-torcontrol does not resolve a hostname if it is given #22236

Expected behavior

-torcontrol should try to resolve a hostname if it is given

Actual behavior

The hostname is passed as an ip so the connection fails

2021-06-13T20:35:54Z tor: Error parsing socket address mynode.local:9051
2021-06-13T20:35:54Z tor: Initiating connection to Tor control port mynode.local:9051 failed

To reproduce

Add 127.0.0.1 mynode to /etc/hosts and pass -torcontrol=mynode:9051 as an argument. The connection fails. Try with -torcontrol=127.0.0.1:9051 and it works.

System information

Bitcoin Core 0.21.1 from https://bitcoincore.org/bin/bitcoin-core-0.21.1/bitcoin-0.21.1-x86_64-linux-gnu.tar.gz Ubuntu 18.04

What if you replace 127.0.0.1 mynode with 127.0.0.1 mynode.local in /etc/hosts and pass -torcontrol=mynode.local:9051 as an argument?

Still get the same error

2021-06-13T20:35:54Z tor: Error parsing socket address mynode.local:9051
2021-06-13T20:35:54Z tor: Initiating connection to Tor control port mynode.local:9051 failed

It works for -proxy. Looks like it calls Lookup() first to resolve the hostname https://github.com/bitcoin/bitcoin/blob/d75a1df6178aabf6f19271786e48bc5d57eddb54/src/init.cpp#L1218-L1226

For -torcontrol it passes the hostname straight through https://github.com/bitcoin/bitcoin/blob/d75a1df6178aabf6f19271786e48bc5d57eddb54/src/torcontrol.cpp#L579-L584

It works for -proxy. Looks like it calls Lookup() first to resolve the hostname. For -torcontrol it passes the hostname straight through

Yes we can try using lookup for torcontrol as well. However I noticed a weird thing: hostname works in Ubuntu but fails in Fedora for proxy.

proxy=localhost:9050

Maybe I need to remove ::1 from hosts file. Ubuntu has a different hosts file(default)

I still have this problem in 22.0. Tor runs in a docker container and also bitcoind in a separete container(both bridged). proxy="host.docker.internal:9050" resolves fine to the docker host 192.168.1.11:9050 but torcontrol=host.docker.internal:9051 fails with

2022-04-07T06:26:53Z torcontrol thread start
2022-04-07T06:26:53Z tor: Error parsing socket address host.docker.internal:9051
2022-04-07T06:26:53Z tor: Initiating connection to Tor control port host.docker.internal:9051 failed
2022-04-07T06:26:53Z torcontrol thread exit

What can I do here when both Tor and bitcoind run in containers?

I still have this problem in 22.0. Tor runs in a docker container and also bitcoind in a separete container(both bridged). proxy="host.docker.internal:9050" resolves fine to the docker host 192.168.1.11:9050 but torcontrol=host.docker.internal:9051 fails with

2022-04-07T06:26:53Z torcontrol thread start
2022-04-07T06:26:53Z tor: Error parsing socket address host.docker.internal:9051
2022-04-07T06:26:53Z tor: Initiating connection to Tor control port host.docker.internal:9051 failed
2022-04-07T06:26:53Z torcontrol thread exit

What can I do here when both Tor and bitcoind run in containers? @juxeii were you able to resolve this? I'm running the same setup as you.

@juxeii nevermind. I fixed by assigning static IPs to tor and bitcoind, using this example https://forums.docker.com/t/static-ip-on-docker-containers/110412/3