From 80efc3a697aee4324e14ce056d197851926db1a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= <maze@google.com>
Date: Wed, 24 Jan 2024 12:35:03 -0800
Subject: [PATCH] BpfNetworkStats: implement bpfRegisterIface() and wire it up
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Test: TreeHugger
  atest libnetworkstats_test
  a_test --iterations=100 NetworkStackIntegrationTests:android.net.NetworkStatsIntegrationTest
Bug: 292156770
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I3b1038f6fb306ed8f2d20a73d2f7c36593cbd739
---
 .../com_android_server_net_NetworkStatsService.cpp |  4 ++++
 .../libs/libnetworkstats/BpfNetworkStats.cpp       | 14 ++++++++++++--
 .../include/netdbpf/BpfNetworkStats.h              |  1 +
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/service-t/jni/com_android_server_net_NetworkStatsService.cpp b/service-t/jni/com_android_server_net_NetworkStatsService.cpp
index 028642fe2c..48ac9938a1 100644
--- a/service-t/jni/com_android_server_net_NetworkStatsService.cpp
+++ b/service-t/jni/com_android_server_net_NetworkStatsService.cpp
@@ -34,11 +34,15 @@
 
 using android::bpf::bpfGetUidStats;
 using android::bpf::bpfGetIfaceStats;
+using android::bpf::bpfRegisterIface;
 using android::bpf::NetworkTraceHandler;
 
 namespace android {
 
 static void nativeRegisterIface(JNIEnv* env, jclass clazz, jstring iface) {
+    ScopedUtfChars iface8(env, iface);
+    if (iface8.c_str() == nullptr) return;
+    bpfRegisterIface(iface8.c_str());
 }
 
 static jobject statsValueToEntry(JNIEnv* env, StatsValue* stats) {
diff --git a/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
index ac5b90eace..8a58e56760 100644
--- a/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
+++ b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
@@ -40,8 +40,8 @@ namespace bpf {
 
 using base::Result;
 
-const BpfMapRO<uint32_t, IfaceValue>& getIfaceIndexNameMap() {
-    static BpfMapRO<uint32_t, IfaceValue> ifaceIndexNameMap(IFACE_INDEX_NAME_MAP_PATH);
+BpfMap<uint32_t, IfaceValue>& getIfaceIndexNameMap() {
+    static BpfMap<uint32_t, IfaceValue> ifaceIndexNameMap(IFACE_INDEX_NAME_MAP_PATH);
     return ifaceIndexNameMap;
 }
 
@@ -50,6 +50,16 @@ const BpfMapRO<uint32_t, StatsValue>& getIfaceStatsMap() {
     return ifaceStatsMap;
 }
 
+void bpfRegisterIface(const char* iface) {
+    if (!iface) return;
+    if (strlen(iface) >= sizeof(IfaceValue)) return;
+    uint32_t ifindex = if_nametoindex(iface);
+    if (!ifindex) return;
+    IfaceValue ifname = {};
+    strlcpy(ifname.name, iface, sizeof(ifname.name));
+    getIfaceIndexNameMap().writeValue(ifindex, ifname, BPF_ANY);
+}
+
 int bpfGetUidStatsInternal(uid_t uid, StatsValue* stats,
                            const BpfMapRO<uint32_t, StatsValue>& appUidStatsMap) {
     auto statsEntry = appUidStatsMap.readValue(uid);
diff --git a/service-t/native/libs/libnetworkstats/include/netdbpf/BpfNetworkStats.h b/service-t/native/libs/libnetworkstats/include/netdbpf/BpfNetworkStats.h
index d2efff5eb1..0f28c1da45 100644
--- a/service-t/native/libs/libnetworkstats/include/netdbpf/BpfNetworkStats.h
+++ b/service-t/native/libs/libnetworkstats/include/netdbpf/BpfNetworkStats.h
@@ -114,6 +114,7 @@ int parseBpfNetworkStatsDevInternal(std::vector<stats_line>& lines,
                                     const BpfMapRO<uint32_t, StatsValue>& statsMap,
                                     const BpfMapRO<uint32_t, IfaceValue>& ifaceMap);
 
+void bpfRegisterIface(const char* iface);
 int bpfGetUidStats(uid_t uid, StatsValue* stats);
 int bpfGetIfaceStats(const char* iface, StatsValue* stats);
 int bpfGetIfIndexStats(int ifindex, StatsValue* stats);