b8cae3f5a6
We always set the proxy explicitly now. So, let us remove this extra bit of code we're not using. Part of https://github.com/ooni/probe/issues/1507.
73 lines
1.9 KiB
Go
73 lines
1.9 KiB
Go
package dialer
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import (
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"context"
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"errors"
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"net"
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"net/url"
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"golang.org/x/net/proxy"
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)
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// ProxyDialer is a dialer that uses a proxy. If the ProxyURL is not configured, this
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// dialer is a passthrough for the next Dialer in chain. Otherwise, it will internally
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// create a SOCKS5 dialer that will connect to the proxy using the underlying Dialer.
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type ProxyDialer struct {
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Dialer
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ProxyURL *url.URL
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}
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// DialContext implements Dialer.DialContext
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func (d ProxyDialer) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
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url := d.ProxyURL
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if url == nil {
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return d.Dialer.DialContext(ctx, network, address)
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}
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if url.Scheme != "socks5" {
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return nil, errors.New("Scheme is not socks5")
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}
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// the code at proxy/socks5.go never fails; see https://git.io/JfJ4g
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child, _ := proxy.SOCKS5(
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network, url.Host, nil, proxyDialerWrapper{Dialer: d.Dialer})
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return d.dial(ctx, child, network, address)
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}
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func (d ProxyDialer) dial(
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ctx context.Context, child proxy.Dialer, network, address string) (net.Conn, error) {
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connch := make(chan net.Conn)
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errch := make(chan error, 1)
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go func() {
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conn, err := child.Dial(network, address)
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if err != nil {
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errch <- err
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return
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}
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select {
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case connch <- conn:
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default:
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conn.Close()
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}
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}()
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select {
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case <-ctx.Done():
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return nil, ctx.Err()
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case err := <-errch:
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return nil, err
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case conn := <-connch:
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return conn, nil
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}
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}
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// proxyDialerWrapper is required because SOCKS5 expects a Dialer.Dial type but internally
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// it checks whether DialContext is available and prefers that. So, we need to use this
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// structure to cast our inner Dialer the way in which SOCKS5 likes it.
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//
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// See https://git.io/JfJ4g.
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type proxyDialerWrapper struct {
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Dialer
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}
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func (d proxyDialerWrapper) Dial(network, address string) (net.Conn, error) {
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return d.DialContext(context.Background(), network, address)
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}
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