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#include <errno.h>
#include <ctype.h>
#define __need_size_t
#include <stddef.h>
#include <string.h>
#include "iconv.h"
#ifndef UNUSED
#define UNUSED __attribute__ ((__unused__))
#endif
static int decode_ascii(int *scalar, const unsigned char *inbuf, int count);
static int decode_iso_8859_1(int *scalar, const unsigned char *inbuf,
int count);
static int decode_utf_8(int *scalar, const unsigned char *inbuf, int count);
static int encode_ascii(int scalar, unsigned char *outbuf);
static int encode_iso_8859_1(int scalar, unsigned char *outbuf);
static int encode_utf_8(int scalar, unsigned char *outbuf);
enum {
ASCII = 0,
UTF_8,
ISO_8859_1
};
struct converter {
int code;
const char *name;
int (*decode)(int *scalar, const unsigned char *inbuf, int count);
int (*encode)(int scalar, unsigned char *outbuf);
};
struct converter supported_codesets[] = {
{
.code = ASCII,
.name = "ASCII",
.decode = &decode_ascii,
.encode = &encode_ascii,
}, {
.code = UTF_8,
.name = "UTF-8" "\0" "UTF8" "\0",
.decode = &decode_utf_8,
.encode = &encode_utf_8,
}, {
.code = ISO_8859_1,
.name = "ISO-8859-1" "\0" "ISO8859-1" "\0",
.decode = &decode_iso_8859_1,
.encode = &encode_iso_8859_1
}, {
.code = -1,
}
};
/* ASCII */
static int decode_ascii(int *scalar, const unsigned char *inbuf,
int UNUSED count)
{
if (*inbuf >= 0x80) {
errno = EILSEQ;
return -1;
}
*scalar = *inbuf;
return 1;
}
static int encode_ascii(int scalar, unsigned char *outbuf)
{
if (scalar >= 0x80)
return 0;
*outbuf = scalar;
return 1;
}
/* ISO-8859-1 */
static int decode_iso_8859_1(int *scalar, const unsigned char *inbuf,
int UNUSED count)
{
*scalar = *inbuf;
return 1;
}
static int encode_iso_8859_1(int scalar, unsigned char *outbuf)
{
if (scalar > 0xff)
return 0;
*outbuf = scalar;
return 1;
}
/* UTF-8 */
/* scalar value utf-8
* 00000000 00000000 0zzzzzzz 0zzzzzzz
* 00000000 00000yyy yyzzzzzz 110yyyyy 10zzzzzz
* 00000000 xxxxyyyy yyzzzzzz 1110xxxx 10yyyyyy 10zzzzzz
* 000wwwxx xxxxyyyy yyzzzzzz 11110www 10xxxxxx 10yyyyyy 10zzzzzz
*
* This implementation only supports the 2 first variants
*/
static int decode_utf_8(int *scalar, const unsigned char *inbuf, int count)
{
int i = inbuf[0];
if (i < 0x80) {
*scalar = i;
return 1;
}
if (count < 2) {
errno = EINVAL;
return -1;
}
i = (i << 8) | inbuf[1];
if ((i & 0xe0c0) != 0xc080) {
errno = EILSEQ;
return -1;
}
*scalar = ((i & 0x1700) >> 2) | (i & 0x3f);
return 2;
}
static int encode_utf_8(int scalar, unsigned char *outbuf)
{
if (scalar < 0x80) {
*outbuf = scalar;
return 1;
}
if (scalar > 0x7ff)
return 0;
outbuf[0] = (scalar >> 6) | 0xc0;
outbuf[1] = (scalar & 0x3f) | 0x80;
return 2;
}
static void toupperstr(char *p)
{
while (p && *p) {
if (*p == '_')
*p = '-';
*p = toupper(*p);
p++;
}
}
static int is_codeset(const char *str, const char *list)
{
while (*list) {
if (strcmp(str, list) == 0)
return 1;
list += strlen(list) + 1;
}
return 0;
}
static int find_converter(const char *str)
{
int i;
char buf[16];
strncpy(buf, str, sizeof(buf));
buf[15] = '\0';
toupperstr(buf);
for (i = 0; supported_codesets[i].code != -1; i++) {
if (is_codeset(buf, supported_codesets[i].name))
return i;
}
return -1;
}
iconv_t iconv_open(const char *tocode, const char *fromcode)
{
int src, dest;
iconv_t cd = (iconv_t) -1;
if (tocode == NULL || fromcode == NULL) {
errno = EINVAL;
goto return_error;
}
src = find_converter(fromcode);
dest = find_converter(tocode);
if (src == -1 || dest == -1) {
errno = EINVAL;
goto return_error;
}
cd = (iconv_t) (dest << 8) | src;
return_error:
return cd;
}
int iconv_close(iconv_t UNUSED cd)
{
return 0;
}
size_t iconv(iconv_t cd, const char **inbuf, size_t *insize,
char **outbuf, size_t *outsize)
{
struct converter *in = &supported_codesets[cd & 0xff];
struct converter *out = &supported_codesets[cd >> 8];
size_t nonidentical = 0;
if (!inbuf || !*inbuf || !outbuf || !*outbuf)
return 0;
while (*insize) {
int scalar, infwd, outfwd;
infwd = in->decode(&scalar, (unsigned char *)*inbuf, *insize);
if (infwd < 0)
goto ret_error;
outfwd = out->encode(scalar, (unsigned char *)*outbuf);
if (outfwd > *outsize) {
errno = E2BIG;
goto ret_error;
}
if (**inbuf != scalar || outfwd == 0)
nonidentical++;
*inbuf += infwd;
*insize -= infwd;
*outbuf += outfwd;
*outsize -= outfwd;
}
if (*outsize)
*outbuf = '\0';
return nonidentical;
ret_error:
return -1;
}
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