refactor: i/errorsx is now i/legacy/errorsx (#479)

We need still to add similar wrappers to internal/netxlite but we
will adopt a saner approach to error wrapping this time.

See https://github.com/ooni/probe/issues/1591

internal/errorsx/quic.go

@@ -1,98 +0,0 @@
-package errorsx
-
-import (
-	"context"
-	"crypto/tls"
-	"net"
-
-	"github.com/lucas-clemente/quic-go"
-	"github.com/ooni/probe-cli/v3/internal/netxlite/errorsx"
-	"github.com/ooni/probe-cli/v3/internal/netxlite/quicx"
-)
-
-// QUICContextDialer is a dialer for QUIC using Context.
-type QUICContextDialer interface {
-	// DialContext establishes a new QUIC session using the given
-	// network and address. The tlsConfig and the quicConfig arguments
-	// MUST NOT be nil. Returns either the session or an error.
-	DialContext(ctx context.Context, network, address string,
-		tlsConfig *tls.Config, quicConfig *quic.Config) (quic.EarlySession, error)
-}
-
-// QUICListener listens for QUIC connections.
-type QUICListener interface {
-	// Listen creates a new listening UDPConn.
-	Listen(addr *net.UDPAddr) (quicx.UDPLikeConn, error)
-}
-
-// ErrorWrapperQUICListener is a QUICListener that wraps errors.
-type ErrorWrapperQUICListener struct {
-	// QUICListener is the underlying listener.
-	QUICListener QUICListener
-}
-
-var _ QUICListener = &ErrorWrapperQUICListener{}
-
-// Listen implements QUICListener.Listen.
-func (qls *ErrorWrapperQUICListener) Listen(addr *net.UDPAddr) (quicx.UDPLikeConn, error) {
-	pconn, err := qls.QUICListener.Listen(addr)
-	if err != nil {
-		return nil, SafeErrWrapperBuilder{
-			Error:     err,
-			Operation: errorsx.QUICListenOperation,
-		}.MaybeBuild()
-	}
-	return &errorWrapperUDPConn{pconn}, nil
-}
-
-// errorWrapperUDPConn is a quicx.UDPLikeConn that wraps errors.
-type errorWrapperUDPConn struct {
-	// UDPLikeConn is the underlying conn.
-	quicx.UDPLikeConn
-}
-
-var _ quicx.UDPLikeConn = &errorWrapperUDPConn{}
-
-// WriteTo implements quicx.UDPLikeConn.WriteTo.
-func (c *errorWrapperUDPConn) WriteTo(p []byte, addr net.Addr) (int, error) {
-	count, err := c.UDPLikeConn.WriteTo(p, addr)
-	if err != nil {
-		return 0, SafeErrWrapperBuilder{
-			Error:     err,
-			Operation: errorsx.WriteToOperation,
-		}.MaybeBuild()
-	}
-	return count, nil
-}
-
-// ReadFrom implements quicx.UDPLikeConn.ReadFrom.
-func (c *errorWrapperUDPConn) ReadFrom(b []byte) (int, net.Addr, error) {
-	n, addr, err := c.UDPLikeConn.ReadFrom(b)
-	if err != nil {
-		return 0, nil, SafeErrWrapperBuilder{
-			Error:     err,
-			Operation: errorsx.ReadFromOperation,
-		}.MaybeBuild()
-	}
-	return n, addr, nil
-}
-
-// ErrorWrapperQUICDialer is a dialer that performs quic err wrapping
-type ErrorWrapperQUICDialer struct {
-	Dialer QUICContextDialer
-}
-
-// DialContext implements ContextDialer.DialContext
-func (d *ErrorWrapperQUICDialer) DialContext(
-	ctx context.Context, network string, host string,
-	tlsCfg *tls.Config, cfg *quic.Config) (quic.EarlySession, error) {
-	sess, err := d.Dialer.DialContext(ctx, network, host, tlsCfg, cfg)
-	if err != nil {
-		return nil, SafeErrWrapperBuilder{
-			Classifier: errorsx.ClassifyQUICHandshakeError,
-			Error:      err,
-			Operation:  errorsx.QUICHandshakeOperation,
-		}.MaybeBuild()
-	}
-	return sess, nil
-}