refactor(iroh-relay)!: server actor task is not a task or actor anymore (#3093)

## Description

- Restructures the server part of the relay to not mainly run an actor,
but onyl proxy between a single actor per connection.
- removes notifying the server about preferred/home relay status, to
simplify the protocol, as this was only used for metrics

Replaces #3073

## Breaking Changes

- renamed `iroh_relay::server::ClientConnRateLimit` to `ClientRateLimit`
- removed `iroh_relay::server::MaybeTlsStreamServer` from the public API
- removed `iroh_relay::client::SendMessage::NotePreferred`

## Notes & open questions

<!-- Any notes, remarks or open questions you have to make about the PR.
-->

## Change checklist

- [ ] Self-review.
- [ ] Documentation updates following the [style
guide](https://rust-lang.github.io/rfcs/1574-more-api-documentation-conventions.html#appendix-a-full-conventions-text),
if relevant.
- [ ] Tests if relevant.
- [ ] All breaking changes documented.

Author: dignifiedquire

Cargo.lock

@@ -90,6 +90,7 @@ webpki = { package = "rustls-webpki", version = "0.102" }
 webpki-roots = "0.26"
 data-encoding = "2.6.0"
 lru = "0.12"
+dashmap = { version = "6.1.0", optional = true }
 
 [dev-dependencies]
 clap = { version = "4", features = ["derive"] }
@@ -116,6 +117,7 @@ default = ["metrics"]
 server = [
     "dep:tokio-rustls-acme",
     "dep:clap",
+    "dep:dashmap",
     "dep:toml",
     "dep:rustls-pemfile",
     "dep:regex",

iroh-relay/Cargo.toml

@@ -327,8 +327,6 @@ impl TryFrom<Frame> for ReceivedMessage {
 pub enum SendMessage {
     /// Send a packet of data to the [`NodeId`].
     SendPacket(NodeId, Bytes),
-    /// Mark or unmark the connected relay as the home relay.
-    NotePreferred(bool),
     /// Sends a ping message to the connected relay server.
     Ping([u8; 8]),
     /// Sends a pong message to the connected relay server.
@@ -339,7 +337,6 @@ impl From<SendMessage> for Frame {
     fn from(source: SendMessage) -> Self {
         match source {
             SendMessage::SendPacket(dst_key, packet) => Frame::SendPacket { dst_key, packet },
-            SendMessage::NotePreferred(preferred) => Frame::NotePreferred { preferred },
             SendMessage::Ping(data) => Frame::Ping { data },
             SendMessage::Pong(data) => Frame::Pong { data },
         }

iroh-relay/src/client/conn.rs

@@ -16,7 +16,7 @@ use iroh_relay::{
         DEFAULT_HTTPS_PORT, DEFAULT_HTTP_PORT, DEFAULT_METRICS_PORT, DEFAULT_RELAY_QUIC_PORT,
         DEFAULT_STUN_PORT,
     },
-    server::{self as relay, ClientConnRateLimit, QuicConfig},
+    server::{self as relay, ClientRateLimit, QuicConfig},
 };
 use serde::{Deserialize, Serialize};
 use tokio_rustls_acme::{caches::DirCache, AcmeConfig};
@@ -543,7 +543,7 @@ async fn build_relay_config(cfg: Config) -> Result<relay::ServerConfig<std::io::
                         bail!("bytes_per_seconds must be specified to enable the rate-limiter");
                     }
                     match rx.bytes_per_second {
-                        Some(bps) => Some(ClientConnRateLimit {
+                        Some(bps) => Some(ClientRateLimit {
                             bytes_per_second: bps
                                 .try_into()
                                 .context("bytes_per_second must be non-zero u32")?,

iroh-relay/src/main.rs

@@ -43,9 +43,6 @@ const MAGIC: &str = "RELAY🔑";
 
 #[cfg(feature = "server")]
 pub(crate) const KEEP_ALIVE: Duration = Duration::from_secs(60);
-// TODO: what should this be?
-#[cfg(feature = "server")]
-pub(crate) const SERVER_CHANNEL_SIZE: usize = 1024 * 100;
 /// The number of packets buffered for sending per client
 #[cfg(feature = "server")]
 pub(crate) const PER_CLIENT_SEND_QUEUE_DEPTH: usize = 512; //32;
@@ -181,7 +178,7 @@ pub(crate) async fn recv_client_key<S: Stream<Item = anyhow::Result<Frame>> + Un
 
     // TODO: variable recv size: 256 * 1024
     let buf = tokio::time::timeout(
-        Duration::from_secs(10),
+        std::time::Duration::from_secs(10),
         recv_frame(FrameType::ClientInfo, stream),
     )
     .await
@@ -593,6 +590,7 @@ mod tests {
     use super::*;
 
     #[tokio::test]
+    #[cfg(feature = "server")]
     async fn test_basic_read_write() -> anyhow::Result<()> {
         let (reader, writer) = tokio::io::duplex(1024);
         let mut reader = FramedRead::new(reader, RelayCodec::test());

iroh-relay/src/protos/relay.rs

@@ -42,8 +42,7 @@ use crate::{
     quic::server::{QuicServer, ServerHandle as QuicServerHandle},
 };
 
-pub(crate) mod actor;
-pub(crate) mod client_conn;
+mod client;
 mod clients;
 mod http_server;
 mod metrics;
@@ -55,7 +54,6 @@ pub mod testing;
 pub use self::{
     metrics::{Metrics, StunMetrics},
     resolver::{ReloadingResolver, DEFAULT_CERT_RELOAD_INTERVAL},
-    streams::MaybeTlsStream as MaybeTlsStreamServer,
 };
 
 const NO_CONTENT_CHALLENGE_HEADER: &str = "X-Tailscale-Challenge";
@@ -177,12 +175,12 @@ pub struct Limits {
     /// Burst limit for accepting new connection. Unlimited if not set.
     pub accept_conn_burst: Option<usize>,
     /// Rate limits for incoming traffic from a client connection.
-    pub client_rx: Option<ClientConnRateLimit>,
+    pub client_rx: Option<ClientRateLimit>,
 }
 
 /// Per-client rate limit configuration.
 #[derive(Debug, Copy, Clone)]
-pub struct ClientConnRateLimit {
+pub struct ClientRateLimit {
     /// Max number of bytes per second to read from the client connection.
     pub bytes_per_second: NonZeroU32,
     /// Max number of bytes to read in a single burst.