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
|
/* addr_and_mask.c
* Routines to fetch IPv4 and IPv6 addresses from a tvbuff and then mask
* out bits other than those covered by a prefix length
*
* $Id$
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
* Copyright 1998 Gerald Combs
*
* This program 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; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdlib.h>
#include <string.h>
#include "tvbuff.h"
#include "addr_and_mask.h"
/*
* These routines return the length of the address in bytes on success
* and -1 if the prefix length is too long.
*/
int
ipv4_addr_and_mask(tvbuff_t *tvb, int offset, guint8 *addr, guint32 prefix_len)
{
guint32 addr_len;
if (prefix_len > 32)
return -1;
addr_len = (prefix_len + 7) / 8;
memset(addr, 0, 4);
tvb_memcpy(tvb, addr, offset, addr_len);
if (prefix_len % 8)
addr[addr_len - 1] &= ((0xff00 >> (prefix_len % 8)) & 0xff);
return addr_len;
}
int
ipv6_addr_and_mask(tvbuff_t *tvb, int offset, struct e_in6_addr *addr,
guint32 prefix_len)
{
guint32 addr_len;
if (prefix_len > 128)
return -1;
addr_len = (prefix_len + 7) / 8;
memset(addr->bytes, 0, 16);
tvb_memcpy(tvb, addr->bytes, offset, addr_len);
if (prefix_len % 8) {
addr->bytes[addr_len - 1] &=
((0xff00 >> (prefix_len % 8)) & 0xff);
}
return addr_len;
}
|
