Add Snell protocol. Refactor MASQUE HTTP/2, Fair Queue. Update XHTTP, OpenVPN, Sudoku, Fallback. Fixes

transport/snell/client.go

@@ -0,0 +1,120 @@
+package snell
+
+import (
+	"context"
+	"net"
+	"strconv"
+	"time"
+
+	obfs "github.com/sagernet/sing-box/transport/simple-obfs"
+	M "github.com/sagernet/sing/common/metadata"
+	N "github.com/sagernet/sing/common/network"
+)
+
+type ClientOptions struct {
+	Dialer   N.Dialer
+	Server   M.Socksaddr
+	PSK      []byte
+	Version  int
+	Reuse    bool
+	ObfsMode string
+	ObfsHost string
+}
+
+type Client struct {
+	dialer   N.Dialer
+	server   M.Socksaddr
+	psk      []byte
+	version  int
+	reuse    bool
+	obfsMode string
+	obfsHost string
+	pool     *Pool
+}
+
+func NewClient(options ClientOptions) *Client {
+	c := &Client{
+		dialer:   options.Dialer,
+		server:   options.Server,
+		psk:      options.PSK,
+		version:  options.Version,
+		reuse:    options.Reuse,
+		obfsMode: options.ObfsMode,
+		obfsHost: options.ObfsHost,
+	}
+	if c.reuse {
+		c.pool = NewPool(func(ctx context.Context) (*Snell, error) {
+			conn, err := c.dialer.DialContext(ctx, N.NetworkTCP, c.server)
+			if err != nil {
+				return nil, err
+			}
+			return c.streamConn(conn), nil
+		})
+	}
+	return c
+}
+
+func (c *Client) streamConn(conn net.Conn) *Snell {
+	switch c.obfsMode {
+	case "tls":
+		conn = obfs.NewTLSObfs(conn, c.obfsHost)
+	case "http":
+		conn = obfs.NewHTTPObfs(conn, c.obfsHost, strconv.Itoa(int(c.server.Port)))
+	}
+	return StreamConn(conn, c.psk, c.version)
+}
+
+func (c *Client) writeHeader(ctx context.Context, conn net.Conn, destination M.Socksaddr, udp bool) (err error) {
+	if deadline, ok := ctx.Deadline(); ok {
+		_ = conn.SetWriteDeadline(deadline)
+		defer conn.SetWriteDeadline(time.Time{})
+	}
+	if udp {
+		err = WriteUDPHeader(conn, c.version)
+		if err == nil && c.version >= Version4 {
+			if sc, ok := conn.(*Snell); ok {
+				err = sc.ReadReply()
+			}
+		}
+		return
+	}
+	err = WriteHeaderWithReuse(conn, destination.AddrString(), uint(destination.Port), c.version, c.reuse)
+	return
+}
+
+func (c *Client) DialContext(ctx context.Context, destination M.Socksaddr) (net.Conn, error) {
+	if c.reuse {
+		conn, err := c.pool.Get()
+		if err != nil {
+			return nil, err
+		}
+		if err = c.writeHeader(ctx, conn, destination, false); err != nil {
+			_ = conn.Close()
+			return nil, err
+		}
+		return conn, nil
+	}
+	conn, err := c.dialer.DialContext(ctx, N.NetworkTCP, c.server)
+	if err != nil {
+		return nil, err
+	}
+	stream := c.streamConn(conn)
+	if err = c.writeHeader(ctx, stream, destination, false); err != nil {
+		_ = conn.Close()
+		return nil, err
+	}
+	return stream, nil
+}
+
+func (c *Client) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
+	conn, err := c.dialer.DialContext(ctx, N.NetworkTCP, c.server)
+	if err != nil {
+		return nil, err
+	}
+	stream := c.streamConn(conn)
+	if err = c.writeHeader(ctx, stream, destination, true); err != nil {
+		_ = conn.Close()
+		return nil, err
+	}
+	return PacketConn(stream), nil
+}