/*
* Copyright 2005 John M Bell <jmb202@ecs.soton.ac.uk>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf 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; version 2 of the License.
*
* NetSurf 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/>.
*/
/** \file
* UTF-8 manipulation functions (implementation).
*/
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <iconv.h>
typedef signed char int8_t;
typedef signed short int16_t;
typedef signed int int32_t;
typedef unsigned char uint8_t;
typedef unsigned short uint16_t;
typedef unsigned int uint32_t;
#include <parserutils/charset/utf8.h>
#include "utils/config.h"
#include "utils/log.h"
#include "utils/utf8.h"
static utf8_convert_ret utf8_convert(const char *string, size_t len,
const char *from, const char *to, char **result);
/**
* Convert a UTF-8 multibyte sequence into a single UCS4 character
*
* Encoding of UCS values outside the UTF-16 plane has been removed from
* RFC3629. This function conforms to RFC2279, however.
*
* \param s_in The sequence to process
* \param l Length of sequence
* \return UCS4 character
*/
uint32_t utf8_to_ucs4(const char *s_in, size_t l)
{
uint32_t ucs4;
size_t len;
perror = parserutils_charset_utf8_to_ucs4
((const uint8_t *) s_in
, l
, &ucs4, &len);
ucs4 = 0xfffd;
return ucs4;
}
/**
* Convert a single UCS4 character into a UTF-8 multibyte sequence
*
* Encoding of UCS values outside the UTF-16 plane has been removed from
* RFC3629. This function conforms to RFC2279, however.
*
* \param c The character to process (0 <= c <= 0x7FFFFFFF)
* \param s Pointer to 6 byte long output buffer
* \return Length of multibyte sequence
*/
size_t utf8_from_ucs4(uint32_t c, char *s)
{
uint8_t *in = (uint8_t *) s;
size_t len = 6;
perror = parserutils_charset_utf8_from_ucs4
(c
, &in
, &len
); if (perror != PARSERUTILS_OK
) { s[0] = 0xef;
s[1] = 0xbf;
s[2] = 0xbd;
return 3;
}
return 6 - len;
}
/**
* Calculate the length (in characters) of a NULL-terminated UTF-8 string
*
* \param s The string
* \return Length of string
*/
size_t utf8_length(const char *s)
{
return utf8_bounded_length
(s
, strlen(s
)); }
/**
* Calculated the length (in characters) of a bounded UTF-8 string
*
* \param s The string
* \param l Maximum length of input (in bytes)
* \return Length of string, in characters
*/
size_t utf8_bounded_length(const char *s, size_t l)
{
size_t len;
perror = parserutils_charset_utf8_length
((const uint8_t *) s
, l
, &len
); return 0;
return len;
}
/**
* Calculate the length (in bytes) of a UTF-8 character
*
* \param s Pointer to start of character
* \return Length of character, in bytes
*/
size_t utf8_char_byte_length(const char *s)
{
size_t len;
perror = parserutils_charset_utf8_char_byte_length
((const uint8_t *) s
, &len);
return len;
}
/**
* Find previous legal UTF-8 char in string
*
* \param s The string
* \param o Offset in the string to start at
* \return Offset of first byte of previous legal character
*/
size_t utf8_prev(const char *s, size_t o)
{
uint32_t prev;
perror = parserutils_charset_utf8_prev
((const uint8_t *) s
, o
, &prev
);
return prev;
}
/**
* Find next legal UTF-8 char in string
*
* \param s The string
* \param l Maximum offset in string
* \param o Offset in the string to start at
* \return Offset of first byte of next legal character
*/
size_t utf8_next(const char *s, size_t l, size_t o)
{
uint32_t next;
perror = parserutils_charset_utf8_next
((const uint8_t *) s
, l
, o
, &next);
return next;
}
/* Cache of previous iconv conversion descriptor used by utf8_convert */
static struct {
char from[32]; /**< Encoding name to convert from */
char to[32]; /**< Encoding name to convert to */
iconv_t cd; /**< Iconv conversion descriptor */
} last_cd;
/**
* Finalise the UTF-8 library
*/
void utf8_finalise(void)
{
if (last_cd.cd != 0)
iconv_close(last_cd.cd);
/* paranoia follows */
last_cd.from[0] = '\0';
last_cd.to[0] = '\0';
last_cd.cd = 0;
}
/**
* Convert a UTF8 string into the named encoding
*
* \param string The NULL-terminated string to convert
* \param encname The encoding name (suitable for passing to iconv)
* \param len Length of input string to consider (in bytes), or 0
* \param result Pointer to location to store result (allocated on heap)
* \return Appropriate utf8_convert_ret value
*/
utf8_convert_ret utf8_to_enc(const char *string, const char *encname,
size_t len, char **result)
{
return utf8_convert(string, len, "UTF-8", encname, result);
}
/**
* Convert a string in the named encoding into a UTF-8 string
*
* \param string The NULL-terminated string to convert
* \param encname The encoding name (suitable for passing to iconv)
* \param len Length of input string to consider (in bytes), or 0
* \param result Pointer to location to store result (allocated on heap)
* \return Appropriate utf8_convert_ret value
*/
utf8_convert_ret utf8_from_enc(const char *string, const char *encname,
size_t len, char **result)
{
return utf8_convert(string, len, encname, "UTF-8", result);
}
/**
* Convert a string from one encoding to another
*
* \param string The NULL-terminated string to convert
* \param len Length of input string to consider (in bytes), or 0
* \param from The encoding name to convert from
* \param to The encoding name to convert to
* \param result Pointer to location in which to store result
* \return Appropriate utf8_convert_ret value
*/
utf8_convert_ret utf8_convert(const char *string, size_t len,
const char *from, const char *to, char **result)
{
iconv_t cd;
char *temp, *out, *in;
size_t slen, rlen;
assert(string
&& from
&& to
&& result
);
if (string[0] == '\0') {
/* On AmigaOS, iconv() returns an error if we pass an
* empty string. This prevents iconv() being called as
* there is no conversion necessary anyway. */
*result = strdup("");
if (!(*result)) {
*result = NULL;
return UTF8_CONVERT_NOMEM;
}
return UTF8_CONVERT_OK;
}
if (strcasecmp(from, to) == 0) {
/* conversion from an encoding to itself == strdup */
slen
= len
? len
: strlen(string
); *(result) = strndup(string, slen);
if (!(*result)) {
*(result) = NULL;
return UTF8_CONVERT_NOMEM;
}
return UTF8_CONVERT_OK;
}
in = (char *)string;
/* we cache the last used conversion descriptor,
* so check if we're trying to use it here */
if (strncasecmp(last_cd.from, from, sizeof(last_cd.from)) == 0 &&
strncasecmp(last_cd.to, to, sizeof(last_cd.to)) == 0) {
cd = last_cd.cd;
}
else {
/* no match, so create a new cd */
cd = iconv_open(to, from);
if (cd == (iconv_t)-1) {
if (errno == EINVAL)
return UTF8_CONVERT_BADENC;
/* default to no memory */
return UTF8_CONVERT_NOMEM;
}
/* close the last cd - we don't care if this fails */
if (last_cd.cd)
iconv_close(last_cd.cd);
/* and copy the to/from/cd data into last_cd */
strncpy(last_cd.
from, from
, sizeof(last_cd.
from)); strncpy(last_cd.
to, to
, sizeof(last_cd.
to)); last_cd.cd = cd;
}
slen
= len
? len
: strlen(string
); /* Worst case = ASCII -> UCS4, so allocate an output buffer
* 4 times larger than the input buffer, and add 4 bytes at
* the end for the NULL terminator
*/
rlen = slen * 4 + 4;
if (!out)
return UTF8_CONVERT_NOMEM;
/* perform conversion */
if (iconv(cd, (void *) &in, &slen, &out, &rlen) == (size_t)-1) {
/* clear the cached conversion descriptor as it's invalid */
if (last_cd.cd)
iconv_close(last_cd.cd);
last_cd.from[0] = '\0';
last_cd.to[0] = '\0';
last_cd.cd = 0;
/** \todo handle the various cases properly
* There are 3 possible error cases:
* a) Insufficiently large output buffer
* b) Invalid input byte sequence
* c) Incomplete input sequence */
return UTF8_CONVERT_NOMEM;
}
*(result
) = realloc(temp
, out
- temp
+ 4); if (!(*result)) {
*(result) = NULL; /* for sanity's sake */
return UTF8_CONVERT_NOMEM;
}
/* NULL terminate - needs 4 characters as we may have
* converted to UTF-32 */
memset((*result
) + (out
- temp
), 0, 4);
return UTF8_CONVERT_OK;
}
static utf8_convert_ret utf8_convert_html_chunk(iconv_t cd,
const char *chunk, size_t inlen,
char **out, size_t *outlen)
{
size_t ret, esclen;
uint32_t ucs4;
char *pescape, escape[11];
while (inlen > 0) {
ret = iconv(cd, (void *) &chunk, &inlen, (void *) out, outlen);
if (ret != (size_t) -1)
break;
if (errno != EILSEQ)
return UTF8_CONVERT_NOMEM;
ucs4 = utf8_to_ucs4(chunk, inlen);
esclen
= snprintf(escape
, sizeof(escape
), "&#x%06x;", ucs4
); pescape = escape;
ret = iconv(cd, (void *) &pescape, &esclen,
(void *) out, outlen);
if (ret == (size_t) -1)
return UTF8_CONVERT_NOMEM;
esclen = utf8_next(chunk, inlen, 0);
chunk += esclen;
inlen -= esclen;
}
return UTF8_CONVERT_OK;
}
/**
* Convert a UTF-8 encoded string into a string of the given encoding,
* applying HTML escape sequences where necessary.
*
* \param string String to convert (NUL-terminated)
* \param encname Name of encoding to convert to
* \param len Length, in bytes, of the input string, or 0
* \param result Pointer to location to receive result
* \return Appropriate utf8_convert_ret value
*/
utf8_convert_ret utf8_to_html(const char *string, const char *encname,
size_t len, char **result)
{
iconv_t cd;
const char *in;
char *out, *origout;
size_t off, prev_off, inlen, outlen, origoutlen, esclen;
utf8_convert_ret ret;
char *pescape, escape[11];
if (len == 0)
cd = iconv_open(encname, "UTF-8");
if (cd == (iconv_t) -1) {
if (errno == EINVAL)
return UTF8_CONVERT_BADENC;
/* default to no memory */
return UTF8_CONVERT_NOMEM;
}
/* Worst case is ASCII -> UCS4, with all characters escaped:
* "&#xYYYYYY;", thus each input character may become a string
* of 10 UCS4 characters, each 4 bytes in length */
origoutlen = outlen = len * 10 * 4;
origout
= out
= malloc(outlen
); if (out == NULL) {
iconv_close(cd);
return UTF8_CONVERT_NOMEM;
}
/* Process input in chunks between characters we must escape */
prev_off = off = 0;
while (off < len) {
/* Must escape '&', '<', and '>' */
if (string[off] == '&' || string[off] == '<' ||
string[off] == '>') {
if (off - prev_off > 0) {
/* Emit chunk */
in = string + prev_off;
inlen = off - prev_off;
ret = utf8_convert_html_chunk(cd, in, inlen,
&out, &outlen);
if (ret != UTF8_CONVERT_OK) {
iconv_close(cd);
return ret;
}
}
/* Emit mandatory escape */
esclen
= snprintf(escape
, sizeof(escape
), "&#x%06x;", string[off]);
pescape = escape;
ret = utf8_convert_html_chunk(cd, pescape, esclen,
&out, &outlen);
if (ret != UTF8_CONVERT_OK) {
iconv_close(cd);
return ret;
}
prev_off = off = utf8_next(string, len, off);
} else {
off = utf8_next(string, len, off);
}
}
/* Process final chunk */
if (prev_off < len) {
in = string + prev_off;
inlen = len - prev_off;
ret = utf8_convert_html_chunk(cd, in, inlen, &out, &outlen);
if (ret != UTF8_CONVERT_OK) {
iconv_close(cd);
return ret;
}
}
iconv_close(cd);
/* Shrink-wrap */
*result
= realloc(origout
, origoutlen
- outlen
+ 4); if (*result == NULL) {
return UTF8_CONVERT_NOMEM;
}
memset(*result
+ (origoutlen
- outlen
), 0, 4);
return UTF8_CONVERT_OK;
}