Fix: dial tcp with context to avoid margin of error

adapters/outbound/base.go

@@ -91,7 +91,13 @@ func (p *Proxy) Alive() bool {
 }
 
 func (p *Proxy) Dial(metadata *C.Metadata) (C.Conn, error) {
-	conn, err := p.ProxyAdapter.Dial(metadata)
+	ctx, cancel := context.WithTimeout(context.Background(), tcpTimeout)
+	defer cancel()
+	return p.DialContext(ctx, metadata)
+}
+
+func (p *Proxy) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
+	conn, err := p.ProxyAdapter.DialContext(ctx, metadata)
 	if err != nil {
 		p.alive = false
 	}
@@ -157,7 +163,7 @@ func (p *Proxy) URLTest(ctx context.Context, url string) (t uint16, err error) {
 	}
 
 	start := time.Now()
-	instance, err := p.Dial(&addr)
+	instance, err := p.DialContext(ctx, &addr)
 	if err != nil {
 		return
 	}

adapters/outbound/direct.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"net"
 
 	C "github.com/Dreamacro/clash/constant"
@@ -10,13 +11,13 @@ type Direct struct {
 	*Base
 }
 
-func (d *Direct) Dial(metadata *C.Metadata) (C.Conn, error) {
+func (d *Direct) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
 	address := net.JoinHostPort(metadata.Host, metadata.DstPort)
 	if metadata.DstIP != nil {
 		address = net.JoinHostPort(metadata.DstIP.String(), metadata.DstPort)
 	}
 
-	c, err := dialTimeout("tcp", address, tcpTimeout)
+	c, err := dialContext(ctx, "tcp", address)
 	if err != nil {
 		return nil, err
 	}

adapters/outbound/fallback.go

@@ -31,9 +31,9 @@ func (f *Fallback) Now() string {
 	return proxy.Name()
 }
 
-func (f *Fallback) Dial(metadata *C.Metadata) (C.Conn, error) {
+func (f *Fallback) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
 	proxy := f.findAliveProxy()
-	c, err := proxy.Dial(metadata)
+	c, err := proxy.DialContext(ctx, metadata)
 	if err == nil {
 		c.AppendToChains(f)
 	}

adapters/outbound/http.go

@@ -3,6 +3,7 @@ package adapters
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"crypto/tls"
 	"encoding/base64"
 	"errors"
@@ -35,8 +36,8 @@ type HttpOption struct {
 	SkipCertVerify bool   `proxy:"skip-cert-verify,omitempty"`
 }
 
-func (h *Http) Dial(metadata *C.Metadata) (C.Conn, error) {
+func (h *Http) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
-	c, err := dialTimeout("tcp", h.addr, tcpTimeout)
+	c, err := dialContext(ctx, "tcp", h.addr)
 	if err == nil && h.tls {
 		cc := tls.Client(c, h.tlsConfig)
 		err = cc.Handshake()

adapters/outbound/loadbalance.go

@@ -54,7 +54,7 @@ func jumpHash(key uint64, buckets int32) int32 {
 	return int32(b)
 }
 
-func (lb *LoadBalance) Dial(metadata *C.Metadata) (c C.Conn, err error) {
+func (lb *LoadBalance) DialContext(ctx context.Context, metadata *C.Metadata) (c C.Conn, err error) {
 	defer func() {
 		if err == nil {
 			c.AppendToChains(lb)
@@ -67,11 +67,11 @@ func (lb *LoadBalance) Dial(metadata *C.Metadata) (c C.Conn, err error) {
 		idx := jumpHash(key, buckets)
 		proxy := lb.proxies[idx]
 		if proxy.Alive() {
-			c, err = proxy.Dial(metadata)
+			c, err = proxy.DialContext(ctx, metadata)
 			return
 		}
 	}
-	c, err = lb.proxies[0].Dial(metadata)
+	c, err = lb.proxies[0].DialContext(ctx, metadata)
 	return
 }
 

adapters/outbound/reject.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"io"
 	"net"
 	"time"
@@ -12,7 +13,7 @@ type Reject struct {
 	*Base
 }
 
-func (r *Reject) Dial(metadata *C.Metadata) (C.Conn, error) {
+func (r *Reject) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
 	return newConn(&NopConn{}, r), nil
 }
 

adapters/outbound/selector.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"net"
@@ -20,8 +21,8 @@ type SelectorOption struct {
 	Proxies []string `proxy:"proxies"`
 }
 
-func (s *Selector) Dial(metadata *C.Metadata) (C.Conn, error) {
+func (s *Selector) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
-	c, err := s.selected.Dial(metadata)
+	c, err := s.selected.DialContext(ctx, metadata)
 	if err == nil {
 		c.AppendToChains(s)
 	}

adapters/outbound/shadowsocks.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"crypto/tls"
 	"encoding/json"
 	"fmt"
@@ -57,8 +58,8 @@ type v2rayObfsOption struct {
 	Mux            bool              `obfs:"mux,omitempty"`
 }
 
-func (ss *ShadowSocks) Dial(metadata *C.Metadata) (C.Conn, error) {
+func (ss *ShadowSocks) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
-	c, err := dialTimeout("tcp", ss.server, tcpTimeout)
+	c, err := dialContext(ctx, "tcp", ss.server)
 	if err != nil {
 		return nil, fmt.Errorf("%s connect error: %s", ss.server, err.Error())
 	}

adapters/outbound/snell.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"fmt"
 	"net"
 	"strconv"
@@ -26,8 +27,8 @@ type SnellOption struct {
 	ObfsOpts map[string]interface{} `proxy:"obfs-opts,omitempty"`
 }
 
-func (s *Snell) Dial(metadata *C.Metadata) (C.Conn, error) {
+func (s *Snell) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
-	c, err := dialTimeout("tcp", s.server, tcpTimeout)
+	c, err := dialContext(ctx, "tcp", s.server)
 	if err != nil {
 		return nil, fmt.Errorf("%s connect error: %s", s.server, err.Error())
 	}

adapters/outbound/socks5.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"crypto/tls"
 	"fmt"
 	"io"
@@ -33,8 +34,8 @@ type Socks5Option struct {
 	SkipCertVerify bool   `proxy:"skip-cert-verify,omitempty"`
 }
 
-func (ss *Socks5) Dial(metadata *C.Metadata) (C.Conn, error) {
+func (ss *Socks5) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
-	c, err := dialTimeout("tcp", ss.addr, tcpTimeout)
+	c, err := dialContext(ctx, "tcp", ss.addr)
 
 	if err == nil && ss.tls {
 		cc := tls.Client(c, ss.tlsConfig)
@@ -60,7 +61,9 @@ func (ss *Socks5) Dial(metadata *C.Metadata) (C.Conn, error) {
 }
 
 func (ss *Socks5) DialUDP(metadata *C.Metadata) (_ C.PacketConn, _ net.Addr, err error) {
-	c, err := dialTimeout("tcp", ss.addr, tcpTimeout)
+	ctx, cancel := context.WithTimeout(context.Background(), tcpTimeout)
+	defer cancel()
+	c, err := dialContext(ctx, "tcp", ss.addr)
 	if err != nil {
 		err = fmt.Errorf("%s connect error", ss.addr)
 		return

adapters/outbound/urltest.go

@@ -33,9 +33,9 @@ func (u *URLTest) Now() string {
 	return u.fast.Name()
 }
 
-func (u *URLTest) Dial(metadata *C.Metadata) (c C.Conn, err error) {
+func (u *URLTest) DialContext(ctx context.Context, metadata *C.Metadata) (c C.Conn, err error) {
 	for i := 0; i < 3; i++ {
-		c, err = u.fast.Dial(metadata)
+		c, err = u.fast.DialContext(ctx, metadata)
 		if err == nil {
 			c.AppendToChains(u)
 			return

adapters/outbound/util.go

@@ -86,15 +86,13 @@ func serializesSocksAddr(metadata *C.Metadata) []byte {
 	return bytes.Join(buf, nil)
 }
 
-func dialTimeout(network, address string, timeout time.Duration) (net.Conn, error) {
+func dialContext(ctx context.Context, network, address string) (net.Conn, error) {
 	host, port, err := net.SplitHostPort(address)
 	if err != nil {
 		return nil, err
 	}
 
 	dialer := net.Dialer{}
-	ctx, cancel := context.WithTimeout(context.Background(), timeout)
-	defer cancel()
 
 	returned := make(chan struct{})
 	defer close(returned)

adapters/outbound/vmess.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"fmt"
 	"net"
 	"strconv"
@@ -31,8 +32,8 @@ type VmessOption struct {
 	SkipCertVerify bool              `proxy:"skip-cert-verify,omitempty"`
 }
 
-func (v *Vmess) Dial(metadata *C.Metadata) (C.Conn, error) {
+func (v *Vmess) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
-	c, err := dialTimeout("tcp", v.server, tcpTimeout)
+	c, err := dialContext(ctx, "tcp", v.server)
 	if err != nil {
 		return nil, fmt.Errorf("%s connect error", v.server)
 	}
@@ -42,7 +43,9 @@ func (v *Vmess) Dial(metadata *C.Metadata) (C.Conn, error) {
 }
 
 func (v *Vmess) DialUDP(metadata *C.Metadata) (C.PacketConn, net.Addr, error) {
-	c, err := dialTimeout("tcp", v.server, tcpTimeout)
+	ctx, cancel := context.WithTimeout(context.Background(), tcpTimeout)
+	defer cancel()
+	c, err := dialContext(ctx, "tcp", v.server)
 	if err != nil {
 		return nil, nil, fmt.Errorf("%s connect error", v.server)
 	}

constant/adapters.go

@@ -58,7 +58,7 @@ type PacketConn interface {
 type ProxyAdapter interface {
 	Name() string
 	Type() AdapterType
-	Dial(metadata *Metadata) (Conn, error)
+	DialContext(ctx context.Context, metadata *Metadata) (Conn, error)
 	DialUDP(metadata *Metadata) (PacketConn, net.Addr, error)
 	SupportUDP() bool
 	Destroy()
@@ -74,6 +74,7 @@ type Proxy interface {
 	ProxyAdapter
 	Alive() bool
 	DelayHistory() []DelayHistory
+	Dial(metadata *Metadata) (Conn, error)
 	LastDelay() uint16
 	URLTest(ctx context.Context, url string) (uint16, error)
 }