source: trunk/samba-3.0.25pre1/source/lib/charcnv.c@ 12

/* 
   Unix SMB/CIFS implementation.
   Character set conversion Extensions
   Copyright (C) Igor Vergeichik <iverg@mail.ru> 2001
   Copyright (C) Andrew Tridgell 2001
   Copyright (C) Simo Sorce 2001
   Copyright (C) Martin Pool 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 can parameterize this if someone complains.... JRA. */

char lp_failed_convert_char(void)
{
        return '_';
}

/**
 * @file
 *
 * @brief Character-set conversion routines built on our iconv.
 * 
 * @note Samba's internal character set (at least in the 3.0 series)
 * is always the same as the one for the Unix filesystem.  It is
 * <b>not</b> necessarily UTF-8 and may be different on machines that
 * need i18n filenames to be compatible with Unix software.  It does
 * have to be a superset of ASCII.  All multibyte sequences must start
 * with a byte with the high bit set.
 *
 * @sa lib/iconv.c
 */


static smb_iconv_t conv_handles[NUM_CHARSETS][NUM_CHARSETS];
static BOOL conv_silent; /* Should we do a debug if the conversion fails ? */

/**
 * Return the name of a charset to give to iconv().
 **/
static const char *charset_name(charset_t ch)
{
        const char *ret = NULL;

        if (ch == CH_UTF16LE) ret = "UTF-16LE";
        else if (ch == CH_UTF16BE) ret = "UTF-16BE";
        else if (ch == CH_UNIX) ret = lp_unix_charset();
        else if (ch == CH_DOS) ret = lp_dos_charset();
        else if (ch == CH_DISPLAY) ret = lp_display_charset();
        else if (ch == CH_UTF8) ret = "UTF8";

#if defined(HAVE_NL_LANGINFO) && defined(CODESET)
        if (ret && !strcmp(ret, "LOCALE")) {
                const char *ln = NULL;

#ifdef HAVE_SETLOCALE
                setlocale(LC_ALL, "");
#endif
                ln = nl_langinfo(CODESET);
                if (ln) {
                        /* Check whether the charset name is supported
                           by iconv */
                        smb_iconv_t handle = smb_iconv_open(ln,"UCS-2LE");
                        if (handle == (smb_iconv_t) -1) {
                                DEBUG(5,("Locale charset '%s' unsupported, using ASCII instead\n", ln));
                                ln = NULL;
                        } else {
                                DEBUG(5,("Substituting charset '%s' for LOCALE\n", ln));
                                smb_iconv_close(handle);
                        }
                }
                ret = ln;
        }
#endif

        if (!ret || !*ret) ret = "ASCII";
        return ret;
}

void lazy_initialize_conv(void)
{
        static int initialized = False;

        if (!initialized) {
                initialized = True;
                load_case_tables();
                init_iconv();
        }
}

/**
 * Destroy global objects allocated by init_iconv()
 **/
void gfree_charcnv(void)
{
        int c1, c2;

        for (c1=0;c1<NUM_CHARSETS;c1++) {
                for (c2=0;c2<NUM_CHARSETS;c2++) {
                        if ( conv_handles[c1][c2] ) {
                                smb_iconv_close( conv_handles[c1][c2] );
                                conv_handles[c1][c2] = 0;
                        }
                }
        }
}

/**
 * Initialize iconv conversion descriptors.
 *
 * This is called the first time it is needed, and also called again
 * every time the configuration is reloaded, because the charset or
 * codepage might have changed.
 **/
void init_iconv(void)
{
        int c1, c2;
        BOOL did_reload = False;

        /* so that charset_name() works we need to get the UNIX<->UCS2 going
           first */
        if (!conv_handles[CH_UNIX][CH_UTF16LE])
                conv_handles[CH_UNIX][CH_UTF16LE] = smb_iconv_open(charset_name(CH_UTF16LE), "ASCII");

        if (!conv_handles[CH_UTF16LE][CH_UNIX])
                conv_handles[CH_UTF16LE][CH_UNIX] = smb_iconv_open("ASCII", charset_name(CH_UTF16LE));

        for (c1=0;c1<NUM_CHARSETS;c1++) {
                for (c2=0;c2<NUM_CHARSETS;c2++) {
                        const char *n1 = charset_name((charset_t)c1);
                        const char *n2 = charset_name((charset_t)c2);
                        if (conv_handles[c1][c2] &&
                            strcmp(n1, conv_handles[c1][c2]->from_name) == 0 &&
                            strcmp(n2, conv_handles[c1][c2]->to_name) == 0)
                                continue;

                        did_reload = True;

                        if (conv_handles[c1][c2])
                                smb_iconv_close(conv_handles[c1][c2]);

                        conv_handles[c1][c2] = smb_iconv_open(n2,n1);
                        if (conv_handles[c1][c2] == (smb_iconv_t)-1) {
                                DEBUG(0,("init_iconv: Conversion from %s to %s not supported\n",
                                         charset_name((charset_t)c1), charset_name((charset_t)c2)));
                                if (c1 != CH_UTF16LE && c1 != CH_UTF16BE) {
                                        n1 = "ASCII";
                                }
                                if (c2 != CH_UTF16LE && c2 != CH_UTF16BE) {
                                        n2 = "ASCII";
                                }
                                DEBUG(0,("init_iconv: Attempting to replace with conversion from %s to %s\n",
                                        n1, n2 ));
                                conv_handles[c1][c2] = smb_iconv_open(n2,n1);
                                if (!conv_handles[c1][c2]) {
                                        DEBUG(0,("init_iconv: Conversion from %s to %s failed", n1, n2));
                                        smb_panic("init_iconv: conv_handle initialization failed.");
                                }
                        }
                }
        }

        if (did_reload) {
                /* XXX: Does this really get called every time the dos
                 * codepage changes? */
                /* XXX: Is the did_reload test too strict? */
                conv_silent = True;
                init_doschar_table();
                init_valid_table();
                conv_silent = False;
        }
}

/**
 * Convert string from one encoding to another, making error checking etc
 * Slow path version - uses (slow) iconv.
 *
 * @param src pointer to source string (multibyte or singlebyte)
 * @param srclen length of the source string in bytes
 * @param dest pointer to destination string (multibyte or singlebyte)
 * @param destlen maximal length allowed for string
 * @param allow_bad_conv determines if a "best effort" conversion is acceptable (never returns errors)
 * @returns the number of bytes occupied in the destination
 *
 * Ensure the srclen contains the terminating zero.
 *
 **/

static size_t convert_string_internal(charset_t from, charset_t to,
                      void const *src, size_t srclen, 
                      void *dest, size_t destlen, BOOL allow_bad_conv)
{
        size_t i_len, o_len;
        size_t retval;
        const char* inbuf = (const char*)src;
        char* outbuf = (char*)dest;
        smb_iconv_t descriptor;

        lazy_initialize_conv();

        descriptor = conv_handles[from][to];

        if (srclen == (size_t)-1) {
                if (from == CH_UTF16LE || from == CH_UTF16BE) {
                        srclen = (strlen_w((const smb_ucs2_t *)src)+1) * 2;
                } else {
                        srclen = strlen((const char *)src)+1;
                }
        }


        if (descriptor == (smb_iconv_t)-1 || descriptor == (smb_iconv_t)0) {
                if (!conv_silent)
                        DEBUG(0,("convert_string_internal: Conversion not supported.\n"));
                return (size_t)-1;
        }

        i_len=srclen;
        o_len=destlen;

 again:

        retval = smb_iconv(descriptor, &inbuf, &i_len, &outbuf, &o_len);
        if(retval==(size_t)-1) {
                const char *reason="unknown error";
                switch(errno) {
                        case EINVAL:
                                reason="Incomplete multibyte sequence";
                                if (!conv_silent)
                                        DEBUG(3,("convert_string_internal: Conversion error: %s(%s)\n",reason,inbuf));
                                if (allow_bad_conv)
                                        goto use_as_is;
                                break;
                        case E2BIG:
                                reason="No more room"; 
                                if (!conv_silent) {
                                        if (from == CH_UNIX) {
                                                DEBUG(3,("E2BIG: convert_string(%s,%s): srclen=%u destlen=%u - '%s'\n",
                                                        charset_name(from), charset_name(to),
                                                        (unsigned int)srclen, (unsigned int)destlen, (const char *)src));
                                        } else {
                                                DEBUG(3,("E2BIG: convert_string(%s,%s): srclen=%u destlen=%u\n",
                                                        charset_name(from), charset_name(to),
                                                        (unsigned int)srclen, (unsigned int)destlen));
                                        }
                                }
                                break;
                        case EILSEQ:
                                reason="Illegal multibyte sequence";
                                if (!conv_silent)
                                        DEBUG(3,("convert_string_internal: Conversion error: %s(%s)\n",reason,inbuf));
                                if (allow_bad_conv)
                                        goto use_as_is;
                                break;
                        default:
                                if (!conv_silent)
                                        DEBUG(0,("convert_string_internal: Conversion error: %s(%s)\n",reason,inbuf));
                                break;
                }
                /* smb_panic(reason); */
        }
        return destlen-o_len;

 use_as_is:

        /* 
         * Conversion not supported. This is actually an error, but there are so
         * many misconfigured iconv systems and smb.conf's out there we can't just
         * fail. Do a very bad conversion instead.... JRA.
         */

        {
                if (o_len == 0 || i_len == 0)
                        return destlen - o_len;

                if (((from == CH_UTF16LE)||(from == CH_UTF16BE)) &&
                                ((to != CH_UTF16LE)||(to != CH_UTF16BE))) {
                        /* Can't convert from utf16 any endian to multibyte.
                           Replace with the default fail char.
                        */
                        if (i_len < 2)
                                return destlen - o_len;
                        if (i_len >= 2) {
                                *outbuf = lp_failed_convert_char();

                                outbuf++;
                                o_len--;

                                inbuf += 2;
                                i_len -= 2;
                        }

                        if (o_len == 0 || i_len == 0)
                                return destlen - o_len;

                        /* Keep trying with the next char... */
                        goto again;

                } else if (from != CH_UTF16LE && from != CH_UTF16BE && to == CH_UTF16LE) {
                        /* Can't convert to UTF16LE - just widen by adding the
                           default fail char then zero.
                        */
                        if (o_len < 2)
                                return destlen - o_len;

                        outbuf[0] = lp_failed_convert_char();
                        outbuf[1] = '\0';

                        inbuf++;
                        i_len--;

                        outbuf += 2;
                        o_len -= 2;

                        if (o_len == 0 || i_len == 0)
                                return destlen - o_len;

                        /* Keep trying with the next char... */
                        goto again;

                } else if (from != CH_UTF16LE && from != CH_UTF16BE &&
                                to != CH_UTF16LE && to != CH_UTF16BE) {
                        /* Failed multibyte to multibyte. Just copy the default fail char and
                                try again. */
                        outbuf[0] = lp_failed_convert_char();

                        inbuf++;
                        i_len--;

                        outbuf++;
                        o_len--;

                        if (o_len == 0 || i_len == 0)
                                return destlen - o_len;

                        /* Keep trying with the next char... */
                        goto again;

                } else {
                        /* Keep compiler happy.... */
                        return destlen - o_len;
                }
        }
}

/**
 * Convert string from one encoding to another, making error checking etc
 * Fast path version - handles ASCII first.
 *
 * @param src pointer to source string (multibyte or singlebyte)
 * @param srclen length of the source string in bytes, or -1 for nul terminated.
 * @param dest pointer to destination string (multibyte or singlebyte)
 * @param destlen maximal length allowed for string - *NEVER* -1.
 * @param allow_bad_conv determines if a "best effort" conversion is acceptable (never returns errors)
 * @returns the number of bytes occupied in the destination
 *
 * Ensure the srclen contains the terminating zero.
 *
 * This function has been hand-tuned to provide a fast path.
 * Don't change unless you really know what you are doing. JRA.
 **/

size_t convert_string(charset_t from, charset_t to,
                      void const *src, size_t srclen, 
                      void *dest, size_t destlen, BOOL allow_bad_conv)
{
        /*
         * NB. We deliberately don't do a strlen here if srclen == -1.
         * This is very expensive over millions of calls and is taken
         * care of in the slow path in convert_string_internal. JRA.
         */

#ifdef DEVELOPER
        SMB_ASSERT(destlen != (size_t)-1);
#endif

        if (srclen == 0)
                return 0;

        if (from != CH_UTF16LE && from != CH_UTF16BE && to != CH_UTF16LE && to != CH_UTF16BE) {
                const unsigned char *p = (const unsigned char *)src;
                unsigned char *q = (unsigned char *)dest;
                size_t slen = srclen;
                size_t dlen = destlen;
                unsigned char lastp = '\0';
                size_t retval = 0;

                /* If all characters are ascii, fast path here. */
                while (slen && dlen) {
                        if ((lastp = *p) <= 0x7f) {
                                *q++ = *p++;
                                if (slen != (size_t)-1) {
                                        slen--;
                                }
                                dlen--;
                                retval++;
                                if (!lastp)
                                        break;
                        } else {
#ifdef BROKEN_UNICODE_COMPOSE_CHARACTERS
                                goto general_case;
#else
                                return retval + convert_string_internal(from, to, p, slen, q, dlen, allow_bad_conv);
#endif
                        }
                }
                if (!dlen) {
                        /* Even if we fast path we should note if we ran out of room. */
                        if (((slen != (size_t)-1) && slen) ||
                                        ((slen == (size_t)-1) && lastp)) {
                                errno = E2BIG;
                        }
                }
                return retval;
        } else if (from == CH_UTF16LE && to != CH_UTF16LE) {
                const unsigned char *p = (const unsigned char *)src;
                unsigned char *q = (unsigned char *)dest;
                size_t retval = 0;
                size_t slen = srclen;
                size_t dlen = destlen;
                unsigned char lastp = '\0';

                /* If all characters are ascii, fast path here. */
                while (((slen == (size_t)-1) || (slen >= 2)) && dlen) {
                        if (((lastp = *p) <= 0x7f) && (p[1] == 0)) {
                                *q++ = *p;
                                if (slen != (size_t)-1) {
                                        slen -= 2;
                                }
                                p += 2;
                                dlen--;
                                retval++;
                                if (!lastp)
                                        break;
                        } else {
#ifdef BROKEN_UNICODE_COMPOSE_CHARACTERS
                                goto general_case;
#else
                                return retval + convert_string_internal(from, to, p, slen, q, dlen, allow_bad_conv);
#endif
                        }
                }
                if (!dlen) {
                        /* Even if we fast path we should note if we ran out of room. */
                        if (((slen != (size_t)-1) && slen) ||
                                        ((slen == (size_t)-1) && lastp)) {
                                errno = E2BIG;
                        }
                }
                return retval;
        } else if (from != CH_UTF16LE && from != CH_UTF16BE && to == CH_UTF16LE) {
                const unsigned char *p = (const unsigned char *)src;
                unsigned char *q = (unsigned char *)dest;
                size_t retval = 0;
                size_t slen = srclen;
                size_t dlen = destlen;
                unsigned char lastp = '\0';

                /* If all characters are ascii, fast path here. */
                while (slen && (dlen >= 2)) {
                        if ((lastp = *p) <= 0x7F) {
                                *q++ = *p++;
                                *q++ = '\0';
                                if (slen != (size_t)-1) {
                                        slen--;
                                }
                                dlen -= 2;
                                retval += 2;
                                if (!lastp)
                                        break;
                        } else {
#ifdef BROKEN_UNICODE_COMPOSE_CHARACTERS
                                goto general_case;
#else
                                return retval + convert_string_internal(from, to, p, slen, q, dlen, allow_bad_conv);
#endif
                        }
                }
                if (!dlen) {
                        /* Even if we fast path we should note if we ran out of room. */
                        if (((slen != (size_t)-1) && slen) ||
                                        ((slen == (size_t)-1) && lastp)) {
                                errno = E2BIG;
                        }
                }
                return retval;
        }

#ifdef BROKEN_UNICODE_COMPOSE_CHARACTERS
  general_case:
#endif
        return convert_string_internal(from, to, src, srclen, dest, destlen, allow_bad_conv);
}

/**
 * Convert between character sets, allocating a new buffer for the result.
 *
 * @param ctx TALLOC_CTX to use to allocate with. If NULL use malloc.
 * @param srclen length of source buffer.
 * @param dest always set at least to NULL
 * @note -1 is not accepted for srclen.
 *
 * @returns Size in bytes of the converted string; or -1 in case of error.
 *
 * Ensure the srclen contains the terminating zero.
 * 
 * I hate the goto's in this function. It's embarressing.....
 * There has to be a cleaner way to do this. JRA.
 **/

size_t convert_string_allocate(TALLOC_CTX *ctx, charset_t from, charset_t to,
                               void const *src, size_t srclen, void *dst, BOOL allow_bad_conv)
{
        size_t i_len, o_len, destlen = MAX(srclen, 512);
        size_t retval;
        const char *inbuf = (const char *)src;
        char *outbuf = NULL, *ob = NULL;
        smb_iconv_t descriptor;
        void **dest = (void **)dst;

        *dest = NULL;

        if (src == NULL || srclen == (size_t)-1)
                return (size_t)-1;
        if (srclen == 0)
                return 0;

        lazy_initialize_conv();

        descriptor = conv_handles[from][to];

        if (descriptor == (smb_iconv_t)-1 || descriptor == (smb_iconv_t)0) {
                if (!conv_silent)
                        DEBUG(0,("convert_string_allocate: Conversion not supported.\n"));
                return (size_t)-1;
        }

  convert:

        if ((destlen*2) < destlen) {
                /* wrapped ! abort. */
                if (!conv_silent)
                        DEBUG(0, ("convert_string_allocate: destlen wrapped !\n"));
                if (!ctx)
                        SAFE_FREE(outbuf);
                return (size_t)-1;
        } else {
                destlen = destlen * 2;
        }

        if (ctx) {
                ob = (char *)TALLOC_REALLOC(ctx, ob, destlen);
        } else {
                ob = (char *)SMB_REALLOC(ob, destlen);
        }

        if (!ob) {
                DEBUG(0, ("convert_string_allocate: realloc failed!\n"));
                return (size_t)-1;
        }
        outbuf = ob;
        i_len = srclen;
        o_len = destlen;

 again:

        retval = smb_iconv(descriptor,
                           &inbuf, &i_len,
                           &outbuf, &o_len);
        if(retval == (size_t)-1)                {
                const char *reason="unknown error";
                switch(errno) {
                        case EINVAL:
                                reason="Incomplete multibyte sequence";
                                if (!conv_silent)
                                        DEBUG(3,("convert_string_allocate: Conversion error: %s(%s)\n",reason,inbuf));
                                if (allow_bad_conv)
                                        goto use_as_is;
                                break;
                        case E2BIG:
                                goto convert;           
                        case EILSEQ:
                                reason="Illegal multibyte sequence";
                                if (!conv_silent)
                                        DEBUG(3,("convert_string_allocate: Conversion error: %s(%s)\n",reason,inbuf));
                                if (allow_bad_conv)
                                        goto use_as_is;
                                break;
                }
                if (!conv_silent)
                        DEBUG(0,("Conversion error: %s(%s)\n",reason,inbuf));
                /* smb_panic(reason); */
                return (size_t)-1;
        }

  out:

        destlen = destlen - o_len;
        if (ctx) {
                ob = (char *)TALLOC_REALLOC(ctx,ob,destlen);
        } else {
                ob = (char *)SMB_REALLOC(ob,destlen);
        }

        if (destlen && !ob) {
                DEBUG(0, ("convert_string_allocate: out of memory!\n"));
                return (size_t)-1;
        }

        *dest = ob;
        return destlen;

 use_as_is:

        /* 
         * Conversion not supported. This is actually an error, but there are so
         * many misconfigured iconv systems and smb.conf's out there we can't just
         * fail. Do a very bad conversion instead.... JRA.
         */

        {
                if (o_len == 0 || i_len == 0)
                        goto out;

                if (((from == CH_UTF16LE)||(from == CH_UTF16BE)) &&
                                ((to != CH_UTF16LE)||(to != CH_UTF16BE))) {
                        /* Can't convert from utf16 any endian to multibyte.
                           Replace with the default fail char.
                        */

                        if (i_len < 2)
                                goto out;

                        if (i_len >= 2) {
                                *outbuf = lp_failed_convert_char();

                                outbuf++;
                                o_len--;

                                inbuf += 2;
                                i_len -= 2;
                        }

                        if (o_len == 0 || i_len == 0)
                                goto out;

                        /* Keep trying with the next char... */
                        goto again;

                } else if (from != CH_UTF16LE && from != CH_UTF16BE && to == CH_UTF16LE) {
                        /* Can't convert to UTF16LE - just widen by adding the
                           default fail char then zero.
                        */
                        if (o_len < 2)
                                goto out;

                        outbuf[0] = lp_failed_convert_char();
                        outbuf[1] = '\0';

                        inbuf++;
                        i_len--;

                        outbuf += 2;
                        o_len -= 2;

                        if (o_len == 0 || i_len == 0)
                                goto out;

                        /* Keep trying with the next char... */
                        goto again;

                } else if (from != CH_UTF16LE && from != CH_UTF16BE &&
                                to != CH_UTF16LE && to != CH_UTF16BE) {
                        /* Failed multibyte to multibyte. Just copy the default fail char and
                           try again. */
                        outbuf[0] = lp_failed_convert_char();

                        inbuf++;
                        i_len--;

                        outbuf++;
                        o_len--;

                        if (o_len == 0 || i_len == 0)
                                goto out;

                        /* Keep trying with the next char... */
                        goto again;

                } else {
                        /* Keep compiler happy.... */
                        goto out;
                }
        }
}

/**
 * Convert between character sets, allocating a new buffer using talloc for the result.
 *
 * @param srclen length of source buffer.
 * @param dest always set at least to NULL 
 * @note -1 is not accepted for srclen.
 *
 * @returns Size in bytes of the converted string; or -1 in case of error.
 **/
size_t convert_string_talloc(TALLOC_CTX *ctx, charset_t from, charset_t to,
                             void const *src, size_t srclen, void *dst,
                             BOOL allow_bad_conv)
{
        void **dest = (void **)dst;
        size_t dest_len;

        *dest = NULL;
        dest_len=convert_string_allocate(ctx, from, to, src, srclen, dest, allow_bad_conv);
        if (dest_len == (size_t)-1)
                return (size_t)-1;
        if (*dest == NULL)
                return (size_t)-1;
        return dest_len;
}

size_t unix_strupper(const char *src, size_t srclen, char *dest, size_t destlen)
{
        size_t size;
        smb_ucs2_t *buffer;
        
        size = push_ucs2_allocate(&buffer, src);
        if (size == (size_t)-1) {
                smb_panic("failed to create UCS2 buffer");
        }
        if (!strupper_w(buffer) && (dest == src)) {
                free(buffer);
                return srclen;
        }
        
        size = convert_string(CH_UTF16LE, CH_UNIX, buffer, size, dest, destlen, True);
        free(buffer);
        return size;
}

/**
 strdup() a unix string to upper case.
 Max size is pstring.
**/

char *strdup_upper(const char *s)
{
        pstring out_buffer;
        const unsigned char *p = (const unsigned char *)s;
        unsigned char *q = (unsigned char *)out_buffer;

        /* this is quite a common operation, so we want it to be
           fast. We optimise for the ascii case, knowing that all our
           supported multi-byte character sets are ascii-compatible
           (ie. they match for the first 128 chars) */

        while (1) {
                if (*p & 0x80)
                        break;
                *q++ = toupper_ascii(*p);
                if (!*p)
                        break;
                p++;
                if (p - ( const unsigned char *)s >= sizeof(pstring))
                        break;
        }

        if (*p) {
                /* MB case. */
                size_t size;
                wpstring buffer;
                size = convert_string(CH_UNIX, CH_UTF16LE, s, -1, buffer, sizeof(buffer), True);
                if (size == (size_t)-1) {
                        return NULL;
                }

                strupper_w(buffer);
        
                size = convert_string(CH_UTF16LE, CH_UNIX, buffer, -1, out_buffer, sizeof(out_buffer), True);
                if (size == (size_t)-1) {
                        return NULL;
                }
        }

        return SMB_STRDUP(out_buffer);
}

size_t unix_strlower(const char *src, size_t srclen, char *dest, size_t destlen)
{
        size_t size;
        smb_ucs2_t *buffer = NULL;
        
        size = convert_string_allocate(NULL, CH_UNIX, CH_UTF16LE, src, srclen,
                                       (void **)(void *)&buffer, True);
        if (size == (size_t)-1 || !buffer) {
                smb_panic("failed to create UCS2 buffer");
        }
        if (!strlower_w(buffer) && (dest == src)) {
                SAFE_FREE(buffer);
                return srclen;
        }
        size = convert_string(CH_UTF16LE, CH_UNIX, buffer, size, dest, destlen, True);
        SAFE_FREE(buffer);
        return size;
}

/**
 strdup() a unix string to lower case.
**/

char *strdup_lower(const char *s)
{
        size_t size;
        smb_ucs2_t *buffer = NULL;
        char *out_buffer;
        
        size = push_ucs2_allocate(&buffer, s);
        if (size == -1 || !buffer) {
                return NULL;
        }

        strlower_w(buffer);
        
        size = pull_ucs2_allocate(&out_buffer, buffer);
        SAFE_FREE(buffer);

        if (size == (size_t)-1) {
                return NULL;
        }
        
        return out_buffer;
}

static size_t ucs2_align(const void *base_ptr, const void *p, int flags)
{
        if (flags & (STR_NOALIGN|STR_ASCII))
                return 0;
        return PTR_DIFF(p, base_ptr) & 1;
}


/**
 * Copy a string from a char* unix src to a dos codepage string destination.
 *
 * @return the number of bytes occupied by the string in the destination.
 *
 * @param flags can include
 * <dl>
 * <dt>STR_TERMINATE</dt> <dd>means include the null termination</dd>
 * <dt>STR_UPPER</dt> <dd>means uppercase in the destination</dd>
 * </dl>
 *
 * @param dest_len the maximum length in bytes allowed in the
 * destination.  If @p dest_len is -1 then no maximum is used.
 **/
size_t push_ascii(void *dest, const char *src, size_t dest_len, int flags)
{
        size_t src_len = strlen(src);
        pstring tmpbuf;

        /* treat a pstring as "unlimited" length */
        if (dest_len == (size_t)-1)
                dest_len = sizeof(pstring);

        if (flags & STR_UPPER) {
                pstrcpy(tmpbuf, src);
                strupper_m(tmpbuf);
                src = tmpbuf;
        }

        if (flags & (STR_TERMINATE | STR_TERMINATE_ASCII))
                src_len++;

        return convert_string(CH_UNIX, CH_DOS, src, src_len, dest, dest_len, True);
}

size_t push_ascii_fstring(void *dest, const char *src)
{
        return push_ascii(dest, src, sizeof(fstring), STR_TERMINATE);
}

size_t push_ascii_pstring(void *dest, const char *src)
{
        return push_ascii(dest, src, sizeof(pstring), STR_TERMINATE);
}

/********************************************************************
 Push an nstring - ensure null terminated. Written by
 moriyama@miraclelinux.com (MORIYAMA Masayuki).
********************************************************************/

size_t push_ascii_nstring(void *dest, const char *src)
{
        size_t i, buffer_len, dest_len;
        smb_ucs2_t *buffer;

        conv_silent = True;
        buffer_len = push_ucs2_allocate(&buffer, src);
        if (buffer_len == (size_t)-1) {
                smb_panic("failed to create UCS2 buffer");
        }

        /* We're using buffer_len below to count ucs2 characters, not bytes. */
        buffer_len /= sizeof(smb_ucs2_t);

        dest_len = 0;
        for (i = 0; buffer[i] != 0 && (i < buffer_len); i++) {
                unsigned char mb[10];
                /* Convert one smb_ucs2_t character at a time. */
                size_t mb_len = convert_string(CH_UTF16LE, CH_DOS, buffer+i, sizeof(smb_ucs2_t), mb, sizeof(mb), False);
                if ((mb_len != (size_t)-1) && (dest_len + mb_len <= MAX_NETBIOSNAME_LEN - 1)) {
                        memcpy((char *)dest + dest_len, mb, mb_len);
                        dest_len += mb_len;
                } else {
                        errno = E2BIG;
                        break;
                }
        }
        ((char *)dest)[dest_len] = '\0';

        SAFE_FREE(buffer);
        conv_silent = False;
        return dest_len;
}

/**
 * Copy a string from a dos codepage source to a unix char* destination.
 *
 * The resulting string in "dest" is always null terminated.
 *
 * @param flags can have:
 * <dl>
 * <dt>STR_TERMINATE</dt>
 * <dd>STR_TERMINATE means the string in @p src
 * is null terminated, and src_len is ignored.</dd>
 * </dl>
 *
 * @param src_len is the length of the source area in bytes.
 * @returns the number of bytes occupied by the string in @p src.
 **/
size_t pull_ascii(char *dest, const void *src, size_t dest_len, size_t src_len, int flags)
{
        size_t ret;

        if (dest_len == (size_t)-1)
                dest_len = sizeof(pstring);

        if (flags & STR_TERMINATE) {
                if (src_len == (size_t)-1) {
                        src_len = strlen((const char *)src) + 1;
                } else {
                        size_t len = strnlen((const char *)src, src_len);
                        if (len < src_len)
                                len++;
                        src_len = len;
                }
        }

        ret = convert_string(CH_DOS, CH_UNIX, src, src_len, dest, dest_len, True);
        if (ret == (size_t)-1) {
                dest_len = 0;
        }

        if (dest_len)
                dest[MIN(ret, dest_len-1)] = 0;
        else 
                dest[0] = 0;

        return src_len;
}

size_t pull_ascii_pstring(char *dest, const void *src)
{
        return pull_ascii(dest, src, sizeof(pstring), -1, STR_TERMINATE);
}

size_t pull_ascii_fstring(char *dest, const void *src)
{
        return pull_ascii(dest, src, sizeof(fstring), -1, STR_TERMINATE);
}

/* When pulling an nstring it can expand into a larger size (dos cp -> utf8). Cope with this. */

size_t pull_ascii_nstring(char *dest, size_t dest_len, const void *src)
{
        return pull_ascii(dest, src, dest_len, sizeof(nstring)-1, STR_TERMINATE);
}

/**
 * Copy a string from a char* src to a unicode destination.
 *
 * @returns the number of bytes occupied by the string in the destination.
 *
 * @param flags can have:
 *
 * <dl>
 * <dt>STR_TERMINATE <dd>means include the null termination.
 * <dt>STR_UPPER     <dd>means uppercase in the destination.
 * <dt>STR_NOALIGN   <dd>means don't do alignment.
 * </dl>
 *
 * @param dest_len is the maximum length allowed in the
 * destination. If dest_len is -1 then no maxiumum is used.
 **/

size_t push_ucs2(const void *base_ptr, void *dest, const char *src, size_t dest_len, int flags)
{
        size_t len=0;
        size_t src_len;
        size_t ret;

        /* treat a pstring as "unlimited" length */
        if (dest_len == (size_t)-1)
                dest_len = sizeof(pstring);

        if (flags & STR_TERMINATE)
                src_len = (size_t)-1;
        else
                src_len = strlen(src);

        if (ucs2_align(base_ptr, dest, flags)) {
                *(char *)dest = 0;
                dest = (void *)((char *)dest + 1);
                if (dest_len)
                        dest_len--;
                len++;
        }

        /* ucs2 is always a multiple of 2 bytes */
        dest_len &= ~1;

        ret =  convert_string(CH_UNIX, CH_UTF16LE, src, src_len, dest, dest_len, True);
        if (ret == (size_t)-1) {
                return 0;
        }

        len += ret;

        if (flags & STR_UPPER) {
                smb_ucs2_t *dest_ucs2 = (smb_ucs2_t *)dest;
                size_t i;

                /* We check for i < (ret / 2) below as the dest string isn't null
                   terminated if STR_TERMINATE isn't set. */

                for (i = 0; i < (ret / 2) && i < (dest_len / 2) && dest_ucs2[i]; i++) {
                        smb_ucs2_t v = toupper_w(dest_ucs2[i]);
                        if (v != dest_ucs2[i]) {
                                dest_ucs2[i] = v;
                        }
                }
        }

        return len;
}


/**
 * Copy a string from a unix char* src to a UCS2 destination,
 * allocating a buffer using talloc().
 *
 * @param dest always set at least to NULL 
 *
 * @returns The number of bytes occupied by the string in the destination
 *         or -1 in case of error.
 **/
size_t push_ucs2_talloc(TALLOC_CTX *ctx, smb_ucs2_t **dest, const char *src)
{
        size_t src_len = strlen(src)+1;

        *dest = NULL;
        return convert_string_talloc(ctx, CH_UNIX, CH_UTF16LE, src, src_len, (void **)dest, True);
}


/**
 * Copy a string from a unix char* src to a UCS2 destination, allocating a buffer
 *
 * @param dest always set at least to NULL 
 *
 * @returns The number of bytes occupied by the string in the destination
 *         or -1 in case of error.
 **/

size_t push_ucs2_allocate(smb_ucs2_t **dest, const char *src)
{
        size_t src_len = strlen(src)+1;

        *dest = NULL;
        return convert_string_allocate(NULL, CH_UNIX, CH_UTF16LE, src, src_len, (void **)dest, True);
}

/**
 Copy a string from a char* src to a UTF-8 destination.
 Return the number of bytes occupied by the string in the destination
 Flags can have:
  STR_TERMINATE means include the null termination
  STR_UPPER     means uppercase in the destination
 dest_len is the maximum length allowed in the destination. If dest_len
 is -1 then no maxiumum is used.
**/

static size_t push_utf8(void *dest, const char *src, size_t dest_len, int flags)
{
        size_t src_len = strlen(src);
        pstring tmpbuf;

        /* treat a pstring as "unlimited" length */
        if (dest_len == (size_t)-1)
                dest_len = sizeof(pstring);

        if (flags & STR_UPPER) {
                pstrcpy(tmpbuf, src);
                strupper_m(tmpbuf);
                src = tmpbuf;
        }

        if (flags & STR_TERMINATE)
                src_len++;

        return convert_string(CH_UNIX, CH_UTF8, src, src_len, dest, dest_len, True);
}

size_t push_utf8_fstring(void *dest, const char *src)
{
        return push_utf8(dest, src, sizeof(fstring), STR_TERMINATE);
}

/**
 * Copy a string from a unix char* src to a UTF-8 destination, allocating a buffer using talloc
 *
 * @param dest always set at least to NULL 
 *
 * @returns The number of bytes occupied by the string in the destination
 **/

size_t push_utf8_talloc(TALLOC_CTX *ctx, char **dest, const char *src)
{
        size_t src_len = strlen(src)+1;

        *dest = NULL;
        return convert_string_talloc(ctx, CH_UNIX, CH_UTF8, src, src_len, (void**)dest, True);
}

/**
 * Copy a string from a unix char* src to a UTF-8 destination, allocating a buffer
 *
 * @param dest always set at least to NULL 
 *
 * @returns The number of bytes occupied by the string in the destination
 **/

size_t push_utf8_allocate(char **dest, const char *src)
{
        size_t src_len = strlen(src)+1;

        *dest = NULL;
        return convert_string_allocate(NULL, CH_UNIX, CH_UTF8, src, src_len, (void **)dest, True);      
}

/**
 Copy a string from a ucs2 source to a unix char* destination.
 Flags can have:
  STR_TERMINATE means the string in src is null terminated.
  STR_NOALIGN   means don't try to align.
 if STR_TERMINATE is set then src_len is ignored if it is -1.
 src_len is the length of the source area in bytes
 Return the number of bytes occupied by the string in src.
 The resulting string in "dest" is always null terminated.
**/

size_t pull_ucs2(const void *base_ptr, char *dest, const void *src, size_t dest_len, size_t src_len, int flags)
{
        size_t ret;

        if (dest_len == (size_t)-1)
                dest_len = sizeof(pstring);

        if (ucs2_align(base_ptr, src, flags)) {
                src = (const void *)((const char *)src + 1);
                if (src_len != (size_t)-1)
                        src_len--;
        }

        if (flags & STR_TERMINATE) {
                /* src_len -1 is the default for null terminated strings. */
                if (src_len != (size_t)-1) {
                        size_t len = strnlen_w((const smb_ucs2_t *)src,
                                                src_len/2);
                        if (len < src_len/2)
                                len++;
                        src_len = len*2;
                }
        }

        /* ucs2 is always a multiple of 2 bytes */
        if (src_len != (size_t)-1)
                src_len &= ~1;
        
        ret = convert_string(CH_UTF16LE, CH_UNIX, src, src_len, dest, dest_len, True);
        if (ret == (size_t)-1) {
                return 0;
        }

        if (src_len == (size_t)-1)
                src_len = ret*2;
                
        if (dest_len)
                dest[MIN(ret, dest_len-1)] = 0;
        else 
                dest[0] = 0;

        return src_len;
}

size_t pull_ucs2_pstring(char *dest, const void *src)
{
        return pull_ucs2(NULL, dest, src, sizeof(pstring), -1, STR_TERMINATE);
}

size_t pull_ucs2_fstring(char *dest, const void *src)
{
        return pull_ucs2(NULL, dest, src, sizeof(fstring), -1, STR_TERMINATE);
}

/**
 * Copy a string from a UCS2 src to a unix char * destination, allocating a buffer using talloc
 *
 * @param dest always set at least to NULL 
 *
 * @returns The number of bytes occupied by the string in the destination
 **/

size_t pull_ucs2_talloc(TALLOC_CTX *ctx, char **dest, const smb_ucs2_t *src)
{
        size_t src_len = (strlen_w(src)+1) * sizeof(smb_ucs2_t);
        *dest = NULL;
        return convert_string_talloc(ctx, CH_UTF16LE, CH_UNIX, src, src_len, (void **)dest, True);
}

/**
 * Copy a string from a UCS2 src to a unix char * destination, allocating a buffer
 *
 * @param dest always set at least to NULL 
 *
 * @returns The number of bytes occupied by the string in the destination
 **/

size_t pull_ucs2_allocate(char **dest, const smb_ucs2_t *src)
{
        size_t src_len = (strlen_w(src)+1) * sizeof(smb_ucs2_t);
        *dest = NULL;
        return convert_string_allocate(NULL, CH_UTF16LE, CH_UNIX, src, src_len, (void **)dest, True);
}

/**
 * Copy a string from a UTF-8 src to a unix char * destination, allocating a buffer using talloc
 *
 * @param dest always set at least to NULL 
 *
 * @returns The number of bytes occupied by the string in the destination
 **/

size_t pull_utf8_talloc(TALLOC_CTX *ctx, char **dest, const char *src)
{
        size_t src_len = strlen(src)+1;
        *dest = NULL;
        return convert_string_talloc(ctx, CH_UTF8, CH_UNIX, src, src_len, (void **)dest, True);
}

/**
 * Copy a string from a UTF-8 src to a unix char * destination, allocating a buffer
 *
 * @param dest always set at least to NULL 
 *
 * @returns The number of bytes occupied by the string in the destination
 **/

size_t pull_utf8_allocate(char **dest, const char *src)
{
        size_t src_len = strlen(src)+1;
        *dest = NULL;
        return convert_string_allocate(NULL, CH_UTF8, CH_UNIX, src, src_len, (void **)dest, True);
}
 
/**
 * Copy a string from a DOS src to a unix char * destination, allocating a buffer using talloc
 *
 * @param dest always set at least to NULL 
 *
 * @returns The number of bytes occupied by the string in the destination
 **/

size_t pull_ascii_talloc(TALLOC_CTX *ctx, char **dest, const char *src)
{
        size_t src_len = strlen(src)+1;
        *dest = NULL;
        return convert_string_talloc(ctx, CH_DOS, CH_UNIX, src, src_len, (void **)dest, True);
}

/**
 Copy a string from a char* src to a unicode or ascii
 dos codepage destination choosing unicode or ascii based on the 
 flags in the SMB buffer starting at base_ptr.
 Return the number of bytes occupied by the string in the destination.
 flags can have:
  STR_TERMINATE means include the null termination.
  STR_UPPER     means uppercase in the destination.
  STR_ASCII     use ascii even with unicode packet.
  STR_NOALIGN   means don't do alignment.
 dest_len is the maximum length allowed in the destination. If dest_len
 is -1 then no maxiumum is used.
**/

size_t push_string_fn(const char *function, unsigned int line, const void *base_ptr, void *dest, const char *src, size_t dest_len, int flags)
{
#ifdef DEVELOPER
        /* We really need to zero fill here, not clobber
         * region, as we want to ensure that valgrind thinks
         * all of the outgoing buffer has been written to
         * so a send() or write() won't trap an error.
         * JRA.
         */
#if 0
        if (dest_len != (size_t)-1)
                clobber_region(function, line, dest, dest_len);
#else
        if (dest_len != (size_t)-1)
                memset(dest, '\0', dest_len);
#endif
#endif

        if (!(flags & STR_ASCII) && \
            ((flags & STR_UNICODE || \
              (SVAL(base_ptr, smb_flg2) & FLAGS2_UNICODE_STRINGS)))) {
                return push_ucs2(base_ptr, dest, src, dest_len, flags);
        }
        return push_ascii(dest, src, dest_len, flags);
}


/**
 Copy a string from a unicode or ascii source (depending on
 the packet flags) to a char* destination.
 Flags can have:
  STR_TERMINATE means the string in src is null terminated.
  STR_UNICODE   means to force as unicode.
  STR_ASCII     use ascii even with unicode packet.
  STR_NOALIGN   means don't do alignment.
 if STR_TERMINATE is set then src_len is ignored is it is -1
 src_len is the length of the source area in bytes.
 Return the number of bytes occupied by the string in src.
 The resulting string in "dest" is always null terminated.
**/

size_t pull_string_fn(const char *function, unsigned int line, const void *base_ptr, char *dest, const void *src, size_t dest_len, size_t src_len, int flags)
{
#ifdef DEVELOPER
        if (dest_len != (size_t)-1)
                clobber_region(function, line, dest, dest_len);
#endif

        if (!(flags & STR_ASCII) && \
            ((flags & STR_UNICODE || \
              (SVAL(base_ptr, smb_flg2) & FLAGS2_UNICODE_STRINGS)))) {
                return pull_ucs2(base_ptr, dest, src, dest_len, src_len, flags);
        }
        return pull_ascii(dest, src, dest_len, src_len, flags);
}

size_t align_string(const void *base_ptr, const char *p, int flags)
{
        if (!(flags & STR_ASCII) && \
            ((flags & STR_UNICODE || \
              (SVAL(base_ptr, smb_flg2) & FLAGS2_UNICODE_STRINGS)))) {
                return ucs2_align(base_ptr, p, flags);
        }
        return 0;
}

/*
  Return the unicode codepoint for the next multi-byte CH_UNIX character
  in the string. The unicode codepoint (codepoint_t) is an unsinged 32 bit value.

  Also return the number of bytes consumed (which tells the caller
  how many bytes to skip to get to the next CH_UNIX character).

  Return INVALID_CODEPOINT if the next character cannot be converted.
*/

codepoint_t next_codepoint(const char *str, size_t *size)
{
        /* It cannot occupy more than 4 bytes in UTF16 format */
        uint8_t buf[4];
        smb_iconv_t descriptor;
        size_t ilen_orig;
        size_t ilen;
        size_t olen;
        char *outbuf;

        if ((str[0] & 0x80) == 0) {
                *size = 1;
                return (codepoint_t)str[0];
        }

        /* We assume that no multi-byte character can take
           more than 5 bytes. This is OK as we only
           support codepoints up to 1M */

        ilen_orig = strnlen(str, 5);
        ilen = ilen_orig;

        lazy_initialize_conv();

        descriptor = conv_handles[CH_UNIX][CH_UTF16LE];
        if (descriptor == (smb_iconv_t)-1 || descriptor == (smb_iconv_t)0) {
                *size = 1;
                return INVALID_CODEPOINT;
        }

        /* This looks a little strange, but it is needed to cope
           with codepoints above 64k which are encoded as per RFC2781. */
        olen = 2;
        outbuf = (char *)buf;
        smb_iconv(descriptor, &str, &ilen, &outbuf, &olen);
        if (olen == 2) {
                /* We failed to convert to a 2 byte character.
                   See if we can convert to a 4 UTF16-LE byte char encoding.
                */
                olen = 4;
                outbuf = (char *)buf;
                smb_iconv(descriptor,  &str, &ilen, &outbuf, &olen);
                if (olen == 4) {
                        /* We didn't convert any bytes */
                        *size = 1;
                        return INVALID_CODEPOINT;
                }
                olen = 4 - olen;
        } else {
                olen = 2 - olen;
        }

        *size = ilen_orig - ilen;

        if (olen == 2) {
                /* 2 byte, UTF16-LE encoded value. */
                return (codepoint_t)SVAL(buf, 0);
        }
        if (olen == 4) {
                /* Decode a 4 byte UTF16-LE character manually.
                   See RFC2871 for the encoding machanism.
                */
                codepoint_t w1 = SVAL(buf,0) & ~0xD800;
                codepoint_t w2 = SVAL(buf,2) & ~0xDC00;

                return (codepoint_t)0x10000 +
                                (w1 << 10) + w2;
        }

        /* no other length is valid */
        return INVALID_CODEPOINT;
}