Perform the multi-stream connections handshake inside smoldot

[tomaka]

cc #2754

In terms of API, this removes the necessity to pass a PeerId when creating a "multi-stream connection". The inner implementation now performs the substream opening and Noise negotiation internally.

[mergify]

Automatically approving tomaka's pull requests. This auto-approval will be removed once more maintainers are active.

[github-actions]

twiggy diff report

Difference in .wasm size before and after this pull request.

---

 Delta Bytes │ Item
─────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
       -8627 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h109c5b84e4bef32f
       +8624 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::hf6a4eec029e8ff75
       -3385 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h9df03109fffbe8fc
       +3326 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h3e744d7e7db6ffac
        +871 ┊ smoldot::libp2p::collection::multi_stream::MultiStreamConnectionTask<TNow,TSubId>::substream_read_write::h86f8ee4480b47eb2
        -791 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::he183e243778ca743
        +755 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h3cb712fc2622b718
        -511 ┊ smoldot::libp2p::collection::multi_stream::MultiStreamConnectionTask<TNow,TSubId>::new::h3bb34b28a0274823
        +445 ┊ smoldot::libp2p::collection::multi_stream::MultiStreamConnectionTask<TNow,TSubId>::new::hc742c6c7cc0d513f
        -398 ┊ core::ptr::drop_in_place<core::future::from_generator::GenFuture<smoldot_light::network_service::tasks::connection_task<smoldot_light_wasm::platform::Platform>::{{closure}}>>::h73107793b246aa38
        +360 ┊ core::ptr::drop_in_place<core::future::from_generator::GenFuture<smoldot_light::network_service::tasks::connection_task<smoldot_light_wasm::platform::Platform>::{{closure}}>>::hbfdd6ab1124aee53
        -351 ┊ smoldot::network::service::ChainNetwork<TNow>::pending_outcome_ok_multi_stream::h01c40207a31920c0
        +325 ┊ smoldot::network::service::ChainNetwork<TNow>::pending_outcome_ok_multi_stream::h3b3f8ddbacac09c6
        +321 ┊ <futures_util::future::poll_fn::PollFn<F> as core::future::future::Future>::poll::h18ad5e85d98e1acb
        -321 ┊ <futures_util::future::poll_fn::PollFn<F> as core::future::future::Future>::poll::h84d8c430c812f3ae
        -208 ┊ futures_util::async_await::random::shuffle::h32ed49da917f59cd
        +208 ┊ futures_util::async_await::random::shuffle::h443f2c022cf2eea2
        -197 ┊ core::ptr::drop_in_place<core::future::from_generator::GenFuture<smoldot_light::network_service::update_round<smoldot_light_wasm::platform::Platform>::{{closure}}>>::he4ac8a3471968db9
        +197 ┊ core::ptr::drop_in_place<core::future::from_generator::GenFuture<smoldot_light::network_service::update_round<smoldot_light_wasm::platform::Platform>::{{closure}}>>::hf8f4e3742c8ddac1
        -197 ┊ smoldot_light::network_service::tasks::connection_task::{{closure}}::{{closure}}::{{closure}}::h4e967583f3ccbfd6
       +1053 ┊ ... and 112 more.
       +1898 ┊ Σ [132 Total Rows]

[tomaka]

Note that the code has a couple of todo!s and unimplemented things, because I don't actually expect it to work first try anyway. This PR is merely an attempt to move #2579 forward. The code that this PR touches isn't used anywhere at the moment (apart from #2579).

[melekes]

are you sure this is easier than the old approach + Rust binding called from JS, which performs Noise handshake?

[tomaka]

are you sure this is easier than the old approach + Rust binding called from JS, which performs Noise handshake?

This is definitely easier. The old approach requires going through the JS<->Rust FFI layer, which is kind of complicated. It also requires proper handling of what to do if an exception is thrown by smoldot, which is also super complicated.