hero1s / tcp-proxy

A TCP proxy in 30 lines of Rust.

Proxy

A simple Rust TCP proxy. Intended to be educational - don't use this in production.

Terminoligy

server - the listener we'd like to proxy tcp connections to. client - the initiator of connections to the server.

Benchmarking

Using localhost:

1. Start the proxy in one terminal window

   cargo run -- -c 0.0.0.0:1212 -s 127.0.0.1:1313

2. Listen on the origin port in another window

   nc -l 1313 > /dev/null
   

3. Send a bunch of traffic from another window

   dd if=/dev/zero bs=1024 count=900000 | nc -v 127.0.0.1 1212
   

Using network namespaces:

If you have a debian linux machine you can use ns_test.sh to run a benchmark using three network namespaces.

Local Results

Using the proxy:

~ dd if=/dev/zero bs=1024 count=900000 | nc -v 127.0.0.1 1212
Connection to 127.0.0.1 port 1212 [tcp/lupa] succeeded!
900000+0 records in
900000+0 records out
921600000 bytes transferred in 4.369209 secs (210930626 bytes/sec)

Connecting directly to the server:

~ dd if=/dev/zero bs=1024 count=900000 | nc -v 127.0.0.1 1313
Connection to 127.0.0.1 port 1313 [tcp/bmc_patroldb] succeeded!
900000+0 records in
900000+0 records out
921600000 bytes transferred in 3.612901 secs (255085873 bytes/sec)

Results

(* 100 (/ 210930626.0 255085873.0))
=> 82.69004610851186

The tcp proxy is 82% the speed of a regular connection.

Network Namespace Results

Using the proxy:

921600000 bytes (922 MB, 879 MiB) copied, 25.4762 s, 36.2 MB/s

Connecting directly to the server:

921600000 bytes (922 MB, 879 MiB) copied, 5.17278 s, 178 MB/s

Results:

(* 100 (/ 36.2 178))
=> 20.337078651685395

the tcp proxy is 20% the speed of a regular connection.