From fe956d9189d17b3f221baeac3c87f8a2019df4fd Mon Sep 17 00:00:00 2001
From: Patrick Rohr <prohr@google.com>
Date: Fri, 14 Jun 2024 22:22:40 -0700
Subject: [PATCH] Add a temporary hack to CS to report netbpfload result

Since BpfHandler::init() in the August module does not wait on
netbpfload (it only loads test.o), post on the ConnectivityService
handler and check that netbpfload ran to completion after 30s.

Log.wtf() on failure as these logs show up in Pitot even on release
builds.

Note that system server does not have access to any of the programs or
maps loaded from test.c, so all it can do is verify that mainline_done
exists.

Test: cuttlefish boots and does not crash
Change-Id: I6d2063f1d4f03207bbb6599b75954cfceb793af4
---
 .../android/server/ConnectivityService.java   | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index ca2cb1548e..ba059ab95a 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -109,6 +109,7 @@ import static android.net.connectivity.ConnectivityCompatChanges.NETWORK_BLOCKED
 import static android.os.Process.INVALID_UID;
 import static android.os.Process.VPN_UID;
 import static android.system.OsConstants.ETH_P_ALL;
+import static android.system.OsConstants.F_OK;
 import static android.system.OsConstants.IPPROTO_TCP;
 import static android.system.OsConstants.IPPROTO_UDP;
 
@@ -268,6 +269,7 @@ import android.stats.connectivity.RequestType;
 import android.stats.connectivity.ValidatedState;
 import android.sysprop.NetworkProperties;
 import android.system.ErrnoException;
+import android.system.Os;
 import android.telephony.SubscriptionManager;
 import android.telephony.TelephonyManager;
 import android.text.TextUtils;
@@ -1834,6 +1836,28 @@ public class ConnectivityService extends IConnectivityManager.Stub
                 new PermissionMonitor(mContext, mNetd, mBpfNetMaps, mHandlerThread);
         mHandlerThread.start();
         mHandler = new InternalHandler(mHandlerThread.getLooper());
+        // Temporary hack to report netbpfload result.
+        // TODO: remove in 2024-09 when netbpfload starts loading mainline bpf programs.
+        mHandler.postDelayed(() -> {
+            // Did netbpfload create the map?
+            try {
+                Os.access("/sys/fs/bpf/net_shared/map_gentle_test", F_OK);
+            } catch (ErrnoException e) {
+                Log.wtf(TAG, "netbpfload did not create map", e);
+            }
+            // Did netbpfload create the program?
+            try {
+                Os.access("/sys/fs/bpf/net_shared/prog_gentle_skfilter_accept", F_OK);
+            } catch (ErrnoException e) {
+                Log.wtf(TAG, "netbpfload did not create program", e);
+            }
+            // Did netbpfload run to completion?
+            try {
+                Os.access("/sys/fs/bpf/netd_shared/mainline_done", F_OK);
+            } catch (ErrnoException e) {
+                Log.wtf(TAG, "netbpfload did not run to completion", e);
+            }
+        }, 30_000 /* delayMillis */);
         mTrackerHandler = new NetworkStateTrackerHandler(mHandlerThread.getLooper());
         mConnectivityDiagnosticsHandler =
                 new ConnectivityDiagnosticsHandler(mHandlerThread.getLooper());