doc: document the availability of DoQ

README.md

@@ -5,13 +5,13 @@
 `dnscore` is a Go library designed for performing DNS measurements.  Its high-level
 API, `*dnscore.Resolver`, is compatible with `*net.Resolver`. Its low-level API,
 `*dnscore.Transport`, provides granular control over performing DNS queries using
-specific protocols (including UDP, TCP, TLS, and HTTPS).
+specific protocols (including UDP, TCP, TLS, HTTPS, and QUIC).
 
 ## Features
 
 - High-level `*Resolver` API compatible with `*net.Resolver` for easy integration.
 - Low-level `*Transport` API allowing granular control over DNS requests and responses.
-- Support for multiple DNS protocols, including UDP, TCP, DoT, and DoH.
+- Support for multiple DNS protocols, including UDP, TCP, DoT, DoH, and DoQ.
 - Utilities for creating and validating DNS messages.
 - Optional logging for structured diagnostic events through `log/slog`.
 - Handling of duplicate responses for DNS over UDP to measure censorship.
@@ -52,11 +52,12 @@ The `*dnscore.Transport` API provides granular control over DNS queries and resp
 See
 
 - [example_https_test.go](example_https_test.go)
+- [example_quic_test.go](example_quic_test.go)
 - [example_tcp_test.go](example_tcp_test.go)
 - [example_tls_test.go](example_tls_test.go)
 - [example_udp_test.go](example_udp_test.go)
 
-for complete examples using DNS over HTTPS, TCP, TLS, and UDP respectively.
+for complete examples using DNS over HTTPS, QUIC, TCP, TLS, and UDP respectively.
 
 See also [internal/cmd/transport/main.go](internal/cmd/transport/main.go) for
 a simple command line tool that demonstrates how to use the `*dnscore.Transport` API

doc.go

@@ -20,7 +20,7 @@ DNS messages.
 
 - Low-level [*Transport] API allowing granular control over DNS requests and responses.
 
-- Support for multiple DNS protocols, including UDP, TCP, DoT, and DoH.
+- Support for multiple DNS protocols, including UDP, TCP, DoT, DoH, and DoQ.
 
 - Utilities for creating and validating DNS messages.
 

resolverconfig.go

@@ -74,7 +74,7 @@ type AddServerOption func(*resolverConfigServer)
 // ServerOptionQueryOptions sets the query options to use for constructing queries
 // to this specific server.If this option is not used, we use the default query options
 // suitable for the protocol used by the server. Specifically, we enable DNSSEC
-// validation and block-length padding for DNS-over-HTTPS and DNS-over-TLS servers.
+// validation and block-length padding for DoT, DoH, and DoQ.
 func ServerOptionQueryOptions(queryOptions ...QueryOption) AddServerOption {
 	return func(s *resolverConfigServer) {
 		s.queryOptions = queryOptions
@@ -103,7 +103,7 @@ func newResolverConfigServer(address *ServerAddr, options ...AddServerOption) re
 
 	// apply the default query options suitable for the protocol used by the server
 	switch address.Protocol {
-	case ProtocolDoH, ProtocolDoT:
+	case ProtocolDoH, ProtocolDoT, ProtocolDoQ:
 		server.queryOptions = append(server.queryOptions, QueryOptionEDNS0(
 			EDNS0SuggestedMaxResponseSizeOtherwise,
 			EDNS0FlagDO|EDNS0FlagBlockLengthPadding))
@@ -143,6 +143,10 @@ func (c *ResolverConfig) servers() []resolverConfigServer {
 	if len(list) == 0 {
 		defaultAddrs := []string{"8.8.8.8", "8.8.4.4"}
 		for _, addr := range defaultAddrs {
+			// TODO(bassosimone): double check whether this is causing
+			// us to always use the max UDP response size also for
+			// encrypted transports. I think this may be the case just
+			// by reading the current code.
 			list = append(list, newResolverConfigServer(
 				NewServerAddr(ProtocolUDP, net.JoinHostPort(addr, "53")),
 				ServerOptionQueryOptions(QueryOptionEDNS0(