From e441ab60a24532779862531abd51c7bab2b1a4a0 Mon Sep 17 00:00:00 2001
From: Chris Eager <chris@signal.org>
Date: Tue, 6 Feb 2024 11:01:27 -0600
Subject: [PATCH] Add metric for IPv4/IPv6 requests count

---
 .../filters/RequestStatisticsFilter.java      | 30 +++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/filters/RequestStatisticsFilter.java b/service/src/main/java/org/whispersystems/textsecuregcm/filters/RequestStatisticsFilter.java
index 606a4029c..449410da7 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/filters/RequestStatisticsFilter.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/filters/RequestStatisticsFilter.java
@@ -8,13 +8,18 @@ package org.whispersystems.textsecuregcm.filters;
 import static com.codahale.metrics.MetricRegistry.name;
 import static java.util.Objects.requireNonNull;
 
+import com.google.common.net.InetAddresses;
 import io.micrometer.core.instrument.Metrics;
 import java.io.IOException;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetAddress;
 import javax.annotation.Nonnull;
 import javax.ws.rs.container.ContainerRequestContext;
 import javax.ws.rs.container.ContainerRequestFilter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.whispersystems.textsecuregcm.metrics.MetricsUtil;
 import org.whispersystems.textsecuregcm.metrics.TrafficSource;
 
 public class RequestStatisticsFilter implements ContainerRequestFilter {
@@ -23,8 +28,12 @@ public class RequestStatisticsFilter implements ContainerRequestFilter {
 
   private static final String CONTENT_LENGTH_DISTRIBUTION_NAME = name(RequestStatisticsFilter.class, "contentLength");
 
+  private static final String IP_VERSION_METRIC = MetricsUtil.name(RequestStatisticsFilter.class, "ipVersion");
+
   private static final String TRAFFIC_SOURCE_TAG = "trafficSource";
 
+  private static final String IP_VERSION_TAG = "ipVersion";
+
   @Nonnull
   private final String trafficSourceTag;
 
@@ -38,8 +47,29 @@ public class RequestStatisticsFilter implements ContainerRequestFilter {
     try {
       Metrics.summary(CONTENT_LENGTH_DISTRIBUTION_NAME, TRAFFIC_SOURCE_TAG, trafficSourceTag)
           .record(requestContext.getLength());
+      Metrics.counter(IP_VERSION_METRIC, TRAFFIC_SOURCE_TAG, trafficSourceTag, IP_VERSION_TAG,
+              resolveIpVersion(requestContext))
+          .increment();
     } catch (final Exception e) {
       logger.warn("Error recording request statistics", e);
     }
   }
+
+  @Nonnull
+  private static String resolveIpVersion(@Nonnull final ContainerRequestContext ctx) {
+    final String ipString = (String) ctx.getProperty(RemoteAddressFilter.REMOTE_ADDRESS_ATTRIBUTE_NAME);
+
+    try {
+      final InetAddress addr = InetAddresses.forString(ipString);
+      if (addr instanceof Inet4Address) {
+        return "IPv4";
+      }
+      if (addr instanceof Inet6Address) {
+        return "IPv6";
+      }
+    } catch (IllegalArgumentException e) {
+      // ignore illegal argument exception
+    }
+    return "unresolved";
+  }
 }