Currently, `tunnel_test` uses a rather naive approach when dispatching
`Transmit`s. In particular, it checks client, gateway and relay
separately whether they "want" a certain packet. In a real network,
these packets are routed based on their IP.
To mimic something similar, we introduce a `Host` abstraction that wraps
each component: client, gateway and relay. Additionally, we introduce a
`RoutingTable` where we can add and remove hosts. With these things in
place, routing a `Transmit` is as easy as looking up the destination IP
in the routing table and dispatching to the corresponding host.
Our hosts are type-safe: client, gateway and relay have different types.
Thus, we abstract over them using a `HostId` in order to know, which
host a certain message is for. Following these patches, we can easily
introduce multiple gateways and relays to this test by simply making
more entries in this routing table. This will increase the test coverage
of connlib.
Lastly, this patch massively increases the performance of `tunnel_test`.
It turns out that previously, we spent a lot of CPU cycles accessing
"random" IPs from very large iterators. With this patch, we take a
limited range of 100 IPs that we sample from, thus drastically
increasing performance of this test. The configured 1000 testcases
execute in 3s on my machine now (with opt-level 1 which is what we use
in CI).
---------
Signed-off-by: Thomas Eizinger <thomas@eizinger.io>
Closes#5199
Not ready for review
```[tasklist]
### Before merging
- [x] Remove that outline at the top
- [x] Replace Mermaid diagrams with pre-rendered SVGs
- [x] Fix or ditch the diagrams
- [x] Use `we` instead of `I`
- [x] Elaborate on Tauri's architecture
- [x] Elaborate on our architecture
- [x] Grep for `TODO`s
- [x] Change "secure tunnel" to "connlib" to be more specific
- [x] Double-check alt texts on images
- [x] Last look
- [x] Fix the publish date
- [x] Last check that I didn't break anything else on the site
```
---------
Signed-off-by: Reactor Scram <ReactorScram@users.noreply.github.com>
Co-authored-by: Jamil <jamilbk@users.noreply.github.com>
