How to proxy traffic depending on the listening port to other proxies?

Question

proxy

Good afternoon,

What is required:
You need to create, so to speak, a proxy-chain of two nodes using one server and rented proxies.
But only without any additional programs on the client (such as proxyfier, proxycap, sockschain, etc.)

What we have:
1) A rented Ubuntu VPS server with Nodejs (root access) it runs a simple socks5 script with an IP address, for example: 0.0.0.1 and listening port 1080
2) There are 10 purchased proxies with the Socks5 protocol (IP:PORT with logins and passwords from each).
For example: 1.2.3.10:3128, 1.2.3.11:3128, 1.2.3.12:3128 etc.
3) Suppose some program on my computer has a proxy add-on, let's call it Soft1.
In Soft1, traffic and all requests are proxied to VPS (that is, to 0.0.0.1:1080)

Task:
It is necessary to make sure that other programs (Soft2, Soft3, Soft4, etc.) also access VPS 0.0.0.1
But to different ports (for example 1081, 1082, 1083).
Next, the VPS should redirect traffic depending on the listening port to different proxies...

For example:
Soft1 (with proxy 0.0.0.1:1080) --> redirect traffic further to proxy 1.2.3.10:3128
Soft2 (with proxy 0.0.0.1:1081 ) --> redirects further traffic to proxy 1.2.3.11:3128
Soft3 (with proxy 0.0.0.1:1082) --> redirects further traffic to proxy 1.2.3.12:3128

What we get:
Soft1 program will see IP
1.2.3.10 Soft2 program will see IP 1.2.3.11
The Soft3 program will have IP 1.2.3.12 visible

The protocol is preferable to Socks5 since each program has a proxy add-on (but you can contact the VPS and via SSH. The downside is that you will have to produce 10 SSH programs on the client, and how then to identify Soft1 from Soft2 to redirect them to different proxies, spawning SSH ports doesn't seem like a good idea...)

I would be glad for any recommendations, tips and hints!

Answer 1

In 3proxy

auth iponly
fakeresolve

allow *
parent 1000 socks5+ 1.2.3.10 3128
socks -i0.0.0.1 -p1080

flush
allow *
parent 1000 socks5+ 1.2.3.11 3128
socks -i0.0.0.1 -p1081

flush
allow *
parent 1000 socks5+ 1.2.3.12 3128
socks -i0.0.0.1 -p1082

...