1 files changed, 88 insertions, 0 deletions
diff --git a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/FilterResolver.java b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/FilterResolver.java
new file mode 100644
index 00000000000..1e2686aa184
--- /dev/null
+++ b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/FilterResolver.java
@@ -0,0 +1,88 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.jdisc.http.server.jetty;
+
+import com.yahoo.jdisc.Metric;
+import com.yahoo.jdisc.NoopSharedResource;
+import com.yahoo.jdisc.Response;
+import com.yahoo.jdisc.handler.FastContentWriter;
+import com.yahoo.jdisc.handler.ResponseDispatch;
+import com.yahoo.jdisc.handler.ResponseHandler;
+import com.yahoo.jdisc.http.HttpRequest;
+import com.yahoo.jdisc.http.filter.RequestFilter;
+import com.yahoo.jdisc.http.filter.ResponseFilter;
+import com.yahoo.jdisc.http.servlet.ServletRequest;
+
+import javax.servlet.http.HttpServletRequest;
+import java.net.URI;
+import java.util.Map;
+import java.util.Optional;
+
+import static com.yahoo.jdisc.http.server.jetty.JDiscHttpServlet.getConnector;
+
+/**
+ * Resolve request/response filter (chain) based on {@link FilterBindings}.
+ *
+ * @author bjorncs
+ */
+class FilterResolver {
+
+    private final FilterBindings bindings;
+    private final Metric metric;
+    private final boolean strictFiltering;
+
+    FilterResolver(FilterBindings bindings, Metric metric, boolean strictFiltering) {
+        this.bindings = bindings;
+        this.metric = metric;
+        this.strictFiltering = strictFiltering;
+    }
+
+    Optional<RequestFilter> resolveRequestFilter(HttpServletRequest servletRequest, URI jdiscUri) {
+        Optional<String> maybeFilterId = bindings.resolveRequestFilter(jdiscUri, getConnector(servletRequest).listenPort());
+        if (maybeFilterId.isPresent()) {
+            metric.add(MetricDefinitions.FILTERING_REQUEST_HANDLED, 1L, createMetricContext(servletRequest, maybeFilterId.get()));
+            servletRequest.setAttribute(ServletRequest.JDISC_REQUEST_CHAIN, maybeFilterId.get());
+        } else if (!strictFiltering) {
+            metric.add(MetricDefinitions.FILTERING_REQUEST_UNHANDLED, 1L, createMetricContext(servletRequest, null));
+        } else {
+            String syntheticFilterId = RejectingRequestFilter.SYNTHETIC_FILTER_CHAIN_ID;
+            metric.add(MetricDefinitions.FILTERING_REQUEST_HANDLED, 1L, createMetricContext(servletRequest, syntheticFilterId));
+            servletRequest.setAttribute(ServletRequest.JDISC_REQUEST_CHAIN, syntheticFilterId);
+            return Optional.of(RejectingRequestFilter.INSTANCE);
+        }
+        return maybeFilterId.map(bindings::getRequestFilter);
+    }
+
+    Optional<ResponseFilter> resolveResponseFilter(HttpServletRequest servletRequest, URI jdiscUri) {
+        Optional<String> maybeFilterId = bindings.resolveResponseFilter(jdiscUri, getConnector(servletRequest).listenPort());
+        if (maybeFilterId.isPresent()) {
+            metric.add(MetricDefinitions.FILTERING_RESPONSE_HANDLED, 1L, createMetricContext(servletRequest, maybeFilterId.get()));
+            servletRequest.setAttribute(ServletRequest.JDISC_RESPONSE_CHAIN, maybeFilterId.get());
+        } else {
+            metric.add(MetricDefinitions.FILTERING_RESPONSE_UNHANDLED, 1L, createMetricContext(servletRequest, null));
+        }
+        return maybeFilterId.map(bindings::getResponseFilter);
+    }
+
+    private Metric.Context createMetricContext(HttpServletRequest request, String filterId) {
+        Map<String, String> extraDimensions = filterId != null
+                ? Map.of(MetricDefinitions.FILTER_CHAIN_ID_DIMENSION, filterId)
+                : Map.of();
+        return JDiscHttpServlet.getConnector(request).createRequestMetricContext(request, extraDimensions);
+    }
+
+    private static class RejectingRequestFilter extends NoopSharedResource implements RequestFilter {
+
+        private static final RejectingRequestFilter INSTANCE = new RejectingRequestFilter();
+        private static final String SYNTHETIC_FILTER_CHAIN_ID = "strict-reject";
+
+        @Override
+        public void filter(HttpRequest request, ResponseHandler handler) {
+            Response response = new Response(Response.Status.FORBIDDEN);
+            response.headers().add("Content-Type", "text/plain");
+            try (FastContentWriter writer = ResponseDispatch.newInstance(response).connectFastWriter(handler)) {
+                writer.write("Request did not match any request filter chain");
+            }
+        }
+    }
+
+}