all tcp sockets will set with default Keep Alive timeout 15s

- fixes #546
- ref #490

crates/shadowsocks-service/src/config.rs

@@ -772,6 +772,10 @@ pub struct Config {
     /// Set `TCP_FASTOPEN` socket option
     pub fast_open: bool,
     /// Set TCP Keep-Alive duration, will set both `TCP_KEEPIDLE` and `TCP_KEEPINTVL`
+    ///
+    /// https://github.com/shadowsocks/shadowsocks-rust/issues/546
+    ///
+    /// If this is not set, sockets will be set with a default timeout
     pub keep_alive: Option<Duration>,
 
     /// `RLIMIT_NOFILE` option for *nix systems

crates/shadowsocks-service/src/local/mod.rs

@@ -42,6 +42,11 @@ pub mod socks;
 pub mod tunnel;
 pub mod utils;
 
+/// Default TCP Keep Alive timeout
+///
+/// This is borrowed from Go's `net` library's default setting
+pub(crate) const LOCAL_DEFAULT_KEEPALIVE_TIMEOUT: Duration = Duration::from_secs(15);
+
 /// Starts a shadowsocks local server
 pub async fn run(mut config: Config) -> io::Result<()> {
     assert!(config.config_type == ConfigType::Local && !config.local.is_empty());
@@ -84,15 +89,15 @@ pub async fn run(mut config: Config) -> io::Result<()> {
     connect_opts.tcp.recv_buffer_size = config.outbound_recv_buffer_size;
     connect_opts.tcp.nodelay = config.no_delay;
     connect_opts.tcp.fastopen = config.fast_open;
-    connect_opts.tcp.keepalive = config.keep_alive;
+    connect_opts.tcp.keepalive = config.keep_alive.or(Some(LOCAL_DEFAULT_KEEPALIVE_TIMEOUT));
     context.set_connect_opts(connect_opts);
 
     let mut accept_opts = AcceptOpts::default();
     accept_opts.tcp.send_buffer_size = config.inbound_send_buffer_size;
     accept_opts.tcp.recv_buffer_size = config.inbound_recv_buffer_size;
     accept_opts.tcp.nodelay = config.no_delay;
     accept_opts.tcp.fastopen = config.fast_open;
-    accept_opts.tcp.keepalive = config.keep_alive;
+    accept_opts.tcp.keepalive = config.keep_alive.or(Some(LOCAL_DEFAULT_KEEPALIVE_TIMEOUT));
 
     if let Some(resolver) = build_dns_resolver(config.dns, config.ipv6_first, context.connect_opts_ref()).await {
         context.set_dns_resolver(Arc::new(resolver));

crates/shadowsocks-service/src/manager/mod.rs

@@ -10,6 +10,7 @@ use shadowsocks::net::{AcceptOpts, ConnectOpts};
 use crate::{
     config::{Config, ConfigType},
     dns::build_dns_resolver,
+    server::SERVER_DEFAULT_KEEPALIVE_TIMEOUT,
 };
 
 pub use self::server::Manager;
@@ -51,14 +52,14 @@ pub async fn run(config: Config) -> io::Result<()> {
     connect_opts.tcp.recv_buffer_size = config.outbound_recv_buffer_size;
     connect_opts.tcp.nodelay = config.no_delay;
     connect_opts.tcp.fastopen = config.fast_open;
-    connect_opts.tcp.keepalive = config.keep_alive;
+    connect_opts.tcp.keepalive = config.keep_alive.or(Some(SERVER_DEFAULT_KEEPALIVE_TIMEOUT));
 
     let mut accept_opts = AcceptOpts::default();
     accept_opts.tcp.send_buffer_size = config.inbound_send_buffer_size;
     accept_opts.tcp.recv_buffer_size = config.inbound_recv_buffer_size;
     accept_opts.tcp.nodelay = config.no_delay;
     accept_opts.tcp.fastopen = config.fast_open;
-    accept_opts.tcp.keepalive = config.keep_alive;
+    accept_opts.tcp.keepalive = config.keep_alive.or(Some(SERVER_DEFAULT_KEEPALIVE_TIMEOUT));
 
     if let Some(resolver) = build_dns_resolver(config.dns, config.ipv6_first, &connect_opts).await {
         manager.set_dns_resolver(Arc::new(resolver));

crates/shadowsocks-service/src/server/mod.rs

@@ -1,6 +1,6 @@
 //! Shadowsocks server
 
-use std::{io, sync::Arc};
+use std::{io, sync::Arc, time::Duration};
 
 use futures::{future, FutureExt};
 use log::trace;
@@ -19,6 +19,11 @@ pub mod server;
 mod tcprelay;
 mod udprelay;
 
+/// Default TCP Keep Alive timeout
+///
+/// This is borrowed from Go's `net` library's default setting
+pub(crate) const SERVER_DEFAULT_KEEPALIVE_TIMEOUT: Duration = Duration::from_secs(15);
+
 /// Starts a shadowsocks server
 pub async fn run(config: Config) -> io::Result<()> {
     assert_eq!(config.config_type, ConfigType::Server);
@@ -64,14 +69,14 @@ pub async fn run(config: Config) -> io::Result<()> {
     connect_opts.tcp.recv_buffer_size = config.outbound_recv_buffer_size;
     connect_opts.tcp.nodelay = config.no_delay;
     connect_opts.tcp.fastopen = config.fast_open;
-    connect_opts.tcp.keepalive = config.keep_alive;
+    connect_opts.tcp.keepalive = config.keep_alive.or(Some(SERVER_DEFAULT_KEEPALIVE_TIMEOUT));
 
     let mut accept_opts = AcceptOpts::default();
     accept_opts.tcp.send_buffer_size = config.inbound_send_buffer_size;
     accept_opts.tcp.recv_buffer_size = config.inbound_recv_buffer_size;
     accept_opts.tcp.nodelay = config.no_delay;
     accept_opts.tcp.fastopen = config.fast_open;
-    accept_opts.tcp.keepalive = config.keep_alive;
+    accept_opts.tcp.keepalive = config.keep_alive.or(Some(SERVER_DEFAULT_KEEPALIVE_TIMEOUT));
 
     let resolver = build_dns_resolver(config.dns, config.ipv6_first, &connect_opts)
         .await