ooni-probe-cli/internal/engine/netx/resolver/decoder.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

55 lines
1.4 KiB
Go

package resolver
import (
"errors"
"github.com/miekg/dns"
)
// The Decoder decodes a DNS reply into A or AAAA entries. It will use the
// provided qtype and only look for mathing entries. It will return error if
// there are no entries for the requested qtype inside the reply.
type Decoder interface {
Decode(qtype uint16, data []byte) ([]string, error)
}
// MiekgDecoder uses github.com/miekg/dns to implement the Decoder.
type MiekgDecoder struct{}
// Decode implements Decoder.Decode.
func (d MiekgDecoder) Decode(qtype uint16, data []byte) ([]string, error) {
reply := new(dns.Msg)
if err := reply.Unpack(data); err != nil {
return nil, err
}
// TODO(bassosimone): map more errors to net.DNSError names
switch reply.Rcode {
case dns.RcodeSuccess:
case dns.RcodeNameError:
return nil, errors.New("ooniresolver: no such host")
default:
return nil, errors.New("ooniresolver: query failed")
}
var addrs []string
for _, answer := range reply.Answer {
switch qtype {
case dns.TypeA:
if rra, ok := answer.(*dns.A); ok {
ip := rra.A
addrs = append(addrs, ip.String())
}
case dns.TypeAAAA:
if rra, ok := answer.(*dns.AAAA); ok {
ip := rra.AAAA
addrs = append(addrs, ip.String())
}
}
}
if len(addrs) <= 0 {
return nil, errors.New("ooniresolver: no response returned")
}
return addrs, nil
}
var _ Decoder = MiekgDecoder{}