Make ipv6_only flag an Option<bool>

Fixes #279. This allows falling back to the system default on None, or
explicitly setting false if the system default happens to be true.

2 files changed, 5 insertions, 5 deletions

diff --git a/.bleep b/.bleep
index c2ad58a..ff01eba 100644
--- a/.bleep
+++ b/.bleep
@@ -1 +1 @@
-50e4cca6db37ad41adb4a8a46445651e28a69fb4
\ No newline at end of file
+afbee799f578048eb9f05afc0abc259ba1d0f40a
\ No newline at end of file
diff --git a/pingora-core/src/listeners/l4.rs b/pingora-core/src/listeners/l4.rs
index 406190e..42adc87 100644
--- a/pingora-core/src/listeners/l4.rs
+++ b/pingora-core/src/listeners/l4.rs
@@ -69,7 +69,7 @@ pub struct TcpSocketOptions {
     /// IPV6_V6ONLY flag (if true, limit socket to IPv6 communication only).
     /// This is mostly useful when binding to `[::]`, which on most Unix distributions
     /// will bind to both IPv4 and IPv6 addresses by default.
-    pub ipv6_only: bool,
+    pub ipv6_only: Option<bool>,
     /// Enable TCP fast open and set the backlog size of it.
     /// See the [man page](https://man7.org/linux/man-pages/man7/tcp.7.html) for more information.
     pub tcp_fastopen: Option<usize>,
@@ -140,10 +140,10 @@ fn apply_tcp_socket_options(sock: &TcpSocket, opt: Option<&TcpSocketOptions>) ->
     let Some(opt) = opt else {
         return Ok(());
     };
-    if opt.ipv6_only {
+    if let Some(ipv6_only) = opt.ipv6_only {
         let socket_ref = socket2::SockRef::from(sock);
         socket_ref
-            .set_only_v6(opt.ipv6_only)
+            .set_only_v6(ipv6_only)
             .or_err(BindError, "failed to set IPV6_V6ONLY")?;
     }
 
@@ -318,7 +318,7 @@ mod test {
     #[tokio::test]
     async fn test_listen_tcp_ipv6_only() {
         let sock_opt = Some(TcpSocketOptions {
-            ipv6_only: true,
+            ipv6_only: Some(true),
             ..Default::default()
         });
         let mut listener = ListenerEndpoint::new(ServerAddress::Tcp("[::]:7101".into(), sock_opt));