3cb782f0a2
While there, modernize the way in which we run tests to avoid depending on the fake files scattered around the tree and to use some well defined mock structures instead. Part of https://github.com/ooni/probe/issues/1591
70 lines
1.7 KiB
Go
70 lines
1.7 KiB
Go
package dnsx
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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 is the network dialer interface assumed by this package.
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type Dialer interface {
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DialContext(ctx context.Context, network, address string) (net.Conn, error)
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}
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// DNSOverUDP is a DNS over UDP RoundTripper.
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type DNSOverUDP struct {
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dialer Dialer
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address string
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}
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// NewDNSOverUDP creates a DNSOverUDP instance.
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func NewDNSOverUDP(dialer Dialer, address string) *DNSOverUDP {
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return &DNSOverUDP{dialer: dialer, address: address}
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}
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// RoundTrip implements RoundTripper.RoundTrip.
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func (t *DNSOverUDP) RoundTrip(ctx context.Context, query []byte) ([]byte, error) {
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conn, err := t.dialer.DialContext(ctx, "udp", t.address)
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if err != nil {
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return nil, err
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}
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defer conn.Close()
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// Use five seconds timeout like Bionic does. See
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// https://labs.ripe.net/Members/baptiste_jonglez_1/persistent-dns-connections-for-reliability-and-performance
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if err = conn.SetDeadline(time.Now().Add(5 * time.Second)); err != nil {
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return nil, err
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}
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if _, err = conn.Write(query); err != nil {
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return nil, err
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}
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reply := make([]byte, 1<<17)
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var n int
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n, err = conn.Read(reply)
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if err != nil {
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return nil, err
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}
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return reply[:n], nil
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}
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// RequiresPadding returns false for UDP according to RFC8467
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func (t *DNSOverUDP) RequiresPadding() bool {
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return false
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}
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// Network returns the transport network (e.g., doh, dot)
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func (t *DNSOverUDP) Network() string {
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return "udp"
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}
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// Address returns the upstream server address.
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func (t *DNSOverUDP) Address() string {
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return t.address
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}
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// CloseIdleConnections closes idle connections.
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func (t *DNSOverUDP) CloseIdleConnections() {
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// nothing to do
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}
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var _ RoundTripper = &DNSOverUDP{}
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