| 1 | package transport |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "crypto/tls" |
| 6 | "errors" |
| 7 | "fmt" |
| 8 | "io" |
| 9 | "net" |
| 10 | "time" |
| 11 | |
| 12 | "github.com/gosuda/portal-tunnel/v2/types" |
| 13 | ) |
| 14 | |
| 15 | type ClientStream struct { |
| 16 | accepted chan net.Conn |
| 17 | handshakeTimeout time.Duration |
| 18 | } |
| 19 | |
| 20 | func NewClientStream(readyTarget int, handshakeTimeout time.Duration) *ClientStream { |
| 21 | return &ClientStream{ |
| 22 | accepted: make(chan net.Conn, max(readyTarget*2, 1)), |
| 23 | handshakeTimeout: handshakeTimeout, |
| 24 | } |
| 25 | } |
| 26 | |
| 27 | func (s *ClientStream) Accept(done <-chan struct{}) (net.Conn, error) { |
| 28 | if s == nil { |
| 29 | return nil, net.ErrClosed |
| 30 | } |
| 31 | select { |
| 32 | case <-done: |
| 33 | return nil, net.ErrClosed |
| 34 | case conn := <-s.accepted: |
| 35 | if conn == nil { |
| 36 | return nil, net.ErrClosed |
| 37 | } |
| 38 | return conn, nil |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | func (s *ClientStream) RunSession( |
| 43 | ctx context.Context, |
| 44 | conn net.Conn, |
| 45 | tlsConfig *tls.Config, |
| 46 | ) (bool, error) { |
| 47 | if s == nil { |
| 48 | return false, net.ErrClosed |
| 49 | } |
| 50 | return s.runSession(ctx, conn, tlsConfig) |
| 51 | } |
| 52 | |
| 53 | func (s *ClientStream) Drain() { |
| 54 | if s == nil { |
| 55 | return |
| 56 | } |
| 57 | for { |
| 58 | select { |
| 59 | case conn := <-s.accepted: |
| 60 | if conn != nil { |
| 61 | _ = conn.Close() |
| 62 | } |
| 63 | default: |
| 64 | return |
| 65 | } |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | func (s *ClientStream) runSession( |
| 70 | ctx context.Context, |
| 71 | conn net.Conn, |
| 72 | tlsConfig *tls.Config, |
| 73 | ) (bool, error) { |
| 74 | if conn == nil { |
| 75 | return false, net.ErrClosed |
| 76 | } |
| 77 | |
| 78 | var marker [1]byte |
| 79 | for { |
| 80 | _ = conn.SetReadDeadline(time.Now().Add(2 * s.handshakeTimeout)) |
| 81 | if _, err := io.ReadFull(conn, marker[:]); err != nil { |
| 82 | _ = conn.Close() |
| 83 | return false, err |
| 84 | } |
| 85 | _ = conn.SetReadDeadline(time.Time{}) |
| 86 | |
| 87 | switch marker[0] { |
| 88 | case types.MarkerKeepalive: |
| 89 | continue |
| 90 | case types.MarkerTLSStart: |
| 91 | if err := s.activate(ctx, conn, tlsConfig); err != nil { |
| 92 | _ = conn.Close() |
| 93 | return true, err |
| 94 | } |
| 95 | return true, nil |
| 96 | case types.MarkerRawStart: |
| 97 | if err := s.activateRaw(ctx, conn); err != nil { |
| 98 | _ = conn.Close() |
| 99 | return true, err |
| 100 | } |
| 101 | return true, nil |
| 102 | default: |
| 103 | _ = conn.Close() |
| 104 | return false, fmt.Errorf("unexpected reverse marker: 0x%02x", marker[0]) |
| 105 | } |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | func (s *ClientStream) activate(ctx context.Context, conn net.Conn, tlsConfig *tls.Config) error { |
| 110 | if tlsConfig == nil { |
| 111 | return errors.New("tls config is unavailable") |
| 112 | } |
| 113 | |
| 114 | tlsConn := tls.Server(conn, tlsConfig) |
| 115 | handshakeCtx, cancel := context.WithTimeout(ctx, s.handshakeTimeout) |
| 116 | defer cancel() |
| 117 | if err := tlsConn.HandshakeContext(handshakeCtx); err != nil { |
| 118 | return err |
| 119 | } |
| 120 | |
| 121 | select { |
| 122 | case <-ctx.Done(): |
| 123 | _ = tlsConn.Close() |
| 124 | return ctx.Err() |
| 125 | case s.accepted <- tlsConn: |
| 126 | return nil |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | func (s *ClientStream) activateRaw(ctx context.Context, conn net.Conn) error { |
| 131 | select { |
| 132 | case <-ctx.Done(): |
| 133 | _ = conn.Close() |
| 134 | return ctx.Err() |
| 135 | case s.accepted <- conn: |
| 136 | return nil |
| 137 | } |
| 138 | } |