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/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2001-2010. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
* compliance with the License. You should have received a copy of the
* Erlang Public License along with this software. If not, it can be
* retrieved online at http://www.erlang.org/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* %CopyrightEnd%
*
*/
#include <string.h>
#include "eidef.h"
#include "eiext.h"
#include "ei_decode_term.h"
#include "putget.h"
/* Returns 0 on successful encoding, -1 on error, and 1 if the term seems
alright, but does not fit in the term structure. If it returns 0, the
index will be incremented, and the term contains the decoded term. */
int ei_decode_ei_term(const char* buf, int* index, ei_term* term)
{
const char* s = buf + *index, * s0 = s;
int len, i, n, sign;
char c;
if (term == NULL) return -1;
c = term->ei_type = get8(s);
switch (c) {
case ERL_SMALL_INTEGER_EXT:
term->value.i_val = get8(s);
break;
case ERL_INTEGER_EXT:
term->value.i_val = get32be(s);
break;
case ERL_FLOAT_EXT:
case NEW_FLOAT_EXT:
return ei_decode_double(buf, index, &term->value.d_val);
case ERL_ATOM_EXT:
len = get16be(s);
if (len > MAXATOMLEN) return -1;
memcpy(term->value.atom_name, s, len);
term->value.atom_name[len] = '\0';
s += len;
break;
case ERL_REFERENCE_EXT:
/* first the nodename */
if (get8(s) != ERL_ATOM_EXT) return -1;
len = get16be(s);
if (len > MAXATOMLEN) return -1;
memcpy(term->value.ref.node, s, len);
term->value.ref.node[len] = '\0';
s += len;
/* now the numbers: num (4), creation (1) */
term->value.ref.n[0] = get32be(s);
term->value.ref.len = 1;
term->value.ref.creation = get8(s) & 0x03;
break;
case ERL_NEW_REFERENCE_EXT:
/* first the integer count */
term->value.ref.len = get16be(s);
/* then the nodename */
if (get8(s) != ERL_ATOM_EXT) return -1;
len = get16be(s);
if (len > MAXATOMLEN) return -1;
memcpy(term->value.ref.node, s, len);
term->value.ref.node[len] = '\0';
s += len;
/* creation */
term->value.ref.creation = get8(s) & 0x03;
/* finally the id integers */
for (i = 0; (i<term->value.ref.len) && (i<3); i++) {
term->value.ref.n[i] = get32be(s);
}
if (term->value.ref.len > 3) {
s += 4 * (term->value.ref.len - 3);
}
break;
case ERL_PORT_EXT:
if (get8(s) != ERL_ATOM_EXT) return -1;
len = get16be(s);
if (len > MAXATOMLEN) return -1;
memcpy(term->value.port.node, s, len);
term->value.port.node[len] = '\0';
term->value.port.id = get32be(s) & 0x0fffffff; /* 28 bits */;
term->value.port.creation = get8(s) & 0x03;
break;
case ERL_PID_EXT:
if (get8(s) != ERL_ATOM_EXT) return -1;
/* name first */
len = get16be(s);
if (len > MAXATOMLEN) return -1;
memcpy(term->value.pid.node, s, len);
term->value.pid.node[len] = '\0';
s += len;
/* now the numbers: num (4), serial (4), creation (1) */
term->value.pid.num = get32be(s) & 0x7fff; /* 15 bits */
term->value.pid.serial = get32be(s) & 0x1fff; /* 13 bits */
term->value.pid.creation = get8(s) & 0x03; /* 2 bits */
break;
case ERL_SMALL_TUPLE_EXT:
term->arity = get8(s);
break; /*return 0;*/
case ERL_LARGE_TUPLE_EXT:
term->arity = get32be(s);
break; /*return 0;*/
case ERL_NIL_EXT:
term->arity = 0;
break;
case ERL_STRING_EXT:
term->size = get16be(s);
return 0;
case ERL_LIST_EXT:
term->arity = get32be(s);
break; /*return 0;*/
case ERL_BINARY_EXT:
term->size = get32be(s);
return 0;
case ERL_SMALL_BIG_EXT:
if ((term->arity = get8(s)) != 4) return -1;
sign = get8(s);
/* Little Endian, and n always positive, except for LONG_MIN */
n = get32le(s);
if (sign) {
/* check for overflow */
if ((n - 1) < 0) return -1;
n = -n;
} else {
/* check for overflow */
if (n < 0) return -1;
}
break;
case ERL_LARGE_BIG_EXT:
return 0;
case ERL_PASS_THROUGH:
return 0;
case ERL_NEW_CACHE:
return -1;
case ERL_CACHED_ATOM:
return -1;
default:
return -1;
}
*index += s-s0;
return 1;
}
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