DNS Replay Tool (drool)

drool can replay DNS traffic from packet capture (PCAP) files and send it to a specified server, with options such as to manipulate the timing between packets, as well as loop packets infinitely or for a set number of iterations. This tool's goal is to be able to produce a high amount of UDP packets per second and TCP sessions per second on common hardware.

The purpose can be to simulate Distributed Denial of Service (DDoS) attacks on the DNS and measure normal DNS querying. For example, the tool could enable you to take a snapshot of a DDoS and be able to replay it later to test if new code or hardening techniques are useful, safe & effective. Another example is to be able to replay a packet stream for a bug that is sequence- and/or timing-related in order to validate the efficacy of subsequent bug fixes.

More information may be found here:

• https://www.dns-oarc.net/tools/drool

Issues should be reported here:

• https://github.com/DNS-OARC/drool/issues

General support and discussion:

• Mattermost: https://chat.dns-oarc.net/community/channels/oarc-software

Known Issues

• IP fragments are currently not processed and will be discarded.
• TCP sessions are not reassembled, each packet is parsed as DNS after discarding the first two bytes.

Usage example

Send all DNS queries twice as fast as found in the PCAP file to localhost using UDP.

drool replay --timing multiply=0.5 --no-tcp file.pcap 127.0.0.1 53

Send all DNS queries over TCP to localhost as they were recorded.

drool replay --timing keep --no-udp file.pcap 127.0.0.1 53

Take all DNS queries found in the PCAP file and send them as fast as possible over UDP to localhost by ignoring both timings, replies and starting 3 threads that will simultaneously send queries.

drool replay --no-tcp --no-responses --threads --udp-threads 3 file.pcap 127.0.0.1 53

Dependencies

drool is built upon dnsjit and requires it to be installed along with autoconf/automake.

Build

sh autogen.sh
./configure
make
make test
make install

Author(s)

Jerry Lundström jerry@dns-oarc.net

Copyright

Copyright (c) 2017-2021, OARC, Inc.

Copyright (c) 2017, Comcast Corporation

All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

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   notice, this list of conditions and the following disclaimer.

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   notice, this list of conditions and the following disclaimer in
   the documentation and/or other materials provided with the
   distribution.

3. Neither the name of the copyright holder nor the names of its
   contributors may be used to endorse or promote products derived
   from this software without specific prior written permission.

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