[xDS] pass HTTP filter name to `GenerateServiceConfig()` method. (#32976)

We need the RBAC filter name as the `policy_name` field in audit logging
context.

src/core/ext/xds/xds_http_fault_filter.cc

@@ -225,7 +225,8 @@ ChannelArgs XdsHttpFaultFilter::ModifyChannelArgs(
 absl::StatusOr<XdsHttpFilterImpl::ServiceConfigJsonEntry>
 XdsHttpFaultFilter::GenerateServiceConfig(
     const FilterConfig& hcm_filter_config,
-    const FilterConfig* filter_config_override) const {
+    const FilterConfig* filter_config_override,
+    absl::string_view /*filter_name*/) const {
   Json policy_json = filter_config_override != nullptr
                          ? filter_config_override->config
                          : hcm_filter_config.config;

src/core/ext/xds/xds_http_fault_filter.h

@@ -48,7 +48,8 @@ class XdsHttpFaultFilter : public XdsHttpFilterImpl {
   ChannelArgs ModifyChannelArgs(const ChannelArgs& args) const override;
   absl::StatusOr<ServiceConfigJsonEntry> GenerateServiceConfig(
       const FilterConfig& hcm_filter_config,
-      const FilterConfig* filter_config_override) const override;
+      const FilterConfig* filter_config_override,
+      absl::string_view filter_name) const override;
   bool IsSupportedOnClients() const override { return true; }
   bool IsSupportedOnServers() const override { return false; }
 };

src/core/ext/xds/xds_http_filters.h

@@ -112,7 +112,8 @@ class XdsHttpFilterImpl {
   // there is no override in any of those locations.
   virtual absl::StatusOr<ServiceConfigJsonEntry> GenerateServiceConfig(
       const FilterConfig& hcm_filter_config,
-      const FilterConfig* filter_config_override) const = 0;
+      const FilterConfig* filter_config_override,
+      absl::string_view filter_name) const = 0;
 
   // Returns true if the filter is supported on clients; false otherwise
   virtual bool IsSupportedOnClients() const = 0;
@@ -138,7 +139,8 @@ class XdsHttpRouterFilter : public XdsHttpFilterImpl {
   const grpc_channel_filter* channel_filter() const override { return nullptr; }
   absl::StatusOr<ServiceConfigJsonEntry> GenerateServiceConfig(
       const FilterConfig& /*hcm_filter_config*/,
-      const FilterConfig* /*filter_config_override*/) const override {
+      const FilterConfig* /*filter_config_override*/,
+      absl::string_view /*filter_name*/) const override {
     // This will never be called, since channel_filter() returns null.
     return absl::UnimplementedError("router filter should never be called");
   }

src/core/ext/xds/xds_http_rbac_filter.cc

@@ -546,12 +546,15 @@ ChannelArgs XdsHttpRbacFilter::ModifyChannelArgs(
 absl::StatusOr<XdsHttpFilterImpl::ServiceConfigJsonEntry>
 XdsHttpRbacFilter::GenerateServiceConfig(
     const FilterConfig& hcm_filter_config,
-    const FilterConfig* filter_config_override) const {
+    const FilterConfig* filter_config_override,
+    absl::string_view filter_name) const {
   Json policy_json = filter_config_override != nullptr
                          ? filter_config_override->config
                          : hcm_filter_config.config;
-  // The policy JSON may be empty, that's allowed.
+  auto json_object = policy_json.object();
-  return ServiceConfigJsonEntry{"rbacPolicy", JsonDump(policy_json)};
+  json_object.emplace("filter_name", std::string(filter_name));
+  // The policy JSON may be empty other than the filter name, that's allowed.
+  return ServiceConfigJsonEntry{"rbacPolicy", JsonDump(Json(json_object))};
 }
 
 }  // namespace grpc_core

src/core/ext/xds/xds_http_rbac_filter.h

@@ -48,7 +48,8 @@ class XdsHttpRbacFilter : public XdsHttpFilterImpl {
   ChannelArgs ModifyChannelArgs(const ChannelArgs& args) const override;
   absl::StatusOr<ServiceConfigJsonEntry> GenerateServiceConfig(
       const FilterConfig& hcm_filter_config,
-      const FilterConfig* filter_config_override) const override;
+      const FilterConfig* filter_config_override,
+      absl::string_view filter_name) const override;
   bool IsSupportedOnClients() const override { return false; }
   bool IsSupportedOnServers() const override { return true; }
 };

src/core/ext/xds/xds_http_stateful_session_filter.cc

@@ -208,7 +208,8 @@ ChannelArgs XdsHttpStatefulSessionFilter::ModifyChannelArgs(
 absl::StatusOr<XdsHttpFilterImpl::ServiceConfigJsonEntry>
 XdsHttpStatefulSessionFilter::GenerateServiceConfig(
     const FilterConfig& hcm_filter_config,
-    const FilterConfig* filter_config_override) const {
+    const FilterConfig* filter_config_override,
+    absl::string_view /*filter_name*/) const {
   Json config = filter_config_override != nullptr
                     ? filter_config_override->config
                     : hcm_filter_config.config;

src/core/ext/xds/xds_http_stateful_session_filter.h

@@ -48,7 +48,8 @@ class XdsHttpStatefulSessionFilter : public XdsHttpFilterImpl {
   ChannelArgs ModifyChannelArgs(const ChannelArgs& args) const override;
   absl::StatusOr<ServiceConfigJsonEntry> GenerateServiceConfig(
       const FilterConfig& hcm_filter_config,
-      const FilterConfig* filter_config_override) const override;
+      const FilterConfig* filter_config_override,
+      absl::string_view filter_name) const override;
   bool IsSupportedOnClients() const override { return true; }
   bool IsSupportedOnServers() const override { return false; }
 };

src/core/ext/xds/xds_routing.cc

@@ -248,8 +248,8 @@ XdsRouting::GeneratePerHTTPFilterConfigs(
         FindFilterConfigOverride(http_filter.name, vhost, route,
                                  cluster_weight);
     // Generate service config for filter.
-    auto method_config_field =
+    auto method_config_field = filter_impl->GenerateServiceConfig(
-        filter_impl->GenerateServiceConfig(http_filter.config, config_override);
+        http_filter.config, config_override, http_filter.name);
     if (!method_config_field.ok()) {
       return absl::FailedPreconditionError(absl::StrCat(
           "failed to generate method config for HTTP filter ", http_filter.name,

test/core/xds/xds_http_filters_test.cc

@@ -303,7 +303,8 @@ TEST_F(XdsFaultInjectionFilterTest, ModifyChannelArgs) {
 TEST_F(XdsFaultInjectionFilterTest, GenerateServiceConfigTopLevelConfig) {
   XdsHttpFilterImpl::FilterConfig config;
   config.config = Json::Object{{"foo", "bar"}};
-  auto service_config = filter_->GenerateServiceConfig(config, nullptr);
+  auto service_config =
+      filter_->GenerateServiceConfig(config, nullptr, /*filter_name=*/"");
   ASSERT_TRUE(service_config.ok()) << service_config.status();
   EXPECT_EQ(service_config->service_config_field_name, "faultInjectionPolicy");
   EXPECT_EQ(service_config->element, "{\"foo\":\"bar\"}");
@@ -314,8 +315,8 @@ TEST_F(XdsFaultInjectionFilterTest, GenerateServiceConfigOverrideConfig) {
   top_config.config = Json::Object{{"foo", "bar"}};
   XdsHttpFilterImpl::FilterConfig override_config;
   override_config.config = Json::Object{{"baz", "quux"}};
-  auto service_config =
+  auto service_config = filter_->GenerateServiceConfig(
-      filter_->GenerateServiceConfig(top_config, &override_config);
+      top_config, &override_config, /*filter_name=*/"");
   ASSERT_TRUE(service_config.ok()) << service_config.status();
   EXPECT_EQ(service_config->service_config_field_name, "faultInjectionPolicy");
   EXPECT_EQ(service_config->element, "{\"baz\":\"quux\"}");
@@ -591,6 +592,17 @@ TEST_F(XdsRbacFilterTest, GenerateFilterConfigOverrideUnparseable) {
       << status;
 }
 
+TEST_F(XdsRbacFilterTest, GenerateServiceConfig) {
+  XdsHttpFilterImpl::FilterConfig hcm_config = {filter_->ConfigProtoName(),
+                                                Json::Object{{"name", "foo"}}};
+  auto config = filter_->GenerateServiceConfig(hcm_config, nullptr, "rbac");
+  ASSERT_TRUE(config.ok()) << config.status();
+  EXPECT_EQ(config->service_config_field_name, "rbacPolicy");
+  EXPECT_EQ(
+      config->element,
+      JsonDump(Json(Json::Object{{"name", "foo"}, {"filter_name", "rbac"}})));
+}
+
 // For the RBAC filter, the override config is a superset of the
 // top-level config, so we test all of the common fields as input for
 // both GenerateFilterConfig() and GenerateFilterConfigOverride().
@@ -1125,7 +1137,8 @@ TEST_F(XdsStatefulSessionFilterTest, OverrideConfigDisabled) {
 TEST_F(XdsStatefulSessionFilterTest, GenerateServiceConfigNoOverride) {
   XdsHttpFilterImpl::FilterConfig hcm_config = {filter_->ConfigProtoName(),
                                                 Json::Object{{"name", "foo"}}};
-  auto config = filter_->GenerateServiceConfig(hcm_config, nullptr);
+  auto config =
+      filter_->GenerateServiceConfig(hcm_config, nullptr, /*filter_name=*/"");
   ASSERT_TRUE(config.ok()) << config.status();
   EXPECT_EQ(config->service_config_field_name, "stateful_session");
   EXPECT_EQ(config->element, JsonDump(Json(Json::Object{{"name", "foo"}})));
@@ -1136,7 +1149,8 @@ TEST_F(XdsStatefulSessionFilterTest, GenerateServiceConfigWithOverride) {
                                                 Json::Object{{"name", "foo"}}};
   XdsHttpFilterImpl::FilterConfig override_config = {
       filter_->OverrideConfigProtoName(), Json::Object{{"name", "bar"}}};
-  auto config = filter_->GenerateServiceConfig(hcm_config, &override_config);
+  auto config = filter_->GenerateServiceConfig(hcm_config, &override_config,
+                                               /*filter_name=*/"");
   ASSERT_TRUE(config.ok()) << config.status();
   EXPECT_EQ(config->service_config_field_name, "stateful_session");
   EXPECT_EQ(config->element, JsonDump(Json(Json::Object{{"name", "bar"}})));