Move charset library to top level.

1 files changed, 768 insertions, 0 deletions

diff --git a/lib/util/charset/charcnv.c b/lib/util/charset/charcnv.c
new file mode 100644
index 0000000000..3e384304cf
--- /dev/null
+++ b/lib/util/charset/charcnv.c
@@ -0,0 +1,768 @@
+/* 
+   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) Jelmer Vernooij 2007
+   
+   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 3 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, see <http://www.gnu.org/licenses/>.
+
+*/
+#include "includes.h"
+#include "system/iconv.h"
+#include "param/param.h"
+
+/**
+ * @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
+ */
+
+struct smb_iconv_convenience {
+	const char *unix_charset;
+	const char *dos_charset;
+	bool native_iconv;
+	smb_iconv_t conv_handles[NUM_CHARSETS][NUM_CHARSETS];
+};
+
+
+/**
+ * Return the name of a charset to give to iconv().
+ **/
+static const char *charset_name(struct smb_iconv_convenience *ic, charset_t ch)
+{
+	switch (ch) {
+	case CH_UTF16: return "UTF-16LE";
+	case CH_UNIX: return ic->unix_charset;
+	case CH_DOS: return ic->dos_charset;
+	case CH_UTF8: return "UTF8";
+	case CH_UTF16BE: return "UTF-16BE";
+	default:
+	return "ASCII";
+	}
+}
+
+/**
+ re-initialize iconv conversion descriptors
+**/
+static int close_iconv(struct smb_iconv_convenience *data)
+{
+	unsigned c1, c2;
+	for (c1=0;c1<NUM_CHARSETS;c1++) {
+		for (c2=0;c2<NUM_CHARSETS;c2++) {
+			if (data->conv_handles[c1][c2] != NULL) {
+				if (data->conv_handles[c1][c2] != (smb_iconv_t)-1) {
+					smb_iconv_close(data->conv_handles[c1][c2]);
+				}
+				data->conv_handles[c1][c2] = NULL;
+			}
+		}
+	}
+
+	return 0;
+}
+
+_PUBLIC_ struct smb_iconv_convenience *smb_iconv_convenience_init(TALLOC_CTX *mem_ctx,
+							 const char *dos_charset,
+							 const char *unix_charset,
+							 bool native_iconv)
+{
+	struct smb_iconv_convenience *ret = talloc_zero(mem_ctx, 
+					struct smb_iconv_convenience);
+
+	if (ret == NULL) {
+		return NULL;
+	}
+
+	talloc_set_destructor(ret, close_iconv);
+
+	ret->dos_charset = talloc_strdup(ret, dos_charset);
+	ret->unix_charset = talloc_strdup(ret, unix_charset);
+	ret->native_iconv = native_iconv;
+
+	return ret;
+}
+
+/*
+  on-demand initialisation of conversion handles
+*/
+static smb_iconv_t get_conv_handle(struct smb_iconv_convenience *ic,
+				   charset_t from, charset_t to)
+{
+	const char *n1, *n2;
+	static bool initialised;
+
+	if (initialised == false) {
+		initialised = true;
+		
+#ifdef LC_ALL
+		/* we set back the locale to C to get ASCII-compatible
+		   toupper/lower functions.  For now we do not need
+		   any other POSIX localisations anyway. When we
+		   should really need localized string functions one
+		   day we need to write our own ascii_tolower etc.
+		*/
+		setlocale(LC_ALL, "C");
+#endif
+	}
+
+	if (ic->conv_handles[from][to]) {
+		return ic->conv_handles[from][to];
+	}
+
+	n1 = charset_name(ic, from);
+	n2 = charset_name(ic, to);
+
+	ic->conv_handles[from][to] = smb_iconv_open_ex(ic, n2, n1, 
+						       ic->native_iconv);
+	
+	if (ic->conv_handles[from][to] == (smb_iconv_t)-1) {
+		if ((from == CH_DOS || to == CH_DOS) &&
+		    strcasecmp(charset_name(ic, CH_DOS), "ASCII") != 0) {
+			DEBUG(0,("dos charset '%s' unavailable - using ASCII\n",
+				 charset_name(ic, CH_DOS)));
+			ic->dos_charset = "ASCII";
+
+			n1 = charset_name(ic, from);
+			n2 = charset_name(ic, to);
+			
+			ic->conv_handles[from][to] = 
+				smb_iconv_open_ex(ic, n2, n1, ic->native_iconv);
+		}
+	}
+
+	return ic->conv_handles[from][to];
+}
+
+
+/**
+ * Convert string from one encoding to another, making error checking etc
+ *
+ * @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
+ * @returns the number of bytes occupied in the destination
+ **/
+_PUBLIC_ ssize_t convert_string(struct smb_iconv_convenience *ic,
+				charset_t from, charset_t to,
+				void const *src, size_t srclen, 
+				void *dest, size_t destlen)
+{
+	size_t i_len, o_len;
+	size_t retval;
+	const char* inbuf = (const char*)src;
+	char* outbuf = (char*)dest;
+	smb_iconv_t descriptor;
+
+	if (srclen == (size_t)-1)
+		srclen = strlen(inbuf)+1;
+
+	descriptor = get_conv_handle(ic, from, to);
+
+	if (descriptor == (smb_iconv_t)-1 || descriptor == (smb_iconv_t)0) {
+		/* conversion not supported, use as is */
+		size_t len = MIN(srclen,destlen);
+		memcpy(dest,src,len);
+		return len;
+	}
+
+	i_len=srclen;
+	o_len=destlen;
+	retval = smb_iconv(descriptor,  &inbuf, &i_len, &outbuf, &o_len);
+	if(retval==(size_t)-1) {
+	    	const char *reason;
+		switch(errno) {
+			case EINVAL:
+				reason="Incomplete multibyte sequence";
+				return -1;
+			case E2BIG:
+				reason="No more room"; 
+				if (from == CH_UNIX) {
+					DEBUG(0,("E2BIG: convert_string(%s,%s): srclen=%d destlen=%d - '%s'\n",
+						 charset_name(ic, from), charset_name(ic, to),
+						 (int)srclen, (int)destlen, 
+						 (const char *)src));
+				} else {
+					DEBUG(0,("E2BIG: convert_string(%s,%s): srclen=%d destlen=%d\n",
+						 charset_name(ic, from), charset_name(ic, to),
+						 (int)srclen, (int)destlen));
+				}
+			       return -1;
+			case EILSEQ:
+			       reason="Illegal multibyte sequence";
+			       return -1;
+		}
+		/* smb_panic(reason); */
+	}
+	return destlen-o_len;
+}
+	
+_PUBLIC_ ssize_t convert_string_talloc_descriptor(TALLOC_CTX *ctx, smb_iconv_t descriptor, void const *src, size_t srclen, void **dest)
+{
+	size_t i_len, o_len, destlen;
+	size_t retval;
+	const char *inbuf = (const char *)src;
+	char *outbuf, *ob;
+
+	*dest = NULL;
+
+	/* it is _very_ rare that a conversion increases the size by
+	   more than 3x */
+	destlen = srclen;
+	outbuf = NULL;
+convert:
+	destlen = 2 + (destlen*3);
+	ob = talloc_realloc(ctx, outbuf, char, destlen);
+	if (!ob) {
+		DEBUG(0, ("convert_string_talloc: realloc failed!\n"));
+		talloc_free(outbuf);
+		return (size_t)-1;
+	} else {
+		outbuf = ob;
+	}
+
+	/* we give iconv 2 less bytes to allow us to terminate at the
+	   end */
+	i_len = srclen;
+	o_len = destlen-2;
+	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";
+				break;
+			case E2BIG:
+				goto convert;		
+			case EILSEQ:
+				reason="Illegal multibyte sequence";
+				break;
+		}
+		DEBUG(0,("Conversion error: %s(%s)\n",reason,inbuf));
+		talloc_free(ob);
+		return (size_t)-1;
+	}
+	
+	destlen = (destlen-2) - o_len;
+
+	/* guarantee null termination in all charsets */
+	SSVAL(ob, destlen, 0);
+
+	*dest = ob;
+
+	return destlen;
+}
+
+/**
+ * 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.
+ **/
+
+_PUBLIC_ ssize_t convert_string_talloc(TALLOC_CTX *ctx, 
+				       struct smb_iconv_convenience *ic, 
+				       charset_t from, charset_t to, 
+				       void const *src, size_t srclen, 
+				       void **dest)
+{
+	smb_iconv_t descriptor;
+
+	*dest = NULL;
+
+	if (src == NULL || srclen == (size_t)-1 || srclen == 0)
+		return (size_t)-1;
+
+	descriptor = get_conv_handle(ic, from, to);
+
+	if (descriptor == (smb_iconv_t)-1 || descriptor == (smb_iconv_t)0) {
+		/* conversion not supported, return -1*/
+		DEBUG(3, ("convert_string_talloc: conversion from %s to %s not supported!\n",
+			  charset_name(ic, from), 
+			  charset_name(ic, to)));
+		return -1;
+	}
+
+	return convert_string_talloc_descriptor(ctx, descriptor, src, srclen, dest);
+}
+
+/**
+ * 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.
+ **/
+static ssize_t push_ascii(struct smb_iconv_convenience *ic, 
+			  void *dest, const char *src, size_t dest_len, int flags)
+{
+	size_t src_len;
+	ssize_t ret;
+
+	if (flags & STR_UPPER) {
+		char *tmpbuf = strupper_talloc(NULL, src);
+		if (tmpbuf == NULL) {
+			return -1;
+		}
+		ret = push_ascii(ic, dest, tmpbuf, dest_len, flags & ~STR_UPPER);
+		talloc_free(tmpbuf);
+		return ret;
+	}
+
+	src_len = strlen(src);
+
+	if (flags & (STR_TERMINATE | STR_TERMINATE_ASCII))
+		src_len++;
+
+	return convert_string(ic, CH_UNIX, CH_DOS, src, src_len, dest, dest_len);
+}
+
+/**
+ * Copy a string from a unix char* src to an ASCII 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.
+ **/
+_PUBLIC_ ssize_t push_ascii_talloc(TALLOC_CTX *ctx, struct smb_iconv_convenience *ic, char **dest, const char *src)
+{
+	size_t src_len = strlen(src)+1;
+	*dest = NULL;
+	return convert_string_talloc(ctx, ic, CH_UNIX, CH_DOS, src, src_len, (void **)dest);
+}
+
+
+/**
+ * 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.
+ **/
+static ssize_t pull_ascii(struct smb_iconv_convenience *ic, char *dest, const void *src, size_t dest_len, size_t src_len, int flags)
+{
+	size_t ret;
+
+	if (flags & (STR_TERMINATE | STR_TERMINATE_ASCII)) {
+		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(ic, CH_DOS, CH_UNIX, src, src_len, dest, dest_len);
+
+	if (dest_len)
+		dest[MIN(ret, dest_len-1)] = 0;
+
+	return src_len;
+}
+
+/**
+ * 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.
+ **/
+static ssize_t push_ucs2(struct smb_iconv_convenience *ic, 
+			 void *dest, const char *src, size_t dest_len, int flags)
+{
+	size_t len=0;
+	size_t src_len = strlen(src);
+	size_t ret;
+
+	if (flags & STR_UPPER) {
+		char *tmpbuf = strupper_talloc(NULL, src);
+		if (tmpbuf == NULL) {
+			return -1;
+		}
+		ret = push_ucs2(ic, dest, tmpbuf, dest_len, flags & ~STR_UPPER);
+		talloc_free(tmpbuf);
+		return ret;
+	}
+
+	if (flags & STR_TERMINATE)
+		src_len++;
+
+	if (ucs2_align(NULL, 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(ic, CH_UNIX, CH_UTF16, src, src_len, dest, dest_len);
+	if (ret == (size_t)-1) {
+		return 0;
+	}
+
+	len += ret;
+
+	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.
+ **/
+_PUBLIC_ ssize_t push_ucs2_talloc(TALLOC_CTX *ctx, struct smb_iconv_convenience *ic, void **dest, const char *src)
+{
+	size_t src_len = strlen(src)+1;
+	*dest = NULL;
+	return convert_string_talloc(ctx, ic, CH_UNIX, CH_UTF16, src, src_len, dest);
+}
+
+
+/**
+ * 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
+ **/
+
+_PUBLIC_ ssize_t push_utf8_talloc(TALLOC_CTX *ctx, struct smb_iconv_convenience *ic, char **dest, const char *src)
+{
+	size_t src_len = strlen(src)+1;
+	*dest = NULL;
+	return convert_string_talloc(ctx, ic, CH_UNIX, CH_UTF8, src, src_len, (void **)dest);
+}
+
+/**
+ 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.
+**/
+
+static size_t pull_ucs2(struct smb_iconv_convenience *ic, char *dest, const void *src, size_t dest_len, size_t src_len, int flags)
+{
+	size_t ret;
+
+	if (ucs2_align(NULL, src, flags)) {
+		src = (const void *)((const char *)src + 1);
+		if (src_len > 0)
+			src_len--;
+	}
+
+	if (flags & STR_TERMINATE) {
+		if (src_len == (size_t)-1) {
+			src_len = utf16_len(src);
+		} else {
+			src_len = utf16_len_n(src, src_len);
+		}
+	}
+
+	/* ucs2 is always a multiple of 2 bytes */
+	if (src_len != (size_t)-1)
+		src_len &= ~1;
+	
+	ret = convert_string(ic, CH_UTF16, CH_UNIX, src, src_len, dest, dest_len);
+	if (dest_len)
+		dest[MIN(ret, dest_len-1)] = 0;
+
+	return src_len;
+}
+
+/**
+ * Copy a string from a ASCII 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
+ **/
+
+_PUBLIC_ ssize_t pull_ascii_talloc(TALLOC_CTX *ctx, struct smb_iconv_convenience *ic, char **dest, const char *src)
+{
+	size_t src_len = strlen(src)+1;
+	*dest = NULL;
+	return convert_string_talloc(ctx, ic, CH_DOS, CH_UNIX, src, src_len, (void **)dest);
+}
+
+/**
+ * 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
+ **/
+
+_PUBLIC_ ssize_t pull_ucs2_talloc(TALLOC_CTX *ctx, struct smb_iconv_convenience *ic, char **dest, const void *src)
+{
+	size_t src_len = utf16_len(src);
+	*dest = NULL;
+	return convert_string_talloc(ctx, ic, CH_UTF16, CH_UNIX, src, src_len, (void **)dest);
+}
+
+/**
+ * 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
+ **/
+
+_PUBLIC_ ssize_t pull_utf8_talloc(TALLOC_CTX *ctx, struct smb_iconv_convenience *ic, char **dest, const char *src)
+{
+	size_t src_len = strlen(src)+1;
+	*dest = NULL;
+	return convert_string_talloc(ctx, ic, CH_UTF8, CH_UNIX, src, src_len, (void **)dest);
+}
+
+/**
+ 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.
+**/
+
+_PUBLIC_ ssize_t push_string(struct smb_iconv_convenience *ic, 
+			     void *dest, const char *src, size_t dest_len, int flags)
+{
+	if (flags & STR_ASCII) {
+		return push_ascii(ic, dest, src, dest_len, flags);
+	} else if (flags & STR_UNICODE) {
+		return push_ucs2(ic, dest, src, dest_len, flags);
+	} else {
+		smb_panic("push_string requires either STR_ASCII or STR_UNICODE flag to be set");
+		return -1;
+	}
+}
+
+
+/**
+ 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.
+**/
+
+_PUBLIC_ ssize_t pull_string(struct smb_iconv_convenience *ic,
+			     char *dest, const void *src, size_t dest_len, size_t src_len, int flags)
+{
+	if (flags & STR_ASCII) {
+		return pull_ascii(ic, dest, src, dest_len, src_len, flags);
+	} else if (flags & STR_UNICODE) {
+		return pull_ucs2(ic, dest, src, dest_len, src_len, flags);
+	} else {
+		smb_panic("pull_string requires either STR_ASCII or STR_UNICODE flag to be set");
+		return -1;
+	}
+}
+
+
+/*
+  return the unicode codepoint for the next multi-byte CH_UNIX character
+  in the string
+
+  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
+*/
+_PUBLIC_ codepoint_t next_codepoint(struct smb_iconv_convenience *ic, 
+				    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;
+
+	descriptor = get_conv_handle(ic, CH_UNIX, CH_UTF16);
+	if (descriptor == (smb_iconv_t)-1) {
+		*size = 1;
+		return INVALID_CODEPOINT;
+	}
+
+	/* this looks a little strange, but it is needed to cope
+	   with codepoints above 64k */
+	olen = 2;
+	outbuf = (char *)buf;
+	smb_iconv(descriptor, &str, &ilen, &outbuf, &olen);
+	if (olen == 2) {
+		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) {
+		return (codepoint_t)SVAL(buf, 0);
+	}
+	if (olen == 4) {
+		/* decode a 4 byte UTF16 character manually */
+		return (codepoint_t)0x10000 + 
+			(buf[2] | ((buf[3] & 0x3)<<8) | 
+			 (buf[0]<<10) | ((buf[1] & 0x3)<<18));
+	}
+
+	/* no other length is valid */
+	return INVALID_CODEPOINT;
+}
+
+/*
+  push a single codepoint into a CH_UNIX string the target string must
+  be able to hold the full character, which is guaranteed if it is at
+  least 5 bytes in size. The caller may pass less than 5 bytes if they
+  are sure the character will fit (for example, you can assume that
+  uppercase/lowercase of a character will not add more than 1 byte)
+
+  return the number of bytes occupied by the CH_UNIX character, or
+  -1 on failure
+*/
+_PUBLIC_ ssize_t push_codepoint(struct smb_iconv_convenience *ic, 
+				char *str, codepoint_t c)
+{
+	smb_iconv_t descriptor;
+	uint8_t buf[4];
+	size_t ilen, olen;
+	const char *inbuf;
+	
+	if (c < 128) {
+		*str = c;
+		return 1;
+	}
+
+	descriptor = get_conv_handle(ic, 
+				     CH_UTF16, CH_UNIX);
+	if (descriptor == (smb_iconv_t)-1) {
+		return -1;
+	}
+
+	if (c < 0x10000) {
+		ilen = 2;
+		olen = 5;
+		inbuf = (char *)buf;
+		SSVAL(buf, 0, c);
+		smb_iconv(descriptor, &inbuf, &ilen, &str, &olen);
+		if (ilen != 0) {
+			return -1;
+		}
+		return 5 - olen;
+	}
+
+	c -= 0x10000;
+
+	buf[0] = (c>>10) & 0xFF;
+	buf[1] = (c>>18) | 0xd8;
+	buf[2] = c & 0xFF;
+	buf[3] = ((c>>8) & 0x3) | 0xdc;
+
+	ilen = 4;
+	olen = 5;
+	inbuf = (char *)buf;
+
+	smb_iconv(descriptor, &inbuf, &ilen, &str, &olen);
+	if (ilen != 0) {
+		return -1;
+	}
+	return 5 - olen;
+}