From 21ce721bc087d679686acedd06ec7d2b19cad164 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= <maze@google.com>
Date: Mon, 13 Jun 2022 17:28:41 -0700
Subject: [PATCH] BpfHandler.h - switch mStatsMapB from BpfMap to BpfMapRO
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We'd like to switch more of these, but this is the only one
where tests don't get in our way.

We'll fix the rest later.  This gives us an *example* for
further testing.

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I9b280c7ba2d19644fc3cdd0c132de85f45df69b4
---
 netd/BpfHandler.cpp | 1 +
 netd/BpfHandler.h   | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/netd/BpfHandler.cpp b/netd/BpfHandler.cpp
index 42d0de5666..5ae8ab6ee3 100644
--- a/netd/BpfHandler.cpp
+++ b/netd/BpfHandler.cpp
@@ -199,6 +199,7 @@ int BpfHandler::tagSocket(int sockFd, uint32_t tag, uid_t chargeUid, uid_t realU
 
     BpfMap<StatsKey, StatsValue>& currentMap =
             (configuration.value() == SELECT_MAP_A) ? mStatsMapA : mStatsMapB;
+    // HACK: mStatsMapB becomes RW BpfMap here, but countUidStatsEntries doesn't modify so it works
     base::Result<void> res = currentMap.iterate(countUidStatsEntries);
     if (!res.ok()) {
         ALOGE("Failed to count the stats entry in map %d: %s", currentMap.getMap().get(),
diff --git a/netd/BpfHandler.h b/netd/BpfHandler.h
index 05b9ebc81d..7e3b94d6e8 100644
--- a/netd/BpfHandler.h
+++ b/netd/BpfHandler.h
@@ -23,6 +23,7 @@
 #include "bpf_shared.h"
 
 using android::bpf::BpfMap;
+using android::bpf::BpfMapRO;
 
 namespace android {
 namespace net {
@@ -61,7 +62,7 @@ class BpfHandler {
 
     BpfMap<uint64_t, UidTagValue> mCookieTagMap;
     BpfMap<StatsKey, StatsValue> mStatsMapA;
-    BpfMap<StatsKey, StatsValue> mStatsMapB;
+    BpfMapRO<StatsKey, StatsValue> mStatsMapB;
     BpfMap<uint32_t, uint32_t> mConfigurationMap;
     BpfMap<uint32_t, uint8_t> mUidPermissionMap;