package dnsforward import ( "context" "fmt" "net" "time" "github.com/AdguardTeam/golibs/errors" "github.com/AdguardTeam/golibs/log" ) // DialContext is an [aghnet.DialContextFunc] that uses s to resolve hostnames. func (s *Server) DialContext(ctx context.Context, network, addr string) (conn net.Conn, err error) { log.Debug("dnsforward: dialing %q for network %q", addr, network) host, port, err := net.SplitHostPort(addr) if err != nil { return nil, err } dialer := &net.Dialer{ // TODO(a.garipov): Consider making configurable. Timeout: time.Minute * 5, } if net.ParseIP(host) != nil { return dialer.DialContext(ctx, network, addr) } addrs, err := s.Resolve(host) if err != nil { return nil, fmt.Errorf("resolving %q: %w", host, err) } log.Debug("dnsforward: resolving %q: %v", host, addrs) if len(addrs) == 0 { return nil, fmt.Errorf("no addresses for host %q", host) } var dialErrs []error for _, a := range addrs { addr = net.JoinHostPort(a.String(), port) conn, err = dialer.DialContext(ctx, network, addr) if err != nil { dialErrs = append(dialErrs, err) continue } return conn, err } // TODO(a.garipov): Use errors.Join in Go 1.20. return nil, errors.List(fmt.Sprintf("dialing %q", addr), dialErrs...) }