kognise / arpchat

Answering the question nobody asked: what if you wanted to text your friends using only ARP?

Geek Repo:Geek Repo

Github PK Tool:Github PK Tool

Duplicated messages on same host

mrkeuz opened this issue Β· comments

Again! Really fun project! πŸš€πŸš€πŸš€

If you run two instances on same host you receive duplicated messages (ONLY on receiver side)

image

Env

cargo +nightly build
cargo 1.60.0-nightly (95bb3c92b 2022-01-18)
Ubuntu 20.04.4 5.4.0-104-generic

I can't seem to reproduce this, but I fixed it by deduplicating messages by id in 8e22e48 which should wipe away this whole class of issues. Gonna make a new release in a couple minutes.

Confirm! Worked as expected on latest 5174daf πŸš€πŸš€πŸš€

@kognise hi again, I understand that it's just fun project, and I'm NOT expected to fix, REALLY.

Just FYI, found several issues:

  • History not show messages that I sent from machine
  • Sometimes users not detected but still receive messages as [unknown]. I've tried restart client - not help. Client that start FIRST not receive user list.
  • At start, messages not deliver at all (couple messages or there is some timeout, I don't get it)

Notes:

  • I run it on Linux β†’ Linux (via Wi-Fi)

  • In Wireshark messages are seems appearing . Can send pcap file to you, by email, if needed (just not want share mac addresses here). Just let me know.
    Here warm-up clients:

    image

image

hmm, that's weird! the implication is that some packets just aren't going through - i don't know if it's an issue of them being mutilated, or if they're just being dropped. could you open arpchat on only one device, reproduce one of the issues, and send me a pcap file from that device? if you'd prefer to email it, you can send to hi@kognise.dev.

if the problem is that the packets are being dropped i could try implementing some retry mechanism but it'll be a bit before i feel like doing something like that. in the meantime i am curious what the issue is :)

What I found, on lo interface all ok. History working, all clients displayed correctly.

image

BUT if you choose wlan/eth0 (both clients runs locally) issue reproduced as described above.

  • Comparing pcaps (lo vs wlan/eth0) seems ARP packets drops/filtered on wlan by some reason ((( Also not see any criminal rules about in iptables, ufw or on router (not sure how arp packets sending in core). Don't know where to dig after. Tested on two machines Ubuntu + Raspbian. Same behavior.
  • sudo does not help (I thought maybe not enough some network permission)
  • pcap details sent to email