1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2001-2013. 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 1 on successful encoding, -1 on error, and 0 if the term seems
alright, but does not fit in the term structure. If it returns 1, 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 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:
case ERL_ATOM_UTF8_EXT:
case ERL_SMALL_ATOM_EXT:
case ERL_SMALL_ATOM_UTF8_EXT:
return ei_decode_atom(buf, index, term->value.atom_name);
case ERL_REFERENCE_EXT:
/* first the nodename */
if (get_atom(&s, term->value.ref.node, NULL) < 0) return -1;
/* 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 (get_atom(&s, term->value.ref.node, NULL) < 0) return -1;
/* 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 (get_atom(&s, term->value.port.node, NULL) < 0) return -1;
term->value.port.id = get32be(s) & 0x0fffffff; /* 28 bits */;
term->value.port.creation = get8(s) & 0x03;
break;
case ERL_PID_EXT:
if (get_atom(&s, term->value.pid.node, NULL) < 0) return -1;
/* 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;
case ERL_LARGE_TUPLE_EXT:
term->arity = get32be(s);
break;
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;
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;
}
|
