121 lines
2.9 KiB
Go
121 lines
2.9 KiB
Go
// SPDX-License-Identifier: BSD-3-Clause
|
|
|
|
package resolvers
|
|
|
|
import (
|
|
"context"
|
|
"crypto/tls"
|
|
"encoding/binary"
|
|
"fmt"
|
|
"io"
|
|
"strings"
|
|
"time"
|
|
|
|
"dns.froth.zone/awl/pkg/util"
|
|
"github.com/miekg/dns"
|
|
"github.com/quic-go/quic-go"
|
|
)
|
|
|
|
// QUICResolver is for DNS-over-QUIC queries.
|
|
type QUICResolver struct {
|
|
opts *util.Options
|
|
}
|
|
|
|
var _ Resolver = (*QUICResolver)(nil)
|
|
|
|
// LookUp performs a DNS query.
|
|
func (resolver *QUICResolver) LookUp(msg *dns.Msg) (resp util.Response, err error) {
|
|
tls := &tls.Config{
|
|
//nolint:gosec // This is intentional if the user requests it
|
|
InsecureSkipVerify: resolver.opts.TLSNoVerify,
|
|
ServerName: resolver.opts.TLSHost,
|
|
MinVersion: tls.VersionTLS12,
|
|
NextProtos: []string{"doq"},
|
|
}
|
|
|
|
// Make sure that TLSHost is ALWAYS set
|
|
if resolver.opts.TLSHost == "" {
|
|
tls.ServerName = strings.Split(resolver.opts.Request.Server, ":")[0]
|
|
}
|
|
|
|
conf := new(quic.Config)
|
|
conf.HandshakeIdleTimeout = resolver.opts.Request.Timeout
|
|
|
|
resolver.opts.Logger.Debug("quic: making query")
|
|
|
|
ctx, cancel := context.WithTimeout(context.Background(), resolver.opts.Request.Timeout)
|
|
defer cancel()
|
|
|
|
connection, err := quic.DialAddr(ctx, resolver.opts.Request.Server, tls, conf)
|
|
if err != nil {
|
|
return resp, fmt.Errorf("doq: dial: %w", err)
|
|
}
|
|
|
|
resolver.opts.Logger.Debug("quic: packing query")
|
|
|
|
msg.Id = 0
|
|
// Compress request to over-the-wire
|
|
buf, err := msg.Pack()
|
|
if err != nil {
|
|
return resp, fmt.Errorf("doq: pack: %w", err)
|
|
}
|
|
|
|
t := time.Now()
|
|
|
|
resolver.opts.Logger.Debug("quic: creating stream")
|
|
|
|
stream, err := connection.OpenStream()
|
|
if err != nil {
|
|
return resp, fmt.Errorf("doq: quic stream creation: %w", err)
|
|
}
|
|
|
|
resolver.opts.Logger.Debug("quic: writing to stream")
|
|
|
|
_, err = stream.Write(rfc9250prefix(buf))
|
|
if err != nil {
|
|
return resp, fmt.Errorf("doq: quic stream write: %w", err)
|
|
}
|
|
|
|
err = stream.Close()
|
|
if err != nil {
|
|
return resp, fmt.Errorf("doq: quic stream close: %w", err)
|
|
}
|
|
|
|
resolver.opts.Logger.Debug("quic: reading stream")
|
|
|
|
fullRes, err := io.ReadAll(stream)
|
|
if err != nil {
|
|
return resp, fmt.Errorf("doq: quic stream read: %w", err)
|
|
}
|
|
|
|
resp.RTT = time.Since(t)
|
|
|
|
resolver.opts.Logger.Debug("quic: closing connection")
|
|
// Close with error: no error
|
|
err = connection.CloseWithError(0, "")
|
|
if err != nil {
|
|
return resp, fmt.Errorf("doq: quic connection close: %w", err)
|
|
}
|
|
|
|
resolver.opts.Logger.Debug("quic: closing stream")
|
|
|
|
resp.DNS = &dns.Msg{}
|
|
|
|
resolver.opts.Logger.Debug("quic: unpacking response")
|
|
|
|
// Unpack response and lop off the first two bytes (RFC 9250 moment)
|
|
err = resp.DNS.Unpack(fullRes[2:])
|
|
if err != nil {
|
|
return resp, fmt.Errorf("doq: unpack: %w", err)
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
// rfc9250prefix adds a two-byte prefix to the input data as per RFC 9250.
|
|
func rfc9250prefix(in []byte) []byte {
|
|
out := make([]byte, 2+len(in))
|
|
binary.BigEndian.PutUint16(out, uint16(len(in)))
|
|
copy(out[2:], in)
|
|
return out
|
|
}
|