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
|
#include <ctype.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <limits.h>
#include <stdio.h>
#include "common.h"
#include "pack.h"
typedef enum pack_status unpacker(void *buf, size_t size, va_list ap);
enum endian { BIG, LITTLE };
uintmax_t read_val(unsigned char *buf, size_t size, enum endian e)
{
unsigned long long val = 0;
for (size_t i = 0; i < size; i++)
val |= (buf[i] & 0xff) << (e == LITTLE ? i : size - i - 1) * 8;
return val;
}
#define X(M) \
M(b, signed char ) \
M(B, unsigned char ) \
M(h, short ) \
M(H, unsigned short ) \
M(i, int ) \
M(I, unsigned ) \
M(l, long ) \
M(L, unsigned long ) \
M(q, long long) \
M(Q, unsigned long long)
enum pack_status unpack(void *buf_, size_t size, const char *fmt, ...)
{
enum endian endianness = BIG;
unsigned char *buf = buf_;
size_t offset = 0;
va_list ap;
va_start(ap, fmt);
for (int i = 0; fmt[i] != '\0'; i++) {
bool sign = islower(fmt[i]);
size_t s;
union {
signed char *b;
unsigned char *B;
short *h;
unsigned short *H;
int *i;
unsigned int *I;
long *l;
unsigned long *L;
long long *q;
unsigned long long *Q;
} arg;
/*void *arg;*/
union { uintmax_t u; intmax_t s; } val;
switch (fmt[i]) {
case '>': endianness = BIG; continue;
case '<': endianness = LITTLE; continue;
case 'b': arg.b = va_arg(ap, signed char *);
case 'B': arg.B = va_arg(ap, unsigned char *);
case 'h': arg.h = va_arg(ap, short *);
case 'H': arg.H = va_arg(ap, unsigned short *);
case 'i': arg.i = va_arg(ap, int *);
case 'I': arg.I = va_arg(ap, unsigned *);
case 'l': arg.l = va_arg(ap, long *);
case 'L': arg.L = va_arg(ap, unsigned long *);
case 'q': arg.q = va_arg(ap, long long *);
case 'Q': arg.Q = va_arg(ap, unsigned long long *);
case 'x': break;
return PACK_FMTINVAL;
}
s = getsize(fmt[i]);
if (s == (size_t)-1) return PACK_FMTINVAL;
if (size - offset < s) return PACK_TOOSMALL;
if (fmt[i] == 'x') goto skip;
val.u = read_val(buf, s, endianness);
fprintf(stderr, "%zu, %llu\n", s, val.u);
if (sign) {
intmax_t vals;
if (!(val.u & (1llu << (s * 8 - 1)))) {
vals = val.u;
} else {
uintmax_t offt = UINTMAX_MAX >> (sizeof offt * CHAR_BIT - s * 8);
vals = val.u - offt - 1;
}
val.s = vals;
fprintf(stderr, "signed %lld\n", val.s);
}
switch (fmt[i]) {
#define D(t, f) fprintf(stderr, "(%p) "#t " = %" #f "\n", (void *)arg.t, *arg.t)
case 'b': *arg.b = val.s; D(b, d); break;
case 'B': *arg.B = val.u; D(B, u); break;
case 'h': *arg.h = val.s; D(h, d); break;
case 'H': *arg.H = val.u; D(H, u); break;
case 'i': *arg.i = val.s; D(i, d); break;
case 'I': *arg.I = val.u; D(I, u); break;
case 'l': *arg.l = val.s; D(l, ld); break;
case 'L': *arg.L = val.u; D(L, lu); break;
case 'q': *arg.q = val.s; D(q, lld); break;
case 'Q': *arg.Q = val.u; D(Q, llu); break;
}
skip:
offset += s;
}
va_end(ap);
return PACK_OK;
}
|
