When opening generated URL: setsockopt: invalid argument

[koterpillar]

When opening the generated URL, I get an error from qrcp:

panic: set tcp 192.168.0.125:56603->192.168.0.31:45022: setsockopt: invalid argument

goroutine 20 [running]:
github.com/claudiodangelis/qrcp/server.tcpKeepAliveListener.Accept({0x10537c440?})
	/home/runner/work/qrcp/qrcp/server/tcpkeepalivelistener.go:48 +0xa0
net/http.(*Server).Serve(0x140002bc0f0, {0x10540e858, 0x140002986a0})
	/opt/hostedtoolcache/go/1.21.13/x64/src/net/http/server.go:3061 +0x2b8
github.com/claudiodangelis/qrcp/server.New.func5()
	/home/runner/work/qrcp/qrcp/server/server.go:339 +0xdc
created by github.com/claudiodangelis/qrcp/server.New in goroutine 1
	/home/runner/work/qrcp/qrcp/server/server.go:332 +0x9fc

qrcp 0.11.6 running on macOS 15.2 (ARM)

[claudiodangelis]

Thanks for reporting, I'll have a look soon.
Does it also happen when receiving files?

[koterpillar]

Yes, it does:

panic: set tcp 192.168.0.125:62462->192.168.0.125:62469: setsockopt: invalid argument

goroutine 20 [running]:
github.com/claudiodangelis/qrcp/server.tcpKeepAliveListener.Accept({0x102fa0440?})
	/home/runner/work/qrcp/qrcp/server/tcpkeepalivelistener.go:48 +0xa0
net/http.(*Server).Serve(0x140002bc0f0, {0x103032858, 0x14000296600})
	/opt/hostedtoolcache/go/1.21.13/x64/src/net/http/server.go:3061 +0x2b8
github.com/claudiodangelis/qrcp/server.New.func5()
	/home/runner/work/qrcp/qrcp/server/server.go:339 +0xdc
created by github.com/claudiodangelis/qrcp/server.New in goroutine 1
	/home/runner/work/qrcp/qrcp/server/server.go:332 +0x9fc

[claudiodangelis]

I could not reproduce the issue, see this job: https://github.com/claudiodangelis/qrcp/actions/runs/13906241740/job/38909832318

I've read somewhere that it might be caused to computer hibernation. Is this the case for you?
Thanks

[koterpillar]

I see that job running qrcp here, but not actually connecting to the URL. I only get the error when I try to open the URL, which probably explains the stack trace.

[claudiodangelis]

Ok noted, do you get the same error if you open the URL with curl?

[koterpillar]

Yes.

[claudiodangelis]

I added this e2e test and it succeeds: https://github.com/claudiodangelis/qrcp/actions/runs/13908227880/job/38916153605#step:4:1

This should have been sufficient to reproduce your issue?

Maybe I'm missing something?

[koterpillar]

When I add -i lo0 to qrcp arguments on my machine:

• There is a one-time system prompt for allowing qrcp to accept incoming connections
• When I allow that, it successfully sends the file through.

But when I don't add -i, I still see setsockopt: invalid argument.

ifconfig shows me a lot of interfaces. -i en0 gives me the same IP (192.168.xxx.xxx from my home router) and fails in the same way.

[claudiodangelis]

Ok, what is the behavior if you use -i any? (Remember to replace the external IP with either 127.0.0.1 or 192.168.x.y in the curl request)

[koterpillar]

When requested over localhost (resolves to [::1]) or 127.0.0.1, sends the file correctly.

When requested over the LAN IP, this happens (no output from qrcp itself):

*   Trying 192.168.0.125:49554...
* Connected to 192.168.0.125 (192.168.0.125) port 49554
> GET /send/ifzk HTTP/1.1
> Host: 192.168.0.125:49554
> User-Agent: curl/8.7.1
> Accept: */*
> 
* Request completely sent off
* Empty reply from server
* Closing connection
curl: (52) Empty reply from server

I seem to have another firewall intercepting the connection here, which will be a separate problem. I'm not sure whether the firewall interferes with SetKeepAlive, maybe keep the bug on hold until reproduced (or not) from another Mac machine.