commit 90c0c3fd1a68f2538f28520805d0d92d331966f3
author Lorenzo Colitti <lorenzo@google.com> Thu Mar 03 17:49:01 2022 +0900
committer Cherrypicker Worker <android-build-cherrypicker-worker@google.com> Wed Jun 01 00:40:57 2022 +0000
tree 9b2014673dfec962eb88a0311a9f021ba67479f6
parent edda01a74467368c7e34883a7358e531c48e45bc

Support more than 8 firewall chains / match types.

In the BPF code, per-UID network access (e.g., for doze mode,
standby, etc.) is stored in UidOwnerValue structures. Each of
these stores that UID's rules in a 32-bit bitmask of
UidOwnerMatchType values, so the code can support ~31 match
types.

However, which match types are enabled is stored in
configuration_map at index UID_RULES_CONFIGURATION_KEY, and
configuration_map only stores 8-bit values. So it's not
possible to define more than 7 match types.

Widen configuration_map to from 8 to 32 bits to match the width
of UidOwnerValue.rule. This doesn't impact memory because
configuration_map only has 2 entries.

Bug: 208371987
Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I7e1eee2daedd66d27965a2dd4ce6b4c3667892f7
(cherry picked from commit 60cbed385dcf3c640674c48b7cd4d60967047cf0)
Merged-In: I7e1eee2daedd66d27965a2dd4ce6b4c3667892f7

bpf_progs/netd.c

diff --git a/bpf_progs/netd.c b/bpf_progs/netd.c
index 33381d7..b4ef7eb 100644
--- a/bpf_progs/netd.c
+++ b/bpf_progs/netd.c
@@ -62,7 +62,7 @@
 DEFINE_BPF_MAP_GRW(stats_map_B, HASH, StatsKey, StatsValue, STATS_MAP_SIZE, AID_NET_BW_ACCT)
 DEFINE_BPF_MAP_GRW(iface_stats_map, HASH, uint32_t, StatsValue, IFACE_STATS_MAP_SIZE,
                    AID_NET_BW_ACCT)
-DEFINE_BPF_MAP_GRW(configuration_map, HASH, uint32_t, uint8_t, CONFIGURATION_MAP_SIZE,
+DEFINE_BPF_MAP_GRW(configuration_map, HASH, uint32_t, uint32_t, CONFIGURATION_MAP_SIZE,
                    AID_NET_BW_ACCT)
 DEFINE_BPF_MAP_GRW(uid_owner_map, HASH, uint32_t, UidOwnerValue, UID_OWNER_MAP_SIZE,
                    AID_NET_BW_ACCT)
@@ -234,7 +234,7 @@
 }
 
 static __always_inline inline void update_stats_with_config(struct __sk_buff* skb, int direction,
-                                                            StatsKey* key, uint8_t selectedMap) {
+                                                            StatsKey* key, uint32_t selectedMap) {
     if (selectedMap == SELECT_MAP_A) {
         update_stats_map_A(skb, direction, key);
     } else if (selectedMap == SELECT_MAP_B) {
@@ -286,7 +286,7 @@
     if (counterSet) key.counterSet = (uint32_t)*counterSet;
 
     uint32_t mapSettingKey = CURRENT_STATS_MAP_CONFIGURATION_KEY;
-    uint8_t* selectedMap = bpf_configuration_map_lookup_elem(&mapSettingKey);
+    uint32_t* selectedMap = bpf_configuration_map_lookup_elem(&mapSettingKey);
 
     // Use asm("%0 &= 1" : "+r"(match)) before return match,
     // to help kernel's bpf verifier, so that it can be 100% certain