/*

 *

 *  libnet 1.1

 *  Build a DNSv4 packet

 *  To view: /usr/sbin/tcpdump -vvvvven -s 0 port 53

 *

 *  Copyright (c) 2003 Frédéric Raynal <pappy@security-labs.org>

 *  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"

#ifdef __WIN32__

#include "../include/win32/getopt.h"

#endif

void

usage(char *prog)

{

    fprintf(stderr, "Usage: %s -d dst_ip -q query_host [-s src_ip] [-t]\n", prog);

    exit(1);

}

int

main(int argc, char *argv[])

{

    char c;

    u_long src_ip = 0, dst_ip = 0;

    u_short type = LIBNET_UDP_DNSV4_H;

    libnet_t *l;

    libnet_ptag_t ip;

    libnet_ptag_t ptag4; /* TCP or UDP ptag */

    libnet_ptag_t dns;

    char errbuf[LIBNET_ERRBUF_SIZE];

    char *query = NULL;

    char payload[1024];

    u_short payload_s;

    printf("libnet 1.1 packet shaping: DNSv4[raw]\n");

    /*

     *  Initialize the library.  Root priviledges are required.

     */

    l = libnet_init(

            LIBNET_RAW4,                            /* injection type */

            NULL,                                   /* network interface */

            errbuf);                                /* error buffer */

    if (!l)

    {

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

        exit(EXIT_FAILURE);

    }

    /*

     * parse options

     */

    while ((c = getopt(argc, argv, "d:s:q:t")) != EOF)

    {

        switch (c)

        {

            case 'd':

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

                {

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

                    exit(EXIT_FAILURE);

                }

                break;

            case 's':

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

                {

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

                    exit(EXIT_FAILURE);

                }

                break;

            case 'q':

                query = optarg;

                break;

            case 't':

                type = LIBNET_TCP_DNSV4_H;

                break;

            default:

                exit(EXIT_FAILURE);

        }

    }

    if (!src_ip)

    {

        src_ip = libnet_get_ipaddr4(l);

    }

    if (!dst_ip  || !query)

    {

        usage(argv[0]);

        exit(EXIT_FAILURE);

    }

    /* 

     * build dns payload 

     */

    payload_s = snprintf(payload, sizeof payload, "%c%s%c%c%c%c%c", 

			 (char)(strlen(query)&0xff), query, 0x00, 0x00, 0x01, 0x00, 0x01);

    /* 

     * build packet

     */

    dns = libnet_build_dnsv4(

	type,          /* TCP or UDP */

	0x7777,        /* id */

	0x0100,        /* request */

	1,             /* num_q */

	0,             /* num_anws_rr */

	0,             /* num_auth_rr */

	0,             /* num_addi_rr */

	payload,

	payload_s,

	l,

	0

	);

    if (dns == -1)

    {

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

        goto bad;

    }

    if (type == LIBNET_TCP_DNSV4_H) /* TCP DNS */

    {

	ptag4 = libnet_build_tcp(

	    0x6666,                                    /* source port */

	    53,                                        /* destination port */

	    0x01010101,                                /* sequence number */

	    0x02020202,                                /* acknowledgement num */

	    TH_PUSH|TH_ACK,                            /* control flags */

	    32767,                                     /* window size */

	    0,                                         /* checksum */

	    0,                                         /* urgent pointer */

	    LIBNET_TCP_H + LIBNET_TCP_DNSV4_H + payload_s, /* TCP packet size */

	    NULL,                                      /* payload */

	    0,                                         /* payload size */

	    l,                                         /* libnet handle */

	    0);                                        /* libnet id */

	if (ptag4 == -1)

	{

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

	    goto bad;

	}

	ip = libnet_build_ipv4(

	    LIBNET_IPV4_H + LIBNET_TCP_H + type + 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 (ip == -1)

	{

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

	    exit(EXIT_FAILURE);

	}

    }

    else /* UDP DNS */

    {

        ptag4 = libnet_build_udp(

            0x6666,                                /* source port */

            53,                                    /* destination port */

            LIBNET_UDP_H + LIBNET_UDP_DNSV4_H + payload_s, /* packet length */

            0,                                      /* checksum */

            NULL,                                   /* payload */

            0,                                      /* payload size */

            l,                                      /* libnet handle */

            0);                                     /* libnet id */

	if (ptag4 == -1)

	{

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

	    goto bad;

	}

	ip = libnet_build_ipv4(

	    LIBNET_IPV4_H + LIBNET_UDP_H + type + payload_s,/* length */

	    0,                                          /* TOS */

	    242,                                        /* IP ID */

	    0,                                          /* IP Frag */

	    64,                                         /* TTL */

	    IPPROTO_UDP,                                /* protocol */

	    0,                                          /* checksum */

	    src_ip,                                     /* source IP */

	    dst_ip,                                     /* destination IP */

	    NULL,                                       /* payload */

	    0,                                          /* payload size */

	    l,                                          /* libnet handle */

	    0);                                         /* libnet id */

	if (ip == -1)

	{

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

	    exit(EXIT_FAILURE);

	}

    }

    /*

     * write 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 DNS packet; check the wire.\n", c);

    }

    libnet_destroy(l);

    return (EXIT_SUCCESS);

  bad:

    libnet_destroy(l);

    return (EXIT_FAILURE);

}