dscpPolicy.c - remove spurious map A/B
The 'switch_comp_map' is never written to,
hence map A is always used anyway...
Additionally this is backwards - ie. the *wrong* maps were A/B:
it is not the cache that should be A/B but rather the policy map(s).
This simplification has the nice benefit of making the program
much simpler and thus presumably optimizing bpf verifier processing
and thus bpfloader runtime during boot.
The fact that these socket cache maps are never cleared from userspace
is a different bug that needs to be fixed.
Bug: 235559605
Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ic2b0d20cd4e9e7290fb9fae38e1625ea1ed85a78
diff --git a/bpf_progs/dscpPolicy.c b/bpf_progs/dscpPolicy.c
index f2116f2..36a2d5b 100644
--- a/bpf_progs/dscpPolicy.c
+++ b/bpf_progs/dscpPolicy.c
@@ -37,16 +37,8 @@
#define IP4_OFFSET(field, header) (header + offsetof(struct iphdr, field))
#define UPDATE_TOS(dscp, tos) (dscp << 2) | (tos & ECN_MASK)
-DEFINE_BPF_MAP_GRW(switch_comp_map, ARRAY, int, uint64_t, 1, AID_SYSTEM)
-
-DEFINE_BPF_MAP_GRW(ipv4_socket_to_policies_map_A, HASH, uint64_t, RuleEntry, MAX_POLICIES,
- AID_SYSTEM)
-DEFINE_BPF_MAP_GRW(ipv4_socket_to_policies_map_B, HASH, uint64_t, RuleEntry, MAX_POLICIES,
- AID_SYSTEM)
-DEFINE_BPF_MAP_GRW(ipv6_socket_to_policies_map_A, HASH, uint64_t, RuleEntry, MAX_POLICIES,
- AID_SYSTEM)
-DEFINE_BPF_MAP_GRW(ipv6_socket_to_policies_map_B, HASH, uint64_t, RuleEntry, MAX_POLICIES,
- AID_SYSTEM)
+DEFINE_BPF_MAP_GRW(ipv4_socket_to_policies_map, HASH, uint64_t, RuleEntry, MAX_POLICIES, AID_SYSTEM)
+DEFINE_BPF_MAP_GRW(ipv6_socket_to_policies_map, HASH, uint64_t, RuleEntry, MAX_POLICIES, AID_SYSTEM)
DEFINE_BPF_MAP_GRW(ipv4_dscp_policies_map, ARRAY, uint32_t, DscpPolicy, MAX_POLICIES, AID_SYSTEM)
DEFINE_BPF_MAP_GRW(ipv6_dscp_policies_map, ARRAY, uint32_t, DscpPolicy, MAX_POLICIES, AID_SYSTEM)
@@ -60,14 +52,7 @@
if (data + l2_header_size > data_end) return;
- int zero = 0;
int hdr_size = 0;
- uint64_t* selected_map = bpf_switch_comp_map_lookup_elem(&zero);
-
- // use this with HASH map so map lookup only happens once policies have been added?
- if (!selected_map) {
- return;
- }
// used for map lookup
uint64_t cookie = bpf_get_socket_cookie(skb);
@@ -137,17 +122,9 @@
RuleEntry* existing_rule;
if (ipv4) {
- if (*selected_map == MAP_A) {
- existing_rule = bpf_ipv4_socket_to_policies_map_A_lookup_elem(&cookie);
- } else {
- existing_rule = bpf_ipv4_socket_to_policies_map_B_lookup_elem(&cookie);
- }
+ existing_rule = bpf_ipv4_socket_to_policies_map_lookup_elem(&cookie);
} else {
- if (*selected_map == MAP_A) {
- existing_rule = bpf_ipv6_socket_to_policies_map_A_lookup_elem(&cookie);
- } else {
- existing_rule = bpf_ipv6_socket_to_policies_map_B_lookup_elem(&cookie);
- }
+ existing_rule = bpf_ipv6_socket_to_policies_map_lookup_elem(&cookie);
}
if (existing_rule && v6_equal(src_ip, existing_rule->src_ip) &&
@@ -250,17 +227,9 @@
// Update map with new policy.
if (ipv4) {
- if (*selected_map == MAP_A) {
- bpf_ipv4_socket_to_policies_map_A_update_elem(&cookie, &value, BPF_ANY);
- } else {
- bpf_ipv4_socket_to_policies_map_B_update_elem(&cookie, &value, BPF_ANY);
- }
+ bpf_ipv4_socket_to_policies_map_update_elem(&cookie, &value, BPF_ANY);
} else {
- if (*selected_map == MAP_A) {
- bpf_ipv6_socket_to_policies_map_A_update_elem(&cookie, &value, BPF_ANY);
- } else {
- bpf_ipv6_socket_to_policies_map_B_update_elem(&cookie, &value, BPF_ANY);
- }
+ bpf_ipv6_socket_to_policies_map_update_elem(&cookie, &value, BPF_ANY);
}
// Need to store bytes after updating map or program will not load.
diff --git a/bpf_progs/dscpPolicy.h b/bpf_progs/dscpPolicy.h
index 455a121..1d8964a 100644
--- a/bpf_progs/dscpPolicy.h
+++ b/bpf_progs/dscpPolicy.h
@@ -15,8 +15,6 @@
*/
#define MAX_POLICIES 16
-#define MAP_A 1
-#define MAP_B 2
#define SRC_IP_MASK_FLAG 1
#define DST_IP_MASK_FLAG 2
@@ -67,4 +65,4 @@
__u8 dscp_val;
__u8 pad[2];
} RuleEntry;
-STRUCT_SIZE(RuleEntry, 2 * 16 + 1 * 4 + 2 * 2 + 2 * 1 + 2); // 44
\ No newline at end of file
+STRUCT_SIZE(RuleEntry, 2 * 16 + 1 * 4 + 2 * 2 + 2 * 1 + 2); // 44
diff --git a/tests/mts/bpf_existence_test.cpp b/tests/mts/bpf_existence_test.cpp
index 0911ecf..95eebb1 100644
--- a/tests/mts/bpf_existence_test.cpp
+++ b/tests/mts/bpf_existence_test.cpp
@@ -88,12 +88,9 @@
SHARED "map_clatd_clat_egress4_map",
SHARED "map_clatd_clat_ingress6_map",
SHARED "map_dscpPolicy_ipv4_dscp_policies_map",
- SHARED "map_dscpPolicy_ipv4_socket_to_policies_map_A",
- SHARED "map_dscpPolicy_ipv4_socket_to_policies_map_B",
+ SHARED "map_dscpPolicy_ipv4_socket_to_policies_map",
SHARED "map_dscpPolicy_ipv6_dscp_policies_map",
- SHARED "map_dscpPolicy_ipv6_socket_to_policies_map_A",
- SHARED "map_dscpPolicy_ipv6_socket_to_policies_map_B",
- SHARED "map_dscpPolicy_switch_comp_map",
+ SHARED "map_dscpPolicy_ipv6_socket_to_policies_map",
NETD "map_netd_app_uid_stats_map",
NETD "map_netd_configuration_map",
NETD "map_netd_cookie_tag_map",