7a9499fee3
Like we did before for the resolver, a dialer should propagate the request to close idle connections to underlying types. See https://github.com/ooni/probe/issues/1591
120 lines
3.4 KiB
Go
120 lines
3.4 KiB
Go
package netxlite
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import (
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"context"
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"net"
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"time"
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)
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// Dialer establishes network connections.
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type Dialer interface {
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// DialContext behaves like net.Dialer.DialContext.
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DialContext(ctx context.Context, network, address string) (net.Conn, error)
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// CloseIdleConnections closes idle connections, if any.
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CloseIdleConnections()
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}
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// underlyingDialer is the Dialer we use by default.
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var underlyingDialer = &net.Dialer{
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Timeout: 15 * time.Second,
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KeepAlive: 15 * time.Second,
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}
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// dialerSystem dials using Go stdlib.
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type dialerSystem struct{}
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// DialContext implements Dialer.DialContext.
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func (d *dialerSystem) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
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return underlyingDialer.DialContext(ctx, network, address)
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}
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// CloseIdleConnections implements Dialer.CloseIdleConnections.
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func (d *dialerSystem) CloseIdleConnections() {
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// nothing
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}
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var defaultDialer Dialer = &dialerSystem{}
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// dialerResolver is a dialer that uses the configured Resolver to resolver a
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// domain name to IP addresses, and the configured Dialer to connect.
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type dialerResolver struct {
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// Dialer is the underlying Dialer.
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Dialer Dialer
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// Resolver is the underlying Resolver.
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Resolver Resolver
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}
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var _ Dialer = &dialerResolver{}
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// DialContext implements Dialer.DialContext.
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func (d *dialerResolver) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
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onlyhost, onlyport, err := net.SplitHostPort(address)
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if err != nil {
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return nil, err
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}
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addrs, err := d.lookupHost(ctx, onlyhost)
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if err != nil {
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return nil, err
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}
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// TODO(bassosimone): here we should be using multierror rather
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// than just calling ReduceErrors. We are not ready to do that
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// yet, though. To do that, we need first to modify nettests so
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// that we actually avoid dialing when measuring.
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var errorslist []error
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for _, addr := range addrs {
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target := net.JoinHostPort(addr, onlyport)
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conn, err := d.Dialer.DialContext(ctx, network, target)
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if err == nil {
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return conn, nil
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}
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errorslist = append(errorslist, err)
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}
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return nil, reduceErrors(errorslist)
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}
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// lookupHost performs a domain name resolution.
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func (d *dialerResolver) lookupHost(ctx context.Context, hostname string) ([]string, error) {
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if net.ParseIP(hostname) != nil {
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return []string{hostname}, nil
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}
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return d.Resolver.LookupHost(ctx, hostname)
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}
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// CloseIdleConnections implements Dialer.CloseIdleConnections.
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func (d *dialerResolver) CloseIdleConnections() {
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d.Dialer.CloseIdleConnections()
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d.Resolver.CloseIdleConnections()
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}
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// dialerLogger is a Dialer with logging.
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type dialerLogger struct {
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// Dialer is the underlying dialer.
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Dialer Dialer
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// Logger is the underlying logger.
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Logger Logger
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}
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var _ Dialer = &dialerLogger{}
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// DialContext implements Dialer.DialContext
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func (d *dialerLogger) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
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d.Logger.Debugf("dial %s/%s...", address, network)
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start := time.Now()
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conn, err := d.Dialer.DialContext(ctx, network, address)
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elapsed := time.Since(start)
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if err != nil {
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d.Logger.Debugf("dial %s/%s... %s in %s", address, network, err, elapsed)
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return nil, err
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}
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d.Logger.Debugf("dial %s/%s... ok in %s", address, network, elapsed)
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return conn, nil
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}
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// CloseIdleConnections implements Dialer.CloseIdleConnections.
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func (d *dialerLogger) CloseIdleConnections() {
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d.Dialer.CloseIdleConnections()
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}
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