ping-latency-injector

ping-latency-injector is a latency injector for ping on server side.

On server, if it receives an ECHOREQUEST ICMPv4 packet, ping-latency-injector is able to delay to reply the ECHOREPLY ICMPv4 packet.

Goody

It's really interesting to hide the network distance on server, which is detect by ping.

In hence, bad guys are unable to detect the real network distance between servers by ping.

However, it's easy to calculate the real latency by subtracting the specified injected latency.

How it works?

It works with XDP and AF_XDP.

1. XDP program check the packet whether it's an ECHOREQUEST ICMPv4 packet.
2. XDP redirects the packet to AF_XDP.
3. AF_XDP sends the packet to user-space application.
4. After the specified latency, application transforms the packet to an ECHOREPLY one.
5. Application sends the transformed packets by AF_XDP.

Build and run

# git clone git@github.com:Asphaltt/ping-latency-injector.git
# cd ping-latency-injector
# go generate && go build
# ./ping-latency-injector -h
Usage of ./ping-latency-injector:
  -D, --dev string   device to inject latency to ping
  -L, --lat string   latency to delay, 1ms <= latency <= 10s (default "1ms")
pflag: help requested
# ./ping-latency-injector -D enp0s8 -L 600ms
2023/03/12 16:01:37 Attached XDP to enp0s8

# echo On other host terminal
# ping -s 1400 -c3 192.168.1.138
PING 192.168.1.138 (192.168.1.138): 1400 data bytes
1408 bytes from 192.168.1.138: icmp_seq=0 ttl=64 time=600.888 ms
1408 bytes from 192.168.1.138: icmp_seq=1 ttl=64 time=0.661 ms  # Cancel suddenly
1408 bytes from 192.168.1.138: icmp_seq=2 ttl=64 time=0.495 ms

--- 192.168.1.138 ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.495/200.681/600.888/282.989 ms

License

BSD-3 License