snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

internal/xds/xdsclient/xdsresource/metadata.go

@@ -0,0 +1,164 @@
+/*
+ *
+ * Copyright 2025 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package xdsresource
+
+import (
+	"fmt"
+	"net/netip"
+
+	"google.golang.org/grpc/internal/envconfig"
+	"google.golang.org/grpc/internal/xds/xdsclient/xdsresource/version"
+	"google.golang.org/protobuf/types/known/anypb"
+
+	v3corepb "github.com/envoyproxy/go-control-plane/envoy/config/core/v3"
+	v3gcpauthnpb "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/http/gcp_authn/v3"
+)
+
+func init() {
+	if envconfig.XDSHTTPConnectEnabled {
+		registerMetadataConverter(version.V3AddressURL, proxyAddressConverter{})
+	}
+	if envconfig.GCPAuthenticationFilterEnabled {
+		registerMetadataConverter(version.V3AudienceURL, audienceConverter{})
+	}
+}
+
+var (
+	// metadataRegistry is a map from proto type to metadataConverter.
+	metadataRegistry = make(map[string]metadataConverter)
+)
+
+// metadataConverter converts xds metadata entries in
+// Metadata.typed_filter_metadata into an internal form with the fields relevant
+// to gRPC.
+type metadataConverter interface {
+	// convert parses the Any proto into a concrete struct.
+	convert(*anypb.Any) (any, error)
+}
+
+// registerMetadataConverter registers the converter to the map keyed on a proto
+// type_url. Must be called at init time. Not thread safe.
+func registerMetadataConverter(protoType string, c metadataConverter) {
+	metadataRegistry[protoType] = c
+}
+
+// metadataConverterForType retrieves a converter based on key given.
+func metadataConverterForType(typeURL string) metadataConverter {
+	return metadataRegistry[typeURL]
+}
+
+// RegisterMetadataConverterForTesting registers the converter for testing
+// purposes and returns a cleanup function to restore the registry to its
+// previous state.
+func RegisterMetadataConverterForTesting(typeURL string) (func(), error) {
+	var conv metadataConverter
+	switch typeURL {
+	case version.V3AddressURL:
+		conv = proxyAddressConverter{}
+	case version.V3AudienceURL:
+		conv = audienceConverter{}
+	default:
+		return nil, fmt.Errorf("unknown typeURL for testing: %s", typeURL)
+	}
+	curConverter, found := metadataRegistry[typeURL]
+	registerMetadataConverter(typeURL, conv)
+	return func() {
+		if found {
+			metadataRegistry[typeURL] = curConverter
+			return
+		}
+		delete(metadataRegistry, typeURL)
+	}, nil
+}
+
+// UnregisterMetadataConverterForTesting unregisters the converter for testing
+// purposes and returns a cleanup function to restore the registry to its
+// previous state.
+func UnregisterMetadataConverterForTesting(typeURL string) func() {
+	curConverter, found := metadataRegistry[typeURL]
+	delete(metadataRegistry, typeURL)
+	return func() {
+		if found {
+			metadataRegistry[typeURL] = curConverter
+		}
+	}
+}
+
+// StructMetadataValue stores the values in a google.protobuf.Struct from
+// FilterMetadata.
+type StructMetadataValue struct {
+	// Data stores the parsed JSON representation of a google.protobuf.Struct.
+	Data map[string]any
+}
+
+// ProxyAddressMetadataValue holds the address parsed from the
+// envoy.config.core.v3.Address proto message, as specified in gRFC A86.
+type ProxyAddressMetadataValue struct {
+	// Address stores the proxy address configured (A86). It will be in the form
+	// of host:port. It has to be either IPv6 or IPv4.
+	Address string
+}
+
+// proxyAddressConvertor implements the metadataConverter interface to handle
+// the conversion of envoy.config.core.v3.Address protobuf messages into an
+// internal representation.
+type proxyAddressConverter struct{}
+
+func (proxyAddressConverter) convert(anyProto *anypb.Any) (any, error) {
+	addressProto := &v3corepb.Address{}
+	if err := anyProto.UnmarshalTo(addressProto); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal resource from Any proto: %v", err)
+	}
+	socketaddress := addressProto.GetSocketAddress()
+	if socketaddress == nil {
+		return nil, fmt.Errorf("no socket_address field in metadata")
+	}
+	if _, err := netip.ParseAddr(socketaddress.GetAddress()); err != nil {
+		return nil, fmt.Errorf("address field is not a valid IPv4 or IPv6 address: %q", socketaddress.GetAddress())
+	}
+	portvalue := socketaddress.GetPortValue()
+	if portvalue == 0 {
+		return nil, fmt.Errorf("port value not set in socket_address")
+	}
+	return ProxyAddressMetadataValue{Address: parseAddress(socketaddress)}, nil
+}
+
+// AudienceMetadataValue holds the audience parsed from the
+// envoy.extensions.filters.http.gcp_authn.v3.Audience proto message, as
+// specified in gRFC A83.
+type AudienceMetadataValue struct {
+	// Audience is the URL of the receiving service that performs token
+	// authentication.
+	Audience string
+}
+
+// audienceConverter implements the metadataConverter interface to
+// handle the conversion of envoy.extensions.filters.http.gcp_authn.v3.Audience
+// protobuf messages into an internal representation.
+type audienceConverter struct{}
+
+func (audienceConverter) convert(anyProto *anypb.Any) (any, error) {
+	audienceProto := &v3gcpauthnpb.Audience{}
+	if err := anyProto.UnmarshalTo(audienceProto); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal the envoy.extensions.filters.http.gcp_authn.v3.Audience resource from Any proto: %v", err)
+	}
+	if audienceProto.GetUrl() == "" {
+		return nil, fmt.Errorf("empty url field in audience metadata")
+	}
+	return AudienceMetadataValue{Audience: audienceProto.GetUrl()}, nil
+}