Refactor: iptables auto config, disabled by default

README.md

@@ -141,16 +141,16 @@ proxies:
     # skip-cert-verify: true
 ```
 
-### IPTABLES auto-configuration
+### IPTABLES configuration
-Only work on Linux OS who support `iptables`, Clash will auto-configuration iptables for tproxy listener when `tproxy-port` value isn't zero.
+Work on Linux OS who's supported `iptables`
 
-If `TPROXY` is enabled, the `TUN` must be disabled.
 ```yaml
 # Enable the TPROXY listener
 tproxy-port: 9898
-# Disable the TUN listener
+
-tun:
+iptables:
-  enable: false
+  enable: true # default is false
+  inbound-interface: eth0 # detect the inbound interface, default is 'lo'
 ```
 Run Clash as a daemon.
 

config/config.go

@@ -100,6 +100,12 @@ type Tun struct {
 	AutoRoute bool             `yaml:"auto-route" json:"auto-route"`
 }
 
+// IPTables config
+type IPTables struct {
+	Enable           bool   `yaml:"enable" json:"enable"`
+	InboundInterface string `yaml:"inbound-interface" json:"inbound-interface"`
+}
+
 // Experimental config
 type Experimental struct{}
 
@@ -107,6 +113,7 @@ type Experimental struct{}
 type Config struct {
 	General      *General
 	Tun          *Tun
+	IPTables     *IPTables
 	DNS          *DNS
 	Experimental *Experimental
 	Hosts        *trie.DomainTrie
@@ -170,6 +177,7 @@ type RawConfig struct {
 	Hosts         map[string]string         `yaml:"hosts"`
 	DNS           RawDNS                    `yaml:"dns"`
 	Tun           RawTun                    `yaml:"tun"`
+	IPTables      IPTables                  `yaml:"iptables"`
 	Experimental  Experimental              `yaml:"experimental"`
 	Profile       Profile                   `yaml:"profile"`
 	Proxy         []map[string]any          `yaml:"proxies"`
@@ -206,6 +214,10 @@ func UnmarshalRawConfig(buf []byte) (*RawConfig, error) {
 			DNSHijack: []string{"0.0.0.0:53"}, // default hijack all dns query
 			AutoRoute: true,
 		},
+		IPTables: IPTables{
+			Enable:           false,
+			InboundInterface: "lo",
+		},
 		DNS: RawDNS{
 			Enable:       false,
 			UseHosts:     true,
@@ -243,6 +255,7 @@ func ParseRawConfig(rawCfg *RawConfig) (*Config, error) {
 
 	config.Experimental = &rawCfg.Experimental
 	config.Profile = &rawCfg.Profile
+	config.IPTables = &rawCfg.IPTables
 
 	general, err := parseGeneral(rawCfg)
 	if err != nil {

go.mod

@@ -23,11 +23,11 @@ require (
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
 	golang.org/x/sys v0.0.0-20220315194320-039c03cc5b86
 	golang.org/x/time v0.0.0-20220224211638-0e9765cccd65
-	golang.zx2c4.com/wireguard v0.0.0-20220310012736-ae6bc4dd64e1
+	golang.zx2c4.com/wireguard v0.0.0-20220318042302-193cf8d6a5d6
-	golang.zx2c4.com/wireguard/windows v0.5.3
+	golang.zx2c4.com/wireguard/windows v0.5.4-0.20220317000008-6432784c2469
 	google.golang.org/protobuf v1.27.1
 	gopkg.in/yaml.v2 v2.4.0
-	gvisor.dev/gvisor v0.0.0-20220315202956-f1399ecf1672
+	gvisor.dev/gvisor v0.0.0-20220319025644-e785bfc153f5
 )
 
 require (

go.sum

@@ -148,10 +148,10 @@ golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1N
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.zx2c4.com/wintun v0.0.0-20211104114900-415007cec224 h1:Ug9qvr1myri/zFN6xL17LSCBGFDnphBBhzmILHsM5TY=
 golang.zx2c4.com/wintun v0.0.0-20211104114900-415007cec224/go.mod h1:deeaetjYA+DHMHg+sMSMI58GrEteJUUzzw7en6TJQcI=
-golang.zx2c4.com/wireguard v0.0.0-20220310012736-ae6bc4dd64e1 h1:iuQdvJn3LrXxz3Iony1qBGVS7kEy2uHYnnjHsVbzq/s=
+golang.zx2c4.com/wireguard v0.0.0-20220318042302-193cf8d6a5d6 h1:kgBK1EGuTIYbwoKROmsoV0FQp08gnCcVa110A4Unqhk=
-golang.zx2c4.com/wireguard v0.0.0-20220310012736-ae6bc4dd64e1/go.mod h1:TjUWrnD5ATh7bFvmm/ALEJZQ4ivKbETb6pmyj1vUoNI=
+golang.zx2c4.com/wireguard v0.0.0-20220318042302-193cf8d6a5d6/go.mod h1:bVQfyl2sCM/QIIGHpWbFGfHPuDvqnCNkT6MQLTCjO/U=
-golang.zx2c4.com/wireguard/windows v0.5.3 h1:On6j2Rpn3OEMXqBq00QEDC7bWSZrPIHKIus8eIuExIE=
+golang.zx2c4.com/wireguard/windows v0.5.4-0.20220317000008-6432784c2469 h1:SEYkJAIuYAsSAPkCffOiYLtq5brBDSI+L0mRjSsvSTY=
-golang.zx2c4.com/wireguard/windows v0.5.3/go.mod h1:9TEe8TJmtwyQebdFwAkEWOPr3prrtqm+REGFifP60hI=
+golang.zx2c4.com/wireguard/windows v0.5.4-0.20220317000008-6432784c2469/go.mod h1:1CeiatTZwcwSFA3cAtMm8CQoroviTldnxd7DOgM/vI4=
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
 google.golang.org/protobuf v1.27.1 h1:SnqbnDw1V7RiZcXPx5MEeqPv2s79L9i7BJUlG/+RurQ=
 google.golang.org/protobuf v1.27.1/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
@@ -163,5 +163,5 @@ gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gvisor.dev/gvisor v0.0.0-20220315202956-f1399ecf1672 h1:aXIFpjZYl3zv2rQyr4rSit5Uq0k7BVXC8lJaDa4Cg7M=
+gvisor.dev/gvisor v0.0.0-20220319025644-e785bfc153f5 h1:a3DiynlmTM9IGW+twgZSDhYNGcnxvU/+pbzrl1xMcJ4=
-gvisor.dev/gvisor v0.0.0-20220315202956-f1399ecf1672/go.mod h1:V4WNP2Uwtx69eOhvLDSQ734EaTJTaBI3P8KgRAlROsg=
+gvisor.dev/gvisor v0.0.0-20220319025644-e785bfc153f5/go.mod h1:tWwEcFvJavs154OdjFCw78axNrsDlz4Zh8jvPqwcpGI=

hub/executor/executor.go

@@ -80,8 +80,8 @@ func ApplyConfig(cfg *config.Config, force bool) {
 	updateProfile(cfg)
 	updateDNS(cfg.DNS, cfg.Tun)
 	updateGeneral(cfg.General, force)
-	updateIPTables(cfg.DNS, cfg.General.TProxyPort, cfg.General.Interface, cfg.Tun.Enable)
+	updateIPTables(cfg)
-	updateTun(cfg.Tun, cfg.DNS.FakeIPRange.IPNet().String())
+	updateTun(cfg.Tun, cfg.DNS)
 	updateExperimental(cfg)
 
 	log.SetLevel(cfg.General.LogLevel)
@@ -176,7 +176,12 @@ func updateRules(rules []C.Rule) {
 	tunnel.UpdateRules(rules)
 }
 
-func updateTun(tun *config.Tun, tunAddressPrefix string) {
+func updateTun(tun *config.Tun, dns *config.DNS) {
+	var tunAddressPrefix string
+	if dns.FakeIPRange != nil {
+		tunAddressPrefix = dns.FakeIPRange.IPNet().String()
+	}
+
 	P.ReCreateTun(tun, tunAddressPrefix, tunnel.TCPIn(), tunnel.UDPIn())
 }
 
@@ -261,51 +266,67 @@ func patchSelectGroup(proxies map[string]C.Proxy) {
 	}
 }
 
-func updateIPTables(dns *config.DNS, tProxyPort int, interfaceName string, tunEnable bool) {
+func updateIPTables(cfg *config.Config) {
-	tproxy.CleanUpTProxyLinuxIPTables()
+	tproxy.CleanupTProxyIPTables()
 
-	if runtime.GOOS != "linux" || tProxyPort == 0 {
+	iptables := cfg.IPTables
+	if runtime.GOOS != "linux" || !iptables.Enable {
 		return
 	}
 
 	var err error
 	defer func() {
 		if err != nil {
-			log.Errorln("Setting iptables failed: %s", err.Error())
+			log.Errorln("[IPTABLES] setting iptables failed: %s", err.Error())
 			os.Exit(2)
 		}
 	}()
 
-	if !dns.Enable || dns.Listen == "" {
+	var (
+		inboundInterface = "lo"
+		tProxyPort       = cfg.General.TProxyPort
+		dnsCfg           = cfg.DNS
+	)
+
+	if tProxyPort == 0 {
+		err = fmt.Errorf("tproxy-port must be greater than zero")
+		return
+	}
+
+	if !dnsCfg.Enable {
 		err = fmt.Errorf("DNS server must be enable")
 		return
 	}
 
-	if tunEnable {
+	_, dnsPortStr, err := net.SplitHostPort(dnsCfg.Listen)
-		err = fmt.Errorf("TUN device must be disabe")
-		return
-	}
-
-	_, dnsPortStr, err := net.SplitHostPort(dns.Listen)
-	if dnsPortStr == "0" || dnsPortStr == "" || err != nil {
-		return
-	}
-
-	dnsPort, err := strconv.Atoi(dnsPortStr)
 	if err != nil {
+		err = fmt.Errorf("DNS server must be enable")
 		return
 	}
 
+	dnsPort, err := strconv.ParseUint(dnsPortStr, 10, 16)
+	if err != nil {
+		err = fmt.Errorf("DNS server must be enable")
+		return
+	}
+
+	if iptables.InboundInterface != "" {
+		inboundInterface = iptables.InboundInterface
+	}
+
 	if dialer.DefaultRoutingMark.Load() == 0 {
 		dialer.DefaultRoutingMark.Store(2158)
 	}
 
-	err = tproxy.SetTProxyLinuxIPTables(interfaceName, tProxyPort, dnsPort)
+	err = tproxy.SetTProxyIPTables(inboundInterface, uint16(tProxyPort), uint16(dnsPort))
+	if err != nil {
+		return
+	}
+
+	log.Infoln("[IPTABLES] Setting iptables completed")
 }
 
 func Cleanup() {
 	P.Cleanup()
-	if runtime.GOOS == "linux" {
+	tproxy.CleanupTProxyIPTables()
-		tproxy.CleanUpTProxyLinuxIPTables()
-	}
 }

listener/tproxy/tproxy_linux_iptables.go

@@ -11,9 +11,9 @@ import (
 )
 
 var (
-	dnsPort       = 0
+	dnsPort       uint16
-	tProxyPort    = 0
+	tProxyPort    uint16
-	interfaceName = ""
+	interfaceName string
 )
 
 const (
@@ -21,7 +21,7 @@ const (
 	PROXY_ROUTE_TABLE = "0x2d0"
 )
 
-func SetTProxyLinuxIPTables(ifname string, tport int, dport int) error {
+func SetTProxyIPTables(ifname string, tport uint16, dport uint16) error {
 	var err error
 	if err = execCmd("iptables -V"); err != nil {
 		return fmt.Errorf("current operations system [%s] are not support iptables or command iptables does not exist", runtime.GOOS)
@@ -40,11 +40,13 @@ func SetTProxyLinuxIPTables(ifname string, tport int, dport int) error {
 	execCmd(fmt.Sprintf("ip -f inet route add local default dev %s table %s", interfaceName, PROXY_ROUTE_TABLE))
 
 	// set FORWARD
-	execCmd("sysctl -w net.ipv4.ip_forward=1")
+	if interfaceName != "lo" {
-	execCmd(fmt.Sprintf("iptables -t filter -A FORWARD -o %s -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT", interfaceName))
+		execCmd("sysctl -w net.ipv4.ip_forward=1")
-	execCmd(fmt.Sprintf("iptables -t filter -A FORWARD -o %s -j ACCEPT", interfaceName))
+		execCmd(fmt.Sprintf("iptables -t filter -A FORWARD -o %s -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT", interfaceName))
-	execCmd(fmt.Sprintf("iptables -t filter -A FORWARD -i %s ! -o %s -j ACCEPT", interfaceName, interfaceName))
+		execCmd(fmt.Sprintf("iptables -t filter -A FORWARD -o %s -j ACCEPT", interfaceName))
-	execCmd(fmt.Sprintf("iptables -t filter -A FORWARD -i %s -o %s -j ACCEPT", interfaceName, interfaceName))
+		execCmd(fmt.Sprintf("iptables -t filter -A FORWARD -i %s ! -o %s -j ACCEPT", interfaceName, interfaceName))
+		execCmd(fmt.Sprintf("iptables -t filter -A FORWARD -i %s -o %s -j ACCEPT", interfaceName, interfaceName))
+	}
 
 	// set clash divert
 	execCmd("iptables -t mangle -N clash_divert")
@@ -70,7 +72,9 @@ func SetTProxyLinuxIPTables(ifname string, tport int, dport int) error {
 	execCmd(fmt.Sprintf("iptables -t nat -I PREROUTING ! -s 172.17.0.0/16 ! -d 127.0.0.0/8 -p udp --dport 53 -j REDIRECT --to %d", dnsPort))
 
 	// set post routing
-	execCmd(fmt.Sprintf("iptables -t nat -A POSTROUTING -o %s -m addrtype ! --src-type LOCAL -j MASQUERADE", interfaceName))
+	if interfaceName != "lo" {
+		execCmd(fmt.Sprintf("iptables -t nat -A POSTROUTING -o %s -m addrtype ! --src-type LOCAL -j MASQUERADE", interfaceName))
+	}
 
 	// set output
 	execCmd("iptables -t mangle -N clash_output")
@@ -95,16 +99,15 @@ func SetTProxyLinuxIPTables(ifname string, tport int, dport int) error {
 	execCmd("iptables -t nat -I OUTPUT -p tcp --dport 53 -j clash_dns_output")
 	execCmd("iptables -t nat -I OUTPUT -p udp --dport 53 -j clash_dns_output")
 
-	log.Infoln("[TPROXY] Setting iptables completed")
 	return nil
 }
 
-func CleanUpTProxyLinuxIPTables() {
+func CleanupTProxyIPTables() {
-	if interfaceName == "" || tProxyPort == 0 || dnsPort == 0 {
+	if runtime.GOOS != "linux" || interfaceName == "" || tProxyPort == 0 || dnsPort == 0 {
 		return
 	}
 
-	log.Warnln("Clean up tproxy linux iptables")
+	log.Warnln("Cleanup tproxy linux iptables")
 
 	if int(dialer.DefaultRoutingMark.Load()) == 2158 {
 		dialer.DefaultRoutingMark.Store(0)
@@ -119,10 +122,12 @@ func CleanUpTProxyLinuxIPTables() {
 	execCmd(fmt.Sprintf("ip -f inet route del local default dev %s table %s", interfaceName, PROXY_ROUTE_TABLE))
 
 	// clean FORWARD
-	execCmd(fmt.Sprintf("iptables -t filter -D FORWARD -i %s ! -o %s -j ACCEPT", interfaceName, interfaceName))
+	if interfaceName != "lo" {
-	execCmd(fmt.Sprintf("iptables -t filter -D FORWARD -i %s -o %s -j ACCEPT", interfaceName, interfaceName))
+		execCmd(fmt.Sprintf("iptables -t filter -D FORWARD -i %s ! -o %s -j ACCEPT", interfaceName, interfaceName))
-	execCmd(fmt.Sprintf("iptables -t filter -D FORWARD -o %s -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT", interfaceName))
+		execCmd(fmt.Sprintf("iptables -t filter -D FORWARD -i %s -o %s -j ACCEPT", interfaceName, interfaceName))
-	execCmd(fmt.Sprintf("iptables -t filter -D FORWARD -o %s -j ACCEPT", interfaceName))
+		execCmd(fmt.Sprintf("iptables -t filter -D FORWARD -o %s -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT", interfaceName))
+		execCmd(fmt.Sprintf("iptables -t filter -D FORWARD -o %s -j ACCEPT", interfaceName))
+	}
 
 	// clean PREROUTING
 	execCmd(fmt.Sprintf("iptables -t nat -D PREROUTING ! -s 172.17.0.0/16 ! -d 127.0.0.0/8 -p tcp --dport 53 -j REDIRECT --to %d", dnsPort))
@@ -130,7 +135,9 @@ func CleanUpTProxyLinuxIPTables() {
 	execCmd("iptables -t mangle -D PREROUTING -j clash_prerouting")
 
 	// clean POSTROUTING
-	execCmd(fmt.Sprintf("iptables -t nat -D POSTROUTING -o %s -m addrtype ! --src-type LOCAL -j MASQUERADE", interfaceName))
+	if interfaceName != "lo" {
+		execCmd(fmt.Sprintf("iptables -t nat -D POSTROUTING -o %s -m addrtype ! --src-type LOCAL -j MASQUERADE", interfaceName))
+	}
 
 	// clean OUTPUT
 	execCmd(fmt.Sprintf("iptables -t mangle -D OUTPUT -o %s -j clash_output", interfaceName))
@@ -146,6 +153,10 @@ func CleanUpTProxyLinuxIPTables() {
 	execCmd("iptables -t mangle -X clash_output")
 	execCmd("iptables -t nat -F clash_dns_output")
 	execCmd("iptables -t nat -X clash_dns_output")
+
+	interfaceName = ""
+	tProxyPort = 0
+	dnsPort = 0
 }
 
 func addLocalnetworkToChain(chain string) {
@@ -167,11 +178,11 @@ func addLocalnetworkToChain(chain string) {
 }
 
 func execCmd(cmdStr string) error {
-	log.Debugln("[TPROXY] %s", cmdStr)
+	log.Debugln("[IPTABLES] %s", cmdStr)
 
 	_, err := cmd.ExecCmd(cmdStr)
 	if err != nil {
-		log.Warnln("[TPROXY] exec cmd: %v", err)
+		log.Warnln("[IPTABLES] exec cmd: %v", err)
 	}
 
 	return err