This is a program that replies to DNS packets with the same packet with the response flags modified according to RFC 1035.
It is intended to provide a baseline measure for system throughput
based on various socket reading APIs, specified with the -m flag:
b: blocking I/On: non-blocking I/O (busy spin)m: mmsg calls (multiple messages per system call)p: use poll(2)s: use select(2)l: use libevent2 (with system specific read calls)
For increased throughput the program can fork multiple children (-f)
and/or multiple threads (-t).
The program can fix each child or thread to a different CPU core
using the -a flag.
If supplied the -r flag the program will open a separate file
descriptor per sub-process using the SO_REUSEPORT socket option.
On exit via SIGINT or SIGTERM it will display the number of
packets that were handled by each sub process.
The code is designed to run on Linux and uses a few non-portable API calls.
It requires libevent2 (and its development packages) to be installed.
To install from git, run autoreconf -i to build the configure script,
and then run ./configure followed by make.