fix: ICMP forwarding on Android: add disable-icmp-forwarding and icmp-timeout options in tun options

core/src/main/cpp/main.c

@@ -116,6 +116,8 @@ Java_com_github_kr328_clash_core_bridge_Bridge_nativeStartTun(JNIEnv *env, jobje
                                                               jstring gateway,
                                                               jstring portal,
                                                               jstring dns,
+                                                              jboolean disable_icmp_forwarding,
+                                                              jint icmp_timeout,
                                                               jobject cb) {
     TRACE_METHOD();
 
@@ -125,7 +127,7 @@ Java_com_github_kr328_clash_core_bridge_Bridge_nativeStartTun(JNIEnv *env, jobje
     scoped_string _dns = get_string(dns);
     jobject _interface = new_global(cb);
 
-    startTun(fd, _stack, _gateway, _portal, _dns, _interface);
+    startTun(fd, _stack, _gateway, _portal, _dns, (int) disable_icmp_forwarding, (int) icmp_timeout, _interface);
 }
 
 JNIEXPORT void JNICALL

core/src/main/golang/native/tun.go

@@ -64,7 +64,7 @@ func (t *remoteTun) close() {
 }
 
 //export startTun
-func startTun(fd C.int, stack, gateway, portal, dns C.c_string, callback unsafe.Pointer) C.int {
+func startTun(fd C.int, stack, gateway, portal, dns C.c_string, disableICMPForwarding C.int, icmpTimeout C.int, callback unsafe.Pointer) C.int {
 	rTunLock.Lock()
 	defer rTunLock.Unlock()
 
@@ -83,7 +83,7 @@ func startTun(fd C.int, stack, gateway, portal, dns C.c_string, callback unsafe.
 
 	app.ApplyTunContext(remote.markSocket, remote.querySocketUid)
 
-	closer, err := tun.Start(f, s, g, p, d)
+	closer, err := tun.Start(f, s, g, p, d, disableICMPForwarding != 0, int64(icmpTimeout))
 	if err != nil {
 		remote.close()
 

core/src/main/golang/native/tun/tun.go

@@ -14,7 +14,7 @@ import (
 	"github.com/metacubex/mihomo/tunnel"
 )
 
-func Start(fd int, stack, gateway, portal, dns string) (io.Closer, error) {
+func Start(fd int, stack, gateway, portal, dns string, disableICMPForwarding bool, icmpTimeout int64) (io.Closer, error) {
 	log.Debugln("TUN: fd = %d, stack = %s, gateway = %s, portal = %s, dns = %s", fd, stack, gateway, portal, dns)
 
 	tunStack, ok := C.StackTypeMapping[strings.ToLower(stack)]
@@ -52,16 +52,18 @@ func Start(fd int, stack, gateway, portal, dns string) (io.Closer, error) {
 	}
 
 	options := LC.Tun{
-		Enable:              true,
-		Device:              sing_tun.InterfaceName,
-		Stack:               tunStack,
-		DNSHijack:           dnsHijack,
-		AutoRoute:           false, // had set route in TunService.kt
-		AutoDetectInterface: false, // implements by VpnService::protect
-		Inet4Address:        prefix4,
-		Inet6Address:        prefix6,
-		MTU:                 9000, // private const val TUN_MTU = 9000 in TunService.kt
-		FileDescriptor:      fd,
+		Enable:                true,
+		Device:                sing_tun.InterfaceName,
+		Stack:                 tunStack,
+		DNSHijack:             dnsHijack,
+		AutoRoute:             false, // had set route in TunService.kt
+		AutoDetectInterface:   false, // implements by VpnService::protect
+		Inet4Address:          prefix4,
+		Inet6Address:          prefix6,
+		MTU:                   9000, // private const val TUN_MTU = 9000 in TunService.kt
+		FileDescriptor:        fd,
+		DisableICMPForwarding: disableICMPForwarding,
+		ICMPTimeout:           icmpTimeout,
 	}
 
 	tunOptions, _ := json.Marshal(options)

core/src/main/java/com/github/kr328/clash/core/Clash.kt

@@ -70,10 +70,12 @@ object Clash {
         gateway: String,
         portal: String,
         dns: String,
+        disableIcmpForwarding: Boolean,
+        icmpTimeout: Int,
         markSocket: (Int) -> Boolean,
         querySocketUid: (protocol: Int, source: InetSocketAddress, target: InetSocketAddress) -> Int
     ) {
-        Bridge.nativeStartTun(fd, stack, gateway, portal, dns, object : TunInterface {
+        Bridge.nativeStartTun(fd, stack, gateway, portal, dns, disableIcmpForwarding, icmpTimeout, object : TunInterface {
             override fun markSocket(fd: Int) {
                 markSocket(fd)
             }

core/src/main/java/com/github/kr328/clash/core/bridge/Bridge.kt

@@ -19,7 +19,16 @@ object Bridge {
     external fun nativeNotifyDnsChanged(dnsList: String)
     external fun nativeNotifyTimeZoneChanged(name: String, offset: Int)
     external fun nativeNotifyInstalledAppChanged(uidList: String)
-    external fun nativeStartTun(fd: Int, stack: String, gateway: String, portal: String, dns: String, cb: TunInterface)
+    external fun nativeStartTun(
+        fd: Int,
+        stack: String,
+        gateway: String,
+        portal: String,
+        dns: String,
+        disableIcmpForwarding: Boolean,
+        icmpTimeout: Int,
+        cb: TunInterface
+    )
     external fun nativeStopTun()
     external fun nativeStartHttp(listenAt: String): String?
     external fun nativeStopHttp()

design/src/main/java/com/github/kr328/clash/design/NetworkSettingsDesign.kt

@@ -70,6 +70,21 @@ class NetworkSettingsDesign(
                 configure = vpnDependencies::add,
             )
 
+            switch(
+                value = srvStore::disableIcmpForwarding,
+                title = R.string.disable_icmp_forwarding,
+                summary = R.string.disable_icmp_forwarding_summary,
+                configure = vpnDependencies::add,
+            )
+
+            editableText(
+                value = srvStore::icmpTimeout,
+                adapter = NullableTextAdapter.Int,
+                title = R.string.icmp_timeout,
+                empty = R.string.icmp_timeout_default,
+                configure = vpnDependencies::add,
+            )
+
             switch(
                 value = srvStore::allowBypass,
                 title = R.string.allow_bypass,

design/src/main/java/com/github/kr328/clash/design/preference/Value.kt

@@ -19,6 +19,16 @@ interface NullableTextAdapter<T> {
             }
         }
 
+        val Int = object : NullableTextAdapter<Int> {
+            override fun from(value: Int): String? {
+                return if (value > 0) value.toString() else ""
+            }
+
+            override fun to(text: String?): Int {
+                return text?.trim()?.toIntOrNull()?.coerceAtLeast(0) ?: 0
+            }
+        }
+
         val String = object : NullableTextAdapter<String?> {
             override fun from(value: String?): String? {
                 return value

design/src/main/res/values/strings.xml

@@ -135,6 +135,10 @@
     <string name="bypass_private_network_summary">Bypass private network addresses</string>
     <string name="dns_hijacking">DNS Hijacking</string>
     <string name="dns_hijacking_summary">Handle all dns packet</string>
+    <string name="disable_icmp_forwarding">Disable ICMP Forwarding</string>
+    <string name="disable_icmp_forwarding_summary">Reply ICMP echo requests locally instead of forwarding them</string>
+    <string name="icmp_timeout">ICMP Timeout (seconds)</string>
+    <string name="icmp_timeout_default">Default</string>
     <string name="block_loopback">Block Loopback</string>
     <string name="block_loopback_summary">Block loopback connections</string>
     <string name="allow_bypass">Allow Bypass</string>

service/src/main/java/com/github/kr328/clash/service/TunService.kt

@@ -222,6 +222,8 @@ class TunService : VpnService(), CoroutineScope by CoroutineScope(Dispatchers.De
                 gateway = "$TUN_GATEWAY/$TUN_SUBNET_PREFIX" + if (store.allowIpv6) ",$TUN_GATEWAY6/$TUN_SUBNET_PREFIX6" else "",
                 portal = TUN_PORTAL + if (store.allowIpv6) ",$TUN_PORTAL6" else "",
                 dns = if (store.dnsHijacking) NET_ANY else (TUN_DNS + if (store.allowIpv6) ",$TUN_DNS6" else ""),
+                disableIcmpForwarding = store.disableIcmpForwarding,
+                icmpTimeout = store.icmpTimeout,
             )
         }
 

service/src/main/java/com/github/kr328/clash/service/clash/module/TunModule.kt

@@ -19,6 +19,8 @@ class TunModule(private val vpn: VpnService) : Module<Unit>(vpn) {
         val gateway: String,
         val portal: String,
         val dns: String,
+        val disableIcmpForwarding: Boolean,
+        val icmpTimeout: Int,
     )
 
     private val connectivity = service.getSystemService<ConnectivityManager>()!!
@@ -61,6 +63,8 @@ class TunModule(private val vpn: VpnService) : Module<Unit>(vpn) {
             gateway = device.gateway,
             portal = device.portal,
             dns = device.dns,
+            disableIcmpForwarding = device.disableIcmpForwarding,
+            icmpTimeout = device.icmpTimeout,
             markSocket = vpn::protect,
             querySocketUid = this::queryUid
         )

service/src/main/java/com/github/kr328/clash/service/store/ServiceStore.kt

@@ -61,6 +61,16 @@ class ServiceStore(context: Context) {
         defaultValue = "system"
     )
 
+    var disableIcmpForwarding by store.boolean(
+        key = "disable_icmp_forwarding",
+        defaultValue = true
+    )
+
+    var icmpTimeout by store.int(
+        key = "icmp_timeout",
+        defaultValue = 0
+    )
+
     var dynamicNotification by store.boolean(
         key = "dynamic_notification",
         defaultValue = true