Description
Powerful generator of DNS traffic, sending and receiving packets through XDP.
Queries are generated according to a textual file which is read sequentially
in a loop until a configured duration elapses. The order of queries is not
guaranteed. Responses are received (unless disabled) and counted, but not
checked against queries.
The number of parallel threads is autodetected according to the number of queues
configured for the network interface.
Options
- -t, –duration seconds
- Duration of traffic generation, specified as a decimal number in seconds
(default is 5.0).
- -T, –tcp[=debug_mode]
- Send queries over TCP. See the list of optional debug modes below.
- -U, –quic[=debug_mode]
- Send queries over QUIC. See the list of optional debug modes below.
- -Q, –qps queries
- Number of queries-per-second (approximately) to be sent (default is 1000).
The program is not optimized for low speeds at which it may lose
communication packets. The recommended minimum speed is 2 packets per thread
(Rx/Tx queue).
- -b, –batch size
- Send more queries in a batch. Improves QPS but may affect the counterpart’s
packet loss (default is 10 for UDP and 1 for TCP/QUIC).
- -r, –drop
- Drop incoming responses. Improves QPS, but disables response statistics.
- -p, –port number
- Remote destination port (default is 53 for UDP/TCP, 853 for QUIC).
- -F, –affinity cpu_spec
- CPU affinity for all threads specified in the format [<cpu_start>][s<cpu_step>],
where <cpu_start> is the CPU ID for the first thread and <cpu_step> is the
CPU ID increment for next thread (default is 0s1).
- -i, –infile filename
- Path to a file with query templates.
- -I, –interface interface
- Network interface for outgoing communication. This can be useful in situations
when the interfaces are in a bond for example.
- -l, –local localIP[/prefix]
- Override the auto-detected source IP address. If an address range is specified
instead, various IPs from the range will be used for different queries uniformly
(address range not supported in the QUIC mode).
- targetIP
- The IPv4 or IPv6 address of remote destination.
- -L, –mac-local
- Override auto-detected local MAC address.
- -R, –mac-remote
- Override auto-detected remote MAC address.
- -h, –help
- Print the program help.
- -V, –version
- Print the program version.
TCP/QUIC debug modes
- 0
- Perform full handshake for all connections (QUIC only).
- 1
- Just send SYN (Initial) and receive SYN-ACK (Handshake).
- 2
- Perform TCP/QUIC handshake and don’t send anything, allow close initiated by counterpart.
- 3
- Perform TCP/QUIC handshake and don’t react further.
- 5
- Send incomplete query (N-1 bytes) and don’t react further.
- 7
- Send query and don’t ACK the response or anything further.
- 8
- Don’t close the connection and ignore close by counterpart (TCP only).
- 9
- Operate normally except for not ACKing the final FIN+ACK (TCP only).
Signals
Sending USR1 signal to a running process triggers current statistics dump
to the standard output.
Notes
Linux kernel 4.18+ is required.
The utility has to be executed under root or with these capabilities:
CAP_NET_RAW, CAP_NET_ADMIN, CAP_SYS_ADMIN, and CAP_SYS_RESOURCE if maximum
locked memory limit is too low on Linux < 5.11.
The utility allocates source UDP/TCP ports from the range 2000-65535.
Examples
Manually created queries file:
abc6.example.com. AAAA
nxdomain.example.com. A
notzone. A
a.example.com. NS E
ab.example.com. A D
abcd.example.com. DS D
Queries file generated from a zone file (Knot DNS format):
cat ZONE_FILE | awk "{print \$1,\$3}" | grep -E "(NS|DS|A|AAAA|PTR|MX|SOA)$" | sort -u -R > queries.txt
Basic usage:
# kxdpgun -i ~/queries.txt 2001:DB8::1
Using UDP with increased batch size:
# kxdpgun -t 20 -Q 1000000 -i ~/queries.txt -b 20 -p 8853 192.0.2.1
Using TCP:
# kxdpgun -t 20 -Q 100000 -i ~/queries.txt -T -p 8853 192.0.2.1