diff options
| -rw-r--r-- | src/charset/codec.c | 2 | ||||
| -rw-r--r-- | src/charset/codecs/Makefile | 2 | ||||
| -rw-r--r-- | src/charset/codecs/codec_ascii.c | 526 |
3 files changed, 529 insertions, 1 deletions
diff --git a/src/charset/codec.c b/src/charset/codec.c index 908b0e5..1dc436d 100644 --- a/src/charset/codec.c +++ b/src/charset/codec.c @@ -10,6 +10,7 @@ #include "charset/aliases.h" #include "charset/codecs/codec_impl.h" +extern parserutils_charset_handler charset_ascii_codec_handler; extern parserutils_charset_handler charset_8859_codec_handler; extern parserutils_charset_handler charset_ext8_codec_handler; extern parserutils_charset_handler charset_utf8_codec_handler; @@ -20,6 +21,7 @@ static parserutils_charset_handler *handler_table[] = { &charset_utf16_codec_handler, &charset_8859_codec_handler, &charset_ext8_codec_handler, + &charset_ascii_codec_handler, NULL, }; diff --git a/src/charset/codecs/Makefile b/src/charset/codecs/Makefile index 37f8bc2..7286ccd 100644 --- a/src/charset/codecs/Makefile +++ b/src/charset/codecs/Makefile @@ -32,7 +32,7 @@ dirstack_$(sp) := $(d) d := $(DIR) # Sources -SRCS_$(d) := codec_8859.c codec_ext8.c codec_utf8.c codec_utf16.c +SRCS_$(d) := codec_ascii.c codec_8859.c codec_ext8.c codec_utf8.c codec_utf16.c # Append to sources for component SOURCES += $(addprefix $(d), $(SRCS_$(d))) diff --git a/src/charset/codecs/codec_ascii.c b/src/charset/codecs/codec_ascii.c new file mode 100644 index 0000000..bce5191 --- /dev/null +++ b/src/charset/codecs/codec_ascii.c @@ -0,0 +1,526 @@ +/* + * 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" + +/** + * US-ASCII charset codec + */ +typedef struct charset_ascii_codec { + parserutils_charset_codec base; /**< Base class */ + +#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_ascii_codec; + +static bool charset_ascii_codec_handles_charset(const char *charset); +static parserutils_charset_codec *charset_ascii_codec_create( + const char *charset, parserutils_alloc alloc, void *pw); +static void charset_ascii_codec_destroy (parserutils_charset_codec *codec); +static parserutils_error charset_ascii_codec_encode( + parserutils_charset_codec *codec, + const uint8_t **source, size_t *sourcelen, + uint8_t **dest, size_t *destlen); +static parserutils_error charset_ascii_codec_decode( + parserutils_charset_codec *codec, + const uint8_t **source, size_t *sourcelen, + uint8_t **dest, size_t *destlen); +static parserutils_error charset_ascii_codec_reset( + parserutils_charset_codec *codec); +static inline parserutils_error charset_ascii_codec_read_char( + charset_ascii_codec *c, + const uint8_t **source, size_t *sourcelen, + uint8_t **dest, size_t *destlen); +static inline parserutils_error charset_ascii_codec_output_decoded_char( + charset_ascii_codec *c, + uint32_t ucs4, uint8_t **dest, size_t *destlen); +static inline parserutils_error charset_ascii_from_ucs4(charset_ascii_codec *c, + uint32_t ucs4, uint8_t **s, size_t *len); +static inline parserutils_error charset_ascii_to_ucs4(charset_ascii_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_ascii_codec_handles_charset(const char *charset) +{ + static uint16_t ascii; + uint16_t match = parserutils_charset_mibenum_from_name(charset, + strlen(charset)); + + if (ascii == 0) { + ascii = parserutils_charset_mibenum_from_name( + "US-ASCII", SLEN("US-ASCII")); + } + + if (ascii != 0 && ascii == match) + return true; + + return false; +} + +/** + * Create a US-ASCII 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_ascii_codec_create(const char *charset, + parserutils_alloc alloc, void *pw) +{ + charset_ascii_codec *codec; + + UNUSED(charset); + + codec = alloc(NULL, sizeof(charset_ascii_codec), pw); + if (codec == NULL) + return NULL; + + 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_ascii_codec_destroy; + codec->base.handler.encode = charset_ascii_codec_encode; + codec->base.handler.decode = charset_ascii_codec_decode; + codec->base.handler.reset = charset_ascii_codec_reset; + + return (parserutils_charset_codec *) codec; +} + +/** + * Destroy a US-ASCII codec + * + * \param codec The codec to destroy + */ +void charset_ascii_codec_destroy (parserutils_charset_codec *codec) +{ + UNUSED(codec); +} + +/** + * Encode a chunk of UCS-4 (big endian) data into US-ASCII + * + * \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_ascii_codec_encode(parserutils_charset_codec *codec, + const uint8_t **source, size_t *sourcelen, + uint8_t **dest, size_t *destlen) +{ + charset_ascii_codec *c = (charset_ascii_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_ascii_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_ascii_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 US-ASCII 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_ascii_codec_decode(parserutils_charset_codec *codec, + const uint8_t **source, size_t *sourcelen, + uint8_t **dest, size_t *destlen) +{ + charset_ascii_codec *c = (charset_ascii_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_ascii_codec_read_char(c, + source, sourcelen, dest, destlen); + if (error != PARSERUTILS_OK) { + return error; + } + } + + return PARSERUTILS_OK; +} + +/** + * Clear a US-ASCII codec's encoding state + * + * \param codec The codec to reset + * \return PARSERUTILS_OK on success, appropriate error otherwise + */ +parserutils_error charset_ascii_codec_reset(parserutils_charset_codec *codec) +{ + charset_ascii_codec *c = (charset_ascii_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 US-ASCII 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_ascii_codec_read_char(charset_ascii_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_ascii_to_ucs4(c, *source, *sourcelen, &ucs4); + if (error == PARSERUTILS_OK) { + /* Read a character */ + error = charset_ascii_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_ascii_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_ascii_codec_output_decoded_char( + charset_ascii_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 US-ASCII + * + * \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_ascii_from_ucs4(charset_ascii_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 { + if (c->base.errormode == PARSERUTILS_CHARSET_CODEC_ERROR_STRICT) + return PARSERUTILS_INVALID; + else + out = '?'; + } + + *(*s) = out; + (*s)++; + (*len)--; + + return PARSERUTILS_OK; +} + +/** + * Convert a US-ASCII 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_ascii_to_ucs4(charset_ascii_codec *c, + const uint8_t *s, size_t len, uint32_t *ucs4) +{ + uint32_t out; + + UNUSED(c); + + if (len < 1) + return PARSERUTILS_NEEDDATA; + + if (*s < 0x80) { + out = *s; + } else { + return PARSERUTILS_INVALID; + } + + *ucs4 = out; + + return PARSERUTILS_OK; +} + +const parserutils_charset_handler charset_ascii_codec_handler = { + charset_ascii_codec_handles_charset, + charset_ascii_codec_create +}; + |