
                (*outbytesleft) -= 5;
                (*inbuf)  += 2;
                (*outbuf) += 5;
        }

        if (*inbytesleft == 1) {
                errno = EINVAL;
                return -1;
        }

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

static size_t iconv_swab(void *cd, const char **inbuf, size_t *inbytesleft,
                         char **outbuf, size_t *outbytesleft)
{
        int n;

        n = MIN(*inbytesleft, *outbytesleft);

        swab(*inbuf, *outbuf, (n&~1));
        if (n&1) {
                (*outbuf)[n-1] = 0;
        }

        (*inbytesleft) -= n;
        (*outbytesleft) -= n;
        (*inbuf) += n;
        (*outbuf) += n;

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

        return 0;
}

static size_t iconv_copy(void *cd, const char **inbuf, size_t *inbytesleft,
                         char **outbuf, size_t *outbytesleft)
{
        int n;

        n = MIN(*inbytesleft, *outbytesleft);

        memmove(*outbuf, *inbuf, n);

        (*inbytesleft) -= n;
        (*outbytesleft) -= n;
        (*inbuf) += n;
        (*outbuf) += n;

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

        return 0;
}

static size_t utf8_pull(void *cd, const char **inbuf, size_t *inbytesleft,
                         char **outbuf, size_t *outbytesleft)
{
        size_t in_left=*inbytesleft, out_left=*outbytesleft;
        const uint8 *c = (const uint8 *)*inbuf;
        uint8 *uc = (uint8 *)*outbuf;

        while (in_left >= 1 && out_left >= 2) {
                unsigned int codepoint;

                if ((c[0] & 0x80) == 0) {
                        uc[0] = c[0];
                        uc[1] = 0;
                        c  += 1;
                        in_left  -= 1;
                        out_left -= 2;
                        uc += 2;
                        continue;
                }

                if ((c[0] & 0xe0) == 0xc0) {
                        if (in_left < 2 ||
                            (c[1] & 0xc0) != 0x80) {
                                errno = EILSEQ;
                                goto error;
                        }
                        codepoint = (c[1]&0x3f) | ((c[0]&0x1f)<<6);
                        if (codepoint < 0x80) {
                                /* don't accept UTF-8 characters that are not minimally packed */
                                errno = EILSEQ;
                                goto error;
                        }
                        uc[1] = codepoint >> 8;
                        uc[0] = codepoint & 0xff;
                        c  += 2;
                        in_left  -= 2;
                        out_left -= 2;
                        uc += 2;
                        continue;
                }

                if ((c[0] & 0xf0) == 0xe0) {
                        if (in_left < 3 ||
                            (c[1] & 0xc0) != 0x80 || 
                            (c[2] & 0xc0) != 0x80) {
                                errno = EILSEQ;
                                goto error;
                        }
                        codepoint = (c[2]&0x3f) | ((c[1]&0x3f)<<6) | ((c[0]&0xf)<<12);
                        if (codepoint < 0x800) {
                                /* don't accept UTF-8 characters that are not minimally packed */
                                errno = EILSEQ;
                                goto error;
                        }
                        uc[1] = codepoint >> 8;
                        uc[0] = codepoint & 0xff;
                        c  += 3;
                        in_left  -= 3;
                        out_left -= 2;
                        uc += 2;
                        continue;
                }

                if ((c[0] & 0xf8) == 0xf0) {
                        if (in_left < 4 ||
                            (c[1] & 0xc0) != 0x80 || 
                            (c[2] & 0xc0) != 0x80 ||
                            (c[3] & 0xc0) != 0x80) {
                                errno = EILSEQ;
                                goto error;
                        }
                        codepoint = 
                                (c[3]&0x3f) | 
                                ((c[2]&0x3f)<<6) | 
                                ((c[1]&0x3f)<<12) |
                                ((c[0]&0x7)<<18);
                        if (codepoint < 0x10000 || codepoint > 0x10ffff) {
                                /* don't accept UTF-8 characters that are not minimally packed */
                                errno = EILSEQ;
                                goto error;
                        }

                        codepoint -= 0x10000;

                        if (out_left < 4) {
                                errno = E2BIG;
                                goto error;
                        }

                        uc[0] = (codepoint>>10) & 0xFF;
                        uc[1] = (codepoint>>18) | 0xd8;
                        uc[2] = codepoint & 0xFF;
                        uc[3] = ((codepoint>>8) & 0x3) | 0xdc;
                        c  += 4;
                        in_left  -= 4;
                        out_left -= 4;
                        uc += 4;
                        continue;
                }

                /* we don't handle 5 byte sequences */
                errno = EINVAL;
                goto error;
        }

        if (in_left > 0) {
                errno = E2BIG;
                goto error;
        }

        *inbytesleft = in_left;
        *outbytesleft = out_left;
        *inbuf = (char *)c;
        *outbuf = (char *)uc;   
        return 0;

error:
        *inbytesleft = in_left;
        *outbytesleft = out_left;
        *inbuf = (char *)c;
        *outbuf = (char *)uc;
        return -1;
}

static size_t utf8_push(void *cd, const char **inbuf, size_t *inbytesleft,
                        char **outbuf, size_t *outbytesleft)
{
        size_t in_left=*inbytesleft, out_left=*outbytesleft;
        uint8 *c = (uint8 *)*outbuf;
        const uint8 *uc = (const uint8 *)*inbuf;

        while (in_left >= 2 && out_left >= 1) {
                unsigned int codepoint;

                if (uc[1] == 0 && !(uc[0] & 0x80)) {
                        /* simplest case */
                        c[0] = uc[0];
                        in_left  -= 2;
                        out_left -= 1;
                        uc += 2;
                        c  += 1;
                        continue;
                }

                if ((uc[1]&0xf8) == 0) {
                        /* next simplest case */
                        if (out_left < 2) {
                                errno = E2BIG;
                                goto error;
                        }
                        c[0] = 0xc0 | (uc[0]>>6) | (uc[1]<<2);
                        c[1] = 0x80 | (uc[0] & 0x3f);
                        in_left  -= 2;
                        out_left -= 2;
                        uc += 2;
                        c  += 2;
                        continue;
                }

                if ((uc[1] & 0xfc) == 0xdc) {
                        /* its the second part of a 4 byte sequence. Illegal */
                        if (in_left < 4) {
                                errno = EINVAL;
                        } else {
                                errno = EILSEQ;
                        }
                        goto error;
                }

                if ((uc[1] & 0xfc) != 0xd8) {
                        codepoint = uc[0] | (uc[1]<<8);
                        if (out_left < 3) {
                                errno = E2BIG;
                                goto error;
                        }
                        c[0] = 0xe0 | (codepoint >> 12);
                        c[1] = 0x80 | ((codepoint >> 6) & 0x3f);
                        c[2] = 0x80 | (codepoint & 0x3f);
                        
                        in_left  -= 2;
                        out_left -= 3;
                        uc  += 2;
                        c   += 3;
                        continue;
                }

                /* its the first part of a 4 byte sequence */
                if (in_left < 4) {
                        errno = EINVAL;
                        goto error;
                }
                if ((uc[3] & 0xfc) != 0xdc) {
                        errno = EILSEQ;
                        goto error;
                }
                codepoint = 0x10000 + (uc[2] | ((uc[3] & 0x3)<<8) | 
                                       (uc[0]<<10) | ((uc[1] & 0x3)<<18));
                
                if (out_left < 4) {
                        errno = E2BIG;
                        goto error;
                }
                c[0] = 0xf0 | (codepoint >> 18);
                c[1] = 0x80 | ((codepoint >> 12) & 0x3f);
                c[2] = 0x80 | ((codepoint >> 6) & 0x3f);
                c[3] = 0x80 | (codepoint & 0x3f);
                
                in_left  -= 4;
                out_left -= 4;
                uc       += 4;
                c        += 4;
        }

        if (in_left == 1) {
                errno = EINVAL;
                goto error;
        }

        if (in_left > 1) {
                errno = E2BIG;
                goto error;
        }

        *inbytesleft = in_left;
        *outbytesleft = out_left;
        *inbuf  = (char *)uc;
        *outbuf = (char *)c;
        
        return 0;

error:
        *inbytesleft = in_left;
        *outbytesleft = out_left;
        *inbuf  = (char *)uc;
        *outbuf = (char *)c;
        return -1;
}