XDRIVE transport: Add "s3" storage backend (#7231)

https://github.com/XTLS/Xray-core/pull/7231#issuecomment-6488077212

.github/workflows/docker.yml

@@ -82,7 +82,7 @@ jobs:
         uses: docker/setup-buildx-action@v4
 
       - name: Login to GitHub Container Registry
-        uses: docker/login-action@v4.6.0
+        uses: docker/login-action@v4.7.0
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}

.github/workflows/test.yml

@@ -35,24 +35,7 @@ jobs:
         if: steps.check-assets.outputs.missing == 'true'
         run: sleep 90
 
-  check-proto:
+  check-format-and-proto:
-    runs-on: ubuntu-latest
-    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
-    steps:
-      - name: Checkout codebase
-        uses: actions/checkout@v7
-      - name: Check Proto Version Header
-        run: |
-          head -n 4 core/config.pb.go > ref.txt
-          find . -name "*.pb.go" ! -name "*_grpc.pb.go" -print0 | while IFS= read -r -d '' file; do
-            if ! cmp -s ref.txt <(head -n 4 "$file"); then
-              echo "Error: Header mismatch in $file"
-              head -n 4 "$file"
-              exit 1
-            fi
-          done
-
-  check-format:
     runs-on: ubuntu-latest
     if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
     permissions:
@@ -68,6 +51,8 @@ jobs:
           cache: false
       - name: Check Format
         run: go run ./infra/vformat/main.go -mode check -pwd ./
+      - name: Check Protobuf
+        run: go run ./infra/vprotogen/main.go -mode check -pwd ./
 
   test:
     needs: check-assets

app/geodata/download.go

@@ -21,7 +21,10 @@ import (
 	"golang.org/x/net/http2"
 )
 
-const idleTimeout = 30 * time.Second
+const (
+	idleTimeout           = 30 * time.Second
+	maxDownloadSize int64 = 256 * 1024 * 1024
+)
 
 // DO NOT EDIT. Ignored by geodata, rejected by Lua.
 const luaGuardHeader = "\x12\x01\x00"
@@ -33,7 +36,6 @@ type stage struct {
 
 type downloader struct {
 	ctx         context.Context
-	httpClient  *http.Client
 	httpsClient *http.Client
 }
 
@@ -61,12 +63,11 @@ func (c *idleConn) Write(b []byte) (int, error) {
 func newDownloader(ctx context.Context, dispatcher routing.Dispatcher, outbound string) *downloader {
 	return &downloader{
 		ctx:         ctx,
-		httpClient:  newClient(ctx, dispatcher, outbound, false),
+		httpsClient: newClient(ctx, dispatcher, outbound),
-		httpsClient: newClient(ctx, dispatcher, outbound, true),
 	}
 }
 
-func newClient(baseCtx context.Context, dispatcher routing.Dispatcher, outbound string, isHTTPS bool) *http.Client {
+func newClient(baseCtx context.Context, dispatcher routing.Dispatcher, outbound string) *http.Client {
 	dial := func(ctx context.Context, network, address string) (net.Conn, error) {
 		var conn net.Conn
 		err := task.Run(ctx, func() error {
@@ -91,7 +92,6 @@ func newClient(baseCtx context.Context, dispatcher routing.Dispatcher, outbound
 			Conn: conn,
 		}, nil
 	}
-	if isHTTPS {
 	return &http.Client{
 		Transport: &http2.Transport{
 			DialTLSContext: func(ctx context.Context, network string, address string, cfg *tls.Config) (net.Conn, error) {
@@ -114,31 +114,12 @@ func newClient(baseCtx context.Context, dispatcher routing.Dispatcher, outbound
 			if req.URL.Scheme != "https" {
 				return errors.New("redirected to non-https URL: ", req.URL.String())
 			}
-				if len(via) >= 10 {
+			if len(via) >= 20 {
-					return errors.New("stopped after 10 redirects")
+				return errors.New("stopped after 20 redirects")
 			}
 			return nil
 		},
 	}
-	} else {
-		return &http.Client{
-			Transport: &http.Transport{
-				Proxy:                 nil,
-				DisableKeepAlives:     true,
-				DialContext:           dial,
-				ResponseHeaderTimeout: idleTimeout,
-			},
-			CheckRedirect: func(req *http.Request, via []*http.Request) error {
-				if req.URL.Scheme != "https" {
-					return errors.New("redirected to non-https URL: ", req.URL.String())
-				}
-				if len(via) >= 10 {
-					return errors.New("stopped after 10 redirects")
-				}
-				return nil
-			},
-		}
-	}
 }
 
 func (d *downloader) download(assets []*Asset) ([]stage, error) {
@@ -203,27 +184,26 @@ func (d *downloader) fetch(rawURL string, writer io.Writer) error {
 	}
 	utils.TryDefaultHeadersWith(req.Header, "nav")
 
-	var client *http.Client
+	resp, err := d.httpsClient.Do(req)
-	if req.URL.Scheme == "https" {
-		client = d.httpsClient
-	} else {
-		client = d.httpClient
-	}
-	resp, err := client.Do(req)
 	if err != nil {
 		return err
 	}
 	defer resp.Body.Close()
 
 	if resp.StatusCode < http.StatusOK || resp.StatusCode >= http.StatusMultipleChoices {
-		io.Copy(io.Discard, resp.Body)
 		return errors.New("unexpected status code: ", resp.StatusCode)
 	}
+	if resp.ContentLength > maxDownloadSize {
+		return errors.New("geodata download exceeds 256 MiB")
+	}
 
-	n, err := io.Copy(writer, resp.Body)
+	n, err := io.Copy(writer, io.LimitReader(resp.Body, maxDownloadSize+1))
 	if err != nil {
 		return err
 	}
+	if n > maxDownloadSize {
+		return errors.New("geodata download exceeds 256 MiB")
+	}
 	if n == 0 {
 		return errors.New("empty response body")
 	}

app/geodata/download_test.go

@@ -7,10 +7,13 @@ import (
 	"net/http/httptest"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	commongeodata "github.com/xtls/xray-core/common/geodata"
 	xlua "github.com/xtls/xray-core/common/lua"
+	"github.com/xtls/xray-core/common/serial"
+	"github.com/xtls/xray-core/core"
 	"github.com/yuin/gopher-lua/parse"
 	"google.golang.org/protobuf/proto"
 )
@@ -31,11 +34,11 @@ func TestDownloadOneLuaGuard(t *testing.T) {
 			if err := os.WriteFile(filepath.Join(dir, "asset.lua"), nil, 0o600); err != nil {
 				t.Fatal(err)
 			}
-			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+			server := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 				_, _ = w.Write([]byte(tc.body))
 			}))
 			defer server.Close()
-			d := &downloader{ctx: context.Background(), httpClient: server.Client()}
+			d := &downloader{ctx: context.Background(), httpsClient: server.Client()}
 			staged, err := d.downloadOne(&Asset{Url: server.URL, File: "asset.lua"})
 			if err != nil {
 				t.Fatal(err)
@@ -71,3 +74,53 @@ func TestDownloadOneLuaGuard(t *testing.T) {
 		})
 	}
 }
+
+func TestProtobufConfigValidation(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("xray.location.asset", dir)
+	for _, name := range []string{"asset.dat", "asset.DAT"} {
+		if err := os.WriteFile(filepath.Join(dir, name), nil, 0o600); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := os.Mkdir(filepath.Join(dir, "directory.dat"), 0o700); err != nil {
+		t.Fatal(err)
+	}
+	server, err := core.New(&core.Config{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = server.Close() })
+	for _, tc := range []struct {
+		name      string
+		config    *Config
+		wantError string
+	}{
+		{"minutely cron", &Config{Cron: "* * * * *"}, ""},
+		{"minimum interval", &Config{Cron: "@every 1m"}, ""},
+		{"short interval", &Config{Cron: "@every 59s"}, "interval must be at least 1 minute"},
+		{"fractional interval", &Config{Cron: "@every 59.999s"}, "interval must be at least 1 minute"},
+		{"invalid cron", &Config{Cron: "invalid"}, "invalid geodata cron"},
+		{"dat extension", &Config{Cron: "@daily", Assets: []*Asset{{Url: "https://example.com/asset.dat", File: "asset.dat"}}}, ""},
+		{"uppercase extension", &Config{Cron: "@daily", Assets: []*Asset{{Url: "https://example.com/asset.dat", File: "asset.DAT"}}}, ""},
+		{"invalid extension", &Config{Cron: "@daily", Assets: []*Asset{{Url: "https://example.com/asset.dat", File: "asset.lua"}}}, "extension must be .dat"},
+		{"missing extension", &Config{Cron: "@daily", Assets: []*Asset{{Url: "https://example.com/asset.dat", File: "asset"}}}, "extension must be .dat"},
+		{"missing file", &Config{Cron: "@daily", Assets: []*Asset{{Url: "https://example.com/asset.dat", File: "missing.dat"}}}, "invalid geodata asset file"},
+		{"directory", &Config{Cron: "@daily", Assets: []*Asset{{Url: "https://example.com/asset.dat", File: "directory.dat"}}}, "asset is not a regular file"},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			config, err := serial.ToTypedMessage(tc.config).GetInstance()
+			if err != nil {
+				t.Fatal(err)
+			}
+			_, err = core.CreateObject(server, config)
+			if tc.wantError == "" {
+				if err != nil {
+					t.Fatal(err)
+				}
+			} else if err == nil || !strings.Contains(err.Error(), tc.wantError) {
+				t.Fatalf("CreateObject() error = %v; want %q", err, tc.wantError)
+			}
+		})
+	}
+}

app/geodata/geodata.go

@@ -2,12 +2,16 @@ package geodata
 
 import (
 	"context"
+	"path/filepath"
+	"strings"
 	"sync"
+	"time"
 
 	"github.com/robfig/cron/v3"
 	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/errors"
 	commongeodata "github.com/xtls/xray-core/common/geodata"
+	"github.com/xtls/xray-core/common/platform/filesystem"
 	"github.com/xtls/xray-core/core"
 	"github.com/xtls/xray-core/features/routing"
 )
@@ -25,6 +29,24 @@ func New(ctx context.Context, config *Config) (*Instance, error) {
 	if config.Cron == "" {
 		return &Instance{}, nil
 	}
+	if len(config.Assets) > 100 {
+		return nil, errors.New("geodata supports at most 100 assets")
+	}
+	for _, asset := range config.Assets {
+		if !strings.EqualFold(filepath.Ext(asset.GetFile()), ".dat") {
+			return nil, errors.New("geodata asset file extension must be .dat")
+		}
+		if _, err := filesystem.ResolveAsset(asset.GetFile()); err != nil {
+			return nil, errors.New("invalid geodata asset file: ", asset.GetFile()).Base(err)
+		}
+	}
+	schedule, err := cron.ParseStandard(config.Cron)
+	if err != nil {
+		return nil, errors.New("invalid geodata cron").Base(err)
+	}
+	if interval, ok := schedule.(cron.ConstantDelaySchedule); ok && interval.Delay < time.Minute {
+		return nil, errors.New("geodata cron interval must be at least 1 minute")
+	}
 
 	g := &Instance{
 		assets: config.Assets,
@@ -44,9 +66,7 @@ func New(ctx context.Context, config *Config) (*Instance, error) {
 		cron.WithChain(cron.SkipIfStillRunning(cron.DiscardLogger)),
 		cron.WithLogger(cron.DiscardLogger),
 	)
-	if _, err := g.tasker.AddFunc(config.Cron, g.execute); err != nil {
+	g.tasker.Schedule(schedule, cron.FuncJob(g.execute))
-		return nil, errors.New("invalid geodata cron").Base(err)
-	}
 	errors.LogInfo(ctx, "scheduled geodata reload with cron: ", config.Cron)
 
 	return g, nil

app/observatory/config.pb.go

@@ -152,23 +152,23 @@ func (x *HealthPingMeasurementResult) GetMin() int64 {
 type OutboundStatus struct {
 	state protoimpl.MessageState `protogen:"open.v1"`
 	// @Document Whether this outbound is usable
-	// @Restriction ReadOnlyForUser
+	//@Restriction ReadOnlyForUser
 	Alive bool `protobuf:"varint,1,opt,name=alive,proto3" json:"alive,omitempty"`
 	// @Document The time for probe request to finish.
-	// @Type time.ms
+	//@Type time.ms
-	// @Restriction ReadOnlyForUser
+	//@Restriction ReadOnlyForUser
 	Delay int64 `protobuf:"varint,2,opt,name=delay,proto3" json:"delay,omitempty"`
 	// @Document The last error caused this outbound failed to relay probe request
-	// @Restriction NotMachineReadable
+	//@Restriction NotMachineReadable
 	LastErrorReason string `protobuf:"bytes,3,opt,name=last_error_reason,json=lastErrorReason,proto3" json:"last_error_reason,omitempty"`
 	// @Document The outbound tag for this Server
-	// @Type id.outboundTag
+	//@Type id.outboundTag
 	OutboundTag string `protobuf:"bytes,4,opt,name=outbound_tag,json=outboundTag,proto3" json:"outbound_tag,omitempty"`
 	// @Document The time this outbound is known to be alive
-	// @Type id.outboundTag
+	//@Type id.outboundTag
 	LastSeenTime int64 `protobuf:"varint,5,opt,name=last_seen_time,json=lastSeenTime,proto3" json:"last_seen_time,omitempty"`
 	// @Document The time this outbound is tried
-	// @Type id.outboundTag
+	//@Type id.outboundTag
 	LastTryTime   int64                        `protobuf:"varint,6,opt,name=last_try_time,json=lastTryTime,proto3" json:"last_try_time,omitempty"`
 	HealthPing    *HealthPingMeasurementResult `protobuf:"bytes,7,opt,name=health_ping,json=healthPing,proto3" json:"health_ping,omitempty"`
 	unknownFields protoimpl.UnknownFields
@@ -257,14 +257,14 @@ func (x *OutboundStatus) GetHealthPing() *HealthPingMeasurementResult {
 type ProbeResult struct {
 	state protoimpl.MessageState `protogen:"open.v1"`
 	// @Document Whether this outbound is usable
-	// @Restriction ReadOnlyForUser
+	//@Restriction ReadOnlyForUser
 	Alive bool `protobuf:"varint,1,opt,name=alive,proto3" json:"alive,omitempty"`
 	// @Document The time for probe request to finish.
-	// @Type time.ms
+	//@Type time.ms
-	// @Restriction ReadOnlyForUser
+	//@Restriction ReadOnlyForUser
 	Delay int64 `protobuf:"varint,2,opt,name=delay,proto3" json:"delay,omitempty"`
 	// @Document The error caused this outbound failed to relay probe request
-	// @Restriction NotMachineReadable
+	//@Restriction NotMachineReadable
 	LastErrorReason string `protobuf:"bytes,3,opt,name=last_error_reason,json=lastErrorReason,proto3" json:"last_error_reason,omitempty"`
 	unknownFields   protoimpl.UnknownFields
 	sizeCache       protoimpl.SizeCache
@@ -324,7 +324,7 @@ func (x *ProbeResult) GetLastErrorReason() string {
 type Intensity struct {
 	state protoimpl.MessageState `protogen:"open.v1"`
 	// @Document The time interval for a probe request in ms.
-	// @Type time.ms
+	//@Type time.ms
 	ProbeInterval uint32 `protobuf:"varint,1,opt,name=probe_interval,json=probeInterval,proto3" json:"probe_interval,omitempty"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache

app/router/command/command.proto

@@ -46,6 +46,7 @@ message RoutingContext {
 //   - attributes: Select connection's additional attributes.
 //   - outbound: Equivalent as "outbound" and "outbound_group", select both
 //     outbound tag and outbound group tags.
+//
 // * If FieldSelectors is left empty, all fields will be returned.
 message SubscribeRoutingStatsRequest {
   repeated string FieldSelectors = 1;

common/geodata/consts.go

@@ -8,23 +8,65 @@ import (
 
 var privateIPMatcher = sync.OnceValue(func() IPMatcher {
 	return common.Must2(IPReg.BuildIPMatcher(common.Must2(ParseIPRules([]string{
-		"0.0.0.0/8",
+		// https://www.iana.org/assignments/iana-ipv4-special-registry
-		"10.0.0.0/8",
+		"0.0.0.0/8",      // "This network"
-		"100.64.0.0/10",
+		"0.0.0.0/32",     // "This host on this network"
-		"127.0.0.0/8",
+		"10.0.0.0/8",     // Private-Use
-		"169.254.0.0/16",
+		"100.64.0.0/10",  // Shared Address Space
-		"172.16.0.0/12",
+		"127.0.0.0/8",    // Loopback
-		"192.0.0.0/24",
+		"169.254.0.0/16", // Link Local
-		"192.0.2.0/24",
+		"172.16.0.0/12",  // Private-Use
-		"192.88.99.0/24",
+		// "192.0.0.0/24",   // IETF Protocol Assignments
-		"192.168.0.0/16",
+		"192.0.0.0/29",   // IPv4 Service Continuity Prefix
-		"198.18.0.0/15",
+		"192.0.0.8/32",   // IPv4 dummy address
-		"198.51.100.0/24",
+		"192.0.0.9/32",   // Port Control Protocol Anycast
-		"203.0.113.0/24",
+		"192.0.0.10/32",  // Traversal Using Relays around NAT Anycast
-		"224.0.0.0/3",
+		"192.0.0.170/32", // NAT64/DNS64 Discovery
-		"::/127",
+		"192.0.0.171/32", // NAT64/DNS64 Discovery
-		"fc00::/7",
+		"192.0.2.0/24",   // Documentation (TEST-NET-1)
-		"fe80::/10",
+		// "192.31.196.0/24",    // AS112-v4
+		"192.52.193.0/24", // AMT
+		// "192.88.99.0/24",  // Deprecated (6to4 Relay Anycast)
+		"192.88.99.2/32", // 6a44-relay anycast address
+		"192.168.0.0/16", // Private-Use
+		// "192.175.48.0/24",    // Direct Delegation AS112 Service
+		"198.18.0.0/15",      // Benchmarking
+		"198.51.100.0/24",    // Documentation (TEST-NET-2)
+		"203.0.113.0/24",     // Documentation (TEST-NET-3)
+		"240.0.0.0/4",        // Reserved
+		"255.255.255.255/32", // Limited Broadcast
+
+		// https://www.iana.org/assignments/multicast-addresses
+		"224.0.0.0/4",
+
+		// https://www.iana.org/assignments/iana-ipv6-special-registry
+		"::1/128", // Loopback Address
+		"::/128",  // Unspecified Address
+		// "::ffff:0:0/96",     // IPv4-mapped Address
+		"64:ff9b::/96",   // IPv4-IPv6 Translat.
+		"64:ff9b:1::/48", // IPv4-IPv6 Translat.
+		"100::/64",       // Discard-Only Address Block
+		"100:0:0:1::/64", // Dummy IPv6 Prefix
+		// "2001::/23",      // IETF Protocol Assignments
+		"2001::/32",     // TEREDO
+		"2001:1::1/128", // Port Control Protocol Anycast
+		"2001:1::2/128", // Traversal Using Relays around NAT Anycast
+		"2001:1::3/128", // DNS-SD Service Registration Protocol Anycast
+		"2001:2::/48",   // Benchmarking
+		"2001:3::/32",   // AMT
+		// "2001:4:112::/48", // AS112-v6
+		// "2001:10::/28",    // Deprecated (previously ORCHID)
+		"2001:20::/28",  // ORCHIDv2
+		"2001:30::/28",  // Drone Remote ID Protocol Entity Tags (DETs) Prefix
+		"2001:db8::/32", // Documentation
+		"2002::/16",     // 6to4
+		// "2620:4f:8000::/48", // Direct Delegation AS112 Service
+		"3fff::/20", // Documentation
+		"5f00::/16", // Segment Routing (SRv6) SIDs
+		"fc00::/7",  // Unique-Local
+		"fe80::/10", // Link-Local Unicast
+
+		// https://www.iana.org/assignments/ipv6-multicast-addresses
 		"ff00::/8",
 	}))))
 })

common/lua/program.go

@@ -11,7 +11,7 @@ import (
 
 	"github.com/xtls/xray-core/common/base64"
 	"github.com/xtls/xray-core/common/errors"
-	"github.com/xtls/xray-core/common/platform"
+	"github.com/xtls/xray-core/common/platform/filesystem"
 	glua "github.com/yuin/gopher-lua"
 	"github.com/yuin/gopher-lua/parse"
 )
@@ -36,7 +36,7 @@ func Compile(script string) (*Program, error) {
 		// TODO: Restore inline script support and re-enable the related tests.
 		return nil, errors.New("currently unavailable")
 		code, err = base64.Decode(script)
-	} else if name, err = platform.ResolveLuaFile(script); err == nil {
+	} else if name, err = filesystem.ResolveLuaFile(script); err == nil {
 		code, err = os.ReadFile(name)
 		// TODO: Restore privileged signature authorization and re-enable the related tests and CLI entries.
 		// if err == nil {

common/lua/program_test.go

@@ -187,18 +187,19 @@ func TestCompileInlineDiagnostics(t *testing.T) {
 */
 
 func TestCompileFileExtension(t *testing.T) {
-	for _, name := range []string{"script", "script.dat", "script.lua.txt", "script.LUA"} {
+	for _, name := range []string{"script", "script.dat", "script.lua.txt"} {
+		if program, err := Compile(name); program != nil || err == nil || !strings.Contains(err.Error(), "Lua file extension must be .lua") {
+			t.Fatalf("Compile(%q) = %v, %v; want nil program and .lua extension error", name, program, err)
+		}
+	}
+	for _, name := range []string{"script.lua", "script.LUA", "script.Lua", "script.lUa"} {
 		path := filepath.Join(t.TempDir(), name)
 		if err := os.WriteFile(path, []byte("value = 42"), 0o600); err != nil {
 			t.Fatal(err)
 		}
-		if program, err := Compile(path); program != nil || err == nil || !strings.Contains(err.Error(), "Lua file extension must be .lua") {
-			t.Fatalf("Compile(%q) = %v, %v; want nil program and .lua extension error", path, program, err)
-		}
-	}
-	path := writeTestScript(t, "value = 42") + string(filepath.Separator) + "."
 		if program, err := Compile(path); program == nil || err != nil {
-		t.Fatalf("Compile(%q) = %v, %v; want acceptance of the resolved .lua path", path, program, err)
+			t.Fatalf("Compile(%q) = %v, %v; want successful compilation", path, program, err)
+		}
 	}
 }
 
@@ -234,10 +235,6 @@ func writeTestScript(t *testing.T, code string) string {
 	if err := os.WriteFile(path, []byte(code), 0o600); err != nil {
 		t.Fatal(err)
 	}
-	path, err := filepath.EvalSymlinks(path)
-	if err != nil {
-		t.Fatal(err)
-	}
 	return path
 }
 

common/net/find_process_linux.go

@@ -4,7 +4,7 @@ package net
 
 import (
 	"bufio"
-	"encoding/hex"
+	"encoding/binary"
 	"fmt"
 	"net"
 	"os"
@@ -45,10 +45,7 @@ func FindProcess(network, srcIP string, srcPort uint16, destIP string, destPort
 		panic("Unsupported network type for process lookup.")
 	}
 
-	targetHexAddr, err := formatLittleEndianString(net.ParseIP(srcIP), Port(srcPort))
+	targetHexAddr := formatProcNetAddress(net.ParseIP(srcIP), Port(srcPort))
-	if err != nil {
-		return 0, "", "", errors.New("failed to format address: ", err)
-	}
 
 	portFallback := ""
 	if network == "udp" {
@@ -87,24 +84,21 @@ func FindProcess(network, srcIP string, srcPort uint16, destIP string, destPort
 	return pid, procName, absPath, nil
 }
 
-func formatLittleEndianString(addr net.IP, port Port) (string, error) {
+func formatProcNetAddress(addr net.IP, port Port) string {
-	ip := addr
 	var ipBytes []byte
-	if ip.To4() != nil {
+	if ipv4 := addr.To4(); ipv4 != nil {
-		ipBytes = ip.To4()
+		ipBytes = ipv4
 	} else {
-		ipBytes = ip.To16()
+		ipBytes = addr.To16()
-	}
-	if ipBytes == nil {
-		return "", errors.New("invalid IP format for ", addr, ": ", ip)
 	}
 
-	for i, j := 0, len(ipBytes)-1; i < j; i, j = i+1, j-1 {
+	var formatted strings.Builder
-		ipBytes[i], ipBytes[j] = ipBytes[j], ipBytes[i]
+	formatted.Grow(len(ipBytes)*2 + 5)
+	for i := 0; i < len(ipBytes); i += 4 {
+		fmt.Fprintf(&formatted, "%08X", binary.NativeEndian.Uint32(ipBytes[i:i+4]))
 	}
-	portHex := fmt.Sprintf("%04X", uint16(port))
+	fmt.Fprintf(&formatted, ":%04X", uint16(port))
-	ipHex := strings.ToUpper(hex.EncodeToString(ipBytes))
+	return formatted.String()
-	return fmt.Sprintf("%s:%s", ipHex, portHex), nil
 }
 
 func findInodeInFiles(filePaths []string, targetHexAddr, portFallback string) (string, error) {

common/platform/filesystem/file.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/xtls/xray-core/common/buf"
 	"github.com/xtls/xray-core/common/platform"
@@ -26,14 +27,6 @@ func ReadFile(path string) ([]byte, error) {
 	return buf.ReadAllToBytes(reader)
 }
 
-func ReadAsset(file string) ([]byte, error) {
-	path, _, err := getAssetFileLocation(file)
-	if err != nil {
-		return nil, err
-	}
-	return ReadFile(path)
-}
-
 func OpenAsset(file string) (io.ReadCloser, int64, error) {
 	path, info, err := getAssetFileLocation(file)
 	if err != nil {
@@ -43,11 +36,6 @@ func OpenAsset(file string) (io.ReadCloser, int64, error) {
 	return r, info.Size(), err
 }
 
-func StatAsset(file string) (os.FileInfo, error) {
-	_, info, err := getAssetFileLocation(file)
-	return info, err
-}
-
 func ResolveAsset(file string) (string, error) {
 	path, _, err := getAssetFileLocation(file)
 	return path, err
@@ -79,17 +67,29 @@ func ReadCert(file string) ([]byte, error) {
 	return ReadFile(platform.GetCertLocation(file))
 }
 
-func CopyFile(dst string, src string) error {
+// ResolveLuaFile finds a local .lua script and returns its absolute path.
-	bytes, err := ReadFile(src)
+// Relative paths: XRAY_LOCATION_CONFDIR > XRAY_LOCATION_CONFIG > working dir > executable dir.
-	if err != nil {
+func ResolveLuaFile(path string) (string, error) {
-		return err
+	if !strings.EqualFold(filepath.Ext(path), ".lua") {
+		return "", errors.New("Lua file extension must be .lua")
 	}
-	f, err := os.OpenFile(dst, os.O_CREATE|os.O_WRONLY, 0o644)
+	if filepath.IsAbs(path) {
-	if err != nil {
+		return path, nil
-		return err
 	}
-	defer f.Close()
+	for _, dir := range []string{
-
+		platform.GetConfDirPath(),
-	_, err = f.Write(bytes)
+		platform.NewEnvFlag(platform.ConfigLocation).GetValue(func() string { return "" }),
-	return err
+		".",
+		platform.GetExecutableDir(),
+	} {
+		if dir != "" {
+			resolved := filepath.Join(dir, path)
+			if _, err := os.Stat(resolved); err == nil {
+				return filepath.Abs(resolved)
+			} else if !os.IsNotExist(err) {
+				return "", err
+			}
+		}
+	}
+	return "", os.ErrNotExist
 }

common/platform/filesystem/file_test.go

@@ -1,13 +1,17 @@
 package filesystem_test
 
 import (
+	"errors"
+	"os"
 	"path/filepath"
 	"testing"
 
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/platform"
 	. "github.com/xtls/xray-core/common/platform/filesystem"
 )
 
-func TestStatAssetRejectsInvalidPath(t *testing.T) {
+func TestResolveAssetRejectsInvalidPath(t *testing.T) {
 	for _, file := range []string{
 		"",
 		".",
@@ -25,8 +29,49 @@ func TestStatAssetRejectsInvalidPath(t *testing.T) {
 		`nested\..\geoip.dat`,
 		filepath.Join(t.TempDir(), "geoip.dat"),
 	} {
-		if _, err := StatAsset(file); err == nil {
+		if _, err := ResolveAsset(file); err == nil {
 			t.Fatalf("expected error for %q", file)
 		}
 	}
 }
+
+func TestResolveLuaFile(t *testing.T) {
+	t.Chdir(t.TempDir())
+	workingDir, err := os.Getwd()
+	common.Must(err)
+	executable, err := os.Executable()
+	common.Must(err)
+	file, err := os.CreateTemp(filepath.Dir(executable), "lua-*.lua")
+	common.Must(err)
+	common.Must(file.Close())
+	defer os.Remove(file.Name())
+
+	name := filepath.Base(file.Name())
+	paths := []string{
+		filepath.Join(t.TempDir(), name),
+		filepath.Join(t.TempDir(), name),
+		filepath.Join(workingDir, name),
+		file.Name(),
+	}
+	t.Setenv(platform.ConfdirLocation, filepath.Dir(paths[0]))
+	t.Setenv(platform.ConfigLocation, filepath.Dir(paths[1]))
+	for _, path := range paths[:3] {
+		common.Must(os.WriteFile(path, nil, 0o600))
+	}
+	if got, err := ResolveLuaFile(paths[2]); err != nil || got != paths[2] {
+		t.Fatalf("absolute path = %q, %v; want %q", got, err, paths[2])
+	}
+	for i, want := range paths {
+		if i == 2 {
+			t.Setenv(platform.ConfdirLocation, "")
+			t.Setenv(platform.ConfigLocation, "")
+		}
+		if got, err := ResolveLuaFile(name); err != nil || got != want {
+			t.Fatalf("resolved path = %q, %v; want %q", got, err, want)
+		}
+		common.Must(os.Remove(want))
+	}
+	if _, err := ResolveLuaFile(name); !errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("missing file error = %v", err)
+	}
+}

common/platform/others.go

@@ -14,7 +14,7 @@ func LineSeparator() string {
 
 // GetAssetLocation searches for `file` in the env dir, the executable dir, and certain locations
 func GetAssetLocation(file string) string {
-	assetPath := NewEnvFlag(AssetLocation).GetValue(getExecutableDir)
+	assetPath := NewEnvFlag(AssetLocation).GetValue(GetExecutableDir)
 	defPath := filepath.Join(assetPath, file)
 	for _, p := range []string{
 		defPath,
@@ -36,6 +36,6 @@ func GetAssetLocation(file string) string {
 
 // GetCertLocation searches for `file` in the env dir and the executable dir
 func GetCertLocation(file string) string {
-	certPath := NewEnvFlag(CertLocation).GetValue(getExecutableDir)
+	certPath := NewEnvFlag(CertLocation).GetValue(GetExecutableDir)
 	return filepath.Join(certPath, file)
 }

common/platform/platform.go

@@ -1,8 +1,6 @@
 package platform // import "github.com/xtls/xray-core/common/platform"
 
 import (
-	"errors"
-	"fmt"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -74,7 +72,7 @@ func NormalizeEnvName(name string) string {
 	return strings.ReplaceAll(strings.ToUpper(strings.TrimSpace(name)), ".", "_")
 }
 
-func getExecutableDir() string {
+func GetExecutableDir() string {
 	exec, err := os.Executable()
 	if err != nil {
 		return ""
@@ -83,7 +81,7 @@ func getExecutableDir() string {
 }
 
 func GetConfigurationPath() string {
-	configPath := NewEnvFlag(ConfigLocation).GetValue(getExecutableDir)
+	configPath := NewEnvFlag(ConfigLocation).GetValue(GetExecutableDir)
 	return filepath.Join(configPath, "config.json")
 }
 
@@ -92,64 +90,3 @@ func GetConfDirPath() string {
 	configPath := NewEnvFlag(ConfdirLocation).GetValue(func() string { return "" })
 	return configPath
 }
-
-// ResolveLuaFile finds a local .lua script and returns its resolved absolute path.
-// Relative paths: XRAY_LOCATION_CONFDIR > XRAY_LOCATION_CONFIG > working dir > executable dir.
-func ResolveLuaFile(path string) (string, error) {
-	if path == "" {
-		return "", errors.New("Lua file path is empty")
-	}
-	paths := []string{path}
-	if !filepath.IsAbs(path) {
-		paths = nil
-		for _, dir := range []string{
-			GetConfDirPath(),
-			NewEnvFlag(ConfigLocation).GetValue(func() string { return "" }),
-			".",
-			getExecutableDir(),
-		} {
-			if dir != "" {
-				paths = append(paths, filepath.Join(dir, path))
-			}
-		}
-	}
-	path, err := resolveFile(paths)
-	if err != nil {
-		return "", err
-	}
-	return resolveLuaTarget(path)
-}
-
-func resolveLuaTarget(path string) (string, error) {
-	path, err := filepath.EvalSymlinks(path)
-	if err != nil {
-		return "", fmt.Errorf("failed to resolve Lua file symlinks: %w", err)
-	}
-	if filepath.Ext(path) != ".lua" {
-		return "", errors.New("Lua file extension must be .lua")
-	}
-	return path, nil
-}
-
-func resolveFile(paths []string) (string, error) {
-	var tried []string
-	for _, path := range paths {
-		path, err := filepath.Abs(path)
-		if err != nil {
-			return "", fmt.Errorf("failed to resolve file path: %w", err)
-		}
-		tried = append(tried, path)
-		info, err := os.Stat(path)
-		if errors.Is(err, os.ErrNotExist) {
-			continue
-		}
-		if err != nil {
-			return "", fmt.Errorf("failed to inspect file %q: %w", path, err)
-		}
-		if !info.Mode().IsRegular() {
-			return "", fmt.Errorf("file is not a regular file: %s", path)
-		}
-		return path, nil
-	}
-	return "", fmt.Errorf("file not found; tried %q: %w", tried, os.ErrNotExist)
-}

common/platform/platform_test.go

@@ -1,11 +1,9 @@
 package platform_test
 
 import (
-	"errors"
 	"os"
 	"path/filepath"
 	"runtime"
-	"strings"
 	"testing"
 
 	"github.com/xtls/xray-core/common"
@@ -66,89 +64,3 @@ func TestGetAssetLocation(t *testing.T) {
 		}
 	}
 }
-
-func TestResolveLuaFile(t *testing.T) {
-	workingDir := t.TempDir()
-	t.Chdir(workingDir)
-	executable, err := os.Executable()
-	common.Must(err)
-	file, err := os.CreateTemp(filepath.Dir(executable), "lua-*.lua")
-	common.Must(err)
-	common.Must(file.Close())
-	defer os.Remove(file.Name())
-
-	name := filepath.Base(file.Name())
-	paths := []string{
-		filepath.Join(t.TempDir(), name),
-		filepath.Join(t.TempDir(), name),
-		filepath.Join(workingDir, name),
-		file.Name(),
-	}
-	t.Setenv(ConfdirLocation, filepath.Dir(paths[0]))
-	t.Setenv(ConfigLocation, filepath.Dir(paths[1]))
-	for _, path := range paths[:3] {
-		common.Must(os.WriteFile(path, nil, 0o600))
-	}
-	for i, path := range paths {
-		paths[i], err = filepath.EvalSymlinks(path)
-		common.Must(err)
-	}
-	if got, err := ResolveLuaFile(paths[2]); err != nil || got != paths[2] {
-		t.Fatalf("absolute path = %q, %v; want %q", got, err, paths[2])
-	}
-	for i, want := range paths {
-		if i == 2 {
-			t.Setenv(ConfdirLocation, "")
-			t.Setenv(ConfigLocation, "")
-		}
-		if got, err := ResolveLuaFile(name); err != nil || got != want {
-			t.Fatalf("resolved path = %q, %v; want %q", got, err, want)
-		}
-		common.Must(os.Remove(want))
-	}
-	if _, err := ResolveLuaFile(name); !errors.Is(err, os.ErrNotExist) {
-		t.Fatalf("missing file error = %v", err)
-	}
-
-	t.Setenv(ConfdirLocation, filepath.Dir(paths[0]))
-	t.Setenv(ConfigLocation, filepath.Dir(paths[1]))
-	common.Must(os.Mkdir(paths[0], 0o700))
-	common.Must(os.WriteFile(paths[1], nil, 0o600))
-	for _, path := range []string{"", name, filepath.Join(t.TempDir(), name)} {
-		if _, err := ResolveLuaFile(path); err == nil {
-			t.Fatalf("accepted invalid path %q", path)
-		}
-	}
-}
-
-func TestResolveLuaFileSymlink(t *testing.T) {
-	for _, tc := range []struct {
-		link, target string
-		valid        bool
-	}{
-		{"alias.lua", "data.dat", false},
-		{"alias.dat", "script.lua", true},
-	} {
-		t.Run(tc.link, func(t *testing.T) {
-			dir, err := filepath.EvalSymlinks(t.TempDir())
-			common.Must(err)
-			target := filepath.Join(dir, tc.target)
-			common.Must(os.WriteFile(target, nil, 0o600))
-			link := filepath.Join(dir, tc.link)
-			if err := os.Symlink(tc.target, link); err != nil {
-				if runtime.GOOS == "windows" {
-					t.Skipf("cannot create symlinks: %v", err)
-				}
-				t.Fatal(err)
-			}
-			got, err := ResolveLuaFile(link)
-			if tc.valid {
-				if err != nil || got != target {
-					t.Fatalf("ResolveLuaFile(%q) = %q, %v; want %q", link, got, err, target)
-				}
-			} else if err == nil || got != "" || !strings.Contains(err.Error(), "Lua file extension must be .lua") {
-				t.Fatalf("ResolveLuaFile(%q) = %q, %v; want .lua extension error", link, got, err)
-			}
-		})
-	}
-}

common/platform/windows.go

@@ -11,12 +11,12 @@ func LineSeparator() string {
 
 // GetAssetLocation searches for `file` in the env dir and the executable dir
 func GetAssetLocation(file string) string {
-	assetPath := NewEnvFlag(AssetLocation).GetValue(getExecutableDir)
+	assetPath := NewEnvFlag(AssetLocation).GetValue(GetExecutableDir)
 	return filepath.Join(assetPath, file)
 }
 
 // GetCertLocation searches for `file` in the env dir and the executable dir
 func GetCertLocation(file string) string {
-	certPath := NewEnvFlag(CertLocation).GetValue(getExecutableDir)
+	certPath := NewEnvFlag(CertLocation).GetValue(GetExecutableDir)
 	return filepath.Join(certPath, file)
 }

common/signal/timer.go

@@ -3,7 +3,11 @@ package signal
 import (
 	"context"
 	"sync"
+	"sync/atomic"
 	"time"
+
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/task"
 )
 
 type ActivityUpdater interface {
@@ -13,10 +17,10 @@ type ActivityUpdater interface {
 type ActivityTimer struct {
 	mu        sync.RWMutex
 	updated   chan struct{}
-	checker   *time.Timer
+	checkTask *task.Periodic
-	timeout   time.Duration
 	onTimeout func()
-	consumed  bool
+	consumed  atomic.Bool
+	once      sync.Once
 }
 
 func (t *ActivityTimer) Update() {
@@ -26,29 +30,30 @@ func (t *ActivityTimer) Update() {
 	}
 }
 
-func (t *ActivityTimer) check() bool {
+func (t *ActivityTimer) check() error {
 	select {
 	case <-t.updated:
-		return true
 	default:
 		t.finish()
-		return false
 	}
+	return nil
 }
 
 func (t *ActivityTimer) finish() {
+	t.once.Do(func() {
+		t.consumed.Store(true)
 		t.mu.Lock()
-	if t.consumed {
+		defer t.mu.Unlock()
-		t.mu.Unlock()
+
-		return
+		common.CloseIfExists(t.checkTask)
-	}
-	t.checker.Stop()
-	t.consumed = true
-	t.mu.Unlock()
 		t.onTimeout()
+	})
 }
 
 func (t *ActivityTimer) SetTimeout(timeout time.Duration) {
+	if t.consumed.Load() {
+		return
+	}
 	if timeout == 0 {
 		t.finish()
 		return
@@ -56,31 +61,25 @@ func (t *ActivityTimer) SetTimeout(timeout time.Duration) {
 
 	t.mu.Lock()
 	defer t.mu.Unlock()
-	if t.consumed {
+	// double check, just in case
+	if t.consumed.Load() {
 		return
 	}
-	t.timeout = timeout
+	newCheckTask := &task.Periodic{
-	t.checker.Reset(timeout)
+		Interval: timeout,
+		Execute:  t.check,
+	}
+	common.CloseIfExists(t.checkTask)
+	t.checkTask = newCheckTask
+	t.Update()
+	common.Must(newCheckTask.Start())
 }
 
 func CancelAfterInactivity(ctx context.Context, cancel context.CancelFunc, timeout time.Duration) *ActivityTimer {
 	timer := &ActivityTimer{
 		updated:   make(chan struct{}, 1),
 		onTimeout: cancel,
-		timeout:   timeout,
-	}
-	timer.checker = time.AfterFunc(timeout, func() {
-		if timer.check() {
-			timer.mu.Lock()
-			defer timer.mu.Unlock()
-			if timer.consumed {
-				return
-			}
-			timer.checker.Reset(timer.timeout)
-		}
-	})
-	if timeout == 0 {
-		timer.SetTimeout(0)
 	}
+	timer.SetTimeout(timeout)
 	return timer
 }

core/core.go

@@ -20,7 +20,7 @@ import (
 var (
 	Version_x byte = 26
 	Version_y byte = 10
-	Version_z byte = 17
+	Version_z byte = 21
 )
 
 var (

core/proto.go

@@ -1,5 +1,3 @@
 package core
 
-//go:generate go install -v google.golang.org/protobuf/cmd/protoc-gen-go@latest
-//go:generate go install -v google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest
 //go:generate go run ../infra/vprotogen/main.go -pwd ./..

features/dns/localdns/client.go

@@ -2,6 +2,7 @@ package localdns
 
 import (
 	"context"
+	"net/netip"
 	"syscall"
 	"time"
 
@@ -100,6 +101,15 @@ func New() *Client {
 			if internet.IsSkippedDNSServer(address) {
 				return nil, errors.New("skipped DNS server ", address)
 			}
+			// A socket of the server's IP version only needs that version bound
+			// to the interface, which a dual-stack one would need both of.
+			if ap, err := netip.ParseAddrPort(address); err == nil && (network == "udp" || network == "tcp") {
+				if ap.Addr().Unmap().Is4() {
+					network += "4"
+				} else {
+					network += "6"
+				}
+			}
 			return d.DialContext(ctx, network, address)
 		},
 	}

go.mod

@@ -4,6 +4,7 @@ go 1.27
 
 require (
 	github.com/apernet/quic-go v0.61.1-0.20260806010916-184d081eef3e
+	github.com/bufbuild/protocompile v0.14.1
 	github.com/ghodss/yaml v1.0.1-0.20220118164431-d8423dcdf344
 	github.com/golang/mock v1.7.0-rc.1
 	github.com/google/go-cmp v0.7.0
@@ -14,7 +15,7 @@ require (
 	github.com/miekg/dns v1.1.73
 	github.com/pelletier/go-toml v1.9.5
 	github.com/pion/stun/v3 v3.1.7
-	github.com/pires/go-proxyproto v0.15.0
+	github.com/pires/go-proxyproto v0.16.0
 	github.com/refraction-networking/utls v1.8.3-0.20260301010127-aa6edf4b11af
 	github.com/robfig/cron/v3 v3.0.1
 	github.com/stretchr/testify v1.12.1
@@ -32,7 +33,7 @@ require (
 	golang.zx2c4.com/wireguard v0.0.0-20250521234502-f333402bd9cb
 	golang.zx2c4.com/wireguard/windows v1.1.1
 	google.golang.org/grpc v1.84.0
-	google.golang.org/protobuf v1.36.12
+	google.golang.org/protobuf v1.36.11
 	h12.io/socks v1.0.3
 	layeh.com/gopher-luar v1.0.11
 	lukechampine.com/blake3 v1.4.1
@@ -58,6 +59,12 @@ require (
 	golang.org/x/text v0.43.0 // indirect
 	golang.org/x/tools v0.51.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20260706201446-f0a921348800 // indirect
+	google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.6.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gvisor.dev/gvisor v0.0.0-20260122175437-89a5d21be8f0 // indirect
 )
+
+tool (
+	google.golang.org/grpc/cmd/protoc-gen-go-grpc
+	google.golang.org/protobuf/cmd/protoc-gen-go
+)

go.sum

@@ -2,6 +2,8 @@ github.com/andybalholm/brotli v1.2.3 h1:8H1qwOkl2LPfjf3YezB90JnCliZb6SInJ/OJkEbA
 github.com/andybalholm/brotli v1.2.3/go.mod h1:rzTDkvFWvIrjDXZHkuS16NPggd91W3kUSvPlQ1pLaKY=
 github.com/apernet/quic-go v0.61.1-0.20260806010916-184d081eef3e h1:5mgtR5gwIgBKMiGI1QdXldZZ+SNor06Nbu1wCBulQBg=
 github.com/apernet/quic-go v0.61.1-0.20260806010916-184d081eef3e/go.mod h1:x7qxEvX6MCVtDuBKHj3E+88+BtrbEMuAL5qGUKItjW8=
+github.com/bufbuild/protocompile v0.14.1 h1:iA73zAf/fyljNjQKwYzUHD6AD4R8KMasmwa/FBatYVw=
+github.com/bufbuild/protocompile v0.14.1/go.mod h1:ppVdAIhbr2H8asPk6k4pY7t9zB1OU5DoEw9xY/FUi1c=
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
@@ -59,8 +61,8 @@ github.com/pion/stun/v3 v3.1.7 h1:uRXMTlGLf89WgItGNyZ6aR5jMTX0NBbybXADpQCzn+E=
 github.com/pion/stun/v3 v3.1.7/go.mod h1:Nq77RW4aRrSNrltf2ksUJLjxWeipj4lnlgdsYIxC8g8=
 github.com/pion/transport/v4 v4.1.0 h1:8S+nF2reM2cJuqC6g78OVy2BBgmbdns+acx3jA97BvQ=
 github.com/pion/transport/v4 v4.1.0/go.mod h1:06hFI+jCFcok2X2MekVufNZ/uzNZXivGBPfviSVcjgM=
-github.com/pires/go-proxyproto v0.15.0 h1:dTshmNbFm/D+0+sbrxUuddPOZ5Y0B7c5NhtsBkm6LqI=
+github.com/pires/go-proxyproto v0.16.0 h1:9KYT/fM3wpjT8bdMEj/7FBcoiUG1KyzEjRYnPu+vz7A=
-github.com/pires/go-proxyproto v0.15.0/go.mod h1:OXsCrKwrK2tXS9YrI5tkHx5xaQlO8FH3lFW76orFh24=
+github.com/pires/go-proxyproto v0.16.0/go.mod h1:n7yhg8yIfNl3KgYDCwBzmeUHNpKTVnUhcWpc7rV4RW4=
 github.com/quic-go/go-ossfuzz-seeds v0.1.0 h1:APacT+iIaNF6fd8AGEiN3bT/Jtkd2jz4v4TzM7MFjy0=
 github.com/quic-go/go-ossfuzz-seeds v0.1.0/go.mod h1:3IOHRbJIc+L6YKMwfDtJAM9Vj9k0YY4muhuyUYk5tbk=
 github.com/quic-go/qpack v0.6.0 h1:g7W+BMYynC1LbYLSqRt8PBg5Tgwxn214ZZR34VIOjz8=
@@ -152,6 +154,10 @@ google.golang.org/genproto/googleapis/rpc v0.0.0-20260706201446-f0a921348800 h1:
 google.golang.org/genproto/googleapis/rpc v0.0.0-20260706201446-f0a921348800/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
 google.golang.org/grpc v1.84.0 h1:soMyaPJ8pAak5PIQ0DGBUir0XRo2fRoMqhNWMLlLxO0=
 google.golang.org/grpc v1.84.0/go.mod h1:ljCht0DrxQrXBDRTZp52Qxh3Ffk8CdYm2sj4O2QN2C0=
+google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.6.0 h1:6Al3kEFFP9VJhRz3DID6quisgPnTeZVr4lep9kkxdPA=
+google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.6.0/go.mod h1:QLvsjh0OIR0TYBeiu2bkWGTJBUNQ64st52iWj/yA93I=
+google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
+google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 google.golang.org/protobuf v1.36.12 h1:pJOKDDOyeXErUroCihFAd5LQuwXBSpVnKGrj5o/fwxc=
 google.golang.org/protobuf v1.36.12/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

infra/conf/freedom.go

@@ -91,6 +91,7 @@ func (c *FreedomConfig) Build() (proto.Message, error) {
 	}
 
 	if c.Fragment != nil {
+		errors.PrintDeprecatedFeatureWarning(`"fragment" in Freedom`, `"fragment" in "streamSettings.finalmask.tcp"`)
 		config.Fragment = new(freedom.Fragment)
 
 		switch strings.ToLower(c.Fragment.Packets) {
@@ -147,6 +148,7 @@ func (c *FreedomConfig) Build() (proto.Message, error) {
 	}
 
 	if c.Noises != nil {
+		errors.PrintDeprecatedFeatureWarning(`"noises" in Freedom`, `"noise" in "streamSettings.finalmask.udp"`)
 		for _, n := range c.Noises {
 			NConfig, err := ParseNoise(n)
 			if err != nil {

infra/conf/geodata.go

@@ -6,7 +6,6 @@ import (
 	"github.com/robfig/cron/v3"
 	"github.com/xtls/xray-core/app/geodata"
 	"github.com/xtls/xray-core/common/errors"
-	"github.com/xtls/xray-core/common/platform/filesystem"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -19,9 +18,6 @@ func (c *GeodataAssetConfig) Build() (*geodata.Asset, error) {
 	if err := validateHTTPS(c.URL); err != nil {
 		return nil, errors.New("invalid geodata asset url: ", c.URL).Base(err)
 	}
-	if _, err := filesystem.StatAsset(c.File); err != nil {
-		return nil, errors.New("invalid geodata asset file: ", c.File).Base(err)
-	}
 	return &geodata.Asset{
 		Url:  c.URL,
 		File: c.File,

infra/conf/geodata_test.go

@@ -1,7 +1,6 @@
 package conf_test
 
 import (
-	"path/filepath"
 	"testing"
 
 	"github.com/xtls/xray-core/app/geodata"
@@ -9,8 +8,6 @@ import (
 )
 
 func TestGeodataConfig(t *testing.T) {
-	t.Setenv("xray.location.asset", filepath.Join("..", "..", "resources"))
-
 	creator := func() Buildable {
 		return new(GeodataConfig)
 	}
@@ -38,27 +35,7 @@ func TestGeodataConfig(t *testing.T) {
 	})
 }
 
-func TestGeodataAssetConfig(t *testing.T) {
-	t.Setenv("xray.location.asset", filepath.Join("..", "..", "resources"))
-
-	if _, err := (&GeodataAssetConfig{
-		URL:  "https://example.com/geoip.dat",
-		File: "geoip.dat",
-	}).Build(); err != nil {
-		t.Fatal(err)
-	}
-
-	if _, err := (&GeodataAssetConfig{
-		URL:  "https://example.com/geoip.dat",
-		File: "missing.dat",
-	}).Build(); err == nil {
-		t.Fatal("expected error")
-	}
-}
-
 func TestGeodataAssetConfigInvalidURL(t *testing.T) {
-	t.Setenv("xray.location.asset", filepath.Join("..", "..", "resources"))
-
 	for _, rawURL := range []string{
 		"",
 		"http://example.com/geoip.dat",

infra/conf/transport_finalmask.go

@@ -15,9 +15,11 @@ import (
 
 	googleuuid "github.com/google/uuid"
 	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/geodata"
 	xlua "github.com/xtls/xray-core/common/lua"
 	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/finalmask/filter"
 	"github.com/xtls/xray-core/transport/internet/finalmask/fragment"
 	"github.com/xtls/xray-core/transport/internet/finalmask/header/custom"
 	"github.com/xtls/xray-core/transport/internet/finalmask/mkcp/aes128gcm"
@@ -74,6 +76,7 @@ var (
 	customVarNamePattern = regexp.MustCompile(`^[A-Za-z_][A-Za-z0-9_]*$`)
 
 	tcpmaskLoader = NewJSONConfigLoader(ConfigCreatorCache{
+		"filter":        func() interface{} { return new(Filter) },
 		"header-custom": func() interface{} { return new(HeaderCustomTCP) },
 		"fragment":      func() interface{} { return new(FragmentMask) },
 		"sudoku":        func() interface{} { return new(Sudoku) },
@@ -81,6 +84,7 @@ var (
 	}, "type", "settings")
 
 	udpmaskLoader = NewJSONConfigLoader(ConfigCreatorCache{
+		"filter":        func() interface{} { return new(Filter) },
 		"header-custom": func() interface{} { return new(HeaderCustomUDP) },
 		"mkcp-legacy":   func() interface{} { return new(MkcpLegacy) },
 		"noise":         func() interface{} { return new(NoiseMask) },
@@ -93,6 +97,23 @@ var (
 	}, "type", "settings")
 )
 
+type Filter struct {
+	BlockedSourceIPs []string `json:"blockedSourceIPs"`
+	AllowedSourceIPs []string `json:"allowedSourceIPs"`
+}
+
+func (c *Filter) Build() (proto.Message, error) {
+	rules, err := geodata.ParseIPRules(c.BlockedSourceIPs)
+	if err != nil {
+		return nil, errors.New(`invalid "blockedSourceIPs"`).Base(err)
+	}
+	allowed, err := geodata.ParseIPRules(c.AllowedSourceIPs)
+	if err != nil {
+		return nil, errors.New(`invalid "allowedSourceIPs"`).Base(err)
+	}
+	return &filter.Config{BlockedSourceIps: rules, AllowedSourceIps: allowed}, nil
+}
+
 type TCPItem struct {
 	Delay     Int32Range       `json:"delay"`
 	Rand      int32            `json:"rand"`

infra/conf/transport_finalmask_filter_test.go

@@ -0,0 +1,79 @@
+package conf_test
+
+import (
+	"encoding/json"
+	"fmt"
+	"net"
+	"strings"
+	"testing"
+
+	"github.com/xtls/xray-core/common/geodata"
+	. "github.com/xtls/xray-core/infra/conf"
+	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/finalmask/filter"
+)
+
+func TestFinalMaskFilter(t *testing.T) {
+	for _, network := range []string{"tcp", "udp"} {
+		for _, test := range []struct {
+			name, settings   string
+			blocked, allowed int
+		}{
+			{"blacklist", `{"blockedSourceIPs":["192.0.2.0/24"]}`, 1, 0},
+			{"whitelist", `{"allowedSourceIPs":["192.0.2.0/24"]}`, 0, 1},
+			{"both", `{"blockedSourceIPs":["192.0.2.0/24"],"allowedSourceIPs":["192.0.2.0/24"]}`, 1, 1},
+			{"empty_whitelist", `{"allowedSourceIPs":[]}`, 0, 0},
+			{"empty_blacklist", `{"blockedSourceIPs":[]}`, 0, 0},
+		} {
+			t.Run(network+"/"+test.name, func(t *testing.T) {
+				input := fmt.Sprintf(`{"finalmask":{"%s":[{"type":"filter","settings":%s}]}}`, network, test.settings)
+				var config StreamConfig
+				if err := json.Unmarshal([]byte(input), &config); err != nil {
+					t.Fatal(err)
+				}
+				built, err := config.Build()
+				if err != nil {
+					t.Fatal(err)
+				}
+				masks := built.Tcpmasks
+				if network == "udp" {
+					masks = built.Udpmasks
+				}
+				if len(masks) != 1 {
+					t.Fatalf("expected one mask, got %d", len(masks))
+				}
+				instance, err := masks[0].GetInstance()
+				if err != nil {
+					t.Fatal(err)
+				}
+				filter, ok := instance.(*filter.Config)
+				if !ok {
+					t.Fatalf("unexpected mask type: %T", instance)
+				}
+				if len(filter.BlockedSourceIps) != test.blocked || len(filter.AllowedSourceIps) != test.allowed {
+					t.Fatalf("unexpected filter policy: %v", filter)
+				}
+				for _, rules := range [][]*geodata.IPRule{filter.BlockedSourceIps, filter.AllowedSourceIps} {
+					for _, rule := range rules {
+						cidr := rule.GetCustom().GetCidr()
+						if cidr.GetPrefix() != 24 || !net.IP(cidr.GetIp()).Equal(net.IPv4(192, 0, 2, 0)) {
+							t.Fatalf("unexpected IP rule: %v", cidr)
+						}
+					}
+				}
+				if _, err := internet.ToMemoryStreamConfig(built); err != nil {
+					t.Fatalf("failed to initialize runtime finalmask: %v", err)
+				}
+			})
+		}
+	}
+	for _, field := range []string{"blockedSourceIPs", "allowedSourceIPs"} {
+		var config Filter
+		if err := json.Unmarshal([]byte(fmt.Sprintf(`{"%s":["192.0.2.0/33"]}`, field)), &config); err != nil {
+			t.Fatal(err)
+		}
+		if _, err := config.Build(); err == nil || !strings.Contains(err.Error(), field) {
+			t.Errorf("expected invalid %s, got %v", field, err)
+		}
+	}
+}

infra/conf/transport_internet.go

@@ -90,6 +90,7 @@ func (c *StreamConfig) Build() (*internet.StreamConfig, error) {
 		config.ProtocolName = protocol
 	}
 
+	var xdriveH3 bool
 	switch strings.ToLower(c.Security) {
 	case "", "none":
 	case "tls":
@@ -104,6 +105,7 @@ func (c *StreamConfig) Build() (*internet.StreamConfig, error) {
 		tm := serial.ToTypedMessage(ts)
 		config.SecuritySettings = append(config.SecuritySettings, tm)
 		config.SecurityType = tm.Type
+		xdriveH3 = config.ProtocolName == "xdrive" && tlsSettings.ALPN != nil && slices.Equal(*tlsSettings.ALPN, StringList{"h3"})
 		if config.ProtocolName == "xdrive" && tlsSettings.ALPN != nil && slices.Equal(*tlsSettings.ALPN, StringList{"http/1.1"}) && tlsSettings.ECHConfigList == "" {
 			// a fingerprint puts its own ALPN into the hello, except Go TLS and the
 			// randomized ones, which take it from the config or send none
@@ -219,6 +221,7 @@ func (c *StreamConfig) Build() (*internet.StreamConfig, error) {
 		})
 	}
 	if c.XDRIVESettings != nil {
+		c.XDRIVESettings.h3 = xdriveH3
 		xs, err := c.XDRIVESettings.Build()
 		if err != nil {
 			return nil, errors.New("Failed to build XDRIVE config.").Base(err)
@@ -260,5 +263,20 @@ func (c *StreamConfig) Build() (*internet.StreamConfig, error) {
 		}
 	}
 
+	if xdriveH3 && c.FinalMask != nil {
+		if c.XDRIVESettings != nil && c.XDRIVESettings.Service == "google-drive" {
+			// noise only sends datagrams of its own ahead of the QUIC ones, the
+			// other masks change those or need a peer that undoes them
+			for _, mask := range c.FinalMask.Udp {
+				if strings.ToLower(mask.Type) != "noise" {
+					return nil, errors.New(`XDRIVE: over h3 to Google Drive the only "udp" mask that works is "noise", not "`, mask.Type, `"`)
+				}
+			}
+		}
+		if config.QuicParams != nil && (config.QuicParams.Congestion == "brutal" || config.QuicParams.Congestion == "force-brutal") {
+			return nil, errors.New(`XDRIVE: brutal is for Hysteria servers, over h3 "congestion" is "bbr" or "reno", not "`, config.QuicParams.Congestion, `"`)
+		}
+	}
+
 	return config, nil
 }

infra/conf/transport_method.go

@@ -997,6 +997,18 @@ type XDriveConfig struct {
 	EagerWindowMs     uint32          `json:"eagerWindowMs"`
 	HoleTimeoutMs     uint32          `json:"holeTimeoutMs"`
 	Template          json.RawMessage `json:"template"`
+	S3                *XDriveS3Config `json:"s3"`
+	Xmux              XmuxConfig      `json:"xmux"`
+
+	// set by StreamConfig when "alpn" is ["h3"]
+	h3 bool
+}
+
+type XDriveS3Config struct {
+	Endpoint  string `json:"endpoint"`
+	Region    string `json:"region"`
+	Bucket    string `json:"bucket"`
+	PathStyle *bool  `json:"pathStyle"`
 }
 
 // Build implements Buildable.
@@ -1015,8 +1027,27 @@ func (c *XDriveConfig) Build() (proto.Message, error) {
 		if len(c.Template) == 0 {
 			return nil, errors.New(`service "template" needs a "template" object`)
 		}
+	case "s3":
+		if c.S3 == nil {
+			return nil, errors.New(`service "s3" needs an "s3" object`)
+		}
 	default:
-		return nil, errors.New(`unknown "service": "`, c.Service, `", use "google-drive", "template" or "local"`)
+		return nil, errors.New(`unknown "service": "`, c.Service, `", use "google-drive", "template", "s3" or "local"`)
+	}
+	if c.Xmux.MaxConnections.To > 0 && c.Xmux.MaxConcurrency.To > 0 {
+		return nil, errors.New("maxConnections cannot be specified together with maxConcurrency")
+	}
+	if c.Xmux == (XmuxConfig{}) {
+		c.Xmux.MaxConnections.From = 1
+		c.Xmux.MaxConnections.To = 1
+		if c.Service == "google-drive" && !c.h3 {
+			// Google gives an h2 connection 1 MiB of window, which a few sessions on
+			// a long rtt would share, an h3 connection has no such limit
+			c.Xmux.MaxConnections.From = 4
+			c.Xmux.MaxConnections.To = 4
+		}
+		c.Xmux.HMaxReusableSecs.From = 1800
+		c.Xmux.HMaxReusableSecs.To = 3000
 	}
 	config := &xdrive.Config{
 		RemoteFolder:      c.RemoteFolder,
@@ -1031,6 +1062,25 @@ func (c *XDriveConfig) Build() (proto.Message, error) {
 		EagerWindowMs:     c.EagerWindowMs,
 		HoleTimeoutMs:     c.HoleTimeoutMs,
 		Template:          string(c.Template),
+		Xmux: &splithttp.XmuxConfig{
+			MaxConcurrency:   newRangeConfig(c.Xmux.MaxConcurrency),
+			MaxConnections:   newRangeConfig(c.Xmux.MaxConnections),
+			CMaxReuseTimes:   newRangeConfig(c.Xmux.CMaxReuseTimes),
+			HMaxRequestTimes: newRangeConfig(c.Xmux.HMaxRequestTimes),
+			HMaxReusableSecs: newRangeConfig(c.Xmux.HMaxReusableSecs),
+			HKeepAlivePeriod: c.Xmux.HKeepAlivePeriod,
+		},
+	}
+	if c.Service == "s3" {
+		config.S3 = &xdrive.S3Config{
+			Endpoint:  c.S3.Endpoint,
+			Region:    c.S3.Region,
+			Bucket:    c.S3.Bucket,
+			PathStyle: c.S3.PathStyle == nil || *c.S3.PathStyle,
+		}
+		if err := xdrive.ValidateS3Config(config); err != nil {
+			return nil, err
+		}
 	}
 	return config, nil
 }

infra/conf/transport_test.go

@@ -9,6 +9,7 @@ import (
 	. "github.com/xtls/xray-core/infra/conf"
 	"github.com/xtls/xray-core/transport/internet"
 	finalmaskcustom "github.com/xtls/xray-core/transport/internet/finalmask/header/custom"
+	"github.com/xtls/xray-core/transport/internet/splithttp"
 	"github.com/xtls/xray-core/transport/internet/xdrive"
 	"google.golang.org/protobuf/proto"
 )
@@ -323,7 +324,7 @@ func TestXDriveRejectsUnknownService(t *testing.T) {
 	if err := json.Unmarshal([]byte(`{"remoteFolder": "/tmp/xdrive", "service": "Dropbox"}`), config); err != nil {
 		t.Fatalf("Unmarshal: %v", err)
 	}
-	if _, err := config.Build(); err == nil || !strings.Contains(err.Error(), `use "google-drive", "template" or "local"`) {
+	if _, err := config.Build(); err == nil || !strings.Contains(err.Error(), `use "google-drive", "template", "s3" or "local"`) {
 		t.Fatalf("expected an unknown service error, got %v", err)
 	}
 }
@@ -424,6 +425,81 @@ func TestXDriveHTTP1ALPNWarning(t *testing.T) {
 	}
 }
 
+// over h3 Google Drive takes only the noise mask, and no service takes brutal
+func TestXDriveH3Checks(t *testing.T) {
+	const (
+		drive       = `"method": "xdrive", "xdriveSettings": {"remoteFolder": "f", "service": "google-drive", "secrets": ["a", "b", "c"]}`
+		local       = `"method": "xdrive", "xdriveSettings": {"remoteFolder": "/tmp/xdrive", "service": "local"}`
+		noise       = `{"type": "Noise", "settings": {"noise": [{"rand": "50-100"}]}}`
+		salamander  = `{"type": "salamander", "settings": {"password": "p"}}`
+		forceBrutal = `{"quicParams": {"congestion": "force-brutal", "brutalUp": "10 mbps"}}`
+	)
+	for _, c := range []struct {
+		alpn, transport, finalmask string
+		ok                         bool
+	}{
+		{`["h3"]`, drive, `{"udp": [` + noise + `]}`, true},
+		{`["h3"]`, drive, `{"udp": [` + salamander + `]}`, false},
+		{`["h3"]`, drive, `{"udp": [` + noise + `, ` + salamander + `]}`, false},
+		{`["h3"]`, local, `{"udp": [` + salamander + `]}`, true},
+		{`["h3"]`, `"method": "xdrive"`, `{"udp": [` + salamander + `]}`, true},
+		{`["h2"]`, drive, `{"udp": [` + salamander + `]}`, true},
+		{`null`, drive, `{"udp": [` + salamander + `]}`, true},
+		{`["h3"]`, drive, `null`, true},
+		{`["h3"]`, drive, `{"quicParams": {"congestion": "bbr"}}`, true},
+		{`["h3"]`, drive, `{"quicParams": {"congestion": "brutal"}}`, false},
+		{`["h3"]`, local, forceBrutal, false},
+		{`["h3", "h2"]`, drive, `{"quicParams": {"congestion": "brutal"}}`, true},
+		{`["h3"]`, `"method": "xhttp"`, forceBrutal, true},
+	} {
+		config := new(StreamConfig)
+		if err := json.Unmarshal([]byte(`{
+			`+c.transport+`,
+			"security": "tls",
+			"tlsSettings": {"alpn": `+c.alpn+`},
+			"finalmask": `+c.finalmask+`
+		}`), config); err != nil {
+			t.Fatalf("Unmarshal: %v", err)
+		}
+		if _, err := config.Build(); (err == nil) != c.ok {
+			t.Errorf("alpn %s, %s, finalmask %s: %v", c.alpn, c.transport, c.finalmask, err)
+		}
+	}
+}
+
+// one h3 connection is not held back by a window like h2, so h3 takes one by default
+func TestXDriveH3Connections(t *testing.T) {
+	for _, c := range []struct {
+		alpn string
+		want int32
+	}{
+		{`["h3"]`, 1},
+		{`["h2"]`, 4},
+		{`null`, 4},
+	} {
+		config := new(StreamConfig)
+		if err := json.Unmarshal([]byte(`{
+			"method": "xdrive",
+			"xdriveSettings": {"remoteFolder": "f", "service": "google-drive", "secrets": ["a", "b", "c"]},
+			"security": "tls",
+			"tlsSettings": {"alpn": `+c.alpn+`}
+		}`), config); err != nil {
+			t.Fatalf("Unmarshal: %v", err)
+		}
+		built, err := config.Build()
+		if err != nil {
+			t.Fatalf("alpn %s: %v", c.alpn, err)
+		}
+		xs, err := built.TransportSettings[0].Settings.GetInstance()
+		if err != nil {
+			t.Fatalf("alpn %s: %v", c.alpn, err)
+		}
+		if got := xs.(*xdrive.Config).Xmux.MaxConnections; got.From != c.want || got.To != c.want {
+			t.Errorf("alpn %s: maxConnections is %d-%d, want %d", c.alpn, got.From, got.To, c.want)
+		}
+	}
+}
+
 func TestXDriveTemplateNeedsTemplate(t *testing.T) {
 	config := new(XDriveConfig)
 	if err := json.Unmarshal([]byte(`{"remoteFolder": "f", "service": "template"}`), config); err != nil {
@@ -513,3 +589,50 @@ func TestXDriveInboundConfig(t *testing.T) {
 		}
 	}
 }
+
+func TestXDriveXmux(t *testing.T) {
+	defaults := func(connections int32) *splithttp.XmuxConfig {
+		return &splithttp.XmuxConfig{
+			MaxConcurrency:   &splithttp.RangeConfig{},
+			MaxConnections:   &splithttp.RangeConfig{From: connections, To: connections},
+			CMaxReuseTimes:   &splithttp.RangeConfig{},
+			HMaxRequestTimes: &splithttp.RangeConfig{},
+			HMaxReusableSecs: &splithttp.RangeConfig{From: 1800, To: 3000},
+		}
+	}
+	for _, c := range []struct {
+		input string
+		want  *splithttp.XmuxConfig
+	}{
+		{`{"service": "google-drive", "secrets": ["a", "b", "c"]}`, defaults(4)},
+		{`{"service": "template", "template": {}}`, defaults(1)},
+		{`{"service": "google-drive", "secrets": ["a", "b", "c"], "xmux": {"maxConcurrency": "1-2", "hMaxRequestTimes": 100, "hKeepAlivePeriod": -1}}`, &splithttp.XmuxConfig{
+			MaxConcurrency:   &splithttp.RangeConfig{From: 1, To: 2},
+			MaxConnections:   &splithttp.RangeConfig{},
+			CMaxReuseTimes:   &splithttp.RangeConfig{},
+			HMaxRequestTimes: &splithttp.RangeConfig{From: 100, To: 100},
+			HMaxReusableSecs: &splithttp.RangeConfig{},
+			HKeepAlivePeriod: -1,
+		}},
+	} {
+		config := new(XDriveConfig)
+		if err := json.Unmarshal([]byte(c.input), config); err != nil {
+			t.Fatalf("%s: Unmarshal: %v", c.input, err)
+		}
+		built, err := config.Build()
+		if err != nil {
+			t.Fatalf("%s: Build: %v", c.input, err)
+		}
+		if got := built.(*xdrive.Config).Xmux; !proto.Equal(got, c.want) {
+			t.Errorf("%s: xmux is %v, want %v", c.input, got, c.want)
+		}
+	}
+
+	config := new(XDriveConfig)
+	if err := json.Unmarshal([]byte(`{"service": "template", "template": {}, "xmux": {"maxConnections": 2, "maxConcurrency": 8}}`), config); err != nil {
+		t.Fatalf("Unmarshal: %v", err)
+	}
+	if _, err := config.Build(); err == nil {
+		t.Error("Build accepted maxConnections with maxConcurrency")
+	}
+}

infra/conf/xray.go

@@ -237,10 +237,11 @@ type OutboundDetourConfig struct {
 
 func requiresTransportSecurity(address *Address) bool {
 	if address == nil || address.Address == nil {
-		return false
+		return true
 	}
 	if address.Family().IsIP() {
-		return !geodata.GetPrivateIPMatcher().Match(address.IP())
+		ip := address.IP()
+		return !ip.IsPrivate() && !ip.IsLoopback() && !ip.IsLinkLocalUnicast()
 	}
 	domain := strings.TrimSuffix(strings.ToLower(address.Domain()), ".")
 	return !geodata.GetPrivateDomainMatcher().MatchAny(domain)

infra/vprotogen/main.go

@@ -1,149 +1,87 @@
 package main
 
 import (
-	"errors"
+	"bytes"
+	"context"
 	"flag"
 	"fmt"
-	"go/build"
+	"io/fs"
-	"io"
-	"net/http"
 	"os"
 	"os/exec"
 	"path/filepath"
-	"regexp"
-	"runtime"
-	"strconv"
 	"strings"
+
+	"github.com/bufbuild/protocompile"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protodesc"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/types/descriptorpb"
+	"google.golang.org/protobuf/types/pluginpb"
 )
 
-var directory = flag.String("pwd", "", "Working directory of Xray vprotogen.")
+var (
+	directory = flag.String("pwd", "", "Working directory of Xray vprotogen.")
+	mode      = flag.String("mode", "generate", "Execution mode. 'generate' (default) compiles and saves changes. 'check' reports out-of-date files and exits with non-zero.")
+)
 
-// envFile returns the name of the Go environment configuration file.
+// topoSort sorts file descriptors so each dependency appears before files importing it.
-// Copy from https://github.com/golang/go/blob/c4f2a9788a7be04daf931ac54382fbe2cb754938/src/cmd/go/internal/cfg/cfg.go#L150-L166
+func topoSort(files []protoreflect.FileDescriptor) []*descriptorpb.FileDescriptorProto {
-func envFile() (string, error) {
+	fileMap := make(map[string]protoreflect.FileDescriptor)
-	if file := os.Getenv("GOENV"); file != "" {
+	for _, f := range files {
-		if file == "off" {
+		fileMap[f.Path()] = f
-			return "", errors.New("GOENV=off")
 	}
-		return file, nil
+
+	visited := make(map[string]bool)
+	var sorted []*descriptorpb.FileDescriptorProto
+
+	var visit func(fd protoreflect.FileDescriptor)
+	visit = func(fd protoreflect.FileDescriptor) {
+		if visited[fd.Path()] {
+			return
 		}
-	dir, err := os.UserConfigDir()
+		visited[fd.Path()] = true
+
+		imports := fd.Imports()
+		for i := 0; i < imports.Len(); i++ {
+			if dep, ok := fileMap[imports.Get(i).Path()]; ok {
+				visit(dep)
+			}
+		}
+		sorted = append(sorted, protodesc.ToFileDescriptorProto(fd))
+	}
+
+	for _, f := range files {
+		visit(f)
+	}
+	return sorted
+}
+
+func runPlugin(pluginName, pwd string, req *pluginpb.CodeGeneratorRequest) (*pluginpb.CodeGeneratorResponse, error) {
+	reqBytes, err := proto.Marshal(req)
 	if err != nil {
-		return "", err
+		return nil, err
 	}
-	if dir == "" {
-		return "", errors.New("missing user-config dir")
-	}
-	return filepath.Join(dir, "go", "env"), nil
-}
 
-// GetRuntimeEnv returns the value of runtime environment variable,
+	cmd := exec.Command("go", "tool", pluginName)
-// that is set by running following command: `go env -w key=value`.
+	cmd.Dir = pwd
-func GetRuntimeEnv(key string) (string, error) {
+	cmd.Stdin = bytes.NewReader(reqBytes)
-	file, err := envFile()
+	cmd.Env = os.Environ()
-	if err != nil {
+	var stdout, stderr bytes.Buffer
-		return "", err
+	cmd.Stdout = &stdout
-	}
+	cmd.Stderr = &stderr
-	if file == "" {
-		return "", errors.New("missing runtime env file")
-	}
-	var data []byte
-	var runtimeEnv string
-	data, readErr := os.ReadFile(file)
-	if readErr != nil {
-		return "", readErr
-	}
-	envStrings := strings.Split(string(data), "\n")
-	for _, envItem := range envStrings {
-		envItem = strings.TrimSuffix(envItem, "\r")
-		envKeyValue := strings.Split(envItem, "=")
-		if strings.EqualFold(strings.TrimSpace(envKeyValue[0]), key) {
-			runtimeEnv = strings.TrimSpace(envKeyValue[1])
-		}
-	}
-	return runtimeEnv, nil
-}
 
-// GetGOBIN returns GOBIN environment variable as a string. It will NOT be empty.
+	if err := cmd.Run(); err != nil {
-func GetGOBIN() string {
+		return nil, fmt.Errorf("%v: %s", err, stderr.String())
-	// The one set by user explicitly by `export GOBIN=/path` or `env GOBIN=/path command`
-	GOBIN := os.Getenv("GOBIN")
-	if GOBIN == "" {
-		var err error
-		// The one set by user by running `go env -w GOBIN=/path`
-		GOBIN, err = GetRuntimeEnv("GOBIN")
-		if err != nil {
-			// The default one that Golang uses
-			return filepath.Join(build.Default.GOPATH, "bin")
 	}
-		if GOBIN == "" {
-			return filepath.Join(build.Default.GOPATH, "bin")
-		}
-		return GOBIN
-	}
-	return GOBIN
-}
 
-func whichProtoc(suffix, targetedVersion string) (string, error) {
+	var resp pluginpb.CodeGeneratorResponse
-	protoc := "protoc" + suffix
+	if err := proto.Unmarshal(stdout.Bytes(), &resp); err != nil {
-
+		return nil, fmt.Errorf("failed to unmarshal response: %w", err)
-	path, err := exec.LookPath(protoc)
-	if err != nil {
-		return "", fmt.Errorf(`
-Command "%s" not found.
-Make sure that %s is in your system path or current path.
-Download %s v%s or later from https://github.com/protocolbuffers/protobuf/releases
-`, protoc, protoc, protoc, targetedVersion)
 	}
-	return path, nil
+	if resp.GetError() != "" {
-}
+		return nil, fmt.Errorf("%s", resp.GetError())
-
-func getProjectProtocVersion(url string) (string, error) {
-	resp, err := http.Get(url)
-	if err != nil {
-		return "", errors.New("can not get the version of protobuf used in xray project")
 	}
-	defer resp.Body.Close()
+	return &resp, nil
-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return "", errors.New("can not read from body")
-	}
-	versionRegexp := regexp.MustCompile(`\/\/\s*protoc\s*v\d+\.(\d+\.\d+)`)
-	matched := versionRegexp.FindStringSubmatch(string(body))
-	return matched[1], nil
-}
-
-func getInstalledProtocVersion(protocPath string) (string, error) {
-	cmd := exec.Command(protocPath, "--version")
-	cmd.Env = append(cmd.Env, os.Environ()...)
-	output, cmdErr := cmd.CombinedOutput()
-	if cmdErr != nil {
-		return "", cmdErr
-	}
-	versionRegexp := regexp.MustCompile(`protoc\s*(\d+\.\d+)`)
-	matched := versionRegexp.FindStringSubmatch(string(output))
-	return matched[1], nil
-}
-
-func parseVersion(s string, width int) int64 {
-	strList := strings.Split(s, ".")
-	format := fmt.Sprintf("%%s%%0%ds", width)
-	v := ""
-	for _, value := range strList {
-		v = fmt.Sprintf(format, v, value)
-	}
-	var result int64
-	var err error
-	if result, err = strconv.ParseInt(v, 10, 64); err != nil {
-		return 0
-	}
-	return result
-}
-
-func needToUpdate(targetedVersion, installedVersion string) bool {
-	vt := parseVersion(targetedVersion, 4)
-	vi := parseVersion(installedVersion, 4)
-	return vt > vi
 }
 
 func main() {
@@ -154,106 +92,147 @@ func main() {
 	flag.Parse()
 
 	if !filepath.IsAbs(*directory) {
-		pwd, wdErr := os.Getwd()
+		pwd, err := os.Getwd()
-		if wdErr != nil {
+		if err != nil {
 			fmt.Println("Can not get current working directory.")
 			os.Exit(1)
 		}
 		*directory = filepath.Join(pwd, *directory)
 	}
-
 	pwd := *directory
-	GOBIN := GetGOBIN()
-	binPath := os.Getenv("PATH")
-	pathSlice := []string{pwd, GOBIN, binPath}
-	binPath = strings.Join(pathSlice, string(os.PathListSeparator))
-	os.Setenv("PATH", binPath)
 
-	suffix := ""
+	isCheck := false
-	if runtime.GOOS == "windows" {
+	switch *mode {
-		suffix = ".exe"
+	case "generate", "":
-	}
+		isCheck = false
-
+	case "check":
-	/*
+		isCheck = true
-		targetedVersion, err := getProjectProtocVersion("https://raw.githubusercontent.com/XTLS/Xray-core/HEAD/core/config.pb.go")
+	default:
-		if err != nil {
+		fmt.Fprintf(os.Stderr, "Unrecognized 'mode': %s. Use 'generate' or 'check'.\n", *mode)
-			fmt.Println(err)
-			os.Exit(1)
-		}
-	*/
-	targetedVersion := ""
-
-	protoc, err := whichProtoc(suffix, targetedVersion)
-	if err != nil {
-		fmt.Println(err)
 		os.Exit(1)
 	}
 
-	installedVersion, err := getInstalledProtocVersion(protoc)
+	if isCheck {
-	if err != nil {
+		fmt.Println("Checking for out-of-date Protobuf generated files...")
-		fmt.Println(err)
-		os.Exit(1)
 	}
 
-	if needToUpdate(targetedVersion, installedVersion) {
+	var protoFiles []string
-		fmt.Printf(`
+	var pbCount int
-You are using an old protobuf version, please update to v%s or later.
+	err := filepath.WalkDir(pwd, func(path string, d fs.DirEntry, err error) error {
-Download it from https://github.com/protocolbuffers/protobuf/releases
+		if err != nil || d.IsDir() {
-
-    * Protobuf version used in xray project: v%s
-    * Protobuf version you have installed: v%s
-
-`, targetedVersion, targetedVersion, installedVersion)
-		os.Exit(1)
-	}
-
-	protoFilesMap := make(map[string][]string)
-	walkErr := filepath.Walk(pwd, func(path string, info os.FileInfo, err error) error {
-		if err != nil {
-			fmt.Println(err)
 			return err
 		}
-
+		if strings.HasSuffix(d.Name(), ".proto") {
-		if info.IsDir() {
+			rel, _ := filepath.Rel(pwd, path)
-			return nil
+			protoFiles = append(protoFiles, filepath.ToSlash(rel))
 		}
-
+		if strings.HasSuffix(d.Name(), ".pb.go") {
-		dir := filepath.Dir(path)
+			pbCount++
-		filename := filepath.Base(path)
-		if strings.HasSuffix(filename, ".proto") {
-			path = path[len(pwd)+1:]
-			protoFilesMap[dir] = append(protoFilesMap[dir], path)
 		}
-
 		return nil
 	})
-	if walkErr != nil {
+	if err != nil {
-		fmt.Println(walkErr)
+		fmt.Println("Walk error:", err)
+		os.Exit(1)
+	}
+	if len(protoFiles) == 0 {
+		if isCheck && pbCount > 0 {
+			fmt.Fprintf(os.Stderr, "Found %d .pb.go files without any .proto files. Remove these orphaned files.\n", pbCount)
+			os.Exit(1)
+		}
+		return
+	}
+
+	compiler := protocompile.Compiler{
+		Resolver: protocompile.WithStandardImports(&protocompile.SourceResolver{
+			ImportPaths: []string{pwd},
+		}),
+		SourceInfoMode: protocompile.SourceInfoStandard,
+	}
+
+	linkedFiles, err := compiler.Compile(context.Background(), protoFiles...)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Protobuf compilation failed:\n%v\n", err)
 		os.Exit(1)
 	}
 
-	for _, files := range protoFilesMap {
+	var fdList []protoreflect.FileDescriptor
-		for _, relProtoFile := range files {
+	for _, f := range linkedFiles {
-			args := []string{
+		fdList = append(fdList, f)
-				"--go_out", pwd,
-				"--go_opt", "paths=source_relative",
-				"--go-grpc_out", pwd,
-				"--go-grpc_opt", "paths=source_relative",
-				"--plugin", "protoc-gen-go=" + filepath.Join(GOBIN, "protoc-gen-go"+suffix),
-				"--plugin", "protoc-gen-go-grpc=" + filepath.Join(GOBIN, "protoc-gen-go-grpc"+suffix),
 	}
-			args = append(args, relProtoFile)
+
-			cmd := exec.Command(protoc, args...)
+	req := &pluginpb.CodeGeneratorRequest{
-			cmd.Env = append(cmd.Env, os.Environ()...)
+		FileToGenerate: protoFiles,
-			cmd.Dir = pwd
+		Parameter:      proto.String("paths=source_relative"),
-			output, cmdErr := cmd.CombinedOutput()
+		ProtoFile:      topoSort(fdList),
-			if len(output) > 0 {
+		// TODO: replace with unknown in the future
-				fmt.Println(string(output))
+		CompilerVersion: &pluginpb.Version{
+			Major: proto.Int32(6),
+			Minor: proto.Int32(33),
+			Patch: proto.Int32(5),
+		},
 	}
-			if cmdErr != nil {
+
-				fmt.Println(cmdErr)
+	var diffCount int
+	generatedFiles := make(map[string]struct{})
+	for _, plugin := range []string{"protoc-gen-go", "protoc-gen-go-grpc"} {
+		resp, err := runPlugin(plugin, pwd, req)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "%s failed: %v\n", plugin, err)
+			os.Exit(1)
+		}
+
+		for _, f := range resp.File {
+			targetPath := filepath.Join(pwd, filepath.FromSlash(f.GetName()))
+			generatedFiles[targetPath] = struct{}{}
+			content := []byte(f.GetContent())
+
+			hasDiff := false
+			existing, err := os.ReadFile(targetPath)
+			if err != nil {
+				hasDiff = true
+			} else {
+				oldNorm := bytes.ReplaceAll(existing, []byte("\r\n"), []byte("\n"))
+				newNorm := bytes.ReplaceAll(content, []byte("\r\n"), []byte("\n"))
+				if !bytes.Equal(oldNorm, newNorm) {
+					hasDiff = true
+				}
+			}
+
+			if hasDiff {
+				diffCount++
+				fmt.Println(targetPath)
+
+				if isCheck {
+					continue
+				}
+
+				if err := os.MkdirAll(filepath.Dir(targetPath), 0o755); err != nil {
+					fmt.Fprintf(os.Stderr, "Error creating directory: %v\n", err)
+					os.Exit(1)
+				}
+				mode := os.FileMode(0o644)
+				if stat, err := os.Stat(targetPath); err == nil {
+					mode = stat.Mode().Perm()
+				}
+				if err := os.WriteFile(targetPath, content, mode); err != nil {
+					fmt.Fprintf(os.Stderr, "Error writing %s: %v\n", targetPath, err)
 					os.Exit(1)
 				}
 			}
 		}
+	}
+
+	if isCheck {
+		if pbCount != len(generatedFiles) {
+			fmt.Printf("Protobuf file count mismatch: found %d, expected %d. Remove orphaned files and regenerate.\n", pbCount, len(generatedFiles))
+			diffCount++
+		}
+		if diffCount > 0 {
+			fmt.Println("Protobuf generated file problem(s) found.")
+			fmt.Println("Please run 'go run ./infra/vprotogen' to regenerate them.")
+			os.Exit(1)
+		}
+		fmt.Println("All Protobuf generated file check has been passed.")
+	}
 }

main/commands/all/api/rules_add.go

@@ -92,6 +92,8 @@ func executeAddRules(cmd *base.Command, args []string) {
 		if err != nil {
 			base.Fatalf("failed to perform AddRule: %s", err)
 		}
+		// if multiple files are specified, use append to merge them instead of overriding previous one
+		shouldAppend = true
 		showJSONResponse(resp)
 	}
 }

main/commands/all/lua/sign.go

@@ -3,6 +3,7 @@ package lua
 import (
 	"os"
 	"path/filepath"
+	"strings"
 
 	xlua "github.com/xtls/xray-core/common/lua"
 	"github.com/xtls/xray-core/main/commands/base"
@@ -32,14 +33,13 @@ func executeSign(cmd *base.Command, args []string) {
 		cmd.Usage()
 	}
 
+	if !strings.EqualFold(filepath.Ext(args[0]), ".lua") {
+		base.Fatalf("Lua file extension must be .lua")
+	}
 	info, err := os.Stat(args[0])
 	if err != nil {
 		base.Fatalf("failed to inspect Lua file: %s", err)
 	}
-	if !info.Mode().IsRegular() {
-		base.Fatalf("Lua input is not a regular file: %s", args[0])
-	}
-
 	code, err := os.ReadFile(args[0])
 	if err != nil {
 		base.Fatalf("failed to read Lua file: %s", err)
@@ -67,14 +67,7 @@ func executeSign(cmd *base.Command, args []string) {
 
 func writeSignedFile(path string, code []byte, mode os.FileMode) error {
 	if info, err := os.Stat(path); err == nil {
-		if !info.Mode().IsRegular() {
-			return &os.PathError{Op: "write", Path: path, Err: os.ErrInvalid}
-		}
 		mode = info.Mode().Perm()
-		path, err = filepath.EvalSymlinks(path)
-		if err != nil {
-			return err
-		}
 	} else if !os.IsNotExist(err) {
 		return err
 	}

main/confloader/external/external.go

@@ -58,18 +58,10 @@ func readConfigFile(file *os.File) ([]byte, error) {
 		return nil, err
 	}
 	if info.Mode().IsRegular() {
-		path, err := filepath.Abs(file.Name())
+		switch strings.ToLower(filepath.Ext(file.Name())) {
-		if err != nil {
-			return nil, err
-		}
-		path, err = filepath.EvalSymlinks(path)
-		if err != nil {
-			return nil, err
-		}
-		switch strings.ToLower(filepath.Ext(path)) {
 		case ".jsonc", ".json", ".yml", ".yaml", ".toml", ".pb", ".protobuf":
 		default:
-			return nil, errors.New("unsupported config file extension: ", path)
+			return nil, errors.New("unsupported config file extension: ", file.Name())
 		}
 	}
 	return io.ReadAll(file)

proxy/dns/dns.go

@@ -381,6 +381,13 @@ func (h *Handler) handleIPQuery(id uint16, qType dnsmessage.Type, domain string,
 		errors.LogInfoInner(context.Background(), err, "pack message")
 		b.Release()
 		timer.SetTimeout(0)
+		return
+	}
+	if len(msgBytes) > buf.Size {
+		b.Release()
+		timer.SetTimeout(0)
+		errors.LogError(context.Background(), "DNS response message too large")
+		return
 	}
 	b.Resize(0, int32(len(msgBytes)))
 

proxy/dokodemo/config.pb.go

@@ -24,11 +24,11 @@ const (
 
 type Config struct {
 	state protoimpl.MessageState `protogen:"open.v1"`
+	// List of networks that the Dokodemo accepts.
+	AllowedNetworks []net.Network     `protobuf:"varint,7,rep,packed,name=allowed_networks,json=allowedNetworks,proto3,enum=xray.common.net.Network" json:"allowed_networks,omitempty"`
 	RewriteAddress  *net.IPOrDomain   `protobuf:"bytes,1,opt,name=rewrite_address,json=rewriteAddress,proto3" json:"rewrite_address,omitempty"`
 	RewritePort     uint32            `protobuf:"varint,2,opt,name=rewrite_port,json=rewritePort,proto3" json:"rewrite_port,omitempty"`
 	PortMap         map[string]string `protobuf:"bytes,3,rep,name=port_map,json=portMap,proto3" json:"port_map,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
-	// List of networks that the Dokodemo accepts.
-	AllowedNetworks []net.Network `protobuf:"varint,7,rep,packed,name=allowed_networks,json=allowedNetworks,proto3,enum=xray.common.net.Network" json:"allowed_networks,omitempty"`
 	FollowRedirect  bool              `protobuf:"varint,5,opt,name=follow_redirect,json=followRedirect,proto3" json:"follow_redirect,omitempty"`
 	UserLevel       uint32            `protobuf:"varint,6,opt,name=user_level,json=userLevel,proto3" json:"user_level,omitempty"`
 	unknownFields   protoimpl.UnknownFields
@@ -65,6 +65,13 @@ func (*Config) Descriptor() ([]byte, []int) {
 	return file_proxy_dokodemo_config_proto_rawDescGZIP(), []int{0}
 }
 
+func (x *Config) GetAllowedNetworks() []net.Network {
+	if x != nil {
+		return x.AllowedNetworks
+	}
+	return nil
+}
+
 func (x *Config) GetRewriteAddress() *net.IPOrDomain {
 	if x != nil {
 		return x.RewriteAddress
@@ -86,13 +93,6 @@ func (x *Config) GetPortMap() map[string]string {
 	return nil
 }
 
-func (x *Config) GetAllowedNetworks() []net.Network {
-	if x != nil {
-		return x.AllowedNetworks
-	}
-	return nil
-}
-
 func (x *Config) GetFollowRedirect() bool {
 	if x != nil {
 		return x.FollowRedirect
@@ -112,11 +112,11 @@ var File_proxy_dokodemo_config_proto protoreflect.FileDescriptor
 const file_proxy_dokodemo_config_proto_rawDesc = "" +
 	"\n" +
 	"\x1bproxy/dokodemo/config.proto\x12\x13xray.proxy.dokodemo\x1a\x18common/net/address.proto\x1a\x18common/net/network.proto\"\xff\x02\n" +
-	"\x06Config\x12D\n" +
+	"\x06Config\x12C\n" +
+	"\x10allowed_networks\x18\a \x03(\x0e2\x18.xray.common.net.NetworkR\x0fallowedNetworks\x12D\n" +
 	"\x0frewrite_address\x18\x01 \x01(\v2\x1b.xray.common.net.IPOrDomainR\x0erewriteAddress\x12!\n" +
 	"\frewrite_port\x18\x02 \x01(\rR\vrewritePort\x12C\n" +
-	"\bport_map\x18\x03 \x03(\v2(.xray.proxy.dokodemo.Config.PortMapEntryR\aportMap\x12C\n" +
+	"\bport_map\x18\x03 \x03(\v2(.xray.proxy.dokodemo.Config.PortMapEntryR\aportMap\x12'\n" +
-	"\x10allowed_networks\x18\a \x03(\x0e2\x18.xray.common.net.NetworkR\x0fallowedNetworks\x12'\n" +
 	"\x0ffollow_redirect\x18\x05 \x01(\bR\x0efollowRedirect\x12\x1d\n" +
 	"\n" +
 	"user_level\x18\x06 \x01(\rR\tuserLevel\x1a:\n" +
@@ -141,13 +141,13 @@ var file_proxy_dokodemo_config_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
 var file_proxy_dokodemo_config_proto_goTypes = []any{
 	(*Config)(nil),         // 0: xray.proxy.dokodemo.Config
 	nil,                    // 1: xray.proxy.dokodemo.Config.PortMapEntry
-	(*net.IPOrDomain)(nil), // 2: xray.common.net.IPOrDomain
+	(net.Network)(0),       // 2: xray.common.net.Network
-	(net.Network)(0),       // 3: xray.common.net.Network
+	(*net.IPOrDomain)(nil), // 3: xray.common.net.IPOrDomain
 }
 var file_proxy_dokodemo_config_proto_depIdxs = []int32{
-	2, // 0: xray.proxy.dokodemo.Config.rewrite_address:type_name -> xray.common.net.IPOrDomain
+	2, // 0: xray.proxy.dokodemo.Config.allowed_networks:type_name -> xray.common.net.Network
-	1, // 1: xray.proxy.dokodemo.Config.port_map:type_name -> xray.proxy.dokodemo.Config.PortMapEntry
+	3, // 1: xray.proxy.dokodemo.Config.rewrite_address:type_name -> xray.common.net.IPOrDomain
-	3, // 2: xray.proxy.dokodemo.Config.allowed_networks:type_name -> xray.common.net.Network
+	1, // 2: xray.proxy.dokodemo.Config.port_map:type_name -> xray.proxy.dokodemo.Config.PortMapEntry
 	3, // [3:3] is the sub-list for method output_type
 	3, // [3:3] is the sub-list for method input_type
 	3, // [3:3] is the sub-list for extension type_name

proxy/freedom/freedom.go

@@ -229,14 +229,19 @@ func (h *Handler) blockDelay(rule *FinalRule) time.Duration {
 func (h *Handler) blackhole(ctx context.Context, input buf.Reader, output buf.Writer, rule *FinalRule, dest *net.Destination) error {
 	delay := h.blockDelay(rule)
 	errors.LogInfo(ctx, "blocked target: ", *dest, ", blackholing connection for ", delay)
-	timer := time.AfterFunc(delay, func() {
+	defer common.Close(output)
+	done := make(chan struct{})
+	go func() { // a DispatchLink inbound's reader ignores Interrupt, so don't wait for this copy
+		_ = buf.Copy(input, buf.Discard)
+		close(done)
+	}()
+	select {
+	case <-done:
+	case <-time.After(delay):
 		common.Interrupt(input)
 		common.Interrupt(output)
 		errors.LogInfo(ctx, "closed blackholed connection to blocked target: ", *dest)
-	})
+	}
-	defer timer.Stop()
-	defer common.Close(output)
-	_ = buf.Copy(input, buf.Discard)
 	return nil
 }
 

proxy/http/client.go

@@ -10,6 +10,7 @@ import (
 	"net/url"
 	"sync"
 	"text/template"
+	"time"
 
 	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/buf"
@@ -86,7 +87,13 @@ func (c *Client) Process(ctx context.Context, link *transport.Link, dialer inter
 	user := server.User
 	var conn stat.Connection
 
-	mbuf, _ := link.Reader.ReadMultiBuffer()
+	var mbuf buf.MultiBuffer
+	if reader, ok := link.Reader.(buf.TimeoutReader); ok {
+		// Don't wait forever: server-first protocols (SMTP, FTP, MySQL...) send nothing until the server greets.
+		mbuf, _ = reader.ReadMultiBufferTimeout(time.Millisecond * 500)
+	} else {
+		mbuf, _ = link.Reader.ReadMultiBuffer()
+	}
 	len := mbuf.Len()
 	firstPayload := bytespool.Alloc(len)
 	mbuf, _ = buf.SplitBytes(mbuf, firstPayload)
@@ -234,7 +241,8 @@ func setUpHTTPTunnel(ctx context.Context, dest net.Destination, target string, u
 			return nil, err
 		}
 
-		resp, err := http.ReadResponse(bufio.NewReader(rawConn), req)
+		reader := bufio.NewReader(rawConn)
+		resp, err := http.ReadResponse(reader, req)
 		if err != nil {
 			rawConn.Close()
 			return nil, err
@@ -245,6 +253,11 @@ func setUpHTTPTunnel(ctx context.Context, dest net.Destination, target string, u
 			rawConn.Close()
 			return nil, errors.New("Proxy responded with non 200 code: " + resp.Status)
 		}
+		// Tunneled bytes (e.g. a server-first greeting) may arrive in the same read as the 200 response.
+		if n := reader.Buffered(); n > 0 {
+			early, _ := reader.Peek(n)
+			return &earlyDataConn{Conn: rawConn, early: early}, nil
+		}
 		return rawConn, nil
 	}
 
@@ -375,6 +388,21 @@ func (h *http2Conn) Close() error {
 	return h.out.Close()
 }
 
+// earlyDataConn returns the bytes read ahead together with the CONNECT response before reading from Conn.
+type earlyDataConn struct {
+	net.Conn
+	early []byte
+}
+
+func (c *earlyDataConn) Read(p []byte) (int, error) {
+	if len(c.early) > 0 {
+		n := copy(p, c.early)
+		c.early = c.early[n:]
+		return n, nil
+	}
+	return c.Conn.Read(p)
+}
+
 func init() {
 	common.Must(common.RegisterConfig((*ClientConfig)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
 		return NewClient(ctx, config.(*ClientConfig))

proxy/socks/temp_udp_listen.go

@@ -2,10 +2,10 @@ package socks
 
 import (
 	"context"
-	"net"
 	"sync/atomic"
 	"time"
 
+	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/common/signal"
 )
 
@@ -14,6 +14,9 @@ func NewTempUDPConn(udpConn net.PacketConn, tcpConn net.Conn, expectedRemote *ne
 		PacketConn:        udpConn,
 		AssociatedTCPConn: tcpConn,
 	}
+	t.Timer = signal.CancelAfterInactivity(context.Background(), func() {
+		t.Close()
+	}, net.ConnIdleTimeout)
 	t.ExpectedRemote.Store(expectedRemote)
 	return t
 }
@@ -60,9 +63,7 @@ func (c *TempUDPConn) RemoteAddr() net.Addr {
 }
 
 func (c *TempUDPConn) SetTimeout(d time.Duration) {
-	c.Timer = signal.CancelAfterInactivity(context.Background(), func() {
+	c.Timer.SetTimeout(d)
-		c.Close()
-	}, d)
 }
 
 func (c *TempUDPConn) Close() error {

proxy/tun/config.pb.go

@@ -7,12 +7,11 @@
 package tun
 
 import (
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
 	reflect "reflect"
 	sync "sync"
 	unsafe "unsafe"
-
-	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
-	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
 )
 
 const (

proxy/tun/packet.go

@@ -41,8 +41,9 @@ const (
 type packet struct {
 	proto    byte
 	src, dst netip.Addr
-	// payload is what follows the IP header
+	// payload is what follows the IP header, without the last rest bytes of it when they are in other buffers
 	payload []byte
+	rest    int
 	// fragment is set if payload is a part of what follows the IP header: the one at offset of the packet
 	// with the number id, which has more after it or not
 	fragment bool
@@ -51,8 +52,8 @@ type packet struct {
 	id       uint32
 }
 
-// parsePacket reads the IP header of b
+// parsePacket reads the IP header of a packet that is b and rest bytes after it
-func parsePacket(b []byte) (p packet, ok bool) {
+func parsePacket(b []byte, rest int) (p packet, ok bool) {
 	if len(b) < ipv4HeaderSize {
 		return p, false
 	}
@@ -60,7 +61,7 @@ func parsePacket(b []byte) (p packet, ok bool) {
 	case 4:
 		size := int(b[0]&0xf) * 4
 		total := int(binary.BigEndian.Uint16(b[2:]))
-		if size < ipv4HeaderSize || total < size || total > len(b) {
+		if size < ipv4HeaderSize || total < size || total > len(b)+rest {
 			return p, false
 		}
 		if f := binary.BigEndian.Uint16(b[6:]); f&0x3fff != 0 {
@@ -69,19 +70,19 @@ func parsePacket(b []byte) (p packet, ok bool) {
 		p.proto = b[9]
 		p.src = netip.AddrFrom4([4]byte(b[12:16]))
 		p.dst = netip.AddrFrom4([4]byte(b[16:20]))
-		p.payload = b[size:total]
+		p.payload, p.rest = b[size:min(total, len(b))], max(total-len(b), 0)
 	case 6:
 		if len(b) < ipv6HeaderSize {
 			return p, false
 		}
 		total := ipv6HeaderSize + int(binary.BigEndian.Uint16(b[4:]))
-		if total > len(b) {
+		if total > len(b)+rest {
 			return p, false
 		}
 		p.proto = b[6]
 		p.src = netip.AddrFrom16([16]byte(b[8:24]))
 		p.dst = netip.AddrFrom16([16]byte(b[24:40]))
-		p.payload = b[ipv6HeaderSize:total]
+		p.payload, p.rest = b[ipv6HeaderSize:min(total, len(b))], max(total-len(b), 0)
 		// hop-by-hop options, routing, destination options
 		for p.proto == 0 || p.proto == 43 || p.proto == 60 {
 			if len(p.payload) < 8 {

proxy/tun/stack.go

@@ -71,6 +71,10 @@ type stack struct {
 	udp    *udpConnectionHandler
 	// addresses are what connections are opened from
 	addresses []netip.Addr
+	// bufs is what read reads a packet into if the tun is a segmenter, one after the other, the headers in the first.
+	// One that keep took is nil. joined is for a packet that is in more than one and is needed in one piece
+	bufs   buf.MultiBuffer
+	joined []byte
 
 	mu    sync.Mutex
 	conns map[flow]*tcpConn
@@ -149,26 +153,66 @@ func (s *stack) Close() error {
 
 // read takes the packets of the tun until it is closed
 func (s *stack) read() {
-	// a tun that does not split segments gives them as large as a packet can be
+	var err error
+	if s.segmenter != nil {
+		err = s.readSegments()
+	} else {
+		// as large as a packet can be, whatever the MTU is
 		b := make([]byte, packetRoom+1<<16)
-	for {
+		for err == nil {
-		b, err := s.tun.ReadPacket(b)
+			var p []byte
-		if err != nil {
+			if p, err = s.tun.ReadPacket(b); err == nil {
+				s.Input(p)
+			}
+		}
+	}
 	s.mu.Lock()
 	closed := s.closed
 	s.mu.Unlock()
 	if !closed {
 		errors.LogErrorInner(s.ctx, err, "[tun] failed to read a packet, no more are read")
 	}
-			return
+}
+
+// readSegments is read for a tun that does not split segments and gives them as large as a packet can be.
+// They are read into buffers for a connection to keep what is large as it is, see keep
+func (s *stack) readSegments() error {
+	s.bufs = make(buf.MultiBuffer, (1<<16)/buf.Size)
+	defer buf.ReleaseMulti(s.bufs)
+	parts := make([][]byte, len(s.bufs))
+	var r room
+	for {
+		for i, b := range s.bufs {
+			if b == nil {
+				s.bufs[i] = buf.New()
+				_, _ = s.bufs[i].ReadFrom(&r)
+				parts[i] = r.b
 			}
-		s.Input(b)
 		}
+		n, err := s.segmenter.ReadParts(parts)
+		if err != nil {
+			return err
+		}
+		s.input(parts[0][:min(n, buf.Size)], max(n-buf.Size, 0))
+	}
+}
+
+// room takes what it is given to read into as read: that is the room of a Buffer as it is, not cleared
+type room struct{ b []byte }
+
+func (r *room) Read(b []byte) (int, error) {
+	r.b = b
+	return len(b), nil
 }
 
 // Input implements Stack. Several tunnels may hand over their packets at once
 func (s *stack) Input(b []byte) {
-	p, ok := parsePacket(b)
+	s.input(b, 0)
+}
+
+// input takes a packet that is b and rest bytes after it, in the bufs that follow the one that b is in
+func (s *stack) input(b []byte, rest int) {
+	p, ok := parsePacket(b, rest)
 	if !ok || p.src.Is4In6() || p.dst.Is4In6() || p.src.IsLoopback() || p.dst.IsLoopback() || p.dst.IsUnspecified() || p.src.IsMulticast() {
 		// nothing comes from many at once, and an address that stands for this machine itself is not one
 		// that the other side of a tun can ask for. Nor is an IPv6 address that stands for an IPv4 one, which
@@ -180,6 +224,10 @@ func (s *stack) Input(b []byte) {
 	}
 	// what was put together may be of two packets with one number, its checksum tells
 	verify := s.verify || p.fragment
+	if p.rest != 0 && (verify || p.proto != protoTCP) {
+		// only a segment of TCP that is not looked at can stay in pieces
+		p.payload, p.rest = s.whole(p.payload, p.rest), 0
+	}
 	if p.fragment {
 		p, ok = s.fragments.add(p)
 	}
@@ -196,6 +244,37 @@ func (s *stack) Input(b []byte) {
 	}
 }
 
+// whole returns in one piece what is b and rest bytes after it, in the bufs that follow the one that b is in
+func (s *stack) whole(b []byte, rest int) []byte {
+	if rest == 0 {
+		return b
+	}
+	s.joined = append(s.joined[:0], b...)
+	for i := 1; rest > 0; i++ {
+		n := min(rest, buf.Size)
+		s.joined = append(s.joined, s.bufs[i].BytesTo(int32(n))...)
+		rest -= n
+	}
+	return s.joined
+}
+
+// keep adds to mb what is b and rest bytes after it, in the bufs that follow the one that b is in: nothing is copied,
+// the buffers are taken for it and no longer read into
+func (s *stack) keep(mb buf.MultiBuffer, b []byte, rest int) buf.MultiBuffer {
+	// b ends where what was read into the first one does, or before it
+	first := s.bufs[0]
+	from := first.Cap() - int32(cap(b))
+	first.Resize(from, from+int32(len(b)))
+	mb, s.bufs[0] = append(mb, first), nil
+	for i := 1; rest > 0; i++ {
+		n := min(rest, buf.Size)
+		s.bufs[i].Resize(0, int32(n))
+		mb, s.bufs[i] = append(mb, s.bufs[i]), nil
+		rest -= n
+	}
+	return mb
+}
+
 // local returns the address that packets to remote are sent from
 func (s *stack) local(remote netip.Addr) (netip.Addr, error) {
 	for _, a := range s.addresses {
@@ -237,6 +316,7 @@ func (s *stack) handleTCP(p packet) {
 		window:  binary.BigEndian.Uint16(t[14:]),
 		options: t[tcpHeaderSize:size],
 		payload: t[size:],
+		rest:    p.rest,
 	}
 
 	s.mu.Lock()
@@ -283,7 +363,7 @@ func (s *stack) refuse(f flow, seg segment) {
 		binary.BigEndian.PutUint32(t[4:], seg.ack)
 		t[13] = tcpRst
 	} else {
-		ack := seg.seq + uint32(len(seg.payload))
+		ack := seg.seq + uint32(len(seg.payload)+seg.rest)
 		if seg.flags&(tcpSyn|tcpFin) != 0 {
 			ack++
 		}

proxy/tun/stack_test.go

@@ -65,6 +65,20 @@ func (l *link) Segments() bool {
 	return l.segments
 }
 
+// ReadParts implements segmenter
+func (l *link) ReadParts(parts [][]byte) (int, error) {
+	select {
+	case packet := <-l.in:
+		n := 0
+		for _, p := range parts {
+			n += copy(p, packet[n:])
+		}
+		return n, nil
+	case <-l.done:
+		return 0, io.EOF
+	}
+}
+
 // WriteSegment implements segmenter as the system does when it sends a segment on: a packet for every mss bytes
 func (l *link) WriteSegment(header []byte, payload [][]byte, mss int) error {
 	data := bytes.Join(payload, nil)
@@ -206,7 +220,7 @@ func (p *peer) receive() segment {
 func (p *peer) dialed() (segment, []byte) {
 	p.t.Helper()
 	b := p.packet()
-	packet, ok := parsePacket(b)
+	packet, ok := parsePacket(b, 0)
 	if !ok || packet.proto != protoTCP || len(packet.payload) < tcpHeaderSize {
 		p.t.Fatal("not a segment: ", b)
 	}
@@ -223,7 +237,7 @@ func (p *peer) segment(b []byte) segment {
 	} else if checksum(sum(b[:size], 0)) != 0 {
 		p.t.Fatal("wrong checksum of the ip header")
 	}
-	packet, ok := parsePacket(b)
+	packet, ok := parsePacket(b, 0)
 	if !ok || packet.proto != protoTCP || packet.src != p.dst.Addr() || packet.dst != p.src.Addr() {
 		p.t.Fatal("not a segment of the connection: ", b)
 	}
@@ -464,19 +478,78 @@ func TestTCPOutOfOrder(t *testing.T) {
 	read(t, a.conn, "jklmno")
 }
 
-// A segment is as large as the system makes it when the tun does not split what it reads.
+// A segment is as large as the system makes it when the tun does not split what it reads, and one that is large,
+// the next and all taken stays in the buffers that such a tun reads it into.
 func TestTCPLargeSegment(t *testing.T) {
+	for _, segments := range []bool{false, true} {
 		conns := make(chan accepted, 1)
 		p, l := newPeer(t, "10.0.0.1:1234", "10.0.0.2:80")
-	newTestStack(t, l, accept(conns))
+		l.segments = segments
+		s := newTestStack(t, l, accept(conns))
+		sent := make([]byte, 200000)
+		rand.Read(sent)
+		// one of no connection is refused as a whole
+		p.send(p.seq, tcpPsh, nil, sent[:20000])
+		if r := p.receive(); r.flags != tcpRst|tcpAck || r.ack != p.seq+20000 {
+			t.Fatal("segments: ", segments, ", not refused: flags ", r.flags, ", ack ", r.ack-p.seq, " after its seq")
+		}
 		p.connect(nil)
 		a := take(t, conns)
 
-	sent := make([]byte, 60000)
+		// one that waits for the one before it, that one, one with a part that came already, small ones around
-	rand.Read(sent)
+		// one that fits a buffer, and the rest
-	p.send(p.seq, tcpAck|tcpPsh, nil, sent)
+		for _, part := range [][2]int{{60000, 90000}, {0, 60000}, {80000, 110000}, {110000, 110100}, {110100, 115100}, {115100, 118100}, {118100, 170000}, {170000, 200000}} {
+			p.send(p.seq+uint32(part[0]), tcpAck|tcpPsh, nil, sent[part[0]:part[1]])
+		}
+		// all of it is taken before anything is read, for the buffers to be as the stack put it in them
+		for r := p.receive(); r.ack != p.seq+uint32(len(sent)); r = p.receive() {
+		}
 		var received []byte
 		for len(received) < len(sent) {
+			mb, err := a.conn.(buf.Reader).ReadMultiBuffer()
+			if err != nil {
+				t.Fatal(err)
+			}
+			// a buffer that was read into starts with the headers, one that was copied to is full
+			if kept := mb[0].Len() == buf.Size-ipv4HeaderSize-tcpHeaderSize; len(received) == 0 && kept != segments {
+				t.Fatal("segments: ", segments, ", the first buffer has ", mb[0].Len(), " bytes")
+			}
+			for _, b := range mb {
+				// and a small one is copied to where the one before it ends
+				if b.Len() < 1000 {
+					t.Fatal("segments: ", segments, ", a buffer of ", b.Len(), " bytes")
+				}
+				received = append(received, b.Bytes()...)
+			}
+			buf.ReleaseMulti(mb)
+		}
+		if !bytes.Equal(received, sent) {
+			t.Fatal("segments: ", segments, ", read something else than what was sent")
+		}
+
+		// no more is taken than the window while nobody reads, of the last one a part,
+		// and what is taken is acknowledged when a quarter of the window is
+		p.seq += uint32(len(sent))
+		sent = make([]byte, (int(s.window)/50000+1)*50000)
+		rand.Read(sent)
+		for i := 0; i < len(sent); i += 50000 {
+			p.send(p.seq+uint32(i), tcpAck|tcpPsh, nil, sent[i:i+50000])
+		}
+		for acked := p.seq; ; {
+			r := p.receive()
+			if taken := int32(r.ack - p.seq); taken > s.window {
+				t.Fatal("segments: ", segments, ", ", taken, " bytes taken with a window of ", s.window)
+			} else if taken == s.window {
+				break
+			}
+			// one that acknowledges nothing more tells that the window opened for what was read before
+			if r.ack != acked && int32(r.ack-acked) < s.window/4 {
+				t.Fatal("segments: ", segments, ", ", r.ack-acked, " bytes acknowledged with a window of ", s.window)
+			}
+			acked = r.ack
+		}
+		received = received[:0]
+		for len(received) < int(s.window) {
 			mb, err := a.conn.(buf.Reader).ReadMultiBuffer()
 			if err != nil {
 				t.Fatal(err)
@@ -486,8 +559,9 @@ func TestTCPLargeSegment(t *testing.T) {
 			}
 			buf.ReleaseMulti(mb)
 		}
-	if !bytes.Equal(received, sent) {
+		if !bytes.Equal(received, sent[:s.window]) {
-		t.Fatal("read something else than what was sent")
+			t.Fatal("segments: ", segments, ", read something else than what the window took")
+		}
 	}
 }
 
@@ -1082,13 +1156,20 @@ func TestTCPSynAfterClose(t *testing.T) {
 }
 
 // A UDP packet starts a connection, which answers from any address, and an echo request is answered.
+// Both can be larger than a buffer of a tun that reads into more than one.
 func TestUDPAndICMP(t *testing.T) {
-	for _, test := range []struct{ src, dst, other string }{
+	large := make([]byte, 20000)
-		{"10.0.0.1:1234", "10.0.0.2:53", "10.0.0.3:5353"},
+	rand.Read(large)
-		{"[fd00::1]:1234", "[fd00::2]:53", "[fd00::3]:5353"},
+	for _, test := range []struct {
+		src, dst, other string
+		segments        bool
+	}{
+		{"10.0.0.1:1234", "10.0.0.2:53", "10.0.0.3:5353", false},
+		{"[fd00::1]:1234", "[fd00::2]:53", "[fd00::3]:5353", true},
 	} {
 		conns := make(chan accepted, 1)
 		p, l := newPeer(t, test.src, test.dst)
+		l.segments = test.segments
 		newTestStack(t, l, accept(conns))
 
 		var b [ipv6HeaderSize + udpHeaderSize]byte
@@ -1105,6 +1186,13 @@ func TestUDPAndICMP(t *testing.T) {
 			t.Fatal("read ", mb.String(), " from ", a.conn.RemoteAddr(), " to ", a.dest, ", error: ", err)
 		}
 		buf.ReleaseMulti(mb)
+		binary.BigEndian.PutUint16(u[4:], uint16(udpHeaderSize+len(large)))
+		setIPLength(b[:n], n+udpHeaderSize+len(large))
+		l.in <- append(b[:n+udpHeaderSize:n+udpHeaderSize], large...)
+		if mb, err = a.conn.(buf.Reader).ReadMultiBuffer(); err != nil || len(mb) != 1 || !bytes.Equal(mb[0].Bytes(), large) {
+			t.Fatal("read ", mb.Len(), " bytes of a large packet, error: ", err)
+		}
+		buf.ReleaseMulti(mb)
 
 		for _, from := range []string{test.dst, test.other} {
 			answer := buf.FromBytes([]byte("defg"))
@@ -1114,7 +1202,7 @@ func TestUDPAndICMP(t *testing.T) {
 				t.Fatal(err)
 			}
 			raw := p.packet()
-			packet, ok := parsePacket(raw)
+			packet, ok := parsePacket(raw, 0)
 			u := packet.payload
 			// the system may have to split it on the way to where it goes
 			if !ok || raw[0]>>4 == 4 && raw[6] != 0 || packet.proto != protoUDP || netip.AddrPortFrom(packet.src, binary.BigEndian.Uint16(u)).String() != from ||
@@ -1133,12 +1221,12 @@ func TestUDPAndICMP(t *testing.T) {
 			proto, request, reply = protoICMPv6, 128, 129
 		}
 		n = putIPHeader(b[:], proto, p.src.Addr(), p.dst.Addr())
-		setIPLength(b[:n], n+12)
+		setIPLength(b[:n], n+8+len(large))
-		l.in <- append(b[:n:n], request, 0, 0, 0, 1, 2, 3, 4, 'a', 'b', 'c', 'd')
+		l.in <- append(append(b[:n:n], request, 0, 0, 0, 1, 2, 3, 4), large...)
-		packet, ok := parsePacket(p.packet())
+		packet, ok := parsePacket(p.joined(), 0)
 		m := packet.payload
-		if !ok || packet.proto != proto || packet.src != p.dst.Addr() || packet.dst != p.src.Addr() || m[0] != reply || string(m[4:]) != "\x01\x02\x03\x04abcd" {
+		if !ok || packet.proto != proto || packet.src != p.dst.Addr() || packet.dst != p.src.Addr() || m[0] != reply || string(m[4:8]) != "\x01\x02\x03\x04" || !bytes.Equal(m[8:], large) {
-			t.Fatal("wrong echo reply: ", packet)
+			t.Fatal("wrong echo reply of ", len(m), " bytes from ", packet.src, " to ", packet.dst)
 		}
 		var ip [ipv6HeaderSize]byte
 		size := putIPHeader(ip[:], proto, packet.src, packet.dst)
@@ -1373,7 +1461,7 @@ func TestUDPDial(t *testing.T) {
 				t.Fatal("wrong header of the packet to ", to, ": ", raw[:ipv4HeaderSize])
 			}
 			numbers[to][binary.BigEndian.Uint16(raw[4:])] = true
-			packet, ok := parsePacket(raw)
+			packet, ok := parsePacket(raw, 0)
 			u := packet.payload
 			if !ok || packet.proto != protoUDP || netip.AddrPortFrom(packet.src, binary.BigEndian.Uint16(u)) != local ||
 				netip.AddrPortFrom(packet.dst, binary.BigEndian.Uint16(u[2:])) != to || string(u[udpHeaderSize:]) != "abc" {
@@ -1395,7 +1483,7 @@ func TestUDPDial(t *testing.T) {
 		if _, err := conn.WriteTo([]byte("abc"), &net.UDPAddr{IP: across.Addr().AsSlice(), Port: int(across.Port())}); err != nil {
 			t.Fatal(err)
 		}
-		if packet, ok := parsePacket(p.packet()); !ok || packet.proto != protoUDP || packet.dst != across.Addr() ||
+		if packet, ok := parsePacket(p.packet(), 0); !ok || packet.proto != protoUDP || packet.dst != across.Addr() ||
 			netip.AddrPortFrom(packet.src, binary.BigEndian.Uint16(packet.payload)) != acrossLocal {
 			t.Fatal("wrong packet to ", across, ": ", packet)
 		}
@@ -1407,7 +1495,7 @@ func TestUDPDial(t *testing.T) {
 		// a stack that takes no connections is one host: it answers a ping of its address and of no other
 		l.in <- ping(p.src.Addr(), netip.MustParseAddrPort(test.other).Addr())
 		l.in <- ping(p.src.Addr(), local.Addr())
-		if packet, ok := parsePacket(p.packet()); !ok || packet.src != local.Addr() || packet.dst != p.src.Addr() || packet.payload[0]&^129 != 0 {
+		if packet, ok := parsePacket(p.packet(), 0); !ok || packet.src != local.Addr() || packet.dst != p.src.Addr() || packet.payload[0]&^129 != 0 {
 			t.Fatal("wrong echo reply: ", packet)
 		}
 		p.silent(20 * time.Millisecond)
@@ -1873,7 +1961,7 @@ func TestFragments(t *testing.T) {
 		if err := a.conn.(buf.Writer).WriteMultiBuffer(buf.MultiBuffer{buf.FromBytes(sent)}); err != nil {
 			t.Fatal(err)
 		}
-		packet, ok := parsePacket(p.joined())
+		packet, ok := parsePacket(p.joined(), 0)
 		u := packet.payload
 		if !ok || packet.fragment || packet.proto != protoUDP || netip.AddrPortFrom(packet.src, binary.BigEndian.Uint16(u)) != p.dst ||
 			netip.AddrPortFrom(packet.dst, binary.BigEndian.Uint16(u[2:])) != p.src || int(binary.BigEndian.Uint16(u[4:])) != len(u) || !bytes.Equal(u[udpHeaderSize:], sent) {
@@ -1898,7 +1986,7 @@ func TestFragments(t *testing.T) {
 		mixed := split(summed(udpPacket(p.src, p.dst, bytes.Repeat([]byte{1}, 2000))), 1024, 11)
 		l.in <- mixed[0]
 		l.in <- split(summed(udpPacket(p.src, p.dst, bytes.Repeat([]byte{2}, 2000))), 1024, 11)[1]
-		packet, ok = parsePacket(p.joined())
+		packet, ok = parsePacket(p.joined(), 0)
 		m = packet.payload
 		if !ok || packet.proto != proto || packet.src != p.dst.Addr() || packet.dst != p.src.Addr() || m[0] != reply || !bytes.Equal(m[8:], sent) {
 			t.Fatal("wrong echo reply: ", packet.src, packet.dst, packet.proto, len(m))
@@ -2040,7 +2128,7 @@ func TestChecksumsAndLoopback(t *testing.T) {
 		l.in <- damaged(echo)
 		p.silent(50 * time.Millisecond)
 		l.in <- echo
-		if packet, ok := parsePacket(p.packet()); !ok || packet.proto != proto || string(packet.payload[4:]) != "\x01\x02\x03\x04abcd" {
+		if packet, ok := parsePacket(p.packet(), 0); !ok || packet.proto != proto || string(packet.payload[4:]) != "\x01\x02\x03\x04abcd" {
 			t.Fatal("wrong echo reply: ", packet)
 		}
 

proxy/tun/tcp_lightweight.go

@@ -49,6 +49,9 @@ const (
 	// tcpParts of how many parts of what was written it is made at most
 	tcpSegment = math.MaxUint16 - ipv6HeaderSize - tcpHeaderSize
 	tcpParts   = 7
+	// tcpKept is how large a payload is at least for the buffers that it was read into to be kept. A smaller one
+	// is copied to where the one before it ends, for a reader to get buffers that are full
+	tcpKept = buf.Size / 2
 
 	// tcpTick is how often a connection that waits for something looks at what it waits for
 	tcpTick = 100 * time.Millisecond
@@ -87,7 +90,9 @@ type segment struct {
 	flags    byte
 	window   uint16
 	options  []byte
+	// payload is without its last rest bytes when those are in other buffers of the stack, see stack.whole
 	payload []byte
+	rest    int
 }
 
 // nextOption returns the first option of o and what follows it, kind is zero when there is none
@@ -749,6 +754,12 @@ func (c *tcpConn) space() uint32 {
 
 // receive takes the payload of a segment. c.mu is held
 func (c *tcpConn) receive(s segment) {
+	// what is large, the next and all taken stays in the buffers that it was read into
+	size := len(s.payload) + s.rest
+	keep := c.stack.bufs != nil && size >= tcpKept && s.seq == c.rcvNxt && size <= int(c.window-c.rcvLen)
+	if !keep {
+		s.payload = c.stack.whole(s.payload, s.rest)
+	}
 	seq, payload, fin := s.seq, s.payload, s.flags&tcpFin != 0
 	if len(payload) == 0 && !fin {
 		if int32(c.rcvNxt-seq) > 0 {
@@ -789,9 +800,14 @@ func (c *tcpConn) receive(s segment) {
 		return
 	}
 
+	if keep {
+		c.rcvQueue = c.stack.keep(c.rcvQueue, payload, s.rest)
+	} else {
+		size = len(payload)
 		c.rcvQueue = buf.MergeBytes(c.rcvQueue, payload)
-	c.rcvLen += int32(len(payload))
+	}
-	c.rcvNxt += uint32(len(payload))
+	c.rcvLen += int32(size)
+	c.rcvNxt += uint32(size)
 	for !fin && len(c.rcvHeld) > 0 && int32(c.rcvNxt-c.rcvHeld[0].seq) >= 0 {
 		h := c.rcvHeld[0]
 		if before := int32(c.rcvNxt - h.seq); before < h.data.Len() {
@@ -809,7 +825,7 @@ func (c *tcpConn) receive(s segment) {
 	c.readable.Signal()
 	// the reader acknowledges what it takes, with one segment for all that came by then.
 	// It is not waited for when it does not read for long
-	if fin || now || c.rcvNxt-c.rcvAcked >= tcpWindow/4 {
+	if fin || now || c.rcvNxt-c.rcvAcked >= uint32(c.window/4) {
 		c.sendAck()
 	} else {
 		c.arm(tcpTick)

proxy/tun/tun.go

@@ -16,10 +16,13 @@ type Tun interface {
 }
 
 // segmenter is a tun whose other side takes TCP segments that are larger than the MTU,
-// splits them only if it has to send them on, and completes their checksum then
+// splits them only if it has to send them on, and completes their checksum then.
+// What it sends comes as it is too, not split to the MTU
 type segmenter interface {
-	// Segments reports whether WriteSegment can be used
+	// Segments reports whether ReadParts and WriteSegment can be used
 	Segments() bool
+	// ReadParts waits for a packet, reads it into parts, one after the other, and returns its size
+	ReadParts(parts [][]byte) (int, error)
 	// WriteSegment writes a packet with a TCP segment whose payload is in parts, to be sent on with mss bytes
 	// of it at most in one. Its checksum is that of the pseudo-header only, not inverted
 	WriteSegment(header []byte, payload [][]byte, mss int) error

proxy/tun/tun_darwin.go

@@ -558,19 +558,16 @@ func ioctlPtr(fd int, req uint, arg unsafe.Pointer) error {
 }
 
 func setinterface(network, address string, fd uintptr, iface *net.Interface) error {
-	var err1, err2 error
-
 	switch network {
 	case "tcp6", "udp6", "ip6":
-		err1 = unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_BOUND_IF, iface.Index)
+		// IPV6_BOUND_IF binds the IPv4 traffic of a dual-stack socket as
-		fallthrough
+		// well, and an IPv6 socket rejects IP_BOUND_IF with EINVAL.
+		return unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_BOUND_IF, iface.Index)
 	case "tcp4", "udp4", "ip4":
-		err2 = unix.SetsockoptInt(int(fd), unix.IPPROTO_IP, unix.IP_BOUND_IF, iface.Index)
+		return unix.SetsockoptInt(int(fd), unix.IPPROTO_IP, unix.IP_BOUND_IF, iface.Index)
 	default:
 		panic(network + " " + address)
 	}
-
-	return errors.Join(err1, err2)
 }
 
 func findOutboundInterface(tunIndex int, fixedName string) (*net.Interface, error) {

proxy/tun/tun_darwin_test.go

@@ -3,7 +3,10 @@
 package tun
 
 import (
+	"context"
+	"net"
 	"sync"
+	"syscall"
 	"testing"
 	"time"
 
@@ -231,3 +234,40 @@ func TestWaitKqueueReportsPersistentFailure(t *testing.T) {
 		}
 	}
 }
+
+// TestSetinterfaceSocketFamilies binds each kind of socket Xray's dialers
+// open to lo0, including the dual-stack one Go opens for UDP.
+func TestSetinterfaceSocketFamilies(t *testing.T) {
+	lo, err := net.InterfaceByName("lo0")
+	if err != nil {
+		t.Skip(err)
+	}
+	lc := net.ListenConfig{Control: func(network, address string, c syscall.RawConn) error {
+		var err error
+		if controlErr := c.Control(func(fd uintptr) {
+			err = setinterface(network, address, fd, lo)
+		}); controlErr != nil {
+			return controlErr
+		}
+		return err
+	}}
+	for _, s := range []struct{ network, address string }{
+		{"udp", "0.0.0.0:0"}, // dual-stack
+		{"udp4", "127.0.0.1:0"},
+		{"udp6", "[::1]:0"},
+		{"tcp4", "127.0.0.1:0"},
+		{"tcp6", "[::1]:0"},
+	} {
+		var closer interface{ Close() error }
+		if s.network[:3] == "udp" {
+			closer, err = lc.ListenPacket(context.Background(), s.network, s.address)
+		} else {
+			closer, err = lc.Listen(context.Background(), s.network, s.address)
+		}
+		if err != nil {
+			t.Errorf("%s %s: %v", s.network, s.address, err)
+			continue
+		}
+		closer.Close()
+	}
+}

proxy/tun/tun_fd.go

@@ -6,6 +6,8 @@ import (
 	"encoding/binary"
 	"os"
 	"sync"
+	"syscall"
+	"unsafe"
 
 	"golang.org/x/sys/unix"
 )
@@ -22,6 +24,14 @@ type fdTun struct {
 	// vnet is the size of the virtio_net_hdr in front of every packet, zero if the tun has none.
 	// With it the system does not split what it sends to the tun and takes what is not split from it
 	vnet int
+	// raw is file for ReadParts, readv what it calls when there may be a packet, iovecs where that reads to:
+	// header, which takes the virtio_net_hdr, and the parts. read and readErr are what came of it
+	raw     syscall.RawConn
+	readv   func(fd uintptr) bool
+	header  [packetRoom]byte
+	iovecs  []unix.Iovec
+	read    int
+	readErr error
 
 	writeLock sync.RWMutex
 	closed    bool
@@ -29,7 +39,25 @@ type fdTun struct {
 
 // newFdTun takes a file descriptor that does not block
 func newFdTun(fd, vnet int) *fdTun {
-	return &fdTun{fd: fd, file: os.NewFile(uintptr(fd), "/dev/net/tun"), vnet: vnet}
+	t := &fdTun{fd: fd, file: os.NewFile(uintptr(fd), "/dev/net/tun"), vnet: vnet}
+	t.raw, _ = t.file.SyscallConn()
+	t.readv = func(fd uintptr) bool {
+		for {
+			n, _, errno := unix.Syscall(unix.SYS_READV, fd, uintptr(unsafe.Pointer(&t.iovecs[0])), uintptr(len(t.iovecs)))
+			switch errno {
+			case 0:
+				t.read, t.readErr = int(n), nil
+			case unix.EINTR:
+				continue
+			case unix.EAGAIN:
+				return false
+			default:
+				t.read, t.readErr = 0, errno
+			}
+			return true
+		}
+	}
+	return t
 }
 
 func (t *fdTun) ReadPacket(b []byte) ([]byte, error) {
@@ -38,6 +66,20 @@ func (t *fdTun) ReadPacket(b []byte) ([]byte, error) {
 	return b[min(t.vnet, n):n], err
 }
 
+// ReadParts implements segmenter
+func (t *fdTun) ReadParts(parts [][]byte) (int, error) {
+	t.iovecs = append(t.iovecs[:0], unix.Iovec{Base: &t.header[0]})
+	t.iovecs[0].SetLen(t.vnet)
+	for i, p := range parts {
+		t.iovecs = append(t.iovecs, unix.Iovec{Base: &p[0]})
+		t.iovecs[i+1].SetLen(len(p))
+	}
+	if err := t.raw.Read(t.readv); err != nil {
+		return 0, err
+	}
+	return max(t.read-t.vnet, 0), t.readErr
+}
+
 func (t *fdTun) WritePacket(header, payload []byte) error {
 	// a virtio_net_hdr of zeros leaves nothing to the system
 	var vnet [packetRoom]byte

proxy/tun/tun_fd_test.go

@@ -0,0 +1,66 @@
+//go:build linux
+
+package tun
+
+import (
+	"bytes"
+	"crypto/rand"
+	"testing"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+// A tun with a virtio_net_hdr reads one packet at a time into parts, without the header, waits for the next one,
+// and stops waiting when it is closed.
+func TestReadParts(t *testing.T) {
+	// what a tun is like: one packet for every read, and a file descriptor that does not block
+	fds, err := unix.Socketpair(unix.AF_UNIX, unix.SOCK_SEQPACKET|unix.SOCK_NONBLOCK|unix.SOCK_CLOEXEC, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer unix.Close(fds[1])
+	tun := newFdTun(fds[0], vnetSize)
+	defer tun.closeFile()
+
+	large := make([]byte, 20000)
+	rand.Read(large)
+	parts := [][]byte{make([]byte, 8192), make([]byte, 8192), make([]byte, 8192)}
+	send := func(packet []byte) {
+		if _, err := unix.Write(fds[1], append(bytes.Repeat([]byte{0xee}, vnetSize), packet...)); err != nil {
+			t.Error(err)
+		}
+	}
+	send(large)
+	send([]byte("small"))
+	for _, packet := range [][]byte{large, []byte("small")} {
+		n, err := tun.ReadParts(parts)
+		if err != nil || n != len(packet) || !bytes.Equal(bytes.Join(parts, nil)[:n], packet) {
+			t.Fatal("read ", n, " bytes of ", len(packet), ", error: ", err)
+		}
+	}
+
+	go func() {
+		time.Sleep(50 * time.Millisecond)
+		send([]byte("later"))
+	}()
+	if n, err := tun.ReadParts(parts); err != nil || string(parts[0][:n]) != "later" {
+		t.Fatal("read ", parts[0][:n], " after waiting, error: ", err)
+	}
+
+	read := make(chan error)
+	go func() {
+		_, err := tun.ReadParts(parts)
+		read <- err
+	}()
+	time.Sleep(50 * time.Millisecond)
+	tun.closeFile()
+	select {
+	case err := <-read:
+		if err == nil {
+			t.Fatal("read after the tun was closed")
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("still waits after the tun was closed")
+	}
+}

proxy/tun/tun_windows.go

@@ -401,6 +401,15 @@ func resolveOnOwn() *savedResolver {
 		if internet.IsSkippedDNSServer(address) {
 			return nil, errors.New("skipped DNS server ", address)
 		}
+		// A socket of the server's IP version only needs that version bound
+		// to the interface, which a dual-stack one would need both of.
+		if ap, err := netip.ParseAddrPort(address); err == nil && (network == "udp" || network == "tcp") {
+			if ap.Addr().Unmap().Is4() {
+				network += "4"
+			} else {
+				network += "6"
+			}
+		}
 		return dialer.DialContext(ctx, network, address)
 	}
 	net.DefaultResolver.PreferGo = true
@@ -558,10 +567,22 @@ func setinterface(network, address string, fd uintptr, iface *net.Interface) err
 
 	switch network {
 	case "tcp6", "udp6", "ip6":
+		dualStack := false
+		if network == "udp6" {
+			ipv6Only, err := windows.GetsockoptInt(windows.Handle(fd), windows.IPPROTO_IPV6, windows.IPV6_V6ONLY)
+			if err != nil {
+				return internet.NewBindError(err)
+			}
+			dualStack = ipv6Only == 0
+		}
 		err1 = windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IPV6, IPV6_UNICAST_IF, iface.Index)
 		if network == "udp6" {
 			err2 = windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IPV6, windows.IPV6_MULTICAST_IF, iface.Index)
 		}
+		// Only dual-stack UDP can send to both IPv4 and IPv6 destinations.
+		if !dualStack {
+			break
+		}
 		fallthrough
 	case "tcp4", "udp4", "ip4":
 		err3 = windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IP, IP_UNICAST_IF, *(*int)(unsafe.Pointer(&index[0])))
@@ -572,7 +593,10 @@ func setinterface(network, address string, fd uintptr, iface *net.Interface) err
 		panic(network + " " + address)
 	}
 
-	return errors.Combine(err1, err2, err3, err4)
+	if err := errors.Combine(err1, err2, err3, err4); err != nil {
+		return internet.NewBindError(err)
+	}
+	return nil
 }
 
 func findOutboundInterface(tunIndex int, fixedName string) (*net.Interface, error) {

testing/scenarios/http_test.go

@@ -16,8 +16,10 @@ import (
 	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/buf"
 	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/protocol"
 	"github.com/xtls/xray-core/common/serial"
 	"github.com/xtls/xray-core/core"
+	"github.com/xtls/xray-core/proxy/dokodemo"
 	"github.com/xtls/xray-core/proxy/freedom"
 	v2http "github.com/xtls/xray-core/proxy/http"
 	v2httptest "github.com/xtls/xray-core/testing/servers/http"
@@ -377,3 +379,88 @@ func TestHttpBasicAuth(t *testing.T) {
 		}
 	}
 }
+
+// Server-first protocols (SMTP, FTP, MySQL) send nothing from the client until the server's
+// greeting arrives, so the HTTP outbound must not wait for a first payload before dialing.
+func TestHTTPOutboundServerFirst(t *testing.T) {
+	tcpServer := tcp.Server{
+		MsgProcessor: xor,
+		SendFirst:    []byte("send first"),
+	}
+	dest, err := tcpServer.Start()
+	common.Must(err)
+	defer tcpServer.Close()
+
+	serverPort := tcp.PickPort()
+	serverConfig := &core.Config{
+		Inbound: []*core.InboundHandlerConfig{
+			{
+				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
+					PortList: &net.PortList{Range: []*net.PortRange{net.SinglePortRange(serverPort)}},
+					Listen:   net.NewIPOrDomain(net.LocalHostIP),
+				}),
+				ProxySettings: serial.ToTypedMessage(&v2http.ServerConfig{}),
+			},
+		},
+		Outbound: []*core.OutboundHandlerConfig{
+			{
+				ProxySettings: serial.ToTypedMessage(&freedom.Config{
+					FinalRules: []*freedom.FinalRuleConfig{{Action: freedom.RuleAction_Allow}},
+				}),
+			},
+		},
+	}
+
+	clientPort := tcp.PickPort()
+	clientConfig := &core.Config{
+		Inbound: []*core.InboundHandlerConfig{
+			{
+				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
+					PortList: &net.PortList{Range: []*net.PortRange{net.SinglePortRange(clientPort)}},
+					Listen:   net.NewIPOrDomain(net.LocalHostIP),
+				}),
+				ProxySettings: serial.ToTypedMessage(&dokodemo.Config{
+					RewriteAddress:  net.NewIPOrDomain(dest.Address),
+					RewritePort:     uint32(dest.Port),
+					AllowedNetworks: []net.Network{net.Network_TCP},
+				}),
+			},
+		},
+		Outbound: []*core.OutboundHandlerConfig{
+			{
+				ProxySettings: serial.ToTypedMessage(&v2http.ClientConfig{
+					Server: &protocol.ServerEndpoint{
+						Address: net.NewIPOrDomain(net.LocalHostIP),
+						Port:    uint32(serverPort),
+					},
+				}),
+			},
+		},
+	}
+
+	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
+	common.Must(err)
+	defer CloseAllServers(servers)
+
+	conn, err := net.DialTCP("tcp", nil, &net.TCPAddr{
+		IP:   []byte{127, 0, 0, 1},
+		Port: int(clientPort),
+	})
+	common.Must(err)
+	defer conn.Close()
+
+	common.Must(conn.SetReadDeadline(time.Now().Add(5 * time.Second)))
+	response := make([]byte, 1024)
+	nBytes, err := conn.Read(response)
+	if err != nil {
+		t.Fatal("no server greeting through HTTP outbound: ", err)
+	}
+	if string(response[:nBytes]) != "send first" {
+		t.Fatal("unexpected first response: ", string(response[:nBytes]))
+	}
+	common.Must(conn.SetReadDeadline(time.Time{}))
+
+	if err := testTCPConn2(conn, 1024, time.Second*5)(); err != nil {
+		t.Error(err)
+	}
+}

testing/scenarios/vless_test.go

@@ -3,6 +3,8 @@ package scenarios
 import (
 	"encoding/base64"
 	"encoding/hex"
+	"fmt"
+	"io"
 	"sync"
 	"testing"
 	"time"
@@ -20,6 +22,7 @@ import (
 	"github.com/xtls/xray-core/proxy/dokodemo"
 	"github.com/xtls/xray-core/proxy/freedom"
 	"github.com/xtls/xray-core/proxy/vless"
+	"github.com/xtls/xray-core/proxy/vless/encoding"
 	"github.com/xtls/xray-core/proxy/vless/inbound"
 	"github.com/xtls/xray-core/proxy/vless/outbound"
 	"github.com/xtls/xray-core/testing/servers/tcp"
@@ -657,3 +660,82 @@ func TestVlessRealityFingerprints(t *testing.T) {
 	}
 	wg.Wait()
 }
+
+// A blocked connection must be closed after blockDelay even while the client keeps it open and sends nothing.
+func TestVlessBlockDelay(t *testing.T) {
+	tcpServer := tcp.Server{
+		MsgProcessor: xor,
+	}
+	dest, err := tcpServer.Start()
+	common.Must(err)
+	defer tcpServer.Close()
+
+	for _, delay := range []uint64{0, 1} {
+		t.Run(fmt.Sprint("blockDelay=", delay), func(t *testing.T) {
+			userID := protocol.NewID(uuid.New())
+			serverPort := tcp.PickPort()
+			serverConfig := &core.Config{
+				Inbound: []*core.InboundHandlerConfig{
+					{
+						ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
+							PortList: &net.PortList{Range: []*net.PortRange{net.SinglePortRange(serverPort)}},
+							Listen:   net.NewIPOrDomain(net.LocalHostIP),
+						}),
+						ProxySettings: serial.ToTypedMessage(&inbound.Config{
+							Users: []*protocol.User{
+								{
+									Account: serial.ToTypedMessage(&vless.Account{
+										Id: userID.String(),
+									}),
+								},
+							},
+						}),
+					},
+				},
+				Outbound: []*core.OutboundHandlerConfig{
+					{
+						ProxySettings: serial.ToTypedMessage(&freedom.Config{
+							FinalRules: []*freedom.FinalRuleConfig{
+								{
+									Action:     freedom.RuleAction_Block,
+									BlockDelay: &freedom.Range{Min: delay, Max: delay},
+								},
+							},
+						}),
+					},
+				},
+			}
+
+			servers, err := InitializeServerConfigs(serverConfig)
+			common.Must(err)
+			defer CloseAllServers(servers)
+
+			conn, err := net.DialTCP("tcp", nil, &net.TCPAddr{
+				IP:   []byte{127, 0, 0, 1},
+				Port: int(serverPort),
+			})
+			common.Must(err)
+			defer conn.Close()
+
+			start := time.Now()
+			common.Must(encoding.EncodeRequestHeader(conn, &protocol.RequestHeader{
+				Version: encoding.Version,
+				User:    &protocol.MemoryUser{Account: &vless.MemoryAccount{ID: userID}},
+				Command: protocol.RequestCommandTCP,
+				Address: dest.Address,
+				Port:    dest.Port,
+			}, &encoding.Addons{}))
+
+			blockDelay := time.Duration(delay) * time.Second
+			common.Must(conn.SetReadDeadline(time.Now().Add(blockDelay + 5*time.Second)))
+			_, err = io.Copy(io.Discard, conn)
+			elapsed := time.Since(start)
+			if err, ok := err.(net.Error); ok && err.Timeout() {
+				t.Fatalf("connection is still open after %v", elapsed)
+			}
+			if elapsed < blockDelay {
+				t.Fatalf("connection is closed after %v, before blockDelay", elapsed)
+			}
+		})
+	}
+}

transport/internet/finalmask/filter/config.go

@@ -0,0 +1,63 @@
+package filter
+
+import (
+	"github.com/xtls/xray-core/common/geodata"
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
+)
+
+func (c *Config) buildFilter() (*filter, error) {
+	if len(c.BlockedSourceIps) == 0 && len(c.AllowedSourceIps) == 0 {
+		return nil, nil
+	}
+	f := new(filter)
+	var err error
+	if len(c.BlockedSourceIps) > 0 {
+		f.blocked, err = geodata.IPReg.BuildIPMatcher(c.BlockedSourceIps)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if len(c.AllowedSourceIps) > 0 {
+		f.allowed, err = geodata.IPReg.BuildIPMatcher(c.AllowedSourceIps)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return f, nil
+}
+
+func (c *Config) Listen(inner net.Listener) (net.Listener, error) {
+	f, err := c.buildFilter()
+	if err != nil {
+		return nil, err
+	}
+	if f == nil {
+		return inner, nil
+	}
+	return &listener{Listener: inner, filter: f}, nil
+}
+
+func (c *Config) WrapConnClient(conn net.Conn, dest *net.Destination, dialer *finalmask.Dialer) (net.Conn, error) {
+	return conn, nil
+}
+
+func (c *Config) WrapConnServer(conn net.Conn) (net.Conn, error) {
+	// TCP filtering is installed by Listen, before per-connection masks.
+	return conn, nil
+}
+
+func (c *Config) WrapPacketConnClient(conn net.PacketConn, dest *net.Destination, dialer *finalmask.Dialer) (net.PacketConn, error) {
+	return conn, nil
+}
+
+func (c *Config) WrapPacketConnServer(conn net.PacketConn, addr net.Addr, lc *finalmask.ListenConfig) (net.PacketConn, error) {
+	f, err := c.buildFilter()
+	if err != nil {
+		return nil, err
+	}
+	if f == nil {
+		return conn, nil
+	}
+	return &packetConn{PacketConn: conn, filter: f}, nil
+}

transport/internet/finalmask/filter/config.pb.go

@@ -0,0 +1,136 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.36.11
+// 	protoc        v6.33.5
+// source: transport/internet/finalmask/filter/config.proto
+
+package filter
+
+import (
+	geodata "github.com/xtls/xray-core/common/geodata"
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
+	reflect "reflect"
+	sync "sync"
+	unsafe "unsafe"
+)
+
+const (
+	// Verify that this generated code is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
+	// Verify that runtime/protoimpl is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
+)
+
+type Config struct {
+	state            protoimpl.MessageState `protogen:"open.v1"`
+	BlockedSourceIps []*geodata.IPRule      `protobuf:"bytes,1,rep,name=blocked_source_ips,json=blockedSourceIps,proto3" json:"blocked_source_ips,omitempty"`
+	AllowedSourceIps []*geodata.IPRule      `protobuf:"bytes,2,rep,name=allowed_source_ips,json=allowedSourceIps,proto3" json:"allowed_source_ips,omitempty"`
+	unknownFields    protoimpl.UnknownFields
+	sizeCache        protoimpl.SizeCache
+}
+
+func (x *Config) Reset() {
+	*x = Config{}
+	mi := &file_transport_internet_finalmask_filter_config_proto_msgTypes[0]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *Config) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*Config) ProtoMessage() {}
+
+func (x *Config) ProtoReflect() protoreflect.Message {
+	mi := &file_transport_internet_finalmask_filter_config_proto_msgTypes[0]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use Config.ProtoReflect.Descriptor instead.
+func (*Config) Descriptor() ([]byte, []int) {
+	return file_transport_internet_finalmask_filter_config_proto_rawDescGZIP(), []int{0}
+}
+
+func (x *Config) GetBlockedSourceIps() []*geodata.IPRule {
+	if x != nil {
+		return x.BlockedSourceIps
+	}
+	return nil
+}
+
+func (x *Config) GetAllowedSourceIps() []*geodata.IPRule {
+	if x != nil {
+		return x.AllowedSourceIps
+	}
+	return nil
+}
+
+var File_transport_internet_finalmask_filter_config_proto protoreflect.FileDescriptor
+
+const file_transport_internet_finalmask_filter_config_proto_rawDesc = "" +
+	"\n" +
+	"0transport/internet/finalmask/filter/config.proto\x12(xray.transport.internet.finalmask.filter\x1a\x1bcommon/geodata/geodat.proto\"\x9e\x01\n" +
+	"\x06Config\x12I\n" +
+	"\x12blocked_source_ips\x18\x01 \x03(\v2\x1b.xray.common.geodata.IPRuleR\x10blockedSourceIps\x12I\n" +
+	"\x12allowed_source_ips\x18\x02 \x03(\v2\x1b.xray.common.geodata.IPRuleR\x10allowedSourceIpsB\x9a\x01\n" +
+	",com.xray.transport.internet.finalmask.filterP\x01Z=github.com/xtls/xray-core/transport/internet/finalmask/filter\xaa\x02(Xray.Transport.Internet.Finalmask.Filterb\x06proto3"
+
+var (
+	file_transport_internet_finalmask_filter_config_proto_rawDescOnce sync.Once
+	file_transport_internet_finalmask_filter_config_proto_rawDescData []byte
+)
+
+func file_transport_internet_finalmask_filter_config_proto_rawDescGZIP() []byte {
+	file_transport_internet_finalmask_filter_config_proto_rawDescOnce.Do(func() {
+		file_transport_internet_finalmask_filter_config_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_transport_internet_finalmask_filter_config_proto_rawDesc), len(file_transport_internet_finalmask_filter_config_proto_rawDesc)))
+	})
+	return file_transport_internet_finalmask_filter_config_proto_rawDescData
+}
+
+var file_transport_internet_finalmask_filter_config_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
+var file_transport_internet_finalmask_filter_config_proto_goTypes = []any{
+	(*Config)(nil),         // 0: xray.transport.internet.finalmask.filter.Config
+	(*geodata.IPRule)(nil), // 1: xray.common.geodata.IPRule
+}
+var file_transport_internet_finalmask_filter_config_proto_depIdxs = []int32{
+	1, // 0: xray.transport.internet.finalmask.filter.Config.blocked_source_ips:type_name -> xray.common.geodata.IPRule
+	1, // 1: xray.transport.internet.finalmask.filter.Config.allowed_source_ips:type_name -> xray.common.geodata.IPRule
+	2, // [2:2] is the sub-list for method output_type
+	2, // [2:2] is the sub-list for method input_type
+	2, // [2:2] is the sub-list for extension type_name
+	2, // [2:2] is the sub-list for extension extendee
+	0, // [0:2] is the sub-list for field type_name
+}
+
+func init() { file_transport_internet_finalmask_filter_config_proto_init() }
+func file_transport_internet_finalmask_filter_config_proto_init() {
+	if File_transport_internet_finalmask_filter_config_proto != nil {
+		return
+	}
+	type x struct{}
+	out := protoimpl.TypeBuilder{
+		File: protoimpl.DescBuilder{
+			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
+			RawDescriptor: unsafe.Slice(unsafe.StringData(file_transport_internet_finalmask_filter_config_proto_rawDesc), len(file_transport_internet_finalmask_filter_config_proto_rawDesc)),
+			NumEnums:      0,
+			NumMessages:   1,
+			NumExtensions: 0,
+			NumServices:   0,
+		},
+		GoTypes:           file_transport_internet_finalmask_filter_config_proto_goTypes,
+		DependencyIndexes: file_transport_internet_finalmask_filter_config_proto_depIdxs,
+		MessageInfos:      file_transport_internet_finalmask_filter_config_proto_msgTypes,
+	}.Build()
+	File_transport_internet_finalmask_filter_config_proto = out.File
+	file_transport_internet_finalmask_filter_config_proto_goTypes = nil
+	file_transport_internet_finalmask_filter_config_proto_depIdxs = nil
+}

transport/internet/finalmask/filter/config.proto

@@ -0,0 +1,14 @@
+syntax = "proto3";
+
+package xray.transport.internet.finalmask.filter;
+option csharp_namespace = "Xray.Transport.Internet.Finalmask.Filter";
+option go_package = "github.com/xtls/xray-core/transport/internet/finalmask/filter";
+option java_package = "com.xray.transport.internet.finalmask.filter";
+option java_multiple_files = true;
+
+import "common/geodata/geodat.proto";
+
+message Config {
+  repeated xray.common.geodata.IPRule blocked_source_ips = 1;
+  repeated xray.common.geodata.IPRule allowed_source_ips = 2;
+}

transport/internet/finalmask/filter/filter.go

@@ -0,0 +1,69 @@
+package filter
+
+import (
+	"github.com/xtls/xray-core/common/geodata"
+	"github.com/xtls/xray-core/common/net"
+)
+
+type listener struct {
+	net.Listener
+	filter *filter
+}
+
+// Accept filters connections after the TCP handshake and before higher-level processing.
+func (l *listener) Accept() (net.Conn, error) {
+	for {
+		conn, err := l.Listener.Accept()
+		if err != nil {
+			return nil, err
+		}
+		if l.filter.rejects(conn.RemoteAddr()) {
+			conn.Close()
+			continue
+		}
+		return conn, nil
+	}
+}
+
+type packetConn struct {
+	net.PacketConn
+	filter *filter
+}
+
+func (c *packetConn) ReadFrom(p []byte) (int, net.Addr, error) {
+	for {
+		n, addr, err := c.PacketConn.ReadFrom(p)
+		// Reads may return both data and an error; filter the data first.
+		if c.filter.rejects(addr) {
+			if err != nil {
+				return 0, nil, err
+			}
+			continue
+		}
+		return n, addr, err
+	}
+}
+
+type filter struct {
+	blocked geodata.IPMatcher
+	allowed geodata.IPMatcher
+}
+
+func (f *filter) rejects(addr net.Addr) bool {
+	var ip net.IP
+	switch addr := addr.(type) {
+	case *net.TCPAddr:
+		ip = addr.IP
+	case *net.UDPAddr:
+		ip = addr.IP
+	case *net.IPAddr:
+		ip = addr.IP
+	default:
+		// Unknown sources cannot satisfy an allowlist.
+		return f.allowed != nil
+	}
+	if f.blocked != nil && f.blocked.Match(ip) {
+		return true
+	}
+	return f.allowed != nil && !f.allowed.Match(ip)
+}

transport/internet/finalmask/filter/filter_test.go

@@ -0,0 +1,311 @@
+package filter
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net"
+	"testing"
+	"time"
+
+	"github.com/pires/go-proxyproto"
+	"github.com/xtls/xray-core/common/geodata"
+	xnet "github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
+)
+
+func TestTCPFilterBeforeOtherMasks(t *testing.T) {
+	for _, policy := range testPolicies(t) {
+		t.Run(policy.name, func(t *testing.T) {
+			blocked4 := sourceConn("192.0.2.1")
+			blocked6 := sourceConn("2001:db8::1")
+			unknown := &testConn{addr: &net.UnixAddr{Name: "filter.sock", Net: "unix"}}
+			missing := new(testConn)
+			allowed := sourceConn("198.51.100.1")
+			allowed6 := sourceConn("2001:db8:1::1")
+			raw := &testListener{conns: []net.Conn{blocked4, blocked6, unknown, missing, allowed, allowed6}}
+			spy := new(recordMask)
+			fm := finalmask.NewFinalMask([]finalmask.TCPMask{spy, policy.config}, nil, nil,
+				func(context.Context, net.Addr) (net.Listener, error) { return raw, nil }, nil, nil)
+			l, err := fm.Listen(context.Background(), &net.TCPAddr{})
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer l.Close()
+			whitelist := len(policy.config.AllowedSourceIps) > 0
+			want := []net.Conn{allowed, allowed6}
+			if !whitelist {
+				want = append([]net.Conn{unknown, missing}, want...)
+			}
+			for _, expected := range want {
+				if got, err := l.Accept(); err != nil || got != expected {
+					t.Fatalf("Accept() = (%v, %v), want %v", got, err, expected)
+				}
+			}
+			// Fake sockets panic on Read or Write. Rejection must not require handshake data.
+			if !blocked4.closed || !blocked6.closed || unknown.closed != whitelist || missing.closed != whitelist || allowed.closed || allowed6.closed || raw.closed {
+				t.Fatal("filter did not close only the blocked connections")
+			}
+			if len(spy.seen) != len(want) {
+				t.Fatal("blocked connections reached the next mask")
+			}
+			for i, conn := range spy.seen {
+				if conn != want[i] {
+					t.Fatal("unexpected connection reached the next mask")
+				}
+			}
+			if conn, err := l.Accept(); conn != nil || !errors.Is(err, io.EOF) {
+				t.Fatalf("listener error was not propagated: (%v, %v)", conn, err)
+			}
+		})
+	}
+}
+
+func TestTCPFilterUsesProxyHeader(t *testing.T) {
+	for _, test := range []struct {
+		name, peer, reported string
+		blocked              bool
+	}{
+		{"blocked_header", "198.51.100.1", "192.0.2.1", true},
+		{"allowed_header", "192.0.2.1", "198.51.100.1", false},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			server, client := net.Pipe()
+			defer server.Close()
+			defer client.Close()
+			if err := server.SetDeadline(time.Now().Add(5 * time.Second)); err != nil {
+				t.Fatal(err)
+			}
+			peer := sourceConn(test.peer)
+			peer.Conn = server
+			conn := proxyproto.NewConn(peer)
+			next := sourceConn("198.51.100.2")
+			l, err := testConfig(t, "192.0.2.0/24").Listen(&testListener{conns: []net.Conn{conn, next}})
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer l.Close()
+			written := make(chan error, 1)
+			go func() {
+				_, err := client.Write([]byte("PROXY TCP4 " + test.reported + " 203.0.113.1 1234 443\r\n"))
+				written <- err
+			}()
+			got, err := l.Accept()
+			if err != nil {
+				t.Fatal(err)
+			}
+			if err := <-written; err != nil {
+				t.Fatal(err)
+			}
+			var want net.Conn = conn
+			if test.blocked {
+				want = next
+			}
+			if got != want || peer.closed != test.blocked {
+				t.Fatal("filter did not follow the address supplied by PROXY protocol")
+			}
+		})
+	}
+}
+
+func TestUDPFilter(t *testing.T) {
+	for _, policy := range testPolicies(t) {
+		t.Run(policy.name, func(t *testing.T) {
+			allowed := &net.UDPAddr{IP: net.ParseIP("198.51.100.1"), Port: 1234}
+			allowed6 := &net.UDPAddr{IP: net.ParseIP("2001:db8:1::1"), Port: 1234}
+			unknown := datagram{data: []byte("unknown"), addr: &net.UnixAddr{Name: "filter.sock", Net: "unixgram"}}
+			missing := datagram{data: []byte("missing address")}
+			raw := &testPacketConn{reads: []datagram{
+				{data: []byte("blocked"), addr: &net.UDPAddr{IP: net.ParseIP("192.0.2.1"), Port: 1234}},
+				{addr: &net.UDPAddr{IP: net.ParseIP("2001:db8::1"), Port: 1234}},
+				unknown,
+				missing,
+				{addr: allowed},
+				{data: []byte("allowed"), addr: allowed},
+				{data: []byte("allowed6"), addr: allowed6},
+				{data: []byte("blocked again"), addr: &net.UDPAddr{IP: net.ParseIP("192.0.2.2"), Port: 1234}},
+			}}
+			fm := finalmask.NewFinalMask(nil, []finalmask.UDPMask{policy.config}, nil, nil, nil,
+				func(context.Context, net.Addr) (net.PacketConn, error) { return raw, nil })
+			conn, err := fm.ListenPacket(context.Background(), &net.UDPAddr{})
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer conn.Close()
+			buf := make([]byte, 64)
+			if len(policy.config.AllowedSourceIps) == 0 {
+				for _, expected := range []datagram{unknown, missing} {
+					n, addr, err := conn.ReadFrom(buf)
+					if err != nil || addr != expected.addr || string(buf[:n]) != string(expected.data) {
+						t.Fatalf("unknown source was not allowed by blacklist: (%q, %v, %v)", buf[:n], addr, err)
+					}
+				}
+			}
+			if n, addr, err := conn.ReadFrom(buf); n != 0 || addr != allowed || err != nil {
+				t.Fatalf("zero-length allowed datagram was lost: (%d, %v, %v)", n, addr, err)
+			}
+			n, addr, err := conn.ReadFrom(buf)
+			if err != nil || addr != allowed || string(buf[:n]) != "allowed" {
+				t.Fatalf("ReadFrom() = (%q, %v, %v)", buf[:n], addr, err)
+			}
+			n, addr, err = conn.ReadFrom(buf)
+			if err != nil || addr != allowed6 || string(buf[:n]) != "allowed6" {
+				t.Fatalf("IPv6 ReadFrom() = (%q, %v, %v)", buf[:n], addr, err)
+			}
+			if _, _, err := conn.ReadFrom(buf); !errors.Is(err, io.EOF) {
+				t.Fatalf("underlying read error was not propagated: %v", err)
+			}
+			if raw.closed {
+				t.Fatal("dropping a packet closed the shared UDP socket")
+			}
+		})
+	}
+}
+
+func TestEmptyFilter(t *testing.T) {
+	for _, empty := range []*Config{{}, {AllowedSourceIps: []*geodata.IPRule{}}} {
+		rawListener := new(testListener)
+		rawPacket := new(testPacketConn)
+		if l, err := empty.Listen(rawListener); err != nil || l != rawListener {
+			t.Fatal("an empty TCP filter should preserve the listener")
+		}
+		if conn, err := empty.WrapPacketConnServer(rawPacket, nil, nil); err != nil || conn != rawPacket {
+			t.Fatal("an empty UDP filter should preserve the socket")
+		}
+	}
+}
+
+func TestUDPFilterReadError(t *testing.T) {
+	for _, policy := range testPolicies(t) {
+		t.Run(policy.name, func(t *testing.T) {
+			for _, test := range []struct {
+				name    string
+				source  net.Addr
+				blocked bool
+			}{
+				{"blocked", &net.UDPAddr{IP: net.ParseIP("192.0.2.1")}, true},
+				{"allowed", &net.UDPAddr{IP: net.ParseIP("198.51.100.1")}, false},
+				{"missing address", nil, len(policy.config.AllowedSourceIps) > 0},
+				{"unknown address", &net.UnixAddr{Name: "filter.sock", Net: "unixgram"}, len(policy.config.AllowedSourceIps) > 0},
+			} {
+				t.Run(test.name, func(t *testing.T) {
+					source := test.source
+					raw := &testPacketConn{reads: []datagram{{data: []byte("partial"), addr: source, err: io.ErrShortBuffer}}}
+					conn, err := policy.config.WrapPacketConnServer(raw, nil, nil)
+					if err != nil {
+						t.Fatal(err)
+					}
+					buf := make([]byte, 32)
+					n, addr, err := conn.ReadFrom(buf)
+					if !errors.Is(err, io.ErrShortBuffer) {
+						t.Fatalf("read error was not preserved: %v", err)
+					}
+					if test.blocked {
+						if n != 0 || addr != nil {
+							t.Fatal("partial data from a blocked source was returned with an error")
+						}
+					} else if n != 7 || addr != source || string(buf[:n]) != "partial" {
+						t.Fatal("partial data from an unblocked source was changed")
+					}
+				})
+			}
+		})
+	}
+}
+
+func testPolicies(t *testing.T) []struct {
+	name   string
+	config *Config
+} {
+	t.Helper()
+	blocked := testConfig(t, "192.0.2.0/24", "2001:db8::/48").BlockedSourceIps
+	allowed := testConfig(t, "198.51.100.0/24", "2001:db8:1::/48").BlockedSourceIps
+	broader := testConfig(t, "192.0.2.0/24", "198.51.100.0/24", "2001:db8::/32").BlockedSourceIps
+	return []struct {
+		name   string
+		config *Config
+	}{
+		{"blacklist", &Config{BlockedSourceIps: blocked}},
+		{"whitelist", &Config{AllowedSourceIps: allowed}},
+		{"both", &Config{BlockedSourceIps: blocked, AllowedSourceIps: broader}},
+	}
+}
+
+func testConfig(t *testing.T, entries ...string) *Config {
+	t.Helper()
+	rules, err := geodata.ParseIPRules(entries)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return &Config{BlockedSourceIps: rules}
+}
+
+type testConn struct {
+	net.Conn
+	addr   net.Addr
+	closed bool
+}
+
+func sourceConn(ip string) *testConn {
+	return &testConn{addr: &net.TCPAddr{IP: net.ParseIP(ip), Port: 1234}}
+}
+
+func (c *testConn) RemoteAddr() net.Addr { return c.addr }
+func (c *testConn) Close() error {
+	c.closed = true
+	if c.Conn != nil {
+		return c.Conn.Close()
+	}
+	return nil
+}
+
+type testListener struct {
+	net.Listener
+	conns  []net.Conn
+	closed bool
+}
+
+func (l *testListener) Accept() (net.Conn, error) {
+	if len(l.conns) == 0 {
+		return nil, io.EOF
+	}
+	conn := l.conns[0]
+	l.conns = l.conns[1:]
+	return conn, nil
+}
+
+func (l *testListener) Close() error { l.closed = true; return nil }
+
+type datagram struct {
+	data []byte
+	addr net.Addr
+	err  error
+}
+
+type testPacketConn struct {
+	net.PacketConn
+	reads  []datagram
+	closed bool
+}
+
+func (c *testPacketConn) ReadFrom(p []byte) (int, net.Addr, error) {
+	if len(c.reads) == 0 {
+		return 0, nil, io.EOF
+	}
+	packet := c.reads[0]
+	c.reads = c.reads[1:]
+	return copy(p, packet.data), packet.addr, packet.err
+}
+
+func (c *testPacketConn) Close() error { c.closed = true; return nil }
+
+type recordMask struct{ seen []net.Conn }
+
+func (m *recordMask) WrapConnClient(c net.Conn, _ *xnet.Destination, _ *finalmask.Dialer) (net.Conn, error) {
+	return c, nil
+}
+
+func (m *recordMask) WrapConnServer(c net.Conn) (net.Conn, error) {
+	m.seen = append(m.seen, c)
+	return c, nil
+}

transport/internet/sockopt_darwin.go

@@ -114,13 +114,13 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 
 		if config.TcpKeepAliveIdle > 0 || config.TcpKeepAliveInterval > 0 {
 			if config.TcpKeepAliveIdle > 0 {
-				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, unix.TCP_KEEPALIVE, int(config.TcpKeepAliveInterval)); err != nil {
+				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, unix.TCP_KEEPALIVE, int(config.TcpKeepAliveIdle)); err != nil {
-					return errors.New("failed to set TCP_KEEPINTVL", err)
+					return errors.New("failed to set TCP_KEEPALIVE", err)
 				}
 			}
 			if config.TcpKeepAliveInterval > 0 {
-				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, sysTCP_KEEPINTVL, int(config.TcpKeepAliveIdle)); err != nil {
+				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, sysTCP_KEEPINTVL, int(config.TcpKeepAliveInterval)); err != nil {
-					return errors.New("failed to set TCP_KEEPIDLE", err)
+					return errors.New("failed to set TCP_KEEPINTVL", err)
 				}
 			}
 			if err := unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1); err != nil {
@@ -204,13 +204,13 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 
 		if config.TcpKeepAliveIdle > 0 || config.TcpKeepAliveInterval > 0 {
 			if config.TcpKeepAliveIdle > 0 {
-				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, unix.TCP_KEEPALIVE, int(config.TcpKeepAliveInterval)); err != nil {
+				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, unix.TCP_KEEPALIVE, int(config.TcpKeepAliveIdle)); err != nil {
-					return errors.New("failed to set TCP_KEEPINTVL", err)
+					return errors.New("failed to set TCP_KEEPALIVE", err)
 				}
 			}
 			if config.TcpKeepAliveInterval > 0 {
-				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, sysTCP_KEEPINTVL, int(config.TcpKeepAliveIdle)); err != nil {
+				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, sysTCP_KEEPINTVL, int(config.TcpKeepAliveInterval)); err != nil {
-					return errors.New("failed to set TCP_KEEPIDLE", err)
+					return errors.New("failed to set TCP_KEEPINTVL", err)
 				}
 			}
 			if err := unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1); err != nil {

transport/internet/system_dialer.go

@@ -2,6 +2,8 @@ package internet
 
 import (
 	"context"
+	go_errors "errors"
+	"runtime"
 	"sync"
 	"syscall"
 	"time"
@@ -69,9 +71,10 @@ func (d *DefaultSystemDialer) Dial(ctx context.Context, src net.Address, dest ne
 		}
 		var lc net.ListenConfig
 		if sockopt != nil || len(Controllers) > 0 {
-			lc.Control = func(network, address string, c syscall.RawConn) error {
+			lc.Control = func(network, _ string, c syscall.RawConn) error {
+				// ListenPacket supplies a local address; dialer controllers need the destination.
 				for _, ctl := range Controllers {
-					if err := ctl(network, address, c); err != nil {
+					if err := ctl(network, destAddr.String(), c); err != nil {
 						return errors.New("failed to apply external controller").Base(err)
 					}
 				}
@@ -91,6 +94,16 @@ func (d *DefaultSystemDialer) Dial(ctx context.Context, src net.Address, dest ne
 			}
 		}
 		packetConn, err := lc.ListenPacket(ctx, srcAddr.Network(), srcAddr.String())
+		var bindErr *BindError
+		if err != nil && runtime.GOOS == "windows" && go_errors.As(err, &bindErr) {
+			// Keep dual-stack UDP when possible. If the interface cannot bind both
+			// families, retry a socket that cannot send on the unbound family.
+			network := "udp6"
+			if destAddr.IP.To4() != nil {
+				network = "udp4"
+			}
+			packetConn, err = lc.ListenPacket(ctx, network, srcAddr.String())
+		}
 		if err != nil {
 			return nil, err
 		}
@@ -197,6 +210,7 @@ func UseAlternativeSystemDialer(dialer SystemDialer) {
 
 // RegisterDialerController adds a controller to the effective system dialer.
 // The controller can be used to operate on file descriptors before they are put into use.
+// It receives the network and resolved remote address, as in net.Dialer.Control.
 // It only works when effective dialer is the default dialer.
 //
 // xray:api:beta

transport/internet/system_dialer_windows_test.go

@@ -0,0 +1,63 @@
+package internet_test
+
+import (
+	"context"
+	"errors"
+	"slices"
+	"syscall"
+	"testing"
+
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet"
+	"golang.org/x/sys/windows"
+)
+
+// TestDialUDPBindFallback checks that a UDP dial whose dual-stack socket
+// cannot be bound to both IP versions, as on an interface without one of
+// them, moves to a socket of the destination's version only, and still
+// fails when that one cannot be bound either.
+func TestDialUDPBindFallback(t *testing.T) {
+	for _, c := range []struct {
+		dest   string
+		reject []string // the kinds of socket that cannot be bound
+		tried  []string // the kinds of socket tried, in order
+		ok     bool
+	}{
+		{"127.0.0.1", nil, []string{"dual"}, true},
+		{"127.0.0.1", []string{"dual"}, []string{"dual", "udp4"}, true},
+		{"::1", []string{"dual"}, []string{"dual", "udp6"}, true},
+		{"127.0.0.1", []string{"dual", "udp4"}, []string{"dual", "udp4"}, false},
+	} {
+		var tried []string
+		internet.ControllersLock.Lock()
+		saved := internet.Controllers
+		internet.Controllers = []func(string, string, syscall.RawConn) error{func(network, _ string, rc syscall.RawConn) error {
+			kind := network
+			if network == "udp6" {
+				rc.Control(func(fd uintptr) {
+					if v6only, _ := windows.GetsockoptInt(windows.Handle(fd), windows.IPPROTO_IPV6, windows.IPV6_V6ONLY); v6only == 0 {
+						kind = "dual"
+					}
+				})
+			}
+			tried = append(tried, kind)
+			if slices.Contains(c.reject, kind) {
+				return internet.NewBindError(errors.New("cannot bind " + kind))
+			}
+			return nil
+		}}
+		internet.ControllersLock.Unlock()
+
+		conn, err := internet.DialSystem(context.Background(), net.UDPDestination(net.ParseAddress(c.dest), 53), nil)
+		if conn != nil {
+			conn.Close()
+		}
+		internet.ControllersLock.Lock()
+		internet.Controllers = saved
+		internet.ControllersLock.Unlock()
+
+		if (err == nil) != c.ok || !slices.Equal(tried, c.tried) {
+			t.Errorf("%s rejecting %v: tried %v, err %v", c.dest, c.reject, tried, err)
+		}
+	}
+}

transport/internet/websocket/connection.go

@@ -46,6 +46,12 @@ func (c *connection) Read(b []byte) (int, error) {
 	for {
 		reader, err := c.getReader()
 		if err != nil {
+			// A close frame with a normal status (1000) or no status (1005) ends
+			// the byte stream the same way a FIN does, so report io.EOF instead
+			// of an error. Other close codes keep their error semantics.
+			if websocket.IsCloseError(err, websocket.CloseNormalClosure, websocket.CloseNoStatusReceived) {
+				return 0, io.EOF
+			}
 			return 0, err
 		}
 

transport/internet/xdrive/client.go

@@ -2,14 +2,25 @@ package xdrive
 
 import (
 	"context"
+	gotls "crypto/tls"
 	"io"
 	"net/http"
+	"reflect"
+	"runtime"
+	"slices"
 	"sync"
 	"time"
 
+	"github.com/apernet/quic-go"
+	"github.com/apernet/quic-go/http3"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/net/cnc"
+	"github.com/xtls/xray-core/common/utils"
 	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/hysteria/congestion"
+	"github.com/xtls/xray-core/transport/internet/hysteria/congestion/bbr"
+	"github.com/xtls/xray-core/transport/internet/splithttp"
 	"github.com/xtls/xray-core/transport/internet/tls"
 )
 
@@ -39,6 +50,10 @@ func (t *serviceTransport) RoundTrip(r *http.Request) (*http.Response, error) {
 		cancel(nil)
 	}
 	r = r.WithContext(ctx)
+	// the headers of chrome as with XHTTP and DoH, net/http and http3 would send
+	// their own user agent after a hello of chrome
+	r.Header = r.Header.Clone()
+	utils.TryDefaultHeadersWith(r.Header, "fetch")
 	if r.Body != nil && r.Body != http.NoBody {
 		r.Body = &progressBody{ReadCloser: r.Body, alive: alive}
 	}
@@ -104,25 +119,40 @@ func (b *progressBody) Close() error {
 }
 
 // newServiceClient returns a client whose requests end after stall without
-// progress, see serviceTransport.RoundTrip
+// progress, see serviceTransport.RoundTrip, and whose connections close when
-func newServiceClient(streamSettings *internet.MemoryStreamConfig, stall time.Duration, maxConns int) *http.Client {
+// connCtx is done. Clients that share h1Hosts share which hosts answer over h1
+func newServiceClient(connCtx context.Context, h1Hosts *sync.Map, streamSettings *internet.MemoryStreamConfig, stall time.Duration, maxConns int) *http.Client {
 	var (
 		tlsConfig *tls.Config
 		sockopt   *internet.SocketConfig
 		fronting  *net.Destination
+		keepAlive = net.ChromeH2KeepAlivePeriod
+		// h3 keeps alive only when asked to, see below
+		h3KeepAlive time.Duration
 	)
 	if streamSettings != nil {
 		tlsConfig = tls.ConfigFromStreamSettings(streamSettings)
 		sockopt = streamSettings.SocketSettings
 		fronting = streamSettings.Destination
+		if config, ok := streamSettings.ProtocolSettings.(*Config); ok && config.Xmux != nil {
+			switch period := config.Xmux.HKeepAlivePeriod; {
+			case period > 0:
+				keepAlive = time.Duration(period) * time.Second
+				h3KeepAlive = keepAlive
+			case period < 0:
+				keepAlive = 0
+			}
+		}
 	}
 	if tlsConfig == nil {
 		tlsConfig = &tls.Config{}
 	}
 	fingerprint := tls.GetFingerprint(tlsConfig.Fingerprint)
 
-	dial := func(ctx context.Context, addr string) (net.Conn, net.Destination, error) {
+	// fronting takes only the address and port, the network stays that of the
-		host, err := net.ParseDestination("tcp:" + addr)
+	// dial, which is UDP for h3 though the destination is built as TCP
+	dial := func(ctx context.Context, network, addr string) (net.Conn, net.Destination, error) {
+		host, err := net.ParseDestination(network + ":" + addr)
 		if err != nil {
 			return nil, host, errors.New("bad address: ", addr).Base(err)
 		}
@@ -136,25 +166,36 @@ func newServiceClient(streamSettings *internet.MemoryStreamConfig, stall time.Du
 		}
 
 		var conn net.Conn
-		if streamSettings.FinalMask != nil {
+		switch {
-			conn, err = streamSettings.FinalMask.DialTCP(ctx, target)
+		case streamSettings.FinalMask == nil:
-		} else {
 			conn, err = internet.DialSystem(ctx, target, sockopt)
+		case target.Network == net.Network_UDP:
+			conn, err = streamSettings.FinalMask.DialUDP(ctx, target)
+		default:
+			conn, err = streamSettings.FinalMask.DialTCP(ctx, target)
 		}
 		if err != nil {
 			return nil, host, errors.New("failed to dial to dest").Base(err)
 		}
+		// h3 closes its QUIC connection instead, as the server never hears of a UDP
+		// socket that closes
+		if network == "udp" {
 			return conn, host, nil
 		}
+		// CloseIdleConnections leaves an h2 connection open while a stream just
+		// canceled has not left it yet
+		stop := context.AfterFunc(connCtx, func() { conn.Close() })
+		return &ctxConn{Conn: conn, stop: stop}, host, nil
+	}
 
 	dialPlain := func(ctx context.Context, network, addr string) (net.Conn, error) {
-		conn, _, err := dial(ctx, addr)
+		conn, _, err := dial(ctx, "tcp", addr)
 		return conn, err
 	}
 
 	// http.Transport picks h2 or h1 by the ALPN in the ConnectionState of the conn
 	dialTLS := func(ctx context.Context, network, addr string) (net.Conn, error) {
-		conn, host, err := dial(ctx, addr)
+		conn, host, err := dial(ctx, "tcp", addr)
 		if err != nil {
 			return nil, err
 		}
@@ -185,7 +226,86 @@ func newServiceClient(streamSettings *internet.MemoryStreamConfig, stall time.Du
 			MaxIdleConns:        maxConns,
 			MaxIdleConnsPerHost: maxConns,
 			MaxConnsPerHost:     connsPerHost,
-			HTTP2:               &http.HTTP2Config{SendPingTimeout: net.ChromeH2KeepAlivePeriod},
+			HTTP2:               &http.HTTP2Config{SendPingTimeout: keepAlive},
+		}
+	}
+
+	var https http.RoundTripper = &secureTransport{h2: secure(1), h1: secure(maxConns), h1Hosts: h1Hosts}
+	// no server offers h3 by ALPN over TCP, so it is used only when asked for alone
+	if slices.Equal(tlsConfig.NextProtocol, []string{"h3"}) {
+		quicParams := streamSettings.QuicParams
+		if quicParams == nil {
+			quicParams = &internet.QuicParams{BbrProfile: string(bbr.ProfileStandard)}
+		}
+		// the defaults are those of quic-go, with no keepalive unless asked for, as
+		// in DoH: http3 never closes a connection that is idle or that it dropped
+		// after an error, so only the idle timeout or the end of connCtx ends it
+		quicConfig := &quic.Config{
+			InitialStreamReceiveWindow:     quicParams.InitStreamReceiveWindow,
+			MaxStreamReceiveWindow:         quicParams.MaxStreamReceiveWindow,
+			InitialConnectionReceiveWindow: quicParams.InitConnReceiveWindow,
+			MaxConnectionReceiveWindow:     quicParams.MaxConnReceiveWindow,
+			MaxIdleTimeout:                 time.Duration(quicParams.MaxIdleTimeout) * time.Second,
+			KeepAlivePeriod:                time.Duration(quicParams.KeepAlivePeriod) * time.Second,
+			MaxIncomingStreams:             quicParams.MaxIncomingStreams,
+			DisablePathMTUDiscovery:        quicParams.DisablePathMtuDiscovery || (runtime.GOOS != "linux" && runtime.GOOS != "windows" && runtime.GOOS != "darwin"),
+			ChromeParrot:                   !quicParams.DisableChromeParrot,
+		}
+		if quicConfig.KeepAlivePeriod == 0 {
+			quicConfig.KeepAlivePeriod = h3KeepAlive
+		}
+
+		https = &http3.Transport{
+			QUICConfig: quicConfig,
+			Dial: func(ctx context.Context, addr string, _ *gotls.Config, cfg *quic.Config) (*quic.Conn, error) {
+				switch quicParams.Congestion {
+				case "", "bbr", "reno":
+				default:
+					// brutal is for Hysteria servers, not services, and a panic here, in
+					// a goroutine of http3, would end the process
+					return nil, errors.New("unsupported congestion control over h3: ", quicParams.Congestion)
+				}
+
+				conn, host, err := dial(ctx, "udp", addr)
+				if err != nil {
+					return nil, err
+				}
+				var pktConn net.PacketConn
+				var udpAddr net.Addr
+				switch c := conn.(type) {
+				case *net.PacketConnWrapper:
+					pktConn = c.PacketConn
+					udpAddr = c.RemoteAddr()
+				case *cnc.Connection:
+					pktConn = &internet.FakePacketConn{Conn: c}
+					udpAddr = &net.UDPAddr{IP: []byte{0, 0, 0, 0}}
+				default:
+					conn.Close()
+					return nil, errors.New("failed to dial to dest: unexpected ", reflect.TypeOf(c))
+				}
+
+				// built for each dial with the host as SNI, as for h2: http3 sets the
+				// SNI on a copy, which a pinned CA and the ECH lookup do not see
+				gotlsConfig := tlsConfig.GetTLSConfig(tls.WithDestination(host))
+				// it is for servers, and ChromeParrot refuses a config that has it
+				gotlsConfig.GetCertificate = nil
+				tr := &quic.Transport{Conn: pktConn, DisableGSO: quicParams.DisableGSO}
+				if !quicParams.DisableChromeParrot {
+					tr.ConnectionIDGenerator = quic.ZeroLengthConnectionIDGenerator{}
+				}
+				qconn, err := tr.Dial(ctx, udpAddr, gotlsConfig, cfg)
+				if err != nil {
+					tr.Close()
+					pktConn.Close()
+					return nil, err
+				}
+				stop := context.AfterFunc(connCtx, func() { qconn.CloseWithError(quic.ApplicationErrorCode(http3.ErrCodeNoError), "") })
+				context.AfterFunc(qconn.Context(), func() { stop(); tr.Close(); pktConn.Close() })
+				if quicParams.Congestion != "reno" {
+					congestion.UseBBR(qconn, bbr.Profile(quicParams.BbrProfile))
+				}
+				return qconn, nil
+			},
 		}
 	}
 
@@ -198,18 +318,30 @@ func newServiceClient(streamSettings *internet.MemoryStreamConfig, stall time.Du
 				MaxIdleConnsPerHost: maxConns,
 				MaxConnsPerHost:     maxConns,
 			},
-			secure: &secureTransport{h2: secure(1), h1: secure(maxConns)},
+			secure: https,
 			stall:  stall,
 		},
 	}
 }
 
+// ctxConn is a connection that connCtx no longer closes once it is closed,
+// so that one that ends on its own leaves nothing behind in connCtx
+type ctxConn struct {
+	net.Conn
+	stop func() bool
+}
+
+func (c *ctxConn) Close() error {
+	c.stop()
+	return c.Conn.Close()
+}
+
 // secureTransport keeps a host to one connection, all that h2 needs, as without
 // a limit parallel requests would each dial their own. A host that answers over
 // h1 moves to a transport with more, since h1 carries one request at a time
 type secureTransport struct {
 	h2, h1  http.RoundTripper
-	h1Hosts sync.Map
+	h1Hosts *sync.Map
 }
 
 func (t *secureTransport) RoundTrip(r *http.Request) (*http.Response, error) {
@@ -222,3 +354,129 @@ func (t *secureTransport) RoundTrip(r *http.Request) (*http.Response, error) {
 	}
 	return resp, err
 }
+
+var errSessionClosed = errors.New("the session is closed")
+
+// connPool hands the sessions of a storage the connections of XMUX, each a
+// client of its own made by newClient
+type connPool struct {
+	mu   sync.Mutex
+	xmux *splithttp.XmuxManager
+}
+
+func newConnPool(config *splithttp.XmuxConfig, newClient func(connCtx context.Context) *http.Client) *connPool {
+	var xmuxConfig splithttp.XmuxConfig
+	if config != nil {
+		xmuxConfig = *config
+	}
+	return &connPool{xmux: splithttp.NewXmuxManager(xmuxConfig, func() splithttp.XmuxConn {
+		ctx, cancel := context.WithCancel(context.Background())
+		return &poolConn{next: newClient(ctx).Transport, cancel: cancel}
+	})}
+}
+
+// poolConn is a connection of XMUX, which closes once XMUX drops it and the
+// requests on it end
+type poolConn struct {
+	next   http.RoundTripper
+	cancel context.CancelFunc
+
+	mu       sync.Mutex
+	inflight int
+	closing  bool
+}
+
+func (c *poolConn) IsClosed() bool {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.closing
+}
+
+func (c *poolConn) Close() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.closing = true
+	if c.inflight == 0 {
+		c.cancel()
+	}
+	return nil
+}
+
+func (c *poolConn) done() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.inflight--
+	if c.closing && c.inflight == 0 {
+		c.cancel()
+	}
+}
+
+// roundTrip sends a request counted in inflight by the caller
+func (c *poolConn) roundTrip(r *http.Request) (*http.Response, error) {
+	resp, err := c.next.RoundTrip(r)
+	if err != nil {
+		c.done()
+		return nil, err
+	}
+	resp.Body = &doneBody{ReadCloser: resp.Body, done: sync.OnceFunc(c.done)}
+	return resp, nil
+}
+
+type doneBody struct {
+	io.ReadCloser
+	done func()
+}
+
+func (b *doneBody) Close() error {
+	err := b.ReadCloser.Close()
+	b.done()
+	return err
+}
+
+// sessionTransport sends the requests of one session over a connection of
+// XMUX, and over another once that one has no requests or time left
+type sessionTransport struct {
+	pool *connPool
+
+	mu     sync.Mutex
+	client *splithttp.XmuxClient
+	closed bool
+}
+
+func (t *sessionTransport) RoundTrip(r *http.Request) (*http.Response, error) {
+	t.mu.Lock()
+	if t.closed {
+		t.mu.Unlock()
+		return nil, errSessionClosed
+	}
+	client := t.client
+	if client == nil || client.LeftRequests.Add(-1) < 0 || !client.UnreusableAt.IsZero() && time.Now().After(client.UnreusableAt) {
+		t.pool.mu.Lock()
+		t.client = t.pool.xmux.GetXmuxClient(r.Context())
+		t.pool.mu.Unlock()
+		t.client.AddRunning()
+		t.client.LeftRequests.Add(-1)
+		if client != nil {
+			client.DoneRunning()
+		}
+		client = t.client
+	}
+	// counted under mu, or another request of the session that moves on could
+	// close the connection before this one is sent
+	conn := client.XmuxConn.(*poolConn)
+	conn.mu.Lock()
+	conn.inflight++
+	conn.mu.Unlock()
+	t.mu.Unlock()
+	return conn.roundTrip(r)
+}
+
+func (t *sessionTransport) Close() {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	t.closed = true
+	if t.client != nil {
+		t.client.DoneRunning()
+		t.client = nil
+	}
+}

transport/internet/xdrive/client_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	gotls "crypto/tls"
+	"crypto/x509"
 	"encoding/base64"
 	"errors"
 	"io"
@@ -11,13 +12,22 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"slices"
+	"strings"
 	"sync"
 	"sync/atomic"
 	"testing"
 	"time"
 
+	"github.com/apernet/quic-go"
+	"github.com/apernet/quic-go/http3"
 	xnet "github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/common/net/cnc"
+	"github.com/xtls/xray-core/common/protocol/tls/cert"
+	"github.com/xtls/xray-core/common/utils"
 	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/finalmask"
+	"github.com/xtls/xray-core/transport/internet/finalmask/noise"
+	"github.com/xtls/xray-core/transport/internet/splithttp"
 	"github.com/xtls/xray-core/transport/internet/tls"
 )
 
@@ -75,7 +85,7 @@ func sniForSettings(t *testing.T, serverName string) string {
 	driveFilesURL = "https://www.googleapis.com/drive/v3/files"
 	defer func() { driveFilesURL = prev }()
 
-	client := newServiceClient(settings, 5*time.Second, 8)
+	client := newServiceClient(context.Background(), new(sync.Map), settings, 5*time.Second, 8)
 	req, err := http.NewRequest(http.MethodGet, driveFilesURL, nil)
 	if err != nil {
 		t.Fatalf("request: %v", err)
@@ -145,7 +155,7 @@ func TestServiceClientEndsOnlyStalledRequests(t *testing.T) {
 		}
 	}))
 	defer server.Close()
-	client := newServiceClient(&internet.MemoryStreamConfig{}, stall, 8)
+	client := newServiceClient(context.Background(), new(sync.Map), &internet.MemoryStreamConfig{}, stall, 8)
 
 	fetch := func(path string, body io.Reader) (int, error) {
 		req, err := http.NewRequest(http.MethodPost, server.URL+path, body)
@@ -217,7 +227,7 @@ func TestServiceClientStallOverTLS(t *testing.T) {
 			}
 			time.Sleep(5 * stall)
 		})
-		client := newServiceClient(server.settings(&tls.Config{}), stall, 8)
+		client := newServiceClient(context.Background(), new(sync.Map), server.settings(&tls.Config{}), stall, 8)
 
 		for _, path := range []string{"/stuck", "/silent"} {
 			start := time.Now()
@@ -240,12 +250,13 @@ func TestServiceClientStallOverTLS(t *testing.T) {
 }
 
 // tlsServer is a TLS server that keeps the last hello it got and counts its
-// connections
+// connections, and those closed
 type tlsServer struct {
 	*httptest.Server
 	mu     sync.Mutex
 	hello  *gotls.ClientHelloInfo
 	conns  atomic.Int32
+	closed atomic.Int32
 }
 
 func newTLSServer(t *testing.T, config *gotls.Config, handler http.HandlerFunc) *tlsServer {
@@ -260,8 +271,11 @@ func newTLSServer(t *testing.T, config *gotls.Config, handler http.HandlerFunc)
 	}
 	s.TLS = config
 	s.Config.ConnState = func(_ net.Conn, state http.ConnState) {
-		if state == http.StateNew {
+		switch state {
+		case http.StateNew:
 			s.conns.Add(1)
+		case http.StateClosed:
+			s.closed.Add(1)
 		}
 	}
 	s.StartTLS()
@@ -298,7 +312,7 @@ func TestServiceClientSpeaksWhatServerPicks(t *testing.T) {
 	for _, protos := range [][]string{chromeALPN, {"http/1.1"}} {
 		server := newTLSServer(t, &gotls.Config{NextProtos: protos}, func(w http.ResponseWriter, r *http.Request) {})
 		for _, config := range []*tls.Config{{}, {NextProtocol: []string{"h2"}}, {NextProtocol: []string{"http/1.1"}}, {Fingerprint: "unsafe"}} {
-			client := newServiceClient(server.settings(config), 5*time.Second, 8)
+			client := newServiceClient(context.Background(), new(sync.Map), server.settings(config), 5*time.Second, 8)
 			resp, err := client.Get(server.URL)
 			if err != nil {
 				t.Fatalf("server %v, alpn %v, fingerprint %q: %v", protos, config.NextProtocol, config.Fingerprint, err)
@@ -318,7 +332,7 @@ func TestServiceClientSpeaksWhatServerPicks(t *testing.T) {
 // offers certificate compression
 func TestServiceClientDefaultsToChrome(t *testing.T) {
 	server := newTLSServer(t, &gotls.Config{NextProtos: chromeALPN}, func(w http.ResponseWriter, r *http.Request) {})
-	client := newServiceClient(&internet.MemoryStreamConfig{}, 5*time.Second, 8)
+	client := newServiceClient(context.Background(), new(sync.Map), &internet.MemoryStreamConfig{}, 5*time.Second, 8)
 	// the test certificate is not trusted, the hello is all that is needed
 	if resp, err := client.Get(server.URL); err == nil {
 		resp.Body.Close()
@@ -332,6 +346,33 @@ func TestServiceClientDefaultsToChrome(t *testing.T) {
 	}
 }
 
+// a request says it is chrome, as the hello does, unless it says what it is
+func TestServiceClientUserAgent(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		io.WriteString(w, r.UserAgent())
+	}))
+	defer server.Close()
+	client := newServiceClient(context.Background(), new(sync.Map), &internet.MemoryStreamConfig{}, 5*time.Second, 8)
+	for ua, want := range map[string]string{"": utils.ChromeUA, "firefox": utils.FirefoxUA, "custom/1.0": "custom/1.0"} {
+		req, _ := http.NewRequest(http.MethodGet, server.URL, nil)
+		if ua != "" {
+			req.Header.Set("User-Agent", ua)
+		}
+		resp, err := client.Do(req)
+		if err != nil {
+			t.Fatal(err)
+		}
+		got, _ := io.ReadAll(resp.Body)
+		resp.Body.Close()
+		if string(got) != want {
+			t.Errorf("with %q the server got %q, not %q", ua, got, want)
+		}
+		if req.Header.Get("User-Agent") != ua || len(req.Header) > min(len(ua), 1) {
+			t.Errorf("with %q the request was changed to %v", ua, req.Header)
+		}
+	}
+}
+
 // parallel requests share one h2 connection instead of dialing one each, the
 // first ones as the later ones, and next to a host that answers over h1
 func TestServiceClientOneConnection(t *testing.T) {
@@ -339,7 +380,7 @@ func TestServiceClientOneConnection(t *testing.T) {
 		time.Sleep(50 * time.Millisecond)
 	})
 	h1 := newTLSServer(t, &gotls.Config{NextProtos: []string{"http/1.1"}}, func(w http.ResponseWriter, r *http.Request) {})
-	client := newServiceClient(server.settings(&tls.Config{}), 5*time.Second, driveMaxInflight)
+	client := newServiceClient(context.Background(), new(sync.Map), server.settings(&tls.Config{}), 5*time.Second, driveMaxInflight)
 	get := func(url string) {
 		resp, err := client.Get(url)
 		if err != nil {
@@ -395,7 +436,7 @@ func TestServiceClientHTTP1(t *testing.T) {
 		server := newTLSServer(t, &gotls.Config{NextProtos: c.protos, EncryptedClientHelloKeys: echKeys}, func(w http.ResponseWriter, r *http.Request) {
 			time.Sleep(50 * time.Millisecond)
 		})
-		client := newServiceClient(server.settings(c.config), 5*time.Second, 8)
+		client := newServiceClient(context.Background(), new(sync.Map), server.settings(c.config), 5*time.Second, 8)
 		get := func() {
 			resp, err := client.Get(server.URL)
 			if err != nil {
@@ -426,7 +467,7 @@ func TestServiceClientHTTP1(t *testing.T) {
 	// without the keys the server gets the outer hello, which offers the ALPN of
 	// Chrome
 	outer := newTLSServer(t, &gotls.Config{NextProtos: chromeALPN}, func(w http.ResponseWriter, r *http.Request) {})
-	if resp, err := newServiceClient(outer.settings(ech), 5*time.Second, 8).Get(outer.URL); err == nil {
+	if resp, err := newServiceClient(context.Background(), new(sync.Map), outer.settings(ech), 5*time.Second, 8).Get(outer.URL); err == nil {
 		resp.Body.Close()
 	}
 	if hello := outer.lastHello(); hello == nil {
@@ -462,7 +503,7 @@ func TestServiceClientHungHandshake(t *testing.T) {
 		server.Listener = &muteFirst{Listener: server.Listener}
 		server.StartTLS()
 		t.Cleanup(server.Close)
-		client := newServiceClient(server.settings(&tls.Config{Fingerprint: fingerprint}), stall, 8)
+		client := newServiceClient(context.Background(), new(sync.Map), server.settings(&tls.Config{Fingerprint: fingerprint}), stall, 8)
 
 		if _, err := client.Get(server.URL); err == nil {
 			t.Fatalf("fingerprint %q: a request got through a handshake that hung", fingerprint)
@@ -488,7 +529,7 @@ func TestServiceClientClosesFailedHandshake(t *testing.T) {
 
 	for _, fingerprint := range []string{"", "unsafe"} {
 		settings := &internet.MemoryStreamConfig{ProtocolName: protocolName, SecuritySettings: &tls.Config{Fingerprint: fingerprint}}
-		go newServiceClient(settings, 5*time.Second, 8).Get("https://" + ln.Addr().String())
+		go newServiceClient(context.Background(), new(sync.Map), settings, 5*time.Second, 8).Get("https://" + ln.Addr().String())
 		conn, err := ln.Accept()
 		if err != nil {
 			t.Fatal(err)
@@ -503,6 +544,446 @@ func TestServiceClientClosesFailedHandshake(t *testing.T) {
 	}
 }
 
+// afterFuncs counts the functions that context.AfterFunc registers on it and
+// that are not stopped yet
+type afterFuncs struct {
+	context.Context
+	live atomic.Int32
+}
+
+// Value hides the cancelCtx below, which context.AfterFunc would use instead
+func (c *afterFuncs) Value(any) any { return nil }
+
+func (c *afterFuncs) AfterFunc(func()) func() bool {
+	c.live.Add(1)
+	return func() bool {
+		c.live.Add(-1)
+		return true
+	}
+}
+
+// a connection that ends on its own, here after Connection: close, leaves
+// nothing on the context that closes the connections of the client
+func TestServiceClientForgetsClosedConnections(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Connection", "close")
+	}))
+	defer server.Close()
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	connCtx := &afterFuncs{Context: ctx}
+	client := newServiceClient(connCtx, new(sync.Map), &internet.MemoryStreamConfig{}, 5*time.Second, 8)
+
+	for range 4 {
+		resp, err := client.Get(server.URL)
+		if err != nil {
+			t.Fatal(err)
+		}
+		resp.Body.Close()
+	}
+	waitFor(t, "the closed connections to leave the context", func() bool { return connCtx.live.Load() == 0 })
+}
+
 type roundTrip func(*http.Request) (*http.Response, error)
 
 func (f roundTrip) RoundTrip(r *http.Request) (*http.Response, error) { return f(r) }
+
+// "hKeepAlivePeriod" of XMUX sets when an idle h2 connection pings, -1 never,
+// and h3 keeps alive only when it is set
+func TestServiceClientKeepAlive(t *testing.T) {
+	for period, want := range map[int64]time.Duration{0: xnet.ChromeH2KeepAlivePeriod, 20: 20 * time.Second, -1: 0} {
+		settings := &internet.MemoryStreamConfig{ProtocolSettings: &Config{Xmux: &splithttp.XmuxConfig{HKeepAlivePeriod: period}}}
+		client := newServiceClient(context.Background(), new(sync.Map), settings, 5*time.Second, 8)
+		h2 := client.Transport.(*serviceTransport).secure.(*secureTransport).h2.(*http.Transport)
+		if got := h2.HTTP2.SendPingTimeout; got != want {
+			t.Errorf("hKeepAlivePeriod %d pings after %v, want %v", period, got, want)
+		}
+	}
+	for period, want := range map[int64]time.Duration{0: 0, 20: 20 * time.Second, -1: 0} {
+		settings := &internet.MemoryStreamConfig{
+			ProtocolSettings: &Config{Xmux: &splithttp.XmuxConfig{HKeepAlivePeriod: period}},
+			SecuritySettings: &tls.Config{NextProtocol: []string{"h3"}},
+		}
+		client := newServiceClient(context.Background(), new(sync.Map), settings, 5*time.Second, 8)
+		if got := client.Transport.(*serviceTransport).secure.(*http3.Transport).QUICConfig.KeepAlivePeriod; got != want {
+			t.Errorf("hKeepAlivePeriod %d keeps h3 alive every %v, want %v", period, got, want)
+		}
+	}
+}
+
+// h3 is used when "alpn" asks for it alone, and only then
+func TestServiceClientH3Selection(t *testing.T) {
+	for _, c := range []struct {
+		alpn []string
+		h3   bool
+	}{
+		{nil, false},
+		{[]string{"h2"}, false},
+		{[]string{"http/1.1"}, false},
+		{[]string{"h3", "h2"}, false},
+		{[]string{"h2", "h3"}, false},
+		{[]string{"h3"}, true},
+	} {
+		client := newServiceClient(context.Background(), new(sync.Map), &internet.MemoryStreamConfig{SecuritySettings: &tls.Config{NextProtocol: c.alpn}}, 5*time.Second, 8)
+		if _, h3 := client.Transport.(*serviceTransport).secure.(*http3.Transport); h3 != c.h3 {
+			t.Errorf("alpn %v: h3 %v, want %v", c.alpn, h3, c.h3)
+		}
+	}
+	if _, h3 := newServiceClient(context.Background(), new(sync.Map), &internet.MemoryStreamConfig{}, 5*time.Second, 8).Transport.(*serviceTransport).secure.(*http3.Transport); h3 {
+		t.Error("h3 without tlsSettings")
+	}
+}
+
+// h3Server is an http3 server that keeps the SNI of each connection, and counts
+// its connections and those closed
+type h3Server struct {
+	port         xnet.Port
+	hash, caHash [32]byte
+	mu           sync.Mutex
+	snis         []string
+	conns        atomic.Int32
+	closed       atomic.Int32
+}
+
+func newH3Server(t *testing.T, handler http.Handler) *h3Server {
+	t.Helper()
+
+	// ECDSA, as ChromeParrot offers no Ed25519, from a CA of its own
+	ca, caHash := cert.MustGenerate(nil, cert.Authority(true), cert.KeyUsage(x509.KeyUsageCertSign))
+	certificate, hash := cert.MustGenerate(ca, cert.DNSNames("www.googleapis.com", "oauth2.googleapis.com"))
+	key, err := x509.ParsePKCS8PrivateKey(certificate.PrivateKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+	conn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1)})
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := &h3Server{port: xnet.Port(conn.LocalAddr().(*net.UDPAddr).Port), hash: hash, caHash: caHash}
+	server := &http3.Server{
+		Handler: handler,
+		TLSConfig: http3.ConfigureTLSConfig(&gotls.Config{
+			Certificates: []gotls.Certificate{{Certificate: [][]byte{certificate.Certificate, ca.Certificate}, PrivateKey: key}},
+			GetConfigForClient: func(hello *gotls.ClientHelloInfo) (*gotls.Config, error) {
+				s.mu.Lock()
+				s.snis = append(s.snis, hello.ServerName)
+				s.mu.Unlock()
+				return nil, nil
+			},
+		}),
+		ConnContext: func(ctx context.Context, c *quic.Conn) context.Context {
+			s.conns.Add(1)
+			context.AfterFunc(c.Context(), func() { s.closed.Add(1) })
+			return ctx
+		},
+	}
+	go server.Serve(conn)
+	t.Cleanup(func() {
+		server.Close()
+		conn.Close()
+	})
+	return s
+}
+
+// settings sends every host to the server over h3, through a destination built
+// as TCP the way conf builds it, and pins the certificate of the server in config
+func (s *h3Server) settings(config *tls.Config) *internet.MemoryStreamConfig {
+	config.NextProtocol = []string{"h3"}
+	config.PinnedPeerCertSha256 = [][]byte{s.hash[:]}
+	return &internet.MemoryStreamConfig{
+		ProtocolName:     protocolName,
+		Destination:      &xnet.Destination{Address: xnet.LocalHostIP, Port: s.port, Network: xnet.Network_TCP},
+		SecuritySettings: config,
+	}
+}
+
+func (s *h3Server) seenSNIs() []string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return slices.Sorted(slices.Values(s.snis))
+}
+
+// one client serves two hosts, and each gets its own SNI unless serverName
+// says otherwise, which is also the name a pinned CA checks the certificate for
+func TestServiceClientH3SNI(t *testing.T) {
+	for _, c := range []struct {
+		serverName string
+		pinCA      bool
+		want       []string
+	}{
+		{"", false, []string{"oauth2.googleapis.com", "www.googleapis.com"}},
+		{"www.google.com", false, []string{"www.google.com", "www.google.com"}},
+		{"", true, []string{"oauth2.googleapis.com", "www.googleapis.com"}},
+	} {
+		server := newH3Server(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
+		settings := server.settings(&tls.Config{ServerName: c.serverName})
+		if c.pinCA {
+			settings.SecuritySettings.(*tls.Config).PinnedPeerCertSha256 = [][]byte{server.caHash[:]}
+		}
+		client := newServiceClient(context.Background(), new(sync.Map), settings, 5*time.Second, 8)
+		for _, url := range []string{"https://www.googleapis.com/drive/v3/files", "https://oauth2.googleapis.com/token"} {
+			resp, err := client.Get(url)
+			if err != nil {
+				t.Fatalf("serverName %q, pinned CA %v, %s: %v", c.serverName, c.pinCA, url, err)
+			}
+			resp.Body.Close()
+			if resp.Proto != "HTTP/3.0" {
+				t.Errorf("serverName %q, %s: went over %s", c.serverName, url, resp.Proto)
+			}
+		}
+		if snis := server.seenSNIs(); !slices.Equal(snis, c.want) {
+			t.Errorf("serverName %q: SNIs %v, want %v", c.serverName, snis, c.want)
+		}
+	}
+}
+
+// a request that stands still ends over h3 too, and says so
+func TestServiceClientStallOverH3(t *testing.T) {
+	const stall = 200 * time.Millisecond
+	server := newH3Server(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/stuck" {
+			w.Write([]byte("x"))
+			w.(http.Flusher).Flush()
+		}
+		time.Sleep(5 * stall)
+	}))
+	client := newServiceClient(context.Background(), new(sync.Map), server.settings(&tls.Config{}), stall, 8)
+
+	for _, path := range []string{"/stuck", "/silent"} {
+		start := time.Now()
+		resp, err := client.Get("https://www.googleapis.com" + path)
+		if err == nil {
+			if resp.Proto != "HTTP/3.0" {
+				t.Fatalf("%s went over %s", path, resp.Proto)
+			}
+			_, err = io.ReadAll(resp.Body)
+			resp.Body.Close()
+		}
+		if !errors.Is(err, errStalled) {
+			t.Errorf("%s gave %v, want %v", path, err, errStalled)
+		}
+		if took := time.Since(start); took > 4*stall {
+			t.Errorf("%s took %v to give up", path, took)
+		}
+	}
+}
+
+// brutal and force-brutal, which are for Hysteria servers, give an error and
+// no panic in a goroutine of http3, where XHTTP and DoH panic on brutal
+func TestServiceClientH3Congestion(t *testing.T) {
+	server := newH3Server(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
+	for _, cc := range []string{"", "bbr", "reno", "brutal", "force-brutal"} {
+		settings := server.settings(&tls.Config{})
+		settings.QuicParams = &internet.QuicParams{Congestion: cc, BrutalUp: 1 << 20}
+		resp, err := newServiceClient(context.Background(), new(sync.Map), settings, 5*time.Second, 8).Get("https://www.googleapis.com/")
+		if err == nil {
+			resp.Body.Close()
+		}
+		if brutal := strings.HasSuffix(cc, "brutal"); brutal != (err != nil) || brutal && !strings.Contains(err.Error(), cc) {
+			t.Errorf("congestion %q gave %v", cc, err)
+		}
+	}
+}
+
+// recordConn keeps the datagrams sent through it
+type recordConn struct {
+	net.PacketConn
+	mu     sync.Mutex
+	sent   [][]byte
+	closed atomic.Bool
+}
+
+func (c *recordConn) WriteTo(p []byte, addr net.Addr) (int, error) {
+	c.mu.Lock()
+	c.sent = append(c.sent, bytes.Clone(p))
+	c.mu.Unlock()
+	return c.PacketConn.WriteTo(p, addr)
+}
+
+func (c *recordConn) Close() error {
+	c.closed.Store(true)
+	return c.PacketConn.Close()
+}
+
+// recorder dials UDP through recordConns and keeps them
+type recorder struct {
+	mu    sync.Mutex
+	conns []*recordConn
+}
+
+func (r *recorder) dialUDP(ctx context.Context, dest xnet.Destination) (net.PacketConn, net.Addr, error) {
+	conn, err := internet.DialSystem(ctx, dest, nil)
+	if err != nil {
+		return nil, nil, err
+	}
+	rec := &recordConn{PacketConn: conn.(*xnet.PacketConnWrapper).PacketConn}
+	r.mu.Lock()
+	r.conns = append(r.conns, rec)
+	r.mu.Unlock()
+	return rec, conn.RemoteAddr(), nil
+}
+
+// a connection ends with its socket once it is idle for its idle timeout, as
+// keepalive is off unless asked for, and so does one whose handshake failed,
+// and neither leaves anything on the context that closes the connections
+func TestServiceClientH3Closes(t *testing.T) {
+	server := newH3Server(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	for _, pin := range [][]byte{server.hash[:], make([]byte, 32)} {
+		rec := new(recorder)
+		settings := server.settings(&tls.Config{})
+		settings.SecuritySettings.(*tls.Config).PinnedPeerCertSha256 = [][]byte{pin}
+		// ChromeParrot would keep the idle timeout at 30 s
+		settings.QuicParams = &internet.QuicParams{MaxIdleTimeout: 1, DisableChromeParrot: true}
+		settings.FinalMask = finalmask.NewFinalMask(nil, nil, nil, nil, rec.dialUDP, nil)
+		connCtx := &afterFuncs{Context: ctx}
+		resp, err := newServiceClient(connCtx, new(sync.Map), settings, 5*time.Second, 8).Get("https://www.googleapis.com/")
+		if err == nil {
+			resp.Body.Close()
+		}
+		if bytes.Equal(pin, server.hash[:]) != (err == nil) {
+			t.Fatalf("pin %x: %v", pin[:4], err)
+		}
+
+		closed := func() bool {
+			rec.mu.Lock()
+			defer rec.mu.Unlock()
+			return len(rec.conns) == 1 && rec.conns[0].closed.Load()
+		}
+		for deadline := time.Now().Add(5 * time.Second); !closed() && time.Now().Before(deadline); {
+			time.Sleep(10 * time.Millisecond)
+		}
+		if !closed() {
+			t.Errorf("pin %x: the socket was left open", pin[:4])
+		}
+		waitFor(t, "the closed connection to leave the context", func() bool { return connCtx.live.Load() == 0 })
+	}
+}
+
+// cncDialer gives UDP as a stream conn, the way dialerProxy does
+type cncDialer struct{}
+
+func (cncDialer) Dial(ctx context.Context, src xnet.Address, dest xnet.Destination, sockopt *internet.SocketConfig) (net.Conn, error) {
+	conn, err := net.Dial("udp", dest.NetAddr())
+	if err != nil {
+		return nil, err
+	}
+	return cnc.NewConnection(cnc.ConnectionInput(conn), cnc.ConnectionOutput(conn), cnc.ConnectionOnClose(conn)), nil
+}
+
+func (cncDialer) DestIpAddress() net.IP { return nil }
+
+// h3 goes over the stream conn of a dialerProxy too
+func TestServiceClientH3DialerProxy(t *testing.T) {
+	internet.UseAlternativeSystemDialer(cncDialer{})
+	defer internet.UseAlternativeSystemDialer(nil)
+
+	server := newH3Server(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
+	resp, err := newServiceClient(context.Background(), new(sync.Map), server.settings(&tls.Config{}), 5*time.Second, 8).Get("https://www.googleapis.com/")
+	if err != nil {
+		t.Fatal(err)
+	}
+	resp.Body.Close()
+	if resp.Proto != "HTTP/3.0" {
+		t.Errorf("went over %s", resp.Proto)
+	}
+}
+
+// xdrive moves data over h3 to a fake Drive, with the noise of a UDP mask sent
+// ahead of the Initial of each connection
+func TestDriveOverH3(t *testing.T) {
+	drive := newFakeDrive(t)
+	server := newH3Server(t, drive.server.Config.Handler)
+	driveTokenURL = "https://oauth2.googleapis.com/token"
+	driveFilesURL = "https://www.googleapis.com/files"
+	driveUploadURL = "https://www.googleapis.com/upload"
+
+	rec := new(recorder)
+	settings := server.settings(&tls.Config{})
+	settings.ProtocolSettings = driveSettings().ProtocolSettings
+	settings.ProtocolSettings.(*Config).Xmux = &splithttp.XmuxConfig{MaxConnections: &splithttp.RangeConfig{From: 4, To: 4}}
+	masks := []finalmask.UDPMask{&noise.Config{Items: []*noise.Item{{Packet: []byte("noise")}}}}
+	settings.FinalMask = finalmask.NewFinalMask(nil, masks, nil, nil, rec.dialUDP, nil)
+
+	client, srv, cleanup := pairWith(t, settings)
+	defer cleanup()
+
+	if _, err := client.Write([]byte("ping")); err != nil {
+		t.Fatalf("client write: %v", err)
+	}
+	expectRead(t, srv, "ping")
+	if _, err := srv.Write([]byte("pong")); err != nil {
+		t.Fatalf("server write: %v", err)
+	}
+	expectRead(t, client, "pong")
+
+	payload := make([]byte, 300000)
+	for i := range payload {
+		payload[i] = byte(i % 251)
+	}
+	go client.Write(payload)
+	if err := srv.SetReadDeadline(time.Now().Add(testPatience)); err != nil {
+		t.Fatalf("SetReadDeadline: %v", err)
+	}
+	got := make([]byte, len(payload))
+	if _, err := io.ReadFull(srv, got); err != nil {
+		t.Fatalf("ReadFull: %v", err)
+	}
+	if !bytes.Equal(got, payload) {
+		t.Fatal("payload mismatch")
+	}
+
+	rec.mu.Lock()
+	defer rec.mu.Unlock()
+	// one for the listener to www.googleapis.com, one for the token to
+	// oauth2.googleapis.com and one of XMUX for each end of the session
+	if len(rec.conns) != 4 {
+		t.Errorf("%d connections went through the mask, want 4", len(rec.conns))
+	}
+	for i, conn := range rec.conns {
+		conn.mu.Lock()
+		sent := conn.sent
+		conn.mu.Unlock()
+		if len(sent) < 2 {
+			t.Errorf("connection %d sent %d datagrams", i, len(sent))
+			continue
+		}
+		// the noise, then a QUIC v1 Initial of 1250 bytes with no source
+		// connection ID, as ChromeParrot sends it
+		first, initial := sent[0], sent[1]
+		if string(first) != "noise" || len(initial) != 1250 || initial[0]&0xf0 != 0xc0 || !bytes.Equal(initial[1:5], []byte{0, 0, 0, 1}) || initial[6+int(initial[5])] != 0 {
+			t.Errorf("connection %d began with %q and %d bytes %x", i, first, len(initial), initial[:min(len(initial), 24)])
+		}
+	}
+}
+
+// over h3 a connection of XMUX is a QUIC connection, which closes once XMUX
+// drops it, so that the server hears of it
+func TestDriveXmuxOverH3(t *testing.T) {
+	drive := newFakeDrive(t)
+	server := newH3Server(t, drive.server.Config.Handler)
+	driveTokenURL = "https://www.googleapis.com/token"
+	driveFilesURL = "https://www.googleapis.com/files"
+	driveUploadURL = "https://www.googleapis.com/upload"
+	settings := server.settings(&tls.Config{})
+	settings.ProtocolSettings = driveSettings().ProtocolSettings
+	settings.ProtocolSettings.(*Config).Xmux = &splithttp.XmuxConfig{HMaxRequestTimes: &splithttp.RangeConfig{From: 3, To: 3}}
+	storage, err := newDriveStorage(settings, settings.ProtocolSettings.(*Config))
+	if err != nil {
+		t.Fatalf("newDriveStorage: %v", err)
+	}
+	session := sessionStorage(storage)
+	defer session.Close()
+
+	for _, name := range []string{"a", "b", "c", "d"} {
+		if err := session.Put(context.Background(), "streams/abc/c2s/"+name, []byte("x")); err != nil {
+			t.Fatalf("Put: %v", err)
+		}
+	}
+	// one for the token, the first of XMUX for 3 requests and one more
+	if n := server.conns.Load(); n != 3 {
+		t.Errorf("the token and 4 requests with 3 to a connection took %d connections", n)
+	}
+	waitFor(t, "the first connection of XMUX to close", func() bool { return server.closed.Load() == 1 })
+}

transport/internet/xdrive/config.pb.go

@@ -7,6 +7,7 @@
 package xdrive
 
 import (
+	splithttp "github.com/xtls/xray-core/transport/internet/splithttp"
 	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
 	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
 	reflect "reflect"
@@ -35,6 +36,8 @@ type Config struct {
 	EagerWindowMs     uint32                 `protobuf:"varint,10,opt,name=eager_window_ms,json=eagerWindowMs,proto3" json:"eager_window_ms,omitempty"`
 	HoleTimeoutMs     uint32                 `protobuf:"varint,11,opt,name=hole_timeout_ms,json=holeTimeoutMs,proto3" json:"hole_timeout_ms,omitempty"`
 	Template          string                 `protobuf:"bytes,12,opt,name=template,proto3" json:"template,omitempty"`
+	Xmux              *splithttp.XmuxConfig  `protobuf:"bytes,13,opt,name=xmux,proto3" json:"xmux,omitempty"`
+	S3                *S3Config              `protobuf:"bytes,14,opt,name=s3,proto3" json:"s3,omitempty"`
 	unknownFields     protoimpl.UnknownFields
 	sizeCache         protoimpl.SizeCache
 }
@@ -153,11 +156,93 @@ func (x *Config) GetTemplate() string {
 	return ""
 }
 
+func (x *Config) GetXmux() *splithttp.XmuxConfig {
+	if x != nil {
+		return x.Xmux
+	}
+	return nil
+}
+
+func (x *Config) GetS3() *S3Config {
+	if x != nil {
+		return x.S3
+	}
+	return nil
+}
+
+type S3Config struct {
+	state         protoimpl.MessageState `protogen:"open.v1"`
+	Endpoint      string                 `protobuf:"bytes,1,opt,name=endpoint,proto3" json:"endpoint,omitempty"`
+	Region        string                 `protobuf:"bytes,2,opt,name=region,proto3" json:"region,omitempty"`
+	Bucket        string                 `protobuf:"bytes,3,opt,name=bucket,proto3" json:"bucket,omitempty"`
+	PathStyle     bool                   `protobuf:"varint,4,opt,name=path_style,json=pathStyle,proto3" json:"path_style,omitempty"`
+	unknownFields protoimpl.UnknownFields
+	sizeCache     protoimpl.SizeCache
+}
+
+func (x *S3Config) Reset() {
+	*x = S3Config{}
+	mi := &file_transport_internet_xdrive_config_proto_msgTypes[1]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *S3Config) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*S3Config) ProtoMessage() {}
+
+func (x *S3Config) ProtoReflect() protoreflect.Message {
+	mi := &file_transport_internet_xdrive_config_proto_msgTypes[1]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use S3Config.ProtoReflect.Descriptor instead.
+func (*S3Config) Descriptor() ([]byte, []int) {
+	return file_transport_internet_xdrive_config_proto_rawDescGZIP(), []int{1}
+}
+
+func (x *S3Config) GetEndpoint() string {
+	if x != nil {
+		return x.Endpoint
+	}
+	return ""
+}
+
+func (x *S3Config) GetRegion() string {
+	if x != nil {
+		return x.Region
+	}
+	return ""
+}
+
+func (x *S3Config) GetBucket() string {
+	if x != nil {
+		return x.Bucket
+	}
+	return ""
+}
+
+func (x *S3Config) GetPathStyle() bool {
+	if x != nil {
+		return x.PathStyle
+	}
+	return false
+}
+
 var File_transport_internet_xdrive_config_proto protoreflect.FileDescriptor
 
 const file_transport_internet_xdrive_config_proto_rawDesc = "" +
 	"\n" +
-	"&transport/internet/xdrive/config.proto\x12\x1exray.transport.internet.xdrive\"\xcb\x03\n" +
+	"&transport/internet/xdrive/config.proto\x12\x1exray.transport.internet.xdrive\x1a)transport/internet/splithttp/config.proto\"\xc8\x04\n" +
 	"\x06Config\x12#\n" +
 	"\rremote_folder\x18\x01 \x01(\tR\fremoteFolder\x12\x18\n" +
 	"\aservice\x18\x02 \x01(\tR\aservice\x12\x18\n" +
@@ -171,7 +256,15 @@ const file_transport_internet_xdrive_config_proto_rawDesc = "" +
 	"\x0feager_window_ms\x18\n" +
 	" \x01(\rR\reagerWindowMs\x12&\n" +
 	"\x0fhole_timeout_ms\x18\v \x01(\rR\rholeTimeoutMs\x12\x1a\n" +
-	"\btemplate\x18\f \x01(\tR\btemplateB5Z3github.com/xtls/xray-core/transport/internet/xdriveb\x06proto3"
+	"\btemplate\x18\f \x01(\tR\btemplate\x12A\n" +
+	"\x04xmux\x18\r \x01(\v2-.xray.transport.internet.splithttp.XmuxConfigR\x04xmux\x128\n" +
+	"\x02s3\x18\x0e \x01(\v2(.xray.transport.internet.xdrive.S3ConfigR\x02s3\"u\n" +
+	"\bS3Config\x12\x1a\n" +
+	"\bendpoint\x18\x01 \x01(\tR\bendpoint\x12\x16\n" +
+	"\x06region\x18\x02 \x01(\tR\x06region\x12\x16\n" +
+	"\x06bucket\x18\x03 \x01(\tR\x06bucket\x12\x1d\n" +
+	"\n" +
+	"path_style\x18\x04 \x01(\bR\tpathStyleB5Z3github.com/xtls/xray-core/transport/internet/xdriveb\x06proto3"
 
 var (
 	file_transport_internet_xdrive_config_proto_rawDescOnce sync.Once
@@ -185,16 +278,20 @@ func file_transport_internet_xdrive_config_proto_rawDescGZIP() []byte {
 	return file_transport_internet_xdrive_config_proto_rawDescData
 }
 
-var file_transport_internet_xdrive_config_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
+var file_transport_internet_xdrive_config_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
 var file_transport_internet_xdrive_config_proto_goTypes = []any{
 	(*Config)(nil),               // 0: xray.transport.internet.xdrive.Config
+	(*S3Config)(nil),             // 1: xray.transport.internet.xdrive.S3Config
+	(*splithttp.XmuxConfig)(nil), // 2: xray.transport.internet.splithttp.XmuxConfig
 }
 var file_transport_internet_xdrive_config_proto_depIdxs = []int32{
-	0, // [0:0] is the sub-list for method output_type
+	2, // 0: xray.transport.internet.xdrive.Config.xmux:type_name -> xray.transport.internet.splithttp.XmuxConfig
-	0, // [0:0] is the sub-list for method input_type
+	1, // 1: xray.transport.internet.xdrive.Config.s3:type_name -> xray.transport.internet.xdrive.S3Config
-	0, // [0:0] is the sub-list for extension type_name
+	2, // [2:2] is the sub-list for method output_type
-	0, // [0:0] is the sub-list for extension extendee
+	2, // [2:2] is the sub-list for method input_type
-	0, // [0:0] is the sub-list for field type_name
+	2, // [2:2] is the sub-list for extension type_name
+	2, // [2:2] is the sub-list for extension extendee
+	0, // [0:2] is the sub-list for field type_name
 }
 
 func init() { file_transport_internet_xdrive_config_proto_init() }
@@ -208,7 +305,7 @@ func file_transport_internet_xdrive_config_proto_init() {
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_transport_internet_xdrive_config_proto_rawDesc), len(file_transport_internet_xdrive_config_proto_rawDesc)),
 			NumEnums:      0,
-			NumMessages:   1,
+			NumMessages:   2,
 			NumExtensions: 0,
 			NumServices:   0,
 		},

transport/internet/xdrive/config.proto

@@ -3,6 +3,8 @@ syntax = "proto3";
 package xray.transport.internet.xdrive;
 option go_package = "github.com/xtls/xray-core/transport/internet/xdrive";
 
+import "transport/internet/splithttp/config.proto";
+
 message Config {
   string remote_folder = 1;
   string service = 2;
@@ -16,4 +18,13 @@ message Config {
   uint32 eager_window_ms = 10;
   uint32 hole_timeout_ms = 11;
   string template = 12;
+  xray.transport.internet.splithttp.XmuxConfig xmux = 13;
+  S3Config s3 = 14;
+}
+
+message S3Config {
+  string endpoint = 1;
+  string region = 2;
+  string bucket = 3;
+  bool path_style = 4;
 }

transport/internet/xdrive/drive.go

@@ -39,11 +39,21 @@ var (
 )
 
 type driveStorage struct {
+	*driveShared
+	// a session has a client and inflight of its own, see session
+	client   *http.Client
+	inflight chan struct{}
+	release  func()
+}
+
+// driveShared is what the sessions of a storage have in common
+type driveShared struct {
+	conns        *connPool
 	folder       string
 	clientID     string
 	clientSecret string
 	refreshToken string
-	client       *http.Client
+	tokenClient  *http.Client
 	tokenURL     string
 	filesURL     string
 	uploadURL    string
@@ -53,8 +63,6 @@ type driveStorage struct {
 	token       string
 	tokenExpiry time.Time
 
-	inflight chan struct{}
-
 	idMu sync.Mutex
 	ids  map[string]string
 }
@@ -72,21 +80,41 @@ func newDriveStorage(streamSettings *internet.MemoryStreamConfig, config *Config
 		}
 	}
 
+	h1Hosts := new(sync.Map)
+	client := newServiceClient(context.Background(), h1Hosts, streamSettings, driveTimeout, driveMaxInflight)
 	return &driveStorage{
+		driveShared: &driveShared{
+			conns: newConnPool(config.Xmux, func(connCtx context.Context) *http.Client {
+				return newServiceClient(connCtx, h1Hosts, streamSettings, driveTimeout, driveMaxInflight)
+			}),
 			folder:       config.RemoteFolder,
 			clientID:     config.Secrets[0],
 			clientSecret: config.Secrets[1],
 			refreshToken: config.Secrets[2],
-		client:       newServiceClient(streamSettings, driveTimeout, driveMaxInflight),
+			tokenClient:  client,
 			tokenURL:     driveTokenURL,
 			filesURL:     driveFilesURL,
 			uploadURL:    driveUploadURL,
 			backoff:      driveInitialBackoff,
-		inflight:     make(chan struct{}, driveMaxInflight),
 			ids:          make(map[string]string),
+		},
+		client:   client,
+		inflight: make(chan struct{}, driveMaxInflight),
 	}, nil
 }
 
+// session returns a storage for one session, over the connections of XMUX
+// until Close, with the token and ids of s
+func (s *driveStorage) session() Storage {
+	transport := &sessionTransport{pool: s.conns}
+	return &driveStorage{
+		driveShared: s.driveShared,
+		client:      &http.Client{Transport: transport},
+		inflight:    make(chan struct{}, driveMaxInflight),
+		release:     transport.Close,
+	}
+}
+
 func flatten(name string) string {
 	return strings.ReplaceAll(name, "/", flatSeparator)
 }
@@ -115,7 +143,7 @@ func (s *driveStorage) accessToken(ctx context.Context) (string, error) {
 	}
 	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 
-	resp, err := s.client.Do(req)
+	resp, err := s.tokenClient.Do(req)
 	if err != nil {
 		return "", errors.New("failed to refresh the access token").Base(err)
 	}
@@ -572,5 +600,8 @@ func (s *driveStorage) List(ctx context.Context, prefix string) ([]Entry, error)
 }
 
 func (s *driveStorage) Close() error {
+	if s.release != nil {
+		s.release()
+	}
 	return nil
 }

transport/internet/xdrive/drive_test.go

@@ -562,6 +562,12 @@ func TestDriveSharedClient(t *testing.T) {
 	if first != second {
 		t.Fatal("same settings did not share one storage")
 	}
+	// a session has an inflight of its own, as large
+	session := sessionStorage(first).(*driveStorage)
+	defer session.Close()
+	if session.inflight == first.(*driveStorage).inflight || cap(session.inflight) != driveMaxInflight {
+		t.Fatalf("a session shares inflight or has cap %d", cap(session.inflight))
+	}
 }
 
 func TestDriveOldServiceName(t *testing.T) {

transport/internet/xdrive/s3.go

@@ -0,0 +1,518 @@
+package xdrive
+
+import (
+	"bytes"
+	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/xml"
+	stderrors "errors"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/transport/internet"
+	"golang.org/x/net/http/httpguts"
+)
+
+type s3Storage struct {
+	*s3Shared
+	client   *http.Client
+	inflight chan struct{}
+	release  func()
+}
+
+type s3Shared struct {
+	conns                *connPool
+	base                 url.URL
+	prefix               string
+	region               string
+	accessKey, secretKey string
+	token                string
+	backoff              time.Duration
+}
+
+func s3Region(region string) string {
+	if region == "" {
+		return "us-east-1"
+	}
+	return region
+}
+
+func ValidateS3Config(c *Config) error {
+	if c == nil || c.S3 == nil {
+		return errors.New(`service "s3" needs an "s3" object`)
+	}
+	u, err := url.Parse(c.S3.Endpoint)
+	if err != nil || (u.Scheme != "https" && u.Scheme != "http") || u.Hostname() == "" ||
+		u.User != nil || u.RawQuery != "" || u.ForceQuery || u.Fragment != "" || u.Opaque != "" {
+		return errors.New("S3 endpoint must be an http(s) URL without credentials, query or fragment")
+	}
+	if !httpguts.ValidHeaderFieldValue(c.S3.Region) || strings.ContainsAny(c.S3.Region, "/, \t") {
+		return errors.New("invalid S3 signing region")
+	}
+	bucket := c.S3.Bucket
+	if !validS3Name(bucket) || strings.Contains(bucket, "/") {
+		return errors.New("S3 needs a bucket name without path separators")
+	}
+	if !c.S3.PathStyle {
+		if net.ParseIP(u.Hostname()) != nil {
+			return errors.New("S3 virtual-hosted addressing requires a DNS endpoint")
+		}
+		// In this mode the bucket is part of the HTTP authority, not its path.
+		if strings.Trim(bucket, "abcdefghijklmnopqrstuvwxyz0123456789-.") != "" || strings.Contains(bucket, "..") ||
+			strings.HasPrefix(bucket, ".") || strings.HasSuffix(bucket, ".") {
+			return errors.New("S3 virtual-hosted addressing requires a DNS-compatible bucket name")
+		}
+	}
+	if !validS3Name(strings.TrimSuffix(c.RemoteFolder, "/")) {
+		return errors.New("S3 remoteFolder must be a nonempty relative prefix without empty, '.' or '..' components")
+	}
+	if len(c.Secrets) < 2 || len(c.Secrets) > 3 || c.Secrets[0] == "" || c.Secrets[1] == "" {
+		return errors.New("S3 needs AccessKeyID, SecretAccessKey and optionally SessionToken in secrets")
+	}
+	for _, secret := range c.Secrets {
+		if !httpguts.ValidHeaderFieldValue(secret) {
+			return errors.New("invalid S3 secret")
+		}
+	}
+	if strings.ContainsAny(c.Secrets[0], "/ ,\t") {
+		return errors.New("invalid S3 AccessKeyID")
+	}
+	return nil
+}
+
+func validS3Name(name string) bool {
+	for _, ch := range name {
+		if ch < 0x20 || ch == 0x7f || ch == '\\' {
+			return false
+		}
+	}
+	for _, part := range strings.Split(name, "/") {
+		if part == "" || part == "." || part == ".." {
+			return false
+		}
+	}
+	return true
+}
+
+func newS3Storage(streamSettings *internet.MemoryStreamConfig, c *Config) (*s3Storage, error) {
+	if err := ValidateS3Config(c); err != nil {
+		return nil, err
+	}
+	base, _ := url.Parse(c.S3.Endpoint)
+	// Encode the endpoint prefix for SigV4 without turning escaped slashes into separators.
+	segments := strings.Split(base.EscapedPath(), "/")
+	for i, segment := range segments {
+		decoded, _ := url.PathUnescape(segment)
+		segments[i] = strings.ReplaceAll(s3EscapePath(decoded), "/", "%2F")
+	}
+	base.RawPath = strings.Join(segments, "/")
+	if !strings.HasSuffix(base.RawPath, "/") {
+		base.Path += "/"
+		base.RawPath += "/"
+	}
+	if c.S3.PathStyle {
+		base.Path += c.S3.Bucket + "/"
+		base.RawPath += s3EscapePath(c.S3.Bucket) + "/"
+	} else {
+		host := c.S3.Bucket + "." + base.Hostname()
+		if base.Port() != "" {
+			host = net.JoinHostPort(host, base.Port())
+		}
+		base.Host = host
+	}
+	if streamSettings == nil {
+		streamSettings = &internet.MemoryStreamConfig{}
+	}
+	h1Hosts := new(sync.Map)
+	newClient := func(ctx context.Context) *http.Client {
+		client := newServiceClient(ctx, h1Hosts, streamSettings, driveTimeout, driveMaxInflight)
+		// A redirect changes the signed host/path. Do not follow it with the old
+		// signature or send the session token to a different endpoint.
+		client.CheckRedirect = s3NoRedirect
+		return client
+	}
+	s := &s3Storage{
+		s3Shared: &s3Shared{
+			conns:     newConnPool(c.Xmux, newClient),
+			base:      *base,
+			prefix:    strings.TrimSuffix(c.RemoteFolder, "/") + "/",
+			region:    s3Region(c.S3.Region),
+			accessKey: c.Secrets[0],
+			secretKey: c.Secrets[1],
+			backoff:   200 * time.Millisecond,
+		},
+		client:   newClient(context.Background()),
+		inflight: make(chan struct{}, driveMaxInflight),
+	}
+	if len(c.Secrets) == 3 {
+		s.token = c.Secrets[2]
+	}
+	return s, nil
+}
+
+func s3NoRedirect(_ *http.Request, _ []*http.Request) error { return http.ErrUseLastResponse }
+
+func (s *s3Storage) session() Storage {
+	transport := &sessionTransport{pool: s.conns}
+	return &s3Storage{
+		s3Shared: s.s3Shared,
+		client:   &http.Client{Transport: transport, CheckRedirect: s3NoRedirect},
+		inflight: make(chan struct{}, cap(s.inflight)),
+		release:  transport.Close,
+	}
+}
+
+func (s *s3Storage) Close() error {
+	if s.release != nil {
+		s.release()
+	}
+	return nil
+}
+
+// SigV4 requires %20 for spaces, uppercase escapes, and unescaped key separators.
+func s3EscapePath(value string) string {
+	const digits = "0123456789ABCDEF"
+	var out strings.Builder
+	for i := 0; i < len(value); i++ {
+		ch := value[i]
+		if ch >= 'a' && ch <= 'z' || ch >= 'A' && ch <= 'Z' || ch >= '0' && ch <= '9' ||
+			ch == '-' || ch == '_' || ch == '.' || ch == '~' || ch == '/' {
+			out.WriteByte(ch)
+		} else {
+			out.WriteByte('%')
+			out.WriteByte(digits[ch>>4])
+			out.WriteByte(digits[ch&15])
+		}
+	}
+	return out.String()
+}
+
+func s3Hash(body []byte) string {
+	sum := sha256.Sum256(body)
+	return hex.EncodeToString(sum[:])
+}
+
+func s3HMAC(key []byte, value string) []byte {
+	h := hmac.New(sha256.New, key)
+	h.Write([]byte(value))
+	return h.Sum(nil)
+}
+
+func (s *s3Storage) sign(req *http.Request, payloadHash string, now time.Time) {
+	stamp, date := now.UTC().Format("20060102T150405Z"), now.UTC().Format("20060102")
+	req.Header.Set("X-Amz-Date", stamp)
+	req.Header.Set("X-Amz-Content-Sha256", payloadHash)
+	headers := "host:" + req.URL.Host + "\nx-amz-content-sha256:" + payloadHash + "\nx-amz-date:" + stamp + "\n"
+	signed := "host;x-amz-content-sha256;x-amz-date"
+	if contentType := req.Header.Get("Content-Type"); contentType != "" {
+		headers = "content-type:" + contentType + "\n" + headers
+		signed = "content-type;" + signed
+	}
+	if s.token != "" {
+		req.Header.Set("X-Amz-Security-Token", s.token)
+		headers += "x-amz-security-token:" + strings.Join(strings.Fields(s.token), " ") + "\n"
+		signed += ";x-amz-security-token"
+	}
+	// Sign the escaped path exactly as sent.
+	canonical := req.Method + "\n" + req.URL.EscapedPath() + "\n" + req.URL.RawQuery + "\n" +
+		headers + "\n" + signed + "\n" + payloadHash
+	scope := date + "/" + s.region + "/s3/aws4_request"
+	toSign := "AWS4-HMAC-SHA256\n" + stamp + "\n" + scope + "\n" + s3Hash([]byte(canonical))
+	key := s3HMAC([]byte("AWS4"+s.secretKey), date)
+	key = s3HMAC(key, s.region)
+	key = s3HMAC(key, "s3")
+	key = s3HMAC(key, "aws4_request")
+	req.Header.Set("Authorization", "AWS4-HMAC-SHA256 Credential="+s.accessKey+"/"+scope+
+		", SignedHeaders="+signed+", Signature="+hex.EncodeToString(s3HMAC(key, toSign)))
+}
+
+func (s *s3Storage) target(key string, query url.Values) string {
+	u := s.base
+	u.Path += key
+	u.RawPath += s3EscapePath(key)
+	// Parameters have fixed ASCII names and one value each; SigV4 uses %20 for spaces.
+	u.RawQuery = strings.ReplaceAll(query.Encode(), "+", "%20")
+	return u.String()
+}
+
+func (s *s3Storage) objectKey(name string) (string, error) {
+	if !validS3Name(name) {
+		return "", errors.New("invalid relative S3 object name")
+	}
+	key := s.prefix + name
+	if len(key) > 1024 {
+		return "", errors.New("S3 object key exceeds 1024 bytes")
+	}
+	return key, nil
+}
+
+// Retries use fresh signatures and hold a concurrency slot until the response body is read.
+func (s *s3Storage) do(ctx context.Context, method, key string, query url.Values, body []byte) (int, []byte, error) {
+	payloadHash := s3Hash(body)
+	backoff := s.backoff
+	var lastErr error
+	var retryAfter time.Duration
+	for attempt := 0; attempt < driveMaxAttempts; attempt++ {
+		if attempt > 0 {
+			delay := max(jitter(backoff), retryAfter)
+			timer := time.NewTimer(min(delay, driveMaxBackoff))
+			select {
+			case <-ctx.Done():
+				timer.Stop()
+				return 0, nil, ctx.Err()
+			case <-timer.C:
+			}
+			backoff = min(backoff*2, driveMaxBackoff)
+		}
+		select {
+		case s.inflight <- struct{}{}:
+		case <-ctx.Done():
+			return 0, nil, ctx.Err()
+		}
+		status, payload, after, err := s.attempt(ctx, method, key, query, body, payloadHash)
+		<-s.inflight
+		if ctx.Err() != nil {
+			return 0, nil, ctx.Err()
+		}
+		if err != nil && (!retryS3Error(err) || status >= 300 && !retryableStatus(status)) {
+			return 0, nil, err
+		}
+		if err == nil && !retryableStatus(status) {
+			return status, payload, nil
+		}
+		lastErr, retryAfter = err, after
+		if lastErr == nil {
+			lastErr = s3ResponseError(method, status, payload)
+		}
+	}
+	return 0, nil, lastErr
+}
+
+func retryS3Error(err error) bool {
+	var dns *net.DNSError
+	if stderrors.As(err, &dns) {
+		return dns.IsTimeout || dns.IsTemporary
+	}
+	var op *net.OpError
+	var network net.Error
+	return stderrors.Is(err, io.EOF) || stderrors.Is(err, io.ErrUnexpectedEOF) || stderrors.Is(err, errStalled) ||
+		stderrors.As(err, &op) || stderrors.As(err, &network) && network.Timeout()
+}
+
+func (s *s3Storage) attempt(ctx context.Context, method, key string, query url.Values, body []byte, hash string) (int, []byte, time.Duration, error) {
+	req, err := http.NewRequestWithContext(ctx, method, s.target(key, query), bytes.NewReader(body))
+	if err != nil {
+		return 0, nil, 0, errors.New("failed to build S3 request")
+	}
+	if method == http.MethodPut {
+		req.Header.Set("Content-Type", "application/octet-stream")
+	}
+	s.sign(req, hash, time.Now())
+	resp, err := s.client.Do(req)
+	if err != nil {
+		if urlErr, ok := err.(*url.Error); ok {
+			err = urlErr.Err
+		}
+		return 0, nil, 0, errors.New("S3 request failed").Base(err)
+	}
+	defer resp.Body.Close()
+	limit := int64(maxSegmentBytes)
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		limit = 64 << 10
+	}
+	payload, err := io.ReadAll(io.LimitReader(resp.Body, limit+1))
+	if err != nil {
+		return resp.StatusCode, nil, 0, errors.New("failed to read S3 response (HTTP ", resp.StatusCode, ")").Base(err)
+	}
+	if int64(len(payload)) > limit {
+		return 0, nil, 0, errors.New("S3 response exceeds size limit")
+	}
+	var after time.Duration
+	if raw := resp.Header.Get("Retry-After"); raw != "" {
+		if seconds, err := strconv.ParseInt(raw, 10, 32); err == nil && seconds > 0 {
+			after = min(time.Duration(seconds)*time.Second, driveMaxBackoff)
+		} else if at, err := http.ParseTime(raw); err == nil {
+			after = min(max(time.Until(at), 0), driveMaxBackoff)
+		}
+	}
+	return resp.StatusCode, payload, after, nil
+}
+
+func s3Missing(status int, payload []byte) bool {
+	if status != http.StatusNotFound {
+		return false
+	}
+	code := s3ErrorCode(payload)
+	return code == "NoSuchKey" || code == "NotFound"
+}
+
+func s3ErrorCode(payload []byte) string {
+	var response struct {
+		XMLName xml.Name `xml:"Error"`
+		Code    string
+	}
+	if xml.Unmarshal(payload, &response) != nil {
+		return ""
+	}
+	return response.Code
+}
+
+func s3ResponseError(method string, status int, payload []byte) error {
+	if code := s3ErrorCode(payload); code != "" {
+		return errors.New("S3 ", method, " answered ", status, " (", strconv.Quote(code), ")")
+	}
+	return errors.New("S3 ", method, " answered ", status)
+}
+
+func (s *s3Storage) Put(ctx context.Context, name string, data []byte) error {
+	key, err := s.objectKey(name)
+	if err != nil {
+		return err
+	}
+	status, payload, err := s.do(ctx, http.MethodPut, key, nil, data)
+	if err != nil {
+		return err
+	}
+	if status != http.StatusOK {
+		return s3ResponseError("PUT", status, payload)
+	}
+	return nil
+}
+
+func (s *s3Storage) Get(ctx context.Context, name string) ([]byte, error) {
+	key, err := s.objectKey(name)
+	if err != nil {
+		return nil, err
+	}
+	status, payload, err := s.do(ctx, http.MethodGet, key, nil, nil)
+	if err != nil {
+		return nil, err
+	}
+	if s3Missing(status, payload) {
+		return nil, errNotFound
+	}
+	if status != http.StatusOK {
+		return nil, s3ResponseError("GET", status, payload)
+	}
+	return payload, nil
+}
+
+type s3ListPage struct {
+	XMLName               xml.Name `xml:"ListBucketResult"`
+	IsTruncated           bool
+	NextContinuationToken string
+	Contents              []struct{ Key string }
+	CommonPrefixes        []struct{ Prefix string }
+}
+
+func (s *s3Storage) list(ctx context.Context, prefix, delimiter string, visit func(*s3ListPage) error) error {
+	query := url.Values{"list-type": {"2"}, "prefix": {prefix}, "max-keys": {"1000"}}
+	if delimiter != "" {
+		query.Set("delimiter", delimiter)
+	}
+	seen := make(map[string]bool)
+	for {
+		status, payload, err := s.do(ctx, http.MethodGet, "", query, nil)
+		if err != nil {
+			return err
+		}
+		if status != http.StatusOK {
+			return s3ResponseError("LIST", status, payload)
+		}
+		var page s3ListPage
+		if err := xml.Unmarshal(payload, &page); err != nil {
+			return errors.New("invalid S3 list response")
+		}
+		// Validate all keys before deleting any objects.
+		for _, item := range page.Contents {
+			if !strings.HasPrefix(item.Key, prefix) {
+				return errors.New("S3 returned an object outside the requested prefix")
+			}
+		}
+		for _, item := range page.CommonPrefixes {
+			if !strings.HasPrefix(item.Prefix, prefix) {
+				return errors.New("S3 returned a directory outside the requested prefix")
+			}
+		}
+		if page.IsTruncated {
+			if page.NextContinuationToken == "" || seen[page.NextContinuationToken] {
+				return errors.New("S3 list pagination did not advance")
+			}
+			seen[page.NextContinuationToken] = true
+		}
+		if err := visit(&page); err != nil {
+			return err
+		}
+		if !page.IsTruncated {
+			return nil
+		}
+		query.Set("continuation-token", page.NextContinuationToken)
+	}
+}
+
+func (s *s3Storage) List(ctx context.Context, prefix string) ([]Entry, error) {
+	key, err := s.objectKey(prefix)
+	if err != nil {
+		return nil, err
+	}
+	key += "/"
+	seen := make(map[string]bool)
+	var entries []Entry
+	add := func(full string) {
+		rest := strings.TrimPrefix(full, key)
+		name, _, _ := strings.Cut(rest, "/")
+		if name != "" && validS3Name(name) && !seen[name] {
+			seen[name] = true
+			entries = append(entries, Entry{Name: name})
+		}
+	}
+	err = s.list(ctx, key, "/", func(page *s3ListPage) error {
+		for _, item := range page.Contents {
+			add(item.Key)
+		}
+		for _, item := range page.CommonPrefixes {
+			add(item.Prefix)
+		}
+		return nil
+	})
+	return entries, err
+}
+
+func (s *s3Storage) deleteObject(ctx context.Context, key string) error {
+	status, payload, err := s.do(ctx, http.MethodDelete, key, nil, nil)
+	if err != nil {
+		return err
+	}
+	if status != http.StatusNoContent && status != http.StatusOK && !s3Missing(status, payload) {
+		return s3ResponseError("DELETE", status, payload)
+	}
+	return nil
+}
+
+// The trailing "/" prevents deleting streams/abcd when removing streams/abc.
+func (s *s3Storage) Delete(ctx context.Context, name string) error {
+	key, err := s.objectKey(name)
+	if err != nil {
+		return err
+	}
+	if err := s.deleteObject(ctx, key); err != nil {
+		return err
+	}
+	return s.list(ctx, key+"/", "", func(page *s3ListPage) error {
+		for _, item := range page.Contents {
+			if err := s.deleteObject(ctx, item.Key); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+}

transport/internet/xdrive/storage.go

@@ -43,11 +43,30 @@ func newStorage(streamSettings *internet.MemoryStreamConfig) (Storage, error) {
 		return sharedStorage(streamSettings, config, func() (Storage, error) {
 			return newTemplateStorage(streamSettings, config)
 		})
+	case "s3":
+		return sharedStorage(streamSettings, config, func() (Storage, error) {
+			return newS3Storage(streamSettings, config)
+		})
 	default:
 		return nil, errors.New("unsupported service: ", config.Service)
 	}
 }
 
+// sessionStorage returns the storage of one session, which takes connections
+// of XMUX until Close, with the token and cache of storage. Local storage has
+// no connections
+func sessionStorage(storage Storage) Storage {
+	switch s := storage.(type) {
+	case *driveStorage:
+		return s.session()
+	case *templateStorage:
+		return s.session()
+	case *s3Storage:
+		return s.session()
+	}
+	return storage
+}
+
 var (
 	sharedMu sync.Mutex
 	shared   = make(map[string]Storage)
@@ -55,6 +74,14 @@ var (
 
 func shareKey(streamSettings *internet.MemoryStreamConfig, config *Config) string {
 	parts := []string{config.Service, config.RemoteFolder}
+	if config.S3 != nil {
+		parts = append(parts, config.S3.Endpoint, s3Region(config.S3.Region), config.S3.Bucket)
+		if config.S3.PathStyle {
+			parts = append(parts, "path-style")
+		} else {
+			parts = append(parts, "virtual-hosted-style")
+		}
+	}
 	parts = append(parts, config.Secrets...)
 	if streamSettings != nil {
 		parts = append(parts, streamSettings.SecurityType)

transport/internet/xdrive/template.go

@@ -33,6 +33,14 @@ type opTemplate struct {
 	Headers    map[string]string `json:"headers"`
 	Body       string            `json:"body"`
 	NamesRegex string            `json:"namesRegex"`
+
+	// HrefPath makes the operation two-step, as in the Yandex Disk REST API: the first request
+	// answers with a JSON body, the URL found at HrefPath is then called with HrefMethod (GET by
+	// default), carrying the payload. The URL is used as given, with neither auth nor headers.
+	HrefPath   string `json:"hrefPath"`
+	HrefMethod string `json:"hrefMethod"`
+
+	presigned bool
 }
 
 type retryTemplate struct {
@@ -54,13 +62,21 @@ type storageTemplate struct {
 }
 
 type templateStorage struct {
-	tmpl    *storageTemplate
+	*templateShared
+	// a session has a client and inflight of its own, see session
 	client   *http.Client
+	inflight chan struct{}
+	release  func()
+}
+
+// templateShared is what the sessions of a storage have in common
+type templateShared struct {
+	conns       *connPool
+	tmpl        *storageTemplate
+	tokenClient *http.Client
 	folder      string
 	secrets     []string
 
-	inflight chan struct{}
-
 	tokenMu     sync.Mutex
 	token       string
 	tokenExpiry time.Time
@@ -94,15 +110,35 @@ func newTemplateStorage(streamSettings *internet.MemoryStreamConfig, config *Con
 		conc = maxTemplateConcurrency
 	}
 
+	h1Hosts := new(sync.Map)
+	client := newServiceClient(context.Background(), h1Hosts, streamSettings, driveTimeout, conc)
 	return &templateStorage{
+		templateShared: &templateShared{
+			conns: newConnPool(config.Xmux, func(connCtx context.Context) *http.Client {
+				return newServiceClient(connCtx, h1Hosts, streamSettings, driveTimeout, conc)
+			}),
 			tmpl:        tmpl,
-		client:   newServiceClient(streamSettings, driveTimeout, conc),
+			tokenClient: client,
 			folder:      config.RemoteFolder,
 			secrets:     config.Secrets,
+		},
+		client:   client,
 		inflight: make(chan struct{}, conc),
 	}, nil
 }
 
+// session returns a storage for one session, over the connections of XMUX
+// until Close, with the token of s
+func (s *templateStorage) session() Storage {
+	transport := &sessionTransport{pool: s.conns}
+	return &templateStorage{
+		templateShared: s.templateShared,
+		client:         &http.Client{Transport: transport},
+		inflight:       make(chan struct{}, cap(s.inflight)),
+		release:        transport.Close,
+	}
+}
+
 const maxTemplateConcurrency = 256
 
 func (s *templateStorage) baseVars() map[string]string {
@@ -216,7 +252,7 @@ func (s *templateStorage) accessToken(ctx context.Context) (string, error) {
 	}
 	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 
-	resp, err := s.client.Do(req)
+	resp, err := s.tokenClient.Do(req)
 	if err != nil {
 		return "", errors.New("failed to fetch the token").Base(err)
 	}
@@ -262,6 +298,11 @@ func (s *templateStorage) do(ctx context.Context, op *opTemplate, vars map[strin
 	backoff := driveInitialBackoff
 	var lastErr error
 
+	url := op.URL
+	if !op.presigned {
+		url = subst(url, vars)
+	}
+
 	for attempt := 0; attempt < driveMaxAttempts; attempt++ {
 		if attempt > 0 {
 			select {
@@ -275,11 +316,15 @@ func (s *templateStorage) do(ctx context.Context, op *opTemplate, vars map[strin
 			}
 		}
 
-		authHeaders, err := s.authHeaders(ctx, vars)
+		var authHeaders map[string]string
+		if !op.presigned {
+			headers, err := s.authHeaders(ctx, vars)
 			if err != nil {
 				lastErr = err
 				continue
 			}
+			authHeaders = headers
+		}
 
 		method := op.Method
 		if method == "" {
@@ -290,7 +335,7 @@ func (s *templateStorage) do(ctx context.Context, op *opTemplate, vars map[strin
 		if body != nil {
 			reader = bytes.NewReader(body)
 		}
-		req, err := http.NewRequestWithContext(ctx, method, subst(op.URL, vars), reader)
+		req, err := http.NewRequestWithContext(ctx, method, url, reader)
 		if err != nil {
 			return 0, nil, errors.New("failed to build request").Base(err)
 		}
@@ -325,7 +370,7 @@ func (s *templateStorage) do(ctx context.Context, op *opTemplate, vars map[strin
 			continue
 		}
 
-		if resp.StatusCode == http.StatusUnauthorized && s.tmpl.Auth.Type == "oauth2" {
+		if resp.StatusCode == http.StatusUnauthorized && s.tmpl.Auth.Type == "oauth2" && !op.presigned {
 			s.invalidateToken()
 			lastErr = errors.New("the service rejected the token")
 			continue
@@ -339,6 +384,22 @@ func (s *templateStorage) do(ctx context.Context, op *opTemplate, vars map[strin
 	return 0, nil, lastErr
 }
 
+// run performs op, following its href when the operation is two-step.
+func (s *templateStorage) run(ctx context.Context, op *opTemplate, vars map[string]string, body []byte) (int, []byte, error) {
+	if op.HrefPath == "" {
+		return s.do(ctx, op, vars, body)
+	}
+	status, payload, err := s.do(ctx, op, vars, nil)
+	if err != nil || status < 200 || status >= 300 {
+		return status, payload, err
+	}
+	href := jsonString(payload, op.HrefPath)
+	if href == "" {
+		return 0, nil, errors.New("the response has no href at ", op.HrefPath)
+	}
+	return s.do(ctx, &opTemplate{Method: op.HrefMethod, URL: href, presigned: true}, vars, body)
+}
+
 func (s *templateStorage) Put(ctx context.Context, name string, data []byte) error {
 	vars := s.baseVars()
 	vars["name"] = s.storedName(name)
@@ -349,7 +410,7 @@ func (s *templateStorage) Put(ctx context.Context, name string, data []byte) err
 		body = []byte(subst(s.tmpl.Put.Body, vars))
 	}
 
-	status, payload, err := s.do(ctx, &s.tmpl.Put, vars, body)
+	status, payload, err := s.run(ctx, &s.tmpl.Put, vars, body)
 	if err != nil {
 		return err
 	}
@@ -363,7 +424,7 @@ func (s *templateStorage) Get(ctx context.Context, name string) ([]byte, error)
 	vars := s.baseVars()
 	vars["name"] = s.storedName(name)
 
-	status, payload, err := s.do(ctx, &s.tmpl.Get, vars, nil)
+	status, payload, err := s.run(ctx, &s.tmpl.Get, vars, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -381,7 +442,7 @@ func (s *templateStorage) Delete(ctx context.Context, name string) error {
 	vars := s.baseVars()
 	vars["name"] = s.storedName(name)
 
-	status, payload, err := s.do(ctx, &s.tmpl.Delete, vars, nil)
+	status, payload, err := s.run(ctx, &s.tmpl.Delete, vars, nil)
 	if err != nil {
 		return err
 	}
@@ -396,7 +457,7 @@ func (s *templateStorage) List(ctx context.Context, prefix string) ([]Entry, err
 	flat := s.storedName(prefix)
 	vars["prefix"] = flat
 
-	status, payload, err := s.do(ctx, &s.tmpl.List, vars, nil)
+	status, payload, err := s.run(ctx, &s.tmpl.List, vars, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -441,5 +502,8 @@ func (s *templateStorage) List(ctx context.Context, prefix string) ([]Entry, err
 }
 
 func (s *templateStorage) Close() error {
+	if s.release != nil {
+		s.release()
+	}
 	return nil
 }

transport/internet/xdrive/template_test.go

@@ -113,7 +113,7 @@ func templateSettings(store *fakeStore, auth map[string]interface{}, secrets []s
 		"delete":  map[string]interface{}{"method": "DELETE", "url": base + "/folder/{name}"},
 		"list": map[string]interface{}{
 			"method":     "PROPFIND",
-			"url":        base + "/folder/",
+			"url":        base + "/folder/?prefix={prefix}",
 			"namesRegex": `<d:href>/folder/([^<]+)</d:href>`,
 		},
 		"retry": map[string]interface{}{"status": []int{429, 500, 502, 503}},
@@ -297,6 +297,12 @@ func TestTemplateConcurrency(t *testing.T) {
 	if cap(storage.inflight) != 4 {
 		t.Fatalf("inflight cap is %d, want 4 from the template", cap(storage.inflight))
 	}
+	// and so has a session, of its own
+	session := storage.session().(*templateStorage)
+	defer session.Close()
+	if session.inflight == storage.inflight || cap(session.inflight) != 4 {
+		t.Fatalf("a session shares inflight or has cap %d, want 4", cap(session.inflight))
+	}
 }
 
 func TestTemplateConcurrencyDefault(t *testing.T) {
@@ -306,3 +312,113 @@ func TestTemplateConcurrencyDefault(t *testing.T) {
 		t.Fatalf("default inflight cap is %d, want %d", cap(storage.inflight), driveMaxInflight)
 	}
 }
+
+// hrefStore mimics the Yandex Disk REST API: upload and download answer with an href
+// to a presigned blob URL, which must be called without the API credentials.
+type hrefStore struct {
+	*fakeStore
+	blobAuth string
+}
+
+func newHrefStore(t *testing.T) *hrefStore {
+	t.Helper()
+
+	store := &hrefStore{fakeStore: &fakeStore{objects: make(map[string][]byte)}}
+	store.server = httptest.NewServer(http.HandlerFunc(store.handle))
+	t.Cleanup(store.server.Close)
+	return store
+}
+
+func (s *hrefStore) handle(w http.ResponseWriter, r *http.Request) {
+	if strings.HasPrefix(r.URL.Path, "/blob/") {
+		s.mu.Lock()
+		if auth := r.Header.Get("Authorization"); auth != "" {
+			s.blobAuth = auth
+		}
+		s.mu.Unlock()
+		r.URL.Path = "/folder/" + strings.TrimPrefix(r.URL.Path, "/blob/")
+		s.fakeStore.handle(w, r)
+		return
+	}
+	if r.Header.Get("Authorization") != "OAuth tok" {
+		w.WriteHeader(http.StatusUnauthorized)
+		return
+	}
+
+	name := r.URL.Query().Get("path")
+	switch r.URL.Path {
+	case "/upload":
+	case "/download":
+		s.mu.Lock()
+		_, ok := s.objects[name]
+		s.mu.Unlock()
+		if !ok {
+			w.WriteHeader(http.StatusNotFound)
+			return
+		}
+	default:
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+	json.NewEncoder(w).Encode(map[string]interface{}{"href": s.server.URL + "/blob/" + name})
+}
+
+func hrefSettings(store *hrefStore) *internet.MemoryStreamConfig {
+	base := store.server.URL
+	settings := templateSettings(store.fakeStore, map[string]interface{}{
+		"type": "static", "header": map[string]interface{}{"Authorization": "OAuth {secret0}"},
+	}, []string{"tok"})
+	cfg := settings.ProtocolSettings.(*Config)
+	var tmpl map[string]interface{}
+	json.Unmarshal([]byte(cfg.Template), &tmpl)
+	tmpl["put"] = map[string]interface{}{"url": base + "/upload?path={name}", "hrefPath": "href", "hrefMethod": "PUT"}
+	tmpl["get"] = map[string]interface{}{"url": base + "/download?path={name}", "hrefPath": "href"}
+	tmpl["list"] = map[string]interface{}{"method": "PROPFIND", "url": base + "/blob/", "namesRegex": `<d:href>/folder/([^<]+)</d:href>`}
+	tmpl["delete"] = map[string]interface{}{"method": "DELETE", "url": base + "/blob/{name}"}
+	raw, _ := json.Marshal(tmpl)
+	cfg.Template = string(raw)
+	return settings
+}
+
+func TestTemplateTwoStep(t *testing.T) {
+	store := newHrefStore(t)
+	settings := hrefSettings(store)
+	storage, err := newTemplateStorage(settings, settings.ProtocolSettings.(*Config))
+	if err != nil {
+		t.Fatalf("newTemplateStorage: %v", err)
+	}
+	ctx := context.Background()
+
+	if err := storage.Put(ctx, "streams/abc/c2s/000000000.seg", []byte("hello")); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+	data, err := storage.Get(ctx, "streams/abc/c2s/000000000.seg")
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if string(data) != "hello" {
+		t.Fatalf("Get returned %q, want hello", data)
+	}
+	if _, err := storage.Get(ctx, "streams/abc/c2s/000000009.seg"); err != errNotFound {
+		t.Fatalf("Get of a missing object returned %v, want errNotFound", err)
+	}
+	if store.blobAuth != "" {
+		t.Fatalf("the presigned href received credentials %q", store.blobAuth)
+	}
+}
+
+func TestTemplateTwoStepTransport(t *testing.T) {
+	store := newHrefStore(t)
+	client, server, cleanup := pairWith(t, hrefSettings(store))
+	defer cleanup()
+
+	if _, err := client.Write([]byte("ping")); err != nil {
+		t.Fatalf("client write: %v", err)
+	}
+	expectRead(t, server, "ping")
+
+	if _, err := server.Write([]byte("pong")); err != nil {
+		t.Fatalf("server write: %v", err)
+	}
+	expectRead(t, client, "pong")
+}

transport/internet/xdrive/xdrive.go

@@ -87,6 +87,7 @@ func Dial(ctx context.Context, dest net.Destination, streamSettings *internet.Me
 	if err != nil {
 		return nil, err
 	}
+	storage = sessionStorage(storage)
 
 	session, err := newSessionID()
 	if err != nil {
@@ -228,8 +229,10 @@ func (l *Listener) claim(session string) bool {
 }
 
 func (l *Listener) newSessionConn(session string) *Conn {
-	return newConn(l.ctx, l.storage,
+	storage := sessionStorage(l.storage)
+	return newConn(l.ctx, storage,
 		downlinkPrefix(session), uplinkPrefix(session), l.params, func() {
+			storage.Close()
 			l.mu.Lock()
 			delete(l.active, session)
 			l.mu.Unlock()

transport/internet/xdrive/xdrive_test.go

@@ -4,16 +4,21 @@ import (
 	"bytes"
 	"context"
 	"crypto/rand"
+	gotls "crypto/tls"
 	"io"
+	"net/http"
 	"os"
 	"strings"
+	"sync"
 	"sync/atomic"
 	"testing"
 	"time"
 
 	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/splithttp"
 	"github.com/xtls/xray-core/transport/internet/stat"
+	"github.com/xtls/xray-core/transport/internet/tls"
 )
 
 const testPatience = 30 * time.Second
@@ -581,3 +586,388 @@ func TestInlinePayload(t *testing.T) {
 		t.Fatalf("called Get %d times for an inline payload", got)
 	}
 }
+
+// runSessions opens n sessions at once, both ends in this process, passes data
+// both ways over each and closes them
+func runSessions(t *testing.T, streamSettings *internet.MemoryStreamConfig, n int) {
+	t.Helper()
+
+	accepted := make(chan stat.Connection, 1)
+	listener, err := Serve(context.Background(), net.LocalHostIP, net.Port(0), streamSettings, func(conn stat.Connection) {
+		accepted <- conn
+	})
+	if err != nil {
+		t.Fatalf("Serve: %v", err)
+	}
+	defer listener.Close()
+
+	var ends []stat.Connection
+	defer func() {
+		for _, end := range ends {
+			end.Close()
+		}
+	}()
+	for range n {
+		client, err := Dial(context.Background(), net.Destination{}, streamSettings)
+		if err != nil {
+			t.Fatalf("Dial: %v", err)
+		}
+		ends = append(ends, client)
+		select {
+		case peer := <-accepted:
+			ends = append(ends, peer)
+		case <-time.After(testPatience):
+			t.Fatal("listener did not accept the session")
+		}
+	}
+	for i := 0; i < len(ends); i += 2 {
+		if _, err := ends[i].Write([]byte("ping")); err != nil {
+			t.Fatalf("client write: %v", err)
+		}
+		expectRead(t, ends[i+1], "ping")
+		if _, err := ends[i+1].Write([]byte("pong")); err != nil {
+			t.Fatalf("server write: %v", err)
+		}
+		expectRead(t, ends[i], "pong")
+	}
+}
+
+// sessionEnd is the session and end of it that a request to the fake store
+// comes from, or "" for the listener and the token
+func sessionEnd(r *http.Request) string {
+	name := strings.TrimPrefix(r.URL.Path, "/folder/")
+	if r.Method == "PROPFIND" {
+		name = r.URL.Query().Get("prefix")
+	}
+	write := r.Method == http.MethodPut
+	parts := strings.Split(name, flatSeparator)
+	switch {
+	case len(parts) > 2 && parts[0] == streamsDir:
+		// each end writes its own direction and reads the other
+		if (parts[2] == uplinkDir) == write {
+			return parts[1] + " client"
+		}
+		return parts[1] + " server"
+	case len(parts) == 2 && parts[0] == sessionsDir && write:
+		_, session, _ := strings.Cut(parts[1], "-")
+		return session + " client"
+	}
+	return ""
+}
+
+// with "maxConcurrency" 1 every end of a session has a connection of its own,
+// with "maxConnections" the ends share that many, and the sessions after them
+// take the same ones again. The listener and the token use none of them, and
+// the sessions get the token once
+func TestXmuxConnections(t *testing.T) {
+	const n = 3
+	for _, c := range []struct {
+		name   string
+		xmux   *splithttp.XmuxConfig
+		conns  int
+		shared bool
+	}{
+		{"maxConcurrency", &splithttp.XmuxConfig{MaxConcurrency: &splithttp.RangeConfig{From: 1, To: 1}}, 2 * n, false},
+		{"maxConnections", &splithttp.XmuxConfig{MaxConnections: &splithttp.RangeConfig{From: 2, To: 2}}, 2, true},
+	} {
+		t.Run(c.name, func(t *testing.T) {
+			resetSharedStorage()
+			t.Cleanup(resetSharedStorage)
+
+			store := &fakeStore{objects: make(map[string][]byte), needAuth: "Bearer tok-fake"}
+			var (
+				mu    sync.Mutex
+				conns = make(map[string]map[string]bool)
+			)
+			server := newTLSServer(t, &gotls.Config{NextProtos: chromeALPN}, func(w http.ResponseWriter, r *http.Request) {
+				end := sessionEnd(r)
+				mu.Lock()
+				if conns[end] == nil {
+					conns[end] = make(map[string]bool)
+				}
+				conns[end][r.RemoteAddr] = true
+				mu.Unlock()
+				store.handle(w, r)
+			})
+			store.server = server.Server
+			settings := templateSettings(store, map[string]interface{}{
+				"type":     "oauth2",
+				"tokenUrl": server.URL + "/token",
+				"form":     map[string]interface{}{"grant_type": "refresh_token", "refresh_token": "{secret0}"},
+				"header":   map[string]interface{}{"Authorization": "Bearer {token}"},
+			}, []string{"refresh"})
+			settings.SecuritySettings = server.settings(&tls.Config{}).SecuritySettings
+			settings.ProtocolSettings.(*Config).Xmux = c.xmux
+
+			runSessions(t, settings, n)
+			mu.Lock()
+			first := conns
+			conns = make(map[string]map[string]bool)
+			mu.Unlock()
+			dialed := server.conns.Load()
+			runSessions(t, settings, n)
+			if got := server.conns.Load(); got != dialed {
+				t.Errorf("the next %d sessions dialed %d connections", n, got-dialed)
+			}
+
+			owner := make(map[string]string)
+			for end, addrs := range first {
+				if end == "" {
+					continue
+				}
+				if len(addrs) != 1 {
+					t.Errorf("%s used %d connections", end, len(addrs))
+				}
+				for addr := range addrs {
+					if owner[addr] != "" && !c.shared {
+						t.Errorf("%s and %s shared a connection", end, owner[addr])
+					}
+					owner[addr] = end
+				}
+			}
+			if len(owner) != c.conns {
+				t.Errorf("%d sessions had %d connections, want %d", 2*n, len(owner), c.conns)
+			}
+			for addr := range first[""] {
+				if owner[addr] != "" {
+					t.Errorf("the listener or the token went over the connection of %s", owner[addr])
+				}
+			}
+			store.mu.Lock()
+			defer store.mu.Unlock()
+			if store.tokens != 1 {
+				t.Errorf("the sessions got the token %d times", store.tokens)
+			}
+		})
+	}
+}
+
+func TestDriveXmuxConnections(t *testing.T) {
+	drive := newFakeDrive(t)
+	server := newTLSServer(t, &gotls.Config{NextProtos: chromeALPN}, drive.server.Config.Handler.ServeHTTP)
+	driveTokenURL = server.URL + "/token"
+	driveFilesURL = server.URL + "/files"
+	driveUploadURL = server.URL + "/upload"
+	settings := driveSettings()
+	settings.SecuritySettings = server.settings(&tls.Config{}).SecuritySettings
+	settings.ProtocolSettings.(*Config).Xmux = &splithttp.XmuxConfig{MaxConnections: &splithttp.RangeConfig{From: 3, To: 3}}
+
+	runSessions(t, settings, 3)
+	if got := server.conns.Load(); got != 4 {
+		t.Errorf("6 ends of sessions with 3 connections and the listener took %d connections", got)
+	}
+
+	drive.mu.Lock()
+	defer drive.mu.Unlock()
+	if drive.tokens != 1 {
+		t.Errorf("6 ends of sessions got the token %d times", drive.tokens)
+	}
+}
+
+// a session knows the hosts that answered the storage over h1, the polling of
+// the listener for one, so it sends requests in a row over one connection, not
+// first over one for h2 that then stays idle, and parallel ones over more
+func TestSessionKnowsHTTP1Hosts(t *testing.T) {
+	check := func(name string, server *tlsServer, storage Storage) {
+		put := func(s Storage, names ...string) {
+			for _, n := range names {
+				if err := s.Put(context.Background(), "streams/abc/c2s/"+n, []byte("x")); err != nil {
+					t.Errorf("%s: Put: %v", name, err)
+				}
+			}
+		}
+		put(storage, "a", "b")
+		before := server.conns.Load()
+		session := sessionStorage(storage)
+		defer session.Close()
+		put(session, "c", "d")
+		if n := server.conns.Load() - before; n != 1 {
+			t.Errorf("%s: 2 requests in a row of a session over h1 took %d connections", name, n)
+		}
+
+		before = server.conns.Load()
+		var wg sync.WaitGroup
+		for _, n := range []string{"e", "f", "g", "h"} {
+			wg.Go(func() { put(session, n) })
+		}
+		wg.Wait()
+		if server.conns.Load() == before {
+			t.Errorf("%s: 4 parallel requests of a session over h1 took one connection", name)
+		}
+	}
+	slow := func(next http.HandlerFunc) http.HandlerFunc {
+		return func(w http.ResponseWriter, r *http.Request) {
+			time.Sleep(20 * time.Millisecond)
+			next(w, r)
+		}
+	}
+
+	store := &fakeStore{objects: make(map[string][]byte)}
+	server := newTLSServer(t, &gotls.Config{NextProtos: []string{"http/1.1"}}, slow(store.handle))
+	store.server = server.Server
+	settings := templateSettings(store, map[string]interface{}{"type": "none"}, nil)
+	settings.SecuritySettings = server.settings(&tls.Config{}).SecuritySettings
+	template, err := newTemplateStorage(settings, settings.ProtocolSettings.(*Config))
+	if err != nil {
+		t.Fatalf("newTemplateStorage: %v", err)
+	}
+	check("template", server, template)
+
+	drive := newFakeDrive(t)
+	server = newTLSServer(t, &gotls.Config{NextProtos: []string{"http/1.1"}}, slow(drive.server.Config.Handler.ServeHTTP))
+	driveTokenURL = server.URL + "/token"
+	driveFilesURL = server.URL + "/files"
+	settings = driveSettings()
+	settings.SecuritySettings = server.settings(&tls.Config{}).SecuritySettings
+	google, err := newDriveStorage(settings, settings.ProtocolSettings.(*Config))
+	if err != nil {
+		t.Fatalf("newDriveStorage: %v", err)
+	}
+	check("drive", server, google)
+}
+
+// with "hMaxRequestTimes" a session moves on to a new connection after that
+// many requests, and the old one closes once the requests on it end, not before
+func TestXmuxRequestLimit(t *testing.T) {
+	store := &fakeStore{objects: make(map[string][]byte)}
+	arrived := make(chan struct{}, 1)
+	release := make(chan struct{})
+	server := newTLSServer(t, &gotls.Config{NextProtos: chromeALPN}, func(w http.ResponseWriter, r *http.Request) {
+		if r.Method == http.MethodGet {
+			arrived <- struct{}{}
+			<-release
+		}
+		store.handle(w, r)
+	})
+	store.server = server.Server
+	settings := templateSettings(store, map[string]interface{}{"type": "none"}, nil)
+	settings.SecuritySettings = server.settings(&tls.Config{}).SecuritySettings
+	settings.ProtocolSettings.(*Config).Xmux = &splithttp.XmuxConfig{HMaxRequestTimes: &splithttp.RangeConfig{From: 3, To: 3}}
+	storage, err := newTemplateStorage(settings, settings.ProtocolSettings.(*Config))
+	if err != nil {
+		t.Fatalf("newTemplateStorage: %v", err)
+	}
+	session := sessionStorage(storage)
+	defer session.Close()
+	put := func(names ...string) {
+		for _, name := range names {
+			if err := session.Put(context.Background(), "streams/abc/c2s/"+name, []byte("x")); err != nil {
+				t.Fatalf("Put: %v", err)
+			}
+		}
+	}
+
+	put("a")
+	got := make(chan error, 1)
+	go func() {
+		_, err := session.Get(context.Background(), "streams/abc/c2s/a")
+		got <- err
+	}()
+	<-arrived
+	put("b", "c")
+	if n := server.conns.Load(); n != 2 {
+		t.Errorf("4 requests with 3 to a connection took %d connections", n)
+	}
+	if server.closed.Load() != 0 {
+		t.Error("the first connection closed under a request")
+	}
+	close(release)
+	if err := <-got; err != nil {
+		t.Errorf("Get on the first connection: %v", err)
+	}
+	waitFor(t, "the first connection to close", func() bool { return server.closed.Load() == 1 })
+
+	put("d", "e", "f")
+	if n := server.conns.Load(); n != 3 {
+		t.Errorf("7 requests with 3 to a connection took %d connections", n)
+	}
+	waitFor(t, "the second connection to close", func() bool { return server.closed.Load() == 2 })
+}
+
+// a session that fails to announce itself lets go of its connection, which the
+// next one takes with "maxConcurrency" 1
+func TestFailedDialReleasesConnection(t *testing.T) {
+	resetSharedStorage()
+	t.Cleanup(resetSharedStorage)
+
+	store := &fakeStore{objects: make(map[string][]byte)}
+	var refuse atomic.Bool
+	refuse.Store(true)
+	server := newTLSServer(t, &gotls.Config{NextProtos: chromeALPN}, func(w http.ResponseWriter, r *http.Request) {
+		if refuse.Load() {
+			w.WriteHeader(http.StatusUnauthorized)
+			return
+		}
+		store.handle(w, r)
+	})
+	store.server = server.Server
+	settings := templateSettings(store, map[string]interface{}{"type": "none"}, nil)
+	settings.SecuritySettings = server.settings(&tls.Config{}).SecuritySettings
+	settings.ProtocolSettings.(*Config).Xmux = &splithttp.XmuxConfig{MaxConcurrency: &splithttp.RangeConfig{From: 1, To: 1}}
+
+	if _, err := Dial(context.Background(), net.Destination{}, settings); err == nil {
+		t.Fatal("Dial announced a session that the service refused")
+	}
+	refuse.Store(false)
+	conn, err := Dial(context.Background(), net.Destination{}, settings)
+	if err != nil {
+		t.Fatalf("Dial: %v", err)
+	}
+	defer conn.Close()
+	if n := server.conns.Load(); n != 1 {
+		t.Errorf("a failed Dial and the next took %d connections", n)
+	}
+}
+
+// a session gets the token over a connection of the storage, not over one of
+// XMUX
+func TestSessionTokenConnection(t *testing.T) {
+	check := func(name string, server *tlsServer, storage Storage) {
+		session := sessionStorage(storage)
+		defer session.Close()
+		if err := session.Put(context.Background(), "sessions/abc", nil); err != nil {
+			t.Fatalf("%s: Put: %v", name, err)
+		}
+		if n := server.conns.Load(); n != 2 {
+			t.Errorf("%s: the token and a Put of a session took %d connections, want 2", name, n)
+		}
+	}
+
+	store := &fakeStore{objects: make(map[string][]byte), needAuth: "Bearer tok-fake"}
+	server := newTLSServer(t, &gotls.Config{NextProtos: chromeALPN}, store.handle)
+	store.server = server.Server
+	settings := templateSettings(store, map[string]interface{}{
+		"type":     "oauth2",
+		"tokenUrl": server.URL + "/token",
+		"header":   map[string]interface{}{"Authorization": "Bearer {token}"},
+	}, nil)
+	settings.SecuritySettings = server.settings(&tls.Config{}).SecuritySettings
+	template, err := newTemplateStorage(settings, settings.ProtocolSettings.(*Config))
+	if err != nil {
+		t.Fatalf("newTemplateStorage: %v", err)
+	}
+	check("template", server, template)
+
+	drive := newFakeDrive(t)
+	server = newTLSServer(t, &gotls.Config{NextProtos: chromeALPN}, drive.server.Config.Handler.ServeHTTP)
+	driveTokenURL = server.URL + "/token"
+	driveFilesURL = server.URL + "/files"
+	settings = driveSettings()
+	settings.SecuritySettings = server.settings(&tls.Config{}).SecuritySettings
+	google, err := newDriveStorage(settings, settings.ProtocolSettings.(*Config))
+	if err != nil {
+		t.Fatalf("newDriveStorage: %v", err)
+	}
+	check("drive", server, google)
+}
+
+// local storage has no connections to keep apart
+func TestLocalSessionStorage(t *testing.T) {
+	storage, err := newLocalStorage(t.TempDir())
+	if err != nil {
+		t.Fatalf("newLocalStorage: %v", err)
+	}
+	if sessionStorage(storage) != Storage(storage) {
+		t.Fatal("a session of local storage got a storage of its own")
+	}
+}