ooni-probe-cli/internal/engine/netx/resolver/dnsoverudp.go
Simone Basso d57c78bc71
chore: merge probe-engine into probe-cli (#201)
This is how I did it:

1. `git clone https://github.com/ooni/probe-engine internal/engine`

2. ```
(cd internal/engine && git describe --tags)
v0.23.0
```

3. `nvim go.mod` (merging `go.mod` with `internal/engine/go.mod`

4. `rm -rf internal/.git internal/engine/go.{mod,sum}`

5. `git add internal/engine`

6. `find . -type f -name \*.go -exec sed -i 's@/ooni/probe-engine@/ooni/probe-cli/v3/internal/engine@g' {} \;`

7. `go build ./...` (passes)

8. `go test -race ./...` (temporary failure on RiseupVPN)

9. `go mod tidy`

10. this commit message

Once this piece of work is done, we can build a new version of `ooniprobe` that
is using `internal/engine` directly. We need to do more work to ensure all the
other functionality in `probe-engine` (e.g. making mobile packages) are still WAI.

Part of https://github.com/ooni/probe/issues/1335
2021-02-02 12:05:47 +01:00

65 lines
1.5 KiB
Go

package resolver
import (
"context"
"net"
"time"
)
// Dialer is the network dialer interface assumed by this package.
type Dialer interface {
DialContext(ctx context.Context, network, address string) (net.Conn, error)
}
// DNSOverUDP is a DNS over UDP RoundTripper.
type DNSOverUDP struct {
dialer Dialer
address string
}
// NewDNSOverUDP creates a DNSOverUDP instance.
func NewDNSOverUDP(dialer Dialer, address string) DNSOverUDP {
return DNSOverUDP{dialer: dialer, address: address}
}
// RoundTrip implements RoundTripper.RoundTrip.
func (t DNSOverUDP) RoundTrip(ctx context.Context, query []byte) ([]byte, error) {
conn, err := t.dialer.DialContext(ctx, "udp", t.address)
if err != nil {
return nil, err
}
defer conn.Close()
// Use five seconds timeout like Bionic does. See
// https://labs.ripe.net/Members/baptiste_jonglez_1/persistent-dns-connections-for-reliability-and-performance
if err = conn.SetDeadline(time.Now().Add(5 * time.Second)); err != nil {
return nil, err
}
if _, err = conn.Write(query); err != nil {
return nil, err
}
reply := make([]byte, 1<<17)
var n int
n, err = conn.Read(reply)
if err != nil {
return nil, err
}
return reply[:n], nil
}
// RequiresPadding returns false for UDP according to RFC8467
func (t DNSOverUDP) RequiresPadding() bool {
return false
}
// Network returns the transport network (e.g., doh, dot)
func (t DNSOverUDP) Network() string {
return "udp"
}
// Address returns the upstream server address.
func (t DNSOverUDP) Address() string {
return t.address
}
var _ RoundTripper = DNSOverUDP{}