refactor: More interface reuse

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/sagernet/gvisor v0.0.0-20241021032506-a4324256e4a3
 	github.com/sagernet/netlink v0.0.0-20240612041022-b9a21c07ac6a
 	github.com/sagernet/nftables v0.3.0-beta.4
-	github.com/sagernet/sing v0.6.0-alpha.3
+	github.com/sagernet/sing v0.6.0-alpha.4
 	go4.org/netipx v0.0.0-20231129151722-fdeea329fbba
 	golang.org/x/exp v0.0.0-20240613232115-7f521ea00fb8
 	golang.org/x/net v0.26.0

go.sum

@@ -22,10 +22,8 @@ github.com/sagernet/netlink v0.0.0-20240612041022-b9a21c07ac6a h1:ObwtHN2VpqE0ZN
 github.com/sagernet/netlink v0.0.0-20240612041022-b9a21c07ac6a/go.mod h1:xLnfdiJbSp8rNqYEdIW/6eDO4mVoogml14Bh2hSiFpM=
 github.com/sagernet/nftables v0.3.0-beta.4 h1:kbULlAwAC3jvdGAC1P5Fa3GSxVwQJibNenDW2zaXr8I=
 github.com/sagernet/nftables v0.3.0-beta.4/go.mod h1:OQXAjvjNGGFxaTgVCSTRIhYB5/llyVDeapVoENYBDS8=
-github.com/sagernet/sing v0.5.1-0.20241109034027-099899991126 h1:pLMpV9pEAinrS9R1n1JLcbNesCl369RfvyxnYCPrkbw=
-github.com/sagernet/sing v0.5.1-0.20241109034027-099899991126/go.mod h1:ARkL0gM13/Iv5VCZmci/NuoOlePoIsW0m7BWfln/Hak=
-github.com/sagernet/sing v0.6.0-alpha.3 h1:GLp9d6Gbt+Ioeplauuzojz1nY2J6moceVGYIOv/h5gA=
-github.com/sagernet/sing v0.6.0-alpha.3/go.mod h1:ARkL0gM13/Iv5VCZmci/NuoOlePoIsW0m7BWfln/Hak=
+github.com/sagernet/sing v0.6.0-alpha.4 h1:h9oshzhaY0ESPC9HERcXtT9MhK7Oyo/IWXVu1uIiw3Y=
+github.com/sagernet/sing v0.6.0-alpha.4/go.mod h1:ARkL0gM13/Iv5VCZmci/NuoOlePoIsW0m7BWfln/Hak=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/vishvananda/netns v0.0.4 h1:Oeaw1EM2JMxD51g9uhtC0D7erkIjgmj8+JZc26m1YX8=
 github.com/vishvananda/netns v0.0.4/go.mod h1:SpkAiCQRtJ6TvvxPnOSyH3BMl6unz3xZlaprSwhNNJM=

monitor.go

@@ -1,8 +1,6 @@
 package tun
 
 import (
-	"net/netip"
-
 	"github.com/sagernet/sing/common/control"
 	E "github.com/sagernet/sing/common/exceptions"
 	"github.com/sagernet/sing/common/x/list"
@@ -31,9 +29,7 @@ type NetworkUpdateMonitor interface {
 type DefaultInterfaceMonitor interface {
 	Start() error
 	Close() error
-	DefaultInterfaceName(destination netip.Addr) string
-	DefaultInterfaceIndex(destination netip.Addr) int
-	DefaultInterface(destination netip.Addr) (string, int)
+	DefaultInterface() *control.Interface
 	OverrideAndroidVPN() bool
 	AndroidVPNEnabled() bool
 	RegisterCallback(callback DefaultInterfaceUpdateCallback) *list.Element[DefaultInterfaceUpdateCallback]

monitor_android.go

@@ -51,14 +51,14 @@ func (m *defaultInterfaceMonitor) checkUpdate() error {
 		return err
 	}
 
-	oldInterface := m.defaultInterfaceName
-	oldIndex := m.defaultInterfaceIndex
-
-	m.defaultInterfaceName = link.Attrs().Name
-	m.defaultInterfaceIndex = link.Attrs().Index
-
+	oldInterface := m.defaultInterface.Load()
+	newInterface, err := m.interfaceFinder.ByIndex(link.Attrs().Index)
+	if err != nil {
+		return E.Cause(err, "find updated interface: ", link.Attrs().Name)
+	}
+	m.defaultInterface.Store(newInterface)
 	var event int
-	if oldInterface != m.defaultInterfaceName || oldIndex != m.defaultInterfaceIndex {
+	if oldInterface == nil || oldInterface.Name != newInterface.Name || oldInterface.Index != newInterface.Index {
 		event |= EventInterfaceUpdate
 	}
 	if oldVPNEnabled != m.androidVPNEnabled {

monitor_darwin.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/sagernet/sing/common/buf"
+	"github.com/sagernet/sing/common/control"
 	E "github.com/sagernet/sing/common/exceptions"
 	"github.com/sagernet/sing/common/logger"
 	"github.com/sagernet/sing/common/x/list"
@@ -106,12 +107,13 @@ func (m *networkUpdateMonitor) Close() error {
 }
 
 func (m *defaultInterfaceMonitor) checkUpdate() error {
-	var (
-		defaultInterface *net.Interface
-		err              error
-	)
+	err := m.interfaceFinder.Update()
+	if err != nil {
+		return E.Cause(err, "update interfaces")
+	}
+	var defaultInterface *control.Interface
 	if m.underNetworkExtension {
-		defaultInterface, err = getDefaultInterfaceBySocket()
+		defaultInterface, err = m.getDefaultInterfaceBySocket()
 		if err != nil {
 			return err
 		}
@@ -144,7 +146,7 @@ func (m *defaultInterfaceMonitor) checkUpdate() error {
 			if ones != 0 {
 				continue
 			}
-			routeInterface, err := net.InterfaceByIndex(routeMessage.Index)
+			routeInterface, err := m.interfaceFinder.ByIndex(routeMessage.Index)
 			if err != nil {
 				return err
 			}
@@ -164,18 +166,20 @@ func (m *defaultInterfaceMonitor) checkUpdate() error {
 	if defaultInterface == nil {
 		return ErrNoRoute
 	}
-	oldInterface := m.defaultInterfaceName
-	oldIndex := m.defaultInterfaceIndex
-	m.defaultInterfaceIndex = defaultInterface.Index
-	m.defaultInterfaceName = defaultInterface.Name
-	if oldInterface == m.defaultInterfaceName && oldIndex == m.defaultInterfaceIndex {
+	oldInterface := m.defaultInterface.Load()
+	newInterface, err := m.interfaceFinder.ByIndex(defaultInterface.Index)
+	if err != nil {
+		return E.Cause(err, "find updated interface: ", defaultInterface.Name)
+	}
+	m.defaultInterface.Store(newInterface)
+	if oldInterface != nil && oldInterface.Name == newInterface.Name && oldInterface.Index == newInterface.Index {
 		return nil
 	}
 	m.emit(EventInterfaceUpdate)
 	return nil
 }
 
-func getDefaultInterfaceBySocket() (*net.Interface, error) {
+func (m *defaultInterfaceMonitor) getDefaultInterfaceBySocket() (*control.Interface, error) {
 	socketFd, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM, 0)
 	if err != nil {
 		return nil, E.Cause(err, "create file descriptor")
@@ -218,24 +222,5 @@ func getDefaultInterfaceBySocket() (*net.Interface, error) {
 	case <-time.After(time.Second):
 		return nil, nil
 	}
-	interfaces, err := net.Interfaces()
-	if err != nil {
-		return nil, E.Cause(err, "net.Interfaces")
-	}
-	for _, netInterface := range interfaces {
-		interfaceAddrs, err := netInterface.Addrs()
-		if err != nil {
-			return nil, E.Cause(err, "net.Interfaces.Addrs")
-		}
-		for _, interfaceAddr := range interfaceAddrs {
-			ipNet, isIPNet := interfaceAddr.(*net.IPNet)
-			if !isIPNet {
-				continue
-			}
-			if ipNet.Contains(selectedAddr.AsSlice()) {
-				return &netInterface, nil
-			}
-		}
-	}
-	return nil, E.New("no interface found for address ", selectedAddr)
+	return m.interfaceFinder.ByAddr(selectedAddr)
 }

monitor_linux_default.go

@@ -4,6 +4,7 @@ package tun
 
 import (
 	"github.com/sagernet/netlink"
+	E "github.com/sagernet/sing/common/exceptions"
 
 	"golang.org/x/sys/unix"
 )
@@ -24,13 +25,13 @@ func (m *defaultInterfaceMonitor) checkUpdate() error {
 			return err
 		}
 
-		oldInterface := m.defaultInterfaceName
-		oldIndex := m.defaultInterfaceIndex
-
-		m.defaultInterfaceName = link.Attrs().Name
-		m.defaultInterfaceIndex = link.Attrs().Index
-
-		if oldInterface == m.defaultInterfaceName && oldIndex == m.defaultInterfaceIndex {
+		oldInterface := m.defaultInterface.Load()
+		newInterface, err := m.interfaceFinder.ByIndex(link.Attrs().Index)
+		if err != nil {
+			return E.Cause(err, "find updated interface: ", link.Attrs().Name)
+		}
+		m.defaultInterface.Store(newInterface)
+		if oldInterface != nil && oldInterface.Name == newInterface.Name && oldInterface.Index == newInterface.Index {
 			return nil
 		}
 		m.emit(EventInterfaceUpdate)

monitor_shared.go

@@ -4,10 +4,10 @@ package tun
 
 import (
 	"errors"
-	"net/netip"
 	"sync"
 	"time"
 
+	"github.com/sagernet/sing/common/atomic"
 	"github.com/sagernet/sing/common/control"
 	"github.com/sagernet/sing/common/logger"
 	"github.com/sagernet/sing/common/x/list"
@@ -38,8 +38,7 @@ type defaultInterfaceMonitor struct {
 	interfaceFinder       control.InterfaceFinder
 	overrideAndroidVPN    bool
 	underNetworkExtension bool
-	defaultInterfaceName  string
-	defaultInterfaceIndex int
+	defaultInterface      atomic.Pointer[control.Interface]
 	androidVPNEnabled     bool
 	noRoute               bool
 	networkMonitor        NetworkUpdateMonitor
@@ -56,13 +55,12 @@ func NewDefaultInterfaceMonitor(networkMonitor NetworkUpdateMonitor, logger logg
 		overrideAndroidVPN:    options.OverrideAndroidVPN,
 		underNetworkExtension: options.UnderNetworkExtension,
 		networkMonitor:        networkMonitor,
-		defaultInterfaceIndex: -1,
 		logger:                logger,
 	}, nil
 }
 
 func (m *defaultInterfaceMonitor) Start() error {
-	_ = m.checkUpdate()
+	m.postCheckUpdate()
 	m.element = m.networkMonitor.RegisterCallback(m.delayCheckUpdate)
 	return nil
 }
@@ -76,16 +74,11 @@ func (m *defaultInterfaceMonitor) delayCheckUpdate() {
 }
 
 func (m *defaultInterfaceMonitor) postCheckUpdate() {
-	err := m.interfaceFinder.Update()
-	if err != nil {
-		m.logger.Error("update interfaces: ", err)
-	}
-	err = m.checkUpdate()
+	err := m.checkUpdate()
 	if errors.Is(err, ErrNoRoute) {
 		if !m.noRoute {
 			m.noRoute = true
-			m.defaultInterfaceName = ""
-			m.defaultInterfaceIndex = -1
+			m.defaultInterface.Store(nil)
 			m.emit(EventNoRoute)
 		}
 	} else if err != nil {
@@ -102,37 +95,8 @@ func (m *defaultInterfaceMonitor) Close() error {
 	return nil
 }
 
-func (m *defaultInterfaceMonitor) DefaultInterfaceName(destination netip.Addr) string {
-	for _, address := range m.interfaceFinder.Interfaces() {
-		for _, prefix := range address.Addresses {
-			if prefix.Contains(destination) {
-				return address.Name
-			}
-		}
-	}
-	return m.defaultInterfaceName
-}
-
-func (m *defaultInterfaceMonitor) DefaultInterfaceIndex(destination netip.Addr) int {
-	for _, address := range m.interfaceFinder.Interfaces() {
-		for _, prefix := range address.Addresses {
-			if prefix.Contains(destination) {
-				return address.Index
-			}
-		}
-	}
-	return m.defaultInterfaceIndex
-}
-
-func (m *defaultInterfaceMonitor) DefaultInterface(destination netip.Addr) (string, int) {
-	for _, address := range m.interfaceFinder.Interfaces() {
-		for _, prefix := range address.Addresses {
-			if prefix.Contains(destination) {
-				return address.Name, address.Index
-			}
-		}
-	}
-	return m.defaultInterfaceName, m.defaultInterfaceIndex
+func (m *defaultInterfaceMonitor) DefaultInterface() *control.Interface {
+	return m.defaultInterface.Load()
 }
 
 func (m *defaultInterfaceMonitor) OverrideAndroidVPN() bool {

monitor_windows.go

@@ -4,6 +4,7 @@ import (
 	"sync"
 
 	"github.com/sagernet/sing-tun/internal/winipcfg"
+	E "github.com/sagernet/sing/common/exceptions"
 	"github.com/sagernet/sing/common/logger"
 	"github.com/sagernet/sing/common/x/list"
 
@@ -101,16 +102,15 @@ func (m *defaultInterfaceMonitor) checkUpdate() error {
 		return ErrNoRoute
 	}
 
-	oldInterface := m.defaultInterfaceName
-	oldIndex := m.defaultInterfaceIndex
-
-	m.defaultInterfaceName = alias
-	m.defaultInterfaceIndex = index
-
-	if oldInterface == m.defaultInterfaceName && oldIndex == m.defaultInterfaceIndex {
+	oldInterface := m.defaultInterface.Load()
+	newInterface, err := m.interfaceFinder.ByIndex(index)
+	if err != nil {
+		return E.Cause(err, "find updated interface: ", alias)
+	}
+	m.defaultInterface.Store(newInterface)
+	if oldInterface != nil && oldInterface.Name == newInterface.Name && oldInterface.Index == newInterface.Index {
 		return nil
 	}
-
 	m.emit(EventInterfaceUpdate)
 	return nil
 }