commit e4c0473bd93e76a0291e2505006d3875fe363c78
author Maciej Żenczykowski <maze@google.com> Thu Mar 02 00:18:05 2023 +0000
committer Maciej Żenczykowski <maze@google.com> Thu Mar 02 00:19:23 2023 +0000
tree db69e7401b470190adf7c1af717c12d7d2e48ba8
parent 2a89cc44ffb86d96a1d54fb9c71d1cd97cc6a1b1

bpf netd - minor perf improvement - move uid check first

effectively no-op, but since it's a trivial check (uid < APP_START),
better do it first, rather than the complex packet parsing in
skip_owner_match().

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I35a9188e108987d48f03a18cdf70ec4cdd715376

bpf_progs/netd.c

diff --git a/bpf_progs/netd.c b/bpf_progs/netd.c
index 84da79d..a998dc6 100644
--- a/bpf_progs/netd.c
+++ b/bpf_progs/netd.c
@@ -350,10 +350,10 @@
 
 static __always_inline inline int bpf_owner_match(struct __sk_buff* skb, uint32_t uid,
                                                   bool egress, const unsigned kver) {
-    if (skip_owner_match(skb, kver)) return PASS;
-
     if (is_system_uid(uid)) return PASS;
 
+    if (skip_owner_match(skb, kver)) return PASS;
+
     BpfConfig enabledRules = getConfig(UID_RULES_CONFIGURATION_KEY);
 
     UidOwnerValue* uidEntry = bpf_uid_owner_map_lookup_elem(&uid);