Change tls_config to return Arc

Since we ultimately need an Arc anyway, let's return one in the first
place to avoid a clone later.

Author: mjgarton

src/lib.rs

@@ -100,6 +100,7 @@ use std::io;
 use std::io::prelude::*;
 use std::iter;
 use std::net;
+use std::sync::Arc;
 
 use myc::constants::CapabilityFlags;
 
@@ -189,7 +190,7 @@ pub trait MysqlShim<W: Read + Write> {
     }
 
     /// Provides the TLS configuration, if we want to support TLS.
-    fn tls_config(&self) -> Option<&rustls::ServerConfig> {
+    fn tls_config(&self) -> Option<Arc<rustls::ServerConfig>> {
         None
     }
 }
@@ -298,7 +299,7 @@ impl<B: MysqlShim<RW>, RW: Read + Write> MysqlIntermediary<B, RW> {
                     )
                 })?;
 
-                self.rw.switch_to_tls(&config)?;
+                self.rw.switch_to_tls(config)?;
 
                 let (seq, handshake) = self.rw.next()?.ok_or_else(|| {
                     io::Error::new(

src/packet.rs

@@ -1,5 +1,5 @@
 use byteorder::{ByteOrder, LittleEndian};
-use rustls::ServerConnection;
+use rustls::{ServerConfig, ServerConnection};
 use std::io;
 use std::io::prelude::*;
 
@@ -68,7 +68,7 @@ impl<W: Read + Write> PacketConn<W> {
         self.maybe_end_packet()
     }
 
-    pub fn switch_to_tls(&mut self, config: &rustls::ServerConfig) -> io::Result<()> {
+    pub fn switch_to_tls(&mut self, config: Arc<ServerConfig>) -> io::Result<()> {
         assert!(self.remaining() == 0); // otherwise we've read ahead into the TLS handshake and will be in trouble.
 
         self.rw.switch_to_tls(config)
@@ -171,6 +171,7 @@ impl AsRef<[u8]> for Packet {
 }
 
 use std::ops::Deref;
+use std::sync::Arc;
 
 use crate::tls;
 impl Deref for Packet {
@@ -250,7 +251,7 @@ impl<T: Read + Write> SwitchableConn<T> {
         SwitchableConn(Some(EitherConn::Plain(rw)))
     }
 
-    pub fn switch_to_tls(&mut self, config: &rustls::ServerConfig) -> io::Result<()> {
+    pub fn switch_to_tls(&mut self, config: Arc<ServerConfig>) -> io::Result<()> {
         let replacement = match self.0.take() {
             Some(EitherConn::Plain(plain)) => {
                 Ok(EitherConn::TLS(tls::create_stream(plain, config)?))

src/tls.rs

@@ -2,13 +2,13 @@ use std::io;
 use std::io::{Read, Write};
 use std::sync::Arc;
 
-use rustls::{self, ServerConnection};
+use rustls::{self, ServerConfig, ServerConnection};
 
 pub fn create_stream<T: Read + Write + Sized>(
     sock: T,
-    config: &rustls::ServerConfig,
+    config: Arc<ServerConfig>,
 ) -> Result<rustls::StreamOwned<ServerConnection, T>, io::Error> {
-    let conn = ServerConnection::new(Arc::new(config.clone())).unwrap();
+    let conn = ServerConnection::new(config).unwrap();
     let stream = rustls::StreamOwned { conn, sock };
     Ok(stream)
 }

tests/main.rs

@@ -15,6 +15,7 @@ use rustls::ServerConfig;
 use std::error::Error;
 use std::io;
 use std::net;
+use std::sync::Arc;
 use std::thread;
 
 use msql_srv::{
@@ -29,7 +30,7 @@ struct TestingShim<Q, P, E, I> {
     on_p: P,
     on_e: E,
     on_i: I,
-    server_tls: Option<rustls::ServerConfig>,
+    server_tls: Option<Arc<rustls::ServerConfig>>,
     client_tls: Option<SslOpts>,
 }
 
@@ -74,8 +75,8 @@ where
         (self.on_q)(query, results)
     }
 
-    fn tls_config(&self) -> Option<&rustls::ServerConfig> {
-        self.server_tls.as_ref()
+    fn tls_config(&self) -> Option<Arc<rustls::ServerConfig>> {
+        self.server_tls.as_ref().map(Arc::clone)
     }
 }
 
@@ -114,7 +115,7 @@ where
     fn with_server_tls(mut self) -> Self {
         let cert = generate_simple_self_signed(vec!["localhost".to_string()]).unwrap();
 
-        self.server_tls = Some(
+        self.server_tls = Some(Arc::new(
             ServerConfig::builder()
                 .with_safe_defaults()
                 .with_no_client_auth()
@@ -123,7 +124,7 @@ where
                     PrivateKey(cert.get_key_pair().serialize_der()),
                 )
                 .unwrap(),
-        );
+        ));
 
         self
     }