From 9d97d95a9cd52050b83a836e14172e98a9ab04e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Sun, 4 Jan 2026 23:24:29 +0800
Subject: [PATCH] Fix TUN interface restart fails with existing addresses

---
 tun_linux.go | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/tun_linux.go b/tun_linux.go
index 7f22644..abca009 100644
--- a/tun_linux.go
+++ b/tun_linux.go
@@ -130,7 +130,7 @@ func (t *NativeTun) configure(tunLink netlink.Link) error {
 			for _, address := range t.options.Inet4Address {
 				addr4, _ := netlink.ParseAddr(address.String())
 				err = netlink.AddrAdd(tunLink, addr4)
-				if err != nil {
+				if err != nil && !errors.Is(err, unix.EEXIST) {
 					return err
 				}
 			}
@@ -139,7 +139,7 @@ func (t *NativeTun) configure(tunLink netlink.Link) error {
 			for _, address := range t.options.Inet6Address {
 				addr6, _ := netlink.ParseAddr(address.String())
 				err = netlink.AddrAdd(tunLink, addr6)
-				if err != nil {
+				if err != nil && !errors.Is(err, unix.EEXIST) {
 					return err
 				}
 			}
@@ -325,6 +325,7 @@ func (t *NativeTun) Close() error {
 	if t.options.EXP_ExternalConfiguration {
 		return common.Close(common.PtrOrNil(t.tunFile))
 	}
+	t.unsetAddresses()
 	return E.Errors(t.unsetRoute(), t.unsetRules(), common.Close(common.PtrOrNil(t.tunFile)))
 }
 
@@ -1016,6 +1017,24 @@ func (t *NativeTun) unsetRules() error {
 	return nil
 }
 
+func (t *NativeTun) unsetAddresses() {
+	if t.options.FileDescriptor > 0 {
+		return
+	}
+	tunLink, err := netlink.LinkByName(t.options.Name)
+	if err != nil {
+		return
+	}
+	for _, address := range t.options.Inet4Address {
+		addr, _ := netlink.ParseAddr(address.String())
+		_ = netlink.AddrDel(tunLink, addr)
+	}
+	for _, address := range t.options.Inet6Address {
+		addr, _ := netlink.ParseAddr(address.String())
+		_ = netlink.AddrDel(tunLink, addr)
+	}
+}
+
 func (t *NativeTun) resetRules() error {
 	t.unsetRules()
 	return t.setRules()