Add NewClient()

common/protocol/http/client.go

@@ -0,0 +1,34 @@
+package http
+
+import (
+	"context"
+	gohttp "net/http"
+
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet"
+)
+
+// NewClient creates an HTTP client with with internal dialer and using the given sockopt.
+// sockopt can only have one or empty.
+func NewClient(sockopt ...*internet.SocketConfig) *gohttp.Client {
+	var Sockopt *internet.SocketConfig
+	switch len(sockopt) {
+	case 0:
+	case 1:
+		Sockopt = sockopt[0]
+	default:
+		panic("sockopt can only be nil or have one")
+	}
+	httpClient := &gohttp.Client{
+		Transport: &gohttp.Transport{
+			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+				dest, err := net.ParseDestination(network + ":" + addr)
+				if err != nil {
+					return nil, err
+				}
+				return internet.DialSystem(ctx, dest, Sockopt)
+			},
+		},
+	}
+	return httpClient
+}

proxy/vmess/aead/authid.go

@@ -10,10 +10,10 @@ import (
 	"hash/crc32"
 	"io"
 	"math"
-	"time"
 
 	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/antireplay"
+	"github.com/xtls/xray-core/proxy/vmess/vtime"
 )
 
 var (
@@ -105,7 +105,7 @@ func (a *AuthIDDecoderHolder) Match(authID [16]byte) (interface{}, error) {
 			continue
 		}
 
-		if math.Abs(math.Abs(float64(t))-float64(time.Now().Unix())) > 120 {
+		if math.Abs(math.Abs(float64(t))-float64(vtime.Now().Unix())) > 120 {
 			continue
 		}
 

proxy/vmess/aead/encrypt.go

@@ -5,14 +5,14 @@ import (
 	"crypto/rand"
 	"encoding/binary"
 	"io"
-	"time"
 
 	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/crypto"
+	"github.com/xtls/xray-core/proxy/vmess/vtime"
 )
 
 func SealVMessAEADHeader(key [16]byte, data []byte) []byte {
-	generatedAuthID := CreateAuthID(key[:], time.Now().Unix())
+	generatedAuthID := CreateAuthID(key[:], vtime.Now().Unix())
 
 	connectionNonce := make([]byte, 8)
 	if _, err := io.ReadFull(rand.Reader, connectionNonce); err != nil {

proxy/vmess/vtime/vtime.go

@@ -0,0 +1,74 @@
+package vtime
+
+import (
+	"context"
+	"runtime"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/xtls/xray-core/common/errors"
+	"github.com/xtls/xray-core/common/platform"
+	"github.com/xtls/xray-core/common/protocol/http"
+)
+
+var timeOffset atomic.Pointer[time.Duration]
+var initOnce sync.Once
+
+func updateTimeMonitor(ctx context.Context, domain string) {
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-time.After(10 * time.Minute):
+			err := updateTime(domain)
+			if err != nil {
+				errors.LogError(ctx, err)
+			}
+		}
+	}
+}
+
+func updateTime(domain string) error {
+	httpClient := http.NewClient()
+	resp, err := httpClient.Get(domain)
+	if err != nil {
+		return errors.New("Failed to access monitor domain").Base(err)
+	}
+	timeHeader := resp.Header.Get("Date")
+	remoteTime, err := time.Parse(time.RFC1123, timeHeader)
+	if err != nil {
+		return errors.New("Failed to parse time from monitor domain").Base(err)
+	}
+	localTime := time.Now()
+	offset := remoteTime.Sub(localTime)
+	if offset < 2*time.Second && offset > -2*time.Second {
+		errors.LogWarning(context.Background(), "Time offset too small, ignoring:", offset)
+		return nil
+	}
+	timeOffset.Store(&offset)
+	return nil
+}
+
+func Now() time.Time {
+	initOnce.Do(func() {
+		timeOffset.Store(new(time.Duration))
+		go func() {
+			domain := platform.NewEnvFlag("xray.vmess.time.domain").GetValue(func() string { return "https://apple.com" })
+			if domain == "" {
+				errors.LogError(context.Background(), "vmess time domain is empty, skip time sync")
+				return
+			}
+			err := updateTime(domain)
+			if err != nil {
+				errors.LogError(context.Background(), err)
+			}
+			errors.LogWarning(context.Background(), "Initial time offset for vmess:", timeOffset.Load())
+			// only one sync should be enough, so disable periodic update for now
+			//go updateTimeMonitor(context.TODO(), domain)
+		}()
+		runtime.Gosched()
+	})
+	offset := timeOffset.Load()
+	return time.Now().Add(*offset)
+}