diff --git a/actix-server/CHANGES.md b/actix-server/CHANGES.md
index 1147dcbd..6985fcaa 100644
--- a/actix-server/CHANGES.md
+++ b/actix-server/CHANGES.md
@@ -2,6 +2,7 @@
## Unreleased - 2023-xx-xx
+- ServerBuilder: add support for MPTCP (optional).
- Minimum supported Rust version (MSRV) is now 1.60.
## 2.2.0 - 2022-12-21
diff --git a/actix-server/Cargo.toml b/actix-server/Cargo.toml
index ade711f4..58f2bba6 100755
--- a/actix-server/Cargo.toml
+++ b/actix-server/Cargo.toml
@@ -28,7 +28,7 @@ futures-core = { version = "0.3.17", default-features = false, features = ["allo
futures-util = { version = "0.3.17", default-features = false, features = ["alloc"] }
mio = { version = "0.8", features = ["os-poll", "net"] }
num_cpus = "1.13"
-socket2 = "0.4.2" # TODO(MSRV 1.64) update to 0.5
+socket2 = "0.5"
tokio = { version = "1.23.1", features = ["sync"] }
tracing = { version = "0.1.30", default-features = false, features = ["log"] }
diff --git a/actix-server/src/builder.rs b/actix-server/src/builder.rs
index b6646081..6e80f64f 100644
--- a/actix-server/src/builder.rs
+++ b/actix-server/src/builder.rs
@@ -14,6 +14,13 @@ use crate::{
Server,
};
+#[derive(PartialEq, Eq, Copy, Clone)]
+pub enum MPTCP {
+ Disabled,
+ TcpFallback,
+ NoFallback,
+}
+
/// [Server] builder.
pub struct ServerBuilder {
pub(crate) threads: usize,
@@ -21,6 +28,7 @@ pub struct ServerBuilder {
pub(crate) backlog: u32,
pub(crate) factories: Vec<Box<dyn InternalServiceFactory>>,
pub(crate) sockets: Vec<(usize, String, MioListener)>,
+ pub(crate) mptcp: MPTCP,
pub(crate) exit: bool,
pub(crate) listen_os_signals: bool,
pub(crate) cmd_tx: UnboundedSender<ServerCommand>,
@@ -45,6 +53,7 @@ impl ServerBuilder {
factories: Vec::new(),
sockets: Vec::new(),
backlog: 2048,
+ mptcp: MPTCP::Disabled,
exit: false,
listen_os_signals: true,
cmd_tx,
@@ -98,6 +107,25 @@ impl ServerBuilder {
self
}
+ /// Enable the MPTCP protocol at the socket level.
+ ///
+ /// This enable the Multiple Path TCP protocol at the socket level. This means it's managed
+ /// by the kernel and the application (userspace) doesn't have to deal with path management.
+ ///
+ /// Only available in Linux Kernel >= 5.6. If you try to set it on a Windows machine or on
+ /// an older Linux machine, this will fail with a panic.
+ ///
+ /// In Addition to a recent Linux Kernel, you also need to enable the sysctl (if it's not on
+ /// by default):
+ /// `sysctl sysctl net.mptcp.enabled=1`
+ ///
+ /// This method will have no effect if called after a `bind()`.
+ #[cfg(target_os = "linux")]
+ pub fn mptcp(mut self, mptcp_enabled: MPTCP) -> Self {
+ self.mptcp = mptcp_enabled;
+ self
+ }
+
/// Sets the maximum per-worker number of concurrent connections.
///
/// All socket listeners will stop accepting connections when this limit is reached for
@@ -146,7 +174,7 @@ impl ServerBuilder {
U: ToSocketAddrs,
N: AsRef<str>,
{
- let sockets = bind_addr(addr, self.backlog)?;
+ let sockets = bind_addr(addr, self.backlog, &self.mptcp)?;
trace!("binding server to: {:?}", &sockets);
@@ -263,13 +291,14 @@ impl ServerBuilder {
pub(super) fn bind_addr<S: ToSocketAddrs>(
addr: S,
backlog: u32,
+ mptcp: &MPTCP,
) -> io::Result<Vec<MioTcpListener>> {
let mut opt_err = None;
let mut success = false;
let mut sockets = Vec::new();
for addr in addr.to_socket_addrs()? {
- match create_mio_tcp_listener(addr, backlog) {
+ match create_mio_tcp_listener(addr, backlog, mptcp) {
Ok(lst) => {
success = true;
sockets.push(lst);
diff --git a/actix-server/src/lib.rs b/actix-server/src/lib.rs
index 532313b6..bec561e1 100644
--- a/actix-server/src/lib.rs
+++ b/actix-server/src/lib.rs
@@ -19,6 +19,7 @@ mod waker_queue;
mod worker;
pub use self::builder::ServerBuilder;
+pub use self::builder::MPTCP;
pub use self::handle::ServerHandle;
pub use self::server::Server;
pub use self::service::ServerServiceFactory;
diff --git a/actix-server/src/socket.rs b/actix-server/src/socket.rs
index 8d2ffe8f..2ef97050 100644
--- a/actix-server/src/socket.rs
+++ b/actix-server/src/socket.rs
@@ -12,6 +12,8 @@ pub(crate) use {
std::os::unix::net::UnixListener as StdUnixListener,
};
+use crate::builder::MPTCP;
+
pub(crate) enum MioListener {
Tcp(MioTcpListener),
#[cfg(unix)]
@@ -224,10 +226,29 @@ mod unix_impl {
pub(crate) fn create_mio_tcp_listener(
addr: StdSocketAddr,
backlog: u32,
+ mptcp: &MPTCP,
) -> io::Result<MioTcpListener> {
use socket2::{Domain, Protocol, Socket, Type};
- let socket = Socket::new(Domain::for_address(addr), Type::STREAM, Some(Protocol::TCP))?;
+ #[cfg(not(target_os = "linux"))]
+ let protocol = Protocol::TCP;
+ #[cfg(target_os = "linux")]
+ let protocol = if mptcp == &MPTCP::Disabled {
+ Protocol::TCP
+ } else {
+ Protocol::MPTCP
+ };
+
+ let socket = match Socket::new(Domain::for_address(addr), Type::STREAM, Some(protocol)) {
+ Ok(sock) => sock,
+ Err(err) => {
+ if mptcp == &MPTCP::TcpFallback {
+ Socket::new(Domain::for_address(addr), Type::STREAM, Some(Protocol::TCP))?
+ } else {
+ return Err(err);
+ }
+ }
+ };
socket.set_reuse_address(true)?;
socket.set_nonblocking(true)?;
@@ -248,7 +269,7 @@ mod tests {
assert_eq!(format!("{}", addr), "127.0.0.1:8080");
let addr: StdSocketAddr = "127.0.0.1:0".parse().unwrap();
- let lst = create_mio_tcp_listener(addr, 128).unwrap();
+ let lst = create_mio_tcp_listener(addr, 128, &MPTCP::Disabled).unwrap();
let lst = MioListener::Tcp(lst);
assert!(format!("{:?}", lst).contains("TcpListener"));
assert!(format!("{}", lst).contains("127.0.0.1"));