all: support h3:// protocol prefix

cmd/cli/cli.go

@@ -1473,7 +1473,11 @@ func processNoConfigFlags(noConfigStart bool) {
 
 	endpointAndTyp := func(endpoint string) (string, string) {
 		typ := ctrld.ResolverTypeFromEndpoint(endpoint)
-		return strings.TrimPrefix(endpoint, "quic://"), typ
+		endpoint = strings.TrimPrefix(endpoint, "quic://")
+		if after, found := strings.CutPrefix(endpoint, "h3://"); found {
+			endpoint = "https://" + after
+		}
+		return endpoint, typ
 	}
 	pEndpoint, pType := endpointAndTyp(primaryUpstream)
 	upstream := map[string]*ctrld.UpstreamConfig{

config.go

@@ -59,6 +59,10 @@ const (
 	controlDComDomain = "controld.com"
 	controlDNetDomain = "controld.net"
 	controlDDevDomain = "controld.dev"
+
+	endpointPrefixHTTPS = "https://"
+	endpointPrefixQUIC  = "quic://"
+	endpointPrefixH3    = "h3://"
 )
 
 var (
@@ -677,12 +681,16 @@ func (uc *UpstreamConfig) netForDNSType(dnsType uint16) (string, string) {
 // initDoHScheme initializes the endpoint scheme for DoH/DoH3 upstream if not present.
 func (uc *UpstreamConfig) initDoHScheme() {
 	switch uc.Type {
-	case ResolverTypeDOH, ResolverTypeDOH3:
+	case ResolverTypeDOH:
+	case ResolverTypeDOH3:
+		if after, found := strings.CutPrefix(uc.Endpoint, endpointPrefixH3); found {
+			uc.Endpoint = endpointPrefixHTTPS + after
+		}
 	default:
 		return
 	}
-	if !strings.HasPrefix(uc.Endpoint, "https://") {
+	if !strings.HasPrefix(uc.Endpoint, endpointPrefixHTTPS) {
-		uc.Endpoint = "https://" + uc.Endpoint
+		uc.Endpoint = endpointPrefixHTTPS + uc.Endpoint
 	}
 }
 
@@ -767,13 +775,16 @@ func defaultPortFor(typ string) string {
 // - If endpoint is an IP address ->  ResolverTypeLegacy
 // - If endpoint starts with "https://" -> ResolverTypeDOH
 // - If endpoint starts with "quic://" -> ResolverTypeDOQ
+// - If endpoint starts with "h3://" -> ResolverTypeDOH3
 // - For anything else -> ResolverTypeDOT
 func ResolverTypeFromEndpoint(endpoint string) string {
 	switch {
-	case strings.HasPrefix(endpoint, "https://"):
+	case strings.HasPrefix(endpoint, endpointPrefixHTTPS):
 		return ResolverTypeDOH
-	case strings.HasPrefix(endpoint, "quic://"):
+	case strings.HasPrefix(endpoint, endpointPrefixQUIC):
 		return ResolverTypeDOQ
+	case strings.HasPrefix(endpoint, endpointPrefixH3):
+		return ResolverTypeDOH3
 	}
 	host := endpoint
 	if strings.Contains(endpoint, ":") {

config_internal_test.go

@@ -178,6 +178,27 @@ func TestUpstreamConfig_Init(t *testing.T) {
 				u:              u2,
 			},
 		},
+		{
+			"h3",
+			&UpstreamConfig{
+				Name:        "doh3",
+				Type:        "doh3",
+				Endpoint:    "h3://example.com",
+				BootstrapIP: "",
+				Domain:      "",
+				Timeout:     0,
+			},
+			&UpstreamConfig{
+				Name:        "doh3",
+				Type:        "doh3",
+				Endpoint:    "https://example.com",
+				BootstrapIP: "",
+				Domain:      "example.com",
+				Timeout:     0,
+				IPStack:     IpStackBoth,
+				u:           u1,
+			},
+		},
 	}
 
 	for _, tc := range tests {