Couldn't connect / timeout results in EOF or empty response on SPN about spn

[northys]

Chrome/curl reports it as empty response. Firefox/httpie reports it as EOF.

[northys]

I think, there are multiple cases when this error occurs. It happened right now when I opened link on a website, I thought it was blocked but F5 loaded it.

I think this can be caused by
a) connection in SPN network between SPN nodes failed / timeouts / whatever
b) the page being loaded through SPN network timeouts / cant connect to edge (last in SPN connection chain) node

[dhaavi]

Hey @northys, thanks for reporting this!

This behavior is a result of how the SPN works. The TCP connection is "terminated" locally and then only the data goes through the SPN. This means that a TCP connection through the SPN will always succeed (within a couple ms) from the view of the application itself.
Should the connection through SPN or from the SPN exit to the destination fail, the connection will be closed without having sent any data, resulting in an EOF or "empty response" error.

You can see that this happens in the "Unexpected Logs" section of the provided debug data.

We can't spoof another response, as most of the time, the connection will be encrypted.

We can probably solve the most of these errors by checking if any data was returned and retrying the connection. This is something I will be looking into in the coming weeks.

[northys]

I would say that it is happening more likely on websites I (or maybe other) never visited. E.g. for websites opened from google search results... And it's always INSTANT.

https://support.safing.io/privatebin/?94e5263409f87d59#G4HA1z3ZezCuS6qTT6FPUKCJLAF71BhcWWAYY5yt3KNa