Do not take cumulative network stats anymore

Use two maps to record the details of network stats and swap and clean
up after system server pulls the stats. The kernel program checks the
bpf map currently enabled before updating the stats and updates on the
corresponding map. Remove the TAG_STATS_MAP since we don't need to worry
about uid stats overflow problem. All the stats can be stored in the
same map until system server scrapes the stats and clean it up.

Bug: 79171384
Test: dumpsys netd trafficcontroller
      CtsUsageStatsTestCases

Change-Id: Ic79e382f51bf21eee78c4cac5a8a97edaf3654cd

1 files changed, 25 insertions, 10 deletions

diff --git a/progs/netd.h b/progs/netd.h
index 6b2d103..ff97753 100644
--- a/progs/netd.h
+++ b/progs/netd.h
@@ -110,21 +110,21 @@ struct bpf_map_def SEC("maps") app_uid_stats_map = {
     .type = BPF_MAP_TYPE_HASH,
     .key_size = sizeof(uint32_t),
     .value_size = sizeof(struct stats_value),
-    .max_entries = UID_STATS_MAP_SIZE,
+    .max_entries = APP_STATS_MAP_SIZE,
 };
 
-struct bpf_map_def SEC("maps") uid_stats_map = {
+struct bpf_map_def SEC("maps") stats_map_A = {
     .type = BPF_MAP_TYPE_HASH,
     .key_size = sizeof(struct stats_key),
     .value_size = sizeof(struct stats_value),
-    .max_entries = UID_STATS_MAP_SIZE,
+    .max_entries = STATS_MAP_SIZE,
 };
 
-struct bpf_map_def SEC("maps") tag_stats_map = {
+struct bpf_map_def SEC("maps") stats_map_B = {
     .type = BPF_MAP_TYPE_HASH,
     .key_size = sizeof(struct stats_key),
     .value_size = sizeof(struct stats_value),
-    .max_entries = TAG_STATS_MAP_SIZE,
+    .max_entries = STATS_MAP_SIZE,
 };
 
 struct bpf_map_def SEC("maps") iface_stats_map = {
@@ -218,8 +218,8 @@ static inline bool skip_owner_match(struct __sk_buff* skb) {
     return false;
 }
 
-static __always_inline BpfConfig getConfig() {
-    uint32_t mapSettingKey = CONFIGURATION_KEY;
+static __always_inline BpfConfig getConfig(uint32_t configKey) {
+    uint32_t mapSettingKey = configKey;
     BpfConfig* config = find_map_entry(&configuration_map, &mapSettingKey);
     if (!config) {
         // Couldn't read configuration entry. Assume everything is disabled.
@@ -233,7 +233,7 @@ static inline int bpf_owner_match(struct __sk_buff* skb, uint32_t uid) {
 
     if ((uid <= MAX_SYSTEM_UID) && (uid >= MIN_SYSTEM_UID)) return BPF_PASS;
 
-    BpfConfig enabledRules = getConfig();
+    BpfConfig enabledRules = getConfig(UID_RULES_CONFIGURATION_KEY);
     if (!enabledRules) {
         return BPF_PASS;
     }
@@ -252,6 +252,15 @@ static inline int bpf_owner_match(struct __sk_buff* skb, uint32_t uid) {
     return BPF_PASS;
 }
 
+static __always_inline inline void update_stats_with_config(struct __sk_buff* skb, int direction,
+                                                            void* key, uint8_t selectedMap) {
+    if (selectedMap == SELECT_MAP_A) {
+        bpf_update_stats(skb, &stats_map_A, direction, key);
+    } else if (selectedMap == SELECT_MAP_B) {
+        bpf_update_stats(skb, &stats_map_B, direction, key);
+    }
+}
+
 static __always_inline inline int bpf_traffic_account(struct __sk_buff* skb, int direction) {
     uint32_t sock_uid = get_socket_uid(skb);
     int match = bpf_owner_match(skb, sock_uid);
@@ -277,12 +286,18 @@ static __always_inline inline int bpf_traffic_account(struct __sk_buff* skb, int
     uint8_t* counterSet = find_map_entry(&uid_counterset_map, &uid);
     if (counterSet) key.counterSet = (uint32_t)*counterSet;
 
+    uint32_t mapSettingKey = CURRENT_STATS_MAP_CONFIGURATION_KEY;
+    uint8_t* selectedMap = find_map_entry(&configuration_map, &mapSettingKey);
+    if (!selectedMap) {
+        return match;
+    }
+
     if (tag) {
-        bpf_update_stats(skb, &tag_stats_map, direction, &key);
+        update_stats_with_config(skb, direction, &key, *selectedMap);
     }
 
     key.tag = 0;
-    bpf_update_stats(skb, &uid_stats_map, direction, &key);
+    update_stats_with_config(skb, direction, &key, *selectedMap);
     bpf_update_stats(skb, &app_uid_stats_map, direction, &uid);
     return match;
 }