06ee0e55a9
* refactor(netx/dialer): hide implementation complexity This follows the blueprint of `module.Config` and `nodule.New` described at https://github.com/ooni/probe/issues/1591. * fix: ndt7 bug where we were not using the right resolver * fix(legacy/netx): clarify irrelevant implementation change * fix: improve comments * fix(hhfm): do not use dialer.New b/c it breaks it Unclear to me why this is happening. Still, improve upon the previous situation by adding a timeout. It does not seem a priority to look into this issue now.
56 lines
1.7 KiB
Go
56 lines
1.7 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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// ErrProxyUnsupportedScheme indicates we don't support a protocol scheme.
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var ErrProxyUnsupportedScheme = errors.New("proxy: unsupported scheme")
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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, ErrProxyUnsupportedScheme
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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{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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cd := child.(proxy.ContextDialer) // will work
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return cd.DialContext(ctx, network, address)
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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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panic(errors.New("proxyDialerWrapper.Dial should not be called directly"))
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}
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