Welcome to the IPv4 Games

29 chillax 14 8/5/2025, 5:31:47 AM ipv4.games ↗

Comments (14)

johnisgood · 40m ago
On the website, there was a link to a game: https://www.familiars.io

I spent an hour playing it! It is quite good.

Is there a source code available for this game?

nicman23 · 2h ago
femboy.cat with a casual 0.2% of the internet
vaylian · 2h ago
But how do they achieve that? Do you use a lot of VPNs?
maverwa · 2h ago
my first guess would be: server honors X-Forwarded-For where it should not?

Edit: looks like thats it: https://github.com/jart/cosmopolitan/blob/master/net/turfwar...

So basically someone is running a script iterates over the whole ipv4 range and calls the claim endpoint with each single adress in the X-Forwared-For http header once.

viraptor · 18m ago
The line just under that prevents public IPs from using that function.
3r7j6qzi9jvnve · 2h ago
That only works if the proxy is sitting on localhost or a local network, just setting the header shouldn't work.

(I came here because I was curious how jart got 127 and 10, but after seeing the source is their's that's less of wonder..)

sgjohnson · 13m ago
bool IsPrivateIp(uint32_t x) {

  return (x >> 24) == 10                   /* 10.0.0.0/8  */

         || (x & 0xfff00000) == 0xac100000 /* 172.16.0.0/12  */

         || (x & 0xffff0000) == 0xc0a80000 /* 192.168.0.0/16  */;
}

the code doesn't consider 127.0.0.0/8 as "private". I'm curious about 10.0.0.0/8 though.*

elitepleb · 2h ago
a simple proof of the opposite is that no one's yet to exploit any of the untaken ranges that way
viraptor · 20m ago
There are VPNs which use residential endpoints. You essentially use other users' IPs there.
cedws · 18m ago
Botnet maybe.
sgjohnson · 17m ago
_nobody_ would waste a botnet of 9 million unique IPs like this.
usui · 7m ago
Well let's not get hasty... These are valuable internet points we're talking about here.
maldonad0 · 1h ago
Maybe spoofing source IPs.
sgjohnson · 25m ago
can't spoof the source IP in TCP communication, as the handshake cannot happen.

With UDP you can send whatever, but obviously you won't be able to receive the response.