add proxy protocol support for UDP proxies (#4810)

Co-authored-by: CrynTox <>

Makefile.cross-compiles

@@ -2,7 +2,7 @@ export PATH := $(PATH):`go env GOPATH`/bin
 export GO111MODULE=on
 LDFLAGS := -s -w
 
-os-archs=darwin:amd64 darwin:arm64 freebsd:amd64 linux:amd64 linux:arm:7 linux:arm:5 linux:arm64 windows:amd64 windows:arm64 linux:mips64 linux:mips64le linux:mips:softfloat linux:mipsle:softfloat linux:riscv64 linux:loong64 android:arm64
+os-archs=darwin:amd64 darwin:arm64 freebsd:amd64 openbsd:amd64 linux:amd64 linux:arm:7 linux:arm:5 linux:arm64 windows:amd64 windows:arm64 linux:mips64 linux:mips64le linux:mips:softfloat linux:mipsle:softfloat linux:riscv64 linux:loong64 android:arm64
 
 all: build
 

README.md

@@ -1025,7 +1025,7 @@ You can get user's real IP from HTTP request headers `X-Forwarded-For`.
 
 #### Proxy Protocol
 
-frp supports Proxy Protocol to send user's real IP to local services. It support all types except UDP.
+frp supports Proxy Protocol to send user's real IP to local services.
 
 Here is an example for https service:
 
@@ -1283,9 +1283,7 @@ frp supports feature gates to enable or disable experimental features. This allo
 To enable an experimental feature, add the feature gate to your configuration:
 
 ```toml
-featureGates = {
-  VirtualNet = true
-}
+featureGates = { VirtualNet = true }
 ```
 
 ### Feature Lifecycle

Release.md

@@ -1,8 +1,4 @@
-### Notes
+## Features
 
-*   **Feature Gates Introduced:** This version introduces a new experimental mechanism called Feature Gates. This allows users to enable or disable specific experimental features before they become generally available. Feature gates can be configured in the `featureGates` map within the configuration file.
-*   **VirtualNet Feature Gate:** The first available feature gate is `VirtualNet`, which enables the experimental Virtual Network functionality (currently in Alpha stage).
-
-### Features
-
-*   **Virtual Network (VirtualNet):** Introduce experimental virtual network capabilities (Alpha). This allows creating a TUN device managed by frp, enabling Layer 3 connectivity between different clients within the frp network. Requires root/admin privileges and is currently supported on Linux and macOS. Configuration is done via the `virtualNet` section and the `virtual_net` plugin. Enable with feature gate `VirtualNet`. **Note: As an Alpha feature, configuration details may change in future releases.**
+* Support for YAML merge functionality (anchors and references with dot-prefixed fields) in strict configuration mode without requiring `--strict-config=false` parameter.
+* Support for proxy protocol in UDP proxies to preserve real client IP addresses.

client/admin_api.go

@@ -165,9 +165,9 @@ func (svr *Service) apiStatus(w http.ResponseWriter, _ *http.Request) {
 		res StatusResp = make(map[string][]ProxyStatusResp)
 	)
 
-	log.Infof("Http request [/api/status]")
+	log.Infof("http request [/api/status]")
 	defer func() {
-		log.Infof("Http response [/api/status]")
+		log.Infof("http response [/api/status]")
 		buf, _ = json.Marshal(&res)
 		_, _ = w.Write(buf)
 	}()
@@ -198,9 +198,9 @@ func (svr *Service) apiStatus(w http.ResponseWriter, _ *http.Request) {
 func (svr *Service) apiGetConfig(w http.ResponseWriter, _ *http.Request) {
 	res := GeneralResponse{Code: 200}
 
-	log.Infof("Http get request [/api/config]")
+	log.Infof("http get request [/api/config]")
 	defer func() {
-		log.Infof("Http get response [/api/config], code [%d]", res.Code)
+		log.Infof("http get response [/api/config], code [%d]", res.Code)
 		w.WriteHeader(res.Code)
 		if len(res.Msg) > 0 {
 			_, _ = w.Write([]byte(res.Msg))
@@ -228,9 +228,9 @@ func (svr *Service) apiGetConfig(w http.ResponseWriter, _ *http.Request) {
 func (svr *Service) apiPutConfig(w http.ResponseWriter, r *http.Request) {
 	res := GeneralResponse{Code: 200}
 
-	log.Infof("Http put request [/api/config]")
+	log.Infof("http put request [/api/config]")
 	defer func() {
-		log.Infof("Http put response [/api/config], code [%d]", res.Code)
+		log.Infof("http put response [/api/config], code [%d]", res.Code)
 		w.WriteHeader(res.Code)
 		if len(res.Msg) > 0 {
 			_, _ = w.Write([]byte(res.Msg))

client/control.go

@@ -189,7 +189,7 @@ func (ctl *Control) handlePong(m msg.Message) {
 	inMsg := m.(*msg.Pong)
 
 	if inMsg.Error != "" {
-		xl.Errorf("Pong message contains error: %s", inMsg.Error)
+		xl.Errorf("pong message contains error: %s", inMsg.Error)
 		ctl.closeSession()
 		return
 	}

client/proxy/proxy.go

@@ -20,13 +20,11 @@ import (
 	"net"
 	"reflect"
 	"strconv"
-	"strings"
 	"sync"
 	"time"
 
 	libio "github.com/fatedier/golib/io"
 	libnet "github.com/fatedier/golib/net"
-	pp "github.com/pires/go-proxyproto"
 	"golang.org/x/time/rate"
 
 	"github.com/fatedier/frp/pkg/config/types"
@@ -35,6 +33,7 @@ import (
 	plugin "github.com/fatedier/frp/pkg/plugin/client"
 	"github.com/fatedier/frp/pkg/transport"
 	"github.com/fatedier/frp/pkg/util/limit"
+	netpkg "github.com/fatedier/frp/pkg/util/net"
 	"github.com/fatedier/frp/pkg/util/xlog"
 	"github.com/fatedier/frp/pkg/vnet"
 )
@@ -176,24 +175,9 @@ func (pxy *BaseProxy) HandleTCPWorkConnection(workConn net.Conn, m *msg.StartWor
 	}
 
 	if baseCfg.Transport.ProxyProtocolVersion != "" && m.SrcAddr != "" && m.SrcPort != 0 {
-		h := &pp.Header{
-			Command:         pp.PROXY,
-			SourceAddr:      connInfo.SrcAddr,
-			DestinationAddr: connInfo.DstAddr,
-		}
-
-		if strings.Contains(m.SrcAddr, ".") {
-			h.TransportProtocol = pp.TCPv4
-		} else {
-			h.TransportProtocol = pp.TCPv6
-		}
-
-		if baseCfg.Transport.ProxyProtocolVersion == "v1" {
-			h.Version = 1
-		} else if baseCfg.Transport.ProxyProtocolVersion == "v2" {
-			h.Version = 2
-		}
-		connInfo.ProxyProtocolHeader = h
+		// Use the common proxy protocol builder function
+		header := netpkg.BuildProxyProtocolHeaderStruct(connInfo.SrcAddr, connInfo.DstAddr, baseCfg.Transport.ProxyProtocolVersion)
+		connInfo.ProxyProtocolHeader = header
 	}
 	connInfo.Conn = remote
 	connInfo.UnderlyingConn = workConn

client/proxy/sudp.go

@@ -205,5 +205,5 @@ func (pxy *SUDPProxy) InWorkConn(conn net.Conn, _ *msg.StartWorkConn) {
 	go workConnReaderFn(workConn, readCh)
 	go heartbeatFn(sendCh)
 
-	udp.Forwarder(pxy.localAddr, readCh, sendCh, int(pxy.clientCfg.UDPPacketSize))
+	udp.Forwarder(pxy.localAddr, readCh, sendCh, int(pxy.clientCfg.UDPPacketSize), pxy.cfg.Transport.ProxyProtocolVersion)
 }

client/proxy/udp.go

@@ -171,5 +171,7 @@ func (pxy *UDPProxy) InWorkConn(conn net.Conn, _ *msg.StartWorkConn) {
 	go workConnSenderFn(pxy.workConn, pxy.sendCh)
 	go workConnReaderFn(pxy.workConn, pxy.readCh)
 	go heartbeatFn(pxy.sendCh)
-	udp.Forwarder(pxy.localAddr, pxy.readCh, pxy.sendCh, int(pxy.clientCfg.UDPPacketSize))
+
+	// Call Forwarder with proxy protocol version (empty string means no proxy protocol)
+	udp.Forwarder(pxy.localAddr, pxy.readCh, pxy.sendCh, int(pxy.clientCfg.UDPPacketSize), pxy.cfg.Transport.ProxyProtocolVersion)
 }

client/service.go

@@ -341,7 +341,7 @@ func (svr *Service) loopLoginUntilSuccess(maxInterval time.Duration, firstLoginE
 		ctl, err := NewControl(svr.ctx, sessionCtx)
 		if err != nil {
 			conn.Close()
-			xl.Errorf("NewControl error: %v", err)
+			xl.Errorf("new control error: %v", err)
 			return false, err
 		}
 		ctl.SetInWorkConnCallback(svr.handleWorkConnCb)

doc/server_plugin.md

@@ -121,7 +121,7 @@ Create new proxy
         // http and https only
         "custom_domains": []<string>,
         "subdomain": <string>,
-        "locations": <string>,
+        "locations": []<string>,
         "http_user": <string>,
         "http_pwd": <string>,
         "host_header_rewrite": <string>,

doc/virtual_net.md

@@ -49,9 +49,7 @@ type = "virtual_net"
 # frpc.toml (client side)
 serverAddr = "x.x.x.x"
 serverPort = 7000
-featureGates = {
-  VirtualNet = true
-}
+featureGates = { VirtualNet = true }
 
 # Configure the virtual network interface
 virtualNet.address = "100.86.0.2/24"

package.sh

@@ -17,7 +17,7 @@ make -f ./Makefile.cross-compiles
 rm -rf ./release/packages
 mkdir -p ./release/packages
 
-os_all='linux windows darwin freebsd android'
+os_all='linux windows darwin freebsd openbsd android'
 arch_all='386 amd64 arm arm64 mips64 mips64le mips mipsle riscv64 loong64'
 extra_all='_ hf'
 

pkg/config/load.go

@@ -111,6 +111,33 @@ func LoadConfigureFromFile(path string, c any, strict bool) error {
 	return LoadConfigure(content, c, strict)
 }
 
+// parseYAMLWithDotFieldsHandling parses YAML with dot-prefixed fields handling
+// This function handles both cases efficiently: with or without dot fields
+func parseYAMLWithDotFieldsHandling(content []byte, target any) error {
+	var temp any
+	if err := yaml.Unmarshal(content, &temp); err != nil {
+		return err
+	}
+
+	// Remove dot fields if it's a map
+	if tempMap, ok := temp.(map[string]any); ok {
+		for key := range tempMap {
+			if strings.HasPrefix(key, ".") {
+				delete(tempMap, key)
+			}
+		}
+	}
+
+	// Convert to JSON and decode with strict validation
+	jsonBytes, err := json.Marshal(temp)
+	if err != nil {
+		return err
+	}
+	decoder := json.NewDecoder(bytes.NewReader(jsonBytes))
+	decoder.DisallowUnknownFields()
+	return decoder.Decode(target)
+}
+
 // LoadConfigure loads configuration from bytes and unmarshal into c.
 // Now it supports json, yaml and toml format.
 func LoadConfigure(b []byte, c any, strict bool) error {
@@ -134,10 +161,13 @@ func LoadConfigure(b []byte, c any, strict bool) error {
 		}
 		return decoder.Decode(c)
 	}
-	// It wasn't JSON. Unmarshal as YAML.
+
+	// Handle YAML content
 	if strict {
-		return yaml.UnmarshalStrict(b, c)
+		// In strict mode, always use our custom handler to support YAML merge
+		return parseYAMLWithDotFieldsHandling(b, c)
 	}
+	// Non-strict mode, parse normally
 	return yaml.Unmarshal(b, c)
 }
 

pkg/config/load_test.go

@@ -187,3 +187,122 @@ unixPath = "/tmp/uds.sock"
 	err = LoadConfigure([]byte(pluginStr), &clientCfg, true)
 	require.Error(err)
 }
+
+// TestYAMLMergeInStrictMode tests that YAML merge functionality works
+// even in strict mode by properly handling dot-prefixed fields
+func TestYAMLMergeInStrictMode(t *testing.T) {
+	require := require.New(t)
+
+	yamlContent := `
+serverAddr: "127.0.0.1"
+serverPort: 7000
+
+.common: &common
+  type: stcp
+  secretKey: "test-secret"
+  localIP: 127.0.0.1
+  transport:
+    useEncryption: true
+    useCompression: true
+
+proxies:
+- name: ssh
+  localPort: 22
+  <<: *common
+- name: web
+  localPort: 80
+  <<: *common
+`
+
+	clientCfg := v1.ClientConfig{}
+	// This should work in strict mode
+	err := LoadConfigure([]byte(yamlContent), &clientCfg, true)
+	require.NoError(err)
+
+	// Verify the merge worked correctly
+	require.Equal("127.0.0.1", clientCfg.ServerAddr)
+	require.Equal(7000, clientCfg.ServerPort)
+	require.Len(clientCfg.Proxies, 2)
+
+	// Check first proxy
+	sshProxy := clientCfg.Proxies[0].ProxyConfigurer
+	require.Equal("ssh", sshProxy.GetBaseConfig().Name)
+	require.Equal("stcp", sshProxy.GetBaseConfig().Type)
+
+	// Check second proxy
+	webProxy := clientCfg.Proxies[1].ProxyConfigurer
+	require.Equal("web", webProxy.GetBaseConfig().Name)
+	require.Equal("stcp", webProxy.GetBaseConfig().Type)
+}
+
+// TestOptimizedYAMLProcessing tests the optimization logic for YAML processing
+func TestOptimizedYAMLProcessing(t *testing.T) {
+	require := require.New(t)
+
+	yamlWithDotFields := []byte(`
+serverAddr: "127.0.0.1"
+.common: &common
+  type: stcp
+proxies:
+- name: test
+  <<: *common
+`)
+
+	yamlWithoutDotFields := []byte(`
+serverAddr: "127.0.0.1"
+proxies:
+- name: test
+  type: tcp
+  localPort: 22
+`)
+
+	// Test that YAML without dot fields works in strict mode
+	clientCfg := v1.ClientConfig{}
+	err := LoadConfigure(yamlWithoutDotFields, &clientCfg, true)
+	require.NoError(err)
+	require.Equal("127.0.0.1", clientCfg.ServerAddr)
+	require.Len(clientCfg.Proxies, 1)
+	require.Equal("test", clientCfg.Proxies[0].ProxyConfigurer.GetBaseConfig().Name)
+
+	// Test that YAML with dot fields still works in strict mode
+	err = LoadConfigure(yamlWithDotFields, &clientCfg, true)
+	require.NoError(err)
+	require.Equal("127.0.0.1", clientCfg.ServerAddr)
+	require.Len(clientCfg.Proxies, 1)
+	require.Equal("test", clientCfg.Proxies[0].ProxyConfigurer.GetBaseConfig().Name)
+	require.Equal("stcp", clientCfg.Proxies[0].ProxyConfigurer.GetBaseConfig().Type)
+}
+
+// TestYAMLEdgeCases tests edge cases for YAML parsing, including non-map types
+func TestYAMLEdgeCases(t *testing.T) {
+	require := require.New(t)
+
+	// Test array at root (should fail for frp config)
+	arrayYAML := []byte(`
+- item1
+- item2
+`)
+	clientCfg := v1.ClientConfig{}
+	err := LoadConfigure(arrayYAML, &clientCfg, true)
+	require.Error(err) // Should fail because ClientConfig expects an object
+
+	// Test scalar at root (should fail for frp config)
+	scalarYAML := []byte(`"just a string"`)
+	err = LoadConfigure(scalarYAML, &clientCfg, true)
+	require.Error(err) // Should fail because ClientConfig expects an object
+
+	// Test empty object (should work)
+	emptyYAML := []byte(`{}`)
+	err = LoadConfigure(emptyYAML, &clientCfg, true)
+	require.NoError(err)
+
+	// Test nested structure without dots (should work)
+	nestedYAML := []byte(`
+serverAddr: "127.0.0.1"
+serverPort: 7000
+`)
+	err = LoadConfigure(nestedYAML, &clientCfg, true)
+	require.NoError(err)
+	require.Equal("127.0.0.1", clientCfg.ServerAddr)
+	require.Equal(7000, clientCfg.ServerPort)
+}

pkg/plugin/client/virtual_net.go

@@ -18,9 +18,10 @@ package client
 
 import (
 	"context"
+	"io"
+	"sync"
 
 	v1 "github.com/fatedier/frp/pkg/config/v1"
-	"github.com/fatedier/frp/pkg/util/xlog"
 )
 
 func init() {
@@ -30,6 +31,8 @@ func init() {
 type VirtualNetPlugin struct {
 	pluginCtx PluginContext
 	opts      *v1.VirtualNetPluginOptions
+	mu        sync.Mutex
+	conns     map[io.ReadWriteCloser]struct{}
 }
 
 func NewVirtualNetPlugin(pluginCtx PluginContext, options v1.ClientPluginOptions) (Plugin, error) {
@@ -43,19 +46,32 @@ func NewVirtualNetPlugin(pluginCtx PluginContext, options v1.ClientPluginOptions
 }
 
 func (p *VirtualNetPlugin) Handle(ctx context.Context, connInfo *ConnectionInfo) {
-	xl := xlog.FromContextSafe(ctx)
-
 	// Verify if virtual network controller is available
 	if p.pluginCtx.VnetController == nil {
 		return
 	}
 
-	// Register the connection with the controller
-	routeName := p.pluginCtx.Name
-	err := p.pluginCtx.VnetController.RegisterServerConn(ctx, routeName, connInfo.Conn)
-	if err != nil {
-		xl.Errorf("virtual net failed to register server connection: %v", err)
-		return
+	// Add the connection before starting the read loop to avoid race condition
+	// where RemoveConn might be called before the connection is added.
+	p.mu.Lock()
+	if p.conns == nil {
+		p.conns = make(map[io.ReadWriteCloser]struct{})
+	}
+	p.conns[connInfo.Conn] = struct{}{}
+	p.mu.Unlock()
+
+	// Register the connection with the controller and pass the cleanup function
+	p.pluginCtx.VnetController.StartServerConnReadLoop(ctx, connInfo.Conn, func() {
+		p.RemoveConn(connInfo.Conn)
+	})
+}
+
+func (p *VirtualNetPlugin) RemoveConn(conn io.ReadWriteCloser) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	// Check if the map exists, as Close might have set it to nil concurrently
+	if p.conns != nil {
+		delete(p.conns, conn)
 	}
 }
 
@@ -64,8 +80,13 @@ func (p *VirtualNetPlugin) Name() string {
 }
 
 func (p *VirtualNetPlugin) Close() error {
-	if p.pluginCtx.VnetController != nil {
-		p.pluginCtx.VnetController.UnregisterServerConn(p.pluginCtx.Name)
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	// Close any remaining connections
+	for conn := range p.conns {
+		_ = conn.Close()
 	}
+	p.conns = nil
 	return nil
 }

pkg/plugin/visitor/virtual_net.go

@@ -60,7 +60,7 @@ func NewVirtualNetPlugin(pluginCtx PluginContext, options v1.VisitorPluginOption
 		return nil, errors.New("destinationIP is required")
 	}
 
-	// Parse DestinationIP as a single IP and create a host route
+	// Parse DestinationIP and create a host route.
 	ip := net.ParseIP(opts.DestinationIP)
 	if ip == nil {
 		return nil, fmt.Errorf("invalid destination IP address [%s]", opts.DestinationIP)
@@ -91,7 +91,7 @@ func (p *VirtualNetPlugin) Start() {
 	if len(p.routes) > 0 {
 		routeStr = p.routes[0].String()
 	}
-	xl.Infof("Starting VirtualNetPlugin for visitor [%s], attempting to register routes for %s", p.pluginCtx.Name, routeStr)
+	xl.Infof("starting VirtualNetPlugin for visitor [%s], attempting to register routes for %s", p.pluginCtx.Name, routeStr)
 
 	go p.run()
 }
@@ -101,10 +101,8 @@ func (p *VirtualNetPlugin) run() {
 	reconnectDelay := 10 * time.Second
 
 	for {
-		// Create a signal channel for this connection attempt
 		currentCloseSignal := make(chan struct{})
 
-		// Store the signal channel under lock
 		p.mu.Lock()
 		p.closeSignal = currentCloseSignal
 		p.mu.Unlock()
@@ -112,7 +110,6 @@ func (p *VirtualNetPlugin) run() {
 		select {
 		case <-p.ctx.Done():
 			xl.Infof("VirtualNetPlugin run loop for visitor [%s] stopping (context cancelled before pipe creation).", p.pluginCtx.Name)
-			// Ensure controllerConn from previous loop is cleaned up if necessary
 			p.cleanupControllerConn(xl)
 			return
 		default:
@@ -120,65 +117,43 @@ func (p *VirtualNetPlugin) run() {
 
 		controllerConn, pluginConn := net.Pipe()
 
-		// Store controllerConn under lock for cleanup purposes
 		p.mu.Lock()
 		p.controllerConn = controllerConn
 		p.mu.Unlock()
 
-		// Wrap pluginConn using CloseNotifyConn
 		pluginNotifyConn := netutil.WrapCloseNotifyConn(pluginConn, func() {
-			close(currentCloseSignal) // Signal the run loop
+			close(currentCloseSignal) // Signal the run loop on close.
 		})
 
-		xl.Infof("Attempting to register client route for visitor [%s]", p.pluginCtx.Name)
-		err := p.pluginCtx.VnetController.RegisterClientRoute(p.ctx, p.pluginCtx.Name, p.routes, controllerConn)
-		if err != nil {
-			xl.Errorf("Failed to register client route for visitor [%s]: %v. Retrying after %v", p.pluginCtx.Name, err, reconnectDelay)
-			p.cleanupPipePair(xl, controllerConn, pluginConn) // Close both ends on registration failure
-
-			// Wait before retrying registration, unless context is cancelled
-			select {
-			case <-time.After(reconnectDelay):
-				continue // Retry the loop
-			case <-p.ctx.Done():
-				xl.Infof("VirtualNetPlugin registration retry wait interrupted for visitor [%s]", p.pluginCtx.Name)
-				return // Exit loop if context is cancelled during wait
-			}
-		}
-
-		xl.Infof("Successfully registered client route for visitor [%s]. Starting connection handler with CloseNotifyConn.", p.pluginCtx.Name)
+		xl.Infof("attempting to register client route for visitor [%s]", p.pluginCtx.Name)
+		p.pluginCtx.VnetController.RegisterClientRoute(p.ctx, p.pluginCtx.Name, p.routes, controllerConn)
+		xl.Infof("successfully registered client route for visitor [%s]. Starting connection handler with CloseNotifyConn.", p.pluginCtx.Name)
 
 		// Pass the CloseNotifyConn to HandleConn.
 		// HandleConn is responsible for calling Close() on pluginNotifyConn.
 		p.pluginCtx.HandleConn(pluginNotifyConn)
 
-		// Wait for either the plugin context to be cancelled or the wrapper's Close() to be called via the signal channel.
+		// Wait for context cancellation or connection close.
 		select {
 		case <-p.ctx.Done():
 			xl.Infof("VirtualNetPlugin run loop stopping for visitor [%s] (context cancelled while waiting).", p.pluginCtx.Name)
-			// Context cancelled, ensure controller side is closed if HandleConn didn't close its side yet.
 			p.cleanupControllerConn(xl)
 			return
 		case <-currentCloseSignal:
-			xl.Infof("Detected connection closed via CloseNotifyConn for visitor [%s].", p.pluginCtx.Name)
-			// HandleConn closed the plugin side (pluginNotifyConn). The closeFn was called, closing currentCloseSignal.
-			// We still need to close the controller side.
+			xl.Infof("detected connection closed via CloseNotifyConn for visitor [%s].", p.pluginCtx.Name)
+			// HandleConn closed the plugin side. Close the controller side.
 			p.cleanupControllerConn(xl)
 
-			// Add a delay before attempting to reconnect, respecting context cancellation.
-			xl.Infof("Waiting %v before attempting reconnection for visitor [%s]...", reconnectDelay, p.pluginCtx.Name)
+			xl.Infof("waiting %v before attempting reconnection for visitor [%s]...", reconnectDelay, p.pluginCtx.Name)
 			select {
 			case <-time.After(reconnectDelay):
-				// Delay completed, loop will continue.
 			case <-p.ctx.Done():
 				xl.Infof("VirtualNetPlugin reconnection delay interrupted for visitor [%s]", p.pluginCtx.Name)
-				return // Exit loop if context is cancelled during wait
+				return
 			}
-			// Loop will continue to reconnect.
 		}
 
-		// Loop will restart, context check at the beginning of the loop is sufficient.
-		xl.Infof("Re-establishing virtual connection for visitor [%s]...", p.pluginCtx.Name)
+		xl.Infof("re-establishing virtual connection for visitor [%s]...", p.pluginCtx.Name)
 	}
 }
 
@@ -187,46 +162,31 @@ func (p *VirtualNetPlugin) cleanupControllerConn(xl *xlog.Logger) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 	if p.controllerConn != nil {
-		xl.Debugf("Cleaning up controllerConn for visitor [%s]", p.pluginCtx.Name)
+		xl.Debugf("cleaning up controllerConn for visitor [%s]", p.pluginCtx.Name)
 		p.controllerConn.Close()
 		p.controllerConn = nil
 	}
-	// Also clear the closeSignal reference for the completed/cancelled connection attempt
 	p.closeSignal = nil
 }
 
-// cleanupPipePair closes both ends of a pipe, used typically when registration fails.
-func (p *VirtualNetPlugin) cleanupPipePair(xl *xlog.Logger, controllerConn, pluginConn net.Conn) {
-	xl.Debugf("Cleaning up pipe pair for visitor [%s] after registration failure", p.pluginCtx.Name)
-	controllerConn.Close()
-	pluginConn.Close()
-	p.mu.Lock()
-	p.controllerConn = nil // Ensure field is nil if it was briefly set
-	p.closeSignal = nil    // Ensure field is nil if it was briefly set
-	p.mu.Unlock()
-}
-
 // Close initiates the plugin shutdown.
 func (p *VirtualNetPlugin) Close() error {
-	xl := xlog.FromContextSafe(p.pluginCtx.Ctx) // Use base context for close logging
-	xl.Infof("Closing VirtualNetPlugin for visitor [%s]", p.pluginCtx.Name)
+	xl := xlog.FromContextSafe(p.pluginCtx.Ctx)
+	xl.Infof("closing VirtualNetPlugin for visitor [%s]", p.pluginCtx.Name)
 
-	// 1. Signal the run loop goroutine to stop via context cancellation.
+	// Signal the run loop goroutine to stop.
 	p.cancel()
 
-	// 2. Unregister the route from the controller.
-	// This might implicitly cause the VnetController to close its end of the pipe (controllerConn).
+	// Unregister the route from the controller.
 	if p.pluginCtx.VnetController != nil {
 		p.pluginCtx.VnetController.UnregisterClientRoute(p.pluginCtx.Name)
-		xl.Infof("Unregistered client route for visitor [%s]", p.pluginCtx.Name)
-	} else {
-		xl.Warnf("VnetController is nil during close for visitor [%s], cannot unregister route", p.pluginCtx.Name)
+		xl.Infof("unregistered client route for visitor [%s]", p.pluginCtx.Name)
 	}
 
-	// 3. Explicitly close the controller side of the pipe managed by this plugin.
+	// Explicitly close the controller side of the pipe.
 	// This ensures the pipe is broken even if the run loop is stuck or HandleConn hasn't closed its end.
 	p.cleanupControllerConn(xl)
-	xl.Infof("Finished cleaning up connections during close for visitor [%s]", p.pluginCtx.Name)
+	xl.Infof("finished cleaning up connections during close for visitor [%s]", p.pluginCtx.Name)
 
 	return nil
 }

pkg/proto/udp/udp.go

@@ -24,6 +24,7 @@ import (
 	"github.com/fatedier/golib/pool"
 
 	"github.com/fatedier/frp/pkg/msg"
+	netpkg "github.com/fatedier/frp/pkg/util/net"
 )
 
 func NewUDPPacket(buf []byte, laddr, raddr *net.UDPAddr) *msg.UDPPacket {
@@ -69,7 +70,7 @@ func ForwardUserConn(udpConn *net.UDPConn, readCh <-chan *msg.UDPPacket, sendCh
 	}
 }
 
-func Forwarder(dstAddr *net.UDPAddr, readCh <-chan *msg.UDPPacket, sendCh chan<- msg.Message, bufSize int) {
+func Forwarder(dstAddr *net.UDPAddr, readCh <-chan *msg.UDPPacket, sendCh chan<- msg.Message, bufSize int, proxyProtocolVersion string) {
 	var mu sync.RWMutex
 	udpConnMap := make(map[string]*net.UDPConn)
 
@@ -110,6 +111,7 @@ func Forwarder(dstAddr *net.UDPAddr, readCh <-chan *msg.UDPPacket, sendCh chan<-
 			if err != nil {
 				continue
 			}
+
 			mu.Lock()
 			udpConn, ok := udpConnMap[udpMsg.RemoteAddr.String()]
 			if !ok {
@@ -122,6 +124,18 @@ func Forwarder(dstAddr *net.UDPAddr, readCh <-chan *msg.UDPPacket, sendCh chan<-
 			}
 			mu.Unlock()
 
+			// Add proxy protocol header if configured
+			if proxyProtocolVersion != "" && udpMsg.RemoteAddr != nil {
+				ppBuf, err := netpkg.BuildProxyProtocolHeader(udpMsg.RemoteAddr, dstAddr, proxyProtocolVersion)
+				if err == nil {
+					// Prepend proxy protocol header to the UDP payload
+					finalBuf := make([]byte, len(ppBuf)+len(buf))
+					copy(finalBuf, ppBuf)
+					copy(finalBuf[len(ppBuf):], buf)
+					buf = finalBuf
+				}
+			}
+
 			_, err = udpConn.Write(buf)
 			if err != nil {
 				udpConn.Close()

pkg/util/net/proxyprotocol.go

@@ -0,0 +1,45 @@
+// Copyright 2025 The frp Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package net
+
+import (
+	"bytes"
+	"fmt"
+	"net"
+
+	pp "github.com/pires/go-proxyproto"
+)
+
+func BuildProxyProtocolHeaderStruct(srcAddr, dstAddr net.Addr, version string) *pp.Header {
+	var versionByte byte
+	if version == "v1" {
+		versionByte = 1
+	} else {
+		versionByte = 2 // default to v2
+	}
+	return pp.HeaderProxyFromAddrs(versionByte, srcAddr, dstAddr)
+}
+
+func BuildProxyProtocolHeader(srcAddr, dstAddr net.Addr, version string) ([]byte, error) {
+	h := BuildProxyProtocolHeaderStruct(srcAddr, dstAddr, version)
+
+	// Convert header to bytes using a buffer
+	var buf bytes.Buffer
+	_, err := h.WriteTo(&buf)
+	if err != nil {
+		return nil, fmt.Errorf("failed to write proxy protocol header: %v", err)
+	}
+	return buf.Bytes(), nil
+}

pkg/util/net/proxyprotocol_test.go

@@ -0,0 +1,178 @@
+package net
+
+import (
+	"net"
+	"testing"
+
+	pp "github.com/pires/go-proxyproto"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBuildProxyProtocolHeader(t *testing.T) {
+	require := require.New(t)
+
+	tests := []struct {
+		name        string
+		srcAddr     net.Addr
+		dstAddr     net.Addr
+		version     string
+		expectError bool
+	}{
+		{
+			name:        "UDP IPv4 v2",
+			srcAddr:     &net.UDPAddr{IP: net.ParseIP("192.168.1.100"), Port: 12345},
+			dstAddr:     &net.UDPAddr{IP: net.ParseIP("10.0.0.1"), Port: 3306},
+			version:     "v2",
+			expectError: false,
+		},
+		{
+			name:        "TCP IPv4 v1",
+			srcAddr:     &net.TCPAddr{IP: net.ParseIP("192.168.1.100"), Port: 12345},
+			dstAddr:     &net.TCPAddr{IP: net.ParseIP("10.0.0.1"), Port: 80},
+			version:     "v1",
+			expectError: false,
+		},
+		{
+			name:        "UDP IPv6 v2",
+			srcAddr:     &net.UDPAddr{IP: net.ParseIP("2001:db8::1"), Port: 12345},
+			dstAddr:     &net.UDPAddr{IP: net.ParseIP("::1"), Port: 3306},
+			version:     "v2",
+			expectError: false,
+		},
+		{
+			name:        "TCP IPv6 v1",
+			srcAddr:     &net.TCPAddr{IP: net.ParseIP("::1"), Port: 12345},
+			dstAddr:     &net.TCPAddr{IP: net.ParseIP("2001:db8::1"), Port: 80},
+			version:     "v1",
+			expectError: false,
+		},
+		{
+			name:        "nil source address",
+			srcAddr:     nil,
+			dstAddr:     &net.UDPAddr{IP: net.ParseIP("10.0.0.1"), Port: 3306},
+			version:     "v2",
+			expectError: false,
+		},
+		{
+			name:        "nil destination address",
+			srcAddr:     &net.TCPAddr{IP: net.ParseIP("192.168.1.100"), Port: 12345},
+			dstAddr:     nil,
+			version:     "v2",
+			expectError: false,
+		},
+		{
+			name:        "unsupported address type",
+			srcAddr:     &net.UnixAddr{Name: "/tmp/test.sock", Net: "unix"},
+			dstAddr:     &net.UDPAddr{IP: net.ParseIP("10.0.0.1"), Port: 3306},
+			version:     "v2",
+			expectError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		header, err := BuildProxyProtocolHeader(tt.srcAddr, tt.dstAddr, tt.version)
+
+		if tt.expectError {
+			require.Error(err, "test case: %s", tt.name)
+			continue
+		}
+
+		require.NoError(err, "test case: %s", tt.name)
+		require.NotEmpty(header, "test case: %s", tt.name)
+	}
+}
+
+func TestBuildProxyProtocolHeaderStruct(t *testing.T) {
+	require := require.New(t)
+
+	tests := []struct {
+		name               string
+		srcAddr            net.Addr
+		dstAddr            net.Addr
+		version            string
+		expectedProtocol   pp.AddressFamilyAndProtocol
+		expectedVersion    byte
+		expectedCommand    pp.ProtocolVersionAndCommand
+		expectedSourceAddr net.Addr
+		expectedDestAddr   net.Addr
+	}{
+		{
+			name:               "TCP IPv4 v2",
+			srcAddr:            &net.TCPAddr{IP: net.ParseIP("192.168.1.100"), Port: 12345},
+			dstAddr:            &net.TCPAddr{IP: net.ParseIP("10.0.0.1"), Port: 80},
+			version:            "v2",
+			expectedProtocol:   pp.TCPv4,
+			expectedVersion:    2,
+			expectedCommand:    pp.PROXY,
+			expectedSourceAddr: &net.TCPAddr{IP: net.ParseIP("192.168.1.100"), Port: 12345},
+			expectedDestAddr:   &net.TCPAddr{IP: net.ParseIP("10.0.0.1"), Port: 80},
+		},
+		{
+			name:               "UDP IPv6 v1",
+			srcAddr:            &net.UDPAddr{IP: net.ParseIP("2001:db8::1"), Port: 12345},
+			dstAddr:            &net.UDPAddr{IP: net.ParseIP("::1"), Port: 3306},
+			version:            "v1",
+			expectedProtocol:   pp.UDPv6,
+			expectedVersion:    1,
+			expectedCommand:    pp.PROXY,
+			expectedSourceAddr: &net.UDPAddr{IP: net.ParseIP("2001:db8::1"), Port: 12345},
+			expectedDestAddr:   &net.UDPAddr{IP: net.ParseIP("::1"), Port: 3306},
+		},
+		{
+			name:               "TCP IPv6 default version",
+			srcAddr:            &net.TCPAddr{IP: net.ParseIP("::1"), Port: 12345},
+			dstAddr:            &net.TCPAddr{IP: net.ParseIP("2001:db8::1"), Port: 80},
+			version:            "",
+			expectedProtocol:   pp.TCPv6,
+			expectedVersion:    2, // default to v2
+			expectedCommand:    pp.PROXY,
+			expectedSourceAddr: &net.TCPAddr{IP: net.ParseIP("::1"), Port: 12345},
+			expectedDestAddr:   &net.TCPAddr{IP: net.ParseIP("2001:db8::1"), Port: 80},
+		},
+		{
+			name:               "nil source address",
+			srcAddr:            nil,
+			dstAddr:            &net.UDPAddr{IP: net.ParseIP("10.0.0.1"), Port: 3306},
+			version:            "v2",
+			expectedProtocol:   pp.UNSPEC,
+			expectedVersion:    2,
+			expectedCommand:    pp.LOCAL,
+			expectedSourceAddr: nil, // go-proxyproto sets both to nil when srcAddr is nil
+			expectedDestAddr:   nil,
+		},
+		{
+			name:               "nil destination address",
+			srcAddr:            &net.TCPAddr{IP: net.ParseIP("192.168.1.100"), Port: 12345},
+			dstAddr:            nil,
+			version:            "v2",
+			expectedProtocol:   pp.UNSPEC,
+			expectedVersion:    2,
+			expectedCommand:    pp.LOCAL,
+			expectedSourceAddr: nil, // go-proxyproto sets both to nil when dstAddr is nil
+			expectedDestAddr:   nil,
+		},
+		{
+			name:               "unsupported address type",
+			srcAddr:            &net.UnixAddr{Name: "/tmp/test.sock", Net: "unix"},
+			dstAddr:            &net.UDPAddr{IP: net.ParseIP("10.0.0.1"), Port: 3306},
+			version:            "v2",
+			expectedProtocol:   pp.UNSPEC,
+			expectedVersion:    2,
+			expectedCommand:    pp.LOCAL,
+			expectedSourceAddr: nil, // go-proxyproto sets both to nil for unsupported types
+			expectedDestAddr:   nil,
+		},
+	}
+
+	for _, tt := range tests {
+		header := BuildProxyProtocolHeaderStruct(tt.srcAddr, tt.dstAddr, tt.version)
+
+		require.NotNil(header, "test case: %s", tt.name)
+
+		require.Equal(tt.expectedCommand, header.Command, "test case: %s", tt.name)
+		require.Equal(tt.expectedSourceAddr, header.SourceAddr, "test case: %s", tt.name)
+		require.Equal(tt.expectedDestAddr, header.DestinationAddr, "test case: %s", tt.name)
+		require.Equal(tt.expectedProtocol, header.TransportProtocol, "test case: %s", tt.name)
+		require.Equal(tt.expectedVersion, header.Version, "test case: %s", tt.name)
+	}
+}

pkg/util/version/version.go

@@ -14,7 +14,7 @@
 
 package version
 
-var version = "0.62.0"
+var version = "0.63.0"
 
 func Full() string {
 	return version

pkg/util/vhost/http.go

@@ -162,7 +162,7 @@ func (rp *HTTPReverseProxy) UnRegister(routeCfg RouteConfig) {
 func (rp *HTTPReverseProxy) GetRouteConfig(domain, location, routeByHTTPUser string) *RouteConfig {
 	vr, ok := rp.getVhost(domain, location, routeByHTTPUser)
 	if ok {
-		log.Debugf("get new HTTP request host [%s] path [%s] httpuser [%s]", domain, location, routeByHTTPUser)
+		log.Debugf("get new http request host [%s] path [%s] httpuser [%s]", domain, location, routeByHTTPUser)
 		return vr.payload.(*RouteConfig)
 	}
 	return nil

pkg/util/vhost/vhost.go

@@ -275,7 +275,7 @@ func (l *Listener) Accept() (net.Conn, error) {
 	xl := xlog.FromContextSafe(l.ctx)
 	conn, ok := <-l.accept
 	if !ok {
-		return nil, fmt.Errorf("Listener closed")
+		return nil, fmt.Errorf("listener closed")
 	}
 
 	// if rewriteHost func is exist

pkg/vnet/controller.go

@@ -87,7 +87,7 @@ func (c *Controller) handlePacket(buf []byte) {
 	case waterutil.IsIPv4(buf):
 		header, err := ipv4.ParseHeader(buf)
 		if err != nil {
-			log.Warnf("parse ipv4 header error:", err)
+			log.Warnf("parse ipv4 header error: %v", err)
 			return
 		}
 		src = header.Src
@@ -98,7 +98,7 @@ func (c *Controller) handlePacket(buf []byte) {
 	case waterutil.IsIPv6(buf):
 		header, err := ipv6.ParseHeader(buf)
 		if err != nil {
-			log.Warnf("parse ipv6 header error:", err)
+			log.Warnf("parse ipv6 header error: %v", err)
 			return
 		}
 		src = header.Src
@@ -137,6 +137,12 @@ func (c *Controller) Stop() error {
 // Client connection read loop
 func (c *Controller) readLoopClient(ctx context.Context, conn io.ReadWriteCloser) {
 	xl := xlog.FromContextSafe(ctx)
+	defer func() {
+		// Remove the route when read loop ends (connection closed)
+		c.clientRouter.removeConnRoute(conn)
+		conn.Close()
+	}()
+
 	for {
 		data, err := ReadMessage(conn)
 		if err != nil {
@@ -181,8 +187,18 @@ func (c *Controller) readLoopClient(ctx context.Context, conn io.ReadWriteCloser
 }
 
 // Server connection read loop
-func (c *Controller) readLoopServer(ctx context.Context, conn io.ReadWriteCloser) {
+func (c *Controller) readLoopServer(ctx context.Context, conn io.ReadWriteCloser, onClose func()) {
 	xl := xlog.FromContextSafe(ctx)
+	defer func() {
+		// Clean up all IP mappings associated with this connection when it closes
+		c.serverRouter.cleanupConnIPs(conn)
+		// Call the provided callback upon closure
+		if onClose != nil {
+			onClose()
+		}
+		conn.Close()
+	}()
+
 	for {
 		data, err := ReadMessage(conn)
 		if err != nil {
@@ -220,27 +236,11 @@ func (c *Controller) readLoopServer(ctx context.Context, conn io.ReadWriteCloser
 	}
 }
 
-// RegisterClientRoute Register client route (based on destination IP CIDR)
-func (c *Controller) RegisterClientRoute(ctx context.Context, name string, routes []net.IPNet, conn io.ReadWriteCloser) error {
-	if err := c.clientRouter.addRoute(name, routes, conn); err != nil {
-		return err
-	}
+// RegisterClientRoute registers a client route (based on destination IP CIDR)
+// and starts the read loop
+func (c *Controller) RegisterClientRoute(ctx context.Context, name string, routes []net.IPNet, conn io.ReadWriteCloser) {
+	c.clientRouter.addRoute(name, routes, conn)
 	go c.readLoopClient(ctx, conn)
-	return nil
-}
-
-// RegisterServerConn Register server connection (dynamically associates with source IPs)
-func (c *Controller) RegisterServerConn(ctx context.Context, name string, conn io.ReadWriteCloser) error {
-	if err := c.serverRouter.addConn(name, conn); err != nil {
-		return err
-	}
-	go c.readLoopServer(ctx, conn)
-	return nil
-}
-
-// UnregisterServerConn Remove server connection from routing table
-func (c *Controller) UnregisterServerConn(name string) {
-	c.serverRouter.delConn(name)
 }
 
 // UnregisterClientRoute Remove client route from routing table
@@ -248,6 +248,12 @@ func (c *Controller) UnregisterClientRoute(name string) {
 	c.clientRouter.delRoute(name)
 }
 
+// StartServerConnReadLoop starts the read loop for a server connection
+// (dynamically associates with source IPs)
+func (c *Controller) StartServerConnReadLoop(ctx context.Context, conn io.ReadWriteCloser, onClose func()) {
+	go c.readLoopServer(ctx, conn, onClose)
+}
+
 // ParseRoutes Convert route strings to IPNet objects
 func ParseRoutes(routeStrings []string) ([]net.IPNet, error) {
 	routes := make([]net.IPNet, 0, len(routeStrings))
@@ -273,7 +279,7 @@ func newClientRouter() *clientRouter {
 	}
 }
 
-func (r *clientRouter) addRoute(name string, routes []net.IPNet, conn io.ReadWriteCloser) error {
+func (r *clientRouter) addRoute(name string, routes []net.IPNet, conn io.ReadWriteCloser) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	r.routes[name] = &routeElement{
@@ -281,7 +287,6 @@ func (r *clientRouter) addRoute(name string, routes []net.IPNet, conn io.ReadWri
 		routes: routes,
 		conn:   conn,
 	}
-	return nil
 }
 
 func (r *clientRouter) findConn(dst net.IP) (io.Writer, error) {
@@ -303,32 +308,29 @@ func (r *clientRouter) delRoute(name string) {
 	delete(r.routes, name)
 }
 
-// Server router (based on source IP routing)
+func (r *clientRouter) removeConnRoute(conn io.Writer) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	for name, re := range r.routes {
+		if re.conn == conn {
+			delete(r.routes, name)
+			return
+		}
+	}
+}
+
+// Server router (based solely on source IP routing)
 type serverRouter struct {
-	namedConns map[string]io.ReadWriteCloser // Name to connection mapping
-	srcIPConns map[string]io.Writer          // Source IP string to connection mapping
+	srcIPConns map[string]io.Writer // Source IP string to connection mapping
 	mu         sync.RWMutex
 }
 
 func newServerRouter() *serverRouter {
 	return &serverRouter{
-		namedConns: make(map[string]io.ReadWriteCloser),
 		srcIPConns: make(map[string]io.Writer),
 	}
 }
 
-func (r *serverRouter) addConn(name string, conn io.ReadWriteCloser) error {
-	r.mu.Lock()
-	original, ok := r.namedConns[name]
-	r.namedConns[name] = conn
-	r.mu.Unlock()
-	if ok {
-		// Close the original connection if it exists
-		_ = original.Close()
-	}
-	return nil
-}
-
 func (r *serverRouter) findConnBySrc(src net.IP) (io.Writer, error) {
 	r.mu.RLock()
 	defer r.mu.RUnlock()
@@ -340,17 +342,41 @@ func (r *serverRouter) findConnBySrc(src net.IP) (io.Writer, error) {
 }
 
 func (r *serverRouter) registerSrcIP(src net.IP, conn io.Writer) {
+	key := src.String()
+
+	r.mu.RLock()
+	existingConn, ok := r.srcIPConns[key]
+	r.mu.RUnlock()
+
+	// If the entry exists and the connection is the same, no need to do anything.
+	if ok && existingConn == conn {
+		return
+	}
+
+	// Acquire write lock to update the map.
 	r.mu.Lock()
 	defer r.mu.Unlock()
-	r.srcIPConns[src.String()] = conn
+
+	// Double-check after acquiring the write lock to handle potential race conditions.
+	existingConn, ok = r.srcIPConns[key]
+	if ok && existingConn == conn {
+		return
+	}
+
+	r.srcIPConns[key] = conn
 }
 
-func (r *serverRouter) delConn(name string) {
+// cleanupConnIPs removes all IP mappings associated with the specified connection
+func (r *serverRouter) cleanupConnIPs(conn io.Writer) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
-	delete(r.namedConns, name)
-	// Note: We don't delete mappings from srcIPConns because we don't know which source IPs are associated with this connection
-	// This might cause dangling references, but they will be overwritten on new connections or restart
+
+	// Find and delete all IP mappings pointing to this connection
+	for ip, mappedConn := range r.srcIPConns {
+		if mappedConn == conn {
+			delete(r.srcIPConns, ip)
+		}
+	}
 }
 
 type routeElement struct {

pkg/vnet/message.go

@@ -33,7 +33,7 @@ func ReadMessage(r io.Reader) ([]byte, error) {
 	var length uint32
 	err := binary.Read(r, binary.LittleEndian, &length)
 	if err != nil {
-		return nil, fmt.Errorf("read message length error: %v", err)
+		return nil, fmt.Errorf("read message length error: %w", err)
 	}
 
 	// Check length to prevent DoS
@@ -48,7 +48,7 @@ func ReadMessage(r io.Reader) ([]byte, error) {
 	data := make([]byte, length)
 	_, err = io.ReadFull(r, data)
 	if err != nil {
-		return nil, fmt.Errorf("read message data error: %v", err)
+		return nil, fmt.Errorf("read message data error: %w", err)
 	}
 
 	return data, nil
@@ -68,13 +68,13 @@ func WriteMessage(w io.Writer, data []byte) error {
 	// Write length
 	err := binary.Write(w, binary.LittleEndian, length)
 	if err != nil {
-		return fmt.Errorf("write message length error: %v", err)
+		return fmt.Errorf("write message length error: %w", err)
 	}
 
 	// Write message data
 	_, err = w.Write(data)
 	if err != nil {
-		return fmt.Errorf("write message data error: %v", err)
+		return fmt.Errorf("write message data error: %w", err)
 	}
 
 	return nil

pkg/vnet/tun.go

@@ -23,7 +23,8 @@ import (
 )
 
 const (
-	offset = 16
+	offset            = 16
+	defaultPacketSize = 1420
 )
 
 type TunDevice interface {
@@ -35,20 +36,45 @@ func OpenTun(ctx context.Context, addr string) (TunDevice, error) {
 	if err != nil {
 		return nil, err
 	}
-	return &tunDeviceWrapper{dev: td}, nil
+
+	mtu, err := td.MTU()
+	if err != nil {
+		mtu = defaultPacketSize
+	}
+
+	bufferSize := max(mtu, defaultPacketSize)
+	batchSize := td.BatchSize()
+
+	device := &tunDeviceWrapper{
+		dev:         td,
+		bufferSize:  bufferSize,
+		readBuffers: make([][]byte, batchSize),
+		sizeBuffer:  make([]int, batchSize),
+	}
+
+	for i := range device.readBuffers {
+		device.readBuffers[i] = make([]byte, offset+bufferSize)
+	}
+
+	return device, nil
 }
 
 type tunDeviceWrapper struct {
-	dev tun.Device
+	dev           tun.Device
+	bufferSize    int
+	readBuffers   [][]byte
+	packetBuffers [][]byte
+	sizeBuffer    []int
 }
 
 func (d *tunDeviceWrapper) Read(p []byte) (int, error) {
-	buf := pool.GetBuf(len(p) + offset)
-	defer pool.PutBuf(buf)
+	if len(d.packetBuffers) > 0 {
+		n := copy(p, d.packetBuffers[0])
+		d.packetBuffers = d.packetBuffers[1:]
+		return n, nil
+	}
 
-	sz := make([]int, 1)
-
-	n, err := d.dev.Read([][]byte{buf}, sz, offset)
+	n, err := d.dev.Read(d.readBuffers, d.sizeBuffer, offset)
 	if err != nil {
 		return 0, err
 	}
@@ -56,20 +82,26 @@ func (d *tunDeviceWrapper) Read(p []byte) (int, error) {
 		return 0, io.EOF
 	}
 
-	dataSize := sz[0]
-	if dataSize > len(p) {
-		dataSize = len(p)
+	for i := range n {
+		if d.sizeBuffer[i] <= 0 {
+			continue
+		}
+		d.packetBuffers = append(d.packetBuffers, d.readBuffers[i][offset:offset+d.sizeBuffer[i]])
 	}
-	copy(p, buf[offset:offset+dataSize])
+
+	dataSize := copy(p, d.packetBuffers[0])
+	d.packetBuffers = d.packetBuffers[1:]
+
 	return dataSize, nil
 }
 
 func (d *tunDeviceWrapper) Write(p []byte) (int, error) {
-	buf := pool.GetBuf(len(p) + offset)
+	buf := pool.GetBuf(offset + d.bufferSize)
 	defer pool.PutBuf(buf)
 
-	copy(buf[offset:], p)
-	return d.dev.Write([][]byte{buf}, offset)
+	n := copy(buf[offset:], p)
+	_, err := d.dev.Write([][]byte{buf[:offset+n]}, offset)
+	return n, err
 }
 
 func (d *tunDeviceWrapper) Close() error {

pkg/vnet/tun_linux.go

@@ -16,35 +16,44 @@ package vnet
 
 import (
 	"context"
+	"crypto/sha256"
+	"encoding/hex"
 	"fmt"
 	"net"
+	"strconv"
+	"strings"
 
 	"github.com/vishvananda/netlink"
 	"golang.zx2c4.com/wireguard/tun"
 )
 
 const (
-	defaultTunName = "utun"
-	defaultMTU     = 1420
+	baseTunName = "utun"
+	defaultMTU  = 1420
 )
 
 func openTun(_ context.Context, addr string) (tun.Device, error) {
-	dev, err := tun.CreateTUN(defaultTunName, defaultMTU)
+	name, err := findNextTunName(baseTunName)
+	if err != nil {
+		name = getFallbackTunName(baseTunName, addr)
+	}
+
+	tunDevice, err := tun.CreateTUN(name, defaultMTU)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create TUN device '%s': %w", name, err)
+	}
+
+	actualName, err := tunDevice.Name()
 	if err != nil {
 		return nil, err
 	}
 
-	name, err := dev.Name()
+	ifn, err := net.InterfaceByName(actualName)
 	if err != nil {
 		return nil, err
 	}
 
-	ifn, err := net.InterfaceByName(name)
-	if err != nil {
-		return nil, err
-	}
-
-	link, err := netlink.LinkByName(name)
+	link, err := netlink.LinkByName(actualName)
 	if err != nil {
 		return nil, err
 	}
@@ -69,7 +78,34 @@ func openTun(_ context.Context, addr string) (tun.Device, error) {
 	if err = addRoutes(ifn, cidr); err != nil {
 		return nil, err
 	}
-	return dev, nil
+	return tunDevice, nil
+}
+
+func findNextTunName(basename string) (string, error) {
+	interfaces, err := net.Interfaces()
+	if err != nil {
+		return "", fmt.Errorf("failed to get network interfaces: %w", err)
+	}
+	maxSuffix := -1
+
+	for _, iface := range interfaces {
+		name := iface.Name
+		if strings.HasPrefix(name, basename) {
+			suffix := name[len(basename):]
+			if suffix == "" {
+				continue
+			}
+
+			numSuffix, err := strconv.Atoi(suffix)
+			if err == nil && numSuffix > maxSuffix {
+				maxSuffix = numSuffix
+			}
+		}
+	}
+
+	nextSuffix := maxSuffix + 1
+	name := fmt.Sprintf("%s%d", basename, nextSuffix)
+	return name, nil
 }
 
 func addRoutes(ifn *net.Interface, cidr *net.IPNet) error {
@@ -82,3 +118,14 @@ func addRoutes(ifn *net.Interface, cidr *net.IPNet) error {
 	}
 	return nil
 }
+
+// getFallbackTunName generates a deterministic fallback TUN device name
+// based on the base name and the provided address string using a hash.
+func getFallbackTunName(baseName, addr string) string {
+	hasher := sha256.New()
+	hasher.Write([]byte(addr))
+	hashBytes := hasher.Sum(nil)
+	// Use first 4 bytes -> 8 hex chars for brevity, respecting IFNAMSIZ limit.
+	shortHash := hex.EncodeToString(hashBytes[:4])
+	return fmt.Sprintf("%s%s", baseName, shortHash)
+}

server/control.go

@@ -224,7 +224,7 @@ func (ctl *Control) Close() error {
 
 func (ctl *Control) Replaced(newCtl *Control) {
 	xl := ctl.xl
-	xl.Infof("Replaced by client [%s]", newCtl.runID)
+	xl.Infof("replaced by client [%s]", newCtl.runID)
 	ctl.runID = ""
 	ctl.conn.Close()
 }

server/dashboard_api.go

@@ -97,14 +97,14 @@ func (svr *Service) healthz(w http.ResponseWriter, _ *http.Request) {
 func (svr *Service) apiServerInfo(w http.ResponseWriter, r *http.Request) {
 	res := GeneralResponse{Code: 200}
 	defer func() {
-		log.Infof("Http response [%s]: code [%d]", r.URL.Path, res.Code)
+		log.Infof("http response [%s]: code [%d]", r.URL.Path, res.Code)
 		w.WriteHeader(res.Code)
 		if len(res.Msg) > 0 {
 			_, _ = w.Write([]byte(res.Msg))
 		}
 	}()
 
-	log.Infof("Http request: [%s]", r.URL.Path)
+	log.Infof("http request: [%s]", r.URL.Path)
 	serverStats := mem.StatsCollector.GetServer()
 	svrResp := serverInfoResp{
 		Version:               version.Full(),
@@ -218,13 +218,13 @@ func (svr *Service) apiProxyByType(w http.ResponseWriter, r *http.Request) {
 	proxyType := params["type"]
 
 	defer func() {
-		log.Infof("Http response [%s]: code [%d]", r.URL.Path, res.Code)
+		log.Infof("http response [%s]: code [%d]", r.URL.Path, res.Code)
 		w.WriteHeader(res.Code)
 		if len(res.Msg) > 0 {
 			_, _ = w.Write([]byte(res.Msg))
 		}
 	}()
-	log.Infof("Http request: [%s]", r.URL.Path)
+	log.Infof("http request: [%s]", r.URL.Path)
 
 	proxyInfoResp := GetProxyInfoResp{}
 	proxyInfoResp.Proxies = svr.getProxyStatsByType(proxyType)
@@ -290,13 +290,13 @@ func (svr *Service) apiProxyByTypeAndName(w http.ResponseWriter, r *http.Request
 	name := params["name"]
 
 	defer func() {
-		log.Infof("Http response [%s]: code [%d]", r.URL.Path, res.Code)
+		log.Infof("http response [%s]: code [%d]", r.URL.Path, res.Code)
 		w.WriteHeader(res.Code)
 		if len(res.Msg) > 0 {
 			_, _ = w.Write([]byte(res.Msg))
 		}
 	}()
-	log.Infof("Http request: [%s]", r.URL.Path)
+	log.Infof("http request: [%s]", r.URL.Path)
 
 	var proxyStatsResp GetProxyStatsResp
 	proxyStatsResp, res.Code, res.Msg = svr.getProxyStatsByTypeAndName(proxyType, name)
@@ -358,13 +358,13 @@ func (svr *Service) apiProxyTraffic(w http.ResponseWriter, r *http.Request) {
 	name := params["name"]
 
 	defer func() {
-		log.Infof("Http response [%s]: code [%d]", r.URL.Path, res.Code)
+		log.Infof("http response [%s]: code [%d]", r.URL.Path, res.Code)
 		w.WriteHeader(res.Code)
 		if len(res.Msg) > 0 {
 			_, _ = w.Write([]byte(res.Msg))
 		}
 	}()
-	log.Infof("Http request: [%s]", r.URL.Path)
+	log.Infof("http request: [%s]", r.URL.Path)
 
 	trafficResp := GetProxyTrafficResp{}
 	trafficResp.Name = name
@@ -386,9 +386,9 @@ func (svr *Service) apiProxyTraffic(w http.ResponseWriter, r *http.Request) {
 func (svr *Service) deleteProxies(w http.ResponseWriter, r *http.Request) {
 	res := GeneralResponse{Code: 200}
 
-	log.Infof("Http request: [%s]", r.URL.Path)
+	log.Infof("http request: [%s]", r.URL.Path)
 	defer func() {
-		log.Infof("Http response [%s]: code [%d]", r.URL.Path, res.Code)
+		log.Infof("http response [%s]: code [%d]", r.URL.Path, res.Code)
 		w.WriteHeader(res.Code)
 		if len(res.Msg) > 0 {
 			_, _ = w.Write([]byte(res.Msg))

server/service.go

@@ -427,7 +427,7 @@ func (svr *Service) handleConnection(ctx context.Context, conn net.Conn, interna
 
 	_ = conn.SetReadDeadline(time.Now().Add(connReadTimeout))
 	if rawMsg, err = msg.ReadMsg(conn); err != nil {
-		log.Tracef("Failed to read message: %v", err)
+		log.Tracef("failed to read message: %v", err)
 		conn.Close()
 		return
 	}
@@ -475,7 +475,7 @@ func (svr *Service) handleConnection(ctx context.Context, conn net.Conn, interna
 			})
 		}
 	default:
-		log.Warnf("Error message type for the new connection [%s]", conn.RemoteAddr().String())
+		log.Warnf("error message type for the new connection [%s]", conn.RemoteAddr().String())
 		conn.Close()
 	}
 }
@@ -488,7 +488,7 @@ func (svr *Service) HandleListener(l net.Listener, internal bool) {
 	for {
 		c, err := l.Accept()
 		if err != nil {
-			log.Warnf("Listener for incoming connections from client closed")
+			log.Warnf("listener for incoming connections from client closed")
 			return
 		}
 		// inject xlog object into net.Conn context
@@ -504,7 +504,7 @@ func (svr *Service) HandleListener(l net.Listener, internal bool) {
 			var isTLS, custom bool
 			c, isTLS, custom, err = netpkg.CheckAndEnableTLSServerConnWithTimeout(c, svr.tlsConfig, forceTLS, connReadTimeout)
 			if err != nil {
-				log.Warnf("CheckAndEnableTLSServerConnWithTimeout error: %v", err)
+				log.Warnf("checkAndEnableTLSServerConnWithTimeout error: %v", err)
 				originConn.Close()
 				continue
 			}
@@ -520,7 +520,7 @@ func (svr *Service) HandleListener(l net.Listener, internal bool) {
 				fmuxCfg.MaxStreamWindowSize = 6 * 1024 * 1024
 				session, err := fmux.Server(frpConn, fmuxCfg)
 				if err != nil {
-					log.Warnf("Failed to create mux connection: %v", err)
+					log.Warnf("failed to create mux connection: %v", err)
 					frpConn.Close()
 					return
 				}
@@ -528,7 +528,7 @@ func (svr *Service) HandleListener(l net.Listener, internal bool) {
 				for {
 					stream, err := session.AcceptStream()
 					if err != nil {
-						log.Debugf("Accept new mux stream error: %v", err)
+						log.Debugf("accept new mux stream error: %v", err)
 						session.Close()
 						return
 					}
@@ -546,7 +546,7 @@ func (svr *Service) HandleQUICListener(l *quic.Listener) {
 	for {
 		c, err := l.Accept(context.Background())
 		if err != nil {
-			log.Warnf("QUICListener for incoming connections from client closed")
+			log.Warnf("quic listener for incoming connections from client closed")
 			return
 		}
 		// Start a new goroutine to handle connection.
@@ -554,7 +554,7 @@ func (svr *Service) HandleQUICListener(l *quic.Listener) {
 			for {
 				stream, err := frpConn.AcceptStream(context.Background())
 				if err != nil {
-					log.Debugf("Accept new quic mux stream error: %v", err)
+					log.Debugf("accept new quic mux stream error: %v", err)
 					_ = frpConn.CloseWithError(0, "")
 					return
 				}
@@ -620,7 +620,7 @@ func (svr *Service) RegisterWorkConn(workConn net.Conn, newMsg *msg.NewWorkConn)
 	xl := netpkg.NewLogFromConn(workConn)
 	ctl, exist := svr.ctlManager.GetByID(newMsg.RunID)
 	if !exist {
-		xl.Warnf("No client control found for run id [%s]", newMsg.RunID)
+		xl.Warnf("no client control found for run id [%s]", newMsg.RunID)
 		return fmt.Errorf("no client control found for run id [%s]", newMsg.RunID)
 	}
 	// server plugin hook

test/e2e/e2e.go

@@ -38,7 +38,7 @@ func RunE2ETests(t *testing.T) {
 	// Randomize specs as well as suites
 	suiteConfig.RandomizeAllSpecs = true
 
-	log.Infof("Starting e2e run %q on Ginkgo node %d of total %d",
+	log.Infof("starting e2e run %q on Ginkgo node %d of total %d",
 		framework.RunID, suiteConfig.ParallelProcess, suiteConfig.ParallelTotal)
 	ginkgo.RunSpecs(t, "frp e2e suite", suiteConfig, reporterConfig)
 }

test/e2e/framework/request.go

@@ -20,7 +20,7 @@ func ExpectResponseCode(code int) EnsureFunc {
 		if resp.Code == code {
 			return true
 		}
-		flog.Warnf("Expect code %d, but got %d", code, resp.Code)
+		flog.Warnf("expect code %d, but got %d", code, resp.Code)
 		return false
 	}
 }
@@ -111,14 +111,14 @@ func (e *RequestExpect) Ensure(fns ...EnsureFunc) {
 
 	if len(fns) == 0 {
 		if !bytes.Equal(e.expectResp, ret.Content) {
-			flog.Tracef("Response info: %+v", ret)
+			flog.Tracef("response info: %+v", ret)
 		}
 		ExpectEqualValuesWithOffset(1, string(ret.Content), string(e.expectResp), e.explain...)
 	} else {
 		for _, fn := range fns {
 			ok := fn(ret)
 			if !ok {
-				flog.Tracef("Response info: %+v", ret)
+				flog.Tracef("response info: %+v", ret)
 			}
 			ExpectTrueWithOffset(1, ok, e.explain...)
 		}

test/e2e/legacy/features/real_ip.go

@@ -93,7 +93,7 @@ var _ = ginkgo.Describe("[Feature: Real IP]", func() {
 			f.RunProcesses([]string{serverConf}, []string{clientConf})
 
 			framework.NewRequestExpect(f).Port(remotePort).Ensure(func(resp *request.Response) bool {
-				log.Tracef("ProxyProtocol get SourceAddr: %s", string(resp.Content))
+				log.Tracef("proxy protocol get SourceAddr: %s", string(resp.Content))
 				addr, err := net.ResolveTCPAddr("tcp", string(resp.Content))
 				if err != nil {
 					return false
@@ -142,7 +142,7 @@ var _ = ginkgo.Describe("[Feature: Real IP]", func() {
 				r.HTTP().HTTPHost("normal.example.com")
 			}).Ensure(framework.ExpectResponseCode(404))
 
-			log.Tracef("ProxyProtocol get SourceAddr: %s", srcAddrRecord)
+			log.Tracef("proxy protocol get SourceAddr: %s", srcAddrRecord)
 			addr, err := net.ResolveTCPAddr("tcp", srcAddrRecord)
 			framework.ExpectNoError(err, srcAddrRecord)
 			framework.ExpectEqualValues("127.0.0.1", addr.IP.String())

test/e2e/v1/features/real_ip.go

@@ -215,7 +215,7 @@ var _ = ginkgo.Describe("[Feature: Real IP]", func() {
 			f.RunProcesses([]string{serverConf}, []string{clientConf})
 
 			framework.NewRequestExpect(f).Port(remotePort).Ensure(func(resp *request.Response) bool {
-				log.Tracef("ProxyProtocol get SourceAddr: %s", string(resp.Content))
+				log.Tracef("proxy protocol get SourceAddr: %s", string(resp.Content))
 				addr, err := net.ResolveTCPAddr("tcp", string(resp.Content))
 				if err != nil {
 					return false
@@ -227,6 +227,56 @@ var _ = ginkgo.Describe("[Feature: Real IP]", func() {
 			})
 		})
 
+		ginkgo.It("UDP", func() {
+			serverConf := consts.DefaultServerConfig
+			clientConf := consts.DefaultClientConfig
+
+			localPort := f.AllocPort()
+			localServer := streamserver.New(streamserver.UDP, streamserver.WithBindPort(localPort),
+				streamserver.WithCustomHandler(func(c net.Conn) {
+					defer c.Close()
+					rd := bufio.NewReader(c)
+					ppHeader, err := pp.Read(rd)
+					if err != nil {
+						log.Errorf("read proxy protocol error: %v", err)
+						return
+					}
+
+					// Read the actual UDP content after proxy protocol header
+					if _, err := rpc.ReadBytes(rd); err != nil {
+						return
+					}
+
+					buf := []byte(ppHeader.SourceAddr.String())
+					_, _ = rpc.WriteBytes(c, buf)
+				}))
+			f.RunServer("", localServer)
+
+			remotePort := f.AllocPort()
+			clientConf += fmt.Sprintf(`
+			[[proxies]]
+			name = "udp"
+			type = "udp"
+			localPort = %d
+			remotePort = %d
+			transport.proxyProtocolVersion = "v2"
+			`, localPort, remotePort)
+
+			f.RunProcesses([]string{serverConf}, []string{clientConf})
+
+			framework.NewRequestExpect(f).Protocol("udp").Port(remotePort).Ensure(func(resp *request.Response) bool {
+				log.Tracef("udp proxy protocol get SourceAddr: %s", string(resp.Content))
+				addr, err := net.ResolveUDPAddr("udp", string(resp.Content))
+				if err != nil {
+					return false
+				}
+				if addr.IP.String() != "127.0.0.1" {
+					return false
+				}
+				return true
+			})
+		})
+
 		ginkgo.It("HTTP", func() {
 			vhostHTTPPort := f.AllocPort()
 			serverConf := consts.DefaultServerConfig + fmt.Sprintf(`
@@ -265,7 +315,7 @@ var _ = ginkgo.Describe("[Feature: Real IP]", func() {
 				r.HTTP().HTTPHost("normal.example.com")
 			}).Ensure(framework.ExpectResponseCode(404))
 
-			log.Tracef("ProxyProtocol get SourceAddr: %s", srcAddrRecord)
+			log.Tracef("proxy protocol get SourceAddr: %s", srcAddrRecord)
 			addr, err := net.ResolveTCPAddr("tcp", srcAddrRecord)
 			framework.ExpectNoError(err, srcAddrRecord)
 			framework.ExpectEqualValues("127.0.0.1", addr.IP.String())