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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*
* $Id: ntp.c,v 1.3 2004/02/20 18:53:49 mike Exp $
*
* libnet 1.1
* Build an NTP Packet
*
* Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#if (HAVE_CONFIG_H)
#include "../include/config.h"
#endif
#include "./libnet_test.h"
int
main(int argc, char **argv)
{
int c;
libnet_t *l;
u_long dst_ip;
libnet_ptag_t t;
char errbuf[LIBNET_ERRBUF_SIZE];
printf("libnet 1.1 NTP packet shaping[raw -- autobuilding IP]\n");
/*
* Initialize the library. Root priviledges are required.
*/
l = libnet_init(
LIBNET_RAW4, /* injection type */
NULL, /* network interface */
errbuf); /* error buf */
if (l == NULL)
{
fprintf(stderr, "libnet_init() failed: %s", errbuf);
exit(EXIT_FAILURE);
}
dst_ip = 0;
while((c = getopt(argc, argv, "d:")) != EOF)
{
switch (c)
{
/*
* We expect the input to be of the form `ip.ip.ip.ip.port`. We
* point cp to the last dot of the IP address/port string and
* then seperate them with a NULL byte. The optarg now points to
* just the IP address, and cp points to the port.
*/
case 'd':
if ((dst_ip = libnet_name2addr4(l, optarg, LIBNET_RESOLVE)) == -1)
{
fprintf(stderr, "Bad destination IP address: %s\n", optarg);
exit(1);
}
break;
}
}
if (!dst_ip)
{
usage(argv[0]);
exit(EXIT_FAILURE);
}
/*
* Build the packet, remmebering that order IS important. We must
* build the packet from lowest protocol type on up as it would
* appear on the wire. So for our NTP packet:
*
* --------------------------------------------------------------------
* | IP | UDP | NTP |
* --------------------------------------------------------------------
* ^ ^ ^
* |-------------- | |
* libnet_build_ipv4()--| | |
* | |
* libnet_build_udp()-------| |
* |
* libnet_build_ntp()------------------------------|
*/
t = libnet_build_ntp(
LIBNET_NTP_LI_AC, /* leap indicator */
LIBNET_NTP_VN_4, /* version */
LIBNET_NTP_MODE_S, /* mode */
LIBNET_NTP_STRATUM_PRIMARY, /* stratum */
4, /* poll interval */
1, /* precision */
0xffff, /* delay interval */
0xffff, /* delay fraction */
0xffff, /* dispersion interval */
0xffff, /* dispersion fraction */
LIBNET_NTP_REF_PPS, /* reference id */
0x11, /* reference ts int */
0x22, /* reference ts frac */
0x33, /* originate ts int */
0x44, /* originate ts frac */
0x55, /* receive ts int */
0x66, /* receive ts frac */
0x77, /* transmit ts interval */
0x88, /* transmit ts fraction */
NULL, /* payload */
0, /* payload size */
l, /* libnet handle */
0); /* libnet id */
if (t == -1)
{
fprintf(stderr, "Can't build NTP header: %s\n", libnet_geterror(l));
goto bad;
}
libnet_seed_prand(l);
t = libnet_build_udp(
libnet_get_prand(LIBNET_PRu16), /* source port */
123, /* NTP port */
LIBNET_UDP_H + LIBNET_NTP_H, /* UDP packet length */
0, /* checksum */
NULL, /* payload */
0, /* payload size */
l, /* libnet handle */
0); /* libnet id */
if (t == -1)
{
fprintf(stderr, "Can't build UDP header: %s\n", libnet_geterror(l));
goto bad;
}
t = libnet_autobuild_ipv4(
LIBNET_IPV4_H + LIBNET_UDP_H + LIBNET_NTP_H,/* packet length */
IPPROTO_UDP,
dst_ip,
l);
if (t == -1)
{
fprintf(stderr, "Can't build IP header: %s\n", libnet_geterror(l));
goto bad;
}
/*
* Write it to the wire.
*/
fprintf(stderr, "l contains a %d byte packet\n", libnet_getpacket_size(l));
c = libnet_write(l);
if (c == -1)
{
fprintf(stderr, "Write error: %s\n", libnet_geterror(l));
goto bad;
}
else
{
fprintf(stderr, "Wrote %d byte NTP packet; check the wire.\n", c);
}
libnet_destroy(l);
return (EXIT_SUCCESS);
bad:
libnet_destroy(l);
return (EXIT_FAILURE);
}
void
usage(char *name)
{
fprintf(stderr,
"usage: %s -d destination_ip\n",
name);
}
/* EOF */
|
