From 027af4d4ee1c02009590447badb8ba89a221169f Mon Sep 17 00:00:00 2001
From: dyhkwong <50692134+dyhkwong@users.noreply.github.com>
Date: Sun, 20 Aug 2023 19:06:37 +0800
Subject: [PATCH] Fix SOCKS5 UDP sniffing accidentially enabled

---
 route/router.go | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/route/router.go b/route/router.go
index 4fa8e8e2..f2926f87 100644
--- a/route/router.go
+++ b/route/router.go
@@ -770,20 +770,22 @@ func (r *Router) RoutePacketConnection(ctx context.Context, conn N.PacketConn, m
 		if metadata.Destination.Addr.IsUnspecified() {
 			metadata.Destination = destination
 		}
-		sniffMetadata, _ := sniff.PeekPacket(ctx, buffer.Bytes(), sniff.DomainNameQuery, sniff.QUICClientHello, sniff.STUNMessage)
-		if sniffMetadata != nil {
-			metadata.Protocol = sniffMetadata.Protocol
-			metadata.Domain = sniffMetadata.Domain
-			if metadata.InboundOptions.SniffOverrideDestination && M.IsDomainName(metadata.Domain) {
-				metadata.Destination = M.Socksaddr{
-					Fqdn: metadata.Domain,
-					Port: metadata.Destination.Port,
+		if metadata.InboundOptions.SniffEnabled {
+			sniffMetadata, _ := sniff.PeekPacket(ctx, buffer.Bytes(), sniff.DomainNameQuery, sniff.QUICClientHello, sniff.STUNMessage)
+			if sniffMetadata != nil {
+				metadata.Protocol = sniffMetadata.Protocol
+				metadata.Domain = sniffMetadata.Domain
+				if metadata.InboundOptions.SniffOverrideDestination && M.IsDomainName(metadata.Domain) {
+					metadata.Destination = M.Socksaddr{
+						Fqdn: metadata.Domain,
+						Port: metadata.Destination.Port,
+					}
+				}
+				if metadata.Domain != "" {
+					r.logger.DebugContext(ctx, "sniffed packet protocol: ", metadata.Protocol, ", domain: ", metadata.Domain)
+				} else {
+					r.logger.DebugContext(ctx, "sniffed packet protocol: ", metadata.Protocol)
 				}
-			}
-			if metadata.Domain != "" {
-				r.logger.DebugContext(ctx, "sniffed packet protocol: ", metadata.Protocol, ", domain: ", metadata.Domain)
-			} else {
-				r.logger.DebugContext(ctx, "sniffed packet protocol: ", metadata.Protocol)
 			}
 		}
 		conn = bufio.NewCachedPacketConn(conn, buffer, destination)