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/*

 * This file is part of LibParserUtils.

 * Licensed under the MIT License,

 *                http://www.opensource.org/licenses/mit-license.php

 * Copyright 2008 John-Mark Bell 

 */

#include 

#include 

#include 

#include 

#include "charset/codecs/codec_impl.h"

#include "utils/endian.h"

#include "utils/utils.h"

#include "charset/codecs/ext8_tables.h"

static struct {

	uint16_t mib;

	const char *name;

	size_t len;

	uint32_t *table;

} known_charsets[] = {

	{ 0, "Windows-1250", SLEN("Windows-1250"), w1250 },

	{ 0, "Windows-1251", SLEN("Windows-1251"), w1251 },

	{ 0, "Windows-1252", SLEN("Windows-1252"), w1252 },

	{ 0, "Windows-1253", SLEN("Windows-1253"), w1253 },

	{ 0, "Windows-1254", SLEN("Windows-1254"), w1254 },

	{ 0, "Windows-1255", SLEN("Windows-1255"), w1255 },

	{ 0, "Windows-1256", SLEN("Windows-1256"), w1256 },

	{ 0, "Windows-1257", SLEN("Windows-1257"), w1257 },

	{ 0, "Windows-1258", SLEN("Windows-1258"), w1258 },

};

/**

 * Windows charset codec

 */

typedef struct charset_ext8_codec {

	parserutils_charset_codec base;	/**< Base class */

	uint32_t *table;		/**< Mapping table for 0x80-0xFF */

#define READ_BUFSIZE (8)

	uint32_t read_buf[READ_BUFSIZE];	/**< Buffer for partial

						 * output sequences (decode)

						 * (host-endian) */

	size_t read_len;		/**< Character length of read_buf */

#define WRITE_BUFSIZE (8)

	uint32_t write_buf[WRITE_BUFSIZE];	/**< Buffer for partial

						 * output sequences (encode)

						 * (host-endian) */

	size_t write_len;		/**< Character length of write_buf */

} charset_ext8_codec;

static bool charset_ext8_codec_handles_charset(const char *charset);

static parserutils_error charset_ext8_codec_create(const char *charset,

		parserutils_alloc alloc, void *pw,

		parserutils_charset_codec **codec);

static parserutils_error charset_ext8_codec_destroy(

		parserutils_charset_codec *codec);

static parserutils_error charset_ext8_codec_encode(

		parserutils_charset_codec *codec,

		const uint8_t **source, size_t *sourcelen,

		uint8_t **dest, size_t *destlen);

static parserutils_error charset_ext8_codec_decode(

		parserutils_charset_codec *codec,

		const uint8_t **source, size_t *sourcelen,

		uint8_t **dest, size_t *destlen);

static parserutils_error charset_ext8_codec_reset(

		parserutils_charset_codec *codec);

static inline parserutils_error charset_ext8_codec_read_char(

		charset_ext8_codec *c,

		const uint8_t **source, size_t *sourcelen,

		uint8_t **dest, size_t *destlen);

static inline parserutils_error charset_ext8_codec_output_decoded_char(

		charset_ext8_codec *c,

		uint32_t ucs4, uint8_t **dest, size_t *destlen);

static inline parserutils_error charset_ext8_from_ucs4(charset_ext8_codec *c,

		uint32_t ucs4, uint8_t **s, size_t *len);

static inline parserutils_error charset_ext8_to_ucs4(charset_ext8_codec *c,

		const uint8_t *s, size_t len, uint32_t *ucs4);

/**

 * Determine whether this codec handles a specific charset

 *

 * \param charset  Charset to test

 * \return true if handleable, false otherwise

 */

bool charset_ext8_codec_handles_charset(const char *charset)

{

	uint32_t i;

	uint16_t match = parserutils_charset_mibenum_from_name(charset,

			strlen(charset));

	if (known_charsets[0].mib == 0) {

		for (i = 0; i < N_ELEMENTS(known_charsets); i++) {

			known_charsets[i].mib =

				parserutils_charset_mibenum_from_name(

						known_charsets[i].name,

						known_charsets[i].len);

		}

	}

	for (i = 0; i < N_ELEMENTS(known_charsets); i++) {

		if (known_charsets[i].mib == match)

			return true;

	}

	return false;

}

/**

 * Create an extended 8bit codec

 *

 * \param charset  The charset to read from / write to

 * \param alloc    Memory (de)allocation function

 * \param pw       Pointer to client-specific private data (may be NULL)

 * \param codec    Pointer to location to receive codec

 * \return PARSERUTILS_OK on success,

 *         PARSERUTILS_BADPARM on bad parameters,

 *         PARSERUTILS_NOMEM on memory exhausion

 */

parserutils_error charset_ext8_codec_create(const char *charset,

		parserutils_alloc alloc, void *pw,

		parserutils_charset_codec **codec)

{

	uint32_t i;

	charset_ext8_codec *c;

	uint16_t match = parserutils_charset_mibenum_from_name(

			charset, strlen(charset));

	uint32_t *table = NULL;

	for (i = 0; i < N_ELEMENTS(known_charsets); i++) {

		if (known_charsets[i].mib == match) {

			table = known_charsets[i].table;

			break;

		}

	}

	assert(table != NULL);

	c = alloc(NULL, sizeof(charset_ext8_codec), pw);

	if (c == NULL)

		return PARSERUTILS_NOMEM;

	c->table = table;

	c->read_buf[0] = 0;

	c->read_len = 0;

	c->write_buf[0] = 0;

	c->write_len = 0;

	/* Finally, populate vtable */

	c->base.handler.destroy = charset_ext8_codec_destroy;

	c->base.handler.encode = charset_ext8_codec_encode;

	c->base.handler.decode = charset_ext8_codec_decode;

	c->base.handler.reset = charset_ext8_codec_reset;

	*codec = (parserutils_charset_codec *) c;

	return PARSERUTILS_OK;

}

/**

 * Destroy an extended 8bit codec

 *

 * \param codec  The codec to destroy

 * \return PARSERUTILS_OK on success, appropriate error otherwise

 */

parserutils_error charset_ext8_codec_destroy (parserutils_charset_codec *codec)

{

	UNUSED(codec);

	return PARSERUTILS_OK;

}

/**

 * Encode a chunk of UCS-4 (big endian) data into extended 8bit

 *

 * \param codec      The codec to use

 * \param source     Pointer to pointer to source data

 * \param sourcelen  Pointer to length (in bytes) of source data

 * \param dest       Pointer to pointer to output buffer

 * \param destlen    Pointer to length (in bytes) of output buffer

 * \return PARSERUTILS_OK          on success,

 *         PARSERUTILS_NOMEM       if output buffer is too small,

 *         PARSERUTILS_INVALID     if a character cannot be represented and the

 *                                 codec's error handling mode is set to STRICT,

 *

 * On exit, ::source will point immediately _after_ the last input character

 * read. Any remaining output for the character will be buffered by the

 * codec for writing on the next call.

 *

 * Note that, if failure occurs whilst attempting to write any output

 * buffered by the last call, then ::source and ::sourcelen will remain

 * unchanged (as nothing more has been read).

 *

 * ::sourcelen will be reduced appropriately on exit.

 *

 * ::dest will point immediately _after_ the last character written.

 *

 * ::destlen will be reduced appropriately on exit.

 */

parserutils_error charset_ext8_codec_encode(parserutils_charset_codec *codec,

		const uint8_t **source, size_t *sourcelen,

		uint8_t **dest, size_t *destlen)

{

	charset_ext8_codec *c = (charset_ext8_codec *) codec;

	uint32_t ucs4;

	uint32_t *towrite;

	size_t towritelen;

	parserutils_error error;

	/* Process any outstanding characters from the previous call */

	if (c->write_len > 0) {

		uint32_t *pwrite = c->write_buf;

		while (c->write_len > 0) {

			error = charset_ext8_from_ucs4(c, pwrite[0],

					dest, destlen);

			if (error != PARSERUTILS_OK) {

				uint32_t len;

				assert(error == PARSERUTILS_NOMEM);

				for (len = 0; len < c->write_len; len++) {

					c->write_buf[len] = pwrite[len];

				}

				return error;

			}

			pwrite++;

			c->write_len--;

		}

	}

	/* Now process the characters for this call */

	while (*sourcelen > 0) {

		ucs4 = endian_big_to_host(*((uint32_t *) (void *) *source));

		towrite = &ucs4;

		towritelen = 1;

		/* Output current characters */

		while (towritelen > 0) {

			error = charset_ext8_from_ucs4(c, towrite[0], dest,

					destlen);

			if (error != PARSERUTILS_OK) {

				uint32_t len;

				if (error != PARSERUTILS_NOMEM) {

					return error;

				}

				/* Insufficient output space */

				if (towritelen >= WRITE_BUFSIZE)

					abort();

				c->write_len = towritelen;

				/* Copy pending chars to save area, for

				 * processing next call. */

				for (len = 0; len < towritelen; len++)

					c->write_buf[len] = towrite[len];

				/* Claim character we've just buffered,

				 * so it's not reprocessed */

				*source += 4;

				*sourcelen -= 4;

				return PARSERUTILS_NOMEM;

			}

			towrite++;

			towritelen--;

		}

		*source += 4;

		*sourcelen -= 4;

	}

	return PARSERUTILS_OK;

}

/**

 * Decode a chunk of extended 8bit data into UCS-4 (big endian)

 *

 * \param codec      The codec to use

 * \param source     Pointer to pointer to source data

 * \param sourcelen  Pointer to length (in bytes) of source data

 * \param dest       Pointer to pointer to output buffer

 * \param destlen    Pointer to length (in bytes) of output buffer

 * \return PARSERUTILS_OK          on success,

 *         PARSERUTILS_NOMEM       if output buffer is too small,

 *         PARSERUTILS_INVALID     if a character cannot be represented and the

 *                                 codec's error handling mode is set to STRICT,

 *

 * On exit, ::source will point immediately _after_ the last input character

 * read, if the result is _OK or _NOMEM. Any remaining output for the

 * character will be buffered by the codec for writing on the next call.

 *

 * In the case of the result being _INVALID, ::source will point _at_ the

 * last input character read; nothing will be written or buffered for the

 * failed character. It is up to the client to fix the cause of the failure

 * and retry the decoding process.

 *

 * Note that, if failure occurs whilst attempting to write any output

 * buffered by the last call, then ::source and ::sourcelen will remain

 * unchanged (as nothing more has been read).

 *

 * If STRICT error handling is configured and an illegal sequence is split

 * over two calls, then _INVALID will be returned from the second call,

 * but ::source will point mid-way through the invalid sequence (i.e. it

 * will be unmodified over the second call). In addition, the internal

 * incomplete-sequence buffer will be emptied, such that subsequent calls

 * will progress, rather than re-evaluating the same invalid sequence.

 *

 * ::sourcelen will be reduced appropriately on exit.

 *

 * ::dest will point immediately _after_ the last character written.

 *

 * ::destlen will be reduced appropriately on exit.

 *

 * Call this with a source length of 0 to flush the output buffer.

 */

parserutils_error charset_ext8_codec_decode(parserutils_charset_codec *codec,

		const uint8_t **source, size_t *sourcelen,

		uint8_t **dest, size_t *destlen)

{

	charset_ext8_codec *c = (charset_ext8_codec *) codec;

	parserutils_error error;

	if (c->read_len > 0) {

		/* Output left over from last decode */

		uint32_t *pread = c->read_buf;

		while (c->read_len > 0 && *destlen >= c->read_len * 4) {

			*((uint32_t *) (void *) *dest) =

					endian_host_to_big(pread[0]);

			*dest += 4;

			*destlen -= 4;

			pread++;

			c->read_len--;

		}

		if (*destlen < c->read_len * 4) {

			/* Ran out of output buffer */

			size_t i;

			/* Shuffle remaining output down */

			for (i = 0; i < c->read_len; i++)

				c->read_buf[i] = pread[i];

			return PARSERUTILS_NOMEM;

		}

	}

	/* Finally, the "normal" case; process all outstanding characters */

	while (*sourcelen > 0) {

		error = charset_ext8_codec_read_char(c,

				source, sourcelen, dest, destlen);

		if (error != PARSERUTILS_OK) {

			return error;

		}

	}

	return PARSERUTILS_OK;

}

/**

 * Clear an extended 8bit codec's encoding state

 *

 * \param codec  The codec to reset

 * \return PARSERUTILS_OK on success, appropriate error otherwise

 */

parserutils_error charset_ext8_codec_reset(parserutils_charset_codec *codec)

{

	charset_ext8_codec *c = (charset_ext8_codec *) codec;

	c->read_buf[0] = 0;

	c->read_len = 0;

	c->write_buf[0] = 0;

	c->write_len = 0;

	return PARSERUTILS_OK;

}

/**

 * Read a character from the extended 8bit to UCS-4 (big endian)

 *

 * \param c          The codec

 * \param source     Pointer to pointer to source buffer (updated on exit)

 * \param sourcelen  Pointer to length of source buffer (updated on exit)

 * \param dest       Pointer to pointer to output buffer (updated on exit)

 * \param destlen    Pointer to length of output buffer (updated on exit)

 * \return PARSERUTILS_OK on success,

 *         PARSERUTILS_NOMEM       if output buffer is too small,

 *         PARSERUTILS_INVALID     if a character cannot be represented and the

 *                                 codec's error handling mode is set to STRICT,

 *

 * On exit, ::source will point immediately _after_ the last input character

 * read, if the result is _OK or _NOMEM. Any remaining output for the

 * character will be buffered by the codec for writing on the next call.

 *

 * In the case of the result being _INVALID, ::source will point _at_ the

 * last input character read; nothing will be written or buffered for the

 * failed character. It is up to the client to fix the cause of the failure

 * and retry the decoding process.

 *

 * ::sourcelen will be reduced appropriately on exit.

 *

 * ::dest will point immediately _after_ the last character written.

 *

 * ::destlen will be reduced appropriately on exit.

 */

parserutils_error charset_ext8_codec_read_char(charset_ext8_codec *c,

		const uint8_t **source, size_t *sourcelen,

		uint8_t **dest, size_t *destlen)

{

	uint32_t ucs4;

	parserutils_error error;

	/* Convert a single character */

	error = charset_ext8_to_ucs4(c, *source, *sourcelen, &ucs4);

	if (error == PARSERUTILS_OK) {

		/* Read a character */

		error = charset_ext8_codec_output_decoded_char(c,

				ucs4, dest, destlen);

		if (error == PARSERUTILS_OK || error == PARSERUTILS_NOMEM) {

			/* output succeeded; update source pointers */

			*source += 1;

			*sourcelen -= 1;

		}

		return error;

	} else if (error == PARSERUTILS_NEEDDATA) {

		/* Can only happen if sourcelen == 0 */

		return error;

	} else if (error == PARSERUTILS_INVALID) {

		/* Illegal input sequence */

		/* Strict errormode; simply flag invalid character */

		if (c->base.errormode ==

				PARSERUTILS_CHARSET_CODEC_ERROR_STRICT) {

			return PARSERUTILS_INVALID;

		}

		/* output U+FFFD and continue processing. */

		error = charset_ext8_codec_output_decoded_char(c,

				0xFFFD, dest, destlen);

		if (error == PARSERUTILS_OK || error == PARSERUTILS_NOMEM) {

			/* output succeeded; update source pointers */

			*source += 1;

			*sourcelen -= 1;

		}

		return error;

	}

	return PARSERUTILS_OK;

}

/**

 * Output a UCS-4 character (big endian)

 *

 * \param c        Codec to use

 * \param ucs4     UCS-4 character (host endian)

 * \param dest     Pointer to pointer to output buffer

 * \param destlen  Pointer to output buffer length

 * \return PARSERUTILS_OK          on success,

 *         PARSERUTILS_NOMEM       if output buffer is too small,

 */

parserutils_error charset_ext8_codec_output_decoded_char(charset_ext8_codec *c,

		uint32_t ucs4, uint8_t **dest, size_t *destlen)

{

	if (*destlen < 4) {

		/* Run out of output buffer */

		c->read_len = 1;

		c->read_buf[0] = ucs4;

		return PARSERUTILS_NOMEM;

	}

	*((uint32_t *) (void *) *dest) = endian_host_to_big(ucs4);

	*dest += 4;

	*destlen -= 4;

	return PARSERUTILS_OK;

}

/**

 * Convert a UCS4 (host endian) character to extended 8bit

 *

 * \param c     The codec instance

 * \param ucs4  The UCS4 character to convert

 * \param s     Pointer to pointer to destination buffer

 * \param len   Pointer to destination buffer length

 * \return PARSERUTILS_OK on success,

 *         PARSERUTILS_NOMEM if there's insufficient space in the output buffer,

 *         PARSERUTILS_INVALID if the character cannot be represented

 *

 * _INVALID will only be returned if the codec's conversion mode is STRICT.

 * Otherwise, '?' will be output.

 *

 * On successful conversion, *s and *len will be updated.

 */

parserutils_error charset_ext8_from_ucs4(charset_ext8_codec *c,

		uint32_t ucs4, uint8_t **s, size_t *len)

{

	uint8_t out = 0;

	if (*len < 1)

		return PARSERUTILS_NOMEM;

	if (ucs4 < 0x80) {

		/* ASCII */

		out = ucs4;

	} else {

		uint32_t i;

		for (i = 0; i < 128; i++) {

			if (ucs4 == c->table[i])

				break;

		}

		if (i == 128) {

			if (c->base.errormode ==

					PARSERUTILS_CHARSET_CODEC_ERROR_STRICT)

				return PARSERUTILS_INVALID;

			else

				out = '?';

		} else {

			out = 0x80 + i;

		}

	}

	*(*s) = out;

	(*s)++;

	(*len)--;

	return PARSERUTILS_OK;

}

/**

 * Convert an extended 8bit character to UCS4 (host endian)

 *

 * \param c     The codec instance

 * \param s     Pointer to source buffer

 * \param len   Source buffer length

 * \param ucs4  Pointer to destination buffer

 * \return PARSERUTILS_OK on success,

 *         PARSERUTILS_NEEDDATA if there's insufficient input data

 *         PARSERUTILS_INVALID if the character cannot be represented

 */

parserutils_error charset_ext8_to_ucs4(charset_ext8_codec *c,

		const uint8_t *s, size_t len, uint32_t *ucs4)

{

	uint32_t out;

	if (len < 1)

		return PARSERUTILS_NEEDDATA;

	if (*s < 0x80) {

		out = *s;

	} else {

		if (c->table[*s - 0x80] == 0xFFFF)

			return PARSERUTILS_INVALID;

		out = c->table[*s - 0x80];

	}

	*ucs4 = out;

	return PARSERUTILS_OK;

}

const parserutils_charset_handler charset_ext8_codec_handler = {

	charset_ext8_codec_handles_charset,

	charset_ext8_codec_create

};