/*

* $Id: tcp2.c,v 1.3 2004/01/28 19:45:00 mike Exp $

*

* libnet 1.1

* raw_tcp.c - Build a TCP 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;

char *cp;

libnet_t *l;

libnet_ptag_t t;

char *payload;

u_short payload_s;

u_long src_ip, dst_ip;

u_short src_prt, dst_prt;

char errbuf[LIBNET_ERRBUF_SIZE];

printf("libnet 1.1 packet shaping: TCP[raw]\n");

/*

* Initialize the library. Root priviledges are required.

*/

l = libnet_init(

LIBNET_RAW4, /* injection type */

NULL, /* network interface */

errbuf); /* errbuf */

if (l == NULL)

{

fprintf(stderr, "libnet_init() failed: %s", errbuf);

exit(EXIT_FAILURE);

}

src_ip = 0;

dst_ip = 0;

src_prt = 0;

dst_prt = 0;

payload = NULL;

payload_s = 0;

while((c = getopt(argc, argv, "d:s:p:")) != 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 separate them with a NULL byte. The optarg now points to

* just the IP address, and cp points to the port.

*/

case 'd':

if (!(cp = strrchr(optarg, '.')))

{

usage(argv[0]);

}

*cp++ = 0;

dst_prt = (u_short)atoi(cp);

if ((dst_ip = libnet_name2addr4(l, optarg, LIBNET_RESOLVE)) == -1)

{

fprintf(stderr, "Bad destination IP address: %s\n", optarg);

exit(EXIT_FAILURE);

}

break;

break;

case 'p':

payload = optarg;

payload_s = strlen(payload);

break;

case 's':

if (!(cp = strrchr(optarg, '.')))

{

usage(argv[0]);

}

*cp++ = 0;

src_prt = (u_short)atoi(cp);

if ((src_ip = libnet_name2addr4(l, optarg, LIBNET_RESOLVE)) == -1)

{

fprintf(stderr, "Bad source IP address: %s\n", optarg);

exit(EXIT_FAILURE);

}

break;

}

}

if (!src_ip || !src_prt || !dst_ip || !dst_prt)

{

usage(argv[0]);

exit(EXIT_FAILURE);

}

t = libnet_build_tcp(

src_prt, /* source port */

dst_prt, /* destination port */

0x01010101, /* sequence number */

0x02020202, /* acknowledgement num */

TH_SYN, /* control flags */

32767, /* window size */

0, /* checksum */

10, /* urgent pointer */

LIBNET_TCP_H + payload_s, /* TCP packet size */

(uint8_t*)payload, /* payload */

payload_s, /* payload size */

l, /* libnet handle */

0); /* libnet id */

if (t == -1)

{

fprintf(stderr, "Can't build TCP header: %s\n", libnet_geterror(l));

goto bad;

}

t = libnet_build_ipv4(

LIBNET_IPV4_H + LIBNET_TCP_H + payload_s, /* length */

0, /* TOS */

242, /* IP ID */

0, /* IP Frag */

64, /* TTL */

IPPROTO_TCP, /* protocol */

0, /* checksum */

src_ip, /* source IP */

dst_ip, /* destination IP */

NULL, /* payload */

0, /* payload size */

l, /* libnet handle */

0); /* libnet id */

if (t == -1)

{

fprintf(stderr, "Can't build IP header: %s\n", libnet_geterror(l));

goto bad;

}

/*

* Write it to the wire.

*/

c = libnet_write(l);

if (c == -1)

{

fprintf(stderr, "Write error: %s\n", libnet_geterror(l));

goto bad;

}

else

{

fprintf(stderr, "Wrote %d byte TCP 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 -s source_ip.source_port -d destination_ip.destination_port"

" [-p payload]\n",

name);

}