From 2abeda9c4222ad7b2a300cdd8d46c2b256896178 Mon Sep 17 00:00:00 2001
From: xqzr <34030394+xqzr@users.noreply.github.com>
Date: Mon, 31 Mar 2025 20:13:57 +0800
Subject: [PATCH] Sockopt: Allow listen `v6only` work for Windows & Darwin
 (#4571)

Completes https://github.com/XTLS/Xray-core/pull/1677

---------

Co-authored-by: RPRX <63339210+RPRX@users.noreply.github.com>
---
 transport/internet/sockopt_darwin.go  | 6 ++++++
 transport/internet/sockopt_windows.go | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/transport/internet/sockopt_darwin.go b/transport/internet/sockopt_darwin.go
index 86af492a..f684de98 100644
--- a/transport/internet/sockopt_darwin.go
+++ b/transport/internet/sockopt_darwin.go
@@ -200,6 +200,12 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 		}
 	}
 
+	if config.V6Only {
+		if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_V6ONLY, 1); err != nil {
+			return errors.New("failed to set IPV6_V6ONLY").Base(err)
+		}
+	}
+
 	return nil
 }
 
diff --git a/transport/internet/sockopt_windows.go b/transport/internet/sockopt_windows.go
index e1c1d25e..cbd3b41e 100644
--- a/transport/internet/sockopt_windows.go
+++ b/transport/internet/sockopt_windows.go
@@ -15,6 +15,7 @@ const (
 	IPV6_UNICAST_IF = 31
 	IP_MULTICAST_IF = 9
 	IPV6_MULTICAST_IF = 9
+	IPV6_V6ONLY = 27
 )
 
 func setTFO(fd syscall.Handle, tfo int) error {
@@ -90,6 +91,12 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 		}
 	}
 
+	if config.V6Only {
+		if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IPV6, IPV6_V6ONLY, 1); err != nil {
+			return errors.New("failed to set IPV6_V6ONLY").Base(err)
+		}
+	}
+
 	return nil
 }