From 682d8849a80062e9a5558b5bb02b274a9c88fb71 Mon Sep 17 00:00:00 2001
From: ilolicon <97431110@qq.com>
Date: Tue, 11 Apr 2023 19:37:37 +0800
Subject: [PATCH] fix: fix not exist interface

---
 packetconn.go | 14 +++++---------
 ping.go       |  6 +++++-
 ping_test.go  |  4 +++-
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/packetconn.go b/packetconn.go
index 3ffa29b..7f03120 100644
--- a/packetconn.go
+++ b/packetconn.go
@@ -18,7 +18,7 @@ type packetConn interface {
 	SetReadDeadline(t time.Time) error
 	WriteTo(b []byte, dst net.Addr) (int, error)
 	SetTTL(ttl int)
-	SetIfaceIndex(iface string)
+	SetIfaceIndex(ifaceIndex int)
 }
 
 type icmpConn struct {
@@ -35,12 +35,8 @@ func (c *icmpConn) SetTTL(ttl int) {
 	c.ttl = ttl
 }
 
-func (c *icmpConn) SetIfaceIndex(iface string) {
-	i, err := net.InterfaceByName(iface)
-	if err != nil {
-		c.ifaceIndex = 0
-	}
-	c.ifaceIndex = i.Index
+func (c *icmpConn) SetIfaceIndex(ifaceIndex int) {
+	c.ifaceIndex = ifaceIndex
 }
 
 func (c *icmpConn) SetReadDeadline(t time.Time) error {
@@ -78,7 +74,7 @@ func (c *icmpv4Conn) WriteTo(b []byte, dst net.Addr) (int, error) {
 	}
 	var cm *ipv4.ControlMessage
 	if 1 <= c.ifaceIndex {
-		// set interface
+		// If not set interface c.ifaceIndex == 0
 		if err := c.c.IPv4PacketConn().SetControlMessage(ipv4.FlagInterface, true); err != nil {
 			return 0, err
 		}
@@ -119,7 +115,7 @@ func (c *icmpV6Conn) WriteTo(b []byte, dst net.Addr) (int, error) {
 	}
 	var cm *ipv6.ControlMessage
 	if 1 <= c.ifaceIndex {
-		// set interface
+		// If not set interface c.ifaceIndex == 0
 		if err := c.c.IPv6PacketConn().SetControlMessage(ipv6.FlagInterface, true); err != nil {
 			return 0, err
 		}
diff --git a/ping.go b/ping.go
index ba10728..d538935 100644
--- a/ping.go
+++ b/ping.go
@@ -422,7 +422,11 @@ func (p *Pinger) Run() error {
 
 	conn.SetTTL(p.TTL)
 	if p.Iface != "" {
-		conn.SetIfaceIndex(p.Iface)
+		iface, err := net.InterfaceByName(p.Iface)
+		if err != nil {
+			return err
+		}
+		conn.SetIfaceIndex(iface.Index)
 	}
 	return p.run(conn)
 }
diff --git a/ping_test.go b/ping_test.go
index 2a99b3b..6a9d1e3 100644
--- a/ping_test.go
+++ b/ping_test.go
@@ -480,6 +480,8 @@ func TestStatisticsLossy(t *testing.T) {
 func TestSetIfaceName(t *testing.T) {
 	pinger := New("www.google.com")
 	pinger.Count = 1
+	pinger.Timeout = time.Second
+	pinger.SetPrivileged(true)
 
 	// Set loopback interface
 	pinger.Iface = "lo"
@@ -662,7 +664,7 @@ func (c testPacketConn) ICMPRequestType() icmp.Type        { return ipv4.ICMPTyp
 func (c testPacketConn) SetFlagTTL() error                 { return nil }
 func (c testPacketConn) SetReadDeadline(t time.Time) error { return nil }
 func (c testPacketConn) SetTTL(t int)                      {}
-func (c testPacketConn) SetIfaceIndex(iface string)        {}
+func (c testPacketConn) SetIfaceIndex(ifaceIndex int)      {}
 
 func (c testPacketConn) ReadFrom(b []byte) (n int, ttl int, src net.Addr, err error) {
 	return 0, 0, nil, nil