From f0a93b4161a670f7b5d9d6ec7e48c241907e2845 Mon Sep 17 00:00:00 2001
From: ospab <ospab@ospab.host>
Date: Sun, 17 May 2026 02:19:59 +0300
Subject: [PATCH] perf: heavily tune UDP socket buffers via socket2 to support
 10Gbps+ micro-burst resilience

---
 Cargo.lock                | 12 +++++++-----
 ostp-client/Cargo.toml    |  1 +
 ostp-client/src/bridge.rs | 11 ++++++++---
 ostp-server/Cargo.toml    |  1 +
 ostp-server/src/lib.rs    |  9 ++++++++-
 5 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 05abac9..ed1a755 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -745,7 +745,7 @@ checksum = "c08d65885ee38876c4f86fa503fb49d7b507c2b62552df7c70b2fce627e06381"
 
 [[package]]
 name = "ostp"
-version = "0.1.55"
+version = "0.1.56"
 dependencies = [
  "anyhow",
  "base64",
@@ -762,7 +762,7 @@ dependencies = [
 
 [[package]]
 name = "ostp-client"
-version = "0.1.55"
+version = "0.1.56"
 dependencies = [
  "anyhow",
  "bytes",
@@ -773,13 +773,14 @@ dependencies = [
  "rand",
  "serde",
  "serde_json",
+ "socket2",
  "tokio",
  "tracing",
 ]
 
 [[package]]
 name = "ostp-core"
-version = "0.1.55"
+version = "0.1.56"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -812,7 +813,7 @@ dependencies = [
 
 [[package]]
 name = "ostp-server"
-version = "0.1.55"
+version = "0.1.56"
 dependencies = [
  "anyhow",
  "bytes",
@@ -820,13 +821,14 @@ dependencies = [
  "rand",
  "serde",
  "serde_json",
+ "socket2",
  "tokio",
  "tracing",
 ]
 
 [[package]]
 name = "ostp-tun-helper"
-version = "0.1.55"
+version = "0.1.56"
 dependencies = [
  "anyhow",
  "chrono",
diff --git a/ostp-client/Cargo.toml b/ostp-client/Cargo.toml
index 810bc5d..6cc94c3 100644
--- a/ostp-client/Cargo.toml
+++ b/ostp-client/Cargo.toml
@@ -16,3 +16,4 @@ serde_json = "1.0"
 json_comments = "0.2"
 portable-atomic.workspace = true
 chrono = "0.4"
+socket2 = "0.6.3"
diff --git a/ostp-client/src/bridge.rs b/ostp-client/src/bridge.rs
index 55f6852..3cb32c3 100644
--- a/ostp-client/src/bridge.rs
+++ b/ostp-client/src/bridge.rs
@@ -609,9 +609,14 @@ impl Bridge {
             max_sent_history: 65536, // Greatly expanded to guarantee that oldest unacked packets are not prematurely popped and lost
         })?;
 
-        let socket = UdpSocket::bind(&self.local_bind_addr)
-            .await
-            .with_context(|| format!("failed to bind local udp {}", self.local_bind_addr))?;
+        let addr = self.local_bind_addr.parse::<std::net::SocketAddr>().map_err(|e| anyhow::anyhow!("invalid bind addr: {}", e))?;
+        let domain = if addr.is_ipv6() { socket2::Domain::IPV6 } else { socket2::Domain::IPV4 };
+        let sock = socket2::Socket::new(domain, socket2::Type::DGRAM, Some(socket2::Protocol::UDP))?;
+        let _ = sock.set_recv_buffer_size(33554432); // 32MB
+        let _ = sock.set_send_buffer_size(33554432); // 32MB
+        sock.bind(&addr.into())?;
+        sock.set_nonblocking(true)?;
+        let socket = UdpSocket::from_std(sock.into())?;
 
         if self.turn_enabled {
             let turn_addr = if self.turn_server.contains(':') {
diff --git a/ostp-server/Cargo.toml b/ostp-server/Cargo.toml
index f5f1ffe..33fda7b 100644
--- a/ostp-server/Cargo.toml
+++ b/ostp-server/Cargo.toml
@@ -13,3 +13,4 @@ ostp-core = { path = "../ostp-core" }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 rand.workspace = true
+socket2 = "0.6.3"
diff --git a/ostp-server/src/lib.rs b/ostp-server/src/lib.rs
index dd852ed..436bd39 100644
--- a/ostp-server/src/lib.rs
+++ b/ostp-server/src/lib.rs
@@ -116,7 +116,14 @@ pub async fn run_server(
         }
     });
 
-    let socket = UdpSocket::bind(&bind_addr).await?;
+    let addr = bind_addr.parse::<std::net::SocketAddr>().map_err(|e| anyhow::anyhow!("invalid bind addr: {}", e))?;
+    let domain = if addr.is_ipv6() { socket2::Domain::IPV6 } else { socket2::Domain::IPV4 };
+    let sock = socket2::Socket::new(domain, socket2::Type::DGRAM, Some(socket2::Protocol::UDP))?;
+    let _ = sock.set_recv_buffer_size(33554432); // 32MB
+    let _ = sock.set_send_buffer_size(33554432); // 32MB
+    sock.bind(&addr.into())?;
+    sock.set_nonblocking(true)?;
+    let socket = UdpSocket::from_std(sock.into())?;
     let protocol_config = ProtocolConfig {
         role: NoiseRole::Responder,
         psk: [0u8; 32],