Take non-incremental network stats from bpf maps
Use two maps to record the details of network stats. Swap and clean up
after system server pulls the stats. The TAG_STATS_MAP is removed since
we don't need to worry about losing the stats for each uid if the eBPF map
is full. All the stats can be stored in the same map now and it is very
unlikely to overflow the map before system server scrapes the stats and
clean it up. Add a benchmark test to measure the performance of creating
and closing pf_key socket. A typical result is:
------------------------------------------------------------------------
Benchmark Time CPU Iterations
------------------------------------------------------------------------
BpfBenchMark/WaitForRcu/1 86615 ns 54858 ns 20209
Bug: 79171384
Test: dumpsys netd trafficcontroller
NetworkUsageStatsTest
Change-Id: Ic79e382f51bf21eee78c4cac5a8a97edaf3654cd
diff --git a/server/TrafficController.h b/server/TrafficController.h
index f089351..c66bc36 100644
--- a/server/TrafficController.h
+++ b/server/TrafficController.h
@@ -145,27 +145,17 @@
BpfMap<uint32_t, StatsValue> mAppUidStatsMap;
/*
- * mUidStatsMap: Store the traffic statistics for a specific combination of
- * uid, iface and counterSet. We maintain this map in addition to
- * mTagStatsMap because we want to be able to track per-UID data usage even
- * if mTagStatsMap is full.
- * Map Key: Struct StatsKey contains the uid, counterSet and ifaceIndex
- * information. The Tag in the StatsKey should always be 0.
+ * mStatsMapA/mStatsMapB: Store the traffic statistics for a specific
+ * combination of uid, tag, iface and counterSet. These two maps contain
+ * both tagged and untagged traffic.
+ * Map Key: Struct StatsKey contains the uid, tag, counterSet and ifaceIndex
+ * information.
* Map Value: struct Stats, contains packet count and byte count of each
* transport protocol on egress and ingress direction.
*/
- BpfMap<StatsKey, StatsValue> mUidStatsMap;
+ BpfMap<StatsKey, StatsValue> mStatsMapA;
- /*
- * mTagStatsMap: Store the traffic statistics for a specific combination of
- * uid, tag, iface and counterSet. Only tagged socket stats should be stored
- * in this map.
- * Map Key: Struct StatsKey contains the uid, counterSet and ifaceIndex
- * information. The tag field should not be 0.
- * Map Value: struct Stats, contains packet count and byte count of each
- * transport protocol on egress and ingress direction.
- */
- BpfMap<StatsKey, StatsValue> mTagStatsMap;
+ BpfMap<StatsKey, StatsValue> mStatsMapB;
/*
* mIfaceIndexNameMap: Store the index name pair of each interface show up
@@ -181,8 +171,16 @@
BpfMap<uint32_t, StatsValue> mIfaceStatsMap;
/*
- * mPowerSaveUidMap: Store uids that have related rules in power save mode owner match
- * chain.
+ * mConfigurationMap: Store the current network policy about uid filtering
+ * and the current stats map in use. There are two configuration entries in
+ * the map right now:
+ * - Entry with UID_RULES_CONFIGURATION_KEY:
+ * Store the configuration for the current uid rules. It indicates the device
+ * is in doze/powersave/standby mode.
+ * - Entry with CURRENT_STATS_MAP_CONFIGURATION_KEY:
+ * Stores the current live stats map that kernel program is writing to.
+ * Userspace can do scraping and cleaning job on the other one depending on the
+ * current configs.
*/
BpfMap<uint32_t, uint8_t> mConfigurationMap GUARDED_BY(mOwnerMatchMutex);