From 6cfee41a56842ec023ab379d09b13770dd476e77 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Sun, 1 Oct 2023 01:00:51 +0800
Subject: [PATCH] Add DefaultInterface func

---
 monitor.go        |  1 +
 monitor_shared.go | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/monitor.go b/monitor.go
index b424256..2a0a419 100644
--- a/monitor.go
+++ b/monitor.go
@@ -32,6 +32,7 @@ type DefaultInterfaceMonitor interface {
 	Close() error
 	DefaultInterfaceName(destination netip.Addr) string
 	DefaultInterfaceIndex(destination netip.Addr) int
+	DefaultInterface(destination netip.Addr) (string, int)
 	OverrideAndroidVPN() bool
 	AndroidVPNEnabled() bool
 	RegisterCallback(callback DefaultInterfaceUpdateCallback) *list.Element[DefaultInterfaceUpdateCallback]
diff --git a/monitor_shared.go b/monitor_shared.go
index 70634ae..a1b2387 100644
--- a/monitor_shared.go
+++ b/monitor_shared.go
@@ -150,6 +150,20 @@ func (m *defaultInterfaceMonitor) DefaultInterfaceIndex(destination netip.Addr)
 	return m.defaultInterfaceIndex
 }
 
+func (m *defaultInterfaceMonitor) DefaultInterface(destination netip.Addr) (string, int) {
+	for _, address := range m.networkAddresses {
+		for _, prefix := range address.addresses {
+			if prefix.Contains(destination) {
+				return address.interfaceName, address.interfaceIndex
+			}
+		}
+	}
+	if m.defaultInterfaceIndex == -1 {
+		m.checkUpdate()
+	}
+	return m.defaultInterfaceName, m.defaultInterfaceIndex
+}
+
 func (m *defaultInterfaceMonitor) OverrideAndroidVPN() bool {
 	return m.options.OverrideAndroidVPN
 }