Add I2P support

[glassez]

Closes #16257.
Supersedes #18462.

[Vort]

Looks like peer list is still having problems.
However, download works and this is good.
Thanks.

[glassez]

Looks like peer list is still having problems.

Yes, I haven't managed to fix it yet.

[glassez]

@Vort
Could you test it again?

[Vort]

Peer list still have no I2P addresses, however, instead of single peer, now several peers can be displayed.
For me, it is enough for initial support:

(attentive reader can notice that something is wrong here, but it can be addressed later too)

[glassez]

Peer list still have no I2P addresses

They are probably inaccessible.
#16257 (comment)
arvidn/libtorrent#7346

[thalieht]

Didn't test.

[jiigen]

Peer list still have no I2P addresses

They are probably inaccessible. #16257 (comment) arvidn/libtorrent#7346

arvidn/libtorrent#7346 (comment)

[jiigen]

Maybe disabling pex and dht for i2p torrents would be a good idea too as these are not supported over i2p by libtorrent yet and, even if i'm not sure, they can break anonimity by contacting clearnet peers. Probalbly @Vort can know more about this.

[Vort]

I disabled DHT, PEX and LSD manually and advise users to do the same.
However, once these features will be correctly implemented, there will be need to do exactly opposite.
So that's why I'm not sure if there is need to spread such information.

[jiigen]

I disabled DHT, PEX and LSD manually and advise users to do the same. However, once these features will be correctly implemented, there will be need to do exactly opposite. So that's why I'm not sure if there is need to spread such information.

Maybe adding them as temporary "greyed out" options defaulting to disabled till these feature will be implemented?
Edit: I don't know if someone is working to add dht and/or pex over i2p to libtorrent actually so I fear that they will not be implemented soon

[Vort]

Maybe adding them as temporary "greyed out" options defaulting to disabled till these feature will be implemented?

I expect they may be useful in mixed mode.
I doubt that it will be easy to implement such graying out logic correctly.
However, developers may know better.

[jiigen]

Maybe adding them as temporary "greyed out" options defaulting to disabled till these feature will be implemented?

I expect they may be useful in mixed mode. I doubt that it will be easy to implement such graying out logic correctly. However, developers may know better.

I thought about something in the ui like:

• Mixed Mode
• Peer Exchange
• DHT
• LSD

With the first that enables the others but shouldnt be possible to enable the others without the first till they are implemented or maybe hidden (and disabled) unless one select mixed mode. @glassez I guess that Qt allows such kind of interactions?
Just an idea...

[xavier2k6]

@glassez This PR & PR#19079 fully closes #2682 right?

[glassez]

@glassez This PR & PR#19079 fully closes #2682 right?

Apparently, yes.