From 5026b3ea9339a29aa831b7976daec993f5a01d5c Mon Sep 17 00:00:00 2001
From: Lorenzo Colitti <lorenzo@google.com>
Date: Mon, 10 May 2021 00:49:14 +0900
Subject: [PATCH] Do not automatically redact TransportInfo objects.

Currently, NetworkCapabilities always redacts the TransportInfo
objects it contains whenever a defensive copy is made. This makes
it impossible to make a defensive copy on a TransportInfo
parcelled from another process without redacting it.

Stop redacting by default; instead rely on ConnectivityService
explicitly calling NetworkCapabilities' redacting constructor
when it returns a NetworkCapabilities object to an app via a
callback or synchronous call. This is currently done by
- createWithLocationInfoSanitizedIfNecessaryWhenParceled, which
  is called from callCallbackForRequest, getNetworkCapabilities,
  and getDefaultNetworkCapabilitiesForUser.
- getNetworkCapabilitiesWithoutUids, which is used when sending
  ConnectivityDiagnosticsManager callbacks. In this method,
  unconditionally redact all information, which is what the code
  did previously due to the default redaction setting for empty
  NetworkCapabilities objects being REDACT_ALL.

Bug: 183938194
Test: atest NetworkCapabilitiesTest
Test: atest FrameworksNetTests CtsNetTestCases HostsideVpnTests
Change-Id: I3108ee94cb0930958e071ba678c3554525b0db82
---
 .../src/android/net/NetworkCapabilities.java  | 22 +++++--------------
 1 file changed, 5 insertions(+), 17 deletions(-)

diff --git a/framework/src/android/net/NetworkCapabilities.java b/framework/src/android/net/NetworkCapabilities.java
index 0bafd5b2f8..d0b107581b 100644
--- a/framework/src/android/net/NetworkCapabilities.java
+++ b/framework/src/android/net/NetworkCapabilities.java
@@ -139,19 +139,13 @@ public final class NetworkCapabilities implements Parcelable {
      */
     private String mRequestorPackageName;
 
-    /**
-     * Indicates what fields should be redacted from this instance.
-     */
-    private final @RedactionType long mRedactions;
-
     public NetworkCapabilities() {
-        mRedactions = REDACT_ALL;
         clearAll();
         mNetworkCapabilities = DEFAULT_CAPABILITIES;
     }
 
     public NetworkCapabilities(NetworkCapabilities nc) {
-        this(nc, REDACT_ALL);
+        this(nc, REDACT_NONE);
     }
 
     /**
@@ -163,10 +157,12 @@ public final class NetworkCapabilities implements Parcelable {
      * @hide
      */
     public NetworkCapabilities(@Nullable NetworkCapabilities nc, @RedactionType long redactions) {
-        mRedactions = redactions;
         if (nc != null) {
             set(nc);
         }
+        if (mTransportInfo != null) {
+            mTransportInfo = nc.mTransportInfo.makeCopy(redactions);
+        }
     }
 
     /**
@@ -175,14 +171,6 @@ public final class NetworkCapabilities implements Parcelable {
      * @hide
      */
     public void clearAll() {
-        // Ensures that the internal copies maintained by the connectivity stack does not set it to
-        // anything other than |REDACT_ALL|.
-        if (mRedactions != REDACT_ALL) {
-            // This is needed because the current redaction mechanism relies on redaction while
-            // parceling.
-            throw new UnsupportedOperationException(
-                    "Cannot clear NetworkCapabilities when mRedactions is set");
-        }
         mNetworkCapabilities = mTransportTypes = mForbiddenNetworkCapabilities = 0;
         mLinkUpBandwidthKbps = mLinkDownBandwidthKbps = LINK_BANDWIDTH_UNSPECIFIED;
         mNetworkSpecifier = null;
@@ -211,7 +199,7 @@ public final class NetworkCapabilities implements Parcelable {
         mLinkDownBandwidthKbps = nc.mLinkDownBandwidthKbps;
         mNetworkSpecifier = nc.mNetworkSpecifier;
         if (nc.getTransportInfo() != null) {
-            setTransportInfo(nc.getTransportInfo().makeCopy(mRedactions));
+            setTransportInfo(nc.getTransportInfo());
         } else {
             setTransportInfo(null);
         }