Add network name constants

common/network/name.go

@@ -0,0 +1,26 @@
+package network
+
+import (
+	"strings"
+
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+var ErrUnknownNetwork = E.New("unknown network")
+
+//goland:noinspection GoNameStartsWithPackageName
+const (
+	NetworkTCP = "tcp"
+	NetworkUDP = "udp"
+)
+
+//goland:noinspection GoNameStartsWithPackageName
+func NetworkName(network string) string {
+	if strings.HasPrefix(network, "tcp") {
+		return NetworkTCP
+	} else if strings.HasPrefix(network, "udp") {
+		return NetworkUDP
+	} else {
+		return network
+	}
+}

protocol/http/client.go

@@ -8,7 +8,6 @@ import (
 	"net/http"
 	"net/url"
 	"os"
-	"strings"
 
 	"github.com/sagernet/sing/common/buf"
 	"github.com/sagernet/sing/common/bufio"
@@ -36,11 +35,16 @@ func NewClient(dialer N.Dialer, serverAddr M.Socksaddr, username string, passwor
 }
 
 func (c *Client) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
-	if !strings.HasPrefix(network, "tcp") {
+	network = N.NetworkName(network)
+	switch network {
+	case N.NetworkTCP:
+	case N.NetworkUDP:
 		return nil, os.ErrInvalid
+	default:
+		return nil, E.Extend(N.ErrUnknownNetwork, network)
 	}
 	var conn net.Conn
-	conn, err := c.dialer.DialContext(ctx, "tcp", c.serverAddr)
+	conn, err := c.dialer.DialContext(ctx, N.NetworkTCP, c.serverAddr)
 	if err != nil {
 		return nil, err
 	}

protocol/http/handshake.go

@@ -97,9 +97,6 @@ func HandleConnection(ctx context.Context, conn net.Conn, reader *std_bufio.Read
 					TLSHandshakeTimeout:   10 * time.Second,
 					ExpectContinueTimeout: 1 * time.Second,
 					DialContext: func(context context.Context, network, address string) (net.Conn, error) {
-						if network != "tcp" && network != "tcp4" && network != "tcp6" {
-							return nil, E.New("unsupported network ", network)
-						}
 						metadata.Destination = M.ParseSocksaddr(address)
 						metadata.Protocol = "http"
 						left, right := net.Pipe()

protocol/socks/client.go

@@ -100,16 +100,20 @@ func NewClientFromURL(dialer N.Dialer, rawURL string) (*Client, error) {
 }
 
 func (c *Client) DialContext(ctx context.Context, network string, address M.Socksaddr) (net.Conn, error) {
+	network = N.NetworkName(network)
 	var command byte
-	if strings.HasPrefix(network, "tcp") {
+	switch network {
+	case N.NetworkTCP:
 		command = socks4.CommandConnect
-	} else {
+	case N.NetworkUDP:
 		if c.version != Version5 {
 			return nil, E.New("socks4: udp unsupported")
 		}
 		command = socks5.CommandUDPAssociate
+	default:
+		return nil, E.Extend(N.ErrUnknownNetwork, network)
 	}
-	tcpConn, err := c.dialer.DialContext(ctx, "tcp", c.serverAddr)
+	tcpConn, err := c.dialer.DialContext(ctx, N.NetworkTCP, c.serverAddr)
 	if err != nil {
 		return nil, err
 	}
@@ -138,7 +142,7 @@ func (c *Client) DialContext(ctx context.Context, network string, address M.Sock
 		if command == socks5.CommandConnect {
 			return tcpConn, nil
 		}
-		udpConn, err := c.dialer.DialContext(ctx, "udp", response.Bind)
+		udpConn, err := c.dialer.DialContext(ctx, N.NetworkUDP, response.Bind)
 		if err != nil {
 			tcpConn.Close()
 			return nil, err
@@ -149,7 +153,7 @@ func (c *Client) DialContext(ctx context.Context, network string, address M.Sock
 }
 
 func (c *Client) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
-	conn, err := c.DialContext(ctx, "udp", destination)
+	conn, err := c.DialContext(ctx, N.NetworkUDP, destination)
 	if err != nil {
 		return nil, err
 	}
@@ -157,7 +161,7 @@ func (c *Client) ListenPacket(ctx context.Context, destination M.Socksaddr) (net
 }
 
 func (c *Client) BindContext(ctx context.Context, address M.Socksaddr) (net.Conn, error) {
-	tcpConn, err := c.dialer.DialContext(ctx, "tcp", c.serverAddr)
+	tcpConn, err := c.dialer.DialContext(ctx, N.NetworkTCP, c.serverAddr)
 	if err != nil {
 		return nil, err
 	}