Support more than 8 firewall chains / match types.

In the BPF code, per-UID network access (e.g., for doze mode,
standby, etc.) is stored in UidOwnerValue structures. Each of
these stores that UID's rules in a 32-bit bitmask of
UidOwnerMatchType values, so the code can support ~31 match
types.

However, which match types are enabled is stored in
configuration_map at index UID_RULES_CONFIGURATION_KEY, and
configuration_map only stores 8-bit values. So it's not
possible to define more than 7 match types.

Widen configuration_map to from 8 to 32 bits to match the width
of UidOwnerValue.rule. This doesn't impact memory because
configuration_map only has 2 entries.

Bug: 208371987
Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I7e1eee2daedd66d27965a2dd4ce6b4c3667892f7
(cherry picked from commit 60cbed385dcf3c640674c48b7cd4d60967047cf0)
Merged-In: I7e1eee2daedd66d27965a2dd4ce6b4c3667892f7
diff --git a/service/native/TrafficController.cpp b/service/native/TrafficController.cpp
index 5581c40..70c7c34 100644
--- a/service/native/TrafficController.cpp
+++ b/service/native/TrafficController.cpp
@@ -454,15 +454,15 @@
 int TrafficController::toggleUidOwnerMap(ChildChain chain, bool enable) {
     std::lock_guard guard(mMutex);
     uint32_t key = UID_RULES_CONFIGURATION_KEY;
-    auto oldConfiguration = mConfigurationMap.readValue(key);
-    if (!oldConfiguration.ok()) {
+    auto oldConfigure = mConfigurationMap.readValue(key);
+    if (!oldConfigure.ok()) {
         ALOGE("Cannot read the old configuration from map: %s",
-              oldConfiguration.error().message().c_str());
-        return -oldConfiguration.error().code();
+              oldConfigure.error().message().c_str());
+        return -oldConfigure.error().code();
     }
     Status res;
     BpfConfig newConfiguration;
-    uint8_t match;
+    uint32_t match;
     switch (chain) {
         case DOZABLE:
             match = DOZABLE_MATCH;
@@ -483,7 +483,7 @@
             return -EINVAL;
     }
     newConfiguration =
-            enable ? (oldConfiguration.value() | match) : (oldConfiguration.value() & (~match));
+            enable ? (oldConfigure.value() | match) : (oldConfigure.value() & (~match));
     res = mConfigurationMap.writeValue(key, newConfiguration, BPF_EXIST);
     if (!isOk(res)) {
         ALOGE("Failed to toggleUidOwnerMap(%d): %s", chain, res.msg().c_str());
@@ -495,17 +495,17 @@
     std::lock_guard guard(mMutex);
 
     uint32_t key = CURRENT_STATS_MAP_CONFIGURATION_KEY;
-    auto oldConfiguration = mConfigurationMap.readValue(key);
-    if (!oldConfiguration.ok()) {
+    auto oldConfigure = mConfigurationMap.readValue(key);
+    if (!oldConfigure.ok()) {
         ALOGE("Cannot read the old configuration from map: %s",
-              oldConfiguration.error().message().c_str());
-        return Status(oldConfiguration.error().code(), oldConfiguration.error().message());
+              oldConfigure.error().message().c_str());
+        return Status(oldConfigure.error().code(), oldConfigure.error().message());
     }
 
     // Write to the configuration map to inform the kernel eBPF program to switch
     // from using one map to the other. Use flag BPF_EXIST here since the map should
     // be already populated in initMaps.
-    uint8_t newConfigure = (oldConfiguration.value() == SELECT_MAP_A) ? SELECT_MAP_B : SELECT_MAP_A;
+    uint32_t newConfigure = (oldConfigure.value() == SELECT_MAP_A) ? SELECT_MAP_B : SELECT_MAP_A;
     auto res = mConfigurationMap.writeValue(CURRENT_STATS_MAP_CONFIGURATION_KEY, newConfigure,
                                             BPF_EXIST);
     if (!res.ok()) {
diff --git a/service/native/TrafficControllerTest.cpp b/service/native/TrafficControllerTest.cpp
index ad53cb8..c44b9d6 100644
--- a/service/native/TrafficControllerTest.cpp
+++ b/service/native/TrafficControllerTest.cpp
@@ -65,7 +65,7 @@
     BpfMap<uint64_t, UidTagValue> mFakeCookieTagMap;
     BpfMap<uint32_t, StatsValue> mFakeAppUidStatsMap;
     BpfMap<StatsKey, StatsValue> mFakeStatsMapA;
-    BpfMap<uint32_t, uint8_t> mFakeConfigurationMap;
+    BpfMap<uint32_t, uint32_t> mFakeConfigurationMap;
     BpfMap<uint32_t, UidOwnerValue> mFakeUidOwnerMap;
     BpfMap<uint32_t, uint8_t> mFakeUidPermissionMap;
 
diff --git a/service/native/include/TrafficController.h b/service/native/include/TrafficController.h
index 79e75ac..d3d52e2 100644
--- a/service/native/include/TrafficController.h
+++ b/service/native/include/TrafficController.h
@@ -155,7 +155,7 @@
      *    Userspace can do scraping and cleaning job on the other one depending on the
      *    current configs.
      */
-    bpf::BpfMap<uint32_t, uint8_t> mConfigurationMap GUARDED_BY(mMutex);
+    bpf::BpfMap<uint32_t, uint32_t> mConfigurationMap GUARDED_BY(mMutex);
 
     /*
      * mUidOwnerMap: Store uids that are used for bandwidth control uid match.