path: root/lib/util/charset/charcnv.c

/* 
   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 "libcli/smb/smb_common.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
 */

/**
 * Convert string from one encoding to another, making error checking etc
 *
 * @param mem_ctx Memory context
 * @param cd Iconv handle
 * @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 iconv_talloc(TALLOC_CTX *ctx, 
				       smb_iconv_t cd,
				       void const *src, size_t srclen, 
				       void *dst)
{
	size_t i_len, o_len, destlen;
	void **dest = (void **)dst;
	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, ("iconv_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(cd,
			   &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 - ",reason));
		dump_data(0, (const uint8_t *) inbuf, i_len);
		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 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
 * on error, returns -1, and sets errno
 **/
_PUBLIC_ ssize_t convert_string_error(struct smb_iconv_convenience *ic,
				      charset_t from, charset_t to,
				      void const *src, size_t srclen,
				      void *dest, size_t destlen, size_t *converted_size)
{
	size_t i_len, o_len;
	ssize_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) {
		if (converted_size) {
			*converted_size = 0;
		}
		errno = EINVAL;
		return -1;
	}

	i_len=srclen;
	o_len=destlen;

	retval = smb_iconv(descriptor,  &inbuf, &i_len, &outbuf, &o_len);

	if (converted_size != NULL)
		*converted_size = destlen-o_len;
	return retval;
}


/**
 * 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_ bool convert_string_convenience(struct smb_iconv_convenience *ic,
					 charset_t from, charset_t to,
					 void const *src, size_t srclen,
					 void *dest, size_t destlen, size_t *converted_size)
{
	ssize_t retval;

	retval = convert_string_error(ic, from, to, src, srclen, dest, destlen, converted_size);
	if(retval==(size_t)-1) {
	    	const char *reason;
		switch(errno) {
		case EINVAL:
			reason="Incomplete multibyte sequence";
			return false;
		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 false;
		case EILSEQ:
			reason="Illegal multibyte sequence";
			return false;
		default:
			return false;
		}
	}
	return true;
}
	
/**
 * 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_ bool convert_string_talloc_convenience(TALLOC_CTX *ctx, 
						struct smb_iconv_convenience *ic, 
						charset_t from, charset_t to, 
						void const *src, size_t srclen, 
						void *dst, size_t *converted_size)
{
	void **dest = (void **)dst;
	smb_iconv_t descriptor;
	ssize_t ret;

	*dest = NULL;

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

	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 false;
	}

	ret = iconv_talloc(ctx, descriptor, src, srclen, dest);
	if (ret == -1)
		return false;
	if (converted_size != NULL)
		*converted_size = ret;
	return true;
}