From 534cccce919b66165eef3cbaaa8e6d29263c26c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Fri, 18 Jul 2025 21:45:48 +0800
Subject: [PATCH] Fix DNS upgrade

---
 option/dns.go | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/option/dns.go b/option/dns.go
index 37445782..0886dd64 100644
--- a/option/dns.go
+++ b/option/dns.go
@@ -180,7 +180,7 @@ func (o *DNSServerOptions) Upgrade(ctx context.Context) error {
 	options := o.Options.(*LegacyDNSServerOptions)
 	serverURL, _ := url.Parse(options.Address)
 	var serverType string
-	if serverURL.Scheme != "" {
+	if serverURL != nil && serverURL.Scheme != "" {
 		serverType = serverURL.Scheme
 	} else {
 		switch options.Address {
@@ -217,7 +217,7 @@ func (o *DNSServerOptions) Upgrade(ctx context.Context) error {
 		o.Type = C.DNSTypeUDP
 		o.Options = &remoteOptions
 		var serverAddr M.Socksaddr
-		if serverURL.Scheme == "" {
+		if serverURL == nil || serverURL.Scheme == "" {
 			serverAddr = M.ParseSocksaddr(options.Address)
 		} else {
 			serverAddr = M.ParseSocksaddr(serverURL.Host)
@@ -232,6 +232,9 @@ func (o *DNSServerOptions) Upgrade(ctx context.Context) error {
 	case C.DNSTypeTCP:
 		o.Type = C.DNSTypeTCP
 		o.Options = &remoteOptions
+		if serverURL == nil {
+			return E.New("invalid server address")
+		}
 		serverAddr := M.ParseSocksaddr(serverURL.Host)
 		if !serverAddr.IsValid() {
 			return E.New("invalid server address")
@@ -242,6 +245,9 @@ func (o *DNSServerOptions) Upgrade(ctx context.Context) error {
 		}
 	case C.DNSTypeTLS, C.DNSTypeQUIC:
 		o.Type = serverType
+		if serverURL == nil {
+			return E.New("invalid server address")
+		}
 		serverAddr := M.ParseSocksaddr(serverURL.Host)
 		if !serverAddr.IsValid() {
 			return E.New("invalid server address")
@@ -261,6 +267,9 @@ func (o *DNSServerOptions) Upgrade(ctx context.Context) error {
 			},
 		}
 		o.Options = &httpsOptions
+		if serverURL == nil {
+			return E.New("invalid server address")
+		}
 		serverAddr := M.ParseSocksaddr(serverURL.Host)
 		if !serverAddr.IsValid() {
 			return E.New("invalid server address")
@@ -274,6 +283,9 @@ func (o *DNSServerOptions) Upgrade(ctx context.Context) error {
 		}
 	case "rcode":
 		var rcode int
+		if serverURL == nil {
+			return E.New("invalid server address")
+		}
 		switch serverURL.Host {
 		case "success":
 			rcode = dns.RcodeSuccess
@@ -295,6 +307,9 @@ func (o *DNSServerOptions) Upgrade(ctx context.Context) error {
 	case C.DNSTypeDHCP:
 		o.Type = C.DNSTypeDHCP
 		dhcpOptions := DHCPDNSServerOptions{}
+		if serverURL == nil {
+			return E.New("invalid server address")
+		}
 		if serverURL.Host != "" && serverURL.Host != "auto" {
 			dhcpOptions.Interface = serverURL.Host
 		}