/* * This file is part of LibParserUtils. * Licensed under the MIT License, *                http://www.opensource.org/licenses/mit-license.php * Copyright 2007 John-Mark Bell <jmb@netsurf-browser.org> */ #include <stdlib.h>#include <string.h> #include <parserutils/charset/mibenum.h> #include "codec_impl.h"#include "utf8impl.h"#include "endian.h"#include "utils.h" /** * UTF-8 charset codec */typedef struct charset_utf8_codec {	parserutils_charset_codec base;	/**< Base class */ #define INVAL_BUFSIZE (32)	uint8_t inval_buf[INVAL_BUFSIZE];	/**< Buffer for fixing up						 * incomplete input						 * sequences */	size_t inval_len;		/*< Byte length of inval_buf **/ #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_utf8_codec; static bool charset_utf8_codec_handles_charset(const char *charset);static parserutils_error charset_utf8_codec_create(const char *charset,		parserutils_alloc alloc, void *pw,		parserutils_charset_codec **codec);static parserutils_error charset_utf8_codec_destroy(		parserutils_charset_codec *codec);static parserutils_error charset_utf8_codec_encode(		parserutils_charset_codec *codec,		const uint8_t **source, size_t *sourcelen,		uint8_t **dest, size_t *destlen);static parserutils_error charset_utf8_codec_decode(		parserutils_charset_codec *codec,		const uint8_t **source, size_t *sourcelen,		uint8_t **dest, size_t *destlen);static parserutils_error charset_utf8_codec_reset(		parserutils_charset_codec *codec);static inline parserutils_error charset_utf8_codec_read_char(		charset_utf8_codec *c,		const uint8_t **source, size_t *sourcelen,		uint8_t **dest, size_t *destlen);static inline parserutils_error charset_utf8_codec_output_decoded_char(		charset_utf8_codec *c,		uint32_t ucs4, uint8_t **dest, size_t *destlen); /** * Determine whether this codec handles a specific charset * * \param charset  Charset to test * \return true if handleable, false otherwise */bool charset_utf8_codec_handles_charset(const char *charset){	return parserutils_charset_mibenum_from_name(charset,				strlen(charset)) ==			parserutils_charset_mibenum_from_name("UTF-8",				SLEN("UTF-8"));} /** * Create a UTF-8 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_utf8_codec_create(const char *charset,		parserutils_alloc alloc, void *pw,		parserutils_charset_codec **codec){	charset_utf8_codec *c; 	UNUSED(charset); 	c = alloc(NULL, sizeof(charset_utf8_codec), pw);	if (c == NULL)		return PARSERUTILS_NOMEM; 	c->inval_buf[0] = '\0';	c->inval_len = 0; 	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_utf8_codec_destroy;	c->base.handler.encode = charset_utf8_codec_encode;	c->base.handler.decode = charset_utf8_codec_decode;	c->base.handler.reset = charset_utf8_codec_reset; 	*codec = (parserutils_charset_codec *) c; 	return PARSERUTILS_OK;} /** * Destroy a UTF-8 codec * * \param codec  The codec to destroy * \return PARSERUTILS_OK on success, appropriate error otherwise */parserutils_error charset_utf8_codec_destroy (parserutils_charset_codec *codec){	UNUSED(codec); 	return PARSERUTILS_OK;} /** * Encode a chunk of UCS-4 (big endian) data into UTF-8 * * \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_utf8_codec_encode(parserutils_charset_codec *codec,		const uint8_t **source, size_t *sourcelen,		uint8_t **dest, size_t *destlen){	charset_utf8_codec *c = (charset_utf8_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) {			UTF8_FROM_UCS4(pwrite[0], dest, destlen, error);			if (error != PARSERUTILS_OK) {				uint32_t len;				if (error != PARSERUTILS_NOMEM)					abort(); 				/* Insufficient output buffer space */				for (len = 0; len < c->write_len; len++) {					c->write_buf[len] = pwrite[len];				} 				return PARSERUTILS_NOMEM;			} 			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) {			UTF8_FROM_UCS4(towrite[0], dest, destlen, error);			if (error != PARSERUTILS_OK) {				uint32_t len;				if (error != PARSERUTILS_NOMEM)					abort(); 				/* 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 UTF-8 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_utf8_codec_decode(parserutils_charset_codec *codec,		const uint8_t **source, size_t *sourcelen,		uint8_t **dest, size_t *destlen){	charset_utf8_codec *c = (charset_utf8_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;		}	} 	if (c->inval_len > 0) {		/* The last decode ended in an incomplete sequence.		 * Fill up inval_buf with data from the start of the		 * new chunk and process it. */		uint8_t *in = c->inval_buf;		size_t ol = c->inval_len;		size_t l = min(INVAL_BUFSIZE - ol - 1, *sourcelen);		size_t orig_l = l; 		memcpy(c->inval_buf + ol, *source, l); 		l += c->inval_len; 		error = charset_utf8_codec_read_char(c,				(const uint8_t **) &in, &l, dest, destlen);		if (error != PARSERUTILS_OK && error != PARSERUTILS_NOMEM) {			return error;		} 		/* And now, fix up source pointers */		*source += max((signed) (orig_l - l), 0);		*sourcelen -= max((signed) (orig_l - l), 0); 		/* Failed to resolve an incomplete character and		 * ran out of buffer space. No recovery strategy		 * possible, so explode everywhere. */		if ((orig_l + ol) - l == 0)			abort(); 		/* Report memory exhaustion case from above */		if (error != PARSERUTILS_OK)			return error;	} 	/* Finally, the "normal" case; process all outstanding characters */	while (*sourcelen > 0) {		error = charset_utf8_codec_read_char(c,				source, sourcelen, dest, destlen);		if (error != PARSERUTILS_OK) {			return error;		}	} 	return PARSERUTILS_OK;} /** * Clear a UTF-8 codec's encoding state * * \param codec  The codec to reset * \return PARSERUTILS_OK on success, appropriate error otherwise */parserutils_error charset_utf8_codec_reset(parserutils_charset_codec *codec){	charset_utf8_codec *c = (charset_utf8_codec *) codec; 	c->inval_buf[0] = '\0';	c->inval_len = 0; 	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 UTF-8 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_utf8_codec_read_char(charset_utf8_codec *c,		const uint8_t **source, size_t *sourcelen,		uint8_t **dest, size_t *destlen){	uint32_t ucs4;	size_t sucs4;	parserutils_error error; 	/* Convert a single character */	{		const uint8_t *src = *source;		size_t srclen = *sourcelen;		uint32_t *uptr = &ucs4;		size_t *usptr = &sucs4;		UTF8_TO_UCS4(src, srclen, uptr, usptr, error);	}	if (error == PARSERUTILS_OK) {		/* Read a character */		error = charset_utf8_codec_output_decoded_char(c,				ucs4, dest, destlen);		if (error == PARSERUTILS_OK || error == PARSERUTILS_NOMEM) {			/* output succeeded; update source pointers */			*source += sucs4;			*sourcelen -= sucs4;		} 		/* Clear inval buffer */		c->inval_buf[0] = '\0';		c->inval_len = 0; 		return error;	} else if (error == PARSERUTILS_NEEDDATA) {		/* Incomplete input sequence */		if (*sourcelen > INVAL_BUFSIZE)			abort(); 		memmove(c->inval_buf, *source, *sourcelen);		c->inval_buf[*sourcelen] = '\0';		c->inval_len = *sourcelen; 		*source += *sourcelen;		*sourcelen = 0; 		return PARSERUTILS_OK;	} else if (error == PARSERUTILS_INVALID) {		/* Illegal input sequence */		uint32_t nextchar; 		/* Strict errormode; simply flag invalid character */		if (c->base.errormode ==				PARSERUTILS_CHARSET_CODEC_ERROR_STRICT) {			/* Clear inval buffer */			c->inval_buf[0] = '\0';			c->inval_len = 0; 			return PARSERUTILS_INVALID;		} 		/* Find next valid UTF-8 sequence.		 * We're processing client-provided data, so let's		 * be paranoid about its validity. */		{			const uint8_t *src = *source;			size_t srclen = *sourcelen;			uint32_t off = 0;			uint32_t *ncptr = &nextchar; 			UTF8_NEXT_PARANOID(src, srclen, off, ncptr, error);		}		if (error != PARSERUTILS_OK) {			if (error == PARSERUTILS_NEEDDATA) {				/* Need more data to be sure */				if (*sourcelen > INVAL_BUFSIZE)					abort(); 				memmove(c->inval_buf, *source, *sourcelen);				c->inval_buf[*sourcelen] = '\0';				c->inval_len = *sourcelen; 				*source += *sourcelen;				*sourcelen = 0; 				nextchar = 0;			} else {				return error;			}

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