From d3d144f54d3d4c7b92f7b9f2db1655c3e0fa4145 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= <maze@google.com>
Date: Fri, 26 Jan 2024 15:15:44 -0800
Subject: [PATCH] BpfNetworkStats: fallback to if_indextoname() on index->name
 map lookup failure
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(this should fix the 4 ipsec tests which don't call the right
 higher APIs that would eventually call into bpfRegisterIface)

Test: TreeHugger, atest libnetworkstats_test
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I3069f3a2f809948cd2e7755745586b78ff3362c9
---
 service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
index e9784ffbb2..d3e331ec81 100644
--- a/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
+++ b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
@@ -51,7 +51,12 @@ const BpfMapRO<uint32_t, StatsValue>& getIfaceStatsMap() {
 }
 
 Result<IfaceValue> ifindex2name(const uint32_t ifindex) {
-    return getIfaceIndexNameMap().readValue(ifindex);
+    Result<IfaceValue> v = getIfaceIndexNameMap().readValue(ifindex);
+    if (v.ok()) return v;
+    IfaceValue iv = {};
+    if (!if_indextoname(ifindex, iv.name)) return v;
+    getIfaceIndexNameMap().writeValue(ifindex, iv, BPF_ANY);
+    return iv;
 }
 
 void bpfRegisterIface(const char* iface) {