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/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 1998-2017. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* %CopyrightEnd%
*/
#include <string.h>
#include <limits.h>
#include "eidef.h"
#include "eiext.h"
#include "putget.h"
static int verify_ascii_atom(const char* src, int slen);
static int verify_utf8_atom(const char* src, int slen);
int ei_encode_atom(char *buf, int *index, const char *p)
{
size_t len = strlen(p);
if (len >= MAXATOMLEN)
len = MAXATOMLEN - 1;
return ei_encode_atom_len_as(buf, index, p, len, ERLANG_LATIN1, 0);
}
int ei_encode_atom_len(char *buf, int *index, const char *p, int len)
{
/* This function is documented to truncate at MAXATOMLEN (256) */
if (len >= MAXATOMLEN)
len = MAXATOMLEN - 1;
return ei_encode_atom_len_as(buf, index, p, len, ERLANG_LATIN1, 0);
}
int ei_encode_atom_as(char *buf, int *index, const char *p,
erlang_char_encoding from_enc,
erlang_char_encoding to_enc)
{
return ei_encode_atom_len_as(buf, index, p, strlen(p), from_enc, to_enc);
}
int ei_encode_atom_len_as(char *buf, int *index, const char *p, int len,
erlang_char_encoding from_enc,
erlang_char_encoding to_enc)
{
char *s = buf + *index;
char *s0 = s;
int offs;
if (len >= MAXATOMLEN && (from_enc & (ERLANG_LATIN1|ERLANG_ASCII))) {
return -1;
}
/*
* Since OTP 20 we totally ignore 'to_enc'
* and alway encode as UTF8.
*/
{
offs = 1 + 1;
switch (from_enc) {
case ERLANG_LATIN1:
if (len >= 256/2) offs++;
len = latin1_to_utf8((buf ? s+offs : NULL), p, len, MAXATOMLEN_UTF8-1, NULL);
break;
case ERLANG_ASCII:
if (verify_ascii_atom(p, len) < 0) return -1;
if (buf) memcpy(s+offs,p,len);
break;
case ERLANG_UTF8:
if (len >= 256) offs++;
if (verify_utf8_atom(p, len) < 0) return -1;
if (buf) memcpy(s+offs,p,len);
break;
default:
return -1;
}
if (buf) {
if (offs == 2) {
put8(s, ERL_SMALL_ATOM_UTF8_EXT);
put8(s, len);
}
else {
put8(s, ERL_ATOM_UTF8_EXT);
put16be(s, len);
}
}
else s+= offs;
}
s += len;
*index += s-s0;
return 0;
}
int
ei_internal_put_atom(char** bufp, const char* p, int slen,
erlang_char_encoding to_enc)
{
int ix = 0;
if (ei_encode_atom_len_as(*bufp, &ix, p, slen, ERLANG_UTF8, to_enc) < 0)
return -1;
*bufp += ix;
return 0;
}
static int verify_ascii_atom(const char* src, int slen)
{
while (slen > 0) {
if ((src[0] & 0x80) != 0) return -1;
src++;
slen--;
}
return 0;
}
static int verify_utf8_atom(const char* src, int slen)
{
int num_chars = 0;
while (slen > 0) {
if (++num_chars >= MAXATOMLEN) return -1;
if ((src[0] & 0x80) != 0) {
if ((src[0] & 0xE0) == 0xC0) {
if (slen < 2 || (src[1] & 0xC0) != 0x80) return -1;
src++;
slen--;
}
else if ((src[0] & 0xF0) == 0xE0) {
if (slen < 3 || (src[1] & 0xC0) != 0x80 || (src[2] & 0xC0) != 0x80) return -1;
src += 2;
slen -= 2;
}
else if ((src[0] & 0xF8) == 0xF0) {
if (slen < 4 || (src[1] & 0xC0) != 0x80 || (src[2] & 0xC0) != 0x80 || (src[3] & 0xC0) != 0x80) return -1;
src += 3;
slen -= 3;
}
else return -1;
}
src++;
slen--;
}
return 0;
}
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