blob: 5b8640cec26e6c849fcdd5125f14490c703bb306 (
plain)
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
|
/*
* Packet buffer structure and utilities.
*
* Copyright (C) 2015 Tobias Klauser <tklauser@distanz.ch>
*
* Based on pkt_buff.h from the netsniff-ng toolkit which is:
*
* Copyright (C) 2012 Christoph Jaeger
*
* This file is part of llmnrd.
*
* llmnrd is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 2 of the License.
*
* llmnrd is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with llmnrd. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef PKT_H
#define PKT_H
#include <assert.h>
#include <stdbool.h>
#include <stdint.h>
#include "log.h"
#include "util.h"
struct pkt {
uint8_t *data;
uint8_t *tail;
size_t size;
};
static inline bool pkt_invariant(struct pkt *p)
{
return p && (p->data <= p->tail);
}
static inline struct pkt *pkt_alloc(size_t size)
{
struct pkt *p = xmalloc(sizeof(*p) + size);
uint8_t *data = (uint8_t *)p + sizeof(*p);
p->data = p->tail = data;
p->size = size;
return p;
}
static inline void pkt_free(struct pkt *p)
{
free(p);
}
static inline size_t pkt_len(struct pkt *p)
{
assert(pkt_invariant(p));
return p->tail - p->data;
}
static inline uint8_t *pkt_put(struct pkt *p, size_t len)
{
uint8_t *data;
assert(pkt_invariant(p));
if (len <= pkt_len(p)) {
data = p->tail;
p->tail += len;
} else {
/* grow packet */
size_t new_size = p->size + len - pkt_len(p);
struct pkt *np = xrealloc(p, sizeof(*np) + new_size);
log_dbg("Reallocating packet from %zu to %zu bytes\n", p->size, new_size);
data = (uint8_t *)np + sizeof(*np);
np->data = data;
np->tail = data + pkt_len(p);
}
return data;
}
static inline void pkt_put_u16(struct pkt *p, uint16_t val)
{
uint16_t *data = (uint16_t *)pkt_put(p, sizeof(val));
*data = val;
}
static inline void pkt_put_u32(struct pkt *p, uint32_t val)
{
uint32_t *data = (uint32_t *)pkt_put(p, sizeof(val));
*data = val;
}
#endif /* PKT_H */
|
