From 06a716f78a14016bc2447fcb08804e3b0e2c34b9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joakim=20Frosteg=C3=A5rd?= <joakim.frostegard@gmail.com>
Date: Sun, 20 Mar 2022 18:41:41 +0100
Subject: [PATCH] ws: implement network.only_ipv6 and network.tcp_backlog

---
 Cargo.lock                       |  1 +
 aquatic_ws/Cargo.toml            |  1 +
 aquatic_ws/src/config.rs         |  7 +++++--
 aquatic_ws/src/workers/socket.rs | 31 ++++++++++++++++++++++++++++++-
 4 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ef96f4d..78cf4aa 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -281,6 +281,7 @@ dependencies = [
  "serde",
  "signal-hook",
  "slab",
+ "socket2 0.4.4",
  "tungstenite",
 ]
 
diff --git a/aquatic_ws/Cargo.toml b/aquatic_ws/Cargo.toml
index 4f1222a..3a4bc77 100644
--- a/aquatic_ws/Cargo.toml
+++ b/aquatic_ws/Cargo.toml
@@ -40,6 +40,7 @@ rustls-pemfile = "0.3"
 serde = { version = "1", features = ["derive"] }
 signal-hook = { version = "0.3" }
 slab = "0.4"
+socket2 = { version = "0.4", features = ["all"] }
 tungstenite = "0.17"
 
 [dev-dependencies]
diff --git a/aquatic_ws/src/config.rs b/aquatic_ws/src/config.rs
index 10ae6e1..95ab65a 100644
--- a/aquatic_ws/src/config.rs
+++ b/aquatic_ws/src/config.rs
@@ -59,7 +59,9 @@ pub struct NetworkConfig {
     /// Bind to this address
     pub address: SocketAddr,
     /// Only allow access over IPv6
-    pub ipv6_only: bool,
+    pub only_ipv6: bool,
+    /// Maximum number of pending TCP connections
+    pub tcp_backlog: i32,
 
     /// Path to TLS certificate (DER-encoded X.509)
     pub tls_certificate_path: PathBuf,
@@ -74,7 +76,8 @@ impl Default for NetworkConfig {
     fn default() -> Self {
         Self {
             address: SocketAddr::from(([0, 0, 0, 0], 3000)),
-            ipv6_only: false,
+            only_ipv6: false,
+            tcp_backlog: 1024,
 
             tls_certificate_path: "".into(),
             tls_private_key_path: "".into(),
diff --git a/aquatic_ws/src/workers/socket.rs b/aquatic_ws/src/workers/socket.rs
index 1de5d46..9f0384c 100644
--- a/aquatic_ws/src/workers/socket.rs
+++ b/aquatic_ws/src/workers/socket.rs
@@ -1,6 +1,7 @@
 use std::borrow::Cow;
 use std::cell::RefCell;
 use std::collections::BTreeMap;
+use std::os::unix::prelude::{FromRawFd, IntoRawFd};
 use std::rc::Rc;
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Arc;
@@ -56,7 +57,8 @@ pub async fn run_socket_worker(
     let config = Rc::new(config);
     let access_list = state.access_list;
 
-    let listener = TcpListener::bind(config.network.address).expect("bind socket");
+    let listener = create_tcp_listener(&config);
+
     num_bound_sockets.fetch_add(1, Ordering::SeqCst);
 
     let (in_message_senders, _) = in_message_mesh_builder.join(Role::Producer).await.unwrap();
@@ -540,3 +542,30 @@ impl ConnectionWriter {
 fn calculate_in_message_consumer_index(config: &Config, info_hash: InfoHash) -> usize {
     (info_hash.0[0] as usize) % config.request_workers
 }
+
+fn create_tcp_listener(config: &Config) -> TcpListener {
+    let domain = if config.network.address.is_ipv4() {
+        socket2::Domain::IPV4
+    } else {
+        socket2::Domain::IPV6
+    };
+
+    let socket = socket2::Socket::new(domain, socket2::Type::STREAM, Some(socket2::Protocol::TCP))
+        .expect("create socket");
+
+    if config.network.only_ipv6 {
+        socket.set_only_v6(true).expect("socket: set only ipv6");
+    }
+
+    socket.set_reuse_port(true).expect("socket: set reuse port");
+
+    socket
+        .bind(&config.network.address.into())
+        .unwrap_or_else(|err| panic!("socket: bind to {}: {:?}", config.network.address, err));
+
+    socket
+        .listen(config.network.tcp_backlog)
+        .unwrap_or_else(|err| panic!("socket: listen {}: {:?}", config.network.address, err));
+
+    unsafe { TcpListener::from_raw_fd(socket.into_raw_fd()) }
+}