Use eBPF map data for per iface stats

After adding the xt_bpf module and ifaceStatsMap, eBPF tool can now
support reading per interface data. So networkStatsFactory should move
away from parsing proc/net/dev and use the eBPF map stats instead.

Bug: 72111305
Test: atest com.android.server.net.NetworkStatsServiceTest
Change-Id: Ibcc6150d00835b3bd33af22a72e4a86e172581cf

core/java/com/android/internal/net/NetworkStatsFactory.java

@@ -176,6 +176,14 @@ public class NetworkStatsFactory {
         return stats;
     }
 
+    public NetworkStats readBpfNetworkStatsDev() throws IOException {
+        final NetworkStats stats = new NetworkStats(SystemClock.elapsedRealtime(), 6);
+        if (nativeReadNetworkStatsDev(stats) != 0) {
+            throw new IOException("Failed to parse bpf iface stats");
+        }
+        return stats;
+    }
+
     /**
      * Parse and return interface-level summary {@link NetworkStats} measured
      * using {@code /proc/net/dev} style hooks, which may include non IP layer
@@ -186,9 +194,9 @@ public class NetworkStatsFactory {
      */
     public NetworkStats readNetworkStatsSummaryDev() throws IOException {
 
-        // Return the stats get from /proc/net/dev if switched to bpf module.
+        // Return xt_bpf stats if switched to bpf module.
         if (mUseBpfStats)
-            return readNetworkStatsIfaceDev();
+            return readBpfNetworkStatsDev();
 
         final StrictMode.ThreadPolicy savedPolicy = StrictMode.allowThreadDiskReads();
 
@@ -242,9 +250,9 @@ public class NetworkStatsFactory {
      */
     public NetworkStats readNetworkStatsSummaryXt() throws IOException {
 
-        // Return the stats get from /proc/net/dev if qtaguid  module is replaced.
+        // Return xt_bpf stats if qtaguid  module is replaced.
         if (mUseBpfStats)
-            return readNetworkStatsIfaceDev();
+            return readBpfNetworkStatsDev();
 
         final StrictMode.ThreadPolicy savedPolicy = StrictMode.allowThreadDiskReads();
 
@@ -406,4 +414,7 @@ public class NetworkStatsFactory {
     @VisibleForTesting
     public static native int nativeReadNetworkStatsDetail(NetworkStats stats, String path,
         int limitUid, String[] limitIfaces, int limitTag, boolean useBpfStats);
+
+    @VisibleForTesting
+    public static native int nativeReadNetworkStatsDev(NetworkStats stats);
 }

core/jni/com_android_internal_net_NetworkStatsFactory.cpp

@@ -205,37 +205,8 @@ static int legacyReadNetworkStatsDetail(std::vector<stats_line>* lines,
     return 0;
 }
 
-static int readNetworkStatsDetail(JNIEnv* env, jclass clazz, jobject stats, jstring path,
+static int statsLinesToNetworkStats(JNIEnv* env, jclass clazz, jobject stats,
-                                  jint limitUid, jobjectArray limitIfacesObj, jint limitTag,
+                            std::vector<stats_line>& lines) {
-                                  jboolean useBpfStats) {
-    ScopedUtfChars path8(env, path);
-    if (path8.c_str() == NULL) {
-        return -1;
-    }
-
-    std::vector<std::string> limitIfaces;
-    if (limitIfacesObj != NULL && env->GetArrayLength(limitIfacesObj) > 0) {
-        int num = env->GetArrayLength(limitIfacesObj);
-        for (int i = 0; i < num; i++) {
-            jstring string = (jstring)env->GetObjectArrayElement(limitIfacesObj, i);
-            ScopedUtfChars string8(env, string);
-            if (string8.c_str() != NULL) {
-                limitIfaces.push_back(std::string(string8.c_str()));
-            }
-        }
-    }
-    std::vector<stats_line> lines;
-
-
-    if (useBpfStats) {
-        if (parseBpfNetworkStatsDetail(&lines, limitIfaces, limitTag, limitUid) < 0)
-            return -1;
-    } else {
-        if (legacyReadNetworkStatsDetail(&lines, limitIfaces, limitTag,
-                                         limitUid, path8.c_str()) < 0)
-            return -1;
-    }
-
     int size = lines.size();
 
     bool grow = size > env->GetIntField(stats, gNetworkStatsClassInfo.capacity);
@@ -308,14 +279,58 @@ static int readNetworkStatsDetail(JNIEnv* env, jclass clazz, jobject stats, jstr
         env->SetObjectField(stats, gNetworkStatsClassInfo.txPackets, txPackets.getJavaArray());
         env->SetObjectField(stats, gNetworkStatsClassInfo.operations, operations.getJavaArray());
     }
-
     return 0;
 }
 
+static int readNetworkStatsDetail(JNIEnv* env, jclass clazz, jobject stats, jstring path,
+                                  jint limitUid, jobjectArray limitIfacesObj, jint limitTag,
+                                  jboolean useBpfStats) {
+    ScopedUtfChars path8(env, path);
+    if (path8.c_str() == NULL) {
+        return -1;
+    }
+
+    std::vector<std::string> limitIfaces;
+    if (limitIfacesObj != NULL && env->GetArrayLength(limitIfacesObj) > 0) {
+        int num = env->GetArrayLength(limitIfacesObj);
+        for (int i = 0; i < num; i++) {
+            jstring string = (jstring)env->GetObjectArrayElement(limitIfacesObj, i);
+            ScopedUtfChars string8(env, string);
+            if (string8.c_str() != NULL) {
+                limitIfaces.push_back(std::string(string8.c_str()));
+            }
+        }
+    }
+    std::vector<stats_line> lines;
+
+
+    if (useBpfStats) {
+        if (parseBpfNetworkStatsDetail(&lines, limitIfaces, limitTag, limitUid) < 0)
+            return -1;
+    } else {
+        if (legacyReadNetworkStatsDetail(&lines, limitIfaces, limitTag,
+                                         limitUid, path8.c_str()) < 0)
+            return -1;
+    }
+
+    return statsLinesToNetworkStats(env, clazz, stats, lines);
+}
+
+static int readNetworkStatsDev(JNIEnv* env, jclass clazz, jobject stats) {
+    std::vector<stats_line> lines;
+
+    if (parseBpfNetworkStatsDev(&lines) < 0)
+            return -1;
+
+    return statsLinesToNetworkStats(env, clazz, stats, lines);
+}
+
 static const JNINativeMethod gMethods[] = {
         { "nativeReadNetworkStatsDetail",
                 "(Landroid/net/NetworkStats;Ljava/lang/String;I[Ljava/lang/String;IZ)I",
-                (void*) readNetworkStatsDetail }
+                (void*) readNetworkStatsDetail },
+        { "nativeReadNetworkStatsDev", "(Landroid/net/NetworkStats;)I",
+                (void*) readNetworkStatsDev },
 };
 
 int register_com_android_internal_net_NetworkStatsFactory(JNIEnv* env) {