setting a proxy overrides listen_interfaces

[arvidn]

The idea with this patch is to simplify the proxy handling. Instead of a proxy being treated as something independent from the network interfaces, it's treated as a network interface itself.

It makes sense that a single proxy really acts as an access point to the internet and when configuring one, whether your machine is multi-homed or not is not relevant, everything is funneled through the proxy.

It simplifies things like:

• UPnP, NAT-PMP, PCP and local service discovery can easily be disabled entirely when using a proxy
• Trackers will only announce once, via the proxy
• There will only be a single DHT running, via the proxy

This change, while cleaning up some common cases, also bans some rare cases. With this patch it will not be possible to combine running SSL torrents with a proxy. The SSL listen socket is also treated as a listen_socket_t. It will no longer be possible to combine multiple listen sockets with a proxy (mostly because there's only one proxy that can be configured).

To make this fully generic, each listen interface (i.e. entry in listen_interfaces setting) would have to have its own proxy configuration. That hardly seems worth the trouble though.

[FranciscoPombal]

With this patch it will not be possible to combine running SSL torrents with a proxy.

Does "SSL torrents" refer to using HTTPS trackers or to BEP 35?

[arvidn]

The latter. The reason is that to open an SSL listen socket (to accept incoming SSL peer connections), you need a listen_socket_t entry for that ssl socket. This patch makes a proxy also be its own kind of listen_socket_t. And there is no support for a listen_socket_t combining both features. Almost nobody uses SSL torrents (afaik), so I don't expect it to be an issue.

UPDATE: I didn't mean "the latter". I meant this feature.

[mederel]

As mentioned in the QBittorrent issue #11735, I compiled the content of the PR and it "fixed" the issue in QBittorrent.

I am running Manjaro Linux and QBittorrent 4.2.3 (community build for Manjaro).
To install the proxy-interface branch, I used the already existing AUR package libtorrent-rasterbar-git and just switch the source download to checkout the branch proxy-interface. But that is Linux, compiling is of course easier.

I think we are yet to see a Windows user compiling it too and corroborating my findings.

Cheers and kudos for the work provided, fantastic!

After that, I am sorry, I am really not well-versed enough in C++ to be in a position to do any kind of code reviews... I am a dev too, only in another language...

[arvidn]

thanks for testing! I will still need to figure out the issue in CI before landing this (and other, more urgent, issues have come up the last few days)

[FranciscoPombal]

@arvidn the situation with qbittorrent/qBittorrent#11735 seems to have improved with this patch (users have been testing with a test build that includes it thanks to @xavier2k6), but there are still UDP tracker issues apparently.

[arvidn]

@xavier2k6 I believe that last commit may have addressed the "already open" issue

[xavier2k6]

@xavier2k6 I believe that last commit may have addressed the "already open" issue

ok, will download from here & compile a new qBittorrent file for testing in #11735

[arvidn]

those last force pushes were just rebasing this on top of latest RC_1_2. it should be essentially the same otherwise.

I think this is in a good state now, ready to land. Anyone wanting to test would be appreciated!

[FranciscoPombal]

A build of qBittorrent with this patch will soon land in this thread qbittorrent/qBittorrent#11735, hopefully some of the people affected by the proxy issue will test it out.

[mederel]

Hi again, I recompiled the latest of proxy-interface and tested again. Working correctly here.
Still QBittorrent 4.2.3 and adapted libtorrent-rasterbar-git package of Manjaro/Arch linux.