ooni-probe-cli/internal/engine/netx/quicdialer/dns.go
Simone Basso c74c94d616
cleanup: remove ConnID, DialID, TransactionID (#395)
We are not using them anymore. The only nettest still using the
legacy netx implementation is tor, for which setting these fields
is useless, because it performs each measurement into a separate
goroutine. Hence, let us start removing this part of the legacy
netx codebase, which is hampering progress in other areas.

Occurred to me while doing testing for the recent changes in
error mapping (https://github.com/ooni/probe/issues/1505).
2021-06-23 13:36:45 +02:00

58 lines
1.5 KiB
Go

package quicdialer
import (
"context"
"crypto/tls"
"net"
"github.com/lucas-clemente/quic-go"
"github.com/ooni/probe-cli/v3/internal/engine/netx/dialer"
)
// DNSDialer is a dialer that uses the configured Resolver to resolve a
// domain name to IP addresses
type DNSDialer struct {
Dialer ContextDialer
Resolver Resolver
}
// DialContext implements ContextDialer.DialContext
func (d DNSDialer) DialContext(
ctx context.Context, network, host string,
tlsCfg *tls.Config, cfg *quic.Config) (quic.EarlySession, error) {
onlyhost, onlyport, err := net.SplitHostPort(host)
if err != nil {
return nil, err
}
// TODO(kelmenhorst): Should this be somewhere else?
// failure if tlsCfg is nil but that should not happen
if tlsCfg.ServerName == "" {
tlsCfg.ServerName = onlyhost
}
var addrs []string
addrs, err = d.LookupHost(ctx, onlyhost)
if err != nil {
return nil, err
}
var errorslist []error
for _, addr := range addrs {
target := net.JoinHostPort(addr, onlyport)
sess, err := d.Dialer.DialContext(
ctx, network, target, tlsCfg, cfg)
if err == nil {
return sess, nil
}
errorslist = append(errorslist, err)
}
// TODO(bassosimone): maybe ReduceErrors could be in netx/internal.
return nil, dialer.ReduceErrors(errorslist)
}
// LookupHost implements Resolver.LookupHost
func (d DNSDialer) LookupHost(ctx context.Context, hostname string) ([]string, error) {
if net.ParseIP(hostname) != nil {
return []string{hostname}, nil
}
return d.Resolver.LookupHost(ctx, hostname)
}