feat: tlsmiddlebox experiment (#817)

See https://github.com/ooni/probe/issues/2124

internal/engine/experiment/tlsmiddlebox/conn_test.go

@@ -0,0 +1,163 @@
+package tlsmiddlebox
+
+import (
+	"context"
+	"errors"
+	"io"
+	"syscall"
+	"testing"
+
+	"github.com/ooni/probe-cli/v3/internal/model/mocks"
+	"github.com/ooni/probe-cli/v3/internal/netxlite"
+)
+
+func TestDialerTTLWrapperConn(t *testing.T) {
+	t.Run("Read", func(t *testing.T) {
+		t.Run("on success", func(t *testing.T) {
+			b := make([]byte, 128)
+			conn := &dialerTTLWrapperConn{
+				Conn: &mocks.Conn{
+					MockRead: func(b []byte) (int, error) {
+						return len(b), nil
+					},
+				},
+			}
+			count, err := conn.Read(b)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if count != len(b) {
+				t.Fatal("unexpected count")
+			}
+		})
+
+		t.Run("on failure", func(t *testing.T) {
+			b := make([]byte, 128)
+			expectedErr := io.EOF
+			conn := &dialerTTLWrapperConn{
+				Conn: &mocks.Conn{
+					MockRead: func(b []byte) (int, error) {
+						return 0, expectedErr
+					},
+				},
+			}
+			count, err := conn.Read(b)
+			if err == nil || err.Error() != netxlite.FailureEOFError {
+				t.Fatal("unexpected err", err)
+			}
+			if count != 0 {
+				t.Fatal("unexpected count")
+			}
+		})
+	})
+
+	t.Run("Write", func(t *testing.T) {
+		t.Run("on success", func(t *testing.T) {
+			b := make([]byte, 128)
+			conn := &dialerTTLWrapperConn{
+				Conn: &mocks.Conn{
+					MockWrite: func(b []byte) (int, error) {
+						return len(b), nil
+					},
+				},
+			}
+			count, err := conn.Write(b)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if count != len(b) {
+				t.Fatal("unexpected count")
+			}
+		})
+
+		t.Run("on failure", func(t *testing.T) {
+			b := make([]byte, 128)
+			expectedErr := io.EOF
+			conn := &dialerTTLWrapperConn{
+				Conn: &mocks.Conn{
+					MockWrite: func(b []byte) (int, error) {
+						return 0, expectedErr
+					},
+				},
+			}
+			count, err := conn.Write(b)
+			if err == nil || err.Error() != netxlite.FailureEOFError {
+				t.Fatal("unexpected err", err)
+			}
+			if count != 0 {
+				t.Fatal("unexpected count")
+			}
+		})
+	})
+}
+
+func TestSetTTL(t *testing.T) {
+	t.Run("success case", func(t *testing.T) {
+		if testing.Short() {
+			t.Skip("skip test in short mode")
+		}
+		d := NewDialerTTLWrapper()
+		ctx := context.Background()
+		conn, err := d.DialContext(ctx, "tcp", "1.1.1.1:80")
+		if err != nil {
+			t.Fatal("expected non-nil conn")
+		}
+		// test TTL set
+		err = setConnTTL(conn, 1)
+		if err != nil {
+			t.Fatal("unexpected error in setting TTL", err)
+		}
+		var buf [512]byte
+		_, err = conn.Write([]byte("1111"))
+		if err != nil {
+			t.Fatal("error writing", err)
+		}
+		r, _ := conn.Read(buf[:])
+		if r != 0 {
+			t.Fatal("unexpected output size", r)
+		}
+		setConnTTL(conn, 64) // reset TTL to ensure conn closes successfully
+		conn.Close()
+		_, err = conn.Read(buf[:])
+		if err == nil || err.Error() != netxlite.FailureConnectionAlreadyClosed {
+			t.Fatal("failed to reset TTL")
+		}
+	})
+
+	t.Run("failure case", func(t *testing.T) {
+		conn := &mocks.Conn{}
+		err := setConnTTL(conn, 1)
+		if !errors.Is(err, errInvalidConnWrapper) {
+			t.Fatal("unexpected error")
+		}
+	})
+}
+
+func TestGetSoErr(t *testing.T) {
+	t.Run("success case", func(t *testing.T) {
+		d := NewDialerTTLWrapper()
+		ctx := context.Background()
+		conn, err := d.DialContext(ctx, "tcp", "1.1.1.1:80")
+		if err != nil {
+			t.Fatal(err)
+		}
+		errno, err := getSoErr(conn)
+		if err != nil {
+			t.Fatal("unexpected error", err)
+		}
+		if !errors.Is(errno, syscall.Errno(0)) {
+			t.Fatal("unexpected errno")
+		}
+	})
+
+	t.Run("failure case", func(t *testing.T) {
+		conn := &mocks.Conn{}
+		errno, err := getSoErr(conn)
+		if !errors.Is(err, errInvalidConnWrapper) {
+			t.Fatal("unexpected error")
+		}
+		if errno != nil {
+			t.Fatal("expected nil errorno")
+		}
+	})
+}