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
|
/*
* libHX/assorted/pack.c
* Copyright Jan Engelhardt, 1999-2005
*
* This file is part of libHX. libHX is free software; you can
* redistribute it and/or modify it under the terms of the GNU Lesser
* General Public License as published by the Free Software Foundation;
* either version 2.1 or (at your option) any later version.
*/
#include <sys/types.h>
#include <stdarg.h>
#include <stdint.h>
#include <string.h>
size_t HX_pack(char *buf, size_t buflen, const char *fmt, ...)
{
char *obp = buf;
int run = 1;
va_list ap;
va_start(ap, fmt);
while (run && *fmt != '\0') {
switch (*fmt++) {
case 'A': /* string with up to 255 chars */
case 'a': {
const char *src = va_arg(ap, const char *);
size_t slen = strlen(src) & 0xFF;
if (buflen < slen + 1) {
run = 0;
break;
}
*buf++ = slen;
memcpy(buf, src, slen);
buf += slen;
buflen -= slen + 1;
break;
}
case 'C': /* unsigned char */
case 'c':
if (buflen-- < 1) {
run = 0;
break;
}
/*
* Minimum object's size being pushed on the stack is 2
* bytes since short int is promoted to int when passed
* thru va_arg and stays uncasted. (FIXME)
*/
*buf++ = va_arg(ap, unsigned int);
break;
case 'H': /* unsigned short */
case 'h':
if (buflen < sizeof(uint16_t)) {
run = 0;
break;
}
*((uint16_t *)buf) = va_arg(ap, uint16_t);
buf += sizeof(uint16_t);
buflen -= sizeof(uint16_t);
break;
case 'L': /* unsigned long */
case 'l':
if (buflen < sizeof(uint32_t)) {
run = 0;
break;
}
*((uint32_t *)buf) = va_arg(ap, uint32_t);
buf += sizeof(uint32_t);
buflen -= sizeof(uint32_t);
break;
case 'S': /* string with up to 65535 chars */
case 's': {
const char *src = va_arg(ap, const char *);
size_t slen = strlen(src) & 0xFFFF;
if (buflen < slen + 2) {
run = 0;
break;
}
*((unsigned short *)buf) = slen;
memcpy(buf += 2, src, slen);
buf += slen;
buflen -= slen + 2;
break;
}
case 'V': /* fixed size string */
case 'v': {
void *src = va_arg(ap, void *);
size_t slen = va_arg(ap, size_t);
if (buflen < slen) {
run = 0;
break;
}
memcpy(buf, src, slen);
buf += slen;
buflen -= slen;
break;
}
} /* switch */
}
va_end(ap);
return buf - obp;
}
|
