From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Pratyush <codelab@pratyush.dev>
Date: Wed, 17 Aug 2022 08:30:59 +0200
Subject: [PATCH] add option of always randomizing MAC addresses

Co-authored-by: renlord <me@renlord.com>
---
 framework/api/current.txt                           |  1 +
 .../java/android/net/wifi/WifiConfiguration.java    | 13 ++++++++++---
 .../com/android/server/wifi/WifiConfigManager.java  |  7 ++++++-
 .../android/server/wifi/WifiConfigurationUtil.java  |  2 +-
 4 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/framework/api/current.txt b/framework/api/current.txt
index ccdd8a7daa..fa4017bf3c 100644
--- a/framework/api/current.txt
+++ b/framework/api/current.txt
@@ -174,6 +174,7 @@ package android.net.wifi {
     method @Deprecated public void writeToParcel(android.os.Parcel, int);
     field @Deprecated public String BSSID;
     field @Deprecated public String FQDN;
+    field @Deprecated public static final int RANDOMIZATION_ALWAYS = 100; // 0x64
     field @Deprecated public static final int RANDOMIZATION_AUTO = 3; // 0x3
     field @Deprecated public static final int RANDOMIZATION_NONE = 0; // 0x0
     field @Deprecated public static final int RANDOMIZATION_NON_PERSISTENT = 2; // 0x2
diff --git a/framework/java/android/net/wifi/WifiConfiguration.java b/framework/java/android/net/wifi/WifiConfiguration.java
index 88582dde76..0d4e3fcc38 100644
--- a/framework/java/android/net/wifi/WifiConfiguration.java
+++ b/framework/java/android/net/wifi/WifiConfiguration.java
@@ -1865,7 +1865,8 @@ public class WifiConfiguration implements Parcelable {
             RANDOMIZATION_NONE,
             RANDOMIZATION_PERSISTENT,
             RANDOMIZATION_NON_PERSISTENT,
-            RANDOMIZATION_AUTO})
+            RANDOMIZATION_AUTO,
+            RANDOMIZATION_ALWAYS})
     public @interface MacRandomizationSetting {}
 
     /**
@@ -1889,16 +1890,22 @@ public class WifiConfiguration implements Parcelable {
      */
     public static final int RANDOMIZATION_AUTO = 3;
 
+    /**
+     * Generate a randomize MAC always
+     */
+    public static final int RANDOMIZATION_ALWAYS = 100;
+
     /**
      * Level of MAC randomization for this network.
      * One of {@link #RANDOMIZATION_NONE}, {@link #RANDOMIZATION_AUTO},
      * {@link #RANDOMIZATION_PERSISTENT} or {@link #RANDOMIZATION_NON_PERSISTENT}.
-     * By default this field is set to {@link #RANDOMIZATION_AUTO}.
+     * {@link #RANDOMIZATION_PERSISTENT} or {@link #RANDOMIZATION_NON_PERSISTENT} or RANDOMIZATION_ALWAYS.
+     * By default this field is set to RANDOMIZATION_ALWAYS in GrapheneOS.
      * @hide
      */
     @SystemApi
     @MacRandomizationSetting
-    public int macRandomizationSetting = RANDOMIZATION_AUTO;
+    public int macRandomizationSetting = RANDOMIZATION_ALWAYS;
 
     /**
      * Set the MAC randomization setting for this network.
diff --git a/service/java/com/android/server/wifi/WifiConfigManager.java b/service/java/com/android/server/wifi/WifiConfigManager.java
index d2f26183c3..e758344204 100644
--- a/service/java/com/android/server/wifi/WifiConfigManager.java
+++ b/service/java/com/android/server/wifi/WifiConfigManager.java
@@ -492,6 +492,10 @@ public class WifiConfigManager {
      * @return
      */
     public boolean shouldUseNonPersistentRandomization(WifiConfiguration config) {
+        if (config.macRandomizationSetting == WifiConfiguration.RANDOMIZATION_ALWAYS) {
+            return true;
+        }
+
         if (!isMacRandomizationSupported()
                 || config.macRandomizationSetting == WifiConfiguration.RANDOMIZATION_NONE) {
             return false;
@@ -641,7 +645,8 @@ public class WifiConfigManager {
     private MacAddress updateRandomizedMacIfNeeded(WifiConfiguration config) {
         boolean shouldUpdateMac = config.randomizedMacExpirationTimeMs
                 < mClock.getWallClockMillis() || mClock.getWallClockMillis()
-                - config.randomizedMacLastModifiedTimeMs >= NON_PERSISTENT_MAC_REFRESH_MS_MAX;
+                - config.randomizedMacLastModifiedTimeMs >= NON_PERSISTENT_MAC_REFRESH_MS_MAX ||
+                config.macRandomizationSetting == WifiConfiguration.RANDOMIZATION_ALWAYS;
         if (!shouldUpdateMac) {
             return config.getRandomizedMacAddress();
         }
diff --git a/service/java/com/android/server/wifi/WifiConfigurationUtil.java b/service/java/com/android/server/wifi/WifiConfigurationUtil.java
index 501a071b34..fb73e08a02 100644
--- a/service/java/com/android/server/wifi/WifiConfigurationUtil.java
+++ b/service/java/com/android/server/wifi/WifiConfigurationUtil.java
@@ -271,7 +271,7 @@ public class WifiConfigurationUtil {
     public static boolean hasMacRandomizationSettingsChanged(WifiConfiguration existingConfig,
             WifiConfiguration newConfig) {
         if (existingConfig == null) {
-            return newConfig.macRandomizationSetting != WifiConfiguration.RANDOMIZATION_AUTO;
+            return newConfig.macRandomizationSetting != WifiConfiguration.RANDOMIZATION_ALWAYS;
         }
         return newConfig.macRandomizationSetting != existingConfig.macRandomizationSetting;
     }