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Diffstat (limited to 'src/charset/codecs/codec_ext8.c')
-rw-r--r--src/charset/codecs/codec_ext8.c575
1 files changed, 575 insertions, 0 deletions
diff --git a/src/charset/codecs/codec_ext8.c b/src/charset/codecs/codec_ext8.c
new file mode 100644
index 0000000..f32f542
--- /dev/null
+++ b/src/charset/codecs/codec_ext8.c
@@ -0,0 +1,575 @@
+/*
+ * This file is part of LibParserUtils.
+ * Licensed under the MIT License,
+ * http://www.opensource.org/licenses/mit-license.php
+ * Copyright 2008 John-Mark Bell <jmb@netsurf-browser.org>
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* These two are for htonl / ntohl */
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
+#include <parserutils/charset/mibenum.h>
+
+#include "charset/codecs/codec_impl.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_charset_codec *charset_ext8_codec_create(const char *charset,
+ parserutils_alloc alloc, void *pw);
+static void 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)
+{
+ uint16_t match = parserutils_charset_mibenum_from_name(charset,
+ strlen(charset));
+
+ if (known_charsets[0].mib == 0) {
+ for (uint32_t 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 (uint32_t 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)
+ * \return Pointer to codec, or NULL on failure
+ */
+parserutils_charset_codec *charset_ext8_codec_create(const char *charset,
+ parserutils_alloc alloc, void *pw)
+{
+ charset_ext8_codec *codec;
+ uint16_t match = parserutils_charset_mibenum_from_name(
+ charset, strlen(charset));
+ uint32_t *table = NULL;
+
+ for (uint32_t i = 0; i < N_ELEMENTS(known_charsets); i++) {
+ if (known_charsets[i].mib == match) {
+ table = known_charsets[i].table;
+ break;
+ }
+ }
+
+ assert(table != NULL);
+
+ codec = alloc(NULL, sizeof(charset_ext8_codec), pw);
+ if (codec == NULL)
+ return NULL;
+
+ codec->table = table;
+
+ codec->read_buf[0] = 0;
+ codec->read_len = 0;
+
+ codec->write_buf[0] = 0;
+ codec->write_len = 0;
+
+ /* Finally, populate vtable */
+ codec->base.handler.destroy = charset_ext8_codec_destroy;
+ codec->base.handler.encode = charset_ext8_codec_encode;
+ codec->base.handler.decode = charset_ext8_codec_decode;
+ codec->base.handler.reset = charset_ext8_codec_reset;
+
+ return (parserutils_charset_codec *) codec;
+}
+
+/**
+ * Destroy an extended 8bit codec
+ *
+ * \param codec The codec to destroy
+ */
+void charset_ext8_codec_destroy (parserutils_charset_codec *codec)
+{
+ UNUSED(codec);
+}
+
+/**
+ * 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) {
+ assert(error == PARSERUTILS_NOMEM);
+
+ for (uint32_t 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 = ntohl(*((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) {
+ 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 (uint32_t 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) = htonl(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) = htonl(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 = c->table[i];
+ }
+ }
+
+ *(*s++) = out;
+ *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] == 0xFFFF)
+ return PARSERUTILS_INVALID;
+
+ out = c->table[*s];
+ }
+
+ *ucs4 = out;
+
+ return PARSERUTILS_OK;
+}
+
+const parserutils_charset_handler charset_ext8_codec_handler = {
+ charset_ext8_codec_handles_charset,
+ charset_ext8_codec_create
+};
+